Soil moisture, organic carbon, and nitrogen content prediction with hyperspectral data using regression models
- Datta, Dristi, Paul, Manoranjan, Murshed, Manzur, Teng, Shyh Wei, Schmidtke, Leigh
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2022
- Type: Text , Journal article
- Relation: Sensors (Basel, Switzerland) Vol. 22, no. 20 (2022), p.
- Full Text:
- Reviewed:
- Description: Soil moisture, soil organic carbon, and nitrogen content prediction are considered significant fields of study as they are directly related to plant health and food production. Direct estimation of these soil properties with traditional methods, for example, the oven-drying technique and chemical analysis, is a time and resource-consuming approach and can predict only smaller areas. With the significant development of remote sensing and hyperspectral (HS) imaging technologies, soil moisture, carbon, and nitrogen can be estimated over vast areas. This paper presents a generalized approach to predicting three different essential soil contents using a comprehensive study of various machine learning (ML) models by considering the dimensional reduction in feature spaces. In this study, we have used three popular benchmark HS datasets captured in Germany and Sweden. The efficacy of different ML algorithms is evaluated to predict soil content, and significant improvement is obtained when a specific range of bands is selected. The performance of ML models is further improved by applying principal component analysis (PCA), a dimensional reduction method that works with an unsupervised learning method. The effect of soil temperature on soil moisture prediction is evaluated in this study, and the results show that when the soil temperature is considered with the HS band, the soil moisture prediction accuracy does not improve. However, the combined effect of band selection and feature transformation using PCA significantly enhances the prediction accuracy for soil moisture, carbon, and nitrogen content. This study represents a comprehensive analysis of a wide range of established ML regression models using data preprocessing, effective band selection, and data dimension reduction and attempt to understand which feature combinations provide the best accuracy. The outcomes of several ML models are verified with validation techniques and the best- and worst-case scenarios in terms of soil content are noted. The proposed approach outperforms existing estimation techniques.
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2022
- Type: Text , Journal article
- Relation: Sensors (Basel, Switzerland) Vol. 22, no. 20 (2022), p.
- Full Text:
- Reviewed:
- Description: Soil moisture, soil organic carbon, and nitrogen content prediction are considered significant fields of study as they are directly related to plant health and food production. Direct estimation of these soil properties with traditional methods, for example, the oven-drying technique and chemical analysis, is a time and resource-consuming approach and can predict only smaller areas. With the significant development of remote sensing and hyperspectral (HS) imaging technologies, soil moisture, carbon, and nitrogen can be estimated over vast areas. This paper presents a generalized approach to predicting three different essential soil contents using a comprehensive study of various machine learning (ML) models by considering the dimensional reduction in feature spaces. In this study, we have used three popular benchmark HS datasets captured in Germany and Sweden. The efficacy of different ML algorithms is evaluated to predict soil content, and significant improvement is obtained when a specific range of bands is selected. The performance of ML models is further improved by applying principal component analysis (PCA), a dimensional reduction method that works with an unsupervised learning method. The effect of soil temperature on soil moisture prediction is evaluated in this study, and the results show that when the soil temperature is considered with the HS band, the soil moisture prediction accuracy does not improve. However, the combined effect of band selection and feature transformation using PCA significantly enhances the prediction accuracy for soil moisture, carbon, and nitrogen content. This study represents a comprehensive analysis of a wide range of established ML regression models using data preprocessing, effective band selection, and data dimension reduction and attempt to understand which feature combinations provide the best accuracy. The outcomes of several ML models are verified with validation techniques and the best- and worst-case scenarios in terms of soil content are noted. The proposed approach outperforms existing estimation techniques.
Magic and antimagic labeling of graphs
- Authors: Sugeng, Kiki Ariyanti
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: "A bijection mapping that assigns natural numbers to vertices and/or edges of a graph is called a labeling. In this thesis, we consider graph labelings that have weights associated with each edge and/or vertex. If all the vertex weights (respectively, edge weights) have the same value then the labeling is called magic. If the weight is different for every vertex (respectively, every edge) then we called the labeling antimagic. In this thesis we introduce some variations of magic and antimagic labelings and discuss their properties and provide corresponding labeling schemes. There are two main parts in this thesis. One main part is on vertex labeling and the other main part is on edge labeling."
- Description: Doctor of Philosophy
- Authors: Sugeng, Kiki Ariyanti
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: "A bijection mapping that assigns natural numbers to vertices and/or edges of a graph is called a labeling. In this thesis, we consider graph labelings that have weights associated with each edge and/or vertex. If all the vertex weights (respectively, edge weights) have the same value then the labeling is called magic. If the weight is different for every vertex (respectively, every edge) then we called the labeling antimagic. In this thesis we introduce some variations of magic and antimagic labelings and discuss their properties and provide corresponding labeling schemes. There are two main parts in this thesis. One main part is on vertex labeling and the other main part is on edge labeling."
- Description: Doctor of Philosophy
Firm growth by women-owned Small and Medium Enterprises in a developing economy setting
- Authors: Jomaraty, Mosfeka
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: The growth experiences of women-owned Small and Medium Enterprises (SMEs) in the context of a developing economy are examined through the lens of pragmatism. This approach views a businesswoman’s ‘belief’, ‘habit’ and ‘doubt’ as critical for researching gender related issues in entrepreneurship. This study explains the growth aspects of women-owned manufacturing and services SMEs of Bangladesh with the aim of addressing two neglected research issues. One is the scarcity of studies on growth oriented women entrepreneurs in developing countries. The other is the lack of focus on very successful high-growth women-owned firms in the context of a strong male-dominated economy. This study adopts a framework developed out of the Diana International Project to evaluate the factors influencing the growth of these successful, growing, Bangladeshi women-owned businesses. In order to evaluate the growth process itself, this framework was then modified with growth resources and actions as explained by Edith Penrose in her 1959 seminal book The Theory of Growth of the Firm. This allows for the investigation of the effects of managerial and entrepreneurial abilities in growth, and the identification of how firms achieve growth. A multiple-case design is adopted, covering sixteen successful growth-oriented firms in the manufacturing and services sector. SMEs were studied as the basis for firm growth from initial venture creation, while the sector concentration on manufacturing and services reflects the urban nature of the study in examining firms that exist in the capital city of Dhaka. Data from in-depth interviews and supporting documents were used for the case studies and integrated with the theoretical framework. Themes were categorised and patterns compared against the framework. The results of this research suggest that SME growth is a process which is gradual and iterative, comprising a series of growth strategies and approaches. The framework identifies interactive connection between different growth variables and highlights how industry sector and the national context of a growing economy facilitate growth of women-owned SMEs. The case study based research seeks to advance scholarship in relation to women’s entrepreneurship globally and contribute to the understanding of growth oriented women’s entrepreneurship. Building upon existing knowledge, this research endeavours to generate new insights and advance theoretical discourse by providing richness and subtlety to the knowledge of growth process and opening up new avenues for future research.
- Description: Doctor of Philosophy
- Authors: Jomaraty, Mosfeka
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: The growth experiences of women-owned Small and Medium Enterprises (SMEs) in the context of a developing economy are examined through the lens of pragmatism. This approach views a businesswoman’s ‘belief’, ‘habit’ and ‘doubt’ as critical for researching gender related issues in entrepreneurship. This study explains the growth aspects of women-owned manufacturing and services SMEs of Bangladesh with the aim of addressing two neglected research issues. One is the scarcity of studies on growth oriented women entrepreneurs in developing countries. The other is the lack of focus on very successful high-growth women-owned firms in the context of a strong male-dominated economy. This study adopts a framework developed out of the Diana International Project to evaluate the factors influencing the growth of these successful, growing, Bangladeshi women-owned businesses. In order to evaluate the growth process itself, this framework was then modified with growth resources and actions as explained by Edith Penrose in her 1959 seminal book The Theory of Growth of the Firm. This allows for the investigation of the effects of managerial and entrepreneurial abilities in growth, and the identification of how firms achieve growth. A multiple-case design is adopted, covering sixteen successful growth-oriented firms in the manufacturing and services sector. SMEs were studied as the basis for firm growth from initial venture creation, while the sector concentration on manufacturing and services reflects the urban nature of the study in examining firms that exist in the capital city of Dhaka. Data from in-depth interviews and supporting documents were used for the case studies and integrated with the theoretical framework. Themes were categorised and patterns compared against the framework. The results of this research suggest that SME growth is a process which is gradual and iterative, comprising a series of growth strategies and approaches. The framework identifies interactive connection between different growth variables and highlights how industry sector and the national context of a growing economy facilitate growth of women-owned SMEs. The case study based research seeks to advance scholarship in relation to women’s entrepreneurship globally and contribute to the understanding of growth oriented women’s entrepreneurship. Building upon existing knowledge, this research endeavours to generate new insights and advance theoretical discourse by providing richness and subtlety to the knowledge of growth process and opening up new avenues for future research.
- Description: Doctor of Philosophy
Efficient data gathering in 3D linear underwater wireless sensor networks using sink mobility
- Akbar, Mariam, Javaid, Nadeem, Khan, Ayesha, Imran, Muhammad, Shoaib, Muhammad, Vasilakos, Athanasios
- Authors: Akbar, Mariam , Javaid, Nadeem , Khan, Ayesha , Imran, Muhammad , Shoaib, Muhammad , Vasilakos, Athanasios
- Date: 2016
- Type: Text , Journal article
- Relation: Sensors (Switzerland) Vol. 16, no. 3 (2016), p.
- Full Text:
- Reviewed:
- Description: Due to the unpleasant and unpredictable underwater environment, designing an energy-efficient routing protocol for underwater wireless sensor networks (UWSNs) demands more accuracy and extra computations. In the proposed scheme, we introduce a mobile sink (MS), i.e., an autonomous underwater vehicle (AUV), and also courier nodes (CNs), to minimize the energy consumption of nodes. MS and CNs stop at specific stops for data gathering; later on, CNs forward the received data to the MS for further transmission. By the mobility of CNs and MS, the overall energy consumption of nodes is minimized. We perform simulations to investigate the performance of the proposed scheme and compare it to preexisting techniques. Simulation results are compared in terms of network lifetime, throughput, path loss, transmission loss and packet drop ratio. The results show that the proposed technique performs better in terms of network lifetime, throughput, path loss and scalability. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
- Authors: Akbar, Mariam , Javaid, Nadeem , Khan, Ayesha , Imran, Muhammad , Shoaib, Muhammad , Vasilakos, Athanasios
- Date: 2016
- Type: Text , Journal article
- Relation: Sensors (Switzerland) Vol. 16, no. 3 (2016), p.
- Full Text:
- Reviewed:
- Description: Due to the unpleasant and unpredictable underwater environment, designing an energy-efficient routing protocol for underwater wireless sensor networks (UWSNs) demands more accuracy and extra computations. In the proposed scheme, we introduce a mobile sink (MS), i.e., an autonomous underwater vehicle (AUV), and also courier nodes (CNs), to minimize the energy consumption of nodes. MS and CNs stop at specific stops for data gathering; later on, CNs forward the received data to the MS for further transmission. By the mobility of CNs and MS, the overall energy consumption of nodes is minimized. We perform simulations to investigate the performance of the proposed scheme and compare it to preexisting techniques. Simulation results are compared in terms of network lifetime, throughput, path loss, transmission loss and packet drop ratio. The results show that the proposed technique performs better in terms of network lifetime, throughput, path loss and scalability. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
The floristic composition and regeneration characteristics of Buloke (Allocasuarina luehmannii) woodland of the Wimmera, Victoria
- Authors: Macaulay, Lisa Ann
- Date: 2006
- Type: Text , Thesis , Masters
- Full Text:
- Description: "The pre-settlement distribution and character of Wimmera Buloke woodlands are described based on historical data including early parish plans. It is suggested the open structure of these woodlands was maintained by relatively frequent fire. The floristic composition of the most intact Wimmera Buloke woodland remnants was intensively surveyed. Five floristic communities are described based on computer-based analysis of species presence data. Eight 'pre-settlement Buloke woodland types' are described based on surface soil texture categories and average annual rainfall zones. Native daisies, chenopods and shrubs are components of the understory that differentiate the 'pre-settlement Buloke woodland types'. [...] A series of experiments was undertaken with the aim of determinig the factors responsible for the paucity of Allocasuarina luehmannii regeneration in remnant Wimmera bushland." Digital file does not include CD with Appendix and fold-out map on back cover see print version.
- Description: Master of Applied Science
- Description: "The pre-settlement distribution and character of Wimmera Buloke woodlands are described based on historical data including early parish plans. It is suggested the open structure of these woodlands was maintained by relatively frequent fire. The floristic composition of the most intact Wimmera Buloke woodland remnants was intensively surveyed. Five floristic communities are described based on computer-based analysis of species presence data. Eight 'pre-settlement Buloke woodland types' are described based on surface soil texture categories and average annual rainfall zones. Native daisies, chenopods and shrubs are components of the understory that differentiate the 'pre-settlement Buloke woodland types'. [...] A series of experiments was undertaken with the aim of determinig the factors responsible for the paucity of Allocasuarina luehmannii regeneration in remnant Wimmera bushland."
- Authors: Macaulay, Lisa Ann
- Date: 2006
- Type: Text , Thesis , Masters
- Full Text:
- Description: "The pre-settlement distribution and character of Wimmera Buloke woodlands are described based on historical data including early parish plans. It is suggested the open structure of these woodlands was maintained by relatively frequent fire. The floristic composition of the most intact Wimmera Buloke woodland remnants was intensively surveyed. Five floristic communities are described based on computer-based analysis of species presence data. Eight 'pre-settlement Buloke woodland types' are described based on surface soil texture categories and average annual rainfall zones. Native daisies, chenopods and shrubs are components of the understory that differentiate the 'pre-settlement Buloke woodland types'. [...] A series of experiments was undertaken with the aim of determinig the factors responsible for the paucity of Allocasuarina luehmannii regeneration in remnant Wimmera bushland." Digital file does not include CD with Appendix and fold-out map on back cover see print version.
- Description: Master of Applied Science
- Description: "The pre-settlement distribution and character of Wimmera Buloke woodlands are described based on historical data including early parish plans. It is suggested the open structure of these woodlands was maintained by relatively frequent fire. The floristic composition of the most intact Wimmera Buloke woodland remnants was intensively surveyed. Five floristic communities are described based on computer-based analysis of species presence data. Eight 'pre-settlement Buloke woodland types' are described based on surface soil texture categories and average annual rainfall zones. Native daisies, chenopods and shrubs are components of the understory that differentiate the 'pre-settlement Buloke woodland types'. [...] A series of experiments was undertaken with the aim of determinig the factors responsible for the paucity of Allocasuarina luehmannii regeneration in remnant Wimmera bushland."
Structural properties and labeling of graphs
- Dafik
- Authors: Dafik
- Date: 2007
- Type: Text , Thesis , PhD
- Full Text:
- Description: The complexity in building massive scale parallel processing systems has re- sulted in a growing interest in the study of interconnection networks design. Network design affects the performance, cost, scalability, and availability of parallel computers. Therefore, discovering a good structure of the network is one of the basic issues. From modeling point of view, the structure of networks can be naturally stud- ied in terms of graph theory. Several common desirable features of networks, such as large number of processing elements, good throughput, short data com- munication delay, modularity, good fault tolerance and diameter vulnerability correspond to properties of the underlying graphs of networks, including large number of vertices, small diameter, high connectivity and overall balance (or regularity) of the graph or digraph. The first part of this thesis deals with the issue of interconnection networks ad- dressing system. From graph theory point of view, this issue is mainly related to a graph labeling. We investigate a special family of graph labeling, namely antimagic labeling of a class of disconnected graphs. We present new results in super (a; d)-edge antimagic total labeling for disjoint union of multiple copies of special families of graphs. The second part of this thesis deals with the issue of regularity of digraphs with the number of vertices close to the upper bound, called the Moore bound, which is unobtainable for most values of out-degree and diameter. Regularity of the underlying graph of a network is often considered to be essential since the flow of messages and exchange of data between processing elements will be on average faster if there is a similar number of interconnections coming in and going out of each processing element. This means that the in-degree and out-degree of each processing element must be the same or almost the same. Our new results show that digraphs of order two less than Moore bound are either diregular or almost diregular.
- Description: Doctor of Philosophy
- Authors: Dafik
- Date: 2007
- Type: Text , Thesis , PhD
- Full Text:
- Description: The complexity in building massive scale parallel processing systems has re- sulted in a growing interest in the study of interconnection networks design. Network design affects the performance, cost, scalability, and availability of parallel computers. Therefore, discovering a good structure of the network is one of the basic issues. From modeling point of view, the structure of networks can be naturally stud- ied in terms of graph theory. Several common desirable features of networks, such as large number of processing elements, good throughput, short data com- munication delay, modularity, good fault tolerance and diameter vulnerability correspond to properties of the underlying graphs of networks, including large number of vertices, small diameter, high connectivity and overall balance (or regularity) of the graph or digraph. The first part of this thesis deals with the issue of interconnection networks ad- dressing system. From graph theory point of view, this issue is mainly related to a graph labeling. We investigate a special family of graph labeling, namely antimagic labeling of a class of disconnected graphs. We present new results in super (a; d)-edge antimagic total labeling for disjoint union of multiple copies of special families of graphs. The second part of this thesis deals with the issue of regularity of digraphs with the number of vertices close to the upper bound, called the Moore bound, which is unobtainable for most values of out-degree and diameter. Regularity of the underlying graph of a network is often considered to be essential since the flow of messages and exchange of data between processing elements will be on average faster if there is a similar number of interconnections coming in and going out of each processing element. This means that the in-degree and out-degree of each processing element must be the same or almost the same. Our new results show that digraphs of order two less than Moore bound are either diregular or almost diregular.
- Description: Doctor of Philosophy
A class of Increasing Positively Homogeneous functions for which global optimization problem is NP-hard
- Authors: Sultanova, Nargiz
- Date: 2009
- Type: Text , Thesis , Masters
- Full Text:
- Description: It is well known that global optimization problems are, generally speaking, computationally infeasible, that is solving them would require an unreasonably large amount of time and/or space. In certain cases, for example, when objective functions and constraints are convex, it is possible to construct a feasible algorithm for solving global optimization problem successfully. Convexity, however, is not a phenomenon to be often expected in the applications. Nonconvex problems frequently arise in many industrial and scienti¯c areas. Therefore, it is only natural to try to replace convexity with some other structure at least for some classes of nonconvex optimization problems to render the global optimization problem feasible. A theory of abstract convexity has been developed as a result of the above considerations. Monotonic analysis, a branch of abstract convex analysis, is analogous in many ways to convex analysis, and sometimes is even simpler. It turned out that many problems of nonconvex optimization encountered in applications can be described in terms of monotonic functions. The analogies with convex analysis were considered to aid in solving some classes of nonconvex optimization problems. In this thesis we will focus on one of the elements of monotonic analysis - Increasing Positively Homogeneous functions of degree one or in short IPH functions. The aim of present research is to show that finding the solution and ²-approximation to the solution of the global optimization problem for IPH functions restricted to a unit simplex is an NP-hard problem. These results can be further extended to positively homogeneous functions of degree ´, ´ > 0.
- Description: Master of Mathematical Sciences (Research)
- Authors: Sultanova, Nargiz
- Date: 2009
- Type: Text , Thesis , Masters
- Full Text:
- Description: It is well known that global optimization problems are, generally speaking, computationally infeasible, that is solving them would require an unreasonably large amount of time and/or space. In certain cases, for example, when objective functions and constraints are convex, it is possible to construct a feasible algorithm for solving global optimization problem successfully. Convexity, however, is not a phenomenon to be often expected in the applications. Nonconvex problems frequently arise in many industrial and scienti¯c areas. Therefore, it is only natural to try to replace convexity with some other structure at least for some classes of nonconvex optimization problems to render the global optimization problem feasible. A theory of abstract convexity has been developed as a result of the above considerations. Monotonic analysis, a branch of abstract convex analysis, is analogous in many ways to convex analysis, and sometimes is even simpler. It turned out that many problems of nonconvex optimization encountered in applications can be described in terms of monotonic functions. The analogies with convex analysis were considered to aid in solving some classes of nonconvex optimization problems. In this thesis we will focus on one of the elements of monotonic analysis - Increasing Positively Homogeneous functions of degree one or in short IPH functions. The aim of present research is to show that finding the solution and ²-approximation to the solution of the global optimization problem for IPH functions restricted to a unit simplex is an NP-hard problem. These results can be further extended to positively homogeneous functions of degree ´, ´ > 0.
- Description: Master of Mathematical Sciences (Research)
A fault-tolerant cascaded switched-capacitor multilevel inverter for domestic applications in smart grids
- Akbari, Ehsan, Teimouri, Ali, Saki, Mojtaba, Rezaei, Mohammad, Hu, Jiefeng, Band, Shahab, Pai, Hao-Ting, Mosavi, Amir
- Authors: Akbari, Ehsan , Teimouri, Ali , Saki, Mojtaba , Rezaei, Mohammad , Hu, Jiefeng , Band, Shahab , Pai, Hao-Ting , Mosavi, Amir
- Date: 2022
- Type: Text , Journal article
- Relation: IEEE Access Vol. 10, no. (2022), p. 110590-110602
- Full Text:
- Reviewed:
- Description: Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached. © 2013 IEEE.
- Authors: Akbari, Ehsan , Teimouri, Ali , Saki, Mojtaba , Rezaei, Mohammad , Hu, Jiefeng , Band, Shahab , Pai, Hao-Ting , Mosavi, Amir
- Date: 2022
- Type: Text , Journal article
- Relation: IEEE Access Vol. 10, no. (2022), p. 110590-110602
- Full Text:
- Reviewed:
- Description: Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached. © 2013 IEEE.
Shared value priorities in groups : The impact of the Bahá’i Faith on Values
- Authors: Afshar, Faezeh
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Values such as honesty, meaning in life, pleasure, justice and freedom are guiding principles in motivating the selection and evaluation of individual behaviour and goals. They are also important for understanding cultural norms, attitudes and practices. In previous studies individuals and groups have often been found to be willing to subordinate their values toward goals and behaviours that are aligned with their own group; their ‘in-group’. Studies of values within a group have not reported evidence for the subordination of their values toward universal goals and behaviours; their ‘out-groups’. This research is the first to examine widely the values held by adherents of the Bahá’i Faith; a world-wide religious community that envisions a united global society. The main aim of this thesis is to discover and explain the system of value priorities held by Bahá’is. Data was obtained from an online survey of over one thousand responses to the cross-culturally validated ‘Schwartz Value Survey’. Data relating to the degree of commitment to religion referred to as religiosity, was also collected in addition to demographic information.
- Description: Doctor of Philosophy
- Authors: Afshar, Faezeh
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Values such as honesty, meaning in life, pleasure, justice and freedom are guiding principles in motivating the selection and evaluation of individual behaviour and goals. They are also important for understanding cultural norms, attitudes and practices. In previous studies individuals and groups have often been found to be willing to subordinate their values toward goals and behaviours that are aligned with their own group; their ‘in-group’. Studies of values within a group have not reported evidence for the subordination of their values toward universal goals and behaviours; their ‘out-groups’. This research is the first to examine widely the values held by adherents of the Bahá’i Faith; a world-wide religious community that envisions a united global society. The main aim of this thesis is to discover and explain the system of value priorities held by Bahá’is. Data was obtained from an online survey of over one thousand responses to the cross-culturally validated ‘Schwartz Value Survey’. Data relating to the degree of commitment to religion referred to as religiosity, was also collected in addition to demographic information.
- Description: Doctor of Philosophy
Optimization based methods for solving some problems in telecommunications and the internet
- Authors: Jia, Long
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: The purpose of this thesis is to develop some new algorithms based on optimization techniques for solving some problems in some areas of telecommunications and the Internet. There are two main parts to this thesis. In the first part we discuss optimization based stochastic and queueing models in telecommunications network corrective maintenance. In the second part we develop optimization based clustering (OBC) algorithms for network evolution and multicast routing. The most typical scenario encountered during mathematical optimization modelling in telecommunications, for example, is to minimize the cost of establishment and maintenance of the networks subject to the performance constraints of the networks and the reliability constraints of the networks as well. Most of these optimization problems are global optimization, that is, they have many local minima and most of these local minima do not provide any useful information for solving these problems. Therefore, the development of effective methods for solving such global optimization problems is important. To run the telecommunications networks with cost-effective network maintenance,we need to establish a practical maintenance model and optimize it. In the first part of the thesis, we solve a known stochastic programming maintenance optimization model with a direct method and then develop some new models. After that we introduce queue programming models in telecommunications network maintenance optimization. The ideas of profit, loss, and penalty will help telecommunications companies have a good view of their maintenance policies and help them improve their service. In the second part of this thesis we propose the use of optimization based clustering (OBC) algorithms to determine level-constrained hierarchical trees for network evolution and multicast routing. This problem is formulated as an optimization problem with a non-smooth, non-convex objective function. Different algorithms are examined for solving this problem. Results of numerical experiments using some artifiicial and real-world databases are reported.
- Description: Doctor of Philosophy
- Authors: Jia, Long
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: The purpose of this thesis is to develop some new algorithms based on optimization techniques for solving some problems in some areas of telecommunications and the Internet. There are two main parts to this thesis. In the first part we discuss optimization based stochastic and queueing models in telecommunications network corrective maintenance. In the second part we develop optimization based clustering (OBC) algorithms for network evolution and multicast routing. The most typical scenario encountered during mathematical optimization modelling in telecommunications, for example, is to minimize the cost of establishment and maintenance of the networks subject to the performance constraints of the networks and the reliability constraints of the networks as well. Most of these optimization problems are global optimization, that is, they have many local minima and most of these local minima do not provide any useful information for solving these problems. Therefore, the development of effective methods for solving such global optimization problems is important. To run the telecommunications networks with cost-effective network maintenance,we need to establish a practical maintenance model and optimize it. In the first part of the thesis, we solve a known stochastic programming maintenance optimization model with a direct method and then develop some new models. After that we introduce queue programming models in telecommunications network maintenance optimization. The ideas of profit, loss, and penalty will help telecommunications companies have a good view of their maintenance policies and help them improve their service. In the second part of this thesis we propose the use of optimization based clustering (OBC) algorithms to determine level-constrained hierarchical trees for network evolution and multicast routing. This problem is formulated as an optimization problem with a non-smooth, non-convex objective function. Different algorithms are examined for solving this problem. Results of numerical experiments using some artifiicial and real-world databases are reported.
- Description: Doctor of Philosophy
An investigation into modification of the engineering properties of salt affected soils using electrokinetics
- Authors: Jayasekera, Samudra
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: Soil salinity (due to ingress of excess amounts of dissolved salts in soil pores) and soil sodicity (due to excess amounts of sodium ions attached to the clay surface) are significant forms of land degradation in many parts of the world in particular in arid and semi arid regions. In Australia, soil salinity has long been identified as the major form of land degradation and the greatest environmental threat. Saline soils cover almost 6% of Australia’s land mass and impose severe threats on agricultural productivity and built infrastructure with an estimated annual loss of $250 million. In recent years, ‘soil sodicity’ is recognised as a far more significant form of land degradation and a severe environmental problem both in terms of affected land area and impact on the environment than is salinity as a problem in Australia. One third of Australian land mass is occupied by sodic soils costing an estimated $2 billion each year in lost production alone, with further significant impacts on the economy due to extensive damage to infrastructure facilities and the environment. [...]
- Description: Doctor of Philosophy
- Authors: Jayasekera, Samudra
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: Soil salinity (due to ingress of excess amounts of dissolved salts in soil pores) and soil sodicity (due to excess amounts of sodium ions attached to the clay surface) are significant forms of land degradation in many parts of the world in particular in arid and semi arid regions. In Australia, soil salinity has long been identified as the major form of land degradation and the greatest environmental threat. Saline soils cover almost 6% of Australia’s land mass and impose severe threats on agricultural productivity and built infrastructure with an estimated annual loss of $250 million. In recent years, ‘soil sodicity’ is recognised as a far more significant form of land degradation and a severe environmental problem both in terms of affected land area and impact on the environment than is salinity as a problem in Australia. One third of Australian land mass is occupied by sodic soils costing an estimated $2 billion each year in lost production alone, with further significant impacts on the economy due to extensive damage to infrastructure facilities and the environment. [...]
- Description: Doctor of Philosophy
Assessing nitrate contamination risks in groundwater : a machine learning approach
- Awais, Muhammad, Aslam, Bilal, Maqsoom, Ahsen, Khalil, Umer, Imran, Muhammad
- Authors: Awais, Muhammad , Aslam, Bilal , Maqsoom, Ahsen , Khalil, Umer , Imran, Muhammad
- Date: 2021
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 11, no. 21 (2021), p.
- Full Text:
- Reviewed:
- Description: Groundwater is one of the primary sources for the daily water requirements of the masses, but it is subjected to contamination due to the pollutants, such as nitrate, percolating through the soil with water. Especially in built-up areas, groundwater vulnerability and contamination are of major concern, and require appropriate consideration. The present study develops a novel framework for assessing groundwater nitrate contamination risk for the area along the Karakoram Highway, which is a part of the China Pakistan Economic Corridor (CPEC) route in northern Pakistan. A groundwater vulnerability map was prepared using the DRASTIC model. The nitrate concentration data from a previous study were used to formulate the nitrate contamination map. Three machine learning (ML) models, i.e., Support Vector Machine (SVM), Multivariate Discriminant Analysis (MDA), and Boosted Regression Trees (BRT), were used to analyze the probability of groundwater contamination incidence. Furthermore, groundwater contamination probability maps were obtained utilizing the ensemble modeling approach. The models were calibrated and validated through calibration trials, using the area under the receiver operating characteristic curve method (AUC), where a minimum AUC threshold value of 80% was achieved. Results indicated the accuracy of the models to be in the range of 0.82–0.87. The final groundwater contamination risk map highlights that 34% of the area is moderately vulnerable to groundwater contamination, and 13% of the area is exposed to high groundwater contamination risk. The findings of this study can facilitate decision-making regarding the location of future built-up areas properly in order to mitigate the nitrate contamination that can further reduce the associated health risks. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Imran” is provided in this record**
- Authors: Awais, Muhammad , Aslam, Bilal , Maqsoom, Ahsen , Khalil, Umer , Imran, Muhammad
- Date: 2021
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 11, no. 21 (2021), p.
- Full Text:
- Reviewed:
- Description: Groundwater is one of the primary sources for the daily water requirements of the masses, but it is subjected to contamination due to the pollutants, such as nitrate, percolating through the soil with water. Especially in built-up areas, groundwater vulnerability and contamination are of major concern, and require appropriate consideration. The present study develops a novel framework for assessing groundwater nitrate contamination risk for the area along the Karakoram Highway, which is a part of the China Pakistan Economic Corridor (CPEC) route in northern Pakistan. A groundwater vulnerability map was prepared using the DRASTIC model. The nitrate concentration data from a previous study were used to formulate the nitrate contamination map. Three machine learning (ML) models, i.e., Support Vector Machine (SVM), Multivariate Discriminant Analysis (MDA), and Boosted Regression Trees (BRT), were used to analyze the probability of groundwater contamination incidence. Furthermore, groundwater contamination probability maps were obtained utilizing the ensemble modeling approach. The models were calibrated and validated through calibration trials, using the area under the receiver operating characteristic curve method (AUC), where a minimum AUC threshold value of 80% was achieved. Results indicated the accuracy of the models to be in the range of 0.82–0.87. The final groundwater contamination risk map highlights that 34% of the area is moderately vulnerable to groundwater contamination, and 13% of the area is exposed to high groundwater contamination risk. The findings of this study can facilitate decision-making regarding the location of future built-up areas properly in order to mitigate the nitrate contamination that can further reduce the associated health risks. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Imran” is provided in this record**
The potential of lime and grand granulated blast furnace slag (ggbfs) mixture for stabilisation of desert silty sands
- Rabbani, Parham, Daghigh, Younes, Atrechian, Mohammad Reza, Karimi, Masoud, Tolooiyan, Ali
- Authors: Rabbani, Parham , Daghigh, Younes , Atrechian, Mohammad Reza , Karimi, Masoud , Tolooiyan, Ali
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Civil Engineering Research Vol. 2, no. 6 (2012), p. 108-119
- Full Text:
- Reviewed:
- Description: This study describes experimental results achieved on the use of Grand Granulated Blast Furnace Slag (GGBFS) and Lime in stabilising desert silty sand for possible use in geotechnical engineering applications, especially for roadways and railways constructions. The GGBFS and lime were added in percentages of 5, 10 and 15% and 1, 3, and 5% respectively, by dry weight of sand. Different laboratory tests such as mechanical aggregation test, hydrometer analysis, liquid-plastic limit, pH value test, compaction, unconfined compressive strength (UCS), California bearing ratio test CBR , were performed on samples to understand the engineering characteristic of soil and influences of mixtures on the silty sand soil. The study results demonstrate significant improvements in unconfined compressive strength and California bearing ratio strength. Moreover the swelling behaviour of mixtures was decreased effectively. Thus mixture of GGBFS and lime can be suggested to improve engineering characteristic of desert silty sands.
- Authors: Rabbani, Parham , Daghigh, Younes , Atrechian, Mohammad Reza , Karimi, Masoud , Tolooiyan, Ali
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Civil Engineering Research Vol. 2, no. 6 (2012), p. 108-119
- Full Text:
- Reviewed:
- Description: This study describes experimental results achieved on the use of Grand Granulated Blast Furnace Slag (GGBFS) and Lime in stabilising desert silty sand for possible use in geotechnical engineering applications, especially for roadways and railways constructions. The GGBFS and lime were added in percentages of 5, 10 and 15% and 1, 3, and 5% respectively, by dry weight of sand. Different laboratory tests such as mechanical aggregation test, hydrometer analysis, liquid-plastic limit, pH value test, compaction, unconfined compressive strength (UCS), California bearing ratio test CBR , were performed on samples to understand the engineering characteristic of soil and influences of mixtures on the silty sand soil. The study results demonstrate significant improvements in unconfined compressive strength and California bearing ratio strength. Moreover the swelling behaviour of mixtures was decreased effectively. Thus mixture of GGBFS and lime can be suggested to improve engineering characteristic of desert silty sands.
Relationships between pumping costs and water quality in optimal operation of regional multiquality water distribution systems
- Authors: Mala-Jetmarova, Helena
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The operation of regional multiquality water distribution systems (WDSs) is a complex task involving multiple objectives in order to meet customer water quantity and quality requirements. These objectives, often conflicting, include scheduling of pumps to minimise pumping costs and mixing different quality waters from sources to ensure adequate quality water for customers. Evolutionary algorithms have been successfully applied to optimise operation of regional WDSs. Although a considerable reduction in pumping costs was demonstrated in past studies, other legitimate objectives, for example water quality, were not considered on an equal basis as they were included as a constraint. This single-objective approach precludes the tradeoffs between the objectives being obtained, so any insight on how to operate such a system cannot be provided should pumping costs and water quality be considered on equal basis. A multi-objective approach is applied in this thesis to optimise operation of regional multiquality WDSs considering pumping costs and water quality as legitimate objectives. Two optimisation models with increasing complexity are proposed. The first model considers two objectives, the pumping costs and a general water quality objective. The second model includes three objectives, the pumping costs and two water quality objectives for turbidity and salinity. The optimisation models are applied to three example networks from the literature using numerous scenarios and water quality data from the Wimmera Mallee Pipeline, Australia. A methodology is proposed to find the optimal solution for the multi‐objective optimisation of the WDS, which links a network simulator with a multi-objective genetic algorithm. Prior to optimisation, the performance of algorithm parameters is evaluated and their sensitivity analysed, for which a new methodology is developed. The following results were obtained. For the two-objective optimisation problem, there is a tradeoff with a competing nature between pumping costs and water quality. It means that reduction in pumping costs cannot be achieved without deterioration of water quality delivered to customers and vice versa. For the three-objective optimisation problem, interestingly, there is not a unique type of tradeoff (either competing or non-competing) between a particular pair of objectives. It is dependent on network hydraulics in combination with water quality at sources and customer water quality requirements. General principles behind the tradeoffs are formulated based on new categorisation of sources, so called consistent/inconsistent water quality (CWQ/IWQ) sources, in relation to customer water quality requirements. A practical approach for system operational strategy is developed for the purpose of long-term operational planning. It enables an operator to schedule supply from multiple sources with minimum pumping costs and customer water quality requirements being satisfied as much as possible, for all predicted water quality scenarios in the system.
- Description: Doctor of Philosophy
- Authors: Mala-Jetmarova, Helena
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The operation of regional multiquality water distribution systems (WDSs) is a complex task involving multiple objectives in order to meet customer water quantity and quality requirements. These objectives, often conflicting, include scheduling of pumps to minimise pumping costs and mixing different quality waters from sources to ensure adequate quality water for customers. Evolutionary algorithms have been successfully applied to optimise operation of regional WDSs. Although a considerable reduction in pumping costs was demonstrated in past studies, other legitimate objectives, for example water quality, were not considered on an equal basis as they were included as a constraint. This single-objective approach precludes the tradeoffs between the objectives being obtained, so any insight on how to operate such a system cannot be provided should pumping costs and water quality be considered on equal basis. A multi-objective approach is applied in this thesis to optimise operation of regional multiquality WDSs considering pumping costs and water quality as legitimate objectives. Two optimisation models with increasing complexity are proposed. The first model considers two objectives, the pumping costs and a general water quality objective. The second model includes three objectives, the pumping costs and two water quality objectives for turbidity and salinity. The optimisation models are applied to three example networks from the literature using numerous scenarios and water quality data from the Wimmera Mallee Pipeline, Australia. A methodology is proposed to find the optimal solution for the multi‐objective optimisation of the WDS, which links a network simulator with a multi-objective genetic algorithm. Prior to optimisation, the performance of algorithm parameters is evaluated and their sensitivity analysed, for which a new methodology is developed. The following results were obtained. For the two-objective optimisation problem, there is a tradeoff with a competing nature between pumping costs and water quality. It means that reduction in pumping costs cannot be achieved without deterioration of water quality delivered to customers and vice versa. For the three-objective optimisation problem, interestingly, there is not a unique type of tradeoff (either competing or non-competing) between a particular pair of objectives. It is dependent on network hydraulics in combination with water quality at sources and customer water quality requirements. General principles behind the tradeoffs are formulated based on new categorisation of sources, so called consistent/inconsistent water quality (CWQ/IWQ) sources, in relation to customer water quality requirements. A practical approach for system operational strategy is developed for the purpose of long-term operational planning. It enables an operator to schedule supply from multiple sources with minimum pumping costs and customer water quality requirements being satisfied as much as possible, for all predicted water quality scenarios in the system.
- Description: Doctor of Philosophy
A new fuzzy logic approach for consistent interpretation of dissolved gas-in-oil analysis
- Abu-Siada, Ahmed, Hmood, Sdood, Islam, Syed
- Authors: Abu-Siada, Ahmed , Hmood, Sdood , Islam, Syed
- Date: 2013
- Type: Text , Journal article
- Relation: IEEE Transactions on Dielectrics and Electrical Insulation Vol. 20, no. 6 (2013), p. 2343-2349
- Full Text:
- Reviewed:
- Description: Dissolved gas analysis (DGA) of transformer oil is one of the most effective power transformer condition monitoring tools. There are many interpretation techniques for DGA results however all these techniques rely on personnel experience more than analytical formulation. As a result, various interpretation techniques do not necessarily lead to the same conclusion for the same oil sample. Furthermore, significant number of DGA results fall outside the proposed codes of the current based-ratio interpretation techniques and cannot be diagnosed by these methods. Moreover, ratio methods fail to diagnose multiple fault conditions due to the mixing up of produced gases. To overcome these limitations, this paper introduces a new fuzzy logic approach to reduce dependency on expert personnel and to aid in standardizing DGA interpretation techniques. The approach relies on incorporating all existing DGA interpretation techniques into one expert model. DGA results of 2000 oil samples that were collected from different transformers of different rating and different life span are used to establish the model. Traditional DGA interpretation techniques are used to analyze the collected DGA results to evaluate the consistency and accuracy of each interpretation technique. Results of this analysis were then used to develop the proposed fuzzy logic model.
- Authors: Abu-Siada, Ahmed , Hmood, Sdood , Islam, Syed
- Date: 2013
- Type: Text , Journal article
- Relation: IEEE Transactions on Dielectrics and Electrical Insulation Vol. 20, no. 6 (2013), p. 2343-2349
- Full Text:
- Reviewed:
- Description: Dissolved gas analysis (DGA) of transformer oil is one of the most effective power transformer condition monitoring tools. There are many interpretation techniques for DGA results however all these techniques rely on personnel experience more than analytical formulation. As a result, various interpretation techniques do not necessarily lead to the same conclusion for the same oil sample. Furthermore, significant number of DGA results fall outside the proposed codes of the current based-ratio interpretation techniques and cannot be diagnosed by these methods. Moreover, ratio methods fail to diagnose multiple fault conditions due to the mixing up of produced gases. To overcome these limitations, this paper introduces a new fuzzy logic approach to reduce dependency on expert personnel and to aid in standardizing DGA interpretation techniques. The approach relies on incorporating all existing DGA interpretation techniques into one expert model. DGA results of 2000 oil samples that were collected from different transformers of different rating and different life span are used to establish the model. Traditional DGA interpretation techniques are used to analyze the collected DGA results to evaluate the consistency and accuracy of each interpretation technique. Results of this analysis were then used to develop the proposed fuzzy logic model.
Single- and multiobjective reinforcement learning in dynamic adversarial games
- Authors: Kurniawan, Budi
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis uses reinforcement learning (RL) to address dynamic adversarial games in the context of air combat manoeuvring simulation. A sequential decision problem commonly encountered in the field of operations research, air combat manoeuvring simulation conventionally relied on agent programming methods that required significant domain knowledge to be manually encoded into the simulation environment. These methods are appropriate for determining the effectiveness of existing tactics in different simulated scenarios. However, in order to maximise the advantages provided by new technologies (such as autonomous aircraft), new tactics will need to be discovered. A proven technique for solving sequential decision problems, RL has the potential to discover these new tactics. This thesis explores four RL approaches—tabular, deep, discrete-to-deep and multiobjective— as mechanisms for discovering new behaviours in simulations of air combat manoeuvring. Itimplements and tests several methods for each approach and compares those methods in terms of the learning time, baseline and comparative performances, and implementation complexity. In addition to evaluating the utility of existing approaches to the specific task of air combat manoeuvring, this thesis proposes and investigates two novel methods, discrete-to-deep supervised policy learning (D2D-SPL) and discrete-to-deep supervised Q-value learning (D2D-SQL), which can be applied more generally. D2D-SPL and D2D-SQL offer the generalisability of deep RL at a cost closer to the tabular approach.
- Description: Doctor of Philosophy
- Authors: Kurniawan, Budi
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis uses reinforcement learning (RL) to address dynamic adversarial games in the context of air combat manoeuvring simulation. A sequential decision problem commonly encountered in the field of operations research, air combat manoeuvring simulation conventionally relied on agent programming methods that required significant domain knowledge to be manually encoded into the simulation environment. These methods are appropriate for determining the effectiveness of existing tactics in different simulated scenarios. However, in order to maximise the advantages provided by new technologies (such as autonomous aircraft), new tactics will need to be discovered. A proven technique for solving sequential decision problems, RL has the potential to discover these new tactics. This thesis explores four RL approaches—tabular, deep, discrete-to-deep and multiobjective— as mechanisms for discovering new behaviours in simulations of air combat manoeuvring. Itimplements and tests several methods for each approach and compares those methods in terms of the learning time, baseline and comparative performances, and implementation complexity. In addition to evaluating the utility of existing approaches to the specific task of air combat manoeuvring, this thesis proposes and investigates two novel methods, discrete-to-deep supervised policy learning (D2D-SPL) and discrete-to-deep supervised Q-value learning (D2D-SQL), which can be applied more generally. D2D-SPL and D2D-SQL offer the generalisability of deep RL at a cost closer to the tabular approach.
- Description: Doctor of Philosophy
Quality Management Practices in Indian SMEs
- Authors: Chakraborty, Ayon
- Date: 2019
- Type: Text , Book chapter
- Relation: Quality Management and Quality Control - New Trends and Developments p.
- Full Text:
- Reviewed:
- Description: The purpose of this chapter is to provide an insight on the status of quality management practices in small and medium-sized enterprises (SMEs) of South India. A survey-based approach was adopted to understand the established quality management practices in the SMEs. A short survey instrument was designed by reviewing the literature on quality management initiatives in SMEs. Sample of 270 manufacturing SMEs across Southern India was selected through stratified random sampling technique. Projects with small teams, management commitment and involvement, communication, and culture change have high influence as success factors in implementing quality initiatives. Overall equipment effectiveness, root cause analysis, bottleneck analysis, and PDCA are often used tools and techniques by the organizations. High cost of training and limited knowledge were the reasons cited for not implementing quality initiatives. The study is an attempt to understand the quality management practices application in SMEs from a specific geographic location. The strength lies in bringing a different perspective from the present studies, whereas specific context of the study limits its generalizability. The findings of this chapter will help the industry to identify current quality management practices in SMEs to focus on improving their performance.
- Authors: Chakraborty, Ayon
- Date: 2019
- Type: Text , Book chapter
- Relation: Quality Management and Quality Control - New Trends and Developments p.
- Full Text:
- Reviewed:
- Description: The purpose of this chapter is to provide an insight on the status of quality management practices in small and medium-sized enterprises (SMEs) of South India. A survey-based approach was adopted to understand the established quality management practices in the SMEs. A short survey instrument was designed by reviewing the literature on quality management initiatives in SMEs. Sample of 270 manufacturing SMEs across Southern India was selected through stratified random sampling technique. Projects with small teams, management commitment and involvement, communication, and culture change have high influence as success factors in implementing quality initiatives. Overall equipment effectiveness, root cause analysis, bottleneck analysis, and PDCA are often used tools and techniques by the organizations. High cost of training and limited knowledge were the reasons cited for not implementing quality initiatives. The study is an attempt to understand the quality management practices application in SMEs from a specific geographic location. The strength lies in bringing a different perspective from the present studies, whereas specific context of the study limits its generalizability. The findings of this chapter will help the industry to identify current quality management practices in SMEs to focus on improving their performance.
The role of Zinc Transporters in modulating Insulin signalling
- Authors: Nield, Alex
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zinc is a cell impermeable transition metal with a large number of biological functions, and is an essential component of the insulin signalling pathway. Cellular free zinc increases insulin sensitivity though it is also toxic at high levels, making it essential for cells to tightly regulate bioavailable levels. This homeostasis is maintained by three groups of proteins known as Zips, ZnTs and metallothioneins (MTs). Zips and ZnTs are zinc transporters with Zips increasing cytosolic zinc by pumping it outside the cell or from organelle stores, while the ZnTs decrease cytosolic zinc. The MTs bind to free zinc in the cytosol, reducing its bioavailability. The rapid release of zinc mediated by these proteins has been implicated as a mechanism of signal pathway activation, through zinc activating and deactivating various signalling proteins. This thesis investigated one zinc transporter in particular, known as Zip7. Zip7 is a novel Zip transporter localised to the endoplasmic reticulum and has been implicated in cell signalling in breast cancer cells through release of zinc from cellular stores in response to extracellular stimuli. The aim of this thesis was to investigate the potential role of this zinc transporter in modulating the insulin signalling pathway. The human Zip7 protein sequence was analysed using various bioinformatics tools to identify regions that may contribute to the proposed novel function of this transporter. The loop regions of Zip7 were found to be poorly conserved between species with the exception of histidine rich regions, which showed a high level of conservation when compared to a diverse series of species and so are suspected to have an essential role in modulating the transport function of Zip7 by binding to zinc. These findings implicate histidine residues as an important functional component of Zip7. In order to identify whether Zip7 expression is essential for a normal insulin response, Zip7 mRNA was reduced via transfection of siRNA in mouse skeletal muscle cells and measurement of markers of insulin signalling. When Zip7 expression was reduced there was a subsequent decrease in the expression of several markers of insulin signalling including Glut4 protein levels, Akt phosphorylation and insulin-mediated glycogen synthesis, indicating that the cells were insulin resistant compared to the control. It was hypothesised that given the proposed role for Zip7 in mediating rapid zinc release and that Zip7 expression is important for normal insulin signalling, Zip7 activation is stimulated by insulin treatment to temporarily increase cytosolic zinc bioavailability as a positive feedback mechanism for prolonging pathway activation. To test this, live cell imaging of zinc flux in cells was performed in cells with reduced Zip7 expression compared to controls. Insulin was shown to cause an increase in cytosolic zinc in C2C12 cells. However when Zip7 expression was reduced, even though the cells showed signs of insulin resistance, there was still an increase in zinc levels mediated by insulin. Insulin treatment is known to induce cellular ROS production and hydrogen peroxide has been suggested to cause a release of zinc due to oxidation of MTs leading to a release of bound zinc. These findings indicate that insulin-stimulated zinc flux is the result of MT oxidation rather than Zip7 activation. Taken together, these results highlight an important role for Zip7 in the insulin signalling pathway and show a previously undescribed positive feedback loop whereby insulin mediates a release of zinc to potentially inhibit PTP1B and other phosphatases to prolong insulin signalling activation. Further work is needed to fully elucidate the role of Zip7 in this pathway.
- Description: Doctor of Philosophy
- Authors: Nield, Alex
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zinc is a cell impermeable transition metal with a large number of biological functions, and is an essential component of the insulin signalling pathway. Cellular free zinc increases insulin sensitivity though it is also toxic at high levels, making it essential for cells to tightly regulate bioavailable levels. This homeostasis is maintained by three groups of proteins known as Zips, ZnTs and metallothioneins (MTs). Zips and ZnTs are zinc transporters with Zips increasing cytosolic zinc by pumping it outside the cell or from organelle stores, while the ZnTs decrease cytosolic zinc. The MTs bind to free zinc in the cytosol, reducing its bioavailability. The rapid release of zinc mediated by these proteins has been implicated as a mechanism of signal pathway activation, through zinc activating and deactivating various signalling proteins. This thesis investigated one zinc transporter in particular, known as Zip7. Zip7 is a novel Zip transporter localised to the endoplasmic reticulum and has been implicated in cell signalling in breast cancer cells through release of zinc from cellular stores in response to extracellular stimuli. The aim of this thesis was to investigate the potential role of this zinc transporter in modulating the insulin signalling pathway. The human Zip7 protein sequence was analysed using various bioinformatics tools to identify regions that may contribute to the proposed novel function of this transporter. The loop regions of Zip7 were found to be poorly conserved between species with the exception of histidine rich regions, which showed a high level of conservation when compared to a diverse series of species and so are suspected to have an essential role in modulating the transport function of Zip7 by binding to zinc. These findings implicate histidine residues as an important functional component of Zip7. In order to identify whether Zip7 expression is essential for a normal insulin response, Zip7 mRNA was reduced via transfection of siRNA in mouse skeletal muscle cells and measurement of markers of insulin signalling. When Zip7 expression was reduced there was a subsequent decrease in the expression of several markers of insulin signalling including Glut4 protein levels, Akt phosphorylation and insulin-mediated glycogen synthesis, indicating that the cells were insulin resistant compared to the control. It was hypothesised that given the proposed role for Zip7 in mediating rapid zinc release and that Zip7 expression is important for normal insulin signalling, Zip7 activation is stimulated by insulin treatment to temporarily increase cytosolic zinc bioavailability as a positive feedback mechanism for prolonging pathway activation. To test this, live cell imaging of zinc flux in cells was performed in cells with reduced Zip7 expression compared to controls. Insulin was shown to cause an increase in cytosolic zinc in C2C12 cells. However when Zip7 expression was reduced, even though the cells showed signs of insulin resistance, there was still an increase in zinc levels mediated by insulin. Insulin treatment is known to induce cellular ROS production and hydrogen peroxide has been suggested to cause a release of zinc due to oxidation of MTs leading to a release of bound zinc. These findings indicate that insulin-stimulated zinc flux is the result of MT oxidation rather than Zip7 activation. Taken together, these results highlight an important role for Zip7 in the insulin signalling pathway and show a previously undescribed positive feedback loop whereby insulin mediates a release of zinc to potentially inhibit PTP1B and other phosphatases to prolong insulin signalling activation. Further work is needed to fully elucidate the role of Zip7 in this pathway.
- Description: Doctor of Philosophy
New Farkas-type results for vector-valued functions : A non-abstract approach
- Dinh, Nguyen, Goberna, Miguel, Long, Dang, Lopez-Cerda, Marco
- Authors: Dinh, Nguyen , Goberna, Miguel , Long, Dang , Lopez-Cerda, Marco
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Optimization Theory and Applications Vol. 182, no. 1 (2019), p. 4-29
- Full Text:
- Reviewed:
- Description: This paper provides new Farkas-type results characterizing the inclusion of a given set, called contained set, into a second given set, called container set, both of them are subsets of some locally convex space, called decision space. The contained and the container sets are described here by means of vector functions from the decision space to other two locally convex spaces which are equipped with the partial ordering associated with given convex cones. These new Farkas lemmas are obtained via the complete characterization of the conic epigraphs of certain conjugate mappings which constitute the core of our approach. In contrast with a previous paper of three of the authors (Dinh et al. in J Optim Theory Appl 173:357-390, 2017), the aimed characterizations of the containment are expressed here in terms of the data.
- Authors: Dinh, Nguyen , Goberna, Miguel , Long, Dang , Lopez-Cerda, Marco
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Optimization Theory and Applications Vol. 182, no. 1 (2019), p. 4-29
- Full Text:
- Reviewed:
- Description: This paper provides new Farkas-type results characterizing the inclusion of a given set, called contained set, into a second given set, called container set, both of them are subsets of some locally convex space, called decision space. The contained and the container sets are described here by means of vector functions from the decision space to other two locally convex spaces which are equipped with the partial ordering associated with given convex cones. These new Farkas lemmas are obtained via the complete characterization of the conic epigraphs of certain conjugate mappings which constitute the core of our approach. In contrast with a previous paper of three of the authors (Dinh et al. in J Optim Theory Appl 173:357-390, 2017), the aimed characterizations of the containment are expressed here in terms of the data.
Graphs and subgraphs with bounded degree
- Authors: Teska, Jakub
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The topology of a network (such as a telecommunications, multiprocessor, or local area network, to name just a few) is usually modelled by a graph in which vertices represent 'nodes' (stations or processors) while undirected or directed edges stand for 'links' or other types of connections, physical or virtual. A cycle that contains every vertex of a graph is called a hamiltonian cycle and a graph which contains a hamiltonian cycle is called a hamiltonian graph. The problem of the existence of a hamiltonian cycle is closely related to the well known problem of a travelling salesman. These problems are NP-complete and NP-hard, respectively. While some necessary and sufficient conditions are known, to date, no practical characterization of hamiltonian graphs has been found. There are several ways to generalize the notion of a hamiltonian cycle. In this thesis we make original contributions in two of them, namely k-walks and r-trestles." --Abstract.
- Description: Doctor of Philosophy
- Authors: Teska, Jakub
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The topology of a network (such as a telecommunications, multiprocessor, or local area network, to name just a few) is usually modelled by a graph in which vertices represent 'nodes' (stations or processors) while undirected or directed edges stand for 'links' or other types of connections, physical or virtual. A cycle that contains every vertex of a graph is called a hamiltonian cycle and a graph which contains a hamiltonian cycle is called a hamiltonian graph. The problem of the existence of a hamiltonian cycle is closely related to the well known problem of a travelling salesman. These problems are NP-complete and NP-hard, respectively. While some necessary and sufficient conditions are known, to date, no practical characterization of hamiltonian graphs has been found. There are several ways to generalize the notion of a hamiltonian cycle. In this thesis we make original contributions in two of them, namely k-walks and r-trestles." --Abstract.
- Description: Doctor of Philosophy