Description:
Vertical handoff plays an important role in guaranteeing users to be always connected in an overlapped multi-network environment. During the vertical handoff procedure, handoff decision is the most important step that affects the normal working of communication. An incorrect handoff decision or selection of a non-optimal network may result in undesirable effects such as higher costs, poor quality of service (QoS) experience, and even dropped communication. Among the existing vertical handoff decision algorithms, the Markov Decision Process (MDP) based algorithm by Stevens-Navarro et al. is promising due to its ability to achieve the optimal expected reward. However, the reward function used by this algorithm is flawed as it favors reducing expected number of vertical handoffs at the expense of diminished expected values of other QoS parameters. This paper presents an extended MDP based algorithm (EMDP) with novel reward function formulation. Analysis shows that EMDP outperforms the MDP based algorithm in terms of improved expected values of all QoS parameters considered while keeping the vertical handoff number reasonably low.
Description:
Australian water organisations currently rank within the nine sectors identified by the Federal Government under the category of Critical Infrastructure (CI), as designated by the Attorney General's Department. As such, water from a CI protection perspective is considered to be a vulnerable target for terrorism. Major global terrorist incidents such as the attack in New York in 2001 coupled with the media interest and associated amplification have highlighted the need for organisations to protect water infrastructure from future attacks. The Victorian Government is leading the path to terrorism risk reduction of CI by the introduction of an Act of Parliament Terrorism (Community Protection) Act 2003, assuring that risk mitigation is in place across the state. One requirement under this Act is to annually practice plans and procedures in the form of scripted Crisis Simulation Exercises (CSE). These CSEs are to ensure that water organisations are more resilient to meet the challenge and maintain business continuity during any future terrorist incident. This includes the interactions and timings of available resources, logistics with appropriate personnel as required and to the appropriate level indicated in the plans. These CSEs can incorporate live actions, testing equipment and personnel within all organisational levels. It is considered that CI organisations which adopt these strategies enhance business survival and continuity, producing a resilient entity prepared for and resistant to penetration by an organised terrorist group or radical cell. This paper provides an overview of a simulation framework to ensure preparedness suitable for mitigation of risk of terrorism in relation to the Australian water industry.
Description:
While the Australian apprenticeship and traineeship system is currently strong, the overall strength belies some areas of weakness. One of these areas is the uneven nature of demand from applicants for positions as apprentices and trainees, which means that some industries, occupations and employers struggle to find enough applicants while others are over-subscribed. While apprenticships or traineeships in some occupations and/or companies offering positions within those occupations find it difficult to attract applicants of a suitable calibre. This paper reports on a research project undertaken during 2010, with 21 employers who employed apprentices and trainees. The different recruitment strategies and outcomes of the companies are described and the possible for companies' apparent success or failure to attract suitable applicants are discussed. Some suggestions for future policy and practice at company, regional and national level are offered.
Description:
While the Australian apprenticeship and traineeship system is currently strong, the overall strength belies some areas of weakness. One of these areas is the uneven nature of demand from applicants for positions as apprentices and trainees, which means that some industries, occupations and employers struggle to find enough applicants while others are over-subscribed. While apprenticships or traineeships in some occupations and/or companies offering positions within those occupations find it difficult to attract applicants of a suitable calibre. This paper reports on a research project undertaken during 2010, with 21 employers who employed apprentices and trainees. The different recruitment strategies and outcomes of the companies are described and the possible for companies' apparent success or failure to attract suitable applicants are discussed. Some suggestions for future policy and practice at company, regional and national level are offered.
Description:
Grade control programs aim to deliver economic tonnes to the mill via accurate definition of ore and waste. The foundation of a successful program is high quality sampling supported by geology and a suitable data management and modelling system. Underground sampling methods include chip, channel and panel samples; grab/muck pile samples; and drill-based samples. Grade control strategy is related to mining method and orebody type. Sampling protocols must be designed to suit the style of mineralisation in question. Holistic studies focussing on ore mineralogy and gold particle deportment, size and distribution are required for sample collection and preparation protocol optimisation through 'Theory of Sampling' application. Where possible, such programs should be undertaken early in the life of a project. Appropriate assaying procedures are also required. Program implementation will require suitably skilled individuals to train and mentor staff, with ongoing Quality Assurance/Quality Control (QA/QC) monitoring and review will allow protocols and staff to be updated as required.
Description:
Hydraulic simulation models have become a valuable tool to manage water distribution networks commencing from their initial design through their operation, assessment of the level of service to customers, system performance improvement, analysis of planning alternatives, to system optimisation. The development of hydraulic models can be a time consuming task with complex and large scale water distribution networks being particularly challenging. The Wimmera Mallee Pipeline (WMP) in Western Victoria, Australia is a recently constructed and unique regional scale water distribution system which consists of over 8,800 km of pressurised pipelines spreading across an area of approximately 20,000 km 2. Currently, the WMP provides water to 34 townships, rural farms and other water users across the Wimmera Mallee region with an annual design capacity of 31.6 mil. m 3. The WMP sources its water from multiple reservoirs in the Grampians mountain ranges in the south and the River Murray in the north. Grampians Wimmera Mallee Water (GWMWater) is the local water organisation responsible for managing the WMP. GWMWater is currently initiating the development of a water market to generate and support growth, and to ensure that water is available for the highest value social, economic or environmental use. The hydraulic models discussed in this paper will assure that informed decisions are made by GWMWater regarding the capacity to deliver water through the pipeline system, and therefore the extent of trade by customers. The philosophy for development of the WMP hydraulic models was to replicate the real system as credibly as possible into the level of required accuracy for decision making, yet enable simple model operation, maintenance and update. The network is modelled to the individual customer level in order to accommodate small diameter pipes. Modelling at this level simplifies the future model maintenance and updates, and also ensures the compatibility with other GWMWater's systems such as Geographic Information System (GIS) and the customer database. A major part of the model development consisted of data preparation. This was undertaken by using "as constructed" GIS asset data captured during the WMP construction and entered into a GIS database (ArcGIS by ESRI). Due to the scale of the system and associated amounts of data, it was essential to develop sophisticated data transformation and validation procedures to simplify the model build which thereby minimised manual data entry and potential sources of errors. This paper focuses on the methodologies and techniques used in data preparation for hydraulic models and development of hydraulic models. An example is also provided of how the models will be used as a decision support tool in water supply and allocation planning.
Description:
This paper looks at two ways to estimate the bulk mineralogy of the rocks for assay intervals. The aim is to find an efficient indicator of the most common minerals in the rock. Phase (modal) analysis has traditionally been done using visual methods such as point counting and image analysis. A modern version of this process is the X-ray point counting routine using the SEM-EDS based software. These methods are too slow and expensive for routine analysis of bulk sample mineralogy at the normal assay spacing. Two sources of data were considered that provide information that can be used to determine the mineral abundance in assay samples. The most widely applied method is (semi-) quantitative X-ray diffraction (QXRD). The QXRD method is most applicable to major minerals and has limited application to minerals at low abundance. The nominal detection limit is 0.5 per cent. Values below five per cent have large errors. A second, less common, method is calculation of mineralogy from chemical assay data. Conversion of chemical analyses to mineralogical analyses depends on the unique chemical composition of each mineral. Elements only found in one mineral are easily accounted for, but many compositions are ambiguous. Deciding on the actual mineralogy is not simple. Recalculation of mineral mode from chemical analyses is more accurate than QXRD when the correct minerals, and mineral compositions, are known. Where only a few QXRD analyses are available they can be used to setup a protocol for calculation of mineralogy from assay data. Linear programming works well in this environment. The best results are obtained when both H 2O and CO 2 are directly measured. Loss-on-ignition (LOI) should be included if these are not available. Where both QXRD and chemical analysis are available for all samples, the best results are obtained using the least squared method to merge the data sets assuming QXRD has much higher analytical errors than chemical assays. The combined method provides more robust results because the high abundance minerals are controlled by the QXRD measurements while the chemical assays improve the precision for low abundance minerals.
Description:
Dimensionality reduction of the problem space through detection and removal of variables, contributing little or not at all to classification, is able to relieve the computational load and instance acquisition effort, considering all the data attributes accessed each time around. The approach to feature selection in this paper is based on the concept of coherent accumulation of data about class centers with respect to coordinates of informative features. Ranking is done on the degree to which different variables exhibit random characteristics. The results are being verified using the Nearest Neighbor classifier. This also helps to address the feature irrelevance and redundancy, what ranking does not immediately decide. Additionally, feature ranking methods from different independent sources are called in for the direct comparison.
Description:
Dimensionality reduction of the problem space through detection and removal of variables, contributing little or not at all to classification, is able to relieve the computational load and the data acquisition effort, considering all data components being accessed each time around. The approach to feature selection in this paper is based on the concept of coherent accumulation of data about class centers with respect to coordinates of informative features. Ranking is done on the degree, to which different variables exhibit random characteristics. The results are being verified using the Nearest Neighbor classifier. This also helps to address the feature irrelevance, what ranking does not immediately decide. Additionally, feature ranking methods available from different independent sources are called in for direct comparison.
Description:
Dimensionality reduction of the problem space through detection and removal of variables, contributing little or not at all to classification, is able to relieve the computational load and instance acquisition effort, considering all the data attributes accessed each time around. The approach to feature selection in this paper is based on the concept of coherent accumulation of data about class centers with respect to coordinates of informative features. Ranking is done on the degree to which different variables exhibit random characteristics. The results are being verified using the Nearest Neighbor classifier. This also helps to address the feature irrelevance and redundancy, what ranking does not immediately decide. Additionally, feature ranking methods from different independent sources are called in for the direct comparison.
Description:
Dimensionality reduction of the problem space through detection and removal of variables, contributing little or not at all to classification, is able to relieve the computational load and the data acquisition effort, considering all data components being accessed each time around. The approach to feature selection in this paper is based on the concept of coherent accumulation of data about class centers with respect to coordinates of informative features. Ranking is done on the degree, to which different variables exhibit random characteristics. The results are being verified using the Nearest Neighbor classifier. This also helps to address the feature irrelevance, what ranking does not immediately decide. Additionally, feature ranking methods available from different independent sources are called in for direct comparison.
Description:
While the main body of literature regarding small-to-medium enterprises is focused on formation and growth, there is insufficient research about the role of both (a) firm size and (b) location on economic growth. The role of firm size and industrial structure on economic growth has been examined by some researchers. Pagano (2003) and Pagano and Schivardi (2000) identified a positive association between average firm size and growth and Carree and Thurik (1999) found evidence that the low number of large firms in an industry could lead to a higher value added growth. The current study attempts to investigate the impact of industry structure and businesses operating within these industries on economic growth. This paper uses “k-means” clustering algorithm to cluster Statistical Local Areas. Regression analysis is utilised to identify drivers of economic growth. Preliminary results suggest that size of business may act as a driver of economic growth but the impact could vary based on location.
Description:
While the main body of literature regarding small-to-medium enterprises is focused on formation and growth, there is insufficient research about the role of both (a) firm size and (b) location on economic growth. The role of firm size and industrial structure on economic growth has been examined by some researchers. Pagano (2003) and Pagano and Schivardi (2000) identified a positive association between average firm size and growth and Carree and Thurik (1999) found evidence that the low number of large firms in an industry could lead to a higher value added growth. The current study attempts to investigate the impact of industry structure and businesses operating within these industries on economic growth. This paper uses “k-means” clustering algorithm to cluster Statistical Local Areas. Regression analysis is utilised to identify drivers of economic growth. Preliminary results suggest that size of business may act as a driver of economic growth but the impact could vary based on location.
Description:
During the vertical handoff procedure, handoff decision is the most important step that affects the normal working of communication. An incorrect handoff decision or selection of a non-optimal network can result in undesirable effects such as higher costs, poor service experience, degrade the quality of service and even break off current communication. The objective of this paper is to determine the conditions under which vertical handoff should be performed in heterogeneous wireless networks. In this paper, we present a comprehensive analysis of different vertical handoff decision algorithms. To evaluate tradeoffs between their performance and efficiency, we propose two improved vertical handoff decision algorithm based on Markov Decision Process which are referred to as MDP_SAW and MDP_TOPSIS. The proposed mechanism assists the terminal in selecting the top candidate network and offer better available bandwidth so that user satisfaction is effectively maximized. In addition, our proposed method avoids unbeneficial handoffs in the wireless overlay networks.
Description:
During the vertical handoff procedure, handoff decision is the most important step that affects the normal working of communication. An incorrect handoff decision or selection of a non-optimal network can result in undesirable effects such as higher costs, poor service experience, degrade the quality of service and even break off current communication. The objective of this paper is to determine the conditions under which vertical handoff should be performed in heterogeneous wireless networks. In this paper, we present a comprehensive analysis of different vertical handoff decision algorithms. To evaluate tradeoffs between their performance and efficiency, we propose two improved vertical handoff decision algorithm based on Markov Decision Process which are referred to as MDP_SAW and MDP_TOPSIS. The proposed mechanism assists the terminal in selecting the top candidate network and offer better available bandwidth so that user satisfaction is effectively maximized. In addition, our proposed method avoids unbeneficial handoffs in the wireless overlay networks.
Description:
Cognitive radio network (CRN) users are inherently expected to experience widely-varied delays due to the uncertainty in wireless channel availability. Supporting delay sensitive real-time services through CRNs, so that visitors are allowed to experience full-scale networking services by opportunistically sharing the spectrum from a number of existing networks without impacting on the primary users, thus remains a challenging task. This paper presents a novel technique to provision QoS guarantee for delay-sensitive services in CRNs having secondary users equipped with multiple radio interfaces. The technique relies on modeling spectrums holes from multiple primary networks through a resultant channel to enable implementing a single server queuing model with random service interruption. Simulation results using ns-2.33 show that using multiple radio interfaces has sheer strength to reduce CRN delay with fewer number of primary channel sensing.