Description:
The large size of raw 3D optical coherence tomography (OCT) volumes poses challenges for deep learning methods as it cannot be accommodated on a single GPU in its original resolution. The direct analysis of these volumes however, provides advantages such as circumventing the need for the segmentation of retinal structures. Previously, a deep learning (DL) approach was proposed for the detection of glaucoma directly from 3D OCT volumes, where the volumes were significantly downsampled first. In this paper, we propose an end-to-end DL model for the detection of glaucoma that doubles the number of input voxels of the previously proposed method, and also boasts an improved AUC = 0.973 over the results obtained using the previously proposed approach of AUC = 0.946. Furthermore, this paper also includes a quantitative analysis of the regions of the volume highlighted by grad-CAM visualization. Occlusion of these highlighted regions resulted in a drop in performance by 40%, indicating that the regions highlighted by gradient-weighted class activation maps (grad-CAM) are indeed crucial to the performance of the model.
Description:
Kinesin nanomotor is a tiny vehicle that transports molecular cargoes within the cells. Many kinesin nanomotors can attach to a single cargo and coordinate their behaviors to transport the cargo. This behavioral coordination of kinesin nanomotors can be defined through a communicational language that kinesin nanomotors follow to transport the cargo. This paper proposes a computational language for kinesin nanomotor which is inspired by the nanomotor's natural behavior. In this technique, we have used behavioral Deterministic Finite Automaton (DFA) model of kinesin nanomotor which indicated internal intelligent and autonomous decision-making process of the nanomotor in response to its cell. In addition, the behavioral responses of kinesin nanomotor to its cell, behavioral DFA model of the nanomotor, were mapped to a computational regular language for the nanomotor. The proposed computational language for kinesin nanomotor was acceptable by the behavioral DFA model and also in good agreement with the natural behavior of the nanomotor. The development of such computational languages among intelligent and autonomous nanoparticles in nature paves the way for constructing potential bio-inspired nanorobotic systems as well as designing of some computational languages for their controlling.
Description:
The advance in technologies helped in providing efficient system that connect people worldwide such as the use of internet. At the same time cyber attackers exploited the vulnerabilities existed in these technologies to conduct large variety of attack activities against the information and systems. Researchers and solution's providers implemented different countermeasure mechanisms to protect the system against attacks and saved the discovered type of attack in attack database for future analysis and decision. Intrusion Detection (ID) system is an example for protecting the system against attacks by monitoring the network activities and updating the attack database for future analysis and protection decision. In addition to IDs, firewall, intrusion prevention, encryption, authorization and authentication are used to protect the system. Furthermore, a supplementary configurations honeypot systems can be used to strengthen the system security.
Description:
The advance in technologies helped in providing efficient system that connect people worldwide such as the use of internet. At the same time cyber attackers exploited the vulnerabilities existed in these technologies to conduct large variety of attack activities against the information and systems. Researchers and solution's providers implemented different countermeasure mechanisms to protect the system against at-tacks and saved the discovered type of attack in attack database for future analysis and decision. Intrusion Detection (ID) system is an example for protecting the system against attacks by monitoring the network activities and updating the attack data-base for future analysis and protection decision. In addition to IDs, firewall, intrusion prevention, encryption, authorization and authentication are used to protect the sys-tem. Furthermore, a supplementary configurations honeypot systems can be used to strengthen the system security.
Description:
Existing contention based nonpersistent medium access control protocols in Wireless Sensor Network (WSN) do not perform well in high contention. Their performances are affected by occurrence of collision due to uniform probability distribution in choosing Time Slot (TS) during backoff period. To address this issue nonuniform probability distribution was proposed. However success rate still drops for higher number of contenders. In this paper we propose CSMA/s (Collision Sense Multiple Access /per Slot based), a new approach in nonuniform contender-aware probability distribution for choosing TS in the backoff period. Rather than taking a premeditated fixed value for contender population size, our proposed scheme embeds neighborhood population size into its bedrock to automatically converge to the actual number of contenders which enables the contender to adaptively choose TS in the backoff period for reducing collision. This method produces better success rate and lower latency for even very high number of contenders.
Description:
Wireless ad hoc networks are self-configurable distributed systems. One of the major problems in traditional wireless ad hoc networks is interference. The interference could be reduced using smart directional antennas. In this study, multibeam smart antennas have been used. When using this type of antenna, two nodes can communicate when both the sending and receiving beams are pointing towards each other. Also, a node can only communicate with a subset of nodes in its neighborhood depending on the number of beams and their beamwidth. Thus, the network topology needs to be dynamic in this case, and by controlling the topology network, performance can be increased. In this paper, we present a framework of a cross layer approach of topology control that interacts with the routing layer and MAC layer and meets the required QoS of different data streams. The approach is fully distributed. When the network is initialized, the algorithm builds an initial connected topology and the routing algorithm uses this topology to find paths for the current communications. Then, depending on the network scenario, current communications and the required QoS, the topology control layer changes the topology to optimize the network performance. This study concerns suburban ad hoc networks (SAHN) where nodes tend to be fixed and are aware of their locations.
Description:
The purpose of this paper is to provide greater insight into environmental accountability and disclosure from a functionalist perspective. Discussion of the utility of information supplied by corporations to discharge accountability is dependent on societal attitudes to the function of the corporation in society, corporate environmental responsibility and the issue of economic growth. Similarly, the usefulness of environmental information is predicated on perceptions of society as to the importance of environmental issues. The polarisation and politicisation of opinion regarding global warming denies scientific evidence and compounds issues of accountability and disclosure. A postal questionnaire was used to determine societal attitudes to key aspects of corporate functionality, accountability and disclosure. Questionnaire participants were drawn from three categories of society; shareholders, environmentalists and shareholder / environmentalists. Results indicate that the majority of respondents believe the function of the corporation in society is economic and social but there is a significant difference between shareholders and the other user groups. The preferred option of respondents regarding environmental accountability is for companies to be in advance of law and opinion. The sustainable development position, described a continuum, is supported by the shareholder and shareholder/environmentalist groups. The survey research method adopted in this paper suffers from the stated perceptions of respondents rather than attempting to reveal attitudes via alternative approaches. This study demonstrates that there is an attitudinal change towards corporate responsibility that will necessitate re-evaluation of corporate disclosure and accountability.
Description:
The purpose of this paper is to provide greater insight into environmental accountability and disclosure from a functionalist perspective. Discussion of the utility of information supplied by corporations to discharge accountability is dependent on societal attitudes to the function of the corporation in society, corporate environmental responsibility and the issue of economic growth. Similarly, the usefulness of environmental information is predicated on perceptions of society as to the importance of environmental issues. The polarisation and politicisation of opinion regarding global warming denies scientific evidence and compounds issues of accountability and disclosure. A postal questionnaire was used to determine societal attitudes to key aspects of corporate functionality, accountability and disclosure. Questionnaire participants were drawn from three categories of society; shareholders, environmentalists and shareholder / environmentalists. Results indicate that the majority of respondents believe the function of the corporation in society is economic and social but there is a significant difference between shareholders and the other user groups. The preferred option of respondents regarding environmental accountability is for companies to be in advance of law and opinion. The sustainable development position, described a continuum, is supported by the shareholder and shareholder/environmentalist groups. The survey research method adopted in this paper suffers from the stated perceptions of respondents rather than attempting to reveal attitudes via alternative approaches. This study demonstrates that there is an attitudinal change towards corporate responsibility that will necessitate re-evaluation of corporate disclosure and accountability.
Description:
Genome-wide association studies (GWAS) and next-generation sequencing (NGS) has led to an increase in information about the human genome and cardiovascular disease. Understanding the role of genes in cardiac function and pathology requires modeling gene interactions and identification of regulatory genes as part of a gene regulatory network (GRN). Feature selection and data reduction not sufficient and require domain knowledge to deal with large data. We propose three novel innovations in constructing a GRN based on heuristics. A 2D Visualised Co-regulation function. Post-processing to identify gene-gene interactions. Finally a threshold algorithm is applied to identify the hub genes that provide the backbone of the GRN. The 2D Visualized Co-regulation function performed significantly better compared to the Pearson's correlation for measuring pairwise associations (t=3.46, df=5, p=0.018). The F-measure, improved from 0.11 to 0.12. The hub network provided a 60% improvement to that reported in the literature. The performance of the hub network was then also compared against ARACNe and performed significantly better (p=0.024). We conclude that a heuristics approach in developing GRNs has potential to improve our understanding of gene regulation and interaction in diverse biological function and disease.
Description:
In image retrieval, an effective dissimilarity (or similarity) measure is required to retrieve the perceptually similar images. Minkowski-type distance is widely used for image retrieval, however it has its limitation. It focuses on distance between image features and ignores the data distribution of the image features, which can play an important role in measuring perceptual similarity of images. To address this limitation, a data dependent measure named m-p, which calculates the dissimilarity using the data distribution rather than geometric distance has been proposed recently. It considers two instances in a sparse region to be more similar than in a dense region. Relying only on data distribution and completely ignoring the geometric distance raise other limitations. This may result in finding two perceptually dissimilar instances similar due to being located in a sparse region or vice versa. We proposed a new hybrid dissimilarity measure and experimental results show that it addresses these limitations.
Description:
Content-based image retrieval (CBIR) is a popular approach to retrieve images based on a query. In CBIR, retrieval is executed based on the properties of image contents (e.g. gradient, shape, color, texture) which are generally encoded into image descriptors. Among the various image descriptors, histogram-based descriptors are very popular. However, they suffer from the limitation of coarse quantization. In contrast, the use of kernel descriptors (KDES) is proven to be more effective than histogram-based descriptors in other applications, e.g. image classification. This is because, in the KDES framework, instead of the quantization of pixel attributes, each pixel equally takes part in the similarity measurement between two images. In this paper, we propose an approach for how the conventional KDES and its improved version can be used for CBIR. In addition, we have provided a detailed insight into the effectiveness of improved kernel descriptors. Finally, our experiment results will show that kernel descriptors are significantly more effective than histogram-based descriptors in CBIR.
Description:
While Grid environment has developed increasingly, unfortunately the importance of fault tolerance has not been remarkable in Grid resource management. On the other hand, the cost of computing by grid is important because grid is an economy-based system. Most organizations intend to spend little on their own computations by grid. Therefore, using a better approach to resource scheduling to avoid fault is necessary. This paper presents a new approach on fault tolerance mechanisms for the resource scheduling on grid by using Case-Based Reasoning technique in a local fashion. This approach applies a specific structure in order to prepare fault tolerance between executer nodes to retain system in a safe state with minimum data transferring. Certainly, this algorithm increases fault tolerant confidence therefore, performance of grid will be high.
Description:
2009 5th IEEE GCC Conference and Exhibition, GCC 2009
Description:
Due to the mission-critical nature of energy management, smart power grids are prime targets for cyber-attacks. A key security objective in the smart grid is to protect the integrity of synchronized real-time measurements taken by phasor measurement units (PMUs). The current communication protocol in substation automation allows the transmission of PMU data in absence of integrity protection for applications that strictly require low communication latency. This leaves the PMU data vulnerable to man-in-the-middle attacks. In this paper, a lightweight and secure integrity protection algorithm has been proposed to maintain the integrity of PMU data, which fills the missing integrity protection in the IEC 61850-90-5 standard, when the MAC identifier is declared 0. The rigorous security analysis proves the security of the proposed integrity protection method against ciphertext-only attacks and known/chosen plaintext attacks. A comparison with existing integrity protection methods shows that our method is much faster, and is also the only integrity protection scheme that meets the strict timing requirement. Not only the proposed method can be used in power protection applications, but it also can be used in emerging anomaly detection scenarios, where a fast integrity check coupled with low latency communications is used for multiple rounds of message exchanges.
Description:
One of the key advantages of cascaded multilevel inverters (CMLI) is their ability to generate medium voltage output by using low voltage rated circuit components. For this reason, CMLI has been given much attention in renewable and industrial applications. However, in spite CMLI advantages, balanced input dc voltage management at the cascaded cells is still considered one of the main drawbacks, which limits its straightforward applications. Moreover, galvanic isolation between the input dc supply and the inverter output voltage is essential for grid-connected application. In such case, a step-up transformer is utilized between the inverter output terminals and the grid. This solution incurs additional cost, increases implementation size, weight and maintenance. In this paper, a CMLI is proposed for medium voltage applications by utilizing high frequency magnetic link to ensure galvanic isolation without the need to a conventional step-up transformer as per the current practice. 3 rd harmonic-injected sine pulse width modulation strategy is adopted as a switching controller for the proposed cascaded inverter that is implemented and tested. Experimental results attest the simulation results and confirm the feasibility of the proposed inverter
Description:
Fully integrated electronic health records (EHR) provide healthcare providers and patients access to records across a health care system and promise efficient and effective provision of health care. However, fully integrated records have proven to be very expensive and difficult to establish. Currently. EHR's have been developed largely to accommodate Western medicine events. These barriers impact on the introduction of EHR's in Sri Lanka, where health budgets are already stretched and Ayurvedic medicine is routinely practiced alongside Allopathic medicine. This article identifies requirements for EHR in the Sri Lankan context and advances a model for the introduction of EHR's that suits that context. The model is justified by drawing on insights and experiences with EHR in Western nations.
Description:
Fully integrated electronic health records (EHR) provide healthcare providers and patients access to records across a health care system and promise efficient and effective provision of health care. However, fully integrated records have proven to be very expensive and difficult to establish. Currently. EHR's have been developed largely to accommodate Western medicine events. These barriers impact on the introduction of EHR's in Sri Lanka, where health budgets are already stretched and Ayurvedic medicine is routinely practiced alongside Allopathic medicine. This article identifies requirements for EHR in the Sri Lankan context and advances a model for the introduction of EHR's that suits that context. The model is justified by drawing on insights and experiences with EHR in Western nations.
Description:
A number of building detection methods have been proposed in the literature. However, they are not effective in detecting small buildings (typically, 50 m(2)) and buildings with transparent roof due to the way area thresholds and ground points are used. This paper proposes a new building mask to overcome these limitations and enables detection of buildings not only with transparent roof materials but also which are small in size. The proposed building detection method transforms the non-ground height information into an intensity image and then analyses the gradient information in the image. It uses a small area threshold of 1 m2 and, thereby, is able to detect small buildings such as garden sheds. The use of non-ground points allows analyses of the gradient on all types of roof materials and, thus, the method is also able to detect buildings with transparent roofs. Our experimental results show that the proposed method can successfully extract buildings even when their roofs are small and/or transparent, thereby, achieving relatively higher average completeness and quality.
Description:
A number of building detection methods have been proposed in the literature. However, they are not effective in detecting small buildings (typically, 50 m(2)) and buildings with transparent roof due to the way area thresholds and ground points are used. This paper proposes a new building mask to overcome these limitations and enables detection of buildings not only with transparent roof materials but also which are small in size. The proposed building detection method transforms the non-ground height information into an intensity image and then analyses the gradient information in the image. It uses a small area threshold of 1 m2 and, thereby, is able to detect small buildings such as garden sheds. The use of non-ground points allows analyses of the gradient on all types of roof materials and, thus, the method is also able to detect buildings with transparent roofs. Our experimental results show that the proposed method can successfully extract buildings even when their roofs are small and/or transparent, thereby, achieving relatively higher average completeness and quality.
Description:
Doubly Fed Induction Generators (DFIGs) are currently extensively used in variable speed wind power plants due to their superior advantages that include reduced converter rating, low cost, reduced losses, easy implementation of power factor correction schemes, variable speed operation and four quadrants active and reactive power control capabilities. On the other hand, DFIG sensitivity to grid disturbances, especially for voltage sags represents the main disadvantage of the equipment. In this paper, a coil is proposed to be integrated within the DFIG converters to improve the overall performance of a DFIG-based wind energy conversion system (WECS). A proportional integral (PI) controller to control the charging and discharging of the coil is introduced. Simulation results reveal the effectiveness of the proposed topology in improving the overall performance of the WECS under study.
Description:
Color image fusion of visible and infra-red imagery can play an important role in multi-sensor night vision systems that are an integral part of modern warfare. Image fusion minimizes the amount of required bandwidth by transmitting the fused image rather than multiple sensor images. Color image fusion can be achieved by combining inputs from original colored sensors or by employing pseudo colorization and color transfer to grayscale images. Various quality measures have been proposed for multi-sensor grayscale image fusion techniques; but no appropriate quality measure has been devised for the quality evaluation of multi-sensor color image fusion. In this paper, we propose a novel color image fusion quality measure, Color Fusion Objective Index (CFOI) based on colorfulness, gradient similarity and mutual information techniques. Experimental results show the effectiveness of CFOI to evaluate the color and salient feature extraction introduced by color fusion techniques into the final fused imagery as well as its consistency with subjective evaluation.