IJITCS Vol. 5, No. 4, Mar. 2013
Cover page and Table of Contents: PDF (size: 236KB)
Information flow control models can be applied widely. This paper discusses only the models preventing information leakage during program execution. In the prevention, an information flow control model dynamically monitors statements that will cause information flows and ban statements that may cause leakage. We involved in the research of information flow control for years and identified that sensitive information may be leaked only when it is output. However, most existing models ignore information flows induced by output statements. We thus designed a new model XIFC (X information flow control) that especially emphasizes the monitoring of output statements. We also designed XIFC as a precise and low runtime overhead model. To achieve this purpose, we took a different viewpoint to re-examine the features offered by existing models and extracted a necessary feature set for the design. Our experiments show that XIFC bans every non-secure information flow and substantially reduces runtime overhead when comparing with our previous work.[...] Read more.
This study investigates the potential of determining atmospheric transmissivity (τ) from NOAA-AVHRR satellite images using a simple methodology. Using this method, hourly transmissivity values over the land surface area of Bangladesh has been determined. The spatio-temporal distribution of τ has been studied by constructing monthly average maps for the whole country for one complete year (February 2005 to January 2006). Yearly average map has been prepared by integrating monthly average maps. Geographical distribution of τ exhibits patterns and trends. It is observed that the value of τ varies from 0.3 to 0.65 with the average maximum value in the month of April and minimum value in the month of November. It is also observed that for western parts of the country, which is the drought prone area, transmissivity values are little bit higher than that at the eastern parts. Relatively lower values of τ in the dry months (November to January) may be due to the effect of particulate or chemical pollution in the atmosphere.[...] Read more.
This paper describes and evaluates four different HSMM (hidden semi-Markov model) training methods for HMM-based synthesis of emotional speech. The first method, called emotion-dependent modelling, uses individual models trained for each emotion separately. In the second method, emotion adaptation modelling, at first a model is trained using neutral speech, and thereafter adaptation is performed to each emotion of the database. The third method, emotion-independent approach, is based on an average emotion model which is initially trained using data from all the emotions of the speech database. Consequently, an adaptive model is build for each emotion. In the fourth method, emotion adaptive training, the average emotion model is trained with simultaneously normalization of the output and state duration distributions. To evaluate these training methods, a Modern Greek speech database which consists of four categories of speech, anger, fear, joy and sadness, was used. Finally, an emotion recognition rate subjective test was performed in order to measure and compare the ability of each of the four approaches in synthesizing emotional speech. The evaluation results showed that the emotion adaptive training achieved the highest emotion recognition rates among four evaluated methods, throughout all four emotions of the database.[...] Read more.
This paper discusses an optical packet switch (OPS) architecture, which utilizes the components like optical reflectors, tunable wavelength converters (TWCs), arrayed waveguide grating (AWG) and pieces of fiber to realize the switching action. This architecture uses routing pattern of AWG, and its symmetric nature, to simplify switch operation significantly. It is also shown that using multi-wavelengths optical reflector, length of delay lines can be reduced to half of its original value. This reduction in length is useful for comparatively larger size packets as for them. It can grow up some kilometers. The considered architecture is compared with already published architecture. Finally, modifications in the architecture are suggested such that switch can be efficiently placed in the backbone network.[...] Read more.
In last decade of computing, a growing popularity for semantic cache schemes has been observed. Numerous techniques have been proposed for improved performance of semantic cache. Semantic cache is aimed towards reducing the network traffic load with the ability to address some queries without contacting the server. Semantic cache overcomes the limitations of previous page-caching and tuple-cache techniques. A prime concern of semantic cache includes query processing (query response-time) and cache management. The efficiency of semantic cache can be improved by using semantic indexing sachems. Semantic indexing sachems are segment based and hierarchical semantic indexing scheme. Both these sachems can improve the efficiency of query processing and cache management. In this paper, we have performed the evaluation of index schemes for Semantic Cache through the experimental study. Evaluations of these schemes are available in literature but experimental study is not available. Through this experiment, we have highlighted which technique is most suited in what kind of scenario.[...] Read more.
Piracy is no new lesson to every user of technology. It is a giant existing in the industry of technology numbing the heights software is reaching in terms of efficiency and use in all the sectors to an extent where even the industry of enterprise, beaurocracy, technology etc. depend upon the use of software in various ways to contribute their needs and success. Dollars are running at stakes of any industry while the piracy is acting as a dominator of all illegal transactions indirectly by giving easy and such illegal access to many users. One such victim is the entertainment industry where movies are being pirated and accessed to users causing millions of dollars of loss to the entertainment industry. Many researchers and technical specialists have made their contributions to save technology. Our paper is another potential solution with a promise of accuracy rate in detecting the pirated movies. It is a known fact that primary detection is the source of prevention. Our paper puts forth a technique that efficiency detects piracy to reduce such illegal downloads using the efficient measures of signature generation, normalization in an effective manner.[...] Read more.
Defense in Depth is practical strategy for achieving Information Assurance in today’s highly datacenter environments. It is a “best practices” strategy in that it relies on the intelligent application of techniques and technologies that exist today. The strategy recommends a balance between the protection capability and cost, performance, and operational considerations. This paper provides an overview of the major elements of the strategy and provides links to resources that provide additional insight. Companies need to address the security challenges of datacenter using a comprehensive defense-in-depth strategy. No single security solution will keep a determined thief from the goal of compromising the hardware or software given enough time and resources. Applying multiple layers of system security will slow the progress made by a thief, and hopefully, force the thief to abandon the pursuit, at the least, resale of the stolen property, and at worst, of confidential corporate data. The Defense in depth is the concept of protecting a Datacenter with a series of defensive mechanisms such that if one mechanism fails, another will already be in place to thwart an attack. In this paper, the main focus is given to highlight the security aspects of data center from perspectives of threats and attacks from one side and approaches for solutions from the other side. The paper also proposes an effective and flexible distributed scheme with two salient features. Our scheme achieves the integration of continual security improvement and Security Risk localization. This paper deals with the implementation of defense in depth at a strategic, principle-based level and provides additional guidance on specific sets of controls that may be applicable to support an organization’s defense in depth initiatives. The paper will present in Section (1) the Defense in depth concept, Section (2) Threats, Adversaries, Motivations, Classes of Attack and Vulnerability Analysis, Section (3) Information Security Assurance, Defense in Multiple Places, Layered Defenses, Security Robustness, Section (4) Design Goals and finally proposed solution and provide The IT Security Role & Functional Matrix.[...] Read more.
In recent past, IT industry has seen massive growth. However it is not much mature in developing countries, facing many challenges particularly in project management. As a result performance of IT industry is not up to the mark and unable to provide professional support as compared to internationally recognized standards to public and private sector organizations. There are many challenges such as shortage of skilled and experienced human resources and high employee turnover. Tough and competitive market condition requires the product to be extremely good in performance, timeline and accuracy. Effective project management and collaborative efforts of the Government and IT professionals can make highly successful market for IT projects. Success rate of private sector organizations is high as compared to public sector organizations in developing countries like Pakistan. In this research we have explored the performance of IT project management in public and private sector organizations of developing countries focusing Pakistan, to find out the reasons of project failure and success in both public and private sector organizations.[...] Read more.
Internal combustion (IC) engines are optimized to meet exhaust emission requirements with the best fuel economy. Closed loop combustion control is a key technology that is used to optimize the engine combustion process to achieve this goal. In order to conduct research in the area of closed loop combustion control, a control oriented cycle-to-cycle engine model, containing engine combustion information for each individual engine cycle as a function of engine crank angle, is a necessity. In this research, the IC engine is modeled according to fuel ratio, which is represented by the mass of air. In this research, a multi-input-multi-output baseline computed fuel control scheme is used to simultaneously control the mass flow rate of both port fuel injection (PFI) and direct injection (DI) systems to regulate the fuel ratio of PFI to DI to desired levels. The control target is to maintain the fuel ratio at stoichiometry and the fuel ratio to a desired value between zero and one. The performance of the baseline computed fuel controller is compared with that of a baseline proportional, integral, and derivative (PID) controller.[...] Read more.
This paper presents, a high speed FPGA implementation of fully digital controller for three-phase Z-Source Inverter (ZSI) with two switching strategies include simple boost control and maximum boost control. In this method total of blocks are based on proposed digital circuits only with combinational logic and using pipelining technique. Since it is vital to have a high speed and effective ZSI controller, a novel digital design for pulse width modulation control have been implemented for simple and maximum boost control of the ZSI. The proposed digit controllers have been successfully synthesized and implemented by Quartus II 9.1V and Cyclone II FPGA, to target device EP2C20F484C6. Achieved result demonstrates that the proposed method has features including reconfigurable, low-cost, high speed and also it is very accurate.[...] Read more.