389 research outputs found
An Analysis of Factors Affecting on Online Shopping Behavior of Consumers
The purpose of this study is to analyze factors affecting on online shopping behavior of consumers that might be one of the most important issues of e-commerce and marketing field. However, there is very limited knowledge about online consumer behavior because it is a complicated socio-technical phenomenon and involves too many factors. One of the objectives of this study is covering the shortcomings of previous studies that didn't examine main factors that influence on online shopping behavior. This goal has been followed by using a model examining the impact of perceived risks, infrastructural variables and return policy on attitude toward online shopping behavior and subjective norms, perceived behavioral control, domain specific innovativeness and attitude on online shopping behavior as the hypotheses of study. To investigate these hypotheses 200 questionnaires dispersed among online stores of Iran. Respondents to the questionnaire were consumers of online stores in Iran which randomly selected. Finally regression analysis was used on data in order to test hypothesizes of study. This study can be considered as an applied research from purpose perspective and descriptive-survey with regard to the nature and method (type of correlation). The study identified that financial risks and non-delivery risk negatively affected attitude toward online shopping. Results also indicated that domain specific innovativeness and subjective norms positively affect online shopping behavior. Furthermore, attitude toward online shopping positively affected online shopping behavior of consumers. Keywords: online shopping, shopping behavior, consumer attitudes, perceived risks, B2C, e-commerce
Comprehensive proteome and phosproteome analysis of human LRRK2 Drosophila model of Parkinson's disease
Gene mutations in the leucine-rich repeat kinase 2 (LRRK2) are the most common cause of autosomal dominant Parkinson`s Disease (PD) and elevated levels of hLRRK2 mutant variants in Drosophila induces PD. Here, we introduced the human LRRK2 (R1441C) variant in dopaminergic neurons of flies and observed a reduced locomotor activity, an age dependent degeneration of dopaminergic neurons, and shorter lifetime. To better understand the hLRRK2 (R1441C) induced pathobiology, we performed stable isotope labeling in fly to accurately quantify the proteome and phosphoproteome dynamics. We quantified almost 3000 proteins and found several regulated cytoskeletal, mitochondrial, and synaptic vesicle (SV) proteins in our PD fly model. To explore the hLRRK2 (R1441C) function more precisely, we compared our model to three different alpha-Synuclein overexpressing fly strains (WT,A30P, A53T), which show a similar PD phenotype. For example, synaptotagmin, syntaxin and rab3 were only affected in hLRRK2 (R1441C) flies compared to all other tested fly strains. Moreover, our global phosphoproteome analysis revealed several synaptic vesicle proteins with enhanced phosphorylation, including synaptojanin (pT1131) and the microtubule-associated protein futsch (pS4106). Consistently, a protein-protein interaction screen confirmed that hLRRK2 is tightly associated with synaptic vesicle proteins. Thus, our results provide a systemic view on the pathobiology mechanism caused by hLRRK and S overexpression and suggest that the increased kinase activity of the hLRRK2 (R1441C) mutant results in enhanced phosphorylation of synaptojanin. These findings may contribute to develop new therapeutic strategies to prevent hLRRK2-induced Parkinson disease
Early Age Properties of Zeolite Cementitious Materials
The cement industry is recognized as being responsible for a large amount of CO2 emission during the production of portland cement. In order to minimize CO2 emissions by limiting the use of cement, natural pozzolans may be a sustainable solution for making concrete. One such natural pozzolan is alumina-silicate based clinoptilolite type of natural zeolite. It has three dimensional crystalline frame structures with extremely small pores having alkali and alkaline earth cations. In the present research, application of natural zeolite as a supplementary cementitious material for producing durable concrete has been investigated. In this respect, clinoptilolite zeolite with very high purity (97%) replaced portland cement at 0, 5, 10, 15, and 20% by mass. Setting time, workability, as well as heat of hydration of paste via isothermal calorimetry was conducted to assess the effects on early age properties. Research results revealed that replacement of zeolite increase the demand for water in the fresh mixture, although this situation can be overcome by adding low amount of high range water reducing admixture without any segregation. Research results also shown that zeolite accelerates the setting time due to the nucleation effect of C-S-H precipitation. Additionally, replacement of portland cement with zeolite can produce lower heat of hydration in the cementitious paste due to adsorption of water by its grain along with slow dissolution process of the fresh mixture. However, from practical point view, incorporation of 15% natural zeolite was found as an appropriate option for improving the early age properties
Demutualization: Pros and Cons for Dhaka Stock Exchange (DSE)
The purpose of this study is to examine the implications of demutualization for Dhaka Stock Exchange (DSE). And this is done by examining the existing literature for the stock exchanges that have already been demutualised. The result of the study indicates that all benefits that go with demutualization are not applicable for Bangladesh. Rather the benefits are contingent upon some factors unique to Bangladesh. So in the process of demutualization the authorities concerned should focus on those factors from which optimum benefits can be derived. However, demutualization is not without risk. So along with benefits risk should be focused on so that appropriate policy can be formed that will ensure successful implementation of demutualization. This study is important to investors, academics and policy makers as it demonstrates what benefits demutualization will bring and what challenges it will create. Since demutualization is a very new concept in Bangladesh, the study extends the literature by demonstrating its pros and cons in the context of Bangladesh. Key Words: Demutualization, Mutual Organization, Corporate Governance
Reasons behind the Practices of Green Banking by Commercial Banks: A case study on Bangladesh
Green banking is a new initiative throughout the world. The leading bankers and entrepreneurs have come forward to save human from environmental disasters. In the context of Bangladesh, if we think about it, we will find the situation to be terrible. Our people have little awareness about environment, air and water pollution, industrial and medical, and household wastes. In this way, we can say green banking is nothing but an 'eco-friendly socially responsible banking system' which drives the whole nation towards a healthy environment and presents an excellent and hazardless banking. We have selected bankers as the possible sample of this study and have conducted probability stratified sampling technique. The total 60 respondents have been selected by the rules of factor analysis. Factor analysis then has been used to analyze the data and to draw the findings. From the factor analysis, it has been found that three factors namely loan & legal factor, environmental factor, and economic factor are the real influencers. These three factors have consolidated variance of 74.957% of the decision with respect to the appropriation of green banking by the commercial banks to make sure sustainable economic development. Keywords: Green Banking, Green Products, Climate Change Issues, Paperless Banking, Online Banking, Mobile Banking, ATM
Information Technology (IT) Integration and Cybersecurity/Security: The Security Savviness of Board of Directors
As Information Technology has become increasingly important to the competitive position of firms, managers have become more sensitive to their organization’s overall IT risk management. Given the significant cyber-attacks that are occurring with disturbing frequency, and the mounting evidence that companies of all shapes and sizes are increasingly under a constant threat of cyber-attacks, ensuring the adequacy of a company’s cybersecurity measures has become a key area of purview for the Board of Directors (BoD). To address this issue, staffing the Board with members who have significant security expertise might be one of the best protective mechanisms in an increasingly risky business environment, both from the perspective of sound corporate governance and in terms of sensible IT governance. We expect that high-tech firms are far likely to have Board members with security expertise, and we expect that the degree to which IT is a differentiator or primary value proposition in the firm will moderate the presence of security expertise at the Board level, and we also expect that internal audit capabilities with security expertise will tend to moderate between a firm’s technological sophistication and security expertise at the Board level
Motivational Factors Influencing on Job Satisfaction: A Case Study on Private Commercial Banking Sector in Rajshahi, Bangladesh
Now a day, bank is a more attractive and profitable business organization in Bangladesh. For the past few decades, numerous studies attempted to explore the relative importance of understanding job satisfaction. Realizing the need to sustain in the banking industry, this study was conducted for exploring the antecedents to the strengthening of job satisfaction. This report is designed for identifying the “Motivational factors influencing on job satisfaction: A case study on private banking sector in Bangladesh.” It is a descriptive study based on the primary and secondary data. Five Private Commercial Banks namely NRBC Bank Ltd. (8 respondent), NCC Bank Ltd. (8 respondent), One Bank Ltd. (8 respondent), Mercantile Bank Ltd. (8 respondent), Islami Bank Ltd. (8 respondent) are considered to conduct the study. 40 sample sizes are dispersed to collect the data, for the consequence of the study researcher considered some factors. Moreover, those factors are taken under the close ended questionnaire and find out the data from sample and to analyze the quantitative data, the researcher explored the internal structure and measurement by using percentage format and tabulation form. Researcher has used five likert scales for rating employee’s job satisfaction. Then researcher has calculated the percentage of each question answer and find out the result. Aggregately 47% of the employees are highly satisfied and it is the highest portion of employees on the level of job satisfaction. Very dissatisfied portion is lowest. Therefore, it can say that most of the private commercial bank employees are satisfied on their job. After considering above factors researcher identify that Salary structure, Management policy and Job environment are motivated private bank employees more than other factors and researcher recommend that private bank authority should be more concentration on the above factors those make their employee more satisfied towards their job and reduce the tendency of switching over. Keywords: Motivational factors, job satisfaction, Salary, reward system, promotion and job environment
Julia Set as a Martin Boundary
Die Julia-Menge der Klasse hyperbolischer rationaler Abbildungen, deren Julia-Menge vollständig unzusammenhängend ist, wird hier identifiziert als die Martin-Grenze (Martin boundary) einer Markovkette durch die Anwendung der Theorie symbolischer Dynamik. Diese Beziehung ermöglicht es, einige thermodynamische Konzepte, wie Entropie, Maß der maximalen Entropie, des Gibbs-Maßes und des Gleichgewichtmaßes, auf potenzialtheoretische Konzepte wie Kapazität und harmonische Maße auf der Julia Menge, auf der eine geeignete Potenzialfunktion definiert ist, zu beziehen. Wir haben hier z.B. das Maß der maximalen Entropie für eine rationale Abbildung auf der Julia Menge identifiziert; es ist einfach das Bildmaß eines bestimmten Bernoulli-Maßes auf dem Schiebungsraum (shift space). Wir haben weiter bewiesen, dass das harmonische Maß auf der Julia-Menge das Bildmaß eines nicht-atomaren, quasi-invarianten, konservativen Maßes auf dem einseitigen Schiebungsraum ist. Wir haben gezeigt, dass dieses quasi-invariante Maß ein Gibbs-Maß darstellt und es mit einem Bernoulli-Maß äquivalent ist. Durch Anwendung des Ruelle-Perron-Frobenius Satzes haben wir abgeleitet, dass das Gibbs-Maß zur Definition eines eindeutigen, gegenüber Verschiebung invarianten, Gleichgewichtsmaßes herangezogen werden kann. Wir haben weiter bewiesen, dass das Gleichgewichtmaß für das logarithmische Potenzial und das klassische harmonische Maß in unserem Fall übereinstimmen. Schließlich haben wir gezeigt, dass ein bestimmtes Dirichlet-Problem für das Fatou-Menge in unserem Fall eine eindeutige Lösung besitzt
On the Use of Software Tracing and Boolean Combination of Ensemble Classifiers to Support Software Reliability and Security Tasks
In this thesis, we propose an approach that relies on Boolean combination of multiple one-class classification methods based on Hidden Markov Models (HMMs), which are pruned using weighted Kappa coefficient to select and combine accurate and diverse classifiers. Our approach, called WPIBC (Weighted Pruning Iterative Boolean Combination) works in three phases. The first phase selects a subset of the available base diverse soft classifiers by pruning all the redundant soft classifiers based on a weighted version of Cohen’s kappa measure of agreement. The second phase selects a subset of diverse and accurate crisp classifiers from the base soft classifiers (selected in Phase1) based on the unweighted kappa measure. The selected complementary crisp classifiers are then combined in the final phase using Boolean combinations. We apply the proposed approach to two important problems in software security and reliability: The detection of system anomalies and the prediction of the reassignment of bug report fields.
Detecting system anomalies at run-time is a critical component of system reliability and security. Studies in this area focus mainly on the effectiveness of the proposed approaches -the ability to detect anomalies with high accuracy. Less attention was given to false alarm and efficiency. Although ensemble approaches for the detection of anomalies that use Boolean combination of classifier decisions have been shown to be useful in reducing the false alarm rate over that of a single classifier, existing methods rely on an exponential number of combinations making them impractical even for a small number of classifiers. Our approach is not only able to maintain and even improve the accuracy of existing Boolean combination techniques, but also significantly reduce the combination time and the number of classifiers selected for combination.
The second application domain of our approach is the prediction of the reassignment of bug report fields. Bug reports contain a wealth of information that is used by triaging and development teams to understand the causes of bugs in order to provide fixes. The problem is that, for various reasons, it is common to have bug reports with missing or incorrect information, hindering the bug resolution process. To address this problem. researchers have turned to machine learning techniques. The common practice is to build models that leverage historical bug reports to automatically predict when a given bug report field should be reassigned. Existing approaches have mainly relied upon classifiers that make use of natural language in the title and description of the bug reports. They fail to take advantage of the richly detailed sequential information that is present in stack traces included in bug reports. To address this, we propose an approach called EnHMM which uses WPIBC and stack traces to predict the reassignment of bug report fields.
Another contribution of this thesis is an approach to improve the efficiency of WPIBC by leveraging the Hadoop framework and the MapReduce programming model. We also show how WPIBC can be extended to support heterogenous classifiers
Applications of Nonlinear Dynamics in Semiconductor Lasers With Time-Delayed Feedback in Microwave Photonics
The main objective of this research is to investigate the rich nonlinear dynamics of a semiconductor \gls{LD} subjected to time-delayed optoelectronic (OE) feedback, emphasizing applications in microwave photonics and communications. A semiconductor LD based OE feedback constitutes an oscillator that produces self-sustained optical output modulation through the intrinsic nonlinearities of the system without needing any external modulators. To explore the wide variety of dynamics in the optical intensity, the LD needs to be perturbed out of the steady-state free-running behavior, so the photodetected optical signal is appropriately amplified prior to feeding it back into the LD injection terminal. The complex dynamics of such an oscillator have been studied theoretically and experimentally in recent decades. In this work, however, we report several novel dynamical effects by re\"{e}xamining this rich nonlinear system with state-of-the-art experiments and supported that by comprehensive modelling.
In particular, we have identified operating conditions that exhibit high-order locking between LD relaxation oscillations with harmonics of the feedback delay frequency for a OE feedback with large delay. We also observe that this system exhibits a stepwise change in LD oscillation frequency as the feedback level is varied. Further, upon varying the injection current near threshold, we also can generate a periodic pulse train with repetition rate at the feedback delay frequency arising from gain-switching between the on and off states of LD. This pulse train grows into pulse clusters as we increase the current. In addition, driving an LD at very high currents and strong feedback results in square-wave pulses whose repetition rate is determined by the feedback delay of the OE loop. The square-waves at a fixed current have been shown to exhibit a double-peaked optical spectrum that depends on the feedback level. These interesting discoveries advance the understanding of the nonlinear OE oscillator and could find applications in communications, sensing, measurement, and spectroscopy.Ph.D
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