Showing papers by "National Taiwan University of Science and Technology published in 2012"

DroidMat: Android Malware Detection through Manifest and API Calls Tracing

Abstract: Recently, the threat of Android malware is spreading rapidly, especially those repackaged Android malware. Although understanding Android malware using dynamic analysis can provide a comprehensive view, it is still subjected to high cost in environment deployment and manual efforts in investigation. In this study, we propose a static feature-based mechanism to provide a static analyst paradigm for detecting the Android malware. The mechanism considers the static information including permissions, deployment of components, Intent messages passing and API calls for characterizing the Android applications behavior. In order to recognize different intentions of Android malware, different kinds of clustering algorithms can be applied to enhance the malware modeling capability. Besides, we leverage the proposed mechanism and develop a system, called Droid Mat. First, the Droid Mat extracts the information (e.g., requested permissions, Intent messages passing, etc) from each applicationi¦s manifest file, and regards components (Activity, Service, Receiver) as entry points drilling down for tracing API Calls related to permissions. Next, it applies K-means algorithm that enhances the malware modeling capability. The number of clusters are decided by Singular Value Decomposition (SVD) method on the low rank approximation. Finally, it uses kNN algorithm to classify the application as benign or malicious. The experiment result shows that the recall rate of our approach is better than one of well-known tool, Androguard, published in Black hat 2011, which focuses on Android malware analysis. In addition, Droid Mat is efficient since it takes only half of time than Androguard to predict 1738 apps as benign apps or Android malware.

Strong metal-support interactions between gold nanoparticles and ZnO nanorods in CO oxidation.

Abstract: The catalytic performances of supported gold nanoparticles depend critically on the nature of support. Here, we report the first evidence of strong metal-support interactions (SMSI) between gold nanoparticles and ZnO nanorods based on results of structural and spectroscopic characterization. The catalyst shows encapsulation of gold nanoparticles by ZnO and the electron transfer between gold and the support. Detailed characterizations of the interaction between Au nanoparticles and ZnO were done with transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), electron paramagnetic resonance (EPR), and FTIR study of adsorbed CO. The significance of the SMSI effect is further investigated by probing the efficiency of CO oxidation over the Au/ZnO-nanorod. In contrast to the classical reductive SMSI in the TiO(2) supported group VIII metals which appears after high temperature reduction in H(2) with electron transfer from the support to metals, the oxidative SMSI in Au/ZnO-nanorod system gives oxygen-induced burial and electron transfer from gold to support. In CO oxidation, we found that the oxidative SMSI state is associated with positively charged gold nanoparticles with strong effect on its catalytic activity before and after encapsulation. The oxidative SMSI can be reversed by hydrogen treatment to induce AuZn alloy formation, de-encapsulation, and electron transfer from support to Au. Our discovery of the SMSI effects in Au/ZnO nanorods gives new understandings of the interaction between gold and support and provides new way to control the interaction between gold and the support as well as catalytic activity.

A Particle Swarm Optimization-Based Maximum Power Point Tracking Algorithm for PV Systems Operating Under Partially Shaded Conditions

Abstract: A photovoltaic (PV) generation system (PGS) is becoming increasingly important as renewable energy sources due to its advantages such as absence of fuel cost, low maintenance requirement, and environmental friendliness. For large PGS, the probability for partially shaded condition (PSC) to occur is also high. Under PSC, the P-V curve of PGS exhibits multiple peaks, which reduces the effectiveness of conventional maximum power point tracking (MPPT) methods. In this paper, a particle swarm optimization (PSO)-based MPPT algorithm for PGS operating under PSC is proposed. The standard version of PSO is modified to meet the practical consideration of PGS operating under PSC. The problem formulation, design procedure, and parameter setting method which takes the hardware limitation into account are described and explained in detail. The proposed method boasts the advantages such as easy to implement, system-independent, and high tracking efficiency. To validate the correctness of the proposed method, simulation, and experimental results of a 500-W PGS will also be provided to demonstrate the effectiveness of the proposed technique.

Expatriate Knowledge Transfer, Subsidiary Absorptive Capacity, and Subsidiary Performance

Abstract: In this study, we theoretically identify three dimensions of expatriate competenciesability, motivation, and opportunity seeking—for knowledge transfer. Integrating the ability-motivation-opportunity framework and the absorptive capacity perspective, we propose that expatriate competencies in knowledge transfer influence a subsidiary's performance through the knowledge received by the subsidiary, but tbat this indirect enect is stronger when subsidiary absorptive capacity is greater. We collected multisource, time-lagged data from 162 British subsidiaries of Taiwanese multinational nrms. The results support our hypotheses. Overall, we contribute to expatriation theory and research by revealing specinc expatriate competencies as well as identifying boundary conditions for successful expatriate knowledge transfer.

The impact of website quality on customer satisfaction and purchase intention: perceived playfulness and perceived flow as mediators

Abstract: The purposes of this study are to examine whether perceived playfulness and perceived flow would mediate the relationships among website quality, customer satisfaction, and purchase intention, as well as to assess the degree of reciprocity between perceived playfulness and perceived flow in an online travel agency context. This study suggested a research framework for testing the relationships among the constructs based on the stimulus-organism-response framework. In addition, this study developed a non-recursive model. After validating the measurement scales, empirical analyses were conducted using structural equation modelling. The findings confirm that website quality affects customers' perceived playfulness and perceived flow, and in turn, would influence their satisfaction and purchase intention. Notably, this study finds that the service quality is more important than information and system quality in influencing customer satisfaction and purchase intention. Furthermore, the study reveals that the relationship between perceived playfulness and perceived flow is reciprocal. Based on the findings, the implications are discussed in the paper and directions for future research are also highlighted.

An online game approach for improving students' learning performance in web-based problem-solving activities

Abstract: In this paper, an online game was developed in the form of a competitive board game for conducting web-based problem-solving activities The participants of the game determined their move by throwing a dice Each location of the game board corresponds to a gaming task, which could be a web-based information-searching question or a mini-game; the former was used to guide the participants to search for information to answer a series of questions related to the target learning issue, while the latter was used to provide supplementary materials during the gaming process To evaluate the performance of the proposed approach, an experiment was conducted on an elementary school natural science course The experimental results showed that the proposed approach not only significantly promoted the flow experience, learning attitudes, learning interest and technology acceptance degree of the students, but also improved their learning achievements in the web-based problem-solving activity

Visual attention for solving multiple-choice science problem: An eye-tracking analysis

Abstract: This study employed an eye-tracking technique to examine students' visual attention when solving a multiple-choice science problem. Six university students participated in a problem-solving task to predict occurrences of landslide hazards from four images representing four combinations of four factors. Participants' responses and visual attention were recorded by an eye tracker. Participants were asked to think aloud during the entire task. A 4 (options) x 4 (factors) repeated measures design, two paired t-tests and effect sizes analyses were conducted to compare the fixation duration between chosen and rejected options and between relevant and irrelevant factors. Content analyses were performed to analyze participants' responses and think aloud protocols and to examine individual's Hot Zone image. Finally, sequential analysis on fixated LookZones was further utilized to compare the scan patterns between successful and unsuccessful problem solvers. The results showed that, while solving an image-based multiple-choice science problem, students, in general, paid more attention to chosen options than rejected alternatives, and spent more time inspecting relevant factors than irrelevant ones. Additionally, successful problem solvers focused more on relevant factors, while unsuccessful problem solvers experienced difficulties in decoding the problem, in recognizing the relevant factors, and in self-regulating of concentration. Future study can be done to examine the reliability and the usability of providing adaptive instructional scaffoldings for problem solving according to students' visual attention allocations and transformations in a larger scale. Eye-tracking techniques are suggested to be used to deeply explore the cognitive process during e-learning and be applied to future online assessment systems.

An integrated approach for main path analysis: Development of the Hirsch index as an example

Abstract: This study enhances main path analysis by proposing several variants to the original approach. Main path analysis is a bibliometric method capable of tracing the most significant paths in a citation network and is commonly used to trace the development trajectory of a research field. We highlight several limitations of the original main path analysis and suggest new, complementary approaches to overcome these limitations. In contrast to the original local main path, the new approaches generate the global main path, the backward local main path, multiple main paths, and key-route main paths. Each of them is obtained via a perspective different from the original approach. By simultaneously conducting the new, complementary approaches, one uncovers the key development of the target discipline from a broader view. To demonstrate the value of these new approaches, we simultaneously apply them to a set of academic articles related to the Hirsch index. The results show that the integrated approach discovers several paths that are not captured by the original approach. Among these new approaches, the key-route approach is especially useful and hints at a divergence–convergence–divergence structure in the development of the Hirsch index. © 2012 Wiley Periodicals, Inc.

Development of a personalized educational computer game based on students’ learning styles

Abstract: In recent years, many researchers have been engaged in the development of educational computer games; however, previous studies have indicated that, without supportive models that take individual students’ learning needs or difficulties into consideration, students might only show temporary interest during the learning process, and their learning performance is often not as good as expected. Learning styles have been recognized as being an important human factor affecting students’ learning performance. Previous studies have shown that, by taking learning styles into account, learning systems can be of greater benefit to students owing to the provision of personalized learning content presentation that matches the information perceiving and processing styles of individuals. In this paper, a personalized game-based learning approach is proposed based on the sequential/global dimension of the learning style proposed by Felder and Silverman. To evaluate the effectiveness of the proposed approach, a role-playing game has been implemented based on the approach; moreover, an experiment has been conducted on an elementary school natural science course. From the experimental results, it is found that the personalized educational computer game not only promotes learning motivation, but also improves the learning achievements of the students.

The "third"-order barrier for technology-integration instruction: Implications for teacher education

Abstract: Technology integration is a major trend in contemporary education practice. When undertaking technology integration in classrooms, a first-order barrier and a second-order barrier, as proposed by Ertmer (1999), can hinder its implementation. The first-order barrier is external, such as lack of adequate access, time, training and institutional support. The second-order barrier includes teachers' personal and fundamental beliefs such as teachers' pedagogical beliefs, technology beliefs, willingness to change. This paper argues that the lack of design thinking by teachers may be the "third"-order barrier for technology integration.

The best vendor selection for conducting the recycled material based on a hybrid MCDM model combining DANP with VIKOR

Abstract: Environmentally conscious manufacturing and product recovery (ECMPRO) has become an obligation of manufacturers, and it has been extended to be the policy and strategy of businesses. Producing recyclable products and using recycled materials are optimal strategies for ECMPRO. Vendor selection (VS) is one of the multiple criteria decision-making (MCDM) problems in strategic supply chain management. The purpose of this article is to propose how the best selection to conduct the recycled materials can be implemented for enhancing and increasing the efficiency of using resources in the manufacturing process through recycled materials VS. Aluminum composite panel (ACP) is a global product, and ACP companies in Taiwan use recycled materials in more than 80% for their products on a quantity basis. Therefore, we selected the ACP industry of Taiwan as an empirical model to study VS and to reveal methods of improving gaps in each criterion for achieving the aspired levels of performance. We use the MCDM model combining DEMATEL-based on ANP (called DANP) with VIKOR to solve the recycled materials VS problems of multiple dimensions and criteria that are interdependent, instead of the independent assumption of an analytic hierarchy process, for mimicking the real-world scenario.

An improved SVD-based watermarking technique for copyright protection

Abstract: The drawbacks of SVD-based image watermarking are false positive, robust and transparency. The former can be overcome by embedding the principal components of the watermark into the host image, the latter is dependent on how much the quantity (i.e., scaling factor) of the principal components is embedded. For the existing methods, the scaling factor is a fixed value; actually, it is image-dependent. Different watermarks need the different scaling factors, although they are embedded in the same host image. In this paper, two methods are proposed to improve the reliability and robustness. To improve the reliability, for the first method, the principal components of the watermark are embedded into the host image in discrete cosine transform (DCT); and for the second method, those are embedded into the host image in discrete wavelets transform (DWT). To improve the robustness, the particle swarm optimization (PSO) is used for finding the suitable scaling factors. The experimental results demonstrate that the performance of the proposed methods outperforms than those of the existing methods.

Fuzzy multiple attributes group decision-making based on ranking interval type-2 fuzzy sets

Abstract: In this paper, we present a new method to deal with fuzzy multiple attributes group decision-making problems based on ranking interval type-2 fuzzy sets. First, we propose a new method for ranking interval type-2 fuzzy sets. Then, we propose a new method for fuzzy multiple attributes group decision-making based on the proposed ranking method of interval type-2 fuzzy sets. We also use some examples to illustrate the fuzzy multiple attributes group decision-making process of the proposed method. The proposed method is simpler than the methods presented in Chen and Lee (2010a, 2010b) for fuzzy multiple attributes group decision-making based on interval type-2 fuzzy sets. It provides us with a useful way for dealing with fuzzy multiple attributes group decision-making problems based on interval type-2 fuzzy sets.

A New Measurement Method for Power Signatures of Nonintrusive Demand Monitoring and Load Identification

Abstract: Based upon the analysis of load signatures, this paper presents a nonintrusive load monitoring (NILM) technique. With a characterizing response associated with a transient energy signature, a reliable and accurate recognition result can be obtained. In this paper, artificial neural networks, in combination with turn-on transient energy analysis, are used to improve recognition accuracy and computational speed of NILM results. To minimize the distortion phenomenon in current measurements from the hysteresis of traditional current transformer (CT) iron cores, a coreless Hall CT is adopted to accurately detect nonsinusoidal waves to improve NILM accuracy. The experimental results indicate that the incorporation of turn-on transient energy algorithm into NILM significantly improve the recognition accuracy and the computational speed.

Supplier selection using analytic network process and data envelopment analysis

Abstract: The present study intends to present a supplier selection method, which also considers green indicators due to environmental protection issues, by using an analysis network process (ANP) as well as data envelopment analysis (DEA). ANP which is able to consider the interdependency between criteria releases the constraint of DEA that the users cannot set up criteria weight preferences. The model evaluation results for high-tech industry show that the proposed method can provide not only reasonable outcomes with a smaller number of decision making units, but can also provide more consistent results.

Compressive Behavior of Steel-Fiber-Reinforced Concrete with a High Reinforcing Index

Abstract: Compression tests on cylinders were performed to characterize the compressive stress-strain behavior of steel fiber-reinforced concrete (SFRC) with a high reinforcing index. The reinforcing index, defined as the product of the volume fraction and the aspect ratio of the fibers, of steel fibers examined was as high as 1.7. Hooked-end fibers of various lengths and aspect ratios were considered. The test results indicated that a higher reinforcing index was associated with a higher strain at the peak stress and a higher toughness of SFRC, up to a reinforcing index approximately equal to that corresponding to a 2% fiber volume fraction. Adding steel fibers had little effect on the modulus of elasticity and compressive strength of SFRC. Long steel fibers and fibers with a lower aspect ratio resulted in a larger increase of the toughness of SFRC. On the basis of the test results, analytical models of the stress-strain curve in compression and toughness of SFRC with a reinforcing index up to 1.7 are developed.

The effects of visual information in eWOM communication

Abstract: Purpose – Electronic word of mouth (eWOM) is a considerably influential factor for consumers to search for product information. Nowadays, consumers can easily post visual information (e.g. pictures or videos) to convey product information and consumption‐related experiences. Yet, prior eWOM studies focused primarily on the verbal information of eWOM. Few studies have paid sufficient attention to the effects of visual information in eWOM communication. The purpose of this paper, therefore, is to employ blogs to investigate the effects of visual information on consumers' perception of eWOM message quality, credibility, product interest, and purchase intention.Design/methodology/approach – The authors conducted two empirical studies in the field of different product categories. Data were collected from subjects ranged in age from 16 to 50 (n=155 for study 1, n=309 for study 2), and analyzed using independent‐samples t test and univariate analysis of variance (ANOVA).Findings – Results show that subjects rate...

Kinematic design considerations for minimally invasive surgical robots: an overview.

Abstract: Background Kinematic design is a predominant phase in the design of robotic manipulators for minimally invasive surgery (MIS). However, an extensive overview of the kinematic design issues for MIS robots is not yet available to both mechanisms and robotics communities. Methods Hundreds of archival reports and articles on robotic systems for MIS are reviewed and studied. In particular, the kinematic design considerations and mechanism development described in the literature for existing robots are focused on. Results The general kinematic design goals, design requirements, and design preferences for MIS robots are defined. An MIS-specialized mechanism, namely the remote center-of-motion (RCM) mechanism, is revisited and studied. Accordingly, based on the RCM mechanism types, a classification for MIS robots is provided. A comparison between eight different RCM types is given. Finally, several open challenges for the kinematic design of MIS robotic manipulators are discussed. Conclusions This work provides a detailed survey of the kinematic design of MIS robots, addresses the research opportunity in MIS robots for kinematicians, and clarifies the kinematic point of view to MIS robots as a reference for the medical community. Copyright © 2012 John Wiley & Sons, Ltd.

Renewable energy supply chains, performance, application barriers, and strategies for further development

Abstract: Due to the depletion of traditional energy resources, such as crude oil, coal, and natural gas, many initiatives all over the world have addressed the efficient use or replacement of these resources. Several renewable energy sources have been introduced as alternatives to traditional sources to protect environmental resources and to improve the quality of life. This study assesses renewable energy sources from a supply chain perspective and presents an investigation of renewable energies focusing on four main components: renewable energy supply chain, renewable energy performance, and barriers and strategies to its development. The study provides managerial insights to governments, researchers, and stakeholders for the initiation of renewable energy use, and suggestions for overcoming the barriers to its development.

Aerobic Granulation: Advances and Challenges

Abstract: Aerobic granulation was developed in overcoming the problem of biomass washout often encountered in activated sludge processes. The novel approach to developing fluffy biosolids into dense and compact granules offers a new dimension for wastewater treatment. Compared with conventional biological flocs, aerobic granules are characterized by well-defined shape and compact buildup, superior biomass retention, enhanced microbial functions, and resilient to toxicity and shock loading. This review provides an up-to-date account on development in aerobic granulation and its applications. Granule characterization, factors affecting granulation, and response of granules to various environmental and operating conditions are discussed. Maintaining granule of adequate structural stability is one of the main challenges for practical applications of aerobic granulation. This paper also reviews recent advances in addressing granule stability and storage for use as inoculums, and as biomass supplement to enhance treatment efficiency. Challenges and future work of aerobic granulation are also outlined.