Digital Commons Network^™

Randomly Projected Kd-Trees With Distance Metric Learning For Image Retrieval, Pengcheng Wu, Steven Hoi, Duc Dung Nguyen, Ying He

Research Collection School Of Computing and Information Systems

Efficient nearest neighbor (NN) search techniques for highdimensional data are crucial to content-based image retrieval (CBIR). Traditional data structures (e.g., kd-tree) usually are only efficient for low dimensional data, but often perform no better than a simple exhaustive linear search when the number of dimensions is large enough. Recently, approximate NN search techniques have been proposed for high-dimensional search, such as Locality-Sensitive Hashing (LSH), which adopts some random projection approach. Motivated by similar idea, in this paper, we propose a new high dimensional NN search method, called Randomly Projected kd-Trees (RP-kd-Trees), which is to project data points into a lower-dimensional …

An Effective Approach To Pose Invariant 3d Face Recognition, Dayong Wang, Steven C. H. Hoi, Ying He

Research Collection School Of Computing and Information Systems

One critical challenge encountered by existing face recognition techniques lies in the difficulties of handling varying poses. In this paper, we propose a novel pose invariant 3D face recognition scheme to improve regular face recognition from two aspects. Firstly, we propose an effective geometry based alignment approach, which transforms a 3D face mesh model to a well-aligned 2D image. Secondly, we propose to represent the facial images by a Locality Preserving Sparse Coding (LPSC) algorithm, which is more effective than the regular sparse coding algorithm for face representation. We conducted a set of extensive experiments on both 2D and 3D …

Identity-Based Strong Designated Verifier Signature Revisited, Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo

Research Collection School Of Computing and Information Systems

Designated verifier signature (DVS) allows the signer to persuade a verifier the validity of a statement but prevent the verifier from transferring the conviction. Strong designated verifier signature (SDVS) is a variant of DVS, which only allows the verifier to privately check the validity of the signer’s signature. In this work we observe that the unforgeability model considered in the existing identity-based SDVS schemes is not strong enough to capture practical attacks, and propose to consider another model which is shown to be strictly stronger than the old one. We then propose a new efficient construction of identity-based SDVS scheme, …

A Sufficient Condition For The Tops-Only Property Of Strategy-Proof Social Choice Functions In The Case Of Two Voters, Huaxia Zeng

Dissertations and Theses Collection (Open Access)

In this thesis, we consider the standard voting model with a finite set of alternatives A and 2 voters, and address the following question: besides Domains D satisfying the

Property T (Chatterji & Sen (2011) ), what are other characteristics of domains that induce every strategy-proof and unanimous social choice function f : Dn → A to satisfy the tops-only property? We impose a minimal richness condition which ensures that for every alternative a ∈ A, there exists a preference ordering where a is maximal. We identify a more general condition on domains that is sufficient for strategy-proofness …

Instance-Based Parameter Tuning Via Search Trajectory Similarity Clustering, Linda Lindawati, Hoong Chuin Lau, David Lo

Research Collection School Of Computing and Information Systems

This paper is concerned with automated tuning of parameters in local-search based meta-heuristics. Several generic approaches have been introduced in the literature that returns a ”one-size-fits-all” parameter configuration for all instances. This is unsatisfactory since different instances may require the algorithm to use very different parameter configurations in order to find good solutions. There have been approaches that perform instance-based automated tuning, but they are usually problem-specific. In this paper, we propose CluPaTra, a generic (problem-independent) approach to perform parameter tuning, based on CLUstering instances with similar PAtterns according to their search TRAjectories. We propose representing a search trajectory as …

Lightweight Delegated Subset Test With Privacy Protection, Xuhua Zhou, Xuhua Ding, Kefei Chen

Research Collection School Of Computing and Information Systems

Delegated subset tests are mandatory in many applications, such as content-based networks and outsourced text retrieval, where an untrusted server evaluates the degree of matching between two data sets. We design a novel scheme to protect the privacy of the data sets in comparison against the untrusted server, with half of the computation cost and half of the ciphertext size of existing solutions based on predicate only encryption supporting inner product.

Trends And Controversies: Ai, Virtual Worlds, And Massively Multiplayer Online Games, Hsinchun Chen, Yulei Zhang, W. S. Bainbridge, Kyong Jin Shim, N. Pathak, M. A. Ahmad, C. Delong, Z. Borbora, A. Mahapatra, J. Srivastava

Research Collection School Of Computing and Information Systems

The rich social media data generated in virtual worlds has important implications for business, education, social science, and society at large. Similarly, massively multiplayer online games (MMOGs) have become increasingly popular and have online communities comprising tens of millions of players. They serve as unprecedented tools for theorizing about and empirically modeling the social and behavioral dynamics of individuals, groups, and networks within large communities. Some technologists consider virtual worlds and MMOGs to be likely candidates to become the Web 3.0. AI can play a significant role, from multiagent avatar research and immersive virtual interface design to virtual world and …

Innovation And Price Competition In A Two-Sided Market, Mei Lin, Shaojin Li, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

We examine a platform's optimal two-sided pricing strategy while considering seller-side innovation decisions and price competition. We model the innovation race among sellers in both finite and infinite horizons. In the finite case, we analytically show that the platform's optimal seller-side access fee fully extracts the sellers' surplus, and that the optimal buyer-side access fee mitigates price competition among sellers. The platform's optimal strategy may be to charge or subsidize buyers depending on the degree of variation in the buyers' willingness to pay for quality; this optimal strategy induces full participation on both sides. Furthermore, a wider quality gap among …

Real-Time Traffic Estimation Using Data Expansion, Roger Lederman, Laura Wynter

Research Collection School Of Computing and Information Systems

This paper presents a method for estimating missing real-time traffic volumes on a road network using both historical and real-time traffic data. The method was developed to address urban transportation networks where a non-negligible subset of the network links do not have real-time link volumes, and where that data is needed to populate other real-time traffic analytics. Computation is split between an offline calibration and a real-time estimation phase. The offline phase determines link-to-link splitting probabilities for traffic flow propagation that are subsequently used in real-time estimation. The real-time procedure uses current traffic data and is efficient enough to scale …

Real-Time Road Traffic Prediction With Spatio-Temporal Correlations, Wanli Min, Laura Wynter

Research Collection School Of Computing and Information Systems

Real-time road traffic prediction is a fundamental capability needed to make use of advanced, smart transportation technologies. Both from the point of view of network operators as well as from the point of view of travelers wishing real-time route guidance, accurate short-term traffic prediction is a necessary first step. While techniques for short-term traffic prediction have existed for some time, emerging smart transportation technologies require the traffic prediction capability to be both fast and scalable to full urban networks. We present a method that has proven to be able to meet this challenge. The method presented provides predictions of speed …

Development Of An Instrument To Measure The Adoption Of Mobile Services, Shang Gao, John Krogstie, Keng Siau

Research Collection School Of Computing and Information Systems

Currently, there is no standard instrument for measuring user adoption of mobile services. Based on the mobile service acceptance model, this paper reports on the development of a survey instrument designed to measure user perception on mobile services acceptance. A survey instrument was developed by using some existing scales from prior instruments and by creating additional items which might appear to fit the construct definitions. In addition, a pilot study was conducted by distributing the survey to 25 users of a mobile service called Mobile Student Information Systems. As a result, a survey instrument containing 22 items were retained. Furthermore, …

Workshop Report From Web2se 2011: 2nd International Workshop On Web 2.0 For Software Engineering, Christoph Treude, Margaret-Anne Storey, Arie Van Deursen, Andrew Begel, Sue Black

Research Collection School Of Computing and Information Systems

Web 2.0 technologies, such as wikis, blogs, tags and feeds, have been adopted and adapted by software engineers. With the annual Web2SE workshop, we provide a venue for research on Web 2.0 for software engineering by highlighting state-of-the-art work, identifying current research areas, discussing implications of Web 2.0 on software engineering, and outlining the risks and challenges for researchers. This report highlights the paper and tool presentations, and the discussions among participants at Web2SE 2011 in Honolulu, as well as future directions of the Web2SE workshop community.

Mining Event Structures From Web Videos, Xiao Wu, Yi-Jie Lu, Qiang Peng, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

The article is discussing the issues of mining event structures from Web video search results using text analysis, burst detection, and clustering as with the proliferation of social media, the volume of Web videos have grown exponentially.

Efficient Strong Designated Verifier Signature Schemes Without Random Oracle Or With Non-Delegatability, Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo

Research Collection School Of Computing and Information Systems

Designated verifier signature (DVS) allows a signer to convince a designated verifier that a signature is generated by the signer without letting the verifier transfer the conviction to others, while the public can still tell that the signature must be generated by one of them. Strong DVS (SDVS) strengthens the latter part by restricting the public from telling whether the signature is generated by one of them or by someone else. In this paper, we propose two new SDVS schemes. Compared with existing SDVS schemes, the first new scheme has almost the same signature size and meanwhile, is proven secure …

Would Price Limits Have Made Any Difference To The 'Flash Crash' On May 6, 2010, Wing Bernard Lee, Shih-Fen Cheng, Annie Koh

Research Collection School Of Computing and Information Systems

On May 6, 2010, the U.S. equity markets experienced a brief but highly unusual drop in prices across a number of stocks and indices. The Dow Jones Industrial Average (see Figure 1) fell by approximately 9% in a matter of minutes, and several stocks were traded down sharply before recovering a short time later. The authors contend that the events of May 6, 2010 exhibit patterns consistent with the type of "flash crash" observed in their earlier study (2010). This paper describes the results of nine different simulations created by using a large-scale computer model to reconstruct the critical elements …

A Usability Study Of A Mobile Content Sharing System, Alton Yeow-Kuan Chua, Dion Hoe-Lian Goh, Khasfariyati Razikin, Ee Peng Lim

Research Collection School Of Computing and Information Systems

We investigate the usability of MobiTOP (Mobile Tagging of Objects and People), a mobile location-based content sharing system. MobiTOP allows users to annotate real world locations with both multimedia and textual content and concurrently, share the annotations among its users. In addition, MobiTOP provides additional functionality such as clustering of annotations and advanced search and filtering options. A usability evaluation of the system was conducted in the context of a travel companion for tourists. The results suggested the potential of the system in terms of functionality for mobile content sharing. Participants agreed that the features in MobiTOP were generally usable …

Enhancing Bag-Of-Words Models By Efficient Semantics-Preserving Metric Learning, Lei Wu, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

The authors present an online semantics preserving, metric learning technique for improving the bag-of-words model and addressing the semantic-gap issue. This article investigates the challenge of reducing the semantic gap for building BoW models for image representation; propose a novel OSPML algorithm for enhancing BoW by minimizing the semantic loss, which is efficient and scalable for enhancing BoW models for large-scale applications; apply the proposed technique for large-scale image annotation and object recognition; and compare it to the state of the art.

From Information Technology To Ice-Cream: One Man's Entrepreneurial Quest For Happiness, Knowledge@Smu

Knowledge@SMU

Medal-winning fencer Wong Toon King is not some swash-buckling corporate hot shot, slashing and hacking at business rivals. Rather, the former government scholar turned serial entrepreneur believes that the important ingredients to building businesses include not just good ideas, but also a knack of identifying trends and a good sense of timing. Most importantly, entrepreneurs need to be happy at what they are doing – even if it means scooping and serving Ben & Jerry's ice-cream every day, said the founder of The Happy People Co., local franchisee of the popular brand of ice-cream.

Understanding Gender Differences In Media Perceptions: A Comparison Of 2d Versus 3d Media, Fiona Fui-Hoon Nah, David Dewester, Brenda Eschenbrenner

Research Collection School Of Computing and Information Systems

We examine gender differences in 2D versus 3D media perceptions. Using the Hunter-Gatherer Theory of Spatial Gender Differences and Jung’s Theory of Psychological Types, we hypothesize differences in men’s and women’s perceptions of skill, challenge, telepresence, and satisfaction with online experiences in 2D versus 3D media interaction. The findings suggest that even though women perceive lower skill levels and greater challenges in using 2D and 3D media than men, women’s sense of telepresence is higher than men in both 2D and 3D media. Women are also more satisfied with their interaction in 2D and 3D media than men.

Protecting And Restraining The Third Party In Rfid-Enabled 3pl Supply Chains, Shaoying Cai, Chunhua Su, Yingjiu Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

“Symmetric secret”-based RFID systems are widely adopted in supply chains. In such RFID systems, a reader’s ability to identify a RFID tag relies on the possession of the tag’s secret which is usually only known by its owner. If a “symmetric secret”-based RFID system is deployed in third party logistics (3PL) supply chains, all the three parties (the sender of the goods, the receiver of the goods and the 3PL provider) should have a copy of those tags’ secrets to access the tags. In case the three parties in 3PL supply chain are not all honest, sharing the secrets among …

A Structure First Image Inpainting Approach Based On Self-Organizing Map (Som), Bo Chen, Zhaoxia Wang, Ming Bai, Quan Wang, Zhen Sun

Research Collection School Of Computing and Information Systems

This paper presents a structure first image inpainting method based on self-organizing map (SOM). SOM is employed to find the useful structure information of the damaged image. The useful structure information which includes relevant edges of the image is used to simulate the structure information of the lost or damaged area in the image. The structure information is described by distinct or indistinct curves in an image in this paper. The obtained target curves separate the damaged area of the image into several parts. As soon as each part of the damaged image is restored respectively, the damaged image is …

Automobile Exhaust Gas Detection Based On Fuzzy Temperature Compensation System, Zhiyong Wang, Hao Ding, Fufei Hao, Zhaoxia Wang, Zhen Sun, Shujin Li

Research Collection School Of Computing and Information Systems

A temperature compensation scheme of detecting automobile exhaust gas based on fuzzy logic inference is presented in this paper. The principles of the infrared automobile exhaust gas analyzer and the influence of the environmental temperature on analyzer are discussed. A fuzzy inference system is designed to improve the measurement accuracy of the measurement equipment by reducing the measurement errors caused by environmental temperature. The case studies demonstrate the effectiveness of the proposed method. The fuzzy compensation scheme is promising as demonstrated by the simulation results in this paper.

Ensemble-Based Method For Task 2: Predicting Traffic Jam, Jingrui He, Qing He, Grzegorz Swirszcz, Yiannis Kamarianakis, Rick Lawrence, Wei Shen, Laura Wynter

Research Collection School Of Computing and Information Systems

In this paper, we describe our solution for ICDM 2010 Contest Task 2 (Jams), where the task is to predict future where the next traffic jams will occur in morning rush hour, given data gathered during the initial phase of this peak period. Our solution, which is based on an ensemble approach, finished Second in the final evaluation.

Trade And Divergence In Education Systems, Pao Li Chang, Fali Huang

Research Collection School Of Economics

This paper presents a theory on the endogenous choice of a country's education policy and the two-way causal relationship between trade and education systems. The setting of a country's education system determines its talent distribution and comparative advantage in trade; the possibility of trade by raising the returns to the sector of comparative advantage in turn induces countries to further diferentiate their education systems and reinforces the initial pattern of comparative advantage. Specifically, the Nash equilibrium choice of education systems by two countries interacting strategically are necessarily more divergent than their autarky choices, although the difference is still less than …

Sequential Investment, Hold-Up And Strategic Delay, Juyuan Zhang, Yi Zhang

Research Collection School Of Economics

We investigate hold-up with simultaneous and sequential investment. We show that if the encouragement effect of sequential complementary investments dominates the delay effect, sequential investment alleviates the underinvestment caused by the hold-up problem. Further, if it is allowed to choose when to invest, strategic delay occurs when the encouragement effect of sequential complementary investments dominates the delay effect.

Chosen-Ciphertext Secure Bidirectional Proxy Re-Encryption Schemes Without Pairings, Jian Weng, Huijie, Robert Deng, Shengli Liu, Kefei Chen

Research Collection School Of Computing and Information Systems

Proxy re-encryption realizes delegation of decryption rights, enabling a proxy holding a re-encryption key to convert a ciphertext originally intended for Alice into an encryption of the same message for Bob. Proxy re-encryption is a very useful primitive, having many applications in distributed file systems, outsourced filtering of encrypted spam, access control over network storage, and so on. Lately, Weng et al. proposed the first unidirectional proxy re-encryption scheme without using bilinear pairs. However, Weng et al.'s construction does not possess collusion resilience, in the sense that a coalition of the proxy and the delegatee can recover the delegator's private …

Revisiting Address Space Randomization, Zhi Wang, Renquan Cheng, Debin Gao

Research Collection School Of Computing and Information Systems

Address space randomization is believed to be a strong defense against memory error exploits. Many code and data objects in a potentially vulnerable program and the system could be randomized, including those on the stack and heap, base address of code, order of functions, PLT, GOT, etc. Randomizing these code and data objects is believed to be effective in obfuscating the addresses in memory to obscure locations of code and data objects. However, attacking techniques have advanced since the introduction of address space randomization. In particular, return-oriented programming has made attacks without injected code much more powerful than what they …

Sequence Alignment Based Analysis Of Player Behavior In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

This study proposes a sequence alignment-based behavior analysis framework (SABAF) developed for predicting inactive game players that either leave the game permanently or stop playing the game for a long period of time. Sequence similarity scores and derived statistics form profile databases of inactive players and active players from the past. SABAF uses global and local sequence alignment algorithms and a unique scoring scheme to measure similarity between activity sequences. SABAF is tested on the game player activity data of Ever Quest II, a popular massively multiplayer online role-playing game developed by Sony Online Entertainment. SABAF consists of the following …

Evaluation Of Protein Backbone Alphabets : Using Predicted Local Structure For Fold Recognition, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

Optimally combining available information is one of the key challenges in knowledge-driven prediction techniques. In this study, we evaluate six Phi and Psi-based backbone alphabets. We show that the addition of predicted backbone conformations to SVM classifiers can improve fold recognition. Our experimental results show that the inclusion of predicted backbone conformations in our feature representation leads to higher overall accuracy compared to when using amino acid residues alone.

3-D Virtual World Education: An Empirical Comparison With Face-To-Face Classroom, Xiaofeng Chen, Keng Siau, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

3-D virtual worlds are increasing in popularity as a means of pedagogical delivery in higher education. In this research, we assess the relative effectiveness of a 3-D virtual world learning environment, Second Life, and traditional face-to-face learning environment. We also assess the efficacy of instructional strategies in these two learning environments and their effects on interactivity, perceived learning, and satisfaction. Our findings suggest that there is an interaction effect of learning environment and instructional strategy. Pair-wise comparisons indicate that when interactive instructional strategy is used, there is no significant difference for perceived learning and satisfaction between 3-D virtual world and …