Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Singapore Management University

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 6121 - 6150 of 8706

Full-Text Articles in Entire DC Network

Automatic Defect Categorization, Ferdian Thung, David Lo, Lingxiao Jiang Oct 2012

Automatic Defect Categorization, Ferdian Thung, David Lo, Lingxiao Jiang

Research Collection School Of Computing and Information Systems

Defects are prevalent in software systems. In order to understand defects better, industry practitioners often categorize bugs into various types. One common kind of categorization is the IBM’s Orthogonal Defect Classification (ODC). ODC proposes various orthogonal classification of defects based on much information about the defects, such as the symptoms and semantics of the defects, the root cause analysis of the defects, and many more. With these category labels, developers can better perform post-mortem analysis to find out what the common characteristics of the defects that plague a particular software project are. Albeit the benefits of having these categories, for …

Go to article

A Feasibility Study Of Crowdsourcing And Google Street View To Determine Sidewalk Accessibility, Kotaro Hara, Victoria Le, Jon Froehlich Oct 2012

A Feasibility Study Of Crowdsourcing And Google Street View To Determine Sidewalk Accessibility, Kotaro Hara, Victoria Le, Jon Froehlich

Research Collection School Of Computing and Information Systems

We explore the feasibility of using crowd workers from Amazon Mechanical Turk to identify and rank sidewalk accessibility issues from a manually curated database of 100 Google Street View images. We examine the effect of three different interactive labeling interfaces (Point, Rectangle, and Outline) on task accuracy and duration. We close the paper by discussing limitations and opportunities for future work.

Go to article

Model Checking Software Architecture Design, Jiexin Zhang, Yang Liu, Jing Sun, Jin Song Dong, Jun Sun Oct 2012

Model Checking Software Architecture Design, Jiexin Zhang, Yang Liu, Jing Sun, Jin Song Dong, Jun Sun

Research Collection School Of Computing and Information Systems

Software Architecture plays an essential role in the high level description of a system design. Despite its importance in the software engineering practice, the lack of formal description and verification support hinders the development of quality architectural models. In this paper, we present an automated approach to the modeling and verification of software architecture designs using the Process Analysis Toolkit (PAT). We present the formal syntax of the Wright# architecture description language together with its operational semantics in Labeled Transition System (LTS). A dedicated model checking module for Wright# is implemented in the PAT verification framework based on the proposed …

Go to article

Natural Sentences As Valid Units For Coded Political Texts, Thomas Daubler, Kenneth Benoit, Slava Mikhaylov, Michael Laver Oct 2012

Natural Sentences As Valid Units For Coded Political Texts, Thomas Daubler, Kenneth Benoit, Slava Mikhaylov, Michael Laver

Research Collection School of Social Sciences

A rapidly growing area in political science has focused on perfecting techniques to treat politicaltext as ‘data’, usually for the purposes of estimating latent traits such as left–right political policypositions.1 More traditional approaches have applied classical content analysis to categorize sub-unitsof political text, such as sentences in manifestos. Prominent examples of this latter approach includethe thirty-year old Comparative Manifestos Project and the Policy Agendas Project.2 ‘Text as data’approaches use machines to convert text to quantitative information and use statistical tools to makeinferences about characteristics of the author of the text. Content analysis schemes use humans to readtextual sub-units and assign …

Go to article

Engaging Students In Higher Education Through Mobile Learning: Lessons Learnt In A Chinese Entrepreneurship Course, Thomas Menkhoff, Magnus Lars Bengsston Oct 2012

Engaging Students In Higher Education Through Mobile Learning: Lessons Learnt In A Chinese Entrepreneurship Course, Thomas Menkhoff, Magnus Lars Bengsston

Research Collection Lee Kong Chian School Of Business

This evaluative-exploratory case study reports pedagogical experiences with using mobiles phones, wikis, and other mobile learning approaches such as podcasts and walking tours as educational tools in the context of an undergraduate course on Chinese Entrepreneurship and Asian Business Networks taught at a university in Singapore. Conceptualized as mobile learning, the paper argues that information and communication technologies (ICT) devices used by Gen Y students as part of their everyday life such as hand phones in combination with social media platforms such as course wikis and other proven pedagogical methods such as mini lectures, field visits, and walking tours can …

Go to article

Estimation Of High-Frequency Volatility: An Autoregressive Conditional Duration Approach, Yiu Kuen Tse, Thomas Tao Yang Oct 2012

Estimation Of High-Frequency Volatility: An Autoregressive Conditional Duration Approach, Yiu Kuen Tse, Thomas Tao Yang

Research Collection School Of Economics

We propose a method to estimate the intraday volatility of a stock by integrating the instantaneous conditional return variance per unit time obtained from the autoregressive conditional duration (ACD) model, called the ACD-ICV method. We compare the daily volatility estimated using the ACD-ICV method against several versions of the realized volatility (RV) method, including the bipower variation RV with subsampling, the realized kernel estimate, and the duration-based RV. Our Monte Carlo results show that the ACD-ICV method has lower root mean-squared error than the RV methods in almost all cases considered. This article has online supplementary material.

Go to article

Proportionality In Interpreting Constitutions: A Comparison Between Canada, The United Kingdom And Singapore And Its Implications For Vietnam, Jack Tsen-Ta Lee Oct 2012

Proportionality In Interpreting Constitutions: A Comparison Between Canada, The United Kingdom And Singapore And Its Implications For Vietnam, Jack Tsen-Ta Lee

Research Collection Yong Pung How School Of Law

Few rights that are guaranteed by constitutions and bills of rights are expressed to be absolute. In many jurisdictions, the legislature is permitted to impose restrictions on rights for specified reasons and under particular conditions. However, constitutional or bill of rights text often do not expressly indicate how the courts should determine that applicants’ rights have been legitimately restricted. To this end, courts in jurisdictions such as Canada and the United Kingdom have adopted the European doctrine of proportionality. Essentially, this requires them to balance opposing types of public interests – the interest sought to be protected by the rights …

Go to article

The Judicial Discretion To Exclude Relevant Evidence: Perspectives From An Indian Evidence Act Jurisdiction, Siyuan Chen Oct 2012

The Judicial Discretion To Exclude Relevant Evidence: Perspectives From An Indian Evidence Act Jurisdiction, Siyuan Chen

Research Collection Yong Pung How School Of Law

Stephen’s ground-breaking Indian Evidence Act contained ideas that appear unfamiliar in the context of modern rules of evidence. Singapore is an Indian Evidence Act jurisdiction which has retained those ideas, such as the non-distinction between relevance and admissibility, the framing of exclusionary rules in inclusionary terms, and the prohibition against relying on common law developments inconsistent with the Evidence Act. These peculiarities should have presented obstacles to the applicability of the common law concept of the judicial discretion to exclude relevant evidence, but this has not been the case. In this article, I first suggest why Singapore courts might have …

Go to article

Oto: Online Trust Oracle For User-Centric Trust Establishment, Tiffany Hyun-Jin Kim, Payas Gupta, Jun Han, Emmanuel Owusu, Jason Hong, Adrian Perrig, Debin Gao Oct 2012

Oto: Online Trust Oracle For User-Centric Trust Establishment, Tiffany Hyun-Jin Kim, Payas Gupta, Jun Han, Emmanuel Owusu, Jason Hong, Adrian Perrig, Debin Gao

Research Collection School Of Computing and Information Systems

Malware continues to thrive on the Internet. Besides automated mechanisms for detecting malware, we provide users with trust evidence information to enable them to make informed trust decisions. To scope the problem, we study the challenge of assisting users with judging the trustworthiness of software downloaded from the Internet. Through expert elicitation, we deduce indicators for trust evidence, then analyze these indicators with respect to scalability and robustness. We design OTO, a system for communicating these trust evidence indicators to users, and we demonstrate through a user study the effectiveness of OTO, even with respect to IE’s SmartScreen Filter (SSF). …

Go to article

Generalization And Induction: More Misconceptions And Clarifications, Eric W. K. Tsang, John N. Williams Oct 2012

Generalization And Induction: More Misconceptions And Clarifications, Eric W. K. Tsang, John N. Williams

Research Collection School of Social Sciences

In ‘Generalization and Induction: Misconceptions, Clarifications, and a Classification of Induction’, we comment on Lee and Baskerville’s (2003) paper ‘Generalizing Generalizability in Information Systems Research’, which attempts to clarify the concept of generalization and classify it into four types. Our commentary discusses the misconceptions in their paper and proposes an alternative classification of induction. Their response ‘Conceptualizing Generalizability: New Contributions and a Reply’ perpetuates their misconceptions and create new ones. The purpose of this rejoinder is to highlight the major problems both in their original paper and in their reply and to provide further clarifications. Lee and Baskerville’s so-called ‘new …

Go to article

The Price Discovery Puzzle In Offshore Yuan Trading: Different Contributions For Different Contracts, David K. Ding, Y. Tse, M. Williams Oct 2012

The Price Discovery Puzzle In Offshore Yuan Trading: Different Contributions For Different Contracts, David K. Ding, Y. Tse, M. Williams

Research Collection Lee Kong Chian School Of Business

No abstract provided.

Go to article

Analysts' Industry Expertise, Ohad Kadan, Leonardo Madureira, Rong Wang, Tzachi Zach Oct 2012

Analysts' Industry Expertise, Ohad Kadan, Leonardo Madureira, Rong Wang, Tzachi Zach

Research Collection Lee Kong Chian School Of Business

Industry expertise is an important aspect of sell-side research. We explore this aspect using a novel dataset of industry recommendations, which are often issued by strategy analysts. We study sell-side analysts' ability to rank industries relative to each other (across-industry expertise), and how it relates to analysts' ability to rank firms in a particular industry (within-industry expertise). We find that analysts express more optimism towards industries with higher levels of investment, past profitability, and past returns. Analysts exhibit across-industry expertise, as portfolios based on industry recommendations generate abnormal returns over both short and long horizons, beyond what would be explained …

Go to article

The Persistence Of Long-Run Abnormal Returns: Evidence From Stock Repurchases And Offerings, Fangjian Fu, Sheng Huang, Hu Lin Oct 2012

The Persistence Of Long-Run Abnormal Returns: Evidence From Stock Repurchases And Offerings, Fangjian Fu, Sheng Huang, Hu Lin

Research Collection Lee Kong Chian School Of Business

Prior studies have documented that stock returns are abnormally high during the years following share repurchases and abnormally low following seasoned equity offerings, relative to various benchmarks of expected returns. While we confirm this evidence in the event data as of 2002, we do not find robust long-run abnormal returns following either stock repurchases or issuances after 2002. Institutional ownership of event stocks has increased substantially in the recent decade, which helps to explain the disappearance of the abnormal performance following corporate stock transactions. The evidence seems consistent with the improved stock market efficiency in recent years, accompanied by reduced …

Go to article

How Do Institutional Investors Trade When Firms Are Buying Back Shares?, Sheng Huang, Zhe (Joe) Zhang Oct 2012

How Do Institutional Investors Trade When Firms Are Buying Back Shares?, Sheng Huang, Zhe (Joe) Zhang

Research Collection Lee Kong Chian School Of Business

We study how institutional investors trade when firms buy back shares. We find that aggregate institutional ownership decline following share repurchase announcements. While some institutions sell shares passively to meet the firm demand for the market to clear, the overall institutional sell-off only accounts for 27% of shares bought back contemporaneously by firms. Many firms experience a net inflow of institutional investment. The decrease in institutional shareholding is greater in firms that experience weaker recent stock performance, display more information uncertainty, have higher institutional ownership, and conduct ill-timed/motivated repurchases that are not endorsed by institutions. And most of the sell-off …

Go to article

Predicting Common Web Application Vulnerabilities From Input Validation And Sanitization Code Patterns, Lwin Khin Shar, Hee Beng Kuan Tan Sep 2012

Predicting Common Web Application Vulnerabilities From Input Validation And Sanitization Code Patterns, Lwin Khin Shar, Hee Beng Kuan Tan

Research Collection School Of Computing and Information Systems

Software defect prediction studies have shown that defect predictors built from static code attributes are useful and effective. On the other hand, to mitigate the threats posed by common web application vulnerabilities, many vulnerability detection approaches have been proposed. However, finding alternative solutions to address these risks remains an important research problem. As web applications generally adopt input validation and sanitization routines to prevent web security risks, in this paper, we propose a set of static code attributes that represent the characteristics of these routines for predicting the two most common web application vulnerabilities—SQL injection and cross site scripting. In …

Go to article

Friends, Family, Or Fools: Entrepreneur Experience And Its Implications For Equity Distribution And Resource Mobilization, Reddi Kotha, Gerard George Sep 2012

Friends, Family, Or Fools: Entrepreneur Experience And Its Implications For Equity Distribution And Resource Mobilization, Reddi Kotha, Gerard George

Research Collection Lee Kong Chian School Of Business

Who helps entrepreneurs raise the resources they need and how much equity does an entrepreneur distribute in return? We use a sample of 611 entrepreneurs in the U.S. to examine why some entrepreneurs are more likely than others to distribute ownership selectively to helpers. We find that entrepreneurs with specific industry experience and start-up experience are able to provide ownership more selectively and raise more resources from their helpers. We refine the categorization of social ties further to make a distinction between professional and familial ties to show that the ownership distribution and types of resource contributions vary by the …

Go to article

Do Analysts Understand The Valuation Implications Of Accounting Conservatism When Forecasting Target Prices?, Jae Bum Kim, Alexander Nekrasov, Pervin Shroff, Andreas Simon Sep 2012

Do Analysts Understand The Valuation Implications Of Accounting Conservatism When Forecasting Target Prices?, Jae Bum Kim, Alexander Nekrasov, Pervin Shroff, Andreas Simon

Research Collection School Of Accountancy

Conservatism in earnings does not have a direct impact on the present value of future cash flows. This paper examines whether financial analysts correctly undo the effect of accounting conservatism incorporated in their own earnings forecasts in arriving at their target price forecasts. Based on prior findings, we consider alternative valuation models/heuristics that may be used by analysts to estimate target prices, e.g. the forward P/E and the PEG ratio. Our evidence suggests that analysts fail to fully undo the effect of accounting conservatism embedded in their forecasts of earnings and earnings growth when estimating their target price forecasts. More …

Go to article

Mandatory Financial Reporting Environment And Voluntary Disclosure: Evidence From Mandatory Ifrs Adoption, Balakrishnan Karthik, Xi Li, Holly Yang Sep 2012

Mandatory Financial Reporting Environment And Voluntary Disclosure: Evidence From Mandatory Ifrs Adoption, Balakrishnan Karthik, Xi Li, Holly Yang

Research Collection School Of Accountancy

Using the mandatory adoption of International Financial Reporting Standards (IFRS) as an exogenous improvement to mandatory financial reporting, we document evidence supporting a complementary effect between mandatory and voluntary disclosures. We find that firms in countries that adopted IFRS in 2005 experience an increase in both the likelihood and frequency of management earnings forecasts relative to firms in countries that did not mandate IFRS. We also find that the increase in management forecasts is higher in countries where prior local GAAP are more different from IFRS or legal enforcement is stronger. Consistent with the confirmatory role of mandatory reporting, we …

Go to article

Duplicate Bug Report Detection With A Combination Of Information Retrieval And Topic Modeling, Anh Tuan Nguyen, Tung Nguyen, Tien Nguyen, David Lo, Chengnian Sun Sep 2012

Duplicate Bug Report Detection With A Combination Of Information Retrieval And Topic Modeling, Anh Tuan Nguyen, Tung Nguyen, Tien Nguyen, David Lo, Chengnian Sun

Research Collection School Of Computing and Information Systems

Detecting duplicate bug reports helps reduce triaging efforts and save time for developers in fixing the same issues. Among several automated detection approaches, text-based information retrieval (IR) approaches have been shown to outperform others in term of both accuracy and time efficiency. However, those IR-based approaches do not detect well the duplicate reports on the same technical issues written in different descriptive terms. This paper introduces DBTM, a duplicate bug report detection approach that takes advantage of both IR-based features and topic-based features. DBTM models a bug report as a textual document describing certain technical issue(s), and models duplicate bug …

Go to article

In-Game Action List Segmentation And Labeling In Real-Time Strategy Games, Wei Gong, Ee-Peng Lim, Palakorn Achananuparp, Feida Zhu, David Lo, Freddy Chong-Tat Chua Sep 2012

In-Game Action List Segmentation And Labeling In Real-Time Strategy Games, Wei Gong, Ee-Peng Lim, Palakorn Achananuparp, Feida Zhu, David Lo, Freddy Chong-Tat Chua

Research Collection School Of Computing and Information Systems

In-game actions of real-time strategy (RTS) games are extremely useful in determining the players' strategies, analyzing their behaviors and recommending ways to improve their play skills. Unfortunately, unstructured sequences of in-game actions are hardly informative enough for these analyses. The inconsistency we observed in human annotation of in-game data makes the analytical task even more challenging. In this paper, we propose an integrated system for in-game action segmentation and semantic label assignment based on a Conditional Random Fields (CRFs) model with essential features extracted from the in-game actions. Our experiments demonstrate that the accuracy of our solution can be as …

Go to article

Sell-Order Liquidity And The Cross-Section Of Expected Stock Returns, Michael Brennan, Tarun Chordia, Avanidhar Subrahmanyam, Qing Tong Sep 2012

Sell-Order Liquidity And The Cross-Section Of Expected Stock Returns, Michael Brennan, Tarun Chordia, Avanidhar Subrahmanyam, Qing Tong

Research Collection Lee Kong Chian School Of Business

We estimate buy- and sell-order illiquidity measures (lambdas) for a comprehensive sample of NYSE stocks. We show that sell-order liquidity is priced more strongly than buy-order liquidity in the cross-section of equity returns. Indeed, our analysis indicates that the liquidity premium in equities emanates predominantly from the sell-order side. We also find that the average difference between sell and buy lambdas is generally positive throughout our sample period. Both buy and sell lambdas are significantly positively correlated with measures of funding liquidity such as the TED spread as well option implied volatility.

Go to article

The Fat Thumb: Using The Thumb's Contact Size For Single-Handed Mobile Interaction, Sebastian Boring, David Ledo, Xiang ‘Anthony’ Chen, Nicolai Marquardt, Anthony Tang, Saul Greenberg Sep 2012

The Fat Thumb: Using The Thumb's Contact Size For Single-Handed Mobile Interaction, Sebastian Boring, David Ledo, Xiang ‘Anthony’ Chen, Nicolai Marquardt, Anthony Tang, Saul Greenberg

Research Collection School Of Computing and Information Systems

Modern mobile devices allow a rich set of multi-finger interactions that combine modes into a single fluid act, for example, one finger for panning blending into a two-finger pinch gesture for zooming. Such gestures require the use of both hands: one holding the device while the other is interacting. While on the go, however, only one hand may be available to both hold the device and interact with it. This mostly limits interaction to a single-touch (i.e., the thumb), forcing users to switch between input modes explicitly. In this paper, we contribute the Fat Thumb interaction technique, which uses the …

Go to article

Verification Of Graph Programs, Christopher M. Poskitt Sep 2012

Verification Of Graph Programs, Christopher M. Poskitt

Research Collection School Of Computing and Information Systems

GP (for Graph Programs) is an experimental nondeterministic programming language which allows for the manipulation of graphs at a high level of abstraction. The program states of GP are directed labelled graphs. These are manipulated directly via the application of (conditional) rule schemata, which generalise double-pushout rules with expressions over labels and relabelling. In contrast with graph grammars, the application of these rule schemata is directed by a number of simple control constructs including sequential composition, conditionals, and as-long-as-possible iteration. GP shields programmers at all times from low-level implementation issues (e.g. graph representation), and with its nondeterministic semantics, allows one …

Go to article

The Effects Of Coaching On Situational Judgment Tests In High-Stakes Selection, Filip Lievens, Tine Buyse, Paul R. Sackett, Brian S. Connelly Sep 2012

The Effects Of Coaching On Situational Judgment Tests In High-Stakes Selection, Filip Lievens, Tine Buyse, Paul R. Sackett, Brian S. Connelly

Research Collection Lee Kong Chian School Of Business

Although the evidence for the use of situational judgment tests (SJTs) in high-stakes testing has been generally promising, questions have been raised regarding the potential coachability of SJTs. This study reports the first examination of the effects of coaching on SJT scores in an operational high-stakes setting. We contrast findings from a simple comparison of SJT scores for coached and uncoached participants (posttest only) with three different approaches to deal with the effects of self-selection into coaching programs, namely using a pretest as a covariate and using two different forms of propensity score-based matching using a wide range of variables …

Go to article

The Educated Middle Class, Their Economics Prospects, And The Arab Spring, Davin Chor, Filipe R. Campante Sep 2012

The Educated Middle Class, Their Economics Prospects, And The Arab Spring, Davin Chor, Filipe R. Campante

Research Collection School Of Economics

The recent uprisings in the Arab World carry a broader lesson, highlighting the importance of sustaining an economy that provides sufficient job opportunities for an increasingly educated and skilled middle class.

Go to article

Economy Can Be Game Changer For The Region, Kim Song Tan, Sim Yee Lau Sep 2012

Economy Can Be Game Changer For The Region, Kim Song Tan, Sim Yee Lau

Research Collection School Of Economics

this article they explore reform of the banking sector in Myanmar.

Go to article

Gambling On Genes: Ambiguity Aversion Explains Investment In Sisters' Children, Brishti Guha Sep 2012

Gambling On Genes: Ambiguity Aversion Explains Investment In Sisters' Children, Brishti Guha

Research Collection School Of Economics

Many men invest in their sisters’ children instead of their wives’. Existing theories addressing such behavior depend on the level of paternity probability in such men’s societies being implausibly low. I link this anthropologically observed investment behavior with the experimentally observed phenomenon that some individuals are ambiguity averse. Arguing that men’s decisions are made under ambiguity, I show that an increase in ambiguity aversion results in investment in sisters’, rather than wives’, children. I show that this can happen even under risk neutrality. I also consider the special cases of a SEU maximizer and of extreme ambiguity aversion in the …

Go to article

Past Consideration Or Unconnected Consideration, Yihan Goh, Man Yip Sep 2012

Past Consideration Or Unconnected Consideration, Yihan Goh, Man Yip

Research Collection Yong Pung How School Of Law

It is trite law that a valid and enforceable contract must be supported by consideration. The recent Court of Appeal case of Rainforest Trading Ltd v State Bank of India Singapore [2012] 2 SLR 713 is a further addition to the local jurisprudence on consideration, specifically the issue of past consideration. This note considers the specific issue of past consideration and argues that its label should be discarded in favour of a more realistic one that correctly emphasises its underlying concerns.

Go to article

To What Extent Could We Detect Field Defects? An Empirical Study Of False Negatives In Static Bug Finding Tools, Ferdian Thung, Lucia Lucia, David Lo, Lingxiao Jiang, Premkumar Devanbu, Foyzur Rahman Sep 2012

To What Extent Could We Detect Field Defects? An Empirical Study Of False Negatives In Static Bug Finding Tools, Ferdian Thung, Lucia Lucia, David Lo, Lingxiao Jiang, Premkumar Devanbu, Foyzur Rahman

Research Collection School Of Computing and Information Systems

Software defects can cause much loss. Static bug-finding tools are believed to help detect and remove defects. These tools are designed to find programming errors; but, do they in fact help prevent actual defects that occur in the field and reported by users? If these tools had been used, would they have detected these field defects, and generated warnings that would direct programmers to fix them? To answer these questions, we perform an empirical study that investigates the effectiveness of state-of-the-art static bug finding tools on hundreds of reported and fixed defects extracted from three open source programs: Lucene, Rhino, …

Go to article

Kbe-Anonymity: Test Data Anonymization For Evolving Programs, Lucia Lucia, David Lo, Lingxiao Jiang, Aditya Budi Sep 2012

Kbe-Anonymity: Test Data Anonymization For Evolving Programs, Lucia Lucia, David Lo, Lingxiao Jiang, Aditya Budi

Research Collection School Of Computing and Information Systems

High-quality test data that is useful for effective testing is often available on users’ site. However, sharing data owned by users with software vendors may raise privacy concerns. Techniques are needed to enable data sharing among data owners and the vendors without leaking data privacy. Evolving programs bring additional challenges because data may be shared multiple times for every version of a program. When multiple versions of the data are cross-referenced, private information could be inferred. Although there are studies addressing the privacy issue of data sharing for testing and debugging, little work has explicitly addressed the challenges when programs …

Go to article

First Prev Next Last