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Novelty Detection For Cross-Lingual News Stories With Visual Duplicates And Speech Transcripts, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo Sep 2007

Novelty Detection For Cross-Lingual News Stories With Visual Duplicates And Speech Transcripts, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

An overwhelming volume of news videos from different channels and languages is available today, which demands automatic management of this abundant information. To effectively search, retrieve, browse and track cross-lingual news stories, a news story similarity measure plays a critical role in assessing the novelty and redundancy among them. In this paper, we explore the novelty and redundancy detection with visual duplicates and speech transcripts for cross-lingual news stories. News stories are represented by a sequence of keyframes in the visual track and a set of words extracted from speech transcript in the audio track. A major difference to pure …

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Difference Computation Of Large Models, Christoph Treude, Stefan Berlik, Sven Wenzel, Udo Kelter Sep 2007

Difference Computation Of Large Models, Christoph Treude, Stefan Berlik, Sven Wenzel, Udo Kelter

Research Collection School Of Computing and Information Systems

Modern software engineering practices lead to large models which exist in many versions. Version management systems should offer a service to compare, and possibly merge, these models. The computation of a difference between large models is a big challenge; current algorithms are too inefficient here. We present a new technique for computing differences between models. In practical tests, this technique has been an order of magnitude faster than currently known algorithms. The main idea is to use a high-dimensional search tree for efficiently finding similar model elements. Individual elements are mapped onto a vector of numerical values using a collection …

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Anonymous And Authenticated Key Exchange For Roaming Networks, Guomin Yang, Duncan S. Wong, Xiaotie Deng Sep 2007

Anonymous And Authenticated Key Exchange For Roaming Networks, Guomin Yang, Duncan S. Wong, Xiaotie Deng

Research Collection School Of Computing and Information Systems

User privacy is a notable security issue in wireless communications. It concerns about user identities from being exposed and user movements and whereabouts from being tracked. The concern of user privacy is particularly signified in systems which support roaming when users are able to hop across networks administered by different operators. In this paper, we propose a novel construction approach of anonymous and authenticated key exchange protocols for a roaming user and a visiting server to establish a random session key in such a way that the visiting server authenticates the user's home server without knowing exactly who the user …

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Keep The Talk Flowing, M. Thulasidas Sep 2007

Keep The Talk Flowing, M. Thulasidas

Research Collection School Of Computing and Information Systems

Specialisation is good. It lets us go deep into a specific field of endeavour, but at the expense of a broad overview of everything.

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Evolutionary Combinatorial Optimization For Recursive Supervised Learning With Clustering, Kiruthika Ramanathan, Sheng Uei Guan Sep 2007

Evolutionary Combinatorial Optimization For Recursive Supervised Learning With Clustering, Kiruthika Ramanathan, Sheng Uei Guan

Research Collection School Of Computing and Information Systems

The idea of using a team of weak learners to learn a dataset is a successful one in literature. In this paper, we explore a recursive incremental approach to ensemble learning. In this paper, patterns are clustered according to the output space of the problem, i.e., natural clusters are formed based on patterns belonging to each class. A combinatorial optimization problem is therefore formed, which is solved using evolutionary algorithms. The evolutionary algorithms identify the "easy" and the "difficult" clusters in the system. The removal of the easy patterns then gives way to the focused learning of the more complicated …

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Ontology-Enriched Semantic Space For Video Search, Xiao-Yong Wei, Chong-Wah Ngo Sep 2007

Ontology-Enriched Semantic Space For Video Search, Xiao-Yong Wei, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Multimedia-based ontology construction and reasoning have recently been recognized as two important issues in video search, particularly for bridging semantic gap. The lack of coincidence between low-level features and user expectation makes concept-based ontology reasoning an attractive midlevel framework for interpreting high-level semantics. In this paper, we propose a novel model, namely ontology-enriched semantic space (OSS), to provide a computable platform for modeling and reasoning concepts in a linear space. OSS enlightens the possibility of answering conceptual questions such as a high coverage of semantic space with minimal set of concepts, and the set of concepts to be developed for …

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Deception In Cyberspace: A Comparison Of Text-Only Vs. Avatar-Supported Medium, Holtjona Galanxhi, Fiona Fui-Hoon Nah Sep 2007

Deception In Cyberspace: A Comparison Of Text-Only Vs. Avatar-Supported Medium, Holtjona Galanxhi, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The use of anthropomorphic avatars provides Internet users the opportunity and freedom to manipulate their identity. As cyberspace becomes a haven for deceptive behavior, human–computer interaction research will need to be carried out to study and understand these deceptive behaviors. The objective of this research is to investigate the behavior of deceivers and non-deceivers (or truth-tellers) in the cyberspace environment. We examine if the intention to deceive others influences one's choice of avatars in the online chat environment. We also investigate if communication medium (text-only vs. avatar-supported chat) influences one's perception of trustworthiness of the communication partner. A lab experiment …

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The Future Of Information Systems Engineering, Keng Siau Sep 2007

The Future Of Information Systems Engineering, Keng Siau

Research Collection School Of Computing and Information Systems

No abstract provided.

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Taking Stock Of The Creative Commons Experiment: Monitoring The Use Of Creative Commons Licenses And Evaluating Its Implications For The Future Of Creative Commons And For Copyright Law, Giorgos Cheliotis, Warren B. Chik, Ankit Guglani, Giri Kumar Tayi Sep 2007

Taking Stock Of The Creative Commons Experiment: Monitoring The Use Of Creative Commons Licenses And Evaluating Its Implications For The Future Of Creative Commons And For Copyright Law, Giorgos Cheliotis, Warren B. Chik, Ankit Guglani, Giri Kumar Tayi

Research Collection Yong Pung How School Of Law

We provide an analysis of the use of Creative Commons (CC) licenses, an approach to licens-ing creative works which has become very popular among authors who wish to promote more liberal sharing and use of their work. We provide data demonstrating the popularity of CC, ex-amine which specific license types within the CC framework are most popular, and then iden-tify contributing factors for the relative popularity of some of the license types. This includes in-dividual author incentives, the consistency and aims of the online communities which adopt CC as a licensing model, the underlying medium (text, photography, audio, video or …

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Grist For The Sceptic's Mill: Rwanda And The African Peer Review Mechanism, Eduard Jordaan Sep 2007

Grist For The Sceptic's Mill: Rwanda And The African Peer Review Mechanism, Eduard Jordaan

Research Collection School of Social Sciences

The article delves into the impact of the African Peer Review Mechanism (APRM) to Rwanda's achievement of greater democracy and respect for political freedom. It aims to show the improbability that the APRM can influence the country due to its insufficient ability and volition to pressure further democratization and respect for political rights on Rwandan government, the APRM's optimistic view of political governance, and the APR Heads of State Forum's ratification of a program of action discounting the issues of democracy and political freedom. The author stresses that the weaknesses of APRM may be attributed to the existing reduced authorization …

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The Soft Embodiment Of Culture: Camera Angles And Motion Through Time And Space, Angela K. Y. Leung, Dov Cohen Sep 2007

The Soft Embodiment Of Culture: Camera Angles And Motion Through Time And Space, Angela K. Y. Leung, Dov Cohen

Research Collection School of Social Sciences

Cultural assumptions about one's relation to others and one's place in the world can be literally embodied in the way one cognitively maps out one's position and motion in time and space. In three experiments, we examined the psychological perspective that Asian American and Euro-American participants embodied as they both comprehended and produced narratives and mapped out metaphors of time and space. In social situations, Euro-American participants were more likely to embody their own perspective and a sense of their own motion (rather than those of a friend), whereas Asian American participants were more likely to embody a friend's perspective …

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Financial Development And International Capital Flows, Jürgen Von Hagen, Haiping Zhang Sep 2007

Financial Development And International Capital Flows, Jürgen Von Hagen, Haiping Zhang

Research Collection School Of Economics

We develop a general equilibrium model with nancial frictions in which internal capital (equity capital) and external capital (bank loans) have di erent rates of return. Financial development raises the rate of return on external capital but has a non-monotonic e ect on the rate of return on internal capital. We then show in a two-country model that capital account liberalization leads to out ow of nancial capital from the country with less developed nancial system. However, the direction of foreign direct investment (FDI, henceforth) depends on the exact degrees of nancial development in the two countries as well as …

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Employee Screening: Theory And Evidence, Fali Huang, Peter Cappelli Sep 2007

Employee Screening: Theory And Evidence, Fali Huang, Peter Cappelli

Research Collection School Of Economics

Arguably the fundamental problem faced by employers is how to elicit effort from employees. Most models suggest that employers meet this challenge by monitoring employees carefully to prevent shirking. But there is another option that relies on heterogeneity across employees, and that is to screen job candidates to find workers with a stronger work ethic who require less monitoring. This should be especially useful in work systems where monitoring by supervisors is more difficult, such as teamwork systems. We analyze the relationship between screening and monitoring in the context of a principal-agent model and test the theoretical results using a …

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Inefficient Worker Turnover, Nicolas L. Jacquet Sep 2007

Inefficient Worker Turnover, Nicolas L. Jacquet

Research Collection School Of Economics

This paper considers the efficiency properties of risk-neutral workers’ mobility decisions in an equilibrium model with search frictions, but no search externalities, when the rent accruing to a match is split through bargaining. Matches are ex ante homogeneous and their true productivity is learnt after the match is formed. It is shown that the efficiency of worker turnover depends on contract enforceability, and that in the absence of complete enforceability the equilibrium fails to be efficient. This is because without complete enforceability firms cannot credibly offer workers contracts that will guarantee them the entire future of all potential future matches.

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The Wto Trade Effect, Pao Li Chang, Myoung-Jae Lee Sep 2007

The Wto Trade Effect, Pao Li Chang, Myoung-Jae Lee

Research Collection School Of Economics

Rose (2004) showed that the WTO or its predecessor, the GATT, did not promote trade, based on conventional econometric analysis of gravity-type equations of trade. We argue that conclusions regarding the GATT/WTO trade effect based on gravity-type equations are arbitrary and subject to parametric misspecifications. We propose using nonparametric matching methods to estimate the 'treatment effect' of GATT/WTO membership, and permutation-based inferential procedures for assessing statistical significance of the estimated effects. A sensitivity analysis following Rosenbaum (2002) is then used to evaluate the sensitivity of our estimation results to potential selection biases. Contrary to Rose (2004), we find the effect …

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A Hybrid Approach To Case Teaching, Swee Liang Tan, Roy Jin Hou Ng Sep 2007

A Hybrid Approach To Case Teaching, Swee Liang Tan, Roy Jin Hou Ng

Research Collection School Of Economics

We structure case based teaching using a combination of computer-support technology and in-class activities. We create and design an on-line learning tool, Case Study On-line (CSOL) that enables instructor to structure the delivery of teaching resources and set up assignment tasks in the system. The tool enables tasks to be set in a way that they can be completed sequentially, and learning resources can be accessed only when required by students. Upon submission of their assignments, students can promptly receive instructor’s explanations to the tasks. Follow up activities take place in class, with the objective to promote active learning. The …

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Building Social Trust: A Human Capital Approach, Fali Huang Sep 2007

Building Social Trust: A Human Capital Approach, Fali Huang

Research Collection School Of Economics

Much evidence suggests individuals differ in their predisposition to cooperate, which is essentially a component of human capital. This paper examines the role of individual cooperative tendencies and their interactions with institutions in generating social trust; it also endogenizes cooperative tendencies using a human-capital investment model. Multiple equilibria and inefficiencies exist due to positive externalities. An innovative finding is that, when institutions are more effective in punishing defecting behaviors, more people invest in cooperative tendencies and hence the endogenous social trust is higher, though the equilibrium cooperative tendencies are lower. This paper provides a plausible explanation for many empirical and …

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Dynamic Treatment Effect Analysis Of Tv Effects On Child Cognitive Development, Fali Huang Sep 2007

Dynamic Treatment Effect Analysis Of Tv Effects On Child Cognitive Development, Fali Huang

Research Collection School Of Economics

We investigate whether TV watching at ages 6-7 and 8-9 affects cognitive development measured by math and reading scores at ages 8-9 using a rich childhood longitudinal sample from NLSY79. Dynamic panel data models are estimated to handle the unobserved child-specific factor, endogeneity of TV watching, and dynamic nature of the causal relation. A special emphasis is put on the last aspect where TV watching affects cognitive development which in turn affects the future TV watching. When this feedback occurs, it is not straightforward to identify and estimate the TV effect. We adopt estimation methods available in the biostatistics literature …

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On The Segmentation Of Markets, Nicolas Laurent Jacquet, Serene Tan Sep 2007

On The Segmentation Of Markets, Nicolas Laurent Jacquet, Serene Tan

Research Collection School Of Economics

This paper endogenizes the market structure of an economy with heterogeneous agents who want to form bilateral matches in the presence of search frictions and when utility is nontransferable. There exist infinitely many marketplaces, and each agent chooses which marketplace to be in: agents get to choose not only whom to match with but also whom they meet with. Perfect segmentation is obtained in equilibrium, where agents match with the first person they meet. All equilibria have the same matching pattern. Although perfect assortative matching is not obtained in equilibrium, the degree of assortativeness is greater than in standard models.

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Some Empirics On Economic Growth Under Heterogeneous Technology, Peter C. B. Phillips, Donggyu Sul Sep 2007

Some Empirics On Economic Growth Under Heterogeneous Technology, Peter C. B. Phillips, Donggyu Sul

Research Collection School Of Economics

A new econometric approach to testing for economic growth convergence is overviewed. The method is applicable to panel data, involves a simple regression based one-sided t-test, and can be used to form a clustering algorithm to assess the existence of growth convergence clubs. The approach allows for heterogeneous technology, utilizes some new asymptotic theory for nonlinear dynamic factor models, and is easy to implement. Some background growth theory is given which shows the form of augmented Solow regression (ASR) equations in the presence of heterogeneous technology and explains sources of potential misspecification that can arise in conventional formulations of ASR …

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Avoiding Arbitrary Exclusion Restrictions Using Ratios Of Reduced-Form Estimates, Myoung-Jae Lee, Pao-Li Chang Sep 2007

Avoiding Arbitrary Exclusion Restrictions Using Ratios Of Reduced-Form Estimates, Myoung-Jae Lee, Pao-Li Chang

Research Collection School Of Economics

We show how to obtain coherent structural-form (SF) exclusion restrictions using the reduced-form (RF) parameter ratios. It will be shown that an over-identified SF corresponds to a group of regressors sharing the same RF ratio value; those regressors should be excluded jointly from the SF. If there is no group structure, then the SF is just-identified; in this case, however, it is no longer clear which regressor should be excluded. Hence, just-identified SF’s are more arbitrary than over-identified SF’s in terms of exclusion restrictions. This is in stark contrast to the notion that the former is less arbitrary than the …

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Improved Maximum-Likelihood Estimation For The Common Shape Parameter Of Several Weibull Populations, Zhenlin Yang, Dennis K. J. Lin Sep 2007

Improved Maximum-Likelihood Estimation For The Common Shape Parameter Of Several Weibull Populations, Zhenlin Yang, Dennis K. J. Lin

Research Collection School Of Economics

The biasness problem of the maximum-likelihood estimate (MLE) of the common shape parameter of several Weibull populations is examined in detail. A modified MLE (MMLE) approach is proposed. In the case of complete and Type II censored data, the bias of the MLE can be substantial. This is noticeable even when the sample size is large. Such a bias increases rapidly as the degree of censorship increases and as more populations are involved. The proposed MMLE, however, is nearly unbiased and much more efficient than the MLE, irrespective of the degree of censorship, the sample sizes, and the number of …

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More Efficient Estimation Of Nonparametric Panel Data Models With Random Effects, Liangjun Su, Aman Ullah Sep 2007

More Efficient Estimation Of Nonparametric Panel Data Models With Random Effects, Liangjun Su, Aman Ullah

Research Collection School Of Economics

We propose a class of two-step estimators for nonparametric panel data models with random effects that are more efficient than the conventional least squares estimators. We establish asymptotic normality for the proposed estimators and derive the most efficient estimator in the class.

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Forecasting The Car Penetration Rate (Cpr) In China: A Nonparametric Approach, Sainan Jin, Liangjun Su Sep 2007

Forecasting The Car Penetration Rate (Cpr) In China: A Nonparametric Approach, Sainan Jin, Liangjun Su

Research Collection School Of Economics

With strong economic growth, the auto industry has made great breakthroughs in recent years and has become a backbone industry in China, while cars play an increasingly important role, and are now the principal part of the auto industry. Both China's government and academic circles take strong interest in the prediction of CPR (i.e. car penetration rate or cars per thousand people), which will be the main guidance for the future industry policy. We summarize the existing problems in recent research and propose to use nonparametric methods to estimate the CPR and its elasticity with respect to GDP per capita …

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Cross-Language And Cross-Media Image Retrieval: An Empirical Study At Imageclef2007, Steven C. H. Hoi Sep 2007

Cross-Language And Cross-Media Image Retrieval: An Empirical Study At Imageclef2007, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

This paper summarizes our empirical study of cross-language and cross-media image retrieval at the CLEF image retrieval track (ImageCLEF2007). In this year, we participated in the ImageCLEF photo retrieval task, in which the goal of the retrieval task is to search natural photos by some query with both textual and visual information. In this paper, we study the empirical evaluations of our solutions for the image retrieval tasks in three aspects. First of all, we study the application of language models and smoothing strategies for text-based image retrieval, particularly addressing the short text query issue. Secondly, we study the cross-media …

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The Mighty Pen, The Almighty Dollar, And The Holy Hammer And Sickle: An Examination Of The Conflict Between Trade Liberalization And Domestic Cultural Policy With Special Regard To The Recent Dispute Between The Us And China On Restrictions On Certain Cultural Products, Shuchao Henry Gao Sep 2007

The Mighty Pen, The Almighty Dollar, And The Holy Hammer And Sickle: An Examination Of The Conflict Between Trade Liberalization And Domestic Cultural Policy With Special Regard To The Recent Dispute Between The Us And China On Restrictions On Certain Cultural Products, Shuchao Henry Gao

Research Collection Yong Pung How School Of Law

The relationship between trade and culture has long been a hot topic in the debate on the conflicts between free trade and non-trade values. The recent case brought by the United States against China in the WTO on the measures affecting trading rights and distribution services for certain publications and audiovisual entertainment products is regarded by many as the latest example of the conflict. This article argues, however, that this case is more about the conflict between economic liberalization and political control. Applying the legal rules under the WTO Agreements and public international law, this paper concludes that the United …

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Practical Elimination Of Near-Duplicates From Web Video Search, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo Sep 2007

Practical Elimination Of Near-Duplicates From Web Video Search, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Current web video search results rely exclusively on text keywords or user-supplied tags. A search on typical popular video often returns many duplicate and near-duplicate videos in the top results. This paper outlines ways to cluster and filter out the nearduplicate video using a hierarchical approach. Initial triage is performed using fast signatures derived from color histograms. Only when a video cannot be clearly classified as novel or nearduplicate using global signatures, we apply a more expensive local feature based near-duplicate detection which provides very accurate duplicate analysis through more costly computation. The results of 24 queries in a data …

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Rushes Video Summarization By Object And Event Understanding, Feng Wang, Chong-Wah Ngo Sep 2007

Rushes Video Summarization By Object And Event Understanding, Feng Wang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper explores a variety of visual and audio analysis techniques in selecting the most representative video clips for rushes summarization at TRECVID 2007. These techniques include object detection, camera motion estimation, keypoint matching and tracking, audio classification and speech recognition. Our system is composed of two major steps. First, based on video structuring, we filter undesirable shots and minimize the inter-shot redundancy by repetitive shot detection. Second, a representability measure is proposed to model the presence of objects and four audio-visual events: motion activity of objects, camera motion, scene changes, and speech content, in a video clip. The video …

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Context-Based Detection Of Clone-Related Bugs, Lingxiao Jiang, Zhendong Su, Edwin Chiu Sep 2007

Context-Based Detection Of Clone-Related Bugs, Lingxiao Jiang, Zhendong Su, Edwin Chiu

Research Collection School Of Computing and Information Systems

Studies show that programs contain much similar code, commonly known as clones. One of the main reasons for introducing clones is programmers' tendency to copy and paste code to quickly duplicate functionality. We commonly believe that clones can make programs difficult to maintain and introduce subtle bugs. Although much research has proposed techniques for detecting and removing clones to improve software maintainability, little has considered how to detect latent bugs introduced by clones. In this paper, we introduce a general notion of context-based inconsistencies among clones and develop an efficient algorithm to detect such inconsistencies for locating bugs. We have …

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Column Heterogeneity As A Measure Of Data Quality, Bing Tian Dai, Nick Koudas, Beng Chin Ooi, Divesh Srivastava, Suresh Venkatasubramanian Sep 2007

Column Heterogeneity As A Measure Of Data Quality, Bing Tian Dai, Nick Koudas, Beng Chin Ooi, Divesh Srivastava, Suresh Venkatasubramanian

Research Collection School Of Computing and Information Systems

Data quality is a serious concern in every data management application, and a variety of quality measures have been proposed, including accuracy, freshness and completeness, to capture the common sources of data quality degradation. We identify and focus attention on a novel measure, column heterogeneity, that seeks to quantify the data quality problems that can arise when merging data from different sources. We identify desiderata that a column heterogeneity measure should intuitively satisfy, and discuss a promising direction of research to quantify database column heterogeneity based on using a novel combination of cluster entropy and soft clustering. Finally, we present …

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