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Spatial Queries In Wireless Broadcast Systems, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee Nov 2004

Spatial Queries In Wireless Broadcast Systems, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Owing to the advent of wireless networking and personal digital devices, information systems in the era of mobile computing are expected to be able to handle a tremendous amount of traffic and service requests from the users. Wireless data broadcast, thanks to its high scalability, is particularly suitable for meeting such a challenge. Indexing techniques have been developed for wireless data broadcast systems in order to conserve the scarce power resources in mobile clients. However, most of the previous studies do not take into account the impact of location information of users. In this paper, we address the issues of …

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On Semantic Caching And Query Scheduling For Mobile Nearest-Neighbor Search, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee Nov 2004

On Semantic Caching And Query Scheduling For Mobile Nearest-Neighbor Search, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Location-based services have received increasing attention in recent years. In this paper, we address the performance issues of mobile nearest-neighbor search, in which the mobile user issues a query to retrieve stationary service objects nearest to him/her. An index based on Voronoi Diagram is used in the server to support such a search, while a semantic cache is proposed to enhance the access efficiency of the service. Cache replacement policies tailored for the proposed semantic cache are examined. Moreover, several query scheduling policies are proposed to address the inter-cell roaming issues in multi-cell environments. Simulations are conducted to evaluate the …

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The D-Tree: An Index Structure For Planar Point Queries Location-Based Wireless Services, Jianliang Xu, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee Nov 2004

The D-Tree: An Index Structure For Planar Point Queries Location-Based Wireless Services, Jianliang Xu, Baihua Zheng, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Location-based services (LBSs), considered as a killer application in the wireless data market, provide information based on locations specified in the queries. In this paper, we examine the indexing issue for querying location-dependent data in wireless LBSs; in particular, we focus on an important class of queries, planar point queries. To address the issues of responsiveness, energy consumption, and bandwidth contention in wireless communications, an index has to minimize the search time and maintain a small storage overhead. It is shown that the traditional point-location algorithms and spatial index structures fail to achieve either objective or both. This paper proposes …

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Logistics Network Design With Differentiated Delivery Lead Time: A Chemical Industry Case Study, Michelle Lee Fong Cheong, Rohit Bhatnagar, Stephen C. Graves Nov 2004

Logistics Network Design With Differentiated Delivery Lead Time: A Chemical Industry Case Study, Michelle Lee Fong Cheong, Rohit Bhatnagar, Stephen C. Graves

Research Collection School Of Computing and Information Systems

Most logistics network design models assume exogenous customer demand that is independent of the service time or level. This paper examines the benefits of segmenting demand according to lead-time sensitivity of customers. To capture lead-time sensitivity in the network design model, we use a facility grouping method to ensure that the different demand classes are satisfied on time. In addition, we perform a series of computational experiments to develop a set of managerial insights for the network design decision making process.

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True Believers Or Moral Absolutists, Seow Hon Tan Nov 2004

True Believers Or Moral Absolutists, Seow Hon Tan

Research Collection Yong Pung How School Of Law

The recent American presidential elections brought to the fore the question of what place moral values have in public decision-making when traditional moral values are not espoused by all in a pluralist society. Even if traditional values - seen as absolutist - are imposed on others through a democratic electoral process, that imposition, particularly in hot button issues like abortion and same-sex marriage, remains difficult to accept.

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Free Will's A Gamble, Seow Hon Tan Nov 2004

Free Will's A Gamble, Seow Hon Tan

Research Collection Yong Pung How School Of Law

The debate over whether Singapore should have a casino has turned from the contest between moral values and social repercussions, on the one hand, and economic values on the other, to whether Singaporeans can be trusted to act responsibly. Put another way, the issue now seems to be whether the approach should be paternalistic, with all its connotations of the nanny state protecting the individual from himself.

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International Joint Ventures And Political Risk, Sundaram Janakiramanan, Lamba Asjeet S. Nov 2004

International Joint Ventures And Political Risk, Sundaram Janakiramanan, Lamba Asjeet S.

Research Collection Lee Kong Chian School Of Business

In recent years, a number of researchers have examined the existence and source of shareholder wealth effects around announcements of international joint ventures. The results of these studies are mixed with no clear answers as to when and why investors attach value to firms using joint ventures to enter overseas markets. In this context, we examine the shareholder wealth effects for 92 international joint venture announcements made by Australian firms during June 1988 - December 1997. We find that, on average, shareholders of firms announcing joint ventures realize an abnormal return of +1.65% over the two-day announcement period of days …

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Watching The Shop From The Front Seat: Determinants Of Venture Capitalists' Representation On The Board, Reddi Kotha, Eli Talmor Nov 2004

Watching The Shop From The Front Seat: Determinants Of Venture Capitalists' Representation On The Board, Reddi Kotha, Eli Talmor

Research Collection Lee Kong Chian School Of Business

Oversight and involvement are essential for a venture capital firm to influence the destiny of the portfolio company. This paper focuses primarily on the venture capital firm’s decision to take a formal responsibility through joining the board. Our study uses a large sample of private British companies that received institutional investment between 1999 and 2002. We examine the determinants of board composition and board size. Contrary to common belief, only 30 % of the companies have any institutional investor (a “VC”) on board. The decision to take a formal board seat is based on the ability to make a contribution: …

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Investing In Hedge Funds: Risks, Returns And Performance Measurement, Francis Koh, Winston T. H. Koh, David K. C. Lee, Kok Fai Phoon Oct 2004

Investing In Hedge Funds: Risks, Returns And Performance Measurement, Francis Koh, Winston T. H. Koh, David K. C. Lee, Kok Fai Phoon

Research Collection Lee Kong Chian School Of Business

Hedge funds are collective investment vehicles that are often established with a special legal status that allows their investment managers a free hand to use derivatives, short sell, and exploit leverage to raise returns and cushion risk. We review various issues relating to the investment in hedge funds, which have become popular with high net-worth individuals and institutional investors, as well as discuss their empirical risk and return profiles. The concerns regarding the empirical measurements are highlighted, and meaningful analytical methods are proposed to provide greater risk transparency in performance reporting. We also discuss the development of the hedge fund …

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A Novel Log-Based Relevance Feedback Technique In Content-Based Image Retrieval, Steven C. H. Hoi, Michael R. Lyu Oct 2004

A Novel Log-Based Relevance Feedback Technique In Content-Based Image Retrieval, Steven C. H. Hoi, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Relevance feedback has been proposed as an important technique to boost the retrieval performance in content-based image retrieval (CBIR). However, since there exists a semantic gap between low-level features and high-level semantic concepts in CBIR, typical relevance feedback techniques need to perform a lot of rounds of feedback for achieving satisfactory results. These procedures are time-consuming and may make the users bored in the retrieval tasks. For a long-term study purpose in CBIR, we notice that the users' feedback logs can be available and employed for helping the retrieval tasks in CBIR systems. In this paper, we propose a novel …

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Moore's Paradoxes, Evans's Principle And Self-Knowledge, John N. Williams Oct 2004

Moore's Paradoxes, Evans's Principle And Self-Knowledge, John N. Williams

Research Collection School of Social Sciences

I supply an argument for Evans’s principle that whatever justifies me in believing that p also justifies me in believing that I believe that p. I show how this principle helps explain how I come to know my own beliefs in a way that normally makes me the best authority on them. Then I show how the principle helps to solve Moore’s paradoxes.

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Structuring Home Video By Snippet Detection And Pattern Parsing, Zailiang Pan, Chong-Wah Ngo Oct 2004

Structuring Home Video By Snippet Detection And Pattern Parsing, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Hand-held camcorders have been popularly used in capturing and documenting daily lives. Nonetheless, searching for personal memories in home videos is still a laborious task. This paper describes novel approaches in detecting snippets and patterns in home videos for content indexing. To deal with the fact that most shots are long and with handshake artifacts, a motion analysis algorithm based on Kalman filter and finite state machine is proposed to decompose videos into tables of snippets. Each snippet is represented by a set of moving and static patterns. The moving patterns are automatically detected and tracked, while the static patterns …

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Clip-Based Similarity Measure For Hierarchical Video Retrieval, Yuxin Peng, Chong-Wah Ngo Oct 2004

Clip-Based Similarity Measure For Hierarchical Video Retrieval, Yuxin Peng, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper proposes a new approach and algorithm for the similarity measure of video clips. The similarity is mainly based on two bipartite graph matching algorithms: maximum matching (MM) and optimal matching (OM). MM is able to rapidly filter irrelevant video clips, while OM is capable of ranking the similarity of clips according to the visual and granularity factors. Based on MM and OM, a hierarchical video retrieval framework is constructed for the approximate matching of video clips. To allow the matching between a query and a long video, an online clip segmentation algorithm is also proposed to rapidly locate …

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Comments On "A Practical (T, N) Threshold Proxy Signature Scheme Based On The Rsa Cryptosystem", Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Oct 2004

Comments On "A Practical (T, N) Threshold Proxy Signature Scheme Based On The Rsa Cryptosystem", Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

In a (t, n) threshold proxy signature scheme based on RSA, any t or more proxy signers can cooperatively generate a proxy signature while t-1 or fewer of them can't do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers. In this article, we discuss the implementation and comparison of some threshold proxy signature schemes that are based on the RSA cryptosystem. Comparison is done on the basis of time complexity, space complexity and communication overhead. We compare the performance of four schemes: Hwang et al., Wen et …

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A Survey Of Online E-Banking Retail Initiatives, P. Southard, Keng Siau Oct 2004

A Survey Of Online E-Banking Retail Initiatives, P. Southard, Keng Siau

Research Collection School Of Computing and Information Systems

Customer demand is forcing banks to provide their services online. There are two successful paths they can take: to grow, or to specialize in providing localized services and information.

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Are Use Case And Class Diagrams Complementary In Requirements Analysis? An Experimental Study On Use Case And Class Diagrams In Uml, Keng Siau, Lihyunn Lee Oct 2004

Are Use Case And Class Diagrams Complementary In Requirements Analysis? An Experimental Study On Use Case And Class Diagrams In Uml, Keng Siau, Lihyunn Lee

Research Collection School Of Computing and Information Systems

Despite the status of united modeling language (UML) as the de facto standard for object oriented modeling, it has received controversial reviews. The most controversial diagram in UML is the use case diagram. Some practitioners claim that use case diagrams are not valuable in requirements analysis and some have even argued that use case diagrams should not be part of UML. This research examined the values of use case diagram in interpreting requirements when use case diagrams are used in conjunction with class diagrams. In other words, the study investigated the possible synergetic values and relationships between the use case …

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Legislative Ethics And Codes Of Conduct, Rick Stapenhurst, Riccardo Pelizzo Oct 2004

Legislative Ethics And Codes Of Conduct, Rick Stapenhurst, Riccardo Pelizzo

Research Collection School of Social Sciences

The purpose of this paper is to discuss why and how ethics reforms have been enacted by many parliaments in the course of the past decade. Our argument is fairly straightforward. Politicians’ perceived irresponsiveness, various forms of misconduct and corruption scandals have eroded voters’ trust in politicians and political institutions. In order to induce a more ethical behavior among politicians as well as to rebuild public trust in political institutions, ethics regimes have been adopted by several legislatures. Such regimes have generally taken two main forms: ethics codes and conduct codes. Ethics codes tend to be fairly general documents: they …

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Informal Animation Sketching: Requirements And Design, Richard C. Davis, James A. Landay Oct 2004

Informal Animation Sketching: Requirements And Design, Richard C. Davis, James A. Landay

Research Collection School Of Computing and Information Systems

We present an interface design for creating informal animations from sketches. Current tools for creating animation are extremely complex. This makes it difficult for designers to prototype animations and nearly impossible for novices to create them at all. Simple animation systems exist but severely restrict the types of motion that can be represented. To guide our design of an animation sketching interface, we conducted field studies into the needs of professional and novice animators. These studies show the wide variety of motions that users desire in informal animations and indicate how to prioritize these types of otion. The interface described …

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House Prices And Fundamental Value, John Krainer, Chi Shen Wei Oct 2004

House Prices And Fundamental Value, John Krainer, Chi Shen Wei

Research Collection Lee Kong Chian School Of Business

The performance of the residential housing market over the last ten years has been remarkable. According to the Office of Federal Housing Enterprise Oversight (OFHEO), house prices have appreciated at an annual rate of 5.4% on average (68.9% over the whole time period). Perhaps even more remarkable is that the performance was strong even when economic activity overall was weak. Average annual appreciation rates have been 7.4% (26% in total) since the collapse of the Nasdaq in 2000 and 7.1% (20% in total) since 2001:Q1, the beginning of the 2001 recession. In contrast, since the start of the 2001 recession, …

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Future Perspectives On Employee Selection: Key Directions For Future Research And Practice, Neil Anderson, Filip Lievens, Karen Van Dam, Ann Marie Ryan Oct 2004

Future Perspectives On Employee Selection: Key Directions For Future Research And Practice, Neil Anderson, Filip Lievens, Karen Van Dam, Ann Marie Ryan

Research Collection Lee Kong Chian School Of Business

A future-oriented perspective for selection and assessment research is presented. Four superordinate themes of critical import to the development of future research are identified: (i) bimodal prediction, (ii) multilevel fit, (iii) applicant reactions and decision making, and (iv) tensions between research and practice in employee selection. Under each theme we pose a number of outstanding questions for research. Implications for practice and the ongoing advancement of the sub-field of selection, traditionally one of the most robust core disciplines in international IWO psychology, are discussed.

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Dynamic Access Control For Multi-Privileged Group Communications, Di Ma, Robert H. Deng, Yongdong Wu, Tieyan Li Oct 2004

Dynamic Access Control For Multi-Privileged Group Communications, Di Ma, Robert H. Deng, Yongdong Wu, Tieyan Li

Research Collection School Of Computing and Information Systems

Recently, there is an increase in the number of group communication applications which support multiple service groups of different access privileges. Traditional access control schemes for group applications assume that all the group members have the same access privilege and mostly focus on how to reduce rekeying messages upon user joining and leaving. Relatively little research effort has been spent to address security issues for group communications supporting multiple access privileges. In this paper, we propose a dynamic access control scheme for group communications which support multiple service groups with different access privileges. Our scheme allows dynamic formation of service …

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Airconn: A Framework For Tiered Services In Public Wireless Lan Hot Spots, A. Acharya, C. Bisdikian, Archan Misra, Y. Ko Oct 2004

Airconn: A Framework For Tiered Services In Public Wireless Lan Hot Spots, A. Acharya, C. Bisdikian, Archan Misra, Y. Ko

Research Collection School Of Computing and Information Systems

Access to the data services via wireless LANs at private and public hot spot sites is becoming commonplace. The goal of the airConn project is to define an architecture and a prototype implementation that enable the provision of premium and non-premium service tiers for both transient and nontransient users of wireless hot spots. airConn provides for dynamic renegotiation of service tiers and facilitates various billing modes. Thus, it enables service providers to increase their revenue opportunities via multiple flexibility manageable service offerings.

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The Paradox Of Promoting Creativity In The Asian Classroom: An Empirical Investigation, Aik Kwang Ng, Ian Smith Oct 2004

The Paradox Of Promoting Creativity In The Asian Classroom: An Empirical Investigation, Aik Kwang Ng, Ian Smith

Research Collection School of Social Sciences

To shed light on the paradox of promoting creativity in the Asian classroom, the authors conducted 3 studies. The 1st study found that novice teachers classified student behaviors as desirable but uncreative (DBU) versus creative but undesirable (CBU). The 2nd study found that conservative-autocratic teachers were more likely to encourage DBU behaviors in class, whereas liberal-democratic teachers were more likely to encourage CBU behaviors in class. The 3rd study found that cultural individualism—collectivism had a positive impact on liberal—democratic teaching attitude but a negative impact on conservative—autocratic teaching attitude. In turn, liberal—democratic teaching attitude had a positive impact on the …

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Improving Transliteration With Precise Alignment Of Phoneme Chunks And Using Contextual Features, Wei Gao, Kam-Fai Wong, Wai Lam Oct 2004

Improving Transliteration With Precise Alignment Of Phoneme Chunks And Using Contextual Features, Wei Gao, Kam-Fai Wong, Wai Lam

Research Collection School Of Computing and Information Systems

Automatic transliteration of foreign names is basically regarded as a diminutive clone of the machine translation (MT) problem. It thus follows IBM’s conventional MT models under the sourcechannel framework. Nonetheless, some parameters of this model dealing with zero-fertility words in the target sequences, can negatively impact transliteration effectiveness because of the inevitable inverted conditional probability estimation. Instead of source-channel, this paper presents a direct probabilistic transliteration model using contextual features of phonemes with a tailored alignment scheme for phoneme chunks. Experiments demonstrate superior performance over the source-channel for the task of English-Chinese transliteration.

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Constructing A Coincident Index Of Business Cycles Without Assuming A One-Factor Model, Roberto S. Mariano, Yasutomo Murasawa Oct 2004

Constructing A Coincident Index Of Business Cycles Without Assuming A One-Factor Model, Roberto S. Mariano, Yasutomo Murasawa

Research Collection School Of Economics

The Stock-Watson coincident index and its subsequent extensions assume a static linear one-factor structure for the component indicators. Such assumption is restrictive in practice, however, with as few as four indicators. In fact, such assumption is unnecessary if one defines a coincident index as an estimate of latent monthly real GDP. This paper considers VAR and factor models for latent monthly real GDP and other coincident indicators, and estimates the models using the observable mixed-frequency series. For US data, Schwartz’s Bayesian information criterion selects a two-factor model. The smoothed estimate of latent monthly real GDP is the proposed index.

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Trans-Normal Distribution: A Flexible Model For Duration And Event-Time Data, Zhenlin Yang Oct 2004

Trans-Normal Distribution: A Flexible Model For Duration And Event-Time Data, Zhenlin Yang

Research Collection School Of Economics

A new family of distributions, called the trans-normal distribution is introduced. Its basic properties are presented. A closely related family of distributions called tran-t distribution is also given along with its basic properties. Trans-normal regression is used as an illustration on the usefullness of the new distribution.

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Indexing And Matching Of Polyphonic Songs For Query-By-Singing System, Tat-Wan Leung, Chong-Wah Ngo Oct 2004

Indexing And Matching Of Polyphonic Songs For Query-By-Singing System, Tat-Wan Leung, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper investigates the issues in polyphonic popular song retrieval. The problems that we consider include singing voice extraction, melodic curve representation, and database indexing. Initially, polyphonic songs are decomposed into singing voices and instruments sounds in both time and frequency domains based on SVM and ICA. The extracted singing voices are represented as two melodic curves that model the statistical mean and neighborhood similarity of notes. To speed up the matching between songs and query, we further adopt proportional transportation distance to index the songs as vantage point trees. Encouraging results have been obtained through experiments.

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Deformable Object Model Matching By Topological And Geometric Similarity, Kwok-Leung Tan, Rynson W. H. Lau, Chong-Wah Ngo Oct 2004

Deformable Object Model Matching By Topological And Geometric Similarity, Kwok-Leung Tan, Rynson W. H. Lau, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

In this paper, we present a novel method for efficient 3D model comparison. The method is designed to match highly deformed models through capturing two types of information. First, we propose a feature point extraction algorithm, which is based on “Level Set Diagram”, to reliably capture the topological points of a general 3D model. These topological points represent the skeletal structure of the model. Second, we also capture both spatial and curvature information, which describes the global surface of a 3D model. This is different from traditional topological 3D matching methods that use only low-dimension local features. Our method can …

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Blocking Reduction Strategies In Hierarchical Text Classification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng, Jaideep Srivastava Oct 2004

Blocking Reduction Strategies In Hierarchical Text Classification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

One common approach in hierarchical text classification involves associating classifiers with nodes in the category tree and classifying text documents in a top-down manner. Classification methods using this top-down approach can scale well and cope with changes to the category trees. However, all these methods suffer from blocking which refers to documents wrongly rejected by the classifiers at higher-levels and cannot be passed to the classifiers at lower-levels. We propose a classifier-centric performance measure known as blocking factor to determine the extent of the blocking. Three methods are proposed to address the blocking problem, namely, threshold reduction, restricted voting, and …

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Compliant Encryption Of Jpeg2000 Codestreams, Yongdong Wu, Robert H. Deng Oct 2004

Compliant Encryption Of Jpeg2000 Codestreams, Yongdong Wu, Robert H. Deng

Research Collection School Of Computing and Information Systems

This paper presents a compliant encryption method for JPEG 2000 codestreams such that the encryption process does not introduce superfluous JPEG2000 markers in the protected codestream, i.e., the protected codestream preserves the syntax of the original codestream. The proposed encryption method works with any standard ciphers, incurs no storage overhead, introduces negligible computational cost and maintains all the desirable properties of the original JPEG 2000 codestream such as error resilience and scalability.

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