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Research Collection School Of Computing and Information Systems

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Structuring Lecture Videos For Distance Learning Applications, Chong-Wah Ngo, Feng Wang, Ting-Chuen Pong Dec 2003

Structuring Lecture Videos For Distance Learning Applications, Chong-Wah Ngo, Feng Wang, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

This paper presents an automatic and novel approach in structuring and indexing lecture videos for distance learning applications. By structuring video content, we can support both topic indexing and semantic querying of multimedia documents. In this paper, our aim is to link the discussion topics extracted from the electronic slides with their associated video and audio segments. Two major techniques in our proposed approach include video text analysis and speech recognition. Initially, a video is partitioned into shots based on slide transitions. For each shot, the embedded video texts are detected, reconstructed and segmented as high-resolution foreground texts for commercial …

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Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim Dec 2003

Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the tremendous growth of XML data over the Web, efficient management of such data becomes a new challenge for database community. Several data management solutions, proposed in recent years, extend the capability of traditional database systems to meet the needs of XML data while alternative approaches introduce new generation databases, named as native XML database management systems. Although traditional databases have mature transaction management and concurrency control techniques, there is still a need to tailor techniques for native XML databases in order to deal with distinct characteristics of XML. In this paper, we propose XStamps, a multiversion timestamps concurrency …

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Creating A Virtual Store Image, P. Katerattanakul, Keng Siau Dec 2003

Creating A Virtual Store Image, P. Katerattanakul, Keng Siau

Research Collection School Of Computing and Information Systems

A study was conducted to describe some of the factors that needed to be considered for a virtual store. It was revealed that the growth of e-commerce and online businesses has made it essential to understand the critical attributes of image for a virtual store. Store image was described as the way in which the store was defined by customers and several studies. The study compiled 77 designs and features into a list used to construct a survey. Four hundred and twenty-seven potential customers were requested to rate the significance of each item on the list. The information gathered identified …

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Aa Flexible And Scalable Authentication Scheme For Jpeg 2000 Image Codestreams, Cheng Peng, Robert H. Deng, Yongdong Wu, Weizhong Shao Nov 2003

Aa Flexible And Scalable Authentication Scheme For Jpeg 2000 Image Codestreams, Cheng Peng, Robert H. Deng, Yongdong Wu, Weizhong Shao

Research Collection School Of Computing and Information Systems

JPEG2000 is an emerging standard for still image compression and is becoming the solution of choice for many digital imaging fields and applications. An important aspect of JPEG2000 is its "compress once, decompress many ways" property [1], i. e., it allows extraction of various sub-images (e.g., images with various resolutions, pixel fidelities, tiles and components) all from a single compressed image codestream. In this paper, we present a flexible and scalable authentication scheme for JPEG2000 images based on the Merkle hash tree and digital signature. Our scheme is fully compatible with JPEG2000 and possesses a "sign once, verify many ways" …

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Content-Aware Authentication Of Motion Jpeg2000 Stream In Lossy Networks, Yongdong Wu, Robert H. Deng Nov 2003

Content-Aware Authentication Of Motion Jpeg2000 Stream In Lossy Networks, Yongdong Wu, Robert H. Deng

Research Collection School Of Computing and Information Systems

Stream authentication schemes (SAS) aim to achieve effective authentication of multicast streams over lossy networks. Almost all the existing SASs is designed for stream data integrity protection only. In this paper, we argue that content integrity protection is more important than data integrity to human users. We present a content-aware SAS in motion JPEG2000 streaming. In our scheme, a chunk of JPEG2000 codestreams is encapsulated into a block of packets using multiple description coding (MDC). Our MDC exploits the inherent structure of motion JPEG2000 codestreams and is used to preserve the semanteme/content of the stream over lossy networks. To achieve …

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Web Unit Mining: Finding And Classifying Subgraphs Of Web Pages, Aixin Sun, Ee Peng Lim Nov 2003

Web Unit Mining: Finding And Classifying Subgraphs Of Web Pages, Aixin Sun, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In web classification, most researchers assume that the objects to classify are individual web pages from one or more web sites. In practice, the assumption is too restrictive since a web page itself may not always correspond to a concept instance of some semantic concept (or category) given to the classification task. In this paper, we want to relax this assumption and allow a concept instance to be represented by a subgraph of web pages or a set of web pages. We identify several new issues to be addressed when the assumption is removed, and formulate the web unit mining …

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A Robust Dissolve Detector By Support Vector Machine, Chong-Wah Ngo Nov 2003

A Robust Dissolve Detector By Support Vector Machine, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

In this paper, we propose a novel approach for the robust detection and classification of dissolve sequences in videos. Our approach is based on the multi-resolution representation of temporal slices extracted from 3D image volume. At the low-resolution (LR) scale, the problem of dissolve detection is reduced as cut transition detection. At the highresolution (HR) space, Gabor wavelet features are computed for regions that surround the cuts located at LR scale. The computed features are then input to support vector machines for pattern classification. Encouraging results have been obtained through experiments.

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Synchronization Of Lecture Videos And Electronic Slides By Video Text Analysis, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Nov 2003

Synchronization Of Lecture Videos And Electronic Slides By Video Text Analysis, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

An essential goal of structuring lecture videos captured in live presentation is to provide a synchronized view of video clips and electronic slides. This paper presents an automatic approach to match video clips and slides based on the analysis of text embedded in lecture videos. We describe a method to reconstruct high-resolution video texts from multiple keyframes for robust OCRrecognition. A two-stage matching algorithm based on the title and content similarity measures between video clips and slides is also proposed.

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Validating Digital Signatures Without Ttp’S Time-Stamping And Certificate Revocation, Jianying Zhou, Feng Bao, Robert H. Deng Oct 2003

Validating Digital Signatures Without Ttp’S Time-Stamping And Certificate Revocation, Jianying Zhou, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

In non-repudiation services where digital signatures usually serve as irrefutable cryptographic evidence for dispute resolution, trusted time-stamping and certificate revocation services, although very costly in practice, must be available, to prevent big loss due to compromising of the signing key. In [12], a new concept called intrusion-resilient signature was proposed to get rid of trusted time-stamping and certificate revocation services and a concrete scheme was presented. In this paper, we put forward a new scheme that can achieve the same effect in a much more efficient way. In our scheme, forward-secure signature serves as a building block that enables signature …

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Automatic Video Summarization By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang Oct 2003

Automatic Video Summarization By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

We propose a unified approach for summarization based on the analysis of video structures and video highlights. Our approach emphasizes both the content balance and perceptual quality of a summary. Normalized cut algorithm is employed to globally and optimally partition a video into clusters. A motion attention model based on human perception is employed to compute the perceptual quality of shots and clusters. The clusters, together with the computed attention values, form a temporal graph similar to Markov chain that inherently describes the evolution and perceptual importance of video clusters. In our application, the flow of a temporal graph is …

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Variations Of Diffie-Hellman Problem, Feng Bao, Robert H. Deng, Huafei Zhu Oct 2003

Variations Of Diffie-Hellman Problem, Feng Bao, Robert H. Deng, Huafei Zhu

Research Collection School Of Computing and Information Systems

This paper studies various computational and decisional Diffie-Hellman problems by providing reductions among them in the high granularity setting. We show that all three variations of computational Diffie-Hellman problem: square Diffie-Hellman problem, inverse Diffie-Hellman problem and divisible Diffie-Hellman problem, are equivalent with optimal reduction. Also, we are considering variations of the decisional Diffie-Hellman problem in single sample and polynomial samples settings, and we are able to show that all variations are equivalent except for the argument DDH ⇐ SDDH. We are not able to prove or disprove this statement, thus leave an interesting open problem. Keywords: Diffie-Hellman problem, Square Diffie-Hellman …

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Adaptive Collusion Attack To A Block Oriented Watermarking Scheme, Yongdong Wu, Robert H. Deng Oct 2003

Adaptive Collusion Attack To A Block Oriented Watermarking Scheme, Yongdong Wu, Robert H. Deng

Research Collection School Of Computing and Information Systems

In this paper, we propose an adaptive collusion attack to a block oriented watermarking scheme [1]. In this attack, traitors conspire to selectively manipulate watermarked blocks to remove the watermark information. To this end, the traitors compare the watermarked blocks generated from the same original block. If two watermarked block are not equal, they average these two blocks to generate a pirated block. Then, replace the watermarked blocks with the pirated blocks so as to build a pirated image. The pirated image has no watermark but has much higher quality than watermarked images. We also give a theoretical analysis on …

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An Efficient Public-Key Framework, Jianying Zhou, Feng Bao, Robert H. Deng Oct 2003

An Efficient Public-Key Framework, Jianying Zhou, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Public-key certificates play an important role in binding the public key with the identity of the owner of the corresponding private key. A certificate might be revoked before its scheduled expiry date by the issuing CA. Efficient and timely distribution of certificate revocation information is a big challenge facing the PKI providers. Existing certificate revocation schemes place a considerable processing, communication, and storage overheads on the CA as well as the relying parties. To improve the current situation, we propose a revocation-free public-key framework, in which the maximum lifetime of a certificate is divided into short periods and the certificate …

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Security Remarks On A Group Signature Scheme With Member Deletion, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Oct 2003

Security Remarks On A Group Signature Scheme With Member Deletion, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

A group signature scheme allows a group member of a given group to sign messages on behalf of the group in an anonymous and unlinkable fashion. In case of a dispute, however, a designated group manager can reveal the signer of a valid group signature. Based on the Camenisch-Michels group signature scheme, Kim, Lim and Lee proposed the first group signature scheme with a member deletion procedure at ICISC 2000. Their scheme is very efficient in both communication and computation aspects. Unfortunately, their scheme is insecure. In this paper, we first identify an effective way that allows any verifier to …

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The Effect Of Domain Knowledge On Icon Visualization, Keng Siau, Fiona Fui-Hoon Nah Aug 2003

The Effect Of Domain Knowledge On Icon Visualization, Keng Siau, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Iconic interfaces are now the de facto interface for most computer systems. Despite the popularity of iconic interfaces and the widespread belief that iconic interfaces are easier to comprehend than non-iconic interfaces, we have not come across any published study that has examined the effect of domain knowledge on end users’ interpretation of icons. An understanding of the relationship between domain knowledge and its effect on interpretation will enable us to design better icons to not only facilitate end users’ interpretation but also reduce misinterpretations of icons. This paper reports on an experimental study that investigates the effect of domain …

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Information Systems Requirements Determination And Analysis: A Mental Modeling Approach, Keng Siau, X. Tan Aug 2003

Information Systems Requirements Determination And Analysis: A Mental Modeling Approach, Keng Siau, X. Tan

Research Collection School Of Computing and Information Systems

Regardless of the system development methodology adopted, being able to understand users’ informationrequirements is vital to the success of an information systems project. The intrinsic communications obstaclesexist within an individual user, among users, and between users and systems analysts. Different requirementsdetermination and analysis (RDA) techniques have been widely used with different outcomes. Some limitations of these techniques can be identified. In this paper, we propose a mental modeling approach to support RDA. Popular in other disciplines, mental modeling techniques have some distinct advantages to overcome some intrinsic communication obstacles in RDA, and to complement other techniques.

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Ladar-Based Detection And Tracking Of Moving Objects From A Ground Vehicle At High Speeds, Chieh-Chih Wang, Charles Thorpe, Arne Suppe Jun 2003

Ladar-Based Detection And Tracking Of Moving Objects From A Ground Vehicle At High Speeds, Chieh-Chih Wang, Charles Thorpe, Arne Suppe

Research Collection School Of Computing and Information Systems

Detection and tracking of moving objects (DATMO) in crowded urban areas from a ground vehicle at high speeds is difficult because of a wide variety of targets and uncertain pose estimation from odometry and GPS/DGPS. In this paper we present a solution of the simultaneous localization and mapping (SLAM) with DATMO problem to accomplish this task using ladar sensors and odometry. With a precise pose estimate and a surrounding map from SLAM, moving objects are detected without a priori knowledge of the targets. The interacting multiple model (IMM) estimation algorithm is used for modeling the motion of a moving object …

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Using Support Vector Machines For Terrorism Information Extraction, Aixin Sun, Myo-Myo Naing, Ee Peng Lim, Wai Lam Jun 2003

Using Support Vector Machines For Terrorism Information Extraction, Aixin Sun, Myo-Myo Naing, Ee Peng Lim, Wai Lam

Research Collection School Of Computing and Information Systems

Information extraction (IE) is of great importance in many applications including web intelligence, search engines, text understanding, etc. To extract information from text documents, most IE systems rely on a set of extraction patterns. Each extraction pattern is defined based on the syntactic and/or semantic constraints on the positions of desired entities within natural language sentences. The IE systems also provide a set of pattern templates that determines the kind of syntactic and semantic constraints to be considered. In this paper, we argue that such pattern templates restricts the kind of extraction patterns that can be learned by IE systems. …

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Adaptive Filters For Continuous Queries Over Distributed Data Stream, Chris Olston, Jing Jiang, Jennifer Widom Jun 2003

Adaptive Filters For Continuous Queries Over Distributed Data Stream, Chris Olston, Jing Jiang, Jennifer Widom

Research Collection School Of Computing and Information Systems

We consider an environment where distributed data sources continuously stream updates to a centralized processor that monitors continuous queries over the distributed data. Significant communication overhead is incurred in the presence of rapid update streams, and we propose a new technique for reducing the overhead. Users register continuous queries with precision requirements at the central stream processor, which installs filters at remote data sources. The filters adapt to changing conditions to minimize stream rates while guaranteeing that all continuous queries still receive the updates necessary to provide answers of adequate precision at all times. Our approach enables applications to trade …

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Secure The Image-Based Simulated Telesurgery System, Yanjiang Yang, Zhenlan Wang, Feng Bao, Robert H. Deng May 2003

Secure The Image-Based Simulated Telesurgery System, Yanjiang Yang, Zhenlan Wang, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Telemedicine services involve transmission of patient data over open computer network, and thus confront serious security challenges when the consequences are a matter of life and death. In this paper, we introduce an image-based simulated system for kyphoplasty telesurgery, wherein special attention is given to the fine-grained security implementation issues. Various security requirements are formalized and corresponding solutions are presented. Consequently, we implement the system to work in a secure way, while taking efficiency as a premier consideration.

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On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa May 2003

On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa

Research Collection School Of Computing and Information Systems

A supply hub is a location generally close to a manufacturer’s facility where all or some of its supplies are warehoused with the agreement that the materials will be paid for only when consumed. Supply hub is an innovative strategy employed by especially the electronics industry to achieve cost reduction and improved responsiveness. After first tracing the developments leading to the establishment of supply hubs, the paper then describes the dynamics of the operation of supply hubs. Case examples are provided to highlight the current practices. Finally, some research issues are identified.

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Tactics-Based Remote Execution For Mobile Computing, Rajesh Krishna Balan, Mahadev Satayanarayana, Soyoung Park, Tadashi Okoshi May 2003

Tactics-Based Remote Execution For Mobile Computing, Rajesh Krishna Balan, Mahadev Satayanarayana, Soyoung Park, Tadashi Okoshi

Research Collection School Of Computing and Information Systems

Remote execution can transform the puniest mobile device into a computing giant able to run resource-intensive applications such as natural language translation, speech recognition, face recognition, and augmented reality. However, easily partitioning these applications for remote execution while retaining application-specific information has proven to be a difficult challenge. In this paper, we show that automated dynamic repartitioning of mobile applications can be reconciled with the need to exploit application-specific knowledge. We show that the useful knowledge about an application relevant to remote execution can be captured in a compact declarative form calledtactics. Tactics capture the full range of meaningful partitions …

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Motion Analysis And Segmentation Through Spatio-Temporal Slices Processing, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang Mar 2003

Motion Analysis And Segmentation Through Spatio-Temporal Slices Processing, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

This paper presents new approaches in characterizing and segmenting the content of video. These approaches are developed based upon the pattern analysis of spatio-temporal slices. While traditional approaches to motion sequence analysis tend to formulate computational methodologies on two or three adjacent frames, spatio-temporal slices provide rich visual patterns along a larger temporal scale. In this paper, we first describe a motion computation method based on a structure tensor formulation. This method encodes visual patterns of spatio-temporal slices in a tensor histogram, on one hand, characterizing the temporal changes of motion over time, on the other hand, describing the motion …

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Energy-Efficient Broadcast And Multicast Trees For Reliable Wireless Communication, Suman Banerjee, Archan Misra, Jihwang Yeo, Ashok Agrawala Mar 2003

Energy-Efficient Broadcast And Multicast Trees For Reliable Wireless Communication, Suman Banerjee, Archan Misra, Jihwang Yeo, Ashok Agrawala

Research Collection School Of Computing and Information Systems

We define energy-efficient broadband and multicast schemes for reliable communication in multi-hop wireless networks. Unlike previous techniques, the choice of neighbors in the broadband and multicast trees in these schemes, are based not only on the link distance, but also on the error rates associated with the link. Our schemes can be implemented using both positive and negative acknowledgement based reliable broadcast techniques in the link layer. Through simulations, we show that our scheme achieves up to 45% improvement over previous schemes on realistic 100-node network topologies. A positive acknowledgment based implementation is preferred. Our simulations show that the additional …

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Stegfs: A Steganographic File System, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou Mar 2003

Stegfs: A Steganographic File System, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou

Research Collection School Of Computing and Information Systems

While user access control and encryption can protect valuable data from passive observers, those techniques leave visible ciphertexts that are likely to alert an active adversary to the existence of the data, who can then compel an authorized user to disclose it. This paper introduces StegFS, a steganographic file system that aims to overcome that weakness by offering plausible deniability to owners of protected files. StegFS securely hides user-selected files in a file system so that, without the corresponding access keys, an attacker would not be able to deduce their existence, even if the attacker is thoroughly familiar with the …

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Health Care Informatics, Keng Siau Mar 2003

Health Care Informatics, Keng Siau

Research Collection School Of Computing and Information Systems

The health care industry is currently experiencing a fundamental change. Health care organizations are reorganizing their processes to reduce costs, be more competitive, and provide better and more personalized customer care. This new business strategy requires health care organizations to implement new technologies, such as Internet applications, enterprise systems, and mobile technologies in order to achieve their desired business changes. This article offers a conceptual model for implementing new information systems, integrating internal data, and linking suppliers and patients.

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Adaptive Transmission Power For Optimal Energy Reliable Multi-Hop Wireless Communication, Suman Banerjee, Archan Misra Mar 2003

Adaptive Transmission Power For Optimal Energy Reliable Multi-Hop Wireless Communication, Suman Banerjee, Archan Misra

Research Collection School Of Computing and Information Systems

We define a transmission power adaptation-based routing technique that finds optimal paths for minimum energy reliable data transfer in multi-hop wireless networks. This optimal choice of the transmission power depends on the link distance between the two nodes and the channel characteristics. Typical energy efficient routing techniques use a transmission power such that the received signal power at the destination minimally exceeds a desired threshold signal strength level. In this paper we argue that such a choice of the transmission power does not always lead to optimal energy routes, since it does not consider differences in the receiver noise levels. …

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Maca-P: A Mac For Concurrent Transmissions In Multi-Hop Wireless Networks, Arup Acharya, Archan Misra, Sorav Bansal Mar 2003

Maca-P: A Mac For Concurrent Transmissions In Multi-Hop Wireless Networks, Arup Acharya, Archan Misra, Sorav Bansal

Research Collection School Of Computing and Information Systems

This paper presents the initial design and performance study of MACA-P, a RTS/CTS based MAC protocol that enables simultaneous transmissions in multihop ad-hoc wireless networks. Providing such low-cost multihop and high performance wireless access networks is an important enabler of pervasive computing. MACA-P is a set of enhancements to the 802.11 DCF that allows parallel transmissions in many situations when two neighboring nodes are either both receivers or both transmitters, but a receiver and a transmitter are not neighbors. Like 802.11, MACA-P contains a contention-based reservation phase prior to data transmission. However, the data transmission is delayed by a control …

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Enterprise-Wide Strategic Information Systems Planning For Shanghai Bell Corporation, Y. Long, Fiona Fui-Hoon Nah, Z. Zhu Jan 2003

Enterprise-Wide Strategic Information Systems Planning For Shanghai Bell Corporation, Y. Long, Fiona Fui-Hoon Nah, Z. Zhu

Research Collection School Of Computing and Information Systems

In response to increasing competition and technological advancement, Shanghai Bell Co., Ltd., a leading telecommunications enterprise located in Shanghai, China, carried out a major initiative to develop its next generation Information Technology/Information Systems (IT/IS) strategic plan. The initiative was prompted by limitations of its current enterprise application systems where the systems were neither able to keep up with the evolving needs due to organizational change nor satisfy the increasing demands for information sharing and data analysis. This case describes the environmental and organizational context of Shanghai Bell Corporation, and the problems and challenges it encountered in developing an enterprise-wide strategic …

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Mobile Communications And Mobile Services, Keng Siau, Z. Shen Jan 2003

Mobile Communications And Mobile Services, Keng Siau, Z. Shen

Research Collection School Of Computing and Information Systems

As wireless technologies evolve, the coming mobile revolution will bring dramatic and fundamental changes to the world. This revolution has already begun and is gaining momentum. The revolution will impact numerous facets of our daily lives and the way business is conducted. It will provide important data in real time to assist decision makers, exert great influence on communications between businesses and their customers, and transform the way we live our lives. This paper examines issues in providing services via wireless technologies, i.e. mobile services. The paper discusses the challenges facing mobile services, such as changes in business strategies, investment …

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