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Displaying 1-45 out of 45 total
Securing BYOD
Found in: IT Professional
By J. Morris Chang,Pao-Chung Ho,Teng-Chang Chang
Issue Date:September 2014
pp. 9-11
Today's IT departments are concerned with the popularity of BYOD, because mixing personal and enterprise data presents security threats to corporate proprietary information. IT departments must develop company security policies that let employees access se...
 
Wireless Broadband Technologies: Access, Security, and Applications
Found in: IT Professional
By Wesley Chou, J. Morris Chang, Shawkang Wu
Issue Date:September 2008
pp. 12-14
Wireless technologies continue to advance to provide faster, more reliable, and more secure service. The articles in this issue provide case studies and practical information to help the IT professional understand existing wireless broadband options as wel...
   
Real-Time Location Systems and RFID
Found in: IT Professional
By J. Morris Chang, Yo-Ping Huang, Simon Liu
Issue Date:March 2011
pp. 12-13
<p>RFID has revolutionized asset tracking and new applications are constantly appearing in the fields of transportation, banking, healthcare, and security. This special issue reports on recent experiences in developing RFID applications, middleware, ...
 
Upper Bounds for Dynamic Memory Allocation
Found in: IEEE Transactions on Computers
By Yusuf Hasan, Wei-Mei Chen, J. Morris Chang, Bashar M. Gharaibeh
Issue Date:April 2010
pp. 468-477
In this paper, we study the upper bounds of memory storage for two different allocators. In the first case, we consider a general allocator that can allocate memory blocks anywhere in the available heap space. In the second case, a more economical allocato...
 
New Trends in Cybersecurity
Found in: IT Professional
By J. Morris Chang
Issue Date:July 2013
pp. 2-3
This year, cybersecurity might be one of the most widely discussed subjects among IT professionals, with three new trends emerging. The field is experiencing an increase in the workforce demand, expanding into broader areas, and starting to address mobile ...
 
Enhanced Fast Base Station Switching
Found in: IEEE Transactions on Mobile Computing
By Kuang-Hui Chi,J. Morris Chang,Ting-Chung Wang
Issue Date:November 2012
pp. 1640-1651
IEEE 802.16-2009 specifies two fast handover mechanisms, fast base station switching and macro diversity handover, to streamline communication for a mobile station (MS). Both operate with a diversity set that lists base stations among which an MS can move ...
 
The New Mobile Computing Landscape
Found in: IT Professional
By Irena Bojanova,J. Morris Chang,Wes Chou,San Murugesan
Issue Date:September 2012
pp. 9-11
The mobile computing revolution has been phenomenal, and its growth continues unabated. Advances in mobile computing and wireless communications, widespread adoption of mobile devices, and the availability of a vast array of low-cost applications that run ...
 
Multithreading in Java: Performance and Scalability on Multicore Systems
Found in: IEEE Transactions on Computers
By Kuo-Yi Chen,J. Morris Chang,Ting-Wei Hou
Issue Date:November 2011
pp. 1521-1534
The performance and scalability issues of multithreaded Java programs on multicore systems are studied in this paper. First, we examine the performance scaling of benchmarks with various numbers of processor cores and application threads. Second, by correl...
 
Guest Editors' Introduction: Data Center Design
Found in: IT Professional
By Wes Chou, J. Morris Chang, Ken Christensen
Issue Date:July 2009
pp. 10-11
The ability of a good data center design to provide security, scalability, and maintainability to an IT operation makes it the cornerstone of a successful enterprise. This introduction to IT Pro's theme issue on data center design explains the basics behin...
 
A hybrid allocator
Found in: Performance Analysis of Systems and Software, IEEE International Symmposium on
By Y. Hasan, J. Morris Chang
Issue Date:March 2003
pp. 214-222
Dynamic memory management can make up to 30% of total program execution time. Object oriented languages like C++ allocate and free dynamic memory prolifically. Since computer memory is a limited resource its efficient utilization is required to minimize wa...
 
Capturing Cognitive Fingerprints from Keystroke Dynamics
Found in: IT Professional
By J. Morris Chang,Chi-Chen Fang,Kuan-Hsing Ho,Norene Kelly,Pei-Yuan Wu,Yixiao Ding,Chris Chu,Stephen Gilbert,Amed E. Kamal,Sun-Yuan Kung
Issue Date:July 2013
pp. 24-28
Conventional authentication systems identify a user only at the entry point. Keystroke dynamics can continuously authenticate users by their typing rhythms without extra devices. This article presents a new feature called cognitive typing rhythm (CTR) to c...
 
Hot Topics in Cloud Computing
Found in: IT Professional
By Liang-Jie Zhang, Jia Zhang, Jinan Fiaidhi, J. Morris Chang
Issue Date:September 2010
pp. 17-19
<p>Cloud computing is no longer just hype. It's quickly evolving and gradually realizing its business value, as the articles in this special issue show. It's now attracting more and more researchers and practitioners, who are creating innovations aro...
 
Grouping-Based Dynamic Power Management for Multi-threaded Programs in Chip-Multiprocessors
Found in: Computational Science and Engineering, IEEE International Conference on
By Mu-Kai Huang, J. Morris Chang, Wei-Mei Chen
Issue Date:August 2009
pp. 56-63
In the embedded systems field, the research focus has shifted from performance to considering both performance and power consumption. Previous research has investigated methods to forecast the processing behavior of programs and adopt Dynamic Voltage and F...
 
Coping with API Evolution for Running, Mission-Critical Applications Using Virtual Execution Environment
Found in: Quality Software, International Conference on
By Bashar Gharaibeh, Tien N. Nguyen, J. Morris Chang
Issue Date:October 2007
pp. 171-180
Recent research showed that the majority of compatibility-breaking changes in a component-based, object-oriented software system are refactorings [5]. The software updating process in such system with the presence of heavily refactored application programm...
 
WiMax: The Emergence of Wireless Broadband
Found in: IT Professional
By Zakhia Abichar, Yanlin Peng, J. Morris Chang
Issue Date:July 2006
pp. 44-48
WiMax has changed the scene of wireless broadband from proprietary solutions to a standards-based industry. Authors discuss WiMax evolution, applications, spectrum issues, standards, and developments.
 
Group-Based Medium Access for Next-GenerationWireless LANs
Found in: A World of Wireless, Mobile and Multimedia Networks, International Symposium on
By Zakhia Abichar, J. Morris Chang, Daji Qiao
Issue Date:June 2006
pp. 35-41
Recently, there has been extensive research interest in increasing the data rates supported by IEEE 802.11 wireless LANs. For this purpose, IEEE 802.11 formed Task Group N to develop specifications for high-data-rate wireless LANs. The medium access in the...
 
Using Scratchpad to Exploit Object Locality in Java
Found in: Computer Design, International Conference on
By Carl S. Lebsack, J. Morris Chang
Issue Date:October 2005
pp. 381-386
<p>Performance of modern computers is tied closely to the effective use of cache because of the continually increasing speed discrepancy between processors and main memory. We demonstrate that generational garbage collection employed by a system with...
 
Towards Pairing Java Applications on SMT Processors
Found in: Modeling, Analysis, and Simulation of Computer Systems, International Symposium on
By Wei Huang, Jiang Lin, Zhao Zhang, J. Morris Chang
Issue Date:September 2005
pp. 7-14
<p>This paper investigates various issues of pairing Java applications for multithreaded execution on Intel?s Hyper- Threading Pentium 4 processor. We first quantify the overall performance of multiprogrammed Java applications using a metric called c...
 
Who is Collecting Your Java Garbage?
Found in: IT Professional
By Chia-Tien Dan Lo, Witawas Srisa-an, J. Morris Chang
Issue Date:March 2003
pp. 44-50
<p>Garbage collection can be a real drain on a Java system. Understanding the different GC algorithms your JVM might use is the first step toward improving system efficiency.</p>
 
Java Distributed Object Models: An Alternative to Corba?
Found in: IT Professional
By George Koutsogiannakis, J. Morris Chang
Issue Date:May 2002
pp. 41-47
<p>Remote method invocation and RMI over IIOP relieve developers of many Corba complexities. Companies looking for a way to achieve interoperability should strongly consider these models.</p>
 
Putting Voice into Wireless Communications
Found in: IT Professional
By Witawas Srisa-an, Chia-Tien Dan Lo, J. Morris Chang
Issue Date:January 2002
pp. 62-64
<p>The Web could be a spoken word away if VoiceXML-based products take off. Find out some basics about this evolving specification.</p>
 
Evaluation of a High-Performance Object Reuse Dynamic Memory Allocation Policy for C++ Programs
Found in: High-Performance Computing in the Asia-Pacific Region, International Conference on
By Woo Hyong Lee, J. Morris Chang, Yusuf Hasan
Issue Date:May 2000
pp. 386
Recently, the importance of dynamic memory management has been increased significantly as there is a growing number of development in object-oriented programs. Many studies show that dynamic memory management is one of the most expensive components in many...
 
Performance Enhancements to the Active Memory System
Found in: Computer Design, International Conference on
By Witawas Srisa-an, Chia-Tien Dan Lo, J. Morris Chang
Issue Date:September 2002
pp. 249
The Active Memory System — a garbage collected memory module was introduced as a way to provide hardware support for garbage collection in embedded systems. The major component in the design was the Active Memory Processor (AMP) that utilized a set of bit-...
 
A Multithreaded Concurrent Garbage Collector Parallelizing the New Instruction in Java
Found in: Parallel and Distributed Processing Symposium, International
By Chia-Tien Dan Lo, Witawas Srisa-an, J. Morris Chang
Issue Date:April 2002
pp. 0059b
Parallel, multithreaded Java applications such as web servers, database servers, and scientific applications are becoming increasingly prevalent. Most of them have high object instantiation rates through the new bytecode that is implemented in a garbage co...
 
A Cool Scheduler for Multi-Core Systems Exploiting Program Phases
Found in: IEEE Transactions on Computers
By Zhiming Zhang,J. Morris Chang
Issue Date:May 2014
pp. 1061-1073
Rapid growth of cloud computing services have led to creation of large scale enterprise data centers which consume great amounts of energy. Data centers usually have an service level agreement (SLA) between the clients and the service providers, which spec...
 
A Medium Access Control Scheme for Wireless LANs with Constant-Time Contention
Found in: IEEE Transactions on Mobile Computing
By Zakhia Abichar, J. Morris Chang
Issue Date:February 2011
pp. 191-204
In today's wireless networks, stations using the IEEE 802.11 Standard contend for the channel using the Distributed Coordination Function (DCF). Research has shown that DCF's performance degrades especially with the large number of stations. This becomes m...
 
Bandwidth Recycling in IEEE 802.16 Networks
Found in: IEEE Transactions on Mobile Computing
By David Chuck, J. Morris Chang
Issue Date:October 2010
pp. 1451-1464
IEEE 802.16 standard was designed to support the bandwidth demanding applications with quality of service (QoS). Bandwidth is reserved for each application to ensure the QoS. For variable bit rate (VBR) applications, however, it is difficult for the subscr...
 
Responding to Security Issues in WiMAX Networks
Found in: IT Professional
By Chin-Tser Huang, J. Morris Chang
Issue Date:September 2008
pp. 15-21
WiMAX technology, the commercialization of the evolving IEEE 802.16 standard, aims to solve the last-mile problem with broadband wireless access at the scale of metropolitan area networks. WiMAX has attracted significant attention and interest because of i...
 
A Performance Analysis of the Active Memory System
Found in: Computer Design, International Conference on
By Witawas Srisa-an, Chia-Tien Dan Lo, J. Morris Chang
Issue Date:September 2001
pp. 0493
Abstract: One major problem of using Java in real-time and embedded devices is the non-deterministic turnaround time of dynamic memory management systems (memory allocation and garbage collection). For the allocation, the nondeterminism is often contribute...
 
Architectural Support for Dynamic Memory Management
Found in: Computer Design, International Conference on
By J. Morris Chang, Witawas Srisa-an, Chia-Tien Dan Lo
Issue Date:September 2000
pp. 99
Recent advances in software engineering, such as graphical user interfaces and object-oriented programming, have caused applications to become more memory intensive. These applications tend to allocate dynamic memory prolifically. Moreover, automatic dynam...
 
Scalable Hardware-Algorithm for Mark-Sweep Garbage Collection
Found in: EUROMICRO Conference
By Witawas Srisa-an, Chia-Tien Dan Lo, J. Morris Chang
Issue Date:September 2000
pp. 1274
The memory intensive nature of object-oriented languages such as C++ and Java has created the need of a high-performance dynamic memory management. Object-oriented applications often generate higher memory intensity in the heap region. Thus, a high-perform...
 
A High-Performance Memory Allocator for Memory Intensive Applications
Found in: High-Performance Computing in the Asia-Pacific Region, International Conference on
By J. Morris Chang, Yusuf Hasan, Woo H. Lee
Issue Date:May 2000
pp. 6
Dynamic memory management (DMM) has been a high cost component in many software systems. Especially, the use of object-orientation often results in an intensive use of dynamic memory, making the dynamic memory performance problem worse. This paper presents...
 
Hardware Support for Concurrent Garbage Collection in SMP Systems
Found in: High-Performance Computing in the Asia-Pacific Region, International Conference on
By J. Morris Chang, Witawas Srisa-an, Chia-Tien Dan Lo
Issue Date:May 2000
pp. 513
In this paper, we propose a heap-partitioning scheme that can eliminate heap contentions in multithreaded applications. Heap partitioning allows each CPU to have its own heap space (called sub-heap). Thus, the heap contention can be eliminated. The propose...
 
On Design-for-Reusability in Hardware Description Languages
Found in: VLSI, IEEE Computer Society Workshop on
By J. Morris Chang, S. Kagan Agun
Issue Date:April 2000
pp. 103
The reuse of electronic components can improve the productivity in the system design. However, without careful planning components are rarely designed for reuse. Hardware Description Languages (HDLs) are commonly used to construct from simple hardware to c...
 
A Dynamic Memory Measuring Tool for C++ Programs
Found in: Application-Specific Software Engineering and Technology, IEEE Workshop on
By Woo Hyong Lee, J. Morris Chang, Yusuf Hasan
Issue Date:March 2000
pp. 155
Dynamic memory management has been a high cost component in many software systems. A study has shown that memory intensive C programs can consume up to 30% of the program run time in memory allocation and liberation. Especially, in C++ programs, they tend ...
 
A Hardware Implementation of Realloc Function
Found in: VLSI, IEEE Computer Society Workshop on
By Witawas Srisa-an, Chia-Tien Dan Lo, J. Morris Chang
Issue Date:April 1999
pp. 106
The memory intensive nature of object-oriented languages such as C++ and Java has created the need of a high-performance dynamic memory management. Object-oriented applications often generate higher memory intensity in the heap region. Thus, high-performan...
 
Design and Evaluation of A Submesh Allocation Scheme for Two-Dimensional Mesh-Connected Parallel Computers
Found in: Parallel Architectures, Algorithms, and Networks, International Symposium on
By J. Morris Chang
Issue Date:December 1997
pp. 303
This paper presents the design and evaluation of a novel submesh allocation algorithm called the Optimized Buddy System which is derived from conventional binary buddy system. Our scheme is made feasible by using a bit-map to represent the status of the pr...
 
A High-Performance Memory Allocator for Object-Oriented Systems
Found in: IEEE Transactions on Computers
By J. Morris Chang, Edward F. Gehringer
Issue Date:March 1996
pp. 357-366
<p><b>Abstract</b>—Object-oriented programming languages tend to allocate and deallocate blocks of memory very frequently. The growing popularity of these languages increases the importance of high-performance memory allocation. For speed...
 
Joint Spectral Efficiency and Power Allocation Optimization in IEEE 802.16m
Found in: IEEE Transactions on Mobile Computing
By Tamer R. Omar,J. Morris Chang
Issue Date:February 2015
pp. 1
With today’s limited bandwidth, high data rate services, and energy efficiency requirements, maximizing the spectral efficiency and minimizing the consumed power becomes essential. Investigating the issues impeding spectral efficiency maximization and cons...
 
Optimizing Spectrum-Energy Efficiency in Downlink Cellular Networks
Found in: IEEE Transactions on Mobile Computing
By Chan-Ching Hsu,J. Morris Chang,Zi-Tsan Chou,Zakhia Abichar
Issue Date:September 2014
pp. 1-1
The popularity of smart mobile devices has brought significant growth of data services for mobile service providers. Mobile users of data services are charged based on the amount of data used. Raising served data amount seemingly increases the profit; ener...
 
QoS Provisioning for Wireless LANs With Multi-Beam Access Point
Found in: IEEE Transactions on Mobile Computing
By Zi-Tsan Chou,Cong-Qi Huang,J. Morris Chang
Issue Date:September 2014
pp. 1-1
Recently, the integration of smart antenna technology into existing wireless local area networks (WLANs) has been one of the hot spots of research work. In this paper, we design an IEEE 802.11-compliant medium access control (MAC) protocol, named M-HCCA, t...
 
Mobile Commerce
Found in: IT Professional
By J. Morris Chang,Joseph Williams,George Hurlburt
Issue Date:May 2014
pp. 4-5
Mobile commerce has exploded in the last five years. Learn about the factors driving this rapid growth and about the applications and issues explored in this special issue on mobile commerce.
   
Secure online banking on untrusted computers
Found in: Proceedings of the 17th ACM conference on Computer and communications security (CCS '10)
By J. Morris Chang, Wenji Chen, Yanlin Peng, Yong Guan
Issue Date:October 2010
pp. 720-722
Frauds and attacks for online banking are increasing quickly. The major platform for current online banking, personal computer, has become untrusted especially under malware attacks. In this study, we design a smart card-based solution called secure online...
     
An energy efficient garbage collector for java embedded devices
Found in: Proceedings of the 2005 ACM SIGPLAN/SIGBED conference on Languages, compilers, and tools for embedded systems (LCTES'05)
By J. Morris Chang, Paul Griffin, Witawas Srisa-an
Issue Date:June 2005
pp. 230-238
This paper presents a detailed design and implementation of a power-efficient garbage collector for Java embedded systems. The proposed scheme is a hybrid between the standard mark-sweep-compact collector available in Sun's KVM and a limited-field referenc...
     
On designing a low-power garbage collector for java embedded devices: a case study
Found in: Proceedings of the 2005 ACM symposium on Applied computing (SAC '05)
By J. Morris Chang, Paul Griffin, Witawas Srisa-An
Issue Date:March 2005
pp. 868-873
This paper presents an energy consumption comparison between two well-known garbage collection algorithms---mark-sweep-compact and reference counting. Our goal is to evaluate the suitability of reference counting as an algorithm for memory-constrained Java...
     
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