• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1815-1818
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• 2002

사용자에게 서비스 할 데이터가 많을 경우 데이터베이스의 여러 볼륨에 저장해서 처리해야 할 경우가 발생한다. 볼륨이 여러 개일 경우 효과적이고 효율적인 접근 방법이 필요하다. 본 논문에서는 SHORE 저장 시스템을 이용할 경우에 효과적이고 효율적인 접근 방법을 알아보고자 한다. single thread, multi thread, multi process, socket 을 이용한 접근 방법을 살펴보고 multi thread 를 이용하는 방법이 가장 효율적인 것을 실험 결과를 통해서 보인다. SHORE thread 는 CPU bound 에 과련된 job 이 많은 경우는 process 를 사용했을 때에 비해 큰 효과가 없으나 I/0 bound 에 관련에 것일 경우는 multi process 를 사용한 것과 비슷한 효과가 있음을 알 수 있다.

• 대한공업교육학회지
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• v.33 no.1
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• pp.265-281
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• 2008

The objective of this study is to show practice example let student experience about concurrent servers based multi-processes and multi-thread among the principles of data communication in ICT(information and communications technology). For this, we first implement multi-process server(fork server) and multi-thread server(thread server), and multi-thread client(thread client), Secondly, for experimental environment, we developed small ethernet networks and measure data transfer time with relation to the number of users. Experimental results show that mean transfer time of thread server is less than that of fork server by 20~61 % on average. Furthermore, it is found that the difference of data transfer time between fork server and thread server is proportional to that of the number of users. Main reason of performance difference dues to the difference between process forking time and thread creation time. We can also find that context switching for process and thread affects the load of web server. Our presentation and experimental results can be applied to used as the educational practice materials with which student can experience data communication principles.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.73-76
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• 2014

With the increasing popularity of multi-core processors, they have been adopted even in embedded systems. Under this circumstance many multimedia applications can be parallelized on multi-core platforms because they usually require heavy computations and extensive memory accesses. This paper proposes an efficient thread-level parallel implementation for color space conversion on multi-core CPU. Thread-level parallelism has been becoming very useful parallel processing paradigm especially on shared memory computing systems. In this work, it is exploited by allocating different input pixels to each thread for concurrent loop executions. For the performance evaluation, this paper evaluate the performace improvements for color conversion on multi-core processors based on the processing speed comparison between its serial implementation and parallel ones. The results shows that thread-level parallel implementations show the overall similar ratios of performance improvements regardless of different multi-cores.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.245-251
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• 2011

Quantities of data in the DMS (Distribution management system) or SCADA (Supervisory control and data acquisition) system is enormously large as illustrated by the usage of term flooding of data. This enormous quantity of data is transmitted to the status data or event data of the on-site apparatus in real-time. In addition, if GIS (Geographic information system) and AMR (Automatic meter reading), etc are integrated, the quantity of data to be processed in real-time increases unimaginably. Increase in the quantity of data due to addition of system or increase in the on-site facilities cannot be handled through the currently used Single Thread format of data processing technology. However, if Multi Thread technology that utilizes LF-POOL (Leader Follower -POOL) is applied in processing large quantity of data, large quantity of data can be processed in short period of time and the load on the server can be minimized. In this Study, the actual materialization and functions of LF POOL technology are examined.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.984-989
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• 2010

In this paper, parallel programming technique by using Java Thread is introduced so as to develop parallel design tool to analyze the small micro flow sensor. To estimate computing time for Thread-level parallelism, the performances of two experimental models for potential problem subject to Thermal transfer equation are examined. As a result, if the number of network PC is increase, computing time for parallelism on network environment is enhanced to be almost n times. The micro sensor design tool based on distributed computing can be utilized to analyze a large scale problem.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1207-1211
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• 2017

Long-Reach PON (LR-PON) is a broadband access network using passive optical network (PON) technology which the reach is extended to 100 km or higher. A major challenge in LR-PON is that the propagation delay between OLT and ONUs is increased by a very significant amount. To effectively and fairly distribute the upstream bandwidth dynamically in LR-PON, we propose a new periodic and multi-thread polling based dynamic bandwidth allocation (DBA) algorithm. We compare the proposed algorithm with traditional DBAs and show its advantage on average packet delay. Numerical results are analyzed under varying offered loads.

• Journal of Information Processing Systems
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• v.18 no.1
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• pp.159-172
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• 2022

The role of the interconnect network, which connects computing nodes to each other, is important in high-performance computing (HPC) systems. In recent years, the peripheral component interconnect express (PCIe) has become a promising interface as an interconnection network for high-performance and cost-effective HPC systems having the features of non-transparent bridge (NTB) technologies. OpenSHMEM is a programming model for distributed shared memory that supports a partitioned global address space (PGAS). Currently, little work has been done to develop the OpenSHMEM library for PCIe-interconnected HPC systems. This paper introduces a prototype implementation of the OpenSHMEM library through a switchless interconnect network using PCIe NTB to provide a PGAS programming model. In particular, multi-interrupt, multi-thread-based data transfer over the OpenSHMEM shared memory model is applied at the implementation level to reduce the latency and increase the throughput of the switchless ring network system. The implemented OpenSHMEM programming model over the PCIe NTB switchless interconnection network provides a feasible, cost-effective HPC system with a PGAS programming model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1528-1534
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• 2015

This paper designed the railway vehicle running device with a proto-type for the railway vehicle maintenance training and developed a propulsion control device simulator equipped the imitation steering wheel. In addition, this paper applied a multi-thread technology in order to implement the staged fault and the propulsion control device protected operation test and an implementation of the failure that occur in actual rail vehicle and confirm the validity as the propulsion control device simulator for the maintenance training.

• Spatial Information Research
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• v.18 no.1
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• pp.57-67
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• 2010

Recently, 2D GIS technology is applied for urban facility management. However, urban facilities are located in 3D space and the information loss is occurring during data abstraction from 3D urban facility to 2D object. Also, the number of urban facilities is increasing steadily and most of urban facilities are located in underground space in the city. Therefore 2D urban facility management system has a limitation on visualization and management for a large number of urban facilities. In this paper, a multi-dimensions urban facility management system based on multi-texture technology is proposed. The proposed system reduces the information loss and improves the readability of information by visualizing urban facilities on 3D virtual space. A multi-texturing technology is applied for integrating of 2D vector data and 3D raster data, and a multi-thread technology is used for improving speed and performance of the system. The proposed technology can be used as a guideline for urban facility monitoring as providing visual information of a facility status with 3D image and facility data.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.331-339
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• 2017

This paper proposes a thread pool management technique of an websocket server that is applicable to embedded systems. WebSocket is a proposed technique for consisting a dynamic web, and is constructed using HTML5 and jQuery. Various studies have been progressing to construct a dynamic web by Apache, Oracle and etc. Previous web service systems require high-capacity, high-performance hardware specifications and are not suitable for embedded systems. The node.js which is consist of HTML5 and jQuery is a typical websocket server which is made by open sources, and is a java script based web application which is composed of a single thread. The node.js has a limitation on the performance for processing a high velocity data on the embedded system. We make up a multi-thread based websoket server which can solve the mentioned problem. The thread pool is managed by a bit register and suitable for embedded systems. To evaluate the performance of the proposed algorithm, we uses JMeter that is a network test tool.