• KIISE Transactions on Computing Practices
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• v.22 no.3
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• pp.151-156
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• 2016

Cloud computing systems require a huge number of storage servers due to the growing implications of power bills, carbon emissions, and logistics of data centers. These considerations have motivated researchers to improve the energy efficiency of storage servers. Most servers use a lot of power irrespective of the amount of computing that they are doing, and one important goal is to redesign servers to be power-proportional. However, Research on large-scale storage systems is hampered by their cost. It is therefore desirable to develop a scalable test-bed for evaluating the power consumption of large-scale storage systems. We are building on open-source projects to construct a test-bed which will contribute to the assessment of power consumption in tiered storage systems. Integrating the cloud application platform can easily extend the proposed testbed laying a foundation for the design and evaluation of low-power storage servers.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.1-8
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• 2012

In this paper, we consider an efficient protocol for the multi-hop relay transmission on a sensor network which can be utilized in a ubiquitous environment. More specifically, we propose an efficient relaying protocol for the distance and position recognition on the proposed sensor network which performs with the differentially bi-orthogonal chirp spread spectrum (DBO-CSS) in the industrial, scientific and medical (ISM) bands. For an efficient networking access, we design and implement four different packet structures, zone information packet, hop information packet, tag information packet, and application serial packet. Additionally, we also propose an efficient position recognition algorithm. Finally, for verification of our proposed protocol's efficiency, we build the testbed system which consists of $15m{\times}15m$ multi-cell and 10 hops in the network.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1376-1384
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• 2008

Numerous researches on network self-configuration have been conducted on Wireless Sensor Network (WSN) and Ad Hoc network but the results have not been applied yet for factory automation. This paper presents development of intelligent process management systems conducting process monitoring and control irrelevant to physical position of a plant operator. The systems are indispensable for diagnosis of rotating machines which cannot exploit wired network. The system was implemented in a Personal Digital Assistant (PDA) using Bluetooth communication protocol. When a mobile terminal reaches to communication range of the process management server, the server detects the mobile terminal to reconfigure plant network automatically. The server authenticates a user of the terminal to download and installs monitoring and control program considering authorized level of the user. If the terminal leaves communication range of the server, it deletes the node from the network and removes the program automatically to save resources and prevent security problems such as missing terminal. Operation of developed functions was verified in a testbed emulating steel-making plant.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.455-460
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• 2008

건설교통부는 국가미래에 대비해 실질적으로 기여할 수 있는 전략적이고 중장기적인 실효성 있는 R&D 혁신 로드맵인 VC-10 사업을 진행하고 있다. 이 과제의 핵심 기술 중에 하나인 유비쿼터스 센서네트워크는 초소형 센서들로 구성된 망으로써 환경 및 재난 재해, u-City 건설, 스마트 하이웨이, 방범 및 국방, 시설 관리, 유통, 등과 같은 다양한 분야에 사용할 수 있는 유비쿼터스 사회의 핵심 요소이다. 이것은 실시간 네트워크를 통해 전송 또는 관리되고 언제, 어디서나, 어떠한 대상과 의사소통이 가능한 지능형 컴퓨팅 환경을 구현하는 것이다. 그러나 이러한 기술을 바탕으로 하는 기존의 시스템들은 특정분야를 위한 독자적인 프로토콜이나 저전력 통신을 제공하는 ZigBee 기반으로 설계되었기 때문에 소규모 범위에서만 서비스 제공이 가능하며 시스템간의 연동이 어렵다. 따라서 본 논문에서는 유비쿼터스 센서네트워크간의 연동성을 고려한 대규모 실시간 모니터링 시스템을 설계하여 다양한 분야로 서비스할 수 있는 테스트베드 구축에 대한 방안을 제시하고자 한다. 여기서 모니터링 대상은 국토의 지반, 환경, 그리고 도심지역 등이다. 이렇게 제시된 방안은 국내실정에 적합한 모니터링 시나리오를 작성하여 테스트베드를 구축 시에 요구된 사항들에 대한 정당성을 입증한다.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.307-319
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• 2014

Because of the rapid rising of water related disasters due to the global warming, the extreme design criteria of levee construction for severe flood has been applied in several developed countries such as USA and Netheland. In Korea, the national river restoration projects were carried out on 4 major rivers in recent several years. The projects consisted of riverbed dredge and levee reinforcement, and new construction have caused wide change of river environment. However, concrete countermeasures for levee safety and river management have not been suggested until now. Therefore, this study assesses the levee safety of Yulji levee located in Hoechon, Nakdong Basin, where the Levee Seepage Monitoring System installed. The stability of levee is assessed based on the simulation performed by SEEP/W(2D unsaturated seepage model) and the simulated results are compared with the observed data. The effects of the flood wave and levee shape on the levee safety are investigated through several simulations.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.125-135
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• 2003

In this paper, we developmed and implemented router and bandwidth broker that provides end-to-end QoS in differentiated service IP networks. Our design goal is to provide end-to-end premium service using the EF PHB. The bandwidth broker and router were implemented in the FreeBSD 4.6 platform. For the DiffServ router, we implemented QoS daemon, rollback managment routine, monitoring, and COPS-PR client. Also, Ive implemented bandwith broker which has SLS and resource management function, and signaling protocols for interfacing intra-and inter-domain. On the testbed, we have validated and evaluated the performance of the implemented DiffServ router and bandwidth broker using the inter-domain signaling protocol client in MS Windows platform. The test results show that the end-to-end QoS can be guaranteed for the inter-domain diffServ by the implemented system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.15-24
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• 2006

We design and implement explicit mobile multicast, named XMIP, by enhancing explicit multicast for a great number of small group multicast communications. XMIP is a straightforward multicast mechanism without maintaining multicast states due to the inheritance from the explicit multicast based on a unicast routing. This research modifies and extends the functionality of each mobility agent of IETF Mobile IP for interworking XMIP XMIP Packets captured by an extended home agent are forwarded to each extended foreign agent through nested tunnels, named X-in-X tunnels, made by the binding table of the extended home agent. X-in-X tunneling mechanism can effectively solve the serious traffic concentration problems of Mobile IP multicast specifications. Finally heterogeneous mobile networks as an XMIP testbed including CDMA2000 1X EV-DO and WLAN are actually established, and a multi-user instant messenger system for small group communications is developed for verifying the feasibility of the proposed protocols.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.12
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• pp.42-53
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• 2011

As IT industry using networks have been developed explosively, online operations that were conducted in offline are increasing rapidly, and even relationship with other people made online. As online crimes are increasing accordingly, building security networks is getting very important. As a result, network separation between business and organization network has been performed recently, but this causes network user inconvenience and efficiency reduction. In this paper, we propose reassociation methods for already separated networks for many public organizations. We implement two reassociation methods using NAT device and shared storage and show their experimental results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.101-108
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• 2007

Parallel processing algorithms, coupled with advanced networking and distributed computing architectures, improve the overall computational performance, dependability, and versatility of a digital signal processing system In this paper, novel parallel algorithms are introduced and investigated for advanced sonar algorithm, conventional matched-field processing (CMFP). Based on a specific domain, each parallel algorithm decomposes the sequential workload in order to obtain scalable parallel speedup. Depending on the processing requirement of the algorithm, the computational performance of the parallel algorithm reveals different characteristics. The high-complexity algorithm, CMFP shows scalable parallel performance on the array of DSP processors. The impact on parallel performance due to workload balancing, communication scheme, algorithm complexity, processor speed, network performance, and testbed configuration is explored.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.955-962
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• 2016

In recent years, there have been emerging needs for standardized software-based motion application development for better scalability and support for multiple operation modes for small quantity batch production. Although a software-based motion system provides a basis for constructing multiple operation modes on a machine, it is not easy to construct such systems without tools for defining multiple motion operation modes and standardized mode-change protocols. This paper proposes a motion recipe concept to overcome this problem; the concept includes the authoring of multiple motion operation modes using the PLCopen-compliant motion function blocks and communication protocols to trigger operation mode changes from an external interface. The motion recipe was implemented by extending an IEC 61131-3 compliant IDE called Beremiz, and the correctness of the motion recipe-based application behavior was verified on a real testbed.