• Journal of Digital Contents Society
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• v.3 no.2
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• pp.245-254
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• 2002

Currently, communication field for automation system can be divided by simple serial communication for communication between each internal devices and network base remote control system that is based on TCP/IP. In spite of great development of network, communication part for internal control is using simple RS232 base until present. Also, development techniques of system developed by object oriented program in modular programming techniques of each function unit. Currently, it developed by component base development technique that is parts unit of software. This is presented by the new alternative of software development techniques as techniques to composition independent operation unit including business logic and is connected to development of new system. Therefore, this research implemented internal communication Emulate in RS232C based on GUI that apply development techniques of component base. that is, I maked component to commnication control part between receiving and sending and, as composite it, Control part did to handling between send and receive data.

• Journal of Digital Contents Society
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• v.6 no.3
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• pp.137-142
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• 2005

CDMA scheme has received a great deal of attenttion as a multiple-access method for future mobile networks. Its main advantage: are higher radio capacity and the capacity of flexible data tranmission. And CDMA scheme is a key technology in the proposals submitted to the ITU on next generation multimedia system with integrated services, namely real-time voice services and non real-time data services. In this paper, capacity evaluation of multiple-input multiple-output(MIMO) Multi-Carrier(MC)/CDMA system is considered to mitigate multiple access interference, partial-band interference and enhance system channel capacity in wireless channel. Recently, to increase the spectrum efficiency and the link reliability, MIMO-MC/CDMA scheme is devised to exploit multi-path in a scattering wireless channel. In particular, the channel capacity of MIMO-MC/CDMA system is evaluated according to Eb/No. Mc, p and B. From the results, in order to inappropriate spacing and the signals are frequency overlapped by partial band interference, the channel capacity of MIMO-MC/CDMA system becomes substantially smaller.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.607-613
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• 2008

A monitoring system for the subway structures using prestrained FBG sensors fixed with partially stripped fibers was developed. The sensor packages had pre-strain controllable fixtures. Tensile and compressive strain of the structure could be measured without slip. The FBG sensor system was applied to the concrete lining structure in Taegu subway. Near the structure, the narrow tunnel construction, for the electric power cables and telecommunication cables, started. We wanted to measure the deformations of the subway structures due to the construction by the FBG sensor. The applied sensors had the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.301-307
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• 2021

In addition to the revival of the Internet of Things, embedded systems, which are at the core of the Internet of Things, require intelligent control as things change. Embedded systems, however, are heavily constrained by resources such as hardware, memory, time and power. When changes are needed to firmware in an embedded system, flash Memory must be initialized and the entire firmware must be uploaded again. Therefore, it is time- and energy-efficient in that areas that do not need to be modified must also be initialized and rewritten. In this paper, we propose how to upload firmware in installments to each sector of flash memory so that only firmware can be replace the firmware in the parts that need to be modified when the firmware needs to be modified. In this paper, the proposed method was evaluated using real target board, and as a result, the time was reduced by about half.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1149-1155
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• 2003

OFDM/SFH(orthogonal frequency division multiplexing/slow frequency hopping) system is the combination of OFDM communication system with frequency hopping(FH) method and OFDM/DS(orthogonal frequency division multiplexing/direct sequence) system combines the OFDM communication system with direct sequence(DS) method in terms of PN(pseudo noise) sequence. These two systems are also can be used for anti-jamming. In this study we analyze performances of OFDM/SFH system and OFDM/DS system with the equal information rate in partial band jamming and tone jamming channel. We find BER(bit error rate) in the variation of JFR(jamming fractional ratio) and JSR(jamming to signal power ratio) of the partial band jamming. Also, BER is found in the several JSR of the single tone or multi tone jamming. OFDM/DS system shows better performance than OFDM/SFH system in partial band jamming environment. OFDM/DS system has about 2.5 ㏈ SNR(signal to noise power ratio) gains than OFDM/SFH system when JFR=4/16 and JSR=0 ㏈ to meet BER=10$\^$-3/. However, OFDM/SFH system has about 3 ㏈ SNR gains than OFDM/DS system at single tone jamming of JSR=5 ㏈. In multi tone jamming, performance of OFDM/SFH system is considerably degraded than OFDM/DS system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.2
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• pp.99-112
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• 2013

This paper presents a subspace system identification for estimating the stiffness matrix and flexural rigidities of a shear building. System matrices are estimated by LQ decomposition and singular value decomposition from an input-output Hankel matrix. The estimated system matrices are converted into a real coordinate through similarity transformation, and the stiffness matrix is estimated from the system matrices. The accuracy and the stability of an estimated stiffness matrix depend on the size of the associated Hankel matrix. The estimation error curve of the stiffness matrix is obtained with respect to the size of a Hankel matrix using a prior finite element model of a shear building. The sizes of the Hankel matrix, which are consistent with a target accuracy level, are chosen through this curve. Among these candidate sizes of the Hankel matrix, more proper one can be determined considering the computational cost of subspace identification. The stiffness matrix and flexural rigidities are estimated using the Hankel matrix with the candidate sizes. The validity of the proposed method is demonstrated through the numerical example of a five-story shear building model with and without damage.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.4 s.304
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• pp.79-86
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• 2005

In this paper, we propose a new LINF(Linear Independent Non-negative Factorization) algorithm for real-time face recognition systea This system greatly consists of the two parts: 1) face extraction part; 2) face recognition part. In the face extraction Part we applied subtraction image, the detection of eye and mouth region , and normalization method, and then in the face recognition Part we used LINF in extracted face candidate region images. The existing recognition system using only PCA(Principal Component Analysis) showed low recognition rates, and it was hard in the recognition system using only LDA(Linear Discriminants Analysis) to apply LDA directly when the training set is small. To overcome these shortcomings, we reduced dimension as the matrix that had non-negative value to be different from former eigenfaces and then applied LDA to the matrix in the proposed system We have experimented using self-organized DAIJFace database and ORL database offered by AT(')T laboratory in Cambridge, U.K. to evaluate the performance of the proposed system. The experimental results showed that the proposed method outperformed PCA, LDA, ICA(Independent Component Analysis) and PLMA(PCA-based LDA mixture algorithm) method within the framework of recognition accuracy.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.189-190
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• 2003

현장에서 많이 사용되고 있는 GIS에 결함이 발생하면 치명적인 사고로 진전될 수가 있다. 본 논문은 모의 GIS내 도전성 파티클 존재시 발생되는 부분방전 신호를 절연 진단 방법중 하나인 UHF법을 이용해 부분방전시 방사되는 방사전자파의 스펙트럼을 분석해 부분방전 진전과정을 판단하였다. 이러한 연구는 현장 GIS 및 $SF_6$ 가스절연 전력설비의 전기적 신뢰성 확보를 위해 UHF 법을 이용한 절연진단 시스템 개발에 중요한 역할을 할 것으로 사료된다.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1558-1560
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• 2001

네트워크 분석기를 이용하여 GIS용 UHF 부분방전 검출장치가 CIGRE 권고안을 만족시킴을 보일 수 있는 방법을 제안하였다. 이 방법은 운전중인 GIS에서도 활용이 가능하며 주파수 영역에서 GIS 내 부분방전신호의 감쇠율을 정확히 측정할 수 있고 측정 시스템의 개별부품에 대한 교정이 필요치 않다. 또한 측정한 GIS의 구간별 감쇠율을 이용해 센서의 종류와 부분방전검출장치 및 GIS의 구성에 따라 센서의 위치를 손쉽게 결정할 수 있다.

• The Journal of Korean Association of Computer Education
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• v.4 no.1
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• pp.19-26
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• 2001

As Operating System is a course about computer system resource management, it is very important to the computer related major students. Asynchronous concurrent processes in a Operating System class is rather difficult to understand. Because most students are not able to understands the part with the explanation and the pseudo code in a text, they need to execute the concurrent programs which are implementing the pseudo code. In this paper, we implemented executable programs using Java thread for the code and proposed those programs to apply to the Operating System education.