• Journal of KIISE:Software and Applications
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• v.27 no.3
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• pp.290-301
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• 2000

Most morphological analysis methods require repetitive procedures of input character code conversion, segmentation and lemmatization of constituent morphemes, filtering of candidate results through looking up lexicons, which causes run-time inefficiency. To alleviate such problem of run-time inefficiency, many systems have introduced the notion of 'pre-analysis' of words. However, this method based on pre-analysis dictionary of surface also has a critical drawback in its practical application because the size of the dictionaries increases indefinite to cover all words. This paper hybridizes both extreme approaches methodologically to overcome the problems of the two, and presents a method of morphological analysis based on pre-analysis of partial words. Under such hybridized scheme, most computational overheads, such as segmentation and lemmatization of morphemes, are shifted to building-up processes of the pre-analysis dictionaries and the run-time dictionary look-ups are greatly reduced, so as to enhance the run-time performance of the system. Moreover, additional computing overheads such as input character code conversion can also be avoided because this method relies upon no graphemic processing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.1
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• pp.42-51
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• 1997

The satellite channel with a line-of-sight signal component is modeled by a shadowed Rician fading channel. We adopt a direct-sequence / code division multiple access (DS / CDMA), which has the advantage to suppress the multipath effect and increase the user capacity. The performance which is evaluated by bit error probability is subjected to the influence of branch number, multi-user number, and spreading code-length. As the result of the analysis, performance advance is achieved with multi-user number decreasing, number of brnaches increasing, and spreading code-length increasing as chip duration is constant. To use both of diversity combining scheme and channel coding is more efficient for performance improvement than the case using diversity combining scheme only. The use of BCH coding and convolutional coding shows better consequence than Hamming coding. Totally, the performance degradation for heavy shadowing is much larger than that for light and average shadowing as heavy shadowing decreases LOS signal.

• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.373-382
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• 2004

In this paper, a register promotion technique that translates memory accesses to register accesses is presented to enhance embedded software performance. In the proposed method, a source code is profiled to generate a memory trace. From the profiling results, target functions with high dynamic call counts are selected, and the proposed register promotion technique is applied only to the target functions to save the compilation time. The memory trace of the target functions is searched for the memory accesses that result in cycle count reduction when replaced by register accesses, and they are translated to register accesses by modifying the intermediate code and allocating promotion registers. The experiments on MediaBench and DSPstone benchmark programs show that the proposed method increases the performance by 14% and 18% on the average for ARM and MCORE, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.991-998
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• 2010

The effect of increasing the elevation of an IHX (intermediate heat exchanger) on the transient performance of the KALIMER-600 reactor pool during the early phase of a loss of normal heat sink accident was investigated. Three reactors equipped with IHXs that were elevated to different heights were designed, and the thermal-hydraulic analyses were carried out for the steady and transient state by using the COMMIX-1AR/P code. In order to analyze the effects of the elevation of an IHX between reactors, various thermal-hydraulic properties such as mass flow rate, core peak temperature, RmfQ (ratio of mass flow over Q) and initiation time of decay heat removal via DHX (decay heat exchanger) were evaluated. It was found that with an increase in the IHX elevation, the circulation flow rate increases and a steep rise in the core peak temperature under the same coastdown flow condition is prevented without a delay in the initiation of the second stage of cooling. The available coastdown flow range in the reactor could be increased by increasing the elevation of the IHX.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.329-338
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• 2000

CHILL language has been used for the software development of electronic switching and telecommunications system. ETRI CHILL-96 language is an extended CHILL language with the notions of object-orientation, concurrency, and generic type. In this paper, we discuss some design and implementation issues of ETRI CHILL-96 compiler. Renaming translation rules and function restructuring techniques are adapted for the purpose of preventing name conflict and producing debugging information. Those new extended features are preprocessed in the compilation and translated to extended CHILL intermediate codes. Such compilation technique enables ETRI CHILL-96 language to hold compatibility with software developed by CHILL language.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1244-1248
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• 2008

지표수-지하수 통합모형인 SWAT-MODLFOW는 토양수가 침루과정을 거쳐 지하수로 유입되는 일방향 구조를 갖고 있어 지하수위 상승 및 하강에 따른 토양수량, 침루량, 중간유출량 등 수문성분량의 변화를 고려할 수 없다. 따라서 본 연구에서는 지하수위 변화에 따른 토양수의 분포양상 변화를 고려할 수 있도록 토양수-지하수간의 연결 구조를 양방향으로 개선하여 두 영역간의 연결성을 강화하였다. 지하수위가 상승할 경우 토양대와 지하수대간의 중첩 영역이 생기게 되는데, 이 중첩 영역을 지하수대로 간주하여 영역 내 흐름거동이 지하수 유동 메커니즘을 따르는 토양수-지하수 결합루틴을 새롭게 제시하였다. 이 결합루틴은 지하수 상승, 하강에 따라 토양수대의 두께가 변하는 가변 토양층 방식(variable soil layer method)으로 계산을 수행할 수 있도록 코드를 구성하였다. 개선된 SWAT-MODLFOW 모형을 무심천 유역에 적용하여 토양수와 지하수간의 상호작용을 해석하고 하천저지대와 같이 지하수위 상승지역에서의 수문성분량의 분포를 보다 현실적으로 구현할 수 있음을 입증하였다.

• Journal of computational fluids engineering
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• v.21 no.1
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• pp.19-29
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• 2016

A Prototype Gen-IV Sodium-cooled Fast Reactor which is one of the $4^{th}$ generation nuclear reactors is in development by Korea Atomic Energy Research Institute. The reactor is composed of four main fluid systems which are categorized by its functions, i.e., Primary Heat Transport System, Intermediate Heat Transport System, Decay Heat Removal System and Sodium-Water Reaction Pressure Relief System. The coolant of the reactor is liquid sodium and sodium-to-sodium heat exchangers are installed at the interfaces between two fluid systems, Intermediate Heat Exchangers between the Primary Heat Transport System and the Intermediate Heat Transport System and Decay Heat Exchangers between the Primary Heat Transport System and the Decay Heat Removal System. For the design and performance analysis of the Intermediate Heat Exchanger and the Decay Heat Exchanger, a computer code was written during previous step of research. In this work, the computer code named "SHXSA" has been validated preliminarily by computational fluid dynamics simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.974-979
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• 2002

There are so many kind of a control program that is applied in various process fields such as power generation plant, water treatment plant, incinerator plant, chemical plant, cement plant etc.. Because an engineer in field edits and changes and debugs and tests properly control programs using text-based control language, it is very hard for the him to apply to plant. Therefore, this research implemented a graphical tool for control program builder that is applicable to various plants and usable engineers having a little knowledge for control language. I wish to run more efficiently precision process control offering function that can see visual expression about flow of control signal and intermediate output values of control program displayed in screen using this implemented function block builder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12C
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• pp.1188-1193
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• 2007

This paper proposes a secure data forwarding scheme on source routing-based ad-hoc networks. The scheme uses two hash-key chains generated from a trusted third party to generate Message Authentication Codes for data integrity The selected MAC keys are delivered to the ad-hoc node using a pre-shared secret between the trusted third party and a node. The proposed scheme does not require the PKI, or the provisioning of the pre-shared secrets among the ad-hoc nodes.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.526-535
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• 2005

우리나라의 주민등록증은 주소지, 주민등록 변호, 얼굴사진, 지문 등 개개인의 방대한 정보를 가진다. 현재의 플라스틱 주민등록증은 위조 및 변조가 쉽고 날로 전문화 되어가고 있다. 따라서 육안으로 위조 및 변조 사실을 쉽게 확인하기가 어려워 사회적으로 많은 문제를 일으키고 있다. 이에 본 논문에서는 주민등록증 영상을 자동 인식할 수 있는 개선된 ART2 기반 RBF 네트워크와 얼굴인증을 이용한 주민등록증 자동 인식 방법을 제안한다. 제안된 방법은 주민등록증 영상에서 주민등록번호와 발행일을 추출하기 위하여 영상을 소벨마스크와 미디언 필터링을 적용한 후에 수평 스미어링을 적용하여 주민등록번호와 발행일 영역을 검출한다. 그리고 4 방향 윤곽선 추적 알고리즘으로 개별 문자를 추출하기 위한 전 단계로 주민등록증 영상에 대해 고주파 필터링을 적용하여 주민등록증 영상 전체를 이진화 한다. 이진화된 주민등록영상에서 COM 마스크를 적용하여 주민등록번호와 발행일 코드를 복원하고 검출된 각 영역에 대해 4 방향 윤곽선 추적 알고리즘으로 개별 문자를 추출한다. 추출된 개별 문자는 개선된 ART2 기반 RBF 네트워크를 제안하여 인식에 적용한다. 제안된 ART2 기반 RBF 네트워크는 학습 성능을 개선하기 위하여 중간충과 출력층의 학습에 퍼지 제어 기법을 적용하여 학습률을 동적으로 조정한다. 얼굴인증은 템플릿 매칭 알고리즘을 이용하여 얼굴 템플릿 데이터베이스를 구축하고 주민등록증애서 추출된 얼굴영역과의 유사도를 측정하여 주민등록증 얼굴 영역의 위조여부를 판별한다.