• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.326-334
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• 1999

There are the fault tolerance technology and the fault avoidance technology to analyze and evaluate the performance of computer system. To improve the relibility of software The N-Version Programming (NVP) technology is known to be the most objective and quantitive. However, when discrete probability distribution is used as estimation model, the values of it's component reliability should be same. In this paper, to resolve this problem, we adapted the genetic algorithms to NVP technology and implement the optimized simulate. and the results were analyzed and estimated. Through this study, we could optimize the reliability of each component and estimate the optimum count in the system reliability.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.2
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• pp.245-256
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• 2016

Prediction of TBM performance is very important for machine selection, and for reliable estimation of construction cost and period. The purpose of this research is to analyze the evaluation process of various prediction models for TBM performance and applied methodology. Based on the solid literature review since 2000, a classification system of TBM performance prediction model is proposed in this study. Classification system suggested in this study can be divided into two stages: selection of input parameter and application of prediction techniques. We also analyzed input and output parameters for prediction model and frequency of use. Lastly, the future research and development trend of TBM performance prediction is suggested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1343-1352
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• 1992

This paper presents a new and easy method to obtain the Fourier transforms of the n-th order cosine-pulses whose maximum amplitudes are uniform. The new method is focused on deriving a formula which is recursively related following their orders and can be well applied to some numerical solutions. On the other hand, this method also offers more compact procedures in view of analytical solutions than the conventional methods because the results are consist of the sum of two functions which are easily calculated. Especially, the formula can be represented as a complete recursion by the separation of coefficients originated by the authors and the resulting difference equation is given by the sum of the original 'sinc' functions shifted by some symmetrical factors and multiplied by some constants. The constants are easily decided from the binomial coefficients and the shifting factors from the corresponding exponential differences in the expansion of $(a+b)^n$.

• Journal of KIISE:Software and Applications
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• v.28 no.12
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• pp.910-920
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• 2001

We developed a SIFC(Slice-based Information Flow Graph) For modeling the information flow on program on the basis of the information flow of a data tokens on program slices. Then we defined a SCM(Slice-based Complexity Measure) for measuring the program complexity by measuring the complexity of information flow on SIFG, We showed that, according to Zuse's approach, it assumed ordinal scale based on atomic modifications on SIFG and that it was additive to binary operation MBSEQ and that it was not additive to binary operation MBALT but satisfied Weyuker's 9th axiom. Also based on comparison with the existing measures, we showed that SCM could measure not only the control and data flow in program but also the physical size of program.

• The Transactions of the Korea Information Processing Society
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• v.2 no.4
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• pp.477-486
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• 1995

This paper describes and constructs object-oriented analysis models using Galois-lattices that we are always studying in discrete mathematics, shows fundamental approaches to maintain the models, analyzes the construction of object-oriented analysis models through good examples. Also, we define several properties of Galois-lattices that have binary relations between class objects, propose the incremental updating algorithms that can update the Galois-lattice whenever new classes are added. This proposal shows that in case of adding new class nodes the results from simulations can implement in constant time and have linearly the incremental structures in worst cases, and in that the growth rate of lattices is proportioned to class nodes in time complexity. This results can achieve the high understandability of object-oriented analysis models and the high traceability of maintenance models. Furthermore it is possible to make more efficient performances of class reusability in advantages of object-oriented systems and support truly the class hierarchical maintenances.

• The Journal of Information Technology and Database
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• v.5 no.1
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• pp.13-37
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• 1998

인터넷 등의 컴퓨터 통신 네트워크의 발달로 인하여 분산된 정보자원의 공유를 통한 자원에 대한 재사용성의 필요성이 대두되었다. IRD(Information Resource Dictionary)는 조직 내에서 관련된 모든 정보에 대한 데이터가 논리적으로 중앙화된 정보저장소(repository)이다. IRD 내의 데이터는 다른 데이터를 기술하므로 이른바 메타 데이터라고 하기도 한다. IRD의 사전(dictionary) 요소는 정보자원의 종류, 정보자원의 의미, 정보자원의 논리적 구조, 정보자원의 위치, 그리고 정보자원의 접근방법 등을 기술한다. FIPS ANSI의 IRDS는 이항 관계를 이용하여 무결성 제약조건을 표현하므로 제약조건 규칙의 표현과 일반적인 추론 규칙의 표현이 제한되어 있으며, 다양한 형태의 무결성 제약조건의 표현과 IRD와 관련된 여러 정보의 도출 또는 추론 및 관리에 관한 사항은 IRD 응용 고유의 문제로 간주하여 언급하고 있지 않다. 한편, FIPS IRDS는 사용자가 SQL 및 IRD에 대한 전문적 지식이 없이는 사용자 질의 작성이 어려운 점등에 대한 문제점을 안고 있다. 본 논문은 FIPS IRDS의 기본모델에서 정보자원 표현, 정보자원들간의 관계, 정보자원의 관리 정보 구분을 명확히 하기 위해 정보자원 모델을 정보자원 표현요소와 정보자원 관리요소의 두 부류로 나누어 구분하고, 각 부류에 대한 자격 질의(competency question)를 통하여 유추된 요소들을 FIPS ANSI IRDS 기본 모델의 스키마 기술 레벨과 스키마 레벨에 첨가함으로써 그 기본 모델을 확장한다. 그리고, FIPS ANSI IRDS가 제공하는 IRD 기술과 관리 기능을 그대로 포함하면서 앞에서 문제점으로 지적된 제약조건 표현과 추론규칙 표현을 위하여 확장된 기본 모델을 중심으로 각 레벨의 구성 요소들의 형식적 의미(formal semantics)와 레벨 내 혹은 레벨 구성요소들간의 관계성(relationship), 그리고 제약조건의 표현과 질의 추론 규칙들을 식별하여 FOPL(First Order Predicate Logic)로 표현한다. 또한, 본 논문은 FOPL로 표현된 predicate들과 규칙들을 구현하기 위하여 Prolog로 변환하기 위한 이론적 방법론을 제시하고 정보자원 관리를 위한 기본 함수들과 스키마 진화(schema evolution)를 위한 방법론을 제안한다.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.448-453
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• 2023

대규모 언어 모델 (Large Language Model, LLM)을 인간의 선호도 관점에서 평가하는 것은 기존의 벤치마크 평가와는 다른 도전적인 과제이다. 이를 위해, 기존 연구들은 강력한 LLM을 평가자로 사용하여 접근하였지만, 높은 비용 문제가 부각되었다. 또한, 평가자로서 LLM이 사용하는 주관적인 점수 기준은 모호하여 평가 결과의 신뢰성을 저해하며, 단일 모델에 의한 평가 결과는 편향될 가능성이 있다. 본 논문에서는 엄격한 기준을 활용하여 편향되지 않은 평가를 수행할 수 있는 평가 프레임워크 및 평가자 모델 'FubaoLM'을 제안한다. 우리의 평가 프레임워크는 심층적인 평가 기준을 통해 다수의 강력한 한국어 LLM을 활용하여 연쇄적 사고(Chain-of-Thought) 기반 평가를 수행한다. 이러한 평가 결과를 다수결로 통합하여 편향되지 않은 평가 결과를 도출하며, 지시 조정 (instruction tuning)을 통해 FubaoLM은 다수의 LLM으로 부터 평가 지식을 증류받는다. 더 나아가 본 논문에서는 전문가 기반 평가 데이터셋을 구축하여 FubaoLM 효과성을 입증한다. 우리의 실험에서 앙상블된 FubaoLM은 GPT-3.5 대비 16% 에서 23% 향상된 절대 평가 성능을 가지며, 이항 평가에서 인간과 유사한 선호도 평가 결과를 도출한다. 이를 통해 FubaoLM은 비교적 적은 비용으로도 높은 신뢰성을 유지하며, 편향되지 않은 평가를 수행할 수 있음을 보인다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.298-301
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• 2007

Magnesium alloy sheets have unique mechanical properties such as high in-plane anisotropy/asymmetry of yield stress and hardening response. The unusual mechanical behavior of magnesium alloys has been understood by the limited symmetry crystal structure of HCP metals or by deformation twinning. In the present study, the continuum plasticity models considering the unusual plastic behavior of magnesium alloy sheet were derived for a finite element analysis. A new hardening law based on two-surface model was developed to consider the general stress-strain response of metal sheets such as Bauschinger effect, transient behavior and the unusual asymmetry. Three deformation modes observed during the continuous tension/compression tests were mathematically formulated with simplified relations between the state of deformation and their histories. In terms of the anisotropy and asymmetry of the initial yield stress, the Drucker-Prager's pressure dependent yield surface was modified to include the anisotropy of magnesium alloys.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.412-424
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• 2022

Since traditional derivative-based optimization for noisy simulation shows bad performance, evolutionary algorithms are considered as substitutes. Especially in case when outputs are binary, more simulation trials are needed to get near-optimal solution since the outputs are discrete and have high and heterogeneous variance. In this paper, we propose a genetic algorithm called SARAGA which adopts dynamic resampling and fitness approximation using surrogate. SARAGA reduces unnecessary numbers of expensive simulations to estimate success probabilities estimated from binary simulation outputs. SARAGA allocates number of samples to each solution dynamically and sometimes approximates the fitness without additional expensive experiments. Experimental results show that this novel approach is effective and proper hyper parameter choice of surrogate and resampling can improve the performance of algorithm.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1103-1111
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• 2000

The hyper-geometric distribution software reliability growth model (HGDM) usually assumes that all the software faults detected are perfectly removed without introducing new faults. However, since new faults can be introduced during the test-and-debug phase, the perfect debugging assumption should be relaxed. In this context, Hou, Kuo and Chang [7] developed a modified HGDM for imperfect debugging environment, assuming tat the learning factor is constant. In this paper we extend the existing imperfect debugging HGDM for tow respects: introduction of random sensitivity factor and allowance of variable learning factor. Then the statistical characteristics of he suggested model are studied and its applications to two real data sets are demonstrated.