• 대한수학회지
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• 제59권3호
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• pp.439-448
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• 2022

For a natural number n, let R(n) denote the number of representations of n as the sum of one square and five cubes of primes. In this paper, it is proved that the anticipated asymptotic formula for R(n) fails for at most $O(N^{{\frac{4}{9}+{\varepsilon}})$ positive integers not exceeding N.

• 대한수학회보
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• 제58권4호
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• pp.1031-1038
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• 2021

The main aim of this article is to study quantitative structure of finite simple exceptional groups F₄(2ⁿ) with n > 1. Here, we prove that the finite simple exceptional groups F₄(2ⁿ), where 2⁴ⁿ + 1 is a prime number with n > 1 a power of 2, can be uniquely determined by their orders and the set of the number of elements with the same order. In conclusion, we give a positive answer to J. G. Thompson's problem for finite simple exceptional groups F₄(2ⁿ).

• 대한음성학회지:말소리
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• 제48호
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• pp.57-67
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• 2003

This paper presents a systematic description of exceptional pronunciations for automatic Korean pronunciation generation. An automatic pronunciation generator in Korean is an essential part of a Korean speech recognition system and a TTS (Text-To-Speech) system. It is composed of a set of regular rules and an exceptional pronunciation dictionary. The exceptional pronunciation dictionary is created by extracting the words that have exceptional pronunciations, based on the characteristics of the words of exceptional pronunciation through phonological research and the systematic analysis of the entries of Korean dictionaries. Thus, the method contributes to improve performance of automatic pronunciation generator in Korean as well as the performance of speech recognition system and TTS system in Korean.

• 대한수학회지
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• 제52권5호
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• pp.955-964
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• 2015

Let K be a number field and let S be a finite set of primes of K containing all the infinite ones. Let ${\alpha}_0{\in}{\mathbb{A}}^1(K){\subset}{\mathbb{P}}^1(K)$ and let ${\Gamma}_0$ be the set of the images of ${\alpha}_0$ under especially all Chebyshev morphisms. Then for any ${\alpha}{\in}{\mathbb{A}}^1(K)$, we show that there are only a finite number of elements in ${\Gamma}_0$ which are S-integral on ${\mathbb{P}}^1$ relative to (${\alpha}$). In the light of a theorem of Silverman we also propose a conjecture on the finiteness of integral points on an arbitrary dynamical system on ${\mathbb{P}}^1$, which generalizes the above finiteness result for Chebyshev morphisms.

• 기술혁신연구
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• 제25권2호
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• pp.153-179
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• 2017

국가연구개발사업 규모가 매년 증가함에 따라 이에 대한 간접비 금액도 증가하고 있다. 간접비는 연구개발사업의 효율적인 추진에 필요하기 때문에 이에 대한 관심도 높아지고 있다. 현재 국가 연구개발과제의 실제 간접비율이 고시비율보다 현저하게 낮다는 주장들이 있다. 하지만 이러한 실제 간접비율의 계산에 고시된 간접비율을 적용하지 않는 간접비 예외사업이 포함되어 낮게 나타난 것으로 파악되고 있다. 그런데 간접비 예외사업은 고시간 접비율의 적용이 곤란한 사업적 특성을 가지고 있는 사업에 한정하여야 하는데, 이에 대한 검토가 미흡한 실정이다. 따라서 간접비 고시비율 예외 적용사업의 타당성을 검토하고, 당해 사업에서 간접비 발생 원인을 탐색하여 적정한 간접비 지급기준을 설정할 필요가 있다. 본 연구에서는 현행 국가연구개발사업의 간접비 고시비율 예외사업을 조사하고, 정률 예외사업의 원가동인을 탐색하여 적정한 간접비 지급기준을 설정함으로써 합리적인 사업관리 방안을 모색하고자 하였다. 원가동인을 탐색하기 위하여 우선 정률예외사업에 대한 특성과 비목구조를 분석하였다. 분석 결과, 4개의 정률예외사업별로 각각 비목 구성의 고유한 특성이 도출되었다. 기반구축사업에서는 연구장비재료비의 비중이 50%로서 가장 높게 나타났으며, 인력양성사업에서는 학생인건비의 비중이 43%로 가장 높게 나타났다. 국제공동예산사업에서는 국제활동비를 식별할 수 없었으나, 연구장비재료비의 비중이 50%로 가장 높으며, 연구활동비가 31%의 비중을 차지하고 있었다. 하지만 평가조정사업은 내부인건비(37%), 연구과제추진비(21%), 연구활동비(19%) 순으로 나타나고 있으며, 기관별로 큰 차이가 없어서 예외적용사업이 아닌 일반사업으로 분류하는 것이 타당한 것으로 판단되었다. 본 연구에서는 이러한 각 사업별로 비목 구성비율의 특성에 따른 원가동인을 고려하여 조정간접비율을 산정하는 식을 마련하였다. 이를 통해 다음과 같이 우리나라 정률예외사업에 적용될 고시 간접비율 설정방안 세 가지를 제시하였다. 1) 사업 특성별로 거액 비목은 간접 비율 계산에서 제외하고 고시비율 적용한다. 2) 정률예외사업을 분리하여 별도의 고정간접비율 적용한다. 3) 고시사업과 통합하되 특정 거액 비목은 제한을 설정하여 고시비율 적용한다. 본 연구는 국가연구개발 정률예외사업에 대하여 처음으로 원가구조를 분석하고, 합리적인 간접비 설정방안을 제시하였다는 데에 그 의의가 있다. 간접비는 직접비와 함께 국가연구개발사업을 효과적으로 수행하는 데에 기여한다. 따라서 본 연구에서 제시된 간접비 고시비율 예외적용 기준안을 통해 국가연구개발사업을 수행하는 연구기관에 실소요 간접비를 지원함으로써 연구개발사업의 효율적 추진을 도모할 것으로 기대된다.

• Genomics & Informatics
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• 제2권3호
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• pp.131-133
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• 2004

MediScore is an information retrieval system, which helps to search for the set of genes associated with a specific disease or the set of diseases associated with a specific gene. Despite recent improvement of natural language processing (NLP) and other text mining approaches to search for disease associated genes, many false positive results come out due to diversity of exceptional cases as well as ambiguities in gene names. In order to overcome the weak points of current text mining approaches, MediScore introduces statistical normalization based on binomial to normal distribution approximation which corrects inaccurate scores caused by common words not representing genes and interactive rescoring by the user to remove the false positive results. Interactive rescoring includes individual alias scoring for each gene to remove false gene synonyms, referring MEDLINE abstracts, and cross referencing between OMIM and other related information.

• 한국기계가공학회지
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• 제20권10호
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• pp.1-8
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• 2021

Cylinder liners used in diesel engines of combat equipment are prone to cavitation due to wet cooling. The damage caused by erosion and corrosion due to cavitation has a fatal effect on the performance and lifespan of a diesel engine. Therefore, a study was conducted to improve the durability of cylinder liners. Two surface treatment techniques were proposed: nitriding and chrome plating. It was observed that the amount of erosion on the surface of nitride-treated cylinder liners was high because the surface-treated part eroded due to its weak impact resistance against the bubble explosion generated by cavitation. In contrast, the chrome-plated cylinder liner had a lower amount of erosion among the specimens subjected to the accelerated test. These results verified that the resistance of chrome-plated liners against cavitation is high. Therefore, it can withstand the impact of bubble explosion. If the chrome plating thickness is set with reference to the KS standard, an exceptional durability of abrasion, wear resistance, and corrosion resistance can be obtained. If the thickness is set between 120~250㎛, it is expected that the durability of the cylinder liner can be improved. Although a recovery method for corroded cylinder liners is suggested, the proposed method has an inherent risk of crack generation. Therefore, further research is required to solve this problem.

• 한국지능시스템학회논문지
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• 제8권6호
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• pp.58-69
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• 1998

This paper introduces a novel neuro-fuzzy system based on the polynomial fuzzy neural network(PFNN) architecture. The PFNN consists of a set of if-then rules with appropriate membership functions whose parameters are optimized via a hybrid genetic algorithm. A polynomial neural network is employed in the defuzzification scheme to improve output performance and to select appropriate rules. A performance criterion for model selection, based on the Group Method of DAta Handling is defined to overcome the overfitting problem in the modeling procedure. The hybrid genetic optimization method, which combines a genetic algorithm and the Simplex method, is developed to increase performance even if the length of a chromosome is reduced. A novel coding scheme is presented to describe fuzzy systems for a dynamic search rang in th GA. For a performance assessment of the PFNN inference system, three well-known problems are used for comparison with other methods. The results of these comparisons show that the PFNN inference system outperforms the other methods while it exhibits exceptional robustness characteristics.

• Management Science and Financial Engineering
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• 제6권1호
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• pp.1-19
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• 2000

This papeer proposes a general approach of the multivariate expontially weighted moving average(MEWMA) chart, in which the smoothing matrix has full elements instead of only diagonal elements. The average run length (ARL) properties of this scheme are examined for a diverse set of quality control environments and the information to design the chhart is provied. Performance of the scheme is measured by estmating ARL and compared to those of two group cumulative sum (CUSUM) chats. The comparison resullts show that the MEWMA chart can improve its ARL performance in detecting a small shifts out-of-control in the start-up stage, the general MEWMA chart of a full smoothing matrix appears to offer an exceptional protection aginst departures from control in the process mean.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.329-338
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• 2011

Business processes are often of long duration, and include internal worker's decision making, which makes business processes to be exposed to many exceptional situations. These properties of business processes makes it difficult to design processes to support uncertainties from internal or external environments. The behavioral properties of business processes mainly depends on the data aspects of business processes. To formalize the data aspect of process modeling, this paper proposes a graph-based model, called Data Dependency Graph (DDG), constructed from dependency relationships specified between business data. The paper also defines a mechanism of describing a set of mapping rules that generates a process model semantically equivalent to a DDG, which is accomplished by allocating data dependencies to component activities.