• 정보과학회 논문지
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• 제44권1호
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• pp.57-62
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• 2017

기존의 전통적인 한국어 형태소 분석 및 품사 태깅 방법론은 먼저 형태소 후보들을 생성한 뒤 수많은 조합에서 최적의 확률을 가지는 품사 태깅 결과를 구하는 두 단계를 거치며 추가적으로 형태소의 접속 사전, 기분석 사전 및 원형복원 사전 등을 필요로 한다. 본 연구는 기존의 두 단계 방법론에서 벗어나 심층학습 모델의 일종인 sequence-to-sequence 모델을 이용하여 한국어 형태소 분석 및 품사 태깅을 추가 언어자원에 의존하지 않는 end-to-end 방식으로 접근하였다. 또한 형태소 분석 및 품사 태깅 과정은 어순변화가 일어나지 않는 특수한 시퀀스 변환과정이라는 점을 반영하여 음성인식분야에서 주로 사용되는 합성곱 자질을 이용하였다. 세종말뭉치에 대한 실험결과 합성곱 자질을 사용하지 않을 경우 97.15%의 형태소 단위 f1-score, 95.33%의 어절단위 정확도, 60.62%의 문장단위 정확도를 보여주었고, 합성곱 자질을 사용할 경우 96.91%의 형태소 단위 f1-score, 95.40%의 어절단위 정확도, 60.62%의 문장단위 정확도를 보여주었다.

• Coupled systems mechanics
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• 제7권5호
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• pp.555-581
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• 2018

The moment-resistant steel frames are frequently used as a load-bearing structure of buildings. Global response of a moment-resistant frame structure strongly depends on connections behavior, which can significantly influence the response and load-bearing capacity of a steel frame structure. The analysis of a steel frame with included joints behavior is the main focus of this work. In particular, we analyze the behavior of two connection types through experimental tests, and we propose numerical beam model capable of representing connection behavior. The six experimental tests, under monotonic and cyclic loading, are performed for two different types of structural connections: end plate connection with an extended plate and end plate connection. The proposed damage-plasticity model of Reissner beam is able to capture both hardening and softening response under monotonic and cyclic loading. This model has 18 constitutive parameters, whose identification requires an elaborate procedure, which we illustrate in this work. We also present appropriate loading program and arrangement of measuring equipment, which is crucial for successful identification of constitutive parameters. Finally, throughout several practical examples, we illustrate that the steel structure connections are very important for correct prediction of the global steel frame structure response.

• 열처리공학회지
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• 제22권1호
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• pp.16-22
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• 2009

The rolling process is an efficient and economical approach for the manufacturing of plate metals. In the rolling process, the temperature variation is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. Also the exit plate thickness is mainly affected by the rolling conditions such as mill modulus, plate thickness and plate width. Hence the thickness variation in top-end is also dependent on these factors. Therefore this study has concentrated on determining the correct amounts of thickness variation due to top-end temperature drop and process parameters.

• 한국생산제조학회지
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• 제8권2호
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• pp.116-116
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• 1999

In this study we propose a novel approach with which design engineers can define and design free-from surface more easily. Free-from surface is defined as a parameterics shape which consists of a set of contr ol points. Parametric shape which not only has the advantage of allowing users to perform design changes efficiently, but also provides designers with a natural design environment in which they can do their work more naturally and creatively. The objective of this study is to develop a PC level freeform surface modelling system which explicitly represents information of part geometry. In this study, freeform surface modeling system consist of three modules : freeform surface modeler, input/output modules and interface with Database. In recent year there are increasing demands for the 5-axis machining of a complicated shape. This study is the development of a CAM software system (or NC module) for the 5-axis machining of a general shape with a flat-end mill, a round-end mill, a ball-end mill.

• 한국공작기계학회논문집
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• 제15권5호
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• pp.79-84
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• 2006

In modem manufacturing, many products that have geometrically complicated features, including three-dimensional sculptured surfaces, are designed and produced. In the production of these complex-shaped mechanical components, e.g. automobile dies, molds, and various engineering applications, the ball-end milling process is one of the most widely used NC machining processes that consists of roughing, semi-finishing and finishing. In semi-finishing, cusps remained after roughing according to the used tools that have two patterns of stairs and wave shapes. These cusp shapes have air-cut in cutting and instability caused by high cutting speed that affects the cutting characteristics such as cutting force and tool wear. Cutting characteristics are measured and analyzed through cutting force, FFT analysis of cutting force and tool wear along cutting length according to low tool paths with same metal removal rate. As a results of the experiments, this study suggests the optimal conditions of tool path and cutting direction. This approach for the cutting characteristics of semi-finishing provides a useful aid for the productivity and efficiency improvements of NC machining processes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권12호
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• pp.3071-3095
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• 2013

Configuring optimization of wireless sensor networks, which can improve the network performance such as utilization efficiency and network lifetime with minimal energy, has received considerable attention in recent years. In this paper, a cross layer optimal approach is proposed for multi-source linear network and grid network under Rayleigh block-fading channels, which not only achieves an optimal utility but also guarantees the end-to-end reliability. Specifically, in this paper, we first strictly present the optimization method for optimal nodal number $N^*$, nodal placement $d^*$ and nodal transmission structure $p^*$ under constraints of minimum total energy consumption and minimum unit data transmitting energy consumption. Then, based on the facts that nodal energy consumption is higher for those nodes near the sink and those nodes far from the sink may have remaining energy, a cross layer optimal design is proposed to achieve balanced network energy consumption. The design adopts lower reliability requirement and shorter transmission distance for nodes near the sink, and adopts higher reliability requirement and farther transmission distance for nodes far from the sink, the solvability conditions is given as well. In the end, both the theoretical analysis and experimental results for performance evaluation show that the optimal design indeed can improve the network lifetime by 20-50%, network utility by 20% and guarantee desire level of reliability.

• 경영과정보연구
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• 제24권
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• pp.45-71
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• 2008

These days the international environmental regulations of the developed countries, especially from the EU, are rapidly changed to the regulations of product-based environment from a conventional end-of-pipe environmental technology. Especially the motive in this paper come from the EU's electrical and electronic equipment environment regulation. It may affect much to whole export of Korea Firms Integrated product policy has the potential to increase not only competitive power in today's global market, but also trade compatibility between countries. Furthermore it is important to make a contribution to sustainable development. CEOs must change their notions about firms' environmental policy from the end-of-pipe approach to the sustainable approach to improve company's competitive power. As emphasized a paradigm of naw environmental management by EU' environmental directives, the company must establish clean production system to save resources and reduces pollutant. Also Korean Company constructs a systematical network to collect EU' environmental regulation information which are changing rapidly. Large company will cooperate with small and medium-sized firm for their win-win strategy in the field of environmental management. Also it is necessary to make the domestic regulations of product-based environment to meet the international environmental regulations.

• 한국수학사학회지
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• 제16권4호
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• pp.33-44
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• 2003

This article shows Hilbert's Paris address within the context of his career and the mathematics of his day. And the text of Hilbert's speech will be considered in some detail, particularly those parts of it that reflects his vision of mathematics most clearly. At the end it is attempted to show the limitations of the standard view of Hilbert as an advocate of a formalist approach to mathematics.

• 한국콘텐츠학회논문지
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• 제19권4호
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• pp.609-620
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• 2019

이 연구는 강 절도 범죄의 공범실행 과정을 전반적으로 살펴보는데 그 목적이 있다. 이를 위하여 2013년 한국형사정책연구원에서 '공범 있는 범죄의 구조와 특성에 관한 연구: 강 절도를 중심으로'를 수행하기 위해 수집된 심층 면접 자료를 이차자료로 활용하였으며, 이차자료를 통해 근거 이론적 접근을 시도하였다. Strauss&Corbin(1990)이 제시한 절차에 따라 사례를 분석한 결과, 개방코딩 단계는 51개의 개념과 22개의 하위 범주, 8개의 상위 범주가 도출되었다. 축코딩 단계는 '코딩 패러다임(coding paradigm)'이라는 분석도구에 따라 인과적 조건은 강 절도 범행원인이다. 맥락적 조건은 공범관계 형성과 공범선택 이유이다. 중심현상은 강 절도 공범실행이다. 중재적 조건은 공범 간 갈등과 검거요인 발생이다. 작용/상호작용 전략은 공범 모두 검거이다. 결과는 공범관계 종료로 구성되었다. 마지막으로 선택코딩 단계는 '공범관계 형성과 종료 사이의 갈등전개'를 핵심범주로 선정하였고, '형성-실행-갈등-검거-종료'라는 과정을 통하여 강 절도의 공범관계를 새롭게 정립하였다.

• 스마트미디어저널
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• 제11권9호
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• pp.9-20
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• 2022

심층강화학습은 자율주행 도메인에서 널리 사용되는 end-to-end 데이터 기반 제어 방법이다. 그러나 기존의 강화학습 접근 방식은 자율주행 과제에 적용하기에는 비효율성, 불안정성, 불확실성 등의 문제로 어려움이 존재한다. 이러한 문제들은 자율주행 도메인에서 중요하게 작용한다. 최근의 연구들은 이런 문제를 해결하고자 많은 시도가 이루어지고 있지만 계산 비용이 많고 특별한 가정에 의존한다. 본 논문에서는 자율주행 도메인에 불확실성 순차 모델링이라는 방법을 도입하여 비효율성, 불안정성, 불확실성을 모두 고려한 새로운 알고리즘 MCDT를 제안한다. 강화학습을 높은 보상을 얻기 위한 의사 결정 생성 문제로 바라보는 순차 모델링 방식은 기존 연구의 단점을 회피하고 효율성과 안정성을 보장하며, 여기에 불확실성 추정 기법을 융합해 안전성까지 고려한다. 제안 방법은 OpenAI Gym CarRacing 환경을 통해 실험하였고 실험 결과는 MCDT 알고리즘이 기존의 강화학습 방법에 비해 효율적이고 안정적이며 안전한 성능을 내는 것을 보인다.