• 인터넷정보학회논문지
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• 제5권6호
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• pp.111-120
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• 2004

소프트웨어의 생산성을 향상시키기 위해 소프트웨어 개발 단계에서 소요되는 비용을 최소화하려는 연구가 다양하게 진행되고 있다. 프로그램 개발 단계에서는 프로그램을 부분적으로 수정하게 되고 프로그램의 부분 수정인 경우에도 프로그램을 편집하여 다시 실행하는데 많은 시간이 소요된다. 프로그램을 수정할 경우 수정한 부분과 이에 영향 받는 부분만을 재실행하기 위한 점진 해석기가 필요하다. 본 논문에서는 프로그램 실행 시 동적 의미 분석 방법에 의해 점진 해석기를 구현하고자 한다. IMPLO(IMPerative Language with Object) 언어를 EBNF(Extended Backus Naur Form) 표기법으로 정의하고 동적 의미 구조를 표현하기 위해 작용식(action equation)을 사용하여 IMPLO 언어에 대한 점진 해석기(incremental interpreter)를 설계하여 구현하고자 한다.

• 정보처리학회논문지A
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• 제11A권3호
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• pp.149-156
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• 2004

소프트웨어가 대형화되고 고도화되어 감에 따라 프로그램 개발 환경에서 프로그래밍 생산성과 효율성을 향상시키기 위해 에디팅. 컴파일링, 디버깅 및 실행을 하나의 통합 환경으로 구축하는 것이 필요하다. 이러한 환경에서 중요한 도구가 되는 것이 점진 번역기이다. 본 논문에서는 소프트웨어의 재 사용성과 생산성을 향상시키기 위해, 에디팅, 디버깅, 점진 해석 및 실행을 하나의 통합 환경으로 구성하여 보다 친근하고 편리하게 사용할 수 있는 사용자 인터페이스를 제공하는 소프트웨어 개발을 위한 통합 점진 해석 시스템을 구축하고자 한다. 객체 지향 언어인 IMPLO(IMPerative Language with Object) 언어를 EBNF 표기법으로 정의하고 이 언어에 대한 점진 해석기를 구현한다. 점진 해석기를 구현하기 위해 정적 의미론을 표현하는 속성 문법을 확장하여 동적인 의미론을 표현할 수 있는 작용 식을 제시한다. 동적 의미 분석 방법에 의해 점진 해석을 수행하고 에디터와 디버거를 가진 통합 점진 해석 시스템을 Lex와 Yacc을 이용해서 C 언어로 프로그래밍하고 SUN에서 X로 구현하였다. 예제 프로그램들의 점진 실행 시간을 전체 프로그램의 실행 시간과 비교했을 때 약 50％ 정도의 속도 개선 효과를 거둘 수 있었다.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3283-3292
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• 2022

Based on the Deep Q-Network(DQN) algorithm of reinforcement learning, an active fault-tolerance method with incremental action is proposed for the control system with sensor faults of the once-through steam generator(OTSG). In this paper, we first establish the OTSG model as the interaction environment for the agent of reinforcement learning. The reinforcement learning agent chooses an action according to the system state obtained by the pressure sensor, the incremental action can gradually approach the optimal strategy for the current fault, and then the agent updates the network by different rewards obtained in the interaction process. In this way, we can transform the active fault tolerant control process of the OTSG to the reinforcement learning agent's decision-making process. The comparison experiments compared with the traditional reinforcement learning algorithm(RL) with fixed strategies show that the active fault-tolerant controller designed in this paper can accurately and rapidly control under sensor faults so that the pressure of the OTSG can be stabilized near the set-point value, and the OTSG can run normally and stably.

• 한국정보과학회논문지:소프트웨어및응용
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• 제26권8호
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• pp.1018-1027
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• 1999

속성 문법은 언어의 정적인 의미구조를 표현하는 형식적인 표기법으로 동적인 의미구조를 표현하기는 부적절하다. 동적 의미구조를 잘 명세하고 명세된 언어를 구현하기 위해서 기존의 속성 문법을 확장하여 언어 구현에 필요한 동적인 작용들(actions)을 잘 표현해야 한다. 본 논문에서는 속성 문법을 확장하여 정적이고 동적인 의미구조를 잘 표현할 수 있는 새로운 작용 식(action equation)을 제시한다. 제시된 작용 식(action equation)의 동적인 의미 구조로 부터 SIMP 언어의 점진 해석기(incremental interpreter)를 설계하고 구현한다. 점진 해석기는 언어 기반의 프로그래밍 환경에서 수정된 부분만을 번역하여 프로그램의 전체 실행 결과를 얻는 해석기를 의미한다. 본 해석기는 SUN 1000에서 Lex와 Yacc을 사용해서 C 언어로 설계하고 구현하였다. 예제 프로그램을 실행시켰을 때 배정 문이나 IF문의 경우는 매우 효율적이었고 Loop의 경우는 재실행될 필요가 있는 영향받는 명령문들이 적을수록 점진 해석이 더 효율적으로 수행된다.Abstract Attribute grammars are a formal notation which expresses the static semantics of programming languages, but they are not suitable for expressing dynamic semantics. To describe dynamic semantics and implement a specified language, we extend attribute grammars and present new action equations which describe static and dynamic semantics. The incremental interpreter of a SIMP language is designed and implemented from the dynamic semantics of presented action equations. The incremental interpreter is to translate only modified part in the language-based programming environments and have results of whole program.Our interpreter is implemented in C with Lex and Yacc on SUN 1000. When we execute example programs, the incremental evaluation of any assignment and IF statements executes efficiently. But in the case of loop, we execute efficiently when the effected statements to be reexecuted in the loop are of small number.

• Geomechanics and Engineering
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• 제36권3호
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• pp.303-316
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• 2024

Seismic records are composed of mainshock and a series of aftershocks which often result in the incremental damage to underground structures and bring great challenges to the rescue of post-disaster and the repair of post-earthquake. In this paper, the repetition method was used to construct the mainshock-aftershocks sequence which was used as the input ground motion for the analysis of dynamic time history. Based on the Daikai station, the two-dimensional finite element model of soil-station was established to explore the failure process of station under different seismic precautionary intensities, and the concept of incremental damage of station was introduced to quantitatively analyze the damage condition of structure under the action of mainshock and two aftershocks. An arc rubber bearing was proposed for the shock absorption. With the arc rubber bearing, the mode of the traditional column end connection was changed from "fixed connection" to "hinged joint", and the ductility of the structure was significantly improved. The results show that the damage condition of the subway station is closely related to the magnitude of the mainshock. When the magnitude of the mainshock is low, the incremental damage to the structure caused by the subsequent aftershocks is little. When the magnitude of the mainshock is high, the subsequent aftershocks will cause serious incremental damage to the structure, and may even lead to the collapse of the station. The arc rubber bearing can reduce the damage to the station. The results can offer a reference for the seismic design of subway stations under the action of mainshock-aftershocks.

• Smart Structures and Systems
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• 제18권1호
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• pp.139-154
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• 2016

This paper is concerned with the dynamics of hyperelastic solids and structures. We seek for a smart control actuation that produces a desired (prescribed) displacement field in the presence of transient imposed forces. In the literature, this problem is denoted as displacement tracking, or also as shape morphing problem. One talks about shape control, when the displacements to be tracked do vanish. In the present paper, it is assumed that the control actuation is provided by imposed eigenstrains, e.g., by the electric field in piezoelectric actuators, or by thermal actuators, or via analogous physical effects, such as magneto-striction or pre-stress. Structures with a controlled eigenstrain-type actuation belong to the class of smart structures. The action of the eigenstrains can be conveniently characterized by actuation stresses. Our theoretical derivations are performed in the framework of the theory of small incremental dynamic deformations superimposed upon a statically pre-deformed configuration of a hyperelastic solid or structure. We particularly ask for a distribution of incremental actuation stresses, such that the incremental displacements follow exactly a prescribed trajectory field, despite the imposed incremental forces are present. An exact solution of this problem is presented under the assumption that the actuation stresses can be tailored freely and applied everywhere within the body. Extending a Neumann-type solution strategy, it is shown that the actuation stresses due to the distributed control eigenstrains must satisfy certain quasi-static equilibrium conditions, where auxiliary body-forces and auxiliary surface tractions are to be taken into account. The latter auxiliary loading can be directly computed from the imposed forces and from the desired displacement field to be tracked. Hence, despite the problem is a dynamic one, a straightforward computation of proper actuator distributions can be obtained in the framework of quasi-static equilibrium conditions. Necessary conditions for the functioning of this concept are presented. Particularly, it must be required that the intermediate configuration is infinitesimally superstable. Previous results of our group for the case of shape control and displacement tracking in linear elastic structures are included as special cases. The high potential of the solution is demonstrated via Finite Element computations for an irregularly shaped four-corner plate in a state of plain strain.

• Steel and Composite Structures
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• 제33권3호
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• pp.389-402
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• 2019

Reinforced concrete walls and buckling restrained braces are effective structural elements that are used to resist seismic loads. In this paper, the behavior of the reinforced concrete walls coupled with buckling restrained braces is investigated. In such a system, there is not any conventional reinforced concrete coupling beam. The coupling action is provided only by buckling restrained braces that dissipate energy and also cause coupling forces in the wall piers. The studied structures are 10-, 20- and 30-story ones designed according to the ASCE, ACI-318 and AISC codes. Wall nonlinear model is then prepared using the fiber elements in PERFORM-3D software. The responses of the systems subjected to the forward directivity near-fault (NF) and ordinary far-fault (FF) ground motions at maximum considered earthquake (MCE) level are studied. The seismic responses of the structures corresponding to the inter-story drift demand, curvature ductility of wall piers, and coupling ratio of the walls are compared. On average, the results show that the inter-story drift ratio for the examined systems subjected to the far-fault events at MCE level is less than allowable value of 3%. Besides, incremental dynamic analysis is used to examine the considered systems. Results of studied systems show that, the taller the structures, the higher the probability of their collapse. Also, for a certain peak ground acceleration of 1 g, the probability of collapse under NF records is more than twice this probability under FF records.

• 한국콘텐츠학회논문지
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• 제13권12호
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• pp.62-69
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• 2013

최근 HCI, 제품디자인, 인지과학 등에서 어포던스에 대한 많은 연구가 진행되고 있다. 또한 게임분야에서도 어포던스에 대한 개념을 적용하여 게이머와 게임 시스템간의 관계를 이해하고자 하는 시도가 증가하고 있다. 그러나 게임의 특성을 고려하지 않고 기존의 HCI에서 중요하게 다루는 사용편의성, 일관성, 유용성 측면으로 연구가 진행되는 문제가 발생하고 있다. 그래서 본 연구는 생태심리학에서 제시한 어포던스(Affordance: 행동유도성) 개념을 토대로 판타지, 다양성, 재미와 같은 게임의 특징을 고려한 어포던스를 규명하는 것을 목적으로 한다. 이를 위해 게임의 기본 장르인 액션게임에서 플랫폼 액션 장르의 게임을 대상으로 게임플레이 전 과정에 대한 Think aloud 방법을 적용하여 프로토콜 분석을 실시하였다. 그 결과 고정 상태로서의 정지, 이동적 어포던스, 변형상태로서의 변형연속, 단일생성, 단일소멸 어포던스, 물리적, 인지적 어포던스가 발견되었다. 본 연구결과는 게임을 어떻게 디자인해야 할지에 대한 중요한 디자인 지침을 제시할 것으로 기대된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.45-52
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• 2003

A finite element procedure to estimate ultimate strength of space frames considering spread of plasticity is presented. The improved displacement field is introduced based on inclusion of second order terms of finite rotations. All the nonlinear terms due to bending and torsional moment as well as axial force are precisely considered. The concept of plastic hinge is introduced and the incremental load/displacement method is applied for the elasto-plastic analysis. The initial yield surface is defined based on the residual stress and the full plastification surface is considered under the combined action of axial force, bending and torsional moments. The elasto-plastic stiffness matrices are derived using the flow rule and the normality condition of the limit function. Finite element solutions for ultimate strength of space frames are compared with available solutions and experimental results.

• Structural Engineering and Mechanics
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• 제24권2호
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• pp.155-180
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• 2006

Many applications in mechanical design involve elastic bodies coming into contact under the action of the applied load. The distribution of the contact pressure throughout the contact interface plays an important role in the performance of the contact system. In many applications, it is desirable to minimize the maximum contact pressure or to have an approximately uniform contact pressure distribution. Such requirements can be attained through a proper design of the initial surfaces of the contacting bodies. This problem involves a combination of two disciplines, contact mechanics and shape optimization. Therefore, the objective of the present paper is to develop an integrated procedure capable of evaluating the optimal shape of contacting bodies. The adaptive incremental convex programming method is adopted to solve the contact problem, while the augmented Lagrange multiplier method is used to control the shape optimization procedure. Further, to accommodate the manufacturing requirements, surface parameterization is considered. The proposed procedure is applied to a couple of problems, with different geometry and boundary conditions, to demonstrate the efficiency and versatility of the proposed procedure.