• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.123-144
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• 2014

Wireless sensor networks are generally deployed for specific applications to accomplish certain objectives over a period of time. To fulfill these objectives, it is crucial that the sensor network continues to function for a long time, even if some of its nodes become faulty. Energy efficiency and fault tolerance are undoubtedly the most crucial requirements for the design of an information extraction protocol for any sensor network application. However, most existing software agent based information extraction protocols are incapable of satisfying these requirements because of static agent itineraries and large agent sizes. This paper proposes an Information Extraction protocol based on Multiple software Agents with Dynamic Itineraries (IEMADI), where multiple software agents are dispatched in parallel to perform tasks based on the query assigned to them. IEMADI decides the itinerary for an agent dynamically at each hop using local information. Through mathematical analysis and simulation, we compare the performance of IEMADI with a well known static itinerary based protocol with respect to energy consumption and response time. The results show that IEMADI provides better performance than the static itinerary based protocols.

• 정보처리학회논문지D
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• 제17D권6호
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• pp.423-430
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• 2010

소프트웨어가 대형화 및 복잡화되고 품질보증 및 관리에 대한 요구가 한층 커짐에 따라 소프트웨어 테스트 활동이 중요시되고 있다. 소프트웨어 테스트 활동은 시스템에 존재하는 결함 발견과 처리가 주요 목적이지만, 현재 시스템의 위험요소를 관리하기 위한 요구 또한 존재한다. 하지만 일반적인 테스트 자동화 도구에서는 테스트케이스를 이용하여 동일한 순서로 테스트를 수행하며, 이러한 테스트 방식은 빈번하게 변경되는 소프트웨어를 테스트함에 있어 결함을 조기에 발견할 가능성이 낮아지고 처리되는 시간이 늦어지게 된다. 이에 따라 본 논문에서는 과거 테스트 이력을 이용하여 테스트케이스에 동적인 가중치를 부여함으로써 위험도가 높은 테스트케이스를 우선적으로 테스트 하여 결함을 빠르게 발견할 수 있도록 가중치를 이용한 테스트케이스 동적 관리 기법을 설계하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1874-1879
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• 2004

This paper validates new type electric power steering (EPS) system which is driven by a uni-direction rotational motor and two electromagnetic clutches. The assist motor of the new type EPS produces a torque for assisting the steering in only one direction and two electromagnetic clutches transmit the assist torque to the pinion gear in either left or right direction with respect to the steering rotation. In order to evaluate the static and dynamic characteristics of the new type EPS, the EPS has been modeled by using the well known customized software such as MSC.ADAMS and MSC.CarSim. The ADAMS software has been used to investigate the static characteristics of the proposed system. ADAMS, however, can not describe dynamics of a vehicle and perform the simulation under the various road conditions. Thus the dynamic characteristics of the vehicle including the EPS are analyzed very well by using the CarSim software. A sinusoidal steering input command is applied to the propose EPS system in order to evaluate the static characteristics, while the double lane changes are applied to the vehicle with the EPS in order to evaluate the dynamic performance. Through a series of simulations, we can conclude that the propose EPS shows the stable dynamic characteristics when the rotational direction is changed.

• Coupled systems mechanics
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• 제1권4호
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• pp.381-395
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• 2012

Dynamic response of Pile Supported Structures is highly depended on Soil Pile Structure Interaction. In this paper, by comparison of experimental and numerical dynamic responses of a prototype jacket offshore platform for both hinge based and pile supported boundary conditions, effect of soil-pile-structure interaction on dynamic characteristics of this platform is studied. Jacket and deck of a prototype platform is installed on a hinge-based case first and then platform is installed on eight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of platform in term of natural frequencies, mode shapes and modal damping are compared for both cases. Effects of adding and removing vertical bracing members in top bay of jacket on dynamic characteristics of platform for both boundary conditions are also studied. Numerical simulation of responses for the studied platform is also performed for both mentioned cases using capability of ABAQUS and SACS software. The 3D model using ABAQUS software is created using solid elements for soil and beam elements for jacket, deck and pile members. Mohr-Coulomb failure criterion and pile-soil interface element are used for considering nonlinear pile soil structure interaction. Simplified modeling of soil-pile-structure interaction effect is also studied using SACS software. It is observed that dynamic characteristics of the system changes significantly due to soil-pile-structure interaction. Meanwhile, both of complex and simplified (ABAQUS and SACS, respectively) models can predict this effect accurately for such platforms subjected to dynamic loading in small range of deformation.

• 제어로봇시스템학회논문지
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• 제10권10호
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• pp.956-960
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• 2004

The Vehicle Dynamic Simulator(VDS) is a key equipment of the performance verification of attitude control subsystem and it simulates the real dynamic environment that spacecraft undergoes during mission operation. All the software models and hardware interfaces necessary for the closed-loop simulation of the spacecraft dynamics are implemented. Using VDS, KOMPAT-2 attitude control logic functions and performance was verified. In this paper, the hardware and software configurations of KOMPSAT-2 VDS was described briefly and the information flow and exchanges between software models and actual hardwares during close loop simulation was described in the systematic point of view.

• 한국정밀공학회지
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• 제18권11호
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• pp.80-85
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• 2001

In Part 2, dynamic cutting force model, thermal behavior model, and feed drive model are presented for development of a virtual machine tool. Some relevant results with brief descriptions for each model are presented to verify the proposed models. Experimental results for each model agreed well with the estimated ones. The developed models in this two-part paper are partially integrated as a comprehensive software environment.

• International Journal of Precision Engineering and Manufacturing
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• 제4권3호
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• pp.42-47
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• 2003

In Part 2 of this paper, the dynamic cutting force model, thermal behavior model, and feed drive model used in the development of a virtual machine tool (VMT) are briefly described. Some results are presented to verify the proposed models. Experimental data agreed well with the predicted results fer each model. A comprehensive software environment to integrate the models into a VMT is also proposed.

• 대한수학교육학회지:학교수학
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• 제2권1호
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• pp.111-144
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• 2000

The purpose of this study is to develop instruction sequence and teaching units for secondary school geometry using dynamic computer software like CabriII, GSP, Wingeom, Poly. For this purpose, literature was reviewed on various issues of geometry education and geometry curriculum using dynamic software. By the literature review, instructional sequence for teaching geometry in middle schools was designed. And, based on the newly developed instructional sequence, one sample teaching unit was developed. The basic principles for the development were to connect intuition geometry and formal geometry, and to emphasize students' investigative experience. Finally, experiment to check out teachers' response to the newly developed material was conducted by using questionnaire.

• 한국정보처리학회논문지
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• 제5권9호
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• pp.2323-2333
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• 1998

어떤 프로그램에서 오류가 발견되었을 때 프로그래머는 어떤 시험 사례(test-case)를 통해 프로그램을 분석한다. 이처럼 현재 입력 값에 영향을 끼치는 모든 명령문들에 관련된 동적 슬라이싱(dynamic slicing)과 이를 구현하는 기술은 실제 테스팅 및 디버깅 분야에서 매우 중요하다고 할 것이다. 본 논문에서는 이러한 동적 프로그램 슬라이스(dynamic program slices)를 산출하는 마킹 알고리즘을 제시하였고 이것을 프로그래밍한 뒤 예제 프로그램을 적용시켜 구현하였다. 구현 결과는 실행 이력에 대한 마킹 테이블(marking table), 동적 종속 그래프(Dynamic Dependence Graph) 그리고, 축소 동적 종속 그래프(Reduced Dynamic Dependence Graph)로 나타내었다. 그리고, 본 논문에서 제시한 효율적인 동적 슬라이스 생성을 위한 마킹 알고리즘과 동적 종속 그래프가 기존의 기법 보다 더 효율성이 높다는 것을 보였다.

• 한국자동차공학회논문집
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• 제18권1호
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• pp.44-50
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• 2010

Durability performance evaluation technology using Virtual Testing Method is a new concept of a vehicle design, which can reduce the automotive components design period and cost. In this paper, the fatigue life of an aluminum knuckle of a passenger car is evaluated using virtual testing method. The flexible multibody dynamic model of a front half car module is generated and solved with service loads which are measured from Belgian roads. Using a multibody dynamic analysis software, the flexible multibody dynamic simulation of a half car model is carried out and the dynamic stress profile of an aluminum knuckle is acquired. The stress profile is exported to a fatigue analysis software and durability performance of an aluminum knuckle is evaluated.