• 한국정보과학회논문지:소프트웨어및응용
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• 제31권10호
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• pp.1304-1319
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• 2004

프로그램 시험 비용은 테스트 데이타를 생성하는 과정을 자동화함으로써 상당히 줄일 수 있다. 테스트 데이타 생성은 보통 선택된 프로그램 경로를 실행하는 입력 값들을 식별하는 데 주안점을 둔다. 지금까지 많은 연구가 있어왔지만 여전히 해결해야할 문제가 있다 그러한 문제들 중에 모양 문제가 있다. 모양 문제는 주어진 프로그램 경로를 수행하기 위해 요구되는 입력 자료구조를 밝혀내는 문제이다. 이 논문에서 이 모양 문제에 대한 새로운 방법을 제시한다. 이 방법은 주어진 경로를 포인터 역 참조가 없는 정적단일 할당문 (Static Single Assignment, SSA) 형태로 변환한다. 이는 주어진 경로 상에 존재하는 각 프로그램 문장을 등식이나 부등식과 같은 제약식으로 간주할 수 있게 해준다. 이러한 제약식에 대한 해는 각 입력 변수에 대한 'points-to relation' 형태로 나타난다. 간단한 예들을 통하여 제안한 방법에 대해 설명한다.에 대해 설명한다.

• Journal of Biosystems Engineering
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• 제24권4호
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• pp.301-308
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• 1999

Path planning for field operation of agricultural machinery is an indispensible part for precision farming or autonomous field operation. In this study, two algorithms (I, II) of generating a time-based shortest operation path were suggested to plan an optimal operation of an agricultural tractor-implement in a rectangular shaped field. The algorithms were based on modification of a minimum spanning tree algorithm, and applied for tractor-implement operations. the generated path was consisted of round operation and returning operation sections. The number of round operation was determined from the condition that a tractor can turn smoothly at headlands. The performance of the algorithms was evaluated by the calculation number for path generation and the total path length generated. Their stability was affected by the number of returning operation, but the algorithm II was considered to be more stable. In addition, the performances of the developed algorithms were compared with those of the conventional field operations at selected field sizes and shapes. The results showed that the algorithms could reduce field operation time greatly. For a 100m$\times$40m field, the reduced path length was 78m. The study also included an user interface program for implementing the algorithms and generating GPS coordinates that could be used in GIS softwares for precision farming.

• 한국정밀공학회지
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• 제27권10호
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• pp.34-39
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• 2010

We developed a path algorithm for ultrafast/wide area laser processing. Demands for high precision laser processing with a wide area has been increasing for a number of applications such as in solar cell battery, display parts, electronic component and automobile industry. Expansion of the area in which laser processing is an important factor to handle the ultrafast/wide area processing, it will require a processing path. Processing path is path of 2- axis stage and stage of change in velocity can be smooth as possible. In this paper, we proposed a smoothingnurbs method of improved speed profile. This method creates soft path from edge part, it is main purpose that scan area ($50mm{\times}50mm$) inside processing path makes path of topology of possible straight line. We developed a simulation tool using Visual C++.

• 로봇학회논문지
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• 제8권1호
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• pp.43-50
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• 2013

$A^*$ algorithm is a global path generation algorithm, and typically create a path using only the distance information. Therefore along the path, a moving vehicle is usually not be considered by driving characteristics. Deceleration at the corner is one of the driving characteristics of the vehicle. In this paper, considering this characteristic, a new evaluation function based path algorithm is proposed to decrease the number of driving path corner, in order to reduce the driving cost, such as driving time, fuel consumption and so on. Also the potential field method is applied for driving of UGV, which is robust against static and dynamic obstacle environment during following the generated path of the mobile robot under. The driving time and path following test was occurred by experiments based on a pseudo UGV, mobile robot in downscaled UGV's maximum and driving speed in corner. The experiment results were confirmed that the driving time by the proposed algorithm was decreased comparing with the results from $A^*$ algorithm.

• 드라이브 ㆍ 컨트롤
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• 제13권1호
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• pp.18-26
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• 2016

This research is conducted to develop an automatic steering system for parallel parking, and the performance of the system was evaluated by parallel parking a conventional vehicle. The automatic steering system consisted of MDPS (motor driven power steering) to control steering, ESC (electronic stability control) to acquire wheel speed, ultrasonic sensors to recognize the parking space, and a controller to communicate and handle data. The parallel parking process using the automatic steering control consisted of parking space recognition, parking path generation, and parking path tracking. The path for parallel parking was generated based on a kinematic model of a conventional vehicle, and a PI controller was used to control the steering angle for path tracking. Parallel parking using the automatic steering control was conducted according to vehicle speed conditions. The results show that the errors on the x-axis and y-axis were below 0.54 m and 0.14 m, respectively, and the error on the steering angle was less than $1^{\circ}$. Therefore, it is possible to implement parallel parking using an automatic steering control system for conventional vehicles.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1995년도 특별강연 및 추계학술발표 개요집
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• pp.54-57
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• 1995

• 인지과학
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• 제4권1호
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• pp.295-317
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• 1993

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.861-862
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• 2011

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.233-240
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• 2016

This paper describes a three-dimensional reference trajectory generation method for giving commands to an unmanned air vehicle (UAV). The trajectory is a set of consecutive curves with constant acceleration during each interval and passing through via-points at specified times or speeds. The functional inputs are three-dimensional positions and times (or speeds) at via-points, and velocities at both boundaries. Its output is the time series of position values satisfying the piecewise constant acceleration condition. To be specific, the shape of the trajectory, known as the path, is first represented by splines using third degree polynomials. A numeric algorithm is then suggested, which can overcome the demerits of cubic spline method and promptly generate a piecewise constant acceleration trajectory from the given path. To show the effectiveness of the present scheme, trajectory generation cases were treated, and their speed calculation errors were evaluated.

• 대한전자공학회논문지SD
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• 제37권6호
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• pp.72-84
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• 2000

경로 지연 고장의 테스트 패턴은 두 개의 패턴을 가진 쌍패턴으로 이루어져 있다. 따라서 가중 무작위 패턴 생성 방법을 이용하여 지연 고장 테스트를 하기 위해서는 기존의 고착 고장을 위한 방법과는 다른 새로운 가중치 생성 방법이 적용되어야 한다. 결정론적 테스트 패턴을 이용하여 가중치를 계산할 때는 테스트 패턴의 집합을 패턴간의 해밍 거리가 너무 크지 않도록 분할하여 주는 것이 일반적이나 지연 고장 테스트에 있어서는 이 분할 방법이 너무 만은 가중치 집합을 생성하게 될 수도 있을 뿐만 아니라 부정확한 가중치를 계산하게 될 수도 있다. 따라서 본 논문에서는 결정론적 테스트 패턴의 분할 없이 가중치를 계산하여 고장 시뮬레이션을 생성하는 실험을 해 보았다. ISCAS 89 벤치마크 회로에 대한 실험 결과는 본 논문에서 제시한 경로 지연 고장을 위한 가중치 생성 방법의 효율성을 보여준다.