• 산업기술연구
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• 제15권
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• pp.23-32
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• 1995

The methodology of automatic generation of tool path for rough cutting of a sculptured surface is proposed with the improved contouring method, unequal level line machining. Considering the surface shape and the diameter of the endmill, the distance between level lines is obtained. To improve MMR, initial rough cutting is processed with the large diameter endmill and the remained material is removed by the relatively small diameter endmill. Tool path is generated from the offset curve of respective level line and the interferences between the tool and workpiece are automatically avoided. After generating NC part program, the sculptured surface is machined at the vertical machining center. From the experimental results, total cutting length and machining time are reduced more effectively than conventional contouring methods.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권7호
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• pp.465-472
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• 2004

Analog CPPN-based optimal road boundary detection algorithm for autonomous vehicle is proposed. The CPPN is a massively connected analog parallel array processor. In the paper, the dynamic programming which is an efficient algorithm to find the optimal path is implemented with the CPPN algorithm. If the image of road-boundary information is utilized as an inter-cell distance, and goals and start lines are positioned at the top and the bottom of the image, respectively, the optimal path finding algorithm can be exploited for optimal road boundary detection. By virtue of the parallel and analog processing of the CPPN and the optimal solution of the dynamic programming, the proposed road boundary detection algorithm is expected to have very high speed and robust processing if it is implemented into circuits. The proposed road boundary algorithm is described and simulation results are reported.

• Asia Marketing Journal
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• 제13권4호
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• pp.29-54
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• 2012

본 연구는 영화 관람과정에서 이루어지는 관객의 정보처리 용이성과 선호도 유창성의 관계를 살펴보기 위한 것이다. 따라서 본 연구는 영화에 대한 정보처리의 유창성 정도가 영화의 선호도 결정 용이성에 영향을 주다고 가정하고, 선행연구를 토대로 영화의 처리 유창성을 물리적 특성의 식별 용이성인 영화의 지각적 유창성과 표적에 대한 의미 처리 용이성을 의미하는 개념적 유창성으로 구분하였다. 그리고 영화를 구성하는 표현 요소들을 지각적 유창성요인과 개념적 유창성요인으로 구분하여 이들의 영향 관계를 탐색하였다. 본 연구의 결과, 첫째, 영화의 개념적 유창성과 지각적 유창성은 모두 영화의 선호도 유창성에 영향을 주는 것으로 나타났다. 둘째, 소리 표현의 식별성과 배우의 역할 표현 식별성은 영화의 지각적 유창성에 영향을 주지만, 영상 표현의 식별성은 유의하지 않은 것으로 탐색되었다. 마지막으로, 대사 표현의 적합성과 스토리 구성력은 영화의 개념적 유창성에 영향을 주는 것으로 탐색되었다.

• 한국정보기술학회 영문논문지
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• 제10권1호
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• pp.37-43
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• 2020

This paper presents analysis of passive metal interconnection of the LNA block in CMOS integrated circuit. The performance of circuit is affected by the geometry of RF signal path. To investigate the effect of interconnection lines, a cascode LNA is designed, and circuit simulations with full-wave electromagnetic (EM) simulations are executed for different positions of a component. As the results, the position of an external capacitor (C_ex) changes the parasitic capacitance of electric coupling; the placement of component affects the circuit performance. This analysis of interconnection line is helpful to analyze the amount of electromagnetic coupling between the lines, and useful to choose the signal path in the layout design. The target of this work is the RF LNA enabling the seamless connection of wireless data network and the following standards have to be supported in multi-band (WCDMA: 2.11~ 2.17 GHz, CDMA200 1x : 1.84~1.87 GHz, WiBro : 2.3~2.4GHz) mobile application. This work has been simulated and verified by Cadence spectre RF tool and Ansoft HFSS. And also, this work has been implemented in a 0.13um RF CMOS technology process.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.939-955
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• 2010

With the progress of IT and mobile positioning technologies, various types of location-based services (LBS) have been proposed and implemented. Finding a shortest path between two nodes is one of the most fundamental tasks in many LBS related applications. So far, there have been many research efforts on the shortest path finding problem. For instance, $A^*$ algorithm estimates neighboring nodes using a heuristic function and selects minimum cost node as the closest one to the destination. Pruning method, which is known to outperform the A* algorithm, improves its routing performance by avoiding unnecessary exploration in the search space. For pruning, shortest paths for all node pairs in a map need to be pre-computed, from which a shortest path container is generated for each edge. The container for an edge consists of all the destination nodes whose shortest path passes through the edge and possibly some unnecessary nodes. These containers are used during routing to prune unnecessary node visits. However, this method shows poor performance as the number of unnecessary nodes included in the container increases. In this paper, we focus on this problem and propose a new border line-based pruning scheme for path routing which can reduce the number of unnecessary node visits significantly. Through extensive experiments on randomly-generated, various complexity of maps, we empirically find out optimal number of border lines for clipping containers and compare its performance with other methods.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.135-139
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• 2002

By means of correlation analysis and path coefficient analysis, 18 characteristics of 325 conserved silkworm races were studied for the selecting efficiency on main silk quality characteristics. The result showed that selecting lines with heavier cocoon weight are beneficial to raise the weight of have. Choosing strains with higher cocoon shell percentage, longer filament length and better reelability percentage is good for increasing non-broken filament length. Selecting lines with medium daily weight of have produced in the fifth instar, medium cocoon shell percentage and simultaneously selecting heavier cocoon shell weight are favorable to promote reelability percentage. Choosing strains with heavier cocoon weight, higher cocoon shell percentage, heavier daily weight of bave produced in the fifth instar and heavier weight of bave but shorter filament length may hopefully breed out a race with thick filament size. And selecting strains with heavier weight of have and fine filament size are beneficial to increase filament length. Selecting lines with higher cocoon shell percentage and heavier weight of bave are favorable to raise raw silk percentage of cocoon. There are no significant direct or indirect correlation coefficient between viability and major characteristics of silk quality. It is, therefore, feasible to breed a silkworm race with excellent vitality and good silk quality as well.

• Computers and Concrete
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• 제12권3호
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• pp.261-283
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• 2013

This paper aims to contribute to the three-dimensional generalization of numerical prediction of crack propagation through the formulation of finite elements with embedded discontinuities. The analysis of crack propagation in two-dimensional problems yields lines of discontinuity that can be tracked in a relatively simple way through the sequential construction of straight line segments oriented according to the direction of failure within each finite element in the solid. In three-dimensional analysis, the construction of the discontinuity path is more complex because it requires the creation of plane surfaces within each element, which must be continuous between the elements. In the method proposed by Chaves (2003) the crack is determined by solving a problem analogous to the heat conduction problem, established from local failure orientations, based on the stress state of the mechanical problem. To minimize the computational effort, in this paper a new strategy is proposed whereby the analysis for tracking the discontinuity path is restricted to the domain formed by some elements near the crack surface that develops along the loading process. The proposed methodology is validated by performing three-dimensional analyses of basic problems of experimental fractures and comparing their results with those reported in the literature.

• 한국정밀공학회지
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• 제13권12호
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• pp.142-150
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• 1996

Nowadays, as the development paeiod of new products becomes even shorter, the importance of Rapid Prototyping Technology(RPT) has been rapidly increased. The major application of RPT is an early verification of product designs and quick production of prototypes for testing. Moreover, RPT is applied not only as a second tooling process such as mold making and investment casting but also as a creating some physical structure in medical field. Despite the remarkable progress of RPT, it is required to improve various problems resulting from application such as production time, accuracy and materials. This paper presents a laser scan path generation for accuracy of stereolithographicparts The methodology of laser scan path generation is discussed based on the stereolithography, The procedure of this research is as follows : 1) Input laser scanning conditions such as a laser beam diameter and a laser scanning interval, 2) Reconstruct original contours without self intersecting offset, 3) Calculate offset about reconstructed contours, 4) Calculate intersection points between horizontal or vertical lines and offset contours for internal hatch, 5) Decide laser shutter on/off points. The algorithm developed and programmed by C language is verified as an efficient method after testing a number of STL files of mechanical parts.

• 한국콘텐츠학회논문지
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• 제6권4호
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• pp.46-54
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• 2006

다수 대의 표면실장기를 포함한 PCB조립라인의 생산성 향상을 위한 방법을 제시한다. PCB조립시간의 단축을 위하여 각 실장기 별로 부품공급 피더의 배치 및 실장순서가 최적화 되어야 하며, 표면실장기들의 라인 밸런스를 위하여 부품 할당이 최적화 되어야 한다. 전체의 최적화 문제를 정수계획문제로 수식화하며, 전향경로문제와 후향경로 문제로 분할하여 구성한다. 클러스터링 알고리즘과 branch-and-bound 알고리즘을 사용하여 전향경로문제의 해를 구하며, 할당 알고리즘과 연결 알고리즘을 사용하여 후향경로 문제의 해를 구한다. 시뮬레이션 결과를 통하여 제안된 방법의 성능을 평가한다.

• 한국정밀공학회지
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• 제26권6호
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• pp.74-80
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• 2009

Path tracking of unmanned vehicle is a basis of autonomous driving and navigation. For the path tracking, it is very important to find the exact position of a vehicle. GPS is used to get the position of vehicle and a direction sensor and a velocity sensor is used to compensate the position error of GPS. To detect path lines in a road image, the bird's eye view transform is employed, which makes it easy to design a lateral control algorithm simply than from the perspective view of image. Because the driving speed of vehicle should be decreased at a curved lane and crossroads, so we suggest the speed control algorithm used GPS and image data. The control algorithm is simulated and experimented from the basis of expert driver's knowledge data. In the experiments, the results show that bird's eye view transform are good for the steering control and a speed control algorithm also shows a stability in real driving.