• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.151-157
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• 1990

This paper presents a method for rapid wire frame drawing of the 3D objects represented by the CSG scheme. When the two CSG trees are combined into one, the intersection parts of the polygons constituting the object corresponds to each subtree are computed, and the boundary representation of the combined object is obtained according to the given combinational operator and stored in the root node. The boundary representation in the root node is used in the wireframe drawing of the object and later computation of boundary representation. Bezier surface is taken as one of the primitive object the scan-line algorithm is used, which subdivides each scan-line into the spans where no polygon is intersected, and renders each span with the CSG representation of the object.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.88-89
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• 2015

In cold weather, the speed of concrete strength development is slow. As a result, construction speed becomes slow and it is problem for all construction site to solve this. So in this study, to shorten removing frame time after placing concrete, mix proportion using early-strength-binder(ESB) and curing method such as using heat line in concrete was considered. At first, concrete mix proportion was examined at -5℃ temperature between ordinary portland cement(OPC) and ESB. And second step, concrete, using mix proportion with OPC, was examined according to curing method(: 1) heat line used and 2) no heat line) and kinds of form (: 1) Deck slab, 2) Half PC slab and 3) SOG slab). All cases are same condition: slab thickness is 1,500mm, double-bubble sheet is used as a curing sheet after placing concrete. After the test, OPC is enough to get strength compared to ESB in special condition and 48~60 hours is needed according to form condition.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.219-225
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• 2018

In this paper, for the testing of tensile strength of dead-end clamp used in transmission line, resulting values were estimated by designing and producing the horizontal version of widely-used vertical tensile tester. Tensile strength test of dead-end clamp for transmission line is essential for quality test of products. Moreover, tensile tester is an equipment that requires high level of reliability which needs to be examined through sampling tests commensurate with total inspection. Frames of tensile tester were made up of H-beams so that it can endure more than 20 [tons] of load capability and the test was implemented for 60[seconds] applying five types of tension. In consequence, the tester could withstand up to 21,600[kg] of weight as well as all types of tension. This newly developed horizontal tensile tester can be utilized in figuring out properties of various materials by estimating tensile strength of materials such as metal, rubber and fiber.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.84-91
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• 2012

The total data of observing interior space was divided into a few time frames for analysis. If we can understand the changing process of observation degree as the observation time passes, we will be able to analyse the characteristic and process of information obtainment in the case of space observation. For this purpose, the observation time was parted into 30 second units and the changing characteristic by time frame and observation area was analysed. The conclusion derived from this study is as the following: First, analysis of observation frequency and time on the basis of the average data of each subject showed that the observation time increased compared with the subject's frequency and the overall trend but that it was difficult for me to think there was a certain trend in the observation time of each subject. However, when I examined the time change by using the trend line which is a dynamic average line representing the observation time from the subjects as the trend element of time series, I could see the trend that the subject's observation time increased at a fixed rate as the frequency increased. Second, when I compared and analysed the average observation area at Area I set up by the time of 30 second unit and the observation area of Area I from the all data, I could see that the former had more degree of concentration at Area I. This analysis enabled me to get the degree of concentration on the observed area every time, and accordingly I could also see that when the data of intensive observation by time frame is analysed, the degree of concentration is dispersed for the subjects to observe very intensively or the area with overlapping observations each time frame can be seen as Area I out of the entire observation data. Third, when I analysed the observation characteristics by time frame at the 6 areas divided at 30 second unit at the rate of the number to the time of observation areas, I could see that as the observation time passed while the number of the observation areas defined as decreased the observation time increased, which means that when the area numbers decreases the area intensively observed by the subjects decreases as the time passes. In spit of that, the increase of time can be interpreted as more intensive observation of a specific area.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.217-231
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• 2003

Coded excitation with complementary Golay sequences is an effective means to increase the SNR and penetration of ultrasound imaging. in which the two complementary binary codes are transmitted successively along each scan-line, reducing the imaging frame rate by half. This method suffers from low frame rate particularly when multiple transmit focusing is employed, since the frame rate will be further reduced in proportion to the number of focal zones. In this paper. a new ultrasound imaging technique based on simultaneous multiple transmit focusing using modified orthogonal Golay codes is proposed to improve lateral resolution with no accompanying decrease in the imaging frame rate, in which a pair of orthogonal Golay codes focused at two different focal depths are transmitted simultaneously. On receive, these modified orthogonal Golay codes are separately compressed into two short pulses and individually focused. These two focused beams are combined to form a frame of image with improved lateral resolution. The Golay codes were modified to improve the transmit power efficiency (TPE) for practical imaging. Computer simulations and experimental results show that the proposed method improves significantly the lateral resolution and penetration of ultrasound imaging compared with the conventional method.

• Journal of the Korean Society for Railway
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• v.2 no.3
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• pp.1-8
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• 1999

In this paper, descibed was the derived algorithm for calculating contact point between wheel and rail and the developed method for rail modeling. The proposed methods use travelling distance to represent rail center line position vector and rail orientation with respect to Newtonian reference frame. The methods call be easily used ill multibody dynamic analysis. Two numerical examples are shown to verify the validity of the proposed methods.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.163-170
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• 2001

Axle Gearbox of the High Speed Train has rotational degree of freedom centered on the Axle Shaft Center Line, and constrained by the Reaction Arm connected to the Bogie Frame via Resilient Ring made of Rubber. This System is laid on the Power Train and can influence on the Power transmitted from Motor to Axle. The stiffeness of the Resilient Ring have to be selected for the Natural Frequency of this System do not overlap with the Teeth-mating Frequency. To confirm the Design Parameters, Calculation and Experiment were executed and compared.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.485-489
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• 1995

From the relationship between the two different views of an object with grid, the three dimensional coordinates of intersection points are determined. The images are captured and digitized with a CCD camera and a frame grabber. To find intersection points, local thresholding and line thinning operations are performed. By establishing the correspondence between the points in the two views, the three dimensional corrdinates of intersection points are calculated.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.130-132
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• 2003

화상회의 시스템에서 원활한 동영상의 전달을 위해서는 주어지는 처리시간에 대하여 그에 상응하는 품질을 보장하는 프레임 스케줄링 방법이 필수적이다 영상 복원 작업에 주어지는 처리시간이 증가함에 따라 그 실행 결과로 얻어지는 영상의 품질이 함께 증가할 것이 요구된다. 본 논문에서는 영상회의 시스템에서의 압축된 영상의 복원 과정에서 프로세서의 처리시간에 따르는 결과 영상의 품질에 대한 QoS함수를 도출하고 이를 IRIS 스케줄링 방안에 적용하는 온-라인 스케줄링 알고리즘을 제안한다. 본 논문에서 제시하는 알고리즘에 대한 모의실험의 결과는 주어진 시스템 성능에 H하여 영상회의에 참여한 모든 화자 영상의 총체적 화질을 향상시킬 수 있음을 보여준다.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.429-436
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• 1998

In this paper, we derive the algorithm for calculating contact point between wheel and rail and develop the method for track modeling. The proposed methods use travelling distance to represent track center line poistion vector and track orientation with respect to Newtonian reference frame. The proposed methods can be easily used in multibody dynamic analysis. Two numerical examples are given to verify the validity of the proposed methods.