• Composites Research
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• 제34권6호
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• pp.350-356
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• 2021

활주 선형의 선박은 직선으로 운항하거나 선회할 때, 그 속도에 따라 위치와 트림이 변화하며, 선체에 큰 저항이 발생한다. 본 논문에서는 탄소복합소재를 선체에 적용하여 선체무게와 내구성이 향상된 레저보트의 전산유체역학을 통해 선형에 대한 저항을 추정하였다. 18ft급 레저보트의 선수부와 선미부의 저항 성능을 확인하고 선형 전체의 유동장을 추정하였으며, 수치해석을 통해 각 트림의 저항을 비교하여 선형에 대한 안정성을 확인하였다. 또한, 선체에 걸리는 힘이 크지 않아 설계된 선형이 충분히 견딜 수 있을 것을 확인하였고, 파도의 파장과 배의 길이를 관성력에 대한 중력의 비로 계산하여 롤링이 얼마의 힘으로 발생하는지 확인하여 보트의 안정성을 분석하였다.

• Journal of Periodontal and Implant Science
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• 제27권3호
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• pp.575-584
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• 1997

The quality of periodontal instrument cutting edge is a basic element of effective root planing procedure. Using instruments, the sharp edge is changed into blunt or beveled edge. With the blunt instrument, the periodontal treatment can't be carried into accuracy and effective. The study on the wear of periodontal curet is insufficient, there are few publications about the change of sharpness of cutting egde after using instrument and a certen reports were published on the study of scanning electron microscope(SEM) examination. In this study, to declare the number of strokes for sharpening of instruments, the changes of cutting edge is measured by the clinical methods, tactile sensitivity examination and refraction light-white line test after scaling strokes and root planing strokes. SEM test was added for defined the changes of cutting edges. The 7/8 Gracey curets that have been never used was tested. Maxillary molars which were extracted from the School of Dental Medicine, Dankook University was used. Subjected teeth had attachment loss more than 6 mm in bucca-lingual surface and sufficient calculus of a band type in cervical area. The strokes of curet were executed 3, 5, 7, 9, 11, 13 times on scaling stroke and 10, 15, 20, 25, 30, 35 times on root planing stroke. A resident has periodontal experience over 3 years carried out the clinical examinations those tactile sensitivity examination and refraction light-white line test 5 times. The case there being tactile sensitivity certenly is 2, the case being felt tactile sensitivity is 1, and the case there not being tactile sensitivity is 0. The visual examination was recorded as following. The case that refracted white line is not recognised is 2, the case that uncerten is 1, and the case that acknowledged is 0. The results were obtained as follows. 1. After scaling strokes, the tactile sensitivity was reduced after 11 strokes and disappeared in 13 strokes. 2. In tactile sensitivity after root planing procedures, sensitivity was reduced after 25 strokes and disappeared in 35 strokes. 3. In case of visual examination, the detection of refracted white line was increased after 9 strokes of scaling procedures and the accuracy of wear wasn't showed after root planing procedures. 4. In SEM, metal projection was observed on new periodontal curet cutting edge and it was disappeared after scaling procedures. 5. In SEM, the cutting edge was showed changing linear into an aspect of the surface after 5 strokes of scaling procedures and 10 strokes of root planing procedures and showed beveled edge in 11 strokes of scaling procedures, 25 strokes of root planing procedures. The results of 3-type examination indicated that the sharpening of curet should be performed after 11 strokes of scaling procedures and 25 strokes of root planing procedures.

• 한국해양공학회지
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• 제30권2호
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• pp.69-74
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• 2016

A new wave-piercing-type high-speed planing boat without a chine was developed, and its basic performance was investigated in a model test, including the resistance, trim, and sinkage. The maximum speed of the developed ship was 35 knots. The hull form was developed by combining a VSV (very slender vessel) and TH (transonic hull), which have large deadrise angles at the bow. The main dimensions were estimated by a statistical approach using actual ship data. The effect of a side fin attached at the stern near the water line was investigated from a resistance point of view. It was found that the developed hull form showed the possibility of a new concept for a high-speed planing hull without a chine, and the side fin played an important role in increasing the resistance performance by controlling the trim and sinkage in the high-speed range.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.249-254
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• 2007

Recently, the items of construction planning have magnified and specialized and the problems occurring at the first step of the construction planing process have complicated. In this research, AHP(Analytic Hierarchy Process) method which is simple to apply and clear to decide has been proposed when a people making a plan at the first step of the construction planing process. As an example, the best solution has been obtained in a railway construction line choice that consist of various items by applying for this method, which proves the possibility of application of this method to the complicated problems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.187-189
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• 2004

This paper investigates the effect of weather factors(such as winds, rain, snows, temperature, clouds and humidity) on transmission line outages. The result shows that weather variables have significant effects on the transmission line historical outages and the relationship between them is nonlinear. Multiple regression analysis using Logit model is proved to be appropriate in forecasting line failure rate in KEPCO systems. It could also provide system operators with useful informations about system operation and planing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.391-393
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• 2004

Transmission line outage is influenced by several weather factors: wind, rain snow, temperature, cloud and humidity. So, in this paper try to see how much each weather factors have effect on the transmission line outage and it is analyzed that which weather variables have close relation with transmission line historical outage data in KEPCO systems. These statistic correlation analysis may provide system operators useful information about system operation and planing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.60-62
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• 2004

Transmission line outage is influenced by several weather factors: wind, rain snow, temperature, cloud and humidity. And most power system reliability studies assume a failure rate. It can be calculated by transmission line outage data and weather data. Also weather is divided into normal weather and adverse weather by failure rate analysis. The effect of failure rate is discussed with both normal weather and adverse weather. It can be used in effective information about system operation and planing.

• 한국인쇄학회지
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• 제20권2호
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• pp.45-56
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• 2002

In these day, our life has been developed with the computer. Printing Industry was introduced the information industry as computer, internet, etc. These are now in daily use and covers the entire work flow - from the planing of the product and the production at domestic printing industry. Then, I suggest the correspondence of changing printing work flow, understanding of digital printing technique, rearing of a special line of business, adjustment in the environment changing of printing technique etc. for the purpose of development of domestic printing industry.

• 로봇학회논문지
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• 제2권3호
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• pp.242-248
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• 2007

Robot system development consists of several sub-tasks such as layout design, motion planing, and sensor programming etc. In general, on-line programming and debugging for such tasks demands burdensome time and labor costs, which motivates an off-line graphic simulation system. MSRS(Microsoft Robotics Studio) released in recent years is an appropriate tool for the graphic simulation system since it supports CCR(Concurrency and Coordination Runtime), DSS(Decentralized System Services), and dynamics simulation based on PhysX and graphic animation as well. In this paper, we developed an MSRS based network simulation system for quadruped walking robots, which controls virtual 3D graphic robots existing in remote side through internet.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2837-2839
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• 2000

We design a stable controller for a mobile robot with variable gains and reference velocity in order to apply the proper gains and reference velocity, which are generated with fuzzy logic in on-line. The stability is guranteed by the Lyapunov theory. The fuzzy logic rules is found in off-line with GA strategy which drives each object function to be the least. The proposed controller is applied smooth path tracking due to the local path planing. Simulation results show robust performances under a different initial conditions.