• 한국컴퓨터그래픽스학회논문지
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• 제8권1호
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• pp.13-20
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• 2002

최근들어 지르코니아 세라믹과 같이 $1500^{\circ}C$에서 소결된 소재를 이용한 인공 치아 보철물의 수요가 증대되고 있다. 그러나 이들 소재의 강도가 너무 높기 때문에 세라믹용 보철물을 기공사가 수작업으로 제작하기란 매우 어려워 CNC 기계를 사용하여 제작하고 있다. CNC 기계에 의한 보철물 제작에 있어 가장 중요한 사항은 치과 의사가 만들고자 하는 형태의 보철물이 3차원으로 정확하게 모델링되어져 있는가이다. 본 논문에서는 인공 치아 주요 보철물인 단일 캡(single cap)과 코너스 코아(conus core)와 같은 단일 코아 보철물를 효과적으로 모델링할 수 있는 기법을 제시하고, 제시된 기법에 의해 모델링된 단일 코아 결과를 소개한다. 특히, 제시된 기법에서는 단일 코아 보철물 모델링을 위해 Minkowski Sum과 ZMap 알고리즘을 사용한다.

• 임상간호연구
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• 제22권1호
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• pp.46-55
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• 2016

Purpose: The purpose of this study was to describe performance and education needs related to neurologic assessment by neurologic ward nurses. Methods: The study was conducted with a cross-sectional descriptive design. Participants, 297 neurologic ward nurses working in ten major hospitals in Seoul and Gyeonggi were surveyed from September 7 to October 1, 2015. Results: The mean score for performance of neurologic assessments was 3.04 points. Performances performed with high quality were orientation exam, mental status documentation, and muscle strength of extremities in that order. Performances performed with low quality were assessment of accessory nerves, hypoglossal nerves, and cerebellum function in that order. There were significant differences according to whether there was ward education programs on neurologic assessment and teaching experiences within a year. These variables significantly affected the quality of neurologic assessment performance. The need for neurologic assessment training was 3.14 points. Conclusion: Amount of performance and demand for education on neurologic assessment, which are required in the clinical setting, were significantly high. To perform neurologic assessments with high quality, development of education program for neurologic assessment and continuous education courses are required at either the department or neurological nursing organization level.

• 한국지진공학회논문집
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• 제3권4호
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• pp.61-70
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• 1999

1994년 Northridge 지진과 1995년 Kobe 지진에서 많은 철골구조물의 보-기둥 접합부에 발생한 규열은 내진성능이 우수한 것으로 알려진 모멘트 저항 철골골조의 내진성능 개선에 대한 연구필요성을 제시하였다 일반적으로 모멘트 저항 골조가 강한 지진을 받을 때 보-기둥 접합부는 강도의 저하없이 소성 회전변형능력이 0.015이면 만족할 수 있다고 한다. 본 연구의 목적은 강한 지진하중에서도 철골구조의 보-기둥 접합부에서 용접부의 균열이 방지되고 연성적으로 충분한 에너지를 흡수하고 소산할 수 있는 접합부의 형태를 제안하고 그 거동을 조사하는 것이다 본 연구에서는 접합부의 형태를 제안하였으며 실험을 통하여 그 거동을 분석하였다 제안된 접합부 시험체에 대한 실험결과는 용접부에 균열이 발생하지 않았으며충분한 변형능력을 나타냈다.

• 감성과학
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• 제17권1호
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• pp.29-38
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• 2014

In recent days, according as ergonomics and aesthetic engineering are important factors in the product market, there is a demand to develop automobile seat and interior designs which are focused on sensitive elements such as aesthetic and comfort features in order to satisfy the sensitive needs of consumers. To meet such demands, car seats are turning into functional and sensitive products that reflect elements of function and entertainment. According to such trends, this research is aimed to develop the illuminating car seat fabric that serve such functions as recognizing and reacting to car environments, which includes sensing over-speed, open doors, and unfastened safety belts through the illuminating car seat fabrics by optical fiber. For this purpose, basic physical properties of optical fiber are analyzed, appropriate weaving and etching technologies are applied, and the woven fabric of optical fiber for car seats are illuminating depend upon car environments. Moreover, the applicable woven fabric of optical fiber is deduced after evaluating the physical properties (such as tensile strength, heatproof, anti-fouling, washable and combustible traits) for the appropriateness of applying the woven fabric of optical fiber to car seats. For this purpose, the woven fabric of optical fiber is covered according to car seat processes; the optical fiber applied to seats is composed that it may be connected to one end of the connector linked to a LED so that it may perform functions like sensing over-speed, open doors, and unfastened safety belts; the sensed signals are transmitted to the control part, and luminescent signals are transmitted to LED.

• 한국정밀공학회지
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• 제19권3호
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• pp.88-94
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• 2002

Recently, the life cycle and the lead-time of a product are to be shortened in order to satisfy consumer's demand. It is thus important to reduce the time and cost in manufacturing trial products. Several technique have been developed and successfully commercialized in the market of RPM(Rapid Prototyping and Manufacturing). However, most commercial systems currently use resins or waxes as the raw materials. So, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome these problems, high-speed machining technology is being investigated worldwide for rapid manufacturing and even for direct rapid tooling application. In this paper, some fundamental experiments and analyses are carried out to obtain the filling time, materials, method, and process parameters for HisRP(High-Speed RP) process. HisRP is a new RP process that is combined high-speed machining with automatic filling. In filling process, Bi58-Sn alloy is chosen as filling material because of the properties of low-melting point, low coefficient of thermal expansion and no harm to environment. Also the use of filling wire it if advantage since it needs simple and flexible mechanism. Then the rapid product, for example a skull, is manufactured for aluminum material by HisRP process with an automatic set-up device thor 4-faces machining.

• Journal of the Korean Wood Science and Technology
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• 제39권6호
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• pp.521-530
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• 2011

구조용 집성재의 시장 수요가 확대되고 다양화되면서 교량이나 파고라와 같이 외기에 노출되는 조건에서 사용하기 위한 고 내구성 구조용 집성재에 대한 시장 요구가 증가할 것으로 예견된다. 따라서 본 연구는 국산 침엽수재로 제조되는 구조용 집성재에 적합한 방부처리 기술 및 기준을 개발하기 위한 목적으로 진행되었다. 본 연구에서는 방부처리된 국산 리기다소나무 제재목을 이용하여 구조용 집성재를 제조하고 제조 단계별 생산수율과 KS 품질기준 충족여부를 평가하였다. 방부집성재의 제조수율은 일반 집성재와 큰 차이를 나타내지 않았으며, 목재자원의 효율적인 활용을 위해서는 집성재 제조수율 향상방안과 함께 부산물에 대한 효율적 활용방안도 함께 검토되어야 한다. 리기다소나무 방부처리재의 경우 불균일한 방부약제 흡수량으로 인하여 구조용 집성재 제조용으로 적합하지 않은 것으로 확인되었으며, 집성재 제조 후에 유용성 방부제를 처리하는 방안에 대한 추가적인 검토가 요구되었다.

• Journal of Information Technology Applications and Management
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• 제26권6호
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• pp.103-117
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• 2019

Demand for high power motors is rapidly increasing as the 4th industry and convergence technology has recently emerged. In order to produce high-strength permanent magnets, the magnets used for magnetization have been increased from DC 300V in the 1970s to DC 2.5kV in the 2010s, Up to DC 10kV in the 2030s, It is expected that higher voltage will be used to magnetize. However, in the case of a magnetizer using an existing electric signal control device, it is necessary to use a control device with a high-voltage insulation function in case a high voltage used for magnetization is leaked to the control device. If a short circuit accident occurs, the controller must be shut down and serious problems such as excessive repair costs arise. In this study, a control system adopting optical communication method instead of electric signal control method is proposed to prevent leakage currents in high-voltage magnetizer. We design a transmitter(Tx) and a receiver(Rx) device for the optical communication control device and implemented a prototype connecting the optical cable. In order to demonstrate the utility of high-voltage magnetizer using the optical communication control device, we analyzed the initial cost and the yearly cost for the years to analyze the net present value. As a result, In the case of the low-voltage magnetizer, the electric signal control method cost less, As the operating voltage of the magnetizer becomes higher. It is confirmed that it takes less cost when the optical communication control device is used.

• 한국전자파학회논문지
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• 제17권12호
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• pp.1212-1223
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• 2006

마이크로웨이브 대역은 무선 서비스의 수요가 많은 대역이지만 주로 장거리 고정 통신용으로 이용되어 전파 모델에 대한 연구가 VHF/UHF 대역보다 적게 이루어졌으나, 최근 마이크로웨이브 대역을 이용한 이동 통신 서비스가 증가됨에 따라 보다 정확성 있는 전파 예측 모델의 개발이 요구되어 왔다. 이동 전파 환경에서 신뢰성있는 전파 예측 모델을 개발하기 위해서는 다양한 전파 환경에서 신호의 반사, 회절 및 산란에 따른 전파 특성에 대한 측정 및 분석이 필요하다. 제시된 8 GHz 대역용 전파 예측 모델은 가시거리 영역과 비가시거리 영역에 맞는 모델을 구분하여 개발된다. 가시거리 영역용 예측 모델은 직접파, 지면 반사파 및 도로 양쪽 건물 반사파에 의한 해석적 결과에 측정된 경로 손실 지수를 적용하여 신호 세기를 예측하고, 비가시거리 영역용 예측 모델은 회절 후 신호 변화 현상에 대한 분석 결과를 이용하여 수신 전력을 예측한다.

• Earthquakes and Structures
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• 제19권5호
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• pp.395-409
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• 2020

With verifications through many relevant researches in the past few decades, adopting the equivalent lateral force procedure for designing seismically isolated structures as a preliminary or even final design approach has become considerably mature and publicly acceptable, especially for seismic isolation systems that mechanically exhibit bilinear hysteretic behavior. During the design procedure, in addition to a given seismic demand, structural designers still need to previously determine three parameters, such as mechanical properties of seismic isolation systems or design parameters and performance indices of seismically isolated structures. However, an arbitrary or improper selection of given parameters might cause diverse or even unacceptable design results, thus troubling structural designers very much. In this study, first, based on the criterion that at least either two design parameters or two performance indices of seismically isolated structures are decided previously, the rationality and applicability of design results obtained from different conditions are examined. Moreover, to consider variations of design parameters of seismically isolated structures attributed to uncertainties of mechanical properties of seismic isolation systems, one of the conditions is adopted to perform bounding analysis for seismic isolation design. The analysis results indicate that with a reasonable equivalent damping ratio designed, considering a specific variation for two design parameters (the effective stiffness and equivalent damping ratio) could present more conservative bounding design results (in terms of isolation displacement and acceleration transmissibility) than considering the same variation but for two mechanical properties (the characteristic strength and post-yield stiffness).

• 복합신소재구조학회 논문집
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• 제3권3호
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• pp.9-21
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• 2012

Concrete filled steel tube (CFT) columns have been widely used in moment resisting frame structures both in seismic zones. This paper discusses the design of such members based on the advanced methods introduced in the 2005 AISC Specification and the 2005 Seismic Provisions. This study focuses particularly on design following both linear and nonlinear methods utilizing equivalent static and dynamic loads for low-rise moment frames. The paper begins with an examination of the significance of pseudo-elastic design interaction equations and the plastic ductility demand ratios due to combined axial compressive force and bending moment in CFT members. Based on advanced computational simulations for a series of five-story composite moment frames, this paper then investigates both building performance and new techniques to evaluate building damage during a strong earthquake. It is shown that 2D equivalent static analyses can provide good design approximations to the force distributions in moment frames subjected to large inelastic lateral loads. Dynamic analyses utilizing strong ground motions generally produce higher strength ratios than those from equivalent static analyses, but on more localized basis. In addition, ductility ratios obtained from the nonlinear dynamic analysis are sufficient to detect which CFT columns undergo significant deformations.