• 상하수도학회지
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• 제9권3호
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• pp.65-77
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• 1995

The kinetics of flocculation of heterodisperse suspension like those in water treatment plants and natural water system are usually described by the Smoluchowski equation, which incorporates collision frequency functions for particle collisions by Brownian motion, fluid shear, and differential sedimentation. These collisionfrequeney functions have been based on a rectilinear view of collisions, i.e., one that ignores short-range forces and changes in fluid motion as particles approach one another. In this research, a curvilinear approach, i.e., one that accounts for hydrodynamic forces and particle interaction in the collision of two different size particles is developed. Collision efficiency factors of each mechanism can be calculated by trajectory analysis (fluid shear and differential sedimentation) or the solution of diffusion equation (Brownian motion). The results are presented as a set of corrections to the rectilinear collision frequency functions for each mechanism.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제10권3호
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• pp.259-272
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• 2004

본 논문에서는 안전한 OSGi 서비스 플랫폼 환경의 구축에 필요한 새로운 보안 아키텍처를 제시한다. 이 보안 아키텍처에는 1) 사용자 인증 메커니즘, 2) 번들 인증 메커니즘, 3) 키 공유 메커니즘, 4) 권한부여 메커니즘이 포함된다. 사용자 인중 메커니즘에서는 안전하고 편리한 사용자 인증을 위해 SSO (single sign-on) 기능을 제공한다. 번들 인증 메커니즘에서는 효율적인 서비스 번들의 인증을 위해 PKI 기반의 전자서명과 대칭키 기반의 MAC을 함께 이용한다. 서비스 게이트웨이의 부트스트래핑 단계에서 수행되는 키 공유 메커니즘은 인증 메커니즘에서 사용되는 비밀키를 안전하게 공유할 수 있는 방법을 제공한다. 마지막으로 권한부여 메커니즘을 통해 서비스 번들의 제공자와 게이트웨이 오퍼레이터가 분산된 보안 정책을 수립할 수 있는 방안을 제시한다. 본 논문은 기존의 OSGi 스펙에서 추상적으로 명세한 보안 기능을 실제로 OSGi 환경에서 적용할 때 필요한 요구사항을 살펴보고 구체적인 보안 아키텍처의 설계와 구현을 통해 해결 방안을 기술한 점에서 중요한 의미를 갖는다.

• 한국정밀공학회지
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• 제25권2호
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• pp.96-104
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• 2008

An egg grading machine is composed of many mechanisms of which functions are to carry eggs to the bucket in that sensors are located to categorize eggs by their weight, to transfer eggs from the basket of packer holder to the mold tray, to feed the mold tray dispenser after egg chairs are filled with eggs. This paper deals with the analysis and new design of packer holder mechanism of which function is transfer eggs vertically from the bucket conveyor to the mold tray dispenser. Egg is fragile to impact so in designing packer holder mechanism it is necessary to estimate moving speed, acceleration and impact when eggs are touched by any links of mechanism and mold tray dispenser. A new packer holder mechanism is proposed in this paper, which use quick return mechanism composed of 6 links with pin and contact joints.

• Geomechanics and Engineering
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• 제8권5호
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• pp.741-756
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• 2015

The prediction of impending collapse of deep tunnel is one of the most difficult problems. Collapse mechanism of deep tunnel in layered soils is derived using a new curved failure mechanism within the framework of upper bound theorem, and effects of seepage forces are considered. Nonlinear failure criterion is adopted in the present analysis, and the possible collapse shape of deep tunnel in the layered soils is discussed in this paper. In the layered soils, the internal energy dissipations along velocity discontinuity are calculated, and the external work rates are produced by weight, seepage forces and supporting pressure. With upper bound theorem of limit analysis, two different curve functions are proposed for the two different soil stratums. The specific shape of collapse surface is discussed, using the proposed curve functions. Effects of nonlinear coefficient, initial cohesion, pore water pressure and unit weight on potential collapse are analyzed. According to the numerical results, with the nonlinear coefficient increase, the shape of collapse block will increase. With initial cohesion of the upper soil increase, the shape of failure block will be flat, and with the lower soil improving, the size of collapsing will be large. Furthermore, the shape of collapsing will decrease with the unit weight decrease.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.735-739
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• 2002

PTB(Power Transfer Breaker) is a device which incorporate the functions of ACB(Air Circuit Breaker) and ATS(Automatic Transfer Switch). ACB is a circuit breaker against overload and ATS is a switching device to transfer the load between two electric power sources. An existing PTB design based upon the 5 bar & cam mechanism has been regarded to be too complex and thus a simpler 4 bar mechanism with trigger lock is proposed. Experimentation and optimization of the trigger lock is presented.

• 디자인학연구
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• 제14권4호
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• pp.137-146
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• 2001

본 연구의 목적은 진화이론을 이용하여 제품의 진화 유형을 밝히고 이를 통해 제품의 발전과정을 이해하는데 있다. 연구의 목적을 위해 진화 메커니즘을 설정하여 제품들을 이에 적용하였고, 그 결과는 '기능의 진화', '형태의 진화', '상징의 진화' 등 세 가지 진화 유형으로 나타났다. 연구 문제인 <제품은 진화하는가>, <왜 진화하는가>, <어떻게 진화하는가>에 대한 답을 찾기 위해, 본 연구는 세 단계로 진행되었다: 첫째, 선학들의 연구 결과를 통하여 제품 진화론을 정의하였다: 둘째, 이를 바탕으로 진화 메커니즘을 설정하였다: 셋째, 제품을 진화 메커니즘에 적용하여 제품의 진화 유형을 구분하였다. 연구의 결과는 정리하면 다음과 같다. ${\bullet}$본 연구에서 제시한 진화 메커니즘은 '진화의 원인'인 '필요와 즐거움', '진화의 시점'인 '결함', '진화의 원동력'인 '이익'등으로 구성된 유기적 장치이다. ${\bullet}$제품을 진화 메커니즘에 적용한 결과, 진화 유형은 '기능의 진화', '형태의 진화', '상징의 진화'등으로 나타났다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제2권1호
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• pp.176-182
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• 1991

한국의 전통사상중에 가장 중요하다고 할 수 있는 효(孝)의 개념과 기능을 발달학적 측면에서 고찰하였다. 효(孝)란 부모-자녀의 상호의존적인 관계로서 사랑을 주고 받는 애착의 관계로 볼 수 있으며, 공격성을 적절히 조절하고 oedipus complex를 해결하는 기능이 있고, 자녀는 부모를 존경하는 한편 부모는 자녀에게 긍정적 동일시(positive identification)의 model이 되어 자녀로 하여금 자아를 실현하도록 도와주는, 일생을 통해 인격형성 전반에 걸쳐 영향을 주는 역동의 개념으로 이해할 수 있겠다.

• Nuclear Engineering and Technology
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• 제29권2호
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• pp.167-174
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• 1997

The method that the operating condition of Control Rod Drive Mechanism (CRDM) can be monitored without mounting sensors within CRDM housing was developed, and by using this developed method the closed-loop controller for the CRDM was designed which can optimize the performance and maximize the reliability of CRDM operation. Neural network is utilized as pattern recognition engine in detecting CRDM actuation. In this paper, most problems in previous open loop system are resolved. The control algorithms for closed-loop system ore developed and implemented within the hardware of timing controller based on microprocessor. All functions in the timing controller ore verified by means of real time CRDM simulator. The results show that the timing controller performs its intended functions properly.

• 한국멀티미디어학회논문지
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• 제19권12호
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• pp.1992-1999
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• 2016

In layered communication architecture, each layer is designed to service its own functions to higher layer while getting serviced by lower layer. Usually layered architectures are not optimized in a total view of whole services and functions. So cross layer design pursues performance enhancements by optimizing in various ways. In LTE, MAC layer uses HARQ mechanism and RLC layer uses ARQ mechanism for retransmission. According to the 3GPP 36.331 specification, two layers' cooperation may not happen in an optimized way. This paper suggests an adaptive MAC layer approach which RLC layer's function might be initiated in MAC layer in advance to utilize MAC layer's idling wasting time for RLC layer's next decision. This adaptive ARQ method in MAC layer speeds up the next retransmission and reduces the overall transmission time. Emulation shows the improved performance in total retransmission time and retransmission success ratio. In wireless shadow area, the retransmission occurs frequently. Our approach has strong points in this poor wireless condition.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2527-2534
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• 2002

An efficient method is proposed for the design of six-bar function generators with complex design tasks. Especially, the desired functions are defined for the entire motion ranges of the input variables. The design problem is defined as a nonlinear optimization problem. A concept of a weighted structural error is introduced for the definition of the objective function. Also simple branch identifiers are incorporated to eliminate the branch problems commonly encountered in a typical linkage synthesis problem. Two example problems of designing a Watt-II type double dwell mechanism and a Stephenson-III type double beat-up mechanism are demonstrated with numerical results. Constraints such as on the Grashof conditions and on the transmission angles are included for practical solutions.