• 한국군사과학기술학회지
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• 제22권6호
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• pp.824-831
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• 2019

For effective development in consideration of the maintainability of the weapon system, it is necessary to understand whether the maintainability design requirements are satisfied at the early phase of development. This requires the application of an early design phase maintainability prediction process to provide opportunities for improvement. By defining the ambiguity group definition, fault isolation level, fault isolation probability, and countermeasures for faults, it was possible to predict early phase development. The MTTR of the initial design phase applying Procedure V to the artillery system was 3.46H, which is about 16 % higher than 2.98H, the MTTR using Procedure II. This is a result of system design ambiguity that has not been specified in the early phase of development.

• 열처리공학회지
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• 제12권1호
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• pp.21-30
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• 1999

The present study were investigated changes of precipitation behaviour of laves phase in ferrite single phase and ferrite-martensite dual phase and precipitation of laves phase under stress. Hardness changes in ferrite phase appeared two hardness peaks by precipitation of initial fine precipitator and laves phase in 3Mo-0.3Si and 3Mo-0.3Si-C specimens, respectively. Hardness changes in martensite phase of 3Mo-0.3Si-C specimen was lower in the initial stage of aging by carbide precipitation and after this, increased by re-hardening due to precipitation of laves phase. In the ferrite phase, laves phase was mainly precipitated, whereas in the martensite phase, carbide was preferentially formed during the initial stage of aging and with increasing aging time, laves phase and carbide were simultaneously precipitated by precipitation of laves phase at around carbide. In the ferrite-martensite interface, laves phase was mainly precipitated and carbide was mainly formed at boundary of lath martensite than grain boundary. Adding the stress in aging, fine precipitator of inital precipitation of laves phase precipitated in (100) of perpendicular to tensile direction and has grown to only followed<010>direction and also, volume fraction of laves phase increased. Consequently, the stress added was accelerated initial precipitation of laves phase.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1007-1014
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• 2015

An optimally designed six-phase induction motor (6PIM) is compared with an initial design induction motor having the same ratings. The Genetic Algorithm (GA) method is used for optimization and multi objective function is considered. Comparison of the optimum design with the initial design reveals that better performance can be obtained by a simple optimization method. Also in this paper each design of 6PIM, is simulated by MAXWELL_2D. The obtained simulation results are compared in order to find the most suitable solution for the specified application, considering the influence of each design upon the motor performance. Construction a 6PIM based on the information obtained from GA method has been done. Quality parameters of the designed motors, such as: efficiency, power losses and power factor measured and optimal design has been evaluated. Laboratory tests have proven the correctness of optimal design.

• 한국전산구조공학회논문집
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• 제29권5호
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• pp.447-454
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• 2016

최근에 각광받고 있는 3D BIM기반 철근 물량 산출 현황을 살펴보면 상용 BIM 도구들이 철근 모델링 기능을 제공하지만 그 기능을 이용해서 철근을 모델링하려고 하면 방대한 양의 모델링 시간이 소요가 되어 현재 실용적으로 사용할 수 있는 BIM 소프트웨어는 없다. 본 연구에서는 BIM 기반 설계 현업에서 실용적인 철근 물량 산출 프로세스를 정리 및 제시하고, 초기설계단계의 단면 정보가 없는 상태에서 기존의 2D방식에 비하여 보다 정확하게 기동, 보, 슬래브, 벽체의 철근 단면 정보를 자동으로 배근해주는 프로그램인 Rebar Automatic Arrangement Program(이하 RAAP)을 개발하였다. 본 연구 결과는 건설프로젝트의 초기 설계단계에서 설계 진행상 구조 부재 단면 설계가 완료되지 않은 상태의 골조 물량 산출 시 적은 노력으로 기존의 2D기반 방식보다 신뢰성을 향상시킨 물량을 산출할 수 있는 기술로 발전시키는데 의미가 있으며, 합리적인 초기 설계단계의 물량 산출 프로그램을 구축할 수 있는 기초 연구로서 활용될 수 있을 것으로 기대된다.

• 한국컴퓨터산업학회논문지
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• 제5권2호
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• pp.261-268
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• 2004

본 연구는 다기능의 광 네트워크에 있어서 256 위상 Opto-ULSI 프로세서를 구현하는 최적위상 디자인을 제안한다. 이미 구성된 8 위상 프로세서에 대한 디자인의 실험 특성을 바탕으로 하여 본 연구에서 액정의 비선형성을 보정하며 최적의 위상을 찾아 대용량의 Opto-ULSI 프로세서를 구현할 수 있다. 이 연구는 최적의 위상 특성을 조사하고 액정의 비선형성 보정방법에 대한 개발을 통해 초기의 8 위상 Opto-ULSI 프로세서 개발을 중심으로 통합된 지능형 포토닉스 시스템 (IIPS)을 위한 광선제어 Opto-ULSI (BS) 프로세서 (OUP) 구현을 목표로 한다.

• 한국전자통신학회논문지
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• 제3권3호
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• pp.158-164
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• 2008

본 논문은 다중기능 광 네트워크에 있어서 256위상 광 ULSI 프로세서를 구현하기 위한 최적위상 도출에 관해 연구한다. 이미 구성된 8위상 프로세서를 실험 및 평가를 위한 기반으로 사용한다. 이 연구에서는 액정의 비선형성을 상쇄시킬 수 있는 최적의 위상을 찾아내어 보다 큰 규모의 광 ULSI 프로세서 구현이 가능하게 한다. 이는 집적화된 지능형 광자유도 시스템(IIPS)에 사용되는 빔 조종 8위상 광 ULSI 프로세서에 기초하여 구현 된다.

• 한국CDE학회논문집
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• 제21권2호
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• pp.186-195
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• 2016

The finite element modeling of a ship for hull structural analysis on the basis of new harmonized common structural rules (CSR-H) is to be extended to the cargo holds in fore and after body of a ship. Unlike the parallel middle-body where the external and internal features of hull are equal along to the longitudinal direction of a ship, in fore and after body, the external and internal features of hull vary linearly or even irregularly in forms of a surface or a curve along to the longitudinal direction of a ship. Thus, it needs lots of design man-hours for the modeling for structural analysis. In order to save man-hours in initial structural design phase of a ship, the specified 3D CAD system has been adopted in shipbuilding industry. Through the interface between CAD and CAE (rule scantling and direct strength assessment), design man-hour in initial design phase can be saved even under the environment of CSR-H.

• 대한치과의사협회지
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• 제53권2호
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• pp.132-142
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• 2015

Purpose : The objective of this research was to investigate an optimization of drill design factors for implant stability and efficacy through comparative evaluation by the cutting time, heat generation and initial stability. Materials and Methods : Three design factors were considered for the purpose of drill design optimization; the number of flute(2 flute, 3 flute), helix angle($15^{\circ}$, $25^{\circ}$) and drill tip shape(straight, 2-phase). Design factors were selected through comparative evaluation by temperature change, cutting time and ISQ value. Results : Heat generation and cutting time are influenced by all design factors(p<0.05). Drill tip shape was the only factors which influenced to the largest initial stability(p<0.05). Conclusion : Drills with 2 flutes, 2-phase formed drill tip, and 25 degrees of helix angle exhibit a better performance than other design.

• 제어로봇시스템학회논문지
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• 제18권6호
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• pp.546-554
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• 2012

This paper suggests a design method of an improved phase control loop for tracking resonant frequency of solid type precision resonant gyroscope. In general, a low cost MEMS gyroscope adapts the automatic gain control loops by taking a velocity feedback configuration. This control technique for controlling the resonance amplitude shows a stable performance. But in terms of resonant frequency tracking, this technique shows an unreliable performance due to phase errors because the AGC method cannot provide an active phase control capability. For the resonance control loop design of a solid type precision resonant gyroscope, this paper presents a phase domain control loop based on linear PLL (Phase Locked Loop). In particular, phase control loop is exploited using a higher order PLL loop filter by extending the first order active PI (Proportion-Integral) filter. For the verification of the proposed loop design, a hemispherical resonant gyroscope is considered. Numerical simulation result demonstrates that the control loop shows a robust performance against initial resonant frequency gap between resonator and voltage control oscillator. Also it is verified that the designed loop achieves a stable oscillation even under the initial frequency gap condition of about 25 Hz, which amounts to about 1% of the natural frequency of a conventional resonant gyroscope.

• Journal of Electrical Engineering and Technology
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• 제1권3호
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• pp.320-326
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• 2006

A single-phase line-start synchronous reluctance motor (LSSynRM) has merits of low cost, high efficiency and reliability. LSSynRM has an unbalanced magnetic circuit caused by flux barriers and various shapes of conductor bars when starting. Thus the motor may generate unstable starting torque in accordance with the initial starting position of the rotor. This paper presents the rotor design to improve starting performance of the LSSynRM. Design variables are the number and the shape of the conductor bars. This design result is compared with the initial prototype and single-phase induction motor.