• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1616-1623
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• 2000

A diaphragm spring is an important component of a clutch assembly, characteristics of which depends largely on that of a diaphragm spring. A diaphragm spring is subject to high stress concentration in driving condition, which frequently causes cracks and fracture around finger area. In this paper, behavior of a diaphragm spring is analysed by finite element method to calculate sensitivity of design parameters, which is used to perform optimal design of diaphragm spring shape. As an object function, hoop stresses are taken and minimized to improve durability. Characteristics of the diaphragm is used as equality constraint to maintain the original design purpose and sequential linear programming(SLP) is utilized as an optimization tool. With optimized design, it is verified that concentrated stress is decreased maintaining release load characteristic.

• Structural Engineering and Mechanics
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• v.54 no.1
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• pp.149-168
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• 2015

In the bolted connections, bolt placements are generally described and are generally made in the direction of design effects and in the perpendicular direction to design effects. In these both directions, the reliability of the distance of bolts to the edges of connection plate and the distance of bolts to each other is investigated for high strength steel connections built up with high strength bolts in this study. For this purpose, simple SL (bearing type shear connection) and SLP (bearing type shear connection for body-fit bolts) type steel connections with St 52 grade steel plates with 8 different thicknesses and with 8.8D grade high strength bolts (HV) were constituted and analyzed under H (Dead Loads+Live Loads+Snow Loads+Roof Loads) and HZ (H Loads+Wind Loads+Earthquake Loads) loadings. Geometric properties, material properties and design actions were taken as random variables. Monte Carlo Simulation method was used to compute failure risk and the first order second moment method was used to determine the reliability indexes of those different distances describing the placement of bolts. Results obtained from computations have been presented in graphics and in a Table. Then, they were compared with some values proposed by some structural codes. Finally, new equations were constituted for minimum and maximum values of distances describing bolt placement by regression analyses performed on those results.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.99-101
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• 2000

Different optimization algorithms have been proposed to solve real and reactive power optimization problems. Most of all, linear programming techniques that employed a simplex method have been extensively used. But, the growth in the size of power systems demands faster and more reliable optimization techniques. An Interior Point(IP) mehod is based on an interior point approach to aim the solution trajectory toward the optimal point and is converged to the solution faster than the simplex method. This paper deals with the use of Successive Linear Programming(SLP) for the solution of the Security Constrained Economic Dispatch(SCED) problem. This problem is solved using the IP method. A comparison with simplex method shows that the interior point technique is reliable and faster than the simplex algorithm.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.12-16
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• 1999

Background and Objectives : The common cause of voice disorders may be bad habits of phonation. faulty vocal habits might aggravate the voice disorder or make the dysphonia. Authors thought the analysis of faulty vocal habits might help to evaluate the causes and to choose the treatment methods in patients with dysphonia. Authors studied to evaluate which vocal habits were used in patients with dysphonia. Materials and Methods : Patients with dysphonia(N= 32) and person without dysphonia(N=20) were evaluated through pre-evaluation test by otolaryngologist and SLP. All subjects were evaluated accordingly Posture of body, expansion of cervical vein, excessive movements of thyroide prominence, position of tongue, tension of lower lip, tension of jaw, breathing pattern related with phonation. Results : In dysphonia group, we found 23 cases with tension of jaw, 15 cases with expansion of cervical vein, 7 cases with bad position of tongue, 3 cases with excessive movement of thyroid prominence and a lot of cases with bad breathing Pattern on Phonation. In control group, only 3 cases with bad position of tongue, 2 cases with tension of lower lip, 1 case with tension of jaw were found. Conclusions : More faulty vocal habits were found in dysphonia group. Authors thought faulty vocal habits could be the cause of dysphonia and aggravate the dysphonia and the control of vocal habits would be very important in patients with dysphonia.

• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.77-84
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• 1999

Numerical design optimization techniques are implemented for the improvement of the ram accelerator performance. The design object is to find the minimum ram tube length required to accelerate projectile from initial velocity $V_0$ to target velocity $V_e$. The premixture is composed of $H_2,\;O_2,\;N_2$ and the mole numbers of these species are selected as design variables. The objective function and the constraints are linearized during the optimization process and gradient-based Simplex method and SLP(Sequential Linear Programming) have been employed. With the assumption of two dimensional inviscid flow for internal flow field, the analyses of the nonequilibrium chemical reactions for 8 steps 7 species lave been performed. To determined the tube length, ram tube internal flow field is assumed to be in a quasi-steady state and the flow velocity is divided into several subregions with equal interval. Hence the thrust coefficients and accelerations for corresponding subregions are obtained and integrated for the whole velocity region. With the proposed design optimization techniques, the total ram tube length had been reduced $19\%$ within 7 design iterations. This optimization procedure can be directly applied to the multi-stage, multi-premixture ram accelerator design optimization problems.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.85-88
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• 2005

유비쿼터스 컴퓨팅 환경에서 분산되어 존재하는 서비스나 디바이스의 효과적인 사용을 위해서는 서비스의 종류나 서비스의 위치 등의 기본적인 정보가 사전에 제공되어야 한다. 이러한 기본 정보를 사용자의 요구에 맞게 정확히 탐색해서 찾아주는 일련의 과정을 서비스 디스커버리(Service Discovery)라 칭하며, 유비쿼터스 같은 분산 이동 환경에서 가장 먼저 구축되어야만 하는 시스템이다. 최근에는 발달된 에이전트 기술을 서비스 디스커버리와 접목시켜 분산되어 있는 서비스와 디바이스 그리고 사용자까지 효율적이고 유용성 있게 관리하는 추세이다. 각국의 기업이나 학교에서 수 많은 에이전트 플랫폼이 개발되어 왔지만, 각기 다른 개발 기준의 적용으로 인하여 에이전트 플랫폼 간의 상호운용(Interoperability)에 어려움이 존재한다. FIPA 에서는 이종 에이전트 플랫폼 간의 제공 서비스 상호운용을 위해서 디스커버리 미들웨어(Discovery Middleware) 모듈을 제안하였다. 본 논문에서는 FIPA-OS 와 JADE 그리고 SLP 플랫폼 들이 서로의 서비스를 공유할 수 있도록, FIPA 에서 제안한 디스커버리 미들웨어를 실질적으로 개발하여 상호간의 서비스 디스커버리가 이루어질 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.399-404
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• 2006

멀티미디어 서비스 제공을 위해 Havi, Jini, LonWorks, UPnP, SLP 등 여러 미들웨어들이 현존하고 있음에도 불구하고, 홈네트워크가 계속 진화함에 따라 다양한 정보가전들에 대해 특화된 새로운 미들웨어들이 계속해서 등장할 것으로 예상된다. 본 논문은 홈네트워크 상에서 이질적인 미들웨어 간의 상호 연동을 위한 통합 구조 방식에 대해 고찰하고, 효율적인 멀티미디어 서비스 지원을 위하여 기존 방식과는 달리 이질적인 미들웨어를 통합하는 표준 메소드 기반의 통합 구조를 제안한다. 본 논문에서 제안한 HOMI 구조 (HOmenetwork Middleware for Interoperability)는 이기종 미들웨어간의 연동을 위해 표준 메소드를 사용하여 이기종 장치들이 서비스를 인식하고 사용할 수 있는 인터페이스를 제공한다. HOMI는 이러한 인터페이스를 통하여 기존의 통합 미들웨어 구조와는 다르게 표준 메소드를 사용하여 장치들간의 연동을 가능하게 함으로써 홈네트워크를 위한 이기종 가전들간 연동의 효율성과 편리성을 향상시켰다. HOMI는 댁내에 존재하는 멀티미디어 데이터 관리를 위하여 통합 멀티미디어 데이터관리 매니저를 두고, 장치들간에 연동이 가능하도록 함으로써 분산되어 있는 멀티미디어 데이터와 서비스를 언제 어디서든지 서비스 받을 수 있도록 지원한다. 마지막으로 HOMI는 통합 미들웨어를 위한 중앙 집중형 구조에서 멀티미디어 데이터 전송에 의한 부하 문제를 Agent들을 여러 장치에 분산할 수 있도록 함으로써 해결하였다.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.388-395
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• 2014

This paper presents a method that generates alternatives of spatial arrangement for naval ships with limited information. To attain this end, GA (General Arrangement) methodology and GA reports of existing naval ships are analyzed. In order to improve the current naval ship spatial arrangement method that relies on the experience and know-hows of designers, we propose a systematic spatial arrangement process using SLP (Systematic Layout Planning), which determines relative positions of the components by analyzing relationships among them. The proposed method, along with the GA process, is applied to a virtual naval ship and layout alternatives are generated to verify usefulness of the method.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.156-156
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• 2015

최근 화석연료의 사용으로 인한 지구온난화 등 환경파괴가 점점 증가하는 추세이며 이로 인해 신재생에너지 중 하나인 수력발전이 주목받고 있다. 수력발전은 물의 위치에너지를 기계에너지로 이를 다시 전기에너지로 변환하는 친환경적인 방식으로 운영된다. 수력발전량은 우리나라 전체 발전량의 1.5% 정도로 적은 양의 발전량을 생산하지만 가동시간이 짧아 전력수요가 급변하는 상황에 대비 가능하기 때문에 수력발전은 필수적이다. 기후변화의 영향으로 연평균강수량은 증가하는 양상을 보이나 연 강수일수는 줄어드는 등 수자원의 불확실성이 증가하고 있는 실정이다. 따라서 미래 불확실한 수자원 공급에 대비할 수 있는 수자원의 효율적 활용에 대한 연구가 필요하다. 본 연구에서는 하천의 유량이 계절에 따라 변동 폭이 크다는 점을 고려하며 월별 발전량을 최대화하기 위해 선형계획법을 적용하는 모형을 구축하였다. 선형계획법은 목적함수와 제약조건식 모두 1차식으로 비선형항을 포함할 수 없으나 초기 해가 불필요하고 최적해가 보장된다는 장점을 가진다. 일부 목적함수나 제약조건식에 비선형항이 포함되어 있을 경우 Successive Linear Programming(SLP), Piecewise Linear Programming(PLP), Taylor Expansion 등의 방법을 이용하여 선형화할 수 있다. 본 연구에서 비선형 제약조건은 Taylor Expansion을 이용하여 선형화하였으며 한강수계 9개 댐의 월간 발전량을 최대화시키는 장기 운영 모형을 구축하였다. 개발 환경은 Linux-CentOS이며 사용프로그램은 통계 분석에 많이 활용되는 R programming이다. R programming은 패키지를 이용한 개발이 용이하고 Windows 뿐만 아니라 Linux, Mac, Unix 등의 운영체제에서도 호환 가능하다는 장점이 있다.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.3
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• pp.109-117
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• 2021

The auditory-perceptual evaluation of speech-language pathologists (SLP) in patients with voice disorders is often regarded as a touchstone in the multi-dimensional voice evaluation procedures and provides important information not available in other assessment modalities. Therefore, it is necessary for the SLPs to conduct a comprehensive and in-depth evaluation of not only voice but also the overall speech production mechanism, and they often encounter various difficulties in the evaluation process. In addition, SLPs should strive to avoid bias during the evaluation process and to maintain a wide and constant spectrum of severity for each parameter of voice quality. Lastly, it is very important for the SLPs to perform a team approach by documenting and delivering important information pertaining to auditory-perceptual characteristics in an appropriate and efficient way through close communication with the laryngologists.