• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.92-100
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• 2006

In many common control charting situations, the statistic to be charted can be viewed as the output of a linear filter applied to the sequence of process measurement data. In recent work that has generalized this concept, the charted statistic is the output of a general linear filter in impulse response form, and the filter is designed by selecting its impulse response coefficients in order to optimize its average run length performance. In this work, we restrict attention to the class of all second-order linear filters applied to the residuals of a time series model of the process data. We present an algorithm for optimizing the design of the second-order filter that is more computationally efficient and robust than the algorithm for optimizing the general linear filter. We demonstrate that the optimal second-order filter performs almost as well as the optimal general linear filter in many situations. Both methods share a number of interesting characteristics and are tuned to detect any distinct features of the process mean shift, as it manifests itself in the residuals.

• 국제초고층학회논문집
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• 제5권4호
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• pp.319-326
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• 2016

The ingenuity of structural engineers in the field of tall and super-tall buildings has led to some of the most remarkable inventions. During this evolution of structural engineering concepts in the last 100 years, the technical challenges that engineers encountered were extraordinary and the advances were unprecedented. However, as the accomplishments of structural engineers are progressing, the desire for taller and safer structures is also increasing. The diagrid structural system is part of this evolving process as it develops a new paradigm for tall building design combining engineering efficiency and new architectural expression. The first appearances of this type of tall buildings have already been constructed and the interest of both engineering and architectural communities is growing mainly due to the many advantages compared to other structural systems. This paper presents a simple approach on optimizing member sizes for the diagonals of steel diagrid tall buildings. The optimizing method is based on minimizing the volume of the diagonal elements of a diagrid structure. The constraints are coming from the stiffness-based design, limiting the tip deflection of the building to widely accepted regulative limits. In addition, the current paper attempts to open the discussion on the important topic of optimization and robustness for tall buildings and also studies the future of the diagrid structural system.

• 소음진동
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• 제8권4호
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• pp.632-642
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• 1998

A method based on finite element discretization is developed for optimizing the polarization profile of PVDF film to create the modal transducer for specific modes. Using this concept, one can design the modal transducer in two-dimensional structure having arbitrary geometry and boundary conditions. As a practical means for implementing this polarization profile without repoling the PVDF film the polarization profile is approximated by optimizing electrode patterns, lamination angles, and poling directions of the multi-layered PVDF transducer. This corresponds to the approximation of a continuous function using discrete values. The electrode pattern of each PVDF layer is optimized by deciding the electrode of each finite element to be used or not. Genetic algorithm, suitable for discrete problems, is used as an optimization scheme. For the optimization of each layers lamination angle, the continuous lamination angle is encoded into discrete value using binary 5 bit string. For the experimental demonstration, a modal sensor for first and second modes of cantilevered composite plate is designed using two layers of PVDF films. The actuator is designed based on the criterion of minimizing the system energy in the control modes under a given initial condition. Experimental results show that the signals from residual modes are successfully reduced using the optimized multi-layered PVDF sensor. Using discrete LQG control law, the modal peaks of first and second modes are reduced in the amount of 12 dB and 4 dB, resepctively.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.75-75
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• 1996

The rapid expansion for the auto-industry and the worldwide trend toward non-asbestos friction materials for brake lining force our industry to transfer into non-asbestos ones from asbestos-based friction materials. Furthermore, it is imperative for the friction materials to have technological excellence and lower production cost to be competitive in the world market. There is no known theoretical procedures to formulate friction materials. It, rather, depends on the trial and error process. Thus, it is quite clear how important it is to accumulate the know-how on the formulation and manufacturing the friction material. This study concerns the practical ways of conceptualizing the formulation and optimizing the manufacturing process. This study focused on the development of formulation for non-asbestos friction material as well as deriving the physical properties of the trial product to prove its validity and applicability. Elaboration of the formula and optimizing scheme of the manufacturing process to get better quality are also sought. Physical properties were obtained by constant velocity test dynamotest, hardness test and strength test. Differential scanning calorimeter was also used to analyze the thermal reactions of organic constituents, microstructures, bond effects, and degree of mixture.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.7-14
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• 1996

The rapid expansion for the auto-industry and the worldwide trend toward non-asbestos friction materials for brake lining force our industry to transfer into non-asbestos ones from asbestos-based friction materials. Furthermore, it is imperative for the friction materials to have technological excellence and lower production cost to be competitive in the world market. There is no known theoretical procedures to formulate friction materials. It, rather, depends on the trial and error process. Thus, it is quite clear how important it is to accumulate the know-how on the formulation and manufacturing the friction material. This study concerns the practical ways of conceptualizing the formulation and optimizing the manufacturing process. This study focused on the development of formulation for non-asbestos friction material as well as deriving the physical properties of the trial product to prove its validity and applicability. Elaboration of the formula and optimizing scheme of the manufacturing process to get better quality are also sought. Physical properties were obtained by constant velocity test dynamotest, hardness test and strength test. Differential scanning calorimeter was also used to analyze the thermal reactions of organic constituents, microstructures, bond effects, and degree of mixture.

• 한국멀티미디어학회논문지
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• 제21권3호
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• pp.415-422
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• 2018

Advances of telecommunication technology bring various changes in journalism field. Reporters started to gather, edit, and transmit content to main server in media company using hand-held smart media and notebook computer. This paper tried to testify valid bit-rate of visual news content using LTE network and mobile phone. Field news like natural disasters need real-time transmission of video content. But broadcasting company normally use heavy ENG system and transmission satellite trucks. We prepared and experimented different types of visual content that has different bit-rates. Transmission tool was LU-60HD mobile system of LiveU Corporation. Transmission result shows that bit-rate of 2Mbps news content is not suitable for broadcasting and VBR (Variable Bit Rate) transmission has better definition quality than CBR (Constant Bit Rate) method. Three different bit-rate of VBR transmission result shows that 5Mbps clip has better quality than 1Mbps and 3Mbps. The higher bit-rate, the better video quality. But if the content has much movements, that cause delay and abnormal quality of video. So optimizing the balance between stability of signal and quality of bit-rate is crucial factor of real-time broadcasting news gathering business.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.250.1-250.1
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• 2014

A multicusp ion source has been used widely in negative hydrogen cyclotrons mainly for radioisotope productions. The ion source is designed to have cusp geometries of magnetic field inside plasma chamber, where ions are confining and their mean lifetimes increase. The magnetic confinement produced a number of permanent magnetic poles helps to increase beam currents and reduce the emittance. Therefore optimizing the number of magnets confining more ions and increasing their mean lifetime in plasma has to be investigated in order to improve the performance of the ion source. In this work a numerical simulation of the magnetic flux density from a number of permanent magnets is carried to optimize the cusp geometries producing the highest plasma density, which is clearly indicated along the full-line cusp geometry. The effect of magnetic fields and a number of poles on the plasma structure are investigated by a computing tool. The electron confinement effect becomes stronger and the density increases with increasing the number of poles. On the contrary, the escape of electrons from the loss cone becomes more frequent as the pole number increases [1]. To understand above observation the electron and ion's trajectories along with different cusp geometries are simulated. The simulation has been shown that the optimized numbers of magnets can improve the ion density and uniformity.

• 정보처리학회논문지A
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• 제17A권1호
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• pp.27-32
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• 2010

Logical Effort의 기법은 회로의 지연 값을 간단한 필산으로 신속하게 측정할 수 있는 기술이다. 이 기법은 설계 공정 시간을 절약하는 장점도 있지만 고정 지연이라는 설계조건에서 회로의 면적이나 전력의 최소화를 도출할 수 있는 논리 경로를 설계하는데 약점도 있다. 이 논문에서는 균형 지연 모형을 제안하고 이 방법을 기반으로 논리경로에서 전력-지연 효율성을 최적화하는 기법을 제안하고자 한다. 본 논문의 기법을 사용하여 8-input AND 게이트의 3가지 서로 다른 설계 회로를 모의 시험한 결과 기존 Logical Effort의 기법보다 약 40%정도 전력 소비의 효율성이 향상되었다.

• 한국공간정보시스템학회 논문지
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• 제11권4호
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• pp.85-88
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• 2009

멀티미디어 시스템에서 최대근접질의는 매우 빈번히 발생하며, 다른 유형의 공간질의에 비하여 처리비용이 많이 요구된다. 최대근접질의의 처리비용을 최적화하기 위해서는 색인에서 검색되는 노드의 수와 연산시간을 최소화할 수 있는 검색거리 측도가 필요하다. 또한 최대근접질의에 따른 검색 노드들을 정확히 선택하기 위해서는 객체들의 순환적 위치 속성을 고려해야 한다. 본 논문은 순환도메인을 갖는 검색공간에서 객체의 순환적 위치속성을 고려한 최대근접질의 처리방법을 제안하고 그 특성을 보인다. 제안한 방법은 최대근접질의의 처리비용을 최적화하기 위한 검색거리 측도인 순환최소거리와 순환최적거리를 사용한다.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1342-1350
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• 2009

This paper investigates the production and optimization of $\beta$-galactosidase enzyme using synthetic medium by Kluyveromyces lactis NRRL Y-8279 in stirred tank bioreactor. Response surface methodology was used to investigate the effects of fermentation parameters on $\beta$-galactosidase enzyme production. Maximum specific enzyme activity of 4,622.7 U/g was obtained at the optimum levels of process variables (aeration rate 2.21 vvm, agitation speed 173.4 rpm, initial sugar concentration 33.8 g/L, incubation time 24.0 hr). The optimum temperature and pH of the $\beta$-galactosidase enzyme produced under optimized conditions were $37^{\circ}C$ and pH 7.0, respectively. The enzyme was stable over a pH range of 6.0-7.5 and a temperature range of $25-37^{\circ}C$. The $K_m$ and $V_{max}$ values for O-nitrophenol-$\beta$-D-galactopyranoside (ONPG) were 1.20 mM and $1,000\;{\mu}mol/min{\cdot}mg$ protein, respectively. The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in $\beta$-galactosidase enzyme production. Hence, this study fulfills the lack of using mathematical and statistical techniques in optimizing the $\beta$-galactosidase enzyme production in stirred tank bioreactor.