• 한국전기전자재료학회논문지
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• 제25권6호
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• pp.426-430
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• 2012

The properties of green sheet were investigated in order to understanding an effects of organic solvent mixture ratio for solid oxide fuel cells fabrication. The purpose of this work is to optimize the slurry condition using the design of experiment to improve green sheet properties. The elongation increased with increasing amount of binder and solvent. With increasing amount of solvent, the air permeability increased but the tensile strength decreased. The best properties of the green sheet appeared amount of the binder 17 wt%, solvent 35 wt% and powder 48 wt%. The optimum condition of green and sintered density for solid oxide fuel cells fabrication was obtained in the sample pressured at 800 $kgf/cm^2$.

• 대한기계학회논문집B
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• 제25권2호
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• pp.235-243
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• 2001

This paper describes a design study of the cylindrical multi-hole premixed burner to be used for condensing gas boiler which can raise performance and reduce NOx emission. In this study, specifications of the multi-hole burner (hole diameters and arrangement) are investigated using model flat burners in terms of flame stability, and combustion characteristics for stability and NOx emission are examined for cylindrical multi-hole burner. As a result, the equivalence ratio for optimum operation condition of the cylindrical burner is around 0.72(0.7∼0.75). In this condition, turn-down ratio becomes 3 : 1 at least which is suitable for proportional control. The NOx and CO emission is less than 40ppm and 25ppm(0$_2$0% basis), respectively. This burner can be applied LPG as well as NG because there is no difference for stable combustion region.

• 품질경영학회지
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• 제44권4호
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• pp.935-949
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• 2016

Purpose: This study attempts to find out the optimum condition of the rotary cutter making pellet in the footwear outsole process. The pellets are used in the process of outsole rubber fabrication to reduce cycle time and save raw material. Methods: Computer simulations are used to analyze the maximum stress in the rotary cutter after designing a variety of cutter shapes. Taguchi method is used to identify the robust condition of the cutter. In $L_{18}$ orthogonal array, the control factors such as knife width, twisted angle, number of knives, diameter, knife depth and supported angle are considered and noise factors like assembly tolerance and amount of antifriction are allocated. Results: It is found that the most important factors to reduce maximum stress in the cutter are supported angle and diameter. Using Tacuchi's results, we can reduce 70% cycle time and 9% raw material compared to the traditional method using cutting die. Conclusion: When designing the rotary cutter, the best conditions are the diameter at its maximum allowable value and supported angle in the boundary of machine inner space.

• 한국항해항만학회지
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• 제26권2호
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• pp.199-207
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• 2002

컴퓨터 시뮬레이션을 통해서 레이더 타겟들에 대한 레이더 유효면적(RCS)을 측정하고, 그들의 성능특성을 분석하였다. 또한, 상용레이더 리프렉터의 구조적 특징을 검토하였다. 그리고, 수동형 레이더 리프렉터의 최적 설계조건을 선택했다. 연구결과, X-band($\lambda$=3.2cm에서 10λ 크기의 원형 평판으로 구성된 옥타헤데랄 형태의 레이더 리프렉터가 최적 성능을 나타냈다. 그러나, 새로 적용될 2000 SOLAS 규정을 수용하기 위해서는 X-band 와 S-band 모두에 적용하기 위해서 더 큰 크기의 원형평판이 필요하다.

• 한국식생활문화학회지
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• 제25권1호
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• pp.54-60
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• 2010

The principal objective of this study was to determine the optimal mixing condition of two different amounts of cabbage and rice flour for the preparation of a cabbage cream soup. The experimental design was based on the central composite design methodology of response surface, which included 10 experimental points, including two replicates for the cabbage and rice flour. Physiochemical and sensory properties were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the mixed final product. Water content and pH values increased with increasing quantities of rice flour. Neither cabbage or rice flour affected the L and a values, but the b value increased with greater quantity of both ingredients. Viscosity increased with increasing added cabbage. Sensory evaluation results were significant in the predicted model for flavor (p<0.05), concentration (p<0.01) and overall quality (p<0.01). As a result, the optimum formulations by numerical and graphical methods were calculated as 111.79 g cabbage and 8.99 g rice flour.

• 화약ㆍ발파
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• 제24권1호
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• pp.29-37
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• 2006

최근 국내 터널현장에서 기계식 장전장비를 활용한 벌크에멀전 (bulk emulsion) 폭약의 수요가 증가되면서 국내 암반 및 주변여건에 적합한 발파의 합리적인 설계기준이 요구되고 있다. 본 연구에서는 현재까지 국내에서 기계식 장전장비를 활용한 벌크에멀젼 폭약을 적용하여 시공한 사례 중 굴진효율 및 여굴량이 양호한 발파결과를 근거로 암반등급별 최적 비장약량과 영역별 적정 장약량을 검토하였다. 또한, 조건을 만족하는 발파결과를 분석하여 RMR 암반분류와 벌크에멀젼 폭약의 최적 비장약량과의 상관식 $({\Upsilon}= 0.669 + (0.0154{\times}RMR),\;r=0.81)$을 얻었고, 영역별로 천공장 변화에 따른 적정 장약량 범위를 산출하였다.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.220-233
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• 2019

Bacterial lysates have become a common ingredient for natural health care. Lactic acid bacteria (LAB) could serve as potential candidates for lysate production: the lactic acids produced by LAB have been utilized for their moisturizing, antimicrobial, and rejuvenating effects, while other substances provide topical benefits and health effects for the skin. Our study aimed to obtain lysate from a LAB S. macedonicus MBF 10-2 through an optimized fermentation using the Response Surface Methodology. Strain MBF10-2 was cultivated in a 2L fermenter tank in de Man Rogosa and Sharpe (MRS) medium and in plant-based peptone modified MRS, i.e. Soy-peptone and Vegitone. The duration and the medium composition (dextrose and soy peptone or proteose peptone) were adjusted to obtain an optimum production of cell lysate. Central Composite Design was employed for Design Expert 7.0.0 by adjusting 3 factors: dextrose (1%, 1.5%, 2%, 2.5%, 3%), soy or proteose peptone (0.5%, 0.75%, 1%, 1.25% and 1.5%), and duration of fermentation (8, 10, 12 14, and 16 h for MRS-Soy peptone and 15, 17, 19, 21, and 23 h for MRS Vegitone). Bacteriocin-Like Inhibitor Substance activity of lysate and pH were used as indicators. The optimum condition for lysate production using MRS Soy Peptone and Vegitone are as follows: dextrose concentration 2.5%, plant-based peptone 1.25%, while optimum fermentation duration were 11.18 h (MRS Soy Peptone) and 17 h (MRS Vegitone) with a starter concentration of 10% at $OD_{600nm}$ $0.2{\pm}0.05$. However, the standard MRS medium produced better quality lysate compared to MRS plant-based peptones.

• 대한기계학회논문집
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• 제14권5호
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• pp.1356-1364
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• 1990

본 연구에서는 단열해석에 재생기효율을 고려함으로써 보다 합리적인 예비설 계조건을 도출하고자 함이다. 스터링기관용 재생기의 특성검토를 통하여 예비설계에 적합한 재생기효율을 정립하며, 기 발표된 단열모델에 대한 해석적 근사해에 적용하는 방법으로 접근한다. 재생기효율이 고려될 경우 기관의 기본형태와 연관된 위상각, 행정체적비, 불용체적비, 압축비등 설계인자의 최적조건에 관하여 취급하며 온도비, 비열비등 부여조건의 변화에 따른 영향을 검토한다.

• 대한환경공학회지
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• 제35권9호
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• pp.624-629
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• 2013

본 연구는 해수담수화 전처리 기술로서 개발된 가압식 정밀여과(microfiltration: MF) 중공사막 모듈(막 면적 $35m^2$)의 성능평가를 목적으로 $1,000m^3/day$ 규모 해수담수화 파일럿플랜트를 대상으로 하였다. 약 3개월 동안 용존공기부상법으로 처리한 원수를 공급하여 $1.5m^3/m^2{\cdot}day$ 정유량 조건에서 여과주기, 유지 세정(chemically enhanced backwash: CEB) 농도와 세정 주기 변화 등에 따른 여과성능과 비용을 분석하였다. MF 막 성능 유지를 위한 유지 세정 시 약품 농도에 의한 영향보다는 반복 세정(4회/일)이 효과적이었으나, 경제적 측면에서는 회수율 제고를 위한 단일 세정 방식이 적절한 것으로 나타났다. 막간차압 및 비용분석을 통해 4가지 운전방식 중 1일 1회 NaOCl 100 mg/L 세정 방식을 최적 운전조건으로 도출하였다. MF 전처리 공정의 유지관리 조건 도출 시에는 성능 평가와 함께, 운전방식에 따른 경제성을 함께 고려하는 것이 적절할 것으로 판단된다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.321-324
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• 2006

LMTT(Linear Motor based Transfer Technology) is a new type of transfer system used in the maritime container terminal for the port automation, and largely consists of a controller, shuttle car, and rail. The shuttle car is divided into the frame part, the driving part, and wheels. In order to design this system, various researches on each part of it must be conducted. In this study, we dealt with the optimum design for the mover of the shuttle car designed from previous studies on the strength of the frame with respect to the number of cross beams to minimize the weight of the shuttle car and to satisfy design criteria of cargo-handling systems in container terminal. For the optimization of the mover, thicknesses of each beam were adopted as design variables, the weight of the frame as objective function, and stress and deflection per unit length as constraint condition.