• 한국기계가공학회지
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• 제6권2호
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• pp.28-33
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• 2007

This paper describes development of low cost precision machine that has a vacuum chuck. This study mainly aims to find out a cutting condition for maintaining optimum surface condition and to examine cutting characteristics of the precision machine that is equipped by diamond bites. The cutting materials is oxygen free copper. Several experiments were carried out to find out the main factors that affect the surface roughness such as principal axis RPM(rotation per minute), feeding speed, and cutting depth. As a result, we obtain The optimum cutting condition of the developed precision machine.

• 대한기계학회논문집
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• 제14권1호
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• pp.225-229
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• 1990

본 연구에서는 외부조건과 입력이 일정하게 주어져 있는 냉동 사이클에 대하 여 열교환기의 용량을 설계변수로 하여 출력과 효율이 최대가 되는 조건, 즉 최적 설 계조건을 살펴 보고자 한다. 아울러 이 조건과 엔트로피 생성 최소조건과의 관계와 비가역 사이클인 경우도 살펴보았다.

• 품질경영학회지
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• 제7권1호
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• pp.3-14
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• 1979

The primary objective of this paper is to aid the scientists and engineers in applying response surface procedures to obtain optimum operating conditions for many technical fields, particularly, for industrial manufacturing process. When a set of data is available from an experimental design, it is often of interest to fit a second order polynomial regression model in k independent variables, and find the condition of the independent variables (e. g., temperature, pressure, etc.) that optimize the response variable (e. g., yield, strength, etc.). This paper proposes a method how to obtain the optimum operating condition, and how 10 find the condition by using the computer. A computer program written in FORTRAN language is attached for the readers who may want to use the computer program.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1622-1625
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• 2005

In modern Automobile Engineers, Modularize of parts is developing tendency that is more effective manufacture system and maintenance, and it also can be bring down the production cost. In this study will expect faults of mold and find the optimum of Casting Condition from the Simulation software (Z-CAST), tensile specimen is attempted for define the basic properties and process condition. In reasult, Diecasting of Seat Motor Housing is expected to be best fitted in Works.

• 한국식품영양학회지
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• 제12권2호
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• pp.191-191
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• 1999

A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{\circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{\circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$\mu$g/ml and the purge efficiency of each compound was over 70%.

• 한국환경보건학회지
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• 제27권3호
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• pp.107-112
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• 2001

This work reports the application of a hollow fiber module(HFM) for Cr(VI) extraction from heavy metal salts mixed solution by using microporous hydrophobic hollow fiber module. In HFM configuration, the organic extraction used for the extraction of Cr(VI) was di-(2-ethyl hexyl) phosphoric acid(D2EHPA) diluted with n-heptane. The study of HFM includes the influence of hydrodynamic and chemical condition, i.e., the flow rate of feed solution, the time of reactive extraction, the concentration of feed solution, and the pH of aqueous phase solutions. Several experiments with synthetic solution of different mixed components system of Cr(VI) solutions established optimum condition to achieve a clean separation of Cr(VI). It was possible to separate Cr(VI) in the presence of metal salts mixed solution, such as Zn(II), Ni(II), Cu(II), and Cd(II) using the HFM technique.

• 품질경영학회지
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• 제27권3호
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• pp.79-93
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• 1999

The common accelerated life test(ALT) consists of test methods applying a constant stress, higher than the use condition stress, to items. There we, however, situations for which a progressive stress ALT, in which the stress on a test item is continuously increased with time, Is more convenient to perform testing and simpler in analyzing data than a constant stress ALT. When a product under constant stress s follows a Weibull distribution with parameters $\theta$(5) and $\beta$, maximum likelihood(ML) estimators of parameters involved in the model are obtained and their asymptotic distributions are derived under stress bounded ramp tests in which the stress is increased linearly from use condition stress to the stress upper bound. The optimum test plans are also found which minimize the asymptotic variance of the ML estimator of the log mean life at design constant stress. For selected values of the design parameters, tables useful for finding optimal test plans are given. The effect of the pre-estimates of design parameters is studied.

• 한국염색가공학회지
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• 제4권3호
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• pp.122-130
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• 1992

To improve the physical properties and the dyeing properties of silk, the silk fabric was treated with urea resin and reactive dyeing. The effects of urea resin concentration, pH of padding bath and curing condition were investigated in order to find optimum condition and the following results are obtained The optimum condition for the crease recovery of silk fabric was urea resin concentration of 80 g/ι, pH of 7, the curings temperature of about 135$^{\circ}C$, and the curing time of 3 minutes. The crease recovery and the thermal insulation ratio of silk fabric were increased by the above treatment. K/S increased as the adding amount of Na$_2$SO$_4$ increased, K/S, however was not affected by the adding amount of Na$_2$CO$_3$. Co1or fastness of the dyed fabrics treated with urea resin were improved slightly compared with untreated ones.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.209-210
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• 2011

This study is aimed to draw a optimum combined fiber mix condition to improve spalling resistance and flowability of ultra high-strength concrete. As a result, W/B 12.5% concrete specimens were prevented spalling with PE0.05+ PP0.1, PE0.05+NY0.1 and W/B 12.5% concrete specimens were prevented spalling with all of combined organic fiber mix condition. But There is no significant influence of steel fiber under 5% volume ratios to prevent spalling. In the scope of this study, we suggest that condition of optimum volume ratio PE0.05+NY0.1 is to improve spalling resistance, flowability and residual compressive strength.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.29-33
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• 1996

This paper aims to clatify the potimum grinding condition for the electroplated diamond wheel in form grinding of Sr-ferrite. The main conclusions obtained were as follows. (1) The flexural strength and surface roughness of ferrite became the highest at the peripheral wheel speed of 1700m/min. (2) In the case of depth of cut larger than 0.4mm, crack layers is induced in the ground surface, the fracture type of chips exhibits slight ductile mode in the depth of cut smaller than 0.2mm. (3) When the depth of cut exceed 0.6mm, the tool life becomes extermely short due to large chipping and brackage. However, at the depth of cut .geq. 0.05mm, the diamond grain shows abrasive wear. (4) The flexural strength and surface roughness increases in proportion to the feed rate.