• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.47-51
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• 2004

The aspherical lens are used as objective lens of optical pickup. The sample product is made before manufacturing the injection mould of lens to examine the design factor. The optimum cutting conditions of the main spindle speed, the depth of cut, the feed rate are found when we cut PMMA and PC lens sample with ultra-precision SPDT. The demanded surface roughness 10 nm Ra, aspherical form error 0.5 ${\mu}m$ P-V for aspherical lens of optical data storage device are satisfied for PMMA, but not satisfied for PC.

• 한국정밀공학회지
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• 제21권6호
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• pp.52-59
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• 2004

Recently the high speed end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on distance of cut, feed rate, revolution of spindle and depth of cut. By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling. And determination($R^2$) coefficient of regression equation had a satisfactory reliability of 76.3% and regression equation of surface roughness is made by regression analysis.

• 한국정밀공학회지
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• 제18권12호
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• pp.130-136
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• 2001

Burrs formed during face milling operations are very hard to characterize because there are many parameters that affect the cutting process. Many researchers have tried to predict burr characteristics including burr size and shapes with various experimental conditions such as cutting speed, feed rate, in-plane exit angle, number of inserts, etc., but it still remains as a challenging problem for the complex combined effects between the parameters. In this paper, the Taguchi method, which is a systematic optimization application in design and analysis of experiments, is introduced to acquire optimum cutting parameters for burr minimization in face milling. Also, analysis of variance (AVOVA) is employed to study the performance characteristics in more detail. Experimental verifications are provided to show the effectiveness of this approach.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.599-606
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• 2019

In this study, it was aimed to find the optimal cutting conditions by measuring and analyzing the dimensional accuracy of SNCM 616 alloy steel, which is commonly used in industry, by precision hole machining using Ø25 mm and 8-blade reamer in CNC-HBM to be. As a result of the roundness and dimensional accuracy, it was found that the spindle speed had a significant effect on the dimensional tolerance value. Optimum cutting conditions are spindle speed 25 rpm and feed rate 20 mm / min.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.101-104
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• 2003

저준위 방사성액체폐기물 처리방법으로 에너지 소모가 적은 경제적이고 효율적인 처리방법을 제시하기 위하여 면 과 Polyester 가 함유된 합성섬유를 증발매체로 하여 자연기상 상태의 건조한 공기를 유입하여 방사성 액체폐기물과 접촉시켜 증발하는 연구를 하였다. 본 연구에서는 자연상태의 공기를 강제 유입시켜 액체의 증발현상, 증발매체표면에서의 물질전달 등 이론을 토대로 방사성액체폐기물을 처리하는 연구를 수행하였다. 실험은 방사성폐액을 직접 사용하였으며, 증발에 영향을 미치는 변수에 따라 증발 단위 면적당 방사성 폐액의 증발량측정 및 제염계수를 조사하였다. 증발효과는 유입공기의 습도가 낮고 공기의 유속과 공급액의 유량이 증가하고 폐액의 온도가 높아질수록 증발량이 증가하였다. 실험결과 습도는 70% 이하, 공급폐액의 유량이 $3.4{\ell}/hr\cdotm^2$ 이상, 공기유속은 1.14~l.47 m/sec 범위가 조업조건이며, 이때 제염계수는 $5.1{\times}10^3$, 배출공기의 방사능 농도는 $4.7{\times}10^{-13}{\mu}Ci/\textrm{m}{\ell}{\cdot}air$로 측정되었다. 공급유량이 $4.6{\ell}/hr\cdotm^2$와 공기유속이 1.47 m/sec일때 최대 증발조건으로 확인되었으며 대기의 온.습도 및 풍속에 따른 실험을 통하여 달톤형의 증발식 Air factor $[\textit{Eh}=(0.018 + 0.0141\textitv) {\delta}textitH]$를 도출하였다.

• 한국수산과학회지
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• 제43권3호
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• pp.217-222
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• 2010

Two 15-week feeding trials were conducted to investigate how the rate and frequency of feeding affected the winter growth of olive flounder ($13^{\circ}C$). In the first experiment, triplicate groups of fish (initial mean weight $117{\pm}6.0$ g) were fed extruded pellets twice a day at feeding rates of 0.1, 0.25, 0.4, 0.55, and 0.57% (satiation) body weight per day (BW/d). The weight gain, specific growth rate, and feed efficiency increased significantly (P<0.05) with the feeding rates from 0.1 to 0.55% BW/d, but no significant differences in these parameters were found for fish fed diets of 0.55% BW/d and satiation. The moisture and ash contents of whole body of fish tended to decrease as the feeding rate increased, but the opposite trend was found for crude lipid content. In the second experiment, triplicate groups of fish (initial mean weight $117{\pm}6.3$ g) were fed extruded pellets to apparent satiation at the three different feeding frequencies: one meal 2 days, one meal a day and two meals a day. The weight gain and specific growth rate of fish fed one meal 2 days were significantly (P<0.05) lower than those of fish fed one or two meals a day, whereas no significant differences in the weight gain and specific growth rate were found between fish fed one and those fed two meals a day. Feed efficiency and condition factor were not significantly affected by feeding frequency. Based on these results, a feeding rate of 0.3% BW/d is recommended as maintenance feeding level, and the optimum feeding frequency is one meal a day with satiation feeding for the growth of olive flounder (117-147 g) during winter ($13^{\circ}C$).

• 한국초지조사료학회지
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• 제23권3호
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• pp.143-150
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• 2003

본 시험은 제주지역의 화산회토양에서 인산시비량 차이(0, 50, 100, 150, 200, 250kg/ha)에 따른 제주재래 대두의 생육형질, 수량 및 사료가치 변화를 구명하기 위하여 2002년 5월 11일부터 2002년 9월 10일까지 시험하였다. 인산시비량이 0에서 250kg/ha로 증가함에 따라 개화기까지의 일수는 92일에서 97일로 지연되었고, 초장은 109cm에서 124cm로 커졌다. 분지수, 엽수, 경직경, 근장 및 근중 등도 인산시비량이 증가함에 따라 점차적으로 우세하였다. 생초수량은 무인산구에서 26.5MT/ha였으나 인산시비량 증가에 따라 점차적으로 증가되어 200kg과 250kg/ha 시비구에서는 각각 36.5MT/ha, 36.9MT/ha로 증수되었으나 두 시비구간의 유의한 차이는 없었다. 인산시비량이 증가함에 따라 건물수량은 6.0MT/ha에서 7.9MT/ha로, 단백질수량은 0.9MT/ha에서 1.4MT/ha로 TDN 수량은 3.4MT/ha에서 4.9MT/ha로 증수되었다. 인산시비량이 증가함에 따라 조단백질 함량은 15.5%에서 18.3%로, 조지방 함량은 2.2%에서 3.3%로, 가용무질소물은 42.5%에서 43.5%로, TDN 함량은 56.7%에서 61.9%로 증가되었으나 이와는 반대로 조회분은 32.1%에서 28.1%로, 조회분 함량은 7.7%에서 6.8%로 감소되었다. 제주지역의 화산회토양에서 제주재래 대두의 사초수량을 최고로 올릴 수 있는 적정 인산시비량은 200kg/ha로 추정할 수 있었다.

• 한국가금학회지
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• 제22권3호
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• pp.179-188
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• 1995

In Experiment 1, microbial assays were conducted on 57 feed ingredient samples to determine the content of total folic acid using Lactobacillus casei(ATCC 7469). Folic acid contents of feed samples pretreated with conjugase, ${\alpha}$-amylase, and a mixture of protease(Pronase)were corn, 09${\pm}$1.18($\pi$g${\pm}$SD); fish meal, 23.05${\pm}$1.27; milo, 29.34${\pm}$0.55; bakery meal, 25.80${\pm}$6.93; meat and bone meal, 56.76${\pm}$4.97; wheat middlings, 85.14${\pm}$2.56; and soybean meal, 193.97${\pm}$3.98. Experiments 2 and 3 were conducted to determine the effects of dietary supplemental folic acid and methionine on the performance of starting broiler chicks for 18 days. Four levels of dietary folic acid(0.24. 0.54,1.14 and 2.34mg/kg) and four levels of dietary methionine(0.45, 0.53,0.61, and 0.69%) were fed in a factorial design. The basal diet was based on corn, isolated soybean protein, meat and bone meal, and fish meal. It contained adequate amounts of all nutrients except methionine and folic acid in both experiments. Increased growth rate was observed in chicks fed the basal diet supplemented with either folic acid or methionine. Total dietary folic acid and methionine plus cysteine requirements for optimum growth were estimated to be 1.80 mg/kg and 0.89% in Experiment 2, and 1.47 mg/kg and 0.91% in Experiment 3, respectively. There were interactions between dietary folic acid and methionine on weight gain in both experiments. Chicks fed diets containing 2.34 mg folic acid /kg tended to display slow growth rate in both experiments. There was a significant linear feed conversion response to folic acid in Experiment 2, and a significant quadratic feed conversion resuonse to methionine in Experiment 3. There were both linear and quadratic liver folic acid responses to dietary folic acid in both experiments. There was no indication that dietary methionine had any effect on liver folic acid content. The incidence of tibial dyschondroplasia increased with increasing supplemental methionine, but were no significant differences detected at 5% level.

• 한국가금학회지
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• 제25권4호
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• pp.185-193
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• 1998

본 연구는 황기의 사료내 첨가·급여가 육계의 항병성, 생산성 및 계육의 품질에 미치는 영향을 구명하고자 시행하였다. 기초사료는 전기 3주와 후기 2주에 각각 21과 19％ 수준의 조단백질이 함유되었다. 시험설계는 황기의 첨가수준을 0, 0.25, 0.50, 1.00％로 4개의 처리구로 하였고, 처리구당 4반복으로 하였으며, 반복당 50수씩 800수를 이용하였다. 증체량, 사료섭취량, 사료요구율은 5주동안 매주 측정하였고, 시험 종료시에 혈액의 성상 및 계육의 지방과 단백질함량을 조사하였다. 황기 첨가구는 대조구에 비하여 성장에 영향을 미치지 못하였으나, 사료섭취량은 대조구에 비하여 현저하게 감소하였고(P<0.05), 사료효율은 0.25％첨가구에서 개선되는 경향을 보였다. 육계용 사료에 황기의 첨가수준이 증가함에 따라서 혈청 콜레스테롤과 AST는 감소하였으며, 헤마토크릿, 지방, 인과 BUN의 수준은 0.25％첨가구에서 감소하였다. 혈청 GH와 IGF-1은 0.50과 1.00％ 황기 급여구에서 대조구에 비하여 낮았다. 0.25와 0.50％황기 첨가구에서 가슴육의 지방과 단백질함량은 대조구에 비하여 증가하는 경향을 보였으나, 0.50％이상의 수준에서는 일관성이 없었다. 본 시험의 결과 육계용 사료에 황기의 적정 첨가수준은 0.25％이하에서 생산성과 항병성 및 계육의 품질을 개선할 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1606-1611
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• 2007

The experiment was conducted to investigate the effects of dihydropyridine on laying performance and fat metabolism of laying hens. Five hundred and forty laying hens, 40 weeks old, were randomly allotted to three groups, each of which included four replicates of 45 hens. The groups were given a basal corn-soybean meal diet supplemented with 0, 150 mg/kg and 300 mg/kg dihydropyridine. Results showed that compared with the control group (0 mg/kg dihydropyridine), supplements of 150 and 300 mg/kg dihydropyridine increased egg production rate by 9.39% (p<0.01) and 12.97% (p<0.01), increased mean egg weight by 3% (p>0.05) and 4.8% (p>0.05), and improved feed efficiency by 9.54% (p<0.05) and 7.25% (p<0.05), respectively; The addition of 150 and 300 mg/kg dihydropyridine decreased percentage of abdominal fat by 35.4% (p<0.05) and 46.9% (p<0.05), decreased liver fat content by 32.4% (p<0.05) and 10.5% (p<0.05), increased HSL activity of abdominal fat by 39.64% (p<0.05) and 48.48% (p<0.05), increased HSL activity of liver by 9.4% (p>0.05) and 47.34% (p<0.05) and increased the content of cAMP in adenohypophysis by 14.67% (p<0.05) and 10.91% (p<0.05), respectively; The inclusion of 150 mg/kg dihydropyridine increased liver superoxide dismutase activity by 69.61% (p<0.05), and increased hepatic apoB concentration by 53.96% (p<0.05); The supplementation of 150 or 300 mg/kg dihydropyridine decreased malondialdehyde concentration of hepatic mitochondria by 30.90% (p<0.01) and 10.39% (p<0.05), respectively; Supplemented dihydropyridine had no significant effects on TG, Ch HDL-C and VLDL-C concentrations in serum; addition of 150 or 300 mg/kg dihydropyridine increased T3 levels in serum by 15.34% (p<0.05) and 11.88% (p<0.05) and decreased insulin concentration by 40.44% (p<0.05) and 54.37% (p<0.05), respectively. The results demonstrated that adding dihydropyridine had the tendency of improving very low density lipoprotein receptor (VLDLR) content in the ovary. It was concluded that dihydropyridine could improve laying performance and regulate the fat metabolism of laying hens and that 150 mg/kg dihydropyridine is the optimum dose for laying birds in practical conditions.