• Journal of the Korean Data and Information Science Society
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• 제11권2호
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• pp.225-233
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• 2000

수명시험에서 시험에 장기간 노출된 대상 부품이나 실험 대상자의 수명은 관측되는 경우보다 관측중단이 일어나기가 쉽다. 이와 같은 경우에 임의중단모형에서 생존함수 추정량으로 흔히 이용되는 Kaplan과 Meier의 추정량은 수명분포의 오른쪽 꼬리부분에서 심각한 편의가 발생된다. 이러한 문제점에 대한 대안으로 정상적으로 관측된 최장수명보다 큰 관측중단수명이 많은 극단적인 오른쪽 관측중단모형에서 새로운 비모수적 생존함수 추정량을 제안하고 그 특성을 몬테칼로 모의실험을 통하여 기존의 추정량과 비교 분석하였다.

• 대한공간정보학회지
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• 제13권3호
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• pp.15-24
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• 2005

국토의 난개발을 방지하기 위해 도입된 토지적성평가는 공간 및 물리적인 특성이 서로 다른 육지와 도서지역의 평가기준을 일률적으로 적용하는 데 있어서 많은 문제점을 내포하고 있다. 본 연구에서는 공간적 지리적 지역적 특성이 뚜렷이 다른 도서지역의 효율적 토지적성평가방법의 연구를 위해서 생활권역을 고려한 평가단위와 이를 기반으로 한 평가지표 개발 등에 관하여 연구였다. 평가권역을 고려한 평가단위에서는 중생활권의 평가가 가장 양호하였으며 거리분석에 있어서는 해양을 고려한 거리 분석방법을 제안하여 도서간의 접근성을 고려한 평가방법을 제시하였다.

• 한국환경과학회지
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• 제20권11호
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• pp.1395-1401
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• 2011

In this study, Life Cycle Assessment(LCA) has been carried out to evaluate the environmental impacts of a metallic can. A 360 mL volume of an aluminum can bottle was used as the functional unit. The results of Life Cycle Inventory(LCI) showed that iron ore and coal were the major parts of the input materials, whereas aluminum can products, carbon dioxide, wastewater, and hazardous wastes were those of the output ones. According to LCA weighting, it was observed that the most significant impact potential was found to be global warming(49.11%) followed by abiotic resource depletion(47.72%). In the whole system, cold rolled steel coil showed the largest environmental impact potential(86%), followed by electricity(14%). Meanwhile, lubricating oil and industrial water had the minor portion of the total environmental impact potentials. It was suggested that the use of cold rolled steel and electricity should be the main source for $CO_2$, resulting in the big impact on global warming.

• Asian-Australasian Journal of Animal Sciences
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• 제19권7호
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• pp.1019-1025
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• 2006

Two experiments were conducted separately to study the effect of astaxanthin on production performance and egg quality in laying hens and meat quality in finishing pigs. In Experiment 1, four hundred Brown Hy-Line layers, 26 weeks of age, were randomly divided into five treatments according to a single factorial arrangement. Each treatment had four replicates comprising 20 birds each. The dietary treatments were: 0, 0.7, 0.9, 1.1 and 1.3 ppm of astaxanthin fed for 14 days. Then all the birds were fed an astaxanthin-free diet (0 ppm astaxanthin) for an additional 7 days. The results showed that dietary astaxanthin had no significant effect on layer production performance. There was no significant effect (p>0.05) on egg weight, yolk height and Haugh unit (HU) with increasing dietary astaxanthin level and increased storage time. Yolk color was linearly increased (p<0.01) with the increasing dietary astaxanthin level and significantly decreased with the increasing storage time (p<0.05). The TBARS value in yolk decreased linearly (p<0.05) with increasing amount of dietary astaxanthin and storage time. When the diets were replaced with the astaxanthin-free feeds, all parameters concerning egg quality decreased with increasing days of measurement, especially the yolk color, and HU significantly decreased (p<0.05). In experiment 2, thirty-six barrows ($L{\times}Y{\times}D$), $107{\pm}3.1kg$ BW, were randomly divided into three treatments according to a single factorial arrangement. Each treatment had three replicates comprising 4 pigs each. The dietary treatments were: 0, 1.5 and 3.0 ppm of astaxanthin fed for 14 days. The results showed that dietary astaxanthin had no significant effects on production performance. There was a linear effect (p<0.05) on dressing percentage, backf.at thickness and loin muscle area with increasing dietary astaxanthin level. There were no significant effects (p>0.05) on the TBARS value, drip loss, meat color, marbling and $L^*$, $a^*$, $b^*$ values. Cholesterol concentration in meat was not affected by dietary addition of astaxanthin. It could be concluded that astaxanthin supplementation was beneficial to improve egg yolk color; egg quality during storage and it also could improve the meat quality of finishing pigs.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1750-1759
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• 2020

The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated K_D value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min^-1 nmol^-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

• 한국수산과학회지
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• 제30권4호
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• pp.614-619
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• 1997

해양오염의 진단을 위한 생화학적 오염지표 설정의 기초연구의 일환으로서 오염의 정도가 심각한 서해산 도다리 (Pleuronichthys cornutus)의 뇌 및 근육중의 acetylcholinesterase (AChE) 및 butyrylcholinesterase (BChE)의 활성, 그리고 lactate dehydrogenase(LDH)의 활성을 분석 평가하였다. 서해안 자연산 도다리의 뇌 및 근육중의 AChE의 활성은 $7,708.2{\pm}549.7\~8,872.7{\pm}515.1\;unit/min/mg$ protein (brain) 및 $4,071.2{\pm}647.9\~6,0245{\pm}493.7unit/min/mg$ protein (muscle)로서 대조군으로 사용한 동해안 포항의 자연산 도다리의 뇌 및 근육중의 AChE의 활성 ($11,168.9{\pm}822\;unit/min/mg\;protein\;(brain)$ 및 $6,812.2{\pm}533.0\;unit/min/mg\;protein\;(muscle);\;100\%$) 대비 각각 $69.1\~79.4\%$ 및 $59.8\~88.4\%$로서 대조군 대비 $20\~30\%$ (뇌) 및 $10\~40\%$ (근육) 정도나 유의적으로 저하되었다. 또한 서해안 자연산 도다리의 뇌 및 근육중의 BChE의 활성은 $274.1{\pm}51.2\~362.1{\pm}27.3\;unit/min/mg\;protein(brain)$ 및 $1,535.4{\pm}301.4\~1,854.7{\pm}250.7\;unit/min/mg\;protein(muscle)$로서 대조군으로 사용한 동해안 포항의 자연산 도다리의 뇌 및 근육중의 BChE의 활성 ($390.2{\pm}32.5\;unit/min/mg\;protein\;(brain)$ 및 $2,732.5{\pm}320.1\;unit/min/mg\;protein\;(muscle);\;100\%$) 대비 $92.8\~70.3\%$ (뇌) 및 $56.2\~67.9\%$ (근육)으로서, 대조군 대비 $10\~30\%$ 및 $35\~45\%$나 유의적으로 저하되었다. 서해안의 자연산 도다리의 혈청중의 LDH의 활성은 격포산 도다리를 제외하고 $0.075{\pm}0.030\~0.078{\pm}0.030\;unit/m\ell\;serum$로서 대조군으로 사용한 동해안 포항의 자연산 도다리의 혈액중의 LDH의 활성 $(0.105{\pm}0.030\;unit/m\ell\;serum;\;100\%)$ 대비 약 $30\%$정도나 유의적으로 저하하였다. 이상의 실험결과에서 볼 때 서해안의 자연산 도다리의 서식환경인 서해안의 오염도 상당히 심각할 것으로 판단된다.

• 한국환경과학회지
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• 제21권12호
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• pp.1529-1533
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• 2012

The objective of this study was to evaluate the effect of applying alum (aluminum sulfate) and aluminum chloride on pH and pathogen populations of Hanwoo manure. A total of 36 steers (8 months old and averaging 300 kg in weight) were used in this trial and allotted to 9 pens (3 replication pens per group with 4 steers per experimental unit, $5{\times}8$ m). Chemical additives were applied as a top dressing with garden rake to a depth of 1 cm of manure with wood shavings in each treatment. The chemical amendments were control (without chemical amendments), 50 g of alum and 50 g of aluminum chloride/kg of Hanwoo manure. The experiment was carried out for 4 weeks. Adding alum and aluminum chloride to Hanwoo manure reduced (P < 0.05) pH compared to untreated controls during the 4-wk period. Both levels of the alum and aluminum chloride treatments tested decreased (P < 0.05) Escherichia coli and Salmonella enterica populations in Hanwoo manure at 2 and 4 weeks. It appears that the reduction in pathogen populations was primarily associated with the lower manure pH. If more strict environmental regulations are put into effect regarding pathogen populations from Hanwoo facilities, treating Hanwoo manure with alum and aluminum chloride may be a good management practice.

• 한국초등과학교육학회지:초등과학교육
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• 제42권3호
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• pp.399-408
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• 2023

본 연구에서는 초등학교 과학 '동물의 생활' 단원 수업에 메이커교육 프로그램을 개발하고 적용하여, 학생들의 학업성취도와 창의적 문제해결력에 미치는 영향을 조사하였다. 메이커교육 프로그램의 주제는 '동물의 특징을 모방한 로봇 VR 전시관 만들기'이다. 프로그램의 단계는 TMI 메이커교육 모형에 따라 과학 개념을 탐구하고, 창의적으로 로봇 VR 전시관을 만드는 활동으로 구성하였다. 연구 결과, 해당 프로그램의 적용은 유의미한 학업성취도와 창의적 문제해결력 향상을 가져왔다는 것을 발견했다(p<.05). 본 연구는 초등 과학 수업에서 메이커교육의 효과성을 입증한 것으로, 메이커교육을 적용하여 학생들의 과학 학습에 대한 흥미와 참여도를 높일 수 있을 것이다. 또한, 다양한 주제와 프로그램을 개발하여 초등학교 과학 수업에서 메이커교육을 더욱 적극적으로 활용할 수 있도록 노력할 필요가 있다. 본 연구의 결과를 일반화하기 위해서는 다양한 연령층과 초등 과학의 다른 영역에서 메이커교육의 효과성을 조사하는 추가적인 연구가 필요하다. 또한, 교육자들이 메이커교육을 효과적으로 활용할 수 있도록 교육 및 교육자 역량 강화가 필요하다.

• 한국환경과학회지
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• 제22권4호
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• pp.425-433
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• 2013

A mass balance of process was calculated by using the analysis of basic unit and environmental assessment of all the processes of Busan fashion color industry cooperative that operates a combined heat and power plant and a bio treatment plant. The mass balance for the combined heat and power plant was done, based on boiler and water treatment processes while each unit reactor was used for the bio treatment plant. From the results above, a resource recycle network, a treatment flowchart for food waste water/wastewater treatment and a carbon reduction program were established.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1224-1229
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• 2003

The combined effects of washing, sanitization and coating of eggshell on the physical and microbiological quality during storage were evaluated at $4^{\circ}$ and $30^{\circ}C$. The interior qualities of the eggs were assessed by weight changes, yolk index, albumen index, Haugh unit value, and microbial contamination of egg shell and egg white during 30 days of storage in untreated, washed, or sanitized and mineral oil-coated eggs. The results suggest that these changes were faster in higher temperature ($30^{\circ}C$) than lower temperature ($4^{\circ}C$) storage, and washed eggs deteriorated faster than untreated eggs. The sanitized and coated eggs maintained the best quality during storage in all parameters measured. The shelf-life of washed, sanitized and coated eggs could be extended 4-5 fold compared to that of washed or untreated eggs.