• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.539-548
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• 1995

The process of yolk absorption and the growth pattern of churn salmon, Oncorhynchus keta alevin were studied. Matured males and females of chum salmon were sampled from the Namdaechun River in the east coast of Korea, and then an artificial fertilization was carried out using their eggs and sperms. Fertilized eggs were incubated in controlled water temperature of $13^{\circ}C$ and samples of 40 alevins were randomly taken at just hatching and at every three days between 12 days alter hatching and yolk absorption. The means of total length and total weight of hatched alevins were respectively 1.97cm and 1.85g and the yolk absorption took about 33 days after hatching, based on the morphological measurement. Growth curves of total length, total weight and somatic weight were fitted well with the Gompertz growth model. However, the shrinking in yolk-sac length, yolk-sac weight, yolk-sac height and yolk-sac volume revealed a linear phenomenon until the absorption of yolk was completed. The relative growth of chum salmon alevin, such as the relationship between total length and total weight, or between total weight and yolk-sac weight, was also studied.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.631-637
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• 2006

In this study, fundamental properties such as fresh and hardened performance of concrete mix(specification : 25-24-18) added fluorine-silicate hybrid based crack reducing agent(FS) were measured. Addition of FS ranged from 0.5% to 2.0% at intervals 0.5% based on cement weight. Adequate dosage(0.5%) of FS derived from basic properties measurements applied and compared resistance for shrinkage crack. The permeability of concrete in the absence(24-S-0.0) and presence(24-S-0.5) of evaluated at a mock-up sized concrete. Concrete added FS improved resistance for shrinkage crack and consequently crack number, length and area decreased to $50{\sim}74.4%$ compared non-added. As well, by the addition of FS, the resistance for permeability and penetration depth to concrete surface region increased 67% and 40%, respectively. Therefore it was confirmed that shrinkage crack resistance and permeability of concrete could be improved by the addition of FS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.35-39
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• 1993

항공기의 플러터 현상을 예방키 위한 개발시의 주요 공학적 임무로는 플러 터 해석, 풍동 플러터 시험, 실기체에 대한 지상진동시험 및 비행 플러터 시 험이 있다. 이들 업무는 군용 항공기의 경우에는 군사 규격서, 민간 항공기 의 경우는 FAR 규정 등에 항공기 개발 및 개조시에는 필히 수행토록 명시 되어 있으며, 특히 개발항공기의 인증을 받기 위해서는 초도 비행전까지 필 수적으로 완료되어야 하는 업무이다. 이중 항공기 지상진동시험은 개발항공 기의 초도 비행전에 실기체를 대상으로 하는 구조 동특성 규명시험으로써 플러터 해석 모델의 정확도를 입증하고 그 해석모델을 수정하거나 개선시키 는데 필요한 구조의 동특성 변수들을 실험적으로 규명하는 시험이다. 이 시 험은 개발된 항공기의 초도비행허가를 획득하고 비행속도제한을 설정키 위 해서 초도비행 직전에 초도 개발 비행기를 대상으로 필수적으로 수행되어야 하는 필수적 시험이다. 이에 따라 개발된 항공기의 전기체 지상진동시험을 수행하였고, 시험데이터의 모달해석을 하였다. 이 시험을 수행하기 위해 3개 의 가진기를 사용하였고, 모두 159개의 지점에서 주파수응답 함수를 얻었다. 최대 48 채널의 데이터 획득시스템을 사용하였으므로, 네번에 걸쳐 측정위치 를 옮겨 전체데이타를 획득하였다. 지상진동 시험의 최종해석 결과는 유한요 소 모델의 유효성을 검토하는데 사용되었고, 시험 데이타를 이용한 가진응답 해석(Forced Response Analysis)을 통하여 비행플러터 시험시에 사용되는 플러터 가진기의 위치선정 및 가진력의 크기를 결정하는데 이용하였다.ncy)가 저주 파수대로 천이(Lower Shift)하는 현상이 나타났으며, 일정한 작업량이라도 작업중량을 줄이고 작업 빈도를 높여서 작업할 경우에 이러한 현상이 더욱 두드러졌다. 작업시간의 경과에 따른 MVIS의 감소 현상은 작업빈도가 높고 비대칭형 작업일 때 가장 크게 나타났다. 총손실을 줄이고, 상대적 비용절감효과를 갖게할 수 있다고 하였다. 따라서 본 연구에서는 성인 여성기성복의 치수적합성을 높이기위하여 출산 후 중년에 접어 들면서 체형이 변화되는 것을 고려하여 연령을 분류하고(18세-34세, 30세-51세), 각 연령 집단에 따른 체형을 각각 3가지로 분류하였다. 이에 따라 의복 생산시의 총손실을 줄이기위한 상의, 하의생산시 필요한 부위별 최적규격치 간격을 제시하였다.적인 기능으로 보여지는 것에 좁혀서 작업능력의 연령증가 변화에 대하여다원적 평가를 하는 것이 실제적이라고 할 수 있다. 따라서 본 연구에서는 인간이 가지고 있는 다수의 기능중에서 수지교 치성과 연령증가와의 관계를 조사한다. 만약 연령증가 만으로 수지교치성을 평가 할 수 없는 경우에는 어떠한 요인이 수지기민성의 변화에 영향을 미치는가를 검토한다.t list)에서 자동적으로 사건들의 순서가 결정되도록 확장하였으며, 설비 제어방식에 있어서도 FIFO, LIFO, 우선 순위 방식등을 선택할 수 있도록 확장하였다. SIMPLE는 자료구조 및 프로그램이 공개되어 있으므로 프로그래머가 원하는 기능을 쉽게 추가할 수 있는 장점도 있다. 아울러 SMPLE에서 새로이 추가된 자료구조와 함수 및 설비제어 방식등을 활용하여 실제 중형급 시스

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.96-102
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• 1981

Effect of shifting planting-time and different nitrogen on the yield and characteristics of plant growth in safflower, Chrthamus Tinctorius L. This study was carried out to investigate the optimum sowing-date and the ecological variations due to differerent amount of nitrogen for safflower on the Experiment Farm of Sang Ji college from March 17 to may 16, 1980, sowing seeds with an interval of 10 days and the amount of nitrogen were applied in 5 levels (Non, half-standard, standard, one and half-ordinary amount-No and twice amount). The triple super phosphate and pottassium chloride were applied only in standard amount. The results obtained are summarized as follows; 1. As sowing-date was delayed, the germination-ratio decreased, germinating speed increased, and the time required to attain the most vigorous germinating stage and days required for germination shortened. 2. Plant height, number of branch and stem diameter showed a decrease as sowing-date was delayed. And at the same time, plant height and number of branch showed a tendency to increase as amount of nitrogen was increased. 3. As sowing-date was delayed, the number of pods and the weight of 1000-grains were decreased. Moreover, the earlier sowing-date was, the more it increased. And as amount of nitrogen was increased, number of pods and yield also were strikingly increased. 4. The fresh-weight of flower with orange and orange-red colour, as influenced by the different sowing-date, was found out to be largest at the begining of April. But increasing amount of nitrogen did not show influence upon the promotion of flowering. 5. Judging from the results reported above, the optimum sowing-date of safflower seemed to be the begining of April; also the culture of safflower seemed to be the effects of much amount of nitrogen.

• The Journal of Engineering Geology
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• v.21 no.2
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• pp.133-145
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• 2011

Unsaturated soil column tests were performed for weathered gneiss soil and weathered granite soil to assess the relationship between infiltration velocity and rainfall condition for different rainfall durations and for multiple rainfall events separated by dry periods of various lengths (herein, 'rainfall break duration'). The volumetric water content was measured using TDR (Time Domain Reflectometry) sensors at regular time intervals. For the column tests, rainfall intensity was 20 mm/h and we varied the rainfall duration and rainfall break duration. The unit weight of weathered gneiss soil was designed 1.21 $g/cm^3$, which is lower than the in situ unit weight without overflow in the column. The in situ unit weight for weathered granite soil was designed 1.35 $g/cm^3$. The initial infiltration velocity of precipitation for the two weathered soils under total amount of rainfall as much as 200 mm conditions was $2.090{\times}10^{-3}$ to $2.854{\times}10^{-3}$ cm/s and $1.692{\times}10^{-3}$ to $2.012{\times}10^{-3}$ cm/s, respectively. These rates are higher than the repeated-infiltration velocities of precipitation under total amount of rainfall as much as 100 mm conditions ($1.309{\times}10^{-3}$ to $1.871{\times}10^{-3}$ cm/s and $1.175{\times}10^{-3}$ to $1.581{\times}10^{-3}$ cm/s, respectively), because the amount of precipitation under 200 mm conditions is more than that under 100 mm conditions. The repeated-infiltration velocities of weathered gneiss soil and weathered granite soil were $1.309{\times}10^{-3}$ to $2.854{\times}10^{-3}$ cm/s and $1.175{\times}10^{-3}$ to $2.012{\times}10^{-3}$ cm/s, respectively, being higher than the first-infiltration velocities ($1.307{\times}10^{-2}$ to $1.718{\times}10^{-2}$ cm/s and $1.789{\times}10^{-2}$ to $2.070{\times}10^{-2}$ cm/s, respectively). The results reflect the effect of reduced matric suction due to a reduction in the amount of air in the soil.

• Food Science and Preservation
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• v.23 no.4
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• pp.479-487
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• 2016

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) and ethylene-absorbent on the qualities of Prunus mume fruit. Prunus mume fruits were stored without film packaging (Cont), packed in LDPE film (Cont-P), and packed with ethylene-absorbent (Cont-PE). Fruits were treated with 1-MCP (1 ppm) for 24 hr at $1^{\circ}C$. After treatment, fruits were packed in LDPE film (MCP-P) and with ethylene-absorbent (MCP-PE) and then stored at $1^{\circ}C$ for 8 weeks. Total soluble solids increased during storage but decreased after 6 weeks while total acidity decreased during storage. Cont was almost completely decayed after 8 weeks of storage while Cont-P, Cont-PE, MCP-PE, and MCP-P were 46, 69, 83, and 5% decayed, respectively. L value decreased but a value increased during storage in all samples. Firmness of peel and flesh of samples decreased gradually for 8 weeks. Respiration rate did not show any significant difference among samples. Ethylene production of Cont showed $0.05{\mu}L/kg/h$ but immediately after 1-MCP treatment, it showed $0.02{\mu}L/kg/h$. Oxalic and malic acids decreased while citric acid increased during storage; fructose and glucose substantially decreased after 8 weeks whereas sorbitol and sucrose increased upto 4 weeks and then decreased thereafter. Based on these results, packing the fruits treated with 1-MCP could extend the freshness of Prunus mume fruit.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.409-413
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• 2004

We have studied quality changes of fully ripe fruit of Korean native pumpkin 'Yangsan' regarding the following parameters: pH, sugar content, weight, water content, contents of crude protein and amino acids during 60 days storage at room temperature. As the results, there was no changes in sugar contents according to the storage period, but pH was changing to a little acidic direction with slight decrease in weight and water content. Contents of total crude proteins and comprising amino acids were increased during the storage period. The main contents of amino acids of the Korean native pumpkin, Yangsan, were glutamic acid (15.5%), aspartic acid (10.1%), lysine (8.7%), valine (7.5%), leucine (7.1%) and alanine (6.6%), which were not highly influenced during storage period. Additionally we have investigated the content of free amino acids and color changes during processing of Yangsan under high temperature at $121^{\circ}C$ and high pressure at $1\;kg/cm^2$. In fully ripe fruits, a total of 29 kinds of free amino acids were detected including 8 kinds of essential amino acids (histidine, isoleucine, leucine, lysine, phenylalanine, methionine, threonine and valine). More than 35% of total free amino acids were aspartic acid (20.3%) and asparagine (15.4%); ornithine, citrullin, and arginine, which are related to Ornithine cycle, were also detected in fully ripe fruits. But when treated with high temperature and high pressure, glutamic acid and arginine were decreased rapidly whereas ammnonium chloride was relatively increased. Moreover "b" value as yellow color indicator was decreased from 17.45 to 9.14 while treated for 60 minutes with high temperature and pressure, caused by the degradation of ${\beta}-carotene$ and other yellowish pigments in Yangsan.

• Korean Journal of Agricultural Science
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• v.19 no.1
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• pp.51-64
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• 1992

This experiment was carried out to elucidate the effects of the thyroid function on lactation in female rats. One hundred and five female rats, whose body weight was approximately 250g with normal parturition, were divided into 3.5 THY, 35 PTU, and 35 CON. The $30{\mu}g$ L-thyroxine per rat was administered subcutaneously for the THY group with 3-days intervals arid 0.03% propylthiouracil solution was drunk for the PTU group. After the treatments body weight, thyroid weights and prolactin levels in serum, and histological changes in thyroid and mammary gland were investigated for 3 weeks with 3-days interval. The results obtained were as follows 1. The body weights of PTU group were lower than those of CON arid THY groups. The changes in body weights were significant between 3 and 6 days and between 15 and 18 days. 2. Differences in thyroid weight among the groups were significant after 9 days, The thyroid weights of PTU group were much higher than those of CON and THY group. 3. The follicular epithelia of PTU group after 6 days showed cuboidal phenomena which were accompanied by hypertrophy and hyperplasia, and this phenomena continued until post weaning period. Those of THY group after 9 days showed a squamous degeneration together with pyknosis. 4. The prolactin concentrations of THY group were higher than the other groups after 12 days. and those of CON group were higher than the others after 18 days. However, those of PTU group were lower all through the period. 5. The secretary epithelial cells of THY and CON groups became cuboidal after 12 days, but after 15 days the differentiation of mammary tissue was progressing in THY group faster than CON group. The degeneration of mammary tissue were observed in PTU group as time lapses, so after 15 days the exfoliation of secretory epithelium and atrophy of alveolus were recognized. 6. The body weights of offspring for all experimental groups were increasing as time lapses, but the values for PTU group were markedly lower than the others.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1503-1510
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• 1999

This study was performed to investigate the physicochemical properties of Korean Citrus sudachi fruit which were harvested at different harvesting time(every 20 days from Sep. 3 to Nov. 8) and region(Seogwipo and Cheju city area). The average weight of Citrus sudachi fruit harvested from Seogwipo area was as twice as that of Cheju area at the same period. The moisture content in fruit peel increased by ripening of fruit, but that of fruit juice showed no difference. The content of reducing sugar in fruit peel and fruit juice increased 2 times from Sep. 3 to Nov. 8. The content of crude fiber decreased both in fruit peel and fruit juice as progression of ripening. Crude protein and ash contents decreased in fruit peel but revealed no differences in the fruit juice during the same period. pH decreased in fruit peel and juice with its ripening. The content of vitamin C decreased by ripening of fruit. The transmittance which is important quality factor in fruit juice increased from Sep. 20 to Oct. 13. The content of free sugar increased about 2 times in fruit peel from Sep. 3 to Nov. 8 and showed 4 times increase in fruit juice at the same period. In the composition ratio of mineral, Ca and K were abundant in the fruit peel, but only K was the most abundant mineral in fruit juice than any others.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.182-186
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• 1985

In order to determine the optimum sowing date of peanut in the middle part of Korea, peanut's 100-grain-weight and physico-chemical compositions for peanut cultivars such as runner (Yeoju landrace), semi-spanish (Suweon No. 15) and spanish types (Wasedairu) to different seeding date which planted at interval of ten days from May 5 to July 4, in 1981, was carried out. The 100-grain-weight and crude fat of peanut were increased from May 5 to May 25, but after that decreased. And the 100-grain-weight of peanut was great in order of Wasedairu, Suweon No. 15 and Yeoju landrace. The highest amount of crude fat was seen in peanuts which was sown at May 25 and May 15. Unsaturated fatty acids are composed of $80{\sim}85%$ of oleic and linoleic acid, but saturated fatty acids are constituted of $10{\sim}15%$ of palmitic acid and $1{\sim}5%$ of stearic and arachidic acid. Composition ratio of fatty acid in peanut was changed greatly according to sowing date. According to the late sowing date linoleic and palmitic acid were increased but oleic acid was decreased, respectively.