• Journal of Korean Society of Forest Science
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• 제85권3호
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• pp.453-461
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• 1996

Three Phyllostachys stands of P. pubescens, P. bambusoides and P. nigra var, henonis in Sunchon were studied to investigate biomass, net production and nutrient distribution. Five $10m{\times}10m$ quadrats were set up and 20 sample culms of 2 years and over were harvested for dimension analysis in each stand. One year old culms and subterranean parts were estimated by the harvested quadrat method. The largest mean DBH, height and basal area were shown in P. pubescens stand, and followed by P. nigra var. henonis stand and P. bambusoides stand. There was little difference in accuracy among three allometric biomass regression models of logWt=A+B1ogD, $logWt=A+BlogD^2H$ and logWt=A+BlogD+ClogH, where Wt, D and H were dry weight, DBH and height, respectively. Analysis of covariance showed that there were significant differences in intercept among the linear allometric biomass regressons of three Phyllostachys species. Biomass included subterranean parts was the largest in P. pubescens stand(103.621t/ha), and followed by P. nigra var. henonis stand(86.447t/ha) and P. bambusoides stand(36.767t/ha). Leaf biomass was 6.3% to 7.8% of total biomass in each stands. The ratio of aboveground biomass and subterranean biomass in each stand was 1.87 to 2.26. Net production included subterranean parts was the greatest in P. pubescens stand(6.115t/ha/yr), and followed by P. nigra var. henonis stand(5.609t/ha/yr) and P, bambusoides stand(3.252t/ha/yr). The highest net assimilation ratio was estimated in P. pubescens stand(2.979), and followed by P. nigra var. henonis stand(2.752) and P. bambusoides stand(2.187). Biomass accumulation ratio of each stand was 2.679 to 5.358. Concentrations of N, P and Mg were the highest in leaves, and followed by subterranean parts, and culms+branches in all three species. Concentration of Ca was the highest in leaves, and followed by culms+branches, and subterranean parts in all three species. The difference in biomass among three species stands was caused by their culm size, leaf biomass, net assimilation ratio, and efficiency of leaves to produce culms.

• Journal of the Korean Society of Food Science and Nutrition
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• 제26권2호
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• pp.327-333
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• 1997

This study was conducted to investigate the effect of Quercus acutissima CARRUTHERS extracts on lipid metabolism. Sprague-Dawley male rats$(110{\pm}10g)$ were fed on containing normal and high fat diets. They were orally administrated(0.02g/100g B.W.) of Quercus aculissima CARRUTHERS ethylacetate-extract and water-extract at the same time once a day respectively. The rats were sacrificed after 6 weeks of feeding periods. In high fat diet group, liver and heart weight were increased but kidney weight was decreased. Contents of total lipid, triglyceride and phospholipid were increased in high fat diet groups. But the degree of increment was reduced by administration of Quercus acutissima CARRUTHERS extracts and water extract was more effective. Significant decrease in serum total lipid content by administration Quercus acutissima CARRUTHERS extracts was not due to decrease of triglyceride content but total cholesterol content. Whereas HDL-cholesterol content was significantly decreased in high fat diet group and improved by administration of Quercus acutissima CARRUTHERS extracts. Total lipid, triglyceride and total cholesterol contents in liver were also increased in high fat diet group but phospholipid content was significantly decreased. The results indicate that Quercus acutissima CARRUTHERS extracts were effective in preventing hyperlipidemia and water extract was more effective.

• Korean Journal of Poultry Science
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• 제42권2호
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• pp.147-156
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• 2015

This study was conducted to investigate the effects of dietary resveratrol on growth performance, blood biochemical parameters, immunoglobulin, and blood antioxidant activity in broiler chicks. Three hundred twenty one-day old broiler chicks were divided 8 treatments (C(-), basal diet; C(+), basal diet with antibiotics; DL-${\alpha}$-tocopherol 20 IU; DL-${\alpha}$-tocopherol 200 IU; resveratrol 20 ppm; resveratrol 200 ppm; methylated resveratrol 20 ppm; methylated resveratrol 200 ppm) with 4 replicates and 10 birds per replicate. Birds were reared for 35 days, and, at the age of 35 days, eight birds of average weight from each replicate were selected for blood samples collection. There were no significant differences on feed intake and feed conversion ratio. But final body weight and weight gain in antibiotics, resveratrol and methylated resveratrol treatments were significantly higher than no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). There were no significant differences on carcass rate and relative organ weights among treatments, however, weights of liver and bursa of februcius in antibiotics, resveratrol and methylated resveratrol treatment were lower than other treatments. Weight of pancreas was high in resveratrol and methylated treatment. On the cecal microflora (total microbes, Coliform bacteria, Salmonella spp., and lactic acid bacteria), these in resveratrol and methylated resveratrol treatments didn't show the differences compared with those in no-antibiotics, antibiotics, and ${\alpha}$-tocopherol treatments. In the serum, there were no significant differences on creatinine, blood urea nitrogen (BUN), total protein, albumin, globulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) among treatments, though globulin contents of reseveratrol 200 ppm and methylated resveratrol 20 ppm treatments decreased compared to those of other treatments. Immunoglobulin (IgA, IgG and IgM) were significantly decreased in antibiotics and resveratrol treatments compared to that of no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). Superoxide dismutase (SOD) like activity tended to increase in resveratrol groups (P<0.05), however, there was no significant difference on malondiakdehyde (MDA) content among treatments. In conclusion, these results showed that resveratrol derived from mulberry can be used as alternative of antibiotics through improvement of broiler's performance and maintain of health.

• Journal of Korean Society of Forest Science
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• 제95권1호
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• pp.82-90
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• 2006

To examine the effects of nitrogen and phosphorus fertilization on soil nitrogen (N) mineralization, we monitored rates of soil nitrogen mineralization and nitrification in 41-year-old pitch pine (Pinus rigida Mill.) and Japanese larch (Larix kaempferi Gordon) stands growing on similar soil condition in central Korea. For this study, we used the buried-bag incubation method. Fertilizers were applied at three levels [control (C), 200 N kg/ha+25 P kg/ha (LNP), and 400 N kg/ha+50 P kg/ha(HNP)] on 5 June, 1996. Mineral soils (0~20 cm) were incubated 6 times with 45-day-interval from 5 June 1996 to 4 June 1997. Initial soil moisture contents were significantly different among sampling dates and between tree species. Initial soil moisture contents were 32% for C, 28% for LNP, and 26% for HNP at the P. rigida stand, and 31% for C, 31% for LNP, and 33% for HNP at the L. kaempferi stand, respectively. Mean daily N mineralization rates were significantly different among sampling dates and treatments. Annual net N mineralization and nitrification were also significantly different between the two tree species. The annual net N mineralization was 10.6 kg/ha/year for C, 23.3 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the P. rigida stand, and 2.0 kg/ha/year for C, 12.1 kg/ha/year for LNP and 16.7 kg/ha/year for HNP at the L. kaempferi stand. The annual nitrification was 2.8 kg/ha/year for C, 7.6 kg/ha/year for LNP and 4.3 kg/ha/year for HNP at the P. rigida stand, and 4.3 kg/ha/year for C, 14.8 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the L. kaempferi stand. The ratios of annual net nitrification to annual net N mineralization were 26% for C, 33% for LNP, 65% for HNP at the P. rigida stand, and 100% for C, 100% for LNP, 40% for HNP at the L. kaempferi stand, respectively. This study indicates that N mineralization in forest may be different by the predominant tree species and fertilization even under similar environments. It is likely that the quality of organic matter might control nitrogen mineralization and nitrification in soils.

• Journal of Korean Society of Environmental Engineers
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• 제35권7호
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• pp.485-494
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• 2013

An efficient extraction method was developed for the analysis of 16 perfluorinated compounds (PFCs) in fish samples. We compared the recoveries from the Ion-Pairing Extraction (IPE), Liquid-Liquid Extraction (LLE), Solid-Phase Extraction (SPE), IPE + SPE method with varying the injection time of the internal standard. As a result, IPE method with the internal standard before extraction was evaluated as the most effective pretreatment method. The RPM (Revolution Per Munite) and pH in IPE-before method were additionally adjusted and the more efficient pretreatment method was established. The total 33 fish samples including liver and gut samples were collected from Korean markets and analyzed PFCs with developed pretreatment method of this study. Total 16 PFC levels in fish samples ranged from ND to 1.67 ng/g with 100% detection frequency. The average PFCs concentrations of muscle, liver and gut samples from fish were compared and showed the following trend: liver (17.8 ng/g) > gut (13.3 ng/g) > muscle (1.67 ng/g). The PFC levels in fish samples were similar or lower than other available previous results of foreign studies.

• Journal of Sericultural and Entomological Science
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• 제32권2호
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• pp.94-100
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• 1990

Yongchonppon, one of the native varities, is the highest clod resistant. For its practical use, feeding test has been implemented in the ordinary rearing and in the branch rearing 1987 through 1988. The results are summarized as follows. 1. The feeding of Yongchonppong at the 4th and 5th instar made 5% decrease in spring and 10% decrease of cocoon yield in autumn, respectively, while cocoon shell ratio was a little less and percentage of raw silk was a little high, as compared to the feeding of Kaeryangppong. 2. The feeding of Yongchonppong at the 4th instar only showed nearly same nearing result as the feeding of Kaeryangppon. 3. In case of the feeding of yongchonppong at the 4th instar and early stage of the 5th instar, cocoon yield and percentage of raw silk marked 96% and 97-98% of Kaeryangppong. 4. The total nitrogen and crude protein of Yongchonnppong was less, while the total carbohydrate, crude ash and crude fat were high, as compared to those of Kaeryangppong. It had more phosphate and boric and less manganese than Kaeryangppong. 5. The leaf aereal weight of Yongchonppong was 1.57g/dcm2 and the leaf thickness was 113$\mu$. The moisture reducing rate marked 41.3% after three hour exposure to the air.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 한국식품영양학회 1997년도 창립 10주년기념 학술심포지움 행사집
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• pp.15-17
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• 1997

암 발생의 원인 중 80% 이상이 식사습관과 환경오염에 있는 것으로 인정되고 있다. 음식물, 담배, 술, 대기오염, 스트레스, 자외선이 그 대표적인 원인물질로 꼽을 수 있으며 그 중에서도 매일 섭취하는 음식물이 가장 중요한 발암요인으로 지적되고 있다. 대장암과 유방암의 발생에 대한 Wynder 등의 역학조사에서도 식사습관이 암 발생에 중요함을 시사 하고 있다. 동물성 단백질과 지방의 다량 섭취가 대장암과 유방암의 발생을 증가 시키고 섬유질이 풍부한 곡류와 야채의 섭취는 대장암 발생을 억제한다는 상관관계가 밝혀졌다. 그러나 우리가 늘 섭취하는 음식물 자체는 대장암과 유방암을 유발하는 기능이 거의 없다. 섭취된 음식물이 암을 일으키려면 장내 부패 미생물의 분해작용에 의하여 발암물질로 변환되는 과정이 필요하다. 그 발암물질들이 장관으로 흡수 자극함으로써 암을 유발할 수 있다. 반대로 일부장내 미생물들은 장내 발암물질들을 무독화 하거나 숙주의 면역기능을 증강 시킴으로써 암 발생을 억제할 수도 있다는 사실을 간과해서는 안 될 것이다. Mitsuoka는 장내 미생물이 암을 유발하는 중요한 요인이라고 강조하였다. Veer 등은 유산균 발효유를 많이 섭취하면 유방암 발생이 억제됨을, 국제암연구위원회는 섬유질을 많이 섭취하고 있는 핀란드 쿠피오의 거주자들에게는 덴마크의 코펜하겐에 거주하는 사람들에 비하여 대장암 발생율이 1/4에 불과하고 분변내 유산간균수는 100배 높은 사실을 역학조사에서 밝혔다. 이 외에 유산균과 발효유제품의 항암효과에 대한 실험결과들이 많이 발표되었다. 여기에서는 유산균의 항암효과에 대한 지금까지의 관련 자료들을 요약, 정리하여 고찰하고자 한다.높은 당 함량을 나타냈으며, T-AS는 70.3%의 당과 7.8%의 단백질로 구성 되었다. GLG 대부분의 분획들은 60~93%의 glucose로 구성된 다당류 이었으며, 주로 $\beta$-glucose로 구성된 다당류 이었다. 아미노산은 Asp 및 Glu의 산성 아미노산과 Ala, Leu 등의 함량이 높게 나타났으며, 비알칼리 추출물에서 Ser과 Thr의 함량이 높게 나타났다. 다당류 T-AS는 평균 분자량이 2,000 kD와 12kD에서 주 peak를 나타냈으며, 수용성 분획의 평균 분자량은 12kD이고 비수용성 분획은 36~2,000 kD의 평균 분자량 분포를 갖는 것으로 나타났다. IR과 NMR 분석 결과 890 cm-1에서 흡수 peak를 나타내어 $\beta$-(1,3)0glucan과 $\beta$-(1,6)-glucan의 구조를 갖는 다당류로 확인 되었다. T-AS 분획은 C:H:O:N의 함량비가 38.9:5.7:49.6:1.84%이며, 이 물질의 융점은 163 $^{\circ}C$로 연한 갈색을 나타낸다. 분리된 GLG의 항암활성 기전 규명을 위해, in vivo 항암실험, 항보체 활성능, 항체 생성능, serum protein 분비능, 대식세포의 탐식능과 활성능 및 세포간 물질 분비 등의 상관관계를 조사하였다. 다당류 GLG 분획물들 가운데 항보체의 활성이 높았던 분획은 sarcome 180에 대한 항암 활성이 높게 나타났다. 다당류 T-AS의 보체 활성화 기작은 classical과 alternative complement pathway의 양 경로를 통해 활성화 되었다.

• The KIPS Transactions:PartD
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• 제11D권5호
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• pp.1011-1020
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• 2004

A lot of work has been done to improve the I/O performance of such a system that store and manage a massive amount of data by distributing them across multiple disks and access them in parallel. Most of the previous work has focused on an efficient mapping from a grid ceil, which is determined bY the interval number of each dimension, to a disk number on the assumption that each dimension is split into disjoint intervals such that entire data space is GRID-like partitioned. However, they have ignored the effects of a GRID partitioning scheme on declustering performance. In this paper, we enhance the performance of mapping function based declustering algorithms by applying a good GRID par-titioning method. For this, we propose an estimation model to count the number of grid cells intersected by a range query and apply a GRID partitioning scheme which minimizes query result size among the possible schemes. While it is common to do binary partition for high-dimensional data, we choose less number of dimensions than needed for binary partition and split several times along that dimensions so that we can reduce the number of grid cells touched by a query. Several experimental results show that the proposed estimation model gives accuracy within 0.5% error ratio regardless of query size and dimension. We can also improve the performance of declustering algorithm based on mapping function, called Kronecker Sequence, which has been known to be the best among the mapping functions for high-dimensional data, up to 23 times by applying an efficient GRID partitioning scheme.

• Korean journal of applied entomology
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• 제41권3호
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• pp.205-209
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• 2002

Effects of temperature on the development and reproduction of the Udea ferrugalis Hubner were investigated at various temperatures (10, 15, 18, 20, 23, 25, 27, 30$\^{C}$). The development times of eggs, larvae, prepupae and pupae were shorter in higher temperatures than in lower ones. Egg and pupa did not develop at 10$\^{C}$. The lower developmental threshold temperatures for eggs, larvae, pupae were 9.5, 9.6 and 11.9$\^{C}$, respectively, and their thermal requirements for development completion were 87.9, 200.9 and 119.7 degree-days at the same temperature, respectively. Adult longevity was 25.2 days at 15$\^{C}$, 7.3 at 23$\^{C}$ and 5.3 at 30$\^{C}$. Mean fecundity per female was higher at 20-23$\^{C}$ compared to other temperatures. Mean generation time in days (T) was shorter in higher temperature region. Net reproductive rate per generation (Ro) was lowest at 15$\^{C}$ (138.2) and it was highest at 20$\^{C}$ (265.4). The intrinsic rate of natural increase (r$\_$m/) was highest at 25$\^{C}$ as 0.247. As a result, it was considered that optimum range of temperature for U. ferrugalis growth was 20.0 to 23$\^{C}$.

• Journal of the Korea Concrete Institute
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• 제22권5호
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• pp.617-624
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• 2010

This paper reports on a comprehensive study on the mechanical properties of expansive fiber-reinforced strainhardening cement composite (SHCC) materials containing various replacement levels (0, 8, 10, 12 and 14%) of an expansive admixture and 1.5% polyethylene (PE) fibers volume fraction. A number of experimental tests were conducted to investigate shrinkage, compressive strength, flexural strength, and direct tension behavior. Test results show that as expected, the different replacement levels of an expansive admixture have an important effect on the evolution of the free shrinkage of SHCC with a rich mixture. At the volume fraction of 1.5%, PE fibers in normal SHCC reduce free shrinkage deformation by about 30% in comparison to plain mortar. The replacement of an expansive admixture in SHCC material has led the SHCC to a better initial cracking behavior. Enhanced cracking tendency improved mechanical properties of SHCC materials with rich mixtures. Note that an increase in the replacement of expansive admixture from 10% to 14% does not lead to a significant improvement for mechanical properties; this implies that the replacement of 10% expansive admixture is sufficient.