• 한국수산과학회지
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• 제46권5호
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• pp.552-558
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• 2013

This study was performed to determine effects of the supplementation of Kimchi lactic acid bacterial culture in extruded pellets (EP) on the growth, body composition, blood chemistry and immune response of olive flounder Paralichthys olivaceus. Four hundred eighty individuals averaging 16.1 g were randomly distributed into 12, 180 L flow-through tanks (forty fish per tank). Four concentrations of Kimchi lactic acid bacterial culture (KL) were prepared: Control (0%), 0.1%, 0.2% and 0.5%. Three concentrations (0.1%, 0.2% and 0.5%) of Kimchi lactic acid bacterial culture were each diluted to 10% of EP weight and then fully absorbed by EP for 10 minutes. Each diet was fed to triplicate groups of fish. Fish were hand-fed to apparent satiation twice a day for 8 weeks. At the end of the 8-week feeding trial, the plasma lysozyme and bacterial activities of fish were determined. In addition, the cumulative mortality of fish was monitored for 8 days after their artificial infection with Edwardsiella tarda. The weight gain, specific growth rate, feed efficiency ratio, protein efficiency ratio, protein retention, hepatosomatic index and condition factor of fish were not affected by dietary supplementation with KL. None of the proximate composition, plasma parameters, lysozyme or bactericidal activities of fish was affected by dietary supplementation with KL. However, the cumulative mortalities of fish fed EP containing 0.1% and 0.5% Kimchi lactic acid bacterial culture were relatively low compared to that of fish fed the control diet. In conclusion, dietary supplementation with KL did not effectively improve growth, feed utilization, body composition, plasma chemistry, lysozyme, bactericidal activities or immune response of olive flounder after E. tarda infection under these experimental conditions.

• 한국어병학회지
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• 제22권2호
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• pp.97-105
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• 2009

본 연구는 양식넙치에 높은 폐사율과 성장저하를 일으키는 스쿠티카섬모충 Miamiensis avidus (syn. Philasterides dicentrarchi)의 성장과 병원성에 미치는 온도의 영향을 알아보았다. in vitro 배양조건에서 이분열에 걸리는 시간은 $5{^{\circ}C}$에서 61.82시간, $10{^{\circ}C}$에서 26.32시간, $15{^{\circ}C}$에서 21.14시간, $20{^{\circ}C}$에서 16.86시간 그리고 25℃에서 는 16.21시간이었다. 최고로 배양 가능한 충수는 $1.54-1.75{\times}10^{5}$/ ml의 범위로 $10{^{\circ}C}$이상의 모든 온도범위에서 유사했다. 넙치(평균 8.34 cm, 4.33g)마리당 $1{\times}10^{2}$/ ul, $1{\times}10^{6}$/ ul, $1{\times}10^{4}$/ ul 과 $1{\times}10^{5}$/ ul 으로 스쿠티카충을 복강에 감염시킨 후 $10{^{\circ}C}$, $15{^{\circ}C}$와 $20{^{\circ}C}$에서 사육하면서 폐사를 관찰하는 실험을 2회 실시한 결과, 수온 $10{^{\circ}C}$에서는 폐사가 현저히 낮았고 온도가 높아질수록 폐사가 증가하였다. 또한 감염농도가 높아질수록 폐사는 증가하였다. 그러므로 스쿠티카섬모충 M. avidus는 온도가 높을수록 증식이 잘 되며 또한 수온이 높아질수록 온도의존적으로 폐사가 증가하므로 폐사를 경감시키기 위해서는 고수온기의 수온관리가 중요한 것으로 사료된다.

• 생물환경조절학회지
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• 제13권1호
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• pp.16-20
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• 2004

목화진딧물은 여러 작물에 헤를 입히는 문제해충이다. 본 연구에서는 목화진딧물의 접종밀도를 달리했을 때 참외의 생육고 당함량에 미치는 영향과 진딧물 제거후 생육의 회복 정도를 알아보고자 수행하였다. 진딧물의 피해를 받은 참외의 증상은 잎이 오그라들고 신초부분이 위축되었다. 목화진딧물이 참외에서 20일간 흡즙한 후 생육은 진딧물을 접종하지 않은 참외에 비해 생육이 월등히 감소하였고, 진딧물의 접종밀도간에는 진딧물의 밀도가 높아질수록 생육이 부진하였다. 초장은 무접종의 1/3수준이었고, 엽면적은 무접종에 비해 12${\sim}$38% 수준이었으며 건물증은 무접종의 30${\sim}$51% 수준이었다. 진딧물을 제거한 후 참외의 생육은 10일 후에는 진딧물의 피해를 받은 잎은 거의 신장하지 못한 채로 있으나, 신초부분의 생육이 다소 회복되었다. 20일 후에는 5마리 접종에서 초장, 엽면적 건물증이 월등히 증가하여 생육이 회복되었다. 진딧물 제거후 시간이 지날수록 회복되는 속도가 빨라졌으며 접종밀도간 회복속도는 5마리 접종이 가장 빨랐다. 주당 진딧물을 접종하였을 때 참외 전체 잎의 당함량에는 차이가 없었으나, 엽당 진딧물을 접종하고 접종한 잎만 분석한 경우는 진딧물누적일수량이 증가할 수록 전체 당 함량이 현저히 감소하였다.

• 한국항공우주학회지
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• 제47권10호
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• pp.747-752
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• 2019

신뢰성 성장 시험을 수행하며 획득하게 되는 고장 정보와 누적 시험수행시간을 이용하면 신뢰성 성장 모델의 모수 추정이 가능하며, 모수 추정을 통해 해당 제품의 MTBF를 예측할 수 있다. 그러나 시험에 대한 비용, 시간 혹은 제품의 특성 등의 여러 제약으로 인해 고장 정보가 구간적으로 획득되거나, 획득한 고장 정보의 샘플 데이터(Sample Data)의 수가 작을 수 있다. 이는 신뢰성 성장 모델의 모수 추정의 오차를 커지게 하는 원인이 될 수 있다. 본 논문에서는 샘플 데이터의 수가 작을 경우 신뢰성 성장 모델의 모수 추정 시 베이지안 기법 기반의 모수 추정 방법의 적용에 대해 연구를 수행하였다. 시뮬레이션 결과 신뢰성 성장 모델의 모수를 추정할 때, MLE를 적용하여 추정하는 방법보다 베이지안 기법을 적용하는 방법이 추정 정확도가 높음을 확인하였다.

• 식물조직배양학회지
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• 제27권4호
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• pp.325-337
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• 2000

All living organisms depend on soil and water for their sustained growth and development. In recent years, sustenance of life in these growth matrices has been adversely affected by the cumulative increase in environmental pollutants resulting from increasing population, growing economies and resource-use. This review provides a glimpse into the problem of global environmental pollution, the traditional technologies available for remediation and the scope of emerging‘plant-based remediation’technologies. Phytoremediation, the use of plants to effectively remove or stabilize contaminants from the growth substrate, is a low cost and ecologically friendly alternative to the common‘dig and dump’technologies. The field of phytoremediation has been driven by the intrinsic need for identification of ideal candidate plant species. To date, there are only a very few identified plants which satisfy all of the prerequisites for use in phytoremediation. The review focuses on one such plant species, the common horticultural plant scented geranium (Pelargonium sp.), with demonstrated potential to remediate metal / salt contaminated soils / aqueous systems. The characterization of tolerance and metal / salt accumulation potential of Pelargonium sp. and its efficacy in remediating complex contaminated sites are described. The unique ability of scented geraniums to tolerate excessive amounts of multi-metals, hydrocarbon and salt mixtures, and at the same time to accumulate significant amounts of metal and salt ions in the biomass, renders this plant species as one of the ideal candidates for remediation.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(3)
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• pp.145-150
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• 1996

Acoustic Emission (AE) technique was applied to stress corrosion cracking of Inconel 600 to investigate the AE capability of detecting crack growth and to obtain the relation between AE characteristics and crack mechanism. The specimens were heat-treated in two conditions (600$^{\circ}C$ for 30 hrs or 700 $^{\circ}C$ for 1 hr) and undergone CERT at two extension rates ( 2.5${\times}$10$^{-5}$ or 1.25${\times}$10$^{－4}$(mm/s)). It was found that the AE peak amplitude from plastic deformation was generally smaller than about 48dB (0.25mV), while Intergranular stress corrosion cracking (IGSCC) and ductile fracture produced higher values of 49 to 70dB (0.3mV to 3mV). The slopes of cumulative amplitude distribution (b-values) were linearly dependent on IGSCC susceptibility and the higher the susceptibility, the smaller the b-value. The monitoring of combined AE parameters such as event rate, amplitude, count and energy can provide effective means to clearly identify the transition from crack initiation and small crack growth to rapid growth of dominant cracks.

• 한국초지조사료학회지
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• 제21권4호
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• pp.211-216
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• 2001

In an effort to investigate the germination and growth characteristics of tannin containing forage crops (such as chicory, birdsfoot trefoil, Lotus pedunculatus, sulla, lespedeza, crownvetch, sainfoin), germinativity, seedling vigor, and productivity were studied. Although the cumulative germination percentage (CGP) of chicory and birdsfoot trefoil was low, the germination rate(GR) and days to reach 50% of final germination(Gt50) were excellent. Crownvetch, lespedeza and sainfoin showed poor germination. Chicory seeds were light but the rate of emergence and establishment were high. Seeds of Lotus pedunculatus and birdsfoot trefoil were also small, but their rates of emergence and establishment were quite good. On the other hand, seeds of sainfoin and crownvetch were heavy but their emergence and establishment rate were very low. Lespedeza was the best in getting over the hot summer, and crownvetch also survived well during summer. Chicory was good in productivity and early growing but its persistence was not good. In case of birdsfoot trefoil and Lotus pedunculatus their early growing were slow but their productivity and persistence were fairly well. Lespedeza, crownvetch, and sainfoin showed poor growth in Korea. Based on the results of this study it can be concluded that chicory would be better to use as short term high productive forage crop, and Lotus pedunculatus and birdsfoot trefoil could be used as continuous functional forage crops in Korea. (Key words : Tannin. Germination. Chicory. Birdsfoot trefoil, Lotus pedunculatus)

• 한국해양공학회지
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• 제2권2호
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• pp.104-111
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• 1988

This paper deals with the micro-surface-cracks behavior on the unnotched smooth specimens of Type 304 stainless steel at $593^{\circ}C$ in air under creep and creep-fatigue conditions that have 10 mim and 1 min load holding times respectively. The behaviors of the micro-surface-cracks have been visualized by means of surface replica method and optical micro-photography. The quantitative characteristics of initiation, growth and coalescence of micro-surface-cracks have been investigated by observing and measuring the crack growth behaviors. some of the important results are as follows: Main crack initiates at grain boundary in the early stage(10 to 20%)of its life time and grows through coalescence and finally leads to fracture. The distribution of micro-surface-crack length, 2a, can be plotted against the composite Weibull distribution. The growth rate of the main crack can be plotted against the stress intensity factor, crack tip opering displacement and J integral.

• 한국가금학회지
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• 제21권4호
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• pp.267-275
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• 1994

Three dietary ME levels of 3,200, 2,900 and 2,600 kcal /kg in the same 13% single-stage low protein diet were compared to evaluate the effect of ME levels of grower diets on egg-type pullet growth and subsequent laying performance. As the ME levels of grower diets decreased, cumulative feed and protein consumptions increased(P<0.05), however, the ME intake and body weight at 18 wk of age decreased(P<0.05). Grower feed cost decreased as the dietary ME level was decreased, but no significant difference was found among dietary ME levels of grower diets. During the laying period, sexual maturity, hen-day egg production and average egg weight were not significantly affected by the ME levels of grower diet, however, daily feed intake and feed required per egg decreased as the dietary ME level of grower diet was reduced(P<0.05). Results of this study indicate that pullets can be reared on the low ME diet of 2,600 kcal /kg and it would he economical to utilize the low energy diet during the growing period when they are reared on a 13% single-stage low protein diet.

• International Journal of Reliability and Applications
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• 제4권1호
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• pp.1-12
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• 2003

Many software reliability growth models (SRGM's) based on a nonhomogeneous Poisson process (NHPP) have been proposed by many researchers. Most of the SRGM's which have been proposed up to the present treat the event of software fault-detection in the testing and operational phases as a counting process. However, if the size of the software system is large, the number of software faults detected during the testing phase becomes large, and the change of the number of faults which are detected and removed through debugging activities becomes sufficiently small compared with the initial fault content at the beginning of the testing phase. Therefore, in such a situation, we can model the software fault-detection process as a stochastic process with a continuous state space. In this paper, we propose a new software reliability growth model describing the fault-detection process by applying a mathematical technique of stochastic differential equations of an Ito type. We also compare our model with the existing SRGM's in terms of goodness-of-fit for actual data sets.