• 한국양식학회지
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• 제16권2호
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• pp.94-98
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• 2003

북쪽말똥성게의 인공종묘생산 기술개발의 일환으로 KCI용액 주사법으로 채란.채정된 알과 정자를 인위적으로 수정시켜 알과 유생의 발달과정 및 수온에 따른 발생속도를 조사하였다. 북쪽말똥성게의 수정난은 직경 122.5 $\mu\textrm{m}$의 구형이며, 알의 발생은 18$^{\circ}C$에서 수정 후 3시간만에 4세포기로 되고, 15시간이 지나면 부화를 하며, 수정 후 3일째에는 4완기 유생, 13일째에는 8완 전기유생, 20일째에는 8완 후기유생으로 되었다. 수온(T)에 따른 각 단계별 소요시간(t)의 관계를 보면, 부화기: 1/t=0.0036WT+0.0088 피라미드기: 1/t=0.0014WT-0.0016 4완기: 1/t=0.0009WT-0.0020 6완기: 1/t=0.0004WT-0.0005 8완기: 1/t=0.0002WT+0.0002로 표시되었다.

• Journal of Ecology and Environment
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• 제38권1호
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• pp.95-107
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• 2015

Because an ecological community consists of diverse species that vary nonlinearly with environmental variability, its dynamics are complex and difficult to analyze. To investigate temporal variations of benthic macroinvertebrate community, we used the community data that were collected at the sampling site in Baenae Stream near Busan, Korea, which is a clean stream with minimum pollution, from July 2006 to July 2013. First, we used a self-organizing map (SOM) to heuristically derive the states that characterizes the biotic condition of the benthic macroinvertebrate communities in forms of time series data. Next, we applied the hidden Markov model (HMM) to fine-tune the states objectively and to obtain the transition probabilities between the states and the emission probabilities that show the connection of the states with observable events such as the number of species, the diversity measured by Shannon entropy, and the biological water quality index (BMWP). While the number of species apparently addressed the state of the community, the diversity reflected the state changes after the HMM training along with seasonal variations in cyclic manners. The BMWP showed clear characterization of events that correspond to the different states based on the emission probabilities. The environmental factors such as temperature and precipitation also indicated the seasonal and cyclic changes according to the HMM. Though the usage of the HMM alone can guarantee the convergence of the training or the precision of the derived states based on field data in this study, the derivation of the states by the SOM that followed the fine-tuning by the HMM well elucidated the states of the community and could serve as an alternative reference system to reveal the ecological structures in stream communities.

• 한국식품과학회지
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• 제21권3호
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• pp.446-452
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• 1989

한국산 맨드래미 꽃의 적색 색소인 베타시아닌 색소의 식품학적 안정성을 조사하기 위하여 온도, pH, water activity, 빛 및 공기조절에 따른 변화를 관찰하였다. 이 적색 색소는 pH4.0에서 가장 안정하였으며, 열에 대한 분해 활성화에너지 (Ea)는 17.55kcal/mol이었다. 일반적으로 당화합물의 첨가는 0.1M농도에서 색소 분해 방지효과가 있었고, 식품속에 존재하는 농도의 유기산, 금속이온 및 항산화제들은 적색 색소의 분해를 심하게 일으키지 않음으로써, 이 적색 색소는 천연식품 색소로서 이용될 가능성이 증명되었다.

• Journal of the korean society of oceanography
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• 제32권1호
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• pp.28-37
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• 1997

Two marine bivalve shells were collected from the eastern and western coastal regions of Korea, respectively. Stable oxygen and carbon isotope profiles are constructed using the incremental sampling along the axis of maximum growth to provide the continuous ${\delta}^{18}$O and ${\delta}^{13}$C records, which register the physical, biological and chemical properties of seawater where the organisms live. Cycles in the ${\delta}^{18}$O profiles are interpreted as annual along with the identification of annual growth bands; the maximum ${\delta}^{18}$O values correspond with the coldest temperature of seawater whereas the minimum ${\delta}^{18}$O values with the warmest temperature. The primary control on the amplitude of the ${\delta}^{18}$O profiles is seasonal variation of seawater temperature. The offset of the baseline between ${\delta}^{18}$O values of the two specimens is attributed to differences in both temperature and seawater ${\delta}^{18}$O values between two localities. The ${\delta}^{13}$C profiles show the similar seasonality of carbon cycling associated with phytoplankton productivity. The offset in the ${\delta}^{13}$C profiles between two specimens may be, as in the case of oxygen isotope profile, attributed to the different ${\delta}^{13}$C value of the seawater DIC (dissolved inorganic carbon) between the western coast and the eastern coast. Relationships between the shell isotopic composition and the coastal water properties of shell growth are readily interpreted from the ${\delta}^{18}$O-${\delta}^{13}$C pair diagram of the shell isotope data, similar to the use of salinity-${\delta}^{18}$O diagram for identifying water masses. The preliminary stable isotope results of this study suggest that mollusk shell isotope geochemistry may be useful to monitor the properties of water masses in the coastal and inner shelf setting around Korea and improve the interpretation of paleoceanography, provided the fossil mollusks are well preserved.

• 한국초전도ㆍ저온공학회논문지
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• 제15권3호
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• pp.40-48
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• 2013

Cryoablation device is a surgical instrument to produce the cooling effect to destroy detrimental biological tissue by utilizing low temperature around 110 K. Usually, this device has the concentrated cooling region, so that it is suitable for concentrated and thick target. Accordingly, it is hard to apply this device for the target which is distributed and thin target. In this study, the design procedure of a closed-loop cryoablation device with multiple J-T expansion part is developed for the treatment of incompetent of great saphenous vein. The developed cyoablation device is designed with the analysis of 1-dimensional (1-D) bio-heat equation. The energy balance is considered to determine the minimum mass flow rate of refrigerant for consecutive flow boiling to develop the uniform cooling temperature. Azeotropic mixed refrigerant R410A and zeotropic mixed refrigerant (MR) of R22 ($CHClF_2$) and R23 ($CHF_3$) are utilized as operating fluids of the developed cryoablation device to form the sufficient temperature and to verify the quality of the inside of cryoablation probe. The experimental results of R410A and the zeotropic MR show the temperature non-uniformity over the range are $244.8K{\pm}2.7K$ and $239.8K{\pm}4.7K$ respectively. The experimental results demonstrate that the probe experiences the consecutive flow boiling over the target range of 200 mm.

• 환경생물
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• 제24권1호
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• pp.60-66
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• 2006

강굴의 자원조성을 위한 생물학적 기초자료를 얻고자 서식어장별 수온과 염분이 강굴의 성장에 미치는 영향을 조사하였다. 서식어장별 수온 범위는 $3.5\sim26.2^{\circ}C$의 범위로 각 정점간 유의한 차이는 없었다. 염분의 경우 $2.6\sim29.5\;psu$의 범위로서 배알도에서 가장 높은 염분농도를 나타내었으며, 상류지역인 돈탁에서 가장 낮은 염분농도를 나타내었다. 비만도의 경우 다른 지역에 비해 상류지역인 돈탁에서 가장 높았다. 비만도는 모든 정점에서 8월에 가장 낮았다. 그 결과 강굴의 산란기는 $6\sim7$월인 것으로 추정되었다. 각 정점별 각고의 크기를 살펴보면 $149.7{\pm}19.8\;mm$ (배알도), $148.6{\pm}21.3\;mm$ (섬진대교) 그리고 $143.1{\pm}17.6$(돈탁)로 나타났다. 각고에 따른 각장(SL), 각폭(SW), 전중(TW) 그리고 육중(MW)의 상관계수 범위 $(r^2)$는 $0.024\sim0.0471$로 나타났다.

• Mycobiology
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• 제45권4호
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• pp.240-254
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• 2017

Cereal grains are the most important food source for humans. As the global population continues to grow exponentially, the need for the enhanced yield and minimal loss of agricultural crops, mainly cereal grains, is increasing. In general, harvested grains are stored for specific time periods to guarantee their continuous supply throughout the year. During storage, economic losses due to reduction in quality and quantity of grains can become very significant. Grain loss is usually the result of its deterioration due to fungal contamination that can occur from preharvest to postharvest stages. The deleterious fungi can be classified based on predominance at different stages of crop growth and harvest that are affected by environmental factors such as water activity ($a_w$) and eco-physiological requirements. These fungi include species such as those belonging to the genera Aspergillus and Penicillium that can produce mycotoxins harmful to animals and humans. The grain type and condition, environment, and biological factors can also influence the occurrence and predominance of mycotoxigenic fungi in stored grains. The main environmental factors influencing grain fungi and mycotoxins are temperature and $a_w$. This review discusses the effects of temperature and $a_w$ on fungal growth and mycotoxin production in stored grains. The focus is on the occurrence and optimum and minimum growth requirements for grain fungi and mycotoxin production. The environmental influence on aflatoxin production and hypothesized mechanisms of its molecular suppression in response to environmental changes are also discussed. In addition, the use of controlled or modified atmosphere as an environmentally safe alternative to harmful agricultural chemicals is discussed and recommended future research issues are highlighted.

• 한국응용곤충학회지
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• 제47권2호
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• pp.163-168
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• 2008

가지잎에서 점박이응애의 온도에 따른 발육 특성을 조사한 결과 17, 22, 27, 32, $37^{\circ}C$에서 점박이응애의 사충률은 $27^{\circ}C$를 기준으로 온도가 올라가거나 내려감에 따라 증가하였고, 부화율은 $17^{\circ}C$와 $37^{\circ}C$에서 낮았다. 발육기간은 온도가 높아짐에 따라 감소하는 경향을 보이고 $37^{\circ}C$에서 5.3일로 가장 짧고, $17^{\circ}C$에서 25.8일로 가장 길었다. 온도와 발육률의 관계를 직선회귀에 의해 분석한 결과 $r^2$값이 0.88 이상으로 본 실험에서 수행한 온도 $17{\sim}37^{\circ}C$범위에서 점박이응애의 발육은 직선회귀에 부합되었다. 발육영점온도는 전체약충기간이 암컷 $12.5^{\circ}C$, 수컷 $12.8^{\circ}C$이었고, 전체약충기간의 유효적산온도는 암컷 80.5,수컷 74.7일도였다. 성충의 수명과 산란기간은 온도가 올라감에 따라 짧아졌고, 암수의 비교에 있어서 암컷이 수컷에 비해 수명이 길었다. 온도에 따른 산란수는 $27^{\circ}C$에서 141.0개로 가장 많았으며, $37^{\circ}C$에서 78.0개로 가장 적어 온도에 따른 변이가 컸다. 온도에 따른 부화율과 암컷의 비율도 $27^{\circ}C$를 정점으로 온도가 높아지거나 낮아지면 감소하였다. 점박이응애의 $R_o$ (순증가율)는 온도가 $27^{\circ}C$를 정점으로 온도가 높아지거나 낮아지면 감소하였고, $r_m$ (내적자연증가율)은 온도가 높아짐에 따라 같이 높아져 $37^{\circ}C$에서 최고치인 0.5652였으며, ${\lambda}$ (기간증가율)도 온도가 높아짐에 따라 높아졌다. DT (배수기간)와 T (평균세대기간)는 온도가 올라감에 따라 감소하였다.

• 한국식품영양과학회지
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• 제17권2호
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• pp.144-148
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• 1988

전분의 겔화 온도에 대한 가열속도, 수분함량 및 지방의 영향을 DSC로 측정한 결과 전분으로부터 지방이 제거됨에 따라 수분결합력이 상승함으로서 겔화 온도는 $4{\sim}5^{\circ}C$ 저하하였으며 탈지전분의 겔화 온도는 $52{\sim}67^{\circ}C$로서 옥수수, 감자, 쌀, 밀의 순으로 감소하였다. 수분함량이 증가할수록 겔화 온도는 상승하였으며 열경제적인 측면에서 전분의 겔화에 필요한 최저수분함량은 $31{\sim}41%$였다. 전분의 가열온도와 시간의 함수인 가열속도와 겔화 온도는 비례의 관계를 나타내었으며 가열속도 $15^{\circ}C/min$에서의 겔화 온도는 $5^{\circ}C/min$에 비하여 약 $2{\sim}4^{\circ}C$ 높은 값을 나타내었으며 겔화에 필요한 엔탈피도 높은 값을 나타내었다. 그러므로 가열온도와 시간의 최적화를 위하여 가열속도는 $5^{\circ}C/min$ 이하로 하는 것이 유용하리라 생각된다.

• 한국수산과학회지
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• 제50권4호
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• pp.437-446
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• 2017

To evaluate the consequences of possible fisheries regulations of anchovy Engraulis japonicus in the Korea Strait, we developed and applied a simulation-based yield-per-recruit (Y/R) model that considered temperature-dependent growth and size-dependent mortality, covering the egg to adult stages. We projected changes in commercial yield and egg production of anchovy with respect to varying biological reference points of 1) the instantaneous fishing mortality, 2) the minimum fork length of anchovy allowed to catch for protecting smaller anchovy ($L_{c,min}$), and 3) the maximum fork length allowed to catch for protecting bigger anchovy ($L_{c,max}$). Our Y/R model showed that the anchovy yield will be maximized at ca. $1.4{\times}10^6tons$ when $L_{c,min}$ ranges between 42-60 mm or at ca. $0.8{\times}10^6tons$ when $L_{c,max}$ ranges from 88-160 mm. At $L_{c,min}=30mm$, the present minimum length of catch, our simulations indicated that the anchovy yield can reach a maximum of $1.2{\times}10^6tons$ in the long-term when the present fishing effort, which annually yields ca. $0.2{\times}10^6tons$ of anchovy, can be increased by a factor of 28. We expect that our simulation-based Y/R model can be applied to other commercially-important small pelagic species in which the traditional Beverton-Holt Y/R model is difficult to apply.