• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.480-484
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• 2002

Accumulation of cadmium (Cd) was investigated in organs (gill, liver, kidney, intestine) of olive flounder (Paralichthys olivaceus) exposed to sub-lethal concentration (5, 10, 50, 100 $\mu$g/L) of Cd for 30 days. Cd exposure resulted in an increased Cd accumulation in liver of flounder for exposure periods and Cd concentration, and Cd accumulation increased linearly with the exposure time. At 20 days of Cd exposure. the order of Cd accumulation in organs was Bill>intestine>liver>kidney and after 30 days of exposure, Cd accumulation in organs was intestine>liver>gill>idney. An inverse relationship was observed between the accumulation factor (AS) and the exposure level, but AE shows an increase with exposure time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.969-976
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• 2004

The wide and growing use of cellular phones has raised the question about the possible health risks associated with radio-frequency electromagnetic fields. It would be helpful for phone users to blow the exposure levels during cellular phone use. But it is very difficult to recognize the amount of exposure, because measuring accurate level of RF is a difficult matter. In this study, we developed a model to estimate the exposure level and the individual risk of exposure by utilizing the available informations that we can get. We used such parameters as usage time a day, total using period, distance between cellular phone and head, slope of cellular phone, hands-free usage, antenna pulled out or not SAR(Specific Absorption Rate) of cellular phone, and flip or folder type. We proposed a model presenting individual risk of RF exposure from level 0 to 10 by using a neural network.

• The Optical Journal
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• s.121
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• pp.71-75
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• 2009

지난호에 필자는 '카메라 매뉴얼을 최소한 10번은 정독하고서 촬영을 나가자'고 강조했다. 장소와 빛에 따라서 조리개와 셔터속도 조절로 인한 노출에 대해서 개념을 이해할 수 있기 때문이다. 이번 시간에는 이에 덧붙여 ISO등 노출에 영향을 주는 또 다른 요소에 대해 알아보겠다. 조리개, 셔터속도, ISO 등 세 가지만 이해하면 사진촬영의 모든 것을 다 배운 것과 같다. 그래도 개념이 잡히지 않는다면 지금까지의 내용을 반복해서 읽고 실습해 보자, 특히 디카 사용자라면 각각의 셔터와 조리개 변경에 따른 사진의 변화를 바로바로 눈으로 확인할 수 있다. 글로만 읽으면 어렵게 생각될 수도 있으나 직접 실습해 본다면 정말 금방 누구나 이해할 수 있는 내용이라고 확신한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.181-182
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• 2010

This study was performed to introduce advanced conditioning and test method to improve problems of the conventional approach for evaluation of durability of FRC.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.62-63
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• 2000

광정보 처리 시스템의 기록매질로 많이 연구되고 있는 포토폴리머는 빛의 세기에 따른 굴절률 변화로 정보를 기록하며, 회절효율이 높은 특성을 가지고 있다. 화학처리 없이 건조처리(dry processing)만으로 쉽게 홀로그램을 제작할 수 있으며, 노출이 곧 자체현상(self-developing)이므로 처리가 간편한 장점을 갖고 있다. 최근에는 높은 저장 밀도와 빠른 액세스 시간을 동시에 제공할 수 있는 홀로그래픽 메모리 시스템의 기록매질로 적용하기 위한 연구가 활발하게 진행되고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.248-249
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• 2000

연안 및 조간대에 서식하고 있는 해산 무척추동물들은 수시로 염분변화에 노출되고 있으므로, 저염분에 노출되고 있는 시간은 생존하기 위하여 수행하는 생리적 조정의 결과로서 성장률 감소를 수반하는 스트레스의 중요한 요인이다. 또한 염분은 해산과 기수지역 생물의 생리적 과정에 영향을 미치며, 종의 분포를 결정 짓는 주요한 환경 요인 중 하나이며, 염분변화에 의해 패류에서 발생하는 전형적인 반응은 섭이활동의 저하, 성장률의 감소와 패각의 폐쇄 등이다(Bohle, 1972; Widdows, 1985). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.445-446
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• 2003

대기오염물질은 배출되면 인위적으로 제거하는 과정이 용이하지 않을 뿐만 아니라 인체, 자연생태계 및 재산상에 다방면으로 피해를 주는 특성을 가지고 있다. 그중에서도 호흡성 먼지 또는 미세먼지라고 부르고 있는 PM-10은 대기 중 체류시간이 길며 인체에 대한 위해도를 갖고 있으나 최선의 대처 방법은 외출을 삼가하는 등의 미세먼지에 대한 노출을 사전에 방지 하는 방법밖에 없는 것으로 알려져 있다. 따라서 미세먼지에 대한 노출을 사전에 막고 이에 대한 대처를 위하여 미세먼지농도의 예보 및 경보 시스템 체제를 가동해야 할 필요성이 대두되고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.475-477
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• 1999

최근 지하공간에서 체류하는 시간이 점차 증가됨에 따라 지하공간상의 특성상 지하공간내 실내공기오염에 따른 위해성에 대한 논의가 계속되고 있다. 지하공간으로 대표적인 지하철 역사의 경우 근무자들이 노출되는 NO$_2$를 포함한 여러 가지 실내공기오염물질들이 역사에 설치된 각종 공조설비의 운영이 적절치 못할 경우 근무자들 뿐만 아니라 지하철 이용 승객들에게도 건강상 악영향을 미칠 우려가 있으므로 그 실태 파악이 요구된다.(중략)

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.629-636
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• 2002

Purpose : Our study was aimed to investigate the characteristics of seizures as well as to determine whether the expression of neuronal nitric oxide synthase expression(nNOS) of hippocampus has an affect in the hyperthermic seizure in developing rat. Methods : Hyperthermic seizures were repeatedly induced twice a week for four weeks in 20-day old Spraque-Dowley rats. Fifty two rats were used as a hyperthermic group and 30 rats used as a normothermic control group. Hyperthermic seizures were induced in a water bath at $45^{\circ}C{\pm}1$ for 4 min. The characteristics of seizures were recorded. Using western blot, hippocampal nNOS expression was measured in normothermic control, hyperthermic non-seizure, and hyperthermic seizure groups, respectively. Results : Eighty seven percent of hyperthermia exposed rats showed generalized tonic-clonic seizure most frequently. The duration of seizure was ranged from 12 to 145 sec(mean 55 sec) and the latency to seizure ranged from 158 to 240 sec(mean 204 sec). The duration of seizure was prolonged but there was no significant difference in the seizure latency as the rat exposed more number of hyperthermia. Interestingly, the expression level of hippocampal nNOS in hyperthermic seizure and hyperthermic non-seizure groups was not different from each other, however, the expression in these groups was lower than that of the control group. Conclusion : Our results indicate that nNOS do not have an affect in this repeated hyperthermic seizures. Further studies are required to clarify a role of nNOS in hyperthermic seizure.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.17-25
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• 2011

In this study, we examined the impact caused by chronic exposure to Mn by investigating the degree of brain activation based on the data of recognition activities using fMRI (functional magnetic resonance imaging). A questionnaire survey, blood tests, and fMRI tests were carried out with respect to two groups. Group 1 was an exposure group consisting of 15 male workers who are 34 years old or older, and who worked for longer than 10 years in a shipbuilding factory as a welder. Group 2 was a control group consisting of 15 workers in manufacturing industries with the same gender and age. The results showed that blood Mn concentration of Group 1($1.3\;{\mu}g/dl$) was significantly higher than that of Group 2($0.8\;{\mu}g/dl$)(p < 0.001), and Pallidal Index (PI) of Group 1 was also significantly higher than that of Group 2 (p < 0.001). PI value of the group whose blood Mn concentration was $0.93\;{\mu}g/dl$ or higher was significantly higher than that of the group whose blood Mn concentration was less than $0.93 \;{\mu}g/dl$ (p < 0.001). As for brain activity area within the control group, the right and the left areas of occipital cortex showed significant activity and the left area of middle temporal cortex, the right area of superior inferior frontal cortex and inferior parietal cortex showed significant activity. Unlike the control group, the exposure group showed significant activity on the right area of superior inferior temporal cortex, the left of insula area. In the comparison of brain activity areas between the two groups, the exposure group showed significantly higher activation than the control group in such areas as the right inferior temporal cortex, the left area of superior parietal cortex and occipital cortex, and cerebellum including middle temporal cortex. However, in nowhere the control group showed more activated area than the exposure group. As the final outcome, chronic exposure to Mn increased brain activity during implementation of arithmetic task. In an identical task, activation increased in superior inferior temporal cortex, and insula area. And it was discovered that brain activity increase in temporal area and occipital area was more pronounced in the exposure group than in the control group. This result suggests that chronic exposure to Mn in the work environment affects brain activation neuro-network.