• 전자공학회논문지SC
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• 제45권3호
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• pp.59-67
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• 2008

최근 휴대폰 보급률이 증가하면서 휴대폰 전자파로 인해 두통, 불면증, 단기간의 기억력 소실 등의 정신 신경 생리학적 증상을 호소하는 휴대폰 전자파 과민증(EHS, Electromagnetic Hypersensitivity) 환자들이 나타나고 있다. 그러나 휴대폰 전자파 과민반응의 원인이 막연한 불안감 때문인지 혹은 전자파 노출로 인한 증상 인지에 대하여 확실한 원인규명이 되지 않고 있다. GSM 방식의 휴대폰의 경우 전자파 노출 시 EHS 군을 대상으로 혈압, 맥박수 변화 및 자각 증상 등의 과민 반응에 대한 연구들이 수행되었으나 일반인과 EHS 군의 실험-대조군 연구로 생체신호, 자각증상 및 전자파 인지 여부에 대한 복합적인 연구와 CDMA 휴대폰 EHS 연구는 거의 없는 실정이다. 본 연구에서는 일반인 19명과 EHS 17명을 대상으로 30분간 300 mW의 CDMA 휴대폰 전자파에 노출 시 교감신경의 흥분을 나타내는 맥박, 호흡수, HRV(heart rate variability)의 변화를 측정하고, 전자파 노출 시 전자파 인지여부와 두통, 피로 등의 자각증상을 조사하였다. 그 결과, 일반인과 EHS 군 모두 전자파 노출여부에 따라 맥박, 호흡수, HRV의 변화가 없었고, 자각증상의 차이도 없었다. 전자파 인지 조사 결과 EHS 군이 일반인 군에 비하여 전자파를 더 잘 인지한다고 볼 수 없었다.

• 한국양식학회지
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• 제20권4호
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• pp.226-231
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• 2007

염분변화에 대한 양식 멍게 Halocynthia roretzi의 생리적 변화를 알아보기 위하여 생존율과 염분감소에 따른 삼투조절능, 산소소비율, 암모니아질소배설률 및 여수율 등의 생리적 반응을 조사하였다. 염분변화에 따른 삼투질농도의 순치시간은 60% 희석해수에서 $20{\sim}46$시간 소요되었으며, 80% 희석해수에서는 $20{\sim}25$시간, 고염분인 110% 해수에서는 노출된 지 $7{\sim}8$시간 만에 순치하여 저염분에 비해 빠르게 순치하였다. 생존율은 염분26.4 psu 이상에서 생존율 80% 이상을 나타내었으며, 6일 동안의 $LS_{50}$은 25.4 psu이었다. 멍게의 산소소비율, 암모니아질소배설률 및 여수율 등의 대사반응은 노출초기에 비해 노출 4일째 증가 혹은 감소의 뚜렷한 반응을 보였으며, O:N비는 노출기간 동안 염분 $26.4{\sim}6.6\;psu$에서 15 이하의 낮은 값을 보이고 있는 것으로 보아 노출초기부터 염분에 대한 스트레스를 심하게 받는 것으로 여겨진다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.523-530
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• 2005

본 연구에서는 IP형 운반용기의 개념설계를 위하여 소내 임시저장중인 방사성폐기물중 $200\;{\ell}$ 잡고체 드럼을 대상으로 운반용기에 적재 가능한 드럼의 최대표면선량률을 제시하고자 하였다. 이를 위해 잡고체 폐기물을 가연성과 비가연성으로 구분하였으며, 각각 혼합핵종이 균일 분포되어있는 경우와 단일핵종(Co-60)이 균일 분포되어있는 경우를 나누어 계산하였다. 연구결과, 가연성 잡고체 드럼에 혼합핵종이 분포되어 있는 경우, IP-1, IP-2-a, IP-2-b형 운반용기에 적재 가능한 최대표면선량률은 각각 3.60E-01, 8.85E-01, 1.27E+01 mSv/hr 이었으며, Co-60이 분포되어 있는 가연성 잡고체 드럼의 최대표면선량률은 각각 3.59E-01, 8.83E-01, 1.25E+01 mSv/hr 이었다. 비가연성 잡고체 드럼에 혼합핵종이 분포되어 있는 경우, IP-1, IP-2-a, IP-2-b형 운반용기에 적재 가능한 최대표면선량률은 각각 7.14E-01, 1.83E+00, 2.69E+01 mSv/hr이었으며, Co-60이 분포되어 있는 비가연성 잡고체 드럼의 최대표면선량률은 각각 7.13E-01, 1.81E-01, 2.62E+01 mSv/hr 으로 계산되었다. 이를 통해 운반가능 방사성내용물의 최대수량을 실측이 용이한 표면선량률 만으로 제시할 수 있었으며, 향후 다른 종류의 폐기물에 대해서도 차폐해석을 수행할 예정이다.

• 한국수정란이식학회지
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• 제9권1호
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• pp.7-14
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• 1994

The present experiments on cryopreservation were designed to examine the effects of solution toxicity, equilibration time and cell stages on the post-thaw survival of bovine IVF embryos. The oocytes were matured in vitro(IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g /ml FSH, 10 $\mu$g /ml LH, 1 $\mu$g /ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. The bovine IVF embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen, and thawed rapidly. 1. after the bovine blastocysts were exposed to EFS solution for 2 min. at room temperature and then they were washed in 0.5 M sucrose solution and TCM-199, they were cultured to examined cryoprotectant induced injury during exposure, Most of the embryos(95.0%) developed to reexpanded blastocoels. However, when the exposure time was extended to 5 and 10 min, these development rates dropped dramatically in 5 min. (69.5%) and 10 min. (47.4%), respectively, 2. When the bovine IVF embryos were vitrified in EFS solution after the equilibration for 1 and 2 min. exposure, The embryos to have reexpanded blastocoels following thawing, washing and culture processes were found to he 82.6 and 73.9%, respectively. However, when the exposure time was extended to 3 min, this survival rate dropped to 18.2%. The optimal time for equilibration of bovine IVF blastocysts in EFS solution seemed to he 1~2 min. 3. When the bovine IVF embryos were equilibrated for 1 min. the significantly (P<0. 05) higher post-thaw survival rates were obtained from the embryos of blastocyst stage(81.3%) than morulae stage(5. 1%). The optimal cell stage for viterification with EFS solution proven to he blastocyst stage in bovine IVF embryos. 4. The number of blastomeres of blastocyst stage was examined with nuclear staining with Hoechst 33342 during 7 to 9 days post-insemination. The cell counts of frozen bovine IVF embryos were found significantly(P$\geq$7.5 and those of the fresh embryos 76.6$\geq$7. 1, which were cultured in the sarne period and conditions as frozen embryos.

• 대한방사선기술학회지:방사선기술과학
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• 제45권4호
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• pp.347-353
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• 2022

In this study, the radiation dose rate was measured by time and distance and evaluated whether radiation dose rate was suitable for domestic and international discharge criteria. In addition, the radiation dose emitted from the patient was measured with a glass dosimeter to evaluate the exposure dose if the caregiver stays in the isolated ward by placing a humanoid phantom instead of the caregiver at a distance of 1 m from the patient, on the second day of treatment. After 23 hours of isolation, the radiation dose rates at a distance of 1 m were 20.54 ± 6.21 µSv/h at 2.96 GBq administration and 27.94 ± 12.33 µSv/h at 3.70 GBq administration. The radiation dose rates at a distance of 1 m were 25.90 ± 2.21 µSv/h when 2.96 GBq was administered and 34.22 ± 10.06 µSv/h when 3.70 GBq was administered after 18 hours of isolation. However, if the isolation period is short may cause unnecessary radiation exposure to the third person. The reading of the attached dosimeter from the morning of the second day of treatment until removal was 0.01 to 0.95 mSv, which is a surface dose determined by the International Commission on Radiation Units and Measurements. And the depth dose was 0.01 to 0.99 mSv. On the second day of treatment, even if the patient caregivers stayed in the isolation ward, the exposure dose of the patient family did not exceed the effective dose limit of 5 mSv recommended by the ICRP and NCRP.

• 생태와환경
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• 제45권4호
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• pp.420-443
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• 2012

An Individual-Based Model (IBM) was developed by employing natural and toxic survival rates of individuals to elucidate the community responses of benthic macroin-vertebrates to anthropogenic disturbance in the streams. Experimental models (dose-response and relative sensitivity) and mathematical models (power law and negative exponential distribution) were applied to determinate the individual survival rates due to acute toxicity in stressful conditions. A power law was additionally used to present the natural survival rate. Life events, covering movement, exposure to contaminants, death and reproduction, were simulated in the IBM at the individual level in small (1 m) and short (1 week) scales to produce species abundance distributions (SADs) at the community level in large (5 km) and long (1~2 years) scales. Consequently, the SADs, such as geometric series, log-series, and log-normal distribution, were accordingly observed at severely (Biological Monitoring Working Party (BMWP<10), intermediately (BMWP<40) and weakly (BMWP${\geq}50$) polluted sites. The results from a power law and negative exponential distribution were suitably fitted to the field data across the different levels of pollution, according to the Kolmogorov-Smirnov test. The IBMs incorporating natural and toxic survival rates in individuals were useful for presenting community responses to disturbances and could be utilized as an integrative tool to elucidate community establishment processes in benthic macroin-vertebrates in the streams.

• Ocean Science Journal
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• 제41권4호
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• pp.211-219
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• 2006

A comparison was made of population of the economically important cockle Anadara (=Scapharca) broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last 20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period. Evidently, these facts are due to the damaging effect of dredging.

• 한국컴퓨터그래픽스학회논문지
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• 제14권3호
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• pp.1-9
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• 2008

본 논문에서는 전통적인 사진 기법에 기반하여 대비가 뚜렷한 흑백 영상을 얻기 위한 새로운 방법을 제안한다. 사진가들은 대비가 뚜렷한 흑백 사진을 얻기 위해 촬영 시 대비 필터(consrast filter)를 사용하여 특정 색이 부각된 흑백 필름을 얻고, 인화 시 버닝(burning)과 닷징(dodging) 같이 국지적 노출을 조절하는 기법을 사용하였다. 본 논문에서는 이러한 흑백 사진 기법에 대한 디지털 버전을 제안하고 이에 기반하여 영상의 시각적 특징을 최대한 유지하는 최적화 기법을 제안한다. 또한, 인접 픽셀간의 유사 가중치를 이용하여 경계를 감안한 연속적인 국지적 노출을 얻게 한다. 제안한 기법은 GPU상에서 구현 가능하며 메가픽셀 영상에 대해서도 시각적 특징을 유지하는 흑백 영상을 대화적 시간 안에 획득할 수 있다.

• Asian Journal of Atmospheric Environment
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• 제5권4호
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• pp.247-262
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• 2011

This study assessed the health risks of childhood exposure to PBDEs via different possible pathways in children's facilities and indoor playgrounds. When PBDE contamination was measured, it was determined through multiple routes, including inhalation of indoor dust, dermal contact with product surfaces and children's hands, and incidental dust ingestion. Samples were collected from various children's facilities (playrooms, daycare centers, kindergartens, and indoor playgrounds) during summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). The hazard index (HI) was estimated for non-carcinogens, and PBDEs, such as TeBDE, PeBDE, HxBDE, and DeBDE, were examined. The sensitivity to the compounds did not exceed 1.0 (HI) for any of the subjects in any facility. However, current data about toxicity does not reflect effects that were fully sensitive in children, so there is uncertainty in the dose-response data. The contribution rates of PBDEs were 71.4 to 96.1% and 3.7 to 28.2% for intake and inhalation exposure, respectively, indicating that intake of floor dust and inhalation are the primary routes.

• 한국환경보건학회지
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• 제44권5호
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• pp.468-479
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• 2018

Objectives: Recently, a report was published that the humidifier disinfectant CMIT/MIT did not cause developmental toxicity and was not detected in systemic circulation as a result of an inhalation toxicity test. Therefore, this study was carried out to investigate any associations between CMIT/MIT exposure and developmental toxicity using the in vivo apical toxicity test method. Methods: Groups of pregnant ICR mice were instilled in the trachea with chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) using a visual instillobot over a period of seven days from days 11 to 17 days post-coitum. For the in vivo apical toxicity test method, an $LD_{50}$-based dose-range finding model was applied to decide the dose range for inducing developmental toxicity. Results: Among the groups of 0, 0.1, 0.5, 1.0, and 1.5 mg ai/kg/day CMIT/MIT, the exposure groups of 0.5 mg and 1.0 ai/kg/day CMIT/MIT were estimated to reflect the thresholds for the stillbirth and death of pregnant mice, respectively. The groups of 0.5, 1.0, and 1.5 mg ai/kg/day CMIT/MIT induced stillbirth rates of 2.57, 10, and 53.8%, respectively. Another exposure group of 0.75 mg ai/kg/day CMIT/MIT did not induce any deaths of pregnant mice and resulted in a stillbirth rate of 8% in only one of six pregnant mice. Conclusions: CMIT/MIT can induce stillbirth in pregnant mice. It was also concluded that CMIT/MIT moves through the pulmonary circulation system and then continues on through systemic circulation and the placenta. There is a possibility of stillbirth and other health causalities in humans beyond the lungs caused by CMIT/MIT exposure.