• 한국전자파학회논문지
• /
• 제15권3호
• /
• pp.291-300
• /
• 2004

이동통신 서비스의 급격한 증가로 인해, EMF(Electromagnetic field)노출의 생물학적 효과에 대한 많은 연구들이 수행되어져 왔다. 그러나 연구 수행에 있어서 필요한 무선 주파수 대역에서의 균일장 생성은 쉬운 일이 아니다. 이러한 어려움을 극복하기 위해 전신노출 시 스템에서의 전기장과 SAR(Specific Absorption Rate) 분포 측정이 발전을 해왔다. 본 논문에서는 EMC 대용 챔버로의 활용 가능성이 높은 전자파 잔향실 챔버를 이용하여 동물 실험용 전신 노출 장치를 개발하였다. 설계된 전자파 잔향실은 시뮬레이션과 측정 데이터를 이용하여 시험영역의 균일장에 대한 유효성을 검증하였다. 마우스에 대한 전신노출 실험에 있어서, 노출된 전자파에 대해 SAR을 확인하기 위해서 FDTD수치해석 방법과 측정 결과를 비교하였다. 전자파 잔향실 내부에서의 전기장 분포 특성을 해석하고, 이러한 해석 결과들을 통계적으로 처리하였다. CDMA 이동전화 주파수 대역에서(PCS ＆ Cellular 대역) 입력 파워 변화에 따른 실험상태에서의 마우스 전신 SAR 평균값 및 국부 최대값을 제시하였다.

• 한국의상디자인학회지
• /
• 제1권1호
• /
• pp.91-107
• /
• 1999

The primary purpose of this study is to inquire into the characteristic of exposure presented in fashion, identify the correct concept of exposure from an aesthetic perspective, and grasp the contemporary meaning of exposure presented in fashion. As a result of study, the following findings were obtained: First, the surrealist style of fashion exhibited representations such as the relocation of the partial details, the harmonization of the natural and the artificial, the emphasis or expansion of each part of the body, and the like. It used highlighted the genital region with ornamentations or used the technique of paradoxically exposing the part of the body always covered. And it exbibited the paradoxical relationship of exposure and concealment by exposing the concealed part of the human body. Second, the post-modern style showed the complicated phenomenon that the values of several meanings such as the historic, the folk, and the like appeared in its fashion. It shares in spatiotemporal eclecticism, pluralistic characteristics and the like found in the post-modern culture. Third, the deconstructive style gets rid of the distinction between the external space and the private space by translating underwears into outer garments. It destroys clothing by tearing or perforating clothing whereby it represents the poor image. Coupled with women‘s psychology of exposure and the new generation’s way of thinking indifferent to others‘ eyes, this fashion of deconstruction occupies the great current of fashion. Deconstructive fashion gets away with the rule of ‘having to wear clothing to suit TPO(Time, Place and Occasion), the traditional norm of wearing clothing.

• 대한인간공학회지
• /
• 제32권4호
• /
• pp.381-387
• /
• 2013

Objective: This paper studies the method of measuring whole-body vibration in the car and terms associated. Background: Human exposure to vibration can be broadly classified as localized and whole-body vibration. The whole-body vibration affects the entire body of the exposed person. It is mainly transmitted through the seat surfaces, backrests, and through the floor to an individual sitting in the vehicle. It can affect the comfort, performance, and health of individuals. Method: Human responses to whole-body vibration can be evaluated by two main standards such as ISO 2631 and BS 6841. The vibration is measured at 8 axes - three translations at feet, 3 translations of hip and two translations of back proposed by Griffin. B&K's sensors used in this study are the 3-axes translational acceleration sensor to measure the translational accelerations at the hip, back and foot. Results: The parameters associated with the whole-body vibration in the car are frequency weightings, frequency weighted root-mean-square, vibration dose values, maximum transient vibration value, seat effective amplitude transmissibility, ride values and ride comfort. Conclusion: Studied the evaluating methods of vibration exposure and ride comfort. Application: Evaluation of whole-body vibration in the car.

• 한국버섯학회지
• /
• 제2권2호
• /
• pp.45-48
• /
• 2004

The effect of $CO_2$ concentration (500, 3,000, $6,000{\mu}{\ell}/{\ell}$) on the mycelial growth and fruit body primordium formation of Ganoderma lucidum on nutrient agar medium was examined. Optimum $CO_2$ concentration for vegetative growth was above $3,000{\mu}{\ell}/{\ell}$. Fruit body initiation was accelerated at higher than $3,000{\mu}{\ell}/{\ell}$ $CO_2$ exposure but the maximum number and size of primordia, and primordium color were not influenced by $CO_2$ concentrations. Whereas each atypical fruiting structure forming stock culture showed different fruiting time under each concentration of $CO_2$ exposure.

• 한국환경생물학회:학술대회논문집
• /
• 한국환경생물학회 2003년도 학술대회
• /
• pp.7-11
• /
• 2003

Interactions of both feminizing and masculinizing chemicals inducing imposex in gastropod were investigated with a long-term exposure experiment. Imposex-free rock shell(Thais-clavigera)was exposed to TBT and other antagonistic chemicals (nonylphenol and DDT), P450 inducer (phenobarbital) and natural sex hormone (estrogen) mixtures for 60 days. None of imposexed-females were found in control, sham (ethanol) and testosterone exposure group, on the other hand imposex was induced in the TBT and all the TBT+antagonist mixture groups. After 60-day exposure, frequency of imposexed-female ranged from 31-68%. Female mean penis length (FMPL) of imposexed-female ranged from 0.87-2.58 mm, and relative penis length indices were from 7.2 to 21.2%. However, the degrees of imposex were different among the exposure groups. The FMPLS of three exposure groups (TBT+estrogen, + DDT and +nonylphe- not) were less than that of the TBT exposure group. Ethoxyresorufin-O-deethylase (EROD) activities in gastropod decreased in the TBT and all the TBT+antagonist ekposure groups compared to the control group. A negative correlation was abtained between TBT body residue and EROD activity, while a positive relationship was obtained between 737 body residue and the degree of imposex except for the TBT +DDT exposure group. Although 737 concentration was relatively high in the TBT+DDT exposure group, the TBT +DDT exposure group demonstrated low EROD activity and low degree of imposex. These results indicate that a certain antagonistic effect of DDT occurred in induction of imposex by TBT.

• Archives of Pharmacal Research
• /
• 제29권12호
• /
• pp.1158-1163
• /
• 2006

More than 95% of lead, a environmental heavy metal, entering into blood accumulates in erythrocytes suggesting erythrocytes as an important target of lead toxicity. Recent studies reported that erythrocytes could contribute to blood coagulation via phosphatidylserine (PS) exposure in erythrocytes. However, in vivo effects of chronic lead exposure especially by drink-ing water on procoagulant activity of erythrocytes have not been studied yet. In the present study, we investigated the effects of chronic exposure of lead by drinking water on erythrocytes in rats. Groups of 40 male rats were provided with drinking water containing various concentrations of lead for 4 weeks and complete blood cell count, procoagulant activities of erythrocytes and platelets were evaluated with basic inspections on body weight and food/water consumption. The administration of lead containing drinking water increased the blood lead level (BLL) in a dose-dependent manner up to $22.39{\pm}2.26\;{\mu}g/dL$. Water consumption was significantly decreased while food consumption or body weight gain was not affected. In contrast to the previous findings with acute lead exposure, chronic lead exposure failed to increase PS exposure in erythrocytes with statistical significance although some trends of enhancement were observed. It implies that a certain adaptation might have happened in body during repeated exposure to lead, resulting in attenuation of PS exposure. With this study, we believe that a valuable information was provided for the study on the toxicological significance and the risk assessment of lead contaminated drinking water.

• 한국산업보건학회지
• /
• 제16권2호
• /
• pp.110-122
• /
• 2006

Objective : This study was conducted to quantify chronic lead exposure from various media(ie. working environment, food, ambient air), and to certify the usefulness of exposure assessment using Monte-Carlo simulation in the fields of occupational health. Methods : Data were obtained from Korean Industrial Health Association, Korea Food and Drug Administration, and the Ministry of Environment. Then lead worker's exposure was estimated indirectly from various media and parameters (ie. volume inhaled, body weight, dietary intake, etc.). Uncertainty was analyzed by Monte Carlo simulation with Crystal Ball software. Exposure doses and hazard indices were simulated with various hypothetical scenarios including weekly working hours and respiratory protective equipment. Results : Without respiratory protective equipment, the total exposure dose per kilogram of body weight of lead workers was estimated as $5.45{\times}10^{-3}mg/kg/day$, and hazard index was estimated as 2.26, and exposure contributions were calculated as follows : working environment(82.42 %); foods(17.57 %); and ambient air(0.01 %). But, if working condition has changed - reduction of working hours and using respiratory protective equipment, the total exposure dose per kilogram of body weight was estimated between $1.34{\times}10^{-3}-1.49{\times}10^{-3}mg/kg/day$, and hazard index was estimated between 0.56 - 0.62. Conclusions : This study suggested that occurrence of hazardous impact(ie. increased blood pressure) through lifetime lead exposure would be expected, and that the Monte-Carlo simulation was useful for the fields of occupational health.

• Journal of Preventive Medicine and Public Health
• /
• 제30권1호
• /
• pp.69-76
• /
• 1997

To exanime in vivo tissue reactions of glass fibers, we injected glass fibers to rats subcutaneously. We made fibers of average dimensions of approximately $2{\mu}m$ in diameter and $60{\mu}m$ in length. After instilation of glass fiber we sacrificed rats sequentially at 1, 3 and 6 months. At 1 month after injection of glass fibers, the exposure area turned to yellow color and formed well-demarcated round mass. The average size of the mass was $1\times0.3cm$. Grossly detectable mass was decreased in size at 6 months compared to 1 or 3 months. Microscopically, strong foreign body reaction to glass fibers, inflammation and fibrosis were observed until 6 months. Foreign body reaction was increased up to 3 months, but it was decreased after 6 months. In scanning electron microscope, there was many bundles of glass fibers around the inflammation area, but the size of glass fibers were gradually reduced from 1 month to 6 months. These results suggest that subcutaneous exposure of glass fiber can provoke strong tissue reaction including foreign body granulomas, inflammation and fibrosis. But glass fiber itself did not produce any neoplastic changes.

• 한국식품영양과학회지
• /
• 제28권6호
• /
• pp.1349-1354
• /
• 1999

This study was carried out to investigate the protective effect of Korean red ginseng water extract (KRG WE) on clinical chemical parameters in male guinea pigs acutely exposed to 2,3,7,8 tetrachlorodibenzo p dioxin(TCDD). Forty male guinea pigs(200 $\pm$20g) were divided into 4 groups. Normal controls(group 1) received vehicle and saline; group 2(single TCDD treated) received TCDD(5 g/kg, single dose) intraperitoneally; group 3 received KRG WE(200mg/kg, i.p.) for 2 weeks from 1 week before TCDD exposure; group 4 received KRG WE for 1 week since the day of TCDD exposure. Increase in body weight was retarded greatly by TCDD exposure. Body weight of animals in group 2 was significantly decreased starting 2 days after TCDD exposure. However, body weight of animals in group 3 increased throughout the experimental period, although the increasing rate was slower than that of group 1. Decrease in body weight was not observed during the experimental period in group 4. Increases in blood glucose, amylase, lipase, total cholesterol, triglyceride, GOT, GPT, and LDH levels by TCDD intoxication were significantly attenuated by the KRG WE treatment(p<0.05). These results provide a strong evidence that Korean red ginseng might be a useful protective agent against TCDD, an endocrine disruptor.

• 대한가정학회지
• /
• 제46권1호
• /
• pp.39-45
• /
• 2008

We analyzed the effects of regular Jjimjilbang(Korean sauna) exposure on the physiological responses in seven elderly farmers(Male=3, Female=4). Jjimjil training group took a bath in Jjimjilbang 8 times twice a week. Jjimjibang exposure was limited three times per day. Rectal temperature, total sweat rate, body fat (%), blood pressure, pulse, $Na^+$ concentration in sweat, and subjective sensation were measured during Jjimjil training exposure. The results are as follow: During Jjimjil exposure, changes of rectal temperature in male farmers were more stabilized than female farmers. The gradual decrease in total sweat rate and Na+ concentration in sweat was observed in both sexes. After Jjimjil exposure, the decrease in blood pressure was observed in both sexes, but not observed changes according to regular Jjimjil exposure. Subjective thermal comfort sensation was changed positively. In conclusion, the regular Jjimjil exposure has positive effects upon improvement in regulation of body temperature, blood pressure, and $Na^+$ concentration especially in heat tolerance.