• Safety and Health at Work
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• 제2권3호
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• pp.201-209
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• 2011

The incidence of asbestos-related diseases (ARD) has increased in the last four decades. In view of the historical use of asbestos in Singapore since the country started banning it in phases in 1989 and the long latency of the disease, the incidence of ARD can be expected to increase further. As occupational exposure to asbestos still occurs, preventive measures to eliminate ARD continue to be required to protect the health of both workers and the public from asbestos exposure. The majority of occupational exposures to asbestos at present occur during the removal of old buildings. Preventive measures have been utilized by different government ministries and agencies in eliminating ARD in Singapore over the past 40 years. These measures have included the enforcement of legislation, substitution with safer materials, and engineering controls during asbestos removal as well as improvements in personal hygiene and the use of personal protective equipment. The existing Workman's Compensation System for ARD should be further refined, given that is currently stipulates that claims for asbestosis and malignant mesothelioma be made within 36 and 12 months after ceasing employment.

• Journal of Preventive Medicine and Public Health
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• 제33권1호
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• pp.17-24
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• 2000

Objectives : To propose the referential data to evaluate the health impacts of Vietnam veterans' children whose father were exposed to herbicides in Vietnam War. Methods : Vietnam veterans who visited to Pusan Veteran Hospital for medical care were recruited from April to October, 1998. They were 71 and asked about their own combat history, symptoms and illness, and health status of their 182 children. The informations were collected by direct and phone interview. Exposure estimation was also performed as exposure score depending on year and unit of participation, and personal episodes related to exposure to herbicide in the war. It classified into three groups; lower(<18.0), moderate(18-53), high$(\geq53)$ exposure group. Results : The mean age and the period into the combat of the veterans were 52.8 years and 15.0 months. The mean exposure score was $18.1{\pm}9.9$, and mainly distributed in lower (46.5%) and moderate(52.1%) exposure group. Most(90.1%) of them were diagnosed as sequelae(21 cases) and suspected sequelae(43 cases) of the herbicides by Korean veteran's hospital diagnostic criteria. The major sequelae was peripheral neuropathy 13 cases, chloracne 5 cases, and the major suspected sequelae was hypertension 20 cases, diabetes mellitus 18 cases, liver disease 12 cases, central neuropathy 11 cases, etc. About birth, 42.2% and 16.9% experienced spontaneous abortion and stillbirth, respectively. The mean exposure score was higher in stillbirth experience group(p<0.05). About half of the children(90 cases, 49.5%) hold the abnormal health status: those were skin pigmentation 38 cases, rash 23 cases, congenital anomaly 15 cases, general weakness 12 cases, purpura 8 cases, visual disturbance 8 cases, etc. These health problems had no association with father's exposure level(p>0.05). Conclusions : These results were depend on their own answers, and expectation for compensation did not excluded, therefore, this study may have limitations: inaccuracy of informations due to recall bias and response bias. Nevertheless, through this study, we could image the fundamental aspect for health impacts of Vietnam veterans' children for preparing the national control program and policy. A large scale epidemiologic study with valid exposure assessment on the health impacts of Vietnam veterans' children is recommneded.

• 한국환경보건학회지
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• 제39권3호
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• pp.197-210
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• 2013

Several US veterans stationed in Korea have told the press that around 250 fifty-five gallon drums of herbicides, including Agent Orange, were buried at Camp Carroll in 1978. Joint Korean-US Agent Orange investigation and environmental and health studies were started in July 2011. Korean soldiers and military personnel who served in Vietnam during 1964-1973 or near the demilitarized zone in Korea during 1967-1970 were exposed to dioxincontaminated Agent Orange. The joint Korean-US Agent Orange investigation team found that herbicides, pesticides, solvents and other chemicals -not Agent Orange- were buried at Camp Carroll. However, there remains the possibility that Agent Orange was stored and buried at Camp Carroll or other military camps in Korea. Adverse health effects have not been clearly explained despite a number of health studies among veterans in Korea with potential Agent Orange exposure. Although the Korean government has been compensating veterans and military personnel with 18 presumptive-service-connected-diseases and their offspring with three diseases, there are many veterans, military personnel and civilians who require the government°Øs support. The environmental study on contaminated sites and health studies among veterans and civilians were initiated three or four decades after possible Agent Orange contamination and exposure. Several toxic chemicals, including dioxin-contaminated Agent Orange, could remain in the environment and could have hazardous effects on the health of exposed people for more than several decades. Further environmental investigations and health studies are needed to ensure public safety and health, and government support should be guaranteed for people potentially exposed to these toxic chemicals.

• Applied Microscopy
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• 제23권1호
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• pp.15-24
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• 1993

버들붕어 뇌와 아가미의 미세구조에 미치는 메틸수은의 독성적 영향과 이에 대한 홍삼의 보상효능을 전자현미경적 방법에 의하여 연구하였다. 뇌 신경세포의 미세구조 변화에 있어서 대조군에 비하여 메틸수은만을 투여한 군에서는 수상돌기와 축색돌기가 상당히 확장되고 핵질과 세포질이 부분적으로 손실되었으며 ribosome의 수적감소와 mitochondria의 팽대가 관찰되었다. 그리고 파괴된 핵과 공포화된 mitochondria를 함유한 괴사세포의 출현은 특이한 관찰이었다. 반면 메틸수은과 홍삼을 병행 투여한 군에서는 메틸수은만을 투여한 군에서 보다 수상돌기와 축색돌기의 확장이 감소되고 ribosome의 수가 증가되었으며 mitochondria의 팽대정도가 상당히 감소되었다. 아가미 새판의 미세구조에 있어서는 Pillar cell과 arm의 붕괴, 표피세포의 확장 및 기저막의 비후가 메틸수은만을 투여한 군에서 관찰되었고 메틸수은과 홍삼을 병행 투여한 군에서는 메틸수은만을 투여한 군에서 보다 arm의 붕괴정도와 기저막의 비후정도가 감소되어 정상세포와 거의 같은 정도로 호전되었다.

• 한국정밀공학회지
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• 제19권3호
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• pp.152-159
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• 2002

SLA (Stereolithography Apparatus) it a process used to rapidly produce polymer components directly from a computer representation of the part. Though SLA is being recognized as an innovative technology, it still cannot be used to fully practical application since it lacks of dimensional accuracy compared to conventional process. If the shrinkage were perfectly uniform and no distortion took place, excellent part accuracy could still be achieved through and appropriate scaling factor when generating the build file. However, in certain geometries involving intersecting thick and thin sections, nonuniform retrain shrinkage becomes the engine of part distortion. In order to improve the part accuracy of SLA, this paper evaluates how largely each parameter of SLA contributes to the part accuracy and estimates the optimal set of parameter which minimizes the dimension error of the test part, "Slab (100mm$\times$100mm$\times$2mm)"and "scale bar"part. Three control parameters such as critical exposure, generation depth and fill cure depth are used.

• 한국산업보건학회지
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• 제27권4호
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• pp.302-312
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• 2017

Objectives: In this study, an evaluation of the working environment of furnace workers was performed and the work-relatedness of the occupational diseases were examined Methods: In this study, two electric furnaces at a single casting business site producing manganese-based iron alloy were selected, and occupational exposures to hazardous substances were evaluated for furnace workers and furnace worker assistants. Results: As a result, total dust concentration were $0.407{\sim}3.001mg/m^3$ and respirable dust concentration were $0.196{\sim}0.584mg/m^3$. The highest concentration of crystalline silica was $0.079mg/m^3$ In the case of Masato and Sosuckwhoi crystalline silica, they contained 90.85% and 4.17% respectively. Manganese concentration was the highest at a $0.205mg/m^3$ maximum. The average of black carbon is $11.56{\mu}g/m^3$ and the maximum concentration is $604.23{\mu}g/m^3$. PAHs concentration was the highest at a $78.301{\mu}g/m^3$ of naphthalene. The concentration of carbon monoxide was 18.82 ppm(total average 3.89 ppm) during pouring, and the maximum is 131 ppm. The formaldehyde concentration was 0.003 to 0.007 ppm. Conclusions: It seems that conditions in the past were worse, since casting has recently been performed only twice per day for about 20 minutes, reducing the amount of pouring, and local exhaust systems have been installed one-by-one. In addition, it was judged that the past exposure levels were higher considering the points measured on the back-side due to the risk of damage to the individual samples. It was found that operators could be exposed to high concentrations of crystalline silica, and that they were also exposed to high concentrations of metal(fume) and carbon monoxide during pouring. Therefore, there is a risk that occupational diseases such as lung cancer and COPD may occur with long-term work in such a process.

• 한국산림과학회지
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• 제86권1호
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• pp.80-86
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• 1997

잡종(雜種)포플러가 어떻게 오존 stress에서 피해(被害)를 최소화하는가를 알아보기 위해서 생장(生長), 광합성율(光合成率), 그리고 초기(初期) Rubisco의 활성(活性)을 조사(調査)하였다. 이 연구(硏究)에서는 Populus trichocarpa${\times}$P. deltoides 삽목묘(揷木苗)를 재료(材料)로 사용(使用)하였다. 오존처리농도(處理濃度)는 90-115 ppb으로, 하루에 6-9시간씩, 126일 동안 처리하였다. 이 연구에서는, 오존에 저항성(抵抗性)을 가지는 포플러는 광합성율(光合成率)과 Rubisco의 활성(活性)을 증가(增加)시켜서 그 물질(物質) 생산량을 유지(維持)하여 stress를 보상(補償)한다는 가설(假說)을 검정(檢定)하였다. 생장(生長), 물질생산량(物質生産量), 광합성율(光合成率), 그리고 초기(初期) Rubisco 활성(活性)이 일반적으로 오존에 의해서 감소(減少)하였다. 뿌리의 생장량은 지상부(地上部)의 피해(被害)를 보상하기 위한 탄소(炭素)의 불균등(不均等)한 분배(分配)때문에, 가장 피해가 심한 부위(部位)였다. 저항성을 가지는 포플러는 오존에 대해서 수체내(樹體內)의 광합성율(光合成率)과 초기 Rubisco 활성을 높여 생산량(生産量)을 유지(維持)하는 생물적(生物的)인 보상(補償)을 하는 것으로 밝혀졌다.

• Safety and Health at Work
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• 제10권3호
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• pp.347-354
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• 2019

Background: The aim of this study was to describe the types of diseases that developed in semiconductor workers who have registered with the Korea Workers' Compensation and Welfare Service (KWCWS) and to identify potential common occupational characteristics by the type of claimed disease. Methods: A total of 55 semiconductor workers with cancer or rare diseases who claimed to the KWCWS were compared based on their work characteristics and types of claimed diseases. Leukemia, non-Hodgkin lymphoma, and aplastic anemia were grouped into lymphohematopoietic (LHP) disorder. Results: Leukemia (n = 14) and breast cancer (n = 10) were the most common complaints, followed by brain cancer (n = 6), aplastic anemia (n = 6), and non-Hodgkin lymphoma (n = 4). LHP disorders (n = 24) accounted for 43%. Sixty percent (n = 33) of registered workers (n = 55) were found to have been employed before 2000. Seventy-six percent (n = 42) of registered workers and 79% (n = 19) among the registered workers with LHP (n = 24) were found to be diagnosed at a relatively young age, ${\leq}40years$. A total of 18 workers among the registered semiconductor workers were finally determined to deserve compensation for occupational disease by either the KWCWS (n = 10) or the administrative court (n = 8). Eleven fabrication workers who were compensated responded as having handled wafers smaller than eight inches in size. Eight among the 18 workers compensated (44 %) were found to have ever worked at etching operations. Conclusion: The distribution of cancer and rare diseases among registered semiconductor workers was closely related to the manufacturing era before 2005, ${\leq}8$ inches of wafer size handled, exposure to clean rooms of fabrication and chip assembly operations, and etching operations.

• 제어로봇시스템학회논문지
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• 제9권4호
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• pp.296-303
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• 2003

A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.

• 한국멀티미디어학회논문지
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• 제25권9호
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• pp.1273-1283
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• 2022

This paper presents a locally adaptive HDR algorithm using the integral image and MSRCR for LDR images with inadequate exposure. There are two categories in controlling the dynamic range, which are global and local tone mappings. Since the global ones are relatively simple but have some limitations at considering regional characteristics, the local ones are often utilized and MSRCR is a representative method. MSRCR gives moderate results, but it requires lots of computations for multi-scale surround Gaussian functions and produces the Halo effect around the edges. Therefore, in order to resolve these main problems, the proposed algorithm remarkably reduces the computation of the surrounds due to the use of the integral image. And a set of variable-sized windows is adopted to decrease the Halo effect, according to the type of pixel's region. In addition, an offset controlling function is presented, which is mainly affected to the subjective image quality and based on the global input and the desired output means. As the results, the proposed algorithm no more use Gaussian functions and can reduce the computation amount and the Halo effect.