• 한국산업보건학회지
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• 제17권3호
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• pp.245-253
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• 2007

This research was performed to evaluate the airborne personal concentration of hazardouse materials during the process of ship construction and surveyed from May 23 to June 30, 2007 in Kyungnam West Distirct, Korea. The subject was 94 ship construction workers exposed to welding fume and respirable particulate. The airborne concentrations of those were compared to Permissible Exposure Limit(PEL) from the Ministry of Labor in Korea. The airborne concentration of 23 samples(48.9%) of welding fumes was less than $5mg/m^3$, that of 16 (34.0%) was between 5 and $10mg/m^3$, and that of 8 (17.0%) was greater than $10mg/m^3$. The airborne concentration of 27 (57.4%) of respirable particulate masses was less than $5mg/m^3$ and the othere are greater than $5mg/m^3$. The welding fumes were identified containing the heavy metasl such as Fe, Mn, Zn, Mg, Ca, and Cu. The respirable particulates has similiar tendency with welding fumes in the component of heavy metals. But the concentration of Ca, Cu, Cr, and Ni turned out to be higher in welding fumes. Twenty (42.6%) of the 47 samples of welding fumes were exceeded PEL. In the heavy metals in welding fumes, ten (21.3%) of the 47 samples of Mn were exceeded PEL. Based on the results, the higher airborne hazardous materials were still exposed to wokers in ship construction process. It is suggested that the appropriate engineering control be applied to minimize the exposed cocnetration in ship building processes.

• 한국산업보건학회지
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• 제19권4호
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• pp.381-389
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• 2009

Confined spaces are inherently dangerous workplace and many fatal and nonfatal accidents have been reported. Even though these accidents occur in various kinds of confined spaces, there has rarely been reported on the health hazard agent, i.e., the types of gases and their concentration ranges. Therefore in this study, we evaluated several toxic and asphyxiating gas concentrations in various confined spaces. We surveyed 57 manholes, 3 sewage treatment plants, 2 yellow radish manufacturing companies and 7 barges to measure the concentrations of oxygen($O_2$), hydrogen sulfide($H_2S$), carbon monoxide(CO), ammonia($NH_3$). Lower Explosion Limits(LEL) and Volatile Organic Compounds (VOCs). Those four types of confined spaces occupies 56% of accidents during last 9 years in Korea. In 57 manholes, the concentration varied according to the types of manholes; rainfall and sewage, and by location; residential and industrial areas. Sewage manhole in industrial area was evaluated as the most hazardous than other types of manhole like rainfall manholes, residential sewage manholes. The highest $H_2S$ concentration and the lowest $O_2$ concentration at sewage manhole in industrial area were 300 ppm, 8.7% respectively. In 3 sewage treatment plants, $H_2S$ and $NH_3$ concentrations were reached up to the 500 ppm and 200 ppm respectively. Two yellow radish manufacturing companies showed the concentrations of 316 ppm, 505.2 ppm, 90 ppm and 15.7% for $H_2S$, CO, VOCs and $O_2$, respectively. Seven barges showed 15.9%~20.9% oxygen concentration. Gas species and concentration ranges varied by the types and location of confined spaces; CO, $H_2S$, $O_2$ could be hazardous in manhole, especially manhole connected to sewage plants. CO, $H_2S$, LEL, $O_2$, $NH_3$ should be controlled in sludge silo and sluge pumping confined spaces in sewage treatment plant. The activity of lifting out radish from the storage tank was evaluated more hazardous rather than the other activities in yellow radish manufacturing industry. The employers must conduct the survey to identify all possible confined spaces in their local workplace prior to performing the tasks. At the national level to reduce the accidents in the confined spaces, we suggest that systemic approach and active education program including possible hazards, standard operation procedures, ventilation plan, and personal protective equipment in confined spaces should be implemented.

• Journal of Radiation Protection and Research
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• 제24권4호
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• pp.215-223
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• 1999

PWR 원전 증기발생기 수실의 방사선장 특성과 그곳에서 작업하는 종사자의 유효선량을 몬테칼로 시뮬레이션으로 평가하였다. 선원항으로는 고리1호기 증기발생기 방사화물 분석결과가 사용되었으며 유효선량 평가에는 MCNP4A코드와 MIRD형 성별 수학적 인형 모의피폭체가 사용되었다. 수실 내부 방사선장은 U튜브 영역에서 내려오는 방사선이 지배적이었으며 극각에 대해 근사적으로 코사인 분포를 나타내었다 유효선량률은 표준성인과 체격이 작은 성인(이 목적으로 15세 모의피폭체가 사용되었다.)의 경우 각각 36.22$mSvh^{-1}$와 37.06$mSvh^{-1}$로서 체격의 영향은 경미했다. 한편, 모의피폭체의 머리, 가슴 및 하복부에 해당하는 위치에서 평가된 조사선량률과 에너지스펙트럼에 대해 ICRU47에서 주어진 주위선량당량 환산계수를 이용해 평가한 등가선량률은 각각 119, 71, 및 58 $mSvh^{-1}$로 나타났다. 따라서 개인선량계 판독에서 얻는 심부선량 또는 유효선량은 앞서 계산한 유효선량률의 2배 정도가 될 것으로 보인다. 이 사실은 일반적인 개인선량계의 경사입사 방사선에 대한 과대/과소 평가 특성과 함께 비정규, 고선량률 방사선장에 종사하는 작업자의 선량계측 계획 및 결과의 해석에 매우 신중해야 함을 알려준다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.666-668
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• 2013

최근 스마트 기기의 빠른 보급과 더불어 스마트 기기의 운영체제에서 동작하는 악성코드의 종류와 수가 급격히 증가하고 있다. 특히 시스템 권한에 대한 접근이 용이한 안드로이드 운영체제를 기반으로 하는 스마트 기기의 경우 악성코드에 노출될 위험이 상대적으로 높다. 안드로이드에서 제공하는 전역 메시지 시스템인 인텐트를 이용하면 어플리케이션들 간의 상호 접근이 가능하며, 디바이스에 의해 가공된 데이터의 접근이 가능하다. 인텐트는 컴포넌트의 재사용성 측면에서 어플리케이션 개발에 편의성을 제공하지만 보안 관점에서 위험 요소로 지적될 수 있다. 따라서 악의적인 목적으로 인텐트를 사용하면 보안에 취약한 상태를 쉽게 유도할 수 있다. 즉, 스마트 기기를 제어할 수 없는 상황으로 만들거나 시스템 자원을 소비하는 등 인텐트를 수신하여 동작하는 어플리케이션들이 취급하는 자원에 접근하여 제어할 수 있게 된다. 특히, 시스템 권한을 획득한 경우 악성 코드를 통해 브로드캐스트 인텐트를 악용하면 스마트 기기의 제어 및 개인 정보 유출과 같은 위험도는 더욱 커지게 된다. 본 논문에서는 인텐트 패턴 검사로 인텐트 발생을 모니터링하고 검증되지 않은 패턴의 인텐트에 대해 탐지하고 차단하는 안드로이드 인텐트의 보안 취약성 대응 기법을 제안한다.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.371-386
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• 1993

This study was carried out to evaluate diagnostic criteria of noise-induced hearing loss (NIHL) among-workers in an iron foundry. Of 1,093 workers under the observation of noise-specific health examination, 184 workers were selected by way of first and second screening audiometric examination. A questionnaire survey, otological examinations, Rinne test and audiometric test were performed and the results were as follows ; The degree of hearing impairment in the left ear was more severe than in the right ear (p<0.05). The difference between hearing threshold of the first and the second hearing test at 1,000 Hz was about 5 dB with a narrow range of deviations while the difference at 4,000 Hz was about -7 dB with a wide range. Of the total study workers, 84.8% were tested within 15 hours away from noise exposure, and the rest after 16 hours. This study has identified that mean hearing loss at 4,000 Hz showed a significant statistical difference among the two study groups while mean hearing loss by 4-divided classification did not. The same phenomena were observed between the group with and without tinnitus and between the group with and without difficulty in hearing (p<0.05). Among 184 workers, 10 workers (5.4%) diagnosed as NIHL by old diagnostic criteria in contrast to 150 workers diagnosed as NIHL by the new diagnostic criteria. There was a significant difference between the two groups in the average hearing loss at 4,000 Hz and 4-divided classification (p<0.01), but there were no significant differences in age, the duration of employment, blood pressure and the duration wearing the personal hearing protector (p>0.05). If we apply Early Loss Index (ELI) method, some workers in younger age group diagnosed as NIHL by the new diagnostic criteria were fallen into within the normal range. In the mean time older age group show reverse results in contrast to the above finding. It is too early to confirm the value of the usage of the new diagnostic criteria in hearing examination. Further study is called for to verify the value of this criteria.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2009년도 학술논문요약집
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• pp.84-85
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• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.

• 한국환경농학회지
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• 제35권4호
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• pp.263-269
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• 2016

본 연구에서는 방제복의 액체침투저항성을 측정하는 방법 중 피펫법을 적용하여 국내 시판중인 5종의 방제복과 일반 shirt에 대해서 체류성, 발수성 그리고 침투성을 측정하였다. ISO 22608 Guideline 'Liquid penetration resistance-Pipette test'에서 요구하는 장치를 사용하였고 시험농약으로는 pendimethalin을 처리하여 GC/MS로 분석하였다. 5종의 방제복은 침투성이 0.0~5.4%로 매우 낮은 침투성을 보였으며 발수성은 67.0~98.1%로 농약이 쉽게 투과되지 않고 물 또는 액체에 의해서 제거될 수 있을 것으로 보였지만, 일반 shirt는 높은 침투성과 낮은 발수성이 확인되어 농약살포 시 손쉽게 피부에 노출될 수 있을 것으로 확인되었다. 현재 국내에서는 방제복에 대한 침투저항성 측정법과 기준이 마련되어 있지 않기 때문에, 본 연구는 방제복의 성능측정의 기준시험법 마련에 도움을 줄 수 있을 것으로 사료된다.

• 대한지역사회영양학회지
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• 제14권1호
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• pp.87-99
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• 2009

The purpose of this study was to investigate the perception of foodservice managers in childcare centers and kindergartens for identifying the vulnerable areas of safety management. The foodservice managers in 1,144 of nationwide childcare centers and kindergartens were surveyed from May to October 2007 to answer a total 72 questions in areas of general characteristics, actual practice of foodservice management and safety management perception. Meals were served in 97.7% of surveyed facilities and 91.0% among them were self-operated. The hiring rate (27.8%) of dietitians in childcare centers was significantly lower than the rate (82.0%) of kindergartens. The needs of dietitian employment between childcare centers and kindergartens differed as 44.9% and 87.5%, respectively. In knowledge on food-borne illnesses, they have the wrong information in the field of season for frequent outbreak, major pathogens and foods causing food-borne illnesses. The food-borne illnesses (36.2%) were indicated as the major problem in foodservice facilities and the degree of risk exposure was considered as safe (70.1%). More than 70% of both facilities answered as sanitary in the status of personal hygiene. Only 38.0% recognized the Facility and Equipment Standard in the Childcare Law and Early Childhood Education Law. In preparation of meals and management of cooking processes, kindergarten scored significantly high compared to childcare centers (p < 0.05 or p < 0.01) while the necessity of standards was not different in both facilities. Among managers surveyed, 28.8% had taken food safety education from professional institutions and more than 80% in both facilities indicated the need of professional educations. These results suggest that it is necessary for the systematic sanitary education of foodservice managers by developing the sanitary management standard as well as the amendment of laws related foodservice in childcare centers and kindergartens.

• 한국융합학회논문지
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• 제8권9호
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• pp.1-7
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• 2017

네트워크 환경의 개발과 고속화가 되면서 수많은 스마트 기기가 개발되고, 사람과 사물의 상호작용을 가능하게 하면서 고속화된 스마트사회를 구현할 수 있다. 사물인터넷의 수가 급증함에 따라 장치, 플랫폼 및 운영 체제, 통신 및 연결된 시스템에 대한 광범위한 새로운 보안 위험 및 문제점들이 부각되고 있다. 사물인터넷(Internet of Things)장비 들이 갖는 물리적인 특성상 기존 일반 시스템에 비해 크기가 작고 저전력, 저비용, 상대적으로 낮은 스펙으로 운용 제작되기 때문에 연산 및 처리 능력이 떨어져 기존 시스템에서 사용하던 보안 솔루션 적용에 한계가 있다. 또한 IoT(Internet of Things)기기들이 네트워크에 항상 연결되어 있는 특성에 따라 도청 및 데이터의 위 변조, 프라이버시 침해, 정보 유출, 비 인가된 접근, 루팅 및 업데이트 취약성 등 개인의 사생활 노출이나 국가의 중요 기밀과 시설에 대한 위협까지 중대한 보안상 문제들이 나타날 수 있다. 따라서 본 논문에서는 사물인터넷(IoT)의 네트워크의 보안위협사례와 피해사례를 조사하고, 취약성을 시나리오를 통해 분석하여 사물인터넷에 의한 재산피해 최소화하기 위한 방안을 제시하였으며, 시나리오를 이용하는 방법으로 취약점을 분석하였다.

• 한국융합학회논문지
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• 제11권5호
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• pp.19-25
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• 2020

모바일 기기 사용자가 증가함에 따라서 민감한 개인정보를 보호하기 위해 다양한 사용자 인증 방식에 대한 연구가 활발하게 진행되고 있다. 지식기반 기법들은 인증 수단 노출이 쉬워 보안성이 저하되는 단점이 존재하며, 소유기반 기법들은 서비스를 사용하기 위한 구축비용 증가 및 사용자 편리성이 낮은 문제점이 존재한다. 이러한 문제를 해결하기 위해 본인의 스마트 기기를 활용하는 사용자 인증 기법인 FIDO 인증 시스템이 제안되었다. FIDO 인증 시스템은 사용자의 생체 정보기반 인증을 수행하기 때문에 인증 수단이 유출되는 위험이 낮으며, 아울러 사용자의 스마트 기기에 인증 정보를 저장하기 때문에, 서버 해킹에 의한 사용자 정보가 노출되는 문제점을 해결한다. 이를 통해 서비스의 보안 수준에 맞는 사용자 인증기술을 선정하고 활용할 수 있다. 논문에서는 FIDO 인증 시스템에 대해 소개하고, FIDO UAF 클라이언트-서버 개발에 필요한 주요 부분을 설명하고 실제 ebay에서 제공하는 UAF 오픈소스를 활용한 구현 예제를 보여준다.