• Journal of Advanced Marine Engineering and Technology
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• 제39권7호
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• pp.716-721
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• 2015

환경오염에 대한 심각성이 대두되면서 대기오염에 대한 규제가 강화되고 있다. 육상에서 사용하는 자동차 및 산업용 발전설비 뿐만아니라 선박용 디젤기관에서도 규제를 시행하고 있어, 대체연료로서 바이오연료에 대한 많은 연구가 진행되고 있다. 따라서 실습선의 발전기관에 직접 바이오연료를 적용하여 기초적인 연구를 하고자 한다. 다만 실습선 안전을 위해 바이오연료의 비율을 많이 하지 못하지만 그래도 실험실에서 하는 작은 기관보다는 대형이면서, 큰 출력기관의 상태를 알아보는 중요한 기초자료가 될 것이다. 선박디젤발전기에서 바이오연료가 연소특성 및 배기배출물특성에 어떤 영향을 미치는지 연구하였다. 그 주요한 결과를 요약하면 다음과 같다. 바이오연료는 물리적 화학적 성분이 디젤경유와 비슷하여 실용 선박기관에 사용이 가능함을 알 수 있었다. 그리고 연료소비율과 NOx는 약간 증가하였으나, 일산화탄소와 매연은 감소하는 경향이 확인되었다. 또한 연소압력은 디젤경유와 바이오연료의 사용에 따라 크게 변화하지 않음을 알 수 있었다.

• 지식경영연구
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• 제21권3호
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• pp.229-247
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• 2020

지식경영 분야의 P2P금융 플랫폼의 성장속에서 빅데이터 및 머신러닝(Machine Learning) 기술을 보유한 회사만이 치열한 경쟁 속에서 생존할 가능성이 높을 것으로 예상된다. 그럼에도 불구하고 관련 서비스를 제공하는 온라인 P2P대출 플랫폼 업체들은 투자자와 대출을 신청하는 중개자로서의 역할을 수행할 뿐이며 투자와 관련된 위험은 모두 투자자에게 귀속시키고 있다. 이러한 이유로, 투자자 입장에서는 투자상품의 안전성을 확인할 수 있는 유일한 방법이 신문이나 온라인 웹사이트를 통한 P2P대출 플랫폼 업체의 평판에만 의존할 수 밖에 없는 실정이다. 또한, 한국의 P2P대출 플랫폼 업체들이 대출자의 개별 신용분석을 체계적으로 실시하여 연체율 등의 시계열 정보를 정확히 파악하기에는 시간적, 경제적 여건이 매우 열악한 상황이다. 그러나, 최근 몇몇 P2P대출 플랫폼 업체들이 업체별 대출자 신용분석에 대한 역량을 가장 중요한 영업자산으로 인식함으로써 빅데이터 및 머신러닝 기술을 바탕으로 인공지능(AI)에 기반한 새로운 신용평가 시스템을 구축하고 시행에 들어가고 있음은 매우 긍정적으로 평가된다. 따라서, 본 연구에서는 신용대출 시장에 주력하고 있으며 인공지능 활용으로 잘 알려진 상위 3개 업체를 대상으로 사례분석 방식을 통해 인공지능을 활용한 대출자 신용분석 절차 및 사용하는 정보 데이터의 종류 등을 분석하고자 한다. 이를 통하여 현 상황에서 P2P 플랫폼 업체들의 인공지능을 통한 신용분석 기법을 이해하고 현 시점에서 국내 인공지능을 활용한 신용분석 방식의 한계점과 개선방안 등을 함께 고찰하고자 한다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• 한국산업보건학회지
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• 제26권3호
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• pp.267-276
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• 2016

Objectives: This study, aims to examine the distribution characteristics of asbestos-containing building materials; risk assessment and area of distribution of asbestos-containing building materials depending on year of construction; building materials; types of building materials; and usage in public buildings in order to create fundamental data for safe management of public buildings. Methods: The asbestos investigation was conducted by an asbestos research institution from March to May 2014, targeting 41 public buildings which were subject to asbestos investigation in South Chungcheong-do Province. With respect to 381 presumed asbestos-containing materials, an investigation was conducted into whether they contained asbestos, asbestos type, content, year of construction, and use in the building were examined, and a risk assessment was performed. Results: Asbestos-containing building materials were used in 35 buildings(85.4%). Among them, 31(88.6%) were public buildings. Asbestos was detected in 73% of 381 suspected asbestos-containing materials, which were mostly ceiling materials (85.2%). The older the buildings, the more they showed a tendency to have a significantly higher risk assessment score. The ratio of average area with asbestos-containing building materials to total floor area was 57.6%, 44.1%, and 17.8% for buildings built in the 1980s, 1990s, and 2000s, respectively. This showed a tendency to be significantly higher with the age of the building. Conclusions: From the results above, it can be concluded that with the age of the buildings, the risk assessment score and the ratio of average area with asbestos-containing building materials to total floor area became significantly higher. Given the concern about the exposure to asbestos of residents and civil petitioners, safety management of older public buildings and measures for dismantling and removal of asbestos-containing building materials should therefore be urgently established.

• 한국산업보건학회지
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• 제26권3호
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• pp.277-285
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• 2016

Objectives: This study was performed in order to evaluate whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) could be detected among residents living near Camp Caroll in Waegwan and whether serum concentrations of dioxins, including 2,3,7,8-TCDD, and organochlorine pesticides (OCPs) are associated with length of residence. Methods: Study subjects totaled 113 (for dioxins) and 190 (for OCPs) adults who were selected from participants in a medical investigation. Serum concentrations of dioxins and OCPs were measured using HRGC/HRMS. Information on length of residence was obtained through questionnaires. Results: 2,3,7,8-TCDD was not detected in serum among all subjects. When length of residence was classified as a categorical variable, after adjusting for confounding variables, only residents living in Waegwan for 40 years or longer tended to have high total TEQ values and 2,3,4,7,8-PeCDF with marginal significances. There was no dose-response relation between length of residence and serum concentrations of these chemicals. In multiple regression models with continuous values of the length of residence, total TEQ value and 1,2,3,4,6,7,8-HpCDF were positively associated with length of residence. However, they explained about 3-5% of total variations of serum concentrations of these compounds, while age, consumption of fatty fish, body mass index, alcohol drinking, and cigarette smoking were main variables affecting serum concentrations of dioxins or OCPs. Conclusions: In the current study, high concentrations of certain compounds were mainly observed among persons who lived in Waegwan for at least for 40 years without a dose-response relation. Therefore, it seems difficult to conclude that length of residence meaningfully contributed to the current serum concentrations of dioxins or OCPs among residents in Waegwan. However, considering the half-life of 2,3,7,8-TCDD and indirect exposure routes, the limitations of the current study design should be considered in the interpretation of the study findings.

• Journal of Preventive Medicine and Public Health
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• 제30권4호
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• pp.840-851
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• 1997

To perform voluntary occupational health program in worksites, regulational supports are necessary. The regulational supports include assessment of current occupational health program and appropriate incentives. The purpose of this study is to find out the requirements of voluntary occupational health program and conditions to be improved. Study population was industrial health managers of both industries with less than 300 workers and over 300 workers, and the member of labor union who is responsible for safety and health in worksite. Two different questionnaire were used to find out the requirements and conditions to be improved respectively, The results were; 1. The category which prevalence rate of occupational injuries and occupational disease should be lower than national average was most important in health managers employed in industries over 300 workers and followed by reporting system, education, worksite policy, work environment assessment, protective equipment, consequently. But those employed in industries less than 300 workers showed high importance in prevalence rate of occupational injuries and disease, reporting system, worksite policy, work environment assessment, protective equipment, education, consequently 2. The members of labor union thought that worksite policy was most important and the next is education, reporting system, work environment assessment, protective equipment, prevalence rate of occupational injuries and disease. 3. There were difference in importance of education and worksite policy according to the size of industries. Reporting system, prevalence rate of occupational injuries and disease, and worksite policy had different importance between members of labor union and health managers. 4. In the results of quiestionnaire for conditions to be improved, the most important condition was top manager's willingness except personal protective equipments, and followed by financial support, legal support. The limitations of this study were the problems of representativeness of study population. but voluntary health program should be performed in worksites which have relatively good occupational health system. So, this selection bias could not disrupt our results.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.

• 한국화재소방학회논문지
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• 제27권3호
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• pp.1-7
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• 2013

전 세계적으로 기후변화 등의 원인으로 산림화재가 대형화되고 있다. 산림이 국토의 약 63.7 %를 차치하며, 산림에 인접해서 산업시설 등의 주요시설들이 많은 국내의 경우에는 산림화재가 대형재난으로 확산될 가능성이 매우 높다. 이에 본 연구에서는 수관화로 발달한 산림화재에서 화염의 복사열이 미치는 피해영향거리를 풍속의 변화에 따라 분석하였다. 또한, 영향거리를 분석하기 위하여 주변시설에 미칠 수 있는 복사열의 안전기준을 조사하였으며, 기준 복사열로 $5kW/m^2$와 $12.5kW/m^2$, $37.5kW/m^2$를 제시하였다. 산림화재 피해영향평가를 위해 FDS의 산림화재 확장 프로그램인 WFDS를 활용하였고, 해석조건으로 국내에 일반적으로 분포가 높은 산림조건에 대해 조사하여 이를 적용하였다. 그 결과는 풍속에 따른 복사열 최대영향거리로 제시하였다. 풍속 0~10 m/s에 있어서 풍속의 증가에 따라 영향거리도 증가하는 경향이 있으며, 풍속 8 m/s에서 영향거리가 최대가 되었다. 또한, 최대 영향거리는 수목 연료의 함수율 증가에 따라 크게 감소하는 것을 확인하였다. 본 연구는 산림화재로 인한 주변시설의 피해영향을 정량적으로 평가하는데 기여할 수 있다.

• 환경위생공학
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• 제11권3호
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• pp.53-61
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• 1996

The subject of this study was to analyse overviews of companies which exceed TLV by industry, hazardous factors, and to estimate the numbers of companies measured in 1993 and the implementation rate of working environment measurement by the act of industrial safety and health The result of this study was as follow. 1. The number of cases which exceed TLV was 5,937 companies. In distribution of excess companies by the scale of workers, small scale cases under the 49 workers were 3,150 companies(53.0%) of total cases, medium scale cases between 50 - 299 workers were 2,248 companies(37.9%), and large scale cases over 300 workers were 539 companies(9.1%). By the industry of excess companies, it was marked high rate in manufacture of fabricared metal products(except machinary and equipment), manufacture of textiles of each 1,048 companies(17.7%), and 1,018 companies(17.1%). By the area of excess companies, it was shown high rate in Kyeongki area marked 1,679 companies(28.3%) and Daegu-Kyeongbuk area were marked 1,417 companies (23.9%). By the hazardous factors of excess companies, noise was recorded high rate in 5,160 companies (86.9%), dust was shown in 1,245 companies(21.0%), organic solvent was marked 130 companies(7.9%). The number of excess factors by the company was 1.2. In this result, the more it was bigger scale companies, the more excess factors were much more and the more it was recorded higher rate in noise organic solvent heavy metals, etc. 2. The measured cases in institutes during 1994 were 1,596 companies, and excess cases were 157 companies(9.8%) among them. By the scale of workers, small scale cases under the 49 workers were 190 companies (17.9%) among 1,064 companies, cases of medium scale cases between 50-299 workers were 127 companies (27.9%) among 463 companies, and large scale cases over 300 workers were 31 companies(44.9%) among 69 companies. In this result industry of the highest rate shown was manufacture of basic metals in 20 companies exceeded among 53 companies (37.7%), and was manufacture of pulp, paper production in 14 companies exceeded among 40 companies(35.0%), and the excess rate were high in bigger scale. 3. Companies estimated by the data of excess cases and excess rate in 1993 were 30,474 implementation rate estimated for measurement of working environment was 34.3% of companies in korean industry. In this result, it was comparatively shown of measurement rate for the working environment in manufacture of pulp, paper product, manufacture of machinary and equipment n.e.c., and of high measurement rate and excess rate in manufacture of electrial machinary and apparatus, and manufacture of basic metals.

• 한국산업보건학회지
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• 제24권3호
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• pp.247-255
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• 2014

Objectives: We reviewed the CAREX (CARcinogen EXposure) program designed to estimate the prevalence of occupational exposure to carcinogens and summarized the advantages and limitations of this program. Methods: All literature, including reports on CAREX and the use of CAREX, were reviewed. The keyword search term was CAREX. Additional articles were identified from references cited in articles and reviewed. Results: An exposure information system, CAREX was developed based on data from the Finnish Institute of Occupational Health of Finland and from the US. CAREX has been applied in several countries, including in the EU, in order to estimate national exposure patterns to carcinogens. The initial exposure assessment carried out through CAREX was aimed at estimating exposures over the period of 1990-1993. To estimate the number of workers exposed to carcinogens by using CAREX, reference exposure prevalence from Finland and the United States was computed, which was then reviewed and corrected by national experts. Finally the overall number of workers exposed to carcinogens can be estimated. We found that CAREX has been used in a total of 18 countries. No Asian country has used CAREX. Conclusions: CAREX can be applied not only to estimate the number of workers exposed to carcinogens in Korea, but also to identify high-risk industries with workers most exposed to carcinogens.