• Journal of Advanced Marine Engineering and Technology
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• 제20권3호
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• pp.19-28
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• 1996

In Asia countries the productions of ship building and marine engines have been increasing, specially Japanese marine industries have worked hard after 1960s and Korean ones after 1980s. Recently the other countries, as Taiwan and China, have been working so that these hour Asian countries are occuping the high level of shared ratio of productions for gross tonnages and horse powers, which are 74 and 64[%] of the world ones ($8.6\times10$+6[GT], $8.6\times10$+6[PS]) in 1994. Korean industries had the highest shared ratio of production of tanker vessel and 2 stroke diesel engine as 45[%]($2.2\times10$+6[GT]) and 37[%]($1.0\times10$+6[PS]) which were more than those of Japan as 34 and 16[%] in 1989 respectively. Some marine databases and their network links among Asian countries are proposed due to the posibility of collection and analyses with their own specifications by the marine industries and operators as well as Japanese ship reliability investigation works(SRIW) like SRIC in Japan. During 1966 and 1996 16 times of SRIW in Japan have been carried out by ship reliability investigation group(SRIG) in Japan. There have been collected and evaluated a great number of field data of failures and maintenances($700\times10$+3[occ], $1.6\times10$+6[MH}) during running hours($13.4\times10$+6[Hrs]), from which many kinds of evaluation indices could be gotten as the three indices of occurring rate$\lambda$(52.2[occ/1000Hrs]), average man-hour mh(2.29[MH/occ]) and manning index MI(119[MH/1000Hrs]). An estimation example having the three indices$\lambda$, mh and MI were shown by the SRIC 1990 Data Base in Japan for the two kinds of fuel oil suppling subsystems which are dual fuel oil one(DFOS) and mono fuel oil one(MFOS). Three indices MI, and mh for DFOS and MFOS results in 7.16 and 5.20[MH/1000Hrs], 2.63 and 2.06[occ/1000 Hrs]. Therefore the more simple subsystem MFOS can save approximately 30[%] of maintenance load. Finlly an utilization methods are shown for the SRIC in Japan by means of computer system and worlwide internet links.

• 보건행정학회지
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• 제2권2호
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• pp.57-89
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• 1992

This study is aimed both to reorient the Health net-works focused to Health Subcenters in times of development of local autonomy in Korea and to collect the fundamental data such as attitude and practice of the directors of Health Subcenter. The materials are collected from 134 out of 258 sampling directors of Health Subcenters with a questionaire by mailing(respond rate 51.9%). The major findings of this fundamental data are as follows. 1. Current average number of outpatients cared by a director of Health Subcenter is found to be 21.6. 2. The directors of Health Subcenter have little deducted hours for Public Health Programme. 3. Number of the Preventive Health Programme worked by a director of Health Subcenter is from 0 to 3. The most major group worked only 1 programme marked at 69.4%. 4. The directors of Health Subcenter express approval opinin marked at 80.2% that their qualification to appoint has to finish intern course. 5. The average diagnosis allowance a month is approximately twenty hundred thousand won. 6. Most of Health Subcenter(market at 94%) adopted a self-supporting account system. 7. The most complaining subject of directors of Health Subcenter is their working environment. The second complaining subject is governmental officier's interference. 8. The average number of outpatients cared by a director of Health Subcenter is found to be certain differentials by their marriage and the duration of employment. Some proposals of development on Health Subcenter based on the result of this research is as follows : 1. The reorganization on Health Subcenter under line of National Health Center Net-work 2. The psychological reorientation of directors of Health Sucenter and officers. 3. Autonomy management of Health Subcenter. 4. Reorientation of status on directors of Health Subcenter.

• 융복합기술연구소 논문집
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• 제3권2호
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• pp.11-15
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• 2013

These days, the quality of goods is required to improve in the process of manufacturing the semiconductor through the short working hours and clean transportation. The non-contact transport device using magnetic levitation can be a solution in the manufacturing process. The non-contact transport device, using electromagnetic actuation, is the system that can actually transport them by only using attraction force from the electromagnetic source without authentic contact. Moreover, the system using electromagnetic force has a substantial number of benefits ranging from unrestricted design to unlimited expansion. Especially, the price is competitive. The non-contact transport device, using electromagnetic force, has another merits in controlling by giving the same amount of attraction force to ferromagnetic body. By controlling the currents given to coil, the operator is able to decide the direction of the transportation. In order to design the optimal system, we implemented five different things such as the presence of the links below the electromagnetic, the electromagnet changes due to coupling method, the change according to the thickness of the links below electromagnet, due to changes in between electromagnetic distance direction, and the size of the current. Through simulations and the optimum design, it seems to control easily and figure out the exact size of power. It might definitely be the non-contact transport that can sharply reduce tiny scratches and particles in the process of manufacturing the semiconductor.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.502-514
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• 1998

The purpose of this study is to observe the corrosion characteristcs of four dental amalgams(CAULK FINE CUT, CAULK SPHERICAL, DISPERSALLOY, TYTIN) and to determine a function of chloride concentration through the anodic polarization curve obtained by using a potentiostat. After each amalgam alloy and Hg being triturated, the triturated mass was inserted into the cylinderical metal mold, and condensed by hydrolic pressure. Each specimen was removed from the metal mold. 24 hours after condensation, specimens were polished with the emery paper and stored at room temperature for 6 months. The anodic polarization curves were employed to compare the corrosion behaviours of the amalgam m KCl and KCl-NaCl solution, which had chlonde concentration of 0.4 g/l, 0.8 g/l, 1.2 gil, and 1.6 gil at $37^{\circ}C$ with 3-electrode potentiostat. After the immersion of specimen in electrolyte for 1 hour, the potential scan was begun. The potential scan range was - 1500mV ~+800mV(vs. S.C.E.) in the working electrode and the scan rate was 50mV/sec. The results were as follows, 1. The corrosion potential. the potential of anodic current peak, and transpassive potential in the solution of high chloride concentration shifted to more cathodic direction than those in the solution of low concentration, and the current density in the solution of high chloride concentration was higher than that in the solution of low concentration. 2. The corrosion potential, the potential of anodic current peak, and transpassive potential for CAULK FINE CUT amalgam were the most cathodic among the others, and the current density were the highest among the others. 3. In the solution of low chloride concentration, the corrosion potential, the potential of anodic current peak, and transpassive potential for DISPERSALLOY were the most anodic among the others, however in the solution of high chloride concentration, those for TYTIN were the most anodic among the others. 4. The anodic polarization curve for CAULK SPHERICAL was similar to that for high copper amalgams.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.95-106
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• 2020

The purpose of this study was to determine the effects of coniferous essential oils (EOs) blended films on insect repellence and crop productivity. Low-density polyethylene (LDPE) film is widely used, especially in agriculture and for food packaging. Ethylene vinyl acetate was blended with LDPE to reduce volatilization of EOs. An EO from Japanese cypress (Chamaecyparis obtusa) was incorporated into the blend film to conduct field research on antimicrobial and insect repellent properties. Among the various concentrations of EO, the highest concentration (2.5%) showed the highest efficiency in terms of pesticidal activity. The ability to inhibit microbial growth can be explained by the lipophilic properties of the EO component, and many studies have already demonstrated this. Agricultural films containing all types of EO have been tested on various crops such as chili, cucumber, Korean melon and have been able to verify their effectiveness in avoiding pests and increasing yields. From these results, it was found that it is reasonable to use a modified film such as a composite film containing an EO for agriculture. Thus, the modified film containing EO has undoubtedly shown impressive potential for reducing the use of pesticides in a variety of ways, not only for agricultural mulching film but also for food and agricultural product packaging. This product is an environmentally friendly chemical and is safe for agricultural and industrial and food packaging applications, among others. In particular, the use of agricultural films significantly reduces the use of pesticides, suggesting that farmers can increase their incomes by reducing working hours and costs, and increasing production.

• 방사선산업학회지
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• 제11권1호
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• pp.47-54
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• 2017

Compared to other occupations, there is a greater risk of exposure to radiation due to the use of radioisotopes in nuclear medicine for diagnostic evaluations and therapy. To consider ways to reduce exposure dose for those in nuclear medicine involved in injection work and elution work among radiation workers as well as for sanitation workers and trainees among frequent workers an investigation into exposure dose and situational analysis from changes in yearly exposure dose evaluations, changes in work environment and changes in forms of inspection were conducted. Exposure dose measurements were taken by using EPD MK2 worn during working hours for one injection worker, one elution worker, two sanitation workers, and one trainee at a general hospital in the Seoul area for three days from July 18th to 20th 2016. Radiation from radioisotopes which are a part of nuclear medicine can significantly affect not only radiation workers who deal with radioisotopes directly but also frequency works as well. According to this study the annual dose limit for elution workers and injection workers were considered safe as the amount of exposure was not large enough to have a significant effect. The limits of this study consist in the duration of this study and the quantity of participants. Also there was a limitation of the measurement device involving accumulated exposure, where the EPD MK2 cannot check the changes in exposure according to a particular activity.

• 한국시뮬레이션학회논문지
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• 제29권3호
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• pp.19-25
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• 2020

밭 농업 기계는 심한 경사지와 험로, 재배 작물별 정형화되지 않은 재배양식으로 인해 개발이 어렵다. 특히 고추 수확 작업은 많은 시간과 인력이 요구되는 작업으로 고령화가 가속화되는 국내 농촌의 큰 문제점이다. 본 연구는 부족한 인력을 대체하고 작업 시간을 줄이며 수확 작업을 기계화하기 위해 개발된 고추 수확기의 동적 특성을 연구하고자 한다. 고추 수확기의 동적 특성을 분석하기 위해 동역학 프로그램인 Recurdyn을 이용하여 진행하였으며 모든 분석은 공차를 전제로 분석을 진행하였다. 시뮬레이션 결과에 따라 주행 플랫폼이 주행할 수 있는 안전 범위를 제시하였다.

• 한국인구학
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• 제8권2호
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• pp.93-99
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• 1985

There have been numerous studies in Korea and other countries of which the major hypotheses are identifying and dearibing the conditions under which the value of children has been formed. The present study proposes to view the formation of the value of children as a correlate of family's consumption-saving and work4eisure behavior pattern. The objectives of the proposed study are to identify the socio-economic and demographic factors determining the family's consumption-saving and work-leisure behavior pattern and to analyse the relationship between the value of children and this behavior pattern. The conceptual framwork of the analysis is that an individual family's socio-economic and demographic factors influence and shape the consumption-saving and work-leisure behaviors and these behaviors in turn influence and reflect the correlates and proximate determinants of the family'sfertility. In this paper, regression model is used to analyse the hypothesized relationship among the various variables. The regression methods used are first and second stage multiple regressions. In addition, MONOVA has been used to show the interactions. Data used are collected from the government publicactions. The major findings from this study are as follows: As the living Standard improves, n individual family's consumption of necessities and its working hours decline, while savings and leisure activities increase. The phenomena result in the fertility reduction as can be seen in the more developed conntries. Child-bearing and rearing activities are found to be the important component to determine the condumption-saving and work-leisure activies. The married women's labor participation, and the investment in education and health are also found to be the factors reducing fertility rate.

• 한국건설관리학회논문집
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• 제22권3호
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• pp.12-20
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• 2021

건설 품질 및 안전 확보, 비용분쟁 방지를 위해 최근, '적정 공사기간' 산정의 중요성이 부각되었다. 건축공사기간 산정기준 마련을 위해서는 상당량의 과거자료 분석이 필요하다. 그러나, 근로시간 단축, 품질규정 강화 및 기후조건 변화 등 건설사업 환경이 이미 변경되어 과거자료의 사용에 대해 많은 전문가들이 의문을 제기하고 있는 실정이다. 또한, 건축공사는 공사 여건에 따라 작업순서, 생산성 등이 매우 다양해 과거 통계치를 활용한 획일적인 공사기간 산정 시 오류 가능성이 상승한다. 따라서, 적극적인 '생각의 전환'을 통해 과거자료 분석 방식에서 현재생산자료 검토 방식으로 변경하는 새로운 해법을 본 연구를 통해 제시하였다. 즉, 설계단계에 '공정관리 전문가' 및 '공종별 시공전문가'를 투입하여, '적정 공사기간'을 검토·산정하는 절차를 제도화하였다.

• 한국컴퓨터정보학회논문지
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• 제26권11호
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• pp.183-189
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• 2021

이 연구는 한국형 양송이버섯 재배 배지 후발효 시스템의 개발을 통해 양송이버섯 농가의 노동력 절감, 생산 사이클 단축을 통한 농가 소득 증가를 목적으로 두고 있다. 한국형 양송이버섯 재배 배지 후발효 시스템은 국내 양송이버섯 농가의 현실을 반영하여 설계되었으며, 후발효 시스템 내의 발효 배지의 온도 차를 줄여 균일한 품질을 보장하는 양송이버섯 재배 배지를 생산할 수 있다. 또한, 성능 실험 결과 배지 후발효 시스템이 40시간의 작업 시간이 단축되었으며, 양송이버섯 배지에 도움이 되는 호기성 세균 및 방선균은 증가함을 알 수 있었으며, 양송이버섯 품질을 저하시키는 사상균은 살균됨을 확인하였다.