• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.202-206
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• 1994

Mathematical model of the pollution rate of substation insulators is constructed, taking the model parameters as wind speed, wind direction, typhoon conditions and rainfall in an hourly basis. The main feature of model construction is to distinguish the effect of each parameter by separately analyzing the positive and negative pollution causing factors. Model parameters for the insulators of Karatsu substation, Saga, Japan were estimated and model validation was done using the actual data, in which the pollution deposits on the insulators were measured using pilot insulator and 'salt meter'. The proposed model of the pollution rate [mg/cm$^{2}$/hr] enables the identification of the effective parameters and prediction of the pollution rate so that it helps for the automatic decision making for insulator cleaning or the model can be used as a tool for the substation engineers to make precautionary measures.

• KDI Journal of Economic Policy
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• v.38 no.4
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• pp.23-44
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• 2016

Household debt in Korea raises concerns about the resilience of the economy due to its size and quality. Against this backdrop, we investigate if household leverage matters for private consumption in adverse economic environments even without severe financial disruptions. We find that the balance sheet positions in terms of the leverage ratio may weaken consumption growth. We also find that the depressive effect of debt on consumption may differ across types of consumer spending and household characteristics. In particular, the effects of indebtedness have been much stronger in relation to durable goods expenditures than in other areas. In addition, debtors in high-income (wealth) groups have also shown downward adjustments in consumption even more so than low-income (wealth) groups. These findings imply that debtors' precautionary behavior may serve as an important channel from leverage to consumer spending.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.659-668
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• 2017

The inverse Weibull distribution (IWD) can be readily applied to a wide range of situations including applications in medicines, reliability and ecology. It is generally known that the lifetimes of test items may not be recorded exactly. In this paper, therefore, we consider the maximum likelihood estimation (MLE) and Bayes estimation of the entropy of a IWD under generalized progressive hybrid censoring (GPHC) scheme. It is observed that the MLE of the entropy cannot be obtained in closed form, so we have to solve two non-linear equations simultaneously. Further, the Bayes estimators for the entropy of IWD based on squared error loss function (SELF), precautionary loss function (PLF), and linex loss function (LLF) are derived. Since the Bayes estimators cannot be obtained in closed form, we derive the Bayes estimates by revoking the Tierney and Kadane approximate method. We carried out Monte Carlo simulations to compare the classical and Bayes estimators. In addition, two real data sets based on GPHC scheme have been also analysed for illustrative purposes.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.366-372
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• 2000

In a power plant, it is generally accepted that a turbine governor system is necessary to control amount of steam supply toward the turbine system. There are many kinds of trouble at this governor system, which is recognized one of the most sensitive systems in the power plant. Especially we have experienced the internal leakage of motorization oil of servo valve. In the study, we investigated the mechanism of an internal leakage such as erosion by foreign materials and corrosion by chemical reaction between chloric healed oil and motorization oil. A precautionary measures is also performed to help the field service engineers.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.27-32
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• 2003

Fire accidents in tunnels and underground installations have resulted in significant loss in terms of life and costs. Several large research projects are launched in Europe to find cost effective ways to upgrade and make such installation more robust against accidents from fires and explosions. For one single tunnel, severe fire accidents are rare and operators and users will have very limit experience, when they do occur. There is a trend to solve the problem with high tech instrumentation and monitoring techniques and to rely on the fire brigade to play a major role in the rescue operation. These precautionary measures are very difficult to validate for the severe fires. For protection against the most critical fires, the safety has to be considered in the design of the tunnel and the technical installation validated so that it operates as indented.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1511-1512
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• 2015

자연재해의 특징은 설계불량이나 조작실수 등과 같이 다른 고장과 달리 위험요인을 인위적으로 저감하는 것이 불가능하다. 또한 자연재해는 규모나 양상에 있어서 매우 다양하며 뇌의 경우 위치와 장소에 따라 피해강도는 1,000배 정도 다른 결과를 초래할 수도 있다. 이와 같은 특징을 가진 자연재해를 완전히 예방하는 것은 비현실적이다. 자연재해에 따라 피해는 위험도와 전력시스템의 취약성이 교차하는 영역에서 발생한다. 피해를 저감하기 위해서는 취약성을 감소시키고, 이 교차 영역을 가능한 작게 하는 것이 기본개념이다.

• Journal of Information Processing Systems
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• v.10 no.3
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• pp.483-490
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• 2014

In today's world, communication, the sharing of information, and money transactions are all possible to conduct via the Internet, but it is important that it these things are done by the actual person. It is possible via several means that an intruder can access user information. As such, several precautionary measures have to be taken to avoid such instances. The purpose of this paper is to introduce the idea of a one-time password (OTP), which makes unauthorized access difficult for unauthorized users. A OTP can be implemented using smart cards, time-based tokens, and short message service, but hardware based methodologies require maintenance costs and can be misplaced Therefore, the quick response code technique and personal assurance message has been added along with the OTP authentication.

• Journal of Preventive Medicine and Public Health
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• v.53 no.3
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• pp.168-170
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• 2020

On December 31, 2019, the Chinese government officially announced that the country had some cases of pneumonia with an unknown cause. By February 8, 2020, there were 24 confirmed cases in Korea, and the number of cases has steadily increased since then. On March 9, 2020, the cumulative number of confirmed cases in Korea was 7382, with 51 deaths. This study examines the characteristics of the coronavirus disease 2019 (COVID-19) outbreak from the perspective of the large-scale number of confirmed COVID-19 cases and deaths. This study is significant in that it emphasizes the precautionary principle in preventing and managing infectious diseases, and makes suggestions for urgently needed public health policies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.289-291
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• 2006

The noise pollution caused by air traffic is one of the popular environmental issues, which consistently gives rise to public discussion today especially among local residents near airports. But, because there is a growing tendency that large residential areas are constructed in flatlands around airports due to a high population density, the importance of the EIA in connection with aircraft noise is increased to take precautionary measures. Therefore, this paper examines the present status and the improvement plan of aircraft noise impact assessment.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.51-55
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• 1990

This study describes the engineering approach adopted to investigate sprinkler head during the early stage of a fire when they are subjected to convective heating and low gas velocities. Comparions are made between the parameters derived using basic methods, ie. ramp test, for evaluating sprinkler parameters(time constant, response time index) is illustrated. Evidence is presented that the propotion of heat loss by conduction from a sprinkler element may very typically employed in the rate of rise test. This fact alone may justfy the precautionary need to perform a limited number of rate of rise tests to confirm a sprinklers capacity to function correctly in reasonably unfavourable yet realistic conditions. The work is aimed primarily at meeting the needs of sprinkler industry.