• 상하수도학회지
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• 제19권3호
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• pp.330-337
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• 2005

This study was carried out to propose the managemental improvement of the purification plants and the distribution facilities which can minimize the formation of disinfection by-products in drinking water distribution system. The disinfection by-products were highly created in the water treatment plant that the organic matters were high and the chlorine dosage was excessive. The concentration of DSPs was shown the highest value in August and the lowest value in December, because of temperature and pre-chlorine dosage effect. From the result of tracer test, the travel time from the treatment plant to the end of pipeline was around 3-4 days in summer, 5-6 days in winter, respectively, and the DSPs concentration of the reservoir(end of pipe) was 2-3 times higher than that of the beginning point. The improvement of the chlorination process and structural reformation of distribution facility was demanded to minimize the DSPs increase from purification plant to the end of pipe.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.52-58
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• 2019

Marine emissions of Volatile Organic Compounds (VOCs) have received much attention because the International Maritime Organization (IMO) requires the installation of vapour emission control systems for the loading of crude oils or petroleum products onto ships. It was recently recognised that significant corrosion occurs inside these vapour emission control systems, which can cause severe clogging issues. In this study, we analysed the chemical composition of drain water sampled from currently operating systems to investigate the primary causes of corrosion in vapour recovery systems. Immersion and electrochemical tests were conducted under simulated conditions with various real drain water samples, and the impact of corrosion on the marine vapour recovery system was carefully investigated. Moreover, corrosion tests on alternative materials were conducted to begin identifying appropriate substitutes. Thermodynamic calculations showed the effects of environmental factors on the production of condensed sulphuric acid from VOC gas. A model of sulphuric acid formation and accumulation by the characteristics of VOC from crude oil and flue gas is suggested.

• 한국표면공학회지
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• 제49권6호
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• pp.604-611
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• 2016

In order to comply with demand for high efficient gas turbines operating at higher temperatures, considerable amounts of research efforts have been performed with searching for the next-generation thermal barrier coatings (TBCs) with respect to coating materials as well as processing methods. In this study, thermal barrier coatings in the $(La_{1-x}Gd_x)_2Zr_2O_7$ system, which is one of the most versatile materials replacing yttria-stabilized zirconia (YSZ), are fabricated by suspension plasma spray with suspension made of synthesized powders via solidstate reaction. Dense, $100{\sim}400{\mu}m$ thick coatings of fluorite-phase zirconate with moderate amount of segmented microstructures are obtained by using suspension plasma spray. Phase formation and thermal diffusivity are characterized with coating compositions. The feasibility of $(La_{1-x}Gd_x)_2Zr_2O_7$ coatings for TBC applications is also discussed.

• 대한교통학회지
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• 제30권3호
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• pp.95-106
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• 2012

수도권 광역철도는 운영 범위의 공간적 확대 및 신설 건설, 급행전철 도입 등 다양한 환경 변화에 직면하고 있으며 이는 이용수요 변화의 원인이 된다. 또한 시간대별 이용수요는 열차운행 특성(운행횟수, 편성량수 등) 뿐만 아니라 광역철도 이용자 서비스 평가 지표 중의 하나인 차내 혼잡도에도 영향을 미친다. 이에 본 연구는 철도의 효율적 운영을 위한 측면에서 열차 편성량수의 최소화와 운영비용, 이용자 서비스간의 관계를 파악하여 최적의 열차편성 조정 대안을 도출하고자 하였다. 시스템 다이나믹스(System Dynamics) 시뮬레이션 프로그램인 Powersim을 활용하여 편성량수 최적화 시뮬레이션을 구현하였으며 그 결과 경부선은 현 운행시에도 한계혼잡도(150%)를 초과하는 역이 일부 존재하여 현행 유지함이 최적이라고 분석된 반면 경인선, 과천선 등의 경우 편성량수를 2~4량 감소시켜도 한계혼잡도를 초과하지 않아 적용 가능할 것으로 분석되었다. 또한 장항선 구간(천안~신창)은 경부선과 동일하게 현재 1편성 10량으로 운행되고 있으나 4량 운행시에도 혼잡도가 크게 증가 하지 않으므로 천안~신창구간의 단거리 셔틀운영방안에 대한 검토가 필요할 것으로 판단된다.

• 보건행정학회지
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• 제4권2호
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• pp.1-26
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• 1994

As the hospital environment is changing rapidly, management is therefore obligated to use new ways to provide better service to patients. For example information system is introduced to some hospitals in Korea. Information system has several benefits such a soperational efficiency by on-line delivery and processing of data, accurate and rapid information production, continuous monitoring of performance and feedback, improvement of work process and better service quality. Still, many hospitals cannot be sure that information system is useful for improving organization performance. Because only one or two area of hospital information system were considered for development and with limited development hospital information system cannot be used effectively. The purpose of this study is to suggest the model of information system utilizaton and to analyze the hospital in formation system in Korea. The results are following; 1. In Korea, proportion of operating system of comuter is 31% of UNIX, 11% of IBM OS and 10% of PC LAN. 2. As we expect, scope of application software and amounts of heardware and software invest ments are affected by concern of CEO. 3. Many CIO(chief information officer) say that the biggest problems are lack of after-service and obsolescence of computer equipments in terms of hardware and shortage of application software for hospital in terms of software. 4. Personnel of information system department is so small that hospital information system can't be improved. 5. During the development of information system, full-time participation of end user is only 20% hospital with almost less than 12 person-month. This study was accomplished by survey through mail questionnaires. Response to the survey was only 55% and it was hard to generalize all the result obtained from this survey. However, We hope that this study would be helpful for helth care organization to acknowlege hospital information system in korea and to design the future architecture and frame of information system.

• 한국가정과교육학회지
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• 제30권1호
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• pp.65-77
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• 2018

이 연구의 목적은 2015 개정 교육과정의 주생활 영역 수업을 통해 교과역량 중 관계형성 역량을 강화하기 위한 방안을 탐색하는데 있다. 이를 위해 2015 개정 기술 가정 교과의 교육과정 문서와 교육과정 성취기준 및 평가준거 성취기준 및 평가기준 문서를 분석하였다. 그리고 평가기준의 동사와 교육과정 내용 체계에 제시된 기능의 내용을 비교 분석하여 교육과정이 학교 현장에서 충실히 반영될 수 있을지의 여부를 탐색하였다. 그리고 주생활 영역 수업을 통한 교과역량 중 관계형성역량을 함양하기 위한 교수 학습 및 평가 방법을 제안하여 2015 개정 교육과정이 충실히 구현될 수 있는 계획안을 제시하였다. 이를 통해 도출된 연구 결과는 다음과 같다. 첫째, 2015 개정 기술 가정 교과의 교육과정 문서에는 교과역량 세 가지를 내용 영역에 따라 분리 제시하였으나, 내용 영역이 3가지 교과역량과 상호 배타적이지 않음을 보여주고 있다. 이는 인간의 능력 개발이 가진 특징 즉 하나의 학습이 하나의 역량으로만 관련되지 않음을 보여준다고 할 수 있다. 둘째, 2015 개정 교육과정 문서의 기능(skills)은 평가기준에 부분적으로 반영되어 있어서, 평가기준을 반영한 교육 평가가 이루어지는 학교 교육에서 교과역량을 평가할 체계를 충실히 반영하기 어려울 수 있음을 보여주고 있다. 따라서 본 연구에서는 교육과정을 실현하는 교사들이 다양한 교과역량을 기르기 위한 노력을 기울여야 할 필요성을 보여준다. 그리고 역량 중심 교육과정이 가진 근본적인 한계를 극복하기 위한 교사 재교육과 교사들의 교육과정 운영을 위한 교수 학습 방법과 평가 방법 개선을 위한 노력이 필요할 것이다.

• 방사성폐기물학회지
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• 제19권1호
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• pp.51-58
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• 2021

Chemical decontamination of primary systems in a nuclear power plant (NPP) prior to commencing the main decommissioning activities is required to reduce radiation exposure during its process. The entire process is repeated until the desired decontamination factor is obtained. To achieve improved decontamination factors over a shorter time with fewer cycles, the appropriate flow characteristics are required. In addition, to prepare an operating procedure that is adaptable to various conditions and situations, the transient analysis results would be required for operator action and system impact assessment. In this study, the flow characteristics in the steady-state and transient conditions for the chemical decontamination operations of the Kori-1 NPP were analyzed and compared via the MARS-KS code simulation. Loss of residual heat removal (RHR) and steam generator tube rupture (SGTR) simulations were conducted for the postulated abnormal events. Loss of RHR results showed the reactor coolant system (RCS) temperature increase, which can damage the reactor coolant pump (RCP)s by its cavitation. The SGTR results indicated a void formation in the RCS interior by the decrease in pressurizer (PZR) pressure, which can cause surface exposure and tripping of the RCPs unless proper actions are taken before the required pressure limit is achieved.

• 한국대기환경학회지
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• 제25권6호
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• pp.523-538
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• 2009

Recently, there has been a keen demand for real-time automatic monitoring of VOCs not only in Korea but other developed countries. We carried out this study to evaluate and to optimize the performance of a continuous automatic monitoring system for hazardous VOCs (HVOCs) in the ambient atmosphere, using an on-line GC system. The online system normally consisted of a Nafion dryer prior to a cold trap of an automatic thermal desorption apparatus and a GC system equipped with two detectors, i.e. PID and ECD. Preliminary tests conducted to check out any contamination of the system revealed an evidence of significant artifact formation of benzene, and it was found that the Nafion dryer (even brand new one) is the source of the benzene artifact. Thus, all the subsequent experiments in this study was carried out inevitably by removing the Nafion dryer. The on-line GC method was investigated with a variety of QC/QA performance criteria such as repeatability, linearity, lower detection limits, and accuracy. In order to find out the best operating condition for the on-line GC system, three different types (in terms of adsorption strength) of cold trap combinations were tested, i.e. (i) Tenax-TA and Carbopack-B combination (weak and hydrophobic); (ii) Tenax-TA, Carbopack-X and Carboxen-1000 combination (strong and hydrophilic); and (iii) Tenax-TA and Carbopack-X combination (medium and hydrophobic/hydrophilic). The USEPA TO-17 manual method was selected as a reference method to evaluate the performance of the on-line method. A series of experiments revealed that the system performance was superior to others when a cold trap packed with hydrophilic adsorbents (Tenax-TA/Carbopack-X/Carboxen-1000 combination) was used and operated at $25^{\circ}C$. However, the system with a cold trap packed with a combination of Tenax-TA and Carbopack-X is more recommended for field applications since the carboxen-1000 adsorbent is too sensitive to water vapor, and hence the performance of the system might be very unstable to humid samples or during rainy days. Furthermore, the precision and accuracy criteria of the Tenax-TA/ Carbopack-X combination were generally compatible with the triple adsorbents cold trap. The continuous automatic monitoring method is, thus, considered very useful to real-time monitoring to understand the variations of VOCs concentrations in ambient air, as it adopts much simpler procedures in sampling, analysis, and data integration steps than manual monitoring methods. However, it should be noted that there is a high possibility of benzene artifacts formation through the Nafion dryer, which is often installed to remove water vapor in air samples before being adsorbed onto the cold trap. Therefore, if a Nafion dryer is used in any studies of monitoring VOCs, the benzene contamination should be carefully examined before carrying out obtaining the data.

• 방사성폐기물학회지
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• 제5권1호
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• pp.65-78
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• 2007

지하 동굴식 처분장의 건설, 운영 및 중-저준위 방사성폐기물을 처분한 이후 발생하게 되는 오염물질(Rn, CH CO, HS, Radiolysis에 의한 방사능 가스 등)은 적절한 공기량을 필요로 한 곳에 정확히 분배시킬 수 있는 환기시스템에 의해 통제되도록 하여야한다. 특히 지하 처분장은 여러 개의 진입 터널, 저장 터널, 공기 유입-배기 터널, 수직갱 등으로 이루어진 복잡한 회로망의 형태로 나타나기 때문에 이에 적절한 기술적 접근이 필요하다. 본 논문에서는 이러한 환기시스템 구축을 위한 기술적 접근을 위해 미국의 WIPP (Waste Isolation Pilot Plant)처분장과 스웨덴의 SFR (Slutforvar for Reaktoravfall) 중-저준위 처분장을 모델로 하여 두 처분장의 소요환기량을 선정하고 설계상 통풍로의 단면적, 길이, 표면 거칠기 등을 고려한 환기회로를 구성하였으며, 수학적으로 계산되는 각 회로의 저항에 대해 기술하였다. 또한 이를 바탕으로 적절한 선풍기의 용량과 수직갱 운용방안을 설계하였다. 두 처분장의 지형상의 규모 및 환기시설 비교 결과, SFR 처분장에 비해 WIPP 처분장에서와 같이 병렬구조가 많을수록 처분장 전체의 저항이 감소되며 이러한 결과로 환기시스템의 운용비 절감효과를 얻을 수 있다는 결론을 얻었다. 따라서 처분용량 증대를 위한 대단면의 SFR 처분장 구조와 전체 저항 감소를 위한 WIPP 처분장의 병렬구조를 조합한 형태가 가장 합리적이며 효율적인 환기가 이루어질 수 있을 것으로 사료된다.

• Asia pacific journal of information systems
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• 제7권2호
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• pp.185-198
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• 1997

Recently the formation of the project team to construct a MIS system is generalized and the relationship of the user and the system personnel in the project team should be important factor in the effectiveness of the team. However, the systematic research about the personality typology of the user and the system personnel is scarcely verified. Considering this necessity, this study is, using the IS personality typology, tried to find the relationship of the user and the system personnel in the project team. One of Jung(1924)'s personality typology is introvert and extrovert, however, this typology is founa to have many facets related with personality category. Recently Ackoff(1996) has tried this category more meaningful, which are subjective-internalizer, subjective-externalizer objective-internalizer one objective-externalizer. Moreover, he has proposed the methodology which could find the assimilarity among the team members. On the basis of this typology, this research is attempted to find the difference of the characteristics of the user and the system personnel. Through this research, we can understand the difference of the characteristics of the user and the system personnel and this understanding can make help us operating the team more effectively. The result has suggested that the effectiveness of the team has relied on the personality type of the user and the system personnel. Especially the personality type of new member who will join into team is an important factor in the effectiveness of teaming. Therefore, when we have a new member into team, we have to consider the personality type of new member. Moreover, the personality type of the management is an another critical factor which should be considered.