• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.3
• /
• pp.330-337
• /
• 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
• /
• v.11 no.1
• /
• pp.52-58
• /
• 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.

• Journal of the Korean institute of surface engineering
• /
• v.49 no.6
• /
• pp.604-611
• /
• 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.

• Journal of Korean Society of Transportation
• /
• v.30 no.3
• /
• pp.95-106
• /
• 2012

The railway service in the Seoul metropolitan area is facing variety of l changes such as extension of service coverage, new construction, and introduction of express service which in turn causes changes on demands. The demand affects train operation characteristics (frequency of service, train formation) as well as on the congestion rate which is one of the major evaluation index in metropolitan area user service. For the efficient operation of the train, the relationship among the minimization of fleet number, operating cost, and service level has been analyzed. Using the Powersim, which is a system dynamics (System Dynamics) simulation program for realizing optimized simulation for train-formation, this paper identified that some stations of Gyeong-bu line exceeded limit congestion rate(150%) of a fleet already that means it is best to maintain current condition of the line; however, the Gyeong-in line and the Gwa-chon line showed no excess of the limit congestion rate so that it is possible to reduce 2-4 fleets of train for efficient operation. In addition, in case of Jang-hang line between Cheon-an and Sin-chang, a train consisting of 10 fleets provides services which is same formation of train for Gyeong-bu line. This study proved that the congestion rate will not rise greatly with only 4 fleets of a train for the service in Jang-hang line, and it is considered that a study for shuttle service between Cheon-an and Sin-chang is necessary.

• Health Policy and Management
• /
• v.4 no.2
• /
• pp.1-26
• /
• 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.

• Journal of Korean Home Economics Education Association
• /
• v.30 no.1
• /
• pp.65-77
• /
• 2018

The purpose of this study is to investigate how to strengthen the formation of relationship competence through the lesson in the housing of the 2015 revised Technology Home Economics curriculum. In order to achieve this goal, we analyzed curriculum documents, achievement standards of curriculum, achievement standards of assessment, and assessment standards of the 2015 revised Technology Home Economics curriculum. Then, we analyzed whether or not the curriculum could be truly reflected in the school site by comparing and analyzing verbs of the assessment standards and curriculum content system. In addition, we suggested the plan to ensure that 2015 revised curriculum can be implemented well by proposing a method of teaching-learning and assessment standards to cultivate the formation of relationship competence among the housing lessons. The results of the study are as follows. First, the 2015 revised Technology Home Economics curriculum are categorized into three subject competences according to the content, but eventually show the content is not mutually exclusive with the three subject competences. It can be said to demonstrate the characteristics of human ability development, that is, one learning can't be related only to one competency. Second, it is difficult to reflect the assessing subject competencies system in school education, where evaluation is carried out based on the assessment standards. This is because the skills of the 2015 revised curriculum documents are partially reflected in the assessment standards. Therefore, this study shows that teachers need to cultivate various subject competencies. In order to overcome the fundamental limitations of the competency-centered curriculum, it is necessary to retrain the teachers as well as to improve teaching and learning methods for operating the curriculum.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.19 no.1
• /
• pp.51-58
• /
• 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.

• Journal of Korean Society for Atmospheric Environment
• /
• v.25 no.6
• /
• pp.523-538
• /
• 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.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.5 no.1
• /
• pp.65-78
• /
• 2007

The pollutants (Rn, CH, CO, HS, radioactive gas from radiolysis) were generated from the process of construction and operation of underground repository, and after disposal of low-intermediate radioactive waste inside there must be controlled by a ventilation system to distribute them in area where enough air is supported. Therefore, a suitable technical approach is needed especially at an underground repository that is equipped with many entry tunnels, storage tunnels, exhaust-blowing tunnels, and vertical shafts in complicated network form. For the technical approach of such a ventilation system, WIPP (Waste Isolation Pilot Plant) in U. S and SFR (Slutforvar for Reaktorafall) low-intermediate radioactive waste repository in Sweden were selected as the models, for calculating the required air quantity, organizing a ventilation network considering cross section, length, surface roughness of the air passage, and describing a calculation of resistance of each circuit. Based on these procedures, a best suited ventilation system was completed with designing proper capacity of fans and operating plan of vertical shafts. As a result of comparing the two repositories based on the geometry dimensions and ventilation facility equipment operation, more parallel circuit as in WIPP, brought decrease in resistance for entire system leading to reduce of operating costs, and the larger cross-sectional area of the SFR, the greater the percentage of disposal capacity. Accordingly, the mixture of parallel circuit of WIPP repository for reducing resistance and SFR repository formation for enlargement of disposal capacity would be the most rational and efficient ventilation system.

• Asia pacific journal of information systems
• /
• v.7 no.2
• /
• pp.185-198
• /
• 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.