• The Korean Journal of Community Living Science
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• v.19 no.4
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• pp.659-672
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• 2008

There is a need to develop diverse cultivation species with reference to the favorites and farming experiences of allotment garden participants, in addition to the crops being cultivated in the gardens. In this study, therefore, a survey on the status of cultivation and the demand for herb crops for the garden participants was conducted. Current trend of the programmes related to allotment garden for city dwellers, executed by various relevant organizations was analyzed. A questionnaire was accomplished by adult participants experiencing farming in allotments. Likewise, interview with farm proprietors was conducted. The results showed that the number of crop species cultivated in allotments was about ten species. The purchase of seeds and nursery plants was mainly dependent on the farmland proprietors. The selection of the crops was made by both wife and husband. The status of herb utilization indicated that 5.7% of participants were cultivating or had cultivated herb plants. Sixty-two percent of participants were not cultivating herb plants because they did not know how. The purposes of using herbs were for medicine and beauty (22.0%), for spices (22.0%) and for enjoyment (29.0%). Thirty-four percent (34.0%) of participants were interested or would like to use the herbs in the future for medicine and beauty, 39.0% for spices and 31.7% for enjoyment. It is expected that the demand for herbs would increase. Also, 78.3% of participants had the intension or had taken into consideration to cultivate the herb plants, if the farmland proprietors would provide the plants. And, they had interest in planting, management and post harvest utilization and if a reference material would be provided as well. An approach to plant new crops might be possible to those who have more than four years of farming experience and possess relatively high level of cultivation techniques. In conclusion, the favorable crop cultivation strategy corresponding to the participants' abilities; and rental process were essential for the sustainable operation of allotment gardens and expanded number of participants. Moreover, there is a need to pay attention to the city dwellers who have a lot of farming experiences in allotment gardens to maintain agriculture and rural community. This is so, because they are interested in agriculture and rural community and most of them replied that they had intentions to move to rural areas in the future.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.169-178
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• 2020

The selection of a third-party logistics (3PL) provider is a critical process for shippers who want to receive competitive logistics service. However, studies analyzing the factors that influence the selection of 3PL provider from the viewpoint of shippers are insufficient. The present study aims to derive factors to be considered when selecting a 3PL provider by domestic shippers and to present the weights of each factor. The analysis results showed that among the major factors, the "operation factor" showed the highest importance, followed by "strategic factor", and "communication factor". The results of compound weights showed that "cost reduction" is the most important factor, followed by the "expertise of the provider", "inventory management ability", and "human resources management". The present study proposed the core factors that should be considered when selecting a 3PL provider from the shipper's viewpoint. This study also has an industrial implication from the viewpoint of 3PL providers because it provides the basic data for enhancing the shipper's satisfaction by reinforcing the factors that are considered important in by shippers. In future research, it is necessary to classify shippers by industry and analyze the differences in the factors that arise in selecting 3PL companies for each industry.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.13-29
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• 2016

In this study, we analyzed the causes of major faults in the biogas plant through the case of gas engine failure when cogenerating electricity and heat using biogas as a fuel in the actual sewage treatment plant and suggested countermeasures. Hydrogen sulfide in the biogas entering the biogas engine and water caused by intermittent malfunction of the water removal system caused intercooler corrosion in the biogas engine. In addition, the siloxane in the biogas forms a silicate compound with silicon dioxide, which causes scratches and wear of the piston surface and the inner wall of the cylinder liner. The substances attached to the combustion chamber and the exhaust system were analyzed to be combined with hydrogen sulfide and other impurities. It is believed that hydrogen sulfide was supplied to the desulfurization plant for a long period of time because of the high content of hydrogen sulfide (more than 50ppm) in the biogas and the hydrogen sulfide was introduced into the engine due to the decrease of the removal efficiency due to the breakthrough point of the activated carbon in the desulfurization plant. In addition, the hydrogen sulfide degrades the function of the activated carbon for siloxane removal of the adsorption column, which is considered to be caused by the introduction of unremoved siloxane waste into the engine, resulting in various types of engine failure. Therefore, hydrogen sulfide, siloxane, and water can be regarded as the main causes of the failure of the biogas engine. Among them, hydrogen sulfide reacts with other materials causing failure and can be regarded as a substance having a great influence on the pretreatment process. As a result, optimization of $H_2S$ removal method seems to be an essential measure for stable operation of the biogas engine.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.301-310
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• 2013

To suggest a standard concerning with the arrangement of bridge equipment, the authors conducted the video observations with 3CCD (charge coupled device) cameras installed on the ceil of the bridge for monitoring the working activities of two bridge teams (the skipper/mate1 and the skipper/mate2) in a Korean coastal large trawler(gross tonnage: 139) for five days from July 30th. 2010 and analyzed of the data. Work elements coded by the work activities were input on the sheet of work analysis by the time unit of 1 sec according to the time occurred. A single work element among the work activities for every 5 minutes was denoted as the number of occurrence. The frequency of equipment usage was limited only in the usage of the equipment. In the case of the navigation and the towing net two ranks were integrated and analyzed. On the other hand, in the case of the casting net and the hauling net, two processes were integrated to as one and then analyzed separately as two ranks. As the results, 15 elements of work was carried out between two bridge teams for the observation; lookout, radar, GPS plotter, fish finder, net monitor, fishing deck, RPM indicator, rudder angle indicator, compass card, for maneuver; steering, ship speed control, trawl winch operation and external communications, paper works and others. It was found that the work load of the skipper per 5 minutes accordance with the navigation, the casting net, the towing net and the hauling net are 20.5 times, 11.9 times, 38.0 times and 9.5 times respectively, the mates are 65.2 times, 66.5 times, 85.7 times and 59.1 times respectively. The radar was shown the highest frequency of the equipment usage and the next was the fish finder, the GPS plotter and the external communications in the case of the navigation. In the case of the towing net the frequency of usage was high the ranking as the radar, the net monitor, the fish finder, the GPS plotter, the steering system and the external communications. In the case of the integrated process both of the casting and hauling net the trawl winch was shown the highest frequency to the skipper and the next was the GPS plotter and the radar, and the steering system was shown the highest frequency to the mate and the next was the radar, the ship speed control system, the GPS plotter, the net monitor and the fish finder.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.134-144
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• 2010

In China, the enhancement of water services has become the most crucial issue confronted with the rapid urbanization and industrialization process. A huge financial gap to meet the demand for water infrastructure and need for adopting advanced operation technology precipitated the rapid growth of PPP over the last 10 years. Diverse schemes of PPP such as TOT, Divestiture, and Management Contract and Lease have been practiced. Local governments and private investors/operator have adjusted their objectives and strategies to avoid potential pitfalls behind BOT projects in China. However, current academic research outcomes do not properly reflect important issues of BOT projects or related case studies in China. This limitation has brought in the lack of assessment of important risks and success factors required for the improvement of the body of risk management. In this regard, this study uses the market analysis method to identify major schemes of PPP water projects and conducts case studies on five PPP projects to identify key risk and success factors in association with each different scheme. It is expected that the risk and success factors identified from the cases will be used as reference to Korean companies which plan to enter the Chinese water market.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.63-78
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• 2017

The purpose of this study is to determine the optimal aggregation interval to increase the reliability when estimating representative value of individual vehicle travel time collected by DSRC equipment in interrupted traffic flow section in National Highway. For this, we use the bimodal asymmetric distribution data, which is the distribution of the most representative individual vehicle travel time collected in the interrupted traffic flow section, and estimate the MSE(Mean Square Error) according to the variation of the aggregation interval of individual vehicle travel time, and determine the optimal aggregation interval. The estimation equation for the MSE estimation utilizes the maximum estimation error equation of t-distribution that can be used in asymmetric distribution. For the analysis of optimal aggregation interval size, the aggregation interval size of individual vehicle travel time was only 3 minutes or more apart from the aggregation interval size of 1-2 minutes in which the collection of data was normally lost due to the signal stop in the interrupted traffic flow section. The aggregation interval that causes the missing part in the data collection causes another error in the missing data correction process and is excluded. As a result, the optimal aggregation interval for the minimum MSE was 3~5 minutes. Considering both the efficiency of the system operation and the improvement of the reliability of calculation of the travel time, it is effective to operate the basic aggregation interval as 5 minutes as usual and to reduce the aggregation interval to 3 minutes in case of congestion.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.06a
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• pp.84-85
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• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.

• Land and Housing Review
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• v.5 no.4
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• pp.225-234
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• 2014

Because of their nature as public facilities, demands that former military facilities be utilized for the public welfare are increasing, thereby leading to an increase in cases in which these military facilities are reestablished as parks. Cases in which former military bases were reestablished as public parks were analyzed; as a result, several implications were derived. First, the objectives of public park projects should be examined from the perspective of the concept of urban regeneration and regional revitalization. Moreover, it is necessary that profits are yielded and that regional identity and history are reproduced through reusing existing facilities as much as possible rather than entirely remodeling former military sites. As parks become larger in size, bases should be reorganized into complexes rather than single facilities or programs. It is also necessary that parks be established in stages considering the enormous expenses required for building public parks. Consequently, because the special characteristics of military facilities can lead to insufficient on-site investigation in the process of establishing parks, thereby incurring a vast amount of costs for design adjustment and contamination disposal, this should be considered in advance. A method of delegating the development rights to partial sites to private businesses and supplementing the costs of park establishment and maintenance with development benefits should be examined. In addition, given that there are various interests and stakes in former military bases, a method of operating a public-private cooperative decision-making organization during project execution should be considered. Finally, policies related to urban parks need to be improved in order to raise funds, expand profitable businesses, facilitate social services and sponsorship, and encourage the participation of trusts and non-profit organizations in park operation and management.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.419-431
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• 2007

The setting of dental hygiene clinics is very important to dental hygiene education, which is the place not only to educate students but also to care clients. The purpose of this study is to provide basic research material for improvement of dental hygiene care system in dental hygiene clinics by analyzing the client satisfaction. A questionnaire survey by means of self-entry method was conducted to find out satisfaction of the client, who was visited to the dental hygiene clinics in the department of dental hygiene, Yonsei University. An analysis of frequency, one way ANOVA and T-Test were performed through SPSS 12.0K program. 1. Most clients were mainly composed of students in Wonju College of Medicine. 2. The clients visited for scaling(85.8%) and oral examination(9.73%) were much than treatment(4.42%). 3. Clients aged 21 to 25 were relatively lower in satisfaction with the facilities, system, attitude than any other ages. 4. The dental hygiene students are the lowest group in satisfaction with the facility, system, attitude than medical and nursing students. 5. The clients satisfaction with dental hygiene clinics was decreased in reverse proportion to visiting frequency. 6. Most of the clients pointed out the problems of appointment system(54.0%) and fee(23.0%), which should be improved than any other operation conditions. 7. Most of the clients were not satisfied with chair time and pain during care. 8. Most clients recognized to receive the better care service than other dental offices(81.3%). Especially, they paid attention to oral health education using phase-contrast microscope. 9. Many clients were dissatisfied with facilities of the dental hygiene clinics(71.7%). The problems of appointment system(54.0%) and chair time of dental hygiene care services(63.6%) had also inconvenienced to clients. The dental hygiene clinics in school play a crucial role in dental hygiene education to foster the student to be competent as a professional dental hygienist in the future. Therefore, well-organized dental hygiene care program based on dental hygiene process is essential. It is also required to improve the environment of dental hygiene clinics including facilities, appointment system and fee etc.

• Atmosphere
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• v.21 no.2
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• pp.197-208
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• 2011

The objective of this study is to describe the short-range forecast system of the Korea Air Force (KAF) and to verificate its performace in 2009 summer. The KAF weather prediction model system, based on the Weather Research and Forecasting (WRF) model (i.e., the KAF-WRF), is configured with a parent domain overs East Asia and two nested domains with the finest horizontal grid size of 2 km. Each domain covers the Korean peninsula and South Korea, respectively. The model is integrated for 84 hour 4 times a day with the initial and boundary conditions from National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) data. A quantitative verification system is constructed for the East Asia and Korean peninsula domains. Verification variables for the East Asia domain are 500 hPa temperature, wind and geopotential height fields, and the skill score is calculated using the difference between the analysis data from the NCEP GFS model and the forecast data of the KAF-WRF model results. Accuracy of precipitation for the Korean penisula domain is examined using the contingency table that is made of the KAF-WRF model results and the KMA (Korea Meteorological Administraion) AWS (Automatic Weather Station) data. Using the verification system, the operational model and parallel model with updated version of the WRF model and improved physics process are quantitatively evaluated for the 2009 summer. Over the East Aisa region, the parallel experimental model shows the better performance than the operation model. Errors of the experimental model in 500 hPa geopotential height near the Tibetan plateau are smaller than errors in the operational model. Over the Korean peninsula, verification of precipitation prediction skills shows that the performance of the operational model is better than that of the experimental one in simulating light precipitation. However, performance of experimental one is generally better than that of operational one, in prediction.