• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.84-95
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• 2011

The purpose of this study is to increase the usage of satisfaction of outdoor exercise equipment installed at parks when plans and designs are made for renovation or formation of parks. In order to do so, the study surveyed and analyzed the usage satisfaction of 150 men and women who use outdoor exercise equipment in neighborhood parks located in Dongtan New Town. There were four factors that affect the variables of usage satisfaction. They can be defined as the main facility factor, awning factor, maintenance factor, and additional facility factor. From the result regression analysis of the total satisfaction rate and the factors, the main facility factor was the most influential of the variables. This could indicate that the facility factor affects the satisfactory rate of outdoor exercise equipment. This research is done only with the examples of neighborhood parks, so it limits the possibility of analysis of seasonal use. It is necessary to conduct analysis research of parks which installed many outdoor exercise equipment, such as a vest-pocket park, children's garden, and pedestrian/urban/metropolitan neighborhood parks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.328-335
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• 2013

The purpose of this study was to evaluate the height of workbench in dental lab for ergonomic body type which dental technicians are suitable and suggest to effective improvement of workspace. For this purpose, we measured the height, weight, body sizes of total 77 junior majoring in dental laboratory science where they study school located in Gyeonggi and Chungcheong area and we research uncomfortable body type when they had a clinical training. For comparative analysis we had visited 15 dental lab and 2 dental lab of general hospital and we had measured the height of workbench and desk including chair and then We had statistical analysis measured value. Especially we analyzed the important factor causing inconvenience for work environment. As a result, we had examined, we found following results The sand table was the most uncomfortable equipment, when they have clinical training. There is no correlation between sexual characteristics of junior in college and selection of uncomfortable equipment. It is reasonable to assume that sand table which is lower than recommended height brings out inconvenience. It is analyzed that the optimum height of sand table in dental lab for junior in college is lower than the recommended height. The optimum height of sand table in dental lab has deviation according to height of junior in college. The height of worktable in dental lab was lower than recommended height. The recommended range could not apply to posture of dental technician with different height uniformly.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.29-36
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• 2015

This study is an 1-D numerical study prior to modification of diesel engine for power plants to natural gas/diesel dual fuel engine using GT-Power with 1.5MW diesel engine for power generation. Natural gas injector was installed to intake manifold for dual fuel engine model. Effects on engine performance and characteristics were investigated when dual fuel is used in unmodified diesel engine. The analysis was done under 5 conditions from 0% to 40% of mixing rate on 720RPM engine speed. As a result of research, the engine performance was decreased as increasing ratio of natural gas. Engine brake power was decreased by 18.4% under 40% mixing rate condition. To clarify the reason, effects of injection timing and period were evaluated with DOE method. Considering this result, optimization was done for these parameters. Also, comparison between performances of dual fueled engine and diesel engine was made after optimizing the timing of injection by DOE method. As a result, engine brake power was decreased by 8.55% under mixing rate 40% condition showing 12.5% improvement.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.69-76
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• 2008

Three failure cases of CNG composite vessels were reported since after January 2005. The 1st and 2nd accidents were indebted to vessel defect and installation mistake. The 3rd was caused by gas leak at pipe connections. In this paper various aspects were studied based on information of the three failure analysis, which must be improved for better safety of the CNG bus system. Overpressure region caused by vessel explosion was theoretically predicted and also assessed by PHAST program. Explosion of 120 l vessel under 20 MPa is equivalent to 1.2 kg TNT explosion. The predicted value by PHAST was more serious than theoretical one. However, actual consequence of explosion was much less than both of the predicted consequences. Since the CNG vessel was designed by the performance based design methodology, it is difficult to verify whether the required process and tests were properly conducted or not after production. If material toughness is not enough, the vessel should be weak in brittle fracture at early in the morning of winter season since the metal temperature can be lower than the transition temperature. If autofrettage pressure is not correct, fatigue failure due to tensile stress during repeated charging is possible. One positive aspect is that fire did not ocurred after vessel failure. This may be indebted to fast diffusion of natural gas which hindered starting fire.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.17-28
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• 2010

A climbing lane is installed to separate low-speed traffic from high-speed traffic if drastic traffic capacity reduction is expected due to a large number of vehicles that slow down in the upward section. Existing studies on climbing lanes have focused on the designation, location of starting and ending points, and installation method of climbing lane with regard to road design standards. However, in terms of traffic operation, it was known that the climbing lanes cause traffic congestion due to the increase of traffic volumes. In this regard, this study aims to establish traffic operational guidance as to how much effects temporary closure of climbing lanes can have on traffic improvement according to the volume-capacity ratio, grade, and composition of trucks. A test section of simulated climbing lane was selected in Nakdong JC bound for Masan(136.9K~133.3K, 3.6km, 3.7%) on Jungbunaeryuk expressway to conduct VISSIM analyses, microscopic traffic simulation based on such control variables as traffic volume(v/c), grade and the trucks ratio. As a result of the analyses, it has been found that v/c and the ratio of trucks are the key variables for efficient traffic management of climbing lanes in order to relieve traffic congestion via climbing lane. If ratio of trucks are more than 50% and when v/c would be 0.8, both climbing lane would be closed and non-operated regardless of grade and ratio of trucks when v/c is 1.0. With the increased traffic due to a five-day work week system, continued peak hours during the weekday, increased and various patterns of congestion on expressway, this study would be expected to contribute to facilitating researches on flexible operational standards for road facilities.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.209-220
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• 2014

This study investigated the problem of the existing rural development plan where the opinions of local residents are excluded due to the lack of expert knowledge and limited participation and sought the village development plan driven by the voluntary participation of local residents by applying a rural forum targeting rural villages to solve the problem. As a result of the study, (1) the problem of the current village development plan should be made based on the participation of local residents, and (2) this problem has remained as an important challenge. Therefore, the village improvement activities that have reflected the opinions of local residents can be said to be (3) the process that seeks the change into the rural planning process led by local residents, and this study derived the ways to ensure the voluntary behavior of local residents, strengthen local residents' capacity to create on-going villages, and expand local residents' participation opportunities in the entire process of rural planning through the application of the rural forum. (4) Although it is generally difficult for local residents to propose opinions directly and exert influence in the rural planning and design process and it is not easy to reduce the difference in the perspective between the professionals and local residents, significance lies in the fact that local residents voluntarily determine the future of their region and derive the plan. Therefore, the experience of decision-making and consensus process through the rural forum can promote the sustainability of the village creation participated by local residents and the increase of local residents' role. This study took one village as an example to reflect the results applied to the rural forum, and it is difficult to determine that it has been fully verified with the method of residents' participation. Therefore, future studies to verify the effectiveness of village creation and seek the empirical utilization measures are needed more, and the operation of education programs and various support plans suitable to the capacity and level of local residents should be promoted rather than the traditional lecture-style stereotyped education in the future for sustainable rural development.

• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.562-570
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• 1995

The recent ABB/CE(Asea Brown Boveri Combustion Engineering) type pressurized oater reactor-s have the on-line monitoring system, i.e., the COLSS(core operating limit supervisory system), to prevent the specified acceptable fuel design limits from being violated during normal operation and anticipated operational occurrences. One of the main functions of COLSS is the on-line monitoring of the DNB(departure from nucleate boiling) overpower margin by calculating the MDNBR(mini-mum DNB ratio) for the measured operating condition at every second. The CETOP-D model, used in the MDNBR calculation of COLSS, is benchmarked conservatively against the TORC mod-el using an inlet flow factor of hot assembly in CETOP-D as an adjustment factor for TORC. In this study, a technique to optimize the CETOP-D inlet flow factor has been developed by elim-inating the excessive conservatism in the ABB/CE's. A correlation is introduced to account for the actual variation of the CETOP-D inlet flow factor within the core operating limits. This technique was applied to the core operating range of the YongGwang Units 3&4 Cycle 1, which results in the increase of 2％ in the DNB overpower margin at the normal operating condition, compared with that from the ABB/CE method.

• Journal of Korean Society of Transportation
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• v.31 no.1
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• pp.47-56
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• 2013

The present study proposed a methodology to analyze the networking efficiency of arterial road networks. The methodology was motivated to design three-dimensional networks and to analyze the networking ability quantitatively, which is a novel approach compared to existing methods depending on the two-dimensional network definition and the qualitative analysis for improving arterial road networks. The method considered the interdependence between high-level freeways and low-level highways, the ITS-based information for traffic and road conditions, and the physical networking. These three factors were quantified by a networking index (NI), and the networking efficiency was measured by a networking rate (NR). The present study proved that the networking efficiency (NR) was influenced by travel information sharing (i.e., ITS) and physical factors. This supports the fact that the integrated improvements of physical and ITS factors are necessary for an arterial road. The proposed method was applied for an actual arterial road network. It was found that the nation-wide NR was higher than that for the metropolitan area, which might be due to the difficulty in switching between high- and low-level networks and the lack of ITS functions in the metropolitan area.

• Tunnel and Underground Space
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• v.20 no.2
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• pp.82-91
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• 2010

Grouting technology is one of the ground improvement methods used in water controlling and reinforcement of rock mass in underground structure construction. It is necessarily required to find out the characteristics of grout flow through discontinuities in a rock mass for an adequate grout design and performance assessment. Laminar flow is not always applicable in simulating a grout flow in a rock mass, since the rock joints usually have apertures at a micro-scale and the flow through these joints is affected by the joint roughness and the velocity profile of the flow changes partially near the roughness. Thus, the influence of joint roughness and aperture on the grout flow in rough rock joint was numerically investigated in this study. The commercial computational fluid dynamics code, FLUENT, was applied for this purpose. The computed results by embedded Herschel-Bulkley model and VOF (volume of fluid) model, which are applicable to simulate grout flow in a narrow rock joint that is filled with air and water, were well compared with that of analytical results and previously published laboratory test for the verification. The injection pressure required to keep constant injection rate of grout was calculated in a variety of Joint Roughness Coefficient (JRC) and aperture conditions, and the effect of joint roughness and aperture on grout flow were quantified.

• Korean Journal of Acupuncture
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• v.22 no.1
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• pp.55-66
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• 2005

Objectives : This study is a random-controlled post-design for confirmation of headache degree, quality of life, and satisfaction to therapeutical effect on chronic headache adults after management of non-medicinal treatment (acupuncture therapy and stellate ganglion block therapy). Methods : 51 clinical experiment participants were gathered and through a questioutaire patients who experienced headache for more than 4 hours a day and more than 15 days per month were qualified as chronic headache patients. The qualified patients were classified in to two groups, acupuncture group (AT group, n=28) and stellate ganglion block group (SGB group, n=23). Treatment was applied 2 times a weeks for 4 weeks. The effects of both groups were analyzed using VAS scores, BPI (Brief Pain Inventory) and the satisfaction degree to the therapy. Results : 1. The recognized score of the headache of AT group and SGB group was reduced indicating the degree of the headache was released. 2. The recognition at damage to the quality of life was reduced post therapy of AT group and SGB group, in which general activity, mood, enjoyment of life, personal relationship, and sleeping showed significant improvement of life quality, 3. The satisfaction degree to the therapy showed lower score than expectation to it in AT group and SGB group, however, it was not significant. Conclusions : The results showed that the four-week non-medicinal treatment (AT and SGB) in chronic headache patients was effective for reducing headache and releasing its damage in daily life, however, no difference in superiority was found. Therefore, non-medicinal treatment (AT therapy and SGB) could be utilized in chronic headache patients.