• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.436-441
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• 2012

Pressure waves are generated and propagate in tunnel when train enters a tunnel with high speed. Compression wave due to the entry of train head propagates along the tunnel and is reflected at tunnel exit as expansion wave. While expansion wave due to the entry of train tail propagates along the tunnel and is reflected at tunnel exit as compression wave. These pressure waves are repeatedly propagated and reflected at tunnel entrance and exit. Severe pressure change per second causes ear-discomfort for passengers in cabin and micro pressure wave around tunnel exit. It is necessary to analyze the transient pressure phenomena in tunnel qualitatively and quantitatively, because pressure change rate is considered as one of major design parameters for an optimal tunnel cross sectional area and the repeated fatigue force on car body. In this study, we developed the characteristics method analysis based on fixed mesh system and compared with the results of real train test. The results of simulation agreed with that of experiment.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.126-133
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• 2007

This study was designed to provide basic visiter information for establishing effective park management strategies. A questionnaire survey was at major entry points in Hallasan National Park(Eorimok and Youngsil). 237 random samples among the visitors on the way back home from their visit were chosen to represent general visitor population. As for the results, visitors' recreational satisfaction level with the area was relatively high. The majority of the visitors were satisfied with 20 uses and management related attributes provided by Hallasan National Park system. However, considering lack of sense of hygienic sanitary facilities, consequential deterioration of natural and cultural resources, and entrance fees as well as other costs, there needs to be a managerial priority on visiter service.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.2
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• pp.45-57
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• 2017

The royal tombs of the Joseon Dynasty are divided into the entrance space of the inner and outer spirits in accordance with the characteristic of the ritual act. In each space, the ritual facilities are arranged and managed according to the characteristics of ritual acts and space. In the case of the Joseon royal tombs listed in the World Heritage List in 2009, further conservation and management of the original form is required, and the need to restore the original form is required. Especially, Yungneung and Geolleung requires landscape management in accordance with the World Heritage site management regulations, for example, management of horizontal 60 degrees view. This study aims to propose a prototype verification, preservation and restoration plan for the landscape around the core area of the damaged source. Through the verification of the old literature and field investigation, conservation and restoration plan is proposed for the landscape of the ridge, the water system, the scenery around the ridge line, and the historical scenery.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.72-75
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• 2003

In this research, we focused on the effects of the orifice internal flow such as cavitation and hydraulic flip. The breakup characteristics such as the breakup length and trajectory were measured by changing the orifice diameter (d), the orifice length/orifice diameter (L/d), the injection pressure and the shapes (sharp and round) of orifice entrance to provide a lot of conditions of the orifice internal flow. It is found that cavitation bubbles that occur inside the sharp-edged orifice make the liquid jet ejecting from the orifice turbulent. In the orifices (L/d = 5), the hydraulic flip phenomenon is shown when the injection pressure is high. In case cavitation occurs it breaks up more earlier than that in case of non-cavitation. In case hydraulic flip occurs, since the area of the liquid jet becomes small, the breakup length is also small as that in case of cavitation. But the liquid column trajectories have a similar tendency irrespective of cavitation.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.237-242
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• 2012

Purpose: The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods: One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results: The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 $mGycm^2$ (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 $mGycm^2$ (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion: We recommend 3.1 mGy (PED), 87.4 $mGycm^2$ (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.597-603
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• 2014

The cargo of ships and offshore structures is the number of oil of combustibility and volatile, oil processing cargo. Furthermore heavy cargo of the vehicle or container box or bulk cargo are occupied the remainder of cargo. In addition, there is a possibility to move the location of the cargo and the vessel because it is received periodic / non-periodic a load of wave and ocean current. Therefore a shipboard hazard is much greater than onshore industry hazard. Monitoring and preparation for safety are necessary things because there is always risk of accidents arise from the impact of the freight and cargo of ships and offshore structures. In this study, we conducted a study with respect to the introduction of the wireless sensor network monitoring system to ensure the safety of the crew and workers on shipboard.

• Journal of architectural history
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• v.19 no.6
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• pp.233-250
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• 2010

Jukseoru as an official pavilion of the government, one of the eight sceneries in Gwndong Area, is located on the cliff over Osipcheon River. This paper interprets form and space of the pavilion with restored old life by analyzing pictures of official party in 18th century in Chosun Dynasty. Every part of the space is occupied by persons by the class and duty: the pricipal guest, nobles, subordinates, gisaengs, court musicians, and guards from the high to the low and from the inside to the outside. Applying the analysis to the Jukseoru pavilion, the noblest lord takes sit on the platform in front of folded screen at main bay under checked ceiling, enclosed by low timber beam. The next northern end bay is a place for subordinates' and servants' waiting for preparation for rice wine. Southern end entrance bay is not a result of later addition but deliberately and originally made for lower place outside the railing of wooden floor: for a waiting woman gisaeng, and subordinates. Outside under the eaves on the platform with bedrock, artificial stone and soil is a place for court musicians, subordinates, and guards. The yard in front of the building is a place for preparing meals by cookers. Every detailed ornamental form is different each other by the place for the occupied class. Existing theory tells that the building, 7 bays gable-and-hipped roof, is a result of structural extention of 2 bays at the 5 bays gabled-roof. However, through the interpretation of old pictures and application to the pavilion, the present Juseoru is not a result of later structural addition, but deliberately designed creation suited to life in hierarchical traditional society.

• The Journal of Korean Academic Society of Nursing Education
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• v.12 no.2
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• pp.170-177
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• 2006

Purpose: This study was performed to identify the relationship between self-esteem and satisfaction in major of nursing students. Methods: Data were collected from the 10th to the 14th of April in 2006, from 281 nursing students in Jeollabuk-Do area. The collected data were analysed by using the SPSS WIN 11.0. Results: The results of this study were as followings: 1) The mean score for self-esteem was $2.89({\pm}.42)$, self-esteem was significantly different according to the general characteristics of grade(F=4.718, p=.010), satisfaction of pocket money(F=11.241, p=.000), satisfaction of present life(F=9.875, p=. 000) and hope for the employment field(F=2.583, p=.026). 2) The mean score for satisfaction in major was $3.79({\pm}.49)$, satisfaction in major was significantly different according to the general characteristics of satisfaction of pocket money(F=5.280, p=.006), motivation of entrance(F=7.384, p=.000), satisfaction of present life(F=27.000, p=.000), hope for the employment field(F=3.019, p=.011) and one of family (t=2.416, p=.017). 3) There was a significant correlation between self-esteem and satisfaction in major(r=.353, p=.000). 4) The most important variables affected satisfaction in major could explain a total 27.9%, were accounted for 22.7% in the satisfaction of present life and 5.2% in the self-esteem by the stepwise multiple regression analysis. Conclusion: As a result, self-esteem was correlated with satisfaction in major in nursing students. Therefore we need to develop various self-esteem program for nursing students.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.1
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• pp.132-146
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• 2013

For several decades, Asian nations such as Korea, Japan and China have been leading the shipbuilding industry since the decline in Europe and America. However, several developing countries such as India, Brazil, etc. are going to make an entrance into the shipbuilding industry. These developing countries are finding technical partners or information providers because they are in situation of little experiences and technologies. Now, the shipbuilding engineering companies of shipbuilding advanced countries are getting a chance of engineering business against those developing countries. The starting point of this business model is green field project for the construction of new shipyard. This business model is started with a design of the shipyard layout. For the conducting of the shipyard layout design, four kinds of engineering parts are required. Those are civil engineering, building engineering, utility engineering and production layout engineering. Among these parts, production layout engineering is most important because its result is the foundation of the other engineering parts and it determines the shipyard capacity during the shipyard operation lifecycle. Previous researches about the shipyard layout design are out of the range from the business requirements because most research cases are in the tower of ivory, which means that there are little consideration of real ship and shipbuilding operation. In this paper, a shipyard layout design for preliminary phase is conducted for the target of newly planned shipyard at Venezuela of South America with an integrated method that is capable of dealing with actual master data from the shipyard. The layout design method of this paper is differentiated from the previous researches in that the actual product data from the target ship and the actual shipbuilding operation data are used for the required area estimation.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.39-46
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• 2007

The aim of this study was to recognize the need of three generation family house that is traditional house type of Korea. First, the pre-research analysis method was used for this study. And then, there are three type's grouping like those are as follows; 1) Recognition of three generation family house. 2) Type of three generation family house. 3) Plans of three generation family house. The analysis results are as follows; If the conditions are better than now, recognition is positive. Type are living together and next doors type can direct access. Some standart plan is been about room's number, house's area, bath's number and so on. Second, try to compare plan - this plan already has been used building - with standard plan. The compare result are as follows; three generation family houses - be used by whom - do not apply to standard plan. Almost houses have a three room that is less than the standard plan. All houses have a number of two bath that is less than the standard plan too. Condition of consideration is suitable to ages in next door type, but in case of living together type that consider user whom is use the inner room. Separation of entrance distinguish between the living together type and the next doors type. In case of living together type Dining with Kitchen room's number is one, but the next doors type have the number of two.