• Journal of Welding and Joining
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• 제29권1호
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• pp.80-84
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• 2011

The weight reduction of the transportations has become an important technical subject Al and Al alloys, especially Al 5052 alloys have been being applied as door materials for automobile. One of the most widely known car weight-reduction methods is to use light and corrosion-resistant aluminum alloys. However, because of high electrical and thermal conductivity and a low melting point, it is difficult to obtain good weld quality when working with the aluminum alloys. Also, Pulse MIG welding is the typical aluminum welding process, but it is difficult to apply to the thin plate, because of melt-through and humping-bead. In order to enhance weld quality, welding parameters should be considered in optimizing the welding process. In this experiment, Al 5052 sheets were used as specimens, and these materials were welded by adopting new Cold Metal Transfer (CMT) pulse process. The proper welding conditions such as welding current, welding speed, torch angle $50^{\circ}$ and gap 0~1mm are determined by tensile test and bead shape. Through this study, range of welding current are confirmed from 100A to 120A. And, the range of welding speed is confirmed from 1.2m/min to 1.5m/min.

• 한국화재소방학회논문지
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• 제28권6호
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• pp.41-46
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• 2014

계단에서의 합류는 건물 피난해석에서 매우 중요한 요소이다. 건물에서의 대규모 피난인이 이동하는 경우 정체가 발생하게 되는 지점은 병목현상이 발생하는 문이나 공간이 좁아지는 지점이 있다. 또한 계단에서의 정체이다. 계단에서의 정체는 상부층에서 내려오는 인원과 연결층에서 진입하려는 인원이 합류하면서 발생된다. 이러한 현상은 초고층 건물일 경우 더욱 심하게 될 것이다. 이러한 현상에 대해 현재 시뮬레이션의 결과에 의존하고 있다. 하지만, 이러한 모사가 정확하게 실제와 같이 구현되는지는 실험과의 비교를 통해 검토해볼 필요가 있다. 본 연구에서는 계단에서의 합류에 대한 실험과 시뮬레이션 적용분석을 수행하고 그 결과를 비교해보았다. 실제 실험과 시뮬레이션의 적용 결과는 차이를 보여주고 있으며, 모델링의 결과가 실제보다 낮은 것으로 나타나고 있다.

• 대한조선학회논문집
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• 제48권1호
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• pp.49-55
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• 2011

Sound insulation performance of a unit cabin mock-up is studied, where two identical rooms simulating cruise ship cabin are installed. STL (Sound Transmission Loss) measurement in the mock-up shows that STL of the partition between rooms is degraded by imperfect door ceiling and gap between wall and floor. It is also observed that gap around lighting and electrical outlet slightly affect the STL in high frequency ranges, since lighting and electrical outlet are supported by mineral wool in the back side due to fire-resistance requirement. Even after all possible gaps are sealed, STL of the partition is found to be lower than that measured in the laboratory by 9 dB. Measurement of SBN (Structure-Borne Noise) reveals that flanking transmission of SBN along the steel deck floor can severely deteriorate STL of the partition. Statistical energy analysis (SEA) of the mock-up confirms importance of the floor SBN control, in which increasing damping is essential to ensure high STL.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.205.2-205.2
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• 2016

The emission test a domestic fabricated cathode is conducted using an easy-replaceable-emitter-type test bench. A simple cylindrical button type cathode is dropped vertically into a cathode cup holder. The cathode is heated by a tungsten wire heater located around the cup holder. The cathode temperature is measured by an optical pyrometer. A high voltage pulse power supply gives the anode-cathode gap voltage up to 20 kV with the pulse width of 15 us. The emitted current from the cathode is captured at a faraday cup and is measured using current transformer and oscilloscope. The test bench is installed in the vacuum chamber with easy access door and, therefore, the cathode can be easily replaceable. We confirmed the emission current density of $15A/cm^2$ and $80A/cm^2$ with a domestic fabricated B-type cathode and a Scandate cathode, respectively. The detailed test result for the cathode will be presented.

• 한국조리학회지
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• 제2권
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• pp.209-235
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• 1996

This study assesses consumer's eating-out pattern for Foodservice industry in Korea. Foodservice industry has become increasingly important because many businessman are looking it difficult to develop successful business as a consequence of the rapid growth in Foodservice industry in Korea This exploratory study originally nation-wide surveyed a 1450 consumer over the country. A research was conducted from July 1, to July 10, 1996 using as its subject domestic consumer over the country. The data obtained from the returned questionnaires was coded and transcribed for statistical analysis. The Statistical Package for social science program (SPSS) was used for computer analysis of the data. Findings indicated the problems of management structures, managerial techniques, and laggard counter measure against the korean government's open-door policy for dining-out industry. It is found that taste, F/B price, atmosphere are considered important in choice of restaurant. And korean consumer think it is that restaurant location, physical, evidence, quality of service, Ads of mouth and cleanliness. With the importance of dining-out industry to the business, economic, and social development of korea, it is imperative to bridge this gap for sustained growth and development. Moreover, this study for advancement and improvement through concrete and multi-directional data collection and in-depth analysis of consumer's eating-out pattern realities is required.

• 한국실내디자인학회논문집
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• 제23권1호
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• pp.162-171
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• 2014

This study aimed to evaluate how universal design principles are embodied in the village community center. It will provide preliminary data on constructing a physical space of village community center as small community space in agricultural districts. To achieving the purpose in this study, the research conducted inspection using checklist to 25 village community centers at Hwasoon, Jeonnam province. The conclusion of this study is as follows: Living room and kitchen/dining room by supportive design urgently need installation of Western Style furniture and solutions of stair gap by accessible design, and also the evaluation is unsuited on a fire-gas alarm system and prevention of electric shook system on safety-oriented design. Entrance evaluated in principle for insufficient on safety handle by supportive design and spare chair by adaptable design, and also it unsuited on the solutions of door sill by accessible design and non-skid by safety-oriented design. Bathroom is insufficient lever handle and safety grip by supportive design, sink isn't suitable by adaptable design. Outdoor space information legislation staircase ramp installation and horizontal installation of the staircase was not built.

• KIEAE Journal
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• 제16권3호
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• pp.121-128
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• 2016

Purpose: The vacuum glazing should constantly retain the gap in vacuum state to maintain high thermal performance. To do so, pillars are used to prevent the glazing from clinging to each other by the atmospheric pressure and therefore surface of the vacuum glazing is consistently affected by residual stress. The vacuum glazing could be applied to curtain wall systems at spandrel area to fulfill a rigorous domestic standard on U-value of the external wall. However, this can lead to high glazing temperature increase by heat concentration at a back panel and finally thermal stress breakage. This study experimentally determined weakness of the vacuum glazing systems on the thermal stress breakage and investigated effect of the residual stress. Method: The experiment first built two scale-down mock-up facilities that replicate the spandrel area in curtain wall, and then installed single low-e glass and vacuum glazing respectively. The two mock-up facilities were exposed to outside to induce the thermal stress breakage. Result: The experiment showed that the temperature occurred the thermal stress breakage was $114.4^{\circ}C$ for the single low-e glass and $118.9^{\circ}C$ for the vacuum glazing respectively. The result also showed the vacuum glazing reached the critical point earlier than the single low-e glass, which means that the vacuum glazing has high potential to occur the thermal shock breakage. In addition, the small temperature difference between two glazing indicates that the residual stress scarcely affects breakage of the vacuum glazing.

• 대한기계학회논문집A
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• 제25권8호
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• pp.1294-1301
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• 2001

In order to reduce the time and cost for assembly, automobile speaker grills have been injection molded with door trims or map pockets in one piece recently. However, several defects such as short shots or air traps can easily occur due to the decreased fluidity of the melting polymer according to the excessive heat transfer to the mold. Therefore, it is necessary to optimize the resin feed system and predict possible defects by CAE analysis. However it is not possible to obtain exact analysis results for the speaker grill by using general shell elements since the heat transfer in the thickness direction which is the dominant factor of the filling stage can not be considered. Therefore, there have been several efforts to simulate the injection molding nature of the speaker grill by using shell elements with an effective thickness which is smaller than the actual thickness of the part. Two empirical values have been recommended for the effective thickness in real practice. One is 50∼70% of the thickness of the speaker grill and another is the gap distance between the adjacent holes. In this paper, CAE analyses of a map pocket with a speaker grill were conducted using shell elements with both of these recommended effective thicknesses, and the predicted flow fronts were compared with the findings from injection molding experiments. The commercial code MOLDFLOW was used for injection molding analysis and an 850 ton injection molding machine was used for experiments.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.182-182
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• 2023

Since China adopted Public Private Partnerships (PPPs) in the 1980s, China has relied on water PPPs to expand appropriate water facilities.. According to the World Bank data from 1994 to 2020, the top five provinces hosted over 40 percent of total PPPs, with four of them located in the Huadong area and one in the Henan area. A vast gap exists between the group attracting the most PPPs and the group hosting the least. This study explores Guangdong and Shandong provinces, which have led most PPPs in China. Coincidently, these areas are also famous for the typical areas to show the Chinese economic policy after the open-door policy. They have achieved economic development and rapid urbanization rates based on the large scale of Foreign Direct Investment inflow and export-oriented manufacturing industry, as well as their active participation in PPPs over the last thirty years. An economic approach can provide valuable insights into the development of water infrastructure. Adequate urban infrastructure has been shown to impact local economic development positively. Water infrastructure also provides a basic and sustainable environment for economic activities by satisfying more water usage, improving the efficiency of the water supply, and reducing water pollution caused by industrial activities. However, it remains only partially understood without inclusive research on the issues related to water resources in each province. For instance, existing studies have been limited to explaining slightly different patterns of water PPPs between Guangdong and Shandong at the beginning of the PPP era. This study aims to elucidate the development pattern of water PPPs in each province from multi-dimensional aspects. Therefore, the study will help understand why China boosted the development of the private water market.

• 한국인구학
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• 제35권2호
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• pp.55-72
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• 2012

일본의 성인자녀와 노부모간 관계에 대한 연구에서 기혼여성과 이들의 친정부모간의 관계에 대한 연구는 충분히 축적되지 못한 실정이다. 이 연구는 세대간 동거여부와 대화빈도를 통해 이러한 세대관계를 접근하고 있다. 일본 기혼여성과 친정부모간 세대관계는 기혼여성들의 배우자, 자녀, 형제자매, 시부모 그리고 친정부모의 상황에 따라 차별적이라는 예측이 가능하다. 이를 위해 <일본 2003년도 제2회 전국가족조사>를 이용해 친정부모와 시부모 양가의 일원이 모두 생존해 있는 30~40대 기혼여성을 분석한 결과는 다음과 같다. 친정부모와 동거할 확률(시부모와의 동거를 통제한 상태)은 부인의 형제자매수가 많을수록 낮게 나타났다. 특히 남자형제가 있는 경우 친정부모와의 동거확률은 두드러지게 낮았다. 이와 함께 친정부모 모두가 생존한 경우보다는 친정아버지만 생존한 경우에 해당 동거확률이 높게 나타났다. 친정부모와의 대화빈도(친정부모와의 동거여부를 통제한 상태)는 시부모와 동거하는 경우에 낮았으며, 형제자매수가 많을수록 낮았다. 한편, 해당 대화빈도는 친정부모 중 한 분만 생존한 경우에 높게 나타났다. 또한, 남편보다 부인의 학력이 높거나 친정부모에 대한 남편의 태도에 만족하는 경우에 친정부모와의 대화빈도가 높게 나타났다. 형제자매수가 많으면 동거가능성도 낮아지지만 대화빈도도 낮아지는 결과는 형제자매간에 세대간 동거나 대화가 어느 정도 분담되고 있음을 의미한다. 한편, 홀로된 친정부모와의 동거가능성이 높고 대화빈도가 많은 점은 노부모에 대한 다양한 지원과 자녀로서의 마음쓰임을 보여준다. 친정부모와의 대화빈도가 시부모와의 동거여부 그리고 부부간 학력차이나 남편의 친정부모에 대한 태도 등에 따라 달라진다는 점은 기혼여성들이 시부모와 남편의 영향에서 자유롭지 못함을 시사한다. 이상의 결과들은 기혼여성들의 세대간 관계를 분석하는 작업에서 다양한 가족관계를 동시에 고찰하고 고민할 필요성을 제기한다.