• Tribology and Lubricants
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• 제30권2호
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• pp.116-123
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• 2014

The objective of this study is to model and simulate the nonlinear lubrication performance of the sliding part between the piston and cylinder wall in a hydrostatic swash-plate-type axial piston pump. A numerical algorithm is developed that facilitates simultaneous calculation of the rotating body motion and fluid film pressure to observe the fluid film geometry and power loss. It is assumed that solid asperity contact, so-called mixed lubrication in this study, invariably occurs in the swash-plate-type axial piston pump, which produces a higher lateral moment on the pistons than other types of hydrostatic machines. Two comparative mixed lubrication models, rigid and elastic, are used to determine the reaction force and sliding friction. The rigid model does not allow any elastic deformation in the partial lubrication area. The patch shapes, reactive forces, and virtual local elastic deformation in the partial lubrication area are obtained in the elastic contact model using a simple Hertz contact theory. The calculation results show that a higher reaction force and friction loss are obtained in the rigid model, indicating that solid deformation is a significant factor on the lubrication characteristics of the reciprocating piston part.

• 한국농공학회지
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• 제12권4호
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• pp.2090-2123
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• 1970

This paper is a report on the research of experimental model test of Andong Fill Dam, which has been planned by the Government of Korea as a project, of its over-flowing capacity in spillway, creation of minus pressure and structure of anti-water impulse in over-flow weir. Andong Fill Dam is one of the project of master development plant for water resources, locating at Nakdong River side of Korea, and is aimed to have a multi-purpose dam for flood-control, irrigation, water power, urban and industrial water supply. This dam is planned to erect in fill-dam type due to the improper soil foundation and condition for concrete dam. The refore for the proper and advantageous points, this is designed as center core fill dam. By a model minimized of Andong Fill Dam, held an experimental model test on water quentity of reservir, discharges of overflow part, low pressure and anti-water impulse of overflow part, which was conducted an experiment by flowing aspects through each section of spillway to find the changes of water pressure and that of water level, and corrected the section of each part in order to conduct a check on the creation of minus pressure not to be over acted to the allowable bundary of the section structure; and for the prevention of concentated scouring at the down stream side of flow.

• 보존과학연구
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• 통권27호
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• pp.103-128
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• 2006

Rock properties of the five storied stone pagoda in the Mooryangsa temple are consist mainly in medium grained biotite granite with partly pegmatite veinlet. A part of the foundation stone is substituted in identical rock properties of the pagoda. The upper part of the pagoda is used purples and stone, gray shale and granodiorite. The most serious problem of the pagoda is structual instability from centered subsidence of the ground in northwestern direction remarkably. In southern view, the upper part of the pagoda also is slanted a little in right, it will need reinforcement by engineering method for structual stability of the stone pagoda. Weathering states of the stone pagoda are affected results of natural and artifical factors due to the surface-exfoliation, fine-fissure, crack, falling offs. On the rock surface of the pagoda, ferro-manganese hydroxide compounds are coated along the rainpathway. Also, bryophyte range concentration spreads raindrops face of roof rock properties, which areadd biological weathering effects. For the synthetic evaluation of the deterioration state, we make detailed surface weathering maps, it will be contribute to investigation for future conservation schemes.

• International Journal of Knowledge Content Development & Technology
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• 제8권2호
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• pp.67-100
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• 2018

This study comprehensively draws a conclusion using factors of economic, social, and educational value and performed a survey on librarians and users to compare and analyze the difference in perception between the two groups. The result are as follows: First, Libraries had the social value not only on research and personal learning but also on establishment and vitalization of communities, provision of opportunities to share ideas between local residents and create something new, and provision of recreation to improve the residents' capability. Second, both groups evaluated the libraries' educational role and function relatively highly. In particular, the librarians scored very high for the items that the libraries' educational role was expanding, the libraries were a part of the educational system, and the libraries' value on reading and literacy was great, and the users thought that libraries had an value because they were a part of education and the educational system. Third, economic value part also obtained relatively lower scores than other values; the mean of the librarian group was 3.46 and the user group was 3.43. Among the economic values, the librarian group scored the highest for the area of economic value for local communities, and the greatest scores were given to manpower development by the users.

• 품질경영학회지
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• 제51권1호
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• pp.1-18
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• 2023

Purpose: In Part 1, the purpose of this study is to examine how a used product provider optimizes a company's profits by comparing an extended warranty to a used product only when selling a product and what it provides later. In addition, in Part 2, an empirical study can confirm the structure in which extended guarantees can work effectively by grasping consumers' purchase intention according to the time of sale of extended guarantees, which is the basic premise of the analysis model of Part 1. Methods: This study aims to conduct not only analytical studies but also empirical studies applying various statistical analysis methods using questionnaires targeting customers and potential consumers who have subscribed to extended warranty services. Results: The study showed that the profits of companies providing extended warranty services were proportional to the coefficient of the extended guarantee service value, so it is necessary to create an environment in which the effect of extended guarantee services can be well realized. In the empirical model, the higher the emotional and economic benefits are perceived, the higher the purchase intention according to the future purchase of extended guarantees. Conclusion: Through this study, various problems that may be caused by the structural diversity of the supply chain providing extended warranties in the future can be viewed and contribute to the theoretical foundation for strategic understanding.

• The Journal of Korean Physical Therapy
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• 제18권6호
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• pp.23-32
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• 2006

Purpose: The purpose of this study is to suggest new strategies available for the physical therapy curriculum development. Method: The curriculum of 4 Universities in 4 countries; America, Australia, Canada and Korea was compared to suggest new curriculum. Results: Overall, curriculum in Korea emphasized skill and technique areas and didn't showed many subjects to take foundation of subject for understanding principles. The experience in clinic is not enough to satisfy international recommendation. Conclusion: We suggest that a new curriculum should be based on the three part which are foundation, essential and selection subject, and extended clinical experience to essentially need to be physical therapy in the world-standard.

• 한국농공학회지
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• 제40권4호
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• pp.94-102
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• 1998

This paper aims at developing the prediction technique of the deformation for the embankment such as sea dike and shore protection relevant to reclamation project along the southern coast of the Korean Peninsula. Generally total deformation of a sea dike over clayey foundation are composed of immediate settlement, plastic deformation and consolidation settlement. Plastic deformation occurs when the ultimate bearing capacity is less than overburden pressure containing the stress increment due to the construction of an embankment. The reliable prediction of total settlement is very important since deformed final geometry of sea dike is directly connected for analysing the safety of the long-term slope failure and piping. During this study, plastic deformation, major part of deformation was analysed using the program developed by authors, whereas immediate settlement and consolidation settlement were predicted by Mochinaka and Sena's method and Terzaghi's 1-dimensional theory of consolidation respectively. In order to validate the prediction technique for the deformation, a case study of Koheung Bay reclamation works was carried out. A good agreement was obtained between observation and prediction, which means the applicability of the technique.

• 한국제4기학회지
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• 제22권2호
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• pp.1-5
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• 2008

Some reverse fault lines pass through the alluvial fans and west hill slope of Bulguksa mountains including Mt. Toham in the directions of N-S and NW-SE. The study area is known as relatively unstable, because of active faults. Assuming the record of earthquake in the Samguksagi, the architects in the construction of the Bulguksa temple should have recognized the possibility of breakdown from the earthquakes and the need for an unique structure against at that time. Against earthquakes, Greavee technique, a stonework construction technique following woothe one and use of Chushouok (Dongtleouok or Chumchaouok) were applied for the construction of Bulguksa temple. By designing the foundation stone with hole, a structure is prevented from motiff Ction that pillarsakdcede from a foundation stone in spite of horizontal load of earthquake while woot construction isaktrong frame at earthquake. The Bulguksa-temple isausually evaluated to be a beautiful architecture from the appeaultces like the weight balltced structure with unique decoration. ampressive architectures are beautiful in balance and harmony coming from the important and specific rolls in its own way by each part of whole structure. This beauty comes from the science.

• 대한조선학회논문집
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• 제36권1호
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• pp.99-108
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• 1999

초고층강제어초(VEry High-rise Steel Artificial Reef, VEHSAR)의 형상 표현과 해석을 위해서 3차원 모델링 프로그램을 Windows 95(또는 Windows NT) 환경하에서 MFC(Microsoft Foundation Class)를 기반으로 한 Visual C++로 개발하였다. 컴퓨터를 통해 미리 초고층 강제어초 건조를 실제와 같이 구현해 봄으로써 문제점의 사전 예측 및 대책 수립 등을 가능케 하는 저비용 고효율의 일관설계시스템을 구축하는 것을 목표로 하는 이 프로그램은 객체지향프로그램 기법과 CAD/CAM기술의 도입으로 생산성 향상이 기대되며, OpenGL이라는 그래픽 라이브러리를 도입하여 좀더 빠른 고화질의 3차원 그래픽을 화면상에 나타나게 할 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.698-705
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• 2004

Application of structural load on soft ground can cause lateral movement as well as ground break due to pressing and shearing of ground. Especially, abutment supported by pile foundation can make pile deformed due to lateral movement of ground in order to have harmful effect on structure. According to the result of this study, it is required to consider disturbance of weak soil layer when using lateral movement countermeasure method by EPS construction method as a result of performing study on safety review and EPS construction method with respect to this based on site where lateral movement occurs due to backside soil filling load at bridge abutment installed on weak ground, and it is required to sufficiently consider soil reduction during design of EPS construction method due to lateral movement deformation of soft clay layer by losing ground horizontal resistance force due to plasticity of ground around pile as well as combination part damage with pile head and expansion foundation.