• Structural Engineering and Mechanics
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• 제49권4호
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• pp.427-448
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• 2014

At present, the time of easy oil and gas is over. Now, the largest part of fossil fuels is concentrated in the deepest levels of tectonic structures and in the sea shelves. One of the most cumbersome operations of their extraction is the bore-hole drilling. In connection with austere tectonic and climate conditions, their drivage every so often is associated with great and diversified technological difficulties causing emergencies on frequent occasions. As a rule, they are linked with drill string accidents. A key role in prediction of these situations should play methods of theoretical modelling. For this reason, there is a growing need for development and implementation of new numerical methods for computer simulation of critical and post-critical behavior of drill strings (DSs). In this paper, the processes of non-linear deforming of a DS in cylindrical cavity of a deep bore-hole are considered. On the basis of the theory of curvilinear flexible rods, non-linear constitutive differential equations are deduced. The effects of the longitudinal non-uniform preloading, action of torque and interaction between the DS and the bore-hole surface are taken into account. Owing to the use of curvilinear coordinates in the constraining cylindrical surface and a specially chosen concomitant reference frame, it became possible to separate the desired variables and to reduce the total order of the equation system. To solve it, the method of continuation the solution by parameter and the transfer matrix technique are applied. As a result of the completed numerical analysis, the critical states of the DS loading in the cylindrical channels of inclined bore-holes are found. It is shown that the modes of the post-critical deforming of the DS are associated with its irregular spiral curving prevailing in the zone of bottom-hole-assembly. The possibility of invariant state generation during post-critical deforming is established, condition of its bifurcation is formulated. It is shown that infinite variety of loads can correspond to one geometrical configuration of the DS. They differ each from other by contact force functions.

• 한국보육지원학회지
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• 제6권3호
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• pp.65-84
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• 2010

본 연구는 저소득층 조손가족 조부모의 인생이야기와 손자녀 양육경험을 살펴보았다. 8명이 연구대상자였으며, 심층면접과 참여관찰법이 연구방법으로 이용되었다. 저소득층 조손가족 조부모의 인생이야기를 살펴본 결과 아동기의 경험으로는 시작부터 불행한 인생, 교육기회 박탈의 차별적 경험이 특징이었다. 청/중년기 경험의 두드러진 주제는 자신의 무능력에 대한 회한이었다. 노년기에는 경제적 어려움이 주요한 주제였다. 조부모의 손자녀 양육경험에서 나타난 주제는 비자발적 양육책임, 고난의 대물림, 가족지지의 부재였다. 그러나 이러한 인생이야기와 손자녀 양육경험의 어려움에도 불구하고, 저소득층 조손가족 조부모는 가족 중심적 가치관, 지역사회의 사회적 지지, 희생을 통한 자기 확인을 바탕으로 손자녀 양육에 적응하는 모습을 보여주었다. 아동기 때의 기본적 신뢰감의 중요성, 경제적 어려움의 경험, 지역사회의 사회적 지지의 중요성, 자신의 희생을 통한 자기 확인을 후속 연구를 위한 주제로 제안하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.692-697
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• 2006

건축물의 유지관리에 대한 중요성이 부각되고 건축물의 수명연장에 대해 많은 관심이 집중되고 있다. 최근 수도권을 중심으로 도심지 등의 주택용지가 부족함에 따라 해결책으로 주상복합건물의 건설이 빠른 속도로 증가하고 있다. 주상복합건물은 부지 내에서 토지이용의 극대화를 가져왔지만, 유지관리단계에서는 관리비용 분담과 관리범위 한계 등으로 인해 상가시설과 주거시설 이해당사자간에 갈등이 발생하는 등 많은 문제점을 내포하고 있다. 본 논문의 목적은 건축물의 초기성능을 유지하고 개선할 수 있도록 설계단계에서 유지관리성능 향상을 위한 체크리스를 제시하는 것이다. 이를 위해 문헌조사 및 설문조사를 실시하여 유지관리의 문제점을 도출하고 설계단계에서의 검토항목을 작성하여 건축계획분야를 중심으로 건축물의 유지관리성능 향상을 위한 가이드라인을 제시하였다. 본 연구결과는 건축물의 생애기간동안 사회적, 물리적, 기능적 변화 요구에 대응하여 유지관리 성능향상에 도움을 줄 것으로 기대된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.159-160
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• 1998

Results of chemistry and biological activity of many years indicate that plants belonging to the Isodon genus are rich in ent-kaurane diterpenoids, which have been revealed to possess biological activities such as antitumor, antibacterial and antiinflammatory effects. In continuation of our research on diterpenoids in medicinal plants of this genus, the acetone extract from the leaves of I. xerophilus, which is a plant native to Yunnan province of China, showed potent antitumor activity against K562. After partition, the most active EtOAc part was studied. Four new diterpenoids named xerophilusin A(l), B(2), C(3), D(4), and eight known compounds including macrocalin B(5) and rabdorosthomin A(6) were isolated, whose structures were elucidated through a series of one- and two-dimensional NMR techniques(DEPT, COSY, HMQC, HMBC and ROESY experiments). Among them, compound 1, 2 and 5 had two unique epoxy units formed by two ether bridges from C-20 to C-7, C-14. Up to now, there are four compounds having such an peculiar structure besides these three compounds. Compound 3 and 4 were two of the few examples possessing $1{\beta}$ substitutes. All the diterpenoid compounds were subjected to the antitumor screening. It is interesting that only xerophilusin A(l), B(2) and macrocalin(5) exhibited significant antitumor activity against K562 by the method of MTT($IC_{50}$ were listed in Table 1.). The results inspired us to infer that the unique ether bridges from C-20 to C-7, C-14 possibly played an important role in the antitumor activity.

• 대한가정학회지
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• 제46권8호
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• pp.55-72
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• 2008

The purpose of this study was to analyze the state of Goryoin housing in Uzbekistan and Korea. Using ethnographic methodologies, it was examined that 20 Goryoin households in Korea in relation to their usage of housing space firstly and also tried 20 Goryoin households in Uzbekistan with the same method. The following conclusion were established; 1). The majority of households in both areas preferred separated kitchen and living room areas. 2). Most households in both areas had a washing machine in bathroom and they regarded bathtub and the drain hole of the bathroom as very necessary. They all preferred separate bathroom and toilet areas in order to allow simultaneous use. 3). Their preferred seating style was chairs on sleeping and eating especially but they treated large family and guest without chairs in both areas. 4). All of them were took their shoes off and wore slippers at home usually and also had a preference for designated shoes space at the entrance to the house. 5) All of households in Uzbekistan and half of them in Korea had a carpet or mat in the bedroom or living room, both for keeping warm and aesthetic reasons. 6). The heating system of apartment in Uzbekistan was radiator and most of private houses had a modified Ondol with radiator but their preferred heating system was modified Ondol in both areas. 7). They all considered the living room as the most important housing space for family and guest in both areas.

• Structural Engineering and Mechanics
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• 제24권6호
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• pp.709-725
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• 2006

In this paper the buckling and post-buckling behavior of slender bars under self-weight are studied. In order to study the post-buckling behavior of the bar, a geometrically exact formulation for the non-linear analysis of uni-directional structural elements is presented, considering arbitrary load distribution and boundary conditions. From this formulation one obtains a set of first-order coupled nonlinear equations which, together with the boundary conditions at the bar ends, form a two-point boundary value problem. This problem is solved by the simultaneous use of the Runge-Kutta integration scheme and the Newton-Raphson method. By virtue of a continuation algorithm, accurate solutions can be obtained for a variety of stability problems exhibiting either limit point or bifurcational-type buckling. Using this formulation, a detailed parametric analysis is conducted in order to study the buckling and post-buckling behavior of slender bars under self-weight, including the influence of boundary conditions on the stability and large deflection behavior of the bar. In order to evaluate the quality and accuracy of the results, an experimental analysis was conducted considering a clamped-free thin-walled metal bar. As this kind of structure presents a high index of slenderness, its answers could be affected by the introduction of conventional sensors. In this paper, an experimental methodology was developed, allowing the measurement of static or dynamic displacements without making contact with the structure, using digital image processing techniques. The proposed experimental procedure can be used to a wide class of problems involving large deflections and deformations. The experimental buckling and post-buckling behavior compared favorably with the theoretical and numerical results.

• 한국농촌간호학회지
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• 제4권1호
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• pp.31-40
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• 2009

Purpose: This research was done do identify and analyze the beginnings of the community health practitioner system in the Republic of Korea (ROK) around 1980. Method: Primary sources were collected and analyzed, mainly newspapers around 1980, the act for health service for rural areas, and other relative publications. Results: The government of the ROK was trying to solve the problem of doctorless villages and regarded the introduction of primary health care (PHC) services using registered nurses (RNs) to be an economic solution to this problem. The Korean Nurses' Association presented 'a plan for community health service' to the government party and medical association in 1976. In this plan, RNs would provide primary care at the sub-county (myun) level, and hospital would provide secondary care. The Korean Public Health Development Research Center was awarded the project 'RNs and nurse aids as CHP for primary care service and their training'. In 1977, 25 RNs began to work as PHC in 3 areas, and interim findings showed that RNs were very capable of doing PHC. The Ministry of Health and Welfare announced long term plans for health and welfare administration including a tertiary health care delivery system. RNs after training were posted to rural areas with no medical services to do medical treatment for mild cases. The Act for health services for rural areas was enacted on December 31, 1980. Enforcement Ordinance and Enforcement Regulations were enacted in 1981. In 1981, 257 CHP were selected, trained, and deployed. In 1983, the president of the ROK announced continuation of the CHP system for residents of medically vulnerable areas. The number of CHP increased from 257 in 1981 to 2038 in 1989.

• 융합보안논문지
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• 제19권2호
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• pp.129-136
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• 2019

지상작전 시 지휘관 및 참모의 주된 업무는 지속적으로 발생되는 상황에 대처하기 위해 수행되는 의사결정의 연속이라고 볼 수 있다. 하지만 현재의 의사결정 과정은 지휘관 및 참모의 정성적인 방법에 의존하고 있기 때문에 제4차 산업혁명을 기반으로 현재 및 미래에 도입되고 있는 의사결정 도구와의 연결을 보장하기 어려운 실정이다. 본 연구에서는 지상작전과 연관된 의사결정 고려요소들의 정량화에 대해 전장정보분석(IPB) 시 접근로 평가요소들의 상대적 중요도를 AHP를 이용하여 도출하는 것을 중심으로 제시된다. 전장정보분석에서 가장 중요한 과정 중에 하나가 접근로에 대한 평가이며, 평가요소에는 목표 접근성 관측과 사계 은폐와 엄폐 장애물, 기동의 용이성 인접 접근로로의 전환 용이성을 포함하고 있다. 기존의 방식은 비교요소에 의한 방법과 장단점에 의한 비교가 있지만, 위 평가요소들의 중요도가 동등하게 적용된다는 문제점이 항상 제기되어 왔다. 전문가집단을 통한 분석적계층과정(AHP) 기법을 적용하였고, 분석결과 목표 접근성이 가장 중요한 평가요소임을 확인할 수 있었다.

• 정보관리학회지
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• 제38권1호
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• pp.87-112
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• 2021

현재 공공도서관의 자원봉사자는 주로 내부 인력보충의 측면으로 관리되고 자원봉사자 관점에서의 고려가 부족하여 참여의 지속성과 경영효과가 제한적이다. 본 연구는 공공도서관 자원봉사자의 참여 동기와 지속 요인들을 검토하고 이 요인들이 자원봉사자의 만족도와 마케팅 의도에 미치는 영향을 파악하는 것을 목적으로 한다. 이를 위해 자원봉사자, 만족도, 동기요인에 대한 이론적 개념을 기반으로 각 변수에 대한 개념 및 측정요인을 확인하였으며, 자원봉사자 5명의 심층면담을 통해 연구가능성 및 고려요인을 검토하였다. 이를 바탕으로 개발된 설문지로 설문조사를 진행하여 수집된 데이터를 기반으로 통계분석을 실시하였다. 분석 결과, 자원봉사자의 참여동기와 지속 요인은 보수 등의 관리적 요인보다 정서적·심리적 요인들이 자원봉사자 만족도와 마케팅 의도에 영향을 미쳤다. 이러한 결과는 관계 중심적 관리 방식으로의 변화의 필요성을 나타내며 자원봉사자를 인력 충원의 관점으로 인식했던 것에서 더 나아가 자원봉사자의 만족을 기반으로 한 공공도서관의 마케팅 자원으로서 활용가치를 높였다는 점에서 의의가 있다.

• 도시과학
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• 제11권2호
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• pp.19-24
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• 2022

Conventional RC beams for crossing small and medium-sized rivers do not have a cross-sectional area, so the floating debris is accumulated and disasters such as damage to bridges occur. To improve this, the PSC method was invented. However, this also had problems such as transverse curvature, increase in dead weight due to cross-sectional shape, and negative moment generated during serialization, so it was necessary to develop a new type of girder. Therefore, it was intended to propose a LIT(Leton Interaction Thrust) girder bridge that is safer and has better performance than the conventional PSC girder with improved section efficiency. Unlike existing girder bridges, the LIT girder has the feature that the change in the strands of the entire girder occurs only in the vertical direction when the first tension is applied because the tendon arrangement is symmetrical by applying the raised portion. In addition, slab continuation generates a secondary moment that is advantageous to the continuous point, effectively controlling the negative moment and preventing the corrosion of the tendon. The dimensions of the cross section were determined, and the arrangement of the strands was designed to conduct structural analysis and detailed analysis. As a result of the structural analysis, the stress of the girder showed results within the allowable compressive stress, and the deflection showed the result within the allowable deflection. showed results. In addition, a detailed analysis was performed to examine the stress distribution around the girder body and the anchorage area and the stress distribution of the embossed portion, and as a result, the stress of the girder body due to the tension force showed a stable level.