• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.63-70
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• 2002

Wear on the tube-to-spring contact is investigated experimentally. The wear is caused by the vibration of the tube while the springs support it. As for the supporting conditions, applied are the contacting normal force (P) of 5 N, just-contact (P = 0 N) and the gap of 0.1 mm. The gap condition is tried far considering the influence of simultaneous impacting and sliding on wear. Results show that the wear volume increases in the order of the gap, the just-contact and the 5 N conditions. This is explained from the contact geometry of the spring, which is convex of smooth contour. The contact shear force is regarded smaller in the case of the gap existence compared with the other conditions. Wear mechanism is considered from SEM observation of the worn surface. The variation of the normal contact traction is analysed using the finite element analysis to estimate the slip displacement range on the contact with consulting the fretting map previously obtained.

• Journal of The Korea Institute of Healthcare Architecture
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• v.19 no.4
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• pp.47-60
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• 2013

Purpose: This study examines construction core plans for the users of vertical-typed general hospitals to effectivly use the flow line. Methods: The study sampled representative 9 hospitals, calculated the depth value through Convex Map of Space Syntax and Justified Graph according to the determination of form of construction cire, and analyzed its functional connectivity. Results: The analysis of the connectivity between operation core part and emergency part of core space with high importance in the hospitals showed that the types of hospital and hospital have the lowest depth value in the spatial phase diagram, where central treatment part and outpatient part are arranged well vertically. Elevators for patients at these hospitals are close to operation and emergency parts actually separated from the elevators for passengers. For shortening of flow line of patients and private movement environment, however, it is desirable to arrange the elevators for patients to be adjacent to the operation parts and to arrange the emergent patient entrances more effectively to separate them from the flow line of visitors and guardians. Implications: Consideration should be taken into account for the effective flow line design. This study hopefully may serve as a stepping stone for the standard design of horizontal/vertical flow line.

• Architectural research
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• v.17 no.4
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• pp.117-126
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• 2015

University residence halls have become one of the most important issues for students when selecting their academic institutions. However, in South Korea, while universities maintain technologically up-to-date facilities, when it comes to safety or security, the management is unsatisfactory. As a result, the number of violent crime has been increasing. However, there are few researches in terms of practical validity of CPTED Guidelines even though a myriad of researchers study about CPTED Guidelines. Therefore, this study endeavours to investigate the validity of theoretical CPTED Guidelines that to what extent it might be adopted for design process. As a methodology, Space Syntax Convex map and Visibility Graph Analysis (VGA) are chosen. As a result, since the types of space which have a high level of Space Syntax Index are analogous with space treated on CPTED Guidelines, it roughly shows that the theoretical CPTED Guidelines could be adopted in practical architectural design process. Furthermore, it reveals that there is a close relationship between detail design guide stated in CPTED Guidelines and the result of VGA. That is, through the analysis, it is proved that the validity of CPTED Guidelines is quite enough to be adopted in practical design process.

• Journal of the Korean Mathematical Society
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• v.45 no.5
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• pp.1393-1404
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• 2008

Let K be a nonempty closed convex subset of a Banach space E. Suppose $\{T_{n}\}$ (n = 1,2,...) is a uniformly asymptotically regular sequence of nonexpansive mappings from K to K such that ${\cap}_{n=1}^{\infty}$ F$\(T_n){\neq}{\phi}$. For $x_0{\in}K$, define $x_{n+1}={\lambda}_{n+1}x_{n}+(1-{\lambda}_{n+1})T_{n+1}x_{n},n{\geq}0$. If ${\lambda}_n{\subset}[0,1]$ satisfies $lim_{n{\rightarrow}{\infty}}{\lambda}_n=0$, we proved that $\{x_n\}$ weakly converges to some $z{\in}F\;as\;n{\rightarrow}{\infty}$ in the framework of reflexive Banach space E which satisfies the Opial's condition or has $Fr{\acute{e}}chet$ differentiable norm or its dual $E^*$ has the Kadec-Klee property. We also obtain that $\{x_n\}$ strongly converges to some $z{\in}F$ in Banach space E if K is a compact subset of E or there exists one map $T{\in}\{T_{n};n=1,2,...\}$ satisfy some compact conditions such as T is semi compact or satisfy Condition A or $lim_{n{\rightarrow}{\infty}}d(x_{n},F(T))=0$ and so on.

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.172-179
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• 2017

The regional trauma center should be a trauma treatment center equipped with facilities, equipments, and manpower capable of providing optimal treatment from emergency surgery to a severely traumatized patient upon arrival at the hospital. In order to establish a medical system for effective severe diseases, it is necessary to prepare architectural planning guidelines for the regional trauma centers. This study analyzes the connectivity, control, integration, and mean depth of current trauma centers using the convex map of space syntax, And to provide basic data for building for more efficient regional trauma center. The major areas that must be included in the regional trauma center are trauma resuscitation room, trauma operating room, trauma intensive care unit, and trauma general ward. It is necessary to carry out the architectural planning to increase the interconnection of the four areas. Also, the elevator plan for trauma patients should be emphasized. In addition, a regional trauma center should be separated from the existing facility for independent operation. According to the case analysis of the space configuration of the regional trauma center, the location of the operating room is most important considering the connection with each department of the hospital and the treatment flow of the severe trauma patients.

• Journal of KIISE:Software and Applications
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• v.26 no.2
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• pp.273-283
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• 1999

래스터 지도에서 직선 또는 곡선과 중첩되어 있는 경우의 문자는 추출하기가 쉽지 않다. 따라서 본 논문에서는 고립되어 있는 문자뿐만 아니라 문자이외의 요소와 중첩되어 있는 문자도 효과적으로 추출할수 있는 분할 정복(divide and conquer) 개념에 기반한 문자 추출방법을 제시한다. 이를 위해 먼저 이미지의 연결 요소로부터 볼록다각형(convex hull)을 생성한다. 그리고 이 다각형이 충분한게 문자영역만을 포함할때가지 볼록 다각형을 이등분하면서 가장 긴 선분(투사 선분)을 기준으로 두 영역으로 분할한다. 다음으로 문자를 추출하기 위해서 이 선분을 기준으로 연결 요소상의 픽셀의 밀집도를 계산하는 알고리즘(프로파일링)을 적용한다. 또한 지도상에서 추출된 개별적인 문자들을 의미있는 단어들로 묶기(grouping)한 새로운 알고리즘을 소개한다. 특히 지도상에 나타나는 문자의 종류는 매우 다양하고 또한 이 문자들이 놓여있는 방향 역시 일정하지 않기 때문에 이러한 단어를 찾는 kd법은 쉽지 않다. 이를 위해 본 논문에서는 3차원 인접 그래프(3-D neighborhood graph)G를 소개한다. 이 그래프 G에서 각 노드는 하나의 분리된 문자를 나타내며 자신의 크기와 위치에 따라서 3차원 공간상에서 위치하게된다. 따라서, 크기가 큰 (작은)문자들은 보다 큰 (작은) z값을 가지고 되며 이 그래프 G에서 서로 인접한 노드들을 연결함으로써 지도상에 존재하는 서로 다른 종류의 문자 스트링을 추출할수 있다. 실험결과는 서로 다른 지도 이미지에 대해서 약 95% 이상의 단어 추출율을 보여준다.

• The Pure and Applied Mathematics
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• v.30 no.2
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• pp.109-129
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• 2023

In this paper, we introduce a second order linear differential operator ^T□: C^∞ (M) → C^∞ (M) as a natural generalization of Cheng-Yau operator, [8], where T is a (1, 1)-tensor on Riemannian manifold (M, h), and then we show on compact Riemannian manifolds, divT = divT^t, and if divT = 0, and f be a smooth function on M, the condition ^T□ f = 0 implies that f is constant. Hereafter, we introduce T-energy functionals and by deriving variations of these functionals, we define T-harmonic maps between Riemannian manifolds, which is a generalization of L_k-harmonic maps introduced in [3]. Also we have studied fT-harmonic maps for conformal immersions and as application of it, we consider fL_k-harmonic hypersurfaces in space forms, and after that we classify complete fL₁-harmonic surfaces, some fL_k-harmonic isoparametric hypersurfaces, fL_k-harmonic weakly convex hypersurfaces, and we show that there exists no compact fL_k-harmonic hypersurface either in the Euclidean space or in the hyperbolic space or in the Euclidean hemisphere. As well, some properties and examples of these definitions are given.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.64-72
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• 2009

The method to generate a digital elevation model(DEM) from contour lines causes a problem in which the low relief landform cannot be clearly presented due to the fact that it is significantly influenced by the expression of micro landform elements according to the interval of contours. Thus, this study attempts to develop a landcover burning method that recovers the micro relief landform of the DEM, which applies buffering and map algebra methods by inputting the elevation information to the landcover. In the recovering process of the micro landform, the DEM was recovered using the buffering method and elevation information through the map algebra for the landcover element for the micro landform among the primary DEM generation, making landcover map, and landcover elements. The recovering of the micro landform was applied based on stream landforms. The recovering of landforms using the buffering method was performed for the bar, which is a polygonal element, and wetland according to the properties of concave/convex through generating contours with a uniform interval in which the elevation information applied to the recovered landform. In the case of the linear elements, such as bank, road, waterway, and tributary, the landform can be recovered by using the elevation information through applying a map algebra function. Because the polygonal elements, such as stream channel, river terrace, and artificial objects (farmlands) are determined as a flat property, these are recovered by inputting constant elevation values. The results of this study were compared and analyzed for the degree of landform expression between the original DEM and the recovered DEM. In the results of the analysis, the DEM produced by using the conventional method showed few expressions in micro landform elements. The method developed in this study well described wetland, bar, landform around rivers, farmland, bank, river terrace, and artificial objects. It can be expected that the results of this study contribute to the classification and analysis of micro landforms, plain and the ecology and environment study that requires the recovering of micro landforms around streams and rivers.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.665-675
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• 2018

The purpose of this study was to identify the characteristics of the home range and habitat use of Rhinolophus ferrumequinum individuals that inhabit urban areas. The bats were tracked using GPS tags. For analysis of the home rage, Minimum Convex Polygon (MCP) and Kernel Home Range (KHR) methods were used. The landscape types of all positional information were analyzed using ArcGIS 9.3.1 (ESRI Inc.). The average home range of 16 R. ferrumequinum individuals was $68.63{\pm}25.23ha$, and the size of the overall home range for the females ($85.49{\pm}25.40ha$) was larger than that for the males ($51.76{\pm}8.30ha$). The highest average home range for the males was found in August ($61.21{\pm}0.01ha$), whereas that for the females was found in September ($112.27{\pm}5.94ha$). The size of 50% KHR ranged from a minimum of 13.26 ha to a maximum of 31.00 for the males and a minimum of 8.02 ha to a maxinum of 42.16 ha for the females, showing no significant differences between the two sexes. In addition, males and females showed no differences in the size of 50% KHR in the monthly comparisons. However, the females showed differences in the size of their core area between periods before and after giving birth. The comparisons between 100% MCP and 50% KHR showed that the types of habitats used by R. ferrumequinum were mostly forest areas, including some farmlands. In addition, comparisons with a land cover map showed that the proportion of broad-leaved forests was the highest, followed by that of mixed forests.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.939-955
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• 2010

With the progress of IT and mobile positioning technologies, various types of location-based services (LBS) have been proposed and implemented. Finding a shortest path between two nodes is one of the most fundamental tasks in many LBS related applications. So far, there have been many research efforts on the shortest path finding problem. For instance, $A^*$ algorithm estimates neighboring nodes using a heuristic function and selects minimum cost node as the closest one to the destination. Pruning method, which is known to outperform the A* algorithm, improves its routing performance by avoiding unnecessary exploration in the search space. For pruning, shortest paths for all node pairs in a map need to be pre-computed, from which a shortest path container is generated for each edge. The container for an edge consists of all the destination nodes whose shortest path passes through the edge and possibly some unnecessary nodes. These containers are used during routing to prune unnecessary node visits. However, this method shows poor performance as the number of unnecessary nodes included in the container increases. In this paper, we focus on this problem and propose a new border line-based pruning scheme for path routing which can reduce the number of unnecessary node visits significantly. Through extensive experiments on randomly-generated, various complexity of maps, we empirically find out optimal number of border lines for clipping containers and compare its performance with other methods.