• Journal of KIISE:Databases
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• v.33 no.6
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• pp.631-643
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• 2006

Moving objects in a mobile environment to change their position based on the change of time require a query with their position as a basis. Efficient Regional Decision for Continuous Skyline Queries requires objectively pre-calculating the OSR(Optimal Skyline Region) regardless of the speed and direction of the moving objects. It proposes techniques to reduce the frequency of continuous queries by choosing a VCircle(Validity Circle) as safe location which has radius of the distance to the closest region with position on the moving object at center. But, a VCircle's area varies based on the Moving object's position from first marked time of continuous query. Therefore, the frequency of its continuous query is variable and also when the object moves inside of OSR, query can re-occur frequently In this paper, we suggest a technique of selecting an IVCircle(Interior Validity Circle) in a Skyline Region as the static Safe Region using the characteristics of the OSR. An Interior IVCircle can be calculated in advance when the OSR is decided. Our experiment shows that the frequency of using IVcircle as safe region reduced than that of using VCircle as safe region by 52.55%.

• KOREAN POULTRY JOURNAL
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• v.8 no.3 s.77
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• pp.61-63
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• 1976

• Journal of Korean Society of Rural Planning
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• v.13 no.3
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• pp.51-60
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• 2007

In terms of the indicators by the type for the landscape plan per the district nit, geographic ecology indicators were the items such as water, water system, topography and climate, while biological ecology indicators were the items such as green zone size, green zone ratio, biotope size and distribution. The sensory and visual indicators were the items such as view point, view axis and skyline, and the accessibility indicator items for the green zone were applied as the socially used indicators. As for the application method according to each indicator, the water or water system was expressed and applied through the slopes and elevation topographic analysis drawings, the climate was expressed and applied through the main direction of the wind and the cold wind pass alley drawings. As for the green zone size and green zone ratio, the land use according to the status and housing area development was compared to present the measured figures. In case of the biotop size and the distribution item, the range was limited to the preparation of the biotope drawings for the focused preservation. As for the view point and view axis, the view point was selected according to the view point to prepare and apply the view analysis drawing in which the view area to be preserved is analyzed. As for the skyline, its landscape photo was composed with the housing area shape, and then skyline photography was applied as the plan in order to propose and consider the various shapes of the skyline. As for the accessibility to the peen zone, the network drawing was drawn to reflect the users' accessibility and continuity of the green zone formed and preserved according to the land use plan and then the drawing was prepared and proposed as the applicable plan.

• Atmosphere
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• v.29 no.5
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• pp.537-550
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• 2019

To analyze the observation environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we analyzed the skyline, Sky View Factor (SVF), and solar radiation due to the surrounding topography and artificial structures using a Digital Elevation Model (DEM), 3D camera, and solar radiation model. Solar energy shielding of 25 km around the station was analyzed using 10 m resolution DEM data and the skyline elevation and SVF were analyzed by the surrounding environment using the image captured by the 3D camera. The solar radiation model was used to assess the contribution of the environment to solar radiation. Because the skyline elevation retrieved from the DEM is different from the actual environment, it is compared with the results obtained from the 3D camera. From the skyline and SVF calculations, it was observed that some stations were shielded by the surrounding environment at sunrise and sunset. The topographic effect of 3D camera is therefore more than 20 times higher than that of DEM throughout the year for monthly accumulated solar radiation. Due to relatively low solar radiation in winter, the solar radiation shielding is large in winter. Also, for the annual accumulated solar radiation, the difference of the global solar radiation calculated using the 3D camera was 176.70 MJ (solar radiation with 7 days; suppose daily accumulated solar radiation 26 MJ) on an average and a maximum of 439.90 MJ (solar radiation with 17.5 days).

• The KIPS Transactions:PartD
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• v.17D no.4
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• pp.245-252
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• 2010

In this paper, we propose an effective filtering method for skyline queries in mobile ad hoc networks (MANETs). Most existing researches assume that data is uniformly distributed. Under these assumptions, the previous works focus on optimizing the energy consumption due to the limited battery power. However, in practice, data distribution is skewed in a specific region. In order to reduce the energy consumption, we propose a new filtering method considering the data distribution. We verify the performance of the proposed method through a comparative experiment with an existing method. The results of the experiment confirm that the proposed method reduces the communication overhead and execution time compared to an existing method.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.17-20
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• 2011

최근 위치 기반 서비스(location-based service)가 발달함에 따라 이동 객체에 대한 다양한 질의 처리 기법들이 연구되고 있다. 그 중에서 다중 속성을 고려할 수 있는 스카이라인 (skyline)과 스카이라인을 응용한 기법으로 리버스 스카이라인 (reverse skyline) 이 연구되었다. 하지만 기존에 연구된 리버스 스카이라인 질의 처리 기법은 객체들의 이동성은 고려되지 많은 연구이다. 본 논문에서는 질의 객체가 이동하는 환경을 고려한 연속적인 리버스 스카이라인 질의 처리 기법을 제안한다. 제안하는 기법은 가지치기(pruning) 기법을 통해 질의에 영향을 주지 않는 객체들을 제외하고, 남은 후보 객체들을 대상으로 모니터링을 수행하여 연속 리버스 스카이라인을 점진적으로 처리한다. 성능평가를 통해 제안하는 기법이 기존 기법에 비해 최대 10배 우수한 성능을 모임을 확인하였다.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.3
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• pp.76-90
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• 2004

The purpose of this study is to extract landscape design elements regulation of the District Unit Plan(DUP) in new town areas, and to find out characteristics in terms of urban design elements in comparison with the psychological and physical aspects. For this purpose, we reviewed urban design elements and design elements in terms of the landscape by DUP and analyzed the activation of landscape on the selected case-area by interviewing experts such as planners, public officials, and professors in the department of urban planning and landscape, as well as the university students. The analysis framework for the case-study consists of 4 components: the section of region, street, building, open space, etc. The new development areas in Daejeon Metropolitan City was chosen as the case study area, because they have been developed by DUP regulations. As a result of this study, we can extract characteristics of landscape. The results indicate that `skyline design',`view corridor design',`landscape design',`street furniture design' and `building design(form, height, color, and elevation)' are the key planning and design factors influencing differences in the landscape preference. This research identifies that there are no detailed planning and design guidelines adopted within the four case study areas in Daejeon for regulating the characteristics of skyline, planting and street furniture while detailed guidelines established for density, building height and site layout. Considering their significant correlation with the level of landscape preference, this study suggests that detailed planning and design guidelines for the characteristics of skyline, rooftop and streetscape should be established in future DUP.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.34-43
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• 1993

In this paper, the characteristics of cable logging operations are discussed from a standpoint of mechanics. An example of standing skyline operations is used to illustrate the mechanical principles. Using force and moment boundary conditions, the maximum allowable payload was formulated as a function of slope profile, system geometry and operation options. This formulation includes fundamental equations for log drag and single segment mechanics. The catenary link model is the basic assumption in simulating cable segment stretches. In order to demonstrate the solution procedures of the formulation, a computer model was developed. The model uses Secant algorithm to determine the solution of the complex nonlinear equation set. Finally, the computer model was demonstrated using a hypothetical data set.

• Korean Architects
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• s.547
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• pp.26-27
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• 2014

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.387-394
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• 2004

In the structural analysis procedure using finite element technique, the performance of a linear equation solver is critical because the linear equation solving part spends most of the computing time for finite element analysis codes. However, most of researchers are still using inefficient profile-based direct solvers such as the band solver or the skyline solver. In this research, we introduce the multifrontal solution method as an efficient direct solution method for structural analysis, and show the efficiency and performance of the multifrontal solution method by comparing the performance of our own implementation of the multifrontal method with the band solver or the skyline solver. In addition, we also compare the performance of our solver with other implementations of the multifrontal method such as WSMP and MUMPS as well as commercial structural analysis packages such as ABAQUS and NASTRAN. Through the performance test results, the usefulness and efficiency of our domain-wise multifrontal solver for structural analysis is shown.