• 한국지리정보학회지
• /
• 제24권2호
• /
• pp.91-101
• /
• 2021

본 연구는 기존 민북마을의 사회공간적 분포 및 변화 등 거시적인 측면에서의 연구를 민통선 변화에 따른 민북마을의 시공간적 분석을 통해 보다 구체적으로 연구하고자 하였다. 이를 위해 정전협정문 제2권 지도와 구글어스, 수치지적도, 행정구역도 등을 공간 자료로 활용하고, 통계연보와 국방부 및 철원군 고시 자료, 토지이용규제시스템, 지적도 속성정보 등을 정리하여 속성자료로 구축하여 민간인통제선의 조정에 따른 민북마을의 변화를 시계열로 공간분석을 실시하였다. 군사시설보호법 제정 이후 민간인통제선이 그려진 1976년 통계연보를 기준으로 20년 단위로 분석하였다. 그 결과 1975년부터 2015년까지 철원의 민간인통제구역 총면적은 105.8km²가 감소하였고, 민북마을 총 14개 중 9개 마을이 해제되고 6개 마을만 존재하게 되었다. 미입주 마을은 기존 조사되거나 통계상의 마을 보다 10개 적은 14개 마을로 분석되었다. 민통선 북상은 민북마을의 고유특성을 사라지게도 할 수 있지만 현재 주민들의 삶과 밀접한 관계가 있는 만큼 신중하게 이루어져야 하며, 마을의 지속가능한 발전과 보전 차원에서의 정책이 수립되어야 한다. 본 연구는 민북지역과 민북마을의 기초가 되는 시·공간 분석을 실시한 데에 의의를 가지며 후속 분석 연구에 필요한 기초자료로서 활용할 수 있을 것이다.

• Architectural research
• /
• 제15권4호
• /
• pp.207-214
• /
• 2013

A form-finding technique is proposed for three-dimensional spatial structures. Two-step discrete finite element (FE) mesh generator based on computer aided geometric design (CAGD) is introduced and used to control the shape of three-dimensional spatial structures. Mathematical programming technique is adopted to search new forms (or shapes) of spatial structures. For this purpose, the strain energy is introduced as the objective function to be minimized and the initial volume (or the initial weight) is considered as constraint function. Numerical examples are carried out to test the capability of the proposed form-finding techniques and provided as benchmark tests.

• 한국공간구조학회논문집
• /
• 제12권4호
• /
• pp.99-108
• /
• 2012

In recently, sky-bridge are often applied to high-rised adjacent buildings for pedestrian bridge. the seisnic response control of adjacent buildings have been studied and magneto-rheological(MR) fluid dampers have been applied to seismic response control. In this study, vibration control effect of the MR damper connected adjacent buildings has been investigated. Adjacent building structures with different natural frequencies were used as example structures. Two typed of control methods, displacement based or velocity based, are applied to determinate control force of MR damper. In this numerical analysis, it has been shown that displacement-based control algorithm is more effective than velocity-based control algorithm for seismic response control of adjacent buildings. And, when displacement-based control method is applied to control of adjacent buildings, the control of building occurred large displacement is more efficient in reducing the seismic response.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.126-132
• /
• 2006

In this paper, we aim to control the sound and vibration spatially, so that a desired physical variable is enhanced within a zone we select. This is somewhat analogous to have manipulators that can draw wave shape in any place we want. Brightness and contrast control have shown that such a manipulation is possible by controlling multiple sources[J.-W. Choi and Y.-H. Kim, J. Acoust. Soc. Am. 111(4), 2002]. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to manipulate spatial distribution of sound by making two different kinds of zone ? the bright and dark zone- at the same time. The primary focus of this study is to unit the theoretical formulation of the brightness and contrast control and to find a link between these methods, as well as its relation to other conventional techniques. It is also shown that we can generate various shape of wave field by transforming the domain we consider.

• Nuclear Engineering and Technology
• /
• 제43권6호
• /
• pp.531-546
• /
• 2011

The backward differentiation formula (BDF) method is applied to a three-dimensional reactor kinetics calculation for efficient yet accurate transient analysis with adaptive time step control. The coarse mesh finite difference (CMFD) formulation is used for an efficient implementation of the BDF method that does not require excessive memory to store old information from previous time steps. An iterative scheme to update the nodal coupling coefficients through higher order local nodal solutions is established in order to make it possible to store only node average fluxes of the previous five time points. An adaptive time step control method is derived using two order solutions, the fifth and the fourth order BDF solutions, which provide an estimate of the solution error at the current time point. The performance of the BDF- and CMFD-based spatial kinetics calculation and the adaptive time step control scheme is examined with the NEACRP control rod ejection and rod withdrawal benchmark problems. The accuracy is first assessed by comparing the BDF-based results with those of the Crank-Nicholson method with an exponential transform. The effectiveness of the adaptive time step control is then assessed in terms of the possible computing time reduction in producing sufficiently accurate solutions that meet the desired solution fidelity.

• 한국공간구조학회지
• /
• 제18권1호
• /
• pp.18-21
• /
• 2018

• 한국공간구조학회논문집
• /
• 제20권3호
• /
• pp.107-116
• /
• 2020

In this paper, the displacement response to seismic loads was analyzed after installing TMD in spatial structures and high-rise buildings. In the case of a spatial structures, since it exhibits complex dynamic behavior under the influence of various vibration modes, it is not possible to effectively control the seismic response by installing only one TMD, unlike ordinary structures. Therefore, after installing eight TMDs in the structure, the correlation between displacement response and mass ratio was examined while changing the mass. The TMD must be designed to have the same frequency as the structure frequency so that the maximum response reduction effect can be exhibited. It can be confirmed that the most important variable is to select the optimal TMD mass in order to install the TMD on the structure and secure excellent control performance against the earthquake load. As a result of analyzing the TMD mass ratio, in the case of high-rise buildings, a mass ratio of 0.4% to 0.6% is preferable. In spatial structures, it is desirable to select a mass ratio of 0.1% to 0.2%. Because this study is based on the theoretical study based on numerical analysis, in order to design a TMD for a real structure, it is necessary to select within a range that does not affect the safety of the structure.

• 한국공간구조학회논문집
• /
• 제19권1호
• /
• pp.75-82
• /
• 2019

In the precedent study, the retractable-roof spatial structure was selected as the analytical model and a tuned mass damper (TMD) was installed to control the dynamic response for the earthquake loads. Also, it is analyzed that the installation location of TMD in the analytical model and the optimal number of installations. A single TMD mass installed in the analytical model was set up 1% of the mass of the whole structure, and the optimum installation location was derived according to the number of change. As a result, it was verified that most effective to install eight TMDs regardless of opening or closing. Thus, in this study, eight TMDs were installed in the retractable-roof spatial structure and the optimum mass ratio was inquired while reducing a single TMD. In addition, the optimum mass distribution ratio was identified by redistributing the TMD masses differently depending on the installation position, using the mass ratio of vibration control being the most effective for seismic load. From the analysis results, as it is possible to confirm the optimum mass distribution ratio according to the optimum mass ratio and installation location of the TMD in the the retractable-roof spatial structure, it can be used as a reference in the TMD design for large space structure.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제17권2호
• /
• pp.99-118
• /
• 2013

The present study focuses on the contribution of a teaching unit to the development of spatial ability of third graders in general and from a gender point of view in particular. The research population consisted of seventy-four pupils: thirty-seven pupils in the experimental group who attended the teaching unit and thirty-seven pupils in the control group. The spatial ability of all the pupils was examined by means of common tests which checked cognitive capabilities of spatial ability. The research findings illustrate an improvement in the spatial ability of the experimental group pupils following the participation in the teaching unit. Moreover, regarding the gender aspect, the findings show that there was no significant differentiation between the spatial ability of third grade boys and the spatial ability of girls of the same age group.

• 대한가정학회지
• /
• 제42권10호
• /
• pp.79-89
• /
• 2004

This study was designed to investigated children's spatial cognitive skills as based on their practice with computer games. The sixty children were divided into 3 groups there were twenty children in experimental group 1 (the geometric game experimental group), twenty children in experimental group 2 (the arcade game experimental group), and twenty children in the control group. The sSpatial cognitive skills of the children were assessed according to by visual speed, mental rotation, and spatial visualization tasks. The rResults showed that computer game practice enhanced the children's spatial skills (visual speed, mental rotation and, spatial visualization). The c Children's mental rotation and spatial visualization showed a significant difference with the type of computer game.