• 한국경제지리학회지
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• 제15권1호
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• pp.116-130
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• 2012

성장동력산업의 육성 정책에 따라 부가가치가 높은 산업을 광역 경제권단위에서 육성하는 정책이 진행되고 있다. 이 분석의 목적은 창조산업의 대표적 분야인 디자인산업을 발전시키고 있는 지식을 기반으로 한 네트워크의 공간적 특성과 기관별 네트워크 구조를 도출하고, 2000년에서 2010년까지의 시간적 변화에 초점을 두어 분석함으로서 앞으로 나아가야 할 방안을 모색해 보고자한다. 먼저 전국 디자인산업의 변화와 시도별 광역별 성장을 살펴보고 심층인터뷰를 실시하여 기관별 네트워크 현황을 파악하였다. 이를 기반으로 디자인산업과 관계된 공동연구 데이터를 가공하여 구조적, 공간적, 시간적인 측면을 고려하여 종합적인 판단으로 공간적 특성과 기관별 네트워크 구조의 변화에 대해 분석하였다. 또한 그룹분석에 활용되는 지표를 이용하여 네트워크의 밀도, 링크수, 집중도를 기준으로 다른 그룹과 상대적으로 변화하는 하는 과정을 비교 분석하였다.

• 사물인터넷융복합논문지
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• 제9권6호
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• pp.111-117
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• 2023

시간-공간적 의존성을 모두 고려하는 방법으로 그래프 신경망과 순환 신경망을 함께 사용하는 연구가 많이 진행되고 있다. 특히 그래프 신경망은 새롭게 활발히 연구되고 있는 분야이다. 서울시 자전거 대여 서비스(일명 따릉이)는 서울시 곳곳에 대여소를 갖추고 있으며 각 대여소에서 대여 정보가 충실하게 기록되어 있는 시계열 자료이다. 각 대여소의 대여 정보는 시간에 따른 주기성을 보이는 시간적인 특성을 갖추고 있으며, 지역적인 특성도 대여 현황에 큰 영향을 미치리라고 생각된다. 지역적 상관관계는 그래프 신경망을 이용하여 잘 이해할 수 있다. 이 연구에서는 서울시 자전거 대여 서비스의 시계열 데이터를 그래프로 재구성하고 그래프 신경망과 순차 신경망을 결합한 대여 예측 모델을 개발하였다. 시간에 따른 주기성과 같은 시간 특성과 지역적인 특성 및 각 대여소의 중요도 정도를 고려하였다. 대여소의 중요도 정도는 대여량 예측에 중요한 인자로 사용됨을 확인하였다.

• Nuclear Engineering and Technology
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• 제56권9호
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• pp.3571-3584
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• 2024

Reactor core transient calculation is very important for the reactor safety analysis, in which the kernel is neutron kinetics calculation by simulating the variation of neutron density or thermal power over time. Compared with the point kinetics method, the time-space neutron kinetics calculation can provide accurate variation of neutron density in both space and time domain. But it consumes a lot of resources. It is necessary to develop a surrogate model that can quickly obtain the temporal and spatial variation information of neutron density or power with acceptable calculation accuracy. This paper uses the time-varying characteristics of power to construct a time function, parameterizes the time-varying characteristics which contains the information about the spatial change of power. Thereby, the amount of targets to predict in the space domain is compressed. A surrogate method using the machine learning is proposed in this paper. In the construction of a neural network, the input is processed by a convolutional layer, followed by a fully connected layer or a deconvolution layer. For the problem of time sequence disturbance, a structure combining convolutional neural network and recurrent neural network is used. It is verified in the tests of a series of 1D, 2D and 3D reactor models. The predicted values obtained using the constructed neural network models in these tests are in good agreement with the reference values, showing the powerful potential of the surrogate models.

• 대기
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• 제20권3호
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• pp.343-353
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• 2010

A regional wind network with complex surface conditions must be designed with sufficient space and time resolution to resolve the local circulations. In this study, the spatial variations of the wind field observed in the Seoul and Jeju regional networks were evaluated in terms of annual, seasons, and months to assess the spatial homogeneity of wind fields within the regional networks. The coherency of the wind field as a function of separation distance between stations indicated that significant coherency was sometimes not captured by the network, as inferred by low correlations between adjacent stations. A meso-velocity scale was defined in terms of the spatial variability of the wind within the network. This problem is predictably most significant with weak winds, dull prevailing wind, clear skies and significant topography. The relatively small correlations between stations imply that the wind at a given point cannot be estimated by interpolating winds from the nearest stations. For the Seoul and Jeju regional network, the meso-velocity scale has typically a same order of magnitude as the speed of the network averaged wind, revealing the large spatial variability of the Jeju network station imply topography and weather. Significant scatter in the relationship between spatial variability of the wind field and the wind speed is thought to be related to thermally-generated flows. The magnitude of the mesovelocity scale was significantly different along separation distance between stations, wind speed, intensity of prevailing wind, clear and cloudy conditions, topography. Resultant wind vectors indicate much different flow patterns along condition of contributing factors. As a result, the careful considerations on contributing factors such as prevailing wind in season, weather, and complex surface conditions with topography and land/sea contrast are required to assess the spatial variations of wind field on a regional network. The results in the spatial variation from the mesovelocity scale are useful to represent the characteristics of regional wind speed including lower surface conditions over the grid scale of large scale atmospheric model.

• 한국실내디자인학회논문집
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• 제22권6호
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• pp.79-87
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• 2013

The purpose of this study clarifies an expression characteristic of the phenomenal space. The architecture is an interface between human and nature. Nature presents herself as phenomena. Thus, the phenomenal space should be approached as the essence of architecture that is to accommodate nature. Phenomenon is related to everyday life and shares flow naturally within it. The phenomenon and everyday life form a relationship through the mediating elements that are time, place, and image. If these mediating elements are developed as spatialized elements, time becomes the converse, place becomes the overlap, and shape becomes the revealing. Also, spatial components that are substituted with these elements are void/solid, form, and materials. The relational characteristics of phenomenal space can be identified through these, and such characteristics are one-ness, continuity, and coincidence of opposites. Phenomenal space is expressed with spatial tones and accepted as spatial atmospheres. For the analysis, 15 works of swiss architects were selected to which spatial elements were applied. And It were composed that analysis by arranging these components as the relational network found that expression characteristics. Trough the analysis, It was found that expression characteristics of phenomenal space of the architecture of Swiss architects were prototypicality, primitiveness, and originality. As a results, It is considered that the role of the space that contains the value of everyday life, the value of the phenomenon is necessary.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
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• pp.149-154
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• 2008

Housing may be construed as a place where people are settled for living, namely, family members make a home and a place, where all human living is grounded. Also, the common housing type of a certain time reflects the living of the time. With the advent of the lifestyle of a new social class attaching importance to the multi-purpose of act and function, complexity, and convenience from the 21st century, people required a housing space where work, rest, living, and recreational activities are overlapped, fused, and integrated on the axes of space and time. In addition, along with the expansion of network and digital convergence from a social perspective, the appearance of new businesses, products, and business models affects the life and culture of consumers, which leads to the destruction of the borders and spheres throughout society. Thus, the study analyzed the characteristics of the spatial organizational type of collective housing in Japanese cities since the 1990s and withdrew the organizational type of each room in order to identify the uniquely differentiated characteristics of Japanese housing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.561-565
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• 1994

An automatic measuring system of three dimensional shape by a projection method with grating pattern from in optical spatial modulator has been developed. The characteristics of the system were studied. This system is composed of a projector, an optical spatial modulator, a CCD camera, and computer. A liquid crystal is used as the optical spatial modulator. The grating patterns that ire projected on the surface of the object are controlled by the computer connected with the optical spatial modulator. The projector patterns are measured by the CCD camera. The data are transferred to the computer. After a transformation into line data, the data are analyzed to obtain the coordinate of the surface of the object. This system has advantages as follows. (1) It is possible to capture the surface topography without any contact. (2) The time required for the measurements is shorter than the light-section method. (3) An optical spatial modulator using a liquid crystal is possible to control the grating patterns accurately by a computer. Surfaces of a plate and a cylinder were measured. The threshold level had an influence on the measurement. It was shown that this system has adequae accuracy in the measurements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.114-130
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• 2021

With the drastic growth of Information and Communication Technology (ICT) industry, global energy consumption is exponentially increased by mobile communications. The huge energy consumption and increased environmental awareness have triggered great interests on the research of dynamic distribution of cell user and traffic, and then designing the energy efficient cellular network. In this paper, we explore the temporal and spatial characteristics of human mobility and traffic distribution using real data set. The analysis results of cell traffic illustrate the tidal effect in temporal and spatial dimensions and obvious periodic characteristics which can be used to design Base Station (BS) dynamic with sleeping or shut-down strategy. At the same time, we designed a new Cell Zooming and BS cooperation mode. Through simulation experiments, we found that running in this mode can save about 35% of energy consumption and guarantee the required quality of service.

• 대한교통학회지
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• 제26권4호
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• pp.185-194
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• 2008

일반적인 도로사업의 수요예측 과정에서 해당도로구간을 어떤 기종점간을 통행하는 차량들이 얼마만큼 이용하는지 알기 위해서 Select Link Analysis가 주로 이용된다. 하지만 이런 결과에 대한 분석방법으로는 현재 Select Link Analysis만이 거의 유일하게 이용되고 있고, 이 외의 분석방법에 대한 연구는 전무한 실정이다. 따라서 전문가들은 각 기종점에서 해당 도로를 이용하여 통행하는 통행량을 알아보는 객관적 자료로서 이 분석방법에 거의 전적으로 의존하고 있다. 본 연구는 Select Link Analysis와는 다른 접근방법을 통해 신설 도로에 대한 각 기종점별 이용 정도를 예측할 수 있는 모형의 개발을 목적으로 하며, 그 접근방법으로는 Network의 시공간적 특성을 이용하였다. 또한 개발된 모형의 유의성 검증을 위해 모형에 의한 결과에 대한 비교지표로서 Select Link Analysis 결과를 이용하였다. 개발된 모형은 지역간 통행과 도시 내부 통행 두 가지의 경우에 대한 사례분석을 통해 그 유의성을 검증하였고, 그 결과 비교지표와의 상관계수가 0.82 정도로 비교적 높게 나타나 본 연구에서 제시한 개념이 유의성을 가짐을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.872-885
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• 2015

The rapid increase of smart mobile devices and mobile applications has led to explosive growth of data traffic in cellular network. Offloading data traffic becomes one of the most urgent technical problems. Recent work has proposed to exploit opportunistic communications to offload cellular traffic for mobile data dissemination services, especially for accepting large delayed data. The basic idea is to deliver the data to only part of subscribers (called target-nodes) via the cellular network, and allow target-nodes to disseminate the data through opportunistic communications. Human mobility shows temporal and spatial characteristics and predictability, which can be used as effective guidance efficient opportunistic communication. Therefore, based on the regularity of human mobility we propose NodeRank algorithm which uses the encounter characteristics between nodes to choose target nodes. Different from the existing work which only using encounter frequency, NodeRank algorithm combined the contact time and inter-contact time meanwhile to ensure integrity and availability of message delivery. The simulation results based on real-world mobility traces show the performance advantages of NodeRank in offloading efficiency and network redundant copies.