• 한국지역지리학회지
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• 제17권4호
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• pp.432-442
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• 2011

기온, 강수와 같은 기후관측 자료들은 공간과 더불어 시간적인 변이를 동시에 나타낸다. 따라서 신뢰성 높은 시계열 분포도 작성을 위해 공간적 자기상관성만을 고려하는 기존 공간 내삽 기법에 시공간적 자기상관성 정보를 반영할 필요가 있다. 이 연구에서는 시계열 기온 분포도 제작을 위해 1개월 동안 1시간 간격으로 획득된 기온 관측소 자료를 대상으로 시공간 크리깅을 적용하였다. 우선 기온자료를 결정론적 경향 성분과 확률론적 잔차 성분으로 분해한 후에, 경향 성분 모델링 과정에 기온과 연관성이 높은 고도 자료를 부가 자료로 통합하여 지형 효과를 반영하는 경향 성분을 모델링하였다. 잔차 성분에 대한 시공간 베리오그램 모델링에는 곱-합 모델을 적용하여 시간과 공간 베리오그램의 상호 연관성을 반영하도록 하였다. 이러한 시공간 베리오그램 모델을 이용하여 시공간 정규 크리깅을 적용한 결과, 기존 공간적 자기상관성만을 고려하는 정규 크리깅과 고도 자료를 부가 자료로 이용하는 회귀분석 크리깅에 비해 상대적으로 높은 예측 능력을 보였다. 이러한 결과는 고도 자료와 더불어 시공간 자기상관성 정보의 이용이 중요함을 지시한다. 따라서 공간적으로 가용할 수 있는 자료의 수가 한계가 있지만 시계열적으로 자료 획득이 가능한 변수를 분석할 때, 시공간 크리깅이 유용한 내삽 방법론으로 적용될 수 있을 것으로 기대된다.

• 한국도서관정보학회지
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• 제23권
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• pp.363-404
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• 1995

This study is to set up a model of minimum and optimum standards for college and university library building areas in Korea. The results of this study are summarized as follows: 1. minimum standards(proposal) At first, Areas needed by factors of space component are as follows: User space --- 0.45 $m^{2}$ per student. Collection space --- 0.0107 $m^{2}$ per volume Staff space --- 10.1 $m^{2}$ per person Space attached to user, collection and staff space --- 5% of the sum of user, collection and staff areas(0.041 $m^{2}$ per student). Nonassignable space --- 25% of the sum of user, collection and staff areas (0.21 $m^{2}$ per student). Next, the formula to calculate the total area of the college and university library building is as follows: N = 0.45T $m^{2}$(a) + 0.0107V $m^{2}$(b) + 10.1S $m^{2}$(c) + 0.05(a+b+c) $m^{2}$, NS = 0.25N $m^{2}$. 2. Optimum standards(proposal) At first, Areas needed by factors of space component are as follows: User spae --- 0.64 $m^{2}$) per student. Collection space --- 0.01 $m^{2}$ per volume Staff space --- 9.7 $m^{2}$ per person Space attached to user, collection and staff space --- 5% of the sum of user, collection and staff areas(0.073 $m^{2}$ per student). Nonassignable space --- 25% of the sum of user, collection and staff areas(0.38 $m^{2}$ per student). Next, the formula to calculate the total area of the college and university library building is as follows: N = 0.64T $m^{2}$(a) + 0.01V $m^{2}$(b) + 9.7S $m^{2}$(c) + 0.05(a+b+c) $m^{2}$, NS = 0.25N $m^{2}$.

• Journal of Astronomy and Space Sciences
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• 제32권4호
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• pp.305-310
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• 2015

In this study, we examined a morningside Pi2 pulsation, with a non-substorm signature, that occurred in very quiet geomagnetic conditions (Kp = 0) at 05:38 UT on December 8, 2012, using data obtained by Van Allen Probes A and B (VAP-A and VAP-B, respectively) and at a ground station. Using 1 sec resolution vector magnetic field data, we measured the X-component of the pulsation from the Abu Simbel ground station (L = 1.07, LT = UT +2 hr, where LT represents local time) in Egypt. At the time of the Pi2 event, Abu Simbel and VAP-A (L = 3.3) were in the morning sector (07:38 LT and 07:59 MLT, respectively, where MLT represents magnetic local time), and VAP-B was in the postmidnight sector (04:18 MLT and L = 5.7). VAP-A and VAP-B observed oscillations in the compressional magnetic field component (Bz), which were in close agreement with the X-component measurements of the Pi2 pulsation that were made at Abu Simbel. The oscillations observed by the satellites and on the ground were in phase. Thus, we concluded that the observed morningside Pi2 pulsation was caused by the cavity resonance mode rather than by ionospheric current systems.

• 방송공학회논문지
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• 제15권6호
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• pp.749-756
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• 2010

신호 공간 다이버시티 기술은 차세대 모바일 방송의 핵심 전송 기술로 주목받고 있는 기술 중 하나이다. 기존의 DVB-T2에 사용되는 Cyclic Q-delay 방식을 MIMO 시스템에 사용할 경우에는 심볼 간 상호 의존성이 증가하여 수신기 복잡도가 크게 증가하는 반면, 이러한 문제를 해결하기 위해서 제안된 '성분 맞교환(Component-Swapping)' 기술을 적용할 경우 상호 의존성이 제한되어 수신기 복잡도가 크게 줄어든다. 본 논문에서는 DVB-T2 16K LDPC 부호를 적용한 경우에 제안된 '성분 맞교환' 기술을 컴퓨터 시뮬레이션을 통해서 분석하고, 기존 기술 대비 BER 성능 및 복잡도 면에서 이득을 가짐을 확인하였다.

• Journal of Information Technology Applications and Management
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• 제12권1호
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• pp.111-123
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• 2005

Many indexing methods were proposed so that process moving object efficiently. Among them, indexing methods like the 3D R-tree treat temporal and spatial domain as the same. Actually, however. both domain had better process separately because of difference in character and unit. Especially in this paper we deal with limited region such as indoor environment since spatial domain is limited but temporal domain is grown. In this paper we present a novel indexing structure, namely STS-tree(Separation of Time and Space tree). based on limited region. STS-tree is a hybrid tree structure which consists of R-tree and one-dimensional TB-tree. The R-tree component indexes static object and spatial information such as topography of the space. The TB-tree component indexes moving object and temporal information.

• 전기학회논문지P
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• 제54권4호
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• Communications for Statistical Applications and Methods
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• 제10권1호
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• pp.19-30
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• 2003

Spatiotemporal statistical models are used for analyzing space-time data in many fields, such as environmental sciences, meteorology, geology, epidemiology, forestry, hydrology, fishery, and so on. It is well known that classical spatiotemporal process modeling requires the estimation of space-time variogram or covariance functions. In practice, the estimation of such variogram or covariance functions are computationally difficult and highly sensitive to data structures. We investigate a Bayesian hierarchical model which allows the specification of a more realistic series of conditional distributions instead of computationally difficult and less realistic joint covariance functions. The spatiotemporal model investigated in this study allows both spatial component and autoregressive temporal component. These two features overcome the inability of pure time series models to adequately predict changes in trends in individual sites.

• 한국실내디자인학회논문집
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• 제21권1호
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• pp.148-158
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• 2012

The objective of this study is to find a possible application of small space utilization of GangSo Housing, so called compact-but-effective housing, through analyzing that of Japanese small housing. We analyze openness of view and flexibility of spaces divided by the physical and architectural aspects as first component and the psychological and interior space aspects as second component. The results showed that Japanese small houses have various unit plan compared to uniformity of Korean houses. Openness of view in Japanese small housing is accomplished by letting in light from the outside using position and shape of the window, looking more spacious using courtyard, void spaces, or sliding door hanging from the ceiling, and creating deception of view using floor-wall plan and appropriate materials. Flexibility of spaces is achieved by combination of first and second components, multipurpose of space and furniture, and variety of storage methods. It is necessary to improve spatial efficiency with consideration of volume-metric planing rather than flat-plane and develop various unit plans to meet residents' needs and demands on compact-but-effective houses.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.911-917
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• 2017

There are generally three folds when developing neural network classifiers. They are as follows: 1) discriminant function; 2) lots of parameters in the design of classifier; and 3) high dimensional training data. Along with this viewpoint, we propose space search optimized polynomial neural network classifier (PNNC) with the aid of data preprocessing technique and simultaneous tuning strategy, which is a balance optimization strategy used in the design of PNNC when running space search optimization. Unlike the conventional probabilistic neural network classifier, the proposed neural network classifier adopts two type of polynomials for developing discriminant functions. The overall optimization of PNNC is realized with the aid of so-called structure optimization and parameter optimization with the use of simultaneous tuning strategy. Space search optimization algorithm is considered as a optimize vehicle to help the implement both structure and parameter optimization in the construction of PNNC. Furthermore, principal component analysis and linear discriminate analysis are selected as the data preprocessing techniques for PNNC. Experimental results show that the proposed neural network classifier obtains better performance in comparison with some other well-known classifiers in terms of accuracy classification rate.

• Journal of Astronomy and Space Sciences
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• 제32권4호
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• pp.317-325
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• 2015

Energy spectra of electron microbursts from 170 keV to 340 keV have been measured by the solid-state detectors aboard the low-altitude (680 km) polar-orbiting Korean STSAT-1 (Science and Technology SATellite). These measurements have revealed two important characteristics unique to the microbursts: (1) They are produced by a fast-loss cone-filling process in which the interaction time for pitch-angle scattering is less than 50 ms and (2) The e-folding energy of the perpendicular component is larger than that of the parallel component, and the loss cone is not completely filled by electrons. To understand how wave-particle interactions could generate microbursts, we performed a test particle simulation and investigated how the waves scattered electron pitch angles within the timescale required for microburst precipitation. The application of rising-frequency whistler-mode waves to electrons of different energies moving in a dipole magnetic field showed that chorus magnetic wave fields, rather than electric fields, were the main cause of microburst events, which implied that microbursts could be produced by a quasi-adiabatic process. In addition, the simulation results showed that high-energy electrons could resonate with chorus waves at high magnetic latitudes where the loss cone was larger, which might explain the decreased e-folding energy of precipitated microbursts compared to that of trapped electrons.