• Title/Summary/Keyword: base space

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PROJECTIVELY FLAT WARPED PRODUCT RIEMANNIAN MANIFOLDS

  • Oh, Won-Tae;Shin, Seung-Soo
    • Journal of applied mathematics & informatics
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    • v.7 no.3
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    • pp.1039-1044
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    • 2000
  • We investigate the projectively flat warped product manifolds and study the geometric structure of the base space and its fibre. Specifically we find the conditions that the scalar curvature of the base space (B,g) vanishes if and only if f is harmonic on (B,g) and the fibre (F,$\bar{g}$) is a space of constant curvature.

COCOMPACT F-BASES AND RELATION BETWEEN COVER AND COMPACTIFICATION

  • Lee, Sang-Deok;Kim, Chang-Il
    • The Pure and Applied Mathematics
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    • v.3 no.2
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    • pp.163-171
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    • 1996
  • Observing that a locally weakly Lindel$\"{o}$f space is a quasi-F space if and only if it has an F-base, we show that every dense weakly Lindel$\"{o}$f subspace of an almost-p-space is C-embedded, every locally weakly Lindel$\"{o}$f space with a cocompact F-base is a locally compact and quasi-F space and that if Y is a dense weakly Lindel$\"{o}$f subspace of X which has a cocompact F-base, then $\beta$Y and X are homeomorphic. We also show that for any a separating nest generated intersection ring F on a space X, there is a separating nest generated intersection ring g on $\phi_{Y}^{-1}$(X) such that QF(w(X, F)) and ($\phi_{Y}^{-1}$(X),g) are homeomorphic and $\phi_{Y}_{x}$(g$^#$)=F$^#$.

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A Study on the Evaluation of Characteristic for Home-base of Variation Type in High School (교과교실형 고등학교 홈베이스의 공간 특성 평가 연구)

  • Seo, Boong-Kyo;Park, Ju-Young
    • Journal of the Korean Institute of Educational Facilities
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    • v.16 no.4
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    • pp.71-78
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    • 2009
  • After the introduction of the 7th revision of curriculum, educational facilities have been requested to change to face new curriculums and have been planned. But, it is actual condition that researches of curriculum and facilities seem to be insufficient. This research will re-establish in an angle of space-syntax based on existed research for home-base area of variation type in high school according to the 7th curriculum. And the each specific character of home-base area representing each type and strong / weak points of area structure of each home-base will be analyzed. And analysis result with the model of variation type in high school visit the on-the-spot inspection result which leads and comparison and with his interview back it leads and currently there is the objective to the evaluation the variation type in high school home-base which is planned regarding the suitable in real use. Each case to the school I visited the scene, not all high schools applied the 7th curriculum courses. Therefore, it is also home-base space capabilities were not being properly utilize. According to 7th curriculum, one of Hall-type home-base and Room-type home-base can be suitable when integration is higher. However, the way the current operational training, it is the best that Distributed-type home-base needs to be included in each curriculum block.

Research on the Domain Formation of Living Base Space of Credit System High Schools - Focused on Japanese Comprehensive High Schools - (학점제 고등학교 생활거점공간의 영역 형성에 관한 연구 - 일본의 총합학과 고등학교를 대상으로 -)

  • Son, Suk-Eui;Kim, Seung-je
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.10
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    • pp.3-10
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    • 2019
  • The high school credit system is a system in which students select complete various subjects, depending on their career, and graduate when their accumulated credit reaches the standard. It is expected that the high school credit system, which guarantees the individual's right of choice, will bring an educational effect that can respond to the student's career aptitude. However, it is expected that problems in the aspect of school life, such as the weakening of class belongingness or difficulty of securing a stable base venue within the school building would be accompanied. This research analyzed students' usage condition depending on the living base space environment feature in schools that are implementing moving-selective class in the aspect of activity domain formation and contemplated the venue evaluation. The purpose is to provide the basic data of an architectural plan of a stable living base space within the school building through this. 'Living base center type' and 'living base dispersion type' school buildings among Japanese integral department high schools were used as the target to analyze the usage condition in the aspect of domain formation. As a result, a conclusion was deducted that student's securement of territory consciousness about the base space and venue construction for the community of various studying groups affects life satisfaction.

Additional degree of freedom in phased-MIMO radar signal design using space-time codes

  • Vahdani, Roholah;Bizaki, Hossein Khaleghi;Joshaghani, Mohsen Fallah
    • ETRI Journal
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    • v.43 no.4
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    • pp.640-649
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    • 2021
  • In this paper, an additional degree of freedom in phased multi-input multi-output (phased-MIMO) radar with any arbitrary desired covariance matrix is proposed using space-time codes. By using the proposed method, any desired transmit covariance matrix in MIMO radar (phased-MIMO radars) can be realized by employing fully correlated base waveforms such as phased-array radars and simply extending them to different time slots with predesigned phases and amplitudes. In the proposed method, the transmit covariance matrix depends on the base waveform and space-time codes. For simplicity, a base waveform can be selected arbitrarily (ie, all base waveforms can be fully correlated, similar to phased-array radars). Therefore, any desired covariance matrix can be achieved by using a very simple phased-array structure and space-time code in the transmitter. The main advantage of the proposed scheme is that it does not require diverse uncorrelated waveforms. This considerably reduces transmitter hardware and software complexity and cost. One the receiver side, multiple signals can be analyzed jointly in the time and space domains to improve the signal-to-interference-plus-noise ratio.

Algebraic Fiber Space Whose Generic Fiber and Base Space Are of Almost General Type

  • Fukuda, Shigetaka
    • Kyungpook Mathematical Journal
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    • v.54 no.2
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    • pp.203-209
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    • 2014
  • We assume that the existence and termination conjecture for flips holds. A complex projective manifold is said to be of almost general type if the intersection number of the canonical divisor with every very general curve is strictly positive. Let f be an algebraic fiber space from X to Y. Then the manifold X is of almost general type if every very general fiber F and the base space Y of f are of almost general type.

A STUDY ON THE PREDICTION OF THE BASE FLOW CHARACTERISTICS OF A LAUNCH VEHICLE USING CFD

  • Kim Younghoon;Ok Honam;Kim Insun
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.258-261
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    • 2004
  • Numerical simulations are made to predict the axial force coefficients of a two-stage launch vehicle, and the results are compared with those by wind tunnel tests. It is found that the forebody axial force is not affected by whether the base of the body is modeled or not. Modeling the sting support used in wind tunnel tests reduced the base axial force compared to the results without it. The present calculation shows that the forebody axial forces are underestimated while the base axial forces are overestimated. The total axial force, therefore, compares with the experimental data with better accuracy by cancelling out the errors of opposite signs. Modeling of the sting support in numerical simulations is found to be necessary to get a better agreement with the experiments for both base and overall axial force coefficients.

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RIEMANNIAN SUBMERSIONS OF SO0(2, 1)

  • Byun, Taechang
    • Journal of the Korean Mathematical Society
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    • v.58 no.6
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    • pp.1407-1419
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    • 2021
  • The Iwasawa decomposition NAK of the Lie group G = SO0(2, 1) with a left invariant metric produces Riemannian submersions G → N\G, G → A\G, G → K\G, and G → NA\G. For each of these, we calculate the curvature of the base space and the lifting of a simple closed curve to the total space G. Especially in the first case, the base space has a constant curvature 0; the holonomy displacement along a (null-homotopic) simple closed curve in the base space is determined only by the Euclidean area of the region surrounded by the curve.