• Title/Summary/Keyword: separating space

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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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Pre-prosthetic minor tooth movement with elastic separating ring & provisional restoration modification: case report (교정용 고무 링의 삽입과 임시 전장관의 수정을 통한 보철 수복 전 인접면 공간 획득: 증례보고)

  • Shin, Han-Eol;Roh, Byoung-Duck;Shin, Yoo-Seok;Lee, Chan-Young
    • Restorative Dentistry and Endodontics
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    • v.37 no.2
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    • pp.114-118
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    • 2012
  • Proximal caries or coronal defect in posterior teeth may result in the loss of proximal space and drifting of neighboring teeth, which makes restoration difficult. Inability to restore proper contours and to align tooth axis properly are commonly encountered problems when planning tooth restoration. Moreover, tilted teeth aggravate periodontal tissue breakdown, such as pseudo-pocket, and angular osseous defect. The purpose of this case presentation is to describe a simple technique for inducing minor tooth movement with orthodontic separating ring and provisional restoration modification. This method was used to create crown placement space on mesially tilted molar. This method is easy, simple and efficient technique which could be used in interproximal space gaining in selected situation.

The Separating Cover Using an Explosive Bolt and Spring Lever (폭발볼트 및 스프링 레버를 이용한 발사관 분리식 덮개)

  • Choi, Won-Hong;Shin, Sang-Mok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.11
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    • pp.922-931
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    • 2017
  • This research paper describes design procedures and those verification with multi-body dynamic analysis and an experiment for the development of an unprecedented type of canister cover, named as the separating cover. In order to overcome drawbacks from the precious rupture type and actuator driven cover, the separating cover was suggested. It has the simplest structure composed of the previously developed explosive bolt and a spring-lever driven system. First of all, mechanical feasibility with proposed design parameters based on mathematical modeling was confirmed through dynamic analysis and then its results showed good agreement with the followed empirical results acquired from a high speed camera. On top of that, a parametric study was conducted to identify the effect of each design parameter on separating performance. It is highly expected that this research contributes to provide military industries with a brand new canister cover having simplicity and cost efficiency and thus it will be very useful in MLRS(Multiple Launch Rocket System).

Separating sets and systems of simultaneous equations in the predual of an operator algebra

  • Jung, Il-Bong;Lee, Mi-Young;Lee, Sang-Hun
    • Journal of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.311-319
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    • 1995
  • Let $H$ be a separable, infinite dimensional, complex Hilbert space and let $L(H)$ be the algebra of all bounded linear operaors on $H$. A dual algebra is a subalgebra of $L(H)$ that contains the identity operator $I_H$ and is closed in the $weak^*$ topology on $L(H)$. Note that the ultraweak operator topology coincides with the $weak^*$ topology on $L(H)$ (see [5]).

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On the Invariance of Primitive Ideals via φ-derivations on Banach Algebras

  • Jung, Yong-Soo
    • Kyungpook Mathematical Journal
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    • v.53 no.4
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    • pp.497-505
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    • 2013
  • The noncommutative Singer-Wermer conjecture states that every derivation on a Banach algebra (possibly noncommutative) leaves primitive ideals of the algebra invariant. This conjecture is still an open question for more than thirty years. In this note, we approach this question via some sufficient conditions for the separating ideal of ${\phi}$-derivations to be nilpotent. Moreover, we show that the spectral boundedness of ${\phi}$-derivations implies that they leave each primitive ideal of Banach algebras invariant.

A Study on PIV Measurement of Multi-Channel Flow with Inclination angle (경사각을 갖는 다층채널 흐름의 PIV 계측에 관한 연구)

  • 조대환
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.05a
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    • pp.153-158
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    • 2000
  • Flow visualization and PIV measurements were conducted to investigate the flow characteristics of multi-channel with inclination angle. The water flow seeded with tiny vegetable powder as tracers revealed details of flow field. The PIV measurement to acquire multi-point velocity data simulatneously was carried out at three space of plates for 5, 10, and 15mm with variation of inlet flow rates of $0.25m^3/h$ and <$0.5m^3/h.$ Experiment results show that space of plates acts a significant role in separating process.

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DIRECT SUM, SEPARATING SET AND SYSTEMS OF SIMULTANEOUS EQUATIONS IN THE PREDUAL OF AN OPERATOR ALGEBRA

  • Lee, Mi-Young;Lee, Sang-Hun
    • Bulletin of the Korean Mathematical Society
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    • v.31 no.2
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    • pp.173-180
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    • 1994
  • Let H be a separable, infinite dimensional, compled Hilbert space and let L(H) be the algebra of all bounded linear operators on H. A dual algebra is a subalgebra of L(H) that contains the identity operator $I_{H}$ and is closed in the ultraweak topology on L(H). Note that the ultraweak operator topology coincides with the wea $k^{*}$ topology on L(H)(see [3]). Bercovici-Foias-Pearcy [3] studied the problem of solving systems of simultaneous equations in the predual of a dual algebra. The theory of dual algebras has been applied to the topics of invariant subspaces, dilation theory and reflexibity (see [1],[2],[3],[5],[6]), and is deeply related with properties ( $A_{m,n}$). Jung-Lee-Lee [7] introduced n-separating sets for subalgebras and proved the relationship between n-separating sets and properties ( $A_{m,n}$). In this paper we will study the relationship between direct sum and properties ( $A_{m,n}$). In particular, using some results of [7] we obtain relationship between n-separating sets and direct sum of von Neumann algebras.ras.s.ras.

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Continuity of Derivations on Banach Algebras

  • Kim, Gwang Hui
    • Journal of the Chungcheong Mathematical Society
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    • v.6 no.1
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    • pp.65-69
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    • 1993
  • In this paper, we show that the module derivation D is continuous on the Banach algebra and the Silov algebra, and also that the derivation restricted by separating space and the radical on the semi prime Banach algebra is continuous.

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A Study on the Flow Characteristics for the Plate Chamber in Type of Oily Parallel Plate Water Separator (평행판식 유수분리기에서 분리판실의 유동특성에 관한 연구)

  • Kim, J.H.;Han, W.H.
    • Journal of Power System Engineering
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    • v.5 no.1
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    • pp.64-72
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    • 2001
  • According to the regulation of IMO, oil discharge from ships is allowed under 15ppm only and an oil filtering equipment is essential. However, for large ships using heavy fuel oil of over S.G 0.98 and viscosity 380cSt and system oil, it has been in difficulty to process with existing filtering type of oily water separator. A parallel plate type oily water separator which is one of gravity type separators can be used as an assistant equipment for the oil filtering system to meet the present IMO standard of 15 ppm, because it is an efficient method in dealing with a large amount of rich oil with high specific gravity. This work is focused on the fundamental investigation of the performance of the plate type oily water separator by visualization method and PIV(Particle Image Velocimetry) measurement to acquire multi-point velocity data simultaneously. The experimental results showed that the space of the plates acts a significant role in separating process and it was found that an important point to minimize a vortex flow is to flow a large amount of fluid in space of the plates in order to promote the efficiency of separation.

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A NEXT GENERATION MULTI-BEAM FOCAL PLANE ARRAY RECEIVER OF TRAO FOR 86-115 GHZ BAND

  • Chung Moon-Hee;Khaikin Vladimir B.;Kim Hyo-Ryoung;Lee Chang-Hoon;Kim Kwang-Dong;Park Ki-Won
    • Journal of Astronomy and Space Sciences
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    • v.23 no.1
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    • pp.19-28
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    • 2006
  • The noise temperature of existing millimeter-wave receivers is already within two or three times quantum noise limit. One of practical ways to increase the observation speed of single dish radio telescope without longer integration time is use of multi-beam focal plane array receiver as demonstrated in several large single dish radio telescopes. In this context the TRAO (Taeduk Radio Astronomy Observatory), which operates a 143n Cassegrain radio telescope, is planning to develop a 4 x 4 beams focal plane array SIS receiver system for 86-115 GHz band. Even though millimeter-wave HEMT LNA-based receivers approach the noise temperature comparable to the SIS receiver at W-band, it is believed that the receiver based on SIS mixer seems to offer a bit more advantages. The critical part of the multi-beam array receiver will be sideband separating SIS mixers. Employing such a type of SIS mixer makes it possible to simplify the quasi-optics of receiver. Otherwise, an SSB filter should be used in front of the mixer or some sophisticated post-processing of observation data is needed. In this paper we will present a preliminary design concept and components needed for the development of a new 3 mm band multi-beam focal plane array receiver.