• Journal of Mechanical Science and Technology
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• 제17권8호
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• pp.1234-1245
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• 2003

An experimental study was carried out to investigate the reduced frequency effect on the near-wake of an elliptic airfoil oscillating in pitch. The airfoil was sinusoidally pitched around the center of the chord between -5$^{\circ}$and ＋25$^{\circ}$angles of attack at an airspeed of 3.4 m/s. The chord Reynolds number and reduced frequencies were 3.3 ${\times}$10$^4$, and 0.1, 0.7, respectively Phase-averaged axial velocity and turbulent intensity profiles are presented to show the reduced frequency effects on the near-wake behind the airfoil oscillating In pitch. Axial velocity defects in the near-wake region have a tendency to increase in response to a reduced frequency during pitch up motion, whereas it tends to decrease during pitch down motion at a positive angle of attack. Turbulent intensity at positive angles of attack during the pitch up motion decreased in response to a reduced frequency, whereas turbulent intensity during the pitch down motion varies considerably with downstream stations. Although the true instantaneous angle of attack compensated for a phase-lag is large, the wake thickness of an oscillating airfoil is not always large because of laminar or turbulent separation.

• 한국정보처리학회논문지
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• 제4권11호
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• pp.2690-2700
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• 1997

본 연구에서는 공유메모리 병렬 컴퓨터 환경에서 N개의 key를 $O(log^2N)$ 시간에 정렬 할 수 있는 병 알고리즘인 SARED-MEMORY-BS와 REDUCED-BS를 설계하였다. REDICED-BS 알고리즘은 각각 로세서에 있는 local memory를 효율적으로 사용할 수 있도록 제안한 parity전략을 사용하였다. 각각의 프로세서에 있는 local memo교를 효율적으로 사용함으로써 REDUCED-BS 알고리즘은 SHARED-MEMORY-BS 알고리즘에 비햐여 통신의 빈도수가 약 1/2정도 감소된 것으로 나타났다. 결과적으로 REDUCED-BS 알고리즘은 병렬 정렬시 통신을 감소시킴으로써 컴퓨터의 사용 효율을 향상시킬 수 있다.

• 대한수학회지
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• 제36권1호
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• pp.97-107
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• 1999

Given a C-dynamical system (A, G, $\alpha$) with a locally compact group G, two kinds of C-algebras are made from it, called the full C-crossed product and the reduced C-crossed product. In this paper, we extend the theory of the classical C-crossed product to the C-dynamical system (A, G, $\alpha$) with a left-cancellative semigroup M with unit. We construct a new C-algebra A $\alpha$rM, the reduced crossed product of A by the semigroup M under the action $\alpha$ and investigate some properties of A $\alpha$rM.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.753-758
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• 1988

In this paper, we propose a new method of designing a reduced-order controller for a linear discrete-time system. Firstly, we study a design problem for a two-degree-of-freedom control system with a feedforward controller. Secondly, in order to obtain a reduced-order controller, frequency-weighted least squares approximation problems are considered. Thirdly, we propose a synthesis procedure of a reduced-order controller. Finally, an example is given to illustrate the effectiveness of this proposed method.

• East Asian mathematical journal
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• 제33권1호
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• pp.75-81
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• 2017

It is a well-known fact that a ring R is regular if and only if every left R-modules is flat. In this article we prove that a ring R is strongly regular if and only if every left R-modules is reduced if and only if every left-R modules is quasi-reduced.

• East Asian mathematical journal
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• 제17권2호
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• pp.275-286
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• 2001

In this paper, a skew polynomial ring $R[x;\alpha]$ of a ring R with a monomorphism $\alpha$ are investigated as follows: For a reduced ring R, assume that $\alpha(P){\subseteq}P$ for any minimal prime ideal P in R. Then (i) $R[x;\alpha]$ is a reduced ring, (ii) a ring R is Baer(resp. quasi-Baer, p.q.-Baer, a p.p.-ring) if and only if the skew polynomial ring $R[x;\alpha]$ is Baer(resp. quasi-Baer, p.q.-Baer, a p.p.-ring).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.20-23
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• 2003

A reduced-state sequence estimation(RSSE) for trellis-coded (TC) 8PSK/cyclic prefixed single carrier(CPSC) with minimum mean-square error-liner equalization(MMSE-LE) on frequency-selective Rayleigh fading channels is proposed. The Viterbi algorithm (VA) is used to search for the best path through the reduced-state trellis combined equalization and TCM decoding. The symbol error probability of the proposed scheme is confirmed by computer simulation.

• East Asian mathematical journal
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• 제37권1호
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• pp.79-85
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• 2021

In this paper, we investigate the valuation of vulnerable exchange option that has credit risk of option issuer. The reduced-form model is used to model credit risk. We assume that credit event is determined by the jump of the counting process with stochastic intensity, which follows the mean reverting process. We propose a simple approach to derive the closed-form pricing formula of vulnerable exchange option under the reduced-form model and provide the pricing formula as the standard normal cumulative function.

• 동의생리병리학회지
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• 제20권5호
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• pp.1159-1165
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• 2006

This study was done to investigate the effects of Gamisojaganggi-tang(GSGT) on immunopathologic changes in OVA-induced asthma model of mice. Pathologic indicators associated with this immune disease, which include cytokines, the number of immune-cells, immunoglobin E (IgE), were examined, and histological changes of bronchial tissues were also examined. The administration of GSGT significantly reduced the lung weight compared with control mice of OVA-induced asthma model. The administration of GSGT significantly reduced the number of total cells in BALF compared with control mice of OVA-induced asthma model. The administration of GSGT significantly reduced the number of eosinophil in BALF compared with control mice of OVA-induced asthma model. The administration of GSGT insignificantly increased the number of monocyte in BALF compared with control mice of OVA-induced asthma model. The administration of GSGT significantly reduced the number of lymphocyte in BAL compared with control mice of OVA-induced asthma model. The administration of GSGT significantly reduced the gene expression of eotaxin in lung tissue compared with control mice of OVA-induced asthma model. The administration of GSGT insignificantly reduced the IL-4 and IL-5 production in BALF compared with control mice of OVA-induced asthma model. The administration of GSGT insignificantly reduced the levels of total IgE and ovalbumin-specific IgE in BALF. The administration of GSGT significantly reduced the levels of ovalbumin-specific IgE whereas the serum levels of total IgE were insignificantly reduced compared with control mice of OVA-induced asthma model. The administration of GSGT moderately reduced bronchial alveolar narrowing, bronchiovascular edema and increase in the size of alveolar space, which shown in control mice of OVA-induced asthma model, in a dose dependent manner. Furthermore, GSGT reduced invasion of inflammatory cells, and proliferation of smooth muscle cells in bronchial tissue. These results suggested that GSGT has suppressive effects on pathologic changes associated with disease progression in asthma through the modulation of immune system. GSGT has potential to use as an anti-asthmatic agents.

• 한국지반환경공학회 논문집
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• 제12권7호
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• pp.31-37
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• 2011

철강의 생산 중에 부산물로 발생하는 전기로 제강 환원슬래그는 토질안정제로서의 적용성, 결합재 및 팽창재로서 활용법에 대한 약간의 연구 보고만 있을 뿐, 전기로 제강 환원슬래그 재활용에 관한 연구 및 시공실적은 거의 없는 실정이다. 본 연구는 전기로 제강 환원슬래그를 토목 분야에 재활용할 수 있는 방법을 모색하는데 이러한 목적을 달성하기 위하여 SEM, XRF 시험을 수행하였다. 이를 바탕으로 풍화토 및 점토와 환원슬래그를 일정한 혼합율로 혼합한 후, 환원슬래그 혼합토의 물리 공학적 특성을 고찰하기 위한 다양한 지반공학적 실내시험을 수행하였다. 다짐시험에서는 환원슬래그의 혼합율이 증가할수록 최대건조단위중량이 감소하고 최적함수비는 증가하였다. 이것은 환원슬래그를 성토재 및 재하재로 사용할 경우, 환원슬래그가 혼합된 풍화토는 지내력의 증가 등의 관점에서는 성토재 및 재하재로 적합하지 않음을 의미한다. 환원슬래그와 풍화토를 혼합한 환원슬래그 혼합토의 전단강도 특성은 일반적인 모래의 내부마찰각보다 약간 크거나 비슷하였고, 투수특성 또한 실트 또는 모래와 비슷한 결과를 확인하였다. 환원슬래그와 점토를 혼합한 환원슬래그 혼합토의 일축압축강도는 순수점토의 일축압축강도보다 크게 나타났고, 재령일수가 증가함에 따라 증가하는 경향을 보였다. 따라서 연약점토 지반의 표층개량에 적용할 경우 개량효과가 있을 것으로 판단된다.