• 천문학회보
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• 제41권2호
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• pp.63.4-64
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• 2016

We aim to investigate inflow history of matters that fall into the satellite systems around a dwarf galaxy in Lambda-Cold Dark Matter model. Each satellite system has unique properties because all satellite systems have different mass inflow history by environments and/or the events such as cosmic reionization and merging with other halos. To trace mass inflow history of the satellite systems, we perform three different cosmological zoom simulations whose galaxy mass is ${\sim}10^{10}M_{sun}$. Each initial zoom simulation covers a cubic box of $1Mpc/h^3$ with 17 million particles. Particle mass for dark matter (DM) and gas components is $M_{DM}=4.1{\times}10^3M_{sun}$ and $M_{gas}=7.9{\times}10^2M_{sun}$, respectively. Thus, each satellite system is resolved with more than hundreds - thousands of particles. We analyze the influence of the gravitational interaction with host galaxy, baryonic matter inflow by various cooling mechanisms, and merging events with other halos on the mass inflow history of satellite systems.

• 한국가시화정보학회지
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• 제15권1호
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• pp.25-31
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• 2017

This study aims to visualize the Marangoni flow inside a droplet placed on heated hydrophobic surface and to measure its internal velocity field. The experimental result shows that the internal velocity increases with the increase of the plate temperature. In addition, the temperature difference induces the initial flow and drives the Marangoni circulation inside the droplet as soon as the evaporation starts (i.e. the thermal Marangoni flow). The fluorescence particles in the droplet trace two large-scale counter-rotating vortex pairs yielding the downwards flow along the vertical central axis. These vortex pairs gradually become small and move towards the contact line as time goes by, and this Marangoni flow sustains only for a half of the total evaporation time.

• 턱관절균형의학회지
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• 제1권1호
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• pp.9-12
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• 2011

Objectives: Functional Cerebrospinal Therapy (FCST) is a rather new physiologic therapeutics. It has passed about two decades since its basic idea was founded. This study briefly reviewed its early history. Methods: The first FCST patient was a stroke patient in the year 1992. Basic ideas of FCST was devised one by one and later developed into a systematic clinical application. The first official lecture was held in the year 2004. Yinyang balance in the meridian-system-based network over the whole body was a mainstay idea. Results: As other stories on newly-developed therapeutics, there was an effort to make a breakthrough for difficult clinical problems, and followed by a creative initial idea along with incessant refinement in the early history of FCST. Conclusions: Patient-centered approaches was a mainspring in the development and refinement of FCST. History of FCST hereafter may well follow the trace.

• 자원환경지질
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• 제30권4호
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• pp.313-320
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• 1997

Geochemical and Sm-Nd isotopic results are reported for amphibolite of the Muju area, Ryeongnam massif. Major and trace element data analyzed indicate that the parental rock of the Muju amphibolite is tholeiitic basalt. The Sm-Nd amphibole-WR-plagioclase data define an isochron corresponding to $1766{\pm}121Ma$ ($1{\sigma}$) (MSWD=1.10) with an initial ratio of $0.51032{\pm}15$. We interpret this age as a metamorphic age of the Muju amphibolite. Tectonic discrimination diagrams clearly fail when they are applied to the Muju amphibolite probably due to compositional variations resulting from crustal contamination and/or degrees of partial melting.

• International Journal of Aeronautical and Space Sciences
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• 제9권1호
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• pp.1-30
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• 2008

When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant any more and start to vary with this temperature. The gas remains perfect; its state equation remains always valid, except, it is named in more by calorically imperfect gas. The aim of this work is to trace the profiles of the supersonic axisymmetric Minimum Length Nozzle to have a uniform and parallel flow at the exit section, when the stagnation temperature is taken into account, lower than the dissociation threshold of the molecules, and to have for each exit Mach number and stagnation temperature shape of nozzle. The method of characteristics is used with the algorithm of the second order finite differences method. The form of the nozzle has a point of deflection and an initial angle of expansion. The comparison is made with the calorically perfect gas. The application is for air.

• 전기학회논문지
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• 제59권2호
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• pp.423-428
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• 2010

In the initial design phase of superscalar microprocessors, a performance model is necessary. A theoretic performance model is very useful since performance for various architecture parameters can be obtained by simply computing equations, without repeating simulations, Previous studies established theoretic performance models using the relation between the instruction window size and the issue width, with the penalties due to branch mispredictions and cache misses. However, the study was intended for unlimited number of functional units, which is insufficient for the real case application. This paper proposes a superscalar microprocessor theoretical performance model which also works for the limited functional units. To enhance the accuracy of our limited functional unit model, instruction dependency rates are employed. By using trace-driven data of SPEC 2000 integer programs as input, this paper shows that the theoretically computed performance of superscalar microprocessor with limited number of functional units is quite similar to the measured performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.899-901
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• 1998

Continuation power flow is a tool that can trace the path of the solution from the base stable solution. However, the base stable solution cannot be calculated when the initial system load is too large to operate at a stable operating point. This case is called as unsolvable case. This paper presents implementation of the optimal load shedding algorithm on continuation power flow. It performs steady-state analysis of power systems at unsolvable case that can occur in contingency analysis. Numerical simulation on 20-bus test system demonstrates that the continuation power flow applying the optimal load shedding algorithm is robust at solvable and unsolvable cases.

• 산업공학
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• 제13권2호
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• pp.246-252
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• 2000

As moulds and dies are manufactured through complex processes under the make-to-order production environment, it is very difficult that the manufacturing activities as like observance of the due date, trace of the progress, etc are controlled with a real time. In this paper, a schedule-planning system using the commercial software Microsoft Project 98 is developed to control the procedures of mould and die manufacturing with real time. Once an initial schedule is planned from the BOM information in the intranet, it is rescheduled by data collected from machines on the shop floor. The system is suitable to medium- or small-sized manufacturing companies as well as large-sized ones, because it can be installed with a low cost.

• 한국컴퓨터정보학회논문지
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• 제24권7호
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• pp.19-29
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• 2019

Requirements traceability is regarded as one of the important quality attributes in software requirements engineering field. If requirements traceability is guaranteed then we can trace the requirements' life throughout all the phases, from the customers' needs in the early stage of the project to requirements specification, deployment, and maintenance phase. This includes not only tracking the development artifacts that accompany the requirements, but also tracking backwards from the development artifacts to the initial customer requirements associated with them. In this paper, especially, we dealt with the traceability between functional requirements and non-functional requirements. Among many Information Retrieval (IR) techniques, we decided to utilize Latent Semantic Indexing (LSI) and Latent Dirichlet Allocation (LDA) in our research. Ultimately, we conducted an experiment on constructing traceability by using two techniques and analyzed the experiment results. And then we provided a comparative study between two IR techniques in constructing traceability between functional requirements and non-functional requirements.

• 정보처리학회논문지B
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• 제9B권3호
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• pp.303-310
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• 2002

연속미디어 데이터를 인터넷을 통해 서비스하기 위해서는 서버의 과부하, 네트워크의 혼잡, 사용자에 대한 응답시간 지연 등의 문제를 해결하여야 한다. 본 논문에서는 연속미디어 프록시 캐쉬에서 데이터를 관리하는 PPC(Popularity-based Prefix Caching) 기법을 제안한다. 사용자 접근 패턴을 반영하는 PPC 기법은 객체들의 앞부분 데이터를 그 객체의 인기에 비례하여 캐슁함으로써 사용자에 대한 초기지연시간을 감소시키고, 캐쉬 공간을 효율적으로 활용하고자 한다. 연속미디어에 대한 사용자 접근의 특성이 이산미디어와는 상이하다는 점을 고려하여, 연속미디어의 인기도를 더욱 정확하게 나타내기 위해서 각 연속미디어에 대한 사용자의 재생 데이터 양과 접근의 최근성을 반영하는 인기도를 제안한다. 그리고 제안하는 기법의 성능을 평가하기 위하여 인터넷 방송국 VOD 서버의 로그 데이터를 이용한 트레이스 기반 모의 실험을 수행하였다. 그 결과, PPC 기법은 BHR, 초기 지연 시간, 재배치의 측면에서 기존의 LRU, LFU 캐슁 기법들에 비하여 성능이 향상되었고, 특히, 초기 지연시간과 재배치 오버 헤드의 감소 측면에서 매우 우수한 성능을 보였다.