• 한국정보처리학회논문지
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• 제6권3호
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• pp.571-579
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• 1999

A Macro-Star graph which has a star graph as a basic module has node symmetry, maximum fault tolerance, and hierarchical decomposition property. And, it is an interconnection network which improves a network cost against a star graph. A matrix star graph also has such good properties of a Macro-Star graph and is an interconnection network which has a lower network cost than a Maco-Star graph. In this paper, we propose a method to embed between a Macro-Star graph and a matrix star graph. We show that a Macro-Star graph MS(k, n) can be embedded into a matrix star graph MS\ulcorner with dilation 2. In addition, we show that a matrix star graph MS\ulcorner can be embedded into a Macro-Star graph MS(k,n+1) with dilation 4 and average dilation 3 or less as well. This result means that several algorithms developed in a star graph can be simulated in a matrix star graph with constant cost.

• 패션비즈니스
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• 제12권6호
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• pp.138-151
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• 2008

This study aims at providing comprehensive data which would be helpful to establish a web shopping mall by analyzing the structure of web fashion star shops which have recently emerged as a result of advances in digital technology and communication. For the purpose of analyzing VMD strategy used in web fashion star shop, we adopt both of the documental and empirical research methods, based on which we examine the concept of E-commerce and current business situation of web fashion star shop industry, and then analyze the main page, product category page and product detail page in a star shop featured by a male pop star within a web shopping mall. According to our analysis of the structure of web fashion star shop, in case of open market, a banner with star's image on it leads to star shop when people click on the link of the banner, and in case of independent mall, they show each star's unique style in the main page. Product category page is linked to each product detail page which presents items of various fashion coordinates, satisfying needs of consumers to follow star's trendy fashion sense.

• 천문학회지
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• 제29권1호
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• pp.19-30
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• 1996

We have examined consequences of strong tidal encounters between a neutron star and a normal star using SPH as a possible formation mechanism of isolated recycled pulsars in globular clusters. We have made a number of SPH simulations for close encounters between a main-sequence star of mass ranging from 0.2 to 0.7 $M_\bigodot$ represented by an n=3/2 poly trope and a neutron star represented by a point mass. The outcomes of the first encounters are found to be dependent only on the dimensionless parameter $\eta'{\equiv}(m/(m+ M))^{1/2}(\gamma_{min}/R_{MS})^{3/2}(m/M)^{{1/6)}$, where m and M are the mass of the main-sequence star and the neutron star, respectively, $\gamma_{min}$ the minimum separation between two stars, and $R_{MS}$ the size of the main-sequence star. The material from the (at least partially) disrupted star forms a disk around the neutron star. If all material in the disk is to be acctreted onto the neutron star's surface, the mass of the disk is enough to spin up the neutron star to spin period of 1 ms.

• 한국멀티미디어학회논문지
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• 제6권3호
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• pp.556-564
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• 2003

스타 그래프와 팬케익 그래프는 하이퍼큐브가 갖는 좋은 성질을 가지면서 하이퍼큐브보다 망 비용이 적은 값을 갖는 상호연결망이다. 매크로-스타 그래프는 스타 그래프를 기본 모듈로 하면서 노드 대칭성, 최대고장허용도, 계층적 분할 성질을 가지면서 스타 그래프보다 망 비용이 개선된 상호연결망이다. 본 논문에서는 그래프의 에지 정의를 이용하여 스타 그래프, 팬케익 그래프, 매크로-스타 그래프 사이의 임베딩 방법을 제시한다. 스타 그래프 $S_n$은 팬케익 그래프 $P_n$에 연장율 4에 임베딩 가능하고, 매크로-스타 MS(2,n)은 팬케익 그래프에 연장율 4에 임베딩 가능함을 보인다. 또한, 팬케익 그래프를 스타 그래프와 매크로-스타 그래프에 임베딩하는 비용이 O(n)임을 보인다.

• Journal of Astronomy and Space Sciences
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• 제31권3호
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• pp.205-214
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• 2014

In this study, a star identification algorithm which utilizes pivot patterns instead of apparent magnitude information was developed. The new star identification algorithm consists of two steps of recognition process. In the first step, the brightest star in a sensor image is identified using the orientation of brightness between two stars as recognition information. In the second step, cell indexes are used as new recognition information to identify dimmer stars, which are derived from the brightest star already identified. If we use the cell index information, we can search over limited portion of the star catalogue database, which enables the faster identification of dimmer stars. The new pivot algorithm does not require calibrations on the apparent magnitude of a star but it shows robust characteristics on the errors of apparent magnitude compared to conventional pivot algorithms which require the apparent magnitude information.

• 한국항공우주학회지
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• 제34권2호
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• pp.96-100
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• 2006

본 논문은 위성의 자세정보를 획득하는 센서로서 과학기술위성2호에 장착하기 위해 개발 중인 이중 머리 별 추적기를 소개한다. 대부분의 별 센서는 위성의 한쪽 방향만 지향하기 때문에 태양 및 지구 영역으로 지향할 경우 별 인식이 불가능하다. 그래서 시스템은 두개의 카메라를 직각의 방향으로 지향하여 동시에 두개의 영상을 입력 받고 하나의 영상에서 별 인식을 실패할 경우 다른 영상에서 별 인식을 수행하여 별 인식률을 높이도록 구현하였다. 논문에서는 이중머리 별 추적기의 시험모델을 소개하고 별 인식 및 별 추적 알고리즘을 제안하였다.

• 천문학논총
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• 제28권3호
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• pp.37-54
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• 2013

China and Korea have a long history of star charts, dating from the prehistoric period. Historically, Korean astronomy has been deeply influenced by China over the last two thousand years, particularly on constellation system. Therefore, Chinese and Korean traditional star charts have many similarities in terms of shape of constellation, number of star, and so forth. Korean star charts, however, have lots of unique characteristics distinguishing from Chinese ones, such as, size of star and position of constellation. Overall knowledge of the Chinese star chart is required to study the Korean star chart. In this paper, I focus on introducing selected star charts in China and Korea. Although this review is very limited, I hope that this paper is helpful in research in the field of historical astronomy.

• Journal of Astronomy and Space Sciences
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• 제16권2호
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• pp.273-284
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• 1999

위성용 star tracker의 국내 개발을 위한 기초 연구의 일환으로 광학계 설계 요소 선정 과정을 연구하였다. 논리적인 광학 요소 선정을 위해 CCD 센서에 결상된 별빛을 관련 전자회로에서 읽고, 처리하는 전 과정을 시뮬레이션하였다. 시뮬레이션으로부터 별의 등급과 성취 가능한 지향 정밀도간의 관계가 구해졌으며, 그 관계로부터 요구되는 star tracker의 지향 정밀도를 만족시키기 위한 최적의 광학요소를 유도하였다. 선정된 광학 요소들은 10 arcsec의 지향 정밀도를 갖는 star tracker의 광학계 설계에 사용되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.467-470
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• 1998

In this paper, we propose a matrix star graph which improves the network cost of the well-known star grah as an interconnection network. We analyze its characteristics in terms of the network parameters, such as degree, scalability, routing, and diameter. The proposed matrix star graph MS2,n has the half degrees of a star graph S2n with the same number of nodes and is an interconnection network with the properties of node symmetry, maximum fault tolerance, and recursive structure. In network cost, a matrix star graph MS2,n and a star graph S2n are about 3.5n2 and 6n2 respectively which means that the former has a better value by a certain constant than the latter has.

• 대한수학회지
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• 제46권6호
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• pp.1179-1192
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• 2009

In this note we give a new generalization of the notions of $Pr{\ddot{U}}fer$ domain and PvMD which uses quasi semistar invertibility, the "quasi P$\star$MD", and compare them with the P$\star$MD. We show in particular that the problem of when a quasi P$\star$MD is a P$\star$MD is strictly related to the problem of the descent to subrings of the P$\star$MD property and we give necessary and sufficient conditions.