• 제목/요약/키워드: S-D assignment

검색결과 63건 처리시간 0.025초

Polynomial Time Algorithm for Multi-Beam SS/TDMA Satellite Communications Scheduling Problem with Frequency-Hopping Ground Stations

  • Lee, Sang-Un
    • 한국컴퓨터정보학회논문지
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    • 제20권7호
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    • pp.33-40
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    • 2015
  • The time slot assignment problem (TSAP) or Satellite Communications scheduling problem (SCSP) for a satellite performs $n{\times}n$ ground station data traffic switching has been known NP-hard problem. This paper suggests $O(n^2)$ time complexity algorithm for TSAP of a satellite that performs $n^2{\times}n^2$ ground station data traffic switching. This problem is more difficult than $n{\times}n$ TSAP as NP-hard problem. Firstly, we compute the average traffic for n-transponder's basic coverage zone and applies ground station exchange method that swap the ground stations until all of the transponders have a average value as possible. Nextly, we transform the D matrix to $D_{LB}$ traffic matrix that sum of rows and columns all of transponders have LB. Finally, we select the maximum traffic of row and column in $D_{LB}$, then decide the duration of kth switch mode to minimum traffic from selected values. The proposed algorithm can be get the optimal solution for experimental data.

송도국제도시 연결도로의 유고상황 발생에 따른 신도시 내부 영향 분석 (Analysis of the effect in the city due to the bridges incidents in Songdo International City)

  • 홍기만;김태균
    • 도시과학
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    • 제10권1호
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    • pp.49-60
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    • 2021
  • The purpose of this study is to analysis the impact on the inside of the new city when an incidents occurs on the Songdo International City connecting road, which has a limited access. The analysis data used KTDB's O/D and network data of the Seoul metropolitan area. In addition, the scenario composition applied a method of reducing the number of lanes on the road according to the situation of incidents, targeting bridges advancing from Songdo International City to the outside in the morning peak hours. The analysis method analyzed the traffic volume, total travel time, total travel kilometer, and route change in the new city based on the results of the traffic allocation model. As a result of the analysis, the range of influence was shown to two types. First, of the seven bridges, Aam 3, Aam 2, and Aam 1 were analyzed to have an impact only in some areas of the northwestern part of the new city. On the other hand, the remaining bridges were analyzed to affect the new city as a whole. The analysis results of this study are expected to be used as basic data to establish the scope of internal road network management when similar cases occur in the future.

MDF 점퍼선 길이 단축을 위한 단자배치에 관한 연구 (Terminal Arrangement on MDF for Short Jumpers)

  • 이일수;정병덕;김청호;임용배;조영현;김현우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.994-998
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    • 1987
  • We calculated the expected length of jumper wires on MDF(Main Distribution Frame) in case of random jumper assignment, and from the calculated results we considered an optimal method of terminal arrangement and terminal expansion for keeping the length of jumper wires short, where MDF is a large frame-work installed in a telephone office for accommodating the terminals which are used for connecting the outside facilities to the inside facilities of the telephone office. We also showed the jumper saving effect in modular frames.

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Vibrational Assignment of S$_8$ from Normal Coordinatie Analysis

  • Chang, Man-Chai;Kim, Hyun-Yong;Jhon, Mu-Shik
    • Bulletin of the Korean Chemical Society
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    • 제6권1호
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    • pp.29-32
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    • 1985
  • Normal modes of crystalline orthorhombic sulfur belonging to the space group $D_{2h}$-Fddd, have been evaluated by taking the lowest temperature phase in the solid. Normal modes are obtained by the valence force field with modified force constants and a quantitative description of the mode is adjusted by the potential energy distribution. Since the full crystal system of orthorhombic sulfur is so large, we intended to calculate the normal modes simply by constructing the imaginary box made by the infinite mass boundary. And the Raman experiment is done by using the more powerful Ar-Kr gas laser with lowering the temperature to ${\sim}10^{\circ}K$.

멀티 에이전트 강화학습 기술 동향 (A Survey on Recent Advances in Multi-Agent Reinforcement Learning)

  • 유병현;데브라니 데비;김현우;송화전;박경문;이성원
    • 전자통신동향분석
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    • 제35권6호
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    • pp.137-149
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    • 2020
  • Several multi-agent reinforcement learning (MARL) algorithms have achieved overwhelming results in recent years. They have demonstrated their potential in solving complex problems in the field of real-time strategy online games, robotics, and autonomous vehicles. However these algorithms face many challenges when dealing with massive problem spaces in sparse reward environments. Based on the centralized training and decentralized execution (CTDE) architecture, the MARL algorithms discussed in the literature aim to solve the current challenges by formulating novel concepts of inter-agent modeling, credit assignment, multiagent communication, and the exploration-exploitation dilemma. The fundamental objective of this paper is to deliver a comprehensive survey of existing MARL algorithms based on the problem statements rather than on the technologies. We also discuss several experimental frameworks to provide insight into the use of these algorithms and to motivate some promising directions for future research.

글로벌 전자무역 마케팅 확산전략에 대한 연구 (A study on the Korea's global e-Trade marketing spreading strategy)

  • Park, Yong-Hwan;Lee, Seung-Kwan
    • 정보학연구
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    • 제7권3호
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    • pp.99-112
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    • 2004
  • 최근 정보기술을 활용하여 무역의 효율을 극대화하고 있다. 이를 위해 전자무역(e-Trade)을 활용하여, 고효율의 글로벌 마케팅을 적극 추진하고 있다. 기존 종합상사의 기능고도화를 목적으로 e무역상사가 등장하여, 새로운 마케팅을 적극 추진하고 있다. 이를 위해서는 계약체결이전의 바이어 발굴 등 마케팅의 고도화가 전자무역을 통해 활성화되고 있으며, 계약체결이후의 운송, 보험, 결제 등의 전자화도 적극 추진하고 있다. 이와 관련하여 e무역상사의 글로벌 마케팅 추진현황을 살펴보고, 향후 지식형 전자무역을 가능하게 해주고 있는 전자무역의 확산을 위한 전략적 제언을 하고자 한다.

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Geminocystis urbisnovae sp. nov. (Chroococcales, Cyanobacteria): polyphasic description complemented with a survey of the family Geminocystaceae

  • Elena Polyakova;Svetlana Averina;Alexander Pinevich
    • ALGAE
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    • 제38권2호
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    • pp.93-110
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    • 2023
  • Progress in phylogenomic analysis has led to a considerable re-evaluation of former cyanobacterial system, with many new taxa being established at different nomenclatural levels. The family Geminocystaceae is among cyanobacterial taxa recently described on the basis of polyphasic approach. Within this family, there are six genera: Geminocystis, Cyanobacterium, Geminobacterium, Annamia, Picocyanobacterium, and Microcrocis. The genus Geminocystis previously encompassed two species: G. herdmanii and G. papuanica. Herein, a new species G. urbisnovae was proposed under the provision of the International Code of Nomenclature for algae, fungi, and plants (ICN). Polyphasic analysis was performed for five strains from the CALU culture collection (St. Petersburg State University, Russian Federation), and they were assigned to the genus Geminocystis in accordance with high 16S rRNA gene similarity to existing species, as well as because of proximity to these species on the phylogenetic trees reconstructed with RaxML and Bayes methods. Plausibility of their assignment to a separate species of the genus Geminocystis was substantiated with smaller cell size; stenohaline freshwater ecotype; capability to complementary chromatic adaptation of second type (CA2); distinct 16S rRNA gene clustering; sequences and folding of D1-D1' and B box domains of the 16S-23S internal transcribed spacer region. The second objective pursued by this communication was to provide a survey of the family Geminocystaceae. The overall assessment was that, despite attention of many researchers, this cyanobacterial family has been understudied and, especially in the case of the crucially important genus Cyanobacterium, taxonomically problematic.

자외선 공명 라만분광법을 이용한 시스-펩티드, 디케토피페라진 연구 (UV Resonance Raman Studies of Cis-Peptide, Diketopiperazine)

  • 송선호
    • 분석과학
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    • 제6권1호
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    • pp.39-45
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    • 1993
  • 시스-펩티드 모델 화합물인 디케토페라진을 수용액과 $D_2O$에서 320~218nm 사이의 여기 파장을 이용하여 라만 스펙트럼을 측정하였다. 본 연구는 공명 증폭되는 아미드 밴드를 명명하고, 그 증폭 메카니즘을 규명하는 데 목적이 있다. 3개의 공명 증폭된 시스-펩티드 표본밴드가 수용액 상태에서 1676, 1533, $806cm^{-1}$에서 관찰되었고, 이것을 각각 아미드, I, II, S 밴드로 명명하였다. $1533cm^{-1}$ 아미드 II 밴드는 수용액 상태의 공명 라만 스펙트럼에서 가장 큰 밴드였으며, 순수한 C-N 신축운동이며, N-H를 N-D로 치환한 결과 $1520cm^{-1}$로 이동되었다. 이 밴드는 아마도 단백질내에 존재하는 시스형 펩티드를 관찰할 수 있는 표본 밴드가 될 것으로 예상된다. 여기 주파수를 바꾸어 가며 얻은 라만 밴드 크기 변화와, Albrecht A-항 모델로부터 시스 펩티드 라만 밴드가 188nm 근방의 펩티드 ${\pi}-{\pi}^*$ 전자 전이에 의하여 공명 증폭됨을 증명하였다. 이러한 자료를 바탕으로 시스 펩티드 ${\pi}^*$ 들뜬 상태의 기하구조는 전자 바닥 상태와 비교하여 C-N 결합이 늘어난 형태일 것으로 제안하였다.

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2개의 밑수를 이용한 Flash A/D 변환기 (A New Flash A/D Converter Adopting Double Base Number System)

  • 김종수;김만호;장은화
    • 융합신호처리학회논문지
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    • 제9권1호
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    • pp.54-61
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    • 2008
  • 본 논문에서는 디지털 신호를 실시간으로 처리하기 인한 TIQ 방식의 Flash 6-bit ADC 회로를 설계하였다. 새로운 논리회로 설계나 소자들의 근접 배치로 ADC의 속도를 향상시키는 대신에 새로운 코드를 이용하여 DSP의 처리능력을 높이도록 하였다. 제안한 코드는 ADC의 출력으로 이진수를 세공하지 않고 2와 3진법을 동시에 사용하는 Double Base Number System(DBNS)방법이다. 전압은 기존의 이진수를 표시하는 방법과 동일하지만, 밑수로 2와 3의 두개를 동시에 사용하여 합의 형태로 표현하는 방법이다. DBNS 표현법은 곱셈기와 가산기를 이용하지 않고 연산을 좌우로 이동하여 연산을 신속히 처리할 수 있다. 디지털 신호처리에서 사용하는 DBNS는 합의 수가 적도록 Canonical 표현을 구하는 알고리즘을 사용하지만, A/D 변환기에서는 Fan-In 문제가 발생하여 균일한 분포를 이루도록 하는 새로운 알고리즘을 개발하였다. HSPICE를 이용한 ADC의 시뮬레이션 결과 0.18um 공정에서 최고 동작속도는 1.6 GSPS이며 최대 소비전력은 38.71mW이였다.

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COMPUTATION OF TOTAL CHROMATIC NUMBER FOR CERTAIN CONVEX POLYTOPE GRAPHS

  • A. PUNITHA;G. JAYARAMAN
    • Journal of applied mathematics & informatics
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    • 제42권3호
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    • pp.567-582
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    • 2024
  • A total coloring of a graph G is an assignment of colors to the elements of a graphs G such that no adjacent vertices and edges receive the same color. The total chromatic number of a graph G , denoted by χ''(G), is the minimum number of colors that suffice in a total coloring. In this paper, we proved the Behzad and Vizing conjecture for certain convex polytope graphs Dpn, Qpn, Rpn, En, Sn, Gn, Tn, Un, Cn,respectively. This significant result in a graph G contributes to the advancement of graph theory and combinatorics by further confirming the conjecture's applicability to specific classes of graphs. The presented proof of the Behzad and Vizing conjecture for certain convex polytope graphs not only provides theoretical insights into the structural properties of graphs but also has practical implications. Overall, this paper contributes to the advancement of graph theory and combinatorics by confirming the validity of the Behzad and Vizing conjecture in a graph G and establishing its relevance to applied problems in sciences and engineering.