• 한국전기전자재료학회논문지
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• 제31권1호
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• pp.11-18
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• 2018

Two-dimensional (2D) materials such as transition metal dichalcogenides have attracted tremendous scientific interests owing to their potential of solving the zero band-gap issue of graphene. In this work, the research areas and technology evolutionary dynamics of the 2D materials were identified using the scientometric method focusing on keyword mapping and clustering. The time-series analysis showed that the technological progress of 2D material is in the early growth period. The overlay mapping analysis were carried out to investigate the technology evolution of 2D materials with time. The strategic diagram of co-word analysis classifying the topological positions of keyword was derived to support the analysis results. It is conjectured that extensive research will be conducted widely on the application of 2D materials not only in electronic and optoelectronic devices, but also in various other fields such as biomedical applications, and that their development will be more rapid based on accumulated results of extant graphene research.

• 한국경영과학회지
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• 제41권3호
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• pp.75-96
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• 2016

This paper investigates the usefulness of drones in an urban delivery system. We define the vehicle and drone routing problem with time window (VDRPTW) and present a model that can describe a dual mode delivery system consisting of drones and vehicles in the metropolitan area. Drones are relatively free from traffic congestion but have limited flight range and capacity. Vehicles are not free from traffic congestion, and the complexity of urban road network reduces the efficiency of vehicles. Using drones and vehicles together can reduce inefficiency of the urban delivery system because of their complementary cooperation. In this paper, we assume that drones operate in a point-to-point manner between the depot and customers, and that customers in the need of fast delivery are willing to pay additional charges. For the experiment datasets, we use instances of Solomon (1987), which are well known in the Vehicle Routing Problem society. Moreover, to mirror the urban logistics demand trend, customers who want fast delivery are added to the Solomon's instances. We propose a hybrid evolutionary algorithm for solving VDRPTW. The experiment results provide different useful insights according to the geographical distributions of customers. In the instances where customers are randomly located and in instances where some customers are randomly located while others form some clusters, the dual mode delivery system displays lower total cost and higher customer satisfaction. In instances with clustered customers, the dual mode delivery system exhibits narrow competition for the total cost with the delivery system that uses only vehicles. In this case, using drones and vehicles together can reduce the level of dissatisfaction of customers who take their cargo over the time-window. From the view point of strategic flexibility, the dual mode delivery system appears to be more interesting. In meeting the objective of maximizing customer satisfaction, the use of drones and vehicles incurs less cost and requires fewer resources.

• 항공우주기술
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• 제4권1호
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• pp.186-195
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• 2005

본 논문에서는 우주비행체 자세제어용으로 추력기 시스템이 사용될 경우의 3축 자세제어설계 문제를 다룬다. 블로우다운 방식의 추력기 시스템이 사용되는 경우를 가정한다. 추력기 시스템의 심각한 시간 지연 효과를 제어설계 시에 적절히 고려하기 위한 방안으로 리미트 사이클 분석 결과를 토대로 최적제어설계 문제를 정의한다. 공진화 기법을 적용해서 주어진 요구조건을 만족하는 최적 롤 제어기 및 최적 피치/요 제어기 설계가 가능함을 보인다. 설계된 제어기에 대한 성능 분석은 비선형 시뮬레이션을 통해 이루어지게 된다.

• 천문학논총
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• 제27권4호
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• pp.289-290
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• 2012

Feedback from accreting BH (AGN) is thought to be responsible for the co-evolution of BHs and galaxies. It is likely to be prominent in the most luminous dust-obscured quasars, particularly those containing radio sources too luminous to be powered by starbursts. In order to investigate the feedback mechanism in detail, we select a unique sample containing ~ 200 of the most luminous obscured QSOs by cross-matching the WISE catalog with the FIRST and NVSS radio surveys. We present overall statistics for the observed range of colors and radio/mid-IR flux density ratio. We also present our efforts to understand the physical and evolutionary nature of these extreme feedback candidates using various telescopes such as Magellan, SOAR, Herschel, and ALMA.

• 정보통신설비학회논문지
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• 제9권4호
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• pp.158-163
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• 2010

KT will deploy HSPA+/CCC network in this year to handle data explosion. CCC is an evolutionary wireless network architecture which divides a node B into baseband and radio part. By collecting baseband units in a digital unit central station and installing only remote units on desired sites, the operator can reduce the total cost of ownership and $CO_2$ emission. In this paper, we describe some expected problems in deploying HSPA+/CCC network, and how to implement the wireless network planning system to solve them effectively.

• International Journal of Automotive Technology
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• 제7권5호
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• pp.595-601
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• 2006

Two No Spin Differential(NSD) models were benchmarked for a project of Dual-Use Technology. The Axiomatic approach is utilized to evaluate the designs of the models. The Independence Axiom is satisfied at the top level of design but not at the second level, which implies the design exhibits coupling and will admit design improvements. The detailed process of design evaluation is described. It is shown that it is possible to develop a unique and evolutionary NSD design by solving the problems that cause coupling within two models.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1992년도 한국우주과학회보 제2권1호
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• pp.13-13
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• 1993

The space and ground based infrared spectra of red supergiants are modeled and arranged in order of their evolutionary status with their theoretical model Parameters. Because of their large amplitude pulsation, the observational data taken at different phases show wide discrepancies. The chemical compositions of the dust shells around red supergiants are affected by the nuclearreactions and dredge-up processes of the cental stars. Those processes aresensitiTelr dependent on the initial ma:ss, the initial chemical coMposition,and the evolutionarr status. Miras, infrared carbon stars, and OHAR starshaTe a close link in their evolution iii many aspects, i.e. the chemicalcomposition, the optical depths and the mass loss rates. The evolutionarytracks for the three classes of red super91iants on infrared Huo-color diagamhave been constructed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.353-356
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• 2004

비선형 시스템의 제어에서 널리 사용되는 방식이 퍼지 제어기이다. 퍼지 제어기에서 가장 중요한 것은 퍼지 룰의 설계이다. 퍼지 룰을 설계하는 많은 기법들이 제안되어 있는데, 최근 들어 진화 알고리즘에 대한 관심이 증가하고 있다 그 중에서도 공생적 공진화 알고리즘이 최적의 퍼지룰을 찾기 위해 이용되는데, 본 논문에서는 스키마 공진화 알고리즘을 이용한다. 스키마 공진화 알고리즘의 성능을 입증하기 위해, 이동 로봇의 행동제어를 위한 퍼지 제어기를 스키마 공진화 알고리즘을 이용하여 설계하고, 다른 공생적 공진화 알고리즘인 바이러스_진화 유전 알고리즘과 Handa의 공진화에 대해 비교하고 실험한다.

• Genomics & Informatics
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• 제1권1호
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• pp.7-19
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• 2003

The latest measure of the relative evolutionary age of protein structure families was applied (based on taxonomic diversity) using the protein structural interactome map (PSIMAP). It confirms that, in general, protein domains, which are hubs in this interaction network, are older than protein domains with fewer interaction partners. We apply a hypothesis of 'biological network evolution' to explain the positive correlation between interaction and age. It agrees to the previous suggestions that proteins have acquired an increasing number of interaction partners over time via the stepwise addition of new interactions. This hypothesis is shown to be consistent with the scale-free interaction network topologies proposed by other groups. Closely co-evolved structural interaction and the dynamics of network evolution are used to explain the highly conserved core of protein interaction pathways, which exist across all divisions of life.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (A)
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• pp.46-48
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• 2006

현재 각 분야에서 다양한 실험 데이터가 산출되면서 이종(heterogeneous) 데이터간의 상관관계 분석에 대한 중요성이 더욱 부각되고 있다. 특히, 대규모 실험에 의해 급속하게 증가하고 있는 대량의 바이오 데이터에서 이런 문제를 해결하기 위한 새로운 데이터 마이닝 방법이 요구된다. 본 논문은 특성이 다른 두 데이터 셋에서 서로 상관관계가 있는 부분 패턴을 파악할 수 있는 새로운 알고리즘을 제안한다. 제안한 알고리즘은 다중 개체 집단을 유지하면서 상호간 공진화하는 확률적 진화컴퓨팅 방법에 기반하고, 전체의 탐색 포인트들을 분해하여 최적해를 찾는 점에서 장점을 가지고 있다. 실험 결과, 본 논문에서는 효모 유전자에 대한 발현 데이터와 모티프 데이터의 이종 데이터에 적용해 보았으며, 이러한 데이터에 있어서 주요 상관관계가 있는 패턴들을 추출한 결과를 제시한다.