• 제목/요약/키워드: Symbiotic systems

검색결과 57건 처리시간 0.017초

Morphological Study of the Digestive Tract of the Mud Crab (Hemigrapsus Penicillatus De Haan) and the Symbiotic Crab (Pinnotheres cyclinus Shen)

  • Moon, Young-Wha;Kim, Han-Hwa
    • Animal cells and systems
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    • 제3권4호
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    • pp.407-412
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    • 1999
  • The influence of eating habits and food type on the ultrastructural characteristics of the digestive tracts was studied under the scanning and transmission electron microscopes in two crustacean decapods (Hemigrapsus penicillatus De Haan; mud crab, Pinnotheres cyclinus Shen; symbiotic crab). The relative ratio of the length of midgut versus hindgut was 1:1 in the mud crab, but 4:1 in the symbiotic crab. Observation through the scanning electron microscope revealed that the midguts of both species have densely-arranged longitudinal mucosal folds with a smooth surface. In the hindgut of the mud crab, mucosal folds were longitudinally oriented, clusters of two to five spines were observed on the cuticular surface, and the length of the spine in the distal hindgut was longer than that in the proximal portion. In the symbiotic crab, the mucosal folds were irregulary arranged, and numerous rudimentary spinal structures were noted on the cuticular surface. Through observation of a transmission electron microscope, the epithelial cells of the midgut in both species had numerous microvilli, but the length of the microvilli was slightly longer in the mud crab than in the symbiotic crab. The central layer of the basement membrane and the muscular layer of the midgut were more developed in the mud crab than in the symbiotic crab. The thickness of the cuticular layer over the hindgut surface in the mud crab was about 4 times than that of the symbiotic crab.

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Monitoring Observations of Active White Dwarf Binary Systems

  • Lee, Hee-Won;Choi, Bo-Eun;Im, Myungshin;Lim, Gu
    • 천문학회보
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    • 제44권2호
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    • pp.60.3-60.3
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    • 2019
  • Binary systems of a white dwarf showing mass transfer activities are classified into cataclysmic variables and symbiotic stars. In the case of cataclysmic variables, the companion is usually a late type main sequence star filling its Roche lobe, where material is transferred through the inner Lagrangian point to form an accretion disk around the white dwarf. The disk becomes unstable and highly viscous when the surface density exceeds the critical density, leading to dwarf nova outbursts. In contrast, symbiotic stars are wide binary systems having a giant as the mass donor. Some fraction of giant stellar wind is accreted to the white dwarf giving rise to various symbiotic activities. In particular, half of symbiotics show Raman O VI at 6830 and 7088, which are important spectroscopic probe of mass transfer process. Monitoring observations using 1 m class telescopes will produce valuable information regarding the mass loss and mass transfer to white dwarf stars, shedding much light on the last stage of stellar evolution of low and intermediate mass stars.

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프랜차이즈 시스템의 평가 지표 개발을 위한 탐색전 연구 - 공생지수(symbiosis index)를 중심으로 - (An Exploratory Study on the Development of Evaluation Factors in Franchise System: Symbiosis Index)

  • 최성식;김홍석;구본혁;이원호;나화숙;한규철
    • 한국프랜차이즈경영연구
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    • 제1권1호
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    • pp.65-85
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    • 2010
  • 프랜차이즈 시스템을 기반으로 하는 하나의 가상기업인 프랜차이즈 기업(Franchise Enterprise)의 개념에서 이 프랜차이즈 기업이 프랜차이즈 사업을 지속적으로 성공하기 위해서는 sub-system 자체도 경쟁력을 갖고 가야하고, 이들 sub-system 간의 공생적 관계(symbiotic relationship)도 프랜차이즈 시스템의 목표인 공생(symbiosis)을 향해서 잘 유지를 해야 한다. 이런 관점에서 프랜차이즈 시스템에 대한 평가는 기존의 프랜차이즈 평가와는 다른 관점에서 진행되어야 할 것으로 보인다. 즉, 기존의 평가 시스템은 가맹본부 중심의 평가에 집중을 하고 있다. 물론 프랜차이즈 시스템의 중심은 가맹본부(가맹본부 시스템)가 되지만 프랜차이즈 시스템을 기반으로 하는 프랜차이즈 기업의 관점에서 보면 가맹본부 시스템과 더불어 다른 하위시스템(가맹점, 벤더, 고객) 간의 공생적 관계가 유지될 때 성공적이고 지속 가능한 사업성과를 기대할 수 있다. 따라서 본 연구에서는 기존 평가시스템을 고찰하고, 지금까지 가맹본부-가맹점 중심의 평가시스템의 관점에서 더 확대하여 4개의 하위 시스템 자체와 이들 간의 공생적 관계(symbiotic relationship)를 통한 공생지수(symbiosis index)를 도출하여 프랜차이즈 시스템의 새로운 평가 모델을 제시하고자 한다.

공생별에서 라만 산란선의 형성 (RAMAN SPECTROSCOPY IN SYMBIOTIC STARS)

  • 이희원
    • 천문학논총
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    • 제15권spc1호
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    • pp.103-112
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    • 2000
  • Symbiotic stars are known as binary systems of a giant with heavy mass loss and a white dwarf accompanied by an emission nebula. They often show bipolar nebulae, and are believed to form an accretion disk around the white dwarf component by attracting the slow but heavy stellar wind around the giant companion. However, the existence and physical properties of the accretion disk in these systems still remain controversial. Unique to the spectra of symbiotic stars is the existence of the symbiotic bands around $6830{\AA}$ and $7088{\AA}$, which have been identified by Schmid (1989) as the Raman scattered features of the O VI $1032{\AA}$ and $1038{\AA}$ doublet by atomic hydrogen. Due to the incoherency of the Raman scattering, these features have very broad profiles and they are also strongly polarized. In the accretion disk emission model, it is expected that the Raman features are polarized perpendicular to the binary axis and show multiple peak structures in the profile, because the neutral scatterers located near the giant component views the accretion disk in the edge-on direction. Assuming the presence of scattering regions outflowing in the polar directions, we may explain the additional red wing or red peak structure, which is polarized parallel to the binary axis. We argue that in the accretion disk emission model it is predicted that the profile of the Raman feature around $6830{\AA}$ is different from the profile of the $7088{\AA}$ because the O VI line optical depth varies locally around the white dwarf component. We conclude that the Raman scattered features are an important tool to investigate the physical conditions and geometrical configuration of the accretion disk in a symbiotic star.

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공생 진화알고리듬을 이용한 유연조립시스템의 공정계획 (Process Planning in Flexible Assembly Systems Using a Symbiotic Evolutionary Algorithm)

  • 김여근;위정미;신경석;김용주
    • 산업공학
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    • 제17권2호
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    • pp.208-217
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    • 2004
  • This paper deals with a process planning problem in the flexible assembly system (FAS). The problem is to assign assembly tasks to stations with limited working space and to determine assembly routing with the objective of minimizing transfer time of the products among stations, while satisfying precedence relations among the tasks and upper-bound workload constraints for each station. In the process planning of FAS, the optimality of assembly routing depends on tasks loading. The integration of tasks loading and assembly routing is therefore important for an efficient utilization of FAS. To solve the integrated problem at the same time, in this paper we propose a new method using an artificial intelligent search technique, named 2-leveled symbiotic evolutionary algorithm. Through computational experiments, the performance of the proposed algorithm is compared with those of a traditional evolutionary algorithm and a symbiotic evolutionary algorithm. The experimental results show that the proposed algorithm outperforms the algorithms compared.

Photometric Variability of Symbiotic Stars at All Time Scales - Magellanic Cloud Systems

  • Angelnoi, Rodlfo
    • 천문학회보
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    • 제42권2호
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    • pp.38.1-38.1
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    • 2017
  • Symbiotic stars are long-orbital-period interacting binaries characterized by extended emission over the whole electromagnetic range and by complex photometric and spectroscopic variability. In this contribution, I will present some high-cadence, long-term optical light curves of confirmed and candidate symbiotic stars in the Magellanic Clouds. By careful visual inspection and combined time series analysis techniques, we investigate for the first time in a systematic way the photometric properties of these astrophysical objects, trying in particular to distinguish the evolutionary status of the cool component, to provide its first-order pulsation ephemeris and to link all this information with the physical parameters of the binary system as a whole. Finally, I will discuss a new, promising photometric technique, potentially able to discover Symbiotic Stars in the Local Group of Galaxies without the recourse to costly spectroscopic follow-up.

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Symbiotic Organisms Search for Constrained Optimization Problems

  • Wang, Yanjiao;Tao, Huanhuan;Ma, Zhuang
    • Journal of Information Processing Systems
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    • 제16권1호
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    • pp.210-223
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    • 2020
  • Since constrained optimization algorithms are easy to fall into local optimum and their ability of searching are weak, an improved symbiotic organisms search algorithm with mixed strategy based on adaptive ε constrained (ε_SOSMS) is proposed in this paper. Firstly, an adaptive ε constrained method is presented to balance the relationship between the constrained violation degrees and fitness. Secondly, the evolutionary strategies of symbiotic organisms search algorithm are improved as follows. Selecting different best individuals according to the proportion of feasible individuals and infeasible individuals to make evolutionary strategy more suitable for solving constrained optimization problems, and the individual comparison criteria is replaced with population selection strategy, which can better enhance the diversity of population. Finally, numerical experiments on 13 benchmark functions show that not only is ε_SOSMS able to converge to the global optimal solution, but also it has better robustness.

공생별에서의 $H_{\alpha}$날개의 편광연구 (POLARIZATION OF $H_{\alpha}$ WINGS RAMAN-SCATTERED IN SYMBIOTIC STARS)

  • 박지용;이희원
    • 천문학논총
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    • 제15권spc1호
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    • pp.147-151
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    • 2000
  • Symbiotic stars, believed to be binary systems of a mass-losing giant and a white dwarf with an emission nebula, are known to exhibit very broad wings around Hex that extend to $\~10^3km\;s^{-1}$. The wing formation mechanism is not a settled matter and recently Lee (2000) proposed that Raman scattering of Ly$\beta$ by neutral hydrogen is responsible for the broad H$\alpha$ wings. In this model, it is predicted that. the Hex wings will be polarized depending on the geometric and kinematic distribution of the scatterers relative to the UV emission region. In this paper, we investigate the polarization of Hex wings in symbiotic stars. Noting that many symbiotic stars possess bipolar nebular morphology, we assume that the distribution of neutral scatterers follows the similar pattern with a receding velocity of several tens of km $s^{-1}$ that mimics the expansion of the neutral envelope of the nebula. It is found that the red wing is more strongly polarized than the blue and main part and that the polarization direction is along the equatorial plane. We obtain a typical degree of polarization $\~10$ percent, however, it varies depending on the detailed distribution of H I scatterers We conclude that spectropolarimetry will provide very important information on the origin of the Hex wings.

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Development of Educational Program for Production Managers Based on a Symbiotic Competition with ABC-G Network

  • Ishihara, Masahiko;Nakano, Makoto;Ishii, Kazuyoshi
    • Industrial Engineering and Management Systems
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    • 제13권3호
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    • pp.258-266
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    • 2014
  • This paper proposes a management system for the educational program of production managers on the basis of value co-creation by the learner and the instructor. The program combines an intelligent knowledge-based approach with the kaizen activity program. The program helps individuals acquire knowledge and skills to ensure the total rather than the partial optimization of processes and operations facilitating continuous improvement in the workplace. To achieve these goals, the program uses models of a learning process and a swing of enlightenment. In addition, the program is supported by a framework of academic, business people, consultants, and government officers. The program was developed using an instructional design approach. This paper discusses the process of developing and managing the educational program between 2006 and 2012 as well as the results obtained.