• 제목/요약/키워드: Flock

검색결과 156건 처리시간 0.021초

Self-Organization for Multi-Agent Groups

  • Kim, Dong-Hun
    • International Journal of Control, Automation, and Systems
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    • 제2권3호
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    • pp.333-342
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    • 2004
  • This paper presents a framework for the self-organization of swarm systems based on coupled nonlinear oscillators (CNOs). In this scheme, multiple agents in a swarm self-organize to flock and arrange themselves as a group using CNOs, which are able to keep a certain distance by the attractive and repulsive forces among different agents. A theoretical approach of flocking behavior by CNOs and a design guideline of CNO parameters are proposed. Finally, the formation scenario for cooperative multi-agent groups is investigated to demonstrate group behaviors such as aggregation, migration, homing and so on. The task for each group in this scenario is to perform a series of processes such as gathering into a whole group or splitting into two groups, and then to return to the base while avoiding collision with agents in different groups and maintaining the formation of each group.

Self-organization of Swarm Systems by Association

  • Kim, Dong-Hun
    • International Journal of Control, Automation, and Systems
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    • 제6권2호
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    • pp.253-262
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    • 2008
  • This paper presents a framework for decentralized control of self-organizing swarm systems based on the artificial potential functions (APFs). The framework explores the benefits by associating agents based on position information to realize complex swarming behaviors. A key development is the introduction of a set of association rules by APFs that effectively deal with a host of swarming issues such as flexible and agile formation. In this scheme, multiple agents in a swarm self-organize to flock and achieve formation control through attractive and repulsive forces among themselves using APFs. In particular, this paper presents an association rule for swarming that requires less movement for each agent and compact formation among agents. Extensive simulations are presented to illustrate the viability of the proposed framework.

육용오리에서 aspergillosis 증례 (A case of aspergillosis in commercial domestic ducks)

  • 추금숙;강미선;이정원
    • 한국동물위생학회지
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    • 제35권2호
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    • pp.165-168
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    • 2012
  • A case of aspergillosis was observed in a flock of 5~10 days old commercial domestic ducks in Jeongeup. The clinical signs were depression and breathing by gasping or rapid opening of the bill. Grossly, lung was attached to pleura with white cheesy plaques. Numerous nodules was found in lung. Histopathologically, severe granulomatous pneumonia with intralesional fungal hypha were observed in the lung. Aspergillus spp. colonies was isolated from fungal culture and identified by polymer chain reaction.

Flexible and Scalable Formation for Swarm Systems

  • Kim Dong-Hun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제5권3호
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    • pp.222-229
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    • 2005
  • This paper presents a self-organizing scheme for multi-agent swarm systems based on coupled nonlinear oscillators (CNOs). In this scheme, unicycle robots self-organize to flock and arrange group formation through attractive and repulsive forces among themselves. The main result is the maintenance of flexible and scalable formation. It is also shown how localized distributed controls are utilized throughout group behaviors such as formation and migration. In the paper, the proposed formation ensures safe separation and good cohesion performance among the robots. Several examples show that the proposed method for group formation performs the group behaviors such as reference path following, obstacle avoidance and flocking, and the formation characteristics such as flexibility and scalability, effectively.

천연염재의 자외선 차단성능 연구 (A Study on Ulraviolet-cut Ability of Silk Fabric Dyed with Natural Dyestuffs)

  • 김월순;최인려
    • 복식문화연구
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    • 제12권1호
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    • pp.1-11
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    • 2004
  • This study was carried out on the process of natural dye substances which can flock ultraviolet rays without producing harmful substances by pollution, germs, etc. While making human body safe in contact, extracting Gardenia, Sappan wood, Radix scutellariae, Cromwell, Mugwort, Gallnut, Lac. Those are used for curing diseases, dyeing silk cloth with those extracts, and examining the color fastness, Ultraviolet protection. From this study, the following conclusion was produced. Brightness was lower in pre-mordanting than in post. And color difference showed that Radix scutellariae was the highest. Aluminum-mordanting showed a higher color difference than Fe. Colorfastness to washing was high in all samples, and the degree of color-changing by washing was the highest in the sample dyed by gardenia, pre-mordanted gallnut showed the highest degree. Colorfastness to perspiration was the highest in gardenia. UV-A test showed that all samples a high rate of 85% or higher compared with test white cloth. Especially, post-mordanted radix scutellariae, pre-mordanted gallnut and post-mordanted sappanwood showed a superior blocking rate.

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산란계에서의 흉강내 기형종 발생보고 (Thoracic teratoma in a laying hen (Deklb brown warren). A case report)

  • 한규삼;이성효;서문정;오언평;채효석;유혜진;임채웅
    • 한국동물위생학회지
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    • 제20권2호
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    • pp.183-189
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    • 1997
  • This article reports a spontaneous thoracic teratoma in a laying hen (Deklb brown warren). In this case, a 40 days old hen was submitted for necropsy as part of an investigation into a flock problem suspected Marek's disease to Chonbuk Veterinary Service Laboratory in 1983. On the gross finding, mass was In the cranial subpulmonary cavity and attached to the vertebral column. It contained fully developed contour feathers. Histologically, feathers were arised from feather follicles complete with arrector plumi muscle, nerve, vessel and mucous gland composed with simple tall columnar epithelium. The outer surface of mass was lined by keratinized or nonkeratinized stratified squamous epithelium. It converted to pseudostratified ciliated columnar epithelium in some area. There were lymphocyte infiltration around gland tissue and eosinophilic intranuclear inclusion bodies in nonkeratinized epithelium. This thoracic teratoma was composed of ectodermal origin, squamous epithelium and nerve, and endodermal origin, mucous gland. This case in laying hen has never been reported in the literature in the world.

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Poultry Coccidiosis-A Concurrent Overview on Etiology, Diagnostic Practices, and Preventive Measures

  • Nawarathne, Shan Randima;Yu, Myunghwan;Heo, Jung Min
    • 한국가금학회지
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    • 제48권4호
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    • pp.297-318
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    • 2021
  • Coccidiosis is a major parasitic disease in the poultry industry, with great economic implications worldwide. It is a ubiquitous protozoan infection caused by several species of the genus Eimeria (host-specific) that colonize and reproduce in the intestine of birds, ultimately altering the health and performance of the flock. At present, several methods are used to diagnose coccidiosis in poultry, including field and laboratory techniques (intestinal lesion scoring, oocyst counting in feces, and biochemical and molecular diagnosis). Traditionally, diagnosed flocks have been treated either by vaccination to improve the active immunity of the birds against coccidiosis or supplementation of prophylactic anticoccidials to ameliorate the deleterious effects of coccidiosis. However, these methods has certain drawbacks such as vaccine-induced coccidiosis, drug resistance, and residual drug accumulation in the host. Consequently, alternative safe anti-coccidial agents, including the use of phytogenic compounds, have been explored for preventing coccidiosis. Here, we provide a simple overview of the literature on poultry coccidiosis by focusing on the etiology, diagnostic practices, and preventive measures.

Enhancement OLSR Routing Protocol using Particle Swarm Optimization (PSO) and Genrtic Algorithm (GA) in MANETS

  • Addanki, Udaya Kumar;Kumar, B. Hemantha
    • International Journal of Computer Science & Network Security
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    • 제22권4호
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    • pp.131-138
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    • 2022
  • A Mobile Ad-hoc Network (MANET) is a collection of moving nodes that communicate and collaborate without relying on a pre-existing infrastructure. In this type of network, nodes can freely move in any direction. Routing in this sort of network has always been problematic because of the mobility of nodes. Most existing protocols use simple routing algorithms and criteria, while another important criterion is path selection. The existing protocols should be optimized to resolve these deficiencies. 'Particle Swarm Optimization (PSO)' is an influenced method as it resembles the social behavior of a flock of birds. Genetic algorithms (GA) are search algorithms that use natural selection and genetic principles. This paper applies these optimization models to the OLSR routing protocol and compares their performances across different metrics and varying node sizes. The experimental analysis shows that the Genetic Algorithm is better compared to PSO. The comparison was carried out with the help of the simulation tool NS2, NAM (Network Animator), and xgraph, which was used to create the graphs from the trace files.

철원지역에서 월동하는 두루미류의 지형과 식생에 의한 미소 취식지 선호성 (Micro Feeding Site Preference of Wintering Cranes by Topography and Vegetation in Cheorwon Basin, Korea)

  • 유승화;김인규;이한수;이기섭
    • 한국환경생태학회지
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    • 제23권5호
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    • pp.418-430
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    • 2009
  • 두루미류 취식무리의 미소 취식지 선호에 대한 특성을 밝히기 위하여 철원지역에서 월동기인 2005년 12월에서 2006년 2월, 2007년 1월에서 2월까지 총 12회 실시하였다. 두루미와 재두루미가 먹이로 하는 쌀 낙곡의 밀도는 논의 중앙보다 가장자리에 많았다. 하지만, 두루미류는 논의 중앙보다는 논둑 인근 지역을 취식장소로 이용하는 경우가 많았다. 상대적으로 재두루미는 두루미에 비하여 논의 중앙 지역을 취식장소로 이용하는 비율이 높았다. 두루미의 경우 논둑이 높고 논둑 식생의 높이가 높은 경우와 논둑 높이와 식생의 높이를 합한 높이가 높은 경우를 취식위치로 선호하였다. 재두루미는 논둑, 식생, 논둑과 식생의 높이 합이 키에 비하여 높은 경우를 선호하지 않았다. 또한, 두루미와 재두루미에서 모두 은폐지역에서 취식하는 비율이 날씨요인과 관계가 없었다. 이러한 결과는 두루미류가 개방된 취식지(수평가시권이 넓은 지역)를 선호한다는 기존 가설과는 달리 은폐된 취식지를 선호하는 것으로 나타났다. 또한 종간의 비교에서는 두루미가 재두루미에 비하여 은폐된 지역을 선호하는 것으로 나타났다. 무리크기별 은폐지역과 비은폐지역 취식비율은 두루미와 재두루미 모두 무리크기를 고려하지 않은 취식비율과 차이가 없었다. 결과적으로 두루미가 은폐지역을 선호하고 재두루미가 은폐지역에 상관없이 취식지를 선택하는 경향은 취식무리의 크기에 좌우되지 않는 종 특이적인 성향을 보였다.

양계농가 전산화 실태에 관한 조사 연구 (A Survey on Current Situation of Computer System Utilization for Poultry Farm Management)

  • 최연호;이상진;신영수
    • 한국가금학회지
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    • 제23권4호
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    • pp.209-219
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    • 1996
  • This research was carried out to get the basic information on the current situation of personal computer utilization for poultry farm management, and the results obtained could be used in developing of the software system for the poultry farm management. Survey method by interview and mail was adopted to carry out the research, and the total number of data used to statistical analyses was k6 poultry farmers. 1. The ratio of the poultry farmers who had the personal computer(P/C) was about 25%, and the most of the layer farmers from age 30 to 40 who manage the flock size 20,000 or above had the P/C. 2. About 70% of the farmers who had P/C have bought the system after 1993, and 83% of those farmers had the P/C-486 or above level system. They bought the P/C with intent to apply it to farm management(39%) and education for children(31%). 3. About 50% of the farmers who had P/C obtained the relevant knowledge for operating computer system by themselves, and the 33% of the P/C-possessed farmers used P/C for word-processor. 4. About 35% of the farmers who had P/C applied their system to analyse the management analyses, and the sarne ratio of the farmers answered that they didn't apply the system to their farm management. 5. About 25% of the farmers who had P/C used package software, and the company which installed the automated cage system offered the software. 6. Most of the farmers considered the computerization of the farm management positively, and they answered that they will apply P/C to their management actively from now on. 7. About 56% of the farmers didn't think that they had sufficient knowledge for operating computer system, and a quarter of them pointed that the difficulty of the buying software for poultry farm management was the most biggest problem to spread out the computerization in the poultry farm. 8. Most of the poultry farmers didn't buy P/C because they didn't have the relevant knowledge for computer system, but they wanted to learn basic knowledge for computer, and they had the intention to apply computer to their management positively. In order to expand the computerization for poultry farm management, appropriate education system for the farmers from age 30 to 40 who manage the flock size 20,000 or above and the development of the software that could be applied to poultry farm management on the spot efficiently should be made.

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