• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.176-180
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• 1998

We may gaze at some peculiar scenes of flocking of birds and fishes. This paper demonstrates that multiple agent mobile robots show complex behaviors from efficient and strategic rules. The simulated flock are realized by a distributed behavioral model and each mobile robot decides its own motion as an individual which moves constantly by sensing the dynamic environment.

• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.99-106
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• 1996

Because of the imminent market opening of livestock and poultry products, Korean poultry industry is faced an influx of contagious diseases from abroad. Due to the increasing trend of intensive and automatic poultry farming, the risks of catching various poultry epidemics are ever more increasing. For the prevention of poultry epidemics, the principles of biosecurity should be observed rather strictly. In addition, regular checking to confirm the presence or absence of latent diseases through serological test, post-mortem examination, and laboratory test, should be carried out routinely. Finally, all kinds of stress factors should be minimized to keep the flock healthy and productive, so that they can achieve their maximum genetic potential.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.86-105
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• 2002

질병진단에 있어서 부검의 중요성은 두 말할 필요가 없다. 왜냐하면 정확한 진단은 질병의 본질과 병원체의 병리기전(pathogenesis)을 이해함으로써 합리적인 치료와 예방대책을 수립할 수 있다. 특히 최근에는 동물질병과 환경 위해 요소 등 공중위생적인 측면이 상당히 부각되어 사람에게도 영향을 줄 수 있는 인수공통 전염병의 예방을 용이하게 한다. 특히 축산업의 발달에 따라 돼지나 닭의 경우는 개체 진료보다는 집단 단위 (herd 또는 flock)의 위생관리가 중요하기 때문에 질병에 대한 역학적 상황 분석과 부검 진단은 필수 불가결한 과정이다. (중략)

• Journal of Embryo Transfer
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• v.30 no.2
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• pp.115-119
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• 2015

The study was carried out to assess the production performances of Japanese quail parent stock raised under open housing system and the study was conducted in a local farm with 2000 Japanese parent stock quail birds (Coturnix coturnix japonica). Observed body weight gain was recorded in each weekend up to 7 weeks of their age; birds gained weight 15.73, 31.45, 47.20, 90.80, 125.27, 153.14 and 175.20 grams, respectively. There have been observed sharp decline of fertility and hatchability of birds with increase of their age. Optimum fertility was recorded at third week and optimum hatchability at fifth week of their age. Average flock uniformity was found 83.68%. The hen day egg production of the flock was recorded 81, 83, 85, 86, 89, 89, 89, 89 and 88% in each weekend, respectively. It may therefore be concluded that Japanese quail parent stock performs well under open housing system in Bangladesh and future study can be taken to better understand their production performances.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.141-150
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• 1991

A local isolate of chicken anemia agent (CAA), isolate 89-69. was tested for pathogenicity for chickens. When chickens from a specific pathogen free (SPF) flock were inoculated intramuscularly with the isolate at one day old, all the chickens showed severe anemia at 14 to 18 days post inoculation(DPI) and returned to normal at 25DPI, Some of the inoculated chickens (27∼33％) died between 13 to 17 DPI's with lesions of severe aplasia of bone marrow and thymic atrophy. In chickens kept in contact with inoculated chickens, some of the chickens had anemia at 25 and 28 DPI's. Virus could be reisolated from inoculated as well as in contact chickens till 21 DPI. Antibodies to CAA could be detected in all inoculated and in contact chickens when tested at 42 DPI by the indirect fluorescent antibody method. When chickens from a different SPF flock were inoculated at one day old, degrees of anemia, both in frequency of incidence and severity, were low These chickens were proved partly to have antibodies to CAA when tested for hatchmates. In a survey for antibodies to CAA in field chicken flocks, one out of 7 flocks(14％) aged 3 to 10weeks was antibody positive whereas 19 out of 20 flocks(95％) over 20 weeks of age were positive. Altogether 29 out of 39 flocks (74％) were antibody positive.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.965-970
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• 2014

In an effort to improve the convergence speed in k-means clustering, we introduce the notion of the birds' movement in a flock. Their motion is characterized by the observation that each bird runs after his nearest neighbor. We utilize this feature in clustering procedure. Once the class of a vector is determined, then a number of vectors in the vicinity of it are assigned to the same class. Experiments have shown that the required number of iterations for termination is significantly lower in the proposed method than in the conventional one. Furthermore, the time of calculation per iteration is more than 5% shorter in the proposed case. The quality of the clustering, as determined from the total accumulated distance between the vector and its centroid vector, was found to be practically the same. It might be phrased that we may acquire practically the same clustering result with shorter computational time.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.98-106
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• 2013

The duty-cycle synchronization among mobile sensor nodes with energy-harvesting is very important. The nodes should keep their duty-cycle same to others as much as possible because they have to cooperate each other and to consume energy efficiently. The distribution of node position in network affects not only node connectivity but also the active time of synchronized nodes, and it relates to network life-time finally. In this paper, we introduce a network topology change algorithm (TCA) for energy-harvesting mobile sensor networks based on self-synchronized duty-cycling. The algorithm tries to change a network topology into a balanced topology where the mobile sensor nodes are unified according to the density of the number of nodes. For TCA, both fluid flow algorithm and flock dispersion algorithm are proposed and they are evaluated through the simulation in agent based modeling language. TCA is applied to the energy-harvesting mobile sensor networks to improve the synchronization of duty-cycle and to reduce the variation of energy consumption among nodes.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.35-42
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• 1982

Data pertaining to the first generation of a Synthetic White Leghorn flock were used to estimate the heritabilities of and genetic correlation between partial egg production(egg number or percentage) or diversely segmented part records and other traits such as age at sexual maturity, residual and annual egg production, and to compare the expected genetic gain from selection on partial egg number or partial percent production with correlated response in other traits. The estimated heritabilites for six measures of egg Production were ranged from 29 to 35, while heritability for age at sexual maturity (SM) was intermediate (48). Genetic correlations between partial egg number (P) and annual egg number. (A), and partial percent production (P') and annual percent production (A') were 51 and 72, respectively. Genetic correlation between P and SM was estimated largely negative (-.64), while correlation bettween P' and SM was positively intermediate(34). In comparing direct response from selection on partial production (P or P') with another response in correlated trait, selection on P would be 25% more efficient than selection of P' for improving A, while selection of P' would be 94% more efficient than selection P for improving A' For shortening SM selection of P would be 98% more efficient than selection on P'.

• Korean Journal of Veterinary Research
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• v.1 no.1
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• pp.54-60
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• 1961

For the purpose of investigating seasonal changes of germinal centers of splenic lymph nodules and of blood lymphocytes of ducks, the spleens of 8 ducks from a flock were observed histologically every season; 2 cases in spring (March and April), 2 in summer (July and August), 2 in autumn (October and November) and 2 in winter (December and January). Blood cells of 8 ducks from the same flock also were counted during the summer (from July to August) and autumn (from October to November) The results obtained were summarized as follows: 1. There were seasonal changes in the germinal centers of lymph nodules, that is, the germinal centers were formed in spring and disappeared in autumn. In summer these were at the stage of transition from formation in spring to disappearance in autumn. In winter, on tile other hand. the process was reversed from the stage of disappearance in autumn to the stage of formation in spring. 2. The germinal center of splenic lymph nodule was encapsulated with a fibrous capsule which disappeared concommitantly with its germinal center. 3. The percentage and absolute value of lymphocytes in autumn were higher than those in summer, the fact that seemed to be not in agreement with Flemming's view that the lymphocytic clear germinal center may be functionally at the stage of lymphocyte formation, but in agreement with Maximow's view that the large lymphocytic clear germinal center is functionally at the stage of resting and medium-sized lymphocytic germinal center may be functionally at the stage of lympocyte formatiom.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.137-146
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• 1997

About Clostridium perfringens causing clinically necrotic enteritis or isolated from the intestinal contens of healthy chicken, We examined the usefulness of a rapid identification method by gas-liquid chromatography as well as the types of toxins. For this study, there were used 169 chickens including 116 broilers, 27 layers and 26 breeders which collected from 9 healty flock and 21 diseased flock showing necrotic enteritis. Among them, Cl perfringens was isolated from 30 chickens(17.8%) including 7 breeders(26.9%), 5 layers(18.5%) and 18 broilers(15.5%). Isolation of Cl perfringens was mainly from ceca (100%) and followed by small intestines(70.0%) and livers(16.7%), respectively. Average concentration of the pathogen in intestinal contents was $10^{3.8}CFU/g$ in cases occuring necrotic enteritis and on the contrary $10^{3.8}CFU/g$ in healthy cases. All isolates tested showed the same characterstics in biochemical tests compared to those in standard strain. Analysis of gas-liquid chromatography to volatile fatty acids produced by Cl perfringens in PYG broth showed the typical peaks of acetic and butyric acids compatible with the standard chromogram and was confirmed as a effective and reliable tool for rapid identification of the bacteria. Toxin types of 30 strains were mostly classified in A type(26 isolates) and the rest in C type(2 isolates) and unidentifed type(2 isolates). All the isolates were highly susceptible to amphicillin, amoxicillin and cephalothin.