• Journal of the Society of Naval Architects of Korea
• /
• v.50 no.5
• /
• pp.307-313
• /
• 2013

This paper presents a simulation for passenger ship evacuation considering determination of evacuating direction based on walking direction potential function. In order to determine walking direction of a passenger, his/her position in two dimensional plane was adopted as a design variable, and fixed boundaries such as walls and obstacles were adopted as constraints. To solve this optimum problem, a walking direction potential function was adopted as an objective function. This potential function was configured as a kind of penalty function and it contained two components. One is a potential function concerned with the distance to the destination, and other is a potential function based on the effect of walls and obstacles. To determine evacuating direction, this problem was solved by minimizing the walking direction potential function every unit time during the simulation. The crowd behavior of the passenger consisted of the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group. With the proposed algorithm, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) were implemented and the direction of passengers and total evacuation time was analyzed.

• Korean Journal of Microbiology
• /
• v.39 no.3
• /
• pp.161-165
• /
• 2003

Ornithobacterium rhinotracheale (OR) is a recently described gram-negative rod-shaped bacterium associated with respiratory tract infection in poultry. In order to investigate current occurrence of OR infection and to evaluate antibiotic susceptibility, the prevalence of OR antibody in domestic chickens were examined and the minimal inhibitory concentrations(MICs) of 8 antibiotics for 11 OR isolates was determined. All isolates tested were mostly susceptible to three antibiotics, ampicillin (MICs ranging from 0.38 ${\mu}g$/ml to 2 ${\mu}g$/ml), tetracycline (MICs 0.094～3 ${\mu}g$/ml) and doxycycline (MICs 0.047～4 ${\mu}g$/ml) but resistant to genatmicin. Ciprofloxacin, norfloxacin, enrofloxacin, and ofloxacin gave most isolates inhibition only in case of a higher concentration (MICs ranged in most cases from 3 ${\mu}g$/ml to 48 ${\mu}g$/ml). Out of 188 chicken flocks including broilers, broiler breeders, and layers, seropositive flock to OR were detected in 5 broilers (4%), 17 broiler breeders (50%), and 16 layers (55.2%), using commercial OR enzyme-linked immunosorbent assay(ELISA) kits. It suggested that OR infection was widespreaded in poultry farms in Korea.

• Korean Journal of Veterinary Service
• /
• v.34 no.4
• /
• pp.353-359
• /
• 2011

Fowl cholera is a contagious acute and chronic disease caused by Pasteurella multocida in both domesticated and wild birds. Acute fowl cholera in both chickens and wild birds has recently been documented in Korea, but the chronic form has not been reported in Korea until now. This study describes the first outbreak of chronic fowl cholera in 13-week-old Arbor Acre broiler breeder chickens submitted to the College of Veterinary Medicine, Kyungpook National University in April 2006. The clinical signs of the affected flock of 9,621 chickens were lameness caused by swollen hock joints, diarrhea, ruffled feathers, and an average weekly mortality of 1.0%. At necropsy, purulent or caseous exudates were found in the hock and wing joints, humerus, and eyes, and severe pneumonia and pericarditis were discovered. Eleven bacterial isolates obtained from the liver, joint, infraorbital sinus and sternal bursa of the submitted chickens were all identified as Pasteurella multocida based on their physiological and biochemical characteristics. Five isolates were examined for antimicrobial susceptibility against 21 different antimicrobial agents including ampicillin. All were resistant to kanamycin, neomycin, and streptomycin, and some were resistant to gentamicin. The tested isolates were all susceptible to the other 17 antimicrobial agents. All 11 isolates were capsular serogroup A based on multiplex polymerase chain reaction. In addition, two of five isolates used in the antimicrobial susceptibility test were identified as somatic serotype 1 by an agar gel diffusion precipitin test, while the others were non-typable.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.10
• /
• pp.1873-1880
• /
• 2016

Most of the energy used to operate a cellular network is consumed by a base station (BS), and reducing the transmission power of a BS is required for energy-efficient cellular networks. In this paper, a distributed transmit power control (TPC) algorithm is proposed based on the flocking model to improve the energy efficiency of a cellular network. Just as each bird in a flock attempts to match its velocity with the average velocity of adjacent birds, in the proposed algorithm each mobile station (MS) in a cell matches its rate with the average rate of the co-channel MSs in adjacent cells by controlling the transmit power of its serving BS. Simulation results show that the proposed TPC algorithm follows the same convergence properties as the flocking model and also effectively reduces the power consumption at the BSs while maintaining a low outage probability as the inter-cell interference increases. Consequently, it significantly improves the energy efficiency of a cellular network.

• Journal of the Korea Convergence Society
• /
• v.12 no.4
• /
• pp.249-258
• /
• 2021

Bitcoin prices have been soaring recently as investors flock to cryptocurrency exchanges. The purpose of this study is to predict the Bitcoin price using a deep learning model and analyze whether Bitcoin is profitable through investment strategy. LSTM is utilized as Bitcoin prediction model with nonlinearity and long-term memory and the profitability of MA cross-over strategy with predicted prices as input variables is analyzed. Investment performance of Bitcoin strategy using LSTM forecast prices from 2013 to 2021 showed return improvement of 5.5% and 46% more than market price MA cross-over strategy and benchmark Buy & Hold strategy, respectively. The results of this study, which expanded to recent data, supported the inefficiency of the cryptocurrency market, as did previous studies, and showed the feasibility of using the deep learning model for Bitcoin investors. In future research, it is necessary to develop optimal prediction models and improve the profitability of Bitcoin investment strategies through performance comparison of various deep learning models.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.506-515
• /
• 2021

Objective: Initial consequence of inbreeding is inbreeding depression which impairs the performance of growth, production, health, fertility and survival traits in different animal breeds and populations. The effect of inbreeding on economically important traits should be accurately estimated. The effect of inbreeding depression on growth traits in sheep has been reported in many breeds. Based on this, the main objective of the present research was to evaluate the impact of inbreeding on some growth traits of Iranian Baluchi sheep breed using quantile regression model. Methods: Pedigree and growth traits records of 13,633 Baluchi lambs born from year 1989 to 2016 were used in this research. The traits were birth weight, weaning weight, six-month weight, nine-month weight, and yearling weight. The contribution, inbreeding and co-ancestry software was used to calculate the pedigree statistics and inbreeding coefficients. To evaluate the impact of inbreeding on different quantiles of each growth trait, a series of quantile regression models were fitted using QUANTREG procedure of SAS software. Annual trend of inbreeding was also estimated fitting a simple linear regression of lamb's inbreeding coefficient on the birth year. Results: Average inbreeding coefficient of the population was 1.63 percent. Annual increase rate of inbreeding of the flock was 0.11 percent (p<0.01). The results showed that the effect of inbreeding in different quantiles of growth traits is not similar. Also, inbreeding affected differently on growth traits, considering lambs' sex and type of birth. Conclusion: Quantile regression revealed that inbreeding did not have similar effect on different quantiles of growth traits in Iranian Baluchi lambs indicating that at a given age and inbreeding coefficient, lambs with different sex and birth type were not equally influenced by inbreeding.

• Korean Journal of Poultry Science
• /
• v.47 no.4
• /
• pp.199-210
• /
• 2020

Footpad dermatitis (plantar surface footpad lesions) is an increasing problem in the global poultry industry, affecting foot quality, overall welfare, and production performance. The growing consumer demand for chicken feet in Asian markets has given poultry companies interest in reducing footpad dermatitis. The lesions are multiply associated with various factors affecting the moisture content of litter such as nutrition, drinker type and management, environmental conditions (e.g., temperature, relative humidity, ammonia levels, ventilation rate), and flock health. This review addresses footpad dermatitis characteristics, causes, and the assessment system to provide a guide for future research.

• Journal of Veterinary Science
• /
• v.23 no.4
• /
• pp.25.1-25.14
• /
• 2022

Background: The commercially available Newcastle disease (ND) vaccines were developed based on Newcastle disease virus (NDV) isolates genetically divergent from field strains that can only prevent clinical disease, not shedding of virulent heterologous virus, highlighting the need to develop genotype-matched vaccines Objectives: This study examined the efficacy of the NDV genotype-matched vaccine, mIBS025 strain formulated in standard vaccine stabilizer, and in carboxymethyl sago starch-acid hydrogel (CMSS-AH) following vaccination via an eye drop (ED) and drinking water (DW). Methods: A challenge virus was prepared from a recent NDV isolated from ND vaccinated flock. Groups of specific-pathogen-free chickens were vaccinated with mIBS025 vaccine strain prepared in a standard vaccine stabilizer and CMSS-AH via ED and DW and then challenged with the UPM/NDV/IBS362/2016 strain. Results: Chickens vaccinated with CMSS-AH mIBS025 ED (group 2) developed the earliest and highest Hemagglutination Inhibition (HI) NDV antibody titer (8log₂) followed by standard mIBS025 ED (group 3) (7log₂) both conferred complete protection and drastically reduced virus shedding. By contrast, chickens vaccinated with standard mIBS025 DW (group 5) and CMSS-AH mIBS025 DW (group 4) developed low HI NDV antibody titers of 4log₂ and 3log₂, respectively, which correspondingly conferred only 50% and 60% protection and continuously shed the virulent virus via the oropharyngeal and cloacal routes until the end of the study at 14 dpc. Conclusions: The efficacy of mIBS025 vaccines prepared in a standard vaccine stabilizer or CMSS-AH was affected by the vaccination routes. The groups vaccinated via ED had better protective immunity than those vaccinated via DW.

• Journal of Veterinary Science
• /
• v.23 no.3
• /
• pp.29.1-29.6
• /
• 2022

In September 2017, an outbreak with high mortality, which showed the typical signs of ND, occurred among a flock of more than 2000 Eurasian collared doves in Konarak, southeast of Iran. A confirmed pigeon paramyxovirus type 1 strain was isolated from the brain tissues of the dead doves. The isolate, which was called Pigeon/Iran/Konarak/Barin/2017, was classified as a highly velogenic NDV. Complete genome sequencing and phylogenetic analysis showed that the isolate belonged to subgenotype XXI.2, which has never been reported from Iran before. The isolate had the highest homology (96.15%) with early 2010s Italian isolates. Further studies will be required to understand the diversity better.

• Animal Bioscience
• /
• v.35 no.5
• /
• pp.778-788
• /
• 2022

Objective: The objective of the study was to understand and document socio-economic characteristics, production parameters, challenges and management practices used by Fijian households which keep indigenous chickens. Methods: A survey involving 200 households was carried out in coastal and inland communities of Fiji's wet and semi-dry ecoregions. Data on the influence of ecoregion and location of households relative to the sea on management practices, challenges and productivity of indigenous chickens were analyzed using logistic regression and general linear model of SAS software. Results: Irrespective of location relative to the sea and ecoregion, households indicated that they kept indigenous chickens for food and income generation. The Welsummer was the most (p>0.05) preferred breed. Households in the semi-dry inland communities had the largest (p<0.05) flocks compared to those in semi-dry coastal communities and the wet region. Chickens in the semi-dry region performed better (p<0.05) than those in the wet region in terms of number of clutches per year and mature live weight. Predators and feed shortages were the biggest challenges faced by households in all areas. The mongoose was ranked as the most (p>0.05) common predator followed by domestic dogs. Most households in the wet ecoregion's coastal communities housed their chickens at night, whereas communities in semi-dry ecoregion housed their chickens most of the time (p<0.05). In all regions, no households sold their chickens to commercial markets (p>0.05). Households in semi-dry ecoregion were more likely (p>0.05) to sell their chickens at the local market place. Conclusion: The productivity of local chickens in Fiji is low because of feed shortage, predators such as the mongoose and lack of market linkages.