• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1222-1228
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• 2016

The objective of this research was to estimate genetic parameters and trends for length of productive life (LPL), lifetime number of piglets born alive (LBA), lifetime number of piglets weaned (LPW), lifetime litter birth weight (LBW), and lifetime litter weaning weight (LWW) in a commercial swine farm in Northern Thailand. Data were gathered during a 24-year period from July 1989 to August 2013. A total of 3,109 phenotypic records from 2,271 Landrace (L) and 838 Yorkshire sows (Y) were analyzed. Variance and covariance components, heritabilities and correlations were estimated using an Average Information Restricted Maximum Likelihood (AIREML) procedure. The 5-trait animal model contained the fixed effects of first farrowing year-season, breed group, and age at first farrowing. Random effects were sow and residual. Estimates of heritabilities were medium for all five traits ($0.17{\pm}0.04$ for LPL and LBA to $0.20{\pm}0.04$ for LPW). Genetic correlations among these traits were high, positive, and favorable (p<0.05), ranging from $0.93{\pm}0.02$ (LPL-LWW) to $0.99{\pm}0.02$ (LPL-LPW). Sow genetic trends were non-significant for LPL and all lifetime production traits. Sire genetic trends were negative and significant for LPL ($-2.54{\pm}0.65d/yr$; p = 0.0007), LBA ($-0.12{\pm}0.04piglets/yr$; p = 0.0073), LPW ($-0.14{\pm}0.04piglets/yr$; p = 0.0037), LBW ($-0.13{\pm}0.06kg/yr$; p = 0.0487), and LWW ($-0.69{\pm}0.31kg/yr$; p = 0.0365). Dam genetic trends were positive, small and significant for all traits ($1.04{\pm}0.42d/yr$ for LPL, p = 0.0217; $0.16{\pm}0.03piglets/yr$ for LBA, p<0.0001; $0.12{\pm}0.03piglets/yr$ for LPW, p = 0.0002; $0.29{\pm}0.04kg/yr$ for LBW, p<0.0001 and $1.23{\pm}0.19kg/yr$ for LWW, p<0.0001). Thus, the selection program in this commercial herd managed to improve both LPL and lifetime productive traits in sires and dams. It was ineffective to improve LPL and lifetime productive traits in sows.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.814-824
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• 2010

The objective of this research was to assess the effect of experience, education, record keeping, labor, and decision making on monthly milk yield per farm (MYF), monthly milk yield per cow (MYC), monthly milk revenue per farm (MRF), and monthly revenue per cow (MRC) of dairy farms supported by a private organization in Central Thailand. The dataset contained 34,082 monthly milk yield and revenue records collected from January 2004 to December 2008 on 497 farms, and information on individual farmer experience and education, record keeping, and decision making obtained with a questionnaire. Farmer experience categories were i) no experience, ii) one year, iii) two to five years, iv) six to ten years, v) eleven to fifteen years, vi) sixteen to twenty years, and vii) more than twenty years. Farmer education categories were i) no education or primary school, ii) high school, and iii) bachelor or higher degree. Record keeping categories were: i) no records and ii) kept records. Labor categories were: i) family, ii) hired people, and iii) family and hired people. Decision making categories were: i) decisions made by farmers themselves, ii) decisions made with help from government officials, and iii) decisions made with help from organization staff. The mixed linear model contained the fixed effects of year-season, farm location-farm size subclass, experience, education, record keeping, labor, and decision making on sire selection, and the random effects of farm and residual. Results showed that longer experience increased (p<0.05) monthly milk yield (MYF and MYC) and revenue (MRF and MRC). Farms that hired people produced the highest (p<0.05) monthly milk yield (MYF and MYC) and revenue (MRF and MRC), followed by farms that used family, and the lowest values were for farms that used both family and hired people. Better educated farmers produced more MYC and MRC (p<0.05) than lower educated farmers. Farms that kept records had higher MYF and MRF (p<0.05) than those without records. Although differences among farms were non-significant, farms that received help from the organization staff had higher monthly milk yield (MYF and MYC) and revenue (MRF and MRC) than those that decided by themselves or with help from government officials. These findings suggested that dairy farmers needed systematic training and continuous support to improve farm milk production and revenues in a sustainable manner.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.320-327
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• 2017

Objective: The objective of this research was to estimate genetic correlations between number of piglets born alive in the first parity (NBA1), litter birth weight in the first parity (LTBW1), number of piglets weaned in the first parity (NPW1), litter weaning weight in the first parity (LTWW1), number of piglets born alive from second to last parity (NBA2+), litter birth weight from second to last parity (LTBW2+), number of piglets weaned from second to last parity (NPW2+) and litter weaning weight from second to last parity (LTWW2+), and to identify the percentages of animals (the top 10%, 25%, and 50%) for first parity and sums of second and later parity traits. Methods: The 9,830 records consisted of 2,124 Landrace (L), 724 Yorkshire (Y), 2,650 LY, and 4,332 YL that had their first farrowing between July 1989 and December 2013. The 8-trait animal model included the fixed effects of first farrowing year-season, additive genetic group, heterosis of the sow and the litter, age at first farrowing, and days to weaning (NPW1, LTWW1, NPW2+, and LTWW2+). Random effects were animal and residual. Results: Heritability estimates ranged from $0.08{\pm}0.02$ (NBA1 and NPW1) to $0.29{\pm}0.02$ (NPW2+). Genetic correlations between reproduction traits in the first parity and from second to last parity ranged from $0.17{\pm}0.08$ (LTBW1 and LTBW2+) to $0.67{\pm}0.06$ (LTWW1 and LTWW2+). Phenotypic correlations between reproduction traits in the first parity and from second to last parity were close to zero. Rank correlations between LTWW1 and LTWW2+ estimated breeding value tended to be higher than for other pairs of traits across all replacement percentages. Conclusion: These rank correlations indicated that selecting boars and sows using genetic predictions for first parity reproduction traits would help improve reproduction traits in the second and later parities as well as lifetime productivity in this swine population.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.27-44
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• 1993

This study was performed to investigate the changes of mandibular condyle by low calcium diet and the effects of irradiation on the bone in osteoporotic state. In order to carry out this experiment, 80 seven-week old Sprague-Dawley strain rats weighing about 150 gm were selected and equally divided into one experimental group of 40 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two group and exposed to irradiation. The two irradiation groups received a single dose of 20 Gy on the jaw area only and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were serially terminated by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After termination, both sides of the dead rats mandibular condyle were removed and fixed with 10% neutral formalin. The bone mineral density of mandibular condyle was measured by use of dual energy X-ray bone densitometer(model DDX-alpha, Lunn Corp., U. S. A.). The mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Japan). Thereafter, the obtained radiographs were observed, and the mandibular condyle was further decalcified and embedded in paraffin as the general method. The specimen sectioned and stained with hematoxylin-eosin, PAS and Rabbit Anti-Human Tumor Necrosis Factor-a observed by a light microscope. The obtained results were as follows: 1. In the non-irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days, and decrease the number of trabeculae of the condyle and resorption of the calcified cartilaginous zone were observed after 3 days. On microscopic observations, the number nd size of trabeculae were decreased after 7 days of experiment. 2. In the irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days and resorption of the calcified cartilaginous zone and decrease the number and coarse of the trabeculae of the condyle were observed. These findings were extended rather than in non-irradiated group with low calcium diet. On microscopic observations, many osteoclasts were detected and the number and size of trabeculae were somewhat decreased after 7 days. Also there was degenerative changes of tissues of bone marrow on the 14th day but that condition was restored on the 21st day of experiment. 3. In the irradiated group with normal diet, the bone mineral density of the condyle was somewhat decreased with times and degree of decrease of the number of trabeculae was somewhat larger than in the non-irradiated group with normal diet. On microscopic observations, the tissues of bone marrow were atrophic and degenerative changes but that condition was restored on the 21st day of experiment. 4. In immunocytochemical findings, in the irradiated and non-irradiated groups with low calcium diet, negative or partial positive response to TNF was observed, but positive response in the normal diet groups.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.43-50
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• 2004

This study had been performed to analyze flushing effects for instantaneous contaminants input with changing dam discharge in River. RMA-2 and RMA-4 models were applied to the downstream part of the Han River(from Jamsil submerged weir to Singok submerged one) The longitudinal dispersion coefficient of $50m^2/s$ was used. The four cases of dam discharges were selected as $500m^3/s,\;1000m^3/s,\;1500m^3/s$ and $2000m^3/s$, respectively, for 1 hour. The drought flow was fixed $200m^3/s$ in the Han River. The arrival time and the concentration of contaminant, the area of dispersion were estimated with RMA-4 model in the downstream part of the Han River. The arrival time which the concentration of contaminants become under 1ppm was analyzed with the stagnant and the instantaneous inflow contaminant at the section of Sungsan Bridge. The more increasing a dam discharge, the more short a dilution time of contaminant. The relation between the dam discharge and dilution time shows linearity. The instantaneous contaminant input was sensitively affected by the dam discharge than the stagnant contaminant one in the river. If it is tried to flush with a temporally increased dam discharge, it should be understood the range of overflowed contaminant dispersion from main channel to tributary channel.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.169-182
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• 2017

This research reviews regulations on logistics/transport industry and attempts to quantify the effects of regulation mitigation on GDP per capita. South Korea's transport industry has been gradually expanding, however, the industrial structure is still short rooted. In 2014, average number of hours worked is 5th highest and wage margin 12th smallest out of 18 industries. Furthermore, the regulations for this industry appear to be stricter than those of other industries. OECD's logistics/transport industry regulatory index for South Korea has been decreasing for the last 40 years but still exceeds those of EU, Japan, US, and other countries. This paper provides supporting reasons for regulatory reforms by analyzing the ripple effects on real GDP. Factors such as the ratio of trade among GDP, the enrollment rate to primary school, energy usage per capita, and population are controlled in the fixed-effect model. Estimation results showed that 1 unit decrease in transport/logistics regulatory index is correlated with 8.1% increase of the real GDP per capita, that is, 10% of deregulation is expected to yield 2.16% increase in GDP per capita. Thus, it is expected that mitigating regulations on market entries, price determination, ownership structures of network industry, vertical integrations can improve the economy of South Korea.

• Journal of agriculture & life science
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• v.46 no.5
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• pp.57-63
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• 2012

The purpose of this study was to estimate genetic parameters for productive traits in Duroc breed. In this study, 40,657 records for productive traits and the pedigree data of 47,974 families were collected from 41 farms registered at the Korean Animal Improvement Association (KAIA) from 2004 to 2011. The REMLf90 program was used to analyze a multiple traits animal model with fixed effects of sex, contemporary group, parity and age at the end of the test as covariate and random effects of animal and residual error. The heritabilities of days to 90 kg (D90KG), average daily gain (ADG), backfat thickness (BF) and eye muscle areas (EMA) were estimated to be 0.334, 0.340, 0.335, and 0.200, respectively. The genetic correlation coefficients were -0.992 between D90KG and ADG, -0.142 between ADG and BF, -0.361 between ADG and EMA, and -0.243 between BF and EMA. Conversely, positive genetic correlations for D90KG with BF and EMA were 0.13 and 0.36, respectively.

• Journal of Korea Trade
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• v.25 no.7
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• pp.92-107
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• 2021

Purpose - This paper analyzes the relationship between trade facilitation and agricultural products exports and estimates the effects of trade facilitation in importing countries on Chinese agricultural products exports, which is of great significance for promoting agricultural trade between China,Japan and Korea and the governments of the three countries to formulate targeted trade facilitation policies. Design/methodology - Based on Wilson (2003) theoretical framework, this paper sets up its own trade facilitation level measurement system by involving four primary indicators and fifteen secondary indicators to evaluate the trade facilitation levels of Japan and Korea from 2011 to 2018 respectively. The paper selected the data on China's agricultural exports at the HS4 level from 2011-2018 and used a fixed-effects model to estimate the effect of changes in trade facilitation levels in trading partner countries on China's agricultural trade. Findings - Our main findings can be summarized as follows: the level of trade facilitation in importing countries has a significantly positive effect on China's agricultural exports. The higher the level of trade facilitation in trading partner countries, the more Chinese agricultural exports trade, i.e. for every 1 percentage point increase in the level of trade facilitation, the volume of exports will increase by 2.299%.The sub-sample test shows that China's main agricultural products exported to Japan and Korea, such as aquatic products, vegetables, fruits and other perishable fresh products, are particularly significantly affected by the level of trade facilitation. Originality/value - First, from the innovation of the research perspective, which is different from the analysis of the existing paper on the overall trade facilitation of all traded commodities. This article is based on the close trade relations between China, Japan and Korea, and the particularity of agricultural products, from the perspective of China's agricultural exports to Japan and Korea, discuss the impact of importing countries-Japan and Korea's trade facilitation levels on China's agricultural exports;Secondly, in this paper, the hierarchical data of the HS4 quartile is used to avoid the information loss of the industry, and to analyse the impact of the importing country's trade facilitation level on the export of different types of agricultural products more scientifically.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.2
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• pp.95-107
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• 2023

The purpose of this study is to investigate the impact of export promotion programs (EPPs) on the export performance of small- and medium-sized enterprises (SMEs), with a specific focus on the influence of EPPs for promising SMEs in the export market. Using data on SMEs provided by the Industrial Bank of Korea (IBK), we conducted a fixed-effects model analysis from 2016 to 2019. Our study shows that EPPs have a positive and significant relationship with export intensity. Further analysis reveals that SMEs utilizing the financing support system provided by EPPs tend to improve their export growth and financial performance relative to their counterparts. While EPPs can assist SMEs with their internationalization efforts, their similarity and redundancy are recognized as potential limitations. This study complements the existing literature that has mainly focused on surveys and cross-sectional analysis by specifying the research subject to promising SMEs in export, and analyzing the effects of the export promotion program supported by IBK Industrial Bank. The results of this study are expected to provide implications for improving SMEs' export capabilities.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.581-594
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• 2012

The goal of this study is to investigate the effects of the chemical lateral boundary conditions (CLBCs) on Community Multi-scale Air Quality (CMAQ) simulations of tropospheric ozone for East Asia. We developed linking tool to produce CLBCs of CMAQ from Goddard Earth Observing System-Chemistry (GEOS-Chem) as a global chemistry model. We examined two CLBCs: the fixed CLBC in CMAQ (CLBC-CMAQ) and the CLBC from GEOS-Chem (CLBC-GEOS). The ozone fields by CMAQ simulation with these two CLBCs were compared to Tropospheric Emission Spectrometer (TES) satellite data, ozonesonde and surface measurements for May and August in 2008. The results with CLBC-GOES showed a better tropospheric ozone prediction than that with CLBC-CMAQ. The CLBC-GEOS simulation led to the increase in tropospheric ozone concentrations throughout the model domain, due to be influenced high ozone concentrations of upper troposphere and near inflow western and northern boundaries. Statistical evaluations also showed that the CLBC-GEOS case had better results of both the index of Agreement (IOA) and mean normalized bias. In the case of IOA, the CLBC-GEOS simulation was improved about 0.3 compared to CLBC-CMAQ due to the better predictions for high ozone concentrations in upper troposphere.