• Korean Journal of Ecology and Environment
• /
• v.49 no.1
• /
• pp.22-30
• /
• 2016

Environmental changes exert harmful effects on organisms inhabiting coastal regions. These changes are also associated with reduced production in aquaculture farms. In this study, we investigated internal and external responses of two Bivalvia species (Crassostrea gigas and Mytilus galloprovincialis) in Gamak Bay under stressful environmental conditions in aquaculture farms. We investigated external responses such as weight, size, and environment exposure time, and analyzed the expression of the HSP70 gene. C. gigas HSP70 gene expression level was significantly high in the C3 aquaculture farm site, but the weight and size of C. gigas were high in the C2 aquaculture farm site. The response of C. gigas HSP70 mRNA was associated with the environmental exposure time in each aquaculture farm. Expression of M. galloprovincialis HSP70 gene was found to be significantly higher in the M2 aquaculture farm site than in the M1 site, whereas the weight of M. galloprovincialis was observed to be higher in the M1 site. The size and environmental exposure time of M. galloprovincialis were similar between M1 and M2 sites. In addition, HSP70 sequences of C. gigas and M. galloprovincialis showed high similarity with that of another marine species. According to our results, there were differences in internal responses following environmental stress in aquaculture farms, with respect to HSP70 gene expression. The results suggest that the HSP70 gene is a useful molecular indicator for monitoring stress responses in Bivalvia species in the field.

• Journal of Animal Environmental Science
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2011

This study was conducted to investigate the actual situation of animal medicine use in Hanwoo farms, which were a total of 114 farms. Items surveyed were preference of animal medicine, choice criterion, purchase route, purchase frequency, antibiotics substitution products, etc. Data were collected from May to June, 2010. The kinds of animal medicine which preferred in Hanwoo farms is probiotics (40.4%). Whereas the lowest preference is immunizing agent (12.3%). There was significant difference among regional group (p<0.05), and the significant difference was also found in different farm size group (p<0.05). The factor of choice for purchase of animal medicine was efficiency (31.6%), first of all. There was significant difference among regional group (p<0.05). The purchase route of animal medicine was mostly supplied with the help of government (41.6%). The significant difference were showed in regional group (p<0.05). But that was not found in farm size group (p>0.05). The highest frequency at purchasing antibiotics was less than 1 time per 1 year (38.6%). There was statistically significant difference among regional group (p<0.05). However, there was not significant difference among farm size group (p>0.05). Probiotics of antibiotics substitution products was mostly preferred (50.9%).

• Journal of Agricultural Extension & Community Development
• /
• v.19 no.2
• /
• pp.321-353
• /
• 2012

This study aims to find out ways of improving life satisfaction of rural elderly by investigating their work and leisure activity, two significant axis of the life in later life. For this purpose, researchers and one assistant researcher visited house, senior citizen's center and health center, in order to have interviews with senior citizen above 65, who are currently working in the field. The summary of the research findings are as follows; First, the average size of the farm land which each senior citizen works on is $9,237.92m^2$ and they mostly work for economic reason. During farming season, they work on average 8.62 hour per day. As primary reasons for why farming work is difficult, "insufficient income" was picked. In fact, the average annual income senior citizens earn from farming is about 15.4 million won. 49.1% of sample senior citizens work both on watered farm and farm, and they are engaged in farming 48.82 years on average, showing that most of their lives have been spent on farming. In spite of these difficulties, most senior citizens showed high intention to continue farming work further. Second, senior citizens turn out to spend their leisure time mostly on public leisure activities such as watching TV, hearing radio and gatherings with families, relatives. However, individual activities such as meditation, yoga, drawing and calligraphy turn out to be low because they require foundations to enjoy. Third, senior citizen in rural areas were divided into four groups by farm work and leisure activity: group separated from work and leisure activity(27.09%), group centered to leisure activity(24.42%), group centered to work(23.75%), and group integrated work and leisure activity(23.75%). Fourth, the groups were different depending on demographic characteristics. Namely, male senior citizen, higher educational level, living in elderly couple households, and satisfied with their economic level belonged to the group integrated work and leisure activity. But senior citizen aged above 65 years old and working for their livelihood belonged to the group centered to work, and most of female and senior citizen aged above 80 years old belonged to the group separated from work and leisure activity. Finally, as the result of analysis of differences in life satisfaction according to farm work and leisure activity of senior citizen in rural areas, the group integrated work and leisure activity, and group centered to leisure activity were higher in life satisfaction than the group separated from work and leisure activity, and group centered to work. The above result indicates that life satisfaction of senior citizen depends upon leisure activity rather than work.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.10 no.1 s.20
• /
• pp.51-54
• /
• 2004

In recently days, the breed fish farm is increased in the beach side for farming fish. In such a farm, the heater is requested for preventing freezing in cold season. The heating material are requested high corrosion resistance and strength for endurance high corrosive salt and pressure. In case of low corrosion resistance and/or strength, the heating element shall be broke down and eventually make spillage or leaking contaminated salt. In the most cases, crevice corrosion is localized form of corrosion usually associated with a stagnant solution on the micro-environmental level. In this study, the crevice corrosion of Ferritic type 430 stainless steel is investigated. The size of specimen is $15{\times}20{\times}3mmt$. Test solution is 1N H2SO4 + 0.05N NaCl. The artificial crevice gap size is $0.24{\times}3{\times}15mmL$. Crevice corrosion is measured under applied voltage 300mV(SCE) to the external surface. the result of this study showed that 1) the induced time for initiation of crevice is 750seconds, 2) potential is dropped in the crevice from the top of gap opening from -320 to -399mV. The result confirmed that the potential drop(IR mechanism) in the crevice is one of mechanism for crevice corrosion.

• Korean Journal of Agricultural Science
• /
• v.46 no.2
• /
• pp.395-404
• /
• 2019

This paper investigated the changes in Hanwoo breeding farms and herds according to their farm size and farm types based on traceability data in the Hanwoo industry. The major results are summarized as follows. First, the notion that small sized farms are breeding farms and middle or large sized farms are fattening farms is wrong. The results show that middle or large farms are not only fattening cattle but also breeding female cattle. Based on cattle data for over 6 months and under the criteria of a female cow ratio of 10 and 90% using the 2/4 quarter of 2018, the results show that the ratio of fattening only farms is 5.7%, that of breeding only farms is 59.0%, and that of fattening and breeding farms is 36.1%. The ratios of fattening, breeding, and both are 13.3, 13.5, and 73.2%, respectively, for a farm size with over 100 cattle. Second, this study found that the ratio of breeding farms over total farms has been increasing continuously over the last 5 years. This trend is apparent in the middle or large sized farms. However, the birth rate of cows is relatively lower in the middle and large sized farms than in the small sized farms. Hence, we can infer that the demand for a detection system for standing estrus in female cattle will increase. Additionally, the government should prepare relevant policies to stabilize the managerial conditions of middle or large sized farms.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.5
• /
• pp.9-17
• /
• 2009

A study on fugitive dusts was conducted at Saemangeum reclaimed land and the neighboring farm located at the west coast of Korea. After the area was completely reclaimed in 2006, halophyte plants and several windbreak systems were installed. The distributions of suspended dust particle was regularly measured through field experiment. The size of dust source area was also analyzed periodically and then it was determined to be in the following order: Buan > Gimje > Gunsan. The suspended dust which were dispersed to the neighboring areas were significantly affected by the size of the soil particles, wind velocity and wind direction. The results of Big Spring Number Eight (BSNE) experiments also showed that the concentration of the fugitive dust generated from the reclaimed land was reduced remarkably by the presence of halophyte plants. Recently, in 2008, the measured dust concentration rate was decreased by an average of 30.6%. The average dust concentration is expected to decrease further as more areas are being covered by halophyte plants.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1858-1861
• /
• 2005

Automatic nut sorting machine used to calculate the size of inserted nut and detect the black spot defection is introduced in this paper. Because most of farm products are imported from the underdeveloped countries, domestic farm products have no place to be sold in market. To overcome this critical situation, lowering the productivity cost is strongly demanded to compete with foreign corps. Imaged processed nut sorting algorithm is developed to the automatic nut sorting machine to remove the sorting time which takes lots of man power. This system is composed of mainly two parts, mechanical parts and vision system. The purpose of mechanical part is supplying the nuts automatically to make computer system capture the images of objects. Simplified mechanical system was assembled followed by 3D simulation by Pro/E design for the adaptive cost effects. Several image processing algorithms are designed to detect the spot defects and calculate the size of nuts. Test algorithm shows good results to the designed automatic nut sorting system.

• Korean Journal of Poultry Science
• /
• v.22 no.1
• /
• pp.15-31
• /
• 1995

This study was carried out to develop a computer software system for poultry breeding by using microcomputer(PC). Through this study, SPPB(Statistical Package for Poultry Breeding) was designed and developed, which can help poultry breeder collect and analyse the chick records. A main feature of the system was the application of user-oriented procedure, for example, choice of the flock file, selection of the family size and the desired traits. Creation of the data files and the breeding files. calculation of the elementary statistics, estimation of the heritability and the genetic and phenotypic correlation coefficients can be obtained by user's choice of the sire and dam family size. Also, it is possible to estimate the various selection indices through this system. Easiness of using this system and the flexibility of the file management could help increasing the efficiency of related practical poultry breeding jobs. Correctness and relationships between the unit programs in the system were proved through the run-test of the SPPB using sample data. Because it wasn't able to collect breeding records at the commercial breeding farm, effectiveness of the system was not proved totally. Also. it will be necessary to develop the integrated software system which make possible to computerize the general works at breeding farm and the genetic analyses of the records from chick breeders.

• Korean Journal of Agricultural Science
• /
• v.48 no.1
• /
• pp.59-71
• /
• 2021

This study investigated the extent to which rice producers from the Ayeyarwaddy Region of Myanmar could improve their productivity if inputs were used efficiently in rice cultivation. To achieve this objective, simple random sampling was used to collect data from 300 rice growers in the study area. Data were analyzed with the translog stochastic frontier approach to understand the production efficiencies. The study further estimated the influencing factors that affect the efficiency levels of rice farmers. The empirical result reveals that the average technical, allocative, and economic efficiencies were at 76.11, 47.85, and 34.15%, respectively. This suggests that there is considerable room for improving rice production by better utilization of the available resources at the current level of technology. This study suggests that strenthening agricultural training programs and adoption of improved rice varieties may reduce overall inefficiencies among rice farmers in Myanmar. Factors like age, household size, education, farming experience, farm size, rice variety, training, and off-farm income have a significant impact on increasing/decreasing farmer's efficiency. Efficiency can be improved by establishing farmer field school programs to increase the scale of operations. The government should encourage young educated people to participate in paddy production and also intervene to reduce input prices and control the quality of seeds.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.1
• /
• pp.109-113
• /
• 2009

Several tidal current power plants are being planned and constructed in Korea utilizing the strong tidal currents along the west and south coasts. A tidal current reaches 9.7 m on the west coast; there are few potential regions for tidal current power generation. The construction of a dam to store water can prevent the circulation of water, causing a great environmental impact on the coast and estuary. The tidal barrage could produce a large amount of power, but it should be carefully considered. The purpose of developing renewable energies is to minimize the environmental impact and to maximize the utilization of clean energy. To produce a great quantity of power, tidal current farms require the placement of numerous units in the ocean. The power generation is very dependent on the size of the rotor and the incoming flow velocity. Also, the interactions between devices contribute greatly to the production of power. The efficiency of a power farm is estimated to determine the production rate. This paper introduces 3 D interaction problems between rotating rotors, considering the axial, transverse, and diagonal distances between horizontal axis tidal current devices.