• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.605-617
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• 2021

The recovery of the sedimentary environment around a fallowing shellfish farm during its rest period after 20 years of long-running operation, was explored in Tongyeong Bay of Korea. Seasonal survey on macrobenthos community was conducted from July 2016 to September 2018 at five stations, which included the fallowing shellfish farm after 20-year operation (FF), a newly installed shellfish farm (NF), a shellfish farm for comparison around the closed shellfish farm (CF), and control stations with no farming activities (Con1, Con2). The total number of species and the density of macrobenthos were higher at the shellfish farm stations than the non-shellfish farm station, and their seasonal changes were significant. The dominant species at the shellfish farm stations was Capitella capitata while Paraprionospio patiens was dominant at the non-shellfish farm stations. The two dominant species were potential organic contamination indicators usually inhabiting the areas with dense organic matter. This suggests that the overall survey area was highly polluted with organic matters. Multivariate analysis showed that the macrobenthic community of CF changed to a level similar to that of Con1 immediately after the investigation, but not to a state above the Con1 level. Furthermore, the changes in NF were not significant when compared to those in CF.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.2
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• pp.1-9
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• 2018

The purpose of this study was to develop guidelines for sustainability of back-to-farm community village in 4 aspects; social environment, maintenance and management, regional environment, and economic environment. These 4 aspects, which count for sustainability, based on the comprehensive comparative analysis about items that field survey and literature suggested. Conclusions of guideline are of the following. The guidelines on social environment are developed by 3 items; resident participation and activity, village leader, decision making in village and person in charge of operation. The guidelines on maintenance and management are developed by 5 items; village operation system, village regulation, transparency of management, village operation expenses, and management type. The guidelines on regional environment are developed by 2 items; support by central and local government, and area projects and connection to regional resources. The guideline on economic environment is not developed due to low demands of based production facilities and income increase facilities.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.126-132
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• 1978

This study was carried out through the survey questionaries in order to get the information for proper operating technique of the two-wheel tractors which are widely used in the farm, and investigated various accidents which occurred during the operation of two-wheel tractors for farm works in 7 Provinces of Korea. The summarized results are as follows ; 1. Annual accident frequency of the two-wheel tractor was 2.07 times, and the average rate of accident was 0.72 times per hour. Its value was the largest in the pre-operations , and the smallest in the threshing operation. 2. The accident distribution according to each month was nearly propertional to the operating hours of the two-wheel tractor. More than 60 % of total accident was concentrated during the rice transplanting and harvesting season. 3. The careless accident was more than 50% of total accident , and inevitable accident about 18% . The rate of careless accident showed the highest in pre-operation such as engine starting, check, and adjustment, and belt change. 4. The serious wounded operator was 7.1 % to total wounded operator , and about 50 % of accident of casualties to operators occurred during haruling operations. 5. The amount of casualties to property was range of 1,000 to 10,000 won, and annual total amount per unit tractor could be estimated to be 10 , 000 won.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.82-84
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• 2008

This paper presents the modeling and power quality analysis of Jeju island power system connected with wind farm, and thermal power plant. It is for indicating the influence of wind farm operation in steady and transient state in Jeju island power system during the HVDC system overhaul period. For the computer simulation, three kinds of main item are modeled, which are 67[MW] wind farm, thermal power plant and Jeju power load. To analyze the influence of the wind power generation to the Jeju power system, two kinds of simulations are carried out by using the PSCAD/EMTDC program. One is the steady state operation under the variable speed wind, and the other is the transient state operation when all of wind farms in Jeju island are disconnected from the Jeju power grid instantaneously on the rated power output. With the comparison of these results, it is useful for analyzing the power quality of Jeju power system versus wind power generation.

• Journal of Korean Society of Rural Planning
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• v.8 no.2 s.16
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• pp.27-41
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• 2002

This research is written for offering an approach to activate the stagnated industry of the tourist farm through analysis of the current operational problems and situation on some existing tourist farm nominated as such by the authority. There will be some considerations from three different categories : local autonomous groups, tourist farm associations and farm owners. On the other hand, it is assumed that this research can also be utilized as a basic material for activating the tourist farms in the suburban area of Taegu City. The operational problems in the suburban area of Taegu City are as follows : lack of a specialized Product development, the farm operation fund, lack of operational or management ability, lack of public information, etc. There are other Problems regarding law, institution and supporting : complexity of the current system involving all kinds of permission, shortage of financial and taxation supporting, lack of training an expert manpower, lack of ability and cooperation of a deskclerk in charge, etc. Here are some suggestions taking into consideration a respective sector of local autonomous group, tourist farm associations and farm owners for activating the tourist farms in the suburban area of Taegu City. First, a mental turnabout toward a tourist farm is needed from local autonomous groups. The law and institutional base should be arranged while the financial and taxation support is materialized. Second, tourist farm associations should amend or reinforce the existing institution to refresh the current recognition toward the tourist farm through many publicity activities. On the other hand, they should develop the overall tourist farm industry into a better service industry of the rural community by keeping an active system of cooperation with other related groups. Finally, It is advised that they should conceive farms and facilities which can symbolize the tourist farm from the stage of the first construction. In addition to a four-season souvenir development, an effective publicity activity and rational investment management. Above all, they should train themselves in terms of a service spirit before they see the prosperity of the tourist farm community.

• Journal of Biosystems Engineering
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• v.37 no.2
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• pp.75-81
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• 2012

Oyster mushroom farm which could not meet optimum temperature range yields non-uniform sized, low quality products. Thus, this study, utilizing STAR CCM+, one of the computational fluid dynamics (CFD) programs, analyzed the impact of air circulation and temperature distribution. Methods: After we visited numerous mushroom farms, we measured the temperature at the discharge ports of heaters, fan capacity, and the locations of the air circulators in the farms. According to the data, most mushroom growers installed the heaters near the entrance and discharge ports of the heaters at the third growing bed on the same height as the heaters in the entrance. The temperature at the discharge port of heater was $1,26^{\circ}C$, and the fan capacity was 4,500 $m^3$/hr. The air circulator was placed in the center of the mushroom farm 50cm above the ground, and its capacity of inlet port was 1,100 $m^3$/hr and discharge port 1,600 $m^3$/hr. The mushroom farm was insulated. Results: According to the analysis of the temperature distribution in the vertical plane of the entrance side, no air circulation causes the high temperature zone of 296~299K at the discharge port of the heater to take up 34% of area while the operation of air circulators causes it to occupy only 9%. This means that not using air circulators leads to a concentration of high temperature at the discharge port near the entrance. In addition, with the results of the analysis of the temperature distribution in the vertical planes of the center, no air circulation causes the temperature zone of 295~298K at the discharge port of the heater to take up 48% of area while the operation of air circulators causes it to occupy 80%. This shows that the high outlet port temperature disseminated to the center. Conclusions: After ninety minute operation of both heater and air circulator, the interior temperature became stabilized in the mushroom farm. Air circulation made the high temperature at the discharge port disseminate to the center and exit in the farm and equalize the temperature distribution.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1055-1062
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• 1996

A method for automatically driving paddy vehicles, such as rice transplanters, etc., straight ahead in a paddy field was investigated . The direction of such vehicles must be precisely controlled to do the operations as straight. However, the alignment of the from wheels becomes distorted due to the unevenness of the ground, preventing the vehicle form going straight. If the proper alignment of the front wheels is maintained , the vehicle can be driven straight ahead greater precision. To investigate the influence of the ground uneveness, the behavior of a paddy vehicle running over an obstacle was quantified. The left wheel ran over an obstacle on a flat concrete road surfaced. When the steering wheel was free, the front wheels were forced toward the left when vehicle went up the obstacle and toward the right when the vehicle went down it. The torsion of the wheel when the vehicle went down the obstacle was larger than that when it went up ,so it turned right 5 degrees. Sinc hydraulic control steering decreased the steering angle , it turned right 3 degrees. These results suggest that a vehicle can be driven straight ahead with high precision when the steering angle is changed in response to the direction and inclination of the vehicle . Such results were obtained in a paddy field tests.

• The Korean Journal of Community Living Science
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• v.22 no.1
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• pp.5-20
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• 2011

It is very important that the development of rural tourism resources and contents for agritourism increases rural household income and vitalizes local economy. In this sense, accelerating the rural traditional food materials into resources plays significant roles for the local economy. The farm-restaurant project, as a part of a development of rural traditional foods can not only help popularize the rural food-culture, but it also promote the consumption of local products by urban customers. It is difficult to manage both types of restaurants which are the dining type and the experience-centered farm restaurants as a farmer. In particular, the managers of the farm restaurants have some operational problems in developing a new menu and an experiential-program using their local farm products. The purpose of this study was to present steps that can be used for the existing menu-improvement and developing new menu processes of the farm restaurants that have been in operation for more than two years. By the purpose of menu developing for a restaurant, this research is designed for the case study. For collecting date for the study, we gained knowledge about the issues concerning menus from in depth interviews with the managers in two subject farm restaurants. The results suggested that a new menu, such as table d'h$\^{o}$te, $\`{a}$ la carte meals, specialties, kids meal, various dressing, are based on solving issues such as a limitation of food materials and the necessity of a kids meal in dining type of farm restaurants. Also, the suggested new menu, such as seasonal specialties and side dishes, are based on solving issues such as urgent development of various experiential programs and necessity of seasonal specialties in experiential type of farm restaurants.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.93-104
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• 2001

A linear chemigation system, integrating agrichemical appication units of pesticide and fertilizer into an irrigation system, was selected as a suitable model for the cost savings in farm management and automation. Technical designs were conducted in the areas of structure, power, drive, control, and hydraulic systems. An experimental farm was sectioned into the fields of 40m by 200m and systemized with the linear-move chemigation system of 36m in span. The chemigation system consisted of a base unit monitoring and controlling overall operation, and a driving unit traveling linearly and injecting agrichemicals. Monitoring and interlocking systems were utilized against unexpected malfunctions of power, injection and drive systems using radio freuency modems between the units. The system can be also modified to various farm sizes and stationary systems of indoor and outdoor.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.104-113
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• 2012

Wind farm grid codes require wind generators to ride through voltage sags, which means that normal power production should be re-initiated once the nominal grid voltage has been recovered. Doubly Fed Induction Generator (DFIG) based wind farm is gaining popularity these days because of its inherent advantages like variable speed operation and independent controllability of active and reactive power over conventional Induction Generator (IG). This paper proposes a new control strategy using DFIGs for stabilizing a wind farm composed of DFIGs and IGs. Simulation analysis by using PSCAD/EMTDC shows that the DFIGs can effectively stabilize the IGs and hence the entire wind farm through the proposed control scheme by providing sufficient reactive power to the system.