• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1351-1354
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• 2002

Wind farm which are composed with wind turbine generators can be a good alternatives to solve environmental problem and solutions to cope with energy crisis for using wind energy. Until now, these wind turbine generators have been being studied on the viewpoint of only active power control for reducing the burden of main grid. In this control scheme, we might demand a reactive power compensator in order to make reparation for the reactive power produced from wind turbine generator itself. Therefore, if the reactive power as well as active power of wind turbine generator were controlled according to the demand of reactive power, the installation of a additional reactive power compensator could be reduced. This paper presents the control method of a active and reactive power for wind turbine generators by means of SVPWM(Space Vector Pulse Width Modulation) inverting method and describes a operational coordination of wind turbine generators. The proposed power control algorithm can simply produce the output power of wind turbine generator needed in wind farm, which can reduce the power of main grid more and exclude a supplementary reactive power compensator. We assumed that wind farm are composed with two kinds of wind turbine generators, AC/DC/AC and induction generator types.

• 한국동물위생학회지
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• 제20권1호
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• pp.95-102
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• 1997

Author investigated internal parasitism for the feces of dog's training center, breeding-dog farm, dairy farm, home by 120 indoor breeding dog and 566 outdoor one in Inchon area. This survey was done from February in 1994 to December in 1995. 1. As a result of total 686 samples, positives were 373(54.4%). Among them, indoor and outdoor breeding dogs were 21(3.1%) 352(51.3%), respectively. 2. According to breeding, it was manifested that 21samples (17.5%) of 120 indoor breeding dogs were positive, and 352 samples(62.2%) of outdoor breeding were positive. 3. The infection rate of dogs for food in dairy farm, breeding dogs in the farm, dog of training center and dog of house is high in order. 4. Infection rate of parasites in 24 dogs breeds, Mongrel dogs were 81.3%, Shepherds were 80.0%, Tosas were 78.4%, Akida and Siberian huskys were 76.2%, Jindos were 55.5%, Pointers were 50.0%, although Afghan hound, Spanial, Shin-tzu, Maltis and Buldog were examined as aparasites negative. 5. After administration with vermicide parasites infection rate were 43.0% in two months. In four months, it were 66.7%, and dogs without vermicide were 87.0%. It seemed like that further research about dosage of vermicide is needed. 6. The rate of single-infection was 37.6% and that of mixed-infection was 16.8%. Among classified 13 types, Ancylostoma caninum 35.6%, Toxocara cams 11.2%, Isospora sp 9.3%, Toxascaris leonina 5.1%, Trychuris vulpis 4.4% were investigated.

• 한국조경학회지
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• 제34권2호
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• pp.1-17
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• 2006

The purpose of this study was to analyze biotope types of urban land-use patterns. Forest areas were considered according to vegetation type and potential for succession. Urban ecosystem structure was analyzed according to land use, land coverage, vegetation structure (actual vegetation, diameter at breast height, layer structure, and revetment). As a results of the classification, the biotopes were divided into 71 types according to the urban ecosystem structure. In the case of the Hanam province, the biotopes were divided into 51 types: 26 forest types; 5 swampy and grass land types; 3 farm land types; 3 types of planted land, and 8 types of urbanization.

• 한국농공학회논문집
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• 제66권3호
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• pp.1-14
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• 2024

Gaining an accurate 3D stream geometry has become feasible with Unmanned Aerial Vehicle (UAV), which is crucial for better understanding stream hydrodynamic processes. The objective of this study was to investigate series of filters to remove stream vegetation and propose the best method for generating Digital Terrain Models (DTMs) using UAV-based point clouds. A stream reach approximately 500 m of the Bokha stream in Icheon city was selected as the study area. Point clouds were obtained in August 1st, 2023, using Phantom 4 multispectral and Zenmuse L1 for Structure from Motion (SfM) and Light Detection And Ranging (LiDAR) respectively. Three vegetation filters, two morphological filters, and six composite filters which combined vegetation and morphological filters were applied in this study. The Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were used to assess each filters comparing with the two cross-sections measured by leveling survey. The vegetation filters performed better in SfM, especially for short vegetation areas, while the morphological filters demonstrated superior performance on LiDAR, particularly for taller vegetation areas. Overall, the composite filters combining advantages of two types of filters performed better than single filter application. The best method was the combination of Progressive TIN (PTIN) and Color Indicies of Vegetation Extraction (CIVE) for SfM, showing the smallest MAE of 0.169 m. The proposed method in this study can be utilized for constructing DTMs of stream and thus contribute to improving the accuracy of stream hydrodynamic simulations.

• 농업과학연구
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• 제22권2호
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• pp.197-208
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• 1995

The first purpose of this study is to build the most effective leisure farming model after classifying them by type, and secondly to examine about how realizing implementation measure of the model. At this time since leisure farm, leisure orchard and leisure ranch were thought as most important types, model for these types was made actually. Three regions in the suburbs of Taejeon city were chosen as proper site in the process of modeling. Methods and contents of public activities for promoting leisure farming were suggested concretely as a measure of carrying out leisure farming plan.

• Journal of Preventive Medicine and Public Health
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• 제38권2호
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• pp.141-146
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• 2005

Objectives: Particulate contaminants, such as total and respirable dusts, can harm the health of farm workers via several routes. The principal aims of this field study were to determine the concentrations and emissions of particulate contaminants: total and respirable dusts, in the different types of swine houses used in Korea, and allow objective comparison between Korea and the other countries in terms of swine housing types. Methods: The swine houses investigated in this research were selected with respect to three criteria: the manure removal system, ventilation mode and growth stage of pigs. Measurements of total and respirable dust concentrations and emissions in the swine houses were carried out on 5 housing types at 15 different farm sites per housing type. The swine houses investigated were randomly selected from farms situated within the central districts in Korea: province of Kyung-gi, Chung-buk and Chung-nam. Results: The total and respirable dust concentrations in the swine houses averaged $1.88\;and\;0.64mg/m^3$, ranging from $0.53\;to\;4.37mg/m^3$ and from $0.18\;to\;1.68mg/m^3$, respectively. The highest concentrations of total and respirable dusts were found in the swine houses with deep-litter bed systems: $2.94mg/m^3\;and\;1.14 mg/m^3$, while the lowest concentrations were found in the naturally ventilated buildings with slats: $0.83mg/m^3\;and\;0.24mg/m^3$, respectively (p<0.05). All the swine houses investigated did not exceed the threshold limit values (TLVs) for total ($10mg/m^3$) and respirable ($2.5mg/m^3$) dusts. The mean emissions of total and respirable dusts, per pig (75 kg in terms of live weight) and area ($m^2$), from the swine houses were 97.33 and 9.55 mg/h/pig and $37.14\;and\;12.83mg/h/m^2$, respectively. The swine houses with deep-litter bed systems showed the highest emissions of total and respirable dusts (p<0.05). However, the emissions of total and respirable dusts from the other swine houses were not significantly different (p>0.05). Conclusion: The concentrations and emissions of total and respirable dusts were relatively higher in the swine houses managed with deep-litter bed systems and ventilated naturally of the different swine housing types tested. In further research, more farms than the number used in this research should be investigated, which will present objective and accurate data on the concentrations and emissions of total and respirable dusts in Korean swine houses. In addition, personal sampling should be performed to objectively assess the exposure level of farm workers to particulate contaminants.

• 대한인간공학회지
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• 제35권4호
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• pp.193-204
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• 2016

Objective: This study carried out base research to build an agricultural safety monitoring system through ICT convergence to reduce safety accidents and enhance welfare in life in the agricultural field. Background: The functions and values of rural villages as the space of living are recognized anew, but occupational accident rate due to farm work accidents is on the rise each year. Therefore, the seriousness of such a problem emerges. The convergence technology combining ICT is recently applied to industries overall, and therefore better services are offered. However, studies on ICT convergence has not yet been applied to the agricultural safety field. Method: This study identified ICT convergence service technology trends and representative serious accident types mainly occurring in agricultural activities. This study defined the major factors of farm work accidents and ICT to solve those accident factors including the sensor technology, wired/wireless communication technology and location information service, and applied them to prototype PCB for the development of an agricultural safety monitoring system. Results: This study proposed an emergency monitoring system for farmers and a harmful environment monitoring system. The ICT technology to prevent farm work accidents can be summarized as sensing technology, ICT and network technology and user interface technology. This study also designed PCB module configuration and situation judgment algorithm as basic research for proposed monitoring system development. Conclusion: The ICT-based agricultural safety monitoring research proposed in this study is expected to become the basis to build a future real time monitoring system, and also is expected to contribute to social safety and welfare service improvement for farmers. Application: The ICT convergence farmer accident prevention system will make contributions to the prevention of serious farm work accidents.

• 농촌계획
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• 제21권3호
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• pp.131-144
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• 2015

With a view to creating beautiful farm villages, this study aims to exploit space syntax and thereby establish a systematic plan for refurbishing common farming facilities in farm villages by expanding a remodeling plan that has so far been focused on farm houses to cover different villages as well as in spatial scope. For this purpose, the study has extracted a system of categories for common ownership facilities in farm villages and applicable elements needed for collaboration in the space of joint production by performing a comprehensive analysis of related literature for the purpose of researching the distribution of common farming facilities. Based on such categorization of applicable elements, the study conducted a field survey of the four types of farm villages such as suburban area (Hwaseong), inland farming-centered area (Jeungpyeong), coastal & plain area (Goheung), and mid-mountain area (Gangneung), through group discussions by participating researchers and field pilot surveys. Also, space analysis has come up with measurements based on the five criteria of integration, local integration, control, connectivity, and spatial depth. And a plan for type-specific remodelling of common farming facilities has been drawn up through standardization based on the values in integration for different villages and spatial depth for common farming facilities. The significance of the current study consists in identifying how the location of common farming facilities influences the characteristics of different villages in terms of spatial structure and then drawing up guidelines for planning their placement.

• Journal of Veterinary Science
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• 제19권6호
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• pp.771-781
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• 2018

Staphylococcus aureus is one of the major pathogens causing bovine mastitis and foodborne diseases associated with dairy products. To determine the genetic relationships between human and bovine or bovine isolates of S. aureus, various molecular methods have been used. Previously we developed an rpoB sequence typing (RSTing) method for molecular differentiation of S. aureus isolates and identification of RpoB-related antibiotic resistance. In this study, we performed spa typing and RSTing with 84 isolates from mastitic cows (22 farms, 72 cows, and 84 udders) and developed a molecular prophage typing (mPPTing) method for molecular epidemiological analysis of bovine mastitis. To compare the results, human isolates from patients (n = 14) and GenBank (n = 166) were used for real and in silico RSTing and mPPTing, respectively. Based on the results, RST10-2 and RST4-1 were the most common rpoB sequence types (RSTs) in cows and humans, respectively, and most isolates from cows and humans clearly differed. Antibiotic resistance-related RSTs were not detected in the cow isolates. A single dominant prophage type and gradual evolution through prophage acquisition were apparent in most of the tested farms. Thus, RSTing and mPPTing are informative, simple, and economic methods for molecular epidemiological analysis of S. aureus infections.

• 한국농공학회논문집
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• 제64권6호
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• pp.35-41
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• 2022

Heavy snow damage can be prevented in advance with an appropriate security system. To develop the security system, we developed a model that predicts snow depth after a few hours when the snow depth is observed, and utilized it to calculate a failure probability with various types of greenhouses and observed snow depth data. We compared the Markov chain model and Bayesian long short-term memory models with varying input data. Markov chain model showed the worst performance, and the models that used only past snow depth data outperformed the models that used other weather data with snow depth (temperature, humidity, wind speed). Also, the models that utilized 1-hour past data outperformed the models that utilized 3-hour data and 6-hour data. Finally, the Bayesian LSTM model that uses 1-hour snow depth data was selected to predict snow depth. We compared the selected model and the shifting method, which uses present data as future data without prediction, and the model outperformed the shifting method when predicting data after 11-24 hours.