• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.78-78
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• 2017

현재 국내에 공급되고 있는 잡곡류 수확기는 보행형 예취기, 탈곡기 위주의 저능률 기계화 수준으로 고능률의 콤바인 수확기 개발이 필요하며, 특히 잡곡류가 소규모 경작지의 영세농가 위주로 재배되어 저가격의 소형 콤바인 수확기 개발이 절실히 요구되고 있다. 따라서 본 연구는 소규모 밭의 두류 및 잡곡 수확작업에 적응성이 뛰어나며, 농기계 임대사업소의 활용도를 높일 수 있고, 여성과 고령자도 쉽게 운전할 수 있어 수확작업의 노동력을 크게 절감할 수 있는 저가격의 25kW급 자주식 소형 콤바인을 개발하고자 시작기를 설계 제작하였다. 시작기의 주요부로 엔진은 25kW/2600rpm 3기통 디젤엔진을 탑재하였으며, 동력전달부는 주변속 3단, 부변속 2단의 선택맞물림 기어식의 변속장치를 이용하였다. 주행부는 궤도형으로 조향클러치와 습식 원판식 제동장치를 채용하였다. 전처리부는 선단거리 1700 mm의 디바이더와 상하좌우 수동 조절되는 회전속도 약 42 rpm의 정오각형 릴로 구성하였으며, 전처리부의 최대 승강높이는 740 mm이었다. 작물이송부는 돌기부착 오거와 체인컨베이어로 구성되어 있으며, 탈곡부는 단동형 축류식의 직경 440 mm, 길이 1180 mm의 급동과 높이 65 mm, 지름 10 mm의 46개 강봉형 급치, 격자형 수망으로 구성하였으며, 회전속도는 약 325 rpm으로 작동하도록 하였다. 선별 정선부는 요동 송풍선별식으로 곡립판, 볏짚체, 곡립체, 송풍팬으로 구성하였고 송풍팬의 회전속도는 약 850 rpm, 요동진동수는 약 5.8 Hz로 작동하도록 하였다. 곡물이송부와 재처리부는 수평이송 외경 103 mm, 수직이송 외경 110 mm의 피치가 모두 82 mm인 스크류컨베이어를 이용하였으며, 곡물탱크는 용량이 250 로 2개의 배출구로 곡물을 포대에 담도록 하였다. 그 외 시작기는 운전조작부, 유압장치부, 전기장치부 등을 갖도록 설계 제작하였다. 전체적인 기체의 크기는 길이${\times}$폭${\times}$높이 $3935{\times}1900{\times}2440mm$이었으며, 기체 중량은 약 1753 kg이었다. 콩 대상 기초 성능시험 결과 시작기의 작업속도는 약 0.5 m/s, 작업능률은 약 11 a/h로 나타났다.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.105-109
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• 1994

This experiment was conducted to know the labor saving effect and reducing production cost by agricultural mechanization in the cultivation of Bupleurum falcatum. Labor reducing effects of the drilling seeder by hand and the machine attached to two wheel tiller were 97%, but emergency rate was highest in the former. Dry root yield per plant was increased by low amount of seed sowing but that yield per unit area was increased at much seeding amount in the seeder attached to the tiller. The drilling seeder by hand was showed highest standing ratio of seedling and produced yield to 84.1kg of root yield per 10a. Labor saving effect was the best at the multipurposes mechanized harvester and labor saving and famer's income ratio were increased to 69% and 50% respectively. Labor time and cost were reduced to 74% and 69% respectively by mechanization of sowing and harvest cultivation practice on Bupleurum falcatum.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.237-246
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• 2019

The Electro-Mechanical Brake (EMB) is the next generation braking system for automobiles and railway vehicles. Current brake systems for high-speed trains generate a braking force using a pneumatic cylinder, but EMB systems produce that force through a combination of an electric motor and a gear. In this study, an EMB operation mechanism capable of generating a high braking force was proposed, and structural and vibration analyses of the gears and shafts, which are the core parts of the mechanisms, were performed. Dynamic structural analysis confirmed that the maximum stress in the analysis model was within the yield strength of the material. In addition, the design that maximizes the diameter of the motor shaft was found to be advantageous in strength, and large shear stress could be generated in the bolt fixing the gear and eccentric shaft. In addition, a test apparatus that can reproduce the mechanism of the analytical model was fabricated to measure the strain of the fixed bolt part, which is the most vulnerable part. The strain measurement results showed that the error between the analysis and measurement was within 10%, which could verify the accuracy of the analytical model.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.2
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• pp.251-271
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• 2008

Maquiladora industries have grown due to the decrease in labor costs caused by Mexico's economic crisis and the increase in possibility of Mexico's advance into North American markets caused by the NAFTA that come into effect since the 1980s and 1990s. Early Marquiladora industries have started to be located in the Northern borders of Mexico using young-female labor forces centered on the textile and electronic part industries. However, after the 1980s, the port soared, and the regional range of Maquiladora industries has also enlarged to 25 states. The most important regions of Maquiladora industries in Mexico are Chihuahua and Baja California and their cities are Ciudad Juares and Tijuana. Maquiladora industries had grown in terms of the cost of product and the employment until the end of the 1990s. However, Maquiladora industries have decreased in the cost of product and the employment since the 2000s. The regional range of Maquiladora industries has enlarged into the entire of Mexico, but most of Maquilador industries is still located in Northern border regions centered on six states. The textile industry is a representative one of Maquiladora industries and the early Maquilador industries have been focused on the textile industry. Thus, the textile industry in Maquiladora shows the same pattern as any other industries in Mexico. However, machinery and electronic part industries have been concentrated on the Northern border states and existing manufacturing zones. In terms of the change in employment by industry, machinery and electronic part industries occupied most high employment proportion and the textile industry sector was the next. The distinguished point is that service industries are growing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.717-727
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• 2017

Researches on the emissions of greenhouse gases in the construction industry, which accounts for 40% of raw materials, 30% of energy consumption, and 30% of $CO_2$ emissions in the entire industry, are mainly focused on studies of LCA. However, it is assessed that $CO_2$ emissions are higher in construction sequence than in operation sequence. Also, it is considered that construction machinery using fossil fuel is a main factor causing environmental load in construction sequence. Therefore, this study analyzes the workload and engine RPM characteristics of the excavator which is the second largest number of registered construction machinery in Korea and the highest utilization rate in actual construction site. The excavator is divided into non-load states and load states where power is transmitted to the excavator. The exhaust gas is analyzed by a direct measurement method using PEMS equipment. $CO_2$ emissions are estimated by analyzing the relationship between RPM and exhaust emission characteristics according to the actual driving conditions. Additionally, we analyze the difference between $CO_2$ emissions of construction machine calculated by this study and $CO_2$ emissions calculated by using carbon emission coefficient.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.3
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• pp.257-265
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• 2016

In this study, an optimal design for motor-driven track type traveling system applied into high clearance working machineries in orchard is proposed. Tractive performance and hill climbing ability were predicted and evaluated for the optimal motor traveling system by taking into account of soil characteristics in orchard utilizing the high clearance working machineries. Design criteria for tractive performance were based on the traction force calculated from tractive effort subtracted by motion resistance, while hill climbing ability had its design criteria that fulfill the climbing 20% slope ground at a speed of 3km/h. Based on the evaluation results of traction and climbing ability, two DC48V, 4500rpm, 1.6kW AC motors were independently applied to both left and right side of orbits; each motor is designed to transmit power on driving sprocket of track type traveling system via 50:1 reduction gear ratio. The motor-driven track type traveling system developed in the study found to have 396 kgf of tractive force, which is 12.5% higher than climbing resistance at orchard soil having 20% slope ground (352 kgf), demonstrating sufficient tractive performance and hill climbing ability.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.86-92
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• 2011

In order to reduce dependence on the fossil fuels and $CO_2$ gas emission in farming activities, the government has pushed ahead with making the self-sufficiency of farming energy up 40% level in green villages. The objectives of this study are to survey the energy consumption of horticultural facilities or agricultural machineries, and to analyze the reduced $CO_2$ gas emission level from fossil fuel to bio-diesel fuel. For the implement of this study, it is necessary to analyze the energy consumption level in the various sector of farming activities, and available renewable energy sources should be selected. Annual total $CO_2$ gas emission in the tillage farming sector was analyzed as $5,667,258\;t-CO_2$ and that in the horticultural facilities occupied $4,932,607\;t-CO_2$, while the $CO_2$ gas emission level of diesel fuel was $3,105,707\;t-CO_2$, and that of the heavy oil showed $1,370,578\;t-CO_2$. The average $CO_2$ gas emission level of horticultural facilities in the country was analyzed as $29,418\;t-CO_2/ha$. Among the total energy consumption of agricultural machineries, tractor used 284,763kL, power tiller spent 221,314 kL, grain drier consumed 145,524kL and combine tractor expend 72,537kL. From the comparison of $CO_2$ gas emission level between fossil fuel and bio-diesel fuel for the horticultural facilities or agricultural machinery in G-City, Jeonbuk Province, the $CO_2$ gas emission level can be reduced by 7% through replacing the fuel from fossil to biodiesel.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1216-1221
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• 2022

Ships tend to be larger to increase the efficiency of cargo transportation. Larger ships lead to increased travel time for ship workers, increased work intensity, and reduced work efficiency. Problems such as increased work intensity are reducing the influx of young people into labor, along with the phenomenon of avoidance of high intensity labor by the younger generation. In addition, the rapid aging of the population and decrease in the young labor force aggravate the labor shortage problem in the maritime industry. To overcome this, the maritime industry has recently introduced technologies such as an intelligent production design platform and a smart production operation management system, and a smart autonomous logistics system in one of these technologies. The smart autonomous logistics system is a technology that delivers various goods using intelligent mobile robots, and enables the robot to drive itself by using sensors such as lidar and camera. Therefore, in this paper, it was checked whether the mobile robot could autonomously drive to the stop sign by detecting the passage way of the ship deck. The autonomous driving was performed by detecting the passage way of the ship deck through the camera mounted on the mobile robot based on the data learned through Nvidia's End-to-end learning. The mobile robot was stopped by checking the stop sign using SSD MobileNetV2. The experiment was repeated five times in which the mobile robot autonomously drives to the stop sign without deviation from the ship deck passage way at a distance of about 70m. As a result of the experiment, it was confirmed that the mobile robot was driven without deviation from passage way. If the smart autonomous logistics system to which this result is applied is used in the marine industry, it is thought that the stability, reduction of labor force, and work efficiency will be improved when workers work.

• Journal of Biosystems Engineering
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• v.10 no.1
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• pp.1-12
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• 1985

The two agricultural zones, mid-and-northen region and southern region, were established according to the possibility of double cropping in the paddy field. For each agricultural zone typically mechanized farming systems with a power tiller for cultivating rice, barley and soybean were established. A computer program, which determines the optimum size of power tiller for the given farm size, the ratio of paddy area to total area and the ratio of double cropping area to the paddy area, was developed. The computer program was executed for the farm sizes, 1 to 3 ha, and the ratios of paddy area to the total area, 60~80%, and the ratio of double cropping area to the total paddy area, 70%. The following conclusions were drawn from analyzing the computer outputs. 1. In the mid-and-northern region, a smaller power tiller (5 or 6 PS) appeared to be more economical for the farm size up to 3 ha. From the viewpoint of fuel consumption a 6 PS power tiller appeared to be more favorable. 2. In the southern region, a smaller tiller (5 or 6 PS) appeared to be more economical for the farm size up to 1.5 ha. But, a larger power tiller (8 or 10 PS) appeared to become more economical as the farm size and the barley planted area increased. 3. For the southern region where rotary tilling is heavily required due to double cropping, it is recommended to develop a power tiller which weighs light like the conventional 5 or 6 PS small power tiller but has lager power.

• Journal of Biosystems Engineering
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• v.15 no.1
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• pp.1-13
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• 1990

Aerodynamic property is the most important factor in designing the pneumatic separator and handling equipment for grains and seeds. Particularly the correct information about the terminal velocities of the corresponding grains and seeds is indispensible. However, a few studies with relation to the terminal velocities of grains and seeds were conducted in this country, even though the terminal velocities of the domestic grains and seeds are required to design those equiments which can be used for the domestic grains and seeds having specific aerodynamic properties. In this study, the terminal velocities for four varieties of varley and six varieties of paddy were investigated by means of two different methods, the suspension method and the drop method in an upward current of air. For measuring the terminal velocities, the vertical wind tunnel which had been examined about the uniform air flow in the previous study was used. In addition, the effect of the size of grains and the moisture content of grain kernel on the terminal velocity was examined. The following conclusions were derived from the study : 1. The different terminal velocities of grains are resulted from the different measuring methods. The terminal velocity measured by the drop method is smaller than that by the suspension method. It is considered that the difference in the terminal velocities is caused by the difference in the projection area of grain which is faced to the air stream. 2. The terminal velocity of grain increases as the size and the moisture content of the kernel increase. 3. The linear regression equations for the terminal velocities of grains were derived in terms of the moisture content of grains by the variety of grains and the measuring method. Also, the linear regression equations for the terminal velocity, based on the weighted size of grains, were derived in terms of the moisture contents of granis.