• Korean Journal of Agricultural Science
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• v.31 no.2
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• pp.161-174
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• 2004

This study is aimed at identifying China's land operating system in the great leap periods. the findings are as follows. For one thing, though the landownership in China was basically performed in public, a portion of private management was allowed. The more this kind of private management allowed, the more the life standard of farmers enhanced. For another thing, the conversion from agricultural cooperatives to people's commune happened swiftly, and the problems according to the conversion arose instantly, which made the operation system changed partially. The last, but not the least, even in the point of the rapid communistic movement, private management was locally accepted in the name of three self and one private management. Besides, as we can recognize from the case study of Daichai village, the operation of a large working group and a small working group was done in political context.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1200-1207
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• 2015

A gateway buoy system connects a underwater network to a terrestrial network, which enables to efficiently monitor the underwater network on a land station. In this paper, we introduce an implemented gateway buoy system which relays gathered data from multiple underwater nodes to a land station in a real time. The gateway buoy hardware system is composed of a underwater acoustic modem system, a radio frequency modem system, and a gateway operating system. in additional, we have implemented a land operating program and a land monitoring program for gateway system and states of underwater network, respectively. We also perform real-sea experiments to verify the performance of the gateway buoy system which real-time monitors underwater network states and gateway system states.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.4
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• pp.154-160
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• 2017

In the former aviation law, only the Ministry of Land, Infrastructure and Transport has to provide air traffic services, In the case of providing aviation transportation service from civilian, such as aviation special education institution, private airfield installer, it was possible to carry out only by receiving a private contract from the government. But at the time of private consignment, the fact that the government has to bear the cost through the contract act. It is pointed out that it is a factor that hinders efficiency in the operation sector. Accordingly, in Article 85 of the Aviation Safety Act, which was enforced in March 2017, legal grounds were established to provide air traffic services excluding the Ministry of Land, Infrastructure and Transport. At the same time, we have introduced the air traffic services operating certification system, which enables the air traffic services to meet the requirements set by the Ministry of Land, Infrastructure and Transport in order to secure the safety of air traffic. In this study, we examine the major issues and problems of the small private control tower operated by the private institute in Korea. The effect of introduction of the air traffic services operating certification system which can introduce all the institutions which do not belong to the control agency in the former aviation law into the institutional system and the operation plan were examined.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1532-1539
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• 2017

The floating photovoltaic system is a new concept in the renewable energy technology. That is similar to land based photovoltaic technology except floating system. So the system needs buoyant objects, mooring, ect, besides modules and supports, and that is able to withstand in water level changes and wind strength. Therefore the floating photovoltaic system is much different from land photovoltaic system. K-water (Korea Water Resources Corporation) has been operating two floating photovoltaic system that's capacity is 100 kW and 500 kW respectively since in summer 2011 for commercial generation, and have construction project for 2,000 kW in Boryeong multipurpose Dam and other areas. Furthermore K-water was developing a tracking-type floating photovoltaic system at Daecheong multipurpose Dam and developed and installed an ocean floating photovoltaic demonstration plant at Sihwa Lake in October 2013 for R&D. In this paper, we introduce that structure of floating photovoltaic system include buoyant structure, mooring system and auxiliary device. Especially the rope which is in part of mooring should be always maintain tension under any water level. Also we explain about structure design concept to wind load in an every loading condition and a kind of structure materials and PV structure types used in water environment. Especially ocean floating PV system is affected by tidal current and typhoon. So there are considering the elements in design. Finally we compare with floating and land photovoltaic on power amount. As a result of that we verified the floating photovoltaic system is more about 6.6~14.2 % efficiency than a general land photovoltaic system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2059-2064
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• 2011

The DGPS systems that is a GPS augmentation system were installed for ocean- and land-service. The ocean-based reference station of 11 site and the land-based reference station of 6 sites are operating for ocean- and land-service. Although the land-based reference stations provide the output power of 500W, the service shadow regions are occurred due to mountain lands and building area. In this paper, the service coverages for land-based reference stations are analyzed in conditions of output power enhancements of reference station. The service shadow areas are deduced from service coverages of land-based reference stations and ocean-based reference stations. The medium frequency-band wave propagation models are considered as DGPS wave propagation model. The service coverages are analyzed by considering the compensated ground surface-conductivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.758-764
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• 2019

The chassis of the Korean light tactical vehicle adopts a frame-on-body structure that uses lightweight design technology in terms of equipment operating characteristics. Military vehicles are operated in much harsher conditions compared to civilian vehicles, including mountainous terrain, especially steep slopes. Due to this characteristic, frame-welded cracks were found on some military vehicles. Therefore, in this paper, road damage analysis was conducted by identifying various roads including the military unit's road. The result confirmed that the operating environment of some military units' tactical road was much harsher than the endurance road test condition. A solution was derived through defect analysis, design review, and actual vehicle driving test. This study can be used as a reference by suggesting the development direction for the durability test of a new vehicle.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.503-511
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• 2015

The purpose of this study is to suggest the introduction plans of forest land bank system for effective forestry management as well as the livelihood stability support of aged forest landowners. It is expected that forest land bank system can contribute to solve forestry management problems caused by small and scattered forest lands, aging forest landowners, and the increase of absentee forest landowners. This study examined an existing related case of Farmland Bank system, and suggested basic directions, main functions, priority, and agency for forest land bank system. The goals of forest land bank system include activating private forest land management, improving forest management scale, and supporting stable forestry income. Based on the examination of this study, main projects of forest land bank involve forest land sale and lease consignment, forest land reverse mortgage, forest land scale improvement project, and forest business recovery support program. In addition, this study discussed potential problems and their solutions in introducing and operating the forest land bank system. This study can play a key role to determine a basic direction and to establish policies of the forest land management.

• Journal of Sensor Science and Technology
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• v.14 no.3
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• pp.198-205
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• 2005

Recently, the systems using multiple sensors such as magnetic, acoustic and pressure sensor are used for detection of underwater objects or vehicles. Those systems have difficulty of maintenance and repair because they operate underwater. Thus, this paper describes a hybrid detection system with long term operating reliability. This has a multi-signal transmission structure to have a high reliability. First, a signal transmission & receiving part, which transfers data from underwater sensors to land and receive control message from land through optical cable, has 4 multi-path. Second, the nodes for signal transmission are connected dually each other with single-hop construction and sensors are connected to a couple of neighboring nodes. This enables the output signal to transmit from a node to the next node and the next but one node together. Also, the signal from a sensor can be transmitted to two nodes at the same time. Therefore, the system with this construction has high reliability in long term operation because it makes possible to transmit sensor data to another node which works normally although a transmission node or cable in system have some faults.

• Spatial Information Research
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• v.19 no.6
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• pp.29-41
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• 2011

Recently, the importance of systematic Land-monitoring has been emphasized. The existing Law does not include any definitions or regulations of monitoring. Although there exist laws regarding examining and measuring the current status of region, utilization, distribution, share, security and management of the data need to be improved. In order to upgrade the Land-monitoring system, several tasks such as terms, building cycle, forms, scope, management team should be well-defined. In this study, problems of the Land-monitoring is investigated by understanding the legislation in the land planning system and its operating system. The setting of the land-monitoring concept in Framework Act on the National Land and revision of specific laws in this field were introduced. Finally, new Land-monitoring legislation covering the improvement of the data-acquisition and co-utilization were suggested.

• Land and Housing Review
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• v.10 no.3
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• pp.9-16
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• 2019

This study aimed at developing control algorithms for operating a variable refrigerant flow (VRF) heating and cooling system with optimal system parameter set-points. Two artificial neural network (ANN) models, which were respectively designed to predict the heating energy cost and cooling energy amount for upcoming next control cycle, was developed and embedded into the control algorithms. Performance of the algorithms were tested using the computer simulation programs - EnergyPlus, BCVTB, MATLAB in an incorporative manner. The results revealed that the proposed control algorithms remarkably saved the heating energy cost by as much as 7.93% and cooling energy consumption by as much as 28.44%, compared to a conventional control strategy. These findings support that the ANN-based predictive control algorithms showed potential for cost- and energy-effectiveness of VRF heating and cooling systems.