• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.

• Environmental and Resource Economics Review
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• v.13 no.4
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• pp.657-684
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• 2004

This study is a theoretical bioeconomic analysis to analyze the effectiveness of Marine Protected Area (MPA) implemented in different stock spatial distributions: Closed System, Source-Sink System, and Density-dependent System. In the analysis, an economic impact of vessel activities is also included and a joint effectiveness of MPA and input control is investigated as well. Results of the analysis show that total fisheries stocks are increased in all systems. However, total harvests are decreased when MPA is implemented in the closed system and in the sink patch of source-sink system. On the contrary, total harvests are increased or decreased according to the rate of stock migration and the level of fisheries stocks in the source patch of source-sink system and in the density-dependent system. Specifically, total harvests are increased more significantly as the rate of migration increases and the level of stock increases higher. In addition, the increase in fishing efforts is restricted due to the increase in fishing cost. Therefore, fishing efforts could not be increased greatly in the fishable area. When input control is combined with MPA, the total stocks could be more increased.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.579-591
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• 1999

The operation of a reservoir system is necessary for establishing the operation rule as well as designing the reservoirs for water resources planning or management. Increasingly complex water resource systems require more advanced operation techniques. As a result, various techniques have been introduced and applied until now. In this study Linear Tracking model based on optimal control theory is applied to the operation of the largest scale multi-reservoir system in the Han river and its applicability proved. This system normally supplies the water resources required downstream for hydro-power and plays a role in satisfying the water demand of the Capital region. For the optimal use of the water resources the Linear Tracking model is designed with the objective to maximize the hydro-power energy subject to the water supply demand. The multi-reservoir system includes the seven main reservoirs in IIan river such as Hwachon, Soyanggang, Chunchon, Uiam, Cheongpyong, Chungju and Paldang. These reservoirs have been monthly operated for the past 21 years. Operation results are analyzed with respect to both hydro"power energy and water supply. Additionally the efficiency of the technique is assessed.sessed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.209-216
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• 2005

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.642-648
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• 2019

Vessels sail according to the COLREG to prevent a collision. However, it is difficult to apply COLREG under special situation as heavy traffic, at this time personal skills of the operator are required. In this case, traffic control is required through the maritime traffic monitoring system. Therefore, maritime traffic management is globally implemented by VTS. In this system, VTS of icer uses the VTS system to assess risks and recommends possible safety operation to vessels with radio systems. This study considers that the risk analysis method with AI (Artificial Intelligence) technology from the operator's aspect. In addition, the research explains the Maritime Traffic Safety Monitoring System, Including AR (Augmented Reality) technology to increase vessel control efficiency. This system is able to predict hazards and risk priorities, and it leads to sequential elimination of dangerous situations. Especially, the hazard situations can be analyzed from operator's perspective of each vessel instead of the VTS officer's aspect, which is more practical than the conventional method. Furthermore, the result of analysis enables to comprehend quantitative hazardous areas and support recommended routes to avoid a collision. As a result, I firmly believe that the system will support to prevent a collision in complex traffic waters. In particular, it could be adopted as a collision prevention system for Maritime Autonomous Surface Ship, which occupies a significant proportion in Maritime 4th industrial revolution.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.777-780
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• 2015

Currently, our country has promoted sustainable growth in agriculture field by expanding the growth engine which is going to creat new value through agrifood industry & ICT convergence, the deployment of computerization in rural areas and the efficiency increase of agricultural administration system. Since the level of domestic agriculture-ICT convergence technology focusing on production areas is at early stage, it is necessary to deploy the successful models through the systematic development of technology and standardization including production, distribution and consumption phase. In addition, because the management and control systems of large glass greenhouse are mostly foreign products with no standardization and related small domestic companies, there is a limit to agri-food & ICT convergence activation led by the agri-food private sector. Also, it is vital to increase productivity & efficiency and improve quality throughout the entire agricultural process including production, distribution and consumption by the fusion of information technology, automatic control technology and unique ICT on existing agricultural technology, Therefore, in this paper we propose the agricultural-ICT convergence technology fields in which our country can lead technology and the standardization plans through analyzing the development, policy and standardization trends on agricultural-ICT convergence technology.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.89-101
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• 2014

Recently, as domestic air traffic dramatically increases, the need of ATC(air traffic control) systems has grown for safe and efficient ATM(air traffic management). Especially, for smooth ATC, it is far more important that performance of display system which should show all air traffic situation in FIR(Flight Information Region) without additional latency is guaranteed. In this paper, we design a ASTERIX(All purpose STructured Eurocontrol suRveillance Information eXchange) parsing module to promote stable ATC by minimizing system loads, which is connected with reducing overheads arisen when we parse ASTERIX message. Our ASTERIX parsing module based on pattern matching creates patterns by analyzing received ASTERIX data, and handles following received ASTERIX data using pre-defined procedure through patterns. This module minimizes display errors by rapidly extracting only necessary information for display different from existing parsing module containing unnecessary parsing procedure. Therefore, this designed module is to enable controllers to operate stable ATC. The comparison with existing general bit level ASTERIX parsing module shows that ASTERIX parsing module based on pattern matching has shorter processing delay, higher throughput, and lower CPU usage.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.1
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• pp.20-26
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• 2016

Sympathetic reaction to grotesque facial injuries with oral bleeding can trigger confusion and generate inefficiency among emergency room personnel. Regardless of the extent of the injury, or of the sympathy elicated, the victim must be evaluated and treated as a whole patient with multiple trauma. There must be no confusion as to order of importance in the steps of evaluation : 1. airway 2. hemorrhage 3. shock 4. associated injuries 5. local injury 6. triage of facial injuries. The most dangerous aspect of oral hemorrhage is the possibility of its obstructing the upper airway. Swallowing large amounts of blood will usually cause gastric irritation and lead to vomiting, thus further complicating the management of the patient. Once a clear airway is assured and hemorrhage have been controlled, consideration is given to possible associated injuries before undertaking treatment of the facial injuries themselves. Status of the cardiopulmonary, gastrointestinal and neuromuscular systems all have a bearing on decisions concerning facial injury treatment. In this light, treatment priority becomes exceeding important. On the other hand, the importance of facial injuries should never be minimized, especially in a mentally retarded patient with oral hemorrhage. This is a case report about oral hemorrhage control as treatment priority in a mentally retarded patient.

• Convergence Security Journal
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• v.17 no.4
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• pp.69-78
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• 2017

Since the September 11, 2001, transnational crimes and terrorism have increased, the importance of border security has been emphasized and integrated CIQ capability has been required. The U.S., Canada, and Australia are consolidating CIQ to strengthen border security, focusing on strengthening travelers and goods immigration control and airports, ports and land border security. In 2003, the U.S. established the Customs and Border Protection(CBP) under the Department of Homeland Security. Canada also established the Canada Border Services Agency(CBSA) under the Public Safety Canada in 2003. The Australian Customs and Border Protection Service was integrated with the Department of Immigration and Border Protection(DIBP) and the Australian Border Force was established in 2015. However, Korea operates a distributed border management system for each CIQ task which is unable to respond to complex border threats such as illegal immigration, entry of terrorists, smuggling of drugs, and gun trade in the airports, ports and land borders. In order to solve this problem, it is possible to consider integrating sequentially the customs and quarantine services which have high similarities, and to integrate the entire CIQ tasks with the Korea Customs Service delegated to the immigration control duties in the mid to long term. There is also a plan to benchmark the CIQ single accountability agencies in the U.S., Canada, and Australia in accordance with the Korean situation and to establish a new integrated border security organization.

• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.55-64
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• 1995

During sleep, relatively major respiratory physiological changes occur in healthy subjects. The contributions and interactions of voluntary and metabolic breathing control systems during waking and sleep are quite different Alterations of ventilatory control occur in chemosensitivity, response to mechanical loads, and stability of ventilation. The activities of intercostal muscles and muscles involved in regulating upper airway size are decreased during sleep. These respiratory physiological changes during sleep compromise the nocturnal ventilatory function, and sleep is an important physiological cause of the nocturnal alveolar hypoventilation. There are several causes of chronic alveolar hypoventilation including cardiopulmonary, neuromuscular diseases. Obstructive sleep apnea syndrome (OSAS) is an important cause of nocturnal hypoventilation and hypoxia. Coexistent cardiopulmonary or neuromuscular disease in patients with OSAS contributes to the development of diurnal alveolar hypoventilation, diurnal hypoxia and hypercapnia. The existing data indicates that nocturnal recurrent hypoxia and fragmentation of sleep in patients with OSAS contributes to the development of systemic hypertension and cardiac bradytachyarrhythmia, and diurnal pulmonary hypertension and cor pulmonale in patients with OSAS is usually present in patients with coexisting cardiac or pulmonary disease. Recent studies reported that untreated patients with OSAS had high long-term mortality rates, cardiovascular complications of OSAS had a major effect on mortality, and effective management of OSAS significantly decreased mortality.