• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.480-486
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• 2011

Conservation of energy and fuel is the trend in smart building design. Radio Frequency Integrated Circuit (RFIC) technology is often used in temperature sensing and signal transmission to manage indoor temperature, but it is rarely applied to the shell of the building. Heat retention and poor insulation in building shells are the largest causes of high energy consumption by indoor air conditioning. Through combining RFIC technology with temperature sensors, this study will develop smart temperature information material that can be embedded in concrete. In addition to accurately evaluating the effectiveness of shell insulation material, the already-designed Building Physiology Information System can monitor long-term temperature changes, leading to smarter building health management.

• 센서학회지
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• 제19권3호
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• pp.197-201
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• 2010

This paper describes the fabrication and characteristics of a NO sensor using ZnO thin film integrated 3C-SiC micro heater based on polycrystalline 3C-SiC thin film of operation in harsh environments. The sensitivity, response time, and operating properties in high temperature and voltages of NO sensors based SiC MEMS are measured and analyzed. The sensitivity of device with pure ZnO thin film at the heater operating power of 13.5 mW ($300^{\circ}C$) is 0.875 in NO gas concentration of 0.046 ppm. In the case of Pt doping, the sensitivity of at power consumption of 5.9 mW ($250^{\circ}C$) was 1.92 at same gas flow rate. The ZnO with doped Pt was showed higher sensitivity, lower working temperature and faster adsorption characteristics to NO gas than pure ZnO thin film. The NO gas sensor integrated SiC micro heater is more strength than others in high voltage and temperature environments.

• International Journal of Aeronautical and Space Sciences
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• 제13권1호
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• pp.64-73
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• 2012

Pointing stability of high precision observation satellites must satisfy the stringent requirements to perform at a designed level. As even a small vibrational disturbance can result in severe degradation of the optical performance, the effects of inorbit vibrational environment on the performance of optical payload must be predicted and analyzed in the design phase in order to ensure that the requirements imposed on the payload are fully met. In this paper, an integrated framework for the evaluation of the performance of optical payloads is developed. The developed simulation tool comprises of the reaction wheel induced disturbance model, state space model of a structure in modal form and Cassegrain reflector model. The performance degradation of the optical system due to jitter is expressed by using modulation transfer function (MTF) and image simulation. Moreover, vibration isolator model is also added to show the effectiveness of using a vibration isolator for the elimination of the effects of jitter in the acquisition of an image.

• 농업과학연구
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• 제47권2호
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• pp.263-273
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• 2020

With the change of the agricultural environment (increased rice production, decreased rice consumption, and rice production policies), converting paddy fields into upland fields is an increasing trend. In terms of conversion into upland fields, subsurface drainage is one of the most important factors for good field crop growth. This study evaluates the performance of a subsurface drainage culvert system in paddy fields and reclaimed lands. The obtained results are briefly summarized as follows: 1) After a comparative evaluation of several subsurface drainage culvert systems, including excavated subsurface drainage and non-excavated subsurface drainage types, type 3 (non-excavated, perforated drain pipe 50 mm, filter mat B50 cm, subsoiling 70 cm and culvert spacing 5 m) shows relatively high values among four types in terms of effectiveness (subsurface discharge capability) and economic efficiency (construction cost). 2) Type 3 has proven that it is suitable for design standards of discharge capacity through field tests performed in paddy fields (three sites: Gong-geom, Gae-san, Juk-san) and reclaimed lands (two sites: Gum-ho, Mi-am). 3) In the experiment of Sesamum indicum growth according to the existence of a drainage system, Sesamum indicum growth with a subsurface drainage culvert system had good value in terms of plant shoot and root length, shoot fresh and dry weight, and root fresh and dry weight).

• IEIE Transactions on Smart Processing and Computing
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• 제5권2호
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• pp.100-106
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• 2016

Spectrum sensing is an integral part of cognitive radio, which seeks to address the perceived spectrum scarcity that is caused by inefficient utilization of the available spectrum. In this paper, a spectrum sensing system using energy detection for analog TV and FM broadcast transmitters as well as modified Integrated Services Digital Broadcasting Terrestrial (ISDB-T) signals is implemented on a software-defined radio platform using GNU' Not Unix (GNU) radio and the N200 Universal Software Radio Peripheral (USRP). Real-time implementation and experimental tests were conducted in Metro Cebu, a highly urbanized area in the southern part of the Philippines. Extensive tests and measurements were necessary to determine spectrum availability, particularly in the TV band. This is in support of the Philippine government' efforts to provide internet connectivity to rural areas. Experimental results have so far met IEEE 802.22 requirements for energy detection spectrum sensing. The designed system detected signals at -114 dBm within a sensing time of 100 ms. Furthermore, the required $P_d({\geq}90)$ and $P_{fa}({\leq}10)$ of the standard were also achieved with different thresholds for various signal sources representing primary users.

• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.528-537
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• 2008

Primary frequency control(PFC) has the ability to regulate short period random variations of frequency during normal operation conditions and also to respond rapidly to emergencies. However, during the past decade, numerous significant sized blackouts occurred worldwide that resulted in serious economic losses. Therefore, the conclusion has been reached that the ability of the current PFC to meet an emergency is poor, and security of power systems should be improved. An alternative to enhance the PFC and thus security is to store excessive amounts of energy during off-peak load periods in efficient energy storage systems for substituting the primary control reserve. In this sense, superconducting magnetic energy storage(SMES) in combination with a static synchronous compensator(STATCOM) is capable of supplying power systems with both active and reactive powers simultaneously and very rapidly, and thus is able to enhance the security dramatically. In this paper, a new concept of PFC based on incorporating a STATCOM-SMES is presented. A complete detailed model is proposed and a new control scheme is designed, comprising an enhanced frequency control scheme, and a fully decoupled current control strategy in d-q coordinates with a novel controller to prevent dc bus capacitors voltage drift/imbalance. The performance of the proposed control schemes is validated through digital simulation carried out using MATLAB/Simulink.

• Journal of Communications and Networks
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• 제18권4호
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• pp.567-579
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• 2016

Several energy saving techniques in cellular wireless networks such as active base station (BS) selection, transmit power budget adaptation and user association have been studied independently or only part of these aspects have been considered together in literature. In this paper, we jointly tackle these three problems and propose an integrated framework, called dynamic cell reconfiguration (DCR). It manages three techniques operating on different time scales for ultimate energy conservation while guaranteeing the quality of service (QoS) level of users. Extensive simulations under various configurations, including the real dataset of BS topology and utilization, demonstrate that the proposed DCR can achieve the performance close to an optimal exhaustive search. Compared to the conventional static scheme where all BSs are always turned on with their maximum transmit powers, DCR can significantly reduce energy consumption, e.g., more than 30% and 50% savings in uniform and non-uniform traffic distribution, respectively.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.639-643
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• 1996

The manufacturing system has been changed from labored manual process system, which is managed and operated by managers and operators, to CIMS(Computer Integrated Manufacturing System) for integration of manufacturing, research, development and consumption in the age of diverse customer's needs[6]. However, because it involves the hierarchical system composed of many sub-systems interface and its installation & setup cost is very expensive, CIMS has many difficulties in constructing the durable optimal system that is able to adapt to rapid in-outer circumstance change. So, HMS(Holonic Manufacturing System), the new conceptual manufacturing system having the self-problem-solving and self-organization[11], is instructed to solve these difficulties that it has in these days. The system flexibility in the HMS is able to be ensured, with the integration of human's strong points into mechatronics manufacturing system to reduce interference among sub-systems. In this paper, the manufacturing process rationalization and integration of the assembly line in an automobile industry, has lots of problems in efficiency and productivity, has been studied in an early stage of converting the present state of process system to HMS, which is human-oriented processing system, to improve the line efficiency, system productivity and reliability by using human capability effectively. This paper is derived into the human-oriented & object-oriented holons settlement of the shop floor system composed of processing, assembly and material handling system for the future holonic manufacturing system, which is going to be computer supported control system.

• 대한한방내과학회지
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• 제41권6호
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• pp.1245-1254
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• 2020

Introduction: The aim of this study was to report the effect of Korean medicine treatments on a stroke patient with acute cerebral infarction. Method: A 63-year-old male with anterior and middle cerebral artery infarction had symptoms of dizziness and disorientation. The patient was treated with Korean medicine therapy, including the herbal medicine "Sunghyuangjunggi-san-gamibang." Treatment progress was assessed using the Korean version of the Modified Barthel Index (K-MBI) and the Korean dizziness handicap inventory (K-DHI). Results: After 14 days of treatment, the K-DHI score decreased from 78 to 7 and the K-MBI score increased from 18 to 24. The patient's main symptoms were improved after the treatment, and no side effects were observed. Conclusion: Korean medicine treatment, including Sunghyuangjunggi-san, might be a recommended therapeutic option for dizziness and disorientation in stroke patients.

• 한국컴퓨터정보학회논문지
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• 제15권11호
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• pp.117-124
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• 2010

중앙 집중적 네트워크 관리 구조인 SNMP(Simple Network Management Protocol)를 무선 네트워크 관리에 적용하면 네트워크 과부하, AP에서의 NAT(Network Address Translation)로 인한 관리의 문제, 그리고 무선 노드의 성능 저하가 발생한다. 본 연구에서는 이러한 문제를 해결하기 위해 MA(Mobile Agent)를 도입한 유무선 네트워크 통합 관리 기법을 제안한다. 제안기법에서 유선 네트워크는 SNMP 기반으로 관리하고 무선 네트워크는 AP 또는 무선 노드에 SNMP를 MA 기반으로 구현하여 관리한다. 또한, SNMP 응답 메시지 내에 중복되는 OID 정보를 줄이는 방법도 제시한다. 분석을 통해 제안 기법이 제시된 문제를 해결하고 무선 노드에 대한 처리 시간이 개선됨을 보인다.