• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1443-1451
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• 2020

The objective of this study is to design a robust power control system for a small pressurized water reactor (PWR) to achieve stable power operations under conditions of external disturbances and internal model uncertainties. For this purpose, the multiple-input multiple-output transfer function models of the reactor core at five power levels are derived from point reactor kinetics equations and the Mann's thermodynamic model. Using the transfer function models, five local reactor power controllers are designed using an H infinity (H_∞) mixed sensitivity method to minimize the core power disturbance under various uncertainties at the five power levels, respectively. Then a multimodel approach with triangular membership functions is employed to integrate the five local controllers into a multimodel robust control system that is applicable for the entire power range. The performance of the robust power system is assessed against 10% of full power (FP) step load increase transients with coolant inlet temperature disturbances at different power levels and large-scope, rapid ramp load change transient. The simulation results show that the robust control system could maintain satisfactory control performance and good robustness of the reactor under external disturbances and internal model uncertainties, demonstrating the effective of the robust power control design.

• Spatial Information Research
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• 제20권5호
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• pp.111-118
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• 2012

측량 기준점은 국민의 재산권 설정과 밀접한 연관이 있는 국가 중요시설물로 국가 또는 지자체에서 관리하고 있다. 따라서 이와 같은 측량 기준점은 측량성과는 물론 데이터베이스 및 표지의 관리에 이르기까지 중요한 국가 자료임에도 그동안 방대한 물량에 따른 인력, 시스템, 관련 제도 등 관리적 측면에서 각종 문제점들이 지속적으로 제기되어 왔다. 현재, 지자체마다 지리정보시스템이 개별적으로 구축 및 운영되고 있으나, 통합, 연계 및 활용 측면에서는 미흡한 실정이다. 따라서 본 연구에서는 지리정보시스템을 기반으로 한 측량 기준점 관련 정보 제공 및 관리를 위한 관리시스템의 기능 개선 방안과 기준점 이전 경비의 선납부제도 정착방안을 제시하였다. 이를 통해 관리자와 사용자 중심의 One-stop 기준점 관리 통합 시스템 구축의 근간을 마련하고, 기준점 망실 원인자 불명에 따른 기준점 복구비 부과 문제를 해결할 수 있을 것이다.

• Animal Systematics, Evolution and Diversity
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• 제24권1호
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• pp.25-32
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• 2008

The Gold-spotted pond frog, Rana plancyi chosenica, designated as a vulnerable species by IUCN Red list. This species is a typical example facing local population threats and extinction due to human activities in South Korea. A strategic conservation plan for this endangered species is urgently needed. In order to provide information for future conservation planning, accurate information on the genetic diversity and taxonomic status is needed for the establishment of conservation units for this species. In this study, we used a molecular genetic approach using the mitochondrial cytochrome b gene and control region sequences to find the genetic diversity of gold-spotted pond frogs within South Korea. We sequenced the mitochondrial DNA cytochrome b gene and control region of 77 individuals from 11 populations in South Korea, and one from Chongqing, China. A total of 15 cytochrome b gene haplotypes and 34 control region haplotypes were identified from Korean gold-spotted pond frogs. Mean sequence diversity among Korean gold-spotted pond frogs was 0.31% (0.0-0.8%) and 0.51% (0.0-1.0%), respectively. Most Korean populations had at least one unique haplotype for each locus. The Taean, Ansan and Cheongwon populations had no haplotypes shared with other populations. There was a sequence divergence between Korean and Chinese gold-spotted pond frogs (1.3% for cyt b; 2.9% for control region). Analysis of genetic distances and phylogenetic trees based on both cytochrome b and control region sequences indicate that the Korean gold-spotted pond frog are genetically differentiated from those in China.

• 지역연구
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• 제34권1호
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• pp.19-30
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• 2018

사회간접자본은 한 사회가 발전하고 정상적으로 작동하는 데 필수적 요소이다. 이러한 중요성에도 불구하고 사회간접자본을 얼마나 투자해야 하는가에 대한 기준은 명확하지 않으며, 투자의 한 축을 담당하고 있는 지방정부의 사회간접자본 투자에 대한 논의는 거의 이루어지지 않았다. 지방정부의 권한이 충분히 보장되면, 지방정부는 주민이 원하는 지방공공재에 대한 투자를 늘린다. 그러한 주민 선호의 반영은 자원배분의 효율성을 가져온다는 것이 분권화 정리의 핵심 개념이다. 본 연구에서는 지방재정을 통해 지방정부의 권한과 자율성을 측정하고 지방정부의 사회간접자본 투자에서도 분권화 정리에 따른 의사결정이 이루어지는가를 살펴본다. 지방정부가 투자에 영향을 줄 수 있는 사회간접자본 시설(도로, 상하수도, 수리치수 시설) 투자에 대한 재원별 탄력성을 추정한 결과 특별 광역시와 그에 속한 기초지자체의 의사결정과 도와 도에 속한 기초지자체의 의사결정은 서로 달랐다. 이러한 차이는 1인당 지방세가 투자에 미치는 영향에서 가장 명확하게 나타났다. 이러한 결과는 지방정부가 주어진 상황에 따라 사회간접자본 투자를 달리하며 투자 결정에 있어 주민 선호를 반영한다는 것을 보여준다. 이것은 사회간접자본 투자에 대한 지방정부의 역할이 커질 때, 자원배분의 효율성이 증가할 수 있음을 보여준다. 그리고 지방정부의 역할 증대는 중앙정부의 재정지원 보다 지방정부의 세입 세출 자율성을 동시에 보장하는 방식이어야 한다는 것을 의미한다.

• The Journal of Korean Physical Therapy
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• 제17권3호
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• pp.429-440
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• 2005

The purpose of this study was to compare the effects of knee joint position sense following local and general load protocols in 25 healthy male subjects. Proprioception of the knee joint was evaluated by measuring absolute angular errors at matching angles before, after and between 2 different types of load protocols. Proprioception tests(on the dominant knee) were performed in which proprioception of the passivepassive reproduced and active-active reproduced knee position was measured. Local load was provided with maximum isokinetic knee extension-flexion on the isokinetic dynamometer(Cybex), and general load was 10 minutes running on a treadmill. Peak torque(knee extension and flexion) and heart rate(beats per minute) was evaluated as an indicator of local and general fatigue during load protocols. The results were as follows: 1. For pasive-pasive reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol(P<.05). However, no significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol (P>.05), no significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P>.05). 2. For active-active reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol (P<.05). Also, significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol(P<.05), significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P<.05). 3. A significant decrease of peak torque of knee extensors and flexors was seen after local load, although heart rate was significantly increased(P<.05). No significant change of peak torque of knee extensors and flexors was seen after general load(P>.05), although heart rate was also significantly increased(P<.05). The previous study revealed that knee proprioception is significantly altered when the muscle mechanoreceptors are dysfunctional due to muscle fatigue, although the joint mechanoreceptors have no significantly effect on knee proprioception when the presence of knee muscle fatigue. However, the results of this study are different from those of the previous study in that muscle weakness of the knee could not be seen after general load. This study shows that general load may diminish motor control by the central nervous system. Proprioceptional decline without muscle weakness of knee after general load suggests a change in the proprioceptional pathway without influence from muscle mechanoreceptors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1332-1336
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• 1990

This paper deals with some analytical and experimental aspects to control a multi-magnet suspended vehicle. Because the response of a multi-magnet vehicle shows mutually coupled interaction, an analytical description of the vehicle dynamics is necessary. For numerical computations, a linearized modelling of vehicle dynamics is dicussed and computer simulation is carried out. And for the experiment, a test vehicle suspended by four magnets has been made and investigated by local control of each magnet. Two algorithms by PID and state feedback control law are used and compared with each other. Some kinds of disturbance characteristics and coupling effects of the width change of the test vehicle are experimented.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권3호
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• pp.46-56
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• 2001

The present study concerns the numerical simulation of a supply airflow control in a variable air volume (VAY) system. A stratified thermal model (multi-zone model) is suggested to predict a local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of an air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated. Further, the influence of control parameters such as the supply air temperature, the PI control factor and the thermostat location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (single zone model) may overestimate the time taken to the set point temperature. It is also found that there exist the appropriate ranges of the control parameters for the optimal airflow control of the VAV system.

• 한국농공학회논문집
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• 제50권3호
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• pp.31-41
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• 2008

There are many agricultural facilities (46.7%) that have been over 30 years in the Republic of Korea (the ratio of reservoirs built before 1945 is 53%, from 1946 to 1971 is 35%). In the case of reservoirs which do most important functions among these facilities, only 3,000 reservoirs are managed by Korea Rural Community & Agriculture Corporation (KRC) and the other 15,000 reservoirs are managed by local authorities (City and Gun). But, 15,000 reservoirs included in City. Gun have been built in more wide area than KRC and the reservoir management system has not been operated well because of shortage of budget and manpower of the local authorities. Particularly, the abnormal weather happened during every summer season recently has ruined a lot of rural community facilities. So flood control function have been more important than irrigation function in agricultural reservoir system and it may be required to introduce new safe, management and maintenance techniques in City Gun reservoirs. So we investigated landscapes and deteriorations of agricultural reservoirs managed by local small governments for revealing not only present usage but also future value. Survey shows that there are no structural managements except typical hydrological reportings and the deterioration of small darn is very serious. There are needs for more systematic management system and equipment methods. Therefore, this study may suggest that reservoir (that takes charge of the greatest deal of weight in all agricultural facilities) must be considered as new concept of the usage and the unification. On the other hand, reservoir must be also developed as amenity resources, natural circumstances and district values.

• 대한두경부종양학회지
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• 제16권2호
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• pp.182-186
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• 2000

The reduction of the postoperative wound pain has been a concern in recent surgery, especially in various types of minimally-invasive surgeries. This study was performed to evaluate the postoperative analgesic effect of the preincisional local anesthesia with the mixture of ketorolac(Tarasyn) and bupivacaine to the surgical site in minimally-invasive thyroid surgeries. Of 491 patients who were scheduled for minimally-invasive thyroid surgeries between October 1999 and July 2000, 244 were randomly assigned to receive a mixture of ketorolac tromethamine 15mg(0.5ml) and 0.25% bupivacaine 3ml via surgical site infiltration 3 minutes prior to the skin incision. The outcomes of these patients were compared to those of the 247 controls. Total number of patients in need of post-operative analgesic requirements(n=39, 16.0%), total dose of postoperative analgesics used($19.6{\pm}8.4mg$ of ketorolac) and Visual Analogue Pain Score(VAS, $2.6{\pm}1.2$) of the preincisional local anesthesia group were significantly lower than those of the control group(p<0.05). The mean postoperative hospital stay was $1.6{\pm}0.4$ days for the preincisional local anesthesia group versus $1.9{\pm}0.7$ days for the control group. The preincisional local infiltration of ketorolac and bupivacaine in the minimally invasive thyroidectomies reduces postoperative wound pain thus would be more beneficial to the patients.

• Spatial Information Research
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• 제8권1호
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• pp.15-29
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• 2000

최근 급변하는 기술환경에서 향상된 정보서비스를 제공하기 위하여 지자체 또는 중앙정부차원에서 막대한 예산을 투입하여 GIS를 활용한 행정업무의 전산화를 추진하고 있거나 추진할 예정이다. 이러한 시점에서 예산의 중복투자 방지, 기 투자재원리 재활용을 극대화한다는 측면에서 행정업무 전산화의 특징을 살펴 행정업무 전산화사업에 있어서 GIS 응용 컴포넌트의 도입 가능성을 검토하고자한다. 본 연구서는 정보통신부 주관사업인 「개방형 GIS 컴포넌트 S/W 개발」 프로젝트에서 토지민원서비스 응용 컴포넌트를 개발하였다. GIS 응용컴포넌트는 OpenGIS의 OLE/COM 기반으로 만들어지며, 그 개발방법으로는 USD (Unified System Development), 시스템설계는 UML(Unified Modeling Language), 컴포넌트의 구현은 Visual C++를 이용하였다. 구현된 컴포넌트들은 Process Control, Map, Print, Statistics 컴포넌트들로서 Visual Basic 과 Delphi를 이용하여 구현된 컴포넌트를 검증하였다. 본 연구의 결과 컴포넌트의 개발이 지자체의 GIS 업무개발에 매우 유용하게 활용될 것으로 판단된다. 그러나 업무활용의 극대화를 위해서는 업무, 자료, 시스템의 표준화가먼저 선행되어야 할 것으로 보인다.