• Nuclear Engineering and Technology
• /
• v.52 no.7
• /
• pp.1443-1451
• /
• 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
• /
• v.20 no.5
• /
• pp.111-118
• /
• 2012

Survey control points managed by national and local governments are associated with civilian's property and they are very important national facilities. Despite the importance of surveying results, Database and mark of survey control points, there are many problems noticed of the management aspects such as manpower, systems, and related law. Currently, each local government has built and operated Geographic Information System(GIS) independently by National Geographic Information Systems(NGIS) results. but it is still difficult to have the integration, linking and utilizing. Therefore, In this study proposed the functional improvement of GIS based control points integrated system for providing information and management and the establishment of first-payment system due to the moving of control points. Through this studies will be able to solve the problem of recovery charges according to unknown contractor and establish the basis of manager and user-centric one-stop integration system.

• Animal Systematics, Evolution and Diversity
• /
• v.24 no.1
• /
• pp.25-32
• /
• 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.

• Journal of the Korean Regional Science Association
• /
• v.34 no.1
• /
• pp.19-30
• /
• 2018

Social overhead capital(SOC) is an essential element for society to be developed and operated normally. In spite of the increase in the importance of SOC, It is difficult to present the criteria for the appropriate investment of SOC. and The discussion on making SOC investments of local government is insufficient. If the local autonomy has been guaranteed, local government increases investment in regional public goods that residents prefer. Reflection of such residents preferences is the driving force to bring the efficiency of resource allocation in the decentralization theorem. In this study, the authority and autonomy of local governments are measured through local finance. and the decision-making of local governments for SOC investment is examined in point of decentralization theorem. In the empirical analysis, the elasticities of fiscal resources are estimated for facilities(road, water and sewage, irrigation canal and flood control) that local governments are involved in investment. These decisions made by metropolitan cities and provinces were different. The difference was most evident in the effect of per capita local tax on investment. These results show that metropolitan cities and provinces that have different situation made investment decisions differently. It shows that local governments reflect the preferences of the residents in making an investment. The main implication of this study is as follow. In case the role of local government in social overhead capital investment is increased, the increase in efficiency of resource allocation occurs. and The fiscal resources must be raised by local taxes rather than the financial resources from the central government.

• The Journal of Korean Physical Therapy
• /
• v.17 no.3
• /
• pp.429-440
• /
• 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
• /
• 1990.10b
• /
• pp.1332-1336
• /
• 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
• /
• v.9 no.3
• /
• pp.46-56
• /
• 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.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.3
• /
• pp.31-41
• /
• 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.

• Korean Journal of Head & Neck Oncology
• /
• v.16 no.2
• /
• pp.182-186
• /
• 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
• /
• v.8 no.1
• /
• pp.15-29
• /
• 2000

In the Recent rapidly changing technology environment the computerization of administration business which is driven or will be driven to give improved information services to people by local government or central government with a huge budget. The possibility of applying GIS application component to the computerization of administration business is investigated to prevent local government from investing redundant money and to reuse the existing investment at this point of time. Land civil service application component was developed at the $\ulcorner Development of Open GIS Component S/W \lrcorner$ project which was managed by Ministry of Information and Communication . GIS application component was based on Open GIS OLE/COM specification for development of standard interface and USD(Unified System Development ) for development method and UML (Unified Modeling Language) for system design and Visual C++ for component implementation. Implemented components were Process Control, Map, Print, Statistics component and were verified by using Visual Basic and Delhi. tis study shows that the development of component is very useful at the GIS application development for local governments. But the standard of business and data and system is the essential prerequisite to maximize business application.