• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.81-86
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• 2010

Since the solar energy resource is the main input for sizing any solar photovoltaic system and solar thermal power system, it is essential to utilize the solar radiation data as a application and development of solar energy system increase. It will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations in Korea. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. From the results, the yearly averaged horizontal global insolation was turned out 3.60kWh/$m^2$/day and a significant difference of horizontal global insolation is observed between 1982~1990 and 1991~1999, 2000~2008 through 16 different cities in Korea.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.233-244
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• 2023

Although artificial intelligence and machine learning technologies have been used in various fields, problems with personal information protection have arisen based on centralized data collection and processing. Federated learning has been proposed to solve this problem. Federated learning is a process in which clients who own data in a distributed data environment learn a model using their own data and collectively create an artificial intelligence model by centrally collecting learning results. Unlike the centralized method, Federated learning has the advantage of not having to send the client's data to the central server. In this paper, we quantitatively present the performance improvement when federated learning is applied using the building change detection learning data. As a result, it has been confirmed that the performance when federated learning was applied was about 29% higher on average than the performance when it was not applied. As a future work, we plan to propose a method that can effectively reduce the number of federated learning rounds to improve the convergence time of federated learning.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.161-166
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• 1990

Infusion of bradykinin (BK) into the renal arteries increases sodium excretion. However, it is not clear whether natriuresis results from the renal hemodynamic effects or from the direct effect on renal tubular sodium transport. Therefore, we examined the effects of BK on the transport-dependent oxygen consumption in the distal tubule (DT) and cortical collecting tubule (CCT) of deoxycorticosterone-treated rats. BK inhibited oxygen consumption in a dose-dependent way with a maximal reduction at $0.1\;{\mu}M$ BK. The inhibitory effect of BK was not present in the absence of sodium or in the presence of ouabain (1 mM). These data imply that the inhibitory effect of BK is restricted to the sodium transport-dependent oxygen consumption. We also investigated the relationship between the effect of BK on oxygen consumption and arachidonic acid metabolism. Mepacrine $(10\;{\mu}M)$, an inhibitor of membrane phospholipases, prevented the inhibitory effect of BK, but indomethacin (0.5 mM) didn't. These results suggest that BK decreases the sodium transport-related oxygen consumption in the rat DT and/or CCT, and that it may be mediated by products of enzymes other than cyclooxygenase.

• Tribology and Lubricants
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• v.25 no.6
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• pp.387-398
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• 2009

The operation condition of recently designed pistons for high power and high speed diesel engine become more severe due to the increment of combustion pressure and temperature. So, in order to overcome high temperature, the application of the mono-metal cast aluminum alloy piston featuring an enclosed cast-in open cooling gallery has increased. In this research, it is developed a PCJ (piston cooling jet) rig tester, described the test procedure and validated the performance of sample piston cooling gallery design. Then the test rig will be used for developing the design technology of piston cooling gallery. The test rig is composed with oil reservoir and pumping system, oil jet system, piston fixing and moving system, collecting oil measuring system, and data measuring and recording system. It will be measured collecting efficiencies under conditions of a few piston positions, oil jet pressures and oil viscosities for a piston cooling gallery. Furthermore, the PCJ rig tester will be used for the optimum design of the oil cooling gallery which being applied to increase the cooling efficiency of pistons in diesel engines satisfying the EURO V emission regulation and the more.

• Journal of Korean Elementary Science Education
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• v.23 no.4
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• pp.305-317
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• 2004

The learning materials in elementary school science textbooks should include all kinds of materials being used by both teachers and students in the science teaching. The major purpose of this research is to analysis textbooks and teacher's guidebooks prepared for the science teaching of 3-6 grade students. To clarify this research, we listed whole of the learning materials of science teaching for each grade and counted numbers being used for whole of the lessons of science. And according to the characteristics and the methods of its preparation of materials, the types of learning materials can be divided into 10 categories such as teaching equipments for science, test materials, consumables, audio-visual aids, teaching equipments in general, collecting' recycling materials, field studies' collected data, breeding' cultivation materials, manufacture materials, and etc. At the result of this research, the 7th national science curriculum needs total 844 items of learning materials for science education. They could be separated into ten types of categories such as 159 items of teaching equipments for science, 65 items of test materials, 116 items of consumables, 198 items of audio-visual aids, 64 items teaching equipments in general, 31 items of collecting' recycling materials, 38 items of field studies (collecting) materials, 17 items of breeding-cultivation materials, 58 items of manufacturing materials, 105 items of other materials. And we found out that there were 332 items of materials for the 3rd grade, 303 items for the 4th grade, 324 items for the 5th grade, and 254 items for the 6th grade. The result of this research could be useful for classroom activities for science teaching.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.41-44
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• 2008

In this paper, major species of tree were discriminated in compartment by using LiDAR data and optic imagery. This is an important work in forest field. A current digital stock map has created the aerial photo and collecting survey data. Unlike high resolution imagery, LiDAR data is not influenced by topographic effects since it is an active sensory system. LiDAR system can measure three dimension information of individual tree. And the main methods of this study were to extract reliable the individual tree and analysis techniques to facilitate the used LiDAR data for calculating tree crown 2D parameter. We should estimate the forest inventory for calculating parameter. 2D parameter has need of area, perimeter, diameter, height, crown shape, etc. Eventually, major species of tree were determined the tree parameters, compared a digital stock map.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.413-416
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• 2009

Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.61 kWh/$m^2$/day and the yearly mean 5.38 kWh/$m^2$/day of the direct normal insolation was evaluated for clear days.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1464-1468
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• 2007

The restoration project of Cheonggyecheon was conducted to creates the refreshing water-friendly environment in the downtown Seoul. It already have passed almost 2 years after restoration. This project changed environment of Cheonggyecheon dramatically, so historic hydrological data became useless. There are not so many hydrological data to manage and control this newly restored urban stream. The main purpose of this study is collecting and analysing the hydrological data of Cheonggyecheon. At first, we analysed the mechanism of Cheonggyecheon discharge using the sewage design maps and some GIS data. We also monitored the water levels and discharges of 5 main points of Cheonggyecheon. Rating curves of these 5 points were derived. There were 249 blocks of water gates which were located at both sides of bank. We also monitored the behaviors of these water gates. Through the these monitorings, some equations were derived to give useful information to the manager of Cheonggyecheon.

• Solar Energy
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• v.6 no.1
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• pp.70-76
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• 1986

Since the solar radiation is the main input for sizing any solar system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy and Resources (KIER) has began collecting horizontal insolation data since May, 1982 at 15 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by the solar system users as well as by research institutes. Among some significant results, we obtained the good results more than we had expected, it is very encouraging that the mean value of Korea's solar radiation is increased by more than 30%.

• Journal of the Korean Solar Energy Society
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• v.29 no.4
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• pp.15-21
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• 2009

Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.60 kWh/$m^2$/day and the yearly mean 2.62 kWh/$m^2$/day of the direct normal insolation was evaluated for all days.