• Journal of Information Processing Systems
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• v.14 no.2
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• pp.396-417
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• 2018

GR-tree and query aggregation techniques have been proposed for spatial query processing in conventional spatial query processing for wireless sensor networks. Although these spatial query processing techniques consider spatial query optimization, time query optimization is not taken into consideration. The index reorganization cost and communication cost for the parent sensor nodes increase the energy consumption that is required to ensure the most efficient operation in the wireless sensor node. This paper proposes itinerary-based R-tree (IR-tree) for more efficient spatial-temporal query processing in wireless sensor networks. This paper analyzes the performance of previous studies and IR-tree, which are the conventional spatial query processing techniques, with regard to the accuracy, energy consumption, and query processing time of the query results using the wireless sensor data with Uniform, Gauss, and Skew distributions. This paper proves the superiority of the proposed IR-tree-based space-time indexing.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.153-156
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• 2006

The domestic solar radial ion data have been measured at 16 different sites all over the country since the beginning of 1980. It is very important that the fundamental data for the estimation and assessment of local solar radiation can be secured this project. In order to estimate available energy resource from solar radiation, it is necessary to have enough data, more than 30 years In any country. However since we have collected solar radiation(global radial ion including direct normal radiation) data only for 10 years we still need to measure insolation to secure the reliability and standardization of measured local solar radial ion data. In brief, the major activities on this R&D include rout me maintenance of the national network for insolation data measurement, evaluation of the collected data, and reliability enhancement for assessing the quality of solar radiation data as well.

• International Journal of Automotive Technology
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• v.8 no.3
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• pp.351-359
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• 2007

In this study, a hierarchical switching control scheme based on robust control theory is proposed for tracking control of vehicle longitudinal acceleration in the presence of large uncertainties. A model set consisting of four multiplicative-uncertainty models is set up, and its corresponding controller set is designed by the LMI approach, which can ensures the robust performance of the closed loop system under arbitray switching. Based on the model set and the controller set, a switching index function by estimating the system gain of the uncertainties between the plant and the nominal model is designed to determine when and which controller should be switched into the closed loop. After theoretical analyses, experiments have also been carried out to validate the proposed control algorithm. The results show that the control system has good performance of robust stability and tracking ability in the presence of large uncertainties. The response time is smaller than 1.5s and the max tracking error is about $0.05\;m/S^2$ with the step input.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.18-26
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• 2012

Recently, there have been suggestions that power factor should be considered to increase the efficiency of electric power supply when evaluating the performance of the electric appliances in standby mode and the related studies have been conducted to improve the efficiency standard of standby power. But, they lack the analysis of the standby power characteristics with the changes of power factor. This study is conducted to analyze the standby power characteristics of TV which is a typical home appliance and reaches a conclusion that the apparent power can be a more reasonable index which reflects the efficiency of electric power supply. It is also found that LED TVs show the best performance in standby mode. Moreover, an example to set standby power standards on TVs to be applied in the future is suggested, considering the energy efficiency policies for appliances.

• Journal of the Korean Institute of Navigation
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• v.22 no.1
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• pp.79-89
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• 1998

When an automatic course-keeping is concerned , as is quite popular in modern navigation, the closed-loop steering system consists of autopilot device, power unit(or telemotor unit), steering gear, magnetic or gyro compass and ship dynamics. In order to estimate steering system of ship in open seas, we need to know the characteristics of each component of the system and also to know the characteristics of disturbance to ship dynamics. Calculation methods of irrgular disturbances are based on the linear superposition principle. In this paper, for the purpose of evaluation of automatic steering of ships , the influences of linear control constants of autopilot on propulsive energy loss are investigated bya performance index is introduced from the viewpoint of energy saving. Numberical calculations are carried out for an are carrier and for a fishing boat in multi-directional waves.

• Bulletin of the Korean Space Science Society
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• 1995.04a
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• pp.21-21
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• 1995

The structures of 17GHz microwave burst for bipolar sunspots have investigated. which included the effects of the projected shapes of radio sources as they traverse across the solar disk using a magnetic loop employing a model of solenoid coils. An ensemble of high-energy electrons confined in the loop be assumed. The projected brightnesls distributions of gyrosynchrotron emission in x- and o-modes are computed and converted into total intensity and circular polarization difference at 17GHz for various heliocentric distances using numerical integration of the transfer equation along the line of sight. The results of computations at 17GHz for optical thin case will be presented. and the effects of the orientation of the loop will be discussed in detail, as well as the effect of size, position, Structure, and polarization of the emission. Also the results of the various physical P8lrameters such as the strength of magnetic field. high and low energy cut-off of accelerated electrons. spectral index and density of electrons will be preslmted. After comparing the results of model calculation with observations. we found that the observations can be well explained in terms of a loop model and its projection effect.effect.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.72-75
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• 1988

In the point-to-point motion on servo system, the control mode which minimizes the performance index including, the impact of end point, time and energy, is proposed. The proposed control mode applied to the feed-back control system of D.C motor and then had a computer simulation. This control mode had less the impact of end point, stedy state error, time and energy than the bang-bang or the saturating- proportional control mode.

• Preventive Nutrition and Food Science
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• v.22 no.1
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• pp.62-66
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• 2017

This study was conducted to determine the rheological properties of gochujang and chogochujang at different temperatures (25, 35, and $45^{\circ}C$). Rheological properties of the samples were determined using a rotational rheometer at a shear range of 1 to $40s^{-1}$. Gochujang and chogochujang were found to be non-Newtonian fluids according to the Herschel-Bulkley model. Yield stress and consistency coefficient of gochujang at different temperatures were higher than those of chogochujang, whereas the opposite was observed for flow behavior index. Moreover, all rheological properties of gochujang and chogochujang decreased with increasing temperature. The consistency coefficient was related to temperature using an Arrhenius-type relationship. Gochujang (14.48 kJ/mol) had slightly higher activation energy than chogochujang (14.03 kJ/mol).

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1120-1123
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• 2008

Efficient, color stable multi-EML WOLED have been fabricated using newly synthesized yellowish green dopant Ir(chpy)3 or Ir(mchpy)3. The devices have high external quantum efficiency of 11.7%, color rendering index of 87, variation of CIE coordinate of (0.02, 0.01) between 10 to 5000 cd/m2, and low roll-off in efficiency with increasing brightness.

• KSBB Journal
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• v.28 no.5
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• pp.275-281
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• 2013

Soil microbial community analysis of farmland soil sprayed with lye in order to use fertilizer in Nigeria was performed. As a control, two kinds of soils not sprayed with lye, located in Eungo and Lagos with general practice in agriculture was selected. Soil sprayed with lye was pH 8.25 through alkalization reaction, while the other soil samples were pH 6.22 and 5.94. Substrate utilization and species diversity index of soil sprayed with lye were low than that of the other soils with the analysis of Biolog ecoplate. As a result of principal component analysis, the relationship between three samples was low. Microbial community analysis was performed by DGGE and most of them were soil uncultured bacterium. Especially, Uncultured Acidobacteria and Uncultured Methylocystis sp., which had been isolated from the rhizosphere of soybean grown in that site were discovered in the soil sprayed with lye.