• Title/Summary/Keyword: Research Program

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Control the crystal size by varying concentrations of precursors for the planar perovskite solar cells

  • Xie, Lin;Hwang, Heewon;Kim, Minjung;Kim, Kyungkon
    • Rapid Communication in Photoscience
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    • v.4 no.4
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    • pp.79-81
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    • 2015
  • The influence of the grain size of the $CH_3NH_3PbI_3$ on the solar cell performance is investigated by controlling the ratio between $CH_3NH_3I$ and $PbI_2$ precursors. As the concentration of the precursors increased from 1.0M to 2.0M, the $CH_3NH_3PbI_3$ grain size increased from ~100nm to ~400nm. The solar cell utilizing the $CH_3NH_3PbI_3$ with large grain size shows improved photocurrent compared to the solar cell utilizing $CH_3NH_3PbI_3$ with small grain size, which is ascribed to the reduced recombination at the boundaries of grains.

Spatial Resolution Improvement Using Over Sampling and High Agile Maneuver in Remote Sensing Satellite

  • Kim, Hee-Seob;Kim, Gyu-Sun;Chung, Dae-Won;Kim, Eung-Hyun
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.2
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    • pp.37-43
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    • 2007
  • Coordination of multiple UAVs is an essential technology for various applications in robotics, automation, and artificial intelligence. In general, it includes 1) waypoints assignment and 2) trajectory generation. In this paper, we propose a new method for this problem. First, we modify the concept of the standard visibility graph to greatly improve the optimality of the generated trajectories and reduce the computational complexity. Second, we propose an efficient stochastic approach using simulated annealing that assigns waypoints to each UAV from the constructed visibility graph. Third, we describe a method to detect collision between two UAVs. FinallY, we suggest an efficient method of controlling the velocity of UAVs using A* algorithm in order to avoid inter-UAV collision. We present simulation results from various environments that verify the effectiveness of our approach.

A Study on Inventory of Cut-Slope using the Mobile PC (Mobile PC를 이용한 절토사면 현황조사에 관한 연구)

  • Rhee, Jong-Hyun;Kim, Seung-Hee;Kim, Seung-Hyun;Koo, Ho-Bon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.813-820
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    • 2008
  • We have developed inventory database program which is available in the mobile PC. The mobile PC is convenient in terms of portability, data input, modification, practicality of various program and data confirmation in site. By utilizing the inventory database program in mobile PC, we are able to complete database in site. Then, database is converted into the Hangul document and Excel worksheet. Also, based on the above procedure, effective management and utilization of inventory on cut-slope can be achieved.

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The Development Plan of the Protection Device Auto-coordination Program in the Distribution Automation System (배전자동화 적용선로 보호기기 자동정정 프로그램 개발)

  • Kang, Moon-Ho;Ha, Bok-Nam;Lim, Seong-Il;Cho, Nam-Hun;Lee, Heung-Ho
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.129-131
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    • 2001
  • In order to improve the reliability of power service and the effective management of distribution power system. DAS (Distribution Automation system) is widely used in KEPCO(Korea Electric Power Corporation) branch offices. Based on the present protective device coordination program which used in KEPCO. this study presents the new concept about both protective device coordination program maximizing the characteristics of DAS and development plan of protective device auto-coordination program with the merits of DAS.

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Thermal Analysis for Design of Propulsion System Employed in LEO Earth Observation Satellite

  • Han C.Y.;Kim J.S.;Lee K.H.;Rhee S.W.
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.248-250
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    • 2003
  • Thermal analysis is performed to protect the propulsion system of low-earth-orbit earth observation satellite from unwanted thermal disaster like propellant freezing. To implement thermal design adequately, heater powers for the propulsion system estimated through the thermal analysis are decided. Based on those values anticipated herein, the average power for propulsion system becomes 22.02 watts when the only one redundant catalyst bed heater is turned on. When for the preparation of thruster firing, 25.93 watts of the average power is required. All heaters selected for propulsion components operate to prevent propellant freezing meeting the thermal requirements for the propulsion system with the worst-case average voltage, i.e. 25 volts.

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Mitochondrial noncoding RNA transport

  • Kim, Kyoung Mi;Noh, Ji Heon;Abdelmohsen, Kotb;Gorospe, Myriam
    • BMB Reports
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    • v.50 no.4
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    • pp.164-174
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    • 2017
  • Mitochondria are cytosolic organelles essential for generating energy and maintaining cell homeostasis. Despite their critical function, the handful of proteins expressed by the mitochondrial genome is insufficient to maintain mitochondrial structure or activity. Accordingly, mitochondrial metabolism is fully dependent on factors encoded by the nuclear DNA, including many proteins synthesized in the cytosol and imported into mitochondria via established mechanisms. However, there is growing evidence that mammalian mitochondria can also import cytosolic noncoding RNA via poorly understood processes. Here, we summarize our knowledge of mitochondrial RNA, discuss recent progress in understanding the molecular mechanisms and functional impact of RNA import into mitochondria, and identify rising challenges and opportunities in this rapidly evolving field.