• Title/Summary/Keyword: Charge carrier

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Forecasting and Analysis of Air Meteorological Service Charge using ARIMA-Intervention Time Series Model (ARIMA-개입모델을 이용한 항공기상정보 사용료 징수액 추정 및 적정성 연구)

  • Kim, Kwang-Ok;Park, Sung-Sik
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.3
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    • pp.9-22
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    • 2018
  • Korea meteorological administration(KMA) has started to levy air meteorological service charge on both national and foreign carriers since 2005. The charge has grown on 2010 and 2014 twice. However, KMA has still kept asking airlines to agree with another increase in the charge due to the low cost of goods recovery ratio of 7%. The air meteorological charge has changed from 2,210 KRW at the beginning to 11,400 KRW as of June 2018. According to ARIMA intervention time series analysis, it was proven national carriers would make a payment of 831 million KRW 2018 and 1,024 million KRW 2019, showing 186.2% and 123.2% increase compared to last year respectively. The total amount of charge for both national LCC and foreign airlines was aggregated up to 1,952 million KRW 2019, 227% bigger than the charge paid at 2017. Considering the 50% increase of consumer price index last decade, the increased charge would impair the global competitiveness of national carriers. It could be suggested that current air meteorological charge scheme be improved to apply overseas trend and for national carriers to have a competitive advantage in global aviation market.

Carrier Conducting Path in the Crystalline Silicon Solar Cells

  • Choi, Pyungho;Kim, Sangsub;Choi, Byoungdeog
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.457-457
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    • 2013
  • Current-voltage (I-V) measurements of crystalline silicon solar cells was conducted under dark conditions with the temperature range of 260 K~350 K. Using the calculation method, we extracted the crucial factors of ideality factor (n) and activation energy (Ea) to investigate the carrier conducting path in the space charge region (SCR) and the quasi-neutral region (QNR). Values of n were decreased with increasing temperature in both SCR and QNR. We also conformed that the value of Ea of SCR was larger than that of QNR about 0.4 eV. The temperature dependence of n indicates that the carrier conducting path is dominated by carrier recombination-generation in the SCR region than in the QNR region.

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A Study on the Period of Carrie's Responsibility (해상운송인의 책임기간에 관한 고찰)

  • 조종주
    • Journal of Korea Port Economic Association
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    • v.18 no.2
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    • pp.135-151
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    • 2002
  • This study focuses on analysing the period of carrier's responsibility. The Hague Rules apply only while the cargo is in carriage. This period of carrier's responsibility begins when the ship' tackle is hooked on the goods for loading and continues until they are unhooked from the lifting gear after discharge. The Hague Rules are consequently said to apply from tackle to tackle. Also The Hamburg Rules lays down the basic principle that the carrier will be responsible for the goods during the time he is in charge of them at the port of loading, during the carriage and at the port of discharge. These period of carrier's responsibility should be determinated according to custom of the port of loading and discharge because of the importance of local custom in the loading and discharge of goods.

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Transient Characteristics of NPT-IGBT with different temperatures (온도 변화에 따른 NPT-IGBT의 과도 특성)

  • 류세환;황광철;안형근;한득영
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.292-295
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    • 2002
  • In this work, transient characteristics of NPT(Non Punch Through)-IGBT(Insulated Gate Bipolar Transistor) have been studied with different temperatures analytically. Power losses are caused by heat generated in MIT-IGBT for steady state and transient state conditions. We therefore have focused on the analysis of excess carrier concentration and excess charge injected into N-drift layer with different temperatures and have obtained anode voltage drop during turn-off with lifetime of 2.4[${\mu}$s].

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The $Al_2O_3$ Passivation Mechanism for c-Si Surface Deposited by ALD Using $O_3$ Oxidant

  • Jo, Yeong-Jun;Jang, Hyo-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.320.1-320.1
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    • 2013
  • We have investigated the effect of surface passivation for crystalline silicon solar cell using ozone-based atomic layer deposited (ALD) $Al_2O_3$. We examined passivation properties such as uniformity, carrier lifetime, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD). Ozone-based ALD $Al_2O_3$ film shows the best carrier lifetime at lower deposition temperature than $H_2O$-based ALD.

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Interfacial Properties of a-Se Thick Films to Solve Charge Trap and Injection Problems (전하 트랩 및 주입 문제를 해결하기 위한 비정질 셀레늄 필름의 계면 특성)

  • Cho, J.W.;Choi, J.Y.;Park, C.H.;Kim, J.H.;Lee, H.W.;Nam, S.H.;Seo, D.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.497-500
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    • 2001
  • Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e.g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current. 缀Ѐ㘰〻ሀ䝥湥牡氠瑥捨湯汯杹

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Charge Pumping Measurements Optimized in Nonvolatile Polysilicon Thin-film Transistor Memory

  • Lee, Dong-Myeong;An, Ho-Myeong;Seo, Yu-Jeong;Kim, Hui-Dong;Song, Min-Yeong;Jo, Won-Ju;Kim, Tae-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.331-331
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    • 2012
  • With the NAND Flash scaling down, it becomes more and more difficult to follow Moore's law to continue the scaling due to physical limitations. Recently, three-dimensional (3D) flash memories have introduced as an ideal solution for ultra-high-density data storage. In 3D flash memory, as the process reason, we need to use poly-Si TFTs instead of conventional transistors. So, after combining charge trap flash (CTF) structure and poly-Si TFTs, the emerging device SONOS-TFTs has also suffered from some reliability problem such as hot carrier degradation, charge-trapping-induced parasitic capacitance and resistance which both create interface traps. Charge pumping method is a useful tool to investigate the degradation phenomenon related to interface trap creation. However, the curves for charge pumping current in SONOS TFTs were far from ideal, which previously due to the fabrication process or some unknown traps. It needs an optimization and the important geometrical effect should be eliminated. In spite of its importance, it is still not deeply studied. In our work, base-level sweep model was applied in SONOS TFTs, and the nonideal charge pumping current was optimized by adjusting the gate pulse transition time. As a result, after the optimizing, an improved charge pumping current curve is obtained.

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Carriers Behavior in Metal-Polymer Interface (금속-고분자 계면에서 캐리어의 거동)

  • Lee, Seung-Hoon;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2313-2314
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    • 2008
  • In this paper, the behaviour of charge carriers near the metal/polymer interface and its effects on conduction and breakdown phenomena are discussed. The metal/polymer interface strongly affects carrier injection, space charge formation and breakdown phenomena. Based on their experimental results, the physical backgrounds of the interfacial phenomena are explained.

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MAGNETOTRANSPORT IN AN N-TYPE DILUTED MAGNETIC SEMICONDUCTOR: (Ga,Mn)N

  • Lee, K. I.;Lee, J. M.;J. Y. Chang;S. H. Han;Lee, W. Y.;M. H. Ham;J. M. Myoung
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.148-149
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    • 2002
  • In recent years, semiconductor spintronics has been rapidly developing due to potential device applications, in which the spin of charge carriers (electrons or holes) provides novel functionalities to carry signals and process information. Diluted magnetic semiconductors (DMSs) are well known to exhibit intriguing properties such as carrier-mediated ferromagnetism and spin-dependent transport resulting from the coupling between the charge transport states and the magnetic moments (spin) [1-3]. (omitted)

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Effects of Energetic Disorder and Mobility Anisotropy on Geminate Electron-hole Recombination in the Presence of a Donor-Acceptor Heterojunction

  • Wojcik, Mariusz;Michalak, Przemyslaw;Tachiya, M.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.795-802
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    • 2012
  • Geminate electron-hole recombination in organic solids in the presence of a donor-acceptor heterojunction is studied by computer simulations. We analyze how the charge-pair separation probability in such systems is affected by energetic disorder of the media, anisotropy of charge-carrier mobilities, and other factors. We show that in energetically disordered systems the effect of heterojunction on the charge-pair separation probability is stronger than that in idealized systems without disorder. We also show that a mismatch between electron and hole mobilities reduces the separation probability, although in energetically disordered systems this effect is weaker compared to the case of no energetic disorder. We demonstrate that the most important factor that determines the charge-pair separation probability is the ratio of the sum of electron and hole mobilities to the rate constant of recombination reaction. We also consider systems with mobility anisotropy and calculate the electric field dependence of the charge-pair separation probability for all possible orientations of high-mobility axes in the donor and acceptor phases. We theoretically show that it is possible to increase the charge-pair separation probability by controlling the mobility anisotropy in heterojunction systems and in consequence to achieve higher efficiencies of organic photovoltaic devices.