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Vegetation Water Status Monitoring around China and Mongolia Desert using Satellite Data (위성자료를 이용한 중국과 몽골 사막주변의 식생수분상태 모니터링)

  • Lee, Ga-Lam;Kim, Young-Seup;Han, Kyoung-Soo;Lee, Chang-Suk;Yeom, Jong-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.94-100
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    • 2008
  • Recently, global warming for climate system is a crucial issue over the world and it brings about severe climate change, abnormal temperature, a downpour, a drought, and so on. Especially, a drought over the earth surface accelerates desertification which has been advanced over the several years mainly originated from a climatic change. The objective of this study is to detect variation of vegetation water condition around China and Mongolia desert by using satellite data having advantage in observing surface biological system. In this study, we use SPOT/VEGETATION satellite image to calculate NDWI (Normalized Difference Water Index) around study area desert for monitoring of status of vegetation characteristics. The vegetation water status index from remotely sensing data is related to desertification since dry vegetation is apt to desertify. We can infer vegetation water status using NDWI acquired by NIR (Near infrared) and SWIR (Short wave infrared) bands from SPOT/VGT. The consequence is that NDWI decreased around desert from 1999 to 2006. The areas that NDWI was decreased are located in the northeast of Mongolian Gobi desert and the southeast of China Taklamakan desert.

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Inter-Annual Variability of Ice Cap in Himalaya (히말라야산맥의 만년설 경년변화 연구)

  • Lee, Chang-Suk;Han, Kyung-Soo;Yeom, Jong-Min;Lee, Ga-Lam;Song, Bong-Guen
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.32-40
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    • 2008
  • In this study, we monitor ice cap using calculated NDSI from September to December in 2001, 2003, 2006, 2007 and snow cover area in 2007 decrease by compare with 2001. Global warming is one of the most important issue in this world. Because global-warming is the reason of various meteorological disasters and extreme weather events in these days and snow and glaciers showed that global warming effect most easily. Snow and glaciers play an important role in Earth cooling system because of their high reflectance. The present study has been carried out monitoring ice cap in Himalayas, using MODIS(Moderate Resolution Imaging Spectroradiometer)data. Indicator to monitoring ice cap, NDSI(Normalized Differenced Snow Index) was used in this study. The NDSI is a spectral band ratio that takes advantage of the spectral differences of snow in visible and short-wave infrared domain to detect snow cover area versus non-snow cover area in a scene. This study is quantitative evaluation about effect of global warming for icecap.

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A Study on Heart Rate Variabilities during Graded Head-up Tilt (점증적 틸트 각도 변화에 대한 심박변동에 관한 연구)

  • Jeong, K.S.;Shin, K.S.;Lee, J.W.;Choi, S.J.;Ahn, J.;Chon, J.S.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.406-409
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    • 1997
  • In this paper, the power spectral analysis and fractral dimension analysis of heart rate variability(HRV) were performed to evaluate effects of orthostatic stress with head-up tilt on autonomic nervous system(ANS) for 24 young and healthy subjects(age: $24{\pm}5yr$.). The ECG and respiration signals were recorded at the tilt angle of $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;70^{\circ}$ and $90^{\circ}$ successively for 5 minutes per each stage under the condition of frequency controlled respiration (0.25Hz). Heart rate(HR) gradually increased as the angle increased. Similarly, according to the increment of angle, normalized low frequency(LF) component(0.05-0.15Hz) gradually increased, whereas normalized high frequency(HF) component (0.20-0.30Hz) was reduced. From these results it is speculated that orthostatic stress, head-up tilt, results in the prevalence of sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone, which seems to mean that autonomic nervous system plays a major role in compensating for disturbances of cardiovascular system due to it.

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A Study on the High Frequency Resonant Inverter using ZVS suitable for IH-Jar (IH-Jar에 적합한 ZVS를 이용한 고주파 공진 인버터에 관한 연구)

  • Park, Dong-Han;Lee, Jong-Hyeon;Oh, Ji-Yong;Kim, Gu-Yong;Kim, Hae-Jun;Won, Jae-Sun;Kim, Jong-Hae
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.870-873
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    • 2018
  • This paper presents the high frequency resonant inverter using ZVS(Zero Voltage Switching) known as the soft switching technology, which can reduce the turn-on and turn-off switching losses. Also, the analysis of the proposed resonant inverter is described by adopting normalized parameters, and its operating characteristics are evaluated according to the switching frequency and parameters. An example of 1.3[kW] IH-Jar design technique is presented based on the characteristic values obtained from the theoretical analysis. To prove the validity of the theoretical analysis, the experimental results using IGBT as the switching devices are additionally presented. In the future, it can be practically used in various power systems such as induction heating cooking, IH-Jar etc.

An Quantitative Analysis of Severity Classification and Burn Severity for the Large Forest Fire Areas using Normalized Burn Ratio of Landsat Imagery (Landsat 영상으로부터 정규탄화지수 추출과 산불피해지역 및 피해강도의 정량적 분석)

  • Won, Myoung-Soo;Koo, Kyo-Sang;Lee, Myung-Bo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.80-92
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    • 2007
  • Forest fire is the dominant large-scale disturbance mechanism in the Korean temperate forest, and it strongly influences forest structure and function. Moreover burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. Vegetation rehabilitation may specifically vary according to burn severity after fire. To understand burn severity and process of vegetation rehabilitation at the damaged area after large-fire is required a lot of man powers and budgets. However the analysis of burn severity in the forest area using satellite imagery can acquire rapidly information and more objective results remotely in the large-fire area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. For classifying fire damaged area and analyzing burn severity of Samcheok fire area occurred in 2000, Cheongyang fire in 2002, and Yangyang fire in 2005 we utilized Normalized Burn Ratio(NBR) technique. The NBR is temporally differenced between pre- and post-fire datasets to determine the extent and degree of change detected from burning. In this paper we use pre- and post-fire imagery from the Landsat TM and ETM+ imagery to compute the NBR and evaluate large-scale patterns of burn severity at 30m spatial resolution. 65% in the Samcheok fire area, 91% in the Cheongyang fire area and 65% in the Yangyang fire area were corresponded to burn severity class above 'High'. Therefore the use of a remotely sensed Differenced Normalized Burn Ratio(${\Delta}NBR$) by RS and GIS allows for the burn severity to be quantified spatially by mapping damaged domain and burn severity across large-fire area.

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Effect of Bupleuri Radix on c-Fos and c-Jun Expression in Ischemic Damaged Hippocampus of the Aged BCAO Rats (시호(柴胡)가 뇌허혈유발 노령(老齡) 흰쥐의 해마 c-Fos 및 c-Jun 발현에 미치는 영향)

  • Park, Soon-Il;Oh, Kyung-Hwan;Ryu, Do-Kyun;Han, Chang-Ho;Chung, Sung-Hyun;Shin, Gil-Cho;Lee, Won-Chul;Hwang, Joo-Won
    • The Journal of Internal Korean Medicine
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    • v.26 no.3
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    • pp.533-542
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    • 2005
  • Objectives : In this study, aged BCAO rats were used to observe the effect of Bupleuri Radix on brain ischemic injury because aging is an important factor in storke. Methods : The brain ischemic injury was induced by temporary closing carotids on both sides in a low blood pressure state, and Bupleuri Radix was orally administered to 18 month-old BCAO rats. The ischemic damaged hippocampus and c-Fos and c-Jun expression were analyzed by the immunohistochemical staining. Result and Conclusions : Results are summarized as fellows; 1. The c-Fos expression after inducing a brain ischemic injury in the hippocampus was more inhibited in the experimental group than in the control group. 2. The normalized optical density of c-Fos expression was more reduced in cornu ammonis(CA)1, dentate gyrus(DG) areas in the experimental group than in the control group. 3. The c-Jun expression after inducing a brain ischemic injury in the hippocampus was more inhibited in the experimental group than in the control group. 4. The normalized optical density of c-Jun expression was more reduced in CA1 and DG areas in the experimental group than in the control group.

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A Study on the Output Voltage Control of Series-Parallel Resonant type DC/DC Converter for Transverse Flux Linear Motor (TELM에 적용한 직병렬 공진형 DC/DC 컨버터의 출력전압 제어에 관한 연구)

  • Hwang Gye Ho;Lee Young Sik;Jeon Jin Yong;Bang Deok Je;Kim Ho Jong;Shin Byoung Chol;Kang Do Hyun;Kim Jong Moo
    • Journal of the Semiconductor & Display Technology
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    • v.4 no.1 s.10
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    • pp.9-16
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    • 2005
  • In this paper, with loosely coupled transformer Relies-parallel resonant type DC/DC converter is analyzed and adopted to the power source of a TFLM(Transverse Flux Linear Motor). To get more efficient operating mode of the series-parallel resonant type DC/DC converter, theoretical analysis using normalized parameters are accepted. The analysis includes a specially made ferrite transformer with two separately wound half cores in order to evaluate analytically and experimentally the changes in magnetizing the leakage fluxes and inductances caused by the distance between the halves. The proposed converter must be operated in switching Pattern III among the three switching patterns for the Zero Voltage Switching operation. According to Pulse Frequency Modulation(PFM) control method, the output voltage of the proposed circuit can be controlled. The results of the theoretical development are compared with practical measurements from a prototype system.

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A Study on Digital RF Repeaters with Interference Cancellation System

  • Han, Yong-Sik;Yang, Woon-Geun
    • Journal of information and communication convergence engineering
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    • v.8 no.2
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    • pp.150-154
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    • 2010
  • In this paper, the adaptive interference cancellation system (ICS) in order to cancel the feedback signal in the wireless communication system is proposed. We cancel the interference with the attenuation signal corresponding to the feedback signal and estimate the feedback signal by using Normalized Least Mean Square (NLMS) algorithm. The proposed scheme showed a better performance of interference cancellation in the measurement results.

Performance Evaluation and Convergence Analysis of a VEDNSS LMS Adaptive Filter Algorithm

  • Park, Chee-Hyun;Hong, Kwang-Seok
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.2E
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    • pp.64-68
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    • 2008
  • This paper investigates noise reduction performance and performs convergence analysis of a Variable Error Data Normalized Step-Size Least Mean Square(VEDNSS LMS) algorithm. Adopting VEDNSS LMS results in higher system complexity, but noise is reduced providing fast convergence speed Mathematical analysis demonstrates that tap coefficient misadjustment converges. This is confirmed by computer simulation with the proposed algorithm.

CONTINUATION THEOREMS OF THE EXTREMES UNDER POWER NORMALIZATION

  • Barakat, H.M.;Nigm, E.M.;El-Adll, M.E.
    • Journal of applied mathematics & informatics
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    • v.10 no.1_2
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    • pp.1-15
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    • 2002
  • In this paper an important stability property of the extremes under power normalizations is discussed. It is proved that the restricted convergence of the Power normalized extremes on an arbitrary nondegenerate interval implies the weak convergence. Moreover, this implication, in an important practical situation, is obtained when the sample size is considered as a random variable distributed geometrically with mean n.