• Title/Summary/Keyword: spectral analysis.

Search Result 2,993, Processing Time 0.029 seconds

A Study on the UAV-based Vegetable Index Comparison for Detection of Pine Wilt Disease Trees (소나무재선충병 피해목 탐지를 위한 UAV기반의 식생지수 비교 연구)

  • Jung, Yoon-Young;Kim, Sang-Wook
    • Journal of Cadastre & Land InformatiX
    • /
    • v.50 no.1
    • /
    • pp.201-214
    • /
    • 2020
  • This study aimed to early detect damaged trees by pine wilt disease using the vegetation indices of UAV images. The location data of 193 pine wilt disease trees were constructed through field surveys and vegetation index analyses of NDVI, GNDVI, NDRE and SAVI were performed using multi-spectral UAV images at the same time. K-Means algorithm was adopted to classify damaged trees and confusion matrix was used to compare and analyze the classification accuracy. The results of the study are summarized as follows. First, the overall accuracy of the classification was analyzed in order of NDVI (88.04%, Kappa coefficient 0.76) > GNDVI (86.01%, Kappa coefficient 0.72) > NDRE (77.35%, Kappa coefficient 0.55) > SAVI (76.84%, Kappa coefficient 0.54) and showed the highest accuracy of NDVI. Second, K-Means unsupervised classification method using NDVI or GNDVI is possible to some extent to find out the damaged trees. In particular, this technique is to help early detection of damaged trees due to its intensive operation, low user intervention and relatively simple analysis process. In the future, it is expected that the utilization of time series images or the application of deep learning techniques will increase the accuracy of classification.

Identification of Phenolic Compounds and Antioxidant Effects from the Exudate of Germinating Peanut (Arachis hypogaea)

  • Lee, Jin-Hwan;Baek, In-Youl;Kang, Nam-Suk;Ko, Jong-Min;Kim, Hyun-Tae;Jung, Chan-Sik;Park, Keum-Yong;Ahn, Young-Sup;Suh, Duck-Yong;Ha, Tae-Joung
    • Food Science and Biotechnology
    • /
    • v.16 no.1
    • /
    • pp.29-36
    • /
    • 2007
  • Five phenolic compounds 1-5 were isolated for the first time from the exudate of geminating peanut (Arachis hypogaea). The structures were fully characterized by analysis of physical and spectral data. All isolated compounds were tested for antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and hydroxyl radical. Compounds 2, 3, and 5 exhibited a strong scavenging effect on DPPH (2: $IC_{50}\;=\;10.4\;{\um}M$, 3: $IC_{50}\;=\;45.2\;{\mu}M$, 5: $IC_{50}\;=\;5.0\;{\mu}M$), and ABTS (2: $IC_{50}\;=\;9.6\;{\mu}M$, 3: $IC_{50}\;=\;5.5\;{\mu}M$, 5: $IC_{50}\;=\;3.3\;{\mu}M$) radical activity, whereas these compounds had weak hydroxyl radical scavenging activity ($IC_{50}\;>\;200\;{\mu}M$). The total phenolic contents of the extracts using n-hexane, EtOAc, and n-BuOH were found to be 96.4-964.3 mg gallic acid equivalent per g dry material (GAE/g) and n-BuOH fraction showed the highest total phenolic content (964.3 mg GAE/g). These studies suggest that the exudate of geminating peanut may possess possible health related benefits to humans.

Effects of Acupuncture Stimulation on the Radial artery's Pressure Pulse Wave in Healthy Young Participants: Protocol for a prospective, single-Arm, Exploratory, Clinical Study

  • Shin, Jae-Young;Ku, Boncho;Kim, Tae-Hun;Bae, Jang Han;Jun, Min-Ho;Lee, Jun-Hwan;Kim, Jaeuk U.
    • Journal of Pharmacopuncture
    • /
    • v.19 no.3
    • /
    • pp.197-206
    • /
    • 2016
  • Introduction: This study aims to investigate the effects of acupuncture stimulation on the radial artery's pressure pulse wave, along with various hemodynamic parameters, and to explore the possible underlying mechanism of pulse diagnosis in healthy participants in their twenties. Methods and analysis: This study is a prospective, single-arm, exploratory clinical study. A total of 25 healthy participants, without regard to gender, in their twenties will be recruited by physicians. Written informed consent will be obtained from all participants. The participants will receive acupuncture once at ST36 on both sides. The radial arterial pulse waves will be measured on the left arm of the subjects by using an applicable pulse tonometric device (KIOM-PAS). On the right arm (appearing twice), electrocardiogram (ECG), photoplethysmogram (PPG), respiration and cardiac output (CO) signals, will be measured using a physiological data acquisition system (Biopac module), while the velocity of blood flow, and the diameter and the depth of the blood vessel will be measured using an ultrasonogram machine on the right arm (appearing twice). All measurements will be conducted before, during, and after acupuncture. The primary outcome will be the spectral energy at high frequencies above 10 Hz ($SE_{10-30Hz}$) calculated from the KIOM-PAS device signal. Secondary outcomes will be various variables obtained from the KIOM-PAS device, ECG, PPG, impedance cardiography modules, and an ultrasonogram machine. Discussion: The results of this trial will provide information regarding the physiological and the hemodynamic mechanisms underlying acupuncture stimulation and clinical evidence for the influence of acupuncture on the pressure pulse wave in the radial artery. Ethics and dissemination: This study was approved by the Institutional Review Board (IRB) of Kyung Hee University's Oriental Medical Center, Seoul, Korea (KOMCIRB-150818-HR-030). The study findings will be published in peer-reviewed journals and presented at national and international conferences. Trial registration number: This trial was registered with the Clinical Research Information Service (CRIS) at the Korea National Institute of Health (NIH), Republic of Korea (KCT0001663), which is a registry in the World Health Organization's (WHO's) Registry Network.

Impulse Response Filtration Technique for the Determination of Phase Velocities from SASW Measurements (SASW시험에 의한 위상속도 결정을 위한 임펄스 응답필터 기법)

  • ;Stokoe, K.H., Il
    • Geotechnical Engineering
    • /
    • v.13 no.1
    • /
    • pp.111-122
    • /
    • 1997
  • The calculation of phase velocities in Spectral-Analysis -of-Surface -Waves (SASW) meas urements requires unwrapping phase angles. In case of layered systems with strong stiffness contrast like a pavement system, conventional phase unwrapping algorithm to add in teger multiples of 2n to the principal value of a phase angle may lead to wrong phase volocities. This is because there is difficulty in counting the number of jumps in the phase spectrum especially at the receiver spacing where the measurements are in the transition Bone of defferent modes. A new phase interpretation scheme, called "Impulse Response Fil traction ( IRF) Technique," is proposed, which is based on the separation of wave groups by the filtration of the impulse response determinded between two receivers. The separation of a wave group is based on the impulse response filtered by using information from Gabor spectrogram, which visualizes the propagation of wave groups at the frequency -time space. The filtered impulse response leads to clear interpretation of phase spectrum, which eliminates difficulty in counting number of jumps in the phase spectrum. Verification of the IRF technique was performed by theoretical simulation of the SASW measurement on a pavement system which complicates wave propagation.opagation.

  • PDF

Analysis on the Performance Degradation of MIMO-OFDM Receiver and Hybrid Interference Cancellation with Low Complexity for the Performance Improvement Under High-Mobility Condition (MIMO-OFDM 수신기의 성능 열화 분석 및 고속 이동환경에서의 성능 향상을 위한 저복잡도 HIC 간섭제거 기법)

  • Kang, Seung-Won;Kim, Kyoo-Hyun;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.32 no.2C
    • /
    • pp.95-112
    • /
    • 2007
  • Spatial Multiplexing techniques, which is a kind of Multiple antenna techniques, provide high data transmission rate by transmitting independent data at different transmit antenna with the same spectral resource. OFDM (Orthogonal Frequency Division Multiplexing) is applied to MIMO (Multiple-Input Multiple-Output) system to combat ISI (Inter-Symbol Interference) and frequency selective fading channel, which degrade MIMO system performance. But, orthogonality between subcarriers of OFDM can't be guaranteed under high-mobility condition. As a result, severe performance degradation due to ICI is induced. In this paper, both ICI and CAI (Co-Antenna Interference) which occurs due to correlation between multiple antennas, and performance degradation due to both ICI and CAI are analyzed. In addition to the proposed CIR (Channel Impulse Response) estimation method for avoiding loss in data transmission rate, HIC (Hybrid Interference Cancellation) approach for guaranteeing QoS of MIMO-OFDM receiver is proposed. We observe the results on analytical performance degradation due to both ICI & CAI are coincide with the simulation results and performance improvement due to HIC are also verified by simulation under SCM-E Sub-urban Macro MIMO channel.

Downlink Performance Analysis for Cell Range Expansion Bias in Heterogeneous Mobile Communication Networks (이종 이동통신 네트워크에서 셀 확장 편향치에 따른 하향 링크 성능 분석)

  • Ban, Tae-Won;Jung, Bang Chul;Jo, Jung-Yeon;Sung, Kil-Young
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.17 no.12
    • /
    • pp.2806-2811
    • /
    • 2013
  • New technologies such as multi-antenna and small cell were proposed as key technology for the next generation mobile system to cope with the explosively increasing mobile data traffic. In particular, heterogeneous mobile communication network which can improve spatial reuse factor by exploiting macro and small cells simultaneously is attracting attention. However, the heterogeneous network has a problem that the utilization of small cells becomes low because the transmit power of macro base stations is much higher than that of small base stations and then the probability that mobile stations are attached to the macro base stations becomes high. This problem is dominant in uplink. The concept of cell range expansion bias to mitigate the problem was proposed by 3GPP and the corresponding standardization is in progress. In this paper, we analyze the downlink performance of the heterogeneous mobile communication network based on a system level simulator with the cell range expansion bias in terms of average cell spectral efficiency.

Analysis of Characteristics of Horizontal Response Spectrum of Ground Motions from 19 Earthquakes (국내 관측자료를 이용한 수평 응답스펙트럼 특성 분석)

  • Kim, Jun-Kyoung
    • Tunnel and Underground Space
    • /
    • v.20 no.6
    • /
    • pp.399-407
    • /
    • 2010
  • The horizontal response spectra using the observed ground motions from the recent more than 19 macro earthquakes were analysed and then were compared to both the seismic design response spectra (Reg Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). 130 horizontal ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that response spectrum have strong dependency on epicentral distance. The results also showed that the horizontal response spectra revealed much higher values for frequency bands above 5 Hz than Reg. Guide (1.60). The results were also compared to the Korean Standard Response Spectrum for the 3 different soil types and showed that the vertical response spectra revealed much higher values for the frequency bands below 0.3 second than the Korean Standard Response Spectrum (SD soil condition). These spectral values dependent on frequency could be related to characteristics of the domestic crustal attenuation and the effect of each site amplification. However, through the qualitative improvements and quantitative enhancement of the observed ground motions, the conservation of horizontal seismic design response spectrum should be considered more significantly for the frequency bands above 5 Hz.

Automatic Selection of Optimal Parameter for Baseline Correction using Asymmetrically Reweighted Penalized Least Squares (Asymmetrically Reweighted Penalized Least Squares을 이용한 기준선 보정에서 최적 매개변수 자동 선택 방법)

  • Park, Aaron;Baek, Sung-June;Park, Jun-Qyu;Seo, Yu-Gyung;Won, Yonggwan
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.3
    • /
    • pp.124-131
    • /
    • 2016
  • Baseline correction is very important due to influence on performance of spectral analysis in application of spectroscopy. Baseline is often estimated by parameter selection using visual inspection on analyte spectrum. It is a highly subjective procedure and can be tedious work especially with a large number of data. For these reasons, it is an objective and automatic procedure is necessary to select optimal parameter value for baseline correction. Asymmetrically reweighted penalized least squares (arPLS) based on penalized least squares was proposed for baseline correction in our previous study. The method uses a new weighting scheme based on the generalized logistic function. In this study, we present an automatic selection of optimal parameter for baseline correction using arPLS. The method computes fitness and smoothness values of fitted baseline within available range of parameters and then selects optimal parameter when the sum of normalized fitness and smoothness gets minimum. According to the experimental results using simulated data with varying baselines, sloping, curved and doubly curved baseline, and real Raman spectra, we confirmed that the proposed method can be effectively applied to optimal parameter selection for baseline correction using arPLS.

Design and Performance Analysis of Hybrid Receiver based on System Level Simulation in Backhaul System (백홀 시스템에서 시스템 레벨 시뮬레이션 기반 하이브리드 수신기 설계 및 성능 분석)

  • Moon, Sangmi;Chu, Myeonghun;Kim, Hanjong;Kim, Daejin;Hwang, Intae
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.52 no.11
    • /
    • pp.3-11
    • /
    • 2015
  • An advanced receiver which can manage inter-cell interference is required to cope with the explosively increasing mobile data traffic. 3rd Generation Partnership Project (3GPP) has discussed network assisted interference cancellation and suppression (NAICS) to improve signal-to-noise-plus-interference ratio (SINR) and receiver performance by suppression or cancellation of interference signal from inter-cells. In this paper, we propose the advanced receiver based on soft decision to reduce the interference from neighbor cell in LTE-Advanced downlink system. The proposed receiver can suppress and cancel the interference by calculating the unbiased estimation value of interference signal using minimum mean square error (MMSE) or interference rejection combing (IRC) receiver. The interference signal is updated using soft information expressed by log-likelihood ratio (LLR). We perform the system level simulation based on 20MHz bandwidth of 3GPP LTE-Advanced downlink system. Simulation results show that the proposed receiver can improve SINR, throughput, and spectral efficiency of conventional system.

On the Diurnal Variation of Cloudiness over the Weatern Pacific by Using GMS-IR Data (GMS-IR 자료를 이용한 서태평양에서의 운량 일변동에 관한 연구)

  • 김영섭;한경수
    • Korean Journal of Remote Sensing
    • /
    • v.13 no.1
    • /
    • pp.1-12
    • /
    • 1997
  • The western equatorial Pacific Ocean, where sea surface temperature is the warmest on the globe, is characterized by numerous convective systems and large annual precipitation. In this region, the cloudiness data with tops higher than 8km level obtained from the GMS-IR data are used to investigate the diurnal variation of cloudiness. The amplitude and phase of diurnal and semi-diurnal cycles are mainly investigated to examine details on the temporal and spatial structure of clouds. Cloudiness variation has typical cycles and each cycle is associated with the air-sea interactive phenomena. Spectral analysis on the cloudiness time series data indicates that 30-60 day, 17-20day, 7-8 day, diurnal and semi diurnal cycle are peaked. During Northern Winter and Southern Summer, the large cloudiness exsists over New Guinea, the adjacent seas of North Australia, and the open oceanic regions east of $160^{\circ}$E. Cloudiness diurnal variability over the lands and their adjacent seas is about 2.0 times larger than that over the open sea regions. That may be due to the difference of specific heat between the land and sea. The maximum and minimum cloudiness appeared at 18:00 and 09:00 hours over the land, and at noon and 21:00 hours over the sea, respectively. The amplitude of diurnal component over the land is 4,7 times larger than that of semi-diurnal component, and 1.5 times over the sea.