• Title/Summary/Keyword: Power Spectral Analysis

Search Result 558, Processing Time 0.024 seconds

An Analysis of EEG Watching Fear of Crime Video (범죄에 대한 두려움 영상 시청 중 발생하는 뇌파 분석)

  • Kim, Yong-Woo;Kang, Hang-Bong
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.7 no.9
    • /
    • pp.361-366
    • /
    • 2018
  • Previous studies on fear of crime used survey and interview to measure fear of crime. However, though these methods can measure fear of crime in past events, they cannot measure real time fear of crime. In this paper, we use EEG to measure fear of crime in real time. We measure and analyze the EEG of subjects watching the video and confirm the difference between three groups classified according to the degree of fear of crime. As a result, about two times more beta waves are shown when a group of subjects with a high degree of fear of crime watches the images of fear of crime and 1.5 times more beta waves are shown among the other groups. Although watching videos related to the crime increased the beta waves, the police video showed little increase in beta waves because the subjects can sense safety in the video even if it is related to crime.

ULF electromagnetic variation associated with seismic wave (지진파에 의해 발생하는 ULF 전자기장 변동)

  • Lee Heuisoon;Lee Choon-Ki;Kwon Byung-Doo;Yang Jun-Mo;Oh Seokhoon;Song Yoonho;Lee Tae Jong;Uchida Toshihiro
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2005.05a
    • /
    • pp.197-202
    • /
    • 2005
  • The electromagnetic signals associated with the seismic activity in the south-east offshore of Kii peninsula, Japan, were clearly recorded at the MT sites in Jeju island, Korea. In this research, we have identified the co-seismic electromagnetic signals associated with the seismic activity and have analyzed the characteristics of significant electromagnetic variations. The analysis of phase velocity, power spectral density, MT impedance and polarization direction shows that the significant earthquake signals have the frequency band of about 0.05 to 0.5 Hz and that the sources of electromagnetic field are local effects of passing seismic waves. The simple approximation using electrokinetic effect successfully explains the co-seismic EM signals coincides with measured data but cannot explain the localities of electromagnetic variations.

  • PDF

Characteristics of thunderstorms relevant to the wind loading of structures

  • Solari, Giovanni;Burlando, Massimiliano;De Gaetano, Patrizia;Repetto, Maria Pia
    • Wind and Structures
    • /
    • v.20 no.6
    • /
    • pp.763-791
    • /
    • 2015
  • "Wind and Ports" is a European project that has been carried out since 2009 to handle wind forecast in port areas through an integrated system made up of an extensive in-situ wind monitoring network, the numerical simulation of wind fields, the statistical analysis of wind climate, and algorithms for medium-term (1-3 days) and short term (0.5-2 hours) wind forecasting. The in-situ wind monitoring network, currently made up of 22 ultrasonic anemometers, provides a unique opportunity for detecting high resolution thunderstorm records and studying their dominant characteristics relevant to wind engineering with special concern for wind actions on structures. In such a framework, the wind velocity of thunderstorms is firstly decomposed into the sum of a slowly-varying mean part plus a residual fluctuation dealt with as a non-stationary random process. The fluctuation, in turn, is expressed as the product of its slowly-varying standard deviation by a reduced turbulence component dealt with as a rapidly-varying stationary Gaussian random process with zero mean and unit standard deviation. The extraction of the mean part of the wind velocity is carried out through a moving average filter, and the effect of the moving average period on the statistical properties of the decomposed signals is evaluated. Among other aspects, special attention is given to the thunderstorm duration, the turbulence intensity, the power spectral density and the integral length scale. Some noteworthy wind velocity ratios that play a crucial role in the thunderstorm loading and response of structures are also analyzed.

Effect of Horizontal Eye Movements on the Heart Rate Variability after Exposure to a Fear-Inducing Film Clip (공포 영화 장면 노출 후 수평적 안구 운동이 심박수 변이도에 미치는 영향)

  • Lee, Haewon;Yum, Myung-Kul;Kim, Seok Hyeon;Lee, Yun Jeong;Kim, Daeho
    • Korean Journal of Biological Psychiatry
    • /
    • v.15 no.1
    • /
    • pp.35-45
    • /
    • 2008
  • Objectives : There has been a continued debate regarding the role of eye movements in Eye Movement Desensitization and Reprocessing(EMDR). This study examined the possible autonomic effect of horizontal eye movements after being exposed to fearful stimuli. Methods : Fifty two healthy adult women were randomly allocated to eye movement or eye fixed groups after watching a five minute fear-inducing film clip. ECG was recorded during the resting state, after watching the clip, and the treatment. A spectral power analysis of the heart rate variability was performed. As the variables violated the rule of normal distribution and the number in each group is small the non-parametric test was used. Results : Overall, we did not find the differences between the groups in both time and frequency domains. Some minor differences found were not consistent with results from previous studies. Conclusions : Effect of eye movement on autonomic nervous system during fear desensitization was not supported in this experiment. Further study with other psychophysiological measures is needed to understand the role of eye movements in treatment of traumatic memory.

  • PDF

Comparative Proteomic Profiling of Pancreatic Ductal Adenocarcinoma Cell Lines

  • Kim, Yikwon;Han, Dohyun;Min, Hophil;Jin, Jonghwa;Yi, Eugene C.;Kim, Youngsoo
    • Molecules and Cells
    • /
    • v.37 no.12
    • /
    • pp.888-898
    • /
    • 2014
  • Pancreatic cancer is one of the most fatal cancers and is associated with limited diagnostic and therapeutic modalities. Currently, gemcitabine is the only effective drug and represents the preferred first-line treatment for chemotherapy. However, a high level of intrinsic or acquired resistance of pancreatic cancer to gemcitabine can contribute to the failure of gemcitabine treatment. To investigate the underlying molecular mechanisms for gemcitabine resistance in pancreatic cancer, we performed label-free quantification of protein expression in intrinsic gemcitabine-resistant and -sensitive human pancreatic adenocarcinoma cell lines using our improved proteomic strategy, combined with filter-aided sample preparation, single-shot liquid chromatography-mass spectrometry, enhanced spectral counting, and a statistical method based on a power law global error model. We identified 1931 proteins and quantified 787 differentially expressed proteins in the BxPC3, PANC-1, and HPDE cell lines. Bioinformatics analysis identified 15 epithelial to mesenchymal transition (EMT) markers and 13 EMT-related proteins that were closely associated with drug resistance were differentially expressed. Interestingly, 8 of these proteins were involved in glutathione and cysteine/methionine metabolism. These results suggest that proteins related to the EMT and glutathione metabolism play important roles in the development of intrinsic gemcitabine resistance by pancreatic cancer cell lines.

Research on Spectral Interference of Microwave Systems (마이크로웨이브 시스템의 주파수 간섭에 관한 연구)

  • Yang, Jae-Soo;Kim, Yoon-Hyun;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.12 no.6
    • /
    • pp.241-249
    • /
    • 2012
  • In the many countries, research about ultra wideband wireless transmission technique is widely studied for efficient utilization of frequency resource due to a sudden increase of demand of frequency resource all over the world. The ultra wideband communication system has the some specific advantages. First, it can transmit data with high speed, second short transmission range can increase the frequency reuse rate, and finally it has high security property. However, there is a interference between ultra wideband system and other communication system but study to solve this problem is insufficient. To efficient utilization of limited frequency resource, a novel frequency avoidance technique and setup the standardization of frequency interference must need. So, the purpose of this paper is that increases communication efficiency of microwave communication systems to analyze the technical trends for transmission of the low power device, and to research the implementation and technical research of wireless access network technique of wideband communication systems.

Performance Analysis of Cooperative Diversity on the Usage of Opportunistic Relay (기회주의적인 중계기 사용에 대한 협력 다이버시티의 성능 분석)

  • Kim, Tae-Wook;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.14 no.3
    • /
    • pp.7-12
    • /
    • 2014
  • The data forwarding transmission is an important function of the relay in cooperative communication in wireless communication systems. However, additional relay cause the waste of power consumption and cost. Therefore, in this paper, we consider how to use the user mobile devices in stead of relays to deal with this problem. In this paper, we proposed the protocol that divide each relay into two states of idle and non-idle. The receiver has two functions of base station and user mobile device. In this case, it is possible that no additional cost, and improve the spectral efficiency and network capacity. We verified BER performance for the proposed protocol over Rayleigh fading through Monte-Carlo simulation.

A SEARCH FOR AGN INTRA-DAY VARIABILITY WITH KVN

  • LEE, TAESEOK;TRIPPE, SASCHA;OH, JUNGHWAN;BYUN, DO-YOUNG;SOHN, BONG-WON;LEE, SANG-SUNG
    • Journal of The Korean Astronomical Society
    • /
    • v.48 no.5
    • /
    • pp.313-323
    • /
    • 2015
  • Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ~1.6% to ~7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

Modal testing and finite element model calibration of an arch type steel footbridge

  • Bayraktar, Alemdar;Altunisk, Ahmet Can;Sevim, Baris;Turker, Temel
    • Steel and Composite Structures
    • /
    • v.7 no.6
    • /
    • pp.487-502
    • /
    • 2007
  • In recent decades there has been a trend towards improved mechanical characteristics of materials used in footbridge construction. It has enabled engineers to design lighter, slender and more aesthetic structures. As a result of these construction trends, many footbridges have become more susceptible to vibrations when subjected to dynamic loads. In addition to this, some inherit modelling uncertainties related to a lack of information on the as-built structure, such as boundary conditions, material properties, and the effects of non-structural elements make difficult to evaluate modal properties of footbridges, analytically. For these purposes, modal testing of footbridges is used to rectify these problems after construction. This paper describes an arch type steel footbridge, its analytical modelling, modal testing and finite element model calibration. A modern steel footbridge which has arch type structural system and located on the Karadeniz coast road in Trabzon, Turkey is selected as an application. An analytical modal analysis is performed on the developed 3D finite element model of footbridge to provide the analytical frequencies and mode shapes. The field ambient vibration tests on the footbridge deck under natural excitation such as human walking and traffic loads are conducted. The output-only modal parameter identification is carried out by using the peak picking of the average normalized power spectral densities in the frequency domain and stochastic subspace identification in the time domain, and dynamic characteristics such as natural frequencies mode shapes and damping ratios are determined. The finite element model of footbridge is calibrated to minimize the differences between analytically and experimentally estimated modal properties by changing some uncertain modelling parameters such as material properties. At the end of the study, maximum differences in the natural frequencies are reduced from 22% to only %5 and good agreement is found between analytical and experimental dynamic characteristics such as natural frequencies, mode shapes by model calibration.

SHM-based probabilistic representation of wind properties: statistical analysis and bivariate modeling

  • Ye, X.W.;Yuan, L.;Xi, P.S.;Liu, H.
    • Smart Structures and Systems
    • /
    • v.21 no.5
    • /
    • pp.591-600
    • /
    • 2018
  • The probabilistic characterization of wind field characteristics is a significant task for fatigue reliability assessment of long-span railway bridges in wind-prone regions. In consideration of the effect of wind direction, the stochastic properties of wind field should be represented by a bivariate statistical model of wind speed and direction. This paper presents the construction of the bivariate model of wind speed and direction at the site of a railway arch bridge by use of the long-term structural health monitoring (SHM) data. The wind characteristics are derived by analyzing the real-time wind monitoring data, such as the mean wind speed and direction, turbulence intensity, turbulence integral scale, and power spectral density. A sequential quadratic programming (SQP) algorithm-based finite mixture modeling method is proposed to formulate the joint distribution model of wind speed and direction. For the probability density function (PDF) of wind speed, a double-parameter Weibull distribution function is utilized, and a von Mises distribution function is applied to represent the PDF of wind direction. The SQP algorithm with multi-start points is used to estimate the parameters in the bivariate model, namely Weibull-von Mises mixture model. One-year wind monitoring data are selected to validate the effectiveness of the proposed modeling method. The optimal model is jointly evaluated by the Bayesian information criterion (BIC) and coefficient of determination, $R^2$. The obtained results indicate that the proposed SQP algorithm-based finite mixture modeling method can effectively establish the bivariate model of wind speed and direction. The established bivariate model of wind speed and direction will facilitate the wind-induced fatigue reliability assessment of long-span bridges.