• Title/Summary/Keyword: time domain data

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Analysis of Soil Moisture Recession Characteristics on Hillslope through the ~ntensive Monitoring Using TDR (산지사면에서의 TDR을 이용한 토양수분 집중모니터링을 통한 토양수분 감쇄특성 분석)

  • Lee Ga Young;Kim Sang Hyun;Kim Ki Hoon;Lee Hye Sun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.1
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    • pp.78-90
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    • 2005
  • The spatial and temporal distribution of soil moisture was characterized from soil moisture data through the intensive monitoring using Time Domain Reflectometry (TDR). The recession of soil moisture after a rainfall event was characterized and the empirical equation was used in the recession curve analysis. Recession analysis provides features of soil moisture variation such as recharge and stability depending upon locations of monitoring. The wetness index was useful for explaining spatial and temporal distributions of soil moisture and recession characteristics at hillslope scale.

Dynamic Aeroelastic Characteristics of an All-Movable Canard with Oscillating Flap Used in UAV (플랩이 있는 무인기 전운동 카나드의 동적공탄성 특성)

  • Kim, Dong-Hyun;Koo, Kyo-Nam;Lee, In;Kim, Sung-Jun;Kim, Sung-Chan;Lee, Jung-Jin;Choi, Ik-Hyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.6
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    • pp.56-63
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    • 2004
  • In this study, dynamic aeroelastic analyses of the canard with oscillating flap are conducted considering the effect of aerodynamic compressibility. The canard model considered herein is an all-movable type with a pitching axis on a canard-rotor-wing aircraft which was considered as one of the major UAV candidates under developing in Korea. The equivalent structural model is constructed based on the initial design data by the Korea smart UAV development center. Both the frequency and the time-domain aeroelastic analyses have been applied to practically conduct parametric studies on the effects of equivalent torsional stiffness. In the case of all-movable control surface with oscillating flap, the equivalent rotational stiffness of the pitch axes are important design parameters. The parametric results for the aeroelastic instability are practically presented.

Fast VQ Codebook Design by Sucessively Bisectioning of Principle Axis (주축의 연속적 분할을 통한 고속 벡터 양자화 코드북 설계)

  • Kang, Dae-Seong;Seo, Seok-Bae;Kim, Dai-Jin
    • Journal of KIISE:Software and Applications
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    • v.27 no.4
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    • pp.422-431
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    • 2000
  • This paper proposes a new codebook generation method, called a PCA-Based VQ, that incorporates the PCA (Principal Component Analysis) technique into VQ (Vector Quantization) codebook design. The PCA technique reduces the data dimensions by transforming input image vectors into the feature vectors. The cluster of feature vectors in the transformed domain is bisectioned into two subclusters by an optimally chosen partitioning hyperplane. We expedite the searching of the optimal partitioning hyperplane that is the most time consuming process by considering that (1) the optimal partitioning hyperplane is perpendicular to the first principal axis of the feature vectors, (2) it is located on the equilibrium point of the left and right cluster's distortions, and (3) the left and right cluster's distortions can be adjusted incrementally. This principal axis bisectioning is successively performed on the cluster whose difference of distortion between before and after bisection is the maximum among the existing clusters until the total distortion of clusters becomes as small as the desired level. Simulation results show that the proposed PCA-based VQ method is promising because its reconstruction performance is as good as that of the SOFM (Self-Organizing Feature Maps) method and its codebook generation is as fast as that of the K-means method.

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Prevalence of overweight and obesity, and dieting attitudes among Caucasian and African American college students in Eastern North carolina: A cross-sectional survey

  • Sira, Natalia;Pawlak, Roman
    • Nutrition Research and Practice
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    • v.4 no.1
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    • pp.36-42
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    • 2010
  • A cross-sectional survey was used to investigate the rates of overweight and obesity (BMI$\geq$25), and eating attitudes among college students. Data were collected at a large southeastern university. Adolescents (ages 18-25) self-reported weight and height (to calculate BMI), and, in addition to demographic information, completed the eating attitudes (EAT 26) scale to assess dieting tendencies. Significance of the mean BMI differences between gender and ethnic background were assessed by one-way analysis of variance (one-way ANOVA). Chi-square was used to determine whether the rate of those with BMI$\geq$25 between gender and ethnic background was statistically significant. While 52.7% of the students' BMI were within the normal weight category, 15.2% were underweight, 21.3% were overweight, and 10.8% were obese. The rate of BMI$\geq$25 differed by gender and ethnicity, with males and African Americans having higher rates. About 12 % of the participants reported disturbed eating behavior, which is lower than previously reported. Even so, results support the generally held belief that disturbed eating attitudes and unhealthy dieting are common among college students, especially among females. At the same time, disturbed eating attitudes are not just the domain of young female students; about 10% of college males reported disturbed eating attitudes. Findings of this study call for obesity prevention/intervention and lifestyle modification outreach programs among college students. Weight status and unhealthy eating behaviors of college. students should be a concern to health care professionals. While obese young adults will likely remain obese throughout their adult life, excessive dieting among students, which is linked to eating disorders and other health hazards, does not provide healthy and adequate alternatives for maintaining a normal BMI. Implications for obesity prevention programs are discussed.

Volume Transport on the Texas-Louisiana Continental Shelf

  • Cho Kwang-Woo
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.48-62
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    • 1998
  • Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

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Association of PNPLA3 Polymorphism with Hepatocellular Carcinoma Development and Prognosis in Viral and Non-Viral Chronic Liver Diseases

  • Khlaiphuengsin, Apichaya;Kiatbumrung, Rattanaporn;Payungporn, Sunchai;Pinjaroen, Nutcha;Tangkijvanich, Pisit
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8377-8382
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    • 2016
  • Background: The aim of this study was to evaluate any association between a single nucleotide polymorphism (SNP) in the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409, C>G) and the development and prognosis in patients with hepatocellular carcinoma (HCC). Materials and Methods: Two hundred heathy controls and 388 HCC cases were included: 211 with HBV, 98 patients with HCV, 29 with alcoholic steatohepatitis (ASH) and 52 with non-alcoholic steatohepatitis (NASH). The SNP was determined by real-time PCR based on TaqMan assays. Results: The prevalence of rs738409 genotypes CC, CG and GG in controls was 91 (45.5%), 88 (44.0%), and 21 (10.5%), respectively, while the corresponding genotypes in all patients with HCC was 158 (40.7%), 178 (45.9%), and 52 (13.4%). The GG genotype had significantly higher distribution in patients with ASH/NASH-related HCC compared with controls (OR=2.34, 95% CI=1.16-4.71, P=0.018), and viral-related HCC cases (OR=2.15, 95% CI=1.13-4.08, P=0.020). However, the frequency of the GG genotype was similar between controls and patients with viral-related HCC. At initial diagnosis, HBV-related HCC were larger and at more advanced BCLC stage than the other HCC groups. There were no significant differences between the GG and non-GG groups regarding clinical characteristics, tumor stage and overall survival. Conclusions: These data suggest an influence of the PNPLA3 polymorphism on the occurrence of HCC in patients with ASH/NASH but not among those with chronic viral hepatitis. However, the polymorphism was not associated with the prognosis of HCC.

Development of Two Dimensional Filter for the Reconstructive Image Processing (영상 재구성 처리를 위한 이차원 필터의 구성)

  • Lee, Hwang-Soo
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.16 no.6
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    • pp.16-21
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    • 1979
  • Two dimensional kernels which reconstruct a tomographic image from a blurred one formed by simple back-projection are investigated in the frequency domain and their performances are compared. The kernels are derived from a point spread function of the tomographic system and have the form of a ramp filter modified by several window functions to suppress ringings or artifacts in the reconstruction. Computer simulation using computer-generated phantom image data with different filter functions has been carried out. In this simulation, it is found that the computation time for 2-D reconstruction is much less than that of 1-D convolution method by a factor of ten or more whereas the reconstructed image quality of the former is far poorer than the latter. In 2-D reconstruction heavy windowing results in less noisy reconstruction but details smear out in this case. The trade-offs between these points are considered.

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Correction of Continuous Motion Effects for Airborne FMCW-SAR System (항공기 기반 FMCW-SAR 시스템의 연속이동효과 보정)

  • Hwang, Ji-hwan;Jung, Jungkyo;Kim, Duk-jin;Kim, Jin-Woo;Shin, He-Sub;Ok, Jae-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.5
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    • pp.410-418
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    • 2017
  • Results of an analysis of the continuous motion effect for FMCW-SAR system and a signal processing to correct it are presented in this paper. SAR images reconstructed by back-projection algorithm are included as well. To analyze how platform velocity and sampling frequency affect the continuous motion effect, FMCW signal model was used, and the signal processing in time-doppler(t, $k_u$) domain was adopted. Then, back-projection algorithm and modified matched-filter was used to reconstruct SAR images, and it was validated using measured data by airborne FMCW-SAR system in X-band frequency.

Transmission Line Parameter Extraction and Signal Integrity Verification of VLSI Interconnects Under Silicon Substrate Effect (실리콘 기판 효과를 고려한 VLSI 인터컨넥트의 전송선 파라미터 추출 및 시그널 인테그러티 검증)

  • 유한종;어영선
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.3
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    • pp.26-34
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    • 1999
  • A new silicon-based IC interconnect transmission line parameter extraction methodology is presented and experimentally examined. Unlike the PCB or MCM interconnects, a dominant energy propagation mode in the silicon-based IC interconnects is not quasi-TEM but slow wave mode(SWM). The transmission line parameters are extracted taking the silicon substrate effect (i.e., slow wave mode) into account. The capacitances are calculated considering silicon substrate surface as a ground. Whereas the inductances are calculated by using an effective dielectric constant. In order to verify the proposed method, test patterns were designed. Experimental data have agreement within 10%. Further, crosstalk noise simulation shows excellent agreements with the measurements which are performed with high-speed time domain measurement ( i.e., TDR/TDT measurements) for test pattern, while RC model or RLC model without silicon substrate effect show about 20~25% underestimation error.

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A Study on the Expressive Characteristics of Conceptual Art in Fashion Design - With a focus on the works of Hussein Chalayan and Martin Margiela - (패션디자인에 나타난 개념미술의 표현적 특성 - 후세인 샬라얀(Hussein Chalayan)과 마틴 마르지엘라(Martin Margiela)의 작품을 중심으로 -)

  • Kim, Rooun;NamKoong, Yoonsun;Hwang, Sun Jin
    • Journal of the Korean Society of Costume
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    • v.63 no.2
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    • pp.55-67
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    • 2013
  • The root of cultural and artistic diversity of modern society goes hand in hand with the appearance of new art concepts that started during the social and cultural turmoil. These concepts crossed the boundaries of traditional and universal aesthetic concepts and value criteria. Since there is a close relationship between the fashion industry and the cultural flow of its times, the purpose of this study is to investigate the influences and applications of conceptual art, which became one of the big frameworks of contemporary art on fashion. The study thus sets out to develop and analyze the collections of Hussein Chalayan and Martin Margiela, who were fashion designers that pursued conceptual and ideal values, from the perspective of conceptual art. The goal was to examine the conceptual thoughts they sought after, and to understand their expressive determinations that they pursued conceptually as well as the superficial formativeness of their works. The characteristics according to the expressive methods and conceptual intentions of conceptual art that specified concepts and ideas were as follows: readymade symbolized objects, expanded intervention, data form from process of changing and implementation, and language as visual metaphors. Then those characteristics of conceptual art were used in this study to analyze the collections of Chalayan and Margiela. As a result, both designers applied and mixed many characteristics of the expressive methods of conceptual art. In modern society, art and fashion share a cultural identity and it can be said that it is an accurate reflection of the time. They are not separate genres. Just like the unique flow of modern society that creates new concepts through mixture and infusion of different disciplines, fashion is included in the domain of art. In addition, understanding and studying other disciplines can make a huge contribution to the growth and development of fashion.