• Title/Summary/Keyword: Coherence Analysis

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Soil-Structure Interaction Analysis of Suspension Bridge for Multiple-Support Seismic Input (다지지점 지진입력에 대한 현수교의 지반-구조물 상호작용해석)

  • 김재민;이명규;신용우
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.182-189
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    • 2003
  • Member actions of long-span suspension bridge due to multiple-support motion are generally larger than those for synchronous support motion frequently employed in aseismic design of a conventional structure. In this study, all the sources of the asynchronous support motion are considered including the loss of coherence and the soil-structure interaction as well as the time delay due to wave propagation of seismic waves. The substructure technique analyzing total soil-foundation-structure system as a superposition of two sub-structures including soil-foundation system and structure itself is employed for the seismic response analysis of the suspension bridge. Finally, an application example is presented to demonstrate applicability of the proposed methodology.

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Reliability of Sasang Constitution Questionnaire Developed by KIOM for Vietnamese (베트남인 대상자를 통해 살펴본 KIOM 체질 설문지 신뢰도 검증)

  • Park, Hye-Joo;Lee, Si-Woo;Dong, Sang-Oak;Thuy, Ta Thu;Yoo, Jong-Hyang
    • Journal of Sasang Constitutional Medicine
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    • v.26 no.1
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    • pp.64-74
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    • 2014
  • Objectives This study aimed to evaluate reliability of questionnaire when self reporting questionnaire created by Korea Institute of Oriental Medicine was applied to Vietnamese. Methods This study began to collect 135 Vietnamese patients questionnaires collaborated with National Hospital of Traditional Medicine located in Hanoi, Vietnam from March to August 2013. All participants for this study filled out the questionnaires respectively. After initial survey finished, additional survey was performed on the same questionnaires used at the beginning eight weeks later. In order to evaluate internal coherence in terms of questionnaires of classification, Cronbach's alpha and Cohen's kappa was measured. Results After analysis of 78 questions collected, less than 0.4 in Kappa was achieved by 21(26.9%) out of 78 questions, 0.4 to 0.75 Kappa by 49(62.8%) and 0.75 over in 5(6.5%) questions, respectively. More than 0.6 Cronbach's alpha was defined from 41 out of 78 questions connected with internal coherence of character, digestion, perspiration, excrement, urine, cold and heat. Conclusions The questionnaire has credibility according to values of Kappa and Cronbach's alpha. Therefore, Sasang Constitution questionnaire can be applied to Sasang Diagnosis. In order to increase usefulness, questions in questionnaire should be revised and validity study must be performed afterwards.

Evaluation of the Dynamic Modulus by using the Impact Resonance Testing Method (비파괴충격파 시험법을 이용한 동탄성계수 평가)

  • Kim, Dowan;Jang, ByungKwan;Mun, Sungho
    • International Journal of Highway Engineering
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    • v.16 no.3
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    • pp.35-41
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    • 2014
  • PURPOSES : The dynamic modulus for a specimen can be determined by using either the non-destructed or destructed testing method. The Impact Resonance Testing (IRT) is the one of the non-destructed testing methods. The MTS has proved the source credibility and has the disadvantages which indicate the expensive equipment to operate and need a lot of manpower to manufacture the specimens because of the low repeatability with an experiment. To overcome these shortcomings from MTS, the objective of this paper is to compare the dynamic modulus obtained from IRT with MTS result and prove the source credibility. METHODS : The dynamic modulus obtained from IRT could be determined by using the Resonance Frequency (RF) from the Frequency Response Function (FRF) that derived from the Fourier Transform based on the Frequency Analysis of the Digital Signal Processing (DSP)(S. O. Oyadigi; 1985). The RF values are verified from the Coherence Function (CF). To estimate the error, the Root Mean Squared Error (RMSE) method could be used. RESULTS : The dynamic modulus data obtained from IRT have the maximum error of 8%, and RMSE of 2,000MPa compared to the dynamic modulus measured by the Dynamic Modulus Testing (DMT) of MTS testing machine. CONCLUSIONS : The IRT testing method needs the prediction model of the dynamic modulus for a Linear Visco-Elastic (LVE) specimen to improve the suitability.

The Sex-Related Differences of EEG Coherences between Patients with Bipolar Disorder and Controls (양극성장애 환자와 대조군에서 뇌파 코히런스의 성별 차이)

  • You, Hyunju;Lee, Yu Sang;An, Eunsoog;Jeong, Donghwa;Kim, Seongkyun;Jeong, Jaeseung;Kwak, Yongtae;Lee, Seungyeoun
    • Korean Journal of Biological Psychiatry
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    • v.22 no.4
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    • pp.205-215
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    • 2015
  • Objectives Sex hormones exposure during the prenatal period has an effect on cerebral lateralization. Male brains are thought to be more lateralized than female brains. Bipolar disorder was known to show abnormalities in cerebral laterality whose characteristics could be estimated by electroencephalography (EEG) coherences. We studied sex-related differences of EEG coherences between healthy controls and patients with bipolar disorder to examine the sex effects in the genesis of bipolar disorder. Methods Participants were 25 patients with bipolar disorder (11 male, 14 female) and 46 healthy controls (23 male, 23 female). EEG was recorded in the eyes closed resting state. To examine dominant EEG coherence associated with sex differences in both groups within five frequency bands (delta, theta, alpha, beta, and gamma) across several brain regions, statistical analyses were performed using analysis of covariance. Results Though statistically meaningful results were not found, some remarkable findings were noted. Healthy control females showed more increased interhemispheric coherences than control males in gamma frequency band. There were no differences in the intrahemispheric coherences between the healthy control males and females. In patients with bipolar disorder, female dominant pattern in interhemispheric coherences was attenuated compared with healthy control. Conclusions Sex differences of EEG coherences, which could be a marker for cerebral laterality, were attenuated in patients with bipolar disorder compared with healthy controls. These results imply that abnormal sex hormone exposure during early development might play some role in the pathogenesis of bipolar disorder.

The Application of InSAR Signature Time Series for Landcover Classification (InSAR Signature 시계열 분석을 통한 토지피복분류)

  • Yun, Hye Won;Choi, Yun Soo;Yoon, Ha Su;Ko, Jong Sik;Cho, Seong Kil
    • Spatial Information Research
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    • v.22 no.1
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    • pp.27-33
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    • 2014
  • Considering the wide coverage, the transparency from climate condition, Interferometric Synthetic Aperture Radar (InSAR) possesses a great potential for the landcover classification as shown in many precedent researches. In addition to the merits of InSAR products for the landcover classification, the time series analysis of InSAR pairs can provide a highly reliable basis to interpret landcover. We applied such idea with the test site in Mountain Baekdu located on the border between North Korea and China. Since it is recently noted as the potential volcanic activation site, the landcover especially the vegetation distribution information is highly essential to validate the reliability of Differential Interferometric Synthetic Aperture Radar (DInSAR) over Mt. Baekdu. The algorithms combining the auxiliary information from Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze the phase coherence and backscatter coefficient of Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) was established. The results using InSAR signatures from two polarization modes of ALOS PALSAR showed high reliability for mining landcover and spatial distribution.

Sonic Velocity Determination using Data from Monopole and Dipole Sources (음파검층에서의 속도결정 - monopole및 dipole소스의 비교 -)

  • Kong, Nam-Young;Lee, Sung-Jin;Zhao, Weijun;Kim, Yeoung-Hwa
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.225-231
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    • 2006
  • As a study of efficient velocity analysis in sonic log, several preexisting techniques have been adopted to the sonic data taken from model borehole in Kangwon National University, and the results were compared. For the data taken from monopole source, Slowness-Time Coherence method which is a common technique for nondispersive wave was used. For the data taken from dipole source, conventional STC and Tang's method(Tang et al., 1995) were used. From the good matches in the P and Stoneley wave velocities, we could confirm the effectiveness of STC computation. We also could find that shear velocity obtained from Tang's method were exactly matched with shear velocity obtained from monopole source, and that the velocity were within the range of S wave velocity values obtained from conventional STC application to dispersive flexural waves.

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Image Retrieval Using the Color Co-occurrence Histogram Describing the Size and Coherence of the Homogeneous Color Region (칼라 영역의 크기와 뭉침을 기술하는 칼라 동시발생 히스토그램을 이용한 영상검색)

  • An Myung-Seok;Cho Seok-Je
    • The KIPS Transactions:PartB
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    • v.13B no.3 s.106
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    • pp.275-282
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    • 2006
  • For the efficient image retrieval, the method has studied that uses color distribution and relations between pixels. This paper presents the color descriptor that stands high above the others in image retrieval capacity. It is based on color co-occurrence histogram that the diagonal part and the non-diagonal part are attached the weight and modified to energy of color co-occurrence histogram, and the number of bins with petty worth have little influence is curtailed. It's verified by analysis that the diagonal part carries size information of homogeneous color region and the non-diagonal part does information about the coherence of it, Moreover the non-diagonal part is more influential than diagonal part in survey of similarity between images. So, the non-diagonal part is attached more weight than the diagonal part as a result of the research. The experiments validate that the proposed descriptor shows better image retrieval performance when the weight for non-diagonal part is set to the value between 0.7 and 0.9.

A Study on the Processes of Elaborating Hypotheses in Abductive Inquiry of Preservice Elementary School Teachers (예비 초등 교사들의 귀추적 탐구 활동에서 가설의 정교화 과정에 관한 연구)

  • Oh, Phil-Seok;Oh, Sung-Jin
    • Journal of The Korean Association For Science Education
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    • v.31 no.1
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    • pp.128-142
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    • 2011
  • The goal of this study was to investigate how hypotheses were elaborated after their initial appearances in the context of scientific problem solving. Data were collected from a class in which preservice elementary school teachers in groups carried out abductive inquiry of earth science. The analysis revealed two major processes of hypothesis elaboration: theory-driven and evidence-driven. The theory-driven process was in turn distinguished into two kinds of subprocesses: one is in pursuit of internal coherence and the other external coherence. The evidencedriven elaboration also had two subprocesses, which were triggered by direct evidence and indirect or analogical evidence, respectively. In addition, hypotheses were more often than not modified by a wrong theory or evidence whether it was driven by a theory or evidence. Implications for science education and related research were discussed.

A Planning Element of Welfare Center for the Elderly based on the Salutogenic Model (건강생성 모델기반 노인복지관 계획 요소)

  • Choi, Joo-young;Park, Sung-jun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.5
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    • pp.61-72
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    • 2019
  • The purpose of this study is to propose the clue of planning guideline for the elderly welfare center supporting the healthy life of the elderly through deriving the planning element of the elderly welfare center based on the Salutogenic Model(SM). The research method was proceeded with literature review. The meaning of Sense of Coherence(SOC) and Generalised Resistance Resources(GRR) which constitute Salutogenic Model is established. The correlation between SOC and GRR is analyzed. The conclusions of this study are as follows. First, EBD, BD, HD, UD, and BFD were studied as planning theories that could enhance the SOC of space. Second, based on the five planning theories, 43 planning elements needed for the elderly welfare center plan were derived. Third, as a result of classifying the plan elements based on the SOC, 'Manageability' is divided into 22 elements, 'Meaningfulness' is 11 and 'Comprehensibility' is 10 elements. Fourth, the details of the SOC items for each theory are as follows: BFD focuses on 'Manageability' with 'Manageability'(74%) and 'Comprehensibility'(26%), but 'Meaningfulness' does not exist. And UD regards 'Comprehensibility'(66%) as important, and 'Manageability' and 'Meaningfulness' as 17%. BD, on the other hand, has a high percentage of 'Meaningfulness'(70%), 'Comprehensibility'(21%) and 'Manageability'(9%). Next, the 'Manageability' of HD and EBD is 46%. And HD was 'Meaningfulness'(34%), 'Comprehensibility'(20%), and EBD was 'Meaningfulness'(30%) and 'Comprehensibility'(24%). The three items of SOC showed different distribution according to the spatial planning theory. As a result of the analysis, the spatial planning theory with the 'Comprehensibility' was related to Universal Design(UD), and the spatial planning theory with the 'Manageability' was related to Barrier-Free Design(BFD). In addition, the spatial planning theory of 'Meaningfulness' was related to Bio-philic Design(BD). Therefore, the plan of the elderly welfare center needs to approach the multidimensional design methodology to enhance the SOC(Sense of Coherence).

Photoacoustic imaging of occlusal incipient caries in the visible and near-infrared range

  • da Silva, Evair Josino;de Miranda, Erica Muniz;de Oliveira Mota, Claudia Cristina Brainer;Das, Avishek;Gomes, Anderson Stevens Leonidas
    • Imaging Science in Dentistry
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    • v.51 no.2
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    • pp.107-115
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    • 2021
  • Purpose: This study aimed to demonstrate the presence of dental caries through a photoacoustic imaging system with visible and near-infrared wavelengths, highlighting the differences between the 2 spectral regions. The depth at which carious tissue could be detected was also verified. Materials and Methods: Fifteen permanent molars were selected and classified as being sound or having incipient or advanced caries by visual inspection, radiography, and optical coherence tomography analysis prior to photoacoustic scanning. A photoacoustic imaging system operating with a nanosecond pulsed laser as the light excitation source at either 532 nm or 1064 nm and an acoustic transducer at 5 MHz was developed, characterized, and used. En-face and lateral(depth) photoacoustic signals were detected. Results: The results confirmed the potential of the photoacoustic method to detect caries. At both wavelengths, photoacoustic imaging effectively detected incipient and advanced caries. The reconstructed photoacoustic images confirmed that a higher intensity of the photoacoustic signal could be observed in regions with lesions, while sound surfaces showed much less photoacoustic signal. Photoacoustic signals at depths up to 4 mm at both 532 nm and 1064 nm were measured. Conclusion: The results presented here are promising and corroborate that photoacoustic imaging can be applied as a diagnostic tool in caries research. New studies should focus on developing a clinical model of photoacoustic imaging applications in dentistry, including soft tissues. The use of inexpensive light-emitting diodes together with a miniaturized detector will make photoacoustic imaging systems more flexible, user-friendly, and technologically viable.