• Title/Summary/Keyword: spectrum analysis

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Association between neonatal jaundice and autism spectrum disorders among children: a meta-analysis

  • Jenabi, Ensiyeh;Bashirian, Saeid;Khazaei, Salman
    • Clinical and Experimental Pediatrics
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    • v.63 no.1
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    • pp.8-13
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    • 2020
  • Autism spectrum disorder is a common neurodevelopmental disorder with an unknown etiology. The correlation between neonatal jaundice and the risk of developing autism spectrum disorder was investigated previously. Some studies showed significant associations, whereas others demonstrated no association. In this meta-analysis, we pooled the results of observational studies to examine the association between neonatal jaundice and the risk of autism spectrum disorder among children. We identified all studies published through April 2018 by conducting a literature search using Web of Science, PubMed, and Scopus databases as well as the reference lists of the retrieved studies. The pooled odds ratios (ORs), rate ratio (RR), and their 95% confidence intervals (CIs) were calculated as random effect estimates of association among studies. We conducted a subgroup analysis to explore any potential sources of intergroup heterogeneity. The pooled estimates of OR and RR showed a considerable correlation between neonatal jaundice and ASD among children (OR, 1.35; 95% CI, 1.02-1.68) and (RR, 1.39; 95% CI, 1.05-1.74). A larger effect size was shown in the pooled estimated crude OR than in the adjusted OR (1.75 [0.96-2.54] vs. 1.19 [1.07-1.30]). This study showed that neonatal jaundice may be associated with ASD and may increase the risk of ASD among children.

Ensemble Model for Urine Spectrum Analysis Based on Hybrid Machine Learning (혼합 기계 학습 기반 소변 스펙트럼 분석 앙상블 모델)

  • Choi, Jaehyeok;Chung, Mokdong
    • Journal of Korea Multimedia Society
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    • v.23 no.8
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    • pp.1059-1065
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    • 2020
  • In hospitals, nurses are subjectively determining the urine status to check the kidneys and circulatory system of patients whose statuses are related to patients with kidney disease, critically ill patients, and nursing homes before and after surgery. To improve this problem, this paper proposes a urine spectrum analysis system which clusters urine test results based on a hybrid machine learning model consists of unsupervised learning and supervised learning. The proposed system clusters the spectral data using unsupervised learning in the first part, and classifies them using supervised learning in the second part. The results of the proposed urine spectrum analysis system using a mixed model are evaluated with the results of pure supervised learning. This paper is expected to provide better services than existing medical services to patients by solving the shortage of nurses, shortening of examination time, and subjective evaluation in hospitals.

Pushover Analysis for Nonlinear Seismic Response of Reinforced Concrete Mixed Building Structures (철근콘크리트 복합구조물의 비선형 지진응답산정을 위한 Pushover해석)

  • Kang Pyeong-Doo;Jun Dae-Han;Kim Jae-Ung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.631-638
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    • 2006
  • This paper considers the nonlinear direct spectrum method to estimate seismic performance of mixed building structures without iterative computations, given dynamic property $T_1$ from stiffness skeleton curve and nonlinear pseudo acceleration $A_{1y}$ and/or ductility ratio $\mu$ from response spectrum. Nonlinear response history analysis has been performed and analysed with various earthquakes for evaluation of correctness and confidence of nonlinear direct spectrum method.

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Theoretical Analysis of the Spontaneous Emission Spectrum of a Device using DFB structures (DFB 구조 소자의 자연 방출 스펙트럼에 관한 이론적 해석)

  • 김부균;최지연;정기석;조성찬;이봉영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.3
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    • pp.45-57
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    • 1995
  • We derive analytic expressions for the spontaneous emission spectrum of a device using DFB structures including the effects of both facet reflections and the phase of a grating. In solution of coupled mode equations. Equations for the reations between the spontaneous emission spectrum and structure parameters of the device are derived to investigate the effect of structure parameters on the spontaneous emission spectrum and operating characteristics of possibility of evaluating the structure parameters of the device from its spontaneous emission spectrum.

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KBC Seismic Design Force for Nonstructural Element (KBC 비구조요소 내진설계 하중)

  • Kim, Dae-Kon
    • Journal of Korean Association for Spatial Structures
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    • v.14 no.1
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    • pp.77-84
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    • 2014
  • Simple 3, 10, and 30-story buildings with a nonstructural element which is located at roof or near the middle of the building height are selected. Based on 2009 Korean Building Code, the seismic design force applied at the nonstructural element is evaluated. Response spectrum analysis is conducted with the design response acceleration spectrum of 2009 Korean Building Code and the analytical response is compared with the seismic design force from the Code. Furthermore, an artificial earthquake based on Korean design response acceleration spectrum and the 50% intensity of El Centro earthquake, which can be considered as the maximum future earthquake possibly occurring in Korea, are selected to conduct time history analysis. When the period of the nonstructural element is shorter than 0.06 second or longer than that of the 1st period of each building, the Code equations of seismic design force for nonstructural element seems to be appropriate. However, the period of the nonstructural element is close to the one of the building's higher mode periods including the 1st period, seismic force of the nonstructural element might exceed the Code specified seismic design force.

Efficient damage assessment for selected earthquake records based on spectral matching

  • Strukar, Kristina;Sipos, Tanja Kalman;Jelec, Mario;Hadzima-Nyarko, Marijana
    • Earthquakes and Structures
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    • v.17 no.3
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    • pp.271-282
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    • 2019
  • Knowing the response of buildings to earthquakes is very important in order to ensure that a structure is able to withstand a given level of ground shaking. Thus, nonlinear dynamic earthquake engineering analyses are unavoidable and are preferable procedure in the seismic assessment of buildings. In order to estimate seismic performance on the basis of the hazard at the site where the structure is located, the selection of appropriate seismic input is known to be a critical step while performing this kind of analysis. In this paper, seismic analysis is performed for a four-story reinforced concrete ISPRA frame structure which is designed according to Eurocode 8 (EC8). A total of 90 different earthquake scenarios were selected, 30 for each of three target spectrums, EC8 spectrum, Uniform Hazard Spectrum (UHS), and Conditional Mean Spectrum (CMS). The aim of this analysis was to evaluate the average maximum Inter-story Drift Ratio (IDR) for each target spectrum. Time history analysis for every earthquake record was obtained and, as a result, IDR as the main measure of damage were presented in order to compare with defined performance levels of reinforced concrete bare frames.

A new non-iterative procedure to estimate seismic demands of structures

  • Mechaala, Abdelmounaim;Chikh, Benazouz
    • Earthquakes and Structures
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    • v.22 no.6
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    • pp.585-595
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    • 2022
  • Using the nonlinear static procedures has become very common in seismic codes to achieve the nonlinear response of the structure during an earthquake. The capacity spectrum method (CSM) adopted in ATC-40 is considered as one of the most known and useful procedures. For this procedure the seismic demand can be approximated from the maximum deformation of an equivalent linear elastic Single-Degree-of-Freedom system (SDOF) that has an equivalent damping ratio and period by using an iterative procedure. Data from the results of this procedure are plotted in acceleration- displacement response spectrum (ADRS) format. Different improvements have been made in order to have more accurate results compared to the Non Linear Time History Analysis (NL-THA). A new procedure is presented in this paper where the iteration process shall not be required. This will be done by estimation the ductility demand response spectrum (DDRS) and the corresponding effective damping of the bilinear system based on a new parameter of control, called normalized yield strength coefficient (η), while retaining the attraction of graphical implementation of the improved procedure of the FEMA-440. The proposed procedure accuracy should be verified with the NL-THA analysis results as a first implementation. The comparison shows that the new procedure provided a good estimation of the nonlinear response of the structure compared with those obtained when using the NL-THA analysis.

Seismic Analysis of LNG Storage Tank (LNG 저장탱크의 내진 해석)

  • Lee, Seung-Pyo;Ha, Sung-Kyu;Koh, Byung-Kab
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.5
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    • pp.1095-1101
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    • 2008
  • In this paper, seismic analysis of LNG storage tank is performed. The analysis models are both pipe and pipe, wall and guide of LNG tank. And equivalent static analysis and response spectrum analysis are applied to these two models, respectively. From the analysis, deflections and equivalent stresses are compared. Results show that response spectrum analysis is more accurate than equivalent static analysis for LNG storage tank.

A Socio-Economic Value Analysis of Sharing Spectrum in Korea (공동사용주파수의 사회경제적 가치분석)

  • Park, Seok-Ji;Kim, Chang-Joo;Park, Duk-Kyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.8
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    • pp.831-840
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    • 2013
  • In this paper, we analyze the telecom services and their socio-economic value for sharing spectrum, which is suitable to access. For this, we suggest a concept and a classification model of sharing spectrum and make a survey for analyzing the socio-economic value of spectrum, 910 MHz which is candidated for sharing between 1.4~4.5 GHz in Korea. Also, we propose mobile telecom service, WiFi, ASA, public service, M2M, and smart home and factory service as service for suitable to sharing spectrum.

A Study on the Vegetation Pattern Using Two-Dimensional Spectral Analysis (2 次元 스펙트럼法을 이용한 植生類型에 대한 硏究)

  • Park, Seung Tai
    • The Korean Journal of Ecology
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    • v.13 no.2
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    • pp.83-92
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    • 1990
  • Two-dimensional analysis provides a comprehensive description of the structure, scales of pattern and directional components in a spatial data set. In spectral analysisi, four functions are illustrated,; the autocorrelation, the periodogram, the R-spectrum and the $\theta$ -spectrum. The R-spectrum and $\theta$ -spectrum function respectively summarize the periodogram in term of scale of pattern and directional components. Sampling is measured in the Naejang National Park area where the Daphniphyllum trees grow. 320 contiguous (15$\times$15)m plots are located along the transect and density of all trees over DBH 3 cm recorded respectively. 12 species of vascular plant are recorded in this survey area. The trend surface of density of all plant are estimated using polynomial regression and are exhibited in 3-dimensional graph and density contour map. Transformation to the corresponding polar spectrum from the periodogram emphasized the directional components and the scales to pattern. R-spectrum corresponding to the scale of pattern of periodogram showed a large peak 15.47 in the interval 9$\theta$-spectrum corresponding to directional components have two peaks 8.28 and 11.05 in the interval $35^{\circ}\theta <45^{\circ}and 125^{\circ}\theta< <135^{\circ}, respectively. Programs to compute all the analyses described in this study was obtained from Dr. Ranshow and was translated to BASIC by the author.

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