• Title/Summary/Keyword: EMA model

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Experimental modal analysis of transverse-cracked rails-influence of the cracks on the real track behavior

  • Domingo, Laura Montalban;Giner, Beatriz Baydal;Martin, Clara Zamorano;Herraiz, Julia I. Real
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.1019-1032
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    • 2014
  • Rails are key elements in railway superstructure since these elements receive directly the train load transmitted by the wheels. Simultaneously, rails must provide effective stress transference to the rest of the track elements. This track element often deteriorates as a consequence of the vehicle passing or manufacturing imperfections that cause in rail several defects. Among these rail defects, transverse cracks highlights and are considered a severe pathology because they can suddenly trigger the rail failure. This study is focused on UIC-60 rails with transverse cracks. A 3-D FEM model is developed in ANSYS for the flawless rail in which conditions simulating the crack presence are implemented. To account for the inertia loss of the rail as a consequence of the cracking, a reduction of the bending stiffness of the rail is considered. The numerical models have been calibrated using the first four bending vibration modes in terms of frequencies. These vibration frequencies have been obtained using the Experimental Modal Analysis technique, studying the changes in the modal parameters of the rails induced by the crack and comparing the results obtained by the model with experimental results. Finally, the calibrated and validated models for the single rail have been implemented in a complete railway ballasted track FEM model in order to study the static influence of the cracks on the rail deflection caused by a load passing.

Hydrograph Separation Using EMMA Model for the Coniferous Forest Catchment in Gwangneung Gyeonggido, Republic of Korea (I) - Determination of the End Members and Tracers -

  • Kim, Kyongha;Yoo, Jae-Yun;Jun, Jae-Hong;Choi, Hyung Tae;Jeong, Yong-Ho
    • Journal of Korean Society of Forest Science
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    • v.95 no.5
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    • pp.556-561
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    • 2006
  • This study was conducted to choose end-members and tracers for application of End Member Mixing Analysis (EMMA) model for the coniferous forest catchment, Gwangneung Gyeongi-do near Seoul metropolitan of South Korea (N $37^{\circ}$ 45', E $127^{\circ}$ 09'). This coniferous forest of Pinus Korainensis and Abies holophylla was planted at stocking rate of $3.0stems\;ha^{-1}$ in 1976. Thinning and pruning were carried out two times in the spring of 1996 and 2004 respectively. We monitored two successive rainfall events during ten days from June 26, 205 to July 5, 2005. Two storm events were selected to determine the end members and natural traces for hydrograph separation. The event 1 amounts to 161.9 m for two days from June 26 to 27, 2005. The event 2 precipitates to 139.2 mm for one day of July 1, 205. Throughfall, groundwater, soil water and stream water of the two events above were sampled through the bulk and automatic sampler. Their chemical properties were analyzed for prediction of the main tracer. The end members that contribute to the stream runoff were identified from the three components including groundwater, soil water and throughfall. Each component and stream water in the two events formed the suitable mixing diagram in case of chloride-nitrate ion and sulfate-potassium ion. Especially, chloride-nitrate ion was found to be the most suitable tracers for EMMA model in the two events.

Effect of errors in pedigree on the accuracy of estimated breeding value for carcass traits in Korean Hanwoo cattle

  • Nwogwugwu, Chiemela Peter;Kim, Yeongkuk;Chung, Yun Ji;Jang, Sung Bong;Roh, Seung Hee;Kim, Sidong;Lee, Jun Heon;Choi, Tae Jeong;Lee, Seung-Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.7
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    • pp.1057-1067
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    • 2020
  • Objective: This study evaluated the effect of pedigree errors (PEs) on the accuracy of estimated breeding value (EBV) and genetic gain for carcass traits in Korean Hanwoo cattle. Methods: The raw data set was based on the pedigree records of Korean Hanwoo cattle. The animals' information was obtained using Hanwoo registration records from Korean animal improvement association database. The record comprised of 46,704 animals, where the number of the sires used was 1,298 and the dams were 38,366 animals. The traits considered were carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS). Errors were introduced in the pedigree dataset through randomly assigning sires to all progenies. The error rates substituted were 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, and 80%, respectively. A simulation was performed to produce a population of 1,650 animals from the pedigree data. A restricted maximum likelihood based animal model was applied to estimate the EBV, accuracy of the EBV, expected genetic gain, variance components, and heritability (h2) estimates for carcass traits. Correlation of the simulated data under PEs was also estimated using Pearson's method. Results: The results showed that the carcass traits per slaughter year were not consistent. The average CWT, EMA, BFT, and MS were 342.60 kg, 78.76 ㎠, 8.63 mm, and 3.31, respectively. When errors were introduced in the pedigree, the accuracy of EBV, genetic gain and h2 of carcass traits was reduced in this study. In addition, the correlation of the simulation was slightly affected under PEs. Conclusion: This study reveals the effect of PEs on the accuracy of EBV and genetic parameters for carcass traits, which provides valuable information for further study in Korean Hanwoo cattle.

Loop Probe Design and Measurement of Electromagnetic Wave Signal for Contactless Cryptographic Analysis (비접촉 암호 분석용 루프 프로브 설계 및 전자파 신호 측정)

  • Choi, Jong-Kyun;Kim, Che-Young;Park, Jea-Hoon;Moon, Snag-Jae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.10
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    • pp.1117-1125
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    • 2007
  • In this paper, a study has been performed on the design of small loop probe and analysis of induced electromagnetic wave signal from a smartcard for contactless cryptographic analysis. Probes for cryptographic analysis are different from conventional EM probes, because the purpose of proposed probe is to obtain the information for secret key analysis of cryptographic system. The waveform of induced voltage on probe must be very close to radiated waveform from IC chip on smartcard because electromagnetic attack makes an attempt to analyze the radiated waveform from smartcard. In order to obtain secret key information, we need to study about cryptographic analysis using electromagnetic waves, an approximate model of source, characteristic of probe for cryptographic analysis, measurement of electromagnetic waves and calibration of probes. We measured power consumption signal on a smartcard chip and electromagnetic wave signal using proposed probe and compared with two signals of EMA point of view. We verified experimently the suitability of the proposed small loop probe for contactless cryptographic analysis by applying ARIA algorithm.

Validity and Reliability of a Korean Version of the Trier Inventory for Chronic Stress (한국어판 축약형 순간 스트레스 측정 도구(Trier Inventory for Chronic Stress: TICS)의 타당도 및 신뢰도 평가)

  • Ryu, Gi Wook;Yang, Yong Sook;Choi, Mona
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.10
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    • pp.530-540
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    • 2020
  • Ecological momentary assessment (EMA) is a method that captures the current experience and behavior of subjects in real time in a natural environment. The data collected by EMA reveals alterations according to the time and context of experience and action. The Trier Inventory for Chronic Stress (TICS) is a tool that measures momentary stress, and is capable of measuring stress experienced in real life. This study was undertaken to verify the validity and reliability after translating the short form TICS into a Korean version. Totally, 89 police officers working at the police station in the capital participated in this study. The mobile application developed for this study was installed on their smartphones, and data were collected four times a day for seven consecutive days. Confirmatory factor analysis and content validity index (CVI) was applied to test the validity, and concurrent validity was evaluated by correlating with the occupational stress score. The model was validated by confirmatory factor analysis, and we obtained good reliabilities (I-CVI=0.83-1, RMSEA=0.104, SRMR=0.104, CFI=0.948, TLI=0.919, Cronbach's alpha=0.839). Our findings indicate the reliability, and validate use of the Korean tool for measuring momentary stress.

Best Practices in the Implementation of Research Infrastructure in the Academic Environment: Shortcomings and Revisions

  • Michal Lorenz;Ema Juranova;Michal Konecny;Hana Kubelkova;Veronika Wolfelova
    • International Journal of Knowledge Content Development & Technology
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    • v.13 no.4
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    • pp.95-117
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    • 2023
  • The Digitalia MUNI ARTS - a local node of the LINDAT/CLARIAH-CZ research infrastructure at the Faculty of Arts of Masaryk University constitutes a repository in the Islandora system. It is used for long-term preservation of research data together with their research environment in the form of digital platforms. We transfer the digital outputs of humanities scholars research to the repository according to a set plan, which is based on best practice recommendations for project management and digital curation. In this paper, we present how the results of interviews with platform developers and infrastructure stakeholders translate into the curation workflow, and a resulting model for migrating digital platforms to the repository. Reflecting on three types of problems we encountered during the implementation of platforms into the repository - communication problems, problems of external dependence, and management problems - we describe a modification of the migration process. We present six recommendations for repository administrators and curators in an academic setting - holding an introductory meeting with developers, researching significant and relevant theories of knowledge domain, consulting license experts, prioritizing requirements, and preparing handover protocol and progress reports.

The Study of the Financial Index Prediction Using the Equalized Multi-layer Arithmetic Neural Network (균등다층연산 신경망을 이용한 금융지표지수 예측에 관한 연구)

  • 김성곤;김환용
    • Journal of the Korea Society of Computer and Information
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    • v.8 no.3
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    • pp.113-123
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    • 2003
  • Many researches on the application of neural networks for making financial index prediction have proven their advantages over statistical and other methods. In this paper, a neural network model is proposed for the Buying, Holding or Selling timing prediction in stocks by the price index of stocks by inputting the closing price and volume of dealing in stocks and the technical indexes(MACD, Psychological Line). This model has an equalized multi-layer arithmetic function as well as the time series prediction function of backpropagation neural network algorithm. In the case that the numbers of learning data are unbalanced among the three categories (Buying, Holding or Selling), the neural network with conventional method has the problem that it tries to improve only the prediction accuracy of the most dominant category. Therefore, this paper, after describing the structure, working and learning algorithm of the neural network, shows the equalized multi-layer arithmetic method controlling the numbers of learning data by using information about the importance of each category for improving prediction accuracy of other category. Experimental results show that the financial index prediction using the equalized multi-layer arithmetic neural network has much higher correctness rate than the other conventional models.

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A Study on the Learning Effects of the Inquiry Training Model for the Home Economics of the Middle School - Focusing of the Unit of Food and Nutrition (중학교 가정과 수업 방법의 개성을 위한 탐구훈련수업의 학습효과 - 식생활 단원을 중심으로-)

  • 한오숙;김갑영
    • Journal of Korean Home Economics Education Association
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    • v.10 no.2
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    • pp.13-28
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    • 1998
  • The purpose of this study is to compare of learning effects between the inquiry training model and traditional lecture method in the unit of food and nutrition of home economics in the middle school and propose a teaching-learning method of home economics in the middle school.For this study I sampled one hundred students both male and female who were in the first grade students of middle school in Ansan city.The students were divided into two groups each of which was composed of one male class and one female class. One was called the inquiry training model group, which was taught by the inquiry training model, the other the traditional lecture method group, which was taught by traditional lecture method .They learned about food and nutrition unit during the same time. To evaluate the effectiveness of learning, learning achievement degree, instruction interest degree, and the powers of exploration process, a creativity lest by using a Questionnaire was gIven.The resuits of this study are as follows: 1. In the traditional lecture method group between the inquiry training model one, the difference of learning achievement degree was not significant. The score of learning achieve ment degree in the inquiry training group, the female class got higher scores than .the maleone, but the difference was not significant. 2. In the test of instruction interest degree, the traditional lecture method group got higher scores than the inquiry training model one. (p<.001.). In the inquiry training group the male class got higher scores than the f ema Ie one. (p < .001 ) 3. In the test of powers of exploration process, the traditional lecture method group got higher scores than the inquiry training model one.( p< .00 1). In the inquiry training group, the male class got higher scores than the female one, but the difference was not significant. 4. In the test of creativity, the traditional lecture method group got higher scores than the inquiry training one. (p < .00 1). In the inquiry training group, the female class got higher scores than the male one, but the difference was not significant Therefore, the inquiry training model is the more effective instruction model for both male and female students, rather than the traditional lecture method for instruction interest de¬gree, powers of exploration process, creativity and extends instruction interest degree for the male studentsale students.

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Estimation of Genetic Parameters for Growth Traits in Yorkshire (요크셔종의 산육형질에 대한 유전모수 추정)

  • Song, Kwang-Lim;Kim, Byeong-Woo;Roh, Seung-Hee;Sun, Du-Won;Kim, Hyo-Sun;Lee, Deuk-Hwan;Jeon, Jin-Tae;Lee, Jung-Gyu
    • Journal of agriculture & life science
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    • v.44 no.3
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    • pp.41-52
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    • 2010
  • This study was conducted to estimate genetic parameters for growth traits using multivariate animal models in Yorkshire breed. For the study, 16,202 records for growth traits collected between the year 1999 and 2005 from Yorkshire pigs in K GGP were used. The effects of environmental factors such as sex, birth year, birth season, parity and birth weight group affected growth traits significantly (p<0.01). Birth weight tended to be positively correlated with average daily gain (ADG) and lean percent. But it seemed to affect age at 90 kg, average adjusted backfat thickness (BF), and eye muscle ares (EMA) negatively. For average pig suckling weight (ASW) and total weight at suckling (TWS), the higher birth weight is the better performance. But, in case of total number of born and number of suckling, the result was shown vice versa. Approximately 10~30% lower heritability estimates were obtained for growth traits by using the model that includes descriptions of common litter effects (CL) than by using the model that ignores those (NCL) for more accurate estimation of heritability. The estimates of heritabilities were 0.468, and 0.328 for ADG, 0.474 and 0.326 for age at 90 kg, 0.452, and 0.396 for BF, 0.240 and 0.200 for EMA and, 0.458, and 0.380 for lean percent in NCL and CL, respectively. Therefore, in order to estimate optimal genetic parameters, it could be inferred that the statistical model which considers litter effects must be applied.

Prosodic Boundary Effects on the V-to-V Lingual Movement in Korean

  • Cho, Tae-Hong;Yoon, Yeo-Min;Kim, Sa-Hyang
    • Phonetics and Speech Sciences
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    • v.2 no.3
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    • pp.101-113
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    • 2010
  • The present study investigated how the kinematics of the /a/-to-/i/ tongue movement in Korean would be influenced by prosodic boundary. The /a/-to-/i/ sequence was used as 'transboundary' test materials which occurred across a prosodic boundary as in /ilnjəʃ$^h$a/ # / minsakwae/ ('일년차#민사과에' 'the first year worker' # 'dept. of civil affairs'). It also tested whether the V-to-V tongue movement would be further influenced by its syllable structure with /m/ which was placed either in the coda condition (/am#i/) or in the onset condition (/a#mi). Results of an EMA (Electromagnetic Articulagraphy) study showed that kinematical parameters such as the movement distance (displacement), the movement duration, and the movement velocity (speed) all varied as a function of the boundary strength, showing an articulatory strengthening pattern of a "larger, longer and faster" movement. Interestingly, however, the larger, longer and faster pattern associated with boundary marking in Korean has often been observed with stress (prominence) marking in English. It was proposed that language-specific prosodic systems induce different ways in which phonetics and prosody interact: Korean, as a language without lexical stress and pitch accent, has more degree of freedom to express prosodic strengthening, while languages such as English have constraints, so that some strengthening patterns are reserved for lexical stress. The V-to-V tongue movement was also found to be influenced by the intervening consonant /m/'s syllable affiliation, showing a more preboundary lengthening of the tongue movement when /m/ was part of the preboundary syllable (/am#i/). The results, together, show that the fine-grained phonetic details do not simply arise as low-level physical phenomena, but reflect higher-level linguistic structures, such as syllable and prosodic structures. It was also discussed how the boundary-induced kinematic patterns could be accounted for in terms of the task dynamic model and the theory of the prosodic gesture ($\pi$-gesture).

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