• Title/Summary/Keyword: Rogers

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Diagnosis Method for Power Transformer using Intelligent Algorithm based on ELM and Fuzzy Membership Function (ELM 기반의 지능형 알고리즘과 퍼지 소속함수를 이용한 유입변압기 고장진단 기법)

  • Lim, Jae-Yoon;Lee, Dae-Jong;Ji, Pyeong-Shik
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.194-199
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    • 2017
  • Power transformers are an important factor for power transmission and cause fatal losses if faults occur. Various diagnostic methods have been applied to predict the failure and to identify the cause of the failure. Typical diagnostic methods include the IEC diagnostic method, the Duval diagnostic method, the Rogers diagnostic method, and the Doernenburg diagnostic method using the ratio of the main gas. However, each diagnostic method has a disadvantage in that it can't diagnose the state of the power transformer unless the gas ratio is within the defined range. In order to solve these problems, we propose a diagnosis method using ELM based intelligent algorithm and fuzzy membership function. The final diagnosis is performed by multiplying the result of diagnosis in the four diagnostic methods (IEC, Duval, Rogers, and Doernenburg) by the fuzzy membership values. To show its effectiveness, the proposed fault diagnostic system has been intensively tested with the dissolved gases acquired from various power transformers.

A Study of A Nonlinear Viscoelastic Model for Elastomeric Bushing in Automotive Suspension System (I) -Axial Mode- (차량현가장치용 일래스토메릭 부시으이 비선형점탄성 모델연구 (I) -축 방향 모드-)

  • 이성범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.154-161
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    • 1999
  • An elastomeric bushing is a device used in automotive suspension systems to cushion the force transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer suface. The relation between the force applied to the shaft or sleeve and their relative deformation is nolinear and exhibits features of viscoelasticity. Numerical solutions of the boundary value problem represent the exact bushing response for use in the method for determining the force relaxation function of the bushing. The new nonlinear viscoelastic bushing model, which is called Pipkin-Rogers model, is proposed and it is shown that the predictions of the proposed force-displacement relation are in very good agreement with the exact results. This new bushing model is thus very suitable for use in multi-body dynamics codes. The success of the present study for axial mode response suggests that the same approach be applied to other modes, such as torsional or radial modes.

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Impact of Individual's Regulatory Focus on Value Perceptions of and Willingness to Invest towards Online Mass-Customized Fashion

  • Bhaduri, Gargi;Kim, Jihyun
    • Fashion, Industry and Education
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    • v.16 no.1
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    • pp.1-18
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    • 2018
  • The purpose of this study was to investigate the influence of consumers' regulatory focus on their perceived values of the product as well as shopping process, and willingness to invest resources for online mass-customized products. Data were collected using an online survey from 251 young adult consumers, particularly those who have prior purchase experience of mass-customized products. Interpretation of results indicated that consumers' promotion regulatory focus impacted their perceived values of the product (social, emotional, monetary, and epistemic but not performance), perceived values of the shopping process (hedonic and utilitarian), and willingness to invest more money, time and effort. However, as anticipated, prevention regulatory focus had no significant influence on the dependent variables. Researchers provide crucial implications for brands of online mass-customized products to segment their market based on regulatory orientation, as well as better cater to customer demands by positioning their products as offering benefits that specifically caters to the needs of such consumers.

Systematic Studies on the Freshwater Goby, Rhinogobius Species (Perciformes, Geobiidae) III. Geographic Variation and Subspecific Differentiation in Rhinogobius giurinus, with a Comment on Genetic Relationships among Four Species of the Genus Rhinogobius in Korea

  • Kim, Jong-Bum;Kim, Jae-Heup;Yang, Suh-Yung
    • Animal cells and systems
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    • v.1 no.4
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    • pp.529-534
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    • 1997
  • Genetic and morphological variations of Rhinogobius giurinus were surveyed. Populations of R.giurinus were clearly divided into two forms (Form-A and Form-B). Starch gel variation of this species. Three loci (Aco, Mpi, aGpd) out of 27 showed fixed allelic differences between Form-A and Form-B and they are well differentiated from each other genetically (Rogers' S=0.871). These two forms, moreover, are found to be allopatric in distribution and morphologi cally different in body length and caudal fin color pattern. Therefore, they are considered as two distinct taxa of subspecific rank. In addition, the genetic relationships among 5 taxa within 4 species of the genus Rhinogobius were investigated. Three species of the Rhinogobius brunneus complex (R.sp. OR, R. sp. CB and R. sp. CO) are well differentiated from each other genetically and two taxa of R. giurinus are genetically divergent from three species of the Rhinosotius brunneus complex (average Nei's D=0.603, average Rogers'=0.534).

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Impacts of self-monitoring tendency and mobile phone dependency on salence of mobile phone case product attributes

  • Kim-Vick, Jihyun;Hahn, Kim H.Y.
    • The Research Journal of the Costume Culture
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    • v.27 no.6
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    • pp.666-680
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    • 2019
  • Prevalent usage of mobile devices among consumers has been well recognized and this is especially imperative among young adult consumers. The mobile phone became the gateway of their communication, media consumption, retail transaction, education, and (virtual) social life. However, there is little empirical research explaining the dynamics behind the psychological underpinning of young adult consumers, specifically Generation Y, to understand their usages and dependency on mobile phones. This study, therefore, aims to unveil antecedents and consequences of Gen Y consumers' mobile phone dependency from a media psychological perspective. We developed a conceptual model based on theory of self-monitoring (Snyder 1974, 1987), extended self-concept (Belk, 1988), and media dependency theory (Ball-Rokeach & Defluer, 1976). Four hundred ninety-eight students in the U.S. provided usable responses to our pencil-and-paper survey. Causal modeling analysis results demonstrated that both ability to modify one's behavior and sensitivity to cues for social appropriate behavior dimensions of the self-monitoring tendency positively predicted one's level of fashion involvement, which in turn positively predicted his/her mobile phone dependency. Individual's mobile phone dependency, fashion involvement and self-monitoring's ability dimension exhibited positive and direct impact on one's perception of the salience of mobile phone case product attributes. Based on the findings, we provided pragmatic and theoretical implications for the industry and academia.

A Comparative Study on the Forecasting Performance of Range Volatility Estimators using KOSPI 200 Tick Data

  • Kim, Eun-Young;Park, Jong-Hae
    • The Korean Journal of Financial Management
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    • v.26 no.2
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    • pp.181-201
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    • 2009
  • This study is on the forecasting performance analysis of range volatility estimators(Parkinson, Garman and Klass, and Rogers and Satchell) relative to historical one using two-scale realized volatility estimator as a benchmark. American sub-prime mortgage loan shock to Korean stock markets happened in sample period(January 2, 2006~March 10, 2008), so the structural change somewhere within this period can make a huge influence on the results. Therefore sample was divided into two sub-samples by May 30, 2007 according to Zivot and Andrews unit root test results. As expected, the second sub-sample was much more volatile than the first sub-sample. As a result of forecasting performance analysis, Rogers and Satchell volatility estimator showed the best forecasting performance in the full sample and relatively better forecasting performance than other estimators in sub-samples. Range volatility estimators showed better forecasting performance than historical volatility estimator during the period before the outbreak of structural change(the first sub-sample). On the contrary, the forecasting performance of range volatility estimators couldn't beat that of historical volatility estimator during the period after this event(the second sub-sample). The main culprit of this result seems to be the increment of range volatility caused by that of intraday volatility after structural change.

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Viscoelastic Modeling of Automotive Bushing for Axial Mode (축방향 모드에 대한 자동차 부싱의 점탄성 모델링)

  • Lee, Seong-Beom;Lee, Su-Young
    • Elastomers and Composites
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    • v.39 no.3
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    • pp.228-233
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    • 2004
  • A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. Since a force-displacement relation for bushings is important for multibody dynamics numerical simulations, the relation is expressed in terms of a force relaxation function and a method of determination by experiments on bushings has been developed. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from experiment. It is shown that the predictions by the proposed force-displacement relation are in very good agreement with the experimental results.

Protection Motivation Theory and Environmental Health Behaviors: A Systematic Mapping

  • Kim, Hyun Kyoung
    • International Journal of Advanced Culture Technology
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    • v.10 no.3
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    • pp.164-173
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    • 2022
  • This study aimed to explore the themes and parameters of environmental health behaviors based on Rogers' protection motivation theory through a systematic mapping review. Using a systematic approach, a literature review was conducted of articles that adopted Rogers' protection motivation theory. A total of 11 articles on protection motivation theory using participants and environmental health as outcomes were identified in a search of CINAHL, Cochrane Library, EMBASE, Eric, PsycARTICLES, PubMed, and RISS between September 1 and September 8, 2021. Themes related to the environment and personal behaviors between 2002 and 2021 were extracted. The parameters based on protection motivation theory were identified through systematic mapping as fear appraisal, rewards of maladaptive response, severity, vulnerability, costs of adaptive response, response efficacy, self-efficacy, and intention. Self-efficacy and response efficacy considerably affected environmental health behaviors. Emotional fear appeal related to environmental hazards motivates an internal process that alters the threat appraisal and their coping appraisal. Environmental behavior perception and intention influenced on environmental health behaviors with small effect sizes. Therefore, a deeper understanding of the severity of environmental health issues could lead to the development of helpful, effective, and intensive interventions to promote healthcare among the vulnerable population.

Design of 24GHz Patch Array Antenna for Detecting Obstacles (장애물 감지용 24GHz 대역 패치 배열 안테나 설계)

  • Lee, Kwang;Kim, Young-Su
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1075-1080
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    • 2021
  • In this paper, we designed a 24.4GHz 2-channel TX and 4-channel RX patch array antenna mounted on a short-range vehicle radar system to simultaneously measure the range and speed of a single object within a single measurement cycle. The antenna was designed and fabricated using Rogers' RO4350B(εr=3.48, 0.5T) board. Through measurement, it was confirmed that the design specifications of antenna gain (> 10dBi or more) and radiation pattern (Elevation HPBW > 10deg.) were satisfied at 24.4 GHz frequency.