• 제목/요약/키워드: How-How

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신호대 잡음비에 무관한 허브 베어링 결함 검출 방법 (Faults Detection Method Unrelated to Signal to Noise Ratio in a Hub Bearing)

  • 최영철;김양한;고을석;박춘수
    • 한국소음진동공학회논문집
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    • 제14권12호
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    • pp.1287-1294
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    • 2004
  • Hub bearings not only sustain the body of a cat, but permit wheels to rotate freely. Excessive radial or axial load and many other reasons can cause defects to be created and grown in each component. Therefore, nitration and noise from unwanted defects in outer-race, inner-race or ball elements of a Hub bearing are what we want to detect as early as possible. How early we can detect the faults has to do with how the detection algorithm finds the fault information from measured signal. Fortunately, the bearing signal has Periodic impulse train. This information allows us to find the faults regardless how much noise contaminates the signal. This paper shows the basic signal processing idea and experimental results that demonstrate how good the method is.

An ESL Teacher's Perspective on Recasts: A Qualitative Exploration of "When" and "How"?

  • Byun, Ji-Hyun;Kayi-Aydar, Hayriye
    • 영어어문교육
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    • 제16권4호
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    • pp.1-18
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    • 2010
  • Recasts, which are defined as implicit types of corrective feedback, have been the focus of numerous SLA researchers for more than a decade. A range of classroom-based observational and experimental research studies have explored how and when language teachers provide recasts to learners' ill-formed utterances and aimed to understand the role of recasts in language acquisition or learning. On the basis of previous studies on recasts, our study investigated when an ESL teacher provided recasts and how recasts were provided in his class. The research questions were as follows: (1) When does an ESL teacher provide recasts? (2) How does the teacher provide recasts? The data came from observations of one ESL classroom as well as consecutive-semi structured interviews with the teacher. The data analysis included transcriptions of teacher-student interactions in the target setting and categories of recasts according to the linguistic phenomena, which prompted recasting. Based on the findings, practical suggestions for ESL teachers were provided. [156 words].

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Reflecting Critical Pedagogy: Its Application to EFL Contexts and Criticism

  • Jeon, Ji-Hyun
    • 영어어문교육
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    • 제15권3호
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    • pp.59-81
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    • 2009
  • The primary goal of this paper was to develop a critical point of view to critical pedagogy when applied to EFL contexts. Critical pedagogy is more concerned about how language can affect personal and social change of teachers and students than it is with how to teach language effectively or in ways that encourage critical thinking on the part of teacher and students. For this goal, this paper introduces the definition, emergence and major constructs of critical pedagogy in a broad way at first. Then, this paper presents how critical pedagogy has an impact on ELT, focusing on how critical pedagogy is applied in ELT contexts and why the application of critical pedagogy in EFL can be criticized, through the review of empirical studies. Reflection of Korean English teaching situation and applicational difficulties of critical pedagogy in Korean ELT are followed.

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RNA Interference in C. elegans: History, Application, and Perspectives

  • Min, Kyoeng-Woo;Lee, Jun-Ho
    • Animal cells and systems
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    • 제11권2호
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    • pp.99-104
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    • 2007
  • RNA interference (RNAi) is the phenomenon of gene silencing by double-stranded RNA (dsRNA) at transcriptional and post-transcriptional levels in a sequence-specific manner. Reverse genetic approaches using RNA interference (RNAi) have become a major tool for biological researches since its discovery in the nematode Caenorhabditis elegans. In this review, we overview how the RNAi phenomenon was discovered and how the underlying mechanism has been elucidated. We also describe and discuss how RNAi experiments can be performed and how RNAi can be used for genetic studies.

Tracing Metallicity in the Scenario of High Velocity Clouds (HVCs) Colliding with our Milky Way

  • 성광현;곽규진
    • 천문학회보
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    • 제39권2호
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    • pp.77.2-77.2
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    • 2014
  • Questions of how our Milky Way evolves through the interaction with its environment have been constantly raised. One particularly interesting question is how the metallicity would change as our Milky Way goes through collision with HVCs. Because of the possibility of HVCs providing fuel for star formation in the Galactic disk, we simulate the collision between HVCs and the Galactic disk. More specifically, we trace how the Galactic metallicity changes throughout the process of HVCs colliding with our Milky Way based upon a specific scenario that HVCs are primordial gas left-overs from an ancient galaxy formation. Such mixing between metal-rich gas (disk) and metal-poor HVC can be traced by running numerical simulations with the FLASH code due to its capability of tracking down the abundance change of a specific element such as carbon at each time step of the hydrodynamic evolution. As for now, we give how this mixing depends on model parameters that we choose such as collision speed, initial metallicities, temperature and so on.

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Systems biology of virus-host signaling network interactions

  • Xue, Qiong;Miller-Jensen, Kathryn
    • BMB Reports
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    • 제45권4호
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    • pp.213-220
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    • 2012
  • Viruses have evolved to manipulate the host cell machinery for virus propagation, in part by interfering with the host cellular signaling network. Molecular studies of individual pathways have uncovered many viral host-protein targets; however, it is difficult to predict how viral perturbations will affect the signaling network as a whole. Systems biology approaches rely on multivariate, context-dependent measurements and computational analysis to elucidate how viral infection alters host cell signaling at a network level. Here we describe recent advances in systems analyses of signaling networks in both viral and non-viral biological contexts. These approaches have the potential to uncover virus- mediated changes to host signaling networks, suggest new therapeutic strategies, and assess how cell-to-cell variability affects host responses to infection. We argue that systems approaches will both improve understanding of how individual virus-host protein interactions fit into the progression of viral pathogenesis and help to identify novel therapeutic targets.

Common and Domain-Specific Cognitive Characteristics of Gifted Students: A Hierarchical Structural Model of Human Abilities

  • Song, Kwang-Han
    • 한국영재학회:학술대회논문집
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    • 한국영재학회 2005년도 춘계학술대회
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    • pp.173-180
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    • 2005
  • The purpose of this study was to identify common and domain-specific cognitive characteristics of gifted students based on a hierarchical structural model of human abilities. This study is based on the premise that abilities identified by tests can appear as observable characteristics in test or school situations. Abilities proposed by major models of intelligence were reviewed in terms of their power to explain cognitive characteristics of gifted students. However, due to the lack of their explanatory power and disagreement on common and domain-specific cognitive abilities, a new hierarchical structural model was conceptualized in a unique way based on interrelationships between abilities proposed by the models. The newly established model hypothesizes a cognitive mechanism that accounts for how domain-specific knowledge is formed, as well as which abilities are common and domain-specific, how they are related functionally, and how they account for common and domain-specific cognitive characteristics of gifted students. The cognitive mechanism has important implications for our understanding of the chronically controversial concepts, 'intelligence' and 'knowledge.' Clearer definitions of what intelligence is (g or multiple), what knowledge is, and how knowledge develops ('genetic or environmental,' 'rationalistic or empiricist') may result from this model.

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최소 분산 켑스트럼을 이용한 자동차 허브 베어링 결함 검출 (Faults Detection in Hub Bearing with Minimum Variance Cepstrum)

  • 박춘수;최영철;김양한;고을석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.593-596
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    • 2004
  • Hub bearings not only sustain the body of a car, but permit wheels to rotate freely. Excessive radial or axial load and many other reasons can cause defects to be created and grown in each component. Therefore, vibration and noise from unwanted defects in outer-race, inner-race or ball elements of a Hub bearing are what we want to detect as early as possible. How early we can detect the faults has to do with how the detection algorithm finds the fault information from measured signal. Fortunately, the bearing signal has periodic impulse train. This information allows us to find the faults regardless how much noise contaminates the signal. This paper shows the basic signal processing idea and experimental results that demonstrate how good the method is.

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Design Strategy Based on Designer Roles in Design-Oriented Firms: A Comparison of Hanssem and Ikea

  • Kim, So-Hyung
    • 유통과학연구
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    • 제13권3호
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    • pp.21-29
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    • 2015
  • Purpose - This paper addresses the role of designers in design-oriented firms and how they should work together with other organization members. The aim of this paper is to investigate how designers generate ideas and cooperate with others as well as how their participation in decision-making reflects on corporate design strategies. Research design, data, and methodology - An in-depth exploratory study examined how designers actually perform their roles in enterprises; in addition, information, knowledge, communication among designers, and sources of creativity were examined. Hanssem and Ikea grew as design-intensive businesses in a declining industry. Data were obtained from interviews with the design staff of each company as well as secondary sources. Results - Designers were found to use their designs to communicate with customers as well as with communities outside of the enterprise; they also participated in overall decision-making in relation to important design strategies. Conclusions - This study emphasized the increasing importance of the innovative and creative role of designers; thus, it might substantially help companies to develop their own design capabilities and deploy design strategies.

엔터프라이즈 시스템 구현의 핵심성공요소에 관한 연구: 프로세스이론을 기반으로 한 실패사례 분석 (A Study on Critical Success Factors for Enterprise Systems Implementation: A Failure Case Analysis Based on Process Theory)

  • 김희웅;곽기영
    • 한국IT서비스학회지
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    • 제6권3호
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    • pp.251-272
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    • 2007
  • Although Enterprise Systems (ES) have promised major strategic benefits and process improvements from business and technology integration, their implementation has been plagued by a high failure rate and difficulty in realizing the promised benefits. For the purpose of understanding implementation failures, previous studies have focused on identifying critical success factors (CSFs) for information systems implementation. However, there has been little research on how these CSFs actually lead to successful results. In this study, based on process theory, we examined the process of ES implementation by explaining how the factors of ES implementation influence each other and how interaction among them produces results. Based on a failure case, we then developed a process model of ES implementation thus allowing us to explain the process of ES implementation. The proposed model facilitated an understanding of how repeating patterns of ES failure can be reversed. This model can be used for guiding new ES implementation projects.