• 제목/요약/키워드: SEM study

검색결과 9,063건 처리시간 0.036초

SEM Tribosystem에 의한 TiN피막의 미시적 마모형태의 천이 조건 (Transition Condition of Microscopic Wear Mode for TiN Coating by SEM Tribosystem)

  • 문봉호
    • 한국기계가공학회지
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    • 제10권3호
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    • pp.100-107
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    • 2011
  • To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process in great detail. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail, using in-situ system. In this study, based on the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. Consequently, four modes were revealed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. Sc(Severity of contact) can clarify transition condition of those microscopic wear modes.

SEM Tribosystem에 의한 CVD TiN막의 미시적 마모 특성 평가 (Evaluation of Microscopic Wear Characteristics for CVD TiN Coatings with SEM Tribosystem)

  • 문봉호
    • 한국표면공학회지
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    • 제37권3호
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    • pp.137-145
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    • 2004
  • This study surveys the microscopic wear of CVD TiN coatings in repeated sliding, using the SEM Tribosystem as in-situ system. According to the research, the depth of wear groove and the specific wear amount are changed by the transition of the microscopic wear mode. This investigation leads to the fact that the change of wear characteristics produces the transition of the wear mode. In this survey, four modes are observed for CVD TiN coatings with the thickness of 1.6$\mu\textrm{m}$: ploughing, powder formation, flake formation and coating delimitation. The microscopic wear properties is quantitatively evaluated in terms with the microscopic wear mode and the specific wear amount. These relationships prove that the observation of wear modes with a SEM Tribosystem is useful to evaluate wear properties.

웹사이트의 사용자 만족과 성과변수의 인과관계에 관한 연구-포털사이트를 중심으로- (A Study on Causal Relations between Website User Satisfaction and Performance Measures)

  • 최재호;백인기;전영호;신정태
    • 대한인간공학회지
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    • 제20권3호
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    • pp.47-60
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    • 2001
  • The purpose of this paper is propose an analytical method for evaluating user satisfaction of Internet website and identifying casual relationships between user satisfaction of Internet website and performance measures as like revisit intention and complaints using the structural equation model (SEM). This paper is intended to identify critical evaluation factors of user satisfaction for Internet website to determine criteria for evaluating the website. and use the criteria to develop a SEM model for quantitatively evaluation of each factors effects of user preference. The SEM model used 5 latent variables for the evaluation factors of website user satisfaction and 2 latent variables for performance evaluation. 2 portal sites were evaluated to construct the SEM model. and 74 subjects participated the website evaluation using the walk-through and face-to face survey method. Analysis results showed that the SEM model was statistically significant for all the 2 websites evaluated.

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익상견갑의 평가를 위한 "Scapulometer"의 신뢰도 연구 (Reliability of Scapular Winging Measurement Using a Scapulometer)

  • 원종혁;최홍식;권혁철
    • 한국전문물리치료학회지
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    • 제17권2호
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    • pp.10-16
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    • 2010
  • This study was undertaken to develop the scapulometer, a measuring tool for scapular winging, and to determine the reliability of scapulometer. Thirty subjects with scapular winging greater than 2 cm participated in this study. Two examiners measured scapular winging using the scapulometer. Standardized measurement position of each subject was as follows: neutral position of shoulder and wrist, $90^{\circ}$ flexion of elbow, and cuff weight of 5% and 10% of body weight (BW) to neutral wrist. The interrater and intrarater reliability were calculated with an intraclass correlation coefficient (ICC) with 95% confidence interval (CI) and standard error of measurement (SEM) at 5% BW and 10% BW. The level of scapular winging was tested between 5% BW and 10% BW with a paired t-test. The interrater reliability was shown to be high at 5% BW (ICC(2,k)=.955, 95% CI=.900~.979, SEM=.07) and at 10% BW (ICC(2,k)=.968, 95% CI=.930~.985, SEM=.06). The intrarater reliability was shown to be high at 5% BW (ICC(2,k)=.921, 95% CI=.842~.961, SEM=.09) and at 10% BW (ICC(2,k)=.906, 95% CI=.813~.954, SEM=.10). The level of scapular winging was significantly different between 5% BW and 10% BW. Conclusively, it is demonstrated that the scapulometer is an objective and qualitative measurement tool for scapular winging.

유류오염부지 정밀조사에 기반한 부지개념모델 구축 및 개선 (Construction and Refinement of Conceptual Site Model Based on Scrutiny of Oil Contaminated Site)

  • 배민서;김민경;김주희;이순재;권만재;조호영
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제28권2호
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    • pp.12-29
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    • 2023
  • Conceptual site model (CSM) development and enhancement for contaminated sites assists in identifying data gaps during the site investigation process. In this study, CSM was developed and enhanced for a contaminated site in Korea as a case study. Site Y was scrutinized four times previously. The site profiles for each scrutiny were reorganized based on the scrutiny reports, and the relevant data was utilized to develop and enhance CSMs. CSM for the first investigation was developed in various forms including table, flowchart, diagram, and narrative formats. CSM was enhanced in a stepwise manner by incorporating the updated profile information obtained in next investigation to existing CSM. The hypothetical data gap analysis between each investigation step was established to meet the purpose of the follow-up investigation. This case study showed that CSM is a useful tool to identify the history and current status of contaminated sites and thereby help in planning supplementary investigations for better site characterization.

Fission source convergence diagnosis in Monte Carlo eigenvalue calculations by skewness and kurtosis estimation methods

  • Ho Jin Park;Seung-Ah Yang
    • Nuclear Engineering and Technology
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    • 제56권9호
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    • pp.3775-3784
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    • 2024
  • In this study, a skewness estimation method (SEM) and kurtosis estimation method (KEM) are introduced to determine the number of inactive cycles in Monte Carlo eigenvalue calculations. The SEM and KEM can determine the number of inactive cycles on the basis that fully converged fission source distributions may follow normal distributions without asymmetry or outliers. Two convergence criteria values and a minimum cycle length for the SEM and KEM were determined from skewness and kurtosis analyses of the AGN-201K benchmark and 1D slab problems. The SEM and KEM were then applied to two OECD/NEA slow convergence benchmark problems to evaluate the performance and reliability of the developed methods. Results confirmed that the SEM and KEM provide appropriate and effective convergence cycles when compared to other methods and fission source density fraction trends. Also, the determined criterion value of 0.5 for both ε1 and ε2 was concluded to be reasonable. The SEM and KEM can be utilized as a new approach for determining the number of inactive cycles and judging whether Monte Carlo tally values are fully converged. In the near future, the methods will be applied to various practical problems to further examine their performance and reliability, and optimization will be performed for the convergence criteria and other parameters as well as for improvement of the methodology for practical usage.