• Title/Summary/Keyword: soundness

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Influence of the Braking Time on the Soundness of Ventilated Disc Brake Systems (제동시간이 통풍형 디스크 브레이크 시스템의 건전성에 미치는 영향)

  • Gwak, Woo-Gyeong;Hong, Chang-Ki;Kim, Youn-Jea
    • Journal of Auto-vehicle Safety Association
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    • v.8 no.1
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    • pp.7-12
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    • 2016
  • In order to analyze the soundness of ventilated disc brake systems, numerical study was performed with various vane shapes. In particular, two different vane type, and the braking time from 3.0 s to 4.5s with the interval of 0.5s were considered. Transient temperature distributions on the ventilated disc brake assembly were calculated using ANSYS CFX ver. 16.1. To elucidate the soundness of ventilated disc brake systems, moreover, the heat transfer coefficients were evaluated. Results were graphically depicted with different geometrical vane configurations and braking time.

FORMALIZING THE META-THEORY OF FIRST-ORDER PREDICATE LOGIC

  • Herberlin, Hugo;Kim, SunYoung;Lee, Gyesik
    • Journal of the Korean Mathematical Society
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    • v.54 no.5
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    • pp.1521-1536
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    • 2017
  • This paper introduces a representation style of variable binding using dependent types when formalizing meta-theoretic properties. The style we present is a variation of the Coquand-McKinna-Pollack's locally-named representation. The main characteristic is the use of dependent families in defining expressions such as terms and formulas. In this manner, we can handle many syntactic elements, among which wellformedness, provability, soundness, and completeness are critical, in a compact manner. Another point of our paper is to investigate the roles of free variables and constants. Our idea is that fresh constants can entirely play the role of free variables in formalizing meta-theories of first-order predicate logic. In order to show the feasibility of our idea, we formalized the soundness and completeness of LJT with respect to Kripke semantics using the proof assistant Coq, where LJT is the intuitionistic first-order predicate calculus. The proof assistant Coq supports all the functionalities we need: intentional type theory, dependent types, inductive families, and simultaneous substitution.

Soundness Evaluation of 120W LED Lighting using Passive Infrared Thermal Imaging Method (수동적 적외선 열화상 기법을 적용한 120W급 LED조명등 건전성 평가)

  • Jung, Yoon-Soo;Gao, Jia-Chen;Kim, Jae-Yeol
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.4
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    • pp.140-146
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    • 2017
  • As energy conservation and environmental issues are emerging as a hot topic around the world, consumers are demanding high-efficiency, eco-friendly products. In this study, the author proposed 120W LED lighting system that replace metal halide lamp (MHL) which is currently used in the industry. Furthermore, it would be possible to provide a perfect opportunity for Korea to rise as a global leader in the LED lighting industry through soundness evaluation of the LED lighting system that is applied.

Is Increasing of Labor Market Policy Expenditure Effective Policy Tool to Lessen the Fiscal Crisis in Welfare State? : The Interaction between Active and Passive Labor Market Policy (노동시장정책의 확대는 복지국가 재정위기 해소에 유효한가? - 소극적·적극적 노동시장정책의 상호작용 효과)

  • Bae, Eunchong;Ko, Hyejin;Cho, Hyojin
    • 한국사회정책
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    • v.24 no.4
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    • pp.185-222
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    • 2017
  • The purpose of this study is to investigate the effect of labor market policy on fiscal soundness of welfare state. The analysis was carried out using cross-sectional panel data regression analysis, stepwise mediating effect analysis and system GMM designed by Baron and Kenny(1986) based on the data from 1985 to 2015 for 20 OECD countries. In setting up the analysis model, this study considers the interaction effect between active and passive labor market policies as well as the time sequence of the outcomes which have been overlooked in the previous studies. The result shows that labor market policies have significant impacts on the fiscal condition of welfare states, which is measured as the levels of national debt in this study. Especially the expenditure on active labor market programs has a positive effect on improving the fiscal soundness of welfare states by promoting the employment rate. In contrast, passive labor market programs expenditure is negatively associated with employment rate growth and it exacerbates the burden of national debt in the short-term. However, when active labor market programs and passive labor market programs are combined, the negative impacts by passive pabor market policies on the fiscal soundness of welfare states are off-set. Therefore this study addresses that although the expansion of the labor market policies can be inimical to the fiscal soundness of welfare states in the short-term, in the long run, they can have effective roles in securing and promoting the fiscal soundness of the welfare states by promoting the employment rate.

An application of integrated water cycle system in U-City (도시 용수 통합관리 방안 연구)

  • Jung, Jin-Hong;Choi, Gye-Woon;Oh, Hyun-Je
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.12
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    • pp.6597-6601
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    • 2013
  • This study aims at suggesting a evaluation method of water cycle soundness in U-City. The distortion of water cycle soundness induced industrialization and urbanization was quantitatively analyzed. In order to evaluate the soundness of water cycle in U-City the reduction ratio of runoff was evaluated in comparison of before the construction of the water recycling facilities for natural water cycle, the reduction ratio of urban water was evaluated in comparison of before the introduction of the artificial recycling facilities for artificial water cycle.

A Study on Performance-based Evaluation Method for Rock Slopes : Deduction of Evaluation Factors (암반비탈면의 성능기반 평가기법 연구 : 평가항목 도출)

  • Lee, Jong-Gun;Suk, Jae-Wook;Kim, Hong-Kyoon;Kim, Yong-Soo;Moon, Joon-Shik
    • Tunnel and Underground Space
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    • v.25 no.1
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    • pp.86-96
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    • 2015
  • In this study, the performance-based evaluation factors for rock slopes have been deducted using Delphi-method. Validity of the result was verified through factor analysis. Performance of rock slope is classified as soundness, stability and durability. Through the Delphi survey, 17 factors including discontinuity orientation are deducted for soundness, 4 factors and 3 factors are selected for stability and durability, respectively. Validation is conducted using Exploratory Factor Analysis (EFA) for 24 factors, and all factors are found to be valid. As a result of Exploratory Factor Analysis (EFA), 3-types of performance were subdivided into internal soundness, external soundness, risk, damage and durability of slopes and protection (reinforcement) facilities.

A study on the Impact of Financial Conditions on Accounting indicators -Focusing on the Financial Soundness of Private Universities- (재정여건이 회계지표에 미치는 영향에 관한 연구 -사립대학 재정건전성을 중심으로-)

  • Park, Tae-Hwan;Bae, Eun-Jin
    • Journal of Digital Convergence
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    • v.19 no.12
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    • pp.273-280
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    • 2021
  • The purpose of this study is to provide implications for fiscal policy by comprehensively examining the relationship between the on-campus retention and university soundness items of four-year private universities in the context of financial contraction of private universities due to suppression of tuition increase. Multiple regression analysis was performed to analyze the correlation of variables and the effect of financial soundness items on accounting indicators using SPSS 25. First, private university's on-campus reservations had an effect on accounting index items. Second, financial soundness items had an effect on accounting index items. Third, the financial condition factors influenced the change of accounting index by the location of the university. Fourth, according to the size of students, financial conditions had an effect on the change in accounting indicators. Government investment and support for private universities should be changed to a paradigm of securing finance through establishment of a development plan, rather than financial support through reduction of quota, and survival should be sought through income diversification policy strategies.

Development of Non-Destrutive Pile Soundness Test Using HWAW Method (HWAW(Harmonic Wavelet Analysis of Wave) 방법을 사용한 말뚝기초의 비파괴 건전도 평가방법의 개발)

  • Park, Hyung-Choon;Kim, Dong-Soo;Cho, Sung-Eun
    • Journal of the Korean Geotechnical Society
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    • v.24 no.8
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    • pp.13-23
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    • 2008
  • The evaluation of soundness of pile is very important for the safety of super structure. In this paper, the HWAW(Harmonic Wavelet Analysis of Wave) method which is developed to determine phase and group velocities of waves is applied to evaluate integrity of pile non-destructivly. The proposed method can evaluate a soundness of pile and pile end condition which is very important factor for pile behaviour. To verity the applicability of HWAW method in non-destructive test for pile, the numerical simulation test using ABAQUS was performed. And the model pile was made and the proposed non-destructive pile tests were applied to evaluate soundness and end boundary condition of model pile in the air and soil box. Through a numerical simulation and model tests, it is shown that the HWAW method has good potential of applying to the evaluation of pile integrity.

A Study on the Assignment of the Vibration Classes to the Power Transformers in Operation (154[kV])

  • Kim, Young-Dal
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.11
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    • pp.52-60
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    • 2009
  • High reliability is essential for power transformers, and their fault causes are reportedly more related to mechanical causes than electrical ones. The transformer soundness judgment currently depends only on the electrical insulation characteristic and the chemical test of the insulation oil, so that there are few fundamental measures against the frequent mechanical damages and failures in transformers. The mechanical soundness judgment techniques are conducted through processes that include structural analysis and vibration resistance treatment during the manufacturing process of each manufacturer, but the vibration is not tested during the design, manufacturing, and operating processes since there are no detailed technical standards and procedures on the vibration problem, which are important in terms of maintenance. Therefore, in this study, vibration phenomena were measured from the 32 power transformers in operation in the substations under the Daejeon Power Transmission District Office of the Korean Electric Power Corporation (KEPCO). The vibration was measured at 24 sections ($6{\times}4$) on one side, and only the maximum values were selected from the measured vibration values. This was because the maximum vibration values more significantly affect the soundness of the transformer than the average vibration values. The vibration classes were given considering the maximum vibration based on ISO 10016-1 (2001).

Model Test of Lining for Estimation of Tunnel Soundness (터널 건전도 평가를 위한 라이닝 모델실험)

  • Kim, Young Keun
    • Magazine of korean Tunnelling and Underground Space Association
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    • v.1 no.2
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    • pp.59-71
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    • 1999
  • Recently, many deformations in tunnel such as crack and leakage were occulted. Specially, the defects of tunnel lining have been a serious problem in safety and stability many repair works for maintenance in tunnel have been carried out. Therefore, it is necessary to estimate the structural cracking for countermeasure in deformed tunnel and to investigate on the characteristics of lining system and the soundness of tunnel. In this study model tests for tunnel lining were carried out using test apparatus and centrifuge, In the direct loading test, the prototype was Kyungbu high-speed railway tunnel and the scale is 1/10, and lining models were made of concrete. Test conditions included load conditions such as direction, shape and type, lining conditions such as single and double lining, thickness, and reinforcement. In centrifuge model test, the prototype was Seoul subway tunnel and the scale is 1/100, and lining models were made of aluminum and hydrostone. Test conditions included tunnel defects such as thickness shortage. behind cavity and longitudinal cracks, reinforcement methods such as epoxy, grouting and carbon sheet. From these model tests , the characteristics of deformation and failure for tunnel lining were estimated, and the structural behaviors of deformed lining and the effects of repair and reinforcement for tunnel lining were researched.

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