• Title/Summary/Keyword: Failure Transition

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Institutional Quality, Regulatory Environment and Microeconomic Performance: Evidence from Transition and Non-transition Developing Countries

  • Ochieng, Haggai Kennedy;Park, Bokyeong
    • East Asian Economic Review
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    • v.25 no.3
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    • pp.273-309
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    • 2021
  • The development of regulatory systems varies between transition and non-transition economies. This suggests that they provide different incentives for entrepreneurial development and could have varied effects on the economy because they have different methods to deal with market failure. However, limited empirical evidence exists to prove the assumption of dichotomy. Using comprehensive data for institutional quality, labor market and financial market development, this research sought to analyze their effect on employment growth at micro level. The results show that the quality of institutions in transition economies are poorer relative to those in non-transition economies, but their financial and labor markets are more developed than the latter. Further analysis for the transition sample shows that the three variables are individually positively related with employment growth. For the non-transition sample, institutional quality and labor market flexibility bear a positive and significant effect on employment. Financial market development enters the model with a negative coefficient when regressed alone, but a joint test of significance finds that all the variables have a positive effect on employment growth. This result could imply that there is interdependence between institutional quality, labor flexibility and financial market development in firm-employment-growth relationship, or complementarity between regulations and the quality of institutions. Alternatively, this finding suggests that a stringently regulated credit market in non-transition economies have a selection effect-allocating credit only to entrepreneurs who already demonstrate strong growth potential. In sum, despite differences in the evolution of regulatory environment between the two samples, both of them complement employment growth at firm level. The overall implication of these findings is that less rigid regulations and coherent policies that are enforced with impartiality provide incentives for firms to expand.

Study of Economic Damage Due to Windows Device Driver Failure (Windows System에서 Device Driver Failure로 인한 경제적인 피해 산출 모델 연구)

  • Kim, Sung-Min
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.1163-1164
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    • 2008
  • From the complexities and functional/operational expectations, the compositions of PC devices requires Device Drivers to deliver full performance of the Hardware. However, due to quick transition of hardwares and expectations of better performance of the system. As a rest users are exposed of unexpected failures of device drivers which will cause malfunction of the system which consequently cause damages in quantity as well as quality wise. In this paper, the method of calculation and/or forecast to unexpected failure will be suggested. It may not be the answer but can be a guide to calculation to economic damage due to device driver failure.

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Behavior of Failure for Embankment and Spillway Transitional Zone of Agriculture Reservoirs due to Overtopping (농업용 저수지 월류시 제체와 여수토 접속부의 붕괴거동)

  • Noh, Jae Jin;Lee, Dal Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.1
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    • pp.71-79
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    • 2014
  • In this study, an experiment with large-scale model was performed according to raising the embankment in order to investigate the behavior of failure for embankment and spillway transitional zone due to overtopping. The pore water pressure, earth pressure, settlement and failure pattern by a rapid drawdown and overtopping were compared and analyzed. The pore water pressure and earth pressure at spillway transitional zone by overtopping increased a rapidly with the expansion of seepage erosion, but the crest showed a smally change due to effect of the inclined core type. And it is considered an useful data that can accurately estimate the possibility of failure of the reservoirs. A settlement at overtopping decreased a rapidly due to failure of crest. The relative settlement difference due to change of the water level at the upstream and downstream slope cause increase largely crack of crest. The behavior of failure by overtopping was gradually enlarged towards reservoirs crest from the bottom of the spillway transition zone, the inclined core after the raising the embankment was influenced significantly to prevent the seepage erosion.

Development of Stochastic Markov Process Model for Maintenance of Armor Units of Rubble-Mound Breakwaters (경사제 피복재의 유지관리를 위한 추계학적 Markov 확률모형의 개발)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.2
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    • pp.52-62
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    • 2013
  • A stochastic Markov process (MP) model has been developed for evaluating the probability of failure of the armor unit of rubble-mound breakwaters as a function of time. The mathematical MP model could have been formulated by combining the counting process or renewal process (CP/RP) on the load occurrences with the damage process (DP) on the cumulative damage events, and applied to the armor units of rubble-mound breakwaters. Transition probabilities have been estimated by Monte-Carlo simulation (MCS) technique with the definition of damage level of armor units, and very well satisfies some conditions constrained in the probabilistic and physical views. The probabilities of failure have been also compared and investigated in process of time which have been calculated according to the variations of return period and safety factor being the important variables related to design of armor units of rubble-mound breakwater. In particular, it can be quantitatively found how the prior damage levels can effect on the sequent probabilities of failure. Finally, two types of methodology have been in this study proposed to evaluate straightforwardly the repair times which are indispensable to the maintenance of armor units of rubble-mound breakwaters and shown several simulation results including the cost analyses.

Strain Distribution of transition zone in a nailed wall (네일로 보강된 구조물에서의 변이영역과 변형률 분포)

  • 장기태;남궁한;유병선;김경태;권병근;이선경
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11b
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    • pp.235-239
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    • 2000
  • For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

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Evaluation of Mechanical Properties of RPV Clad by Small Punch Tests

  • Lee, Joo-Suk;Kim, In-Sup
    • Nuclear Engineering and Technology
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    • v.34 no.6
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    • pp.574-585
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    • 2002
  • The microstructural characteristics and its related mechanical properties of RPV cladding have been investigated using small punch (SP) tests. SA508 Cl.3 RPV steel plates were overlay cladded with the type ER309L welding consumables by submerged arc welding process. Although the RPV clad material had a small portion of 5 ferrite phase, it still showed the ductile to brittle transition behavior The transition temperature was determined by the SP test and it depended on the content of $\sigma$ phase, specimen size, and determination methods. The fracture appearance of SP specimen was changed from circumferential to radial cracking as test temperature became low, and below the transition temperature region, ER309L cladding usually fractured along the 6 ferrite by the low temperature failure of ferrite phase.

Strain Distribution of Transition Zone in a Nail Wall (네일로 보강된 구조물에서의 변이영역과 변형률 분포)

  • Chang, Ki-Tae;NamGung, Han;Yoo, Byung-Sun
    • Journal of the Korean Geophysical Society
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    • v.8 no.1
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    • pp.39-43
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    • 2005
  • For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain istribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

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A rough flat-joint model for interfacial transition zone in concrete

  • Fengchen Li;J.L. Feng
    • Computers and Concrete
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    • v.34 no.2
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    • pp.231-245
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    • 2024
  • A 3D discrete element model integrating the rough surface contact concept with the flat-joint model is suggested to examine the mechanical characteristics of the interfacial transition zone (ITZ) in concrete. The essential components of our DEM procedure include the calculation of the actual contact area in an element contact-pair related to the bonded factor using a Gaussian probability distribution of asperity height, as well as the determination of the contact probability-relative displacement form using the least square method for further computing the force-displacement of ITZs. The present formulations are implemented in MUSEN, an open source development environment for discrete element analysis that is optimized for high performance computation. The model's meso-parameters are calibrated by using uniaxial compression and splitting tensile simulations, as well as laboratory tests of concrete from the literature. The present model's DEM predictions accord well with laboratory experimental tests of pull-out concrete specimens published in the literature.

Probabilistic Fracture Mechanics Analysis of Boling Water Reactor Vessel for Cool-Down and Low Temperature Over-Pressurization Transients

  • Park, Jeong Soon;Choi, Young Hwan;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.545-553
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    • 2016
  • The failure probabilities of the reactor pressure vessel (RPV) for low temperature over-pressurization (LTOP) and cool-down transients are calculated in this study. For the cool-down transient, a pressure-temperature limit curve is generated in accordance with Section XI, Appendix G of the American Society of Mechanical Engineers (ASME) code, from which safety margin factors are deliberately removed for the probabilistic fracture mechanics analysis. Then, sensitivity analyses are conducted to understand the effects of some input parameters. For the LTOP transient, the failure of the RPV mostly occurs during the period of the abrupt pressure rise. For the cool-down transient, the decrease of the fracture toughness with temperature and time plays a main role in RPV failure at the end of the cool-down process. As expected, the failure probability increases with increasing fluence, Cu and Ni contents, and initial reference temperature-nil ductility transition ($RT_{NDT}$). The effect of warm prestressing on the vessel failure probability for LTOP is not significant because most of the failures happen before the stress intensity factor reaches the peak value while its effect reduces the failure probability by more than one order of magnitude for the cool-down transient.

The role of mass transfer layer on the tribological characteristics of silver-coated surfaces

  • Yang, Seung-Ho;Kong, Ho-Sung;Yoon, Eui-Sung;Kim, Dae-Eun
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.153-154
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    • 2002
  • Wear map of silver coatings on AISI 52100 has been constructed to delineate the wear transition behavior with the change in operating conditions in various environments. Three main regimes were clearly identified: (i) elastic/plastic deformation of silver coating without failure. (ii) mild wear regime after initial failure of silver coating and (iii) severe wear regime. In the mild wear regime, the contact surfaces were covered with transfer layers of agglomerated wear particles. The transfer layer acted as a protective layer and resulted in low friction even after the initial failure of the coated films, whose characteristics were strongly dependent on both the operating and environmental conditions. Also, the existence of the critical sliding speed, above which no transfer layer was able to form, was discussed in the work.

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