• Title/Summary/Keyword: component failure

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The Effects of Demographic Factors on Children's wear Brand Preference and Their Reasons, and Brand Evaluation (paper no.3)

  • Koo, In-Sook
    • Journal of Fashion Business
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    • v.15 no.3
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    • pp.32-50
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    • 2011
  • This study is designed to analyze the effects of demographic factors on children's wear brand preference and their reasons, and brand evaluations. A total of 355 usable data was collected from housewives in three metropolitan cities (Seoul, Daejeon, and Sungnam) in Korea. An ANOVA and crossing analysis were used to determine the strength(percentage) among several dependent variables. Also, regression analysis was used to examine the effects of demographic factors on each factor and component related to fashion brand evaluation. Overall, ANOVA and crossing analysis results showed that the visual attributions (variables) of clothing marked significantly higher scores than others (functional attributions). This result is noteworthy because it is opposite of common stereotypes and prejudices that selectors who first recognize visual information (aesthetic attributions) as a clothing buying criteria should be unsatisfied with them after wearing. Therefore, this research suggests that the chief reason in determining the outcome of success or failure in fashion industry depends on their trend productions with fashion image creation by reflecting the exclusive trends based on consumer's taste and wants.

Protection of Mercury induced Acute Respiratory Injury by Inhaled Oxidizing Agent (수은에 의한 급성호흡손상시 산화물질의 억제효과)

  • 황태호
    • Journal of Life Science
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    • v.11 no.3
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    • pp.259-265
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    • 2001
  • Mercury vapor inhalation-induced acute respiratory failure(ARF) has been reported to be fatal. This study was designed to observe the possible mechanism of inhaled mercury vapor poisoning in the respiratory system. Sixty percent of rats(12/20) exposed to mercury vapor were dead within 72 hours of exposure whereas all the rats(20/20) exposed to mercury vapor combined with dithiothreitol(DTT) vapor survived. The histological observation showed that ARF was a direct cause of the death induced by mercury vapor inhalation, which was significantly circumvented by DTT vapor. Cyclic AMP mediated chloride secretion was inhibited by luminal side but not serosal side sulfhydryl blocking agents (Hf$^{2+}$ $\rho$-chloromercuribenzoic acid or $\rho$-chloromercuriphenyl sulfonic acid) in a dose-dependent manner in a primary cultured rat airway monolayer. The inhibitory component of cAMP induced chloride secretion was completely restored by luminal side DTT(0.5mM). these results suggest that the oxidized form(Hg$^{2+}$) of mercury vapor(Hg0) contribute to ARF and subsequent death. The finding is important as it can provide important information regarding emergency manipulation of ARF patients suffering from by mercury vapor poisoning.ing.

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Base Structure Design of Laptop HDD for Anti-Shock Performance (내충격 성능 향상을 위한 랩탑 하드디스크의 베이스 설계)

  • Lim, Seung-Ho;Park, No-Cheol;Park, Young-Pil;Park, Kyoung-Su;Seol, Woong;Kim, Kyung-Tae
    • Transactions of the Society of Information Storage Systems
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    • v.5 no.2
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    • pp.76-81
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    • 2009
  • Mobile devices have become an important part of daily life. This is especially true of laptop PCs, which are portable enough to be used almost anywhere. Laptop PCs, however, cannot be nomadic if each component is not robust enough to endure rugged laptop operating environment. Generally, external shock makes collision on head-disk interface and damage to read-write performance. To minimize the likelihood of failure, shock analysis must be incorporated into the design of hard disk drive in laptop. This research explores the structure modification of laptop HDD base, for improving shock performance using finite element analysis which considers the flexibility of whole HDD structure. FE model is verified by modal test and finely tuned. Then we obtained the transmitted acceleration of spindle and pivot and the relative displacement between disk and slider head as shock response. Based on shock simulation, the structural dynamics modification is performed and the primary design parameters are extracted.

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A Divece for Reducing the Zero phaze Harmonics of Neutral Line of Power Facility (전기수용설비의 중성선 영상분고조파전류저감장치)

  • Kang, Chang-Won;Choi, Gil-Soo;Han, Sung-Bae;Kim, Bum-Soo;Chung, Yeon-Hae;Lee, Ki-Cheol
    • Electric Engineers Magazine
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    • v.228 no.8
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    • pp.43-48
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    • 2001
  • Wide use of non-linear loads such as personal computers, monitors, laser printers, variable speed drives, UPS systems and other electronic equipment have led to harmonics becoming #1 issue in the electrical industry today. Commercial and Industrial building power distribution systems, designed for the old, linear-style loads especially when found in high densities. Some common power system problems include overloaded neutral conductors, overheated distribution transfOlmers, high neutral-to-ground voltage, poor power factor and distortion of the voltage waveform supplying these loads. The power quality problems, particularly high voltage distortion, have been known to cause equipment downtime due to malfunctions and component failure.

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Behaviour of steel joints under fire loading

  • da Silva, Luis Simoes;Santiago, Aldina;Real, Paulo Vila;Moore, David
    • Steel and Composite Structures
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    • v.5 no.6
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    • pp.485-513
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    • 2005
  • This paper presents a state-of-the-art on the behaviour of steel joints under fire loading and some recent developments in this field, currently being carried out by the authors. Firstly, a review of the experimental research work on steel joints is presented, subdivided into isolated member tests, sub-structure tests and tests on complete building structures. Special emphasis is placed on the seventh Cardington test, carried out by the authors within a collaborative research project led by the Czech Technical University in Prague. Secondly, a brief review of various temperature distributions within a joint is presented, followed by a discussion of the behaviour of isolated joints at elevated temperature, focussing on failure modes and analytical procedures for predicting the moment-rotation behaviour of joints at elevated temperature. Finally, a description of the coupled behaviour of joints as part of complete structures is presented, describing previous work and investigations on real fire (including heating and cooling phases) currently being carried out by the authors.

Investigating the fatigue failure characteristics of A283 Grade C steel using magnetic flux detection

  • Arifin, A.;Jusoh, W.Z.W.;Abdullah, S.;Jamaluddin, N.;Ariffin, A.K.
    • Steel and Composite Structures
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    • v.19 no.3
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    • pp.601-614
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    • 2015
  • The Metal Magnetic Memory (MMM) method is a non-destructive testing method based on an analysis of the self-magnetic leakage field distribution on the surface of a component. It is used for determining the stress concentration zones or any irregularities on the surface or inside the components fabricated from ferrous-based materials. Thus, this paper presents the MMM signal behaviour due to the application of fatigue loading. A series of MMM data measurements were performed to obtain the magnetic leakage signal characteristics at the elastic, pre-crack and crack propagation regions that might be caused by residual stresses when cyclic loadings were applied onto the A283 Grade C steel specimens. It was found that the MMM method was able to detect the defects that occurred in the specimens. In addition, a justification of the Self Magnetic Flux Leakage patterns is discussed for demonstrating the effectiveness of this method in assessing the A283 Grade C steel under cyclic loadings.

COMPASS - New modeling and simulation approach to PWR in-vessel accident progression

  • Podowski, Michael Z.;Podowski, Raf M.;Kim, Dong Ha;Bae, Jun Ho;Son, Dong Gun
    • Nuclear Engineering and Technology
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    • v.51 no.8
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    • pp.1916-1938
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    • 2019
  • The objective of this paper is to discuss the modeling principles of phenomena governing core degradation/melting and in-vessel melt relocation during severe accidents in light water reactors. The proposed modeling approach has been applied in the development of a new accident simulation package, COMPASS (COre Meltdown Progression Accident Simulation Software). COMPASS can be used either as a stand-alone tool to simulate in-vessel meltdown progression up to and including RPV failure, or as a component of an integrated simulation package being developed in Korea for the APR1400 reactor. Interestingly, since the emphasis in the development of COMPASS modeling framework has been on capturing generic mechanistic aspects of accident progression in light water reactors, several parts of the overall model should be useful for future accident studies of other reactor designs, both PWRs and BWRs. The issues discussed in the paper include the overall structure of the model, the rationale behind the formulation of the governing equations and the associated simplifying assumptions, as well as the methodology used to verify both the physical and numerical consistencies of the overall solver. Furthermore, the results of COMPASS validation against two experimental data sets (CORA and PHEBUS) are shown, as well as of the predicted accident progression at TMI-2 reactor.

Studies on the Acute Toxicity and Histological Changes in Fish Exposed to Furrural (Furfural 어류급성독성 및 조직병리에 관한 연구)

  • 이철우;최성수;최필선;이상협;이길철;박광식
    • Environmental Analysis Health and Toxicology
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    • v.12 no.3_4
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    • pp.55-59
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    • 1997
  • Furfural, an organic solvent, is widely used as synthetic component material in producing chemical products. However, furfural has been reported that it shows strong toxicities to human being showing intense stimulus to skin, eyes, mucous membrane and nerve system. It is also known to cause anemia, liver cirrhosis, kidney failure and genetic toxicity in the human being working in the exposed area. LD$_{50}$ of furfural for peritoneal injected mouse has been known around 20mg/kg, but the acute toxicity on aquatic organisms such as fish, daphnid or algae are not well known, compared to those on rodents. In this experiment, we studied on the fish toxicity of furfural using Japanese Medaka (Orvzias latipes) and Common Carp (Cvprinus carpio). We also observed histological changes in the fish organs. The LC$_{50}$ were 12. Smg/L in Japanese Medaka and 21.8 mg/L in Common Carp, respectively. When Common Carps were exposed to 120mg/L of furfural concentration for 30 minutes, blood congestion in gills and lysis of secondary lamella were shown. Though the muscle of caudal fin was not completely eroded, its epidermic cells were shown to be necrotic in various parts. Tissue atrophy and cell necrosis were also shown in the liver of Common Carps exposed to furfural. From these results, furfural seems to cause histological damages on liver, an internal organ as well as on external organs such as gills and fins eventhough the fish were exposed for a short-term.

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Development of a Dedicated Model for a Real-Time Simulation of the Pressurizer Relief Tank of the Westinghouse Type Nuclear Power Plant (웨스팅하우스형 원자력발전소 가압기 방출 탱크의 실시간 시뮬레이션을 위한 전문모델 개발)

  • 서재승;전규동
    • Journal of the Korea Society for Simulation
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    • v.13 no.2
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    • pp.13-21
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    • 2004
  • The thermal-hydraulic model ARTS which was based on the RETRAN-3D code adopted in the domestic full-scope power plant simulator which was provided in 1998 by KEPRI. Since ARTS is a generalized code to model the components with control volumes, the smaller time-step size should be used even if converged solution could not get in a single volume. Therefore, dedicated models which do not force to reduce the time-step size are sometimes more suitable in terms of a real-time calculation and robustness. In the case of PRT(Pressurizer Relief Tank) model, it is consist of subcooled water in bottom and non-condensable gas in top. The sparger merged under subcooled water enhances condensation. The complicated thermal-hydraulic phenomena such as condensation, phase separation with existence of non-condensable gas makes difficult to simulate. Therefore, the PRT volume can limit the time-step size if we model it with a general control volume. To prevent the time-step size reduction due to convergence failure for simulating this component, we developed a dedicated model for PRT. The dedicated model was expected to provide substantially more accurate predictions in the analysis of the system transients. The results were resonable in terms of accuracy, real-time simulation, robustness and education of operators, complying with the ANSI/ANS-3.5-1998 simulator software performance criteria and RETRAN-3D results.

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Distributed System Architecture Modeling of a Performance Monitoring and Reporting Tool (분산 시스템의 성능 모니터링과 레포팅 툴의 아키텍처 모델링)

  • Kim, Ki;Choi, Eun-Mi
    • Journal of the Korea Society for Simulation
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    • v.12 no.3
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    • pp.69-81
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    • 2003
  • To manage a cluster of distributed server systems, a number of management aspects should be considered in terms of configuration management, fault management, performance management, and user management. System performance monitoring and reporting take an important role for performance and fault management. In this paper, we present distributed system architecture modeling of a performance monitoring and reporting tool. Modeling architecture of four subsystems are introduced: node agent, data collection, performance management & report, and DB schema. The performance-related information collected from distributed servers are categorized into performance counters, event data for system status changes, service quality, and system configuration data. In order to analyze those performance information, we use a number of ways to evaluate data corelation. By using some results from a real site of a company and from simulation of artificial workload, we show the example of performance collection and analysis. Since our report tool detects system fault or node component failure and analyzes performances through resource usage and service quality, we are able to provide information for server load balancing, in short term view, and the cause of system faults and decision for system scale-out and scale-up, in long term view.

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