• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.62-68
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• 2016

The feeder cable assembly is an automotive part used for telecommunication. If it malfunctions, the control and safety of the automobile can be put at risk. ALT (Accelerated Life Testing) is a testing process for products in which they are subjected to conditions (stress, strain, temperatures, etc.) in excess of their normal service parameters in an attempt to uncover faults and potential modes of failure in a short amount of time. Failure is caused by defects in the design, process, quality, or application of the part, and these defects are the underlying causes of failure or which initiate a process leading to failure. Thermal shock occurs when a thermal gradient causes different parts of an object to expand by different amounts. Thermal shock testing is performed to determine the ability of parts and components to withstand sudden changes in temperature. In this research, the main causes of failure of the feeder cable assembly were snapping, shorting and electro-pressure resistance failure. Using the Coffin-Manson model for ALT, the normal conditions were from Tmax = $80^{\circ}C$ to Tmin = $-40^{\circ}C$, the accelerated testing conditions were from Tmax = $120^{\circ}C$ to Tmin = $-60^{\circ}C$, the AF (Acceleration Factor) was 2.25 and the testing time was reduced from 1,000 cycles to 444 cycles. Using the Bxlife test, the number of samples was 5, the required life was B0.04%.10years, in the acceleration condition, 747 cycles were obtained. After the thermal shock test under different conditions, the feeder cable assembly was examined by a network analyzer and compared with the Weibull distribution modulus parameter. The results obtained showed good results in acceleration life test mode. For the same reliability rate, the testing time was decreased by a quarter using ALT.

• Asian Journal of Innovation and Policy
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• v.7 no.1
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• pp.79-102
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• 2018

In an entrepreneurial ecosystem, the failure rate of startups is extremely high at 90%, and every startup that fails becomes an orphan. This phenomenon leads to higher costs of failure for the entrepreneurs in the ecosystem. Failed startups have many lessons to offer to the ecosystem and offer guidance to the potential entrepreneur, and this area is not fully explored compared to the literature on successful startups. We use a case based method distinguishing a failed startup and a successful startup, studying the entrepreneurial characteristics and firm level factors which cause the failures, in the technology startup ecosystem of Bangalore. We study one of the modes of exit adopted by failed startup entrepreneurs and draw key lessons on causes that culminate in failures. We have identified that factors such as the time to minimum viable product cycle, time for revenue realization, founders' complementary skillsets, age of founders with their domain expertise, personality type of founders, attitude towards financial independence and willingness to avail mentorship at critical stages, will decisively differentiate failed startups from the successful ones. Accordingly, implications have been derived for potential entrepreneurs for reducing the cost of failures in the entrepreneurial ecosystem.

• Journal of the Korean Society of Safety
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• v.26 no.6
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• pp.104-110
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• 2011

In FMEA, the risk priority number(RPN) is used for risk evaluation on each failure mode. It is obtained by multiplying three components, i.e., severity, occurrence, and detectability of the corresponding failure mode. Each of the three components are usually determined on the basis of the past experience and technical knowledge. But this approach is not strictly objective in evaluating risk of a given failure mode and thus provide somewhat less scientific measure of risk. Assuming a homogeneous Poisson process for occurrence of the failures and causes, we propose a more scientific approach to evaluation of risk in FMEA. To quantify severity of each failure mode, the mission period is taken into consideration for the system. If the system faces no failure during its mission period, there are no losses. If any failure occurs during its mission period, the losses corresponding to the failure mode incurs. A longer remaining mission period is assumed to incur a larger loss. Detectability of each failure mode is then incorporated into the model assuming an exponential probability law for detection time of each failure cause. Based on the proposed model, an illustrative example and numerical analyses are provided.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1792-1797
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• 2007

This paper try to find root-cause of failure in a connector used in transmitting signals for throttle body control in automotives by analyzing possible failure causes and performing experiments to simulate the cable failure in field. The connector comprises fins, wires, and case moldings. The failure is due to degradation of initial clamping force required fixing fins and wires in the connector. Expansion and compression of the case molding material surrounding fins would cause the degradation. Investigations of strict initial claming force and control of thermal expansion property of the molding are required to prevent the failure.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.57-63
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• 2005

In the calendar and the advertising catalog, the surface is usually coated by coating polypropylene film. The delamination failure of coating film depends on surface roughness and quality of the substrate paper. In this paper, the mechanisms of delamination failure between the coating film and the paper is investigated by using the root cause analysis as one of techniques of reliability evaluation. The papers used in failure analysis are three kind products made by two domestic and one foreign companies. It found that the main causes of delamination failure between the coating film and the paper were the creation of microvoids caused by shape of filler and their growth caused by contraction of paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.586-592
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• 2004

In this study, the failure analysis of a decanter is carried out and the methods of performance improvement are presented. The decanter is a centrifugal separator that is used to separate water and solids from municipal and industrial sludge. Therefore, the decanter should be designed to improve the dewatering of sludge. Besides high performance, the decanter should guarantee its life time under a severe using condition. For theses reasons, the failure analysis and performance improvement of the decanter are studied. It is found from this study that the failure is caused by mass unbalance, wear, clogging or crack. If these failure causes are prevented, the life time as well as the performance is expected to be improved.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.337-337
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• 2001

High voltage ceramic capacitors are widely applied in power electronic circuits, such as filters, snubbers, and resonant circuits, due to their excellent features of high voltage endurance and low aging. This paper presents a result of failure analysis and reliability evaluation for high voltage ceramic capacitors. The failure nodes and failure mechanisms were identified in order to understand the failure physics in a component. The causes of failure mechanisms for zero resistance phenomena under withstanding voltage test in high voltage ceramic capacitors molded by epoxy resin were studied by establishing an effective closed-loop failure analysis. Also, the condition for dielectric breakdown was investigated. Particular emphasis was placed on breakdown phenomena at the ceramic-epoxy interface. The validity of the results in this study was confirmed by the results of accelerated testing. Thermal shock test as well as pressure cooker test for high voltage ceramic capacitor mounted on a magnetron were implemented. Delamination between ceramic and epoxy, which, might cause electrical short in underlying circuitry, can occur during curing or thermal cycling. The results can be conveniently used to quickly identify defective lots, determine mean time to failure (MTTF) of each lot at the level of Inspection, and detect major changes in the vendors processes.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.32-41
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• 1989

We scrutinized the 64 cases of TGA and Taussig-Bing anomaly who underwent Senning and Mustard operations from Jan. 1981 to May 1988. The ratio of male to female was 45; 19, and the age at operation varied from 2 months to 18 years [mean 18.9*32.9 months]. The in-hospital mortality was in 24 cases [37.5%] and the major causes were myocardial failure and congestive heart failure associated with arrhythmias. The risk factors for hospital mortality were complex TGA, prolonged bypass time and high postoperative CVP. In addition, mortality increased during the first year the procedure was used. Late mortality occurred in 6 cases and the major causes was congestive heart failure, and there was not any significant risk factor noted in late mortality. Early arrhythmia developed in 37.5%, all of which were transient and self limited and 7 cases of early mortality were related to the arrhythmias. Late arrhythmias developed in 8 cases, but 7 cases were transient. One case died with junctional tachycardia. Of significance the one case that died late by arrhythmia had a similar junctional tachycardia in the early postoperative period. The survival rate in all cases disregarding initial in-hospital mortality 1YSR 89.8% and 5YSR 84.3%, but because of short duration of follow up this is not significant. We concluded that early hospital mortality could be decreased by operating at an earlier age and by adjusting the appropriate operation method.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.1
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• pp.15-19
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• 2001

Current leakage is the major failure mode of semiconductor device characteristic failures. Conventionally, failures such as short circuit breaks and gate breakdowns have been analyzed and the detected causes have been reflected in the fabrication process. By using a wafer-level emission-leakage failure analysis method (in-line QC), we analyzed leakage mode failure, which is the major failure detected during the probe inspection process for LSIs, typically DRAMs and CMOS logic LSIs. We have thus developed a new technique that copes with the critical structural failures and random failures that directly affect probe yields.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.276-285
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• 2000

Paraquat is a very potent herbicide which causes fatal toxicity when ingested, and there is no specific antidote against it. Human ingestion induces acute renal failure, hepatic dysfunction and progressive respiratory failure with high mortality rate. Clinical investigation and medical treatment were done on two cases of acute renal failure caused by paraquat poisoning admitted to the Department of Internal Medicine, Wonkwang University Oriental Chonju Medical Hospital. We report two cases of patients who survived after acute paraquat intoxication, by means of oriental medicine such as Gamdutang, a typical antidote of toxins, chinese ink as an absorbent and burned powder of Rhei Radix et Rhizoma for laxative and so on, western medicine such as gastric lavage, diuretics and fluid therapy. We suggest more experiments and studies related to such treatment for paraquat poisoning be conducted.