• Journal of Digital Contents Society
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• v.15 no.2
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• pp.301-308
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• 2014

The mass storage of data and the importance of storage capacity lately has emerged. In this paper, we suggest the new method which estimate life cycle from acceleration life test about 2.5 inch hard disk driver as mass storage, which minimize the difference between real market annual failure rate and estimated failure rate. we obtain market transfer capacity per hours from returned 2.5inch hard disk drives about 309 numbers and accelerating transfer capacity per hours from acceleration life test. we calculate acceleration factor about duty cycle and estimate annual failure rate from failure rate and acceleration factors: temperature acceleration factor, duty cycle acceleration factor, the transfer capacity per hour represent the 93.4 % of user is 5.8 GB/hour, the transfer capacity per hour from acceleration life test is 81.4 GB/hour. the acceleration factor of duty cycle is 14.1. annual failure rate is stabilized at market one year after, annual failure rate is between 0.3 and 0.378. estimated annual failure rate is 0.4, so it is matched at 75~94 % between estimate annual failure rate and market annual failure rate. This study influence the estimate method of annual failure rate by the result of acceleration life cycle of manufacture.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.1
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• pp.47-70
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• 1985

This study was presented of the 1,872 cases of infertile couples who visited and examined at the sterility clinic of Department of Obstetrics & Gynecology, Seoul National University Hospital from Sept., 1980 to Dec., 1983. Age, duration of infertility, past medical history, and other general factors were analyzed, and the factors responsible for infertility were classified and discussed. Mode of treatment, outcome of pregnancy, pregnancy rate responsible for each factor were also presented. The results were as follows: 1) The infertility was primary in 1,128, or 60.3% and secondary in 744, or 39.7%. 2) The age between 26 and 30 years of age comprised about one half of the total patients. 3) The duration of infertility between 1 and 4 years comprised about three quarters of the total patients, and the mean duration was 3.8 years. 4) The most common medical history in primary infertility was tuberculous disease, and that in secondary infertility was history of previous laparotomy. 5) About two thirds of antecedent pregnancies were abortion. 6) The major etiologic factor of infertility were male factor in 12.3%, tubal factor in 38.8%, ovulatory failure in 25.4%, uterine factor in 8.8%, cervical factor in 5.2%, peritoneal factor in 9.5%, and no demonstrable cause in 11.3%. 7) The types of male factor were azoospermia in 61.6%, oligospermia in 25.8%, low motility in 11.6%, and other abnormality in 1.0%. 8) The types of ovulatory failure were ovarian failure in 7.4%, hypothalamo-pituitary failure in 8.1 %, hypothalamo-pituitary dysfunction (including Polycystic ovarian syndrome) in 30.2%, and hyperprolactinemia in 22.4%. 9) The types of uterine factor were endometrial tuberculosis in 27.5%, uterine synechia in 33.8%, uterine anomaly in 19.7%, myoma and polyp in 9.1 %, and luteal phase defect in 9.9%. 10) The types of peritoneal factor were pelvic adhesion in 80.9% and endometriosis in 19.6%. 11) Surgeries were done in 408 patients, and they were salpingolysis, lysis of extraadnexal adhesion, salpingostomy, fimbrioplasty, ovarian wedge resection for polycystic ovarian disease, tubo-tubal anastomosis, and tubo-uterine implantation in orders. 12) 243 pregnancies were achieved during the infertility work-up, of which livebirth was 46.5%, ectopic pregnancy was 7.4%, spontaneous abortion was 7.8%, and on-going pregnancy or lost to follow-up was 36.2%. 13) Pregnancy rates in various factors were male factor in 18.7%, ovulatory factor in 31.7%, tubal factor in 24.2%, uterine factor in 34.6%, cervical factor in 19.0%, peritoneal factor in 29.0%, combined factors in 10.5%, and unexplained infertility in 37.1%. Pregnancy rate in whole patients was 25.2%.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.609-614
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• 2001

This paper is to explain reasonable shear behavior that can apply usually to reinforced concrete beams on the basic concepts of existent analysis and experimental research information. This study is succession $paper^{2) 3) 4) 5)}$ of treatise announced in existing and main control variable of reinforced concrete beams with stirrups used internal force state factor($\alpha$). Shear failure of reinforced concrete beams with stirrups is Influenced greatly because of the actual geometrical shape(a/d) of the concrete and flexural reinforcement steel ratio, stirrup reinforcement ratio and concrete compression strength, size effect etc. Therefore, shear behavior of reinforced concrete beams with stirrups that flexural crack is happened can be explained easily through proper extent proposal of internal force state factor($\alpha$) that express internal force state flowing. Use existent variable truss model by analysis model to explain arch action. Also, wish to compose each failure factors and correlation with internal force state factor by function, and when diagonal cracks happens, internal force state factor($\alpha$) study whether shear stress and some effect are.

• Industrial Engineering and Management Systems
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• v.8 no.4
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• pp.247-256
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• 2009

In mass production industries such as steel making that have large equipment, sudden stops of production process due to machine failure can cause severe problems. To prevent such situations, machine diagnosis techniques play important roles. Many methods have been developed focusing on this subject. In this paper, we propose a method for the early detection of the failure on rotating machine, which is the most common theme in the machine failure detection field. A simplified method of calculating autocorrelation function is introduced and is utilized for ARMA model identification. Furthermore, an absolute deterioration factor such as Bicoherence is introduced. Machine diagnosis can be executed by this simplified calculation method of system parameter distance with weight. Proposed method proved to be a practical index for machine diagnosis by numerical examples.

• Journal of Applied Reliability
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• v.14 no.2
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• pp.93-96
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• 2014

RFID (Radio Frequency IDentification) system is recognition technology which can maintain various object's information. Reliability of RFID tags is the most important factor in RFID system. In this paper, we proposed ALT (Accelerated Life Test) method for UHF RFID tags. Temperature and humidity were adopted as stress factors and the accelerated life tests were conducted in three different conditions. We performed failure analysis for identifying failure mechanism and statistical analysis of test data. In the statistical analysis, we employed Inverse Power law for relationship between tag's life and stress. Through the statistical analysis, we proposed acceleration factor for several levels of temperature-humidity. The reliability qualification test plans were also designed for the tag's target reliability.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.643-650
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• 2002

The large planar failure has occurred in a rock cut slope of highway construction site in Boeun. This area is considered as unstable since the discontinuities whose orientations are similar to the orientation of the failure plane, are observed in many areas. Therefore, several analysis techniques such as SMR, stereographic analysis, limit equilibrium, numerical analysis, which are commonly used in rock slope stability analysis, are adopted in this area. In order to analyze the stress redistribution and nonlinear displacement caused by cut, which are not obtained in limit equilibrium method, the UDEC and shear strength reduction technique were used in this study Then the factors of safety evaluated by shear strength reduction technique and limit equilibrium were compared. In addition, the factor of safety under fully saturated slope condition was calculated and subsequently, the effect of the reinforcement was evaluated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.393-401
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• 2021

In this paper, we proposed a numerical model based on moment-curvature, to evaluate the resistance of reinforced concrete (RC) members subjected to blast loading. To consider the direct shear failure mode, we introduced a dimensionless spring element based on the empirical direct shear stress-slip relation. Based on the dynamic increase factor equations for materials, new dynamic increase factor equations were constructed in terms of the curvature rate for the section which could be directly applied to the moment-curvature relation. Additionally, equivalent bending stiffness was introduced in the plastic hinge region to consider the effect of bond-slip. To verify the validity of the proposed model, a comparative study was conducted against the experimental results, and the superiority of this numerical model was confirmed through comparison with the analytical results of the single-degree of freedom model. Pressure-impulse (P-I) diagrams were produced to evaluate the resistance of members against bending failure and direct shear failure, and additional parametric studies were conducted.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.78-88
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• 2012

Previous construction failure researches were focused on the utilization plan based on failure information and development of failure classification. However, it has limitation to set up the plan for prevention of construction failure due to the lack of the number of on-site staffs. In order to prevent effectively construction failure, a prevention plan should be established through quantitative evaluation of failure causes. The purpose of this study is to suggest the assessment method for selection Critical Management Factor(CMF) and to analyze the CMF on the apartment structural framework using FMEA(Failure Mode and Effective Analysis) which is one of the methods of quantitative evaluation. The element of risk evaluation separated degree of failure risk and prevention respectively. The assessment method for selection of CMF can be utilized for planning proactive solutions on the failure, and it can be also selected critical factors about each project phases, type of facility and construction work.

• Korea Journal of Hospital Management
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• v.1 no.1
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• pp.136-153
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• 1996

The purpose of this study is to identify the factors hindering hospital reengineering project in one university hospital. The data was collected by the self-administered Questionnaire to 288 members of the hospital in Pusan on April 5-18, 1996. This study took some statistical methodologies, such as descriptive analysis, factor analysis and logit model analysis. The results were as follows; First, in the descriptive analysis for whether the hospital reengineering named RUSH94 was a success or not, the subjects judged that it was not successful and regarded their fable mutual communication as the main factor. Second, in the reason of failure at the reengineering project, the group who thought that the failure factor was the lack of mutual consensus checked the scores of the first factor produced from the factor analysis.

• Journal of Chest Surgery
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• v.23 no.2
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• pp.275-284
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• 1990

A serious problem after cardiovascular surgery known as Multiple Organ Failure[MOF] whereby several vital organs successively demonstrate dysfunction in spite of intensive postoperative treatment has recently arisen. We have made a retrospective study of the clinical records of 137 patients who underwent cardiovascular surgery during past two years [1987-1988]. Fourteen patients [10%] developed multi-organ failure postoperatively with the results of seven death [50%]. In fatal group, preoperative poor cardiac function [Cardiac Index<2.0L/min/m2] was considered important prognostic factor and infection 5 disseminated intravascular coagulation complicating gastrointestinal bleeding were the leading cause of death. In conclusion, evaluation of multiple factors concerning multi-organ failure demonstrates preoperative poor functional preservation of vital organs is the main factor. So early diagnosis k management for each of the failing organs & prevention of infection are mandatory of the treatment of these critically ill patients.