• Journal of Mechanical Science and Technology
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• 제20권4호
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• pp.473-481
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• 2006

Predicting fatigue life by numerical methods was almost impossible in the field of rubber materials. One of the reasons is that there is not obvious fracture criteria caused by nonstandardization of material and excessively various way of mixing process. But, tearing energy as fracture factor can be applied to a rubber-like material regardless of different types of fillers, relative to other fracture factors and the crack growth process of rubber could be considered as the whole fatigue failure process by the existence of potential defects in industrial rubber components. This characteristic of fatigue failure could make it possible to predict the fatigue life of rubber components in theoretical way. FESEM photographs of the surface of industrial rubber components were analyzed for verifying the existence and distribution of potential defects. For the prediction of fatigue life, theoretical way of evaluating tearing energy for the general shape of test-piece was proposed. Also, algebraic expression for the prediction of fatigue life was derived from the rough cut growth rate equation and verified by comparing with experimental fatigue lives of dumbbell fatigue specimen in various loading condition.

• 한국수산경영학회:학술대회논문집
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• 한국수산경영학회 2007년도 추계학술발표회 및 심포지엄
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• pp.167-184
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• 2007

The objectives of this paper are to identify the causes of the corporate distress and to develop a distress prediction model with the financial information in fishery industry. In this study, the corporate distress is defined as economic failure and technical insolvency. Economic failure occurs by reduction, shut-down, or change of the business and technical insolvency results from failure to pay the financial debt of companies. The 33 distressed firms from 1991 to 2003 were composed by 14 economic failure companies, 15 technical insolvency companies. 4 companies applied to the both cases. The analysis of distress prediction of fishery companies were accomplished according to the distress definition. The analysis was carried out as two steps. The first step was the univariate analysis, which was used for checking the prediction power of individual financial variable. The t-test is used to identify the differences in financial variables between the distressed group and the non-distressed group. The second step was to develop distress prediction model with logistic regression. The variables showed the significant difference in univariate analysis were selected as the prediction variables. The financial ratios, used in the logistic regression model, were selected by backward elimination method. To test stability of the distress prediction model, the whole sample was divided as three sub-samples, period 1(1990$\sim$1993), period 2(1994$\sim$1997), period 3(1998$\sim$2002). The final model built from whole sample appled each three sub-samples. The results of the logistic analysis were as follows. the growth, profitability, stability ratios showed the significant effect on the distress. the some different result was found in the sub-sample (economic failure and technical insolvency). The growth and the profitability were important to predict the economic failure. The profitability and the activity were important to predict technical insolvency. It means that profitability is the really important factor to the fishery companies.

• 수산경영론집
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• 제39권2호
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• pp.61-79
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• 2008

The objectives of this paper are to identify the causes of the corporate distress and to develop a distress prediction model with the financial information in fishery industry. In this study, the corporate distress is defined as economic failure and technical insolvency. Economic failure occurs by reduction, shut - down, or change of the business and technical insolvency results from failure to pay the financial debt of companies. The 33 distressed firms from 1991 to 2003 were composed by 14 economic failure companies, 15 technical insolvency companies. 4 companies applied to the both cases. The analysis of distress prediction of fishery companies were accomplished according to the distress definition. The analysis was carried out as two steps. The first step was the univariate analysis, which was used for checking the prediction power of individual financial variable. The t - test is used to identify the differences in financial variables between the distressed group and the non - distressed group. The second step was to develop distress prediction model with logistic regression. The variables showed the significant difference in univariate analysis were selected as the prediction variables. The financial ratios, used in the logistic regression model, were selected by backward elimination method. To test stability of the distress prediction model, the whole sample was divided as three sub-samples, period 1(1990 - 1993), period 2(1994 - 1997), period 3(1998 - 2002). The final model built from whole sample appled each three sub - samples. The results of the logistic analysis were as follows. the growth, profitability, stability ratios showed the significant effect on the distress. the some different result was found in the sub - sample (economic failure and technical insolvency). The growth and the profitability were important to predict the economic failure. The profitability and the activity were important to predict technical insolvency. It means that profitability is the really important factor to the fishery companies.

• 한국군사과학기술학회지
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• 제16권5호
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• pp.675-682
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• 2013

Reliability analysis and prediction of next failure time is critical to sustain weapon systems, concerning scheduled maintenance, spare parts replacement and maintenance interventions, etc. Since 1981, many methodology derived from various probabilistic and statistical theories has been suggested to do that activity. Nowadays, many A.I. tools have been used to support these predictions. Support Vector Regression(SVR) is a nonlinear regression technique extended from support vector machine. SVR can fit data flexibly and it has a wide variety of applications. This paper utilizes SVM and SVR with combining time series to predict the next failure time based on historical failure data. A numerical case using failure data from the military equipment is presented to demonstrate the performance of the proposed approach. Finally, the proposed approach is proved meaningful to predict next failure point and to estimate instantaneous failure rate and MTBF.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.507-510
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• 2001

Brittle failure mechanism has been well known as growth of initial micro-damage, that causes macro crack and failure in the end. Several precise criteria are suggested recently, based on experiments values in a whole load range. Among them, Mohr-Coulomb's criterion is used widely these days, but it has a big error compared with the real failure behavior since it does not show reciprocal actions of stresses. In this study, a new brittle failure criterion is proposed, which includes the effects of brittle damage evolution by taking a brittle damage parameter specifically. Comparisons between the proposed model and the previous ones are also given.

• 동력기계공학회지
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• 제9권1호
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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.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.401-408
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• 2003

EPS(Expanded Polystyrene) has been used in a variety of applications as a solution of difficult soil conditions encountered in construction activities. Although there has been significant worldwide growth in the use of EPS as a lightweight fill material, it has a few failure cases before and after the construction. This paper described the observed failures of EPS structures up In date around the world. Also, method of quality control was proposed for site monitoring.

• Clinical and Experimental Pediatrics
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• 제54권7호
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• pp.277-281
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• 2011

Failure to thrive (FTT) is a term generally used to describe an infant or child whose current weight or rate of weight gains is significantly below that expected of similar children of the same age, sex and ethnicity. It usually describes infants in whom linear growth and head circumference are either not affected, or are affected to a lesser degree than weight. FTT is a common problem, usually recognized within the first 1-2 years of life, but may present at any time in childhood. Most cases of failure to thrive involve inadequate caloric intake caused by behavioral or psychosocial issues. The most important part of the outpatient evaluation is obtaining an accurate account of a child's eating habits and caloric intake. Routine laboratory testing rarely identifies a cause and is not generally recommended. FTT, its evaluation, and its therapeutic interventions are best approached by a multi-disciplinary team includes a nutritionist, a physical therapist, a psychologist and a gastroenterologist. Long term sequelae involving all areas of growth, behavior and development may be seen in children suffering from FTT. Early detection and early intervention by a multidisciplinary team will minimize its long term disadvantage. Appropriate nutritional counseling and anticipatory guidance at each well child visit may help prevent some cause of FTT.

• 치과방사선
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• 제28권1호
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• pp.285-297
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• 1998

This report details a case of 8-year-old girl showing failure of odontogenesis after chemo-radiation therapy for the rhabdomyosarcoma at the age of 4. The observed results were as follows : 1. Past history revealed that she had received for a total radiation dose of 4430cGy, 29 fractions in 6 weeks and chemotherapy with vincristine, actinomycin D and cytoxan, followed as maintenance phase for 2 years. 2. The patient was symptom -free and appointed for the treatment of multiple dental caries. 3. Oral examination showed hypoplastic enamel on whole erupted permanent teeth and showed retarded eruption. 4. Conventional radiograms showed failure of root development including abrupt cessation of root formation and root agenesis, and microdontia, missing teeth, irregular enamel, dislocation of the impacted teeth. Additional finding showed good healing bone pattern on the left mandibular ramus and angle area. 5. Cephalometric analysis revealed failure of bite raising due to incomplete eruption of all the first molars and made it possible to suspect entrapped mandibular growth and then Class II tendency growth. 6. There was correlation between the time of chemo-radiation therapy and the damage of the teeth.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 제4회 추계심포지움
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• pp.85-89
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• 1996

성장저해는 만성신부전 (chronic renal failure, CRF) 소아환자나 실험동물에게서 나타나는 합병증의 하나로, 그 발생기전이 잘 알려져 있지 않다. 성장저해를 일으키는 원인으로 비내분비적 요인 (metabolic acidosis, renal osteodystrophy, anemia)과 내분비적 요인의 복합적 결과로 생각하나, 비내분비적 요인들은 약물투여로 그 증세를 완화시켜도 성장저해에 대한 궁극적 치료효과는 나타나지 않는다. 따라서 성장 호르몬 (Growth Hormone, GH)이 관여하는 내분비적 요인의 변화에 그 병리기전이 있을 것으로 연구되어 왔다. GH는 직접적 성장 효과와 Insulin-like growth factor-1(IGF-I)을 간으로부터 유리시켜 나타나는 간접적 성장효과를 가지고 있다. 그런데 CRF환자의 GH 및 IGF-I 의 혈중 농도는 정상이거나, 흑은 오히려 증가상태에 있음에도 볼구하고 성장저해가 일어나는 것으로 보아, 환자의 말단기관 (end-organ)에 원인을 알 수 없는 저항성 (resistance)이 있다고 규정되어진다.