• 한국공작기계학회논문집
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• 제13권4호
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• pp.16-22
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• 2004

Shape optimization was performed to obtain the precise shape of cutouts including the internal shape of cutouts in laminated composite plates by three dimensional modeling using solid element. The volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. The volume control of the growth-strain method makes Tsai-Hill failure index at each element uniform in laminated composites under the initial volume. Then shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminated composite plate, (2) The optimal shapes on the various load conditions and cutouts were obtained, (3) The maximum Tsai-Hill failure index was reduced up to 67% when shape optimization was performed under the initial volume by volume control of growth-strain method.

• Steel and Composite Structures
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• 제15권4호
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• pp.357-377
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• 2013

In order to study the degradation and damage behaviors of steel frame welded connections, two series of tests in references with different connection constructions were carried out subjected to various cyclic loading patterns. Hysteretic curves, degradation and damage behaviours and fatigue properties of specimens were firstly studied. Typical failure modes and probable damage reasons were discussed. Then, various damage index models with variables of dissipative energy, cumulative displacement and combined energy and displacement were summarized and applied for all experimental specimens. The damage developing curves of ten damage index models for each connection were obtained. Finally, the predicted and evaluated capacities of damage index models were compared in order to describe the degraded performance and failure modes. The characteristics of each damage index model were discussed in depth, and then their distributive laws were summarized. The tests and analysis results showed that the loading histories significantly affected the distributive shapes of damage index models. Different models had their own ranges of application. The selected parameters of damage index models had great effect on the developing trends of damage curves. The model with only displacement variable was recommended because of a more simple form and no integral calculation, which was easier to be formulated and embedded in application programs.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.84-89
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• 2005

The design of composite joint is a very important research area because they are often the weakest areas in composite structures. In this paper, the failure load of the mechanically fastened composite joint with the clamping force was predicted by the failure area index method. By the suggested failure area index method, the strength of the mechanically fastened composite joint could be predicted within 22.5% when clamping force was applied to the composite joint.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.79-82
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• 2003

With the wide application of fiber-reinforced composite material in aero-structures and mechanical parts, the design of composite joint have become a very important research area because they are often the weakest areas in composite structures. In this paper, the failure area index method to predict the failure load of the mechanically fastened composite joint was used and the prediction accuracies of the linear finite element analysis were compared with those of nonlinear finite element analysis.

• 대한한방부인과학회지
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• 제26권1호
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• pp.109-120
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• 2013

Objectives: The purpose of this study is to report the effects of oriental medicine on 2 patients with premature ovarian failure. Methods: The patients who had amenorrhea caused by premature ovarian failure were treated by oriental medicine such as herb medication, acupuncture and moxibustion. We evaluated the results of treatments by change of symptoms, serum hormone assay, basal body temperature and Kupperman's Index. Results: After oriental medicine, the patients could have their normal menstrual cycle. Also serum hormone assay, basal body temperature and Kupperman's Index were improved. Conclusions: This study shows that oriental medicine has effects on patients with premature ovarian failure. And serum hormone assay, basal body temperature and Kupperman's Index would be valid measurement to evaluate the effect of treatments for premature ovarian failure.

• 해양환경안전학회지
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• 제26권3호
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• pp.227-232
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• 2020

This paper develops a risk index based on an indicator of risk assessment in terms of coastal activity location and accident type. The risk index is derived from a formula which adds the consequence of failure to a vulnerability value, then subtracts the mitigation value. Specifically, the consequence of failure is the number of casualties in coastal activity locations. An indicator of vulnerability refers to coastal environment elements and social elements. A pointer of mitigation includes managerial and organizational elements that indicate the capabilities of coastal activities. A risk rating of coastal activity location is found from a risk matrix consisting of the accident location and type. The purpose of this study is to prevent accidents at coastal activity locations by allowing the Coastal police guard to monitor effectively and inform visitors of potential risks.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.275-280
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• 2004

Shape optimization was performed to obtain the precise shape of cutouts including the internal shape of cutouts in laminated composite plates by three dimensional modeling using solid element. The volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. The volume control of the growth-strain method makes Tsai-Hill failure index at each element uniform in laminated composites under the initial volume. Then shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study. (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminate composite, (2) The optimal shapes of the various load conditions and cutouts were obtained, (3) The maximum Tsal-Hill failure index was reduced up to 67% when shape optimization was peformed under the initial volume by volume control of growth-strain method.

• Geomechanics and Engineering
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• 제12권2호
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• pp.313-326
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• 2017

Based on the reliability theory and limit analysis method, the roof stability of a shallow tunnel is investigated under the condition of surface settlement. Nonlinear Hoek-Brown failure criterion is adopted in the present analysis. With the consideration of surface settlement, the internal energy and external work are calculated. Equating the rate of energy dissipation to the external rate of work, the expression of support pressure is derived. With the help of variational approach, a performance function is proposed to reliability analysis. Improved response surface method is used to calculate the Hasofer-Lind reliability index and the failure probability. In order to assess the validity of the present results, Monte-Carlo simulation is performed to examine the correctness. Sensitivity analysis is used to estimate the influence of different variables on reliability index. Among random variables, the unit weight significantly affects the reliability index. It is found that the greater coefficient of variation of variables lead to the higher failure probability. On the basis of the discussions, the reliability-based design is achieved to calculate the required tunnel support pressure under different situations when the target reliability index is obtained.

• 대한임상독성학회지
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• 제18권2호
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• pp.116-122
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• 2020

Acute respiratory failure is an important risk factor for mortality in patients with acute pesticide poisoning. Therefore, it is necessary to investigate the risk factors to predict respiratory failure in these patients. This study retrospectively investigated the clinical features of respiratory failure among patients with acute pesticide poisoning requiring mechanical ventilation. This study included patients who were admitted with intentional poisoning by pesticide ingestion from January 2017 to December 2019. Paraquat intoxication was excluded. Among 469 patients with acute pesticide poisoning, 398 patients were enrolled in this study. The respiratory failure rate was 30.4%. The rate of respiratory failure according to the type of pesticide was carbamate (75.0%), organophosphate (52.6%), glufosinate (52.1%), glyphosate (23%), pyrethroid (8.9%), and others (17%). The mortality was 25.6% in the respiratory failure group. The risk factors for respiratory failure were old age, low body mass index, and ingestion of more than 300 mL. In conclusion, respiratory failure is a risk factor for mortality in pesticide poisoning. Old age, low body mass index, and ingestion of more than 300 mL are the risk factors for predicting respiratory failure.

• 한국임상수의학회지
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• 제23권4권
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• pp.427-431
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• 2006

Pulse Doppler ultrasonographic evaluation was performed to investigate the resistive index (RI) of the Interlobar renal artery in 17 dogs (32 kidneys) which were diagnosed with an acute renal failure caused by ochratoxin-A and citrinin contaminated commercial diet. RI was investigated in 7 normal beagle dogs and recovered patients. The mean of RI was resulted as $0.69{\pm}0.04$ in normal dog, however, significantly (p<0.001) increased as $0.76{\pm}0.05$ in renal failure dog. But RI had no relationship with the results of blood chemistry, urine analysis, and excretory urographic image quality. From these results, even though the results of the renal function test were within a normal reference range, it was considered that RI index is more reliable to represent a damaged renal parenchyma, and may have the potential to be a useful clinical tool in monitoring of the renal function.