• Korean Journal of Social Welfare Studies
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• v.43 no.1
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• pp.275-304
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• 2012

This study explores the case manager's experiences in terms of how they were challenged by the difficulties of the case management process, overcame them, and obtained the positive outcomes. Qualitative methodologies were used, employing a focus group interview with 10 case managers. The findings suggest that case managers were aware of the importance of strength among clients and communities. Case managers commented that they tried to actualized the principles of Strength Case Management, thereby facing the changes and growths among clients and communities. Several suggestions were made for the effective settlement of Strength Case Management.

• Journal of Korean Society for Quality Management
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• v.24 no.3
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• pp.19-30
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• 1996

We treat problems of estimating reliability R(t) = P[Y(t) ＞ X(t)] in the time dependent strength-stress model in which a unit of stress X(t) is subjected to environmental strength Y(t) at time t. In this paper we introduce a special model of R(t) with fixed strength and unaccumulated stress case, and propose a Mann-Whitney-Wilcoxon type estimator of R(t).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.101-104
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• 2004

If predicting of compressive strength of construction in construction field at early age is possibile, rational strength management & schedule plan is possible. With method for predicting strength of concrete, many researchers have been making study of maturity method. On the other hand, nowadays rationalization of construction capacity and reduction of a term of works due to improvement of construction capacity and application of a new method of construction is gathering strength with important issue. In accordance with this present condition, construction is being progressed in winter, but proper construction mothed and countermeasure for strength management is not established in case of winter construction. Therefore to investigate application in construction field at winter of strength prediction model that developed at former study, this study aim to measure application of developed strength prediction model through manufacture of mock-up concrete according to kind of strength level at 5$^{\circ}C$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.79-82
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• 2008

It has been reported that destruction test by core collection is the most reliable of the structural concrete strength in present building construction field. But it causes low efficiency by damage and cutting in structure due to the core collection. It also has some problems in repairing. Additionally in case of strength test with management specimen, different environment compared to the structure environment cause problems about estimation precise structure strength. Therefore, it is required to develop structure direct strength test that has test values and credibility above the ones obtained by core specimen collection strength test and seasonal specimen test to suggest a reasonable and practical management method of structural concrete.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.129-147
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• 1990

This study is to refer to the optimization problems when the stress and strength follow the time dependent model, considering a decision making process in the design methodology from reliability viewpoint. Reliability of a component can be expressed and computed if the probability distributions for the stress and strength in the time dependent case are known. The factors which determine the parameters of the distributions for stress and strength random variables can be controlled in design problems. This leads to the problem of finding the optimal values of these parameters subject to resources and design constraints. This paper is to present techniques for solving the optimization problems at the design stage like as minimizing the total cost to be spent on controlling the stress and strength parameters for random variables subject to the constraint that the component must have a specified reliability, alternatively, maximizing the component reliability subject to certain constraints on amount of resources available to control the parameters. The derived expressions and computations of reliability in the time dependent case and some optimization models of these cases are discussed. The special structure of these models is exploited to develop the optimization techniques which are illustrated by design examples.

• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.509-526
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• 2016

Purpose: We would like to find the alternative method for the weathering test on rubber coated fabrics and adhesive-coated fabrics for the military products, KS M 0706 (Sunshine carbon arc) to KS M ISO 4892-2 (Xenon arc). Methods: We measured the tensile strength of adhesive-coated fabrics and adhesive products treated with sunshine carbon arc and xenon arc during 100, 150 and 200 hours, respectively. All of the results were treated with statistical test, ANOVA method. We also validate the surface modifications caused by treatment method and time by using FT-IR ATR and, SEM. Results: In case of the thick adhesive-coated fabrics (app. 1 mm), there was no distinctive difference on tensile strength by treatment method and time. In case of the thin mask hood (app. 0.22 mm) and TENT (app. 0.5 mm), there was distinctive difference on tensile strength. Especially, carbon arc showed a huge lowering properties. We could validate the curing from light and moisture, and the functional group change from cross-linking and oxidation using FT-IR ATR. In case of IBS, there was a surface cracks on SEM images. In case of mask hood, there was no distinctive differences, except for a particle falling from decreased affinity between rubber and particles caused by carbon arc. Conclusion: We concluded that there was no problems for changing xenon arc weathering test with same treatment time on IBS, KM7, K21 and adhesive products. In case of TENT and mask hood, there was a difference in tensile strength in accordance with the change of the treated time and method.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.69-86
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• 2020

Purpose: This study aims to determine the optimal conditions for the spot welding process that mechanically connects the case of a cylindrical secondary battery and the negative tab. Methods: We use 33 factorial design to derive the optimal conditions for the spot welding process. The pulling strength, the cross-sectional area of nugget, and the shock test life are selected as response variables, which can represent the resistance welding quality. The input variables are selected as the welding time, welding voltage, and pressure, which are the controllable factors in the spot welding process. Results: The main effects of welding time and welding voltage and the interaction effect of welding time and welding voltage are significant. Conclusion: The optimal conditions for the spot welding process to mechanically join the negative electrode tab of the cylindrical secondary battery and the battery case are developed. The result shows that the pulling strength is increased by 44% compared to before improvement under optimal conditions.

• Journal of the Korean Professional Engineers Association
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• v.33 no.1
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• pp.83-88
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• 2000

Taguchi developed and provided various independent methods for actual application in design of experiments. Taguchi method is described in philosophy, method and others related to quality management. This thesis is one of case studies for improving the bond strength of epoxy resin by Taguchi method which is applied as a optimum developing tool in six sigma management revolution in many companies.

• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.757-768
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• 2014

Purpose: In this paper we present a case study of developing fast curing adhesives for insulation material of LNG carriers using an extreme vertices design with four mixture components. Three material properties are considered - shear strength, viscosity, and tensile strength. In the optimization experiment, we used hardness instead of tensile strength due to shortage of specimens. Methods: We employ four-factor extreme vertices design with 19 runs and desirability function approach for simultaneously optimizing three responses. After selecting optimal condition of the mixture components, we do confirmation experiments to verify the reproducibility of the optimal condition under manufacturing circumstance. Results: Simultaneous optimal condition for the three responses, that is, shear strength, viscosity, and harness is obtained. At the optimal condition, confirmation experiments are executed in manufacturing circumstance. The variation for the shear strength is not satisfactory, which is due to the variation of the humidity. Conclusion: At the optimal condition three material properties are satisfactory. To reduce the variability for the shear strength, robust design is needed.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.993-996
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• 2008

It has been reported that destruction test by core collection is the most reliable of the structural concrete strength in present building construction field. But it causes low efficiency by damage and cutting in structure due to the core collection. It also has some problems in repairing. Additionally in case of strength test with management specimen, different environment compared to the structure environment cause problems about estimation precise structure strength. Therefore, it is required to develop structure direct strength test that has test values and credibility above the ones obtained by core specimen collection strength test and seasonal specimen test to suggest a reasonable and practical management method of structural concrete.