• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.473-476
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• 2008

USN(Ubiquotous Sensor Network) has been applied to various fields of industries such as logistics, environment management, traffic management, as well as IT industries including home network and telematics. Among the important techniques required to implement aforementioned applications, location management scheme is essential. In this paper, we proposed and implemented a new location measurement scheme based on RSSI of sensor node for campus car location management.

• Management & Information Systems Review
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• v.1
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• pp.133-165
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• 1997

In the situation of Korean company today it is considered that the necessity of developing a corporate culture is not only more important than ever, but also indispensable to the organization management in the future. Focused on the development of corporate culture, the purpose of this study is to find out the influence of the direction of corporate culture development on its own strength. The method of this study is the empirical method based on theoretical one with the previous bibliographical studies. It is thought that in viewpoints of the culture pragmatists, the development of corporate culture means the intentional and systematic creation of culture. And, the direction of corporate culture development is thought as the management philosophy a corporate desires, or the desirous direction of corporate culture to express the management policy. According to the results of this study, it is found that the progressive direction of the corporate culture development has the most intensive influence on the various sides. Therefore, the management should research and develop the progressive value of culture more deeply, to get the effective development of corporate culture.

• Journal of Korea Multimedia Society
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• v.18 no.6
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• pp.753-762
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• 2015

As the computer graphic technology has developed rapidly, the management of visual effects production has also changed. However, the insufficient rest and the inefficiency of communication have resulted in more pressure which would weaken the strength of the whole team. For searching the possible solution, this research has applied the SCRUM in VFX production and analyzed the impact of SCRUM for VFX project management. SCRUM was first used in the projects of software development, but now there are already many successful examples of introducing SCRUM into their facilities in various fields. This paper has used SCRUM in the experimental group and present methodology in VFX project management in the control group for the same project. Based on the analysis of the questionnaire investigation from both group with using t-test for data analysis, it has confirmed the credibility of the questions in the questionnaire index as α > 0.72. With the result of analysis based on the corresponding samples of the t-test, it shows the diversity of SCRUM for project management, and the convenience of communication within the team can enhance the team strength. Follow-up research will attend to provide more suggestions for applying SCRUM in other areas in project management.

• International Journal of Reliability and Applications
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• v.8 no.1
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• pp.111-124
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• 2007

In this paper, we apply insightful statistical reliability tools to manage and seek improvements in the strengths of Oriented Strand Board (OSB). As a part of the OSB manufacturing process, the product undergoes destructive testing at various intervals to determine compliance with customers' specifications. Workers perform these tests on sampled cross sections of the OSB panel to measure the tensile strength, also called internal bond (IB), in pounds per square inches until failure. Additional stiffness strength tests include parallel and perpendicular elasticity indices (EI), which are taken from cross sectional samples of the OSB panel in the parallel and perpendicular directions with respect to the orientation of the wood strands. We explore both graphically and statistically these "pressure-to-failures" of OSB. Also, we briefly comment on reducing sources of variability in the IB and EI of OSB.

• International Journal of Reliability and Applications
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• v.7 no.2
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• pp.177-186
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• 2006

Typical confidence intervals for a mean or mean residual life (MRL) are centered about the mean or mean residual life. We discuss novel confidence intervals that produce statements like "we are 95% confident that the MRL function, e(t), is greater than a prespecified $\mu_o$ for all t in the interval [0, $\hat{\theta})$)" where $\hat{\theta}$ is determined from the sample data, confidence level, and $\mu_o$. Also, we can have statements like 'we are 95% confident that the MRL of population 1, namely $e_1$(t), is greater than the MRL of population 2, $e_2$(t), for all t in the interval [0, $\hat{\theta}$)" where $\hat{\theta}$ is determined from the sample data and confidence level. We illustrate these one and two sample confidence intervals on internal bonds (tensile strengths) for an important modem engineered wood product, called medium density fiberboard (MDF), used internationally.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.169-176
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• 2007

Recently, construction industry has been magnified while various cooperative relationship makes steady process. So importance of management during construction is gathering strength. Therefore, we need systematic management gradually. But almost management of construction industry that performs these day is focused on construction phase not design phase. The purpose of the present study is to find the effective way of design management with enhancing the process of design phase.

• Computers and Concrete
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• v.12 no.6
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• pp.755-774
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• 2013

Considering the well known environmental issues of cement manufacturing (direct and indirect levels of $CO_2$ emissions), clinker replacement by supplementary cementing materials (SCM) can be a very promising first step in reducing considerably the associated emissions. However, such a reduction is possible up to a particular level of SCM utilization, influenced by the rate of its pozzolanic reaction. In this study a (4-step) structured methodology is proposed in order to be able to further adjust the concrete mix design of a particular SCM, in achieving additional reduction of the associated levels of $CO_2$ emissions and being at the same time accepted from a derived concrete strength and service life point of view. On this note, the aim of this study is twofold. To evaluate the environmental contribution of each concrete component and to provide the best possible mix design configuration, balanced between the principles of sustainability (low environmental cost) and durability (accepted concrete strength and service life ). It is shown that such a balance can be achieved, by utilising SCM by-products in the concrete mix, reducing in this way the fixed environmental emissions without compromising the long-term safety and durability of the structure.

• Journal of the Korean Society for information Management
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• v.27 no.3
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• pp.265-281
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• 2010

The proposed method in this study is the Maximal Concept-Strength Recognition Method(MCR). In case that we don't know which database is the most suitable for automatic-classification when new database is imported, MCR method can support to select the most similar database among many databases in the legacy system. For experiments, we constructed four heterogeneous scholarly databases and measured the best performance with MCR method. In result, we retrieved the exact database expected and the precision value of MCR based automatic-classification was close to the best performance.

• Journal of Korean Society for Quality Management
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• v.9 no.1
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• pp.3-11
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• 1981

A stress-strength model is formulated for s of k systems consisting of identical components. We consider minimum variance unbiased (MVU) estimation of system reliability for data consisting of a random sample from the stress distribution and one from the strength distribution when the two distirubtions are Weibull with unknown scale parameters and same known shape parameter. The asymptotic distribution of MVU estimate of system reliability in the model is obtained by using the standard asymptotic properties of the maximum likelihood estimate of system reliability and establishing their equivalence. Uniformly most accurate unbiased confidence intervals are also obtained for system reliability. Empirical comparison of the two estimates for small samples is studies by Monte Carlo simulation.