• Applied Science and Convergence Technology
• /
• v.26 no.2
• /
• pp.21-25
• /
• 2017

The shape of the reflection spectrum is complex and appears to overlap with several signals, because the surface state is uneven due to the natural oxide film, so that the spectrum becomes a complicated signal shape divided into regions 1 and 2 due to diffuse reflection. On the other hand, it is seen that the reflection spectrum after PEO surface treatment is overlapped with several signals. In addition, the reflectance of the energy band varies from 1.32 to 1.46 eV. Usually, the MgO-type oxide film was observed at an energy band of ~4.2 eV. The thickness of the oxide film was increased as the DC voltage was increased by the thin film thickness meter (QuaNix; 7500M) after Plasma Electrolytic Oxidation (; PEO) surface treatment. This is because the higher the DC voltage, the easier the binding of the $OH^-$ ions in the solution solution and the $Mg^+$ ions of the magnesium alloy. An important part of the bonding of ordinary ions is the energy source (plasma) which can promote bonding. However, when a certain threshold voltage or more is applied, the material is adversely affected. The oxide film of the surface may be destroyed without increasing the thickness of the oxide film, that is, whitening of the material may occur.

• Industrial Engineering and Management Systems
• /
• v.4 no.1
• /
• pp.36-46
• /
• 2005

In traditional production lines, such as assembly lines, each worker is usually assigned to a fixed task, which is beneficial since it reduces the amount of training needed for workers to master their assigned tasks. However, when workers complete their tasks at different speeds, the slowest worker will determine the overall pace of the production line and limit production. To avoid this problem, the self-balancing production line was introduced. In this type of production line, each worker works dynamically, thus they can maintain balanced production. Previous research analyzing the performance of these lines has ignored the walk-back time associated with dynamic workers. U-shaped production lines have also been analyzed and policies for such lines have been proposed. However, the walk-back time cannot be ignored in practice, and research taking this factor into account is needed to enable balanced production and thus the maximum production rate. In this paper, we propose production policies for a production line with the walk-back time taken into account, and define and analyze the conditions for self-balancing. Furthermore, we have compared the performance of such a line with that of other production lines under the same conditions, and the results show the superiority of this line in certain cases.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.5 no.2
• /
• pp.63-69
• /
• 2001

In this study, we shall be concerned with computing in parallel a few of the smallest eigenvalues and their corresponding eigenvectors of the eigenvalue problem, $Ax={\lambda}Bx$, where A is symmetric, and B is symmetric positive definite. Both A and B are large and sparse. Recently iterative algorithms based on the optimization of the Rayleigh quotient have been developed, and CG scheme for the optimization of the Rayleigh quotient has been proven a very attractive and promising technique for large sparse eigenproblems for small extreme eigenvalues. As in the case of a system of linear equations, successful application of the CG scheme to eigenproblems depends also upon the preconditioning techniques. A proper choice of the preconditioner significantly improves the convergence of the CG scheme. The idea underlying the present work is a parallel computation of the Multi-Color Block SSOR preconditioning for the CG optimization of the Rayleigh quotient together with deflation techniques. Multi-Coloring is a simple technique to obatin the parallelism of order n, where n is the dimension of the matrix. Block SSOR is a symmetric preconditioner which is expected to minimize the interprocessor communication due to the blocking. We implemented the results on the CRAY-T3E with 128 nodes. The MPI(Message Passing Interface) library was adopted for the interprocessor communications. The test problems were drawn from the discretizations of partial differential equations by finite difference methods.

• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.2
• /
• pp.1-7
• /
• 2008

This paper presents a method to design a repetitive controller that is robust to variations in the system parameters. The uncertain parameters are specified probabilistically by their probability distribution functions. Instead of working with the distribution functions directly, the repetitive controller is designed from a set of models that are generated from the specified probability functions. With this multiple-model design approach, any number of uncertain parameters that follow any type of distribution functions can be treated. furthermore, the controller is derived by minimizing a frequency-domain based cost function that produces monotonic convergence of the tracking error as a function of repetition number. Numerical illustrations show how the proposed multiple-model design method produces a repetitive controller that is significantly more robust than an optimal repetitive controller designed from a single nominal model of the system.

• Journal of Industrial Convergence
• /
• v.2 no.1
• /
• pp.139-158
• /
• 2004

The purpose of this study is to examine antecedents and outcomes of trust toward supervisor in organization. The model is developed by reviewing previous research providing various perspectives. Antecedents consisted of three trustworthy behaviors - ability, benevolence, integrity - and three transformational leader behaviors - performance management, motivation, team-orientation -, and job satisfaction and organizational commitment is used outcome variables of trust. Data was collected from 206 employees in 6 organizations in broadcasting industry, using self-report questionnaire. Study finding is as following. First, trust in model was composed by 2 type - affect-based trust and cognition-based trust -, not divided in empirical analysis. Second, regression analysis for trust carry out independently, jointly with trustworthy behaviors and leadership behaviors. In antecedents of trust trustworthy behaviors, ability and benevolence has positive effects to trust, integrity has negative relationship with trust. It was high correlation between trustworthy behavior and leadership behavior. Especially, it has highly correlate(correlation efficient 0.69) between ability and team-orientation that influences trust strongly. Third, trust was not significant relationship with individual variables such as age, period with supervisor. Only, it found significant gap in variables and found out different relationship between variables among organizations distinctly. Fourth, job satisfaction and organizational commitment was positive influenced by trust and found out strong relationship between trust and organizational commitment.

• Journal of Industrial Convergence
• /
• v.19 no.4
• /
• pp.9-15
• /
• 2021

The purpose of the study is to find out the difference between high school students' hopes and the school happiness of each cluster of grits. Method: 282 high students' responses were analyzed through correlation analysis and cluster analysis. Results: First, There is a positive correlation between hope and grit and school happiness. Second, Hope and Grit appeared in four clusters. School happiness had the highest "high psychological capital" group and the lowest "low psychological capital. Conclusion: It was discussed that the agency thinking and effort perseverance of grit should be reflected in the curriculum of general high schools. In addition, we propose to develop questionnaires for practical measurements.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.6
• /
• pp.100-106
• /
• 2012

Recently, the demand to acquire and improve durability performance has steadily risen in rubber components design. In design process of a rubber component, an analytical prediction is the most effective way to improve fatigue life. Existing methods of analytical estimation have mainly used an equation for fatigue life obtained from fatigue test data. However, such formula is rarely used due to costs and time required for fatigue testing, as well as randomness of rubber materials. In this paper, we describe fatigue life estimation of rubber component using only the results from a relatively simple tearing test. We estimated fatigue life of the Janggu type fatigue specimen and the automotive motor mount, and evaluated reliability of the proposed method by comparing the estimated values with actual test results.

• Journal of Korea Multimedia Society
• /
• v.22 no.5
• /
• pp.626-637
• /
• 2019

Due to the rapid development of computer and digital technologies, those technologies were used in advertising. In order to meet the needs of marketing, a virtual space or character using 3D graphic augmented reality technology was developed and applied to advertisement. This study analyzed the characteristics of augmented reality in terms of interface design and spatial expression of augmented reality through case study. Firstly, we wanted to find the relationship between the types of the augmented reality advertisement and interface effects. Secondly, we wanted to find the spatial expression methods. The sample survey case studies based on 42 articles from 2012 to 2018 using Chinese and Korean site sharing augmented reality advertisement. The results of the case studies were divided into two parts. Firstly, the relationship between augmented reality types and interface effects were found basing on the augmented reality index. It means that the augmented reality index can be illustrated by using the augmented reality type. Simultaneously, the augmented reality type can be illustrated using the interface effect. The second part was that the types of display were used as a spatial representation. And the results showed that mobile display and public place display were the most frequently used.

• Journal of Engineering Education Research
• /
• v.24 no.3
• /
• pp.42-49
• /
• 2021

This paper deals with the development and application of a 3D printing education program implemented to cultivate creative fusion-type talents required by the 4th Industrial Revolution. Specifically, the entire process developed by applying the ADDIE program development model, from 3D modeling to post-processing of printed materials, was performed individually and for each team for about 200 second-year college students for two weeks. Through this program, students develop the basic ability to apply 3D printing to the learning curriculum, the ability to solve problems through cooperative interactions between team members, and convergence thinking ability by collaborating within the team by students from various major fields. They are proved by analyzing an education satisfaction survey conducted after application of the program. In conclusion, the program of this paper presents a methodology for effective 3D printing education in universities.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.2
• /
• pp.51-57
• /
• 2017

The first thing to be prioritized is to set the scope of the management system when establishing an information security management system for systematic and effective information security management. It is important to set the scope for an organization's information security goals due to the scope affects the organization's overall information security activities. If the scope is set incorrectly, it might become impossible to protect important services and therefore, the scope of the management system should be determined in consideration of the core business services of the organization. We propose a core service selection model based on the organization's mission-critical service and high risk service in order to determine the effective information security management system scope in this paper. Core service selection criteria include the type of service, contribution to sales, socio-economic impact, and linkage with other services.