• Journal of Advanced Marine Engineering and Technology
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• v.25 no.5
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• pp.1086-1090
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• 2001

In this paper, a method deciding the permissible gains of the P and PT controllers for a retarded process under stable condition is proposed. For analysis, the controlled process is assumed to be first-order system with time delay. At first, the adjustable parameter sets causing stability limit are obtained based on the frequency domain condition which makes the roots of the characteristic equation locate on the imaginary axis. And the cut-in frequency ${\omega}_p$ to bring the parameter set to P control from PI control is derived is derived in terms of L and $T_m$ then ${\omega}_p$ is used to compute the maximum gain with stable condition. The results indicate that the permissible controller gains can be described by a unique if parameters L and $T_m$ are know.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.18-24
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• 2009

The most dominate aspect in machine works using CNC devices in industrial production processes is the precision of the product and the Cycle Time. To this day, many studies on the external factors of the technology to reduce the Cycle Time have advanced amid to the advancements in cam soft development for manual programs and the numerous studies on high speed and precision machining. This study experimented various functions of the sequence pattern flow and arranged system development technologies of past few years to develop and applicate various usage of adjustment factors within the CNC, so it would be more understandable to the user and would enable them to make high speed and precision products more faster develop and. In order to reduce the Cycle Time, the mechanism of machine tools has to be analysed and applied, in addition to program reduction and improvement of the manufacture process.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.69-78
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• 2001

This paper presents a process and operation planning system and an NC code post-processor for effective machining of press dies for production of cars. Based on the machining feature, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor adjusts feedrates along the tool path to reduce machining time while maintaining the quality. The adjustment rule is selected based on the machining load estimated by virtual machining.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.47-57
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• 2005

We conducted a content analysis of the researches published for a 7-year period (1997-2003) in the Korean Journal of Play Therapy (Korean Association for Play Therapy) and The Journal of Play Therapy (Korean Association of Psychological Rehabilitation for Children). Specifically, we analyzed a total of 156 articles for research contents, instruments, subjects, statistical analytic methods, and references. The results of the study are as follows: First, the principal areas of research activity and publication were specific theoretical review, personality, and adjustment research. Most outcomes, processes, and outcome researches were conducted in a form of case study. Second, typical samples contained 4 to 6 year old children or elementary schoolers. A lot of them were counseling center clients or normally adapted children. Third, 37% of the articles used ANOVA-related statistical analytic methods, and 35% of them used descriptive statistical analytic methods. Lastly, many articles averagely cited foreign references written 11 years prior to domestic references.

• Journal of the Korean Society of Costume
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• v.44
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• pp.77-89
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• 1999

The present study aims at developing standardized patterns of ready-made Korean traditional costume for women in twenties and at suggesting classified standards so that consumers can buy high quailty clothes easily without dissatisfaction on unsuitable measurments. It was found from the dressing experiment results that new-concept patterns of Korean jackets onsidering women's bodies were seriously required because jackets fabricated by conventional patterns were not properily fitted to their bodies. During the processes of patten development, dressing experiment, and subsequent pattern adjustment, measurment standards classified by women's bodies were established, and new standardized patterns were developed in accordance with characteristics of women's bodies. These findings suggested that future studies on the pattern modification should be achieved continuously in consideration of ages, tastes, and fashions of modern women consumers.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.137-144
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• 2016

This paper aims to ensure describe the a spring-back prevention technique for improving shape fixability by using an ultra-high strength steel sheet with 980 MPa to develop a lightweight seat rail parts. Ultra-high strength steel gives a potential for considerable weight reduction and a cost-effective way to produce energy efficient vehicles. The influence of a spring-back of seat rail parts on the shape fixability in forming processes was investigated to be solved by an adjustment of the appropriate tool design and process parameters. The computed results for improving shape fixability were in good agreement with the experimental results.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.644-649
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• 2006

In this paper, a methodology for estimating the model parameters of a discrete-time system and tuning a digital PID controller based on the estimated model and a genetic algorithm is presented. To deal with optimization problems regarding parameter estimation and controller tuning, pseudo-parallel genetic algorithms(PPGAs) are used. The parameters of a discrete-time system are estimated using both the model adjustment technique and a PPGA. The digital PID controller is described by the pulse transfer function and then its three gains are tuned based on both the model reference technique and another PPGA. A set of experimental works on two processes are carried out to illustrate the performance of the proposed method.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.157-162
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• 2006

Recently, the humidity adjustment of indoor air is of great importance in air conditioning system as a applied, in buildings, vehicles, and containers for storage and transport of perishable products. Membrane dehumidification or air is potentially attractive because it offers low capital and operating costs, along with low energy consumption. And membrane dehumidification process attracted the attention of the public instead of the other dehumidification processes, such as adsorption, absorption, and refrigeration cycles and so on. In this study, the prepared hydrophilic inorganic membrane-based dehumidifiers(membrane air dehumidification) examined the performance of dehumidification. The surface-modified inorganic membrane prepared in this study showed high dehumidification efficiency(over 80%). The membrane might be very useful for dehumidification industries.

• Korean Journal of Human Ecology
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• v.24 no.2
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• pp.171-184
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• 2015

This study is aimed at proposing and managing a program to foster married immigrant women who have bilingual-bicultural abilities. Four stages of research processes were followed. Firstly, bilingual teacher training was contemplated field experience and preceding research. Secondly, specialist groups reviewed and verified considerations of content validity. Thirdly, seventeen valid participants were selected and they worked on programs of ten sessions. Fourthly, the effectiveness of the program was verified through a survey of satisfaction. This study has its significance as a program that reflects the theory and reality to establish their identity reinforce the capability and arouse the multi-cultural consciousness.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.643-645
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• 2000

This paper puts emphasis on navigation in virtual environment, which is one of the major interfaces for the interactivity between human and virtual environment in virtual reality circumstances and worlds. It proposes a new navigation method: 2d Map-Based navigation, which prevents user's spatial lost in 3D Virtual Environment. The 2D Map-Based Navigation is composed of three major processes, Constant Velocity Navigation, Collision Detection and Avoidance, and Path Adjustment. The 2D Map-Based Navigation can reduce user's difficulties and improve user's sense of presence and reality in the virtual environments. The experiment study proved that the 2D Map-Based Navigation is a very natural, straightforward and useful navigation interface in the virtual environment.