• Journal of Power Electronics
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• v.8 no.1
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.87-93
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• 2018

Ground source heat pump(GSHP) system is one of the high efficiency heat source systems which utilizes the constant geothermal energy of a underground water or soil. However, the design of conventional GSHP system in the domestic market is dependent on the experience of the designer and the installer, and it causes increase of initial installation cost or degradation of system performance. Therefore, it is necessary to develop a guideline and the optimal design method to maintain stable performance of the system and reduce installation cost. In this study, in order to optimize the GSHP system, design factors according to ground heat exchanger(GHX) type have been examine by simulation tool. Furthermore, the design factors and the correlation of a single U-tube and a double U-tube were analyzed quantitatively through sensitivity analysis. Results indicated that, the length of the ground heat exchanger was greatly influenced by grout thermal conductivity for single U-tube and pipe spacing for double U-tube.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.37-44
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• 2018

This research aims to suggest the composition of multi-functional furniture for single households, responding to the changes of consumption pattern caused by the recent trends of the single-person household living in a small residential space. It is expected that a multi-functional furniture for single households in the current context should be increased the efficiency of spaces. Using a customized questionnaire, we examined the preferences of multi-functional furniture composition for single households. A questionnaire was developed by collecting images using key words related to multi-functional furniture and analyzing the final images by multi-functionality, furniture classification system and behavior. The most preferred multi-functional furniture composition are counter-tops and chest of drawers, followed by chest of drawers and beds, counter-tops and tableware, lighting and beds, closets and drawers. This research contributes significantly in that it suggests the basic data of optimized flexible multi-functional furniture design for single-person household by linking various behaviors and furniture in the house.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.144-149
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• 1993

This paper discusses a design of a nonlinear control for a class of single-input double-output nonlinear mechanical systems. When conventional linearization methods are applied to the mechanical systems, some problems of oscillation and unstable phenomena arise. The proposed nonlinear control system resolves these problems. In this design the eigenvalues of the closed-loop nonlinear system are assigned to desired locations and local asymptotic stability of the closed-loop system. is guaranteed. The design method is applied to an inverted pendulum system with a moving weight mechanism. Experimental results show that the proposed nonlinear controller is more effective for stability than the usual linear controller.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.190-190
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• 2000

This paper presents a multirate state feedback control (MRSFC) method for systems sensitive to disturbance and noise based on the multirate estimator design using the current estimator. MRSFC updates the controller output slower than the measurement sampling frequency of system output by a lifting factor R=T$\sub$c//T$\sub$s/. The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system. The multirate estimator gain is obtained from solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system. Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.5
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• pp.258-265
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• 1985

A design method for a single-input single-output discrete time model reference adaptive system is described in this paper. By using the state-variable filters into inputs and outputs in reference model and unknown system, a simple adaptive structure which use all accessible signals can be constructed. Some papers for the adaptive shstem is which thw relative degree of unknown system have one or two have been reported, but the resulting adaptive system are intricate in structures and the design theories for the model reference adaptive system are not generalized. In this paper, for having two or more relative degrees, it has been verified that an adaptive scheme can be obtained by introducing a simple linear filter.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.534-544
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• 1995

Many electronic products employ menu-driven interfaces for user-system dialogue. Unlike the software user interfaces, a small single-line display, such as a Liquid Crystal Display, is typically used to present menu items. Since the display can show only a single menu item at a time, more serious navigation problems are expected with single-line display menus(SDM). This study attempts to provide a set of unique guidelines for the design of the SDM based on empirical results. A human factors experiment was conducted to examine the effects of four design variables: menu structure, user experience, navigation aid, and number of targets. The usability of design alternatives was measured quantitatively in four different aspects, which were speed, accuracy, inefficiency of navigation, and subjective user preference. The analysis of variance was used to test the statistical effects of the design variables and their interaction effects. A set of design guidelines was drawn from the results which can be applied to the design of human-system interfaces of a wide variety of electronic consumer products using such displays. Since more generalized guidelines could be provided by constructing prediction models based on the empirical data, some powerful performance models are also required for the SDM. As a preliminary study, a survey was done on the performance models for ordinary computer menus.

• Journal of Families and Better Life
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• v.20 no.6
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• pp.219-227
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• 2002

This study was conducted to examine housing preferences among single-person households and to propose guidelines for housing design choices for single people. One hundred and sixty responses to the questionnaire developed by this researcher were analyzed utilizing frequencies, percentages, and t-tests. There were significant differences between single households and non-single households in various aspects of housing preferences. Differences were found in the desired type and size of housing, needed amount of space, and the importance of space itself. Single persons wanted to live in a small apartment, about 83.45$m^2$ (25.29 pyung) size. They consider the bathroom and the master bedroom more important than the living room and kitchen. They prefer to have specifically function-oriented rooms such as shower, home office, computer room, exercise room, or leisure space. Single persons consider information-technological facilities within an apartment very important. They would like to adopt automatic and electronic technology in the house, such as optical communication network, automatic air-cleaning system, and internet TV. Housing preferences differ significantly according to socio-demographic variables such as gender and age. I propose in this study a small-sized, information-, high-tech- and leisure-oriented design that corresponds with the actual housing preferences of the single-person households.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5202-5207
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• 2011

A temperature control system is very important part in many industrial applications. Typical development procedures for temperature control system consist of several stages such as conceptual system design, construction of physical system, controller design based on the mathematical model for the system, and performance test. Since the mathematical model is usually obtained with the aid of system identification technique based on repeated experiments after construction of the physical system, the above procedures require very large amount of time and cost. It takes also large amount of time in the controller design and performance test procedures. In this paper, a virtual development scheme, which can predict the performance of the temperature control system prior to construction of physical system, for rapid validation of the initial system design is proposed. The effectiveness of the proposed scheme is shown by using SISO (Single Input Single Output) example.

• Korean Journal of Social Welfare
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• v.60 no.2
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• pp.175-209
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• 2008

The purpose of this study, which has its focus on the utilization of single-system design for practice evaluation, is to evaluate the effectiveness of cognitive behavioral therapy of depression by using a AB design. 3 inpatients in a local hospital with a diagnosis of major depressive disorder agreed to participate in this study. The AB design includes a 2weeks of the baseline phase and 3 weeks of the intervention phase. More than one outcome measures were used in order to validate the results of the measurement. Data were analyzed statistically as well as visually. Tools such as trend line and trend index were used to improve the accuracy of the visual analysis and the 3 standard deviation approach was used for statistical significance test. The results showed that all clients improved. This study lists some advantages of using single-system design for evaluating clinical practice: monitoring, encouraging clients' active role in social work process, and easy data analysis.