• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.350-353
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• 1994

This paper presents a method to calculate the characteristic root areas and loci band of control systems with uncertainties. First, equations of boundary curves of root areas in the case of additive and multiplicative perturbation are derived. Then, an algorithm for the calculation of the array of closed curves is presented. When the upper bound of the absolute values of frequency responses for the uncertain part, is also frequency-dependent, the frequency-dependent, terms are included in the characteristic equation of the nominal system. This lead to the boundary equations of the root, areas for control systems with frequency-dependent uncertainty. Numerical examples of the control systems with multiplicative perturbations including frequency-dependent terms are presented to verify this calculation method. Finally, its applications to the design of robust control systems, e.g., passive adaptive control systems are also discussed.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.137-144
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• 2014

This study examined the effect of beauty involvement on self-satisfaction by conspicuous consumption tendency groups. A questionnaire method was used for this study. The subjects of this research were females in their 20s~50s. We distributed 580 questionnaires ets; constantly, 554 sets were used in the final analysis. Data were analyzed by factor analysis, ANOVA, cluster analysis, Cronbach's alpha coefficient and multiple regression analysis. Beauty consumption behavior factors were classified with hair styling, skin management, make-up and body shaping. Self-satisfaction factors were classified with living, appearance, economic and interpersonal relation. This study classified 4 conspicuous consumption groups (active, passive, syntonic and individuality & frugal group). The active conspicuous consumption group was unsatisfied with most of the self-satisfaction factors. The passive conspicuous consumption group was more interested in skin management factors than other factors. The syntonic conspicuous consumption group was interested in make-up, body shaping and skin management in order to provide a positive impression to other people. The individuality & frugal group was most interested in body shaping that could be achieved at low cost through exercise and diet.

• Advances in aircraft and spacecraft science
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• v.7 no.4
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• pp.309-333
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• 2020

The proposed study aims to numerically investigate the performance of hydrofoils in the context of amphibious aircraft application. In particular, we also study the effectiveness of a slotted hydrofoil in minimizing the cavitation phenomenon, to improve the overall water take-off performance of an amphibious aircraft. We use the ICON A5 as a base model for this study. First, we propose an approach to estimate the required hydrofoil surface area and to select the most suitable airfoil shape that can minimize cavitation, thus improving the hydrodynamic efficiency. Once the hydrofoil is selected, we perform 2D numerical studies of the hydrodynamic and cavitating characteristics of a non-slotted hydrofoil on ANSYS Fluent. In this work, we also propose to use a slotted hydrofoil to be a passive method to control the cavitation performance through the boundary layer control. Numerical results of several slotted configurations demonstrate notable improvement on the cavitation performance. We then perform a multiobjective optimization with a response surface model to simultaneously minimize the cavitation and maximize the hydrodynamic efficiency of the hydrofoil. The optimization takes the slot geometry, including the slot angle and lengths, as the design variables. In addition, a global sensitivity study has been carried and it shows that the slot widths are the more dominant factors.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.91-99
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• 2016

The safety of nuclear power plants has received much attention; this safety largely depends on the continuous availability of electrical energy source during all modes of nuclear power plant operation. A station blackout (SBO) describes the loss of the off-site electric power, the failure of the emergency diesel generators, and the unavailability of the alternate AC (AAC) power. Consequently, all systems that are AC powered such as the safety injection, shutdown cooling, component cooling water, and essential service water systems are unavailable. The aim of this study is to investigate the deficiencies of the existing alternatives for coping with an extended SBO for APR1400 design. The method is analyzing the existing deficiencies and proposing an optimal solution for the NPP design during the extended SBO. This study, established a new passive system, called passive decay heat removal system (PDHRS), using systems engineering approach.

• The Journal of Society for e-Business Studies
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• v.19 no.1
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• pp.1-14
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• 2014

This paper presents the development of a stock control system of POP system design based on RFID in SCM and its economic efficiency. A stock control system is proposed for 900MHz passive type RFID system. The RFID system is composed of a RFID reader and four antennas to read the tag IDs. A cost estimation model is adapted based on the total product profit by various tag prices. The result of the economic efficiency analysis can indicate any invested model for the automation system which have initial investment should be used. This solution indicates the limit of the break even point according to the input. And it can be concluded that the stock control can be developed by RFID readers and passive tags with directional arrangement of several antennas. Also, the economical evaluation model can be a decision method for company to adapt the new developed system.

• Smart Structures and Systems
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• v.23 no.6
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• pp.521-536
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• 2019

Using magnetorheological (MR) dampers in multiswitch open-loop control mode has been shown to be cost-effective for cable vibration mitigation. In this paper, a method for analyzing the damping performance of taut cables incorporating MR dampers in open-loop control mode is developed considering the effects of damping coefficient, damper stiffness, damper mass, and stiffness of the damper support. Making use of a three-element model of MR dampers and complex modal analysis, both numerical and asymptotic solutions are obtained. An analytical expression is obtained from the asymptotic solution to evaluate the equivalent damping ratio of the cable-damper system in the open-loop control mode. The individual and combined effects of the damping coefficient, damper stiffness, damper mass and stiffness of damper support on vibration control effectiveness are investigated in detail. The main thrust of the present study is to derive a general formula explicitly relating the normalized system damping ratio and the normalized damper parameters in consideration of all concerned effects, which can be easily used for the design of MR dampers to achieve optimal open-loop vibration control of taut cables.

• Korean Institute of Interior Design Journal
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• v.19 no.4
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• pp.58-65
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• 2010

The purpose of this study is to be applied with the basic data for the design method in the housing space which is differential. So, we analyzed the expression method and the application characteristic to materials of units in housing complex. To that, we researched on the condition of finishing material about the kind of material, color, texture and pattern for components in living room space. The results of this study are as follows : First, at the present time, the Object concept is expressed by 'mixing' and 'juxtaposition' of material, texture and pattern of finishing materials in housing space. But, we could find that the Object concept was used restrictively in housing space. So, we have to find different expression methods to be the effective and differential design by being applied Object concept for the housing space. Second, the 'mixing' which is the method to express the Object concept is showed in only 'art wall'. so, we can estimate that the method is the limited method to plan the varied housing. It is needed various expression methods to design components for the housing space. Third, it showed that the 'mixing' was a passive expression method using a little differential for design of housing space. We could estimate that similar methods were applied to the housing design. By results of this study, we can think that the develop study is needed to find design methods for expression of the Object in housing space.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.187-197
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• 2010

The longitudinal reinforcement ratio for the performance-based design of columns was studied. Unlike the existing design codes using uniform minimum reinforcement ratio and effective stiffness for all columns, the longitudinal reinforcement ratio of columns was defined as the function of various design parameters. To evaluate the minimum reinforcement ratio, two conditions were considered: 1) prevention of passive yielding of compression re-bars due to the creep and shrinkage of concrete under sustained service loads; and 2) ultimate flexural strength greater than the cracking moment capacity to maintain the ductility of columns for earthquake design. In addition, the effective flexural stiffness of columns for structural analysis was determined according to the longitudinal reinforcement ratio. The design method addressing the three criteria was proposed. The proposed method was applied to a design example.

• Korean Institute of Interior Design Journal
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• v.25 no.3
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• pp.21-30
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• 2016

For the elderly with declining sensory due to aging, various sense stimulation factors provided in indoor environment is desirable healing environment. This study aims to propose the direction of sensory healing environment by adapting the richness of natural environment in indoor place based on the biophilic design theory with implementation method of sensory richness environment. The healing environment was limited to the ward in the beginning, but it has widened its range to the whole place, and the lobby is considered quiet important to healing. Therefore, this study selected lobby space of geriatric hospital as study subject. As for the study method, we deducted the analytic matrix focusing on the property and elements of the direct and indirect experience of nature appearing in the biophilic design theory, and analyzed the field investigation of subject space. Also, this study paid attention to point where the hotel lobby leads the change of emotional environment, and conducted analysis and comparison by deciding this is what the hotel and geriatric hospital should direct to. As the result, the biophilic design factor of hotel is actively expressed by complex direction of various factors, but as for the geriatric hospital, it was rather passive and simple in expression. The adaptation ratio between hotel and geriatric hospital was almost more than twice times difference in average.

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.16-26
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• 2010

In recent, as rediscovery of the modern value is developed through the support by the government and the reinterpretation of the traditional culture, a Korean-style house(Hanok) also becomes an object of interest. Among these various viewpoints to see the Korean-style house, the necessity of a new spatial design approach to contain the types and functions of the architectural space of the Hanok appropriate to the modern society is raised which is not a passive approach to preserve the existing cultural assets. Out of the methods of the new spatial design of the Hanok which reflect the paradigm of the times, this study has the purpose to make an approach from the viewpoint of 'Restoration design'. As the 21 st century started, the recycle design whose active discussion and performance is made largely by Europe and Japan can be called a design method in the hardware part which enables continuous adaptive use of a building by applying a new use purpose and method to a building which doesn't use the recycle design or has low efficiency. In that meaning, it can be considered to be a very important architectural activity historically, archltecturally and spatially. Based on the methodological characteristics of the recycle design, this study largely divides the types of recycle into coherent recycle and imagery recycle and dedto s detailed methods of space, consinto ion and material and wardrobe used for each case to analyze the methods of concrete recycle design through the methodological analysis of recycle cases of the existing modern buildings. For the objects of recycle cases of the Hanok made recently based on the design methods acquired here, it was examined how the architectural and spatial characteristics of the Hanok can be reconsinto ed through what kinrecycmethods. The approach of the recycle design is considered to be a cornerstone to show a new architectural and spatial value in the viewpoint of the Hanok existence in modern times.