• Journal of Power Electronics
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• v.10 no.3
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• pp.277-284
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• 2010

This paper presents a novel hybrid carrier based space vector modulation for cascaded multilevel inverters. The proposed technique inherits the properties of carrier based space vector modulation and the fundamental frequency modulation strategy. The main characteristic of this modulation are the reduction of power loss, and improved harmonic performance. The carrier based space vector modulation algorithm is implemented with a TMS320F2407 digital signal processor. A Xilinx Complex Programmable Logic Device is used to develop the hybrid PWM control algorithm and it is integrated with a digital signal processor for hybrid carrier based space vector PWM generation. The inverter offers less weighted total harmonic distortion and it operates with equal electrostatic and electromagnetic stress among the power devices. The feasibility of the proposed technique is verified by spectral analysis, simulation, and experimental results.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.29.3-29.3
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• 2009

Recent observations for the Galactic globular clusters (GCs) have shown that a number of GCs have characteristic features of multiple stellar populations, such as multiple main-sequences (MSs), splits in sub-giant branch (SGB), bimodal and/or extended horizontal branches (HBs). Based on the population synthesis models, we investigate star formation histories of the GCs with multiple populations, $\omega$ Cen, M54, NGC 1851, NGC 6388, NGC 6441, and NGC 2808, by comparing synthetic model color-magnitude diagrams (CMDs) with observations. We adopt most up-to-date Yonsei-Yale (Y2) stellar evolutionary tracks and isochrones from MS to post-HB, as well as improved color-temperature transformations from the recent stellar atmosphere libraries. Our models show that the observed features can be naturally explained by assuming the presence of helium-enhanced subpopulations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.117-118
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• 2014

The unfloored space and floor is one of characteristic of traditional house in Korea. This space is used to connecting passage between room or entrance of house. Currently, according to decline of heat insulation property thereby becoming decrepit house, native is repairing it for block external environment such as rain, wind and so on. But, variety problem is happening from wrong repair. This object of this study is current status and analysis on problem of unfloored space and floor repair. As a result, current status of repair is classified repair type, installation position and using form. And position of problem is confirmed connection between original house and extend space.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.1
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• pp.11-22
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• 2017

The main purpose of this research is to consider educational environment, concept, and spatial organization and its characteristic based on the early 20th century European child-centered educational philosophy. For this process, the study of the following have been done : 1) Literature review, which includes educational ideology, perspective of child development of Maria Montessori, Rudolf Steiner, Peter Peterson, and Celestin Freinet. 2) Comparisons of spatial organization and classrooms of schools operated with the educational philosophy of mentioned philosophers from above. These schools have classrooms(or multi-purpose space near classroom) contained self-directed individual learning space, group and collaborative learning space, and training space of practical life. These configuration of learning space intended 1) learning based on individual child's interest, experience 2) developing of responsibility based on freedom 3) sociality and community spirit of children.

• Architectural research
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• v.23 no.2
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• pp.29-37
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• 2021

Early in the communist era, many cities in modern China experienced a special period of passive industrialization during which the construction of urban spaces laid the spatial urban foundation. During this period, the city construction was carried out rapidly under the administrative intervention of the government. The passive industrialization caused by taking economic construction as the center made the city construction deviate from the correct track and resulted in a variety of problems. Focusing on ecological space change, this paper selects Zhengzhou as an example of many similar cities in China, and analyzes the impact of passive industrialization on urban ecological spaces from the perspectives of city scale, city layout and city construction management system. The analysis results reveal that the construction of urban ecological space under the influence of passive industrialization induced a lagging characteristic, led to insufficient integrity of urban ecological space, and placed great pressure on the urban environment. Finally, the paper puts forward some methods to optimize the urban ecological space.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.470-475
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• 2009

This paper is the study which is head tracker using pattern matching. Proposal algorithm obtains initial attitude of head tracker using pattern matching. Optical head tracker consists of infrared LEDs(features) which are attached helmet as pattern, stereo infrared cameras. Proposal algorithm analyzes patterns by error rate of feature distance and estimates feature characteristic number. Initial attitude of head tracker is obtained to compare map data and feature characteristic number.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.513-518
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• 1993

In this paper, we consider the handling f a flexible object using dual-arm manipulators. We choose both the side arms as rigid, and the objects to be manipulated as flexible. Our purpose is to realize position control for the flexible object while suppressing its vibration. In particular, the problem taken up here is the stability of the control system while manipulating the object. We propose that the traditional approach to investigate the robot system be expanded to include the object's characteristics (thus transferring the stability of the robot system into the full assembly system). We define a handling characteristic while manipulating the object. Finally, the relationship between the handling characteristic and the positional constraint condition in the hold position of the arms is studied while considering the stability of the control system.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.756-761
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• 2007

This papered is concerned with the crashworthiness characteristics analysis of the non-step bus when it is crashed or roll-over analysis. Computer simulations is implemented using LS-Dyna explicit code which can effectively analysis dynamic response with the lapse of time. We construct a FEM model of the non-step bus under development according to the safety rules used in Europe for composite non-step buses. The crash energy and absorption rate are evaluated to understand crashworthiness characteristic of the composite non-step bus. Body deformation is also examined whether the survival space is secured for passengers.

• ETRI Journal
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• v.25 no.5
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• pp.305-314
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• 2003

In this paper, we present a soft IP compiler for the Reed-Solomon decoder that generates a fully synthesizable VHDL core exploiting characteristic parameters and design constraints that we newly classify for the soft IP. It produces a structural design with an estimable regular architecture based on a finite state machine with a datapath (FSMD). Since characteristic parameters provide different design points on the design space, using one of two simple procedures called the constructive search with area increment (CSAI) and constructive search with speed decrement (CSSD) for design space exploration, the core compiler makes it possible for an IP user to create the Reed-Solomon decoder with appropriate sub-architectures without synthesizing many models. Experimental results show that the IP compiler can apply to several industry standards.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.36-43
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• 2015

Optimizing multiple design characteristics which are usually in conflict with each other in the injection molding process is frequently becoming a critical problem for designers who work in this area. The purpose of this work is to develop an automated design methodology for optimizing two such design characteristics found in injection-molded parts. A value function based on decision-making theory is used as a means of evaluating the performance of a two-characteristic design alternative. Also, a design space reduction algorithm based on Taguchi's orthogonal arrays is utilized to discover an optimal design alternative. Verification of the developed design methodology is carried out for an actual model with two design characteristics, the weld line and the gate location, to be optimized in computer simulation experiments.