• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1102-1110
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• 2006

This paper addresses the problem of computing grasp stability of the object for two-fingered robots in two dimensions. The concepts of force-closure and dual space are introduced and discussed in novel point of view, and we transform friction cones in a robot work space to line segments in a dual space. We newly define a grasp stability index by calculating intersection condition between line segments in dual space. Moreover, we propose a method to find the optimal grasp points of the given object by comparing the defined grasp stability index. Its validity and effectiveness are investigated and verified by simulations for quadrangle object and elliptic objects.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.54-58
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• 2008

Despite rapid social changes, there have been little distinctive or fast shifts in living space, and the kind of housing design that could address the diverse need of residents is required. In the future, complex trend that is built on a mix and match of different sorts of styles is expected to be in vogue. The introduction of natural elements and ornamental factors such as books, antiques and art works into living spaces that are artificial things is expected to contribute to helping people lead a richer and Individual life. This study attempted to present a housing design by instilling culture in an existing living space and making it fit into a new lifestyle. After the position of natural and ornamental components was fixed, a contemporary modern living space was designed, for which art works would become necessary and sufficient conditions. A plane figure of the new living space was offered, and then detailed design for each part was provided. Finally, a finalized design pattern that was suitable for the selected concept was presented.

• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.883-894
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• 2021

The aim of this work is to introduce for the first time the concept of D-set. This is done by defining a special type of cover called a D-cover. we present some results to study the properties of D-compact spaces and their relations with other topological spaces. Several examples are discussed to illustrate and support our main results. Our results extend and generalized many will known results in the literature.

• Journal of Astronomy and Space Sciences
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• v.40 no.3
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• pp.93-100
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• 2023

A study of uncertainty analysis was conducted on four key thermophysical properties of molten Platinum using a noncontacting levitation technique. More specifically, this work demonstrates a detailed reporting of the uncertainties associated with the density, volumetric thermal expansion coefficient, surface tension and viscosity measurements at higher temperatures for a widely used refractory metal, Platinum using electrostatic levitation (ESL). The microgravity experiments were conducted using JAXA's Electrostatic Levitation Furnace (ELF) facility on the International Space Station and the terrestrial experiments were conducted using NASA's Marshal Space Flight Center's ESL facility. The performance of these two facilities were then quantified based on the measurement precision and accuracy using the metrological International Standards Organization's Guide to the Expression of Uncertainty Measurement (GUM) principles.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.25-28
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• 2001

Today enterprises are bringing forward the strong needs for the Global Work Space that is able to realize the collaboration of the virtual enterprise in order to achieve the rapid entrance to market, the quality improvement as well as the cost reduction of their new products. Especially, they are building the efficient Product Management Infrastructure in parallel with the real-time knowledge management for the information generated in the course of a product lifecycle and the Process Innovation making the Concurrent Engineering possible. Building a system in the web environment cannot be the entire effort to realize the Global Work Space within an enterprise that is an essential factor for the reduction of a product development period which in turn contributes to Time to Market. Various work models and processes are found in enterprises and many different application programs are developed and utilized to support these. This study proposes a scheme for the optimized Collaborative Workflow System Architecture that is able to take in and apply various application programs accompanied by the product development work process. Through this, we are to examine various limits and problems existing in the real-time collaborative system between enterprises and to reform these.

• Research in Community and Public Health Nursing
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• v.22 no.4
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• pp.420-428
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• 2011

Purpose: The purpose of this study was to investigate the relations between fatigue and work-related factors in workers. Methods: A total of 204 subjects aged between 21 and 59 were selected through convenient sampling. Data were collected with a self-reported questionnaire from May 20 to 31, 2011. Collected data were analyzed with SPSS/WIN 17.0. Results: Difference in fatigue according to general characteristics was significant according to duty type. Difference in fatigue according to occupational characteristics was significant according to work intensity, work speed, demand of work concentration, work space, physical environment, largest weight by hands, vibration, visual demand of work, difficulty of work practice, work stress, and rest hours in holiday. There was a positive correlation between fatigue and occupational characteristics. Stepwise multiple regression analyses showed that educational level, work intensity, and rest hours in holiday were the strongest factors associated with fatigue ($R^2$=.363 p<.001). These factors explained fatigue by 36.3%. Conclusion: The findings of this study may be useful in understanding workers' fatigue and developing more specific fatigue relief programs.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.691-711
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• 2011

This study examines the preliminary license and approval facilitation standards for improvements in quality for childcare centers focusing on the number of children, building space standards, facilities and equipment, and childcare program. Data from 48 caese was collected from childcare centers nationwide in Korea through a questionnaire and building plan. The first step for starting care licensing is to work out the ages and numbers of children within four or five age ranges. The second step is to work out the number of children as small, medium, or large considering staff to child ratios and building size. The Nnext step is to make a choice about childcare service quality classification as minimum, fair, or good, considering space requirements per child for the building, the classroom and the outdoor playground. The next step is to make a choice of space organization relating to service programs, considering the sleeping and eating area, indoor play area, toilet & washing facilities, classroom layouts such as cluster type, double zone type, single zone type, and others. Also, each room and entrance, office, kitchen, storage, laundry, teacher's area, and chilldren's area, need to be checked for space requirements and performances. The last step is to arrange the childcare program with the building and site plan. In conclusion childcare service quality will get better by upgrading of license regulation especially in minimum space requirements per child, corresponding with an increase in GNP and housing area per person. This is needed for childcare licensing in order to determine the quality level of childcare service.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.241-253
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• 2011

The present thesis is to concretize process stages and methods for effective use of online CGTS(creative group thinking system), or the web-storming program, in space design and to propose a support system for idea generation specific to space design. For the purpose of this study, activity factors in space design process and functional factors of the web-storming program were written into an interaction matrix, which was used for a questionnaire survey on correlations. Then, the results of the interaction matrix were visualized and analyzed following the procedure of observation-interpretation-application. The analysis found that the schematic design stage is most correlated where close collaboration is performed in the process of space design and that differences in correlation arise upon division of work. As such, the present study proposed 'provision of media for ideas in accordance with specific process and UI optimization' as a means of improving usability in schematic design that is closely correlated and suggested an idea to enhance the applicability of web-storming system in division of work.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.239.1-239.1
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• 2012

This paper presents the results of one of early sciences with Korean VLBI Network (KVN): a large fringe survey of compact radio sources at 43GHz. We established the catalog of correlated flux densities in three ranges of baseline projection lengths of 637 sources from a 43 GHz (Q-band) survey observed with the Korean VLBI Network. Of them, 623 sources have not been observed before at Q-band with VLBI. The goal of this work in the early science phase of the new VLBI array is twofold: to evaluate the performance of the new instrument that operates in a frequency range of 22--129 GHz and to build a list of objects that can be used as targets and as calibrators. We have observed the list of 799 target sources with declinations down to $-40{\circ}$. Among them, 724 were observed before with VLBI at 22 GHz and had correlated flux densities greater than 200 mJy. The overall detection rate is 78%. The detection limit, defined as the minimum flux density for a source to be detected with 90% probability in a single observation, was in a range of 115--180 mJy depending on declination. However, some sources as weak as 70 mJy have been detected. Of 623 detected sources, 33 objects are detected for the first time in VLBI mode. We determined their coordinates with the median formal uncertainty 20 mas. The results of this work set the basis for future efforts to build the complete flux-limited sample of extragalactic sources at frequencies 22 GHz and higher at 3/4 of the celestial sphere.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.4
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• pp.601-610
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• 2018

Since the building construction works are repeated vertically in a limited space, there is not a great need for the location information of each activity in the schedule management. On the other hand, civil engineering works such as road and railway projects consist of a large number of earthworks, long bridges, and long tunnels. These types of work should be controlled in a horizontal space according to the linear axis of several tens of kilometers. In other words, since most of the activities are managed in the unit of distance from the start point to the end point, it is possible to improve the efficiency of the schedule management by linking the location information of the activity with the schedule data in the schedule management system. This study presents a methodology for creating a linear schedule chart specific to a project with horizontal work space and compares the convenience with the existing Gantt chart. In addition, the methodology of linking linear schedule chart to the 4D CAD system, which is a typical BIM technology in the construction phase, is presented to improve the usability of BIM. The practical applicability of the proposed methodology was verified statistically.