• International conference on construction engineering and project management
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• 2009.05a
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• pp.1161-1165
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• 2009

Safety of workers and productivity in construction site are affected according to the conflict status of work spaces which are performed at a time. The interference among the work spaces in construction site should be minimized because it becomes a blocking factor that causes construction delay and low productivity. Those factors can be managed by reasonable H&S (Health & Safety) practice. This research suggests the requirements of H&S practice and rules to establish the strategy of H&S management based on the literature reviews related to H&S rule. The suggested H&S rule can be visualized for searching space conflict point if the rule is linked with visual simulation tool. Accordingly the research results can be used for improving and visualizing construction productivity by work space control in 4D/nD CAD system.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.11-18
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• 2007

Recently 3D GIS and its applications are getting attention increasingly as various ubiquitous-related techniques for 3D spaces are being developed. Although they call for quantitative measures such as accessibility, most accessibilityrelated studies are limited to 2D networks, not 3D indoor space levels. In this paper, we develop an accessibility index applicable to 3D models. We first examine the theory of Space Syntax which has been developed and used to measure the connectivity or relationships between spatial segments in urban or architectural environments. Then, we expand the principle to a more general form so it can be applied to both street and indoor space levels. We incorporate different types of impedances in moving between places including distances, turns and transfers between floors into the traditional Space Syntax that measures the spatial depths solely based on the structural forms. Finally, we illustrate the use of the proposed measure comparatively using a campus building.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.47.2-47.2
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• 2013

We present ultraviolet (UV) color-magnitude relations (CMRs) of early-type dwarf galaxies in the Viro cluster, combining Galaxy Evolution Explorer (GALEX) UV data with SDSS optical data, based on the Extended Virgo Cluster catalog (EVCC). We find that dwarf lenticular galaxies (dS0s) show a surprisingly distinct and tight locus separated from that of ordinary dEs, which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. The observed CMR of dS0s is well matched by models with relatively long delayed star formation. The dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment. Most early type dwarf galaxies with blue UV colors (FUV-r < 6 and NUV-r < 4) are identified as those showing spectroscopic hints of recent or ongoing star formation activities. In any case UV photometry provides a powerful teel to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories. lenticular galaxies, and irregular high surface brightness (HSB) galaxies, respectively. Dwarf elliptical galaxies and dwarf irregular LSB galaxies occupy the similar structural parameter spaces. We suggest that giant elliptical galaxies and dwarf elliptical galaxies may have different origin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.212-218
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• 2007

This paper presents a implementation of speed sensorless vector control of induction motor using MATLAB/SIMULINK and dSPACE DS1104. Proposed flux estimation algorithm, which utilize the combination of the voltage model based on stator equivalent model and the current model based on rotor equivalent model, enables stable estimation of rotor flux. Proposed rotor speed estimation algorithm utilizes the estimated flux. And the estimated rotor speed is used to speed control of induction motor. Overall system consists of speed controller, current controller, and flux controller using the most general PI controller. Speed sensorless vector control algorithm is implemented as block diagrams using MATLAB/SIMULINK. And realtime control is performed by dSPACE DS1104 control board and Real-Time-Interface(RTI).

• Spatial Information Research
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• v.22 no.6
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• pp.33-43
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• 2014

As the number of people who live indoor space has been increased, the interest in 3D indoor spatial information has been grown. Object-Oriented 3D indoor space modeling including indoor spatial information has performed in level of detail 4, and modeling data is able to be constructed based on various raw data which are as-built drawing, laser scanning, BIM data, and camera. 3D indoor space modeling has been worked based on established indoor space modeling process, and the result can be used for various application fields such as indoor space pedestrian navigation, facility management, disaster management, and so on. However, the modeling process has limitations to perform indoor space modeling efficiently, because the process is complicated and wastes time at modeling work. In this paper, we propose evaluation on practical use of raw data for 3D indoor space modeling purpose on supporting efficient indoor space modeling through analyzing the established process. Therefore, we define the requirements to evaluate the practical use of raw data and propose the verification method. In addition, as-built drawing which has been used in Seoul 3D indoor space modeling project will be applied to proposed method as a raw data.

• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.303-314
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• 2017

With increased human activity in space, the risk of re-entry and collision between space objects is constantly increasing. Hence, the need for space situational awareness (SSA) programs has been acknowledged by many experienced space agencies. Optical and radar sensors, which enable the surveillance and tracking of space objects, are the most important technical components of SSA systems. In particular, combinations of radar systems and optical sensor networks play an outstanding role in SSA programs. At present, Korea operates the optical wide field patrol network (OWL-Net), the only optical system for tracking space objects. However, due to their dependence on weather conditions and observation time, it is not reasonable to use optical systems alone for SSA initiatives, as they have limited operational availability. Therefore, the strategies for developing radar systems should be considered for an efficient SSA system using currently available technology. The purpose of this paper is to analyze the performance of a radar system in detecting and tracking space objects. With the radar system investigated, the minimum sensitivity is defined as detection of a $1-m^2$ radar cross section (RCS) at an altitude of 2,000 km, with operating frequencies in the L, S, C, X or Ku-band. The results of power budget analysis showed that the maximum detection range of 2,000 km, which includes the low earth orbit (LEO) environment, can be achieved with a transmission power of 900 kW, transmit and receive antenna gains of 40 dB and 43 dB, respectively, a pulse width of 2 ms, and a signal processing gain of 13.3 dB, at a frequency of 1.3 GHz. We defined the key parameters of the radar following a performance analysis of the system. This research can thus provide guidelines for the conceptual design of radar systems for national SSA initiatives.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.1-12
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• 2003

The purpose of this study was to design the method of 3D space calibration to reduce RMSE by statistical analysis when using the DLT algorithm and control frame. Control frame for 3D space calibration was consist of $1{\times}3{\times}2m$ and 162 contort points adhere to it. For calculate of 3D coordination used two methods about 2D coordination on image frame, 2D coordinate on each image frame and mean coordination. The methods of statistical analysis used one-way ANOVA and T-test. Significant level was ${\alpha}=.05$. The compose of methods for reduce RMSE were as follow. 1. Use the control frame composed of 24-44 control points arranged equally. 2. When photographing, locate control frame to center of image plane(image frame) o. use the lens of a few distortion. 3. When calculate of 3D coordination, use mean of 2D coordinate obtainable from all image frames.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.345-352
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• 2005

This paper aims to design Game Rendering Engine for real-time 3D online games. Previous, in order to raise rendering speed, BSP tree was used to partitioned space in Quake Game Engine. A game engine is required to develop for rapidly escalating of 3D online games in Korea. too. Currently rendering time is saved with the hardware accelerator which is working on the high-level computer system. On the other hand, a game engine is needed to save rendering time for users with low-level computer system. Therefore, a game rendering engine is which reduces rendering time by PVS look-up table using Empty space BSP tree designed and implemented in this paper

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.40-44
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• 2018

As the information society developed rapidly now, office software based on IoT has released along with office appliances that we encountered in everyday life, providing more convenient services. Now a days, in addition to writing documents for recording, it has importance to create documents for effective document presentation and information transmission. In this paper, we have been presented and designed in 3D virtual space from 2D for effective information transmission in real time. The suggested program, which implements part of the design, enables the voice and visual information to be effectively communicated while conveniently exploring or showing documents in a virtual 3D space. It provides a method of automatically placing documents in 3D virtual space, designing virtual camera movements that effectively explore them, and suggesting how to connect voice information to each document in real time.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.542-547
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• 2003

A new approach to design of a discrete-time robust $H_{\infty}$ filter in finite horizon case is proposed. It is shown that robust $H_{\infty}$ filtering problem can be cast into the minimization problem of an indefinite quadratic form, which can be solved by implementing the Kalman filter defined in Krein space. The proposed filter is readily derived by simply augmenting the state space model and has the robustness property against the parameter uncertainties of a given system.