• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.173-179
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• 2017

This paper proposes a robust impedance controller for high-DOF robots. The model-based control of a higher DOF robot uses a numerical dynamic model because the analytical dynamic model is difficult to be derived and this means that modeling error is inevitable. The impedance control in the task space is affected by joint motions and has more difficulties in the higher DOF robots. In addition, the disturbances must be decoupled in the control of high DOF robot. This paper proposes a robust impedance controller based on integral sliding mode control (ISMC) and disturbance observer(DOB) for high-DOF robot manipulator. The ISMC is used to improve the robustness of the impedance control and to preserve its nominal performance. DOB is also employed to cancel the effects of input disturbances and to reduce the maximum gain of the ISMC which eventually determines the input chattering size.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.237-243
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• 2017

In this paper, the detection performance of the electro-optical telescopes which observes and surveils space objects including artificial satellites, is analyzed. To perform the Modeling & Simulation(M&S) based analysis, satellite orbit model, telescope model, and the atmospheric model are constructed and a detection scenario observing the satellite is organized. Based on the organized scenario, pointing accuracy is analyzed according to the Field of View(FOV), which is one of the key factors of the telescope, considering pointing angle command error. In accordance with the preceding result, detection possibility according to the pixel-count of the detector and the FOV of the telescope is analyzed by discerning detection by Signal-to-Noise Ratio(SNR). The result shows that pointing accuracy increases with larger FOV, whereas the detection probability increases with smaller FOV and higher pixel-count. Therefore, major specification of the telescope such as FOV and pixel-count should be determined considering the result of M&S based analysis performed in this paper and the operational circumstances.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.753-758
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• 2017

The ray-shooting problem is to find the first intersection point on the surface of given geometric objects where a ray moving along a straight line hits. Since rays are usually given in the form of queries, this problem is typically solved as follows. First, a data structure for a collection of objects is constructed as preprocessing. Then, the answer for each query ray is quickly computed using the data structure. In this paper, we consider the ray-shooting problem about the set of vertical line segments on the x-axis. We present a new data structure called a convex layer tree for n vertical line segments given by input. This is a tree structure consisting of layers of convex hulls of vertical line segments. It can be constructed in O(n log n) time and O(n) space and is easy to implement. We also present an algorithm to solve each query in O(log n) time using this data structure.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.20-25
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• 2004

On July $18^{th}$, 2003, Incheon International Airport Corporation(lIAC) signed the Construction Management Service Contract with KIDS consortium (composed of Kun-Won Eng., ITM Corp, Do-Hwa Eng, Space Croup) for the $2^{nd}$ phase construction protect consists of landfill, $\#3$ runway, remote Concourse, IAT, BHS, cargo terminal, etc scheduled to be finished by the end of 2008. KIDS dispatched qualified engineers to the Construction Management Division of IIAC for providing technical assistance to IIAC members to pursue project goals in tulle. within budget with appropriate quality level to build one of leading hul] airports for the Northeast Asia legion in the $21^{st}$ century. The work scope covers upgrading various project procedures and related computer programs, cost and schedule control, design supervision for building design including support systerns such as HVAC, fire protection, elevators and escalators, boarding bridges, electrical and communication systems, and technical support for IAT/BHS, QA/QC, field test and inspection, start-up and commissioning, etc. The purpose of this paper is to introduce the major activities of the Construction Management Services performing at the IIA project for your reference.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.1
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• pp.73-82
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• 2004

As a new service category to better support TCP traffic in ATM networks, the Guaranteed Frame Rate (GFR) service category aims to support minimum cell rate guarantee, fairly distribute available bandwidth while keeping the simplicity of Unspecified Bit Rate (UBR). In this paper, we proposed a buffer management scheme which uses the per-VC accounting of single FWO queue and capable of supporting both GFR.1 and GFR.2 conformance definition. The proposed buffer management deal with GFR.1 and GFR.2 conformance definitions differentially by controlling the number of CLP=0 cell and CLP=1 cell which are occupying buffer space. The simulation results show that our proposed scheme satisfies the requirements of GFR services as well as improves total fairness index and each conformance definition fairness index.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.61-70
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• 1996

M-ary differential phase shift keying(DPSK)is a bandwidth efficient digital modulation technique and recently has attracted increased attention in mobile satellite communication application where the available radio bandwidth is limited. Coherent detection offers good BER performance in AWGN channel. However, it requires long acquisition times in fading environment. In this paper, we analyze the BER performance of M-ary DPSK signal using the Multiple Differ- ential Feedback Detection(MDFD) technique in Rician fading and shadowed Rician fading channel. MDFD is an efficient scheme to decrease the performance gap between differential and coherent reception by increasing the complexity of the conventional differential receiver to some extent. Compared to the multiple symbol maximum likelihood detection technique, the multiple differential feedback detection technique has a much simpler structure for hardware implementation. Espe- cially, this technique has application to land mobile satellite channel which can vary in time and space between AWGN and rapidly fading channel.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.1
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• pp.148-163
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• 2008

As with cities, all components of a campus must be carefully calibrated to provide the facilities, services like energy, water, electricity, information and communication; classrooms, libraries and laboratories for working; transportation networks and systems for movement of persons, goods, and services; athletic and other facilities for health and competition; places to eat, recreate and socialize; places to display and store works of arts; spaces for the performing arts' spaces for active assembly or solitary pondering. The goal of this study is how to observe the campus planning and development as a part in the context of the community. This study was taken into account neighborhood concerns and Harvard design guidelines. As an observer for the university's northern campus edge, this study suggests in the context of a long and sometimes turbulent history of dialogue and negotiations between Harvard University and first host community, Agassiz which is one of Cambridge's thirteen neighborhoods.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.6
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• pp.850-856
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• 2012

Bilateration using two fixed nodes has been used in the field of the real time indoor location system in the narrow space such as building or ship passage. However, as the distance between the fixed nodes increases or any obstructions exist in their zone, it is difficult to detect the location of mobile node(user) due to the degradation of its reception ratio. In order to compensate for these problems, this paper presents, based on IEEE 802.15.4a chirp signal, a new real time indoor location system using stride measurement algorithm which can calculate the location through sensors attached to user. The proposed system consists of an ultrasonic sensor to measure the leg length, a geomagnetic sensor to recognize the user's orientation, and an inertial sensor to obtain the angle between the legs. The experimental results are shown that the proposed system has twice or more accurate output compared with conventional indoor location method in the section which is partially out of communication reachability.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.56-65
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• 2015

The purpose of this study is to find out the possibility of the healing function of art museums in modern times with the precedent studies and to explore the healing potential specifically. There have been studies on the various healing programs regarding patients with Alzheimer, learning disability, seniors, etc. The researcher approached this study in three aspects, art appreciation, space, communication as healing potential of art museums. These findings will be able to draw more social attention on art museums. Therefore, this study will provide a new perspective on the art museums to people concerned art museums. And it will make the professionals, working for company workers, students and other people suffering under the modern stress, recognize the art museums as a place to look inside in the professionals' own mind and to heal as well as a place for culture and sophistication. These findings will be able to draw more social attention on art museums.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.62-69
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• 2012

The newly developed field of media art is quickly making progress to include various and up-to-date forms of expression. Unlike in traditional art, the communication between the art and the viewer has become vastly important, in which the viewer is an active agent who participates and interacts with the artwork. These digital artworks can now be readily observed in everyday places and things, rather than being confined solely in the gallery space. By encouraging open interaction with the public, media art has become more accessible. Accordingly, this thesis examines the construction of a real-time multimedia clock piece using particle systems. Time has always been a significant theme in the realm of traditional art, which continues to be explored extensively in various forms of expression. In an attempt to express the continuity of time and the state of being value of existence based on technological skills, the thesis presents an artwork that uses the popular medium of a clock while also providing both usability and emotional satisfaction for the viewer's sensibility through interaction.