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Complementary Filtering for the Self-Localization of Indoor Autonomous Mobile Robots (실내 자율형 주행로봇의 자기위치 추정을 위한 보상필터 설계)

  • Han, Jae-Won;Hwang, Jong-Hyon;Hong, Sung-Kyoung;Ryuh, Young-Sun
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.11
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    • pp.1110-1116
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    • 2010
  • This paper present an effective complementary filtering method using encoder and gyro sensors for the self-localization(including heading and velocity) of indoor mobile robot. The main idea of the proposed approach is to find the pros and cons of each sensor through a various maneuvering tests and to design of an adaptive complementary filter that works for the entire maneuvering phases. The proposed method is applied to an indoor mobile robot and the performances are verified through extensive experiments.

A Comparative Study on Methods for Implementing VHDL Design Database (VHDL 설계 데이터베이스 구현 방법의 비교 연구)

  • 최승욱;최기영
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.7
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    • pp.966-973
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    • 1995
  • In this paper, we compare several methods for implementing a VHDL design database through a case study on VHDL tool development system. We implemented three versions of the VHDL design database which the VHDL tool development system is based on. The first version was coded in the C programming language following value-oriented paradigm. The second one was coded in the C++ programming language following object-oriented paradigm. The third one was implemented using an existing object-oriented database. Based on our experience, we present quantitatively the pros and cons of each implementation method. The value-oriented version was most difficult to implement but showed good performance. Compared to the value- oriented version, the C++ version was twice as easy to implement and showed about the same performance. Using an existing object-oriented database allowed easiest implementation but resulted in a 1.5 to 6 times slower version.

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Development of a 4-axis Auto-aligning System for Precision Measurement of 2-axis Feeding Systems Using Laser Interferometer (2축 이송계 정밀도 측정을 위한 레이저 간섭계 4축 자동정렬장치 개발)

  • Kim, Hyun-Soo;Hong, Seong-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.9
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    • pp.75-80
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    • 2000
  • Although laser interferometer is widely accepted as a tool for measurement of motion accuracy the set-up procedure is time-consuming because of the strict requirement on alignment between laser head and optic units. This paper presents a 4-axis auto-aligning system which is useful for easy set-up of laser interferometer so as to evaluate precision of a 2-axis feeding system. This paper proposes two ideas for alignment in laser interferometer set-up: one is use of mirror and retroreflectors. and the other is taking advantage of the pre-defined movement and peculiar characteristic of retroreflecotrs. The pros and cons of the two methods are discussed. Illustrative experimental results are presented in which the developed system is applied to a XY table.

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Prospective on Prevention of Dental Caries and Water Fluoridation (미래지향적인 관점에서 본 치아우식증 예방과 음용수 불소화)

  • Park, Gi-Cheol;Kim, Wan-Gyu
    • The Journal of the Korean dental association
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    • v.38 no.1 s.368
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    • pp.86-93
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    • 2000
  • Water fluoridation in conjunstion with wide use of fluoride dentifrices has been a major factor responsible for the decline in dental caries during the second half of the 20th century throughout the world. The history of water of water fluoridation is a classic public health program leading to epidemiologic investigation and community-based public health dentistry program. Although other fluoride-containing products are available, water fluoridation remains as the most safe and cost-effective method of delivering fluoride to omost communities. regardless of age. educational attainment. or income levels,. This review deals with pros and cons of water fluoridation and prospective analysis of state-of-the-art on issues related to the use of fluoride. An "optimal" fluoride concentration of 0.7-1.2 ppm has been recommended for preventing dental caries with a minimal dental fluorosis and no systemic health consequences.

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MiSA (Method of Integrated Spectral Analysis) to Evaluate Structural Integrity of Tunnel Concrete Lining (터널 콘크리트 라이닝의 구조적 특성평가를 위한 탄성파 기법, MiSA의 개발)

  • 김기봉;추진호;조성호;조미라
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.49-56
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    • 2001
  • The techniques to make assessment of the structural integrity of underground structures include Infrared thermagraphy, GPR using the reflection of the electromagnetic wave, ultrasonic test, seismic methods using the propagation of elastic wave, and etc These methods have pros and cons in the assessment of the structural integrity in the complex environment of the underground structure, so that a single method alone is not enough to evaluate parameters required for the assessment. In this study, a new seismic method was proposed to improve the existing methods and to provide an additional information like stiffness of concrete. The proposed method combines the advantages of the modified impact-echo test and the SASW method. To verify the validity of the proposed method, a large scale model of a tunnel concrete liner was built and the proposed method was applied to the center of the model and also to the corner of the model which has several distinct reflection boundaries.

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A study on the overhaul method for a Tandem type EDG on Nuclear Power Plant (원자력발전소 Tandem 형 비상디젤발전기의 최적 정비 방안 연구)

  • Han, Sung-Heum;Lim, Woo-Sang;Ha, Che-Wung
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2036-2037
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    • 2008
  • An Emergency Diesel Generator (EDG) manufactured by a French company Wartsila SACM, is a tandem type engine, consisted of two 10 cylindered diesel engines on each side. Manual provided by the manufacturer states that engine bearing requires inspection every 15 years. However, it is difficult for an inspector to access through a manhole located in the lower compartment of engine. Furthermore, during a routine or scheduled maintenance, it is not possible to disassemble main engine bearing and crank shaft, and perform inspection. Two methodologies are suggested here to resolve the problem. One method is to lift the engine and partially perform the maintenance service, and the other method is to disassemble the engine completely and to perform maintenance service by the manufacturer. Pros and cons of two methodologies were thoroughly compared.

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Controversies on governing the rates of protein evolution

  • Choi, Sun-Shim
    • Interdisciplinary Bio Central
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    • v.1 no.3
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    • pp.11.1-11.5
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    • 2009
  • One of the main issues of molecular evolution is to reveal the principles dictating protein evolutionary rates. A traditional hypothesis posits that protein evolutionary rates are mostly determined by the average functional importance of amino acids in a given protein. Thus the correlations of evolutionary rates with different variables such as PPI, gene essentiality and expression abundance have been studied to test the traditional hypothesis. Recently, mRNA expression abundance among the variables has drawn much attention, not only because it shows relatively strong correlation with protein evolutionary rates, but also because of the controversies surrounding an alternative hypothesis against the traditional one. Here, I will give an overview over the traditional hypothesis, and summarize the different variables that have been found to correlate with protein evolutionary rates. Then I will introduce pros and cons on the two different hypotheses.

Comparative study on displacement measurement sensors for high-speed railroad bridge

  • Cho, Soojin;Lee, Junhwa;Sim, Sung-Han
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.637-652
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    • 2018
  • This paper presents a comparative study of displacement measurement using four sensors that are being used in the field: they are a ring gauge, a laser Doppler vibrometer (LDV), a vision-based displacement measurement system (VDMS), and an optoelectronic displacement meter (ODM). The comparative study was carried out on a brand-new high-speed railroad bridge designed to produce displacements within a couple of millimeters under the loading of a high-speed train. The tests were carried out on a single-span steel plate girder bridge two times with different train loadings: KTX and HEMU. The measured displacement is compared as raw and further discussion was made on the measurement noise, peak displacement, and frequency response of four sensors. The comparisonsare summarized to show the pros and cons of the used sensors in measuring displacement at a typical high-speed railroad bridge.

Real-time Interactive Particle-art with Human Motion Based on Computer Vision Techniques (컴퓨터 비전 기술을 활용한 관객의 움직임과 상호작용이 가능한 실시간 파티클 아트)

  • Jo, Ik Hyun;Park, Geo Tae;Jung, Soon Ki
    • Journal of Korea Multimedia Society
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    • v.21 no.1
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    • pp.51-60
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    • 2018
  • We present a real-time interactive particle-art with human motion based on computer vision techniques. We used computer vision techniques to reduce the number of equipments that required for media art appreciations. We analyze pros and cons of various computer vision methods that can adapted to interactive digital media art. In our system, background subtraction is applied to search an audience. The audience image is changed into particles with grid cells. Optical flow is used to detect the motion of the audience and create particle effects. Also we define a virtual button for interaction. This paper introduces a series of computer vision modules to build the interactive digital media art contents which can be easily configurated with a camera sensor.

Distributed Mobility Management Strategy with Pointer Forwarding Technique

  • Wie, Sunghong;Jang, Jaeshin
    • Journal of information and communication convergence engineering
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    • v.13 no.4
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    • pp.248-256
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    • 2015
  • With the dramatic increase in mobile traffic in recent years, some of the limitations of mobility management frameworks have magnified. The current centralized mobility management (CMM) strategy has various problems, such as a suboptimal routing path, low scalability, signaling overhead, and a single point of failure. To overcome these weaknesses in the CMM strategy, the Internet Engineering Task Force has been discussing distributed mobility management (DMM) strategies. The fundamental concept of a DMM strategy is to distribute the mobility anchors closer to the users. While the distribution of mobility anchors results in low-cost traffic delivery, it increases the signaling cost. To reduce this higher signaling cost, we propose a new DMM strategy applying the pointer forwarding technique. The proposed strategy keeps the existing tunnels and extends the traffic path as much as possible. In this paper, we analyze the performance of the pointer forwarding-DMM strategy and discuss its pros and cons.