• Title/Summary/Keyword: distance university

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A Study on the Minimum Safe Distance Under the Low Speed Sailing of T.S. HANBADA (실습선 한바다호의 저속 항해시 최소안전 이격거리에 관한 연구)

  • Park Young-Soo;Ji Sang-Won;Lee Yun-Sok;Jung Chang-Hyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.5-10
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    • 2005
  • T.S. HANBADA will navigate to maintain the adequate distance between own ship and other ships safely for about 17 hours on the about 2 kts. On the above situation, M broadcasting station requires to maintain the distance from 100m to 500m between ships. This paper aims to calculate the minimum safe distance between ships, the distance is assessed by using ES Model which is a quantitative model for evaluating the difficulty of shiphandling. After marine traffic flow simulation, minimum safe distance for HANBADA on the 2kts is about 260m based ES value. On this paper, the result was compared about its distance to the actual navigating distance.

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Smoothed RSSI-Based Distance Estimation Using Deep Neural Network (심층 인공신경망을 활용한 Smoothed RSSI 기반 거리 추정)

  • Hyeok-Don Kwon;Sol-Bee Lee;Jung-Hyok Kwon;Eui-Jik Kim
    • Journal of Internet of Things and Convergence
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    • v.9 no.2
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    • pp.71-76
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    • 2023
  • In this paper, we propose a smoothed received signal strength indicator (RSSI)-based distance estimation using deep neural network (DNN) for accurate distance estimation in an environment where a single receiver is used. The proposed scheme performs a data preprocessing consisting of data splitting, missing value imputation, and smoothing steps to improve distance estimation accuracy, thereby deriving the smoothed RSSI values. The derived smoothed RSSI values are used as input data of the Multi-Input Single-Output (MISO) DNN model, and are finally returned as an estimated distance in the output layer through input layer and hidden layer. To verify the superiority of the proposed scheme, we compared the performance of the proposed scheme with that of the linear regression-based distance estimation scheme. As a result, the proposed scheme showed 29.09% higher distance estimation accuracy than the linear regression-based distance estimation scheme.

Effects of Joint Position on the Distraction Distance in Patients with Adhesive Capsulitis of Glenohumeral Joint

  • Park, Sam Sik;Kim, Ki Do;Hwang, Yong Pil;Moon, Ok Kon;Kim, Bo Kyung;Choi, Wan Suk
    • Journal of International Academy of Physical Therapy Research
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    • v.6 no.1
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    • pp.824-827
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    • 2015
  • The purpose of this study was to investigate the effects of joint position on the distraction distance in patients with adhesive capsulitis of glenohumeral joint. The study was conducted upon 20 adults in their 40's with the findings of adhesive capsulitis of glenohumeral joint. These subjects were subdivided into 3 groups, which were a group with neutral position(n=7), second group with resting position(n=7) and third group with end-range position(n=6). After having the subject wearing sleeveless shirts exposing armpit and lying straight on the plinth, a physical therapist with OMT qualification pulled glenohumeral joint at the Grade III of Kaltenborn-Evjenth traction; and the distance between glenoid fossa and humeral head was measured with ultrasound. Following the application of traction, the group with resting position($.67{\pm}0.29$) exhibited the longest distance between humeral head and glenoid fossa, and it was followed by neutral position($.50{\pm}0.25$) and end-range position($.35{\pm}.21$) in this order. From the comparison of these groups, there was no significant difference in distraction distance between resting position and neutral position; and there was again no significant difference in distraction distance between end-range position and neutral position. However, there was a significant difference in distraction distance between end-range position and resting position(p<.05). Upon application of the Grade III of Kaltenborn-Evjenth traction, it was evident that the distance between humeral head and glenoid fossa can be varied depending on the location of the joint.

Feature extraction with distance measures and fuzzy entropy

  • Lee, Sang-Hyuk;Kim, Sung-Shin;Hyeon Bae;Kim, Youn-Tae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.543-546
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    • 2003
  • Representation and quantification of fuzziness are required for the uncertain system modelling and controller design. Conventional results show that entropy of fuzzy sets represent the fuzziness of fuzzy sets. In this literature, the relations of fuzzy enropy, distance measure and similarity measure are discussed, and distance measure is proposed. With the help of relations of fuzzy entropy, distance measure and similarity measure, fuzzy entropy is proposed by the distance measure. Finally, proposed entropy is applied to measure the fault signal of induction machine.

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Electrical Characteristics of PV Module According to Optical Characteristics of Back-sheet (PV모듈에서 후면Sheet의 광학적 특성에 따른 전기적 출력 특성)

  • Lee, Jin-Seob;Kang, Gi-Hwan;Park, Chi-Hong;Yu, Gwon-Jong;Ahn, Hyung-Gun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
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    • 2008.11a
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    • pp.42-47
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    • 2008
  • In this paper, we analyze the electrical characteristics of PV depending on distance among solar cells before and after lamination process. From the result, the PV module's maximum power increases about 3.37% when solar cells's distance is 10mm. And the maximum power increases up to 8.42% when solar cells's maximum distance is 50mm. It is assumed that PV module's surface temperature decreases because of increasing distance between solar cells that would give high power generation. Also, short distance between solar cell and frame result in contamination on glass. When considering reduced maximum power caused by contaminant, from that. we can fabricated PV module of lower cost with high performance.

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Approach of Self-mixing Interferometry Based on Particle Swarm Optimization for Absolute Distance Estimation

  • Li, Li;Li, Xingfei;Kou, Ke;Wu, Tengfei
    • Journal of the Optical Society of Korea
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    • v.19 no.1
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    • pp.95-101
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    • 2015
  • To accurately extract absolute distance information from a self-mixing interferometry (SMI) signal, in this paper we propose an approach based on a particle swarm optimization (PSO) algorithm instead of frequency estimation for absolute distance. The algorithm is utilized to search for the global minimum of the fitness function that is established from the self-mixing signal to find out the actual distance. A resolution superior to $25{\mu}m$ in the range from 3 to 20 cm is obtained by experimental measurement, and the results demonstrate the superiority of the proposed approach in comparison with interpolated FFT. The influence of different external feedback strength parameters and different inertia weights in the algorithm is discussed as well.

Development of PSD Sensor Based Range Finder System Using Linearizing Function of Voltage-Distance Conversion

  • Kim, Yu-Chan;Ryoo, Young-Jae;Song, Jeong-Gon;Lee, Ju-Sang
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1427-1430
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    • 2005
  • In this paper, the range finder system using a PSD sensor suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of a PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. For a known environment, a mobile robot scans the surroundings using a PSD sensor that can rotate $360^{\circ}$. Finally, the performance and accuracy of the developed system are verified according to the comparison the distance by proposed function with real distance

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Electrochemical Signal Amplification by Redox Cycling in Distance-Controlled Nanogap Devices

  • Park, Dae Keun;Park, Jong Mo;Shin, Jong-Hwan;Yun, Wan Soo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.269-269
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    • 2013
  • Redox cycling in between the two working electrodes in an electrochemical cell can lead a great signal enhancement. In this work, we report on a systematic examination of current amplification along with the decrease in the gap distance of a nanogap device which was fabricated by the combination of photo and chemical lithography [1]. The gap distance was controlled by the chemical lithographic process of surfacecatalyzed growth of metallic layer on pre-defined electrodes with wider initial gap. Enhancement of the redox current of ferri/ferrocyanide was observed upon gap distance reduction and the current is amplified about a thousand times in this redox system when the gap distance was decreased from 200 nm to 30 nm. The experimental results were discussed on the basis of the cyclic voltammetry (CV), atomic force microscopy (AFM) and scanning electron microscopy (SEM).

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3D Spreader Position Information by the CCD Cameras and the Laser Distance Measuring Unit for ATC

  • Bae, Dong-Suk;Lee, Jung-Jae;Lee, Bong-Ki;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1679-1684
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    • 2004
  • This paper introduces a novel approach that can provide the three dimensional information on the movement of a spreader by using two CCD cameras and a laser distance sensor, which enables an ALS (Automatic Landing System) to be used for yard cranes at a harbor. So far a kind of 2D Laser scanner sensor or laser distance measuring units are used as corner detectors for the geometrical matching between the spreader and a container, which provides only 2D information which is not enough for an accurate and fast ALS system required presently. In addition to this deficiency in performance, the price for the system is too high to be adopted widely for the ALS. Therefore, to overcome these defects, a novel method to acquire the three dimensional information for the movement of a spreader including skew and sway angles is proposed using two CCD cameras and a laser distance sensor. To show the efficiency of proposed algorithm, real experiments are performed to show the accuracy improvement in distance measurement by fusing the sensory information of CCD camera and laser distance sensor.

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A Distance Estimation Algorithm Based on Multi-Code Ultrasonic Sensor and Received Signal Strength (다중 코드 초음파와 전파 신호 강도를 이용한 거리 측정)

  • Cho, Bong-Su;Kim, Phil-Soo;Moon, Woo-Sung;Baek, Kwang-Ryul
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.2
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    • pp.149-156
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    • 2011
  • This paper reveals a distance estimation algorithm based on multi-code ultrasonic and wireless sensor network. For measuring the distances among the sensor nodes, each ultrasonic transmitter transmits multi-code ultrasonic signal simultaneously. Receivers use cross correlation method to separate the coded signals. The information of measured distances is broadcasted to each sensor node by wireless sensor network. The wireless sensor network measures the distance among the sensor nodes using the received signal strength of the broadcasting. The multi-code ultrasonic have a limitation of measurable distance. And the received signal strength is affected from an environment. This paper measures a distance using ultrasonic and a received signal strength in short range. These measured data are applied to the least square estimation algorithm. By the expansion of the fitting curve, a distance measurement in long range using the received signal strength is compensated. The coupled system reduce the error to an acceptable level.