• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.77-84
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• 2006

We should measure receiver tracking threshold and command threshold of the satellite in Integrate System Test (IST) in order to check the normal received power range of LEO(Low Earth Orbit) satellite S-band receiver. In this paper, the algorithm of threshold measurement is examined and the result measured in Integrated System Test is displayed. And than, the factor could have an effect on the result of threshold measurement except the capability of receiver itself was analyzed and compensated as many as distorted value according to that analysis.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.263-265
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• 2009

In order to improve the output efficiency of the PV system, we adopt maximum power point tracking(MPPT) techniques. This paper analyzes a two-mode MPPT method based on the variable step size incremental conductance method and constant voltage MPPT method. Compared with the conventional MPPT method, the proposed method can effectively improve the MPPT speed and maximize the efficiency with the irradiation and temperature changing. In this paper, a theoretical analysis is provided and feasibility of this method is proved by simulation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.1
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• pp.95-102
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• 2018

Only the habitat characteristics and breeding status of Paridae have been studied, in addition to the lack of research on Parus varius varius, there is no study on the home-range in the post fledging period. This study was analyzed the home-range size of Parus varius varius in the post fledging period. The survey was conducted in the site located in Dankook Univ. Cheonan Campus(Middle Chungcheong Province). We captured five newborn Parus varius varius using artificial nest was installed before. Radio-tracking was carried out for analysis of home-range, and MCP (Minimum Convex Polygon) was used for analysis. We analyzed 1 individual tracked 15 days (VT5) and 4 individuals which missing radio-tracking transmitter within 3 days (VT1~VT4). Home-range of VT5 gradually increased to 1,38ha, 1.42ha, 2.14ha in the order of early, middle, late period. On the other hand, moving distance was decreased to 174.558m 125.129m, 120.180m. Home-range of V1~VT4 was estimated as 0.81ha which was 75.3% share of home-range of VT5 in early period. As the result it was found that home-range is formed far apart from artificial nest that has been influenced by human being interference, thereafter gradually adapting to interference and spreading close to artificial nest. through this research, we can construct basic ecological data for protecting habitat of Parus varius varius and increasing life rate. As first radio-tracking study of Parus varius varius home-range in the post fledging period, it is expected to be useful for the future study of home-range.

• Smart Structures and Systems
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• v.6 no.9
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• pp.1057-1077
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• 2010

An early detection of structural damages is critical for the decision making of repair and replacement maintenance in order to guarantee a specified structural reliability. Consequently, the structural damage detection, based on vibration data measured from the structural health monitoring (SHM) system, has received considerable attention recently. The traditional time-domain analysis techniques, such as the least square estimation (LSE) method and the extended Kalman filter (EKF) approach, require that all the external excitations (inputs) be available, which may not be the case for some SHM systems. Recently, these two approaches have been extended to cover the general case where some of the external excitations (inputs) are not measured, referred to as the adaptive LSE with unknown inputs (ALSE-UI) and the adaptive EKF with unknown inputs (AEKF-UI). Also, new analysis methods, referred to as the adaptive sequential non-linear least-square estimation with unknown inputs and unknown outputs (ASNLSE-UI-UO) and the adaptive quadratic sum-squares error with unknown inputs (AQSSE-UI), have been proposed for the damage tracking of structures when some of the acceleration responses are not measured and the external excitations are not available. In this paper, these newly proposed analysis methods will be compared in terms of accuracy, convergence and efficiency, for damage identification of structures based on experimental data obtained through a series of laboratory tests using a scaled 3-story building model with white noise excitations. The capability of the ALSE-UI, AEKF-UI, ASNLSE-UI-UO and AQSSE-UI approaches in tracking the structural damages will be demonstrated and compared.

• Korean Institute of Interior Design Journal
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• v.25 no.3
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• pp.51-59
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• 2016

The technique for Eye-tracking is to trace the movements of pupils so that the eye's exploration response to be digitized. The procedure of Observation Experiment shows a mutual environmental characteristics between men and measuring devices. In order to improve the reliability and to secure the objectivity of the data acquired from eye-tracking, it is very important to analyze the procedures for the experiment to be prepared and the test data to be saved. Based on this viewpoint, the convergent exploration activities at the observation experiment with the objects of sport images were examined to find out what influences the context effect given by experimental environments have on this experiment. In addition, the starting time of attention affecting the reliability of observation data has been estimated. When the observation time is to be subdivided by the unit of second. The attention disperses for the individual characteristics to be appreciated. However, in case of analysis by the overall average, there was the problem that the section of attention dispersed to make it difficult to analyze the subjects' observation features. The study results made it possible to understand the physiological characteristics which were near unconsciousness, when there was an intensive attention for the first 3 seconds and the observation data were shown to be in ordinary range after 4 seconds. The analysis of observation with the focus of the intensive attention enabled the analysis with the first 3 seconds excepted so that it might approach the ordinary range of observation data. The distribution of attention for the first 3 seconds showed the intensive attention, which was on the center. The emergence of intensive attention and the overlapping of the centers can be considered as a context effect due to the correction for the preparing process of experiment. Accordingly, it is thought to be helpful to the security of objectivity and the construction of reliability of eye-tracking data to analyze the observation features shown after the deletion of the data for the first 3 seconds.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.609-620
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• 2010

In order to provide a tailored education for learners within the ubiquitous environment, it is critical to undertake an analysis of the learning activities of learners. For this purpose, SCORM (Sharable Contents Object Reference Model), IMS LD (Instructional Management System Learning Design) and other standards provide learning design support functions, such as, progress checks. However, in order to apply these types of standards, contents packaging is required, and due to the complicated standard dimensions, the facilitation level is lower than the work volume when developing the contents and this requires additional work when revision becomes necessary. In addition, since the learning results are managed by the server there is the problem of the OS being unable to save data when the network is cut off. In this study, a system is realized to manage the actions of learners through the event interception of a web-browser by using event hooking. Through this technique, all HTMLbased contents can be facilitated again without additional work and saving and analysis of learning results are available to improve the problems following the application of standards. Furthermore, the ubiquitous learning environment can be supported by tracking down learning results when the network is cut off.

• Journal of KSNVE
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• v.9 no.3
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• pp.613-620
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• 1999

Brake judder{or cold judder) caused by the disc thickness variation(DTV) is investigated experimentally, This cold judder is often perceived by steering wheel vibration, brake pedal pulsation, and vehicle body vibration. In this paper, how the DTV profile affects the vibration characteristics of vehicle body is shown by order tracking analysis(OTA) and operational vibration analysis(OVA) The tri-axial vibrations are measured at the knuckle, lower rm, and the body side of the lower arm. Also, measured are the wheel speed and the detail DTV profile. The interpretations of OTA results in three directions of tested vehicle indicate the relative importance in the contribution of the run-out and the DTV to the judder vibration. Also, the OVA results show the prominent vibration amplitude of the lower arm in the direction of the vehicle movement. in which the second order of wheel speed is dominant. These results could be used to diagnose the judder problem and to establish the correction methods.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.4
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• pp.135-144
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• 2018

The domestic pigsty environment is highly vulnerable to the spread of respiratory diseases such as foot-and-mouth disease because of the small space. In order to manage this issue, a variety of studies have been conducted to automatically analyze behavior of individual pigs in a pig pen through a video surveillance system using a camera. Even though it is required to correctly segment touching pigs for tracking each pig in complex situations such as aggressive behavior, detecting the correct boundaries among touching pigs using Kinect's depth information of lower accuracy is a challenging issue. In this paper, we propose a segmentation method using motion information of the touching pigs. In addition, our proposed method can be applied for detecting tracking errors in case of tracking individual pigs in the complex environment. In the experimental results, we confirmed that the touching pigs in a pig farm were separated with the accuracy of 86%, and also confirmed that the tracking errors were detected accurately.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.250-256
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• 2009

This paper presents a robotic tower-crane system using encoder and gyroscope sensors as path tracking devices. Tower crane work is often associated with falling accidents and industrial disasters. Such problems often incur a loss of time and money for the contractor. For this reason, many studies have been done on an automatic tower crane. As a part of 5-year 23-million-dollar research project in Korea, we are developing a robotic tower crane which aims to improve the safety level and productivity. We selected a luffing tower crane, which is commonly used in urban construction projects today, as a platform for the robotic tower crane system. This system comprises two modules: the automated path planning module and the path tracking module. The automated path planning system uses the 3D Cartesian coordinates. When the robotic tower crane lifts construction material, the algorithm creates a line, which represents a lifting path, in virtual space. This algorithm seeks and generates the best route to lift construction material while avoiding known obstacles from real construction site. The path tracking system detects the location of a lifted material in terms of the 3D coordinate values using various types of sensors including adopts encoder and gyroscope sensors. We are testing various sensors as a candidate for the path tracking device. This specific study focuses on how to employ encoder and gyroscope sensors in the robotic crane These sensors measure a movement and rotary motion of the robotic tower crane. Finally, the movement of the robotic tower crane is displayed in a virtual space that synthesizes the data from two modules: the automatically planned path and the tracked paths. We are currently field-testing the feasibility of the proposed system using an actual tower crane. In the next step, the robotic tower crane will be applied to actual construction sites with a following analysis of the crane's productivity in order to ascertain its economic efficiency.

• Education of Primary School Mathematics
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• v.23 no.1
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• pp.1-26
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• 2020

The purpose of this study was to analyze the process of reading and understanding mathematics lesson plan through eye-tracking to suggest implications of pre-service teacher education. As a result of the analysis, the pre-service teachers felt that the mathematics lesson plans were more difficult than the experienced teacher, they read and understood the mathematics lesson plan in sequential order. Experienced teachers, on the other hand, used a hypertext reading strategy to find key topics and make connections in order to grasp the flow of instruction in mathematics lesson plan. Based on these results, several suggestions were drawn for pre-service teachers when teaching their ability to read and understand mathematics lesson plan.