• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.726-729
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• 2006

As a active soundscape facility, P.A. system is a useful instrument to give place identity and vitality by letting out music, environmental music, bird singing sound etc. In this study, to know the optimistic distance and sound level range of introducing sound, sound levels due to distance were measured and subject responses were checked by questionnaire. Levels from 64dB to 71dB are recommended by subjects. And the optimistic level of introducing level is related with level variance of sound source. The results of this study could used for street furniture location design and P.A. system output level.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2393-2395
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• 2001

The mobile robot is used as an instrument of transportation in automated plant. But the greater part of the moving method is the wheel-type. The wheel-type robot is easier control than the track-type, However the track-type is better than the wheel-type in bad landform(bend landform, an incline plane, stairs). In this paper, we propose the navigation algorithm of track-type robot in order to improve a defect of wheel-type. We experiment in bend landfrom and even ground to differentiate the navigation method. To estimate robot pose, we use the 80196 in a close distance and the vision-board in a long distance. Each data is managed in main PC and then the part of managing correspond to every sensor. We also use twelve supersonic wave-sensors to recognize external surroundings. As the result of experiment, we analyze the algorithm of control and make possible surroundings-adaptation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.329-336
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• 2010

This study deals with the measurement of reflectivity as well as the distance accuracy with Terrestrial Laser Scanner(TLS) using time of flight methods and near infrared wave length, for a variety of user-made targets. Especially, point clouds' reflection to several targets was measured with Gretag Macbeth il spectrophotometer in the office. And the distance accuracy in comparison to reference distance for TLS performance evaluation, was tested after scanning the user-made targets and measuring the inter-pillars distances over the precise EDM calibration baseline. The results of test was shown that except white resin objects, with approx. 10m and 170m inter-pillar distances, other targets achieved the distance accuracy of several millimeters(mm) with respect to standard distances. Future work should be concentrate on a few parameters influencing on the distance accuracy such as atmospheric correction, instrument correction, the additive constant or zero/index correction, etc.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.18-25
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• 2006

Existing outdoor lighting evaluation methods for the city beautification at night, the measurements are limited by one point to analyze the photometric data. However, this methods could not represent the diversity of photometric result from the distance. This study aims to propose the new outdoor lighting evaluation method of structure surface luminance in accordance with the measuring distance. For the purpose, the field measurement and simulation of an illuminated structure were conducted by CS-100, Digital Photometry Instrument ProMetric 1400, and the Lightscape v 3.2 from the distance of 100[m], 300[m], 500[m]. The result shows that evaluation of the surface luminance by the distance should be measured from about 100[m] of an illuminated object for getting the familiar result from computer simulation.

• Explosives and Blasting
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• v.29 no.2
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• pp.43-50
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• 2011

This study measured a vibration level at each distance of construction fields where blasts occur using Lion measuring instrument and used BlastmateIII to measure vibration velocity at the same distance. A total 130 blasts occurred with the weight of a total of 5,180 kg and the number of blast holes per blast was 5, 10 and 20. The weight of 4 kg was used for each hole. Vibrations caused by blast was measured at the distance with the same velocity and level. Measurements were carried 15~102 m away from the blast source. and 273 data on vibration velocity and level were obtained from eight measurements. It analysed data on vibration velocity measured based on existing correlation formulas and compared them to real measurements to analyse interrelationship.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.279-285
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• 2012

Albeit the use of terrestrial 3D laser scanner (TLS) in the parts of landslide monitoring, cultural heritage documentation, civil engineering, urban engineering, etc. is increasing more and more, there is no international standardization regulation about the accuracy evaluation of the geometric element values, target, instrument calibration and test procedures, etc. Accordingly, this study deals with the manufacturing of TLS performance test target and the evaluation of TLS distance measurement and shows its suitability as the test target.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.23-31
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• 2014

In this study, the method to measure effectively the ground surface displacement of slope was proposed using the Laser Distance Measurer (LDM). Applying the proposed technique is more simple and easier than the complicated and high-priced instrument to measure the ground surface displacement. LDM is an instrument that the red laser aimed at the target and then the reflected laser used for calculating the distance. The advantages of LDM are easy operating method, high measurement precision and lower in price. To check the feasibility, the proposed method applied to the real site that the ground surface displacement of slope was occurred continuously. The ground surface displacements were occurred in various points of the natural and cut slopes located at the lower part of coal mine waste heap due to the load of waste heap. To measure directly the ground surface displacement in this site, 6 measurement sections and 26 measurement points were selected. As the result of the displacement measured by the proposed technique within a certain period time, the accumulative ground surface displacement could be measured as well as the velocity of displacement could be estimated. Also, the progress direction of ground surface displacement can be confirmed and predicted through the analysis of all measured result.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.53-64
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• 2014

The purpose of the study is to develop a scale for measuring learning outcomes in the distance teacher training programs. In order to develop the measurement instrument, the forty-four items were developed based on the literature review and ten experts' review. For data collection, a web-based survey was conducted among teachers taking a distance teacher training program at National Education Training Institute. With the data of 205 sample size from the first survey, the Exploratory Factor Analysis was conducted and seven factors were identified. In order to validate the test, the Confirmatory Factor Analysis was performed with 293 respondents from the second survey. In conclusion, this study reports the reliability and validity of a scale for learning outcomes in distance teacher training programs consisting of seven factors with 34 items; 1) system quality, 2) content quality, 3) service quality, 4) use, 5) benefit, 6) satisfaction, 7) transfer.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.10-18
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• 2001

The existing measurement system to ground-surface displacement survey of the slope has been including the hazard for the measure in site and the difficulty for install, maintenance and control of expensive instruments, which are impossible of whole survey on the slope surface. To overcome of those defects, Softcopy Photogrammertry method is used, which can measure displacement of ground-surface on the slope and structure deformation vectors. Recently, the survey methods applying the advantages of Photogrammetry and Digital Photogrammetry Survey are widely used. In this study, therefore, the development and application of the new instrument mechanism on the the site example are studied. Through the application of Softcopy Photogrammetry, the 3-D data of ground surface on the dangerous slope could be effectively obtained at the long distance, which are obtained through the reform process of contour line. Those are different to the results of the Close-Range Photogrammetry analysis. In ground instrumentation parts, the new practical system shall be the technical base to improve of the instrument machine as well as can be widely applied in civil engineering and others branch.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.388-393
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• 1992

An infrared range finder using a self-mixing laser diode (SM-LD), which has been proposed and developed by the Authors, can measure not only a range of a moving target but its velocity simultaneously. In this paper, described is that the precise mode-hop pulse train can be obtained by employing a new signal processing circuit even when the backscattered light returning into the SM-LD is much more weaker. As a result, the distance to a tilted square sheet made from aluminium or white paper, which is placed 10 cm through 60 cm from the SM-LD, is measured with accuracy of a few percent even when the tilting angle is less than 75 degrees or 85 degrees, respectively. And in this paper, described is the range-image recognition of a plane object under the condition of standstill. The output laser beam is scanned by scanning two plane mirrors-equipped with each stepping motor. And we succeeded in the acquisition of the range-image of a plane object in a few tens of seconds. Furthermore, described is a feasibility study about the range-image recognition of a slowly moving plane object.