• Title/Summary/Keyword: Roughness index

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The study on the improvement of measuring longitudinal roughness index for airport runway using a laser profilometer (레이저 평탄성장비를 사용한 공항활주로 종단 평탄성지수 측정개선에 관한 연구(I))

  • 박기순;손형호;전현욱
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.755-760
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    • 1998
  • This study was performed to improve the evaluation of the longitudinal roughness index for various profilometers at airport runway. Especially, a laser type of profilemeter subjected to the longitudinal roughness index has been focused. The test result show that a new type of profile index, IRI(International roughness index) resulted from a laser type of profilometer was profitable for airport runway etc.. The present study provides useful results for the improvement of evaluation of the conventional profile index.

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A Study on Index of Vegetation Surface Roughness using Multiangular Observation

  • Konda, Asako;Kajiwara, Koji;Honda, Yoshiaki
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.673-678
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    • 2002
  • A satellite remote sensing is useful for vegetation monitoring. But it has some problem. One of these, it is difficult to find a difference of vegetation surface roughness using satellite remote sensing. Each vegetation type has unique surface roughness, for example needle leaves forest, broad leaves forest and grassland. Difference of vegetation surface roughness can be detected by satellite multiangular observation. In this study, objective is to propose index of vegetation surface roughness using BRF property. General vegetation indices are calculated from nadir data of satellite data. A proposed index is calculated from two different observation zenith angle data. Two different zenith data can provide BRF (Bi-directional Reflectance Factor) property of satellite observation data. A proposed index was able to detect different value on where NDVI shows similar high value areas of rice field and forest. This index is useful for vegetation monitoring.

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The Influence of Rock Joint Roughness and Normal Stress on Shear Behaviour (거칠기와 수직응력에 따른 암석 절리면의 전단거동)

  • Lee, Myoung-Ho;Kim, Jong-Woo;Chang, Kwang-Taek
    • Tunnel and Underground Space
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    • v.17 no.3 s.68
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    • pp.186-196
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    • 2007
  • In this study, direct shear tests were carried out on the 30 rock joint samples in order to investigate the influence of roughness and normal stress on the shear behaviour. Joint roughness profiles were measured by use of 3D laser profiler, and then the samples were equally classified into three individual groups according to the roughness index of rock joints. Peak shear strength, residual shear strength, shear stiffness, dilation angle of rock joints were investigated in condition of five different constant normal load. Peak shear strength was increased as roughness index was increased, and the influence of roughness on strength was found to be more considerable in case of lower normal stress condition. Residual shear strength and shear stiffness were increased as roughness index and normal stress were increased. Finally dilation angle was decreased as normal stress was increased, but it was increased as roughness index was increased in the same normal stress condition.

Development of Weigh Calculation Method for Pavement Roughness Index Considering Vehicle Wandering Distribution (원더링 분포를 고려한 도로포장 평탄성 지수의 가중치 산정기법 개발)

  • Lee, Jaehoon;Sohn, Ducksu;Park, Jejin;Cho, Yoonho
    • International Journal of Highway Engineering
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    • v.19 no.5
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    • pp.89-96
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    • 2017
  • PURPOSES: This study aims to develop a rational procedure for estimating the pavement roughness index considering vehicle wandering. METHODS : The location analysis of the passing vehicle in the lane was performed by approximately 1.2 million vehicles for verification of the wandering distribution. According to verification result, the distribution follows the normal distribution pattern. The probability density function was estimated using each lane's wandering distribution model. Then the procedure for applying a weighted value into the lane profile was conducted using this function. RESULTS : The modified index, MRIw, with consideration towards applying the wandering weighted value application was computed then compared with MRI. It was found that the Coefficient of Variation for distribution of lateral roughness index in the lane was high in the case of a large difference between each index (i.e., MRIw and MRI) observed. CONCLUSIONS : This result confirms that the new procedure with consideration of the weight factor can successfully improve the lane representative characteristics of the roughness index.

Performance Analysis of Batch Process Terrain Relative Navigation Using Area based Terrain Roughness Index for Lunar Lander (영역기반 지형 험준도 지수를 이용한 달착륙선의 일괄처리방식 지형상대항법 성능분석)

  • Ku, Pyung-Mo;Park, Young-Bum;Park, Chan-Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.7
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    • pp.629-639
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    • 2016
  • Batch process TRN(Terrain Relative Navigation) using an altimeter is a technique to correct position by correlating a series of periodically measured terrain height profile and terrain height candidate profile of the DEM(Digital Elevation Map). However, it is generally known that the performance of TRN is degraded when measured terrain height profile and terrain height candidate profiles of the DEM are similar at hill or repetitive terrain. In this paper, area based terrain slope roughness index[11] is applied and area based terrain curvature roughness index which can detect similarity of terrain in ROI(Region Of Interest) is proposed to overcome this problem. Applying terrain roughness indexes to terrain relative navigation system of lunar lander, it is shown that TRN using area based terrain roughness results in improved performance compared to conventional trajectory based method through simulation.

A Feasibility Study of Constitution Discrimination Using a Measurement Device for Dynamic Friction Coefficients of the Back of a Hand (손등피부 운동 마찰계수 측정기를 이용한 체질 판별 가능성 연구)

  • Kim, Keun-Ho;Woo, Yung-Jae;Lee, Hae-Jung;Lee, Yu-Jung;Kim, Jong-Yeol
    • Journal of Sasang Constitutional Medicine
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    • v.22 no.4
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    • pp.20-29
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    • 2010
  • 1. Objectives Our goal is to observe the feasibility of constitution discrimination from computing quantitative roughness index from dynamic friction coefficients and their gradients with the measurement device of skin friction with 3-Axis load cell sensor. 2. Methods In the traditional Korean medicine, skin diagnosis is one of the examination methods to discriminate Sasang constitution since it was known that Tae-eumin has rough skin, and Soyangin has smooth one. It is based on the skin roughness on the back of one's hand for the discrimination. The measurement device of skin friction with 3-axis load cell sensor has been developed in order to provide quantitative skin roughness through dynamic friction coefficients. The effective interval of the coefficients is obtained from the automatic sampling algorithm to use their curvature and slope. Then, Fisher's discriminant function of them makes the discrimination. 3. Results The success rate of extracting the effective interval was about 90% and the discriminant accuracy between Tae-eumin and Soyangin was 70% and 68% for men and women, respectively. The entire methods showed the possibility to distinguish between Tae-eumin and Soyangin by using stochastic properties of roughness index, which can make the entire system to include the measurement, the computation of the roughness index and the discrimination of constitution automatical. 4. Conclusions The measurement device, the automatic sampling algorithm of dynamic friction coefficients and the constitution discrimination algorithm were developed, respectively, and their combination can become the serial and automatic procedure for quantitative and objective skin diagnosis, which mimics the movement of the Oriental medical doctors' skin diagnosis. It can be applied to healthcare as well as the diagnosis of constitution in a u-Health system soon.

Effect of Roughness and Densification of Precalendered Sheet on Surface Roughening

  • Youn, Hye-Jung;Lee, Hak-Lae;Chin, Seong-Min;Lee, Sang-Gil;Choi, Ik-Sun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.5 s.118
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    • pp.47-53
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    • 2006
  • To meet the ever increasing quality demand of coated papers and duplex boards, the local gloss variation and print unevenness must be avoid. To do this, surface roughening phenomenon which affects local gloss and print unevenness was investigated. In this study, the effect of roughness and densification of sheet obtained at various calendering conditions on surface roughening was examined. To evaluate the calendering effect properly we introduced a new value of roughening index by moisture for evaluation of surface roughening. Caliper and roughness of sheet decreased with increasing of calendering temperature and pressure, and the remarkable reduction of those properties occurred at the temperature around Tg. Roughening index increased when the amount of water increased and calendaring temperature and pressure increased. And as the sheet became denser by calendering, the roughening index increased to some extent. But roughening index by moisture is the lowest for sheet precalendered at higher temperature condition. When the surface of calendered sheet is rougher, there is more roughening of surface. The severe condition of calendering made the roughening index by moisture small.

Development of Surface Roughness Index using Gyroscope (자이로스코프를 이용한 노면 평탄도 분류지수 개발)

  • Hong, Sun-Gi;Park, Jun-Mo
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.3
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    • pp.127-132
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    • 2020
  • In this study, the process of providing information necessary to remove physical barriers such as road slopes that obstruct the activities of the disabled is in progress. Through experiments, we implement a quantified road surface roughness index that enables the implementation of IoT-based systems necessary for the elderly and the disabled to safely move to their destination. As a preliminary study, a road surface measurement device using a gyroscope was devised. To check the roughness and flatness of the road surface, X, Y displacement, and acceleration displacement were measured using a gyroscope. By calculating the measured data, the roughness and flatness of the road surface were quantified from 0 to 100. We implemented an algorithm that divides this index into 4 stages, displays it on a map, and provides it to users. Finally, a system for the disabled and elderly electric wheelchair users to secure basic mobility was established.

A COMPARATIVE STUDY ON SURFACE ROUGHNESS OF GLASS IONOMER CEMENT BY SURFACE COATING AGENT (표면도포제에 따른 수복용 글라스 아이오노머 세멘트의 표면조도 비교)

  • Choi, Byung-Jai;Hwang, Dong-Hwan
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.4
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    • pp.915-924
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    • 1996
  • The purpose of this paper is to investigate the surface roughness of glass ionomer cement during initial setting time followed by applying surface coating agent. No other finishing or polishing procedure is done and each surface coating agents (varnish, adhesive, gloss, sealant) are used after filling of glass ionomer cement. Surface roughness indices(Ra) are measured and surface contours are obtained electronically by Surfcorder SEF-30D(Kosaka laboratory Ltd., Japan). The results are as follows: 1. During initial setting time, surface roughness increases slightly regardless of surface coating agents. But it is statistically insignificant. (p>0.05) 2. Among surface coating agents used, Ra indices of group using varnish are high significantly compared to other groups regardless of elapsed time.(p<0.05) Among the groups which has used other surface coating agents except for the varnish group, similar Ra index all over the experiment is obtained, when compared to control group (no agent). 3. If no surface treatment is performed, tri-cure glass ionomer cement (Vitremer) has higher Ra Index than light cure glass ionomer cement (Fuji II LC) (t<0.05). But there is no difference between two groups in Ra index if any kinds of agents are applied except for sealant. (t>0.05)

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A study on analysis to time series data by using vegetation surface roughness index

  • Konda, Asako;Kajiwara, Koji;Honda, Yoshiaki
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.706-708
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    • 2003
  • Index for difference of vegetation surface roughness (BSI: Bi-directional reflectance factor structure Index) was proposed in our laboratory (Konda et al., 2000). It is thought that BSI is useful vegetation index for vegetation monitoring. If it can be applied for global covered satellite data, detailed monitoring of global vegetation can be expected. However, in order to apply BSI to global satellite data, there are some problems to be solved. In this study, in order to make global data set of BSI, it arranged about processing of the global satellite data for making BSI data sets.

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