• Title/Summary/Keyword: Roughness Index

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Development of an Automatic Transverse and Longitudinal Road Profile Measurement System (노면 종.횡단 요철 자동 측정 시스템 개발)

  • Eom, Jung-Hyun;Seo, Dong-Sun;Huh, Woong;Roo, Myong-Chan;Kim, Joon-Bum
    • Journal of IKEEE
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    • v.5 no.1 s.8
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    • pp.75-84
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    • 2001
  • The reliable data relating to the condition of road surface is of increasing importance to deliver the road condition to driver and road management authority. This paper describes the development of a new high-speed. automatic, road data collection system, which collects the longitudinal road data with ${\sim}30cm$ interval covering full width of the road at 100km/h speed. The system calculates the international roughness index (IRI) from the collected data and displays the IRI and road profile data on the screen. To develope the system, we implement an optical range finder, advanced distance and motion detectors, and signal processing and display modules. The measurement accuracy of the system at 70km/h operation speed shows ${\pm}0.1m/km$ in the IRI for the standard road. To confirm the performance of the developed system, we also measure the IRI of a deployed highway road and compare the results with a conventional system and human eye measurement results.

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Azimuthal Angle Scan Distribution, Third Order Response, and Optical Limiting Threshold of the Bismarck Brown Y:PMMA Film

  • Fadhil Abass Tuma;Hussain Ali Badran;Harith Abdulrazzaq Hasan;Riyadh Chassib Abul-Hail
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.721-731
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    • 2023
  • This paper studies various roughness parameters, besides waviness, texture, and nonlinear parameters of Bismarck brown Y (BBY)-doped Poly(methyl methacrylate) (PMMA) films based on the computed values of optical limiting (OL) threshold power and nonlinear refractive index. The films' morphology, grain size, and absorption spectra were investigated using atomic force microscopy in conjunction with ultraviolet-visible (UV-Vis) spectrophotometer. The particle size of the films ranged between 4.11-4.51 mm and polymer films showed good homogeneity and medium roughness, ranging from 1.11-4.58 mm. A polymer film's third-order nonlinear optical features were carried out using the Z-scan methodology. The measurements were obtained by a continuous wave produced from a solid-state laser with a 532 nm wavelength. According to the results, BBY has a nonlinear refractive index of 10-6 cm2/W that is significantly negative and nonlinear. The optical limiting thresholds are roughly 10.29, 13.52, and 18.71 mW, respectively. The shift of nonlinear optical features with the film's concentration was found throughout the experiment Additionally, we found that the polymer samples have outstanding capabilities for restricting the amount of optical power that may be transmitted through them. We propose that these films have the potential to be used in a wide variety of optoelectronic applications, including optical photodetectors and optical switching.

A Study on the Mapping of Wind Resource using Vegetation Index Technique at North East Area in Jeju Island (영상자료의 식생지수를 이용한 제주 북동부 지역의 풍력자원지도 작성에 관한 연구)

  • Byun, Ji Seon;Lee, Byung Gul;Moon, Seo Jung
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.15-22
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    • 2015
  • To create a wind resource map, we need a contour map, a roughness map and wind data. We need a land cover map for the roughness map of these data. A land cover map represents the area showing similar characteristics after color indexing based on the scientific method. The features of land cover is classified by Remote sensing technique. In this study, we verified the application of the NDVI technique is reasonable after we created the wind resource map using roughness maps by unsupervised classification and NDVI technique. As a result, the wind resource map using the NDVI technique showed a 60% accordance rate and difference in class less than one. From the results, The NDVI technique is found alternative to create roughness maps by the unsupervised classification.

Conveyance Verification through Analysis of River Vegetation and Soil Impact using Sentinel-2 (Sentinel-2를 활용한 하천의 식생 및 토양 영향 분석을 통한 통수능 검정)

  • Bang, Young Jun;Choi, Byeong Jun;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.4
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    • pp.37-45
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    • 2021
  • Flooding damage may occur due to an unexpected increase in rainfall in summer. Previously, the roughness coefficient, which is a major factor of conveyance, was calculated through on-site measurement, but in case of on-site measurement, there are many limits in accurately grasping changes in vegetation. In this study, the vegetation index (NDVI) was calculated using the Sentinel-2 optical images, and the modified roughness coefficient was calculated through the density and distribution area of the vegetation. Then the calculated roughness coefficient was applied to HEC-RAS 1D model and verified by comparing the results with the water level at the water level station directly downstream of the Soyang River dam. As a result, the error rate of the water level decreased about 14% compared to applying the previous roughness coefficient. Through this, it is expected that it will be possible to refine the flood level of rivers in consideration of seasonal flood characteristics and to efficiently maintain rivers in specific sections.

Surface characteristics and bonding performance of polymer restorative materials for dental CAD/CAM systems (치과 캐드캠 시스템에서 사용되는 고분자 수복재료들의 표면특성과 접착양상)

  • Kim, Jae-Hong;Kim, Ki-Baek
    • Journal of Technologic Dentistry
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    • v.41 no.3
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    • pp.203-209
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    • 2019
  • Purpose: The purpose of this study was to investigate the mechanical properties of polymer prosthetic and restorative materials for dental CAD/CAM using two test method; surface characteristics and shear bond strength. Methods: Commercialized CAD/CAM polymer blanks were investigated; One kinds of PMMA, and one PEKK blanks. A total of 20 PMMA and PEKK specimens were prepared, and each group was divided into 10 specimens. Average surface roughness was observed under surface profilometer. The contact angle was measured with a surface electrooptics. The bond strength was evaluated by a universal testing machine at a crosshead speed of 5mm/min. The data were statistically analyzed using independent t-test and Fisher's exact test(P<0.05). Results: The PMMA and PEKK group showed a significant difference in the shear bond strength with the composite resin(P<0.05). The surface roughness of the PEKK group was higher than that of the PMMA group. The fracture mode were observed in PEKK groups with 50% showing adhesive remnant index score. Conclusion: PEEK is used as substructure material and composite veneering material is applied. PEKK resins will contribute to the development of successful products that will provide structural and aesthetic satisfaction.

A Study on the Adhesive Characteristics of Nano Scale Particles Considering Asperity Interaction (거칠기 돌기의 상호작용을 고려한 미세입자의 응착특성에 관한 연구)

  • Lee, Chang-Hun;Lee, Kyong-Hun;Yoon, Jun-Ho;Shin, Young-Eui
    • Journal of Welding and Joining
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    • v.26 no.1
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    • pp.56-62
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    • 2008
  • In this paper, elastic and plastic adhesion index was very important in deciding adhesive characteristics and varying elastic and plastic index, dimensionless load and pull-off force were analyzed and simulated. Finally, using AFM, experimental surface roughness parameters of substrates and pull-off force between tip and substrates were produced. Using these values, pull-off forces were calculated and were compared with experimental pull-off forces. Through simulation and experiment, it was found that interaction of asperity also had very important influence on adhesive contact.

Development of Rumbling Index and its Identification (럼블링 음질 인덱스와 음질요소 관계 규명)

  • 김병수;박동철;이상권
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.997-1002
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    • 2004
  • Rumbling sound is one of the most important interior sound of a passenger car. The conventional rumbling noise research was focused on the reduction of the A-weighted sound pressure level. However A-weighted sound pressure level can not give the whole story about the rumbling sound of a passenger car. In this paper, we employed sound metric which is the subjective parameter used in psycoacoustics. According to recent research results, the relation between sound metrics and subjective evaluation is very complex and has nonlinear characteristics. In order to estimate this nonlinear relationship, artificial neural network theory has been applied to derivation of sound quality index for rumbling sound of a passenger car.

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Effect of Surface Profiles on Pavement Fatigue Life (포장 프로파일이 포장 피로수명에 미치는 영향 분석)

  • Park, Dae-Wook;An, Deok-Soon;Kwon, Soo-Ahn
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.167-174
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    • 2009
  • The simulation of dynamic load was conducted based on surface profile on asphalt concrete pavement, vehicle speeds, and suspension types using a truck simulation program. The results of the simulated dynamic load based on different surface profile, vehicle speeds, and suspension types are analyzed. As pavement roughness and vehicle speed are increased, the dynamic load was increased. Walking beam suspension produces greater dynamic load than air spring suspension. Pavement damage index is calculated based on covariance of dynamic load and Paris-Erdogan fracture parameter, n which is based on creep compliance tests of asphalt mixtures used in Korea. The higher covariance of dynamic load, confidence level, and fracture parameter are used, the greater pavement damage index is obtained. Specification of pavement roughness can be developed in various vehicle speeds and asphalt mixtures, and pay factor can be determined after constructing asphalt concrete pavement using pavement damage concepts.

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Polishing of ferrule endfaces of the plastic optical fiber connector for automobiles (자동차용 POF 광커넥터 페룰 단면 연마공정 연구)

  • Jeong M.Y.;Kim C.S.;Lee H.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.468-472
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    • 2005
  • This paper is to investigate the influence of the endface quality on the loss characteristics of a plastic optical fiber connector for in-car network service. Using the parameters of the surface roughness and applied load, insertion loss of connector is measured. Due to scattering and change of refractive index, an optimal condition for low-loss coupling exists. We present the optimal condition as surface roughness $R_{rms}$ = 8 nm and contact load up to 50 N.

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Chip breakability evaluation in turning by an orthogonal array method (직교배열법에 의한 선삭가공시 칩절단성 평가)

  • 배병중;박태준;양승한;이영문
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.10a
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    • pp.279-284
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    • 2000
  • The object of this paper is to evaluate the chip breakability using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. L$\sub$9/(3$^4$) orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. The evaluation of chip breakability is used the chip breaking index(C$\sub$B/), non-dimensional parameter. And the analysis of variance (ANOYA)-test has been used to check the significance of cutting parameters. Using the result of ANOYA-test, the experimental equation of chip breakability, which consists of significant cutting parameters, has been developed. The coefficient of determination of this equation is 0.866.

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