• Title/Summary/Keyword: Indirect Inspection

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An Empirical Study on the Recognized Necessity by Vietnamese Users for the Motorcycle Inspection System (베트남 사용자가 인식하는 이륜차 검사제도 필요성에 관한 실증연구)

  • Lee, Yang-Ho;Ryu, Ki-Hyun;Son, Sung-Ho;Jung, Se-Hee
    • Journal of Auto-vehicle Safety Association
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    • v.10 no.2
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    • pp.43-49
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    • 2018
  • Southeast Asia is a strategic market for both technology and inspection system to enter simultaneously. At the core market is Vietnam which is know to have the fourth highest registration of motorcycles as of 2016. The Motorcycle Inspection System is a social regulation, furthermore, the impact of the system is delivered through indirect means such as minimization of social cost. Therefore, measurements on the perception of users on the needs for an inspection system serves as valuable data to simultaneously enter this markets. This research is an empirical study on the perception of Vietnamese users on the needs to adopt a motorcycle inspection system based on data collected through surveys and is aimed at conducting a preliminary investigation on consumer behavior in Vietnam. The empirical study conducted through surveys revealed that Vietnamese motorcycle users perceive the needs for an inspection system for maintenance, safe operations and selling used vehicles at a reasonable price. In addition, the study also verified that the safe operations factor has a moderating effect due to interaction between prevention of illegal vehicle and reduction of emission gases. This research results present implications in developing equipment adapted to the local area in order to enter into a strategic market. Moreover, it is expected that the findings will also serve as valuable data for bilateral cooperation between the two countries and the diffusion of technology.

Surface Defect Inspection Method of Iron Samples using Image Processing (영상처리를 이용한 용선시편의 표면결함 검사방법)

  • Ahn, H.S.;Jeong, K.W.;Kim, J.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.10
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    • pp.78-88
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    • 1995
  • For producing iron or steel products with good quality, the concentration of the material components should be analyzed quickly with high relability using XRF(Fluorescent X-Ray Spectrometer). Since the analysis results are much dependent upon the surface con- dition, the samples have to be prepared to have good test condition. This study presents an image processing system for inspecting the surface condition of the iron test sample. In order to use thd computer vision system, we need to develop a lighting device and image processing algorithm. For the adequate lighting device of inspection system, the indirect lighting device is contrived to cut the external light and provide uniform, stable and cold light. The image processing algorithm is aimed to reduce inspection time and to get similar analyzing results to those of the experienced operators. At first, the image processing algorithm checks whether the surface of the iron sample is ground well or not. Then, the defects; hole or dig are conted and surface condition is evaluated. In addition, the algorithm gives the reliability of the analyzing results in order to help operator's decision.

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Influence of Micro-Structural Characteristics of Concrete on Electrical Resistivity (콘크리트의 미세구조 특성이 전기저항에 미치는 영향)

  • Yoon, In-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.122-129
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    • 2013
  • Since electrical resistivity of concrete can be measured in a more rapid and simple way than chloride diffusivity, it should be primarily regular quality control of the electrical resistivity of concrete which provides the basis for indirect of quality control of chloride diffusivity during concrete construction. If this is realized, the electrical resistivity of concrete can be a crucial parameter to establish maintenance strategy for marine concrete structures. The purpose of this study is to develop, design and test a surface electrical resistivity measurement protocol. Microstructural affecting factors such as capillary water, porosity, tourtousity, and so on, on the electrical resistivity of concrete were examined taking into account for mixing proportion properties, and hydration stage. This study can provide a non-destructive approach for durability design of marine concrete. From the relationship between electrical resistivity and chloride diffusivity, it is expected that the result is subsequently used as a calibration curve for an indirect control of the chloride diffusivity based on regular measurements of the electrical resistivity during concrete construction.

Techniques for Characterizing Surface Deterioration of Epoxy Exposed to Ozone Damage (오존에 노출된 에폭시 코팅재의 표면 열화특성 평가기술)

  • Choi, Sung-Min
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.167-177
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    • 2014
  • New technologies for water purification are continuously emerging to address global water quality problems, and one such technology involves advanced hermetic water purification facilities made by concrete that utilize ozone treatment processes. Better knowledge about surface deterioration of epoxy coating exposed to ozone treatment is needed as a foundation for development of improved methods and materials in the future. This study utilized atomic force microscopy (AFM), nanoindentation methods, and existing indirect methods such as visual observation, changes in mass, surface observation and chrominance analysis, to evaluate epoxy water-resistance and anti-corrosiveness. This study considered six different epoxy formulations to assess typical degradation characteristics of epoxy surfaces with regard to water-resistance/anti-corrosiveness. AFM and nanoindentation techniques emerged as promising direct methods with potential to provide quantitative measures of surface quality that are improvements upon existing indirect methods. The experiments also confirmed that some of the epoxy-coatings were severely iMPacted by ozone exposure, and thus the results demonstrate that concern about such deterioration is justified.

Evaluation on diagnostic efficiency of the standard tube agglutination test for bovine brucellosis (소 브루셀라병 표준시험관응집반응법 진단효율 평가)

  • Sung, So-Ra;Kim, Ji-Yeon;Her, Moon;Lee, Kichan;Gu, Jeong-Hui;Kang, Sung-Il;Lee, Hyang-Keun;Kim, Suk-Mi;Jung, Suk-Chan
    • Korean Journal of Veterinary Service
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    • v.35 no.4
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    • pp.269-273
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    • 2012
  • A confirmatory serological test, the standard tube agglutination test (STAT) is evaluated for the diagnostic efficiency in brucellosis Korea. A total of 345 bovine samples were collected from regional veterinary branch under national brucellosis monitoring program from January 2010 to June 2012 in Korea. These samples were diagnosed as suspected serum and brucellosis positive by the Rose Bengal test (RBT) and the STAT, respectively. The STAT was compared and evaluated with three serological test such as the indirect-enzyme linked immunosorbent assay (I-ELISA), competitive-enzyme linked immunosorbent assay (C-ELISA) and fluorescence polarisation assay (FPA) prescribed for international trade by OIE. Among the 345 bovine serum samples, 302 (87.5%) were diagnosed as positive in the STAT, while 215 (62.3%), 223 (64.6%) and 194 (56.2%) serum samples were diagnosed as positive for brucellosis in the I-ELISA, C-ELISA and FPA, respectively. The STAT showed quite high positive results as compared with three prescribed tests of OIE. FPA, I-ELISA and C-ELISA have shown 60.6%, 64.9% and 67.2% correlation, respectively as compared to the STAT. However correlations of three prescribed tests ranged high 84.1~97.7%. Especially, correlation between I-ELISA and C-ELISA is quite high, 97.7%. These results suggest that the STAT has shown many false-positive reactions. Therefore, additional serological test, such as ELISAs and FPA, would be necessary to adopt as a confirmatory test in the national surveillance program of bovine brucellosis in Korea.

Brucellosis in sheep and goat of Bogra and Mymensingh districts of Bangladesh

  • Rahman, Md. Siddiqur;Hahsin, Md. Ferdous Ali;Ahasan, Md. Shamim;Her, Moon;Kim, Jeong Yeong;Kang, Sang Il;Jung, Suk Chan
    • Korean Journal of Veterinary Research
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    • v.51 no.4
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    • pp.277-280
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    • 2011
  • Brucellosis is the most important bacterial disease of livestock in Bangladesh. The present study was conducted to determine the seroprevalence of brucellosis in goat and sheep in Mymensingh and Bogra districts of Bangladesh using slow agglutination test and Rose Bengal test as screening test and indirect enzyme linked immunosorbent assay as confirmatory test. Questionnaire based data on age, gender, area, client's complaint, number of animals in herds, disease history, reproductive problems such as abnormal uterine discharge, abortion or previous abortion in sheep and goat and their reproductive diseases were recorded. A total of 200 sera samples were collected from 80 sheep and 120 goats. The prevalence of brucellosis in goat was 2.50% and 1.25% in sheep. Positive reactors were only detected in female of both goat and sheep. In this study, there existed a significant association among abortion and the prevalence of brucellosis (p < 0.01). The prevalence of brucellosis in sheep and goat in Bangladesh is not negligible, and it is therefore worth considering the adoption of preventive measures.

Hilbert transform based approach to improve extraction of "drive-by" bridge frequency

  • Tan, Chengjun;Uddin, Nasim
    • Smart Structures and Systems
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    • v.25 no.3
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    • pp.265-277
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    • 2020
  • Recently, the concept of "drive-by" bridge monitoring system using indirect measurements from a passing vehicle to extract key parameters of a bridge has been rapidly developed. As one of the most key parameters of a bridge, the natural frequency has been successfully extracted theoretically and in practice using indirect measurements. The frequency of bridge is generally calculated applying Fast Fourier Transform (FFT) directly. However, it has been demonstrated that with the increase in vehicle velocity, the estimated frequency resolution of FFT will be very low causing a great extracted error. Moreover, because of the low frequency resolution, it is hard to detect the frequency drop caused by any damages or degradation of the bridge structural integrity. This paper will introduce a new technique of bridge frequency extraction based on Hilbert Transform (HT) that is not restricted to frequency resolution and can, therefore, improve identification accuracy. In this paper, deriving from the vehicle response, the closed-form solution associated with bridge frequency removing the effect of vehicle velocity is discussed in the analytical study. Then a numerical Vehicle-Bridge Interaction (VBI) model with a quarter car model is adopted to demonstrate the proposed approach. Finally, factors that affect the proposed approach are studied, including vehicle velocity, signal noise, and road roughness profile.

Numerical Bayesian updating of prior distributions for concrete strength properties considering conformity control

  • Caspeele, Robby;Taerwe, Luc
    • Advances in concrete construction
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    • v.1 no.1
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    • pp.85-102
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    • 2013
  • Prior concrete strength distributions can be updated by using direct information from test results as well as by taking into account indirect information due to conformity control. Due to the filtering effect of conformity control, the distribution of the material property in the accepted inspected lots will have lower fraction defectives in comparison to the distribution of the entire production (before or without inspection). A methodology is presented to quantify this influence in a Bayesian framework based on prior knowledge with respect to the hyperparameters of concrete strength distributions. An algorithm is presented in order to update prior distributions through numerical integration, taking into account the operating characteristic of the applied conformity criteria, calculated based on Monte Carlo simulations. Different examples are given to derive suitable hyperparameters for incoming strength distributions of concrete offered for conformity assessment, using updated available prior information, maximum-likelihood estimators or a bootstrap procedure. Furthermore, the updating procedure based on direct as well as indirect information obtained by conformity assessment is illustrated and used to quantify the filtering effect of conformity criteria on concrete strength distributions in case of a specific set of conformity criteria.

Technology for the Detection of Corrosion Defects in Buried Pipes of Nuclear Power Plants with 3D FEM (3D 유한요소법을 이용한 원전 매설배관 부식결함 탐상기술 개발)

  • Kim, Jae-Won;Lim, Bu-Taek;Park, Heung-Bae;Chang, Hyun-Young
    • Corrosion Science and Technology
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    • v.17 no.6
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    • pp.292-300
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    • 2018
  • The modeling of 3D finite elements based on CAD data has been used to detect sites of corrosion defects in buried pipes. The results generated sophisticated profiles of electrolytic potential and vectors of current distributions on the earth surface. To identify the location of defects in buried pipes, the current distribution on the earth surface was projected to a plane of incidence that was identical to the pipe locations. The locations of minimum electrolytic potential value were found. The results show adequate match between the locations of real and expected defects based on modeling. In addition, the defect size can be calculated by integrating the current density curve. The results show that the defect sizes were $0.74m^2$ and $0.69m^2$, respectively. This technology may represent a breakthrough in the detection of indirect damage in various cases involving multiple defects in size and shape, complex/cross pipe systems, multiple anodes and stray current.

Effectiveness of Direct Safety Regulations on Manufacturers and Users of Industrial Machines: Its Implications on Industrial Safety Policies in Republic of Korea

  • Choi, Gi Heung
    • Safety and Health at Work
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    • v.8 no.1
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    • pp.59-66
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    • 2017
  • Background: Despite considerable efforts made in recent years, the industrial accident rate and the fatality rate in the Republic of Korea are much higher than those in most developed countries in Europe and North America. Industrial safety policies and safety regulations are also known to be ineffective and inefficient in some cases. Methods: This study focuses on the quantitative evaluation of the effectiveness of direct safety regulations such as safety certification, self-declaration of conformity, and safety inspection of industrial machines in the Republic of Korea. Implications on safety policies to restructure the industrial safety system associated with industrial machines are also explored. Results: Analysis of causes in industrial accidents associated with industrial machines confirms that technical causes need to be resolved to reduce both the frequency and the severity of such industrial accidents. Statistical analysis also confirms that the indirect effects of safety device regulation on users are limited for a variety of reasons. Safety device regulation needs to be shifted to complement safety certification and self-declaration of conformity for more balanced direct regulations on manufacturers and users. An example of cost-benefit analysis on conveyor justifies such a transition. Conclusion: Industrial safety policies and regulations associated with industrial machines must be directed towards eliminating the sources of danger at the stage of danger creation, thereby securing the safe industrial machines. Safety inspection further secures the safety of workers at the stage of danger use. The overall balance between such safety regulations is achieved by proper distribution of industrial machines subject to such regulations and the intensity of each regulation. Rearrangement of industrial machines subject to safety certification and self-declaration of conformity to include more movable industrial machines and other industrial machines with a high level of danger is also suggested.