• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.170-173
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• 2007

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1238-1241
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• 1993

A fuzzy mathematical model is presented that can be applied to support the inspection of organizations by an internal or external evaluation group. The model offers the opportunity to deal with the situation of common practice in which such evaluations are considered as a time series rather than single events. A hypothetical but realistic example is given to illustrate the computational procedure involved.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.15-23
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• 2023

Through the revision of the Framework Act on Administrative Regulations (July 17, 2019), the government minimized regulations and applied the comprehensive negative regulation principle to enhance economic vitality. However, a legally mandatory certification system has been applied to marine pollution prevention materials and chemicals, and inspection is conducted every time a product is sold, suppressing the autonomy of manufacturers. In addition, the majority of manufacturers of marine pollution prevention materials and chemicals are small businesses; therefore, they take the approach of producing small quantities of products whenever a buyer requests an order. Consequently, the need for deregulation was raised to ensure autonomy of the market and industry, and improve efficiency in accordance with the current trend of approval, performance test, and inspection systems for marine pollution prevention materials and chemicals. In this study, problems within the current system were identified and improvement plans are proposed through comparison and analysis of domestic and foreign systems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.155-163
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• 2009

The purpose of this paper is to investigate the bond strength between old and new concrete as well as flexural tensile strength of concrete. To achieve this purpose, a comprehensive experimental program has been set up and strength tests using a series of specimens have been carried out. The present study represents that the flexural bond strength between old and new concrete is much smaller than that of flexural tensile strength. The ratio of bond strength to flexural tensile strength ranged through 15~27%. It is seen that concrete-to-concrete bond strength has been affected by curing condition. Also, test results of tensile strength show that recommendation by ACI 363 committee is estimated to be more realistic than another recommendations for predicting tensile strength of concrete.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1525-1534
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• 2018

Objective: The aim of this study was to examine the use of outcome-based observations within Assured Dairy Farm scheme (ADF), Soil Association Organic Standards (SA), and cross compliance (CC) farm assessment reports. Methods: A total of 449 ADF reports, 37 SA reports and 26 CC reports were analyzed and their objective comments categorized as either resource-based or outcome-based. Results: A mean of 61.0% of ADF questions were responded to with comments, in comparison to 25.0% of SA and, 21.0% of CC report questions. The SA and CC reports had significantly more outcome-based comments than the ADF (p<0.001). The assessors' tendency of choosing resource-based approach was revealed in the questionnaire results. Conclusion: Generally, the comments were comprehensive and contained professional judgements. Large numbers of comments provided in the ADF reports were mostly compliant and resource-based evidence, which serves as proof of assessment rather than aiding the certifying process. The inclusion of specific welfare outcome measures in the SA inspection likely increased the use of outcome-based comments in the reports, irrespective of whether the farm achieved compliance with a given standards. The CC scheme, on the other hand, focused on providing outcome-based evidence to justify noncompliant decisions.

• Computers and Concrete
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• v.2 no.6
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• pp.439-454
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• 2005

When deterioration of concrete is observed in a structure, it is highly desirable to determine the cause of such deterioration. Only by understanding the cause can an appropriate repair strategy be implemented to address both the cause and the symptom. In colder climates, bridge deck deterioration is often caused by chlorides from de-icing salts, which penetrate the concrete and depassivate the embedded reinforcement, causing corrosion. Bridge decks can also suffer from other deterioration mechanisms, such as alkali-silica reaction, freeze-thaw, and shrinkage. There is a need for a comprehensive and integrative system to help with the inspection and evaluation of concrete bridge deck deterioration before decisions are made on the best way to repair it. The purpose of this research was to develop a model to help with the diagnosis of concrete bridge deck deterioration that integrates the symptoms observed during an inspection, various deterioration mechanisms, and the probability of their occurrence given the available data. The model displays the diagnosis result as the probability that one of four deterioration mechanisms, namely shrinkage, corrosion of reinforcement, freeze-thaw and alkali-silica reaction, is at fault. Sensitivity analysis was performed to determine which probabilities in the model require refinement. Two case studies are included in this investigation.

• Earthquakes and Structures
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• v.8 no.4
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• pp.821-841
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• 2015

This paper proposes a two-stage imaging approach for quantitative inspection of damages in metallic plates using the fundamental anti-symmetric mode of ($A_0$) Lamb wave. The proposed approach employs a number of transducers to transmit and receive $A_0$ Lamb wave pulses, and hence, to sequentially scan the plate structures before and after the presence of damage. The approach is applied to image the corrosion damages, which are simplified as a reduction of plate thickness in this study. In stage-one of the proposed approach a damage location image is reconstructed by analyzing the cross-correlation of the wavelet coefficient calculated from the excitation pulse and scattered wave signals for each transducer pairs to determine the damage location. In stage-two the Lamb wave diffraction tomography is then used to reconstruct a thickness reduction image for evaluating the size and depth of the damage. Finite element simulations are carried out to provide a comprehensive verification of the proposed imaging approach. A number of numerical case studies considering a circular transducer network with eight transducers are used to identify the damages with different locations, sizes and thicknesses. The results show that the proposed methodology is able to accurately identify the damage locations with inaccuracy of the order of few millimeters of a circular inspection area of $100mm^2$ and provide a reasonable estimation of the size and depth of the damages.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.111-123
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• 2006

In the design of bridges, exact evaluation of traffic loading is very important for the safety and maintenance of bridges. In general, traffic loading is represented by live load (including impact load) and fatigue load. For exact evaluation of traffic loading, it is important to get reliable and comprehensive truck data including the traffic and weight information. It requires the development of Bridge Weigh-In-Motion (BWIM), which measures the truck weights without stopping the traffic. Objectives of the study is (1) to develop the BWIM system, (2) to verified the system in bridges in Highways.

• Smart Structures and Systems
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• v.29 no.1
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• pp.221-235
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• 2022

Manual inspection of steel box girders on long span bridges is time-consuming and labor-intensive. The quality of inspection relies on the subjective judgements of the inspectors. This study proposes an automated approach to detect and segment cracks in high-resolution images. An end-to-end cascaded framework is proposed to first detect the existence of cracks using a deep convolutional neural network (CNN) and then segment the crack using a modified U-Net encoder-decoder architecture. A Naïve Bayes data fusion scheme is proposed to reduce the false positives and false negatives effectively. To generate the binary crack mask, first, the original images are divided into 448 × 448 overlapping image patches where these image patches are classified as cracks versus non-cracks using a deep CNN. Next, a modified U-Net is trained from scratch using only the crack patches for segmentation. A customized loss function that consists of binary cross entropy loss and the Dice loss is introduced to enhance the segmentation performance. Additionally, a Naïve Bayes fusion strategy is employed to integrate the crack score maps from different overlapping crack patches and to decide whether a pixel is crack or not. Comprehensive experiments have demonstrated that the proposed approach achieves an 81.71% mean intersection over union (mIoU) score across 5 different training/test splits, which is 7.29% higher than the baseline reference implemented with the original U-Net.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.327-336
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• 2023

The focus of this research was to devise a conceptual methodology for drone usage and to assess the viability of safety checklist items specific to drone application in safety oversight. The appraisal was grounded in a focus group interview involving professionals from construction management and safety fields. The proposed process was segmented into four stages: 1) pre-flight phase for flight plan development, 2) drone flight phase for safety condition inspection utilizing checklist items, 3) post-flight phase for visual asset analysis, and 4) documentation and management phase. Furthermore, the research scrutinized the applicability of 32 distinct safety checklist items for drone operations. The primary aim of this investigation was to probe the possible deployment of drones as part of construction safety inspections at work sites. However, it bears mentioning that subsequent research should strive to gather a more extensive sample size through questionnaire surveys, thereby facilitating quantitative analysis. Administering such surveys would yield more comprehensive data compared to a focus group interview, which was constrained by a limited participant count. In summation, this study lays a foundational groundwork for understanding the potential advantages and challenges associated with integrating drones into construction safety management.