• Journal of Information Technology Services
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• v.11 no.4
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• pp.153-170
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• 2012

When companies or institutes manage data, in order to utilize it as useful resources for decision-making, it is essential to offer precise and reliable data. While most small and medium-sized enterprises and public institutes have been investing a great amount of money in management and maintenance of their data systems, the investment in data management has been inadequate. When public institutions establish their data systems, inspection has been constantly carried out on the data systems in order to improve safety and effectiveness. However, their capabilities in improving the quality of data have been insufficient. This study develops an automatic tool to diagnose the quality of data in a way to diagnose the data quality condition of the inspected institute quantitatively at the stage of design and closure by inspecting the data system and proves its practicality by applying the automatic tool to inspection. As a means to diagnose the quality, this study categorizes, in the aspect of quality characteristics, the items that may be improved through diagnosis at the stage of design, the early stage of establishing the data system and the measurement items by the quality index regarding measurable data values at the stage of establishment and operation. The study presents a way of quantitative measurement regarding the data structures and data values by concretizing the measurement items by quality index in a function of the automatic tool program. Also, the practicality of the tool is proved by applying the tool in the inspection field. As a result, the areas which the institute should improve are reported objectively through a complete enumeration survey on the diagnosed items and the indicators for quality improvement are presented quantitatively by presenting the quality condition quantitatively.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1053-1065
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• 2018

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (${\geq}3mm$) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.35-44
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• 2012

In the current maintenance system of building, safety inspection and precise safety diagnosis have been applied only for Type 1 and 2 buildings. Considering the fact that middle and small-size buildings take up 99.4% of total buildings, it is necessary to implement safety diagnosis for the buildings to make long lasting buildings. This study suggested improvement methods for adjusting the existing evaluation items to middle and small-size buildings by reviewing the current diagnosis system and a survey. Based on the methods, an improved model, which modified the existing diagnosis model, was developed by applying fuzzy theory. If the improved model of this study is applied on site, the buildings except Type 1 and 2 could be maintained constantly. In the future studies, it is necessary to implement the developed model practically, to strengthen the feasibility of the model.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.2
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• pp.1-8
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• 2024

The expansion joint is installed to offset the expansion of the superstructure and must ensure sufficient gap during its service life. In detailed guideline of safety inspection and precise safety diagnosis for bridge, damage due to lack or excessive gap is specified, but there are insufficient standards for determining the abnormal behavior of superstructures. In this study, a data-based maintenance was proposed by continuously monitoring the expansion-gap data of the same expansion joint. A total of 2,756 data were collected from 689 expansion joint, taking into account the effects of season. We have developed a method to evaluate changes in the expansion joint-gap that can analyze the thermal movement through four or more data at the same location, and classified the factors that affect the superstructure behavior and analyze the influence of each factor through deep learning and explainable artificial intelligence(AI). Abnormal behavior of the superstructure was classified into narrowing and functional failure through the expansion joint-gap evaluation graph. The influence factor analysis using deep learning and explainable AI is considered to be reliable because the results can be explained by the existing expansion gap calculation formula and bridge design.

• Progress in Medical Physics
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• v.29 no.4
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_2
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• pp.239-245
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• 2022

Using the fatigue limit (∆σ_unsm) and residual stress (σ_r) of the UNSM smooth specimen, the harmless maximum crack depth (a_hlm) according to the crack aspect ratio (As) was evaluated. In addition, the relationship between the minimum crack depth (a_NDI1, a_NDI2) detectable by non-destructive inspection(NDI), the crack depth (a₂₅, a₅₀) that reduces the fatigue limit by 25% and 50%, and a_hlm were evaluated. The harmless crack condition was determined by the deepest crack point (point A). Since a_hlm is larger than a₂₅ and a₅₀, a₂₅ and a₅₀ can secure the safety and reliability of steel via UNSM. Because a_NDI1 and a_NDI2 are larger than a₂₅ and a₅₀, cracks in a₂₅ and a₅₀ cannot be detected by non-destructive testing. Therefore it is necessary to apply more precise NDI.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.30-42
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• 2022

Due to the increase in construction of tunnels, the burdens of maintenance works for tunnel structures have been increasing in Korea. In addition, the increase of traffic volume and aging of materials also threatens the safety of tunnel facilities, therefore, maintenance costs are expected to increase significantly in the future. Accordingly, automated condition assessment technologies like image-based tunnel scanning system for inspection and diagnosis of tunnel facilities have been proposed. For image-based tunnel scanning system, it is key to create a planar image through stitching of multiple images captured by tunnel scanning system. In this study, performance of feature-based stitching algorithms suitable for stitching tunnel scanning images was evaluated. In order to find a suitable algorithm SIFT, ORB, and BRISK are compared. The performance of the proposed algorithm was determined by the number of feature extraction, calculation speed, accuracy of feature matching, and image stitching result. As for stitching performance, SIFT algorithm was the best in all parts of tunnel image. ORB and BRISK also showed satisfactory performance and short calculation time. SIFT can be used to generate precise planar images. ORB and BRISK also showed satisfactory stitching results, confirming the possibility of being used when real-time stitching is required.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.130-138
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• 2015

According to the "Safety Evaluation Detailed Instructions (Dam)", a precise safety inspection is carried out for dams that exceed a certain scale. However, as the Hydrological Safety Evaluation from various evaluation standards is designed to evaluate the safety of existing dams considering PMF(Probable Maximum Flood), the evaluation is much less applicable for most agricultural reservoirs. Therefore, the Hydrological Safety Guidelines for agricultural reservoirs are expected to be re-evaluated considering the diverse risk factors with the coefficient model and AHP(Analytic Hierarchy Process) in this study. The coefficient model has been developed by selecting the hydrological safety superordinate subordinate evaluation factors to reflect diverse risk factors of agricultural reservoirs. This study indicated that in the short term, improving the safety check condition evaluation grade will be useful to improve the hydrological safety of the agricultural reservoir because it can be performed immediately.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.235-243
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• 2014

According to the "Safety Evaluation Detailed Instructions (Dam)", precise safety inspection is carried out for dams that exceed a certain scale. However, as the Hydrological Safety Evaluation from various evaluation standards is designed to evaluate the safety of existing dams considering PMF, the evaluation is much less applicable for most agricultural reservoirs. Therefore, the Hydrological Safety Guidelines for agricultural reservoirs are expected to be re-evaluated considering the diverse risk factors with the coefficient model and AHP in this study. The coefficient model has been developed by selecting the hydrological safety superordinate subordinate evaluation factors to reflect diverse risk factors of agricultural reservoirs. After calculating the sum of indicators score for each evaluation factors, validation procedures were performed for the questionnaire which a panel answered. The practical coefficient has eventually been estimated for the hydrological safety evaluation considering the diverse risk factors. The conclusions acquired based on the study done are that both most agricultural reservoirs were classified as flood defense capability is insufficient and agricultural reservoirs which meet embankment-freeboard standards considering PMF was overestimated.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.109-128
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• 2022

The precise inspection for safety and diagnosis (PISD) of tunnel has been conducted by the special act on safety control of public structures. However, the present assessment for the segmental lining of TBM tunnel has limitation such as: NDTs for integrity, segmental configuration for field inspection, and consideration for jacking system. Even if the number of TBM tunnel is less than 1% of enrolled facility in FMS, more attention to maintenance should be necessary due to its usage such as multi-use facility and national important facility. Compared to NATM tunnel, excavated by drilling and blasting and then installed lining by cast-in-place within 6~12 m, TBM tunnel is cut out ground by disk and cutter-bit and then assembled 7 pieces of precast segment, 1.2~1.4 m wide. Different features of design, construction, and maintenance should be considered to be more exact evaluation of TBM tunnel. The characteristics of defect is categorized and analyzed with 11 operational TBM tunnels in domestic subway. To be more comprehend various particular defects, foreign studies have been also adapted. Crack and leakage are categorized in 7 patterns. Breakage/spalling and corrosion are also grouped into 3 patterns. Patterned defects or damages are fed back in design, construction, and are useful guidelines for maintenance stage in future.