• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.486-491
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• 2016

Disturbance/vibration reduction is critical in many applications using machine vision. The off-focusing or blurring error caused by vibration degrades the machine performance. In line with this, real-time disturbance estimation and avoidance are proposed in this study instead of going with a more familiar approach, such as the vibration absorber. The instantaneous motion caused by the disturbance is sensed by an attitude heading reference system module. A periodic vibration modeling is conducted to provide a better performance. The algorithm for vibration avoidance is described according to the vibration modeling. The vibration occurrence function is also proposed, and its parameters are determined using the genetic algorithm. The proposed algorithm is experimentally tested for its effectiveness in the vision inspection system.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.237-240
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• 2006

Almost 30 years have been passed since the first nuclear power plant was operated in Korea. Many studies have been actively conducted from the early 1990's in order to develop the deterioration management system for concrete structures in NPPs(Nuclear Power Plants) accordingly. Base on these studies, a systematic deterioration management program has developed and operated since 1997. According to this program, systematic inspections to provide database and evaluation were periodically performed (every overhaul at intervals of $12{\sim}18$ month and every five years). Accumulated deterioration database was usefully utilized for the NPP PSR (Periodic Safety Review). In this paper, the long-term durability and integrity of Kori 1,2 NPP concrete structures which are the oldest ones in Korea were evaluated based on the precise inspection database and regulatory inspection results including compressive strength, depth of carbonation, amount of chlorination and spontaneous potential of reinforcing bar, etc. It was noted that Kori 1,2 NPP structures have not any serious durability problems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.1
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• pp.109-122
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• 2022

The purpose of information security activities is to reduce large-scale material and human accidents that are concerned about hacking damage to important systems, such as control systems, through periodic preventive activities in addition to finding the cause and taking follow-up measures after damage caused by hacking. For this reason, although each institution is using a security work audit model in accordance with the relevant regulations, it is not easy to conduct company-wide inspection activities due to the constraints of manpower and time. Therefore, in this paper, we will analyze the major vulnerabilities of public institutions over the past 10 years and present a security audit model that can perform efficient security activities compared to the models for domestic and foreign security audits.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4313-4318
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• 2016

Background: This study documented the performance of providers of visual inspection with acetic acid (VIA) at primary health centers, assessing their compliance with the VIA skills checklist and determinants of non-compliance, and exploring their perceptions of VIA training sessions. Materials and Methods: A cross-sectional study was conducted among VIA providers in the $Mekn\grave{e}s$-Tafilalet region of Morocco. Structured observation of their performance was conducted through supervisory visits and multiple focus group discussions (FGDs). Results: Performance of all the recommended steps for effective communication was observed in a low proportion of procedures (36.4%). Midwives/nurses had higher compliance than general practitioners (GPs) (p<0.001). All recommended steps for VIA examination were performed for a high proportion of procedures (82.5%). Compliance was higher among midwives/nurses than among GPs (p<0.001) and among providers in rural areas than those in urban areas (p<0.001). For pre-VIA counselling, all recommended steps were performed for only 36.8% of procedures. For post-VIA counseling, all recommended steps were performed in a high proportion (85.5% for VIA-negative and 85.1% for VIA-positive women). Midwives/nurses had higher compliance than GPs when advising VIA-positive women (p=0.009). All infection prevention practices were followed for only 14.2% of procedures, and compliance was higher among providers in rural areas than those in urban areas (p<0.001). Most FGD participants were satisfied with the content of VIA training sessions. However, they suggested periodic refresher training and supportive supervision. Conclusions: Quality assurance of a cervical cancer screening program is a key element to ensure that the providers perform VIA correctly and confidently.

• Structural Engineering and Mechanics
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• v.31 no.5
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• pp.507-526
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• 2009

Based on numerical and experimental methods, a systematic structural evaluation of a steel natatorium in service was carried out in detail in this paper. Planning of inspection tasks was proposed firstly according to some national codes in China in order to obtain the economic and reliable results. The field visual inspections and static computation were conducted in turn under in-service environmental conditions. Further a three-dimensional finite element model was developed according to its factual geometry properties obtained from the field inspection. An analytical modal analysis was performed to provide the analytical modal properties. The field vibration tests on the natatorium were conducted and then two different system identification methods were used to obtain the dynamic characteristics of the natatorium. A good correlation was achieved in results obtained from the two system identification methods and the finite element method (FEM). The numerical and experimental results demonstrated that the main structure of the natatorium in its present status is safe and it still satisfies the demand of the national codes in China. But the roof system such as purlines and skeletons must be removed and rebuilt completely. Moreover the system identification results showed that field vibration test is sufficient to identify the reliable dynamic properties of the natatorium. The constructive suggestion on structural evaluation of the natatorium is that periodic assessment work must be maintained to ensure the natatorium's safety in the future.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.2
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• pp.153-169
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• 2018

A submarine has a pressure hull that can withstand high hydraulic pressure and therefore, requires the use of highly advanced shipbuilding technology. When producing a pressure hull, periodic inspection, repair, and maintenance are conducted to maintain its soundness. Of the maintenance methods, Non-Destructive Testing (NDT) is the most effective, because it does not damage the target but sustains its original form and function while inspecting internal and external defects. The NDT process to detect defects in the welded parts of the submarine is applied through Magnetic particle Testing (MT) to detect surface defects and Ultrasonic Testing (UT) and Radiography Testing (RT) to detect internal defects. In comparison with RT, UT encounters difficulties in distinguishing the types of defects, can yield different results depending on the skills of the inspector, and stores no inspection record. At the same time, the use of RT gives rise to issues related to worker safety due to radiation exposure. RT is also difficult to apply from the perspectives of the manufacturing of the submarine and economic feasibility. Therefore, in this study, the Phased Array Ultrasonic Testing (PAUT) method was applied to propose an inspection method that can address the above disadvantages by designing a probe to enhance the precision of detection of hull defects and the reliability of calculations of defect size.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.165-173
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• 2023

The data management and the evaluation of defects in the bridge are generally conducted based on inspection and diagnosis data, including the exterior damage map and defect quantity table prepared by periodic inspection. Since most of these data are written in 2D-based documents and are difficult to digitize in a standardized manner, it is challenging to utilize them beyond the defined functionality. This study proposed methods to efficiently build a BIM (Building Information Modeling)-based bridge damage model from raw data of inspection report and to manage and utilize the damage information linking to bridge model through the spread sheet data generated by COBie (Construction Operations Building Information Exchange). In addition, a method to conduct the condition assessment of defects in bridge was proposed based on an automatic evaluation process using digitized bridge member and damage information. The proposed methods were tested using superstructure of PSC-I girder concrete bridge, and the efficiency and effectiveness of the methods were verified.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.26-31
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• 2022

Changwon City has the second highest accident rate with 79.6 according to the city bus accident rate. In fact, 250,000 people use the city bus a day in Changwon, The number of accidents is increasing gradually. In addition, a recent fire accident occurred in the engine room of a city bus (CNG) in Changwon, which has gradually expanded the public's anxiety. In the case of business vehicles, the government conducts inspections with a short inspection cycle for the purpose of periodic safety inspections, etc., but it is not in the monitoring stage. In the case of city buses, the operation records are monitored using Digital Tacho Graph (DTG). As such, driving records, methods, etc. are continuously monitored, but inspections are conducted every six months to ascertain the safety and performance of automobiles. It is difficult to identify real-time information on automobile safety. Therefore, in this study, individual automobile management solutions are presented through machine learning techniques of inspection results based on driving records or habits by linking DTG data and Vehicle Inspection Management System (VIMS) data for city buses in Changwon from 2019 to 2020.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1485-1494
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• 2023

The bow of the nuclear fuel assembly is a well-known phenomenon. One of the vital criteria during the history of nuclear fuel development has been fuel assembly's mechanical stability. Once present, the fuel assembly bow can lead to safety issues like excessive water gap and power redistribution or even incomplete rod insertion (IRI). The extensive bow can result in assembly handling and loading problems. This is why the fuel assembly's bow is one of the most often controlled geometrical factors during periodic fuel inspections for VVER when compared e.g. to on-site fuel rod gap measurements or other instrumental measurements performed on-site. Our proposed screening method uses existing video records for fuel inspection. We establish video frames normalization and aggregation for the purposes of bow measurement. The whole process is done by digital image processing algorithms which analyze rotations of video frames, extract angles whose source is the fuel set torsion, and reconstruct torsion schema. This approach provides results comparable to the commonly utilized method. We tested this new approach in real operation on 19 fuel assemblies with different campaign numbers and designs, where the average deviation from other methods was less than 2 % on average. Due to the fact, that the method has not yet been validated during full scale measurements of the fuel inspection, the preliminary results stand for that we recommend this method as a complementary part of standard bow measurement procedures to increase measurement robustness, lower time consumption and preserve or increase accuracy. After completed validation it is expected that the proposed method allows standalone fuel assembly bow measurements.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.65-74
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• 2007

Vehicle inspection is a system to help all vehicles function safely through periodic maintenance. Vehicle inspections have been performed since 1962 in Korea by the government in order to reduce traffic accidents due to vehicle defects. Also, vehicle inspections may help protect citizens against uninsured vehicles and illegal vehicle remodeling by discovering and disclosing those vehicles. The prime objective of vehicle inspection is to guarantee all vehicles drive safely on the road by inspecting and fixing items which can affect traffic accidents. In addition, vehicle inspections may help to improve the public order related to vehicle operations and prevent crime through the confirmation of vehicle identity and authentication of ownership. Although there are many benefits of vehicle inspection. there are some negative opinions of the system. In this study, a methodology to analyze the effectiveness of the vehicle inspection system quantitatively in terms of traffic safety was developed. According to the developed methodology. accidents were reduced by 23.735, which is 11% of the total number of accidents in 2005.