• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.43-54
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• 2019

In this study, results of completion inspection are investigated according to the performance of the firefighting construction supervision personnel and according to the necessity of clean air supply in a performance test of the firefighting construction supervision personnel. The results of the completion inspection are measured and the causes of defects in the fire protection facilities after issuance of a completion inspection certificate are analyzed. The findings of this investigation can be used to minimize the risk of apartment fires and improve the performance of firefighting construction supervision personnel. The results of this study are summarized as follows. First, the results of the completion inspection conducted by the firefighting construction supervision personnel varies according to particular occupation. The performance of fire facility supervisors from design companies and fire construction companies were significantly higher than the fire officers. Therefore, it is necessary to employ supervisors who have experience in supervising the construction of apartments, in order to improve the performance of fire construction supervision officers. Second, the analysis of the completion inspection results according to the necessity of a clean air supply for performance tests of firefighting construction supervision personnel showed that the necessity of a clean air supply was significantly higher for fire facility supervisors from design companies and fire construction companies than for the fire officers. In order to improve, the completion inspection should be carried out up until the completion date of the building. In addition, a system needs to be established to ensure that clients are not able to demand that a completion inspection certificate be issued on the construction completion date. Finally, it is found that defects of completion inspection after issuance of a completion inspection certificate affects the result of the completion inspection. The results of the completion inspections conducted by the fire facility supervisors from design companies and fire construction companies were affected significantly less by defects than that of the general contractors. Research shows that faults have occured in firefighting facilities after the issuance of a completion inspection certificate due to the client and the construction company demanding the issuance of the completion inspection certificate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.157-158
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• 2019

Reinforcing bars are an important material for tensile strength of structures. For this reason, the inspection of the reinforcing bars confirming the layout and omission is very important for the safety of the structures. However, the current method of inspecting of the reinforcing bars through photographs of specific areas is difficult to identify condition all reinforcing bars. And It is also difficult to confirm after completion of a building. Therefore, reinforcing bar inspection using 3D scanner is required for automation of rebar inspection and database construction. For this purpose, this study test application of automated inspection method for rebar inspection using 3D scanner and discuss the effect of this method.

• Journal of the Korean Operations Research and Management Science Society
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• v.21 no.1
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• pp.115-129
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• 1996

A reliability Acceptance Sampling Plan (RASP) is developed for testing the exponential mean lifetime under the periodic (i. e., equally-spaced) inspection and Type I censoring. Under the periodic inspection, the exact sampling distribution of maximum likelihood (ML) estimator of mean can not be derived. Hence sample size and acceptance criterion are determined by the algorithm proposed on the basis of Monte Carlo simulation such that the producer's and consumer's risks are satisfied for given censoring time and number of inspections. In addition, the developed RASP is compared in terms of sampling size, OC curve, and expected completion time. The effects for the RASP by the chosen inspection scheme are also discussed.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.6
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• pp.331-337
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• 2023

Due to the aging of a building, 38.8% (about 2.82 million buildings) of the total buildings are old for more than 30 years after completion and are located in a blind spot for an inspection, except for buildings subject to regular legal inspection (about 3%). Such existing buildings require users to self-inspect themselves and make efforts to take preemptive risks. The scope of this study was defined as the general public's visual self-inspection of buildings and was limited to structural members that affect the structural stability of old buildings. This study categorized possible damage to reinforced concrete to check the structural safety of buildings and proposed a checklist to prevent the damage. A damage assessment methodology was presented during the inspection, and a self-inspection scenario was tested through a chatbot connection. It is believed that it can increase the accessibility and convenience of non-experts and induce equalized results when performing inspections, according to the chatbot guide.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.19-28
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• 2017

In this paper, detailed safety inspection reports on the 915 expressway bridges which had been published from 1996 to 2010 are collected and condition of these bridges are analyzed. Damages are categorized into 'damage by defect', 'damage by physical force', and 'damage by deterioration' and the concept of damage possession rate is introduced to investigate the occurrence time and the characteristics of damages. Based on the top 10 damage patterns of expressway bridges and the deterioration characteristics of heavy snow and freezing cold area, reasonable improvement direction of inspection activity is suggested. From this study, it is known that improvement of inspection regularization during construction or at completion stage of bridges is needed. Since the deterioration progress of the heavy snow and freezing cold area is faster than that of general area, environmental characteristics should be considered in inspection activity. The results of present study can be widely used for improvement of inspection activity of expressway bridges.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2598-2604
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• 2002

Robots that can move along the narrow and rough tube are very important as the request for the inspection increases. It is necessary for the inspection robots to have a capability to move successfully at even overturned situation and have a simple mechanism to reduce the unexpected failure possibility fer the successful completion of the given mission. Through this paper, the authors propose a novel and simple mechanism using a combination cam device to generate the locomotive motion of multi-legs. This robot uses one DC motor and one combination cam shaft to generate the locomotive motion and can move rough tubes without failure even at the overturned situation. The robot also shows enough fragging force fer the connected line that is very important for a wired inspection robot. Kinematics analysis to design the specification of the robot will be followed and several applications show this robot's potential capabilities.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.1 s.244
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• pp.90-96
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• 2006

Since Risk Based Inspection(RBI) was introduced to quality the risks for jet engine and nuclear power, the technique has been expanded to the area of petrochemical plant. Recently among USA and Europe, window-based computer programme for RBI has been rapidly developed. When local companies procure such program to apply to their plants, it is difficult to build up a proper database as well as expect a good result. In this regards, K-RBI programme accustomed to Korean environments was developed. After completion of the programme in 2004, it was tested by 2 local petrochemical plants and was produced fruitful results. By using these programme, we are expecting accident prevention through risk based planning and implementing of equipment inspection, and saving dollars caused by procuring foreign expensive programme.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.1
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• pp.123-140
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• 1997

In this paper we consider closed flow line systems with samploing inspections. The total number of parts in the system is assumed to be N. The processings carried out of each station do not always meet the requirement of quality. Therefore, upon completion of its processing at each station, a part is inspected to determine whether the processings meet the requirement of quality or not. We assume that inspection are done on a random basis. If a part is found to be defective by an inspection, it is fed back to the apropriate station. Two different cases will be considered in this study : a three-station flow line system with infinite buffers and a two-station flow line system with finite buffers. For each case, we will develop an exact method to obtain the performance measures such as throughput, machinen utilization, average outgoing quality and manufacturing lead time. For the case of the two-station flow line system ith finite buffers, we will also develop an approximation method using a stage-aggregation technique. Then using buffers, we will also develop an approximation method using a stage-aggregation technique. Then using these results, we will try to find an optimal inspection policy which maximizes the expected net profit under a certain cost structure. Although we present the results only for the two or three station flow line system in this paper, the results obtained in this paper can be extended easily to the system which consists of more than two or three stations.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.208-216
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• 2003

ISO 14649 (data model for STEP-NC) is a new interface scheme or language for CAD-CAM-CNC chain under established by ISO TC184 SCI. Up to this point, the new language is mainly made for milling and turning, and other processes such as EDM will be completed in the future. Upon completion, it will be used as the international standard language for e-manufacturing paradigm by replacing the old machine-level language, so called M&G code used since 1950's. With the rich information contents included in the new language, various intelligent functions can be made by the CNC as the CNC knows what-to-make and how-to-make. In particular, On-Machine Inspection required for quality assurance in the machine level, can be done based on the information of feature­based tolerance graph. Previously, On-Machine inspection has been investigated mainly for milling operation, and only a few researches were made for turning operation without addressing the data model. In this thesis, we present a feature-based on-machine inspection process by the 4 Tasks: 1) proposing a new schema for STEP-NC data model, 2) converting the conventional tolerance scheme into that of STEP-NC, 3) modifying the tolerance graph such that the tolerance can be effectively measured by the touch probe on the machine, and 4) generating collision-free tool path for actual measurement. Task 1 is required for the incorporation of the presented method in the ISO 14649, whose current version does not much include the detailed schema for tolerance. Based on the presented schema, the tolerance represented in the conventional drafting can be changed to that of STEP-NC (Task 2). A special emphasis was given to Task 3 to make the represented tolerance accurately measurable by the touch probe on the machine even if the part setup is changed. Finally, Task 4 is converting the result of Task into the motion of touch probe. The developed schema and algorithms were illustrated by several examples including that of ISO 14649 Part 12.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.23-29
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• 2021

The purpose of this study is to reduce the probability of occurrence of electric fires as a preemptive preventive measure, and to strengthen the capability of preventing electric fires by strengthening the cooperative function between electric fire-related departments and establishing a cooperative system. In this study, the general aspects of electric fires were identified by reviewing the literature such as ignition mechanisms of electric fires. And the major electrical fires that occurred in the last 10 years were classified into ignition factors (short circuit, overload/overcurrent, and earth leakage/ground fault) and ignition sources (wiring/wiring appliances, electrical equipment/household appliances). And the 4M technique was used to analyze the potential causes of ignition at the fire site and to suggest preventive measures. In the case In this study, out of 48 electrical fires in the past 10 years, 16 short-circuit fires, 3 overload/overcurrent fires, 3 short-circuit and earth fault fires, 16 fires in wiring/wiring appliances, and 10 fires in electrical equipment/home appliances classified as cases. And prevention measures were presented in terms of human, machine, media, and management by using the 4M technique. For the preemptive prevention of electric fires, strengthening the compulsory electrical safety inspection and making it mandatory to report when new or expanding electric facilities, charging a fee for electric safety inspection for detached houses and granting benefits subject to inspection completion, improvement of the electric safety voluntary inspection table and safety indications; It was suggested as a policy to organize and operate electrical safety inspection personnel in a two-person team (mixed), establish a close work cooperation system with related organizations, and strengthen electrical safety education and publicity.