• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.127-132
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• 2018

The amount of generated Circulating Fluidized Bed Combustion ash (CFBC ash) is annually increasing, but most CFBC ash has been landfilled and discarded due to the limited utilization. The major chemical compositions of CFBC ash are $SiO_2$, CaO and $CaSO_4$, which could form hydration products by reacting with water as self-cementing property such as cement. The purpose of the this study is to derive the optimal mix proportions to improve polymer-modified mortar with the use of CFBC ash which has the self-cementing property. In order to develop polymer-modified mortar, three mix proportions were determined, and fundamental properties for the mixtures were obtained. As a result, the optimal mixture containing 10 percent of silica fume, 1.0 percent of polymer and 3.5 percent of expansive additives were proposed in this study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.26-38
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• 2020

Mixture design of self-compacting concrete is a typical multi-criteria decision making problem and conventional mixture designs are based on the low level engineering method like trials and errors through iteration method to satisfy the various requirements. This study concerns with performing the straightforward multiobjective design optimization of economic SCC mixture considering relative importances of the various requirements and cost-effectives of SCC. Total five requirements of 28day compressive strength, filling ability, segregation stability, material cost and mass were taken into consideration to prepare the objective function to be formulated in form of the weighted-multiobjective mixture design optimization problem. Economic SCC mixture computational design can be given in a rational way which considering material costs and the relative importances of the requiremets and from the result of this study it is expected that the development of SCC mixtue computational design and the consequent univeral concrete material design optimization methodology can be advanced.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.161-168
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• 2009

In this study, the concrete, in which the steel fiber(SF) with different volume-surface ratios and lengths was intermixed in High flowing Self-Compacting Concrete(HSCC), was produced to compare with steel fiber reinforced concrete as a part of plan to improve the workability and the quality of steel fiber reinforced concrete. As the result of experiment, the flowing and passing characteristics of HSCC intermixed with SF was highly improved as there was no fiber ball phenomenon due to the effect of high flowability and the viscosity, and in the identical range of compressive strength, it showed the tendency that the splitting and flexural strength was increasing as the length was getting longer regardless of volume-surface ratio when compared with HSCC which was intermixed with SF. It is estimated that in case of application of HSCC intermixed with steel fiber to work sites, it would be possible to improve the workability and the quality which would be better than that of steel fiber reinforced concrete which has been used.

• Journal of Fisheries and Marine Sciences Education
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• v.16 no.2
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• pp.187-198
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• 2004

The purpose of this study is to provide the basic data to activate the operation of the volunteer activities. The specified subjects for this study are how different is it in the changes of the self-concept and the satisfaction and the intention of the continuance of volunteer activities according to the type of volunteer work and guiding organization for middle school students. For this study, 64 students, the homogeneous ability group, were intentionally assigned in the preliminary inspection of self-concept and 16 students were randomly allocated respectively for 4 groups. The consequences based on the result are as follow: First, it has more influence with the group activities than the individual on the changes in the self-concept. But, there isn't meaningful difference by each guiding organization. Therefore, the school has to provide with activating middle school student's activities by developing various weekly and monthly club volunteer activities. Second, for the satisfaction and the intention of continuance among the guiding organization, it has meaningful difference in the group activities only, not in the individual ones. It gives the ground for the government to provide intensified support to the leaders of the group and grant the incentives to the group of distinguished activities, in the perspective of developing sociality, promoting the group volunteer activities.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.217-223
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• 2007

This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.627-632
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• 2016

In this paper, we propose a new vision-based defect inspection system for the surface of hot slabs. To minimize the influence of self-emission from slab surfaces with high temperature, an optic method based on blue LED light and a blue pass filter is proposed. Because the slab surface is partially covered with scales, which are unavoidable oxidized substances caused during manufacturing, it is difficult to distinguish between vertical cracks and scale. In order to resolve this problem and to improve the detection performance, the use of a Gabor filter and dynamic programming are proposed. Finally, the effectiveness of the proposed method is shown by means of experiments conducted on images of hot slabs that were obtained from an actual slab production line.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.597-607
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• 2023

Purpose: The Ministry of Employment and Labor has been working hard to ensure the safety of workers due to heavy rain during natural disasters as the responsible ministry in charge of preventing industrial accidents and health problems for workers. Accordingly, the Ministry of Employment and Labor intends to analyze actual cases of responding to heavy rain disasters and suggest ways to improve the response system. Method: An emergency response system implemented to respond to heavy rain disasters with an internal expert group composed of those in charge of disaster work at headquarters, local government offices, and Korea Occupational Safety and Health Agency, and an external expert group composed of professors, consulting representatives, and disaster managers from other ministries. Contents on self-inspection by industry, workplace inspection, use of serious siren, safety management and restoration work guidance were reviewed. Result: First of all, it is necessary to check the regular contact system from time to time, and it is also necessary to prepare and distribute detailed self-checklists for each industry. In addition, it is necessary to check the implementation of self-inspection when inspecting workplaces, and it seems necessary to have measures to increase the readability of information notified through serious disaster sirens. In addition, since safety work is done in the form of a contract, it seems necessary to prepare specific safety guidelines. Conclusion: In order to protect the lives of workers due to seasonal harm and risk factors, unlike the passive coping methods of the past, abnormal weather should not be regarded as an unexpected situation, and it should be actively and preemptively responding beyond the conventional framework.

• Journal of Preventive Medicine and Public Health
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• v.45 no.2
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• pp.78-89
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• 2012

Objectives: Although vaccination rates have increased, problems still remain in the storage and handling of vaccines. This study focused on inspecting actual vaccine storage status and awareness, and comparing them before and after education was provided. Methods: In the primary inspection, a status survey checklist was completed by visual inspection. A questionnaire on the awareness of proper vaccine storage and handling was also administered to vaccine administrators in private medical institutions in 4 regions in Gyeongsangbuk-province. One-on-one education was then carried out, and our self-produced manual on safe vaccine storage and management methods was provided. In the secondary inspection, the investigators visited the same medical institutions and used the same questionnaire and checklist used during the primary inspection. The results before and after education were compared, by treating each appropriate answer as 1 point. Results: The average checklists score was 9.74 (out of 15 points), which increased significantly after education was provided (by 0.84, p<0.001). The participants demonstrated improved practices in recording storage temperatures(p=0.016), storing vaccines in the center of the refrigerator (p=0.004), storing vaccines with other medication and nonmedical items (p=0.031) after education. The average score calculated from the questionnaires was 10.48 (out of 14points), which increased after education (by 1.03, p<0.001). Conclusions: This study suggests that vaccine storage practices and awareness are inadequate, but can be partially improved by providing relevant education. Repetitive education and policy-making are required to store vaccines safely because one-off education and unenforced guidelines offer limited efficacy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.157-163
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• 2022

Recently, with the development of automation in the industrial field, research on anomaly detection is being actively conducted. An application for anomaly detection used in factory automation is camera-based defect inspection. Vision camera inspection shows high performance and efficiency in factory automation, but it is difficult to overcome the instability of lighting and environmental conditions. Although camera inspection using deep learning can solve the problem of vision camera inspection with much higher performance, it is difficult to apply to actual industrial fields because it requires a huge amount of normal and abnormal data for learning. Therefore, in this study, we propose a network that overcomes the problem of collecting abnormal data with 72 geometric transformation deep learning methods using only normal data and adds an outlier exposure method for performance improvement. By applying and verifying this to the MVTec data set, which is a database for auto-mobile parts data and outlier detection, it is shown that it can be applied in actual industrial sites.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.737-746
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• 2023

As the core infrastructure to lead technical innovation for the fourth industrial revolution, economic value and utilizations of radiowaves are increased rapidly. The objectives of this study are to recognize the growing trend of radio stations that transmit information using radiowaves, a limited resource of the country, and to propose developed plans for the radio stations operation system in line with the changing radio technology and use environment. To be specific, the detailed implementation procedures and methods of the system were derived in accordance with the government's plan to convert the complete inspection of radio stations into a SDoC(Self Declaration of Conformity) by the telco. SDoC is a policy that grants autonomy and responsibility for radio waves interference management to existing telecom operator recognized as having radio stations operating capabilities. It has significance in that the function of radio stations inspection, which is a representative technical regulation, is efficiently distributed to the government and the private sector. This study has significance in providing reference for expediting deregulation in the radiowaves management policy.