• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.137-144
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• 2019

For the structures near the seismogenic fault, the evaluation of seismic performance against near-fault ground motions is important as well as for design ground motions. In this study, characteristics of seismic behaviors and seismic performance of the pile-bent bridge constructed on the thick soft soil site with various weak soil layers were analyzed. The input ground motions were synthesized by the directivity pulse parameters for intra-plate regions. The ground motion acceleration histories of each layer were obtained by one-dimensional site response analysis. Each soil layer was modeled by equivalent linear springs, and multi-support excitations with different input ground motions at each soil spring were applied for nonlinear seismic analyses. The analysis result by the near-fault ground motions and ground motions matched to design spectra were compared. In case of the near fault ground motion input, the bridge behaved within the elastic range but the location of the maximum moment occurred was different from the result of design ground motion input.

• Fire Science and Engineering
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• v.30 no.2
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• pp.133-140
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• 2016

Currently, the maintenance of fire products at the site of fire-fighting property are presumably carried out by a fireand/or self. On the other hand, of the special fire-fighting property, only 3.4% of them are the target for a comprehensive precision inspection, which is performed by fire protection management firms. Aging fire products for the rest of special fire-fighting property are absolutely beyond any inspection and reliability verification. This is also true with respect to general households. In this report, the current practice of fire products' useful life management at the site of fire-fighting property were studied. For this study, 32 items of fire products were identified. For the sample data, public institutions and 17 cities and provinces were classified into 18 groups, from which 30 sample targets for each group were determined. Of these targets 422 samples were recovered, based on which this study for establishing a useful 'Management Control System of the Fire Products and its Useful Life' was conducted.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.51-59
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• 2016

Measurements of the automobile manufacturers are available anywhere and anytime, directly based on the criterion of failure is measured. The maintenance of high-precision production activities is direct evidence of the fact that competitive manufacturing activities are very important in determining the success of companies to recall defective starting from raw material costs. The current manufacturing sites produce calipers and clearance gauge the degree of tool only specific. Therefore, judging the quality, including the number of errors, requires a lot of attention to the dimension failures in day-to-day measurements and measurement tasks and duties repeated in difficult situations. In this paper, we aim to develop a vehicle manufacturing plant site using each of the manufacturing processes while operating a measurement tool. We display it using the Image Processing PC-based S/W with all those visual facts by management and recorded as image information a more accurate and current situation to obtain information and share visual measurements. We carry out research on the design and development vision inspection algorithm applied for pattern-recognition techniques that can help manufacturing site quality control.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.198-204
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• 2010

The cover of truck agitator give in a part to prevent the lower flowing of fresh concrete when the concrete are transported from the ready mixed concrete plant to the construction field. As a result of the question data, it show up a dirty image to the general civil society. Due to the above image, it is predicted to affect the image of the construction company, so we did the site experiment of the flowing, the amounts of air, the temperature change of concrete with the concrete left in the site, to find out the usefulness. Also, for the comparing with this, we got the result by doing the inner experiment with the same condition. As the result of the experiment, the cover of truck agitator affect little to the reduction of slump. The change of the air amount, regardless of the existence of cover, was not effected much in proper level until 60minutes. In addition, The compression strength was proper to the goal design strength until 90minutes regardless of the cover of truck agitator exist or not exist.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.95-103
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• 2016

The absolute value management method is widely used in the most of the earth retaining construction, which evaluates the safety by comparing measurement result and management criteria. Therefore, the management criteria is the standard to evaluate the safety of the site, and in other words, the criteria is a direct factor of the evaluation. That means that the safety of the site can not be acquired if the management criteria is not proper, even though the measurement system is perfectly set. However, many of field technicians do not have rely on the current management criteria, and they even recognize the necessity of the revision. Therefore, in this study, the necessity of the revision was studied. Also, the optimum criteria selection and the application were performed based on the test results of earth retaining deflection and probabilistic theory. The absolute value management method was used for this study. The details are tabulated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.110-117
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• 2011

Seashore landfill projects use undersea pump dredging method for construction of airport and factory site. Coarse grain soil from the dredging is considered for use at inland. West sea shore bottom consists of primarily coarser grained silt-sand and this component contains far more percentage than is the case with East sea and South sea area. This soil shows very different characteristic at consolidation and compaction behavior. This research targets to utilize this type of dredging soil. Test specimen is from West sea (Saemangum) dredged soil landfill site. Model analysis is done for getting prediction of original soil relative density and N-value from dynamic compaction energy variance. Dynamic compaction energy is calculated for efficient foundation design.

• Korean Journal of Construction Engineering and Management
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• v.21 no.5
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• pp.38-45
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• 2020

Presently, safety management of facilities is conducted as a site-oriented safety inspection, but depending on the facilities, there are difficulties in access to the site, and the cost and time of inspection are inefficient due to excessive reliance on human resources. Therefore, the necessity of sensor-based safety management is being raised to ensure the safety of the facility at all times, and various studies on sensor safety management are being conducted, but the research on verification of practicality is still insufficient. Therefore, the improvement points were presented through analysis of domestic and international studies, and additional processes for setting sensor attachment location and threshold were derived by analyzing the H city sensor safety management process, and practicality of sensor safety management was verified through sensor data measurement values. It is expected that efficient, sensor-based facility safety management will be possible if clear criteria and ongoing practicality verification for the additional processes presented in this study should be carried out in the future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.3
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• pp.24-30
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• 2003

As domestic buildings have been large-scaled, diversified and high-rise, there have been a consistent demand for design, development of construction technology and accident prevention activity as well as quality enhancement. In spite of governmental and related institutions' efforts for reducing national losses which come from numerous accidents, there have been endless small and large accidents on the construction site and thus, it is urgent to conduct empirical researches in this area. Currently safety supervision system in construction industry has enforced harm and danger prevention planning system, however it merely stick to other existing materials. In addition, it is difficult to put it into practice in that it requires bearing too much burden to draw out the planning itself in a case of large construction work. Consequently in this paper we select evaluation criteria by construction progress, classify into several categories, and regard potential danger which often occurs, as a evaluation criterion. Further step is to allow workers or collaborated companies to express their expert opinions or experiences and to encourage quality and process control and autonomous safety control by applying PSM(Process Safety Management) method using AHP(Analytic Hierarchy Process) and to development of PSM evaluation method in the construction. The reason why PSM method should be quantitative and substantial progress is because it contributes Korean constructing companies to enhancing their safety control ability and to taking an equal stance just like developed countries, thereby strengthening their competitive edges. Boost of safety control system by PSM method could make an enormous contribution to preventing construction accidents on the site by establishing and securing an autonomous safety control system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.171-180
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• 2007

The quality of ready-mixed concrete(henceforth abbreviated remicon) is influenced by various factors such as ingredient of material, difference of property, mixing ratio, mixing time, mixing error, conditioning of construction, method of curing and temperature, humidity time in transportation. These factors make it hard to confirm the quality of remicon till placing in site. As the quality control in field is very important to ensure the quality of building. Moreover in modern building production, the more important the inquiry of performance improvement, the more important the manufacture and the quality control of remicon. In this study, to examine and analyze the quality of remicon we used slump, air content and compressive strength in 7, 28 days as to remicon which placed during on year. As a result, we found that the slump and air content were satisfied with reference code and the compressive strength was more than the design standard strength so we concluded that the quality control of remicon was to be agreeable.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.149-160
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• 2008

In this study, the research was carried out on how to identify the modal parameter by acquiring the output response of the structure only through the smart sensor system. The objective of this research is to verify the performance and the on-site adaptability of the smart sensor system that have been actively researched as the advanced measuring system so far. Smart Sensor System was developed so that the real-time dynamic measurement can be performed by means of MEMS-type accelerated sensor, 8 bit CPU, wireless MODEM. In the modal parameter identification test, random excitation was added to the cantilever beam, and then the response of the structure was obtained using the smart sensor system and the wire measurement system respectively. In analyzing the data, modal parameter was identified using NExT & ERA algorithm. Furthermore, the optimal measurement location was selected through EOT algorithm in order to obtain the qualified output response. Result of the test, it was possible to verify the on-site applicability of the smart sensor.