• Tunnel and Underground Space
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• v.2 no.2
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• pp.199-211
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• 1992

Blasting vibrations of 3 quarries and 5 construction sites were measured and investigated with two reference data. Square and cubic root scaled distance were similar in fitness to peak particle velocity of individual blasting site, but the former is better fitted in total. It was suggested that the limit scaled distance for domestic surface blasting be 40kg/$\textrm{cm}^2$ for 10mm/s level and 60kg/$\textrm{cm}^2$ for 5mm/s level, which were lower than the OSM's regulation. Prevailing vibration components were in the order of radial, vertical and transverse directions. Prevailing vibration components were in the order of radial, vertical and transverse directons. Site factors K and m were 242 and -1.283 for all studied area, 357 and -1.348 for construction sites, 118 and -1.160 for quarries. Most prevailing frequency was in the range of 10~2Hz. Overlapping effect of delayed blasting vibrations were insignificant. Vibration history of delayed blasting was longer than simultaneous blasting, and it became longer as measuring distance increased. Wave form and predominant frequencies were more complicated for delayed blasting than instantaneous blasting. The influence of blasting scale and measuring distance were not significant to determine peak particle velocity equation.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.3-10
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• 2006

This study proposes a method to measure the positional accuracy of the implemented GIS polygon data. Also, it aims to present a possibility to analyze the occurrence types of positional errors by improving the measuring methods of positional accuracy based on the existing individual methods and by linking individual methods. As a result of the actual application of the methodology to the test area, it was possible to measure the positional accuracy in target test areas and to analyze the occurrence causes (types) of positional errors through each index linking (linking methodologies). Also, research results allowed confirming the applicability of the methodology. However, complementary research for each standard numerical value is recommended in order to ensure the validity of methodology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4995-5014
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• 2018

As the area covered by the CPS grows wider, agencies such as public institutions and critical infrastructure are collectively measuring and evaluating information security capabilities. Currently, these methods of measuring information security are a concrete method of recommendation in related standards. However, the security controls used in these methods are lacking in connectivity, causing silo effect. In order to solve this problem, there has been an attempt to study the information security management system in terms of maturity. However, to the best of our knowledge, no research has considered the specific definitions of each level that measures organizational security maturity or specific methods and criteria for constructing such levels. This study developed an information security maturity model that can measure and manage the information security capability of critical infrastructure based on information provided by an expert critical infrastructure information protection group. The proposed model is simulated using the thermal power sector in critical infrastructure of the Republic of Korea to confirm the possibility of its application to the field and derive core security processes and goals that constitute infrastructure security maturity. The findings will be useful for future research or practical application of infrastructure ISMSs.

• Tunnel and Underground Space
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• v.27 no.5
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• pp.295-302
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• 2017

In this study, a new quantitative instrumentation and measurement standards applicable to the field of mining has been proposed to improve the problems of the current measurement practices that apply the measuring standards of the civil engineering field (road, railway, etc.). With the data coordination of the mine reclamation corporation, we collected data on ground subsidence in the abandoned mine area, and studied various techniques for establishing a new management reference value based on the manual measurement data measured in the field. As a result, new instrumentation and measurement standards is set up and proposed by using statistics like the average value, the third quartile, the 95% confidence, and the maximum value.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.3
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• pp.39-45
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• 2002

A simple and low cost stylus profiler made of ferrite cores is developed. The devised profiler consists of a contact probe, a measuring transducer, a signal processing unit, and a motorized stage. The contact probe attached to 4-bar spring maintains sufficient stiffness to protect disturbances. An overlap-area type inductive position sensing system is selected as a measuring transducer, which has high sensitivity, repeatability and linearity. The transducer is composed of coil bundles and ferrite cores which have good electromagnetic characteristics in spite of low cost. The repeatability of the profiler with the proposed inductive sensing system is better than 50nm. Experimental results are shown that the proposed profiler can measure the line or 3D profile of an object with sub-micron features.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.576-582
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• 2015

The efficiencies of thermal power system using fossil fuel depend on heat exchangers which extract energy from the exhaust gas before it is expelled to the atmosphere. To increase heat transfer efficiency it is very important to maintain the surface of heat exchanger as clean condition. The accepted skill of cleaning of fouled surface of heat exchanger is soot blowing. A high pressure jet of air is forced through the flat surface of plate to remove the deposit of fouling. There is, however, little knowledge of the fundamental principles of how the jet behave on the surface and how the jet actually removes the deposit. Therefore, the study focuses on the measuring of cleaning area and cleaning dwell time after accumulating the simulated deposit on the flat surface. The deposit test rig was built for the study and simulated deposit material is used after measuring the physical property of the each material by shearing stress test. Much data was obtained for the analysis by the parameters change such as the different jet speed, different inner pressure and variable distance of the jet from the test rig surface. The experimental data was compared with the theoretical equation and most of the data matches well except some extreme cases.

• Fire Science and Engineering
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• v.23 no.4
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• pp.104-111
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• 2009

To research about the fire spread in Korean apartment house, a full-scale fire test in a four-story apartment was executed. The fire started at the third floor, and originated from overheated cooking oil in the kitchen. The apartment included all combustibles in general house. Through measuring temperature, measuring the concentration of oxygen and observing, we investigated the fire spread inside the apartment house. As a result, we got the data of the time needed for the initiation of fire, the time for fire to spread into each area in the house, and the time required until flash-over was seen. Also we grasped the understanding of the fire spread to the upper floor.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.118-125
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• 2000

Gloss uniformity on unprinted coated papers is oftenly called as 'Surface Feeling' in market and roles as a very important criteria when a customer choose a paper. However, there is few researches on this quality so far and even there isn't much knowledge on the characteristics of gloss variation, ie what it is, where it comes from etc. Therefore, there should be a pre-research on its characteristics, factors, measuring method or tools prior to the following development activities. In this paper, we obtained about a dozen of papers including foreign products and measured not only basic properties of them, but also various characteristics related to ununiformity. Our experiments went further to printing, but that area is excluded in this paper. Also, we investigated several instruments for measuring gloss variation by an objective way all over the world and tested with our own samples so that we tried to find out which one is best-correlated with visual appreciation and suggest its results as possible. We found out several things from these experiments including what is difference between good and bad gloss uniformity, the factors of gloss variation, and the results of measurement for gloss variation with instruments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.2
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• pp.127-135
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• 2004

The calibration of lens to be used and the planning of photographing planning layout is very important to achieve the requested accuracy in the precision measurement by close-range photogrammetry. Establishment of absolute coordinate system is regarded as another important factor for the purpose of measuring absolute deformation of photogrammetric object. In this study, the following tasks were performed : (1) calibration of super-wide-angle lens or focal length 21mm fer close-range photographing used by 35mm metric camera, (2) development of the measuring system for monitoring of absolute deformation through periodic observation of small area, and, (3) application of this system to monitor the absolute deformation of surface of underwater structure in fixed cycle and to present the efficiency of the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.960-965
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• 2014

Transmission loss of specimen is calculated by measuring energy of incident and transmission and using reverberant room of large size. But normal measurement of transmission loss has trouble because it is actually demanded that large area and specimen of certain size is satisfied with condition of diffused sound field. Especially, in case of mechanical component, interested frequency band is mid-frequency band between 500 ~ 2k Hz, and it is used to be available to minimize a reverberation chamber under conditions satisfying acoustic one because production of specimen for transmission loss measurement has limit. But, as in semi-reverberation room, it is difficult to satisfy condition of diffuse sound field and modification factor is applied to complement that. Correction factor when measuring transmission loss using semi-reverberation chamber is required accuracy because it works as main factor determining reliability of reuslts on transmission loss. In this study, it is analyzed that an effect on correction factor based on varying materials and sizes of specimens in order to deduction of it. Also It is confirmed that applied by elicited correction factor with actual railway vehicle's floor has reliability.