• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.511-525
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• 2021

The purpose of this study is to develop a design guideline to provide user-friendly experience and convenience for the online support system for the curriculum at primary/secondary schools. To achieve the objective, best practices of overseas on the online support system for curriculum as well as prior research were analyzed. In addition, UX/UI usability problems and needs were derived through a survey of 74 professionals and teachers who are monitoring NCIC and high school credit system sites. Based on the analysis of best practices of overseas and survey results, the draft of the design guideline was derived, and Delphi method was conducted by experts to re- vise the design guidelines and evaluate their validity. This study is meaningful in that it suggests the direction of improvement of the system currently being serviced and the direction of the design of the system to be developed in the future, by providing design guidelines that can be generally applied to online support systems that perform tasks related to the curriculum.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.436-441
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• 2009

A fiber optic sensor is prospective to be applied to structural health monitoring. Especially, a fiber Bragg grating(FBG) sensor is one of the most popular sensors for the structural health monitoring. The FBG sensor has several demodulation systems for tracking the shift of the Bragg wavelength. The dynamic bandwidth is dependent on the demodulation system. In this paper, the sensing mechanism is that the slope of the optical spectrum of FBG could be used as its sensitivity when the tunable laser shot the monochromatic laser wavelength at the highest slope point. In this technique, the high sensitivity is guaranteed even though the sensing range is limited. In an example of the application, the composite plate embedding a FBG sensor was manufactured by using an autoclave method and the above sensing mechanism was applied to the composite plate. Firstly, the natural frequencies of the plate were successfully measured by the FBG sensor during the impact hammer test. Secondly, a high-power speaker was used to force the plate to be vibrated at the specific frequency that was one of the natural frequencies. During the shaking, the FBG sensor measures the dynamic characteristics and ESPI was also used to measure the mode shape. From the two dynamic tests, the availability of the FBG sensor system and the ESPI was proven as a technique for measuring the dynamic characteristics of composite structure.

• KIEAE Journal
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• v.7 no.4
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• pp.147-152
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• 2007

Numerous non-destructive tests(NDT) to assess the safety of real structures have been developed. System identification(SI) techniques using dynamic responses and behaviors of structural systems become an outstanding issue of researchers. However the conventional SI techniques are identified to be non-practical to the complex and tall buildings, due to limitation of the availability of an accurate data that is magnitude or location of external loads. In most SI approaches, the information on input loading and output responses must be known. In many cases, measuring the input information may take most of the resources, and it is very difficult to accurately measure the input information during actual vibrations of practical importance, e.g., earthquakes, winds, micro seismic tremors, and mechanical vibration. However, the desirability and application potential of SI to real structures could be highly improved if an algorithm is available that can estimate structural parameters based on the response data alone without the input information. Thus a technique to estimate structural properties of building without input measurement data and using limited response is essential in structural health monitoring. In this study, shaking table tests on three-story plane frame steel structures were performed. Out-put only model analysis on the measured data was performed, and the dynamic properties were inverse analyzed using least square method in time domain. In results damage detection was performed in each member level, which was performed at story level in conventional SI techniques of frequency domain.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.283-288
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• 2007

As constructions are changing variously from the size and efficiency, the role of supervision services tend to reach beyond mere monitoring or supervision to prevent fraudulence, but tend to extend toward a system that manages all the stages of the construction industry. There are growing demand to improve government operated corporation systems to secure high quality public facilities, and reviews on construction supervision system and supervision services roles, function, responsibility and obligations have been the topics among advanced researchers. However, the circumstance is that researches on the construction supervision service compensation and supervision services assignment criteria that serve as basis of such construction supervision system improvement are insufficient, and for practical development of construction supervision system, researches on construction supervision service compensation and supervision services assignment criteria will need to precede. Hence, this research purports to propose improvement directions of construction supervision system by deducing problems through condition survey on the construction supervision services ordered by public organizations.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.8-13
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• 2011

All over the nation, a lot of industrial complex utilize gas as their energy source. Possibilities are fire, explosion, and leakage could happen any time in these large complexes. To prevent these tragic accidents and to minimize the damage when the accident occurs, the development of diagnostic technology for these facilities is imperative. The safety check is conducted on an individual and partial basis, currently. Accordingly, the accumulation and improvement of the safety management technology is necessary in order to make all the different checking techniques and management systems compatible, since checking processes, result interpretation techniques, and subsequent prognoses are not the same. The program provides damage scenarios from gas leakage. The output enables policy makers to predict the degree of infliction. Through this program, engineers are able to design an effective gas safety program to operate and maintain ubiquitous gas facilities.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1435-1447
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• 2015

Finance Companies are operating a security solution such as E-DRM(Enterprise-Digital Right Management), Personal information search, DLP(Data Loss Prevention), Security of printed paper, Internet network separation system, Privacy monitoring system for privacy leakage prevention by insiders. However, privacy leakages are occurring continuously and it is difficult to the association analysis about relating to the company's internal and external distribution of private document. Because log system operated in the separate and independent security solutions. This paper propose a systematic chains that can correlatively analyze business systems and log among heterogeneous security solutions organically and consistently based on security documents. Also, we suggest methods of efficient detection for Life-Cycle management plan about security documents that are created in the personal computer or by individual through the business system and distribution channel tracking about security documents contained privacy.

• Smart Structures and Systems
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• v.22 no.2
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• pp.133-137
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• 2018

Increasing interest in prognostics and health management has heightened the need for wireless sensor networks (WSN) with efficient power sources. Piezoelectric energy harvesters using Pb(Zr,Ti)O3 (PZT) are one of the candidate power sources for WSNs as they efficiently convert mechanical vibration energy into electrical energy. These types of devices are resonated at a specific frequency, which has a significant impact on the amount of energy harvested, by external vibration. Hence, precise prediction of mechanical deformation including modal analysis of piezoelectric devices is crucial for estimating the energy generated under specific conditions. In this study, an experimental vibrational system capable of controlling a wide range of frequencies and accelerations was designed to generate mechanical vibration for piezoelectric energy harvesters. In conjunction with MATLAB, the system automatically finds the resonance frequency of harvesters. A small accelerometer and non-contact laser displacement sensor are employed to investigate the mechanical deformation of harvesters. Mechanical deformation under various frequencies and accelerations were investigated and analyzed based on data from two types of sensors. The results verify that the proposed system can be employed to carry out vibration experiments for piezoelectric harvesters and measurement of their mechanical deformation.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.427-440
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• 2006

Electromagnetic(EM) survey has been in use for over a half century as a standard routine for, mineral exploration in many parts of the world. But EM survey work and serious research effort were initiated in Korea only as late as in early 1980s, largely inspired by four pioneers who did their graduate studies in the U.S.A. in 1970s. Nevertheless domestic achievements in the field of EM survey are remarkable in the last two decades: the field operations and related interpretational skills appear to have reached a global standard, even compared with the most advanced in other countries, virtually in a whole spectrum of the method which includes magneto-tellurics(MT), Controlled Source Audio-frequency Magneto-tellurics(CSAMT), geomagnetic sounding, small loop survey systems, Very Low Frequency(VLF), Ground Penetrating Radar(GPR), time domain surveys, and noise analysis. Besides mineral exploration, EM survey has been applied in Korea to hydrogeology, geotechnical engineering, non-destructive investigation of structures, unexplored ordnance(UXO) investigation, environmental monitoring, and archaeological investigation as well. Now that original contributions of several Korean geophysicists are found even in new frontiers such as high-frequency EM survey, investigation in time-domain EM field for buried metal objects and structures, and also modem data inversion scheme, it is duly hoped that they make some technical breakthrough to unravel still entangled knots of EM survey method in a forseeable future.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.1
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• pp.9-20
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• 2016

Ozone has been a problem in big cities. That is secondary air pollutant produced by nitrogen oxide and VOCs in the atmosphere. In order to solve this, the first to be the analysis of the $NO_x$ and VOCs. The main source of nitrogen oxide is the road mobile. Industrial sources in Seoul are particularly low, and mobile traffics on roads are large, so 45% of total $NO_x$ are estimated that road mobile emissions in Seoul. Thus, it is necessary to clarify the relation with the activity of road mobile source and $NO_x$ concentration. In this study, we analyzed the 4 locations with roadside automatic monitoring systems in their center. The V.K.T. calculating areas are set in circles with 50 meter spacing, 50 meter to 500 meter from their center. We assumed the total V.K.T. in the set radius affect the $NO_x$ concentration in the center. We used the hourly $NO_x$ concentrations data for the 4 observation points in July for the interference of the other sources are minimized. We used the intersection traffic survey data of all direction for construction of the V.K.T. data, the mobile activities on the roads. ArcGIS application was used for calculating the length of roads in the set radius. The V.K.T. data are multiplied by segment traffic volume and length of roads. As a result, the $NO_x$ concentration can be expressed as linear function formula for V.K.T. with high predictive power. Moreover we separated background concentration and concentrations due to road mobile source. These results can be used for forecasting the effect of traffic demand management plan.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.133-142
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• 2010

P-type fire control panel, currently in use, has a big hazard that can cause the large scaled human death tolls and property damage in the massive fire because it is difficult to identify in real time the location of fire outbreak and whether search-device are broken down or not. In this paper, I suggest that the integrated fire automation system on based p-type fire control panel should be used, which can detect in real time the signal that occur when whether search-device are broken down or not, and can detect the arisen circumstances information of p-type fire control panel on the fire signal in the far away. The devised systems have designed and embodied the analysis of circumstances information and module that can analyze the circumstances information from the p-type fire control panel and the part of internet access installment which can gather and deliver the circumstances information from the fire prevention facility receiver.