• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.439-440
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• 2012

New analysis methods complement classical approaches in the vehicle NVH development by reducing and accelerating iteration steps to obtain a target sound. Therefore, tools are required that allow an integrative approach of sound engineering and structural analysis and enable a precise simulation and modification based on measured data. The Response Modification Analysis (RMA) is such a hybrid solution, which provides indications of relevant transfer paths taking into account the sensitivity of response channels to modifications of reference channels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.211-217
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• 2020

Technology planning in the defense field aims to develop core technologies in order to develop weapon systems to satisfy the force integration period by researching and analyzing necessary technologies for weapon systems. In the past, core technology development projects were conducted by deriving core technology based on the main required operational capability. But in this case, there is the limitation that technologies which are necessary to develop weapon systems but do not directly affect required operational capability, such as system integration technologies, are not considered. In this paper, we propose a work breakdown structure-based technology research and analysis methodology that prevents vacant technologies by identifying core technologies that must be secured for the development of weapon systems at the component level. With the proposed methodology, it is possible to identify technologies that must be acquired to realize the required operational capability of systems or which must be secured even they do not affect the required operational capability.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.3
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• pp.29-43
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• 2012

This study evaluated 23 botanic gardens and arboretums under two main categories including professional group and operational group. As for professional group, the main difference between the functions of botanic gardens and arboretums was analyzed. In the case of operational group compared professional group respectively, on categories including importance of function and implementation, seeking to provide fundamental data of botanic gardens and arboretums by enhancing the quality of visitors and examining functional differences. The result of a difference in arboretums' function between professional and operational groups, the study analyzed the importance of botanic gardens and arboretums in terms of detailed categories such as research, education, collection, display, retention, and service for visitors. As a result, professional group showed retention 4.32>education 4.11>research 4.09>service for visitors 4.05, and operational group showed retention 3.70>service 3.52>education 3.41>research 3.37, indicating that both groups had retention as the most selected answer. Looking closely at the functions of the currently implemented detailed categories of botanic gardens and arboretums, such as research, education, collection, display, retention, and service for visitors, the study showed that 91.3% selected rare species and individual multiplication for research function, 78.3% chose education of natural ecosystem for children for education, 73.9% answered space for experiencing nature for display, and 73.9% also replied managon, diof rare species, reproduction, and retention of native plants' species for retention category, and service for visitors showed 95.7% for implementation. The study could not clearly point out the influence between predictors due to absence of an established comprehensive evaluation model. Also, it analyzed and reviewed comparison of functions of professional group and operational group, but in the future, it should conduct study on a systemic and objective classification of botanic gardens and arboretums to clearly examine the difference in views between groups, which also requires, at the same time, study on management policy of botanic gardens and arboretums or suggesting guidelines that suit types of forms, and also study on facilities and program development that can be applied to each class.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.5
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• pp.340-350
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• 2020

A rapid refresh wave forecasting system has been developed using the sea wind on the Korea Local Analysis and Prediction System. We carried out a numerical experiment for wind-wave interaction as an important parameter in determining the forecasting performance. The simulation results based on the seasons of with typhoon and without typhoon has been compared with the observation of the ocean data buoy to verify the forecasting performance. In case of without typhoon, there was an underestimate of overall forecasting tendency, and it confirmed that an increase in the wind-wave interaction parameter leads to a decrease in the underestimate tendency and root mean square error (RMSE). As a result of typhoon season by applying the experiment condition with minimum RMSE on without typhoon, the forecasting error has increased in comparison with the result without typhoon season. It means that the wave model has considered the influence of the wind forcing on a relatively weak period on without typhoon, therefore, it might be that the wave model has not sufficiently reflected the nonlinear effect and the wave energy dissipation due to the strong wind forcing.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.514-523
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• 2021

Using the precipitation data observed at the Gochang Standard Weather Observatory (GSWO) during the winter seasons from 2014 to 2016, we analyzed the precipitation characteristics of the winter observation environment. For this study, we used four different types of precipitation gauges, i.e., No Shield (NS), Single Alter (SA), Double Fence Intercomparison Reference (DFIR), and Pit Gauge (PG). We analyzed the data from each to find differences in the accumulated precipitation, characteristics of the precipitation type, and the catch efficiency according to the wind speed based on the DFIR. We then classified these into three precipitation types, i.e., rain, mixed precipitation, and snow, according to temperature data from Gochang's Automated Synoptic Observing System (ASOS). We considered the DFIR to be the standard precipitation gauge for our analysis and the cumulative winter precipitation recorded by each other gauge compared to the DFIR data in the following order (from the most to least similar): SA, NS, and PG. As such, we find that the SA gauge is the most accurate when compared to the standard precipitation gauge used (DFIR), and the PG system is inappropriate for winter observations.

• Applied Microscopy
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• v.45 no.2
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• pp.101-105
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• 2015

Numerous digital image analysis techniques have been developed with regard to transmission electron microscopy (TEM) with the help of programming. DigitalMicrograph (DM, Gatan Inc., USA), which is installed on most TEMs as operational software, includes a script language to develop customized software for image analysis. Based on the DM script language, this work provides a script source listing for quantitative strain measurements based on a geometric phase analysis.

• KIEE International Transactions on Power Engineering
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• v.3A no.3
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• pp.168-176
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• 2003

The Korea Electric Power Corporation (KEPCO) has installed an 80 MY A Unified Power Flow Controller (UPFC) at its 154㎸ 'Kang-Jin Substation in South Korea. The device, manufactured by Siemens & Hyusung, has been operational since October 2002. The Korea Electric Power Research Institute (KEPRI), a division of KEPCO was tasked to study operational strategies that could be employed for the UPFC and surrounding reactive support devices concerning problems of low voltages and overloads in the Mokpo & Gwangju areas. Particular apprehension surrounded the possibility of delay in the installation of a new 345㎸ transmission line from 2005 to beyond 2010. The studies were to specifically determine whether these problems could be eliminated by application of a UPFC. The analysis included determining the UPFC operating point under various conditions, investigations of the coordination between the UPFC and a HYDC line terminating in this area, and the design of a supplementary damping controller for the UFPC. This paper summarizes the results of those studies, demonstrating the dynamic characteristics of the operation of this UPFC operation in the Korean power system.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1049-1068
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• 2015

In the paper, the authors propose the application of operational deflection shapes (ODS) for the detection of structural changes in technical objects. The ODS matrix is used to formulate the spatial filter that is further used for damage detection as a classical modal filter (Meirovitch and Baruh 1982, Zhang et al. 1990). The advantage of the approach lies in the fact that no modal analysis is required, even on the reference spatial filter formulation and other components apart from structural ones can be filtered (e.g. harmonics of rotational velocity). The proposed methodology was tested experimentally on a laboratory stand, a frame-like structure, excited from two sources: an impact hammer, which provided a wide-band excitation of all modes, and an electro-dynamic shaker, which simulated a harmonic component in the output spectra. The damage detection capabilities of the proposed method were tested by changing the structural properties of the model and comparing the results with the original ones. The quantitative assessment of damage was performed by employing a damage index (DI) calculation. Comparison of the output of the ODS filter and the classical modal filter is also presented and analyzed in the paper. The closing section of the paper describes the verification of the method on a real structure - a road viaduct.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.85-92
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• 2013

PURPOSES: The purpose of this paper is to estimate expected effects on traffic operational and economic aspects of 2+1 roads application in Korea. METHODS : Micro simulation study using VISSIM 5.0 was used to analyze the operation efficiency of 2+1 roads compared to two-lane highways and four-lane highways. Some scenarios for various traffic volumes were set up in order to analyze the effect of 2+1 roads under various traffic situations. Also imaginary road networks were set up for each type of roads. The MOEs to measure the operation efficiency were selected with average travel speed and delay. For analyzing economic effect of 2+1 roads, construction cost of a specific imaginary 2+1 road was compared to construction cost of a four-lane highway with same conditions. RESULTS: The results of study show that a 2+1 road is more effective with 19 percents higher average travel speed and 39 percents lower average delay than a two-lane highway. In the economic analysis, construction costs to construct a 2+1 road are saved as approximately 26.4~40.7 percents when compared to construction of four-lane highway. CONCLUSIONS: It can be concluded that 2+1 roads can improve the traffic operational level of service for two-lane highways and 2+1 roads can be applied as an effective design alternative for higher-volume two-lane highways in Korea.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.3
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• pp.105-114
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• 2012

Various RFID-based smart-walk systems have been developed for guiding disabled people. The system sends appropriate message whenever the disabled people arrived at a specific point. We propose universal design concept and optimization techniques for the smart-walk systems. Universal design concept can be adopted for supporting various kinds of disabled such as a blind person, a hearing-impaired person, or a foreigner in a system. It can be supported by storing appropriate messages set in the message database table depending on the kinds of the disabled. System optimization can be done by analyzing operational log(stream) data accumulated in the system. Useful information can be extracted by analyzing or mining the accumulated operational log data. We show various analysis results from the operational log data.