• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1263-1271
• /
• 1999

This paper designs the performance analysis layer for the various performance analysis of parallel programs using event expressions are similar to the normal program language to analyze the events which display a dynamic state exchange of a program. The event expressions suggest operations for overloading and functions which are needed in performance analysis, such as a filtering operation, data format translation functions, performance analysis, static functions, and etc. By using the event expressions, the programmer can modify the event trace data to analyze the performance and analyze more easily and variously than the pre-developed tools.

• Geomechanics and Engineering
• /
• v.29 no.3
• /
• pp.369-376
• /
• 2022

Accurately evaluating and predicting the performance of facilities is a key task in establishing a maintenance strategy for facilities. The importance of performance evaluation is becoming more pronounced, especially when the aging of facilities requires a huge budget. In this study, performance assessment models were developed for road and railway tunnels. Delphi analysis was performed to identify sub-elements necessary to evaluate the performance of a tunnel. The relative importance of the evaluation factors was derived from the AHP analysis. The correlation analysis was performed between each assessment factor and the final result to verify the significance of the model. For the correlation analysis, the survey data measured through precision safety diagnosis in tunnels in use was applied. The cost effectiveness analysis was also conducted according to the scenarios with different composition of performance factors in order to improve the practical applicability of the evaluation model developed in this study.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.6 no.3
• /
• pp.103-110
• /
• 2003

The present work was conducted to achieve the better understanding of the performance analysis technique for the expander type air turbo ramjet engine. For this purpose, the performance analysis was carried out using a small engine(8.0kN thrust) with two types of fuels. From this analysis, at the same input condition, the thrust of methane-fueled engine was 25% lower than that of hydrogen. In addition, the case of methane shows the inapplicable engine performance cycle.(i.e., The compressor work exceeds the turbine output power) These results come mainly from the different heating value of each fuel and specific heat. This analysis also shows that, to build a same performance cycle as the hydrogen case, the methane-fueled engine requires increased air and fuel flow rates, increased turbine expansion ratio, and decreased compressor pressure ratio.

• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.4
• /
• pp.341-349
• /
• 2022

When designing a new RNSS signal, the performance analysis for the legacy signal providing the same service, is required to determine the performance requirements. However, there are few studies on the secured service (SS) signal performance analysis, and the waveform is the only published information on the signal design component of the SS signal. Therefore, in this paper, we introduce several figures-of-merit (FoMs) that can be used for performance analysis in terms of the waveform. And then, we calculate the FoMs, such as autocorrelation main peak to secondary peak ratio (AMSR), spectral efficiency, Gabor bandwidth, multipath error, and jamming resistance quality factor, for the existing SS signals and discuss the analysis results. Finally, we conclude that the superior waveform for each FoM is different, and that the consideration of the trade-off relationship between the FoMs is required for waveform design.

• The Journal of Korea Robotics Society
• /
• v.17 no.2
• /
• pp.164-171
• /
• 2022

Recently, interest of a dual arm robot which can replace humans is increasing in order to improve the working environment and solve the labor shortage. Various studies related with design and analysis of dual-arm robots have been conducted because dual arm robots can have various kinematic configurations according to the objective task. It is necessary to evaluate the work performance according to various kinematic structures of the dual arm robot to maximize its effectiveness. In the paper, the performance analysis is studied according to the shoulder configuration and the wrist configuration of the dual-arm robot by using main performance indices such as manipulability, condition number, and minimum singular value by assigning proper weight values to each objective motion. Performance analysis for the robotic assembly process is effectively carried out for each representative dual arm robot configuration.

• Educational Technology International
• /
• v.20 no.1
• /
• pp.1-24
• /
• 2019

The purpose of this study is to determine priorities for designing digital citizenship education based on the key indicators of importance-performance. Survey data were collected from 283 university students in South Korea and analyzed with Importance-Performance Analysis to diagnose the current level of digital citizenship and draw their needs for educational treatment. The results showed that for all the factors except the Technical Skills (TS), the level of importance was significantly higher than that of performance. Another finding indicated that in the Importance-Performance matrix all the factors were located in the first quadrant (i.e. maintaining the current state) and the third quadrant (i.e. low demands for improvement). Specifically, two items located in the second quadrant where urgent treatment is required could have to do with the increasingly active participation in socio-political issues raised in South Korea. This study offered a window into what to focus on when designing digital citizenship education based on the systematic analysis of the needs for digital citizenship education in South Korea.

• Management Science and Financial Engineering
• /
• v.3 no.1
• /
• pp.39-56
• /
• 1997

This paper applies the binary tree classifier and discriminant analysis methods to predicting failures of banks and insurance companies. In this study, discriminant analysis is generally better than the binary tree classifier in the classification of bank defaults; the binary tree is generally better than discriminant analysis in the classification of insurance company defaults. This situation can be explained that the performance of a classifier depends on the characteristics of the data. If the data are dispersed appropriately for the classifier, the classifier will show a good performance. Otherwise, it may show a poor performance. The two data sets (bank and insurance) are analyzed to explain the better performance of the binary tree in insurance and the worse performance in bank; the better performance of discriminant analysis in bank and the worse performance in insurance.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.21 no.2
• /
• pp.105-114
• /
• 2017

Nonlinear analysis for seismic performance evaluation of existing building usually takes 4~5 times more than linear analysis based on KBC code. To obtain accurate results from the nonlinear analysis, there are a lot of things to be considered for nonlinear analysis modeling. For example, reinforcing layout, applied load and seismic details affect behavior of structural members for the existing building. Engineer-oriented computerized system was developed for engineers to evaluate effective seismic performance of existing buildings with abiding by seismic design principles. Using the engineer-oriented program, seismic performance evaluation of reinforced concrete building was performed. Nonlinear hinge properties were applied with real time multiple consideration such as section layout, section analysis result, applied load and performance levels. As a result, the building was evaluated to satisfy LS(Life Safety) performance level. A comparison between engineer-oriented and program-oriented results is presented to show how important the role of structural engineer is for seismic performance evaluation of existing buildings.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.11
• /
• pp.995-1000
• /
• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.5
• /
• pp.635-643
• /
• 2003

Parametric study for the analysis of performance characteristics of a planar -type solid oxide fuel cell(SOFC) using computational flow analysis is conducted. A planar -type SOFC, which is composed by two gas channels (fuel and ai.) and one set of anode-electrolyte-cathode assembly, is modeled as a two -dimensional isothermal case. Results of computational analysis of flow field including distributions of mass fractions in gas channels are used to the performance analysis of the fuel cell. Flow analysis makes it possible to consider current density distributions along the length of the cell in the process of performance analysis of the SOFC. As results of parametric study, it is found that the mole fraction of fuel at the inlet of fuel channel, operating pressure and temperature are closely related to the performance characteristics of SOFC.