• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.33-41
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• 2017

Composite Floor system infilled with PCM(Phase Change Material) between upper and lower steel plates was developed to apply the steel frame. When steel frames were applied this system, it can absolutely reduce the duration of construction due to dry construction method. However to apply this system as a structural floor member without fire resistance covering, it must have 2 hours fire resistance performance. Because PCM consisted of three quarters of section with thermal insulation performance, fire resistance performance of this floor system was expected to easily have 2 hours fire resistance performance. This paper was to investigate behavior characteristics of PCM infilled floor system at elevated temperature using FEM analysis to develop the fire resistance performance of it.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.715-723
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• 2018

The energy storage system consists of batteries, power conditioning system and energy management system. If ESS is installed and operated in the field, SAT(Site Acceptance Test) of ESS is being essentially required for the safety and performance of ESS. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool. Therefore, this paper proposes the modeling of portable test equipment in order to evaluate the performance and reliability of ESS by using the PSCAD/EMTDC S/W. And also, the prototype of 30[kW] scaled portable test equipments is implemented based on the S/W modeling. From the results of various simulations and testings such as power quality, LVRT and anti-islanding tests, it is confirmed that 30[kW] scaled portable test equipment is useful for SAT of ESS, because the simulation results of PSCAD/EMTDC are identical to them of 30[kW] test equipment at the same test conditions.

• Journal of Biosystems Engineering
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• v.13 no.2
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• pp.28-37
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• 1988

This study was conducted to construct the soil bin system and associated microcomputer-based data acquisition system which is to be used for the effective evaluation of wheel performance. The soil bin system consists of four main parts; soil bin, carriage drive system, test carriage and soil processing carriage. The test carriage was constructed to measure the five performance parameters of testing wheels; pulling forte, motion resistance, sinkage and rotational speed of test wheel, and speed of test carriage. The test wheel is powered by a hydraulic system up to 8 ps. Soil processing carriage was designed to provide uniform test soil condition across the toil bin, and reproduction of soil conditions found satisfiable. The data acquisition system consists of APPLE II PLUS microcomputer, strain amplifier, I/O interface, A/D converter, digital counter and various transducers. It takes about 0.86 seconds to measure a set of performance parameters and store on the floppy disk simultaneously. Series of experiment showed that this system can be used effectively for evaluating the wheel performance associated with soil.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.4
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• pp.25-31
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• 1994

A system for EMAT, which generates ultrasound by electro-magnectic forces and performs nondestructive testing in noncontact, was established. By linking it with a 3 axis scanning system and a data acquisition and processing system the automation of EMAT testing was attempted. A EMAT sensor was fabricated and the directivity pattern of it was measured. To be suitable automation, it has a transmitter and a receiver in one case and the main beam direction of it can be controlled by the frequency of driving signal. A program which controls the EMAT system, the 3 axis scanner and the data acquisition and processing system was developed. It also processes acquired data and displays the processing results. IBM-PC/AT compatible PC was used as main controller and the stratage of the program is emulation of real devices on the PC monitor. To provide the performance of the established EMAT system, two aluminium blocks containing artificial flaws and a welded aluminium block were tested. The result of the tests were satisfactory.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.88-92
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• 2004

Most studies in the past in testing and benchmarking on Intrusion Detection System (IDS) were conducted as comparisons, rather than evaluation, on different IDSs. This paper presents the evaluation of the performance of one of the open source IDS, snort, in an inexpensive high availability system configuration. Redundancy and fault tolerance technology are used in deploying such IDS, because of the possible attacks that can make snort exhaust resources, degrade in performance and even crash. Several test data are used in such environment and yielded different results. CPU speed, Disk usage, memory utilization and other resources of the IDS host are also monitored. Test results with the proposed system configuration environment show much better system availability and reliability, especially on security systems.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.638-647
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• 1994

This paper describes the real time Hardware-In-the Loop Simulation(HILS) that is an efective tool for design, testing and performance evaluation of the guidanc eflight system. The real time HILS was performed by using a 3-axis flight motion simulator, real time computer, I/O system and flight control system hardware along with the assumed flight trajectory of the guidance flight system. Also, we proved the validity of the real time HILS is the guidance flight system by comparing its simulation results with the software simulation data and telemetry data.

• Journal of Korea Multimedia Society
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• v.18 no.12
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• pp.1501-1508
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• 2015

In this paper, we describe a case study to improve performance through the load testing of multi-tired system for financial accounts before the system opening. The load test was conducted after the data collection tools(Performance Monitor, DB PSSDiag) were installed. By analyzing the collected log, we were able to identify the main sector requiring performance improvements among the presentation tier, web tier, business logic tier and data tier. The ASP.NET server-down on the web tier could be improved by modifying the parameter values in the configuration file. Some server downs occurred on the business logic tier when a large number of users access at the same time, were more difficult to be solved. By analyzing the hang-dump at the server-down time, we were able to find a process that caused the problem. and we had to modify the relevant codes. For major performance improvements of the data-tier, indices of some queries was optimized by using the built-in DBMS query analyzer, after analyzing the log of long-response-time queries. The problems and solutions considered in this case study will be a reference for the performance improvement of a multi-layer system with the similar structure.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1318-1320
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• 2003

According to the computerization of railway signalling system, necessity of communication protocol for interface between these equipments is increasing. Therefore the research on communication protocol structure that is required according to computerization trend of these signalling goes. In our research the existed protocol currently used was analyzed, and the simulation modeling for performance analysis is deduced. Based on this simulation model the performance analysis and comparison is carried out, and also validation test is executed about new designed protocol.

• Journal of Information Technology Services
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• v.16 no.3
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• pp.103-111
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• 2017

The real time scheduling is a key research area in high performance computing and has been a source of challenging problems. A periodic task is an infinite sequence of task instance where each job of a task comes in a regular period. The RMS (Rate Monotonic Scheduling) algorithm has the advantage of a strong theoretical foundation and holds out the promise of reducing the need for exhaustive testing of the scheduling. Many real-time systems built in the past based their scheduling on the Cyclic Executive Model because it produces predictable schedules which facilitate exhaustive testing. In this work we propose hybrid scheduling method which combines features of both of these scheduling algorithms. The original rate monotonic scheduling algorithm didn't consider the uniform sampling tasks in the real time systems. We have enumerated some issues when the RMS is applied to our hybrid scheduling method. We found the scheduling bound for the hard real-time systems which include the uniform sampling tasks. The suggested hybrid scheduling algorithm turns out to have some advantages from the point of view of the real time system designer, and is particularly useful in the context of large critical systems. Our algorithm can be useful for real time system designer who must guarantee the hard real time tasks.

• Journal of Hydrogen and New Energy
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• v.34 no.1
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• pp.77-82
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• 2023

The fuel cell in fuel cell electric vehicle utilizes oxygen in the atmosphere, which requires the use of an air cleaner system to minimize the intake of harmful pollutants. To estimate the performance of the air cleaner system, the pressure drop between the filter inlet and outlet is used under the rated air flow condition. In this study, the effect of sensor error in this air cleaner testing is experimentally carried out. It is found that the errors of the temperature sensor does not significantly affect the estimation of pressure drop. However, in the case of the pressure sensor, 5% sensor error results in the error of pressure drop estimation by 3%. Therefore, it is recommended that the measurement accuracy of the pressure sensor mounted in test system should be maintained at less than 5%.