• Journal of Korean Society for Atmospheric Environment
• /
• v.21 no.2
• /
• pp.227-242
• /
• 2005

The aim of this study is to relieve the poor ventilation problem of the diesel locomotive engine load test building, located in an urban area. This paper evaluates the ventilation performances of the studied load test building based on the temperature measurement experiment and the computational fluid dynamics (CFD) during the engine load test. The temperature rise caused by the radiator blower of the building was turned out to be the main cause of disturbing the thermal conditions of the building. The indoor temperature distributions simulated by Fluent were validated with the temperature measurement results obtained from the studied building. The simulation results indicated that the comfort condition of this building was poor We suggested several remedial changes in the duct structure of this building for the improvement of the comfort conditions. In addition, a prototype drawing combining several improved design options was proposed. and then the simulation of the temperature distribution in the proposed prototype was performed. The result indicated that the indoor thermal condition of this proposed building was improved when compared with that of the current building.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.258-262
• /
• 2007

Satellite launch vehicle is exposed to some dynamic environment during its flight. Particularly, the safety of launch vehicle structure is surely verified under vibration environment in low frequency range. Sine sweep test is generally performed to describe this low frequency vibration environment. Dynamic property of vibration fixture is considered to get the correct property of target object. This vibration fixture should really be an extension of the armature in the form of a very rigid structure that can transfer the required force at the required frequency. An optimum fixture would have its lower natural frequency about 50% higher than the highest required forcing frequency in order to avoid fixture resonances during the test. In this study, the vibration mode analysis considering the mass of target object to design the vibration fixture. And the modal test of vibration fixture is performed to conform the design.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1581-1584
• /
• 2008

In this study, performance Assesment of the existing tunnel drain and higher permeable for the In-plane Test. Two separate simulation tests from geotexitile and Lightweight Foamed Mortar compare. perfomed:the one is the in-plane test and the other is the clogging phenomenon test. As a result, NATM Composite used to Ligheweight Foamed Mortar pemability 80%, more than existing tunnel drain. Also, clogging phenomenon test do low assesment more than existing tunnel drain geotextile.

• Journal of Navigation and Port Research
• /
• v.35 no.9
• /
• pp.741-747
• /
• 2011

Ecological toxicity testing of the whole-effluent from the ozone ballast water treatment system was conducted as specified in the quality assurance project plans (QAPP). The growth inhibition test with microalgae, acute aquatic toxicity test with the Rotifer reproduction, toxicity test (or population growth) with the Rotifer, survival and growth toxicity test with larval fish and sediment toxicity test with amphipod were carried out to evaluate ecological toxicity on the movile test barge.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.15-18
• /
• 2004

In this paper, it is implemented the monitoring system for TV advertisement using video watermark. The functions of an advertisement monitoring system are automatically monitoring for the time, length, and index of the on-air advertisement, saving the log data, and reporting the monitoring result. The performance of the video watermark used in this paper is tested for TV advertisement monitoring. This test includes LAB test and field test. LAB test is done in laboratory environment and field test in actually broadcasting environment. LAB test includes PSNR, distortion measure in image, and the watermark detection rate in the various attack environment such as AD/DA(analog to digital and digital to analog) conversion, noise addition, and MPEG compression The result of LAB test is good for the TV advertisement monitoring. KOBACO and SBS are participated in the field test. The watermark detection rate is 100% in both the real-time processing and the saved file processing. The average deviation of the watermark detection time is 0.2 second, which is good because the permissible average error is 0.5 second.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.49-52
• /
• 2007

Vacuum facility is required for high altitude space environment test to develop small thruster. We, at Chungnam National University, developed vacuum test facility up to $10^{-5}$ torr to simulate $100{\sim}120km$ altitude environment. Prior to operation, we predict vacuum pump performances and present preliminary calculation and experiments.

• Journal of Korean Society for Atmospheric Environment
• /
• v.4 no.1
• /
• pp.23-32
• /
• 1988

The exposure level of respirable dust and silica for the coal workers of underground coal mines in Taebaek area was evaluated. Personal air samplers were attached to the coal workers-drillers, coal cutters, their helpers, haulers, and separators. Normality and lognormality of respirable dust and silica concentrations were tested by Kolmogorov-Smirnov one-sample test, differences of means of respirable dust and silica concentration were tested by group-t-test and paired t-test, and relation between respirable dust and silica concentration were tested by regression test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.747-750
• /
• 2004

After launching, spacecraft is exposed to extreme environments. So spacecraft should be tested after design/manufacture to verify whether components can be operated functionally. Acceleration transferred from launch vehicle to spacecraft produces quasi-static load, sine vibration and random vibration. Random vibration is also induced by acoustic vibrations transferred by surface of spacecraft. And shock vibration is produced when spacecraft is separated from launch vehicle. To verify operation of spacecraft under these launch environments, separation shock test, sine vibration test, acoustic vibration test and random vibration test should be performed. This paper describes these launch environment test requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.11
• /
• pp.915-920
• /
• 2013

Units developed for a real satellite should pass space environmental tests and launch environment tests. Thermal Vacuum Test, one of the space environmental test, simulates extreme thermal environment encountered in on-orbit operation of satellite. Many payloads which adapt non-traditional, brand-new technology are developed by developers who is not familiar to space engineering field. There might be some possibility of mistakes which result in serious problem due to lack of experience, especially from planning to performing thermal vacuum test. In this paper, brief overview of thermal environmental test related to a satellite development is summarized in order to prepare and perform the thermal test.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.184-187
• /
• 2001

This study presents procedure and analysis method for not well known slug interference tests. Results of the slug interference tests were compared with those of pumping and recovery tests and conventional slug tests.