• Journal of dental hygiene science
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• v.8 no.3
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• pp.183-187
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• 2008

The objective of this study was to assess the level of contamination of dental equipment surfaces by Staphylococcus aureus and to obtain basic information for the prevention against cross infection between students and outpatients. Human samples were collected by rubbing the oral cavity, anterior noses, and lip of students and outpatients with sterile cotton swabs. Environmental samples were collected from 11 sites at practical laboratory, 4 sites at seminar room, and 5 sites at sterilizing room before, during, and after clinical procedures. These samples were cultured on brain-heart infusion agar at $37^{\circ}C$ for 24 hours. Gram-stained and identified as S. aureus colonies were counted each period and these results were analyzed by t-test and ANOVA test. In human, oral cavity showed the greatest S. aureus counts and there were no statistically significant differences between students and outpatient. Practical laboratory revealed the greatest S. aureus among all environmental groups. The greatest number of S. aureus was observed during clinical procedures (P < 0.05) and light handles, chair head, and spittoon showed a high level of statistically significant differences. In conclusion, S. aureus was dispersed in human and dental clinical environment and increased their number during clinical procedures.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.5
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• pp.411-429
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• 2022

Instrumentations are essential in NATM tunnels, however measuring instruments are installed and applied without performance verification procedures due to insufficient research on methods, procedures, regulations, etc. to verify the reliability of the measuring instruments. In this study, domestic and foreign regulations relating to the verification and calibration of instruments were investigated and necessities for accreditation standards were proposed. In order to identify the causes of the defects, an external inspection was performed on rock bolt stressmeter and rod extensometer, which are measuring instruments with relatively complex structures. For verifying the performance of these instruments, verification devices were developed that can load step-by-step and the causes of defects were identified in measuring instruments of nine domestic manufacturers. Through the performance test, a number of measuring instruments were found to be defective. It was important to test the performance of the instruments in the state of a finished product and accordingly performance inspection methods and procedures were proposed. The results of this study are expected to help preparing related regulations for verifying instrument performance and selecting instruments in the field.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.4
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• pp.51-66
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• 2001

There occurred a moderate size earthquake of Magnitude 5 in Whagae-Myun, Hadong-GUn, Kyongsangnam-Do on July 4, 1936. It caused severe damage to the buildings and other structures in Sang-Gye-Sa, a Buddhist Temple. The top component of a five-story stone pagoda was tipped over and fell down to the ground during the earthquake. In order to have accurate and quantitative estimate of the peak acceleration level of that earthquake, a full-scale model was constructed through rigorous verification process. The complete model was mounted on a shaking table and subjected to the dynamic tests. Two kinds of tests were performed: exploratory test and fragility test. The exploratory test was done with low acceleration level. In the fragility test, the behavior of the model was carefully monitored while increasing the acceleration level. The construction details of the model are provided and test procedures are reported. Finally important test results are presented and their implications are discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.297-308
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• 2007

The granulation equipment of concentrated wastes is manufactured for the polymer solidification of concentrated wastes. It uses liquid sodium silicate as a granulating agent for the granulating of dried powder containing boric acid. The granulating agent is sprayed in the form of droplet and mean size of dried granules is $2{\sim}4mm$. The new technology which has been used for the polymer solidification of spent resin in U.S. and certified by Nuclear Regulatory Commission (NRC) is successfully applied to concentrated wastes. This uses in-situ solidification process within drum without mechanical mixing. Maximum loading of waste can be achieved without increasing of waste volume. Polymer waste forms were evaluated with several test such as fire test, compressive strength test, leaching test, immersion test, irradiation test, and thermal cycling test according to standard test procedures.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.599-609
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• 2005

There are many test parameters in the DTV measurement, which uses several test measuring instruments and miscellaneous devices. To operate all of those devices and analyse test results is a tedious and time-consuming process with a high error rate committed by inexperienced test crews. In this paper, we propose an integrated DTV measurement and analysis system(IMAS) that remotely controls and manages any instruments with standard network interface. This system can take, organize, store the field data into an integrated database and easily produce systematic output according to user-defined form. It can also measure several types of digital broadcasting signals such as DTV, DMB, DAB with generalized measurement procedures. Proposed measurement system was applied in the DTV field test by KBS and proved that it could enhance the accuracy and efficiency of entire test sequences and also dramatically reduce measurement time compared to conventional measurement systems.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Journal of Drive and Control
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• v.15 no.3
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• pp.14-20
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• 2018

Wet clutches in an automatic transmission enable the transmission of the engine power by the frictional torque experienced and noted between disk and plates. Since the clutch frictional torque considerably affects the shift quality of an automatic transmission as well as the durability of the machinery, its friction characteristics must be carefully examined to meet the design requirements. The SAE No. 2 friction test machine is a well-known standard to evaluate mainly the friction characteristics of plate clutches along with the required automatic transmission fluids. This paper reviews the experimental analysis of the wet clutch friction characteristics by using the exclusively developed clutch test machine which is capable of controlling the clutch test procedure, in accordance with the applicable test standard and processing of the experimental data automatically. As the clutch test machine is designed for the accommodation of dual clutches which is applied to the real transmission, it can evaluate not only the clutch friction characteristics, but also an actuation performance of a measured clutch piston. In respect to friction characteristics involving dynamic friction coefficients, the energy absorbed in a clutch disk and the recorded temperatures of clutch plates during braking actions and procedures are also investigated. Additionally, the change of friction coefficients by the use of the repeated clutch application is also observed with the endurance test functions of an accurately calibrated and dedicated clutch test machine.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.75-89
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• 1993

The present paper describes an application of UA(Uncertainty Analysis) to seakeeping model test, basically according to the Performance Test Code of ASME(American Society of Mechanical Engineers), in which all the possible error sources involved in the preparation of test, calibration of instruments, data acquisition and analysis are quantified, and summed up with error propagation coefficients to the final uncertainties. The differences between the static test such as resistance and propulsion test and the dynamic test like seakeeping test are clearly identified during all the procedures of UA and asymmetric bias errors are considered. The DRE(data reduction equation) subject to present UA are the heave and pitch response amplitude operator and nondimensionalized absolute frequency. The usefulness of UA in seakeeping test were confirmed not only for quantifying errors and improving measurement accuracy but also for the validation of various seakeeping analysis tools.

• Advances in aircraft and spacecraft science
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• v.9 no.3
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• pp.195-215
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• 2022

The increasing interest in CubeSat platforms ant their capability of enlarging the frontier of possible missions impose technology improvements. Miniaturized electrical propulsion (EP) systems enable new mission for multi-unit CubeSats (6U+). While electric propulsion systems have achieved important level of knowledge at equipment level, the investigation of the mutual impact between EP system and CubeSat technology at system level can provide a decisive improvement for both the technologies. The interaction between CubeSat and EP system should be assessed in terms of electromagnetic emissions (both radiated and conducted), thermal gradients, high electrical power management, surface chemical deposition, and quick and reliable data exchanges. This paper shows how a versatile CubeSat Test Platform (CTP), together with standardized procedures and specialized facilities enable the acquisition fundamental and unprecedented information. Measurements can be taken both by specific ground support equipment placed inside the vacuum facility and by dedicated sensors and subsystems installed on the CTP, providing a completely new set of data never obtained before. CTP is constituted of a 6U primary structure hosting the EP system, representative CubeSat avionics and batteries. For the first test campaign, CTP hosts the ambipolar plasma propulsion system, called Regulus and developed by T4I. After the integration and the functional test in laboratory environment, CTP + Regulus performed a Test campaign in relevant environment in the vacuum chamber at CISAS, University of Padua. This paper is focused on the test campaign description and the main results achieved at different power levels for different duration of the firings.

• Journal of Auto-vehicle Safety Association
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• v.6 no.1
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• pp.5-9
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• 2014

Over the past ten years, since the introduction of the side crash test regulation in Europe, much research work has been performed internationally to develop new and modified test procedures to improve the level of occupant protection offered by vehicles in side crash test. This research has been co-ordinated and finally contributed to development of an AE-MDB(Advanced European Moving Deformable Barrier) and WorldSID (Worldwide Side Impact Dummy). EuroNCAP(European New Car Assessment Program) has the plan to conduct AE-MDB side crash test using WorldSID from 2015 by replacing Progressive MDB and EuroSID II. Automobile manufacturers need to respond to these changes closely. This paper is to find dominant control factor and analyze it of WorldSID 50%ile dummy injury through AE-MDB side crash test by predicting best and worst condition. And control factors will be validated within EuroNCAP regulations. This paper is analyzed by DFSS(Design for six sigma) which contains 5 control factors and is evaluated by ANOVA with the data as a result of LS-DYNA analysis correlated with crash pulse from 50 kph AE-MDB side crash test using WorldSID 50%ile dummy.