• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.19-22
• /
• 1997

This paper studies the arousal effects of aroma and warning sound using EDA(Electrodermal Activity:EDA), Aroma stimulus started at Nz value over 1.2. Warning sound was prepared according to the arousal evaluation and control criteria. As a result, the warning sound could be controlled the arousal level in all the mKSS state. Aroma stimulus was able to prevent drowsy more than warning sound in the mKSS 3 state(the first stage of drowsiness). Therefor, aroma stimulus was can be used for arousal control at that state. Futhermore, arousal control was shown to be more effective with presentation of both aroma and warning sounds than each presentation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.04a
• /
• pp.115-119
• /
• 2003

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water body can accumulate in sediment at much higher levels, the purpose of this study was to make convenient sampling method and optimal treatment of sediment for water quality improvement in reservoir or stream based on an evaluation of degree of contamination. Results for analysis of S-reservoir sediments were observed that copper concentration of almost areas were higher than the regulation of soil pollution (50 mg/1) for the riverbed. S-stream sediments were observed that copper, arsenic and TPH concentration of almost areas were exceeded soil pollution concerning levels for factorial areas. We used Remscreen(version. 1.0) program which is contaminated soil recovery program to select optimal treatment method of contaminant sediments. The result was shown in the order of Thermal Calcination > Excavation, Retrieval and Off-site Disposal(comparative less then contaminant) > Low Temperature Thermal Desorption + Solidification/Stabilization.

• Proceedings of the KWS Conference
• /
• 2005.06a
• /
• pp.396-398
• /
• 2005

At present, fatigue design of welded structures is primarily based on nominal stress or hot spot stress approach with a series of classified weld S-N curves. However, these methods are known to possess drawbacks, such as difficulty associated with defining proper nominal stress and the finite element sue sensitivity etc. Recently, a mesh-size insensitive structural stress definition is proposed by Battelle that gives a stress state at weld toe with relatively large mesh size. The structural stress definition is based on the elementary structural mechanics theory and provides an effective measure of a stress state in front of weld toe. As an experimental validation of the structural stress method in obtaining the fatigue strength of weldments, a series of experiment is carried out for various sizes of weldments. Based on the result from this study, it is expected to develop a more precise fatigue strength evaluation technique and to save time period required in the fatigue design of ship and offshore structures.

• Journal of Korea Technology Innovation Society
• /
• v.8 no.3
• /
• pp.1175-1198
• /
• 2005

The objective of the study is to verify the relationship between technology valuation indexes and corporate's performance in ventures by business operating periods. The result of the study is expected to be useful in loan evaluation, investment decision, internal management decision making and business improvement. The results of study is as follows. First, in early stage ventures, we find that three major valuation index(technology feasibility, economic efficiency, productivity) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Second, in growth stage ventures, we find that three major valuation index(business feasibility, general marketability, technology marketability) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Third, in early stage ventures, we find that at least thirty-eight minor valuation index elements are significant ex-ante variables which are discriminating between firms' going concern and firms' failure and in growth stage ventures, thirty-one minor valuation index elements are significant in various analysis' results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.10a
• /
• pp.363-366
• /
• 2008

It was accomplished that failure analysis not only failure numbers but also power system components every years. and these informations help power system operation considerably. power system equipment were occurred a break down by natural phenomenon and aging but it was not able to predict this failure number. But many papers and technical repots study for each equipment failure rate and reliability evaluation methods. so this paper show a failure number prediction whole power system component using Markov theory not each component failure probability. the result present a next month system failure number prediction.

• Journal of Industrial Technology
• /
• v.31 no.A
• /
• pp.71-78
• /
• 2011

As the need for predicting the flood stage of river from torrential downpouring caused by climate change is increasingly emphasized, the study, centered on the area of Gangwon-do Inje-gun and Jeongseon-gun of local river, is to develop peak water level regression equation by rainfall. Through the correlation between rainfall and peak water level, it is confirmed that rainfall according to duration and peak water level have a high correlation coefficient. Based on this, a relational expression of rainfall and peak water level is verified and then the adequacy of the calculated expression is analyzed and the result shows that a very accurate prediction is not easy to achieve but a rough prediction of the change of water level at each point is possible.

• Journal of the military operations research society of Korea
• /
• v.27 no.1
• /
• pp.10-27
• /
• 2001

This paper deals with the application of PRICE model in estimating the proper acquisition cost for weapon budgeting phase. The PRICE(Parametric Review of Information for Costing and Evaluation) Hardware model is a computerized method for deriving cost estimates of electronic and mechanical hardware assemblies and systems. The model can be used in obtaining not only initial cost estimates in conceptual phase, but also detailed cost estimates in budgeting phase depending on available historical and empirical data. We analyzed first step cost estimate parameters and derived cost equations using PRICe output dta. Using weight and complexity, We can find cost variation. Sensitivity analysis shows that cost increases exponentially as complexity increases exponentially as complexity increases. We estimated KAAV\`s (Korea Amphibious Assault Vehicle) production cost using the PRICE model and compare with engineering cost estimates which is based on actual production data submitted by the production company. The result shows that tow estimates are close within $\pm2%$ differences.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.673-676
• /
• 2006

Steel FibreReinforced Shotcrete(SFRS) is one of the main tunnel support along with the rock bolt during the excavation and after the completion of the tunnel. In the standard qualification of the SFRS defined by Korea Highway Corporation, 28 day core specimen has to meet the compressive strength of 19.6 MPa and over 90 % fibre contents. Furthermore, for the 28 days brick shaped specimen made by shooting, flexural strength should be over 4.4 MPa and flexural toughness ratio which can be calculated from flexural toughness factor has to meet more than 68% of flexural strength. In shotcrete, accelerating agent is added for the rapid strength development. Silicate and aluminate type agents are known to develop shotcrete strength rapidly, however, has such problem to degrade the middle and long term strength. Hence, using poly carboxylic super plasticizer, it was aimed to enhance the quality of the shotcrete with the lower water-cement ratio and the same level of workability. The present paper shows the part of the field test result and its analysis.

• Journal of Biomedical Engineering Research
• /
• v.17 no.4
• /
• pp.535-544
• /
• 1996

In this paper, we analyzed the coil-magnet type vibrating transducer for the implantable middle ear hearing aid which is appropriate for patient's hearing level, and an experimental transducer system is designed For the objective and quantitative analysis of the transducer, a theoretical equivalent model containing coil, magneto and inner ear is developed To perform effective evaluation of the transducer, a transforming ratio Tr is introduced and its range that is suitable for practical implantable middle ear hearing device is foun4 The result of applying physical parameters of ear system to the proposed analytical model shows that frequency response of the coil magrlet type vibrator is predominantly governed by resistive impedance of the coil rather than inertia effect of the magnet and the inner parameters. In addition, we realized an experimental middle ear hearing aid system to show the theoretical validity of designed system and this will provide the basis of the development for actually implantable system.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.3
• /
• pp.417-422
• /
• 2022

In this study, the development of a three-screw pump for high-capacity discharge was carried out. Benchmarking and reverse engineering for advanced products were performed to design and manufacture power rotor and idler rotor for high capacity and high pressure. Through flow analysis, performance verification of the entire design was performed and prototypes were manufactured. As a result of performance evaluation on prototypes, it was found that the development specifications were satisfied.