• KIEAE Journal
• /
• v.11 no.6
• /
• pp.37-42
• /
• 2011

This Paper aims for analyzing the effect of opening types on wind-driven ventilation performance in basement parking lots of apartment. The scale model of basement parking lot was made, wind tunnel tests conducted. Wind pressure of three opening types was measured, wind pressure coefficient calculated. As the result, it showed that the air flow pattern of stack type opening was strongly changed by wind direction, but it was almost not at scuttle vent type. But, as for the difference of wind pressure coefficient, stack type opening was more than the other two types.

• Wind and Structures
• /
• v.31 no.3
• /
• pp.197-207
• /
• 2020

Knowledge on the design value of extreme wind pressure coefficients (EWPC) of a specific zone of buildings is essential for the wind-resistant capacity of claddings. This paper presents a method to estimate the representative EWPC introducing the multivariate extreme value model. The spatial correlations of the extreme wind pressures at different locations can be consider through the multivariate extreme value. The moving average method is also adopted in this method, so that the measured point pressure can be converted to wind pressure of an area. The proposed method is applied to wind tunnel test results of a large flat roof building. Comparison with existing methods shows that it can give a good estimation for all target zones with different sizes.

• Nuclear Engineering and Technology
• /
• v.30 no.5
• /
• pp.396-402
• /
• 1998

Experiments on the steamside corrosion and hydrogen pick-up of Zircaloy-4 under high pressure up to 10.3MPa are carried out to estimate the pressure effects on the kinetics. Temperature and reaction time are determined to be 37$0^{\circ}C$ and 72hours for the pre-transition test and $700^{\circ}C$ and 210minutes for the post-transition test, respectively. Results show that under 10.3MPa pressure the oxidation reaction is 50% and 100% enhanced in the pre-and the post-transition regime, respectively. Total amount of hydrogen uptake in the reaction is proportionally increased as corrosion weight gain is elevated. However, pick-up fraction is not affected by the high pressure. The fraction is almost twice greater than that in the waterside corrosion. Edges in the specimens play a certain role in the enhancement, especially in the post-transition regime. To identify physical property changes of oxide film such as micro-cracks or micro-pores, careful and thorough examination must be needed with some special techniques.

• 연구논문집
• /
• s.30
• /
• pp.129-135
• /
• 2000

Double boss type composite pressure bottles have been developed widely but single boss type had not because there are some difficulty in technical point. In this paper a research was performed to develop composite pressure vessel in conjunction with design, fabrication, and test. Fiber pattern and angles were decided by CADFIL software and they are [liner/$15^{\circ}$/$15^{\circ}$/$90^{\circ}$/$18^{\circ}$/$90^{\circ}$/$21^{\circ}$/$21^{\circ}$/$90^{\circ}$]. Fabrication of bottles was done by AEA's 5-axis filament winding machine. During fabrication fiber optic sensor were embedded to measure were behavior of structure at the applied internal pressure. Even though satisfied test results were not obtained, the experimental set-up of fiber optics showed the possibility for the application of filament wound vessels. However, the conventional strain and fabrication of single boss composite bottles.

• Journal of Ocean Engineering and Technology
• /
• v.14 no.1
• /
• pp.74-79
• /
• 2000

The purpose of this paper is to recycle coal ash as structural backfill materials from electric power plants. Two million tons of coal ash are produced annually. The laboratory test was executed for the basic compatibility as substitution for structural backfill materials and the optimal mixture ratio(fly ash : bottom ash) was decided. In addition the model test was performed using medium scale earth pressure model with small size earth pressure cells model box data logger and some other apparatuses. Mixed coal ash and excellent backfill materials(coheisonless soil SW) were compared in the view of lateral earth pressure variation depending on wall displacement. The reduction of earth pressure when coal ash was used as a bockfill material was monitored comparing to that of cohesionless soil. the cost and environmental pollutants by treating coal ash can be reduced through developing the recycling technology.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.06a
• /
• pp.21-31
• /
• 2001

The last 30 years have been significant worldwide growth in the use of EPS as a lightweight fill material. A new construction method was introduced, which reduces earth pressure acting on culvert and conduit by placing a thin layer of EPS. This paper analyzes the compressible inclusion function of EPS and geogrid which can results in reduction of earth pressure by arching that is the behaviour of soil-structure system involving redistribution of soil stress around the structure. Field test was conducted to evaluate the reduction of vertical earth pressure using EPS and geogrid inclusion. Based on field test it is found that the magnitude of reduced vertical earth pressure was about 24~50% compared to conventional method.

• Journal of Information Technology Services
• /
• v.10 no.1
• /
• pp.135-149
• /
• 2011

In this paper, we propose the high-risk group detection model for patients with high blood pressure using case-based reasoning. The proposed model can be applied for public health maintenance organizations to effectively manage knowledge related to high blood pressure and efficiently allocate limited health care resources. Especially, the focus is on the development of the model that can handle constraints such as managing large volume of data, enabling the automatic learning to adapt to external environmental changes and operating the system on a real-time basis. Using real data collected from local public health centers, the optimal high-risk group detection model was derived incorporating optimal parameter sets. The results of the performance test for the model using test data show that the prediction accuracy of the proposed model is two times better than the natural risk of high blood pressure.

• Proceedings of the KIPE Conference
• /
• 2008.10a
• /
• pp.160-162
• /
• 2008

This paper presents the practical pressure control of hydraulic oil-pump system using SR drive for industrial application. In order to get a high performance of pressure dynamics in actual application, a data based PID control scheme is proposed in this paper. The look-up table from pre-measured data produces an approximately proper current reference according to motor speed and oil-pressure. And, PID controller can compensate the pressure error. With the combination of two references, the proposed control scheme can get a fast dynamics and stable operation. Furthermore, the suitable current controller considering the nonlinear characteristics of SRM(Switched Reluctance Motor) and practical test method for data measuring are introduced. The proposed control scheme is verified by the experimental test.

• Wind and Structures
• /
• v.4 no.6
• /
• pp.481-494
• /
• 2001

Wind tunnel pressure tests were conducted on a 1:100 scale model of a large industrial building with solar panels mounted parallel to the flat roof. The model form was chosen to have the same aspect ratio as the Texas Tech University test building. Pressures were simultaneously measured on the roof, and on the topside and underside of the solar panel, the latter two combining to produce a nett panel pressure. For the configurations tested, varying both the lateral spacing between the panels and the height of the panels above the roof surface had little influence on the measured pressures, except at the leading edge. The orientation of the panels with respect to the wind flow and the proximity of the panels to the leading edge had a greater effect on the measured pressure distributions. The pressure coefficients are compared against the results for the roof with no panels attached. The model results with no panels attached agreed well with full-scale results from the Texas Tech test building.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.5
• /
• pp.351-356
• /
• 2008

In this study, we had the stress analyses of TBP used in Tall Building and determined the working pressure of TBP. We knew the four fact. First, the place acted maximum stress is axial direction of branched part. Second, working pressure is more than 2.0 MPa. Third, stress in branched part is less than yielding strength at hydrostatic test pressure. Fourth, the ratio(stress/yielding stress at hydrostatic test pressure) is $0.4{\sim}0.6$(KS D 3562 Sch 40), $0.3{\sim}0.4$(KS D 3576 20S).