• Journal of Power System Engineering
• /
• v.20 no.3
• /
• pp.57-63
• /
• 2016

This paper presents the experimental result and theoretical analysis result to investigate the correlation between the operating force, angle and locking torque for vehicle hood frame. Also, we derived the experimental equation that using the results for experiment and theory. The hood frame is switching-devices used for opening and closing the vehicle hood. It needs the correlation data between locking torques of each joint, operating force and angle of hood frame. The correlation data for torque and reaction force of hood frame obtained through experiment and theory analysis. Finally, the experimental equation of the locking torque prediction for the hood frame is derived.

• Structural Engineering and Mechanics
• /
• v.64 no.3
• /
• pp.287-292
• /
• 2017

In the present research, an available flexural stiffness degradation model was modified and a new comprehensive model called "X-NFSD" was developed. The X-NFSD model is capable of predicting the flexural stiffness degradation of composite specimen at different states of stresses and at room temperature. The model was verified by means of different experimental data for chopped strand mat/epoxy composites under displacement controlled bending loading condition at different displacements and states of stresses. The obtained results provided by the present model are impressively in very good agreement with the experimental data and the mean value of error of 5.4% was achieved.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.3
• /
• pp.9-15
• /
• 2003

An experimental study has been carried out as a basic research for development of the friction drag reduction technology for ships by polymer injection. Experimental apparatus and procedures have been devised and prepared to measure the changes of the wall friction with injection of a polymer solution and basic experimental data on the friction drag reduction are obtained for a turbulent fiat-plate boundary layer and fully-developed channel flows. Variations of the friction drag reduction with some important parameters of polymer injection, such as the concentration of polymer solution, its injection flow rate and the measuring position downstream from the injection slot, are also investigated. Important experimental data and results obtained in the present study are presented. The amount of friction drag reduction up to 50% is observed.

• Journal of Fisheries and Marine Sciences Education
• /
• v.10 no.1
• /
• pp.63-68
• /
• 1998

The microbubble splits injection system are improved for the enhancement efficiency of viscous frictional drag reduction. It was confirmed that the experimental results is effective more than Mercle's[7] using the present system in the comparisons. And the new experimental equation is derived to get viscous frictional drag reduction useful for the present experimental data. The new experimental equation approaches Mercle's[7] experimental data wel.

• Journal of Ocean Engineering and Technology
• /
• v.33 no.4
• /
• pp.358-363
• /
• 2019

The acoustic power is used as a primary index characterizing underwater sound sources and could be defined by its source level. The source level has been assessed using various experimental techniques such as the reverberation time method and reverberant tank plot method. While the reverberation time method requires reverberation time data extracted in a preliminary experiment in a reverberant water tank, the reverberant tank plot method only needs acoustic pressure data directly obtained at the reverberation water tank. In this research, these experimental techniques were studied in comparative experiments to estimate the source levels of underwater sources in a reverberant water tank. This paper summarizes the basic theories and procedures of these experimental techniques and presents the experimental results for an underwater source in a long cuboid water tank using each technique, along with a discussion.

• Journal of Mechanical Science and Technology
• /
• v.20 no.9
• /
• pp.1399-1409
• /
• 2006

An improved friction model was proposed with consideration of the effect of the sliding speed, the contact pressure and the temperature, and it was implemented into a user subroutine of a commercial FEM code, ABAQUS/Explicit. Then, a smooth tire was simulated for free rolling, driving, braking and cornering situations using the improved friction model and the Coulomb friction model, and the effect of the friction models on the slip, the frictional energy distribution and the cornering force and moment was analyzed. For the free rolling, the driving and the braking situations, the improved friction model and the Coulomb friction model resulted in similar profiles of the slip and the frictional energy distributions although the magnitudes were different. The slips obtained from the simulations were in a good correlation with experimental data. For the cornering situation, the Coulomb friction model with the coefficient of friction of 1 or 2 resulted in lower or higher cornering forces and moments than experimental data. In addition, in contrast to experimental data it did not result in a maximum cornering force and a decrease of the cornering moment for the increase of the speed. However, the improved friction model resulted in similar cornering forces and moments to experimental data, and it resulted in a maximum cornering force and a decrease of the cornering moment for the increase of the speed, showing a good correlation with experimental data.

• Journal of the Korean earth science society
• /
• v.36 no.4
• /
• pp.367-389
• /
• 2015

This study developed an experimental program for mapping temperature and salinity distribution around the Korean marginal seas using Ocean Data View (ODV) software. Serial ocean observational data have been analyzed after being converted to the ODV compatible format using a separated program newly developed for this study. When this new experimental program was applied to 65 pre-service teachers, it was found that the quality of assignment completion with a new program improved compared with that of the same group who used the existing program. A questionnaires was employed to delve into participants' satisfaction of the new program. Findings depicted that accurate and quick drawing of isoline drew the highest responses of satisfaction, and confirmed positive responses to the understanding and application of this new experimental program.

• Fire Science and Engineering
• /
• v.33 no.4
• /
• pp.50-58
• /
• 2019

The prediction performance of B-RISK was evaluated for the fire behaviors of combustibles in a compartment using Fire Dynamics Simulator (FDS). First of all, to predict the heat release rate (HRR) for two combustible sets, the HRR for one combustible set and the design fire curve were used as input values for B-RISK. Comparing results of B-RISK calculations with experimental data for two combustible sets, it was found that B-RISK results predicted insufficiently for fire growth rate of experimental data but there was good agreement for maximum HRR and total HRR with the experimental data. And the B-RISK results were used for input values of FDS to evaluate the fire behaviors of B-RISK results. Comparing results of FDS calculations with experimental data, the simulation results showed that the temperature and concentrations of O₂, CO₂ in the fire growth phase were different from the experimental data. However, when using the B-RISK result for percentile 70%, the simulation results sufficiently predicted the overall fire behaviors.

• Journal of the Society of Naval Architects of Korea
• /
• v.35 no.4
• /
• pp.19-26
• /
• 1998

In this paper, we studied the Similar Ship(SS) concept[1,2] as a method to an experimental and semi-emperical approach for the estimation of hull hydrodynamic forces and hull-propeller-rudder interaction coefficients and used these methods to predict ship's manoeuvrability. The SS concept is adopted to use experimental data of prototype ships for manoeuvrability prediction of a new ship. The SS concept is composed of the key components as follows: existence of experimental data about prototype ship, availability of semi-emperical method for estimating the changes of hull force, a method to correct the prototype ship data. On the basis of these concepts, we attempted to simulate manoeuvrability at ballast and scantling draft conditions by making use of experimental data at full load draft condition and to simulate manoeuvrability of new ships by making use of experimental data for prototype. From present calculation, it was found that the present method can predict the ship's manoeuvrability accurately at early design stage.

• The Research Journal of the Costume Culture
• /
• v.19 no.5
• /
• pp.1049-1060
• /
• 2011

The purpose of this study was to develop a shirt pattern that enhances the functionality of golf swing motions. The pattern was made with 3D body surface shape data that changed according to dynamic golf postures. The data were collected from the golf swing motions. The 3D body surface data in golf swing postures piled up on the 3D surface data in a static posture. The results showed that the surface shape data changed more in the address, back swing, and finish postures than the other swing postures. The experimental pattern was developed with 3D surface scan data in those three golf swing motions. The pattern had raglan sleeves and the front-bodied piece was divided into two pieces with a princess line, which comes from armscye line of the address posture. The back bodice piece was divided into three pieces with a yoke line and a back princess line. The yoke line was made by back shoulder shape in the back swing posture. The level of comfort of the experimental garment and commercial golf shirts was evaluated by 38 women golfers. The experimental garment pattern was evaluated to be more comfortable in golf swing postures than commercial golf shirts.