• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.185-190
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• 2015

The purpose of this study is developing the quantify the seat belt pulling Noise index and evaluation method. This paper presents the objective method to evaluate the emotional feeling about the pulling Noise of the seat belt. The physical quantification is required to objectively evaluate the emotional feeling of the pulling Noise. This is called the "Noise metric." The Noise metric is should correlated to the subjective rating of the pulling Noise. The pulling Noise index is developed throughout the linear regression of the Noise metric and the subjective rating. The developed index is used for the objective evaluation of the emotional feeling about the pulling Noise of a seat belt throughout the modification of seat belt components.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.41-46
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• 2007

Lightweight multi-layered boards with high stiffness for the automotive interior trims were developed, which were composed of a single material. The boards were constructed in the form of substrate/core/substrate with newly developed materials. The materials which have high tensile strength and elongation were selected for the substrate materials, and those which have high compressive strength and low density were selected for the core materials. 25 types of multi-layered boards were fabricated using the selected substrate and core materials. The compatibility with the skin materials, the formability and the tensile strength and flexural strength of the specimens were evaluated. The results show that three types of multi-layered boards(Kenboard/EPP foam/Kenboard, Twintex/PP honeycomb/Twintex, Curv sheet/EPP foam/Curv sheet) are appropriate for the automotive interior trims. Considering the ease of materials supply and the economical aspect, Kenboard/EPP foam/Kenboard is thought to be the most realistic alternative.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.871-876
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• 2011

In this paper, the equilibrium flight conditions of a Korean Traditional Bangpae Kite with low aspect ratio were analyzed by it's aerodynamic data of wind tunnel test. The data of aerodynamic forces and center of pressure of the Kite were used to calculate the relative length of bridles to satisfy the condition of settling the kite to the static equilibrium steady state between ${\theta}=30^{\circ}{\sim}60^{\circ}$. From this equilibrium flight performance analysis, we obtained ($0.88{\pm}0.02$)c of the rear bridle length corresponding to 0.88c of fixed front bridle length. These results were exact agreement with the relative bridle lengths by Korean classical method.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.4
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• pp.308-312
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• 2001

This study was carried out to develop a basic form of planning hull type fishing boat. G/T 10ton class is selected as object hull form, and hull form is designed in Chosun University. A series of test results of LCG variations for S different LCG points are presented in this paper. The test was performed in Davidson Laboratory, and the scope of tests include resistance, trim and sinkage.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.270-281
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• 2017

In this paper, a vibratory disturbance to the rotor system generated by gyroscopic precession through helicopter rotor is examined. Also, active vibration reduction method is designed and simulated by designing feedback controller. For this purpose, structural analysis is carried out using EDISON's geometric exact beam program which can analyze the rotor with the cantilever condition. And the aeroelastic analysis is performed by coupling it with the simple aerodynamic model. In order to obtain the real-time structural response, the EDISON program analysis results were modeled by nonlinear equations and the Newton-Raphson method was used for the trim analysis.

• International Journal of Aeronautical and Space Sciences
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• v.9 no.1
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• pp.121-128
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• 2008

This paper describes the modeling and autopilot design procedure of a Blended Wing-Body(BWB) UAV. The BWB UAV is a tailless design that integrates the wing and the fuselage. This configuration shows some aerodynamic advantages of lower wetted area to volume ratio and lower interference drag as compared to conventional type UAV. Also, BWB UAV may be increase payload capacity and flight range. However, despite of these benefits, this type of UAV presents several problems related to flying qualities, stability, and control. In this paper, the detailed modeling procedure of BWB UAV and stability analysis results using the linearized model at trim condition are represented. Finally, we designed the autopilot of BWB UAV based on a simple control allocation scheme and evaluated its performance through nonlinear simulation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.78-84
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• 2013

The primary objective of the current work is to develop efficient numerical code to assess the resistance performance of the twin hull form. Resistance performance for the two different twin hull forms with asymmetric and symmetric mono hull using developed code are evaluated. Numerical calculations and model tests have been compared to validate a developed code used in the current work. Comparison were carried out through sinkages of the bow and stern, trim angle and wave-making resistance. Comparative analysis regarding hydrodynamic characteristic of different twin hull forms is worthy of application in the hull form development stage.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.1
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• pp.20-26
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• 2011

A weakly nonlinear seakeeping methodology for predicting motions and loads is presented in this paper. This methodology assumes linear radiation and diffraction forces, calculated in the frequency domain, and fully nonlinear Froude-Krylov and hydrostatic forces, evaluated in the time domain. The particular approach employed here allows to overcome numerical problems connected to the determination of the impulse response functions. The procedure is divided into three consecutive steps: evaluation of dynamic sinkage and trim in calm water that can significantly influence the final results, a linear seakeeping analysis in the frequency domain and a weakly nonlinear simulation. The first two steps are performed employing a three-dimensional Rankine panel method. Nonlinear Froude-Krylov and hydrostatic forces are computed in the time domain by pressure integration on the actual wetted surface at each time step. Although nonlinear forces are evaluated into the time domain, the equations of motion are solved in the frequency domain iteratively passing from the frequency to the time domain until convergence. The containership S175 is employed as a test case for evaluating the capability of this methodology to correctly predict the nonlinear behavior related to wave induced motions and loads in head seas; numerical results are compared with experimental data provided in literature.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.3
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• pp.335-342
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• 2009

Motion characteristics of a planing craft are sensitively changed according to its weight and longitudinal center of gravity. In this paper, planing craft model tests were performed in calm water for various test conditions and Froude numbers. Sinkage and trim were measured to analyze the relations between the attitudes of a planing craft and the weight and center of gravity of it. Theoretical formula for the prediction of the attitudes of a prismatic planing hull was modified so that it can be applied to the prediction of the attitudes of a non-prismatic planing hull, and the calculation results by the modified formula were in good agreements with the experimental data.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.577-583
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• 2014

Three major classes of retroviral restriction factors (APOBEC3G, Tetherin, and TRIM5${\alpha}$) have been identified in mammals. Restriction factors are cellular proteins that are able to limit viral replication by targeting specific steps of the viral life cycle. To evaluate which restriction factor is the most effective to inhibit the replication of porcine endogenous retroviruses (PERVs), the antiviral activity of each restriction factor was compared. In pseudotype assay, the antiviral activity of human tetherin against PERV pseudotype was slightly weaker than that of human APOBEC3G (hA3G). A combination of tetherin and hA3G was more potent than each individual restriction factor. We questioned whether a combination of tetherin and hA3G could also inhibit the spreading replication of PERV. In agreement with the pseudotype assay, two restriction factors inhibit infectious PERV replication in a spreading infection. In this study, hA3G could strongly inhibit the replication of PERV, but tetherin modestly restricted it. Based on these results, we concluded that a combination of tetherin and hA3G is the most effective way to restrict PERV. A combination of different restriction factors will encourage the development of a new approach to treat retroviral disease.