• 한국의류산업학회지
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• 제1권2호
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• pp.182-187
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• 1999

The study was conducted on the change of value of physical properties, mechanical properties, appearance of seams as repeated washing and drying with 1, 3, 5, 7, 10, 15, 20 times. Commercial cotton 100%, cotton/polyester 80/20% and polyester 100% dress shirts were used to investigate drying characteristics and physical properties and compare of each materials after repeated drying. The mechanical properties like tensile, shear, surface, compression, thickness and weight were measured by the KES-FB system.

• 한국환경복원기술학회지
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• 제5권6호
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• pp.9-13
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with cement. And confirm the reinforcing effects with admixture such as cement. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and cement reinforced soil. In order to determine proper moisture content and mixing ratio, pilot test was carried out for soil and cement reinforced soil. And the mixing ratio of cement admixture was fixed 3%, 6%, 9% and 12% by the weight of dry soil. As the experimental results, the maximum dry unit weight(${\gamma}_{dmax}$) was increased with the mixing ratio and then shown the peak at 10% reinforced soil, but the optimum moisture content(OMC) and the volume change was decreased with the ratio increase. And the compressive strength volume change was decreased with mixing ratio increased.

• 한국의류산업학회지
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• 제14권3호
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• pp.486-491
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• 2012

This study examined the sound characteristics of Taekwondo uniform fabrics to investigate the relationship between the sound parameters and the mechanical properties of the fabric as well as to provide the conditions to maximize the frictional sound of the uniform. Frictional sounds of 6 fabrics for Taekwondo uniforms were generated by the Simulator for Frictional Sound of Fabrics. The frictional speeds were controlled at low(0.62 m/s), at mid(1.21 m/s) and at high(2.25 m/s) speed, respectively. The frictional sounds were recorded using a Data Recorder and Sound Quality System subsequently, the physical sound properties such as SPL(Sound Pressure Level) and Zwicker's psychoacoustic parameters were calculated. Mechanical properties of specimens were measured by KES-FB. The SPL, Loudness(Z) values increased while Sharpness(Z) value decreased. In the physical sound parameter, specimen E had the highest SPL value at low speed and specimen B at high speed. In case of Zwicker's psychoacoustic parameters, the commercially available Taekwondo uniform fabrics(E, F) showed higher values of Loudness(Z), Sharpness(Z), and Roughness(Z), that indicates they can produce louder, shaper and rougher sounds than other fabrics for Taekwondo uniforms. The decisive factors that affected frictional sounds for Taekwondo uniforms were W(weight) as well as EM(elongation at maximum load) at low speed and WC(compressional energy) at high speed.

• Journal of the Korean Physical Society
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• 제73권10호
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• pp.1519-1528
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• 2018

The objective of the present study is the development of a comprehensive air chemical kinetic model that includes 11 species and 54 chemical reactions for the numerical investigation of air nonequilibrium inductively coupled plasmas. The two-dimensional, compressible Navier-Stokes equations coupled with the electromagnetic-field equations were employed to describe the fundamental characteristics of an inductive plasma. Dunn-Kangs 32 chemical-reaction model of air was reconstructed and used as a comparative model. The effects of the different chemical kinetic models on the flow field were analyzed and discussed at identical/different working pressures. The results theoretically indicate that no matter the working pressure is low or high, the use of the 54 chemical kinetic model presented in this study is a better choice for the numerical simulation of a nonequilibrium air ICP.

• 한국산업융합학회 논문집
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• 제9권1호
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• pp.5-11
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• 2006

This study was performed to determine the effect of structural characteristics of selected wool fabrics on mechanical and thermal properties. 52 wool fabrics, including 18 plain woven fabrics and 34 twill and satin woven fabrics were used as samples woven with various weft density for the study. Several physical characteristics such as mechanical properties, keeping warmth ratio of wool fabrics were measured. Data analyses including 1) analysis of tactile and thermal comfort sensation were performed. the following were obtained from the results: The main factors affecting keeping warmth ratio were thickness and bulk density. The keeping warmth ratio of samples increased with increasing thickness and decreasing bulk density of samples. In addition, coefficient of friction of the samples increased with keeping warmth ratio of samples. The above results show that wearing sensation and comfort properties of fabrics are changed depending on the end-use, and thus, above results can be used to manufacture of fabrics for specific end-use with high comfort properties.

• Journal of Mechanical Science and Technology
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• 제17권11호
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• pp.1756-1766
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• 2003

Numerical modeling is carried out to investigate forced convective heat transfer to near-critical water in developing laminar flow through a circular tube. Due to large variations of thermo-physical properties such as density, specific heat, viscosity, and thermal conductivity near thermodynamic critical point, heat transfer characteristics show quite different behavior compared with pure forced convection. With flow acceleration along the tube unusual behavior of heat transfer coefficient and friction factor occurs when the fluid enthalpy passes through pseudocritical point of pressure in the tube. There is also a transition behavior from liquid-like phase to gas-like phase in the developing region. Numerical results with constant heat flux boundary conditions are obtained for reduced pressures from 1.09 to 1.99. Graphical results for velocity, temperature, and heat transfer coefficient with Stanton number are presented and analyzed.

• 한국염색가공학회지
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• 제16권4호
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• pp.36-44
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• 2004

This research surveys the differences of fabric mechanical properties according to the different looms and the fabric positions with relation to warp and weft weaving tensions on the Picanol and Omega looms respectively. For this purpose, the grey fabrics woven in the previous paper are processed in dyeing and finishing processes, and the processing shrinkages are measured on each processes such as dryer, scouring, pre-set, dyeing and final-set using the fabric density and width. The mechanical properties of the finished fabrics are measured and discussed with relation to the warp and weft weaving tensions of the two looms and the variations of the fabric mechanical properties according to the fabric positions are also discussed. In addition, the fabric thickness according to the fabric positions such as right, left selvedges and center of the fabrics is also measured and discussed with the characteristics of the Picanol and Omega looms.

• Journal of Mechanical Science and Technology
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• 제18권10호
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• pp.1799-1808
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• 2004

Knowledge of airflow characteristics in nasal cavity is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. Since the final goal of these works is their contribution to the diagnosisand treatment of nasal diseases, the next step on this topic is naturally studies for disordered nasal cavities. In this paper, as the first application, airflows in the normal and abnormal nasal cavities with adenoid vegetation are investigated experimentally by PIV, and comparisons of both cases are appreciated. Dense CT data and careful treatment of model surface under the ENT doctor's advice provide more sophisticatedcavity model. The CBC PIV algorithm with window offset is used for PIV flow analysis. Average and RMS distributions are obtained for inspirational and expirational nasal airflows. Airflow characteristics that are related with the abnormalities in nasal cavity are presented.

• 한국정밀공학회지
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• 제25권10호
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• pp.130-136
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• 2008

The purpose of this study was to investigate chaotic characteristics of major joint motions during treadmill walking. Gait experiments were carried out for 20 healthy young women. The subjects were asked to walk on a treadmill at their own natural speeds. The chaos analysis was used to quantify nonlinear motions of eleven major joints of each woman. The joints analyzed included the neck and the right and left shoulders, elbows, hips, knees and ankles. The recorded gait patterns were digitized and then coordinated by motion analysis software. Lyapunov exponent for every joint was calculated to evaluate joint characteristics from a state space created by time series and its embedding dimension. This study shows that differences in joint motion were statistically significant.

• 한국의류산업학회지
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• 제8권4호
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• pp.441-448
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• 2006

This research is the hair damage as treating a permanent wave before and after that is compared and analyzed the change of physical and mechanical properties. This is the survey of women's hair in 20 years old. On the basis of this we would like to analyze a extend of hair damage. Also, we would to show a basic data for hair damage prevention and hair improvement to keep the beautiful and healthy hair. The conclusion is as follow. : The swelling degree after the treatment was found to be greater than before permanent wave treatment. For the formational characteristics wave, untreated hair certainly had more elastic S curl wave than damaged hair in all the permanent wave treatments, and damaged hair and extremely damaged hair had less elasticity and had saggy S curl wave. The protein permanent and soft permanent wave had thicker, gorgeous, and better elastic wave than the regular permanent wave and direct heating permanent wave in all the hair condition. As the degree of damage on hair got greater, the tensile strength dramatically decreased and as the degree of damage got greater, the elongation was great as well. For treatment method, direct heating permanent wave showed the greatest effect, causing the most damage.