• Title/Summary/Keyword: Physical Parameters

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Sound Characteristics and Mechanical Properties of Taekwondo Uniform Fabrics (태권도 도복 직물의 소리 특성과 역학적 성질)

  • Jin, Eun-Jung;Cho, Gil-Soo
    • Fashion & Textile Research Journal
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    • v.14 no.3
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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.

Analysis on the Relationship of Soil Parameters of Marine Clay (해성점토의 토질정수 상관성 분석)

  • Heo, Yol;Yun, Seokhyun;Jung, Keunchae;Oh, Seungtak
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.4
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    • pp.37-45
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    • 2008
  • Normally consolidated and slightly overconsolidated soft clay layer is widely distributed in the south coast of Korea. To ensure the efficient and economical construction design of any structure to be built on this soft soil, exhaustive studies are required related to geotechnical engineering properties. In this study, the relationship of the physical properties of southern marine clay in the Korea Peninsula were examined, including natural water content, specific gravity, total unit weight, initial void ratio, liquid limit, plastic limit, and physical properties of activity and soil parameters. For the parameter relationship analysis, the latest relatively reliable data on the large harbor construction work were used, optimum values were deducted with linear regression and non-linear regression between soil parameters, water content or initial void ratio appears to be very large. Moreover, in the linear and involution pattern regression, equal coefficient of determination appeared. The relationship of the different parameters was shown to be excellent in the non-linear regression of involution equation and exponential equation pattern compared with the findings of linear regression analysis.

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Relationship between angiotensin-converting enzyme gene polymorphism and muscle damage parameters after eccentric exercise

  • Kim, Jooyoung;Kim, Chang-Sun;Lee, Joohyung
    • Korean Journal of Exercise Nutrition
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    • v.17 no.2
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    • pp.25-34
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    • 2013
  • This study was conducted to investigate the relationship between ACE gene polymorphism and muscle damage parameters after eccentric exercise. 80 collegiate males were instructed to take an eccentric exercise with the elbow flexor muscle through the modified preacher curl machine for 2 sets of 25 cycles (total 50 cycles). The maximal isometric strength, muscle soreness, creatine kinase (CK), and myoglobin (Mb) were measured before exercise, and 0, 24, 48, 72, and 96 hrs after exercise. The result showed that after the eccentric exercise, the maximal isometric strength significantly decreased by more than 50% (p < 0.001) and the muscle soreness, CK, and Mb significantly increased compared to those before the exercise (p < 0.001). The ACE gene polymorphism of the subjects was classified using real-time polymerase chain reaction (real-time PCR). The result showed that it consisted of 38 cases of type II (46.4%), 33 cases of type ID (43.4%), and 9 cases of type DD (10.2%). The Hardy-Weinberg equilibrium for ACE gene polymorphism was shown to have p = 0.653, which showed that each allele was evenly distributed. Although significant differences in the changes in the maximal isometric strength, muscle soreness, CK, and Mb were found according to time course (p < 0.001), no significant differences in the changes in the maximal isometric strength, muscle soreness, CK, and Mb were found according to ACE gene polymorphism. Furthermore, no significant difference in the changes in the muscle damage parameters was found according to interaction between ACE gene polymorphism and time course (p > 0.05). In conclusion, the level of the muscle damage parameters changed in the injured muscle after eccentric exercise, but these changes in the muscle damage parameters were not affected by ACE gene polymorphism. The result of this study indicates that ACE gene is not a candidate gene that explains muscle damage.

The Effect of Intensive Mobility Training on the Gait Performance of Patients with Parkinson's Disease

  • Lee, In-Hee
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.196-201
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    • 2014
  • Purpose: The novelty of intensive mobility training (IMT) is its intensive nature. The purpose of this study was to examine the effect of IMT in patients with Parkinson's disease. Methods: Subjects participated in 3 hours/day for ten days (30 hours). Gait parameters of interest were the timed up-and-go test, 10-m walk test, and step length and width. Measures were made at baseline before commencement of training (pre-training) and at the end of the two-week training period (post-training). Results: Seven patients with Parkinson's disease enrolled in the study. On average, participants are able to tolerate 141 minutes of activity during a 180-minute session. Results showed that, after 10 consecutive days training, subjects significantly improved for all parameters; the timed up-and-go test, 10-m walk test, and stride length and step width. Conclusion: This study's findings show that gait properties in patients with Parkinson's disease can be improved with IMT.

Modified Tikhonov regularization in model updating for damage identification

  • Wang, J.;Yang, Q.S.
    • Structural Engineering and Mechanics
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    • v.44 no.5
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    • pp.585-600
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    • 2012
  • This paper presents a Modified Tikhonov Regularization (MTR) method in model updating for damage identification with model errors and measurement noise influences consideration. The identification equation based on sensitivity approach from the dynamic responses is ill-conditioned and is usually solved with regularization method. When the structural system contains model errors and measurement noise, the identified results from Tikhonov Regularization (TR) method often diverge after several iterations. In the MTR method, new side conditions with limits on the identification of physical parameters allow for the presence of model errors and ensure the physical meanings of the identified parameters. Chebyshev polynomial is applied to approximate the acceleration response for moderation of measurement noise. The identified physical parameter can converge to a relative correct direction. A three-dimensional unsymmetrical frame structure with different scenarios is studied to illustrate the proposed method. Results revealed show that the proposed method has superior performance than TR Method when there are both model errors and measurement noise in the structure system.

Effects of Surface Geometry on Polyelectrolyte Adsorption

  • Park, Young-G.;Kim, Key-Seek;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.2
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    • pp.149-156
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    • 2000
  • For the adsorption of polyelectrolyte at the surface of polyacrylamide gel particle, preferential adsorption of the large polyelectrolyte such as DNA is governed by the surface area of an adsorbent. The adsorption equilibrium constant can be varied by surface geometry of porous polymer, and it can be described as a function of ionic strength and surface area. Physical parameters affecting the adsorption were estimated using the theoretical governing equation of polyelectrolyte which electrophoretically moved along the column, and geometrical surface area was estimated by Waldman-Mayer's physical model. The separation of polyelectrolytes was studied using the physical parameters estimated by ionic strength and surface geometry.

ON SEVERAL NEW CONTIGUOUS FUNCTION RELATIONS FOR k-HYPERGEOMETRIC FUNCTION WITH TWO PARAMETERS

  • Chinra, Sivamani;Kamalappan, Vilfred;Rakha, Medhat A.;Rathie, Arjun K.
    • Communications of the Korean Mathematical Society
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    • v.32 no.3
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    • pp.637-651
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    • 2017
  • Very recently, Mubeen, et al. [6] have obtained fifteen contiguous function relations for k-hypergeometric functions with one parameter by the same technique developed by Gauss. The aim of this paper is to obtain seventy-two new and interesting contiguous function relations for k-hypergeometric functions with two parameters. Obviously, for $k{\rightarrow}1$ we recover the results obtained by Cho, et al. [2] and Rakha, et al. [8].

RF Glow Discharge and TiN Thin Film Characteristics in a Plane Electrode System (평판형 전극계의 RF 글로우 방전특성 및 TiN 박막특성)

  • Kwak, D.J.;Kim, D.H.;Kim, H.J.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1838-1840
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    • 1996
  • In order to study the relationship between the physical properties of glow discharge plasma and the physical behavior of TiN thin film, electrical characteristics of RF discharge plasma driven at 13.56MHz in a parallel-plate electrode system were measured. Plasma parameters, such as electron density and temperature, are also studied since they may be considered as one of the very important factors deciding the physical properties of TiN thin film under given conditions of applied biasd voltage and pressure. The TiN thin film were fabricated over a wide range of discharge conditions, and some of the general relationships between the measured plasma parameters and the properties of TiN thin film were discussed.

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Prediction of the mechanical properties of granites under tension using DM techniques

  • Martins, Francisco F.;Vasconcelos, Graca;Miranda, Tiago
    • Geomechanics and Engineering
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    • v.15 no.1
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    • pp.631-643
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    • 2018
  • The estimation of the strength and other mechanical parameters characterizing the tensile behavior of granites can play an important role in civil engineering tasks such as design, construction, rehabilitation and repair of existing structures. The purpose of this paper is to apply data mining techniques, such as multiple regression (MR), artificial neural networks (ANN) and support vector machines (SVM) to estimate the mechanical properties of granites. In a first phase, the mechanical parameters defining the complete tensile behavior are estimated based on the tensile strength. In a second phase, the estimation of the mechanical properties is carried out from different combination of the physical properties (ultrasonic pulse velocity, porosity and density). It was observed that the estimation of the mechanical properties can be optimized by combining different physical properties. Besides, it was seen that artificial neural networks and support vector machines performed better than multiple regression model.

Physical Properties of Nylon Textured Yarn according to False Twist Texturing Parameters (I) - Effect of Speed and Draw Ratio - (가연조건에 따른 나일론 섬유의 물성 (I) - 가연속도와 연신비의 영향 -)

  • Hu, Jong-Tea
    • Textile Coloration and Finishing
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    • v.20 no.1
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    • pp.28-35
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    • 2008
  • Texturing is the process of including a characteristic of a natural fiber in a synthetic fiber. The most common method of it the false twist texturing. Nylon textured yarn is primarily manufactured by the disk type. The major process parameters or the disk type false twist machine ratio, disk/yarn, and heater temperature. This study therefore investigated the effects of false twist texturing, especially speed and draw ratio, on the physical properties of nylon textured yarn. The increase of speed was proportional to the increase of unwinding tension, which could reduce the production efficiency by elevating the tension affecting to fiber during the process. In addition, the increase of speed was inversely proportional to the increase of crimp rigidity of nylon textured yarn. Draw ratio was proportionally increased with the increase of tenacity and the reductions of fineness and elongation, showing the influence or draw ratio to the ultimate physical properties of textured yarn.