• Title/Summary/Keyword: Differential Validity

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A Study on the Development of Fashion Sensibility (Part II) (패션감성의 측정도구 개발에 관한 연구(제2보))

  • 이경희;김유진
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.5
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    • pp.505-516
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    • 2003
  • The purpose of this study was to develop the measurement of fashion sensibility and to verify the validity and utility. The survey has been done 91 photos selected in fashion magazines with 25 semantic differential hi-polar scale. The obtained data were analyzed by MDS, Discriminant analysis and Regression analysis. The major findings of this research were as follows. 1. According to the sensibility positioning, fashion image was classified by 4 group and agreed with constructing factors of fashion. 2. As result of the discrimination analysis, distinguishable fashion sensibility among design elements of clothing was related to refined, pleasant, feel like buying sensibility. 3. As result of the regression analysis, Preference was related to looking good, refined, and sweet, Buying needs related to likable, looking good and natural, Riches related to elegant, neat and refined, Pleasure related to looking good, elegant and bright. 4. The fashion design properties were different regarding Preference, Buying needs. Riches and Pleasure. Preference and Buying needs were related to H-line, similarity color combination, cotton and linen, Riches related to brilliance texture, ruffle and flounces, Pleasure related to fit and sexy design of clothing.

Metagonimus yokogawai (Trematoda: Heterophyidae): From Discovery to Designation of a Neotype

  • Shimazu, Takeshi;Kino, Hideto
    • Parasites, Hosts and Diseases
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    • v.53 no.5
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    • pp.627-639
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    • 2015
  • Metagonimus yokogawai (Katsurada, 1912) Katsurada, 1912 (Trematoda: Heterophyidae) is parasitic in the small intestine of mammals including man and birds in Far Eastern Russia, Korea, Japan, China, and Taiwan. In the present study, the metacercariae and adults of M. yokogawai were redescribed to designate a neotype of this fluke together with reviews of previous studies including study histories from the first discovery to now. We particularly, attempted to review the study histories and morphological descriptions of M. yokogawai for the species validity, and compared with the morphological characteristics and life cycles of the closely related species, Metagonimus takahashii and Metagonimus miyatai. Finally, we proposed a differential key for the 8 known Metagonimus species distributed in East Asia. Metacercariae were obtained from the body muscles of sweetfish (Plecoglossus altivelis) collected in the Asahi River at Takebe-cho, Kita-ku, Okayama City, Okayama Prefecture, Japan. Adults were recovered from the small intestine of Syrian golden hamsters, to which the metacercariae had been fed 14 days before. A neotype was selected out of the present adult specimens. The Asahi River at Takebo-cho became the type locality of M. yokogawai. In conclusion, the present review shows that M. yokogawai, M. takahashii, and M. miyatai are valid and discriminated by means of morphological characteristics.

Analysis of the Thermal Processes in the Iron-Making Facility - Modeling Approach (제선 설비의 열공정 해석 모델링 접근 방법)

  • Yang, Won;Ryu, Chang-Kook;Choi, Sang-Min;Choi, Eung-Soo;Ri, Deok-Won;Huh, Wan-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.7
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    • pp.747-754
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    • 2004
  • Thermo-fluid characteristics in coke oven, sintering machine and blast furnace in iron-making facility are key processes related to the quality and productivity of the pig iron. Solid material in the processes usually forms a bed in a gas flow. For simulation of the processes by mathematical model, the solid beds are idealized to be a continuum and a reacting solid flow in the gas flow. Governing equations in the form of partial differential equations for the solid material can be constructed based on this assumption. Iron ore sintering bed is simulated and limited amount of parametric study have been performed. The results have a good agreement with the experimental results or physical phenomena, which shows the validity and applicability of the model.

Porosity-dependent free vibration analysis of FG nanobeam using non-local shear deformation and energy principle

  • Gafour, Youcef;Hamidi, Ahmed;Benahmed, Abdelillah;Zidour, Mohamed;Bensattalah, Tayeb
    • Advances in nano research
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    • v.8 no.1
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    • pp.37-47
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    • 2020
  • This work focuses on the behavior of non-local shear deformation beam theory for the vibration of functionally graded (FG) nanobeams with porosities that may occur inside the functionally graded materials (FG) during their fabrication, using the non-local differential constitutive relations of Eringen. For this purpose, the developed theory accounts for the higher-order variation of transverse shear strain through the depth of the nanobeam. The material properties of the FG nanobeam are assumed to vary in the thickness direction. The equations of motion are derived from Hamilton's principle. Analytical solutions are presented for a simply supported FG nanobeam with porosities. The validity of this theory is verified by comparing some of the present results with other higher-order theories reported in the literature, the influence of material parameters, the volume fraction of porosity and the thickness ratio on the behavior mechanical P-FGM beam are represented by numerical examples.

Application of Optimal Control Techniques to SWATH Motion Control (반잠수 쌍동선의 최적 운동제어기 설계)

  • Chan-Wook Park;Bo-Hyeon Heo;Chun-Tae Song
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.2
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    • pp.65-77
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    • 1994
  • This paper presents a derailed application procedure of the linear quadratic(LQ) theory for a SWATH heave and pitch control. A time domain model of coupled, linear time-invariant second order differential equations is derived from the frequency response model with the frequency dependent added mass and damping approximated as constant values at the heave natural frequency. Wave exciting forces are modeled as a sum of sinusoids. A systematic selection procedure of state and control weighting matrices is presented to obtain good transient behavior and acceptable fin movement. The validity of this controller design process is throughly investigated by simulations both in time domain and frequency domain and singular value plots of transfer function matrices. The finally designed control system shows good overall performances revealing that the applicability of the present study is proved successful.

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Nonlinear model to predict the torsional response of U-shaped thin-walled RC members

  • Chen, Shenggang;Ye, Yinghua;Guo, Quanquan;Cheng, Shaohong;Diao, Bo
    • Structural Engineering and Mechanics
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    • v.60 no.6
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    • pp.1039-1061
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    • 2016
  • Based on Vlasov's torsional theory of open thin-walled members and the nonlinear constitutive relations of materials, a nonlinear analysis model to predict response of open thin-walled RC members subjected to pure torsion is proposed in the current study. The variation of the circulatory torsional stiffness and warping torsional stiffness over the entire loading process and the impact of warping shear deformation on the torsion-induced rotation of the member are considered in the formulation. The torque equilibrium differential equation is then solved by Runge-Kutta method. The proposed nonlinear model is then applied to predict the behavior of five U-shaped thin-walled RC members under pure torsion. Four of them were tested in an earlier experimental study by the authors and the testing data of the fifth one were reported in an existing literature. Results show that the analytical predictions based on the proposed model agree well with the experimental data of all five specimens. This clearly shows the validity of the proposed nonlinear model analyzing behavior of U-shaped thin-walled RC members under pure torsion.

Temperature dependent buckling analysis of graded porous plate reinforced with graphene platelets

  • Wei, Guohui;Tahouneh, Vahid
    • Steel and Composite Structures
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    • v.39 no.3
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    • pp.275-290
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    • 2021
  • The main purpose of this research work is to investigate the critical buckling load of functionally graded (FG) porous plates with graphene platelets (GPLs) reinforcement using generalized differential quadrature (GDQ) method at thermal condition. It is supposed that the GPL nanofillers and the porosity coefficient vary continuously along the plate thickness direction. Generally, the thermal distribution is considered to be nonlinear and the temperature changing continuously through the thickness of the nanocomposite plates according to the power-law distribution. To model closed cell FG porous material reinforced with GPLs, Halpin-Tsai micromechanical modeling in conjunction with Gaussian-Random field scheme are used, through which mechanical properties of the structures can be extracted. Based on the third order shear deformation theory (TSDT) and the Hamilton's principle, the equations of motion are established and solved for various boundary conditions (B.Cs). The fast rate of convergence and accuracy of the method are investigated through the different solved examples and validity of the present study is evaluated by comparing its numerical results with those available in the literature. A special attention is drawn to the role of GPLs weight fraction, GPLs patterns through the thickness, porosity coefficient and distribution of porosity on critical buckling load. Results reveal that the importance of thermal condition on of the critical load of FGP-GPL reinforced nanocomposite plates.

Critical buckling of functionally graded nanoscale beam with porosities using nonlocal higher-order shear deformation

  • Benahmed, Abdelillah;Fahsi, Bouazza;Benzair, Abdelnour;Zidour, Mohamed;Bourada, Fouad;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.69 no.4
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    • pp.457-466
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    • 2019
  • This paper presents an efficient higher-order nonlocal beam theory for the Critical buckling, of functionally graded (FG) nanobeams with porosities that may possibly occur inside the functionally graded materials (FG) during their fabrication, the nonlocal elastic behavior is described by the differential constitutive model of Eringen. The material properties of (FG) nanobeams with porosities are assumed to vary through the thickness according to a power law. The governing equations of the functionally graded nanobeams with porosities are derived by employing Hamilton's principle. Analytical solutions are presented for a simply supported FG nanobeam with porosities. The validity of this theory is studied by comparing some of the present results with other higher-order theories reported in the literature, Illustrative examples are given also to show the effects of porosity volume fraction, and thickness to length ratios on the critical buckling of the FG beams.

Development of MATLAB/Simulink Modular Simulation Toolbox for Space Shuttle Main Engine (MATLAB/Simulink 모듈화 기반 우주왕복선 주엔진 시뮬레이션 툴박스 개발)

  • Cho, Woosung;Cha, Jihyoung;Ko, Sangho
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.4
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    • pp.50-60
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    • 2019
  • This paper introduces the development of a toolbox for the Space Shuttle Main Engine(SSME) based on MATLAB/Simulink. A mathematical model of rocket engine creation and validation can be a complex process, the development of a rocket engine toolbox simplifies this process, thereby facilitating engine performance optimization as well as new design development. The mathematical modeling of the SSME dealt with in this paper is formed by 32 first-order differential equations derived from seven governing equations. We develop the toolbox for the SSME classifying each module according to the engine components. Further, we confirm the validity of the toolbox by comparing the results of the simulation obtained using the toolbox with those obtained using the original simulation of the engine.

Management of the energy harvesting for MEMS/NEMS via newmark current method

  • Shang, Kun;Shan, Huafeng;Alkhalaf, Salem;Marzouki, Riadh;Khadimallah, Mohamed Amine
    • Advances in nano research
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    • v.12 no.6
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    • pp.567-581
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    • 2022
  • The free and forced vibration in addition to electric energy harvesting of a piezoelectric disk resting on two-parameter foundation modeled by modified couple stress as well as Kirchhoff plate theory is probed. The governing equations and boundary conditions are obtained using Hamilton's principle. Then, the free and forced vibration are solved using numerical solutions, generalized differential quadrature method (GDQM) and Newmark-beta method. The forced vibration is resulted from a base excitation load. Also, the possible voltage which can be harvested from this system is obtained using generalized integral quadrature method. The validity of the formulation and solution procedure is confirmed using a compassion study. The impact of parameters such as length effect, inner to outer radius ratio, and foundations parameters on the free and forced vibration as well as energy harvesting is investigated in detail. This paper can be a basis for future studies in the area of piezoelectric harvesters in small scales.