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حرية الوصول المقاله
1 - بررسی برهم کنش اطلاعات در شرکتهای بازار سرمایه ایران با استفاده از ماتریس آنتروپی انتقال
عارفه محقق محسن حمیدیان سید علی حسینی اسفیدواجانی غلامرضا جعفریتمرکز مطالعه حاضر بر روی بازار مالی بورس ایران است. در واقع، هدف مطالعه حاضر، بررسی میزان انتقال اطلاعات در شرتهای عضو بورس با استفاده از ماتریس آنتروپی انتقال است. سرمایه گذاری در بازار سرمایه و خرید سهام شرکت هایی که دارای آنتروپی زیاد می باشند با ریسک زیادی همراه است أکثرتمرکز مطالعه حاضر بر روی بازار مالی بورس ایران است. در واقع، هدف مطالعه حاضر، بررسی میزان انتقال اطلاعات در شرتهای عضو بورس با استفاده از ماتریس آنتروپی انتقال است. سرمایه گذاری در بازار سرمایه و خرید سهام شرکت هایی که دارای آنتروپی زیاد می باشند با ریسک زیادی همراه است به دلیل بالا بودن ریسک و احتمال ورشکستگی ممکن است اصل و سود سرمایه از بین برود. داده های مربوط به حجم معاملات- کیفیت افشا- شاخص ماهیانه- حاکمیت شرکتی و کیفت سود برای ۲۷شرکت از بازار بورس ایران و قیمت ماهیانه نفت اوپک- نرخ تورم ماهیانه- نرخ ازر -قیمت اونس طلا در بازه ی زمانی سال های ۱۳۸۸تا ۱۳۹۶دریافت کردیم. اهمیت ویژه بازار سرمایه در توسعه اقتصاد از طریق هدایت موثر سرمایه ها و تخصیص بهینه منابع غیرقابل انکار است . سرمایه گذاری در بازار سرمایه مستلزم تصمیم گیری می باشد که این خود نیازمند دستیابی به اطلاعات در خصوص وضعیت آینده قیمت بازار سهام می باشد . بعد از یک سری تغییرات شدید که پشت سرهم شکل گرفته ، روند تغییرات داده ها به سمت منفی شدن حرکت میکند به عبارتی در یک سیکل امتدادی و پیوسته هر چه درجه تغییرات بیشتر باشد احتمال نزدیک شدن به یک حالت سکون بیشتر می شود. تفاصيل المقالة -
حرية الوصول المقاله
2 - Free Torsional Vibration Analysis of Hollow and Solid Non-Uniform Rotating Shafts Using Distributed and Lumped Modeling Technique
A Saghafi M .A AziziIn this paper, the torsional free vibration of solid and hollow rotating shafts with non-uniform tapered elements are investigated. To this end, the exact solution and also transfer matrix for the free torsional vibration of a hollow tapered shaft element with uniform t أکثرIn this paper, the torsional free vibration of solid and hollow rotating shafts with non-uniform tapered elements are investigated. To this end, the exact solution and also transfer matrix for the free torsional vibration of a hollow tapered shaft element with uniform thickness and also solid element are firstly obtained. Then, the natural frequencies are determined based on distributed and lumped modeling technique (DLMT). This technique is similar to transfer matrix method (TMM) but the exact solution is employed to obtain the transfer matrixes of the distributed element, therefore, there is no approximation and the natural frequencies and mode shapes are the exact values. To confirm the reliability of the presented method, the simulation results are compared with the results obtained from the other methods such as finite element method. It is shown that the proposed method provides highly accurate results and it can be simply applied to the complex torsional systems. تفاصيل المقالة -
حرية الوصول المقاله
3 - Dynamic Analysis of Offshore Wind Turbine Towers with Fixed Monopile Platform Using the Transfer Matrix Method
M Feyzollahzadeh M.J MahmoodiIn this paper, an analytical method for vibrations analysis of offshore wind turbine towers with fixed monopile platform is presented. For this purpose, various and the most general models including CS, DS and AF models are used for modeling of wind turbine foundation a أکثرIn this paper, an analytical method for vibrations analysis of offshore wind turbine towers with fixed monopile platform is presented. For this purpose, various and the most general models including CS, DS and AF models are used for modeling of wind turbine foundation and axial force is modeled as a variable force as well. The required equations for determination of wind turbine tower response excited by the Morrison force are derived based on Airy wave theory. The transfer matrix is derived for each element of the tower using Euler-Bernoulli’s beam differential equation and the global transfer matrix is obtained considering boundary conditions of the tower and constructing the point matrix. The effective wave force is intended in several case studies and Persian Gulf Environmental conditions are examined for the installation of wind farms. Finally, the obtained results by the transfer matrix method are compared with the results of the finite elements method and experimental data which show good agreement in spite of low computational cost. تفاصيل المقالة -
حرية الوصول المقاله
4 - Whirling Analysis of Axial-Loaded Multi-Step Timoshenko Rotor Carrying Concentrated Masses
K Torabi H Afshari H NajafiIn this paper, exact solution for two-plane transverse vibration analysis of axial-loaded multi-step Timoshenko rotor carrying concentrated masses is presented. Each attached element is considered to have both translational and rotational inertia. Forward and backward f أکثرIn this paper, exact solution for two-plane transverse vibration analysis of axial-loaded multi-step Timoshenko rotor carrying concentrated masses is presented. Each attached element is considered to have both translational and rotational inertia. Forward and backward frequencies and corresponding modes are obtained using transfer matrix method (TMM). The effect of the angular velocity of spin, value of the translational and rotational inertia, position of the attached elements and applied axial force on the natural frequencies are investigated for various boundary conditions. تفاصيل المقالة -
حرية الوصول المقاله
5 - Optical Excitation of Surface Plasmon Polariton in Thin Gold, silver and Copper Metal Layers and Measuring the Metal Layer
Behnam KazempourIn this paper, we employed the attenuated total reflection (ATR) technique to theoretically and experimentally measure the thickness of metal thin films and compare together them. The computations of the present study were carried out using characteristics matrix method أکثرIn this paper, we employed the attenuated total reflection (ATR) technique to theoretically and experimentally measure the thickness of metal thin films and compare together them. The computations of the present study were carried out using characteristics matrix method. The ATR technique is based on the excitation of surface polaritons. In the ATR spectra polariton, the surface polaritons manifest themselves as sharp reflectivity minima. We used this minimum to measure the thickness of a silver layer coated on the surface of a prism. We observed that the measured value has a good agreement with the real thickness of the layer. تفاصيل المقالة -
حرية الوصول المقاله
6 - Designing real-time biosensors and chemical sensors based on symmetrical photonic crystal heterostructures
maryam sharifi Habib Tajalli Hamid Pashaei Adl Payman TajalliIn this paper, we introduce and analytically demonstrate a novel biosensor based on the light-matter interaction in a classic topological photonic crystal (PC) heterostructure, which consists of two opposite-facing 5-period PCs separated by a microfluidic channel. Becau أکثرIn this paper, we introduce and analytically demonstrate a novel biosensor based on the light-matter interaction in a classic topological photonic crystal (PC) heterostructure, which consists of two opposite-facing 5-period PCs separated by a microfluidic channel. Because of the excitation of topological edge mode (TEM) at the interface of the two PCs, the strong coupling between incident light and TEM produces a high-quality resonance peak, which can be used to detect very small changes in the refractive index of biomaterials such as Jurkat Cells inside the microfluidic channel. The proposed biosensor has a sensitivity as high as 240 nm/RIU and figure of merit (FOM) higher than 250. تفاصيل المقالة -
حرية الوصول المقاله
7 - 1D Photonic Crystal Based-Biosensor for Multiple Biomarkers Detection
Farzaneh Bayat Kazem Jamshidi-GhalehIn this work, a highly sensitive 1D photonic crystal (1DPC) based biosensor is introduced and theoretically studied using the transfer matrix method, which has the capability of detecting multiple biomarkers, simultaneously. An m by n gradient refractive index (GRIN) le أکثرIn this work, a highly sensitive 1D photonic crystal (1DPC) based biosensor is introduced and theoretically studied using the transfer matrix method, which has the capability of detecting multiple biomarkers, simultaneously. An m by n gradient refractive index (GRIN) lens array is introduced to the center of a 1DPC structure as a defect layer that is surrounded by two microfluidic channels. By irradiating a white light source to the structure, a multiplex array of the concentric rainbow appears on the output plane. The frequency range of these rainbows is highly dependent on the effective refractive index of the fluid inside the two microfluidic channels. By functionalizing the surfaces around the channels with an m by n antibody array and interacting with the various biomarkers with them, each element of the rainbow array displays the changes in the concentration of a different biomarker. Any change in the concentration of the biomarkers can cause a variation in the effective refractive index of the fluid and it leads to a shift in the produced rainbow frequency range on the output plane. The size and number of the generated rainbow array can be engineered by the central defect layer's refractive index distribution function. تفاصيل المقالة -
حرية الوصول المقاله
8 - 1D Photonic Crystal-Based Biosensor for Multiple Biomarkers Detection
Farzaneh Bayat Kazem Jamshidi-GhalehIn this paper, a highly sensitive 1D photonic crystal (1DPC) based biosensor is introduced and theoretically studied using the transfer matrix method, which has the capability of detecting multiple biomarkers, simultaneously. An m by n gradient refractive index (GRIN) l أکثرIn this paper, a highly sensitive 1D photonic crystal (1DPC) based biosensor is introduced and theoretically studied using the transfer matrix method, which has the capability of detecting multiple biomarkers, simultaneously. An m by n gradient refractive index (GRIN) lens array is introduced to the center of a 1DPC structure as a defect layer that is surrounded by two microfluidic channels. By irradiating a natural light source to the structure, a multiple array of the concentric rainbow appears on the output plane. The frequency range of these rainbows is highly dependent on the effective refractive index of the fluid inside the two microfluidic channels. By functionalizing the surfaces around the channels with an m by n antibody array along with the interaction of the various biomarkers, each element of the rainbow array displays the changes in the concentration of a different biomarker. Any change in the concentration of the biomarkers can cause a variation in the effective refractive index of the fluid and thus lead to a shift in the generated rainbow frequency range of the output. The size and number of the generated rainbow array may be engineered by using the central defect layer's refractive index distribution function. تفاصيل المقالة -
حرية الوصول المقاله
9 - Theoretical investigation of optical properties of Aluminum zig-zag thin films
Maryam Gholizadeh Arashti Mahsa FakharpourThe transmission matrix method was applied to model the reflection and transmission co-polarization spectra of zig-zag aluminum thin films by different arm numbers and lengths and the optical spectra of the zig-zag nanostructures for both s- and p- polarized lights were أکثرThe transmission matrix method was applied to model the reflection and transmission co-polarization spectra of zig-zag aluminum thin films by different arm numbers and lengths and the optical spectra of the zig-zag nanostructures for both s- and p- polarized lights were obtained at different incident angles. According to the results, for the s- polarized incident light, the transmission reduces and the reflection increases by incident angle. For the p- polarized light, the reflection reduces else for the incident directions near the Bruster’s angle and the transmission almost remains constant. The numbers of Bragg peaks via arm number were also considered for s-polarized light at the 〖60〗^° incident angle. The results determined four arms as the period of zig-zag structure. Besides, the red and blue shifts were observed for the wavelengths smaller and greater than 550 nm, respectively. At last, no Bragg peak was observed for p-polarized light at all incident angles. تفاصيل المقالة
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