• Title/Summary/Keyword: core principle

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A Novel Dual-Input Boost-Buck Converter with Coupled Inductors for Distributed Thermoelectric Generation Systems

  • Zhang, Junjun;Wu, Hongfei;Sun, Kai;Xing, Yan;Cao, Feng
    • Journal of Power Electronics
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    • v.15 no.4
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    • pp.899-909
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    • 2015
  • A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

Global Corporate Citizenship: Cross-cultural Comparison of Best Practices in the Global Automotive Industry

  • Lee, Jung Wan;Tan, Wie Nie
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.1
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    • pp.261-271
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    • 2019
  • The study aims to investigate corporate social responsibility (CSR) best practices of the world automotive industry - Peugeot, BMW, Ford, Hyundai and Toyota among others - and recommend that they plan their business strategies and managerial responses accordingly. Based on the comparative research and case studies, this research finds that all five automobile manufacturers have taken very similar measures and actions in order to establish and maintain a high level of CSR practices. Sustainability was a core value in all five companies and served as a guiding principle in every aspect and approach of their business. This study finds that all five companies have CSR strategies in place to increase energy efficiency as well as reduce the usage and wastage of water in their production and plants. This research also finds that all companies monitor their suppliers and their own production process to ensure that they maintain their CSR standards. More impressively, this sustainable management practice is transferred along the companies' supply chain through education and training. Their suppliers and business partners are closely monitored to make sure that their high CSR standards are respected and followed. However, we find that there also are some differences in terms of their CSR deliveries and activities.

Modal analysis of FG sandwich doubly curved shell structure

  • Dash, Sushmita;Mehar, Kulmani;Sharma, Nitin;Mahapatra, Trupti R.;Panda, Subrata K.
    • Structural Engineering and Mechanics
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    • v.68 no.6
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    • pp.721-733
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    • 2018
  • The modal frequency responses of functionally graded (FG) sandwich doubly curved shell panels are investigated using a higher-order finite element formulation. The system of equations of the panel structure derived using Hamilton's principle for the evaluation of natural frequencies. The present shell panel model is discretised using the isoparametric Lagrangian element (nine nodes and nine degrees of freedom per node). An in-house MATLAB code is prepared using higher-order kinematics in association with the finite element scheme for the calculation of modal values. The stability of the opted numerical vibration frequency solutions for the various shell geometries i.e., single and doubly curved FG sandwich structure are proven via the convergence test. Further, close conformance of the finite element frequency solutions for the FG sandwich structures is found when compared with the published theoretical predictions (numerical, analytical and 3D elasticity solutions). Subsequently, appropriate numerical examples are solved pertaining to various design factors (curvature ratio, core-face thickness ratio, aspect ratio, support conditions, power-law index and sandwich symmetry type) those have the significant influence on the free vibration modal data of the FG sandwich curved structure.

Active control of three-phase CNT/resin/fiber piezoelectric polymeric nanocomposite porous sandwich microbeam based on sinusoidal shear deformation theory

  • Navi, B. Rousta;Mohammadimehr, M.;Arani, A. Ghorbanpour
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.753-767
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    • 2019
  • Vibration control in mechanical equipments is an important problem where unwanted vibrations are vanish or at least diminished. In this paper, free vibration active control of the porous sandwich piezoelectric polymeric nanocomposite microbeam with microsensor and microactuater layers are investigated. The aim of this research is to reduce amplitude of vibration in micro beam based on linear quadratic regulator (LQR). Modified couple stress theory (MCST) according to sinusoidal shear deformation theory is presented. The porous sandwich microbeam is rested on elastic foundation. The core and face sheet are made of porous and three-phase carbon nanotubes/resin/fiber nanocomposite materials. The equations of motion are extracted by Hamilton's principle and then Navier's type solution are employed for solving them. The governing equations of motion are written in space state form and linear quadratic regulator (LQR) is used for active control approach. The various parameters are conducted to investigate on the frequency response function (FRF) of the sandwich microbeam for vibration active control. The results indicate that the higher length scale to the thickness, the face sheet thickness to total thickness and the considering microsensor and microactutor significantly affect LQR and uncontrolled FRF. Also, the porosity coefficient increasing, Skempton coefficient and Winkler spring constant shift the frequency response to higher frequencies. The obtained results can be useful for micro-electro-mechanical (MEMS) and nano-electro-mechanical (NEMS) systems.

Dilemma of Multicultural Coexistence: Korean Schools in Japanese Society

  • Ha, Kyung Hee
    • Journal of Contemporary Eastern Asia
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    • v.19 no.2
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    • pp.20-39
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    • 2020
  • In order to overturn the exclusion of Korean schools from the newly implemented free tuition program (2010) as part of sanctions against North Korea, members of Korean schools and Japanese supporters have focused on "students' innocence" and "multicultural coexistence" as viable frameworks to explain why the students are sympathetic and legitimate subjects who deserve equal rights. Examining different political strategies employed by the Korean schools and their supporters through ethnography and media analysis, the article pays close attention to how they claim their eligibility for these rights while they negotiate state surveillance and intervention in the process. I argue that in their efforts to gain recognition as deserving and sympathetic subjects, Korean schools are trapped in what political theorist Patchen Markell calls a "permanent temptation" in pursuing "recognition." Anti-North Korea sentiments in Japan have made the desire for good recognition even more urgent among Korean school community members. The paper will demonstrate that the search for recognition unwittingly reinforces and perpetuates existing relations of subordination and state dominance over their education as it has forced the Korean schools to accept various "conditions" that would radically alter the core principle, mission, and pedagogy of Korean school education that is rooted in decolonizing theory and praxis. This paper will shed lights on dilemma of multicultural coexistence the Korean minority population faces in Japan today.

The Study of Religious Medical Treatment in the Canonical Scripture of Daesoon Jinrihoe in Korea (韓國大巡真理會《典經》之宗教醫療研究)

  • Chung, Yun-ying
    • Journal of the Daesoon Academy of Sciences
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    • v.39
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    • pp.249-274
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    • 2021
  • The aim of this article is to investigate the religious medical treatments performed by Kang Jeungsan as recorded in The Canonical Scripture, the main scripture of the Korean new religion, Daesoon Jinrihoe. The unity of mind and body is the core principle underlying Kang Jeungsan's religious medical treatments. He believed treating the mind of his patients was more important and necessary than treating their diseases. As such, he believed the only way to treat critical illness was to keep preserve the mind-body unity of his patients. Massage was a physical therapy often used by Kang Jeungsan. The medicinal materials that he commonly used were the Four-substance Decoction (四物湯 samultang), Minor Bupleurum Decoction (小柴胡湯 soshihotang), quince (木瓜 mokgwa *Pseudocydonia sinensis; not papaya), and rehmannia (生地黃 saengjihwang). Kang Jeungsan's religious medical treatments were characteristic of Daoist healing methods. His Daoist style healing methods included multiple techniques such as treating diseases through correcting Qi, exorcising malevolent entities, transferring diseases to a different host, removing a disease through the changing of clothes, pouring medicine into the ground, combining the usage of talisman and incantations, and treating the common people. Among these techniques, Jeungsan's pouring medicine into the ground was especially innovative.

Buckling and vibration of porous sandwich microactuator-microsensor with three-phase carbon nanotubes/fiber/polymer piezoelectric polymeric nanocomposite face sheets

  • Arani, Ali Ghorbanpour;Navi, Borhan Rousta;Mohammadimehr, Mehdi
    • Steel and Composite Structures
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    • v.41 no.6
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    • pp.805-820
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    • 2021
  • In this research, the buckling and free vibration of three-phase carbon nanotubes/ fiber/ polymer piezoelectric nanocomposite face sheet sandwich microbeam with microsensor and micro-actuator surrounded in elastic foundation based on modified couple stress theory (MCST) is investigated. Three types of porous materials are considered for sandwich core. Higher order (Reddy) and sinusoidal shear deformation beam theories are employed for the displacement fields. Sinusoidal surface stress effects are extracted for sinusoidal shear deformation beam theory. The equations of motion are derived by Hamilton's principle and then the natural frequency and critical buckling load are obtained by Navier's type solution. The determined results are in good agreement with other literatures. The detailed numerical investigation for various parameters is performed for this microsensor-microactuator. The results reveal that the microsensor-microactuator enhanced by increasing of Skempton coefficient, carbon nanotubes diameter length to thickness ratio, small scale factor, elastic foundation, surface stress constants and reduction in porous coefficient, micro-actuator voltage and CNT weight fraction. The valuable results can be expedient for micro-electro-mechanical (MEMS) and nano-electro-mechanical (NEMS) systems.

Modeling the Relationship between Expected Gain and Expected Value

  • Won, Eugene J.S.
    • Asia Marketing Journal
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    • v.18 no.3
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    • pp.47-63
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    • 2016
  • Rational choice theory holds that the alternative with largest expected utility in the choice set should always be chosen. However, it is often observed that an alternative with the largest expected utility is not always chosen while the choice task itself being avoided. Such a choice phenomenon cannot be explained by the traditional expected utility maximization principle. The current study posits shows that such a phenomenon can be attributed to the gap between the expected perceived gain (or loss) and the expected perceived value. This study mathematically analyses the relationship between the expectation of an alternative's gains or losses over the reference point and its expected value, when the perceived gains or losses follow continuous probability distributions. The proposed expected value (EV) function can explain the effects of loss aversion and uncertainty on the evaluation of an alternative based on the prospect theory value function. The proposed function reveals why the expected gain of an alternative should exceed some positive threshold in order for the alternative to be chosen. The model also explains why none of the two equally or similarly attractive options is chosen when they are presented together, but either of them is chosen when presented alone. The EV function and EG-EV curve can extract and visualize the core tenets of the prospect theory more clearly than the value function itself.

Experimental study on bearing capacity of PFCC column-RC beam joint reinforced with CST

  • Ping Wu;Dongang Li;Feng Yu;Yuan Fang;Guosheng Xiang;Zilong Li
    • Steel and Composite Structures
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    • v.47 no.1
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    • pp.19-36
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    • 2023
  • An experimental study of eleven PVC-FRP Confined Concrete (PFCC) column-Reinforced Concrete (RC) beam joints reinforced with Core Steel Tube (CST) under axial compression is carried out. All specimens are designed in accordance with the principle of "weak column and strong joint". The influences of FRP strips spacing, length and steel ratio of CST, height and stirrup ratio of joint on mechanical behavior are investigated. As the design anticipated, all specimens are destroyed by column failure. The failure mode of PFCC column-RC beam joint reinforced with CST is the yielding of longitudinal steel bars, CST and stirrups of column as well as the fracture of FRP strips and PVC tube. The ultimate bearing capacity decreases as FRP strips spacing or joint height increases. The effects of other three studied parameters on ultimate bearing capacity are not obvious. The strain development rules of longitudinal steel bars, PVC tube, FRP strips, column stirrups and CST are revealed. The effects of various studied parameters on stiffness are also examined. Additionally, an influence coefficient of joint height is introduced based on the regression analysis of test data, a theoretical formula for predicting bearing capacity is proposed and it agrees well with test data.

Thermoelastic eigenfrequency of pre-twisted FG-sandwich straight/curved blades with rotational effect

  • Souvik S. Rathore;Vishesh R. Kar;Sanjay
    • Structural Engineering and Mechanics
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    • v.86 no.4
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    • pp.519-533
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    • 2023
  • This work focuses on the dynamic analysis of thermal barrier coated straight and curved turbine blades modelled as functionally graded sandwich panel under thermal environment. The pre- twisted straight/curved blade model is considered to be fixed to the hub and, the complete assembly of the hub and blade are assumed to be rotating. The functionally graded sandwich composite blade is comprised of functionally graded face-sheet material and metal alloy core. The constituents' material properties are assumed to be temperature-dependent, however, the overall properties are evaluated using Voigt's micromechanical scheme in conjunction with the modified power-law functions. The blade model kinematics is based on the equivalent single-layer shear deformation theory. The equations of motion are derived using the extended Hamilton's principle by including the effect of centrifugal forces, and further solved via 2D- isoparametric finite element approximations. The mesh refinement and validation tests are performed to illustrate the stability and accurateness of the present model. In addition, frequency characteristics of the pre-twisted rotating sandwich blades are computed under thermal environment at various sets of parametric conditions such as twist angles, thickness ratios, aspect ratios, layer thickness ratios, volume fractions, rotational velocity and blade curvatures which can be further useful for designing the blade type structures under turbine operating conditions.