Search

This work presents two 4-bit resistor-string digital-to-analog converters (R-DAC) designed in 22nm FDSOI technology. Both DACs are connected to a shared resistor string to make the final layout more compact. The small on-resistance of the Transmission-Gate (TG) switches designed in the FDSOI node yields a low Internal non-linearity (INL) and Differential non-linearity (DNL) in the DACs output. The effect of the temperature variations on the linearity performance of the DACs is also studied. It is shown that the temperature gradients can be compensated for by equally distributing the switches on the layout area. Post-layout simulations show an approximately fixed INL and DNL of, respectively, 0. 17LSB and 0. 1LSB over a wide temperature range from-40°C to 125{0} C. Two R-DACs dissipate the static/dynamic power of 0. 12/0.155mW with the layout size of only 70 mu m{2}, showing a high performance for two 4-bit DACs.

In this paper, the benefits of the Negative-Capacitance FET (NCFET) in the design of a Low Noise Amplifier (LNA) are assessed. The effect of gain enhancement due to the Ferroelectric (Fe) layer on the performance of a common-source (CS) LNA is analytically modeled for NCFETs with 14 nm FinFET as the base technology. Simulations show a high gain for the NCFET-based LNA. Such performance in conjunction with the integrability with CMOS technology indicates the potential of NCFET for analog/RF design.

‘Common Law’ judicial systems follow the doctrine of precedent, which means the legal principles articulated in court judgements are binding in subsequent cases in lower courts. For this reason, lawyers must search prior judgements for the legal principles that are relevant to their case. The difficulty for those within the legal profession is that the information that they are looking for may be contained within a few paragraphs or sentences, but those few paragraphs may be buried within a hundred-page document. In this study, we create a schema based on the relevant information that legal professionals seek within judgements and perform text classification based on it, with the aim of not only assisting lawyers in researching cases, but eventually enabling large-scale analysis of legal judgements to find trends in court outcomes over time.

In this paper, a small-signal model of Negative Capacitance FETs (NCFETs) is developed and the analog performance of NCFETs is studied using the developed model. A new ferroelectric factor K is introduced to capture the ferroelectric gain in NCFETs as compared to traditional small signal MOSFET/FinFET models. Using our new NCFET small-signal model, we show analog design trade-offs between various analog benchmarks such as gain, bandwidth, cut-off frequency, and linearity. Additionally, the developed model is used to demonstrate trade-offs in NCFET analog performance as ferroelectric parameters are changed. Results show that if pushed for a higher intrinsic gain via thicker Fe layers in NCFETs, the linearity of the device suffers. This reveals inherent device level trade-off in NCFETs for analog circuit performance.

This paper presents for the first-time a physics-based non-linear large signal model for Ka-band GaN power amplifier design using the new industry standard ASM-HEMT compact model. A novel methodology combining the effectiveness and accuracy of modeling the intrinsic device region with ASM-HEMT, and distributed effects at Ka-band with electromagnetic (EM) simulations is developed. The intrinsic semiconductor region for each finger of the GaN HEMT device is modeled with ASM-HEMT, and in a multi-finger device, the single finger model is coupled with EM simulations capturing distributed effects accurately. The developed non-linear model shows excellent accuracy with measured non-linear data for a commercial GaN-HEMT device, and with measurements performed on a Ka-band MMIC power amplifier.

Mumbai is the commercial capital of the country. The economy and morphology of the city has been shaped by the physical infrastructure but has neglected the ecological and social aspects in planning. This has led to the extreme vulnerability of the region to ecological and social negative externalities. The region experiences urban flooding every year disrupting the daily lives and inflicting loss to both the life and livelihood of many. Also, the state of emergency due to climate change that the planet deals with fighting sustenance for humankind is a severe challenge. Especially Mumbai, one of the largest cities in the world, is at risk of being wiped out. It is built from an archipelago of islands, the city’s historic downtown core-the island city is particularly vulnerable along with most of the suburban districts. This leads to an urgent need for providing resilience to the socio-ecological system in the region by providing climate adaptive capacity against floods., Architecture, Urbanism and Building Sciences | Complex Cities

This paper presents a generalized formulation of a decoupling scheme for n ×n multivariable processes. The proposed Adj dynamic decoupling {mathcal{K}}-builds on deriving the decoupler based on the adjoint of the process transfer function matrix. The decoupler is designed such that it contains lesser dynamics yet ensures a performance close to the ideal decoupling. The proposed scheme always ensures the realiz-ability of the decoupler while providing a superior decoupling performance. Procedure for deriving the decoupler with simple rules is presented in this manuscript. The half-rule is utilized to obtain a simplistic description of the higher-order models. The applicability of the proposed decoupling scheme for lower as well as high-dimensional MIMO processes is demonstrated through various simulation studies. The effectiveness of the proposed scheme against existing decoupler is highlighted with a comparative performance evaluation study.

his manuscript introduces an optimal detuning approach for designing a centralized PI control system for multi-input multi-output (MIMO) processes. Based on the approach, two multivariable PI controller designs are proposed in this manuscript. The proposed approach formulates the centralized PI controller design problem in an optimization framework and transforms it into an equivalent detuning parameter(s) design problem. While the centralized controller design with the proposed 1-Optimal Detuning Parameter (ODP) method is carried out as a multi-stage problem, the proposed 2-ODP method formulates the controller design as a single-stage optimization problem. An effective transfer function (ETF) parameterization followed by controller synthesis using the IMC theory and further the optimal detuning comprises the various stages in 1-ODP design. In this regard, a novel ETF parameterization procedure for large scale processes or systems with higher-order elements is presented in this manuscript. Contrary to the centralized controller design in the kp,ki space, where the dimensionality of the optimization problem blows at O(2n2), the proposed 1-ODP and 2-ODP design methods always aim at solving a uni- and bi-dimensional optimization problem, respectively, irrespective of the dimensionality of the MIMO process. Hence, the proposed method is easily applicable even to high-dimensional MIMO processes. Several illustrative industrial MIMO systems are considered to demonstrate the applicability of the proposed methods to highly interacting and large scale processes. The simulation studies show that the proposed methods performs better as compared to the other centralized PI controller designs. Even with parameter variations, the proposed methods give satisfactory closed-loop performance. Further, robust stability analysis for the proposed designs is performed by considering multiplicative input and output uncertainties.

This paper presents a generalized formulation of a decoupling scheme for n ×n multivariable processes. The proposed Adj dynamic decoupling {mathcal{K}}-builds on deriving the decoupler based on the adjoint of the process transfer function matrix. The decoupler is designed such that it contains lesser dynamics yet ensures a performance close to the ideal decoupling. The proposed scheme always ensures the realiz-ability of the decoupler while providing a superior decoupling performance. Procedure for deriving the decoupler with simple rules is presented in this manuscript. The half-rule is utilized to obtain a simplistic description of the higher-order models. The applicability of the proposed decoupling scheme for lower as well as high-dimensional MIMO processes is demonstrated through various simulation studies. The effectiveness of the proposed scheme against existing decoupler is highlighted with a comparative performance evaluation study.

his manuscript introduces an optimal detuning approach for designing a centralized PI control system for multi-input multi-output (MIMO) processes. Based on the approach, two multivariable PI controller designs are proposed in this manuscript. The proposed approach formulates the centralized PI controller design problem in an optimization framework and transforms it into an equivalent detuning parameter(s) design problem. While the centralized controller design with the proposed 1-Optimal Detuning Parameter (ODP) method is carried out as a multi-stage problem, the proposed 2-ODP method formulates the controller design as a single-stage optimization problem. An effective transfer function (ETF) parameterization followed by controller synthesis using the IMC theory and further the optimal detuning comprises the various stages in 1-ODP design. In this regard, a novel ETF parameterization procedure for large scale processes or systems with higher-order elements is presented in this manuscript. Contrary to the centralized controller design in the kp,ki space, where the dimensionality of the optimization problem blows at O(2n2), the proposed 1-ODP and 2-ODP design methods always aim at solving a uni- and bi-dimensional optimization problem, respectively, irrespective of the dimensionality of the MIMO process. Hence, the proposed method is easily applicable even to high-dimensional MIMO processes. Several illustrative industrial MIMO systems are considered to demonstrate the applicability of the proposed methods to highly interacting and large scale processes. The simulation studies show that the proposed methods performs better as compared to the other centralized PI controller designs. Even with parameter variations, the proposed methods give satisfactory closed-loop performance. Further, robust stability analysis for the proposed designs is performed by considering multiplicative input and output uncertainties.

his manuscript introduces an optimal detuning approach for designing a centralized PI control system for multi-input multi-output (MIMO) processes. Based on the approach, two multivariable PI controller designs are proposed in this manuscript. The proposed approach formulates the centralized PI controller design problem in an optimization framework and transforms it into an equivalent detuning parameter(s) design problem. While the centralized controller design with the proposed 1-Optimal Detuning Parameter (ODP) method is carried out as a multi-stage problem, the proposed 2-ODP method formulates the controller design as a single-stage optimization problem. An effective transfer function (ETF) parameterization followed by controller synthesis using the IMC theory and further the optimal detuning comprises the various stages in 1-ODP design. In this regard, a novel ETF parameterization procedure for large scale processes or systems with higher-order elements is presented in this manuscript. Contrary to the centralized controller design in the kp,ki space, where the dimensionality of the optimization problem blows at O(2n2), the proposed 1-ODP and 2-ODP design methods always aim at solving a uni- and bi-dimensional optimization problem, respectively, irrespective of the dimensionality of the MIMO process. Hence, the proposed method is easily applicable even to high-dimensional MIMO processes. Several illustrative industrial MIMO systems are considered to demonstrate the applicability of the proposed methods to highly interacting and large scale processes. The simulation studies show that the proposed methods performs better as compared to the other centralized PI controller designs. Even with parameter variations, the proposed methods give satisfactory closed-loop performance. Further, robust stability analysis for the proposed designs is performed by considering multiplicative input and output uncertainties.

This paper presents a generalized formulation of a decoupling scheme for n ×n multivariable processes. The proposed Adj dynamic decoupling {mathcal{K}}-builds on deriving the decoupler based on the adjoint of the process transfer function matrix. The decoupler is designed such that it contains lesser dynamics yet ensures a performance close to the ideal decoupling. The proposed scheme always ensures the realiz-ability of the decoupler while providing a superior decoupling performance. Procedure for deriving the decoupler with simple rules is presented in this manuscript. The half-rule is utilized to obtain a simplistic description of the higher-order models. The applicability of the proposed decoupling scheme for lower as well as high-dimensional MIMO processes is demonstrated through various simulation studies. The effectiveness of the proposed scheme against existing decoupler is highlighted with a comparative performance evaluation study.

Mumbai is the commercial capital of the country. The economy and morphology of the city has been shaped by the physical infrastructure but has neglected the ecological and social aspects in planning. This has led to the extreme vulnerability of the region to ecological and social negative externalities. The region experiences urban flooding every year disrupting the daily lives and inflicting loss to both the life and livelihood of many. Also, the state of emergency due to climate change that the planet deals with fighting sustenance for humankind is a severe challenge. Especially Mumbai, one of the largest cities in the world, is at risk of being wiped out. It is built from an archipelago of islands, the city’s historic downtown core-the island city is particularly vulnerable along with most of the suburban districts. This leads to an urgent need for providing resilience to the socio-ecological system in the region by providing climate adaptive capacity against floods., Architecture, Urbanism and Building Sciences | Complex Cities

Neuromorphic or bioinspired computational platforms, as an alternative for von-Neumann structures, have benefitted from the excellent features of emerging technologies in order to emulate the behavior of the biological brain in an accurate and energy-efficient way. Integrability with CMOS technology and low power consumption make ferroelectric field-effect transistor (FEFET) an attractive candidate to perform such paradigms, particularly for image processing. In this article, we use the FEFET device to make energy-efficient oscillatory neurons as the main parts of neural networks for image processing applications, especially for edge detection. Based on our simulation results, we estimated a significant energy efficiency compared with other technologies, which shows roughly 5-120\times reduction, depending on the design.

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECSs) are turning out to be one of the major players with immense potential to meet the future energy demands. These WECSs are quickly becoming primary source of energy in coastal regions, islands, where they operate in autonomous mode. In this paper, a control strategy for controlled power extraction from a WECS, operating in islanded mode is presented. The proposed control strategy enables limited as well as maximum power extraction from WECSs with desired load voltage profile while minimizing the installation as well as the operating costs associated with the use of expensive batteries in the system. The motive behind using batteries in the system is to facilitate transient stability and enhance reliability. As opposed to pitch angle control, in the present work, real power control is attained by field-oriented control (FOC) of permanent magnet synchronous generator (PMSG). The operating point of the WECS is decided based on the wind turbine characteristics and the demanded power. Proper decoupling and feed-forward techniques have been deployed to eliminate cross-coupling and mitigate the effect of load side disturbances. Simulations are carried out under varying load demand as well as changing weather conditions to demonstrate the applicability and effectiveness of the proposed control strategy

Most industrial processes being MIMO have multivariable interactions, which makes controller design a challenging task. As one input can potentially affect all outputs, a controller action in one loop could destabilize other loops. In this paper we explore the possibility of designing a decentralized PI controller for a multivariable process using SISO tuning rules. The objective is to identify if SISO IMC tuning rules would work for MIMO processes or not. It was found that under certain conditions, the SISO design is also applicable for multivariable systems. The tuning methods considered here are the internal model control (IMC) and Skogestad/ Simple IMC (SIMC). The tuning rules are simple, model based, they easily relate model parameters to controller parameters and work reasonably well for a wide range of processes. Simulations are carried out and various performance indices have been evaluated and compared against other methods to demonstrate the effectiveness of the proposed (IMC and SIMC) tuning methods for multivariable systems

Most industrial processes being MIMO have multivariable interactions, which makes controller design a challenging task. As one input can potentially affect all outputs, a controller action in one loop could destabilize other loops. In this paper we explore the possibility of designing a decentralized PI controller for a multivariable process using SISO tuning rules. The objective is to identify if SISO IMC tuning rules would work for MIMO processes or not. It was found that under certain conditions, the SISO design is also applicable for multivariable systems. The tuning methods considered here are the internal model control (IMC) and Skogestad/ Simple IMC (SIMC). The tuning rules are simple, model based, they easily relate model parameters to controller parameters and work reasonably well for a wide range of processes. Simulations are carried out and various performance indices have been evaluated and compared against other methods to demonstrate the effectiveness of the proposed (IMC and SIMC) tuning methods for multivariable systems

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECSs) are turning out to be one of the major players with immense potential to meet the future energy demands. These WECSs are quickly becoming primary source of energy in coastal regions, islands, where they operate in autonomous mode. In this paper, a control strategy for controlled power extraction from a WECS, operating in islanded mode is presented. The proposed control strategy enables limited as well as maximum power extraction from WECSs with desired load voltage profile while minimizing the installation as well as the operating costs associated with the use of expensive batteries in the system. The motive behind using batteries in the system is to facilitate transient stability and enhance reliability. As opposed to pitch angle control, in the present work, real power control is attained by field-oriented control (FOC) of permanent magnet synchronous generator (PMSG). The operating point of the WECS is decided based on the wind turbine characteristics and the demanded power. Proper decoupling and feed-forward techniques have been deployed to eliminate cross-coupling and mitigate the effect of load side disturbances. Simulations are carried out under varying load demand as well as changing weather conditions to demonstrate the applicability and effectiveness of the proposed control strategy

A field experiment on African marigold (TagetserectaL.) was conducted during winter season of 2014-15 to study the effect of NPK, biofertilizers and plant spacings on growth and yield of African marigold (Tagetes erecta Linn). The treatment combinations F6 100 % RDF of NPK + Azotobacter + PSB recorded the maximum longevity of intact flower (27.93), average diameter of flower (7.37 cm), average weight of flower (8.96 g) number of flowers per plant (56.54), yield of flowers per plant (515.62 g), per plot (11.93 kg) and highest flower yield ha (184.13 q). The spacing D3 (60× 60 cm) registered significant (5 %) maximum longevity of intact flower, larger size flower (7.80 cm), average weight of flower (9.14 g) and highest flower yield per plant (456.22 g). Highest flower yield per plot (10.19 kg), number of flower per plant (52.22) and per hectare flower yield (157.29 q/ha) with 60× 45 cm. These results are conclusive that application of 100 % RDF of NPK + Azotobacter+ PSB and plant spacing (60× 45 cm) may positively increase the growth and flowers yield parameters of marigold.

Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms.

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

With continuous depletion of conventional sources of energy, Wind Energy Conversion Systems (WECS) are turning out to be one of the major players with immense potential to meet the future energy demands. It is one of the most preferable source, as it can be installed onshore as well as offshore. But with the increasing penetration of wind energy into power system, wind energy conversion systems (WECSs) should be able to control the power flow for limited as well as maximum power point tracking. Apart from tracking desired power, there are some other issues which needs to be addressed for stable and reliable operation of WECS in grid connected as well as islanded mode. In the grid connected mode synchronization of the system to the grid and maintenance of dc-link voltage in absence of ESS are the main control requirements apart from controlled power extraction from the wind turbine. Unlike the grid connected mode, where most of the system level dynamics are imposed by the grid and hence load voltage magnitude an frequency are dictated by the grid itself, in the autonomous operation of WECS the load voltage magnitude and frequency control comes in as additional control requirements other than controlled power extraction from Wind Turbine. However the usage of batteries in the system is unavoidable due to stability and reliability issues. In contrast to the traditional pitch angle control, this work focusses on field oriented speed control of permanent magnet synchronous generator (PMSG) for controlling the active power flow based on the wind turbine characteristics. A back to back AC/DC/AC topology is implemented for interfacing the WECS to the distribution network with various power electronic interfaces providing the necessary control over the power flow. By maintaining the dclink voltage constant and by deploying PLL, power balance and grid v synchronization are attained respectively in grid connected operation of WECS. For the standalone operation of WECS, however

Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms.

We present a lightweight and highly versatile architecture for replicating the resistance of a source memristor into a destination memristor. This can be useful for storing or backing up sensed analogue information, e.g. sensed resistance, voltage, etc, in a single memristor. The architecture, which is simple and power efficient, is also able to produce non-linear digital codes during the replication process for added security by taking advantage of the non-linear behaviour of memristors. The generated codes can also be used to retrieve the analogue value within acceptable conversion errors, with circuit elements already built into the replicator. We also show that the architecture demonstrates physical uncloneable properties.