MULTI-ITEM SHELF-SPACE ALLOCATION OF BREAKABLE ITEMS VIA GENETIC ALGORITHM

MAITI, MANAS KUMAR,MAITI, MANORANJAN 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.20 No.1

A general methodology is suggested to solve shelf-space allocation problem of retailers. A multi-item inventory model of breakable items is developed, where items are either complementary or substitute. Demands of the items depend on the amount of stock on the showroom and unit price of the respective items. Also demand of one item decreases (increases) due to the presence of others in case of substitute (complementary) product. For such a model, a Contractive Mapping Genetic Algorithm (CMGA) has been developed and implemented to find the values of different decision variables. These are evaluated to have maximum possible profit out of the proposed system. The system has been illustrated numerically and results for some particular cases are derived. The results are compared with some other heuristic approaches- Simulated Annealing (SA), simple Genetic Algorithm (GA) and Greedy Search Approach (GSA) developed for the present model.

Design of Single Cell Membrane Shape and Array Configuration for MEMS Based Micromachined Ultrasonic Sensor to Improve the Performance: A Three Dimensional Model Characterization

Reshmi Maity,N. P. Maity,Srinivasa Rao Karumuri,Girija Sravani,K. Guha 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.6

The output acoustic energy of a capacitive micromachined ultrasonic transducer (CMUT) can be enhanced by adjusting its membrane structure. In this paper three dissimilar membranes shapes of CMUT: circular, rectangular and hexagonal, were aimed and 3D finite element method simulated using adaptive meshing technique. The displacement as well as strain and stress outputs for a single membrane and an array of four membranes on a single substrate were obtained. The simulated results are supported by analytical modeling. A static bias of 40 V and a signal of amplitude 100 mV are employed. A pressure of 8603.98 N/m 2 resulting in a force of 16.894 μN was applied at the membrane. Fixtures were provided on every possible face of the structure except the face 1 (membrane). The outcomes showed that the membrane displacement is highest for a circular geometry under same uniform pressure and area of vibration. Moreover as the distance between the elemental membranes increases the displacement decreases for circular and hexagonal membranes while the reverse behavior is observed for rectangular membranes.

Fringing Capacitive Effect of Silicon Carbide Based Nano-Electro-Mechanical-System Micromachined Ultrasonic Transducers: Analytical Modeling and FEM Simulation

Reshmi Maity,N. P. Maity,K. Srinivasa Rao,Girija Sravani,K. Guha,S. Baishya 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.5

This paper models the fringing fi eld eff ects in a capacitive micromachined ultrasonic transducer (CMUT) structure for determining the sensitivity of the device. CMUT is used as a medical imaging component which can be an important module for sustainable healthcare system. The capacitance value of the device is evaluated based on Younes Ataiiyan’s method. To determine the equivalent capacitance of the device, the capacitances of the membrane, gap and silicon nitride insulating layer are associated in series. Mason’s modeling techniques are used to evaluate the membrane displacement. Circular membrane approximation model has been considered. Eff ects of the variation in membrane thickness, gap separation, and membrane radius on membrane displacement are investigated. The analytical prediction has been validated with the finite element method simulation results through PZFlex. Three dimensional modeling is carried out to accurately capture the characteristic behavior of the device. The agreements of both results are excellent which verifi es that fringing field effects exist in the device operation.

Effects of Hafnium Oxide on Surface Potential and Drain Current Models for Subthreshold Short Channel Metal–Oxide–Semiconductor-Field-Effect-Transistor

N. P. Maity,Reshmi Maity,Subir Dutta,Subhasish Deb,K. Girija Sravani,K. Srinivasa Rao,S. Baishya 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.3

Surface potential and drain current models for a physically based double halo metal–oxide–semiconductor-fi eld-eff ect-transistor(MOSFET) are reported. The proposed models have been established in sub-threshold mode of MOSFET operation. The depletion layer depth used in the pseudo two dimensional Poisson’s equation comprises the effect of two symmetrical pocket implantations at both the ends of the channel region. In this effort, improvement in the investigation is brought in by taking lateral asymmetric channel owing to non-uniform doping. The conventional silicon-dioxide (SiO2) material is replaced with a promising high-k dielectric material hafnium oxide (HfO2) to analyze the surface potential and drain current models. Analytical results have been compared using Synopsys technology computer aided design (TCAD). Excellent conformities between the analytical models and simulations are observed.

Design of a Non-uniform Serpentine Asymmetric Cantilever RF-MEMS Shunt Capacitive Switch for RADAR Applications

Ch. Gopichand,Reshmi Maity,N. P. Maity,K. Srinivasa Rao,Koushik Guha,Santanu Maity,Ameen Eisnawi 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.4

This paper presents the design and simulation of Cantilever type RF-MEMS Capacitive shunt switch with meanders and perforations. The main objective of this paper is to reduce the pull-in voltage and increases isolation of the proposed switch. Electro-mechanics and Solid-mechanics are used to simulate the proposed switch by using COMSOL Multiphysics software. The capacitance, switching time, stress analysis are calculated and compare both theoretical and simulation results of the proposed switch. By varying diff erent beam thickness, materials, an air gap between the beam and signal line to calculate spring constant and pull-in voltage. The proposed switch having pull-in voltage is 1.371 V, the dielectric material Si 3 N 4 is to improve the capacitance analysis of the switch. The up and downstate capacitance is 7.073 fF, 1.259 pF. The RF performance is simulated by using Ansoft HFSS tool, the switch performs at low frequencies at 1–4 GHz range. The return (S 11 ) and insertion loss (S 12 ) of the proposed switch is − 30 dB, − 0.0516 dB and the switch having good isolation (S 21 ) is − 37.5 dB at 1.5 GHz frequency. The switch is suitable for radar and satellite communication applications.

Low Pull-in-Voltage RF-MEMS Shunt Switch for 5G Millimeter Wave Applications

P. Ashok Kumar,K. Srinivasa Rao,B. Balaji,M. Aditya,N. P. Maity,Reshmi Maity,Santanu Maity,Ameen El Sinawi,Koushik Guha,K. Girija Sravani 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.6

RF MEMS switches have been employed in many commercial and defense applications due to their high potentiality at microwave and millimeter wave frequencies. In this paper, an RF MEMS shunt switch is designed with perforations and without perforations and simulated using iterative meanders for millimeter wave 5G applications. The proposed iterative meander offers a low spring-constant of 0.68 N/m and reduces the pull-in-voltage upto 1.8 V. The proposed perforated switch design is more reliable which operates with less transition time of 11.2 μs with a quality factor of 1.69. The switch possesses high capacitance ratio of 63. During ON condition, the switch shows low insertion loss of − 0.24 dB at 41 GHz and high isolation of − 46.7 dB at 38 GHz. The performance of the switch is analyzed by simulating it using COMSOL Multiphysics 5.2v (FEM tool). The obtained simulation results shows close approximation with the theoretical results and the switch is efficiently used for 5G millimeter wave applications.

Damage assessment of structures from changes in natural frequencies using genetic algorithm

Maity, Damodar,Tripathy, Rashmi Ranjan Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.19 No.1

A method is presented to detect and assess the structural damage from changes in natural frequencies using Genetic Algorithm (GA). Using the natural frequencies of the structure, it is possible to formulate the inverse problem in optimization terms and then to utilize a solution procedure employing GA to assess the damages. The technique has been applied to a cantilever beam and a plane frame, each one with different damage scenario to study the efficiency of the developed algorithm. A laboratory tested data has been used to verify the proposed algorithm. The study indicates the potentiality of the developed code to solve a wide range of inverse identification problems in a systematic way. The outcomes show that this method can detect and estimate the amount of damages with satisfactory precision.

Self-Size-Limiting Nanoscale Perforation of Graphene for Dense Heteroatom Doping

Maiti, Uday Narayan,Thapa, Ranjit,Lim, Joonwon,Li, Dong Jun,Kim, Kwang Ho,Kim, Sang Ouk American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>A scalable and controllable nanoscale perforation method for graphene is developed on the basis of the two-step thermal activation of a graphene aerogel. Different resistance to the thermal oxidation between graphitic and defective domains in the weakly reduced graphene oxide is exploited for the self-limiting nanoscale perforation in the graphene basal plane via selective thermal degradation of the defective domains. The resultant nanoporous graphene with a narrow pore-size distribution addresses the long-standing challenge for the high-level doping of graphene with lattice-mismatched large-size heteroatoms (S and P). Noticeably, this novel heteroatom doping strategy is demonstrated to be highly effective for oxygen reduction reaction (ORR) catalysis. Not only the higher level of heteroatom doping but also favorable spin and charge redistribution around the pore edges leads to a strong ORR activity as supported by density functional theory calculations.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08391/production/images/medium/am-2015-08391s_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08391'>ACS Electronic Supporting Info</A></P>

Bio-waste onion skin as an innovative nature-driven piezoelectric material with high energy conversion efficiency

Maiti, Sandip,Kumar Karan, Sumanta,Lee, Juhyun,Kumar Mishra, Avnish,Bhusan Khatua, Bhanu,Kon Kim, Jin Elsevier 2017 Nano energy Vol.42 No.-

<P><B>Abstract</B></P> <P>Development of non-toxic, ultra-sensitive, and flexible bio-inspired piezoelectric nanogenerator has become a great challenge for next generation biomedical applications. High performance organic/inorganic materials based piezoelectric nanogenerators suffer from several unavoidable problems such as complex synthesis and high toxicity. Biodegradable and biocompatible piezoelectric material is utmost needed in in-vivo condition to harvest energy for biomedical applications. Here, we report a novel bio-piezoelectric nanogenerator (BPNG) using naturally abundant self-aligned cellulose fibrous untreated onion skin (OS) as efficient piezoelectric material having piezoelectric strength of ∼ 2.8 pC/N. The fabricated OSBPNG generated output voltage, current, instantaneous power density and high piezoelectric energy conversion efficiency of ≈ 18V, ≈ 166nA, ≈ 1.7μW/cm<SUP>2</SUP>, and ≈ 61.7%, respectively, and turn on 30 green LEDs by a single device under repeated compressive stress of ≈ 34kPa and ≈ 3.0Hz frequency. In addition, maximum output voltage (≈ 106V) was achieved when 6 units are connected in series, which instantaneously turns on 73 combined LEDs (30 green, 25 blue, and 18 red). OSBPNG is highly effective during throat movement such as coughing, drinking and swallowing. Furthermore, because it works at very low pressure originating from heart pulse or beat, it could be used in pacemakers and health care units. Finally, OSBPNG successfully differentiates speech signals, indicating its potential for speech recognition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel homespun approach for bio-piezoelectric nanogenerator (OSBPNG) using onion skin. </LI> <LI> Plant materials are more useful than living creatures in both handling and supply. </LI> <LI> It works at low pressure even from heart pulse, that can be used in health care unit. </LI> <LI> OSBPNG shows output voltage of 18 V with high energy conversion efficiency (61.7%). </LI> <LI> Maximum output voltage (106 V) achieved by assembling 6 units, which turn on 73 LEDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Naturally driven bio-waste and biocompatible onion skin base piezoelectric nanogenerator with high output performance (output voltage and area power density of ≈ 18V, and ≈ 1.7μW/cm<SUP>2</SUP>) and high energy conversion efficiency (≈ 61.7%) has been fabricated through simple homespun device fabrication method. More details on the materials and application can be found in the manuscript.</P> <P>[DISPLAY OMISSION]</P>

Evaluation of Hepatoprotective Potential of Cassia tora Leaf Extract

Maity, Tapan Kumar,Mandal, Subhash C.,Mukherjee, Pulok K.,Saha, Kakali,Das, J.,Saha, B.P.,Pal, M. The Korean Society of Pharmacognosy 1997 Natural Product Sciences Vol.3 No.2

Methanolic extract of the leaves of Cassia tom was evaluated for its hepatoprotective potentials in rats by inducing hepatotoxicity with carbon tetrachloride. The extract at a dose of 400 mg/kg orally showed significant protective effect by lowering the serum levels of transaminase (SGOT and SGPT), bilirubin and alkaline phosphatase (ALP). The effects produced were comparable to that of a standard hepatoprotective agent.