Design and Analysis of 3D-MAPS (3D Massively Parallel Processor with Stacked Memory)

Dae Hyun Kim,Athikulwongse, Krit,Healy, Michael B.,Hossain, Mohammad M.,Moongon Jung,Khorosh, Ilya,Kumar, Gokul,Young-Joon Lee,Lewis, Dean L.,Tzu-Wei Lin,Chang Liu,Panth, Shreepad,Pathak, Mohit,Minzhe IEEE 2015 IEEE Transactions on Computers Vol. No.

<P>This paper describes the architecture, design, analysis, and simulation and measurement results of the 3D-MAPS (3D massively parallel processor with stacked memory) chip built with a 1.5 V, 130 nm process technology and a two-tier 3D stacking technology using 1.2 \microm-diameter, 6 \micro m-height through-silicon vias (TSVs) and 3.4\nbsp\microm-diameter face-to-face bond pads. 3D-MAPS consists of a core tier containing 64 cores and a memory tier containing 64 memory blocks. Each core communicates with its dedicated 4KB SRAM block using face-to-face bond pads, which provide negligible data transfer delay between the core and the memory tiers. The maximum operating frequency is 277 MHz and the maximum memory bandwidth is 70.9 GB/s at 277 MHz. The peak measured memory bandwidth usage is 63.8 GB/s and the peak measured power is approximately 4 W based on eight parallel benchmarks.</P>

Fast Layout Generation of RF Embedded Passive Circuits Using Mathematical Programming

Pathak, M.,Sung Kyu Lim IEEE 2012 IEEE transactions on components, packaging, and ma Vol.2 No.1

<P>In this paper, we present a methodology for the automatic generation of layout for radio frequency (RF) designs using embedded passives. Our methodology is divided into three steps: 1) pre-layout optimization; 2) placement and routing; and 3) post-layout optimization. We show that our methodology generates layouts with small area and good performance response within a fraction of design time compared with fully manual design effort. We make use of circuit models to represent and optimize the physical layout of the resistance-inductance-capacitance (RLC) components as well as the entire RF circuit that uses them. We perform non-linear mathematical programming-based optimization at various stages of the methodology to achieve high quality layouts. Full wave electromagnetic simulations are kept completely out of the design loop, so our methodology significantly reduces design time. We have used our methodology to successfully generate layouts for large-scale filter circuits.</P>

Prevalence of Phytophthora Blight of Pigeonpea in the Deccan Plateau of India

M. Sharma,S. Pande,M. Pathak,J. Narayana Rao,P. Anil Kumar,D. Madhusudan Reddy,V. I. Benagi,D. M. Mahalinga,K. K. Zhote,P. N. Karanjkar,B. S. Eksinghe 한국식물병리학회 2006 Plant Pathology Journal Vol.22 No.4

drechsleri f. sp. cajani is the third potentially important disease of pigeonpea in the Deccan Plateau (DP) of India after wilt and sterility mosaic. In the rainy-season of 2005, an outbreak of PB was seen throughout DP. To quantify the incidence and spread of the disease, a systematic survey was conducted in the major pigeonpea growing regions of DP during the crop season 2005. Attempts were made to determine the effect of cropping systems on the PB development and identify resistant cultivars, if any, grown by farmers and on research farms. Widespread incidence of PB was recorded on improved, and or local cultivars grown in different intercropping systems. Majority of improved cultivars grown at research farms were found susceptible to PB (>10% disease incidence). Pigeonpea intercropped with groundnut, black gram and coriander had less disease incidence (≤10%). Three wilt and SM resistant pigeonpea cultivars KPL 96053, ICPL 99044, and ICPL 93179 were found resistant (<10%) to PB as well. However, their resistance to PB needs confirmation under optimum disease development environments.

Narrowband ultraviolet B emission from gadolinium activated Y₃Ga₅O₁₂ nano-garnets

Pathak, M.S.,Singh, N.,Singh, Vijay,Watanabe, S.,Rao, T.K.Gundu,Lee, Jung-Kul Elsevier 2018 Materials research bulletin Vol.97 No.-

<P><B>Abstract</B></P> <P>Gadolinium (Gd<SUP>3+</SUP>) doped Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB> nanocrystalline garnet was prepared by nitrate-fuel combustion technique that involves organic fuel glycine. Sample characterization was performed by powder X-ray diffraction and scanning electron microscope. Upon ultraviolet light excitation at 273nm, Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB>:Gd<SUP>3+</SUP> sample exhibits a sharp narrowband ultraviolet B emission at 311.9nm. The electron spin resonance spectrum of gadolinium doped Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB> samples exhibit resonance signals with the effective g values at <I>g</I> ≈2.0, 2.2 and 5.8. These signals are attributed to Gd<SUP>3+</SUP> ion located in distorted surroundings experiencing a relatively strong crystal field.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A narrowband ultraviolet B emitting nano-garnet was synthesized. </LI> <LI> Narrow band centered at 311.9nm, good for phototherapy application. </LI> <LI> EPR results indicate the possible location of the Gd<SUP>3+</SUP> ion. </LI> <LI> Gd<SUP>3+</SUP> ion is likely to be located at the distorted dodecahedral site. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Narrowband ultraviolet B emitting Gd doped CaAl₂O₄ phosphors – An ESR and photoluminescence study

Pathak, M.S.,Singh, N.,Singh, Vijay,Watanabe, S.,Gundu Rao, T.K.,Seshadri, M.,Lee, Jung-Kul Elsevier 2018 Journal of luminescence Vol.204 No.-

<P><B>Abstract</B></P> <P>Phosphors with the composition Ca<SUB>1-x</SUB>Gd<SUB>x</SUB>Al<SUB>2</SUB>O<SUB>4</SUB> (x = 0.0025–0.09) were synthesized by a simple combustion route in a short time. The formation of the as-prepared combustion products was confirmed by the X-ray diffraction analysis, indicating the formation of a monoclinic phase. The PL spectroscopy assessment shows that with increasing Gd<SUP>3+</SUP> concentration, the ultraviolet emission from Gd<SUP>3+</SUP> at 314 nm (<SUP>6</SUP>P<SUB>7/2</SUB>→<SUP>8</SUP>S<SUB>7/2</SUB>) progressively enhanced. The Gd<SUP>3+</SUP>-doped CaAl<SUB>2</SUB>O<SUB>4</SUB> displays electron spin resonance signals with the effective g values at <I>g</I> ≈ 1.95, 2.9, and 3.7. Additional lines were also observed at the approximate g values of ~2.2 and 5.3. Gd<SUP>3+</SUP> ion located in the distorted surroundings and experiencing relatively strong crystal field, give rise to low field lines. Distorted surroundings in the present system may result from the nearness of the charge compensator oxygen vacancies.</P>

Synthesis and investigations on correlation between EPR and optical properties of Fe doped Li₂SiO₃

Pathak, M.S.,Gopal, N.O.,Singh, N.,Mohapatra, M.,Rao, J.L.,Lee, Jung-Kul,Singh, Vijay Elsevier 2018 Journal of non-crystalline solids Vol.500 No.-

<P><B>Abstract</B></P> <P>Iron doped lithium metasilicate sample was synthesized using a combustion technique and characterized by XRD (X ray diffraction), SEM (scanning electron microscopy), FTIR (Fourier transform infrared spectroscopy), optical, and EPR (electron paramagnetic resonance) analyses. The phase purity of the combustion synthesized products was confirmed by XRD analysis. SEM data suggested the formation of a porous compound by virtue of the entrapment of the gases that evolved during the sample synthesis. FTIR data confirmed the formation of SiO bonds in the system. Optical data confirmed the existence of both divalent and trivalent iron in the system. Characteristic absorption bands in the region 215–270 nm and 535–620 nm were observed due to the presence of Fe<SUP>3+</SUP> in Oh and Td geometry respectively. On the other hand, the presence of bands at 967 and 1442 nm suggested the stabilisation of Fe<SUP>2+</SUP> also in both Oh and Td geometries, respectively. The divalent iron being a non-Kramer ion, could not be observed by EPR. However, strong temperature-dependent EPR signals were observed in the sample owing to Fe<SUP>3+</SUP>. By analyzing the EPR data, super-paramagnetic type of behaviour was observed in the system. Furthermore, the relaxation times along with other EPR spectroscopic parameters were estimated for the system.</P>

Posture Control Strategy of a Platform using a RP Manipulator

M. M. Gor,P. M. Pathak,A. K. Samantaray,J.-M. Yang,S. W. Kwak 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper is an attempt to develop a posture control strategy for quadruped robot. Here, a concept of posture control is proposed, in which, a revolute and prismatic (RP) manipulator with payload at the end is used to control the body orientation. For the said analysis necessary model is developed in the bond graph and efficacy of the proposed strategies is validated through simulation results of the developed model.

Control of compliant legged quadruped robots in the workspace

Gor, M M,Pathak, P M,Samantaray, A K,Yang, J-M,Kwak, S W SAGE Publications 2015 Simulation Vol.91 No.2

<P>Locomotion control of a quadruped robot requires a well-defined gait pattern (i.e., a coordinated actuation of its four legs in some particular fashion with respect to time). It is of practical importance to move the leg tips in a desired trajectory in order to achieve specific objectives such as to avoid obstacles, minimize energy consumption and locomotion time. Along with body displacement, body orientation is an equally important limit parameter during each leg step of the gait pattern. There are several possible gait patterns that maintain stable and aesthetically pleasing locomotion, and most of these are biologically inspired. This article presents quadruped locomotion control in the workspace through a novel control scheme in which the leg forward motion is controlled in the workspace while the body forward motion is controlled by providing the required effort directly to the joint actuators. In this control approach, the leg tip trajectory error drives a proportional-integral controller that is then transformed through the Jacobian to generate the corrective joint torques. For the body forward motion, leg motion is arrested and the joints are provided with opposite motion, which are controlled by a proportional-integral-derivative controller. The proposed method is simple and easy to implement in the workspace. The performance of the proposed control scheme is evaluated through simulations and animations.</P>

Photoluminescence properties of green emitting CaY₂Al₄SiO₁₂:Tb³⁺ garnet phosphor

Bhagat, M.S.,Shinde, K.N.,Singh, N.,Pathak, M.S.,Singh, Pramod K.,Pawar, S.U.,Singh, Vijay Elsevier 2018 Optik Vol.161 No.-

<P><B>Abstract</B></P> <P>The photoemission properties of a microcrystalline-powder Tb<SUP>3+</SUP>-doped CaY<SUB>2</SUB>Al<SUB>4</SUB>SiO<SUB>12</SUB> garnet phosphor were studied. The microcrystalline materials were obtained using the sol–gel method that yields chemically homogeneous and microparticle-sized powders. X-ray powder diffraction (XRPD) and scanning electron microscope (SEM) analyses were used to reveal the crystallinity, crystal structure, and surface morphology of the prepared CaY<SUB>2</SUB>Al<SUB>4</SUB>SiO<SUB>12</SUB>:Tb<SUP>3+</SUP> garnet phosphor. The samples showed a green-emission characteristic at around 544 nm with an excitation at 271 nm. A concentration quenching was observed with the increasing of the Tb<SUP>3+</SUP> concentration. The effect of the Tb<SUP>3+</SUP> doping and the photoluminescence properties were also investigated, leading to the proposal of a feasible interpretation by the authors.</P>

Prevalence of Phytophthora Blight of Pigeonpea in the Deccan Plateau of India

Sharma, M.,Pande, S.,Pathak, M.,Rao, J. Narayana,Kumar, P. Anil,Reddy, D. Madhusudan,Benagi, V.I.,Mahalinga, D.M.,Zhote, K.K.,Karanjkar, P.N.,Eksinghe, B.S. The Korean Society of Plant Pathology 2006 Plant Pathology Journal Vol.22 No.4

Phytophthora blight(PB), caused by Phytophthora drechsleri f. sp. cajani is the third potentially important disease of pigeonpea in the Deccan Plateau(DP) of India after wilt and sterility mosaic. In the rainy-season of 2005, an outbreak of PB was seen throughout DP. To quantify the incidence and spread of the disease, a systematic survey was conducted in the major pigeonpea growing regions of DP during the crop season 2005. Attempts were made to determine the effect of cropping systems on the PB development and identify resistant cultivars, if any, grown by farmers and on research farms. Widespread incidence of PB was recorded on improved, and or local cultivars grown in different intercropping systems. Majority of improved cultivars grown at research farms were found susceptible to PB(>10% disease incidence). Pigeonpea intercropped with groundnut, black gram and coriander had less disease incidence(${\leq}10%$). Three wilt and SM resistant pigeonpea cultivars KPL 96053, ICPL 99044, and ICPL 93179 were found resistant(<10%) to PB as well. However, their resistance to PB needs confirmation under optimum disease development environments.