Implementation of All-Optical 1x4 Memory Register Unit using the Micro-Ring Resonator Structures

Implementation of switching activity in the all-optical domain is one of the most important aspects in the field of modern high-speed and secured communication technology. Micro-ring Resonator (MRR) based switching activity can be used to implement all-optical active low tri-state buffer logic and clocked D flip-flop. The paper describes the switching activity of micro-ring resonator structures and the switching activity is further used to implement the effective all-optical 4 - bit memory register using the appropriate arrangement of all-optical tri-state buffers and clocked D flip-flops with the functionality of RD and WR. The complete description of layouts and switching mechanisms of all-optical 4-bit memory registers have been explained and appropriate MATLAB simulation results are presented to observe the suitability of the proposed unit. The analysis shows that implementation of tri-state buffer logic and D flip-flop assisted 4-bit memory register in the all-optical domain includes the considerable advantages of optical communication e.g. immunity to electromagnetic interference, parallel computing, compactness, signal security, etc. The manuscript describes the detailed analysis of performance parameters e. g. extinction ratio, contrast ratio, amplitude modulation, on-off ratio, and switching speed of micro-ring resonator structures to achieve an efficient selection of device parameters and finally describes an efficient technique to implement all-optical MRR based 1 x 4 memory registers.

A Programmable Mechanical Maxwell’s Demon

We introduce and investigate a simple and explicitly mechanical model of Maxwell’s demon—a device that interacts with a memory register (a stream of bits), a thermal reservoir (an ideal gas) and a work reservoir (a mass that can be lifted or lowered). Our device is similar to one that we have briefly described elsewhere, but it has the additional feature that it can be programmed to recognize a chosen reference sequence, for instance, the binary representation of π . If the bits in the memory register match those of the reference sequence, then the device extracts heat from the thermal reservoir and converts it into work to lift a small mass. Conversely, the device can operate as a generalized Landauer’s eraser (or copier), harnessing the energy of a dropping mass to write the chosen reference sequence onto the memory register, replacing whatever information may previously have been stored there. Our model can be interpreted either as a machine that autonomously performs a conversion between information and energy, or else as a feedback-controlled device that is operated by an external agent. We derive generalized second laws of thermodynamics for both pictures. We illustrate our model with numerical simulations, as well as analytical calculations in a particular, exactly solvable limit.

A Programmable Mechanical Maxwell's Demon

We introduce and investigate a simple and explicitly mechanical model of Maxwell's demon -- a device that interacts with a memory register (a stream of bits), a thermal reservoir (an ideal gas) and a work reservoir (a mass that can be lifted or lowered). Our device is similar to one that we have briefly described elsewhere [1], but it has the additional feature that it can be programmed to recognize a chosen reference sequence, for instance, the binary representation of $\pi$. If the bits in the memory register match those of the reference sequence, then the device extracts heat from the thermal reservoir and converts it into work to lift a small mass. Conversely, the device can operate as a generalized Landauer's eraser (or copier), harnessing the energy of a dropping mass to write the chosen reference sequence onto the memory register, replacing whatever information may previously have been stored there. Our model can be interpreted either as a machine that autonomously performs a conversion between information and energy, or else as a feedback-controlled device that is operated by an external agent. We derive generalized second laws of thermodynamics for both pictures. We illustrate our model with numerical simulations, as well as analytical calculations in a particular, exactly solvable limit.

OUVIR O ESPAÇO GEOGRÁFICO: a formação territorial de Itabaiana (Sergipe) nas memórias

LISTENING TO THE GEOGRAPHICAL SPACE: the territorial formation ofItabaiana (Sergipe) in the memoriesESCUCHAR EL ESPACIO GEOGRÁFICO: la formación territorial de Itabaiana (Sergipe) en las memóriasO presente artigo proporciona uma discussão sobre como o recurso da memória – construída socialmente – desempenha papel relevante na leitura geográfica do espaço. Esta leitura é realizada através do registro de memória de sujeitos sociais históricos e atuantes, residentes do município de Itabaiana, Sergipe. O principal objetivoé entender como estes sujeitos sociais contribuíram para a formação territorial desse município a partir, principalmente, da análise de temas e questões suscitados por cada umdeles. Como recurso metodológico, a realização de entrevistas, apoiadas na História Oral. Os depoimentos registrados são analisados a fim de se obter um quadro de temas relativos à formação territorial de Itabaiana. A experiência com os depoimentos tem possibilitado a compreensão de marcas sociais e territoriais inerentes ao processo de exploração e formação do território: algumas passíveis de associações com a historiografia, outras próprias à história de vida das pessoas e à compreensão de seu espaço tempo.Palavras-chave: Formação Territorial; Itabaiana; Memória; Geografia.ABSTRACTThe present article provides a discussion on how the memory resource - socially constructed - plays a relevant role in the geographic reading of space. This reading is performed through the memory register of historical and active social subjects, residents of the municipality of Itabaiana, Sergipe. The main objective is to understand how these social subjects contributed to the territorial formation of this municipality, based mainly on the analysis of themes and issues raised by each of them. As a methodological resource, interviews were conducted, supported by Oral History. The recorded statements are analyzed in order to obtain a table of subjects related to the territorial formation of Itabaiana. The experience with the testimonies has made it possible to understand the social and territorial marks inherent to the process of exploration and formation of the territory: some of them may be associated with historiography, others are appropriate to the life history of the people and the understanding of their space time.Keywords: Territorial Formation; Itabaiana; Memory; Geography.RESUMENEl presente artículo proporciona una discusión sobre cómo el recurso de la memoria - construida socialmente - desempeña un papel relevante en la lectura geográfica del espacio. Esta lectura se realiza a través del registro de memoria de sujetos sociales históricos y actuantes, residentes del municipio de Itabaiana, Sergipe. El principal objetivo es entender cómo estos sujetos sociales contribuyeron a la formación territorial de ese municipio a partir, principalmente, del análisis de temas y cuestiones suscitados por cada uno de ellos. Como recurso metodológico, se realizaron entrevistas apoyadas en la Historia Oral. Los testimonios registrados son analizados a fin de obtener un cuadro de temas relativos a la formación territorial de Itabaiana. La experiencia con los testimonios ha posibilitado la comprensión de marcas sociales y territoriales inherentes al proceso de explotación y formación del territorio: algunas pasibles de asociaciones con la historiografía, otras propias a la historia de vida de las personas y la comprensión de su espacio tiempo.Palabras clave: Formación Territorial; Itabaiana; Memoria; Geografía.

Remember like humans

Visual tracking is a challenging computer vision task due to the significant observation changes of the target. By contrast, the tracking task is relatively easy for humans. In this article, we propose a tracker inspired by the cognitive psychological memory mechanism, which decomposes the tracking task into sensory memory register, short-term memory tracker, and long-term memory tracker like humans. The sensory memory register captures information with three-dimensional perception; the short-term memory tracker builds the highly plastic observation model via memory rehearsal; the long-term memory tracker builds the highly stable observation model via memory encoding and retrieval. With the cooperative models, the tracker can easily handle various tracking scenarios. In addition, an appearance-shape learning method is proposed to update the two-dimensional appearance model and three-dimensional shape model appropriately. Extensive experimental results on a large-scale benchmark data set demonstrate that the proposed method outperforms the state-of-the-art two-dimensional and three-dimensional trackers in terms of efficiency, accuracy, and robustness.

Design and Implementation of Synthesizable 32-bit Four Stage Pipelined RISC Processor in FPGA Using Verilog/VHDL

This paper is delineating the design and implementation of high performance, synthesizable 32-bit pipelined Reduced Instruction Set Computer (RISC) Core. The design of the Harvard Architecture based 32-bit RISC Core involves design of 32-bit Data-path Unit, Control Unit, 32-bit Instruction Memory, 32-bit Data Memory, Register file with each register of size 32 bit. The processor is divided into Fetch, Decode, Execute and Write Back block in order to implement a four-stage pipeline. A 2*16 LCD is connected to the processor IO block to show the instruction execution sequence for demonstration in FPGA. The RISC Core is designed using Verilog HDL and VHDL and is tested in ISIM Simulator. The implementation of the processor is done in a Spartan 3E Starter Board using Xilinx ISE 14.7. All of the instructions incorporated with the processor have been tested successfully both in simulation and hardware implementation in FPGA.DOI: http://dx.doi.org/10.3126/njst.v15i1.12021 Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 81-88

TOWARDS A MULTIMODE QUANTUM MEMORY FOR SINGLE PHOTONS

In this paper, an optical memory based on an ensemble of cold Cesium atoms interacting with light in the electromagnetically induced transparency (EIT) regime is studied in view of spatially multimode quantum storage. The interfacing protocol involves a control field, generating EIT for the very weak field that carries the quantum signal to be stored and enabling its mapping into the collective hyperfine coherence of the cold atomic ensemble. For the demonstration of multimode storage, the signal pulse at the single photon level is prepared in a mode with (OAM), while the control field is in a TEM00 mode. After the writing process, the information is kept in the memory register. In the retrieval phase, the information is read back from atoms to light and we show that these pulses at the single photon level with OAM can be stored and retrieved with a preserved spatial phase and a good efficiency.

Cognitive Memory

Taking inspiration from life experience, the authors have devised a new form of computer memory. Certain conjectures about human memory are keys to the central idea. This paper presents a design of a practical and useful “cognitive” memory system in which the new memory does not function like a computer memory where specific data is stored in specific numbered registers; retrieval is done by reading the contents of the specified memory register, or done by matching key words as with a document search. Incoming sensory data would be stored at the next available empty memory location and could be stored redundantly at several empty locations. The stored sensory data would neither have key words nor would it be located in known or specified memory locations. Retrieval would be initiated by a prompt signal from a current set of sensory inputs or patterns. The search would be done by a retrieval system that makes use of auto-associative artificial neural networks. In this paper, the authors present a practical application of this cognitive memory system to human facial recognition.