Behavioral synthesis from VHDL using structured modeling

This dissertation describes work in behavioral synthesis involving the development of a VHDL Synthesis System VSS which accepts a VHDL behavioral input specification and performs technology independent synthesis to generate a circuit netlist of generic components. The VHDL language is used for input and output descriptions. An intermediate representation which incorporates signal typing and component attributes simplifies compilation and facilitates design optimization.A Structured Modeling methodology has been developed to suggest standard VHDL modeling practices for synthesis. Structured modeling provides recommendations for the use of available VHDL description styles so that optimal designs will be synthesized.A design composed of generic components is synthesized from the input description through a process of Graph Compilation, Graph Criticism, and Design Compilation. Experiments were performed to demonstrate the effects of different modeling styles on the quality of the design produced by VSS. Several alternative VHDL models were examined for each benchmark, illustrating the improvements in design quality achieved when Structured Modeling guidelines were followed

Structured modeling for VHDL synthesis

This report will describe a proposed modeling style for the use of the VHSIC Hardware Description Language (VHDL) in design synthesis. We will describe the operations and underlying assumptions of four design models currently understood and used in practice by designers: combinational logic, functional descriptions (involving clocked components such as counters), register transfer (data path) descriptions, and behavioral (instruction set or processor) designs. We will illustrate the various uses of the VHDL description styles (structural, dataflow and behavioral) to represent characteristics of each of these design models. Emphasis is placed on how VHDL constructs should be used in order to synthesize optimal designs

VSS : a VHDL synthesis system

This report describes a register transfer synthesis system that allows a designer to interact with the design process. The designer can modify the compiled design by changing the input description, selecting optimization and mapping strategies, or graphically changing the generated design schematic. The VHDL language is used for input and output descriptions. An intermediate representation which incorporates signal typing and component attributes simplifies compilation and facilitates design optimization. The compilation process consists of two phases. First, a design composed of generic components is synthesized from the input description. Second, this design is translated into components from a particular library by a mapper and optimized by a logic optimizer. Redesign to new technologies can be accomplished by changing only the component library

Herschel/HIFI detections of hydrides towards AFGL 2591: Envelope emission versus tenuous cloud absorption

The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH^+, NH, OH^+, H_2O^+, while NH^+ and SH^+ have not been detected. All molecules except for CH and CH^+ are seen in absorption with low excitation temperatures and at velocities different from the systemic velocity of the protostellar envelope. Surprisingly, the CH(J_(F,P) = 3/2_(2,−) − 1/2_(1,+)) and CH^+(J = 1−0, J = 2−1) lines are detected in emission at the systemic velocity. We can assign the absorption features to a foreground cloud and an outflow lobe, while the CH and CH^+ emission stems from the envelope. The observed abundance and excitation of CH and CH^+ can be explained in the scenario of FUV irradiated outflow walls, where a cavity etched out by the outflow allows protostellar FUV photons to irradiate and heat the envelope at larger distances driving the chemical reactions that produce these molecules

Submillimeter Imaging of NGC 891 with SHARC

The advent of submillimeter wavelength array cameras operating on large ground-based telescopes is revolutionizing imaging at these wavelengths, enabling high-resolution submillimeter surveys of dust emission in star-forming regions and galaxies. Here we present a recent 350 micron image of the edge-on galaxy NGC 891, which was obtained with the Submillimeter High Angular Resolution Camera (SHARC) at the Caltech Submillimeter Observatory (CSO). We find that high resolution submillimeter data is a vital complement to shorter wavelength satellite data, which enables a reliable separation of the cold dust component seen at millimeter wavelengths from the warmer component which dominates the far-infrared (FIR) luminosity.Comment: 4 pages LaTeX, 2 EPS figures, with PASPconf.sty; to appear in "Astrophysics with Infrared Surveys: A Prelude to SIRTF

Water abundance variations around high-mass protostars: HIFI observations of the DR21 region

Context. Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. Aims. We study the distribution of dust continuum and H_(2)O and ^(13)CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact H ii region. Methods. Herschel-HIFI spectra near 1100 GHz show narrow ^(13)CO 10–9 emission and H_(2)O 1_(11)–0_(00) absorption from the dense core and broad emission from the outflow in both lines. The H_(2)O line also shows absorption by a foreground cloud known from ground-based observations of low-J CO lines. Results. The dust continuum emission is extended over 36” FWHM, while the ^(13)CO and H_(2)O lines are confined to ≈24” or less. The foreground absorption appears to peak further North than the other components. Radiative transfer models indicate very low abundances of ~2×10^(-10) for H_(2)O and ~8×10^(-7) for ^(13)CO in the dense core, and higher H_(2)O abundances of ~4×10^(-9) in the foreground cloud and ~7×10^(-7) in the outflow. Conclusions. The high H_(2)O abundance in the warm outflow is probably due to the evaporation of water-rich icy grain mantles, while the H_(2)O abundance is kept down by freeze-out in the dense core and by photodissociation in the foreground cloud

Submillimeter continuum observations of Sagittarius B2 at subarcsecond spatial resolution

We report the first high spatial resolution submillimeter continuum observations of the Sagittarius B2 cloud complex using the Submillimeter Array (SMA). With the subarcsecond resolution provided by the SMA, the two massive star-forming clumps Sgr B2(N) and Sgr B2(M) are resolved into multiple compact sources. In total, twelve submillimeter cores are identified in the Sgr B2(M) region, while only two components are observed in the Sgr B2(N) clump. The gas mass and column density are estimated from the dust continuum emission. We find that most of the cores have gas masses in excess of 100 M$_{\odot}$ and column densities above 10$^{25}$ cm$^{-2}$. The very fragmented appearance of Sgr B2(M), in contrast to the monolithic structure of Sgr B2 (N), suggests that the former is more evolved. The density profile of the Sgr B2(N)-SMA1 core is well fitted by a Plummer density distribution. This would lead one to believe that in the evolutionary sequence of the Sgr B2 cloud complex, a massive star forms first in an homogeneous core, and the rest of the cluster forms subsequently in the then fragmenting structure.Comment: 4 pages, 2 figures, accepted by A&A letter

Multi-agent system for dynamic manufacturing system optimization

This paper deals with the application of multi-agent system concept for optimization of dynamic uncertain process. These problems are known to have a computationally demanding objective function, which could turn to be infeasible when large problems are considered. Therefore, fast approximations to the objective function are required. This paper employs bundle of intelligent systems algorithms tied together in a multi-agent system. In order to demonstrate the system, a metal reheat furnace scheduling problem is adopted for highly demanded optimization problem. The proposed multi-agent approach has been evaluated for different settings of the reheat furnace scheduling problem. Particle Swarm Optimization, Genetic Algorithm with different classic and advanced versions: GA with chromosome differentiation, Age GA, and Sexual GA, and finally a Mimetic GA, which is based on combining the GA as a global optimizer and the PSO as a local optimizer. Experimentation has been performed to validate the multi-agent system on the reheat furnace scheduling problem

Persepsi Dan Tingkat Ketergantungan Masyarakat Terhadap Sumberdaya Alam Taman Nasional Aketajawe Lolobata Di Provinsi Maluku Utara

Penelitian ini merupakan kajian persepsi dan ketergantungan masyarakat terhadap sumberdaya alam di sekitar kawasan Taman Nasional Aketajawe Lolobata khususnya blok Aketajawe. Pengambilan data dilaksanakan pada bulan Oktober 2010 dan Juni tahun 2011 di tiga desa yang bersentuhan langsung dengan kawasan. Tujuan penelitian ini untuk mengetahui ketergantungan masyarakat terhadap sumberdaya alam di dalam dan sekitar kawasan taman nasional dan pengaruhnya terhadap keberlangsungan hidup masyarakat. Metode pemilihan responden dilakukan secara purposif dan analisis data menggunakan statistik deskriptif, dengan intensitas sampling 10%. Hasil penelitian menunjukkan bahwa Masyarakat Kobe Kulo memiliki persepsi tidak baik hingga sedang, sedangkan persepsi masyarakat Tayawi adalah sedang, dan persepsi masyarakat Binagara adalah sedang hingga baik. Ketergantungan masyarakat terhadap kayu dikelompokkan menjadi tiga berdasarkan kegunaannya yaitu sebagai bahan bangunan, perkakas rumah tangga, dan bahan bakar. Hasil hutan bukan kayu yang dimanfaatkan adalah rotan, pandan, woka, sagu, pala, sayuran, buah-buahan, dan tumbuhan obat tradisional, serta satwa liar yang dikonsumsi masyarakat adalah rusa, babi hutan, telur burung gosong dan angsa hutan. Sebagian besar masyarakat beranggapan bahwa hutan merupakan tempat memenuhi kebutuhan hidup, namun pengetahuan tentang keberadaan taman nasional masih minim