Advanced Design Methodology Research Articles

Improved Switching Strategy for Selective Harmonic Elimination in DC-AC Signal Generation via Pulse-Width Modulation

We present an advanced design methodology for pulse-width-modulated (PWM) DC-AC signal generation. Using design methods based on the Walsh transform, AC sinusoidal signals can be approximated by suitable PWM signals. For different AC amplitudes, the switching instants of the PWM signals can be efficiently computed by using appropriate systems of explicit linear equations. However, the equation systems provided by conventional implementations of this approach are typically only valid for a restricted interval of AC amplitudes and, in general, a supervised implementation of several equation systems is necessary to cover the full AC amplitude range. Additionally, obtaining suitable equation systems for designs with a large number of switching instants requires solving a complex optimization problem. In defining the constitutive pulses of a PWM signal, a suitable partition of the time interval is used as a reference system. In the new methodology, pulses are chosen to be symmetric with respect to the partition points, and the switching times are specified by means of switching ratios with respect to the endpoint subintervals. This approach leads to particularly simple Walsh series representations, introduces a remarkable computational simplification, and achieves excellent results in reducing the harmonic distortion.

New Developments of Product Design Methodology

Design and R&D (Research and Development) of products play an important role in development and competitiveness of enterprise. How to do the works better We think that most advanced product design methodology should be used on design, research and development of products. So-called most advanced product design methodology is that based on “the Scientific Outlook on Development” that we set up recent years. New developments of product design methodology include: At first it has been classified that more than seventy theories and methods proposed by domestic and overseas scholars in recent 100 years; QCTES was instead of IQCTES including six requirements of product design; traditional design stages were replaced with four new stages including investigation, planning, implement and inspection; green design was replaced with harmonious design; traditional design method was replaced with deep-layer design method; concept and connotation of product top-layer design were proposed; more detailed contents of product systematic design were advanced; formulas of complete system and product design quality, and connection equation between design objective, design content and design method were submitted. We got good effects to apply above product design methodology on many product designs recent years.

The Pentele Danube‐bridge in Dunaújváros, Hungary Design, Research and Construction

AbstractThe main part of the bridge is a basket handle type tied‐arch bridge. The geometrical size, structural solutions and erection method of the bridge required preliminary research and advanced design methodology. This paper gives a general outline about the construction of the steel structure of the arch bridge and emphasizes some of the design aspects.

Investigation of forward flow distributed combustion for gas turbine application

New innovative advanced combustion design methodology for gas turbine applications is presented that is focused on the quest towards zero emissions. The new design methodology is called colorless distributed combustion (CDC) and is significantly different from the currently used methodology. In this paper forward flow modes of CDC have been investigated for application to gas turbine combustors. The CDC provides significant improvement in pattern factor, reduced NO x emission and uniform thermal field in the entire combustion zone for it to be called as an isothermal reactor. Basic requirement for CDC is carefully tailored mixture preparation through good mixing between the combustion air and product gases prior to rapid mixing with fuel so that the reactants are at much higher temperature to result in hot and diluted oxidant stream at temperatures that are high enough to autoignite the fuel and oxidant mixture. With desirable conditions one can achieve spontaneous ignition of the fuel with distributed combustion reactions. Distributed reactions can also be achieved in premixed mode of operation with sufficient entrainment of burned gases and faster turbulent mixing between the reactants. In the present investigation forward flow modes consisting of two non-premixed combustion modes and one premixed combustion mode have been examined that provide potential for CDC. In all the configurations the air injection port is positioned at the opposite side of the combustor exit, whereas the location of fuel injection ports is changed to give different configurations. Two combustion geometries resulting in thermal intensity of 5 MW/m 3-atm and 28 MW/m 3-atm are investigated. Increase in thermal intensity (lower combustion volume) presents many challenges, such as, lower residence time, lower recirculation of gases and effect of confinement on jet characteristics. The results are presented on the global flame signatures, exhaust emissions, and radical emissions using experiments and flowfield using numerical simulations. Ultra-low NO x emissions are found for both the premixed and non-premixed combustion modes at the two thermal intensities investigated here. Almost colorless flames (no visible flame signatures) have been observed for the premixed combustion mode. The reaction zone is observed to be significantly different in the two non-premixed modes. Higher thermal intensity case resulted in lower recirculation of gases within the combustion chamber and higher CO levels, possibly due to lower associated residence time. The characteristics at the two thermal intensity combustors investigated here were found to be similar.

A fast interactive reverse-engineering system

A new method of reverse engineering for fast, simple and interactive acquisition and reconstruction of a virtual three-dimensional (3D) model is presented. We propose an active stereo acquisition system, which makes use of two infrared cameras and a wireless active-pen device, supported by a reconstruction method based on subdivision surfaces. In the 3D interactive hand sketching process the user draws and refines the 3D style-curves, which characterize the shape to be constructed, by simply dragging the active-pen device; then the system automatically produces a low-resolution mesh that is naturally refined through subdivision surfaces. Several examples demonstrate the ability of the proposed advanced design methodology to produce complex 3D geometric models by the interactive and iterative process that provides the user with a real-time visual feedback on the ongoing work.

Advanced Design Methodology of High-Performance Sub-100-nm-Channel GAA MOSFET

This paper reconsiders the design methodology of the short-channel GAA SOI MOSFET and proposes an advanced concept to enhance its performance. The new ideas are based on gate field engineering and source and drain diffusion engineering. Validity of the proposal is demonstrated by device simulations

Advanced Design Methodology of High-Performance Sub-100-nm-Channel GAA MOSFET -Longitudinal Field Engineering-

not Available.

中越沖地震の柏崎刈羽原子力発電所影響評価研究分科会の活動 : 原子力発電所の機器等の地震安全に関する技術課題と研究・開発ロードマップの検討(中越沖地震の柏崎刈羽原子力発電所影響評価研究分科会,<特集>第13回動力・エネルギー技術シンポジウム)

This paper describes technical issues for the seismic safety of nuclear power plant components and also shows preliminary roadmaps for the solution of the issues. After the Chuetsu-oki earthquake of July 2007, research committees were established in JSME and AESJ for the discussion of the effect of the earthquake on NPP components. Ten technical issues due to the earthquake are pointed out and the discussion concerning the roadmaps has started to solve each issue. The goal of the activity is for the advanced design methodology with seismic safety.

Top-down design methodology of a multi-bit continuous-time delta–sigma modulator

Transistor-level simulation of complex systems involving analog and digital parts is a time-consuming task. The growing interaction of analog and digital devices calls for the use of top-down design methodologies, resulting in behavioral modeling at different levels of abstraction. In this article, an advanced design methodology using a combination of behavioral models and transistor-level models is presented. This methodology is very interesting for complex mixed-signal IC design, improving the design flexibility and reducing the simulation time. To validate the proposed methodology, a continuous-time delta---sigma modulator based on a high-speed low-resolution quantizer is modeled, taking into account their nonidealities such as excess loop delay, clock jitter and feedback DAC element mismatch. The main features of the multi-bit quantizer are 3-bit resolution with 4 GHz sampling rate and FOM of about 7 pJ/conv. This modulator samples signals at high-IF, performing directly the analog-to-digital conversion in the modern RF front-end receivers.

Advanced Gas Turbine Concept, Design and Evaluation Methodology. Preliminary Design of Highly Loaded Low Pressure Gas Turbine of Aircraft Engine

This article deals with the conceptual approach to optimize efficiency and power of a highly loaded gas turbine flow path design. Different problems were analyzed during low pressure turbine (LPT) preliminary design of high-bypass aircraft jet engine.

Dunaujvaros Danube Bridge: Construction, Design and Research

As a part of an extensive highway development program in Hungary a new Danube bridge is under construction in Dunaujvaros, about 70 km south of Budapest. The 1676.8 m bridge will be completed in the autumn of 2006. The main part of the bridge is a basket handle type tied arch bridge with a span of 307.8 m. The geometrical size, structural solutions and erection method of the bridge required preliminary research and advanced design methodology. This paper gives a general outline of the bridge construction and emphasizes some of the design and research aspects of the arch bridge. (A)

Advanced design methodology for single and dual voltage wound core power transformers based on a particular finite element model

The paper presents an accurate and cost effective three-dimensional finite element model for the analysis and design of wound core, shell type, power transformers, focusing on the short-circuit impedance evaluation. The model efficiency lies on the detailed representation of the transformer geometry along with the adoption of a particular reduced scalar potential formulation enabling three-dimensional magnetostatic problem solution without prior source field calculation. Its accuracy is validated through local field measurements and through comparison of the calculated short-circuit impedance value with the measured one for several commercial wound core, shell type transformers. In such transformers, involving extensive winding parts out of the core window, the detailed representation of the transformer geometry, including the winding cooling ducts, provides accurate results for low densities of the three-dimensional finite element mesh, resulting to reduction of the required calculation time. The model is used in the development of a computational tool, which enables the automated and accurate transformer characteristics prediction, adopted to the manufacturing process. This tool has also been applied in the impedance calculation for different winding connections of dual voltage transformers, thus providing the information needed for the achievement of an accurate design and the enhancement of the manufacturer's ability to reduce design margins. The methodology presented in this paper has been incorporated in the design process of a transformer manufacturing industry.

Wide dynamic range snapshot APS for ultra low-power applications

A novel wide dynamic range (WDR) snapshot active pixel sensor for ultra-low power applications is presented. The proposed imager allows capturing of fast moving objects in the field of view and provides WDR by applying adaptive exposure time to each pixel, according to the local illumination intensity level. Driven by low-power dissipation requirements, the proposed pixel is operated by dual low voltage supplies (1.2 and 1.8 V) and utilizes an advanced low-power sensor design methodology. A test chip of a 32*32 array has been implemented in a standard 0.35-/spl mu/m CMOS technology. A single pixel occupies 18*32 /spl mu/m area and is expected to dissipate 18.5 nW at video rate. System architecture and operation are discussed and simulation results are presented.

An Application of the AKADAM Approach to Intelligence Analyst Work

This paper emphasizes the use of cognitive task analysis to gain significant insight into the unique domain of intelligence analysts, how intelligence analysts view this domain, and how this domain can be replicated in a controlled simulation environment in which innovative tools and procedures can be empirically tested. Details of two comprehensive knowledge elicitation sessions involving intelligence analysts are provided as an example of using the Advanced Knowledge Acquisition and Design (AKADAM) methodology to obtain contextually relevant information for use in developing a homeland defense-oriented simulation/experimental task. Several distinctive characteristics of intelligence analyst functionality were discovered, including the multi-source integration of relevant information, complex cognitive analysis, and team collaboration in decision-making. Additional themes such as social interaction and the limitations of current analysis tools were identified.

Production-based Design Methodology for Shipboard Machinery Spaces

U.S. shipyards are experiencing a lack of stock designs when compared with worldclass shipyards. Shipyards in this country usually develop "unique designs" from scratch. New designs are traditionally performed by design agents, who do not account sufficiently for production requirements and constraints. This process typically results in excessive production re-engineering and/or rework. This paper presents a production-based methodology that is being developed under the National Shipbuilding Research Program/American Shipbuilding Enterprise (NSRP/ASE) Project 21, Develop and Implement World-Class U.S. Material Standards and Parametric Design Rules to Support Commercial and Naval Auxiliary Ship Construction. This methodology utilizes a zonal design approach that leverages work previously accomplished under the Shipbuilding Technology contract between Designers & Planners, Inc., and the Carderock Division of the Naval Surface Development Center in the 1994–1998 time frame. Under this contract, a collocated team with representatives of domestic and foreign shipbuilders, ship owners, vendors, and designers developed world-class engine rooms. Results of this previously conducted research were summarily reported in the Maritime Reporter. The advanced design methodology presented in this paper incorporates production requirements early in the design process that can result in significant savings in design cost and schedule, production costs, and construction cycle time. The methodology addresses how (1) machinery equipment should be grouped into functional volumes and blocks; (2) the interfaces between functional volumes and blocks and between zones should be considered; (3) producibility issues should be considered early in the design process; (4) the information should be collected and archived for use in future designs. An example is provided to show how this advanced methodology could be used to shorten design time and cost and enhance the producibility of future shipboard machinery spaces.

A single WDM multi/demultiplexer for all SMF transmission windows in 1280-1680 nm

A new advanced design methodology for multi/demultiplexers based on holographic concave gratings is presented. The proposed design is benchmarked against a single grating operating in the entire useful range of the single-mode fiber (1280-1680 nm). In addition, a new design for a grating serving as a 1000 wavelength-division-multiplexing channel demultiplexer within the 1450-1650 nm spectral range is given. It is shown that the new mount offers considerably improved performance.

Design Methodology for a DVB Satellite Receiver ASIC

This contribution describes design methodology and implementation of a single-chip timing and carrier synchronizer and channel decoder for digital video broadcasting over satellite (DVB-S). The device consists of an A /D converter with AGC, timing and carrier synchronizer with matched filter, Viterbi decoder including node synchronization, byte and frame synchronizer, convolutional de-interleaver, Reed Solomon decoder, and a descrambler. The system was designed in accordance with the DVB specifications. It is able to perform Viterbi decoding at data rates up to 56 Mbit /s and to sample the analog input values with up to 88 MHz. The chip allows automatic acquisition of the convolutional code rate and the position of the puncturing mask. The symbol synchronization is performed fully digitally by means of interpolation and controlled decimation. Hence, no external analog clock recovery circuit is needed. For algorithm design, system performance evaluation, co-verification of the building blocks, and functional hardware verification an advanced design methodology and the corresponding tool framework are presented which guarantee both short design time and highly reliable results. The chip has been fabricated in a 0.5 µm CMOS technology with three metal layers. A die photograph is included.

The Tower City concept - shelf-shaping megastructure for a city infrastructure to be built by mobile, robotized factories

In many ways we are at a point in history that may be compared to the early stages of the Industrial Revolution. Many observers share the view that we are presently in what may be coined as the Cybernetic Revolution or perhaps more accurately, as the Information Age. Although such periods offer exciting opportunities to visionary individuals, it is important to remember that, historically, very high prices have been paid for growth and changes that occurs too rapidly. In the case of the building Industry in particular, when approaching times of rapid growth, it is important that a broad vision and a multilateral perspective be adopted when addressing any specific issue that deals with innovative concepts such as Mobile Building Systems, Rapid Assembled Structures, Automation and Robotics. In the case of any rapidly developing technology, it is most important that a focused perspective is constantly maintained at the research level so that the evolution of the technology may be carefully directed to the greatest extent possible, towards the common good. Otherwise, as has happened in the past, shortsighted innovations, however well intended, may bring with them enormous Sociological and Ecological cost. Speculations as to the consequences of innovations in relation to other fields, as well as intuitions about future urban and social needs, should serve as guide lines for the development of research in new advanced material, design methodology and construction process.

Computerized design of low-noise face-milled spiral bevel gears

An advanced design methodology is proposed for the face-milled spiral level gears with modified tooth surface geometry that provides a reduced level of noise and has a stabilized bearing contact. The approach is based on the local synthesis of the gear drive that provides the “best” machine-tool settings. The theoretical aspects of the local synthesis approach are based on the application of a predesigned parabolic function for absorption of undesirable transmission errors caused by misalignment and the direct relations between principal curvatures and directions for mating surfaces. The meshing and contact of the gear drive is synthesized and analyzed by a computer program. The generation of gears with the proposed geometry design can be accomplished with existing equipment. A numerical example that ilustrates the proposed theory is presented.

Magnetic Bearing Stage for Photolithography

This paper describes a linear magnetic bearing stage which controls a suspended object in six degrees of freedom. The intended application is for X-Y wafer positioning in photolithography stages. Magnetic bearings offer superior performance and resolution over existing mechanical X-Y stages. An advanced prototype magnetic bearing stage that improves the ideas verified in the existing stage has been designed and is currently under construction. The paper will also present the advanced stage design methodology used and the reasons for the decisions made.