Layout Comparison Research Articles

Comparative Analysis of Transmission Housings to Evaluate Whining Noise Performance

A quite cabin is always a preferred choice of the customer. Powertrain acts as a source for many noise and vibration problems in a passenger car. Transmission plays a major role in modulating the power from engine to the drive train and is exposed to a high vibration and noise environments. Hence design of transmission for low vibration & noise is need of the hour. This paper attempts to perform a comparative study of 6 housings of different design of a two-wheel drive passenger car to evaluate the vibration performance and Noise radiation characteristics by using FEM (Finite Element Method) & BEM (Boundary Element Method) & finite element analysis techniques. The authors also try to put forward a layout comparison study for the housings and conclude what design is best suited for better NVH whine performance in view of vibrations & sound radiation. These indicative results from this paper can be referred by the design & analysis engineers during early product development of the transmission.
 Keywords: Transmission, Housings, Whining Noise, Bionic Design, NVH Analysis, Durability Analysis, Study of Housings, Housings NVH Analysis

Impact of Variability on Novel Transistor Configurations in Adder Circuits at 7nm FinFET Technology

This research work focuses on implementation of the FinFET-based complementary metal-oxide-semiconductor (CMOS) Full Adder circuits for different transistor configurations using ASAP7 FinFET model. First, this work examines FinFET-based AND-OR-invert (AOI) gates using different topologies, and second, a FinFET-based CMOS Full Adder circuit at the 7[Formula: see text]nm technology node is analyzed with respect to its process, voltage and temperature (PVT) variability effect measured in terms of the normalized standard deviation of different performance metrics. The comparison is made between conventional (CFFA1) and proposed (FFA2, FFA3, FFA4, FFA5, FFA6, FFA7 and FFA8) FinFET-based CMOS full adder circuits. The aim is to determine the optimal design configuration of the FinFET full adder circuit with the minimum impact of PVT variability. On examining the power delay product (PDP) variability, it is found that variations in FFA2, FFA3, FFA4, FFA5, FFA6, FFA7 and FFA8 are significantly lower than CFFA1 by 6.30%, 4.68%, 10.30%, 65.48%, 68.05%, 65.61% and 17.20%, respectively. Among all the proposed configurations, normalized standard deviation [Formula: see text] for the PDP metric is lowest in FFA6, followed by FFA7, FFA5, FFA8, FFA4, FFA2 and FFA3. The normalized standard deviation [Formula: see text] for power dissipation, however, is lowest in FFA8. In addition, a layout comparison analysis of conventional and proposed full adder circuits reveals that FFA7 has the least area, followed by FFA8, FFA6, FFA5, FFA3, FFA4, FFA2 and CFFA1. The area of FFA2, FFA3, FFA4, FFA5 and FFA6 has decreased by 3.29%, 3.51%, 3.50%, 5.14% and 5.52%, while FFA7 and FFA8 have experienced a decrease in area by 13.87% and 14.36%, respectively, as compared to conventional CFFA1. The proposed layout of FinFET-based CMOS Full Adders can be directly transferred into the foundry’s production line for manufacturing purposes. The overall investigation led us to conclude that FFA8 is the most efficient of all due to the lowest power variation, lower delay variation and lower PDP variation, moreover it has a reduced layout area among all the discussed designs. However, there is a tradeoff in terms of penalty in nominal power, propagation delay and PDP in the proposed topologies.

Layout Comparison and Parameter Optimization of Supercritical Carbon Dioxide Coal-Fired Power Generation Systems under Environmental and Economic Objectives.

In the current studies, the supercritical carbon dioxide coal-fired power generation systems show efficiency and cost advantages over the traditional steam-based power systems. However, few studies have considered simultaneously environmental and economic objectives in the multi-objective analysis process. This study conducts a layout comparison and parameter optimization of the systems under the above two objectives. Initially, the thermodynamic, environmental, and economic models of the systems are established. Subsequently, the optimal layout is determined by the two-stage layout comparison. Further, multi-objective optimization is performed for the selected layout, and the optimal design parameters are determined by the decision process. Finally, the sensitivities of three selected parameters to the optimization results are analyzed. The results show that the basic layout coupled with overlap and intercooling schemes is optimal. Its ultimate environmental impact (UEI) and levelized cost of electricity (LCOE) are 219.8 kp-eq and 56.9 USD/MWh, respectively. The two objectives UEI and LCOE are conflicting. Based on a trade-off between them, the maximum temperature/pressure of the system is determined to be 635.3 °C/30.1 MPa. The coal price per unit of heat shows the highest sensitivity, and the pinch temperature difference of the recuperator shows opposite sensitivities at the UEI below 218 kp-eq and above 223 kp-eq.

ShiTouzhai hydropower station hub layout pattern comparison research of pre-feasibility study stage

The selection of the layout scheme is the key content of the pre-feasibility study of large and medium-sized hydropower stations. Based on the topographical and geological conditions, and considering the construction conditions, reservoir flooding, project investment and other factors, this paper makes an in-depth analysis of the layout comparison and design of the pre-feasibility stage of Shitouzhai Hydropower station, in order to provide beneficial inspiration for similar project design.

Immersive Modular Factory Layout Planning using Augmented Reality

We present an immersive analytics approach to enhance production line planning. It enables experts to analyze the performance and spatial implications of already drafted production layouts in-situ on the shop floor. The approach is implemented as an augmented reality application prototype. Experts can interactively combine the computational capabilities of layout simulations with their experience allowing to consider possibly unmodeled restrictions. Our interactive approach is enhanced by automated layout suggestions using a genetic algorithm as well as an automated layout comparison. Further, we provide information about the layout’s optimization potential based on the calculation and visualization of critical paths in the layout.

Conceptual design of a Blended Wing Body MALE UAV

The current work is an aerodynamic design study of a Blended Wing Body (BWB) Medium-Altitude-Long-Endurance (MALE) Unmanned-Aerial-Vehicle (UAV). Using a combined approach of presizing tools and computational simulations, a step-by-step layout design study was conducted to define the key layout characteristics and select the optimal airframe-engine combination. Trade studies were also carried out to optimize the aerodynamic performance and stability. The traditional sizing and aerodynamic estimation methods were adopted to incorporate the characteristics of the BWB platform, whereas CFD computations were employed in order to calculate the aerodynamic and stability coefficients, during the layout comparison and trade studies. Drawings and tables are provided to show the progression of the design study at each stage. The performance specifications are also compared with a conventional UAV platform to point out the main advantages and disadvantages of the BWB for MALE UAV applications.

Efficient, High Brightness 1030 nm DBR Tapered Diode Lasers With Optimized Lateral Layout

Efficient, high brightness 1030 nm distributed Bragg reflector (DBR) tapered diode lasers with optimized lateral waveguide and grating designs are presented in this paper. The layout changes were carried out in order to enhance the diffraction efficiency of the manufactured DBR gratings and improve the spatial mode filtering for these lasers. In this study, lasers with straight waveguide and grating, straight waveguide and tapered grating, and tapered waveguide and straight grating are compared. The lasers provide an optical output power up to 15.5 W and narrowband emission over the whole power range. Within the studied parameter range, the highest central lobe output power of 10.1 W is obtained for a laser with a tapered grating. The layout comparison also shows that the influence of the applied ridge waveguide injection current density on the central lobe power is significantly different. Here, the lateral design with a tapered grating is the most robust layout. Compared to previous approaches for DBR tapered diode lasers, optimized waveguide and grating designs and their impact on laser performance may help to increase the application potential of such devices.

Layout evaluation at earlier stages of machine tool design:form-shaping function-based approach

Some important parameters of the machine tool layout have to be selected in the early stages of design when a shortage of information makes application of the finite element method impractical. As a computer-aided tool in these stages, the form-shaping function (FSF)-based approach can be used. It allows evaluation of the kinematic and geometric errors and compliance issue static deformations, which contribute significantly to the total machining error as applied to precision machine tools. The FSF-based methodology gives important information allowing layouts’ comparison and structure optimization under uncertainty in requirements and limitations relating to the designed machine under strong time constraints. Six different layouts of a turning center are investigated to compare the effect of geometrical errors and compliance of machine structure on part accuracy in the range of less than five microns. Motion errors of machine tool components were measured by laser equipment during machine tool assembly and inspection. Compliance-induced errors are included in the evaluation to take into consideration cutting forces. Obtained data were used as the input for simulation of machining a sample workpiece—a sphere whose size, position, and form errors are used as criteria for layout comparison. Since the FSF-based results correlate well with the experimental data, the developed approach can be considered as an effective tool for application in the early stages of machine design.

Optimal configuration for programmable Mössbauer experiments

Based on channel independency of recently developed Mössbauer instrumentation an approximation to optimal configuration of experiments is presented. The analysis relies on the presumption that all the available channels of the spectrum are not equally efficient for a given experimental application. A quantification of this concept is presented and a method for different channel layout comparison is proposed. The optimization of recorded spectra is important in dynamic experiments where efficiency in data taking imposes feasibility limits as well as in static applications as a way of reducing experimental time.

The cellular manufacturing paradox: a critical review of simulation studies

PurposeA number of simulation studies have been conducted previously by several researchers, in order to compare the performance of cellular and functional layouts. The purpose of this paper is to highlight the lack of objectivity of a number of these studies, in order to explain the origin of their conflicting conclusions.Design/methodology/approachA taxonomy of the main experimental factors and performance measure used in the main simulation comparative studies is followed by a critical assessment of ten of these studies. The analysis is focused on the objectivity of the layout comparison methodologies. Then, the determined shortcomings are categorized and some of them are illustrated by way of simulation.FindingsThe revealed shortcomings are most likely responsible for the conflicting conclusions of the studies and may well explain what is called in the literature the “cellular paradox.”Originality/valueThis work sets up the basis for an objective comparison methodology between the two manufacturing system layouts. Such a methodology should in fact be free of all the highlighted objectivity flaws.

Hierarchy Restructuring for Hierarchical LVS Comparison

A new hierarchical layout vs. schematic (LVS) comparison system for layout verification has been developed. The schematic hierarchy is restructured to remove ambiguities for consistent hierarchical matching. Then the circuit hierarchy is reconstructed from the layout netlist by using a modified SubGemini algorithm recursively in bottom-up fashion. For efficiency, simple gates are found by using a fast rule-based pattern matching algorithm during preprocessing. Experimental results show that our hierarchical netlist comparison technique is effective and efficient in CPU time and in memory usage, especially when the circuit is large and hierarchically structured.

Safety implications of bicycle paths at signalized intersections

This paper presents a quantitative meta-analysis of studies evaluating, by means of the Bayesian method, the safety effectiveness of different bicycle facilities at road junctions. This is preceded by a discussion of background theories and an up-to-date presentation of today's knowledge of the cyclist's safety at intersections; alternative layouts in Scandinavia, and Sweden in particular, are shown. The project consists of a literature survey as well as interviews with experts and cyclists, and an attempt to weave together these different sources in estimating the effect of a particular layout. In summary, few studies from the Scandinavian countries exist that have treated this area with an acceptable methodology. Combined results, with the Bayesian technique, are therefore presented for only one layout comparison: accident risks for cyclists at signalized intersections with and without a cycle path. The results of this aggregation may be unreliable as well, due to deficiencies in the studies. New field studies should be initiated. The “experts'” prior opinion was that the introduction of the cycle path would, on average, increase the risk by about 20%, while interviewed cyclists considered that a cycle path would decrease the risk by about 20%. The conclusion that can be drawn so far from combining results shows that the most likely effect of introducing a cycle path is that the risk will increase by about 40% for a passing cyclist. The probability that the effect will be the opposite, i.e. that the risk will decrease, is very small (about 2%). These combined results are based primarily on cross-section studies, where the layouts have not been “randomly allotted”. It is therefore likely that the risk increase may have been overestimated. The probability that the “real” effect is accident reduction is therefore somewhat greater than 2%. How much greater cannot be estimated from these studies.

A multifactor approach to selecting computer generated electronics assembly facility layouts

This research proposes a method for comparing computer generated electronics assembly facility layouts. CRAFT, ALDEP, and CORELAP outputs are disccused in terms of quantitative measures such as flow inefficiency, distance between functional areas and growth capacity. Flow linearity, access to functional areas, and maintenance of critical relationships between functional areas are examined for qualitative layout comparison. Although 3 software packages' output were compared, the approach could easily be applied to comparing the outputs dervied from one layout software package. Results taken from the implementation of the comparison method at a Fortune 500 electronics manufacturing firm are presented. An algorithmic method is presented which has not been developed into software and in which the authors have no commercial interest. Use of the method, MASL, Multifactor Approach for Selecting Layouts, enhanced the utility and performance measurement of the computer generated layouts for the electronics assembly area of the plant.

Integrated injection logic-present and future

Integrated injection logic (I/SUP 2/L) or merged transistor logic (MTL) incorporating lateral p-n-p transistors as current sources and multicollector n-p-n transistors as invertors, are discussed. Speed-power products of 0.13 pJ per gate have been measured in a five-stage closed-loop invertor chain, and packing densities of 400 gates/mm/SUP 2/ have been achieved. A layout comparison with MOS logic is presented. A possible way of producing faster circuits is proposed.