model Estimating Spatio-Temporal Risks from Volcanic Eruptions Using an Agent-Based Model By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:50:00 +0000 J Jumadi, Nick Malleson, Steve Carver and Duncan Quincey: Managing disasters caused by natural events, especially volcanic crises, requires a range of approaches, including risk modelling and analysis. Risk modelling is commonly conducted at the community/regional scale using GIS. However, people and objects move in response to a crisis, so static approaches cannot capture the dynamics of the risk properly, as they do not accommodate objects’ movements within time and space. The emergence of Agent-Based Modelling makes it possible to model the risk at an individual level as it evolves over space and time. We propose a new approach of Spatio-Temporal Dynamics Model of Risk (STDMR) by integrating multi-criteria evaluation (MCE) within a georeferenced agent-based model, using Mt. Merapi, Indonesia, as a case study. The model makes it possible to simulate the spatio-temporal dynamics of those at risk during a volcanic crisis. Importantly, individual vulnerability is heterogeneous and depends on the characteristics of the individuals concerned. The risk for the individuals is dynamic and changes along with the hazard and their location. The model is able to highlight a small number of high-risk spatio-temporal positions where, due to the behaviour of individuals who are evacuating the volcano and the dynamics of the hazard itself, the overall risk in those times and places is extremely high. These outcomes are extremely relevant for the stakeholders, and the work of coupling an ABM, MCE, and dynamic volcanic hazard is both novel and contextually relevant. Full Article Article
model Do Farm Characteristics or Social Dynamics Explain the Conversion to Organic Farming by Dairy Farmers? An Agent-Based Model of Dairy Farming in 27 French Cantons By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:52:00 +0000 Qing Xu, Sylvie Huet, Eric Perret and Guillaume Deffuant: The drivers of conversion to organic farming, which is still a residual choice in agriculture, are poorly understood. Many scholars argue that farm characteristics can determine this choice but do not exclude the role of social dynamics. To study this issue, we developed an agent-based model in which agents' decisions to shift to organic farming are based on a comparison between satisfaction with the current situation and potential satisfaction with an alternative farming strategy. A farmer agent’s satisfaction is modelled using the Theory of Reasoned Action. This makes it necessary to compare an agent's productions over time with those of other agents to whom the former attributes considerable credibility (“important others”). Moreover, farmers make technical changes that affect their productions by imitating other credible farmers. While we first used this model to examine simple and abstract farm populations, here we also adapted it for use with data from an Agricultural Census concerning the farm characteristics of dairy farming in 27 French “cantons”. Based on domain expertise, data and previous research, we propose certain laws for modelling the impact of conversion on the farm production of milk and the environment. The simulations with “real” populations of farms confirm the important impact of farm characteristics. However, our results also suggest a complex impact of social dynamics that can favour or impede the diffusion of organic farming through dynamic implicit networks of similarity and credibility. We confirm the great importance of demographic changes in farm characteristics. Full Article Article
model Phase Transition in the Social Impact Model of Opinion Formation in Scale-Free Networks: The Social Power Effect By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:53:00 +0000 Alireza Mansouri and Fattaneh Taghiyareh: Human interactions and opinion exchanges lead to social opinion dynamics, which is well described by opinion formation models. In these models, a random parameter is usually considered as the system noise, indicating the individual's inexplicable opinion changes. This noise could be an indicator of any other influential factors, such as public media, affects, and emotions. We study phase transitions, changes from one social phase to another, for various noise levels in a discrete opinion formation model based on the social impact theory with a scale-free random network as its interaction network topology. We also generate another similar model using the concept of social power based on the agents' node degrees in the interaction network as an estimation for their persuasiveness and supportiveness strengths and compare both models from phase transition viewpoint. We show by agent-based simulation and analytical considerations how opinion phases, including majority and non-majority, are formed in terms of the initial population of agents in opinion groups and noise levels. Two factors affect the system phase in equilibrium when the noise level increases: breaking up more segregated groups and dominance of stochastic behavior of the agents on their deterministic behavior. In the high enough noise levels, the system reaches a non-majority phase in equilibrium, regardless of the initial combination of opinion groups. In relatively low noise levels, the original model and the model whose agents' strengths are proportional to their centrality have different behaviors. The presence of a few high-connected influential leaders in the latter model consequences a different behavior in reaching equilibrium phase and different thresholds of noise levels for phase transitions. Full Article Article
model Metamodels for Evaluating, Calibrating and Applying Agent-Based Models: A Review By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:54:00 +0000 Bruno Pietzsch, Sebastian Fiedler, Kai G. Mertens, Markus Richter, Cédric Scherer, Kirana Widyastuti, Marie-Christin Wimmler, Liubov Zakharova and Uta Berger: The recent advancement of agent-based modeling is characterized by higher demands on the parameterization, evaluation and documentation of these computationally expensive models. Accordingly, there is also a growing request for "easy to go" applications just mimicking the input-output behavior of such models. Metamodels are being increasingly used for these tasks. In this paper, we provide an overview of common metamodel types and the purposes of their usage in an agent-based modeling context. To guide modelers in the selection and application of metamodels for their own needs, we further assessed their implementation effort and performance. We performed a literature research in January 2019 using four different databases. Five different terms paraphrasing metamodels (approximation, emulator, meta-model, metamodel and surrogate) were used to capture the whole range of relevant literature in all disciplines. All metamodel applications found were then categorized into specific metamodel types and rated by different junior and senior researches from varying disciplines (including forest sciences, landscape ecology, or economics) regarding the implementation effort and performance. Specifically, we captured the metamodel performance according to (i) the consideration of uncertainties, (ii) the suitability assessment provided by the authors for the particular purpose, and (iii) the number of valuation criteria provided for suitability assessment. We selected 40 distinct metamodel applications from studies published in peer-reviewed journals from 2005 to 2019. These were used for the sensitivity analysis, calibration and upscaling of agent-based models, as well to mimic their prediction for different scenarios. This review provides information about the most applicable metamodel types for each purpose and forms a first guidance for the implementation and validation of metamodels for agent-based models. Full Article Article
model Emergence of Small-World Networks in an Overlapping-Generations Model of Social Dynamics, Trust and Economic Performance By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:55:00 +0000 Katarzyna Growiec, Jakub Growiec and Bogumił Kamiński: We study the impact of endogenous creation and destruction of social ties in an artificial society on aggregate outcomes such as generalized trust, willingness to cooperate, social utility and economic performance. To this end we put forward a computational multi-agent model where agents of overlapping generations interact in a dynamically evolving social network. In the model, four distinct dimensions of individuals’ social capital: degree, centrality, heterophilous and homophilous interactions, determine their generalized trust and willingness to cooperate, altogether helping them achieve certain levels of social utility (i.e., utility from social contacts) and economic performance. We find that the stationary state of the simulated social network exhibits realistic small-world topology. We also observe that societies whose social networks are relatively frequently reconfigured, display relatively higher generalized trust, willingness to cooperate, and economic performance – at the cost of lower social utility. Similar outcomes are found for societies where social tie dissolution is relatively weakly linked to family closeness. Full Article Article
model Homophily as a Process Generating Social Networks: Insights from Social Distance Attachment Model By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:56:00 +0000 Szymon Talaga and Andrzej Nowak: Real-world social networks often exhibit high levels of clustering, positive degree assortativity, short average path lengths (small-world property) and right-skewed but rarely power law degree distributions. On the other hand homophily, defined as the propensity of similar agents to connect to each other, is one of the most fundamental social processes observed in many human and animal societies. In this paper we examine the extent to which homophily is sufficient to produce the typical structural properties of social networks. To do so, we conduct a simulation study based on the Social Distance Attachment (SDA) model, a particular kind of Random Geometric Graph (RGG), in which nodes are embedded in a social space and connection probabilities depend functionally on distances between nodes. We derive the form of the model from first principles based on existing analytical results and argue that the mathematical construction of RGGs corresponds directly to the homophily principle, so they provide a good model for it. We find that homophily, especially when combined with a random edge rewiring, is sufficient to reproduce many of the characteristic features of social networks. Additionally, we devise a hybrid model combining SDA with the configuration model that allows generating homophilic networks with arbitrary degree sequences and we use it to study interactions of homophily with processes imposing constraints on degree distributions. We show that the effects of homophily on clustering are robust with respect to distribution constraints, while degree assortativity can be highly dependent on the particular kind of enforced degree sequence. Full Article Article
model A Dynamic Computational Model of Social Stigma By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:57:00 +0000 Myong-Hun Chang and Joseph Harrington: The dynamics of social stigma are explored in the context of diffusion models. Our focus is on exploring the dynamic process through which the behavior of individuals and the interpersonal relationships among them influence the macro-social attitude towards the stigma. We find that a norm of tolerance is best promoted when the population comprises both those whose conduct is driven by compassion for the stigmatized and those whose focus is on conforming with others in their social networks. A second finding is that less insular social networks encourage de-stigmatization when most people are compassionate, but it is instead more insularity that promotes tolerance when society is dominated by conformity. Full Article Article
model The ODD Protocol for Describing Agent-Based and Other Simulation Models: A Second Update to Improve Clarity, Replication, and Structural Realism By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:58:00 +0000 Volker Grimm, Steven F. Railsback, Christian E. Vincenot, Uta Berger, Cara Gallagher, Donald L. DeAngelis, Bruce Edmonds, Jiaqi Ge, Jarl Giske, Jürgen Groeneveld, Alice S.A. Johnston, Alexander Milles, Jacob Nabe-Nielsen, J. Gareth Polhill, Viktoriia Radchuk, Marie-Sophie Rohwäder, Richard A. Stillman, Jan C. Thiele and Daniel Ayllón: The Overview, Design concepts and Details (ODD) protocol for describing Individual- and Agent-Based Models (ABMs) is now widely accepted and used to document such models in journal articles. As a standardized document for providing a consistent, logical and readable account of the structure and dynamics of ABMs, some research groups also find it useful as a workflow for model design. Even so, there are still limitations to ODD that obstruct its more widespread adoption. Such limitations are discussed and addressed in this paper: the limited availability of guidance on how to use ODD; the length of ODD documents; limitations of ODD for highly complex models; lack of sufficient details of many ODDs to enable reimplementation without access to the model code; and the lack of provision for sections in the document structure covering model design rationale, the model’s underlying narrative, and the means by which the model’s fitness for purpose is evaluated. We document the steps we have taken to provide better guidance on: structuring complex ODDs and an ODD summary for inclusion in a journal article (with full details in supplementary material; Table 1); using ODD to point readers to relevant sections of the model code; update the document structure to include sections on model rationale and evaluation. We also further advocate the need for standard descriptions of simulation experiments and argue that ODD can in principle be used for any type of simulation model. Thereby ODD would provide a lingua franca for simulation modelling. Full Article Article
model Computational Models That Matter During a Global Pandemic Outbreak: A Call to Action By jasss.soc.surrey.ac.uk Published On :: Wed, 01 Apr 2020 12:59:00 +0000 Flaminio Squazzoni, J. Gareth Polhill, Bruce Edmonds, Petra Ahrweiler, Patrycja Antosz, Geeske Scholz, Émile Chappin, Melania Borit, Harko Verhagen, Francesca Giardini and Nigel Gilbert: The COVID-19 pandemic is causing a dramatic loss of lives worldwide, challenging the sustainability of our health care systems, threatening economic meltdown, and putting pressure on the mental health of individuals (due to social distancing and lock-down measures). The pandemic is also posing severe challenges to the scientific community, with scholars under pressure to respond to policymakers’ demands for advice despite the absence of adequate, trusted data. Understanding the pandemic requires fine-grained data representing specific local conditions and the social reactions of individuals. While experts have built simulation models to estimate disease trajectories that may be enough to guide decision-makers to formulate policy measures to limit the epidemic, they do not cover the full behavioural and social complexity of societies under pandemic crisis. Modelling that has such a large potential impact upon people’s lives is a great responsibility. This paper calls on the scientific community to improve the transparency, access, and rigour of their models. It also calls on stakeholders to improve the rapidity with which data from trusted sources are released to the community (in a fully responsible manner). Responding to the pandemic is a stress test of our collaborative capacity and the social/economic value of research. Full Article Article
model Emerging models: Small firms giving up office space to save rent By www.financialexpress.com Published On :: 2020-04-27T05:30:00+05:30 Given the Indian economy could well contract in 2020-21,following the disruption to the pandemic, even bigger companies might enourage some employees to work from home. For small businesses there might be no other option. Full Article Industry
model Kerala Model: Weekend mobile, TV shops thrive but supply a constraint By www.financialexpress.com Published On :: 2020-04-29T01:30:00+05:30 The concern is genuine as new hotspots are emerging in districts like Idukki and Kottayam that were earlier in the green zone and considered safe. Full Article Industry
model Creating a Marketing Mix Model for a Better Marketing Budget: Analytics Corner By feedproxy.google.com Published On :: Tue, 22 May 2018 11:00:00 GMT Using R programming, marketers can create a marketing mix model to determine how sustainable their audience channels are, and make better ad spend decisions. Here's how Full Article
model Mini Cooper BS6 models listed on website: Why 5-door and Clubman are missing By www.financialexpress.com Published On :: 2020-04-23T18:32:00+05:30 Only the Countryman now is available with a diesel engine in India while all other models come with the familiar 2.0-litre petrol motor. Full Article
model Mini rushes to change ‘Corona Spoke’ wheel design name for electric model: Now called this! By www.financialexpress.com Published On :: 2020-04-24T13:47:45+05:30 The Mini Cooper SE made its debut last year with a funky wheel design which they then called the ‘Corona Spoke’, which has turned out to be somewhat inappropriate in recent times. Full Article
model Honda Cars launches online booking portal for all models amid lockdown with Honda from Home initiative By www.financialexpress.com Published On :: 2020-04-27T14:00:00+05:30 As the nation continues to be under lockdown due to the coronavirus pandemic. Honda cars India has launched an online portal for prospective customers who can book their Honda model of their choosing sitting at home, safe from COVID-19. Full Article
model SAS Customer Intelligence 360: Unified data model, marketing attribution and AutoML By feedproxy.google.com Published On :: Thu, 26 Mar 2020 12:00:15 +0000 Excitement levels are high for the March 2020 release of SAS Customer Intelligence 360, which includes multiple years of research and development culminating in enhancements to the platform's underlying data model. The changes will introduce the unification of a comprehensive data model recording both: Customer behavior -- what users are [...] SAS Customer Intelligence 360: Unified data model, marketing attribution and AutoML was published on Customer Intelligence Blog. Full Article Uncategorized AI analytic base tables machine learning interpretability marketing analytics predictive analytics
model Tutorial: Character Modeling for 3D Applications By feedproxy.google.com Published On :: 2018-09-25T13:06:00+05:30 Introduction Character modeling is the process of creating a character within the 3D space of computer programs. The techniques for character modeling are essential for third - and first - person e... Full Article
model FICCI panel seeks relief based on Dutch-model wage subsidy By www.financialexpress.com Published On :: 2020-04-15T00:01:00+05:30 The letter has urged, mainly for wage subsidy to large employers, on the lines of the Netherlands and Australia . Full Article Economy
model Highway projects: Infrastructure panel wants HAM curtailed, favours BOT model; here’s why By www.financialexpress.com Published On :: 2020-05-05T14:38:00+05:30 The Hybrid Annuity Model (HAM) for highway projects that insulates private developers from virtually any commercial risks, is putting stress on the highly-leveraged balance sheet of the National Highways Authority of India (NHAI), and should therefore be ‘downplayed’. Full Article Infrastructure Roadways
model This Volkswagen first model to celebrate world premiere at Frankfurt Motor Show By www.financialexpress.com Published On :: 2019-08-31T02:26:31+05:30 The ID.3 is the first fully electric model based on the new MEB platform Full Article Industry
model BS-VI TVS Apache RTR 160 4V explained in images: New features & price compared to BS-IV model By www.financialexpress.com Published On :: 2019-12-11T16:02:00+05:30 Full Article
model Polestar Precept Concept Gallery: See the upcoming Tesla Model S and Porsche Taycan rival in detail By www.financialexpress.com Published On :: 2020-04-09T15:21:00+05:30 Full Article
model Why Ops-ing is in (DevOps, ModelOps, DataOps) By feedproxy.google.com Published On :: Thu, 27 Feb 2020 18:31:48 +0000 Jim Harris explains the relevance of DevOps, DataOps and ModelOps for data analytics practitioners. The post Why Ops-ing is in (DevOps, ModelOps, DataOps) appeared first on The Data Roundtable. Full Article Uncategorized dataops DevOps ModelOps operationalizing analytics
model ‘Disciplined’ northeast emerges as model of COVID-19 management: Jitendra Singh By www.financialexpress.com Published On :: 2020-05-09T14:57:00+05:30 He said within six years of the Modi government, the northeastern region has emerged as the model for development for the entire country. Full Article Health Lifestyle
model Displaying contents of a modeless dialog box during execution of a SKILL script By feedproxy.google.com Published On :: Tue, 05 May 2020 00:47:02 GMT I have a modeless informational dialog box defined at the beginning of a SKILL script, but its contents don't display until the script finishes. How do you get a modeless dialog box contents to display while a SKILL script is running? procedure(myproc() prog((myvars) hiDisplayAppDBox() ; opens blank dialog box - no dboxText contents show until script completes! ....rest of SKILL code in script...launches child processes );prog );proc Full Article
model Generating IBIS models in cadence virtuoso By feedproxy.google.com Published On :: Wed, 04 Sep 2019 20:25:36 GMT I'm trying to generate IBIS models for the parts that I'm designing. I'm designing using CADENCE Virtuoso. I'm wondering if there is a tutorial for generating IBIS models in CADENCE Virtuoso. Please pardon me if my question is broad. Full Article
model IC Packagers: Shape Connectivity in the Allegro Data Model By community.cadence.com Published On :: Tue, 28 Apr 2020 13:14:00 GMT Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain... [[ Click on the title to access the full blog on the Cadence Community site. ]] Full Article
model How to install PLL Macro Model Wizard? By feedproxy.google.com Published On :: Tue, 10 Mar 2020 04:13:35 GMT Hello, I am using virtuoso version IC 6.1.7-64b.500.1, and I am trying to follow the Spectre RF Workshop-Noise-Aware PLL Design Flow(MMSIM 7.1.1) pdf. I could find the workshop library "pllMMLib", but I cannot find PLL Macro Model Wizard, and I attached my screen. Could you please help me install the module "PLL Macro Model Wizard"? Thanks a lot! Full Article
model Looking for ADVFC32 SPICE Model By feedproxy.google.com Published On :: Mon, 16 Mar 2020 13:56:51 GMT I'm working on a circuit that requires the input voltage to be converted to a frequency, transmitted over an optical cable, and then converted back to a voltage. I am attempting to simulate this circuit using Eagle ngSpice simulations. The voltage to frequency converters that I am using are ADVFC32 and made by Analog Devices. However, I can't seem to find a SPICE model for this component. Analog Devices does not provide it on their website. Can anyone find a SPICE Model for this part? I'm new to working with electronics so any help/advice you can provide would be appreciated. Full Article
model Design of DC motor model By feedproxy.google.com Published On :: Tue, 21 Jan 2020 07:32:56 GMT Hi I want develope basic circuit of DC motor which consist of resistor, inductor and back emf in capture and check its simulation in pspice, for reference I have attached image and link. https://www.precisionmicrodrives.com/content/ab-025-using-spice-to-model-dc-motors/ . Full Article
model IC Packagers: Shape Connectivity in the Allegro Data Model By feedproxy.google.com Published On :: Tue, 28 Apr 2020 13:14:00 GMT Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain (any-angle routing, filled planes, and a multitude of pad ...(read more) Full Article Allegro Package Designer Allegro PCB Editor
model Is it possible to find or create a Pspice model for the JT3028, LD7552 components? By feedproxy.google.com Published On :: Fri, 01 May 2020 21:35:59 GMT I would like to add these components to the component bank in ORCAD simulation. Even an accessible or free course that explained how to create these components. Full Article
model how to add section info to extsim_model_include? By feedproxy.google.com Published On :: Wed, 22 Apr 2020 22:12:45 GMT i had encountered error message like this before. but in liberate, i did not find the entry to input section info. Full Article
model Simulating IBIS Model using Spectre By feedproxy.google.com Published On :: Thu, 30 Apr 2020 23:17:12 GMT I have a question regarding simulating IBIS model using Spectre. IBIS model generation always has the die capacitance included and in the generated IBIS file you will have this value as “C_comp” value. Does the Spectre accounts for this capacitance from the IBIS file while computing the time domain voltage waveform during simulation ? If I add additional capacitance outside in the testbench, to model the die capacitance, then it will be double counting. Does anyone know if Spectre is already accounting this C_comp during the time domain voltage wave computation from IBIS file, during simulation ? Full Article
model Importing a capacitor interactive model from manufacturer By feedproxy.google.com Published On :: Mon, 04 May 2020 08:51:16 GMT Hello, I am trying to import (in spectre) an spice model of a ceramic capacitor manufactured by Samsung EM. The link that includes the model is here :- http://weblib.samsungsem.com/mlcc/mlcc-ec.do?partNumber=CL05A156MR6NWR They proved static spice model and interactive spice model. I had no problem while including the static model. However, the interactive model which models voltage and temperature coefficients seems to not be an ordinary spice model. They provide HSPICE, LTSPICE, and PSPICE model files and I failed to include any of them. Any suggestions ? Full Article
model Ultrasim does not converge with BSIMBULK model By feedproxy.google.com Published On :: Tue, 05 May 2020 09:16:51 GMT Hello, I am using ultrasim Version 18.1.0.314.isr5 64bit 03/26/2019 06:33 (csvcm20c-2). When I run my netlist, ultrasim is blocked in the first DC stage and takes forever. Then it will fail or never progress. I am using a 22nm BSIMBULK model. I tried to tune different accuracy and convergence aids options but noting works. When I run the same netlist with spectre it works fine with no problem. Also, If I use another model (not BULKSIM), ultrasim will work and converge with no problem. My first feeling is that ultrasim has a problem with using BSIMBULK model. Could you please advice, Thank you, Kotb Full Article
model Is there a simple way of converting a schematic to an s-parameter model? By feedproxy.google.com Published On :: Fri, 08 May 2020 20:06:07 GMT Before I ask this, I am aware that I can output an s-parameter file from an SP analysis. I'm wondering if there is a simple way of creating an s-parameter model of a component. As an example, if I have an S-parameter model that has 200 ports and 150 of those ports are to be connected to passive components and the remaining 50 ports are to be connected to active components, I can simplify the model by connecting the 150 passive components, running an SP analysis, and generating a 50 port S-parameter file. The problem is that this is cumbersome. You've got to wire up 50 PORT components and then after generating the s50p file, create a new cellview with an nport component and connect the 50 ports with 50 new pins. Wiring up all of those port components takes quite a lot of time to do, especially as the "choosing analyses" form adds arrays in reverse (e.g. if you click on an array of PORT components called X<0:2> it will add X<2>, X<1>, X<0> instead of in ascending order) so you have to add all of them to the analyses form manually. Is any way of taking a schematic and running some magic "generate S-Parameter cellview from schematic cellview" function that automates the whole process? Full Article
model The Elephant in the Room: Mixed-Signal Models By feedproxy.google.com Published On :: Wed, 05 Nov 2014 11:45:00 GMT Key Findings: Nearly 100% of SoCs are mixed-signal to some extent. Every one of these could benefit from the use of a metrics-driven unified verification methodology for mixed-signal (MD-UVM-MS), but the modeling step is the biggest hurdle to overcome. Without the magical models, the process breaks down for lack of performance, or holes in the chip verification. In the last installment of The Low Road, we were at the mixed-signal verification party. While no one talked about it, we all saw it: The party was raging and everyone was having a great time, but they were all dancing around that big elephant right in the middle of the room. For mixed-signal verification, that elephant is named Modeling. To get to a fully verified SoC, the analog portions of the design have to run orders of magnitude faster than the speediest SPICE engine available. That means an abstraction of the behavior must be created. It puts a lot of people off when you tell them they have to do something extra to get done with something sooner. Guess what, it couldn’t be more true. If you want to keep dancing around like the elephant isn’t there, then enjoy your day. If you want to see about clearing the pachyderm from the dance floor, you’ll want to read on a little more…. Figure 1: The elephant in the room: who’s going to create the model? Whose job is it? Modeling analog/mixed-signal behavior for use in SoC verification seems like the ultimate hot potato. The analog team that creates the IP blocks says it doesn't have the expertise in digital verification to create a high-performance model. The digital designers say they don’t understand anything but ones and zeroes. The verification team, usually digitally-centric by background, are stuck in the middle (and have historically said “I just use the collateral from the design teams to do my job; I don’t create it”). If there is an SoC verification team, then ensuring that the entire chip is verified ultimately rests upon their shoulders, whether or not they get all of the models they need from the various design teams for the project. That means that if a chip does not work because of a modeling error, it ought to point back to the verification team. If not, is it just a “systemic error” not accounted for in the methodology? That seems like a bad answer. That all makes the most valuable guy in the room the engineer, whose knowledge spans the three worlds of analog, digital, and verification. There are a growing number of “mixed-signal verification engineers” found on SoC verification teams. Having a specialist appears to be the best approach to getting the job done, and done right. So, my vote is for the verification team to step up and incorporate the expertise required to do a complete job of SoC verification, analog included. (I know my popularity probably did not soar with the attendees of DVCON with that statement, but the job has to get done). It’s a game of trade-offs The difference in computations required for continuous time versus discrete time behavior is orders of magnitude (as seen in Figure 2 below). The essential detail versus runtime tradeoff is a key enabler of verification techniques like software-driven testbenches. Abstraction is a lossy process, so care must be taken to fully understand the loss and test those elements in the appropriate domain (continuous time, frequency, etc.). Figure 2: Modeling is required for performance AFE for instance The traditional separation of baseband and analog front-end (AFE) chips has shifted for the past several years. Advances in process technology, analog-to-digital converters, and the desire for cost reduction have driven both a re-architecting and re-partitioning of the long-standing baseband/AFE solution. By moving more digital processing to the AFE, lower cost architectures can be created, as well as reducing those 130 or so PCB traces between the chips. There is lots of good scholarly work from a few years back on this subject, such as Digital Compensation of Dynamic Acquisition Errors at the Front-End of ADCS and Digital Compensation for Analog Front-Ends: A New Approach to Wireless Transceiver Design. Figure 3: AFE evolution from first reference (Parastoo) The digital calibration and compensation can be achieved by the introduction of a programmable solution. This is in fact the most popular approach amongst the mobile crowd today. By using a microcontroller, the software algorithms become adaptable to process-related issues and modifications to protocol standards. However, for the SoC verification team, their job just got a whole lot harder. To determine if the interplay of the digital control and the analog function is working correctly, the software algorithms must be simulated on the combination of the two. That is, here is a classic case of inseparable mixed-signal verification. So, what needs to be in the model is the big question. And the answer is, a lot. For this example, the main sources of dynamic error at the front-end of ADCs are critical for the non-linear digital filtering that is highly frequency dependent. The correction scheme must be verified to show that the nonlinearities are cancelled across the entire bandwidth of the ADC. This all means lots of simulation. It means that the right level of detail must be retained to ensure the integrity of the verification process. This means that domain experience must be added to the list of expertise of that mixed-signal verification engineer. Back to the pachyderm There is a lot more to say on this subject, and lots will be said in future posts. The important starting point is the recognition that the potential flaw in the system needs to be examined. It needs to be examined by a specialist. Maybe a second opinion from the application domain is needed too. So, put that cute little elephant on your desk as a reminder that the beast can be tamed. Steve Carlson Related stories - It’s Late, But the Party is Just Getting Started Full Article metrics-driven methodology real number modeling uvm CPF RNM UPF mixed signal MDV verification
model Take Advantage of Advancements in Real Number Modeling and Simulation By feedproxy.google.com Published On :: Mon, 26 Feb 2018 23:00:00 GMT Verification is the top challenge in mixed-signal design. Bringing analog and digital domains together into unified verification planning, simulating, and debugging is a challenging task for rapidly increasing size and complexity of mixed-signal designs. To more completely verify functionality and performance of a mixed-signal SoC and its AMS IP blocks used to build it, verification teams use simulations at transistor, analog behavioral and real-number model (RNM) and RTL levels, and combination of these. In recent years, RNM and simulation is being adopted for functional verification by many, due to advantages it offers including simpler modeling requirements and much faster simulation speed (compared to a traditional analog behavioral models like Verilog-A or VHDL-AMS). Verilog-AMS with its wreal continue to be popular choice. Standardization of real number extensions in SystemVerilog (SV) made SV-RNM an even more attractive choice for MS SoC verification. Verilog-AMS/wreal is scalar real type. SV-RNM offers a powerful ability to define complex data types, providing a user-defined structure (record) to describe the net value. In a typical design, most analog nodes can be modeled using a single value for passing a voltage (or current) from one module to another. The ability to pass multiple values over a net can be very powerful when, for example, the impedance load impact on an analog signal needs to be modeled. Here is an example of a user-defined net (UDN) structure that holds voltage, current, and resistance values: When there are multiple drives on a single net, the simulator will need a resolution function to determine the final net value. When the net is just defined as a single real value, common resolution functions such as min, max, average, and sum are built into the simulator. But definition of more complex structures for the net also requires the user to provide appropriate resolution functions for them. Here is an example of a net with three drivers modeled using the above defined structural elements (a voltage source with series resistance, a resistive load, and a current source): To properly solve for the resulting output voltage, the resolution function for this net needs to perform Norton conversion of the elements, sum their currents and conductances, and then calculate the resolved output voltage as the sum of currents divided by sum of conductances. With some basic understanding of circuit theory, engineers can use SV-RNM UDN capability to model electrical behavior of many different circuits. While it is primarily defined to describe source/load impedance interactions, its use can be extended to include systems including capacitors, switching circuits, RC interconnect, charge pumps, power regulators, and others. Although this approach extends the scope of functional verification, it is not a replacement for transistor-level simulation when accuracy, performance verification, or silicon correlation are required: It simply provides an efficient solution for discretely modeling small analog networks (one to several nodes). Mixed-signal simulation with an analog solver is still the best solution when large nonlinear networks must be evaluated. Cadence provides a tutorial on EEnet usage as well as the package (EEnet.pkg) with UDN definitions and resolution functions and modeling examples. To learn more, please login to your Cadence account to access the tutorial. Full Article real number modeling analog Mixed-Signal RNM mixed-signal verification
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model Engineering Possibilities Versus Practical Implementation: Utility Portfolios and Business Models By feedproxy.google.com Published On :: 2015-04-30T11:40:00Z Europe’s utilities are re-evaluating their business models due to the energy transition. Members of POWER-GEN Europe’s Advisory Board consider how a reliance on fossil fuels is no longer politically desirable, forcing utilities to transform their portfolios to adapt to radical change. Full Article Microgrids Energy Efficiency Hydropower Baseload Storage Energy Efficiency Bioenergy Wind Power Solar Project Development Geothermal
model The Perfect Model of a Spirit-Empowered Life (Galatians 5:16–26) By feeds.gty.org Published On :: Sun, 15 Apr 2018 00:00:00 Check here each week to keep up with the latest from John MacArthur's pulpit at Grace Community Church. Full Article Galatians
model FCA consultation paper on discretionary commission models and commission disclosure By www.eversheds.com Published On :: 2019-10-24 1. FCA Final Report on Motor Finance In March 2019, the FCA published its Final Report on motor finance. Our briefing note on the Final Report can be found Full Article
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model Hyundai Motor Set to Develop Pickup Truck Model Aiming at U.S. Market By english.hankyung.com Published On :: 2017-08-24 07:55 Hyundai Motor is currently in the works to develop a pickup truck model for the U.S. market. Michael O'Brien, vice president in charge of product planning for Hyundai Motor America, said on August 22 in a press conference, "The top management approved a project to develop a pickup truck model." Pickup trucks are highly popular in the United States. There is only one pickup truck model available in Korea, which is Ssangyong Motor's Korando Sports.Hyundai Motor unveiled a pickup truck concept mode... Full Article
model Ghana’s Abedi, Nigeria’s Okocha and Liberia’s Weah picked as ultimate role models By article.wn.com Published On :: Sat, 09 May 2020 15:36 GMT The African football legends provided inspiration for many during their playing days ...... Full Article