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  • ✇Semiconductor Engineering
  • AI For Data ManagementAdam Kovac
    Data management is becoming a significant new challenge for the chip industry, as well as a brand new opportunity, as the amount of data collected at every step of design through manufacturing continues to grow. Exacerbating the problem is the rising complexity of designs, many of which are highly customized and domain-specific at the leading edge, as well as increasing demands for reliability and traceability. There also is a growing focus on chiplets developed using different processes, includ
     

AI For Data Management

30. Květen 2024 v 09:03

Data management is becoming a significant new challenge for the chip industry, as well as a brand new opportunity, as the amount of data collected at every step of design through manufacturing continues to grow.

Exacerbating the problem is the rising complexity of designs, many of which are highly customized and domain-specific at the leading edge, as well as increasing demands for reliability and traceability. There also is a growing focus on chiplets developed using different processes, including some from different foundries, and new materials such as glass substrates and ruthenium interconnects. On the design side, EDA and verification tools can generate terabytes of data on a weekly or even a daily basis, unlike in the past when this was largely done on a per-project basis.

While more data can be used to provide insights into processes and enable better designs, it’s an ongoing challenge to manage the current volumes being generated. The entire industry must rethink some well-proven methodologies and processes, as well as invest in a variety of new tools and approaches. At the same time, these changes are generating concern in an industry used to proceeding cautiously, one step at a time, based on silicon- and field-proven strategies. Increasingly, AI/ML is being added into design tools to identify anomalies and patterns in large data sets, and many of those tools are being regularly updated as algorithms are updated and new features are added, making it difficult to know exactly when and where to invest, which data to focus on, and with whom to share it.

“Every company has its own design flow, and almost every company has its own methodology around harvesting that data, or best practices about what reports should or should not be written out at what point,” said Rob Knoth, product management director in Cadence’s Digital & Signoff group. “There’s a death by 1,000 cuts that can happen in terms of just generating titanic volumes of data because, in general, disk space is cheap. People don’t think about it a lot, and they’ll just keep generating reports. The problem is that just because you’re generating reports doesn’t mean you’re using them.”

Fig. 1: Rising design complexity is driving increased need for data management. Source: IEEE Rising Stars 2022/Cadence

As with any problem in chip design, there is opportunity in figuring out a path forward. “You can always just not use the data, and then you’re back where you started,” said Tony Chan Carusone, CTO at Alphawave Semi. “The reason it becomes a problem for organizations is because they haven’t architected things from the beginning to be scalable, and therefore, to be able to handle all this data. Now, there’s an opportunity to leverage data, and it’s a different way. So it’s disruptive because you have to tear things apart, from re-architecting systems and processes to how you collect and store data, and organize it in order to take advantage of the opportunity.”

Buckets of data, buckets of problems
The challenges that come with this influx of data can be divided into three buckets, said Jim Schultz, senior staff product manager at Synopsys. The first is figuring out what information is actually critical to keep. “If you make a run, designers tend to save that run because if they need to do a follow up run, they have some data there and they may go, ‘Okay, well, what’s the runtime? How long did that run take, because my manager is going to ask me what I think the runtime is going to be on the next project or the next iteration of the block. While that data may not be necessary, designers and engineers have a tendency to hang onto it anyway, just in case.”

The second challenge is that once the data starts to pour in, it doesn’t stop, raising questions about how to manage collection. And third, once the data is collected, how can it be put to best use?

“Data analytics have been around with other types of companies exploring different types of data analytics, but the differences are those are can be very generic solutions,” said Schultz. “What we need for our industry is going to be very specific data analytics. If I have a timing issue, I want you to help me pinpoint what the cause of that timing violation is. That’s very specific to what we do in EDA. When we talk about who is cutting through the noise, we don’t want data that’s just presented. We want the data that is what the designer most cares about.”

Data security
The sheer number of tools being used and companies and people involved along the design pathway raises another challenge — security.

“There’s a lot of thought and investment going into the security aspect of data, and just as much as the problem of what data to save and store is the type of security we have to have without hindering the user day-to-day,” said Simon Rance, director of product management at Keysight. “That’s becoming a bigger challenge. Things like the CHIPS Act and the geopolitical scenarios we have at the moment are compounding that problem because a lot of the companies that used to create all these devices by themselves are having to collaborate, even with companies in different regions of the globe.”

This requires a balancing act. “It’s almost like a recording studio where you have all these knobs and dials to fine tune it, to make sure we have security of the data,” said Rance. “But we’re also able to get the job done as smoothly and as easily as we can.”

Further complicating the security aspect is that designing chips is not a one-man job. As leading-edge chips become increasingly complex and heterogeneous, they can involve hundreds of people in multiple companies.

“An important thing to consider when you’re talking about big data and analytics is what you’re going to share and with whom you’re going to share it,” said Synopsys’ Schultz. “In particular, when you start bringing in and linking data from different sources, if you start bringing in data related to silicon performance, you don’t want everybody to have access to that data. So the whole security protocol is important.”

Even the mundane matters — having a ton of data makes it likely, at some point, that data will be moved.

“The more places the data has to be transferred to, the more delays,” said Rance. “The bigger the data set, the longer it takes to go from A to B. For example, a design team in the U.S. may be designing during the day. Then, another team in Singapore or Japan will pick up on that design in their time zone, but they’re across the world. So you’re going to have to sync the data back and forth between these kinds of design sites. The bigger the data, the harder to sync.”

Solutions
The first step toward solving the issue of too much data is figuring out what data is actually needed. Rance said his team has found success using smart algorithms that help figure out which data is essential, which in turn can help optimize storage and transfer times.

There are less technical problems that can rear their heads, as well. Gina Jacobs, head of global communications and brand marketing at Arteris, said that engineers who use a set methodology — particularly those who are used to working on a problem by themselves and “brute forcing” a solution – also can find themselves overwhelmed by data.

“Engineers and designers can also switch jobs, taking with them institutional knowledge,” Jacobs said. “But all three problems can be solved with a single solution — having data stored in a standardized way that is easily accessible and sortable. It’s about taking data and requirements and specifications in different forms and then having it in the one place so that the different teams have access to it, and then being able to make changes so there is a single source of truth.”

Here, EDA design and data management tools are increasingly relying on artificial intelligence to help. Schultz forecasted a future where generative AI will touch every facet of chip development. “Along with that is the advanced data analytics that is able to mine all of that data you’ve been collecting, instead of going beyond the simple things that people have been doing, like predicting how long runtime is going to be or getting an idea what the performance is going to be,” he said. “Tools are going to be able to deal with all of that data and recognize trends much faster.”

Still, those all-encompassing AI tools, capable of complex analysis, are still years away. Cadence’s Knoth said he’s already encountered clients that are reluctant to bring it into the mix due to fears over the costs involved in disk space, compute resources, and licenses. Others, however, have been a bit more open-minded.

“Initially, AI can use a lot of processors to generate a lot of data because it’s doing a lot of things in parallel when it’s doing the inferencing, but it usually gets to the result faster and more predictably,” he said. So while a machine learning algorithm may generate even more vast amounts of data, on top of the piles currently available, “a good machine learning algorithm could be watching and smartly killing or restarting jobs where needed.”

As for the humans who are still an essential component to chip design, Alphawave’s Carusone said hardware engineers should take a page from lessons learned years ago from their counterparts in the software development world.

These include:

  • Having an organized and automated way to collect data, file it in a repository, and not do anything manually;
  • Developing ways to run verification and lab testing and everything in between in parallel, but with the data organized in a way that can be mined; and
  • Creating methods for rigorously checking in and out of different test cases that you want to consider.

“The big thing is you’ve got all this data collected, but then what is each of each of those files, each of those collections of data?” said Carusone. “What does that correspond to? What test conditions was that collected in? The software community dealt with that a while ago, and the hardware community also needs to have this under its belt, taking it to the next level and recognizing we really need to be able to do this en masse. We need to be able to have dozens of people work in parallel, collecting data and have it all on there. We can test a big collection of our designs in the lab without anyone having to touch a thing, and then also try refinements of the firmware, scale them out, then have all the data come in and be analyzed. Being able to have all that done in an automated way lets you track down and fix problems a lot more quickly.”

Conclusion
The influx of new tools used to analyze and test chip designs has increased productivity, but those designs come with additional considerations. Institutions and individual engineers and designers have never had access to so much data, but that data is of limited value if it’s not used effectively.

Strategies to properly store and order that data are essential. Some powerful tools are already in place to help do that, and the AI revolution promises to make even more powerful resources available to quickly cut down on the time needed to run tests and analyze the results.

For now, handling all that data remains a tricky balance, according to Cadence’s Knoth. “If this was an easy problem, it wouldn’t be a problem. Being able to communicate effectively, hierarchically — not just from a people management perspective, but also hierarchically from a chip and project management perspective — is difficult. The teams that do this well invest resources into that process, specifically the communication of top-down tightening of budgets or top-down floorplan constraints. These are important to think about because every engineer is looking at chip-level timing reports, but the problem that they’re trying to solve might not ever be visible. But if they have a report that says, ‘Here is your view of what your problems are to solve,’ you can make some very effective work.”

Further Reading
EDA Pushes Deeper Into AI
AI is both evolutionary and revolutionary, making it difficult to assess where and how it will be used, and what problems may crop up.
Optimizing EDA Cloud Hardware And Workloads
Algorithms written for GPUs can slice simulation time from weeks to hours, but not everything is optimized or benefits equally.

The post AI For Data Management appeared first on Semiconductor Engineering.

  • ✇Semiconductor Engineering
  • Fundamental Issues In Computer Vision Still UnresolvedKaren Heyman
    Given computer vision’s place as the cornerstone of an increasing number of applications from ADAS to medical diagnosis and robotics, it is critical that its weak points be mitigated, such as the ability to identify corner cases or if algorithms are trained on shallow datasets. While well-known bloopers are often the result of human decisions, there are also fundamental technical issues that require further research. “Computer vision” and “machine vision” were once used nearly interchangeably, w
     

Fundamental Issues In Computer Vision Still Unresolved

2. Květen 2024 v 09:08

Given computer vision’s place as the cornerstone of an increasing number of applications from ADAS to medical diagnosis and robotics, it is critical that its weak points be mitigated, such as the ability to identify corner cases or if algorithms are trained on shallow datasets. While well-known bloopers are often the result of human decisions, there are also fundamental technical issues that require further research.

“Computer vision” and “machine vision” were once used nearly interchangeably, with machine vision most often referring to the hardware embodiment of vision, such as in robots. Computer vision (CV), which started as the academic amalgam of neuroscience and AI research, has now become the dominant idea and preferred term.

“In today’s world, even the robotics people now call it computer vision,” said Jay Pathak, director, software development at Ansys. “The classical computer vision that used to happen outside of deep learning has been completely superseded. In terms of the success of AI, computer vision has a proven track record. Anytime self-driving is involved, any kind of robot that is doing work — its ability to perceive and take action — that’s all driven by deep learning.”

The original intent of CV was to replicate the power and versatility of human vision. Because vision is such a basic sense, the problem seemed like it would be far easier than higher-order cognitive challenges, like playing chess. Indeed, in the canonical anecdote about the field’s initial naïve optimism, Marvin Minsky, co-founder of the MIT AI Lab, having forgotten to include a visual system in a robot, assigned the task to undergraduates. But instead of being quick to solve, the problem consumed a generation of researchers.

Both academic and industry researchers work on problems that roughly can be split into three categories:

  • Image capture: The realm of digital cameras and sensors. It may use AI for refinements or it may rely on established software and hardware.
  • Image classification/detection: A subset of AI/ML that uses image datasets as training material to build models for visual recognition.
  • Image generation: The most recent work, which uses tools like LLMs to create novel images, and with the breakthrough demonstration of OpenAI’s Sora, even photorealistic videos.

Each one alone has spawned dozens of PhD dissertations and industry patents. Image classification/detection, the primary focus of this article, underlies ADAS, as well as many inspection applications.

The change from lab projects to everyday uses came as researchers switched from rules-based systems that simulated visual processing as a series of if/then statements (if red and round, then apple) to neural networks (NNs), in which computers learned to derive salient features by training on image datasets. NNs are basically layered graphs. The earliest model, 1943’s Perceptron, was a one-layer simulation of a biological neuron, which is one element in a vast network of interconnecting brain cells. Neurons have inputs (dendrites) and outputs (axons), driven by electrical and chemical signaling. The Perceptron and its descendant neural networks emulated the form but skipped the chemistry, instead focusing on electrical signals with algorithms that weighted input values. Over the decades, researchers refined different forms of neural nets with vastly increased inputs and layers, eventually becoming the deep learning networks that underlie the current advances in AI.

The most recent forms of these network models are convolutional neural networks (CNNs) and transformers. In highly simplified terms, the primary difference between them is that CNNs are very good at distinguishing local features, while transformers perceive a more globalized picture.

Thus, transformers are a natural evolution from CNNs and recurrent neural networks, as well as long short-term memory approaches (RNNs/LSTMs), according to Gordon Cooper, product marketing manager for Synopsys’ embedded vision processor family.

“You get more accuracy at the expense of more computations and parameters. More data movement, therefore more power,” said Cooper. “But there are cases where accuracy is the most important metric for a computer vision application. Pedestrian detection comes to mind. While some vision designs still will be well served with CNNs, some of our customers have determined they are moving completely to transformers. Ten years ago, some embedded vision applications that used DSPs moved to NNs, but there remains a need for both NNs and DSPs in a vision system. Developers still need a good handle on both technologies and are better served to find a vendor that can provide a combined solution.”

The emergence of CNN-based neural networks began supplanting traditional CV techniques for object detection and recognition.

“While first implemented using hardwired CNN accelerator hardware blocks, many of those CNN techniques then quickly migrated to programmable solutions on software-driven NPUs and GPNPUs,” said Aman Sikka, chief architect at Quadric.

Two parallel trends continue to reshape CV systems. “The first is that transformer networks for object detection and recognition, with greater accuracy and usability than their convolution-based predecessors, are beginning to leave the theoretical labs and enter production service in devices,” Sikka explained. “The second is that CV experts are reinventing the classical ISP functions with NN and transformer-based models that offer superior results. Thus, we’ve seen waves of ISP functionality migrating first from pure hardwired to C++ algorithmic form, and now into advanced ML network formats, with a modern design today in 2024 consisting of numerous machine-learning models working together.”

CV for inspection
While CV is well-known for its essential role in ADAS, another primary application is inspection. CV has helped detect everything from cancer tumors to manufacturing errors, or in the case of IBM’s productized research, critical flaws in the built environment. For example, a drone equipped with the IBM system could check if a bridge had cracks, a far safer and more precise way to perform visual inspection than having a human climb to dangerous heights.

By combining visual transformers with self-supervised learning, the annotation requirement is vastly reduced. In addition, the company has introduced a new process named “visual prompting,” where the AI can be taught to make the correct distinctions with limited supervision by using “in-context learning,” such as a scribble as a prompt. The optimal end result is that it should be able to respond to LLM-like prompts, such as “find all six-inch cracks.”

“Even if it makes mistakes and needs the help of human annotations, you’re doing far less labeling work than you would with traditional CNNs, where you’d have to do hundreds if not thousands of labels,” said Jayant Kalagnanam, director, AI applications at IBM Research.

Beware the humans
Ideally, domain-specific datasets should increase the accuracy of identification. They are often created by expanding on foundation models already trained on general datasets, such as ImageNet. Both types of datasets are subject to human and technical biases. Google’s infamous racial identification gaffes resulted from both technical issues and subsequent human overcorrections.

Meanwhile, IBM was working on infrastructure identification, and the company’s experience of getting its model to correctly identify cracks, including the problem of having too many images of one kind of defect, suggests a potential solution to the bias problem, which is to allow the inclusion of contradictory annotations.

“Everybody who is not a civil engineer can easily say what a crack is,” said Cristiano Malossi, IBM principal research scientist. “Surprisingly, when we discuss which crack has to be repaired with domain experts, the amount of disagreement is very high because they’re taking different considerations into account and, as a result, they come to different conclusions. For a model, this means if there’s ambiguity in the annotations, it may be because the annotations have been done by multiple people, which may actually have the advantage of introducing less bias.”

Fig.1 IBM’s Self-supervised learning model. Source: IBM

Fig. 1: IBM’s Self-supervised learning model. Source: IBM

Corner cases and other challenges to accuracy
The true image dataset is infinity, which in practical terms leaves most computer vision systems vulnerable to corner cases, potentially with fatal results, noted Alan Yuille, Bloomberg distinguished professor of cognitive science and computer science at Johns Hopkins University.

“So-called ‘corner cases’ are rare events that likely aren’t included in the dataset and may not even happen in everyday life,” said Yuille. “Unfortunately, all datasets have biases, and algorithms aren’t necessarily going to generalize to data that differs from the datasets they’re trained on. And one thing we have found with deep nets is if there is any bias in the dataset, the deep nets are wonderful at finding it and exploiting it.”

Thus, corner cases remain a problem to watch for. “A classic example is the idea of a baby in the road. If you’re training a car, you’re typically not going to have many examples of images with babies in the road, but you definitely want your car to stop if it sees a baby,” said Yuille. “If the companies are working in constrained domains, and they’re very careful about it, that’s not necessarily going to be a problem for them. But if the dataset is in any way biased, the algorithms may exploit the biases and corner cases, and may not be able to detect them, even if they may be of critical importance.”

This includes instances, such as real-world weather conditions, where an image may be partly occluded. “In academic cases, you could have algorithms that when evaluated on standard datasets like ImageNet are getting almost perfect results, but then you can give them an image which is occluded, for example, by a heavy rain,” he said. “In cases like that, the algorithms may fail to work, even if they work very well under normal weather conditions. A term for this is ‘out of domain.’ So you train in one domain and that may be cars in nice weather conditions, you test in out of domain, where there haven’t been many training images, and the algorithms would fail.”

The underlying reasons go back to the fundamental challenge of trying to replicate a human brain’s visual processing in a computer system.

“Objects are three-dimensional entities. Humans have this type of knowledge, and one reason for that is humans learn in a very different way than machine learning AI algorithms,” Yuille said. “Humans learn over a period of several years, where they don’t only see objects. They play with them, they touch them, they taste them, they throw them around.”

By contrast, current algorithms do not have that type of knowledge.

“They are trained as classifiers,” said Yuille. “They are trained to take images and output a class label — object one, object two, etc. They are not trained to estimate the 3D structure of objects. They have some sort of implicit knowledge of some aspects of 3D, but they don’t have it properly. That’s one reason why if you take some of those models, and you’ve contaminated the images in some way, the algorithms start degrading badly, because the vision community doesn’t have datasets of images with 3D ground truth. Only for humans, do we have datasets with 3D ground truth.”

Hardware implementation, challenges
The hardware side is becoming a bottleneck, as academics and industry work to resolve corner cases and create ever-more comprehensive and precise results. “The complexity of the operation behind the transformer is quadratic,“ said Malossi. “As a result, they don’t scale linearly with the size of the problem or the size of the model.“

While the situation might be improved with a more scalable iteration of transformers, for now progress has been stalled as the industry looks for more powerful hardware or any suitable hardware. “We’re at a point right now where progress in AI is actually being limited by the supply of silicon, which is why there’s so much demand, and tremendous growth in hardware companies delivering AI,” said Tony Chan Carusone, CTO of Alphawave Semi. “In the next year or two, you’re going to see more supply of these chips come online, which will fuel rapid progress, because that’s the only thing holding it back. The massive investments being made by hyperscalers is evidence about the backlogs in delivering silicon. People wouldn’t be lining up to write big checks unless there were very specific projects they had ready to run as soon as they get the silicon.”

As more AI silicon is developed, designers should think holistically about CV, since visual fidelity depends not only on sophisticated algorithms, but image capture by a chain of co-optimized hardware and software, according to Pulin Desai, group director of product marketing and management for Tensilica vision, radar, lidar, and communication DSPs at Cadence. “When you capture an image, you have to look at the full optical path. You may start with a camera, but you’ll likely also have radar and lidar, as well as different sensors. You have to ask questions like, ‘Do I have a good lens that can focus on the proper distance and capture the light? Can my sensor perform the DAC correctly? Will the light levels be accurate? Do I have enough dynamic range? Will noise cause the levels to shift?’ You have to have the right equipment and do a lot of pre-processing before you send what’s been captured to the AI. Remember, as you design, don’t think of it as a point solution. It’s an end-to-end solution. Every different system requires a different level of full path, starting from the lens to the sensor to the processing to the AI.”

One of the more important automotive CV applications is passenger monitoring, which can help reduce the tragedies of parents forgetting children who are strapped into child seats. But such systems depend on sensors, which can be challenged by noise to the point of being ineffective.

“You have to build a sensor so small it goes into your rearview mirror,” said Jayson Bethurem, vice president of marketing and business development at Flex Logix. “Then the issue becomes the conditions of your car. The car can have the sun shining right in your face, saturating everything, to the complete opposite, where it’s completely dark and the only light in the car is emitting off your dashboard. For that sensor to have that much dynamic range and the level of detail that it needs to have, that’s where noise creeps in, because you can’t build a sensor of that much dynamic range to be perfect. On the edges, or when it’s really dark or oversaturated bright, it’s losing quality. And those are sometimes the most dangerous times.”

Breaking into the black box
Finally, yet another serious concern for computer vision systems is the fact that they can’t be tested. Transformers, especially, are a notorious black box.

“We need to have algorithms that are more interpretable so that we can understand what’s going on inside them,” Yuille added. “AI will not be satisfactory till we move to a situation where we evaluate algorithms by being able to find the failure mode. In academia, and I hope companies are more careful, we test them on random samples. But if those random samples are biased in some way — and often they are — they may discount situations like the baby in the road, which don’t happen often. To find those issues, you’ve got to let your worst enemy test your algorithm and find the images that break it.”

Related Reading
Dealing With AI/ML Uncertainty
How neural network-based AI systems perform under the hood is currently unknown, but the industry is finding ways to live with a black box.

The post Fundamental Issues In Computer Vision Still Unresolved appeared first on Semiconductor Engineering.

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