Second, the conditions of the certification will place an obligation on the component supplier to keep the integrator informed of any bugs that are discovered in the component that could potentially affect safe operation. For a non-certified component, this information may not be readily available and it is not clear how a product that relies on a component can satisfy a safety function without this information.
Note that this not only includes software components such as MySQL, which are integrated directly into the product, but also embedded code inside devices sourced from a third party — a postscript printer may contain a significant amount of code.
In that case, it may be very difficult to identify and gain access to all of the code. Aligning Release Cycles Whether a certified or uncertified component is used, the question of integrating release cycles needs to be addressed. Each component may have a different release cycle, and these release cycles need to be coordinated with the release cycle of the integrated product.
Section 6. BCI must decide whether to use an external certification body to issue the certificate for its Operating System, or to use its own, internal, resources. If an external body is chosen, then BCI will need to confirm that body is accredited to issue certificates against the appropriate standard.
If BCI intends to use its own resources and perform a selfcertification, then it will need to confirm that this will be acceptable to ADC. This is not the end of the story. This requirement also adds cost to the operating system because BCI will have to dedicate staff to the audit each year. After much negotiation, an agreement could be reached, whereby the source code and the infrastructure to build it will be put into escrow — a neutral place where ADC can get access under predefined conditions, such as BCI going out of business or stopping support for the component.
This agreement also demands that, as BCI makes bug fixes to the component, the version in escrow will be kept up to date. In all the mathematics that I did, the essential point was to find the right architecture.
Once the main lines of the structure are right, then the details miraculously fit. The problem is the overall design. Freeman Dyson The chapters in this part of the book describe a number of architectural and design patterns.
These are covered in Chapter 8. Selecting suitable patterns means acknowledging that many architectural balances have to be achieved. Many characteristics of a system pull against each other — the architect satisfies one at the expense of another.
Trade-offs need to be consciously taken into account and the justifications recorded. Reference [1] which I wrote with Akramul Azim provides some examples of these tensions and points out the scarcity of tools available to help an analyst resolve them. It is possible to think of systems where safety is preserved by high reliability and others where safety demands high availability.
Systems that work in offline mode lie in the first category. For many systems that provide functional safety, occasional unreliability can be tolerated, while unavailability is dangerous. This is particularly true of systems where continuous operation is required and where self-correcting algorithms have been used to reduce the chances of a dangerous situation occurring. The Kalman filter — see page — is an example of such an algorithm.
If occasional values are unreliable, they may work their way out of the algorithm over time without any dangerous condition having occurred. In this case, unreliability may be tolerated, whereas an unavailability would be unacceptable. That a balance is required between availability and reliability is particularly clear when replication or diversification is used in the architecture see Chapter However, this two-out-of-two 2oo2 design reduces system availability because the failure of either subsystem renders the complete system inoperative.
If, rather than comparing both outputs, the first output is accepted, then the availability of the system increases, but the reliability decreases. In some systems, the relative importance of availability and reliability may change dynamically. In this case the availability of the control system may be more important than reliability. Consider a device that automatically stops a train when some event occurs.
The unnecessarily stopped train is, however, not useful. In this case, I suggest that the system be held in its safe state permanently the train never moves, etc. This raises howls of protest, but I claim that the resulting system meets the requirements given to the engineering team. The moral is that, before we can balance safety against usefulness, we need to have requirements on each. It is trivially easy to build a very safe system. A device moving to its design safe state generally becomes useless; what is worse is that it puts stress onto the larger system its environment into which it has been incorporated.
In that case, the effect of a move to the design safe state is unpredictable. In particular, for systems where a human operator is involved, the device moving to its design safe state frequently can cause a human operator to start working around the safety measures: jamming interlocks open, etc. For these reasons, the balance between usability and safety needs to be considered carefully; there are actually four states of the system as listed in Table 7. Table 7. External Stress?
In state B, the system is safe, but useless. State C is the most worrying situation; this state occurs when the system fails to move to its design safe state when a dangerous condition occurs. State D occurs when the dangerous condition is detected and the device correctly moves to its design safe state. Notice that the system is useful in only one of the four states, whereas it is safe in three of them.
Following the usability analysis, if such an opportunity exists, it may be possible to permit one of the subsystems to restart and resynchronize following a disagreement between the two processors.
If this can be done quickly, it may not undermine the safety of the system. If one of the subsystems can repeat the calculation during that time, it might be better from the safety point of view to allow it to do so, because systems that move to their design safe state too readily can, in themselves, be a hazard.
This is something that would need to be addressed in the hazard and risk analysis and in the failure analysis. This innocent state of affairs has changed rapidly, and today almost every device provides many entry points for a malicious attacker.
USB ports, operator keyboards, Wi-Fi, Bluetooth, and, in cars, even wireless tire pressure connections and maintenance tools provide points of direct access for attackers. Reliance on the integrity of external signals, such as the global positioning system GPS and the global system for mobile communications GSM , provides attack surfaces for jamming or spoofing.
Newspapers and research papers are already reporting systems within cars being taken over by roadside hackers. See, for example, reference [2] by Karl Koscher et al. As vehicle-to-vehicle V2V and vehicle-to-infrastructure V2I communication becomes common for collision avoidance, even more attack surfaces will be opened. Additionally, as the software in vehicles becomes more complex, ever more frequent software updates must be issued, and each software update requires the opening of some port into the device.
Reference [3] by Simon Burton et al. Good people make slips and errors; in a safe system those errors should not escalate to untoward incidents, harm or other safety issues. These simple and nicely contrasting definitions raise immediate tensions. A secure system may not be very usable. Thus a hospital system may end up with everyone sharing the same password, as this is much easier than remembering individual passwords and logging in and out repeatedly. This has apparently spawned a cottage industry of special clamps that allow the driver to violate the requirement and still have the system drive autonomously.
It is easy to see how poor security can produce a safety hazard, but one problem with increasing security is that it almost always compromises system performance. If a database is encrypted to improve security, it takes longer to access; if a strong password is enforced on the operator interface to a medical device, it slows down access.
Performance is not something that can always be given up lightly. This may preclude a secure boot process or the checking of the signature on the software image at startup, thereby reducing the system security.
This possibility needs to be recognized in the hazard and risk analysis as a potential risk and suitable mitigation should be put in place to detect it. Time replication repeating the same computation on the same hardware, possibly using recovery blocks or coded processors particularly reduces system performance, but other techniques to increase the probability of getting a correct system response, such as disabling cacheing on the processor, also directly hit performance.
Implementation Balance There is one further balance that the architect or designer needs to consider. As the programmers implement the system they will need guidance on how to program.
It is possible to program for high performance fast, tightly knit code , for testability, for ease of maintenance, for efficiency of the static analysis tools, for efficient runtime error detection, or for code readability. These demands work against each other.
High-performance code is likely to be less readable, less easily maintained, less likely to detect runtime errors, and less amenable to deep static analysis than is code specifically written with those characteristics in mind. Striving for high performance may particularly reduce the possibilities of runtime error detection.
To facilitate this, data may be replicated, stored in diverse forms, or covered by a check-sum. Checking these at runtime will always reduce the performance of the system. Programmers need to be aware of the priorities for each module they produce. The design of module A might specify that it is not time critical, and so the priorities when creating the code are for runtime error coverage, ease of testability, efficiency of the static analysis tools, and ease of maintenance, in that order.
Module B might need to be programmed for speed, even if this means that more work will have to be spent testing and maintaining it, and even though fewer runtime errors will be detected. In practice, one problem may be getting the programmers to pay attention to the allocated priorities — some programmers like to be heroic and insist on coding for high performance, irrespective of the prioritization of other characteristics. Integration testing might, for example, find that a module that was not specified at design time as needing to have high performance, needs that performance.
This could involve not only design, but also implementation, rework. Summary The design and implementation of any system, but particularly an embedded system designed for a safety-critical application, are subject to balances and tradeoffs. A long list of elements must be balanced, including safety, performance, security, usability, availability and reliability.
The analysis of these should be carried out explicitly and any decisions made should be recorded. This allows those decisions to be reviewed in the light of experience. Hobbs and A. Koscher, A. Czeskis, F. Roesner, S. Patel, T. Kohno, S. Checkoway, D. McCoy, B. Kantor, D. Anderson, H. Shacham, and S. Burton, J.
Likkei, P. Vembar, and M. Dale and T. Anderson, eds. It is not uncommon to increase the cost of an item by a factor of ten for each factor of ten degradation accomplished. Norman R. Augustine Why Detect Errors? Once the system is running, it is too late to detect faults, but errors often leave observable traces. By detecting the error, it may be possible to avoid a failure completely, but even if it is not, it may be possible to log details of the problem and inform the larger system into which the failing component is embedded before the failure occurs.
Some techniques for detecting an error, as listed in section 7. The associated description given in C. ISO dedicates section 7. Given the models listed in reference [1], some of which date back to the s, this last point is disappointing. Anomaly Detection Anomaly detection is the application of an algorithm to a series of events to decide whether one or more of the events is unexpected in the light of the history of the events up to that point.
Humans are very good at this: One glance at Figure 8. This section describes two different types of algorithm for detecting such anomalies and deciding how anomalous they are. The purpose of detecting an anomaly is that it may be an error caused by a fault. If this error can be detected and handled before a failure occurs, then the system may be able to move to its design safe state in a controlled manner.
Two types of anomalies can be identified: point anomalies, such as occur in Figure 8. The remainder of this chapter deals with detecting anomalies at runtime in systems. Anomaly detection can also be useful offline, during integration testing — see page Anomaly Detection and the Standards While not listed explicitly, anomaly detection is a form of plausibility check recommended in section 7. It can be harder to justify the use of a learning rather than a static algorithm, because the functionality of the system is not predefined, depending instead on what the system learns.
Such dynamic algorithms are discouraged by the standards. This can be mitigated somewhat, at the cost of decreased flexibility, by letting the system learn in a controlled environment, perhaps during verification testing or from event logs gathered from the field. The resulting static algorithm can then be deployed. Figure 8. Neural networks and support vector machines are particularly useful for anomaly detection see reference [3] by Markos Markou and Sameer Singh because no a priori assumptions need to be made about the properties of data.
In general, when a neural network is used as a classifier, it is its weakness in handling anomalies that makes it respond poorly. As reference [3] points out, it is exactly this weakness that becomes a strength when the network is actually being used to detect anomalies. Much of the research being carried out on anomaly detection is aimed toward the detection of malicious intrusions into networks by attackers and the examination of financial databases, looking for patterns of fraud.
The results of this work have to be carefully considered to see whether those security-related techniques also apply to more general anomaly detection of the type required to detect faults becoming errors.
One promising area that I think is possibly underdeveloped is that of using wavelet transforms to detect anomalies.
The wavelet transform of a time series, such as those shown in Figures 8. I consider two types of anomaly detection in the remainder of this chapter: Markov chains and Kalman filters.
The file descriptors were leaking extremely regularly, and this was anomalous. Examples As examples of anomaly detection, we will use the fictitious samples illustrated in Figures 8. The values in Figure 8. I have assumed that the resource is an open file descriptor, but it could be an amount of memory, a number of locked mutexes, or any other resource whose usage can be measured precisely. The values are assumed to be the speed measurements from a forward-facing Doppler radar on a train.
In contrast with Figure 8. Such a situation, where a sensor is providing inexact and possibly anomalous values, and where the main system needs to handle these, reflects the conditions aboard Qantas Flight 73, as described on page We can easily pick out the anomalies in Figures 8.
If so, how anomalous? He lived from to and made many important contributions to the theory of stochastic processes. His life was spent in academia although he was dismissed from his professorship at St. Petersburg University in for refusing to report to the authorities any revolutionary tendencies among his students. System States The first step in representing a system as a Markov chain is to itemise its possible states. For the system shown in Figure 8.
The history of how state i was reached is irrelevant. This is described more thoroughly in Chapter 11, but assume for the system in Figure 8. To apply a Markov chain, we must assume that this will not depend on any earlier values. In Figure 8. During a downward cycle, the probability of moving from descriptors in use to in use is much higher than it would be on an upward cycle. To avoid this, our representation of the system state will have to include details of whether the system is on the downward or upward part of the cycle.
So the system state might be U or D. In principle, it would then be possible to draw a diagram showing the possible transitions between states and their likelihood. From Figure 8. Using the learning data described in the next section, there would be about states and arrows between them. In some systems, the system states themselves form a Markov chain; in other systems, it may occur that internally the system is operating in accordance with a Markov chain, but that these states are not directly visible.
Learning the Transition Probabilities In order to decide when something is anomalous, we need to know what is normal. For a Markov chain, we build the probability of transitions between states by observing normal behavior, possibly during system testing, possibly during field trials.
This allows us to build a matrix of transition probabilities. Training consists of observing the system and determining what proportion of the transitions out of state i are moves to state j.
For example, for the system in Figure 8. It found that the transition probabilities out of state U were as shown in Table 8. From that state, the probability is greater At this stage in the analysis, it would perhaps be better to replace the U and D on each state with an indicator not just of the last state change, but of the average of the last few state changes.
Error Detection and Handling Table 8. From a practical point of view, this matrix is likely to be very sparse i. Some languages, such as Python, support associative arrays directly; in other languages, the construct may have to be emulated.
For example, during the learning phase on the file descriptors, the system never went directly from to file descriptors in use. The sim addresses the tiniest of details, including the use of special toggle switches that lock into place automatically using electromagnets.
Many a hacker is a fan of the cheapest calipers on the market. However, their batteries often die when left in a drawer for a long time. The result was a quick-and-dirty mod that allows the calipers to be powered by a AAA battery. The average AAA cell has times the capacity of the typical LR44 coin cells used in these devices.
The researchers who identified the problem were able to prepare a working prototype of the exploit. The vulnerability is caused by storing pointers to a shared memory area scoreboard used to communicate between the child and parent PHP-FPM process. The main PHP-FPM process that coordinates the work is started as root and spawns several child processes that run under an unprivileged user usually www-data or nobody and are directly involved in executing PHP scripts.
Iain Davis of In This Together joins Whitney for an important conversation on the network of institutions, corporations and governments that are at the center of global decision-making. This global public-private partnership already exerts considerable control over our lives and our society and is quickly moving to control even more. However, automation also complements labor, raises output in ways that lead to higher demand for labor, and interacts with adjustments in labor supply.
The Task Force released an interim report in September of Its overriding conclusion was that the likelihood that AI and automation would wipe out major workforce sectors in the near future was exaggerated. On Oct. Brian Kelsey, a state chair with the American Legislative Exchange Council, alleging that he broke multiple federal campaign finance laws. The alleged scheme involved illegal contributions to his congressional campaign passed through a state-level PAC and used by a political nonprofit to boost his election effort.
The American Legislative Exchange Council ALEC is a pay-to-play operation where legislators and corporate lobbyists meet behind closed doors to write model legislation that a radical right-wing, pro-corporate and pro-Republican agenda on everything from voter suppression and climate denial to crushing unions and undermining public education.
This directive is from a state that still has statues of Confederate President Jefferson Davis and James Marion Sims, a discredited gynecologist who experimented on enslaved African women without the benefit of anesthesia or antiseptics, in front of the State Capitol building.
No more Dr. King in the Alabama curriculum! If only we could remove him from the Alabama curriculum and the American political scene.
This lesson on the European Enlightenment for the high school World History curriculum is part of a series of posts that explore what a critical perspective looks like in a social studies classroom.
A Critical Race Theory lens is part of that critical perspective. Original by Benjamin Henrion. F FII. Over the years, more than 3, software companies accross Europe have supported our calls against software patenting [ref1][ref2].
We hereby call for an urgent investigation on the accusations regarding Mdme Frohlinger European Commission official in charge of the file under Mr Barnier till and her near-successful attempt to recycle the impact assessment of the UPC. We call for an urgent freeze of the untransparent and undemocratic law making work being done behind closed doors by the Preparatory Committee of the UPC as long as this verification has not been made.
In the context of Brexit difficulties, we are calling on reopening the negotiations on that precise point ex art , where the UK put their veto in Our second concern is that the proposed UPC court fees of The goal to make the patent system cheaper has not been reached, quite the opposite. Dietmar Harhoff, Ph. The Patent Package of consists of 2 regulations and 1 international agreement. In the 2 impact assessments attached to the 2 regulations of , you still cannot find an updated impact assessment of the Court system [ref9]:.
The Impact Assessment study of was about the old Community Patent project, and not about the Unitary Patent Package of , which differ significatively on many important aspects, and none of the proposed changes were assessed in an updated Impact Assessment :. The enhanced cooperation was used in December to bypass the blockage of Spain and Italy over the language issue, meaning the new Unitary Patent would not be covering all the Member States, but only in the participating ones, which creates some effects of market distorsion;.
Another difference is that the participation of the European Union and its institutions is avoided. The European Parliament is the only democratic institution where citizens and companies could make their complaints heard in case of problems, like increasing patent trolls problems, and over the disfunctions of the European Patent Office EPO or the Unified Patent Court UPC ;.
The financing of the Court system would have been done at least partially with EU funds , while the project is financed by contributing Member States and companies that litigate in front of the Court; the project of did not had a self-financed objective , which is a controversial topic as Courts should not have financial targets and it could endanger the integrity of Justice and promote patent maximalism decisions; due to that change in financing, the UPCA later was designed to have a self-financing goal; this can explain why the proposed court fees of On the point of financing, in April , some British members of the Scrutiny Committee of the British Parliament had already questioned the validity of the outdated impact assessment in their report [ref17]:.
With the change of that, following the enhanced cooperation, the EU funding was then not going to be available anymore. About Impact Assessments in general, we can understand that some DGs are relunctant to produce such assessments of their own policies [ref18]:.
National impact assessments carried out by some member states Poland, Czech Republic came back negative about the impact of such project for their economy B EUR over 30 years according to the Polish study commissioned to Deloitte [ref19].
Individual numbers for each country of Europe do not exist, as there is no serious impact assessment of this important reform. Posted in News Roundup at am by Dr. SUSE is committed to delivering innovative, enterprise solutions with great partners, like Sysdig, that empower customers to overcome their technical challenges. One increasingly popular solution today is to add a container layer to the software stack, giving each application its own temporary, sandboxed environment without needing the resources required for a complete stand-alone virtual machine.
And as a bonus, containers make it easier to deploy applications efficiently in a cloud or across a local computing cluster. I wanted to get my feet wet with container technology without the risk of accidentally running up hefty cloud charges, so I decided to try out the Turing Pi, which lets you use up to seven Raspberry Pi compute modules as a cluster.
But what looks like a row of slots for memory chips are slots for compute modules. A version that supports the latest, Compute Module 4 has been announced but there is no word yet on pricing or a release date.
OpenStack vs AWS is a discussion that almost every organisation must conduct when adopting a cloud strategy. This is because OpenStack and AWS are undoubtedly some of the most popular cloud technologies in both public and private cloud space. While AWS is the most popular commercial cloud platform, OpenStack remains its most popular open source equivalent. Both have their own pros and cons.
But which one is better for you? Or even more importantly, can you use both to reap their benefits at no extra cost? In the following blog post, we will try to answer these questions. Zink is something quite wonderful. A Linux Mesa driver that creates an OpenGL implementation on top of Vulkan and it just keeps on getting more impressive.
After three and a half years since the last significant release formed release the X. Org Server Starting with the presented branch, a new issue numbering scheme has been put into operation, allowing you to immediately see how long ago this or that version was published.
By analogy with the Mesa project, the first number of the version reflects the year, the second number indicates the serial number of the significant release for the year, and the third number is used to flag corrective updates.
Tor Tools is an application indicator and GUI frontend for the Tor proxy client service and other technologies to make your Linux system totally private. The Tor Browser does a great job as a private browser but there are many other applications communicating with the internet on your system.
For commercial usage, there are several mainstream options to consider, which are often regarded as industry-standard. However, they are not available for Linux. Hence, when it comes to Linux, you will have to make a different set of choices as per the available options. WordPress has served me well since But I finally got bored with managing the OAMP stack and having to deal with plugins updates, spam comments and general security warning because of the PHP backend. Finding files based on their size can help you figure out which files are taking up the most space on your hard drive.
Whether you need to free up storage, or just want to see which files are largest, there are plenty of Linux commands that can help. Check out some of the examples below to get started. Create your own personal cloud storage by installing NextCloud on Debian 11 Bullseye Linux server using the command given here in this step-by-step tutorial. Ksnip is a free and open-source Qt-based screenshot tool with editing feature. I use the app regularly to add annotations e.
Want to speed up your downloads on Linux? Check out Xtreme Download Manager. This guide will show you how to install and use the Xtreme Download Manager on Linux. The Witness is a puzzle-exploration game developed and published by Thekla Inc. In the game, the player explores an open island and solves puzzles hidden in the environment.
FirewallD is a complex firewall system for Linux operating systems. It ships by default on Fedora and many other Linux OSes, and for a good reason. It is powerful, highly configurable, and secure.
Follow along as we show you how to set up FirewallD on Ubuntu Server the easy way! Today we are looking at how to install RawTherapee on a Chromebook. Soon after I installed Devuan and wrote an article about, they released a new version. So this article is about how to upgrade Devuan 3. Redis is an in-memory data structure store, used as a distributed, in-memory key—value database, cache and message broker, with optional durability.
Redis supports different kinds of abstract data structures, such as strings, lists, maps, sets, sorted sets, HyperLogLogs, bitmaps, streams, and spatial indices. Linux users often face issues with broken operating systems due to many reasons. This issue frequently occurs when turning on the system after a major software crush, update failure, or physical damage to the system. In that case, you might not want to erase the current operating system entirely and reinstall Ubuntu.
There are ways that you can use to fix your broken Ubuntu OS without reinstalling it on your machine. The date command in Linux is used to display or set system date and time. It allows users to display time in various formats and calculates the past and future dates.
Busy time in Dota 2 land for Valve with a major update just being shipped for the free to play MOBA, with Marci hopping over from the anime to the game. Linux desktop environment contains a bundle of applications created in a manner to work with one another and give a consistent User Experience UX. A tremendous sum of Linux clients inclines toward to work on the OS through the terminal of the command-line, but you will also be able to use the graphical UI rather than using the terminal.
Since there is no particular best Linux desktop environment as it depends upon distinctive components like simple to utilize, memory consumption, compatibility, and usefulness. Every user has their own requirements, so choose the best fit for your own.
All laptop owners, not just Thinkpads, who have an integrated fingerprint reader or owners of an external reader will be able to configure KDE so that you can authenticate with the tip of your finger. Keep in mind that this blog only covers the tip of the iceberg! KDE Plasma 5. KDE developers ended out October working on more Wayland fixes along with other improvements to this open-source desktop.
KDE developer Nate Graham is out with his usual weekly development summary for all of the happenings going on for this major free software project. Some of the KDE highlights for this week included…. Version 3. Yocto provides a system for building embedded Linux distributions. The full release notes have further information. To take a step back, might lead you to fall off a cliff. When I realised that none of these require a graphical environment, I decided to see if I could live entirely within a tty, just like the old times.
Chromium Browser has been updated to Google Chrome Browser has been updated to version The Oracle Linux team has created a simple script with instructions that you can use to switch your CentOS 8, 7 and 6 systems to Oracle Linux. Find mods geeks like you and connect with them. Download Apps that you cannot even find in Play Store search results. Join Our Community! We have a great team including developers, designers, and Traders.
The Team always working hard to give you the maximum profit. Here is the log of the most recent transactions including withdraw and deposit made by our users. This is a Revolutionary Money Making Platform! Not only we guarantee the fastest and the most exciting returns on your investments, but we also guarantee the security of your investment. We accept all major cryptocurrencies and fiat payment methods to make your investment process easier with our platform.
We may use cookies or any other tracking technologies when you visit our website, including any other media form, mobile website, or mobile application related or connected to help customize the Site and improve your experience. Cookie Policy. Profit Calculator You must know the calculation before investing in any plan, so you never make mistakes. World Basketball Challenge. Agario Unblocked Private Servers List latest. Armored Warfare.
Dead Trigger v1. Download Plague Inc. MOD, Unlocked free apk on android. Fortnite online. Fortnite: Battle Royale - Download size and how to install. Armed with Wings Hacked. Feudalism 2 Hacked. LearnToFly Hacked. Potty Racers 2 hacked. Skies Of War Hacked.
0コメント