on 18-Sep-2018 (Tue)

Annotation 3315996167436

 #blockchain A decentralised database with minimal trust between nodes would al- low for the creation of a global ledger. Such a ledger would have many useful applications in finance, trade, supply chain tracking and more. We present Corda, a decentralised global database, and describe in detail how it achieves the goal of providing a platform for decentralised app develop- ment. We elaborate on the high level description provided in the paper Corda: An introduction 1 and provide a detailed technical discussion

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 1 Introduction In many industries significant effort is needed to keep organisation specific databases in sync with each other. In the financial sector the effort of keeping different databases synchronised, reconciling them to ensure they actually are synchronised and resolving the ‘breaks’ that occur when they are not represents a significant fraction of the total work a bank actually does! Why not just use a shared relational database? This would certainly solve a lot of problems using only existing technology, but it would also raise more questions than answers: • Who would run this database? Where would we find a sufficient supply of angels to own it? • In which countries would it be hosted? What would stop that country abusing the mountain of sensitive information it would have? • What if it were hacked? • Can you actually scale a relational database to fit the entire financial system? • What happens if The Financial System™ needs to go down for mainte- nance? • What kind of nightmarish IT bureaucracy would guard changes to the database schemas? • How would you manage access control

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Annotation 3316011896076

 • Nodes are arranged in an authenticated peer to peer network. All com- munication is direct. • There is no block chain 3 . Transaction races are deconflicted using plug- gable notaries. A single Corda network may contain multiple notaries that provide their guarantees using a variety of different algorithms. Thus Corda is not tied to any particular consensus algorithm. (§7) • Data is shared on a need-to-know basis. Nodes provide the dependency graph of a transaction they are sending to another node on demand, but there is no global broadcast of all transactions. • Bytecode-to-bytecode transpilation is used to allow complex, multi-step transaction building protocols called flows to be modelled as blocking code. The code is transformed into an asynchronous state machine, with checkpoints written to the node’s backing database when messages are sent and received. A node may potentially have millions of flows active at once and they may last days, across node restarts and even upgrades. Flows expose progress information to node administrators and users and may interact with people as well as other nodes. A Flow library is provided to enable developers to re-use common Flow types such as notarisation, membership broadcast and so on.

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Annotation 3316025527564

 3 The peer to peer network 3.1 Network overview A Corda network consists of the following components: • Nodes, communicating using AMQP/1.0 over TLS. Nodes use a relational database for data storage. • A permissioning service that automates the process of provisioning TLS certificates. • A network map service that publishes information about nodes on the network. • One or more notary services. A notary may itself be distributed over multiple nodes. • Zero or more oracle services. An oracle is a well known service that signs transactions if they state a fact and that fact is considered to be true. They may also optionally also provide the facts. This is how the ledger can be connected to the real world, despite being fully deterministic. A purely in-memory implementation of the messaging subsystem is provided which can inject simulated latency between nodes and visualise communica- tions between them. This can be useful for debugging, testing and educational purposes. Oracles and notaries are covered in later sections. 3.2 Identity and the permissioning service Unlike Bitcoin and Ethereum, Corda is designed for semi-private networks in which admission requires obtaining an identity signed by a root authority. This assumption is pervasive – the flow API provides messaging in terms of identities, with routing and delivery to underlying nodes being handled automatically. There is no global broadcast at any point. This ‘identity’ does not have to be a legal or true identity. In the same way that an email address is a globally unique pseudonym that is ultimately rooted by the top of the DNS hierarchy, so too can a Corda network work with arbitrary self-selected usernames. The permissioning service can implement any policy it likes as long as the identities it signs are globally unique. Thus an entirely anonymous Corda network is possible if a suitable IP obfuscation system like Tor 6 is also used.

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 ned in terms o

Complex number - Wikipedia
}+(bc+ad)i} (commutative and distributive properties) = ( a c − b d ) + ( b c + a d ) i {\displaystyle =(ac-bd)+(bc+ad)i} (fundamental property of i). The division of two complex numbers is defi<span>ned in terms of complex multiplication, which is described above, and real division. When at least one of c and d is non-zero, we have a + b i c + d i = ( a c + b d c 2 + d 2 ) + ( b c − a d c 2 + d 2

Flashcard 3316142705932

Question
lex multiplication
[default - edit me]

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Complex number - Wikipedia
tive and distributive properties) = ( a c − b d ) + ( b c + a d ) i {\displaystyle =(ac-bd)+(bc+ad)i} (fundamental property of i). The division of two complex numbers is defined in terms of comp<span>lex multiplication, which is described above, and real division. When at least one of c and d is non-zero, we have a + b i c + d i = ( a c + b d c 2 + d 2 ) + ( b c − a d c 2 + d 2 ) i . {\displaystyle {\

Annotation 3316145065228

 n basis of ti

Introduction to Second Order Systems
we have two methods of analyzing the working and functioning of a control system named as: Time domain analysis Frequency domain analysis The time domain analyzes the functioning of the system o<span>n basis of time. This analysis can only be applied when nature of input plus mathematical model of the control system is known. Expressing the main input signals is not an easy task and cannot be det

Flashcard 3316147162380

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[default - edit me]
re two comp

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Introduction to Second Order Systems
e applied when nature of input plus mathematical model of the control system is known. Expressing the main input signals is not an easy task and cannot be determined by simple equations. There a<span>re two components of any system’s time response, which are: Transient response Steady state response In order to judge the functioning and behavior of a system, typical and standard test signals ar

Annotation 3316148210956

 leration, constant ve

Introduction to Second Order Systems
nt response Steady state response In order to judge the functioning and behavior of a system, typical and standard test signals are used. The characteristics of an input signal are constant acce<span>leration, constant velocity, a sudden change or a sudden shock. We have already discussed four types of test signals i.e. Impulse Step Ramp Parabolic We already discussed first order systems in detail in the

Flashcard 3316149783820

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[default - edit me]
hange or a sudde

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Introduction to Second Order Systems
der to judge the functioning and behavior of a system, typical and standard test signals are used. The characteristics of an input signal are constant acceleration, constant velocity, a sudden c<span>hange or a sudden shock. We have already discussed four types of test signals i.e. Impulse Step Ramp Parabolic We already discussed first order systems in detail in the previous article. It said that th

Flashcard 3316152929548

Question
what is a group?
it is an algebraic structure consisting of a set of elements equipped with an operation that combines any two elements to form a third element and that satisfies four conditions called the group axioms, namely closure, associativity, identity and invertibility.

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Group (mathematics) - Wikipedia
his article is about basic notions of groups in mathematics. For a more advanced treatment, see Group theory. The manipulations of this Rubik's Cube form the Rubik's Cube group. In mathematics, <span>a group is an algebraic structure consisting of a set of elements equipped with an operation that combines any two elements to form a third element and that satisfies four conditions called the group axioms, namely closure, associativity, identity and invertibility. One of the most familiar examples of a group is the set of integers together with the addition operation, but the abstract formalization of the group axioms, detached as it is from the

Flashcard 3316155288844

Question
[default - edit me]
A group is a set, G with an operation(group law of G) [...] that combines any two elements a and b to form another element, denoted ab or ab. The set and operation, (G, •) satisfies the group axioms

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Group (mathematics) - Wikipedia
y on numerous bizarre coincidences to exist. The axioms for groups give no obvious hint that anything like this exists. Richard Borcherds in Mathematicians: An Outer View of the Inner World [4] <span>A group is a set, G, together with an operation • (called the group law of G) that combines any two elements a and b to form another element, denoted a • b or ab. To qualify as a group, the set and operation, (G, •), must satisfy four requirements known as the group axioms:[5] Closure For all a, b in G, the result of the operation, a • b, is also in G.b[›] Associativity For all a, b and c in G, (a • b) • c = a • (b • c). Identity element There exists an e

Annotation 3316883000588

 Kaag, the philosophy-department chair at the University of Massachusetts at Lowell, began experimenting with what might be called first-person philosophy—not desiccated fodder for arcane journals but robust inquiry into what he calls the “stuff of everyday life”—in his 2016 book, American Philosophy: A Love Story

How to Live Better, According to Nietzsche
article appears in the October 2018 issue. Subscribe now to support 160 years of independent journalism and save up to 78%. Starting at only \$24.50. View more stories from the issue. Subscribe <span>Kaag, the philosophy-department chair at the University of Massachusetts at Lowell , began experimenting with what might be called first-person philosophy—not desiccated fodder for arcane journals but robust inquiry into what he calls the “stuff of everyday life”—in his 2016 book, American Philosophy: A Love Story.Mingling romance and scholarship, Kaag related how he stumbled onto the private library of a 20th-century philosophical eminence, then out of a miserable marriage and into the arms of h

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 Mingling romance and scholarship, Kaag related how he stumbled onto the private library of a 20th-century philosophical eminence, then out of a miserable marriage and into the arms of his now-wife, the Kantian philosopher Carol Hay. As Kaag and Hay worked to preserve the library’s holdings, they didn’t find consolation, exactly. Instead, they grappled with transcendentalists like Ralph Waldo Emerson and pragmatists like William James. Along the way, they came to regard love as a challenge rather than a balm. In Hiking With Nietzsche, Kaag describes the draw of Nietzsche’s marital ideal—a union that embodies “the will of two to create the one that is more than those who created it,” never lapsing into “one long stupidity.”

How to Live Better, According to Nietzsche
e called first-person philosophy—not desiccated fodder for arcane journals but robust inquiry into what he calls the “stuff of everyday life”—in his 2016 book, American Philosophy: A Love Story.<span>Mingling romance and scholarship, Kaag related how he stumbled onto the private library of a 20th-century philosophical eminence, then out of a miserable marriage and into the arms of his now-wife, the Kantian philosopher Carol Hay. As Kaag and Hay worked to preserve the library’s holdings, they didn’t find consolation, exactly. Instead, they grappled with transcendentalists like Ralph Waldo Emerson and pragmatists like William James. Along the way, they came to regard love as a challenge rather than a balm. In Hiking With Nietzsche, Kaag describes the draw of Nietzsche’s marital ideal—a union that embodies “the will of two to create the one that is more than those who created it,” never lapsing into “one long stupidity.” MORE STORIES [imagelink] How an 18th-Century Philosopher Helped Solve My Midlife Crisis ALISON GOPNIK [imagelink] The Gradual Disappearance of Jane Ashland Casts an Unlikely Spell ANN H

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 Kaag is fascinated by the idea of decadence—which Nietzsche first broached in The Birth of Tragedy, and which would preoccupy him for the rest of his life: “Is it perhaps possible to suffer from over-abundance?” he asked. “Is there perhaps such a thing as neuroses of health?” Blending biography, intellectual history, and personal essay, Kaag follows three related journeys: Nietzsche’s evolution from adolescent upstart to middle-aged iconoclast, Kaag’s youthful attempt to retrace Nietzsche’s footsteps through the Swiss Alps, and Kaag’s adult effort to retrace his own retracing, this time with Hay and their 3-year-old daughter in tow. The result is not just an approachable introduction to Nietzsche’s thought. Kaag’s book is also, despite its cloying title, a confirmation that philosophy thrives when it provides an antidote to the wholesome doldrums of sanity.

How to Live Better, According to Nietzsche
s former relevance—to tether it to the mess of daily experience. Hiking With Nietzscheexplores two related but distinct reckonings with the blandishments of modern life, Kaag’s and Nietzsche’s. <span>Kaag is fascinated by the idea of decadence—which Nietzsche first broached in The Birth of Tragedy , and which would preoccupy him for the rest of his life: “Is it perhaps possible to suffer from over-abundance?” he asked. “Is there perhaps such a thing as neuroses of health?” Blending biography, intellectual history, and personal essay, Kaag follows three related journeys: Nietzsche’s evolution from adolescent upstart to middle-aged iconoclast, Kaag’s youthful attempt to retrace Nietzsche’s footsteps through the Swiss Alps, and Kaag’s adult effort to retrace his own retracing, this time with Hay and their 3-year-old daughter in tow. The result is not just an approachable introduction to Nietzsche’s thought. Kaag’s book is also, despite its cloying title, a confirmation that philosophy thrives when it provides an antidote to the wholesome doldrums of sanity. Nietzsche, born in 1844, led the kind of maladjusted life that contemporary therapies and self-help books are designed to rehabilitate. He was a lonely, awkward young man whose attempts

Annotation 3316887719180

 Nietzsche’s academic career was marked by a number of dazzlingly early successes. At 24, he was the youngest tenured faculty member at the University of Basel. But by 28, he had been demoted from wunderkind to pariah, thanks in large part to the publication of his first book, The Birth of Tragedy (1872). More a work of creative interpretation than a piece of faithful exegesis, the debut departed sharply from accepted philological method, infuriating Nietzsche’s colleagues. It argued that two aesthetic tendencies vied for dominance in ancient Greece: the Dionysian, a primordial blurring of the borders dividing self and world, and the Apollonian, a rationalist paradigm that positioned art as an ordered alternative to the havoc of life. Though Nietzsche regarded these two forces as mutually enhancing—and he lauded tragedy for wedding them—his real allegiance lay with the Dionysian, as his life and work went on to attest.

How to Live Better, According to Nietzsche
maters, the University of Bonn and the University of Leipzig, were short-lived and half-hearted. “He actually didn’t like beer,” Kaag reports. “He liked pastries. And he liked studying—a lot.” <span>Nietzsche’s academic career was marked by a number of dazzlingly early successes. At 24, he was the youngest tenured faculty member at the University of Basel. But by 28, he had been demoted from wunderkind to pariah, thanks in large part to the publication of his first book, The Birth of Tragedy (1872). More a work of creative interpretation than a piece of faithful exegesis, the debut departed sharply from accepted philological method, infuriating Nietzsche’s colleagues. It argued that two aesthetic tendencies vied for dominance in ancient Greece: the Dionysian, a primordial blurring of the borders dividing self and world, and the Apollonian, a rationalist paradigm that positioned art as an ordered alternative to the havoc of life. Though Nietzsche regarded these two forces as mutually enhancing—and he lauded tragedy for wedding them—his real allegiance lay with the Dionysian, as his life and work went on to attest. The hostility that The Birth of Tragedy spawned among philologists solidified Nietzsche’s break with academic culture. In 1879, when he was 34, declining health compelled him to leave h

Annotation 3316889292044

 At 19, Kaag shared Nietzsche’s distaste for the “scripted” routines and glib gratifications that make modern life so deplorably easy. When he arrived in Basel on a research trip, he recoiled at his surroundings: The train station was “a model of Swiss precision,” and the streets were “too straight, too quiet, too mundane.” He quickly abandoned his plans to ruminate on Nietzsche from the confines of Basel’s library and instead decided to follow his idol’s grueling alpine route to “Splügen, then to Grindelwald at the foot of the Eiger, then to the San Bernardino Pass, to Sils-Maria, and finally to the towns of Northern Italy.” He wanted, he writes, “to feel something, to break through the anesthesia, to prove to myself that I wasn’t just asleep

How to Live Better, According to Nietzsche
to the next. As he grappled with the specter of decadence, his austere and itinerant life represented a rejection of the indulgent spirit dulling the haute bourgeoisie of fin de siècle Europe. <span>At 19, Kaag shared Nietzsche’s distaste for the “scripted” routines and glib gratifications that make modern life so deplorably easy. When he arrived in Basel on a research trip, he recoiled at his surroundings: The train station was “a model of Swiss precision,” and the streets were “too straight, too quiet, too mundane.” He quickly abandoned his plans to ruminate on Nietzsche from the confines of Basel’s library and instead decided to follow his idol’s grueling alpine route to “Splügen, then to Grindelwald at the foot of the Eiger, then to the San Bernardino Pass, to Sils-Maria, and finally to the towns of Northern Italy.” He wanted, he writes, “to feel something, to break through the anesthesia, to prove to myself that I wasn’t just asleep.” How did “Nietzsche cultivate the existential defiance or courage that led [him] up the mountain?” Kaag asks. It probably started something like this—in a very simple refusal to act on

Flashcard 3316890864908

Question
juvenile
childish; immature.

status measured difficulty not learned 37% [default] 0

How to Live Better, According to Nietzsche
o Power , the posthumously published book that many consider his magnum opus. This core provocation, the heart of his teachings and his notoriously hyperbolic style, is by turns enthralling and <span>juvenile. Mercifully, 37-year-old Kaag is aware of the raw, adolescent quality of some of Nietzsche’s most radical insights, and he acknowledges that during his own infatuation with his hero he

Flashcard 3316893224204

Question
enthralling
capturing and holding one's attention; fascinating.

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How to Live Better, According to Nietzsche
te in The Will to Power , the posthumously published book that many consider his magnum opus. This core provocation, the heart of his teachings and his notoriously hyperbolic style, is by turns <span>enthralling and juvenile. Mercifully, 37-year-old Kaag is aware of the raw, adolescent quality of some of Nietzsche’s most radical insights, and he acknowledges that during his own infatuation with

Flashcard 3316895583500

Question
hyperbolic style
someone is hyperbolic, they tend to exaggerate things as being way bigger deals than they really are. Hyperbolic statements are tiny dogs with big barks: don't take them too seriously. Hyperbolic is an adjective that comes from the word hyperbole, which means an exaggerated claim.

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How to Live Better, According to Nietzsche
reme exercises,” Nietzsche wrote in The Will to Power , the posthumously published book that many consider his magnum opus. This core provocation, the heart of his teachings and his notoriously <span>hyperbolic style, is by turns enthralling and juvenile. Mercifully, 37-year-old Kaag is aware of the raw, adolescent quality of some of Nietzsche’s most radical insights, and he acknowledges that during

Annotation 3316897942796

 When he heads back to his family after a day of lonely hiking, he reflects, “Perhaps a pilgrim triumphs not in hardship, but in the rare moment when they learn to accept something soft at home.” This sounds like an un-Nietzschean lesson, and Kaag’s clichés can sometimes leave us wondering whether he embraces Wittgenstein’s vision of philosophy after all.

How to Live Better, According to Nietzsche
both laments and celebrates his maturation. He smiles for a family photo and entertains fleeting worries that he has become “a grinning domesticated animal,” one of the pampered. How to resist? <span>When he heads back to his family after a day of lonely hiking, he reflects, “Perhaps a pilgrim triumphs not in hardship, but in the rare moment when they learn to accept something soft at home.” This sounds like an un-Nietzschean lesson, and Kaag’s clichés can sometimes leave us wondering whether he embraces Wittgenstein’s vision of philosophy after all. But to Kaag’s credit, he is determined to inject hints of extremity into his outwardly stable life. By the time he returns to America, he has modified his conception of how, exactly, we

Annotation 3316899515660

 But to Kaag’s credit, he is determined to inject hints of extremity into his outwardly stable life. By the time he returns to America, he has modified his conception of how, exactly, we should go about steeling ourselves in the face of the decadent imperatives of a consumerist, conformist world. What Kaag overlooked in his youth is that Nietzsche does not prescribe difficulty for its own sake. Though the metaphorical language Nietzsche employed throughout his career is wildly inconsistent, he was ultimately an advocate of health—but health, he emphasized, is not synonymous with enjoyment. On the contrary, health requires the trials that beget a strong constitution

How to Live Better, According to Nietzsche
accept something soft at home.” This sounds like an un-Nietzschean lesson, and Kaag’s clichés can sometimes leave us wondering whether he embraces Wittgenstein’s vision of philosophy after all. <span>But to Kaag’s credit, he is determined to inject hints of extremity into his outwardly stable life. By the time he returns to America, he has modified his conception of how, exactly, we should go about steeling ourselves in the face of the decadent imperatives of a consumerist, conformist world. What Kaag overlooked in his youth is that Nietzsche does not prescribe difficulty for its own sake. Though the metaphorical language Nietzsche employed throughout his career is wildly inconsistent, he was ultimately an advocate of health—but health, he emphasized, is not synonymous with enjoyment. On the contrary, health requires the trials that beget a strong constitution (and Nietzsche did not have SoulCycle in mind). In The Will to Power, he wrote, To those human beings who are of any concern to me I wish suffering, desolation, sickness, ill-treatment,

Annotation 3316901088524

 Kaag needed two trips to the Alps to grasp that Nietzsche counsels us to celebrate our suffering because we can avoid it only if we avoid engagement—only if we insulate ourselves from the hardship that is part and parcel of even the most placid human existence. Kaag concludes that a celebration of life needn’t entail self-immolation, but it necessarily entails difficulty. “The self does not lie passively in wait for us to discover it. Selfhood is made in the active, ongoing process, in the German verb werden, ‘to become,’ ” he writes.

How to Live Better, According to Nietzsche
ure of self-mistrust, the wretchedness of the vanquished: I have no pity for them, because I wish them the only thing that can prove today whether one is worth anything or not—that one endures. <span>Kaag needed two trips to the Alps to grasp that Nietzsche counsels us to celebrate our suffering because we can avoid it only if we avoid engagement—only if we insulate ourselves from the hardship that is part and parcel of even the most placid human existence. Kaag concludes that a celebration of life needn’t entail self-immolation, but it necessarily entails difficulty. “The self does not lie passively in wait for us to discover it. Selfhood is made in the active, ongoing process, in the German verb werden, ‘to become,’ ” he writes. Life goes on for Kaag, of course, and the threat of complacency looms: “Syllabi were dutifully written. Conferences were studiously organized. Bathrooms were meticulously cleaned.” But

Annotation 3316902661388

 Life goes on for Kaag, of course, and the threat of complacency looms: “Syllabi were dutifully written. Conferences were studiously organized. Bathrooms were meticulously cleaned.” But Kaag resists—not by fasting or hiking mountains in inadequate footwear but by recalling as often as possible, in the intervals between deadening and dulling, that “things must suffer, go dark, perish before they live again. This is not an escape or respite from life but rather its realization.” Kaag may have outgrown his youthful dramatics, but he continues to let philosophy upend him. It once took him all the way to the edge of an Alpine precipice, to the brink of starvation. It went on to undo one marriage and inspire another. And it continues to heal us, not by making us feel better, but by making us well.

How to Live Better, According to Nietzsche
ssarily entails difficulty. “The self does not lie passively in wait for us to discover it. Selfhood is made in the active, ongoing process, in the German verb werden, ‘to become,’ ” he writes. <span>Life goes on for Kaag, of course, and the threat of complacency looms: “Syllabi were dutifully written. Conferences were studiously organized. Bathrooms were meticulously cleaned.” But Kaag resists—not by fasting or hiking mountains in inadequate footwear but by recalling as often as possible, in the intervals between deadening and dulling, that “things must suffer, go dark, perish before they live again. This is not an escape or respite from life but rather its realization.” Kaag may have outgrown his youthful dramatics, but he continues to let philosophy upend him. It once took him all the way to the edge of an Alpine precipice, to the brink of starvation. It went on to undo one marriage and inspire another. And it continues to heal us, not by making us feel better, but by making us well. <span>

Flashcard 3316912098572

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#blockchain
Question
A Corda network consists of the following components:
• Nodes, communicating using AMQP/1.0 over TLS. Nodes use a relational database for data storage.
• A permissioning service that automates the process of provisioning TLS certificates.
• A network map service that publishes information about nodes on the network.
• One or more notary services. A notary may itself be distributed over multiple nodes.
• Zero or more oracle services. An oracle is a well known service that signs transactions if they state a fact and that fact is considered to be true.

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Open it
3 The peer to peer network 3.1 Network overview A Corda network consists of the following components: • Nodes, communicating using AMQP/1.0 over TLS. Nodes use a relational database for data storage. • A permissioning service that automates the process of provisioning TLS certificates. • A network map service that publishes information about nodes on the network. • One or more notary services. A notary may itself be distributed over multiple nodes. • Zero or more oracle services. An oracle is a well known service that signs transactions if they state a fact and that fact is considered to be true. They may also optionally also provide the facts. This is how the ledger can be connected to the real world, despite being fully deterministic. A purely in-memory implementation of the m

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Flashcard 3316915244300

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#blockchain
Question
Identity and the permissioning service

Unlike Bitcoin and Ethereum, Corda is designed for semi-private networks in which admission requires obtaining an identity signed by a root authority. This assumption is pervasive – the flow API provides messaging in terms of identities, with routing and delivery to underlying nodes being handled automatically. There is no global broadcast at any point. This ‘identity’ does not have to be a legal or true identity. In the same way that an email address is a globally unique pseudonym that is ultimately rooted by the top of the DNS hierarchy, so too can a Corda network work with arbitrary self-selected usernames. The permissioning service can implement any policy it likes as long as the identities it signs are globally unique. Thus an entirely anonymous Corda network is possible if a suitable IP obfuscation system like Tor 6 is also used

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Open it
ommunica- tions between them. This can be useful for debugging, testing and educational purposes. Oracles and notaries are covered in later sections. 3.2 Identity and the permissioning service <span>Unlike Bitcoin and Ethereum, Corda is designed for semi-private networks in which admission requires obtaining an identity signed by a root authority. This assumption is pervasive – the flow API provides messaging in terms of identities, with routing and delivery to underlying nodes being handled automatically. There is no global broadcast at any point. This ‘identity’ does not have to be a legal or true identity. In the same way that an email address is a globally unique pseudonym that is ultimately rooted by the top of the DNS hierarchy, so too can a Corda network work with arbitrary self-selected usernames. The permissioning service can implement any policy it likes as long as the identities it signs are globally unique. Thus an entirely anonymous Corda network is possible if a suitable IP obfuscation system like Tor 6 is also used. <span>

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Flashcard 3316919438604

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#blockchain
Question
Distributed databases vs Decentralized databases
distributed database like BigTable 2 scales to large datasets and transaction volumes by spreading the data over many computers. However it is assumed that the computers in question are all run by a single homogenous organisation and that the nodes comprising the database all trust each other not to misbehave or leak data. In a decentralised database, such as the one underpinning Bitcoin 3 , the nodes make much weaker trust assumptions and actively cross-check each other’s work. Such databases trade performance and usability for security and global acceptance

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distributed database like BigTable 2 scales to large datasets and transaction volumes by spreading the data over many computers. However it is assumed that the computers in question are all run by a single homogenous organisation and that the nodes comprising the database all trust each other not to misbehave or leak data. In a decentralised database, such as the one underpinning Bitcoin 3 , the nodes make much weaker trust assumptions and actively cross-check each other’s work. Such databases trade performance and usability for security and global acceptance

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Flashcard 3316923108620

Tags
#blockchain
Question
Corda features
• Nodes are arranged in an authenticated peer to peer network. All com- munication is direct.
• There is no block chain 3 . Transaction races are deconflicted using plug- gable notaries. A single Corda network may contain multiple notaries that provide their guarantees using a variety of different algorithms. Thus Corda is not tied to any particular consensus algorithm. (§7)
• Data is shared on a need-to-know basis. Nodes provide the dependency graph of a transaction they are sending to another node on demand, but there is no global broadcast of all transactions.
• Bytecode-to-bytecode transpilation is used to allow complex, multi-step transaction building protocols called flows to be modelled as blocking code. The code is transformed into an asynchronous state machine, with checkpoints written to the node’s backing database when messages are sent and received. A node may potentially have millions of flows active at once and they may last days, across node restarts and even upgrades. Flows expose progress information to node administrators and users and may interact with people as well as other nodes. A Flow library is provided to enable developers to re-use common Flow types such as notarisation, membership broadcast and so on.

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• Nodes are arranged in an authenticated peer to peer network. All com- munication is direct. • There is no block chain 3 . Transaction races are deconflicted using plug- gable notaries. A single Corda network may contain multiple notaries that provide their guarantees using a variety of different algorithms. Thus Corda is not tied to any particular consensus algorithm. (§7) • Data is shared on a need-to-know basis. Nodes provide the dependency graph of a transaction they are sending to another node on demand, but there is no global broadcast of all transactions. • Bytecode-to-bytecode transpilation is used to allow complex, multi-step transaction building protocols called flows to be modelled as blocking code. The code is transformed into an asynchronous state machine, with checkpoints written to the node’s backing database when messages are sent and received. A node may potentially have millions of flows active at once and they may last days, across node restarts and even upgrades. Flows expose progress information to node administrators and users and may interact with people as well as other nodes. A Flow library is provided to enable developers to re-use common Flow types such as notarisation, membership broadcast and so on.

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Annotation 3316928613644

 The difference between define an object and build an object: Define an object: a geometric object in Salome is defined only the six basic geometric objects Building an object: a geometric object in Salome can be built by objects other than the basic ones Example: the cube Define: eight vertex , twelve edge , etc. Build: two vertex in the global coordinate system (parallel to global axis)

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Annotation 3316930186508

 A wire is not necessarily plane.

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Annotation 3316931759372

 A wire is collection of several edge

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Annotation 3316933332236

 A face is not necessarily plane

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Annotation 3316934905100

 A shell is collection of several face

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Annotation 3316944866572

 We can define as many local coordinate system objects as necessary. In particular, a local coordinate system object allows you to define the workplane of the 2D sketch utility. Remarque: The global coordinate system is created by default. If you accidentally destroy it, you can re-draw it using the New entity Basic Origin and Base Vectors command.

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Annotation 3316946439436

 To construct shell with hole(s), use face with hole(s)

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Flashcard 3316949585164

Question
In python, list = [1,2,3,4,5,6] can be reduced to list2 = [2,4, 6] using either the [...] higher order function or list comprehension
filter

status measured difficulty not learned 37% [default] 0

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Flashcard 3316954565900

Question
In python, list = [1,2,3,4,5,6] can be reduced to list2 = [2,4, 6] using either the filter higher order function or [...] .
list comprehension

status measured difficulty not learned 37% [default] 0

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Flashcard 3316957711628

Question
In python, reduce list = [1,2,3,4,5,6] to list2 = [2,4, 6] using the filter function: list2 = [...]
filter(lambda x: x%2==0, list)

status measured difficulty not learned 37% [default] 0

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Flashcard 3316960857356

Question
In python, reduce list = [1,2,3,4,5,6] to list2 = [2,4, 6] using the list comprehension: list2 = [...]
[x for x in list if x%2==0]

status measured difficulty not learned 37% [default] 0

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Flashcard 3316965313804

Question
In python list = [1,2,3,4] can be mapped to list2 = [2,4,6,8] using either the [...] (higher order) function or list comprenension.
map

status measured difficulty not learned 37% [default] 0

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Flashcard 3316968459532

Question
In python list = [1,2,3,4] can be mapped to list2 = [2,4,6,8] using either the map (higher order) function or [...]
list comprehension

status measured difficulty not learned 37% [default] 0

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Flashcard 3316971605260

Question
In python, map list = [1,2,3,4] to list2 = [2,4,6,8] using the map function: list2 = [...]
map(lambda x: x*2, list)

status measured difficulty not learned 37% [default] 0

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Flashcard 3316974750988

Question
In python, map list = [1,2,3,4] to list2 = [2,4,6,8] using list comprehension: list2 = [...]
[x*2 for x in list]

status measured difficulty not learned 37% [default] 0

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Flashcard 3316977896716

Question
In Python, functions that change the called upon object (e.g. list.sort() ) return [...] to make it clear that no new object was created and that the object itself was changed.
None

status measured difficulty not learned 37% [default] 0

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Flashcard 3316981042444

Question
In python, there are two ways to sort a list: using list. [...] or using the more generic built-in sorted() method.
sort()

status measured difficulty not learned 37% [default] 0

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Flashcard 3316984188172

Question
In python, there are two ways to sort a list: using list.sort() or using the more generic built-in [...] method.
sorted()

status measured difficulty not learned 37% [default] 0

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Flashcard 3316987333900

Question
In python, the build-in generic sorted() method, accepts any [...] object as an argument to sort but will always return a list.
iterable

status measured difficulty not learned 37% [default] 0

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Flashcard 3316990479628

Question
In python, the build-in generic sorted() method, accepts any iterable object as an argument to sort but will always return a [...] .
list

status measured difficulty not learned 37% [default] 0

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Flashcard 3316995460364

Question
In python, create a sorted word list from the sentance "the longest word in this sentance it", sorting the words by length (shortest to longest): sorted_length_words = [...]
sorted(str.split("the longest word is"), key=len)

status measured difficulty not learned 37% [default] 0

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Flashcard 3316998606092

Question
In python, sort list of items = [["rice", 1.2, 5], ["beans", 0.8, 9], ["wheat", 1.1, 20]] by price (second value in the sublists), sort in place (i.e. change "items" directly).
items.sort(key=lambda x: x[1])

status measured difficulty not learned 37% [default] 0

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Flashcard 3317001751820

Question
In python, the proper way to split a string like "a bunch of words" into a list of words is: [...]
str.split("a bunch of words")
OR: "a buch of words".split()

status measured difficulty not learned 37% [default] 0

Flashcard 3317004373260

Question
In python, [...] are functions that do not just return one result, but rather an entire sequence of results.
genrators

status measured difficulty not learned 37% [default] 0

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Flashcard 3317007518988

Question
In python, generators return an entire sequence of results one at a time, by using the [...] statement.
yield

status measured difficulty not learned 37% [default] 0

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Flashcard 3317010664716

Question
In python, generator functions, which are an easy way to create iterators, are especially useful as a replacement for [...] lists.
Very long/very big/too big to hold in memory
any variation of this is good answer:)

status measured difficulty not learned 37% [default] 0

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Flashcard 3317013810444

Question
In python, a generator expression, is the equavilant for generators what a [...] is for lists
list comprehensions

status measured difficulty not learned 37% [default] 0

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Flashcard 3317016956172

Question
In python, a [...] [...] , is the equavilant for generators what a list comprehension is for lists
generator expression

status measured difficulty not learned 37% [default] 0

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Flashcard 3317020101900

Question
In python, create a generator expression that takes a list = [1,2,3,4,5,6] and doubles each item. gen_exp = [...]
(x*2 for x in list)
^^^ NOTE the surrounding ROUND BRACKETS

status measured difficulty not learned 37% [default] 0

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Flashcard 3317023247628

Question
In python, commonly generator objects are used in [...] .
for loops

status measured difficulty not learned 37% [default] 0

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Flashcard 3317026393356

Question
In python, classes are created using the [...] statement.
class

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Flashcard 3317031111948

Question
In python class definitions, all defined instance methods take as the first argument an instance of the class to which the function is being applied, by convension this argument is named: [...]
self

status measured difficulty not learned 37% [default] 0

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Flashcard 3317034257676

Question
In python class definitions, all defined instance methods take as the [...] argument an instance of the class to which the function is being applied, by convension this argument is named: self
first

status measured difficulty not learned 37% [default] 0

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Flashcard 3317037403404

Question
In python, [...] variables, share values among all the instances of the class and are defined at the top of the class without the self. prefix
class

status measured difficulty not learned 37% [default] 0

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Flashcard 3317040549132

Question
In python, class variables, share values among all the instances of the class and are defined at the top of the class without the [...] prefix
self.

status measured difficulty not learned 37% [default] 0

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Flashcard 3317043694860

Question
In python, class variables, share values among all the instances of the class and are urually defined at the [...] of the class without the self. prefix
top

status measured difficulty not learned 37% [default] 0

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Flashcard 3317049199884

Question
In python, class variables, share values among all the [...] of the class and are defined at the top of the class without the self. prefix
instances

status measured difficulty not learned 37% [default] 0

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Flashcard 3317052345612

Question
In python create an instance of the below Empolyee class called kevin:
class Employee(object):
def __init__(self, name):
self.name = name

Employee("kevin")

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Flashcard 3317055491340

Question
In python, you can use the [...] (object) function to get a list of instance variables and methods of a particular object.
dir

status measured difficulty not learned 37% [default] 0

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Flashcard 3317058637068

Question
In python class definitions, special methods that begin and end with [...] , are usually not called directly by the programmer but automatically by the python interpretor
double underscore (e.g.: __len__)

status measured difficulty not learned 37% [default] 0

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Flashcard 3317062569228

Question
In python class definitions, special methods that begin and end with double underscore, are usually not [...] but automatically by the python interpretor
called directly by the programmer

status measured difficulty not learned 37% [default] 0

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Flashcard 3317065714956

Question
In python, do pretty print of "the amount is 4.99" using the amount variable, where amount = 4.99
print 'the amount is %0.2f' % amount

status measured difficulty not learned 37% [default] 0

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Flashcard 3317068860684

Question
In python, you have class Employee, now define inheritence class SpecialEmployee. Write just the first line of the class definition
class SpecialEmployee(Employee):

status measured difficulty not learned 37% [default] 0

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Annotation 3317069909260

 A line object is a special edge object because it is straight whereas a edge object can be curved (see objects circle , ellipse , and arc )

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Annotation 3317071482124

 o build circle : New entity Basic Circle The circle object will create a curved edge object that closes on itself. So it has only one object vertex (but which is not the center!)

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Annotation 3317076725004

 The Bezier curve ( ): is a edge curved object defined by its control points (Beziers polynomials). The set constitutes a (single) object edge curve (which can constitute an open or closed curve). This object contains two vertex objects and one edge object for the open case and one vertex object for the closed case. It can also be defined by a parametric parametric equation with three parameters. Since this curve is not interpolating, it does not pass through all vertex objects but only by the first and the last

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Flashcard 3317078297868

Question
In python, complete the following code snippet to show how subclass needs to set some additional instance variable (i.e. employee_number) on top of the name instance variable inherited from its parent class:

class Employee(object):
def __init__(self, name):
self.name = name
class SpecialEmployee(Employee):
def __init__(self, name, employee_number):
[...]
self.employee_number = employee_number
Employee.__init__(self, name)

status measured difficulty not learned 37% [default] 0

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Flashcard 3317081443596

Question
In python, you have object kevin = Employee("kevin") , how do you check if kevin is an instance of the Employee class (or any of its parent classes)?
isinstance(kevin, Employee)

status measured difficulty not learned 37% [default] 0

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Annotation 3317084589324

 extruding a wire will create an object of type shell extruding a face will create an object of type solid

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Annotation 3317086424332

 n Salome, an object block is a geometric entity that will allow to mesh with rectangles or hexahedrons.