27 Eylül 2010 Pazartesi

Kite Runner

The Kite Runner is a novel by Khaled Hosseini. Published in 2003 by Riverhead Books, it is Hosseini's first novel, and was adapted into a film of the same name in 2007.

The Kite Runner tells the story of Amir, a young boy from the Wazir Akbar Khan district of Kabul, who befriends Hassan, the son of his father's Hazara servant. The story is set against a backdrop of tumultuous events, from the fall of Afghanistan's monarchy through the Soviet invasion, the mass exodus of refugees to Pakistan and the United States, and the rise of the Taliban regime.

The Kite Runner received the South African Boeke Prize in 2004. It was the first 2005 best seller in the United States, according to Nielsen BookScan. It was also voted the Reading Group Book of the Year for 2006 and 2007 and headed a list of 60 titles submitted by entrants to the Penguin/Orange Reading Group prize.


The Kite Runner was published in 2003 and in 2007 adapted as a motion picture starring Khalid Abdalla (Amir), Homayoun Ershadi (Baba), and Ahmad Khan Mahmoodzada (Hassan). Directed by Marc Forster and with a screenplay by David Benioff, this movie won numerous awards and was nominated for an Oscar (2008), the BAFTA Film Award (2008) and the Critics Choice Award (2008). However, Manhola Dargis of the New York Times states that "The back of my paperback copy of this Khaled Hosseini novel is sprinkled with words like 'powerful' and 'haunting' and 'riveting' and 'unforgettable'. It's a good guess this film will be rolled around in a similarly large helping of lard."

In addition to the film adaptation, the novel was also adapted to the stage by Bay Area playwright Matthew Spangler. David Ira Goldstein (Arizona Theater Company Artistic Director) directed a cast that included Barzin Akhavan as Amir, Demosthenes Chrysan (General Taheri), Gregor Paslawsky (Rahim Khan) and James Saba (Ali), all from New York City, Thamos Fiscelle (Baba) of Los Angeles, and Bay Area actors Craig Piaget (Young Amir), Lowell Abellon (Young Hassan), Rinabeth Apostol (Soraya), Adam Yazbeck (Assef), Zarif Kabier Sadiqi, Wahab Shayek, and Lani Carissa Wong. The cast was joined on stage by Tabla player Salar Nader.

The Kite Runner was given its southwest premiere on stage at the Arizona Theatre Company in September-October 2009. David Ira Goldstein again directed. The cast was the same except that Korken Alexander replaced Adam Yazbeck as Assef and Remi Sandri replaced Demosthenes Chrysan as General Taheri.

The Kite Runner is receiving its Mid-West premiere at Actor's Theatre of Louisville directed by Artistic Director, Marc Masterson. The Cast includes Jos Viramontes (Amir), Jose Pere Flores (Young Amir), Nasser Faris (Baba), Matt Pascua (Hassan/Sohrab), Zarif Kabier Sadiqi (Assef), James Saba (Ali/Zaman), Remi Sandri (General Taheri), Aadya Bedi (Sorya), Omar Koury (Farid), Ariya Ghahramani, Kario Pereira-Bailey and Annie Pesch. The cast is once again joined by Salar Nader playing life Tabla for the production.

25 Eylül 2010 Cumartesi


An array of 17 purpose-built oxygen-depleted titanium dioxide memristors built at HP Labs, imaged by an atomic force microscope. The wires are about 50 nm, or 150 atoms, wide. Electric current through the memristors shifts the oxygen vacancies, causing a gradual and persistent change in electrical resistance.

A memristor (a portmanteau of "memory resistor") is a passive two-terminal circuit element in which the resistance is a function of the time history of the current and voltage through the device. Memristor theory was formulated and named by Leon Chua in a 1971 paper.

On April 30, 2008 a team at HP Labs announced the development of a switching memristor. Based on a thin film of titanium dioxide, it has a regime of operation with an approximately linear charge-resistance relationship. These devices are being developed for application in nanoelectronic memories, computer logic, and neuromorphic computer architectures.

A memristor is a passive two-terminal electronic component for which the resistance (dV/dI) is proportional to the amount of charge that has flowed through the circuit. When current flows in one direction through the device, the resistance increases; and when current flows in the opposite direction, the resistance decreases. When the current is stopped, the component retains the last resistance that it had, and when the flow of charge starts again, the resistance of the circuit will be what it was when it was last active.

More generally, a memristor is a two-terminal component in which the resistance depends on the integral of the input applied to the terminals, rather than on the instantaneous value of the input at the terminals. Since the element "remembers" the amount of current that has passed through it in the past, it was tagged by Chua with the name "memristor." A general memristor is any of various kinds of passive two-terminal circuit elements that maintain a functional relationship between the time integrals of current and voltage. This function, called memristance, is similar to variable resistance. Specifically engineered memristors provide controllable resistance, but such devices are not commercially available. Other devices such as batteries and varistors have memristance, but it does not normally dominate their behavior. The definition of the memristor is based solely on fundamental circuit variables, similar to the resistor, capacitor, and inductor. Unlike those three elements, which are allowed in linear time-invariant or LTI system theory, memristors are nonlinear and may be described by any of a variety of time-varying functions of net charge. There is no such thing as a generic memristor. Instead, each device implements a particular function, wherein either the integral of voltage determines the integral of current, or vice versa. A linear time-invariant memristor is simply a conventional resistor.

In his 1971 paper, memristor theory was formulated and named by Leon Chua, extrapolating the conceptual symmetry between the resistor, inductor, and capacitor, and inferring that the memristor is a similarly fundamental device. Other scientists had already proposed fixed nonlinear flux-charge relationships, but Chua's theory introduced generality.

Like other two-terminal components (e.g., resistor, capacitor, inductor), real-world devices are never purely memristors ("ideal memristor"), but will also exhibit some amount of capacitance, resistance, and inductance.

Williams' solid-state memristors can be combined into devices called crossbar latches, which could replace transistors in future computers, taking up a much smaller area.

They can also be fashioned into non-volatile solid-state memory, which would allow greater data density than hard drives with access times potentially similar to DRAM, replacing both components. HP prototyped a crossbar latch memory using the devices that can fit 100 gigabits in a square centimeter, and has designed a highly scalable 3D design (consisting of up to 1000 layers or 1 petabit per cm3).[7] HP has reported that its version of the memristor is currently about one-tenth the speed of DRAM. The devices' resistance would be read with alternating current so that the stored value would not be affected.

Some patents related to memristors appear to include applications in programmable logic, signal processing, neural networks, and control systems.

Recently, a simple electronic circuit consisting of an LC network and a memristor was used to model experiments on adaptive behavior of unicellular organisms. It was shown that the electronic circuit subjected to a train of periodic pulses learns and anticipates the next pulse to come, similarly to the behavior of slime molds Physarum polycephalum subjected to periodic changes of environment. Such a learning circuit may find applications, e.g., in pattern recognition.

18 Eylül 2010 Cumartesi


90377 Sedna is a trans-Neptunian object, discovered in 2003, which currently lies about three times as far from the Sun as Neptune. However, its farthest orbital distance from the Sun is estimated to be 960 astronomical units (AU), and thus it is, for the majority of its orbit, the most distant known object in the Solar System after long-period comets.

Roughly two-thirds the size of Pluto, Sedna is hypothetically large enough to be rounded by its own gravity, and thus would qualify as a dwarf planet under current definitions. However, its distance from the Sun makes determining its shape difficult. Spectroscopy has revealed that Sedna's surface composition is similar to that of some other trans-Neptunian objects, being largely a mixture of water, methane and nitrogen ices with tholins. Its surface is one of the reddest in the Solar System.

Sedna's exceptionally long and elongated orbit, taking approximately 12,000 years to complete, and distant point of closest approach to the Sun, at 76 AU, have led to much speculation as to its origin. The Minor Planet Center currently places Sedna in the scattered disc, a group of objects sent into highly elongated orbits by the gravitational influence of Neptune. However, this classification has been contested, as Sedna never comes close enough to Neptune to have been scattered by it, leading some astronomers to conclude that it is in fact the first known member of the inner Oort cloud. Others speculate that it might have been tugged into its current orbit by a passing star, perhaps one within the Sun's birth cluster, or even that it was captured from another star system. Another hypothesis suggests that its orbit may be evidence for a large planet beyond the orbit of Neptune. Astronomer Mike Brown, who co-discovered Sedna as well as the dwarf planets Eris, Haumea, and Makemake, believes it to be the most scientifically important trans-Neptunian object found to date, as understanding its peculiar orbit is likely to yield valuable information about the origin and early evolution of the Solar System.

Orbit and rotation

Barring comets, Sedna has the longest orbital period of any known object in the Solar System, calculated at between 11,800 and 12,100 years. This represents a best-fit solution, as Sedna has only been observed over a brief part of its orbital arc. Its orbit is extremely elliptical, with an aphelion estimated at 960 AU and a perihelion at about 76 AU. At its discovery it was approaching perihelion at 89.6 AU from the Sun, and was the most distant object in the Solar System yet observed. Eris was later detected by the same survey at 97 AU. Although the orbits of some long-period comets extend farther than that of Sedna, they are too dim to be discovered except when approaching perihelion in the inner Solar System. Even as Sedna nears its perihelion in late 2075 to mid 2076, the Sun would appear merely as a bright star in its sky: with an angular diameter too small to resolve as a disc, it would be only 100 times brighter than a full Moon on Earth.

When first discovered, Sedna was believed to have an unusually long rotational period (20 to 50 days). It was initially speculated that Sedna's rotation was slowed by the gravitational pull of a large binary companion, similar to Pluto's moon Charon. A search for such a satellite by the Hubble Space Telescope in March 2004 found nothing, and subsequent measurements from the MMT telescope suggest a much shorter rotation period, only about 10 hours, rather typical for bodies of its size.

5 Eylül 2010 Pazar

Bulldozer Core (AMD)

Bulldozer is the codename AMD has given to one of the next-generation CPU cores after the K10 microarchitecture for the company's M-SPACE design methodology, with the core specifically aimed at 10 watt to 100 watt TDP computing products. Bulldozer is a completely new design developed from the ground up. AMD claims dramatic performance-per-watt improvements in HPC applications with Bulldozer cores. Products implementing the Bulldozer core are planned for release in 2011.

According to AMD, Bulldozer-based CPUs will be based on advanced 32nm SOI process technology and utilize a new approach to multithreaded computer performance that, according to press notes, "balances dedicated and shared compute resources to provide a highly compact, high core count design that is easily replicated on a chip for performance scaling." In other words, by eliminating some of the redundancies that naturally creep into multicore designs, AMD hopes to take better advantage of its hardware capabilities, while utilizing less power.

The Bulldozer cores will support most of the instruction sets currently implemented in Intel processors (including SSE4.1, SSE4.2, AES, CLMUL), future Instruction sets announced by Intel (AVX), as well as future instruction sets proposed by AMD (XOP and FMA4).

As of November 2009, Bulldozer-based implementations built on 32nm SOI with HKMG are scheduled to arrive in 2011 for both servers and desktops, as the 16-core Opteron processor codenamed Interlagos and as the 4- or 8-core desktop processor codenamed Zambezi.

Bulldozer is the next-generation micro-architecture and processor design developed from the ground up by AMD. Bulldozer will be the first major redesign of AMD’s processor architecture since 2003, when the firm launched its Athlon 64/Opteron (K8) processors. Bulldozer will feature two 128-bit FMA-capable FPUs which can be combined into one 256-bit FPU. This design is accompanied with two integer cores each with 4 pipelines (the fetch/decode stage is shared). Bulldozer will also introduce shared L2 cache in the new architecture. AMD calls this design a "Bulldozer module". A 16-core processor design would feature eight of these modules, but the operating system will see each module as two physical cores.

The module is similar to an SMT core, but enhanced with a dedicated integer core and scheduler for each thread. Because the shared floating point core is significantly enhanced, performance could get beyond that of two equivalent Bobcat cores while one of the running threads is integer-only.

Bulldozer Design Breakdown

* Two tightly coupled, "conventional" x86 out-of-order processing engines which AMD internally named module
(Single-Module ==> Dual-Core, Dual-Module ==> Quad-Core, Quad-Module ==> Octa-Core etc...)
* Between 8MB to 16MB of L3 cache shared among all Modules on the same silicon die
* DDR3-1866 and Higher Memory Level Parallelism
* Dual channel DDR3 integrated memory controler (support for PC3-12800 (DDR3-1600))
* Cluster Multi-threading (CMT) Technology
* Bulldozer module consists of the following:
o 128kB L2 cache inside each module (shared between module cores)
o 4kB L1 data cache per core and 2-way 16kB L1 instruction cache per module L1 cache, Fruehe for THW
o Two dedicated integer cores
- each consist of 2 ALU and 2 AGU which are capable for total of 4 independent arithmetic or memory operations per clock per core
- duplicating integer schedulers and execution pipelines offers dedicated hardware to each of two threads which significantly increase performance in multithreaded integer applications
- second integer core increases Bulldozer module die by around 12%, which at chip level adds about 5% of total die space[9]
o Two symmetrical 128-bit FMAC (fused multiply-add (FMA) capability) Floating Point Pipelines per module that can be unified into one large 256-bit wide unit if one of integer cores dispatch AVX instruction and two symmetrical x87/MMX/3DNow! capable FPPs for backward compatibility with SSE2 non-optimized software
* 32nm SOI process with implemented first generation GF's High-K Metal Gate (HKMG)
* Support for AMD's only SSE5 128-bit instructions
- incl. three smaller supplemental extensions CVT16, XOP and FMA4 instruction set, which are now part of SSE5 specification (since May 2009 revision)
* Support for Intel's Advanced Vector Extensions (AVX) (Supports 256-Bit FP Operations via AVX)SSE4.1, SSE4.2, AES, CLMUL), future Instruction sets announced by Intel (AVX), as well as future instruction sets proposed by AMD (XOP and FMA4
* Hyper Transport Technology rev.3.1 (3.20 GHz, 6.4 GT/s, 51.6 GB/s, 16-bit uplink/16-bit downlink) [first implemented into HY-D1 revision "Magny-Cours" on the socket G34 Opteron platform in March 2010 and "Lisbon" on the socket C32 Opteron platform in June 2010]
* Socket AM3+ (AM3r2)
- 938pin(?), DDR3 support
- will retain only backwards compatiblity with previous Socket AM3/AM2 processors ("new AM3+ socket for consumer versions of Bulldozer CPUs. AM2 and AM3 processors will work in the AM3+ socket, but Bulldozer chips will not work in non-AM3+ motherboards")
* Min-Max Power Usage - 10-100 watts
* Bulldozer Module sharing levels Bulldozer module

3 Eylül 2010 Cuma

Deniable Encryption

In cryptography and steganography, deniable encryption is encryption that allows its users to convincingly deny the fact that the data is encrypted or, assuming that the data is obviously encrypted, its users can convincingly deny that they are able to decrypt it. Such convincing denials may or may not be genuine, e.g., although suspicions might exist that the data is encrypted, it may be impossible to prove it without the cooperation of the users. In any case, even if the data is encrypted then the users genuinely may not have the ability to decrypt it. Deniable encryption serves to undermine an attacker's confidence either that data is encrypted, or that the person in possession of it can decrypt it and provide the associated plaintext.

Normally ciphertexts decrypt to a single plaintext and hence once decrypted, the encryption user cannot claim that he encrypted a different message. Deniable encryption allows its users to decrypt the ciphertext to produce a different (innocuous but plausible) plaintext and insist that it is what they encrypted. The holder of the ciphertext will not have the means to differentiate between the true plaintext, and the bogus-claim plaintext.

Deniable encryption allows an encrypted message to be decrypted to different sensible plaintexts, depending on the key used, or otherwise makes it impossible to prove the existence of the real message without the proper encryption key. This allows the sender to have plausible deniability if compelled to give up his or her encryption key. The notion of "deniable encryption" was introduced by Julian Assange & Ralf Weinmann in the Rubberhose filesystem and explored in detail in a paper by Ran Canetti, Cynthia Dwork, Moni Naor, and Rafail Ostrovsky in 1996.

Modern forms of deniable encryption

Modern deniable encryption techniques exploit the pseudorandom permutation properties of existing block ciphers, making it cryptographically infeasible to prove that the ciphertext is not random padding data generated by a cryptographically secure pseudorandom number generator. This is used in combination with some decoy data that the user would plausibly want to keep confidential that will be revealed to the attacker, claiming that this is all there is. This form of deniable encryption is sometimes referred to as "steganographic encryption".

One example of deniable encryption is a cryptographic filesystem that employs a concept of abstract "layers", where each layer would be decrypted with a different encryption key. Additionally, special "chaff layers" are filled with random data in order to have plausible deniability of the existence of real layers and their encryption keys. The user will store decoy files on one or more layers while denying the existence of others, claiming that the rest of space is taken up by chaff layers. Physically, these types of filesystems are typically stored in a single directory consisting of equal-length files with filenames that are either randomized (in case they belong to chaff layers), or cryptographic hashes of strings identifying the blocks. The timestamps of these files are always randomized. Examples of this approach include Rubberhose filesystem and PhoneBookFS.

Another approach utilized by some conventional disk encryption software suites is creating a second encrypted volume within a container volume. The container volume is first formatted by filling it with encrypted random data and then initializing a filesystem on it. The user then fills some of the filesystem with legitimate, but plausible-looking decoy files that the user would seem to have an incentive to hide. Next, a new encrypted volume (the hidden volume) is allocated within the free space of the container filesystem which will be used for data the user actually wants to hide. Since an adversary cannot differentiate between encrypted data and the random data used to initialize the outer volume, this inner volume is now undetectable. Concerns have, however, been raised for the level of plausible deniability in hiding information this way – the contents of the "outer" container filesystem (in particular the access or modification timestamps on the data stored) could raise suspicions as a result of being frozen in its initial state to prevent the user from corrupting the hidden volume. This problem can be eliminated by instructing the system not to protect the hidden volume, although this could result in lost data. FreeOTFE and BestCrypt can have many hidden volumes in a container; TrueCrypt is limited to one hidden volume.

Needless to say, insecure block ciphers or pseudorandom number generators can make it possible to compromise the deniability of such filesystems. To escape the assumption that the used pseudorandom number generation is cryptographically secure, it has been advised to instead fill the encrypted space with pseudorandom data which has itself been encrypted, thus being protected by a separate encryption key since encrypted data is impossible to differentiate from encrypted data In addition to that, the flawed use of block cipher modes of operation can also compromise the cipher algorithm due to watermarking attacks.

2 Eylül 2010 Perşembe


Singularity is a video game developed by Raven Software published by Activision and released for Microsoft Windows, Xbox 360, and PlayStation 3, Singularity is Raven Software's second title based on Epic Games' Unreal Engine 3. The title was announced at Activision's E3 2008 press conference.

The game takes place on a mysterious island known as "Katorga-12" where Russian experiments involving "E99" took place during the height of the Cold War era. Sometime during 1955, a terrible catastrophe involving experiments attempting to form a "Singularity" occurred on the island, causing the island's very existence to be covered up by the Russian government. The player controls Nate Renko, a Black Ops soldier who is sent to investigate bizarre radiation emissions coming from the island. The operation goes poorly when team crashes during transport and the operation is scrapped. After regaining consciousness, Renko discovers that the island is constantly shifting between the time periods of 1955 and 2010. Renko acidentally shifts the timeline by saving a scientist who died in 1955. Renko finds the TMD (Time Manipulation Device), a device created by Dr. Victor Barisov. Barisov, the scientist who was in charge of the Katorga-12 experiments, reveals that a man named Nikolai Demichev, also a scientist on Katorga-12, used E99 technology to conquer the world. During the quest to stop Demichev, the player deals with hostile Russian forces in both time periods, and the mutated flora, fauna and former residents of the island, some of which have developed extreme power of their own.

In response to the United States' development and deployment of the atomic bomb, Joseph Stalin makes nuclear research the top scientific priority of the USSR. On a small island near Kamchatka, scientists discover an isotope of E99 that has strange properties. A research base named Katorga-12 is established on the island. E99-related research continued on the island until late 1955, when the island was destroyed by an accident. The Soviet government then erased any information about Katorga-12 and suppressed public knowledge of the accident.

In 2010, a sudden electromagnetic surge from Katorga-12 damages an American spy satellite. A military reconnaissance team is sent to investigate the uninhabited island, but a second surge causes their helicopter to crash. Captain Nathaniel Renko, a member of the reconnaissance team, enters the abandoned scientific complex on the island, where he phases between 1955 and 2010.

Renko is first transported back to 1955 during a major fire at the facility, where he saves one Nikolai Demichev. As this happens, an unidentified man yells, "Renko, stop! Don't let Demichev live!", before being killed by a ceiling collapse. Dr. Demichev would have otherwise died in the fire; by rescuing him, Renko altered history. Renko is abruptly returned to the year 2010, where he discovers that the island has changed. He encounters strange and violent creatures, and regroups with Devlin, a second survivor of the helicopter crash. Both soldiers are captured by Russian soldiers under the command of Demichev. Devlin demands asylum at the American embassy, at which point he is executed by Demichev.

Renko is saved by an organization called Mir-12. Mir-12 is a secretive resistance organization that bases its existence off of a journal recovered from the accident on Katorga-12. The journal declares that Nathaniel Renko will be able to stop Demichev using the "TMD", or "Time Manipulation Device". This device was apparently created by Dr. Viktor Barisov, who died in a laboratory accident, leaving Demichev to command the research base and eventually rule the world. Kathryn tells Renko to find the TMD and use it to go back in time and save Barisov. Renko succeeds and returns to 2010, where Barisov is now alive and well.

Barisov and Renko plan to fix history by going back in time and destroying the island's Singularity tower with an E-99 bomb. Renko recovers an E99 bomb from a sunken ship (the Pearl), but Kathryn dies in the process.

Renko and Barisov then fight their way into the Singularity Tower, which lies at the heart of Katorga-12. When they reach the tower's reactor, Renko travels back in time and uses the E99 bomb to destroy the reactor; he returns to 2010 moments before the tower is destroyed. It is implied that this explosion triggered the destruction of the Singularity and mutated the island's population.

Upon returning to 2010, Renko finds that nothing has changed. He sees Demichev holding Barisov at gunpoint. Demichev reveals that he rebuilt the facility after the bomb was detonated (presumably at another location). Renko shoots and non-fatally wounds Demichev, freeing Barisov. Barisov realizes that Demichev's rescue is what altered the timeline, and tells Renko that the only way to fix the timeline is for Renko to go back in time and stop himself from rescuing Demichev. Demichev reveals that Renko already tried that; he was the unidentified man that Renko saw in the fire. The three realize that the only way for Renko to stop Demichev's rescue is to kill his past self. Demichev offers Renko unlimited power in exchange for the TMD. The player is left with a choice resulting in three endings, based on whether Renko shoots Demichev, Barisov, or both men.

If the player shoots Barisov, he joins forces with Demichev and the team succeed in taking over most of the world, with Renko training the Katorga-12 mutants as soldiers and using them as first wave attackers in all of his battles. But with his control of the TMD, Demichev feels Renko is even more powerful than he is and takes precautionary measures against him by starting a weapons research program in the former United States. This settles the world into another Cold War with Renko on one side and Demichev on the other, although Renko is most likely to win, seeing he has almost complete control over the East and his power is slowly consuming the West.

If the player shoots both Demichev and Barisov, Renko leaves Katorga-12 and allows the world to fall into chaos. The public believes his very existence to be a myth as he disappears with the TMD in his possession. The Singularity explodes some years later and destroys the eastern coast of Russia and the Western coast of Alaska. Katorga-12 mutants escape onto mainland Russia and wreak havoc. A new leader rises in the former United States and is reported to be very aggressive and tyrannical as he leads the entire world with an iron fist. The in-game cutscenes and narration heavily imply the leader to be Renko himself.

If the player chooses to kill Demichev, or if he shoots neither man, then Barisov urges Renko to go back in time and stop himself from rescuing Demichev by killing his past self. The player then assumes the position of the man who shouted at Renko in the fire, only instead of being crushed by debris, he shoots the past Renko. Shooting the past version of Renko sends the narrative back to Devlin and Renko's arrival at Katorga-12. The game's intro credits are shown written in Russian, the helicopters bear the hammer and sickle on the side, and Devlin, armed with a Russian weapon, comments that monitoring Katorga-12 is a waste of time. The helicopter moves past the statue seen in the intro credits, but it has changed into a massive monument to Barisov wearing the TMD. Renko seems to have retained his memories from the rest of the game, as he checks his left hand when he sees the monument. Renko and Devlin's mission is called off by their dispatcher -- Red Fleet instead of Titan One -- and Devlin refers to Renko as "comrade". It is implied that Barisov recovered the TMD from the fire and used it to unite the world under Soviet rule.

A post-credit scene shows a wounded Kathryn emerging in 1955 from the Pearl's wreckage and hiding in an office. Bleeding heavily, she writes "Renko" in the Mir-12 journal.