Zigzag

This paper presents the architecture and VHDL design of a Two Dimensional Discrete Cosine Transform (2D-DCT) with Quantization and zigzag arrangement. This architecture is used as the core and path in JPEG image compression hardware. The 2D- DCT calculation is made using the 2D- DCT Separability property, such that the whole architecture is divided into two 1D-DCT calculations by using a transpose buffer. Architecture for Quantization and zigzag process is also described in this paper. The quantization process is done using division operation. This design aimed to be implemented in Spartan-3E XC3S500 FPGA. The 2D- DCT architecture uses 1891 Slices, 51I/O pins, and 8 multipliers of one Xilinx Spartan-3E XC3S500E FPGA reaches an operating frequency of 101.35 MHz One input block with 8 x 8 elements of 8 bits each is processed in 6604 ns and pipeline latency is 140 clock cycles.

"In wartime, the truth is so precious that she should always be attended by a bodyguard of lies." Winston Churchill once said, and nowhere was this more important in defending the operational security of the Allied invasion of Europe. Operation Bodyguard was essential amongst Allied deception operations during the Second World War. To systematically distract, disorientate and confuse the German high command as to the date, time and location of the greatest sea-borne landing in history. This deception owes, in no small part, it's success to the brave men and women of the double-cross organisation who played such a pivotal role in hoodwinking the Wehrmacht.

This presentation suggests that this design carried a series of religious meanings when employed within an Islamic context. That the "zigzag" design was "read" in the literal sense, in the combination of the written Arabic numbers 7 and 8 joined together. These, when added together total 15, with these two numbers summed, thereby a repeat design read as representing the repetition of the number 6. The number 6 representing the letter wav meaning "and", as in "and Allah"; and, as also representing the sum of the total number of Sura in the Holy Quran, 1+1+4=6. The repeat of the number 6 being read as both representing and repeating the numerical equivalent of the Name Allah, 66, visually read as zikr, wav=6 +Allah (66), as also reminding of the traditional total number of letters forming the Holy Quran, 6,666. Further, there is the association of this design with light, as it has been employed to represent the reflection of sunlight from the surface of water, as also employed to represent the reflection of light from a polished mirror, as also a design on candlesticks, thereby reminding of the relationship between sun and sunlight and The Light of the Almighty, employed by the designers-nakkaş as a sign, to remind in this temporal world of the nur illahi, of the Light of the Almighty. Hence the use of this design on the Kaba kiswah, on minarets, as on flags and tombs as on tomb coverings etc.

ÖZET Bu bildiri "zikzak" motifinin İslami bağlamda kullanıldığında bir seri dini anlam taşıdığını önermektedir. Motif "metin" olarak okunduğunda Arap rakamları olan 7 ve 8'in birleşiminden oluşur. Bu sayılar toplandığında 15=6 sayısını verir ki Arapça 6 sayısını gösteren şekil aynı zamanda "ve" anlamına gelen "wav" harfinin de şeklidir. "Wav" "ve Allah" olarak okunabileceği gibi, aynı zamanda Kur' an' daki surelerin sayısının da toplamına da işaret eder (1+1+4=6). Allah'ın adının rakamsal ve görsel tekrarı olarak kabul edildiğinde zikzak motifi (wav Allah=66) zikir olarak okunabileceği gibi sayısal olarak tekrarı da Kur' an'ı oluşturan harflerin toplamını (6666) betimliyor olabilir. Öte yandan, zikzak motifinin su yüzeyinden ya da aynadan yansıyan ışığa benzerliğinden yola çıkarak ışıkla bağlantısı da kurulabilir, ki motif şamdanlarda sıklıkla kullanılmıştır. Güneş ile Allah'ın ışığı bağlantısından yola çıkarak, motifin nakkaşlar tarafından geçici dünyada Nur'u İllahi'yi sembolize etmek üzere tercih edildiği önerilebilir. Bu okuma ile desenin Kabe Örtüsünde, minarelerde, sancaklarda ve mezar örtüleri gibi dini bağlamlarda kullanılması açıklanabilir.

This paper presents the architecture and VHDL design of a Two Dimensional Discrete Cosine Transform (2D-DCT) with Quantization and zigzag arrangement. This architecture is used as the core and path in JPEG image compression hardware. The 2D-DCT calculation is made using the 2D-DCT Separability property, such that the whole architecture is divided into two 1D-DCT calculations by using a transpose buffer. Architecture for Quantization and zigzag process is also described in this paper. The quantization process is done using division operation. This design aimed to be implemented in Spartan-3E XC3S500 FPGA. The 2D-DCT architecture uses 1891 Slices, 51I/O pins, and 8 multipliers of one Xilinx Spartan-3E XC3S500E FPGA reaches an operating frequency of 101.35 MHz One input block with 8 x 8 elements of 8 bits each is processed in 6604 ns and pipeline latency is 140 clock cycles .

European vipers (genus Vipera) are venomous and often have a distinctive dorsal zigzag pattern. The zigzag pattern of vipers has been suggested to be an example of disruptive colouration which reduces the detectability of a snake. However, recent studies suggest that the patterns have an aposematic function, although those experiments did not exclude the possibility of disruptive colouration. We used plasticine replicas of snakes to examine whether the zigzag pattern of European vipers provides protection from avian predator attacks via disruptive or aposematic function, or if the zigzag pattern might simultaneously serve both antipredatory functions. Experiments were conducted in the Coto Doñana National Park southern Spain. In the experiment, predation pressure caused by birds was compared between zigzag pattern (patterns were painted with and without disruptive effect i.e. breaking body outline or not), classical disruptive colouration (non-randomly placed patterns that breaks body outline) and control markings (replicas with length wise stripes and models without painted pattern) on natural and controlled backgrounds. We found that zigzag patterned snake replicas suffered less predation than striped ones regardless of the background, providing further evidence that the zigzag pattern of European vipers functions as a warning signal against predators. However, we did not find evidence that the zigzag pattern involves a disruptive effect.

The stitched and quilted 'intimate textiles' artwork titled Áine was started pre-lockdown in January 2020 on a two-week residency at the Tyrone Guthrie Centre, Ireland. I wrote about the design:

"The spirals come from the Neolithic Tomb of Newgrange in Ireland where the midwinter sun penetrates the seventeen feet long chamber deep into the earth and illuminates a carved stone - this only happens on the winter solstice, and only 12 people are allowed on the site and in the chamber before dawn on 21 December. I was there on the 1996 solstice. I was 'bumped up' the incredibly long list by a lovely civil servant in Dublin who acknowledged that Northern Ireland was edging towards the end of the "Troubles" (in 1998) by telling me that "we need to help our brothers and sisters in the North". And so I got into that chamber long before dawn, and we silently watched a grey finger of light creep into the dark and lengthen until it tickled that inner stone. Spirals are female and zigzags are male. The materials are 'intimate textiles', worn on bodies and then discarded, so corsets, lingerie, nighties, bras, slips, suspenders for stockings, and my pricked finger added a drop of my blood... So, in here are my concerns: women, intimacy, sex, death, birth, Ireland and its conflicts, stains and blood, and of course an under-current of shame which goes alongside all the rest....

With the rapid development of information technology and multimedia, the use of digital data is increasing day by day. So it becomes very essential to protect multimedia information from piracy and also it is challenging. A great deal of Copyright owners is worried about protecting any kind of illegal repetition of their information. Hence, facing all these kinds of problems development of the techniques is very important. Digital watermarking considered as a solution to prevent the multimedia data.

In this paper, an idea of watermarking is proposed and implemented. In proposed watermarking method, the original image is rearranged using zigzag sequence and DWT is applied on rearranged image. Then DCT and SVD are applied on all high bands LH, HL and HH. Watermark is then embedded by modifying the singular values of these bands. Extraction of watermark is performed by the inversion of watermark
embedding process. For choosing of these three bands it gives facility of mid-band and pure high band that ensures good imperceptibility and more robustness against different kinds of attacks.

Watermarking is the process of inserting predefined patterns into multimedia data in a way that the degradation of quality is minimized and remain at an imperceptible level. Many digital water marking algorithms have been proposed in special and transform domains. On the other hand, frequency domain-based techniques can embed more bits for watermark and are
more robust to attack. Some transforms such as Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are used for watermarking in the frequency domain. In this thesis, we compare the DCT watermarking algorithms and especially the DWT watermarking algorithms based on robustness criteria.

Density-functional theory (DFT) in combination with the nonequilibrium Green’s function formalism is used to study the effect of substitutional doping on the electronic transport properties of V-shaped edge distorted zigzag graphene nanoribbons (DZGNRs), in which DZGNRs with the various widths of four-, six-, and eight-zigzag chains are passivated by H atoms. In this work, Si atoms are used to substitute carbon atoms located at the center of the samples. Our calculated results have determined that Si can change the material type by the number of dopants. We found that the transmission spectrum strongly depends on the various widths. The width of eight-zigzag chains exhibits the largest transmission among four- and six-zigzag chains, and the single Si substitution presents larger transmission than the double case. The obtained results are explained in terms of electron localization in the system due to the presence of distortion at edge and impurities. The relationships between the t...

Spin caloritronics refers to generating spin current by thermal gradient. Spin caloritronics is an emerging new subfield of condensed matter physics concerned with coupled spin, charge, and energy transport in small structures and devices. In this paper, thermally induced spin transport in a magnetized zigzag graphene nanoribbon is explored. Using non-equilibrium Green’s function (NEGF) method in a tight-binding model, a temperature gradient applied between the left and right nonmagnetic electrodes, as thermal reservoirs in a magnetized zigzag graphene nanoribbon model junction so that the flowing of the up-spin and down-spin currents in the opposite directions can be induced which may be modulated by tuning of the back gate voltage. Furthermore, some thermoelectric properties of the junction, such as the spin-dependent Seebeck effect, electrical conductance, electron thermal conductance, and thermoelectric efficiency (ZT) of the model evaluated. Our calculations for the thermoelect...

As organizations increasingly rely on groups to solve problems requiring solutions spanning multiple functional areas and representing diverse cons titue:ncies, improving students’ group problem-solving skills has become an important issue in education. Research suggests that a large part of improving group problem-solving skills involves teaching students how to manage the influence of individual psychological preferences on group interactions effectively during the problem-solving process. This paper introduces a generic group zig zag (GZZ) model for facilitating group convergence in the problem-solving process by incorporating the E-I attitude preference into the original zig zag (ZZ). The advent of computerized organizational information processing in the 1960s ushered in an era of unprecedented organizational change. The complex interplay between the rapid advancement of information technology (IT) and changes in the business environment led to profound changes in how organizat...

We consider a zigzag nanoribbon of MoS2 and study its spin-dependent conductance and spin-polarization in presence (absent) of an external electric field. The field is not only perpendicular to the molybdenum plane (called vertical field Ez) but also to the transport direction of electrons (called transverse field Et). It is shown that, while in the absent of the external electric field, two bands of seven bands are spin split in the valence band but no spin splitting is seen at point . Under applying the electric field we show, the ribbon behaves as a prefect spin up (down) filter if and only if the both components of the electrical field are present. Finally it is shown that, by changing the strength of , the ribbon acts as a spin inverter for fixed values of Ez .

The effect of geometric parameters of the zigzag, rectangular, and serpentine channels on convective heat transfer coefficient and pressure drop was investigated using computational fluid dynamics (CFD). The same boundary conditions were considered in all channels, and the number of steps was equal to 10. The simulations were performed for turbulent flows (liquid water as the operating fluid), and the Reynolds number (Re) range between 20000 and 60000 was selected. The zigzag channel showed the best thermal performance, and the serpentine channel showed the best hydraulic performance. The thermal-hydraulic performance (THP) factor was employed for comparing the channels. As the complexity of the channel's surfaces increased, the two parameters of convective heat transfer coefficient (positive factor) and pressure drop (negative factor) increased simultaneously. Therefore, predictive correlations for friction factor and Nusselt number were presented using a genetic algorithm (GA), The multiobjective optimization was performed to obtain the most appropriate Nusselt number and minimum friction factor as the two basic objective functions. The resulting Pareto set, which includes the optimum geometric dimensions of the heat exchangers, allows a designer to chooce the geometries based on higher heat transfer or lower pumping power.

European vipers (genus Vipera) are venomous and often have a distinctive dorsal zigzag pattern. The zigzag pattern of vipers has been suggested to be an example of disruptive colouration which reduces the detectability of a snake. However, recent studies suggest that the patterns have an aposematic function, although those experiments did not exclude the possibility of disruptive colouration. We used plasticine replicas of snakes to examine whether the zigzag pattern of European vipers provides protection from avian predator attacks via disruptive or aposematic function, or if the zigzag pattern might simultaneously serve both antipredatory functions. Experiments were conducted in the Coto Don ̃ana National Park southern Spain. In the experiment, predation pressure caused by birds was compared between zigzag pattern (patterns were painted with and without disruptive effect i.e. breaking body outline or not), classical disruptive colouration (non- randomly placed patterns that breaks body outline) and control markings (replicas with length wise stripes and models without painted pattern) on natural and controlled back- grounds. We found that zigzag patterned snake replicas suffered less predation than striped ones regardless of the background, providing further evidence that the zigzag pattern of European vipers functions as a warning signal against predators. However, we did not find evidence that the zigzag pattern involves a disruptive effect.

The realistic shapes of N doped graphene nanoribbons (GNRs) can be realized by considering nearly zigzag-edged (NZE) imperfections and pyridine defects (3NV). The paper focuses on NZE-GNRs with 3NV that is populated by Scandium abbreviated as Sc/NZE-3NVGNRs. Systematic calculations have clarified roles of the nano-shapes of NZE-3NVGNRs in its formation, energetics, stability and electron states functionalized with Sc using density functional theory (DFT) formalisms. According to DFT calculations, the magnitude of the spin that is attributed to the rise of magnetic order is closely linked to the altered shape of the ribbon edges. Also, calculations show that the stability of Sc functionalization at the 3NV and NZE site is thermodynamically stable and is dictated by a strong binding energy (BE). The magnitude of the BE is enhanced when the zigzag edge is short or the ribbon width is narrow, suggesting a reduced clustering of Sc atoms over the Sc-doped NZE-3NVGNRs. Results also show th...

ABSTRACT There are many different hypertext systems and paradigms, each with their apparent advantages. However the distinctions are perhaps not as significant as they seem. If we can reduce the core linking functionality to some common structure, which allows us to ...

We investigate the vibrational properties of two kinds of single-wall ZnO nanotubes. The simulations are carried out for three types of zigzag nanotubes (5,0), (8,0), (10,0) and armchair nanotubes (3,3), (4,4), (6,6). The natural frequencies are determined by means of the molecular mechanics approach with the universal force field potential. The first four natural frequencies are obtained for length/diameter ratio of about 5–20. The vibration modes associated with these frequencies have been computed. Closed-form analytical expressions have been derived using the continuum shell theory for the physical explanations of the simulations results. We observe that the natural frequencies decrease as the aspect ratios increase. The results follow similar trends with results of previous studies for carbon nanotubes (CNT). However, the magnitudes of the frequencies are lower from the corresponding CNT counterparts, indicating that ZnO nanotubes are comparatively less stiff.