Journal articles: 'QCA'

1

Tahir, Iqmal, Mudasir Mudasir, Irza Yulistia, and Mustofa Mustofa. "QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP ANALYSIS (QSAR) OF VINCADIFFORMINE ANALOGUES AS THE ANTIPLASMODIAL COMPOUNDS OF THE CHLOROQUINOSENSIBLE STRAIN." Indonesian Journal of Chemistry 5, no. 3 (June 15, 2010): 255–60. http://dx.doi.org/10.22146/ijc.21800.

Full text

Abstract:

Quantitative Structure-Activity Relationship (QSAR) analysis of vincadifformine analogs as an antimalarial drug has been conducted using atomic net charges (q), moment dipole (), LUMO (Lowest Unoccupied Molecular Orbital) and HOMO (Highest Occupied Molecular Orbital) energies, molecular mass (m) as well as surface area (A) as the predictors to their activity. Data of predictors are obtained from computational chemistry method using semi-empirical molecular orbital AM1 calculation. Antimalarial activities were taken as the activity of the drugs against chloroquine-sensitive Plasmodium falciparum (Nigerian Cell) strain and were presented as the value of ln(1/IC50) where IC50 is an effective concentration inhibiting 50% of the parasite growth. The best QSAR model has been determined by multiple linier regression analysis giving QSAR equation: Log (1/IC50) = 9.602.qC1 -17.012.qC2 +6.084.qC3 -19.758.qC5 -6.517.qC6 +2.746.qC7 -6.795.qN +6.59.qC8 -0.190. -0.974.ELUMO +0.515.EHOMO -0.274. +0.029.A -1.673 (n = 16; r = 0.995; SD = 0.099; F = 2.682) Keywords: QSAR analysis, antimalaria, vincadifformine.

APA, Harvard, Vancouver, ISO, and other styles

2

Joy, Upal Barua, Shourov Chakraborty, Sharnali Islam, Hasan U. Zaman, and Mehedi Hasan. "Quantum-Dot Cellular Automata-Based Full Adder Design: Comprehensive Review and Performance Comparison." Advances in Materials Science and Engineering 2023 (January 10, 2023): 1–13. http://dx.doi.org/10.1155/2023/6784413.

Full text

Abstract:

Being one of the promising techniques for future computing systems, quantum-dot cellular automata (QCA)-based circuit design has gained massive interest among researchers due to which numerous QCA-based full adder (FA) circuits have been designed. Due to numerous QCA FA circuits available in the existing literature, researchers find it difficult to invest the time to search, implement, simulate, and analyze QCA FAs to find the best-suited design according to their needs. Existing review articles do not present a complete overview and performance comparison of QCA FAs. Also, the existing articles do not include quite a number of QCA FA designs in the literature review. As a result, a detailed review including all possible QCA FAs becomes essential. Therefore, rather than going for a new QCA FA design, this research aims to aid researchers by providing an extensive literature review and comprehensive study on existing QCA FAs. A total of 47 QCA FAs have been considered for analysis. The QCA FA implementation method and performance parameters are summarized in a tabular manner to provide a quick overview and comparison of the QCA FAs.

APA, Harvard, Vancouver, ISO, and other styles

3

Taheri, Zahra, Abdalhossein Rezai, and Hamid Rashidi. "Novel single layer fault tolerance RCA construction for QCA technology." Facta universitatis - series: Electronics and Energetics 32, no. 4 (2019): 601–13. http://dx.doi.org/10.2298/fuee1904601t.

Full text

Abstract:

Quantum-dot Cellular Automata (QCA) technology has become a promising and accessible candidate that can be used for digital circuits implementation at Nanoscale, but the circuit design in the QCA technology has been limited due to fabrication high-defect rate. So, this issue is an interesting research topic in the QCA circuits design. In this study, a novel 3-input Fault Tolerance (FT) Majority Gate (MG) is developed. Accordingly, an efficient 1-bit QCA full adder is developed using the developed 3-input MG. Then, a new 4-bit FT QCA Ripple Carry Adder (RCA) is developed based on the proposed 1-bit FT QCA FA. The developed circuits are implemented in the QCA Designer tool version 2.0.3. The results indicate that the developed QCA circuits provide advantages compared to other QCA circuits in terms of double and single cell missing defect, area and delay time.

APA, Harvard, Vancouver, ISO, and other styles

4

Mokhtari, Dariush, Abdalhossein Rezai, Hamid Rashidi, Faranak Rabiei, Saeid Emadi, and Asghar Karimi. "Design of novel efficient full adder architecture for Quantum-dot Cellular Automata technology." Facta universitatis - series: Electronics and Energetics 31, no. 2 (2018): 279–85. http://dx.doi.org/10.2298/fuee1802279m.

Full text

Abstract:

In this paper the novel coplanar circuits for full adder implementation in Quantum-dot Cellular Automata (QCA) technology are presented. We propose a novel one-bit full adder circuit and then utilize this new circuit to implement novel four-bit Ripple Carry Adder (RCA) circuit in the QCA technology. The QCA Designer tool version 2.0.1 is utilized to implement the designed QCA full adder circuits. The implementation results show that the designed QCA full adder circuits have an improvement compared to other QCA full adder circuits.

APA, Harvard, Vancouver, ISO, and other styles

5

Shiri, Ahmadreza, Abdalhossein Rezai, and Hamid Mahmoodian. "Design of efficient coplanar 1-bit comparator circuit in QCA technology." Facta universitatis - series: Electronics and Energetics 32, no. 1 (2019): 119–28. http://dx.doi.org/10.2298/fuee1901119s.

Full text

Abstract:

QCA technology is an emerging and promising technology for implementation of digital circuits in nano-scale. The comparator circuits play an important role in digital circuits. In this work, a new and efficient coplanar 1-bit comparator circuit is proposed and evaluated in the QCA technology. The designed coplanar 1-bit QCA comparator circuit is constructed based on majority gate, XNOR gate and inverter gate that are designed carefully. The functionality of the designed coplanar 1-bit QCA comparator circuit is verified by using QCADesigner version 2.0.3. The obtained results indicate that the designed 1-bit QCA comparator circuit requires 0.03 ?m2 area and 38 QCA cells. It also has 0.5 clock cycles delay. The comparison demonstrates that the designed QCA comparator circuit provides improvements in comparison with other QCA comparator circuits in terms of effective area, cell count, and delay as well as cost.

APA, Harvard, Vancouver, ISO, and other styles

6

Liu, Xuqing, Xiaofei Wang, Donghao Chen, and Honggang Zhang. "Automatic Quantitative Coronary Analysis Based on Deep Learning." Applied Sciences 13, no. 5 (February 25, 2023): 2975. http://dx.doi.org/10.3390/app13052975.

Full text

Abstract:

As a core technique to quantitatively assess the stenosis severity of coronary arteries, quantitative coronary analysis (QCA) is urgently supposed to become more automated and intelligent, especially for regions lacking expertise and technology. The existing QCA methods highly depend on manual operation, which is time-consuming and subject to personal experience. This study innovatively proposes a fully automatic QCA workflow based on artificial intelligence (AI-QCA), which can quickly and accurately make a quantitative assessment of stenosis severity. The whole AI-QCA workflow mainly consists of three parts: the boundary-aware segmentation on the coronary angiogram (CAG) images, the AI-enabled coronary artery tree construction, and the diameter fitting and stenosis detection. Experiments show that the precision, recall, and F1 score of the segmentation, evaluated on 1322 CAGs, are 0.866, 0.897, and 0.879, respectively. Furthermore, the RMSE between diameter stenosis assessed by AI-QCA and manual QCA served by senior experts, evaluated on 249 CAGs, is 0.064, and the Pearson coefficient is 0.765. Meanwhile, the operation time can be reduced from tens of minutes to several seconds by AI-QCA. As a conclusion, the proposed AI-QCA is able to quickly quantify stenosis parameters as accurately as senior experts, which is significant for the intelligent diagnosis and treatment of coronary artery disease.

APA, Harvard, Vancouver, ISO, and other styles

7

Cong, Peizhong, and Enrique P. Blair. "Clocked molecular quantum-dot cellular automata circuits tolerate unwanted external electric fields." Journal of Applied Physics 131, no. 23 (June 21, 2022): 234304. http://dx.doi.org/10.1063/5.0090171.

Full text

Abstract:

Quantum-dot cellular automata (QCA) may provide low-power, general-purpose computing in the post-CMOS era. A molecular implementation of QCA features nanometer-scale devices and may support [Formula: see text]THz switching speeds at room-temperature. Here, we explore the ability of molecular QCA circuits to tolerate unwanted applied electric fields, which may come from a variety of sources. One likely source of strong unwanted electric fields may be electrodes recently proposed for the write-in of classical bits to molecular QCA input circuits. Previous models have shown that the input circuits are sensitive to the applied field, and a coupled QCA wire can successfully transfer the input bit to downstream circuits despite strong applied fields. However, the ability of other QCA circuits to tolerate an applied field has not yet been demonstrated. Here, we study the robustness of various QCA circuits by calculating their ground state responses in the presence of an applied field. To do this, a circuit is built from several QCA molecules, each described as a two-state system. A circuit Hamiltonian is formed and diagonalized. All pairwise interactions between cells are considered, along with all correlations. An examination of the ground state shows that these QCA circuits may indeed tolerate strong unwanted electric fields. We also show that circuit immunity to the dominant unwanted field component may be obtained by choosing the orientation of constituent molecules. This suggests that relatively large electrodes used for bit write-in to molecular QCA need not disrupt the operation of nearby QCA circuits. The circuits may tolerate significant electric fields from other sources as well.

APA, Harvard, Vancouver, ISO, and other styles

8

Berry, Colin, Philippe L. L’Allier, Jean Grégoire, Jacques Lespérance, Sylvie Levesque, Reda Ibrahim, and Jean-Claude Tardif. "Comparison of Intravascular Ultrasound and Quantitative Coronary Angiography for the Assessment of Coronary Artery Disease Progression." Circulation 115, no. 14 (April 10, 2007): 1851–57. http://dx.doi.org/10.1161/circulationaha.106.655654.

Full text

Abstract:

Background— The relative merits of quantitative coronary analysis (QCA) and intravascular ultrasound (IVUS) for the assessment of progression/regression in coronary artery disease are uncertain. To explore this subject further, we analyzed the angiographic and IVUS data derived from a contemporary clinical trial population. Methods and Results— We investigated the relationships between QCA and IVUS at single time points (n=525) and also for the changes over time (n=432). QCA and IVUS data underwent central laboratory analyses. Statistically significant correlations were observed between the QCA coronary artery score and the IVUS-derived lumen volume ( r =0.65, P <0.0001) and total vessel volume ( r =0.55, P <0.0001) and between the QCA cumulative coronary stenosis score and percent atheroma volume on IVUS ( r =0.32, P <0.0001) at baseline for matched segments. A similar pattern of correlations was observed for global (all segments) QCA-derived and single-vessel IVUS-derived data. There were statistically significant but weak correlations between the changes over time in lumen dimensions on QCA and IVUS ( P =0.005) and between the change in cumulative coronary stenosis score on QCA and percent atheroma volume on IVUS ( r =0.14, P =0.01). Nevertheless, patients with and without angiographic progression had changes in plaque volume on IVUS of 9.13 and 0.20 mm 3 , respectively ( P =0.028). Conclusions— QCA- and IVUS-derived measures of lumen dimensions are correlated at single time points and for changes over time. Although the change in percent atheroma volume is only weakly correlated with QCA changes as continuous variables, disease progression on QCA is associated with significant increases in plaque volume on IVUS compared with no angiographic progression.

APA, Harvard, Vancouver, ISO, and other styles

9

Sherif, Noora H., Mohammed Hussien Ali, and Najim Abdallah Jazea. "Design and implementation reversible multiplexer using quantum-dot cellular automata approach." Bulletin of Electrical Engineering and Informatics 11, no. 6 (December 1, 2022): 3383–91. http://dx.doi.org/10.11591/eei.v11i6.4307.

Full text

Abstract:

Rapid progress in the field of nanotechnology includes using quantum dot-cellular automata (QCA) as a replacement for conventional transistor-based complementary metal oxide semiconductor (CMOS) circuits in the construction of nano-circuits. Due to ultra low thermal dissipation, rapid clocking, and extremely high density, the QCA is a rapidly growing field in the nanotechnological field to inhibit the field effect transistor (FET)-based circuit. This paper discusses and evaluates two multiplexer (MUX) architectures: an innovative and effective 4×1 MUX structure and an 8×1 MUX structures using QCA technology. The suggested architectural designs are constructed using the Fredkin and controlled-NOT (CNOT) gates. These constructions were designed to simulate using tool QCA designer 2.0.3. The 591 and 1,615 cells would be used by the 4×1 and 8×1 QCA MUX architectures, respectively. The simulation results demonstrate that, when compared to the previous QCA MUX structures, the suggested QCA MUX designs have the best clock latency performance and use of different gate types.

APA, Harvard, Vancouver, ISO, and other styles

10

Verweij, Stefan, and Elen-Maarja Trell. "Qualitative Comparative Analysis (QCA) in Spatial Planning Research and Related Disciplines: A Systematic Literature Review of Applications." Journal of Planning Literature 34, no. 3 (April 11, 2019): 300–317. http://dx.doi.org/10.1177/0885412219841490.

Full text

Abstract:

Qualitative comparative analysis (QCA) is a potentially interesting method for spatial planning researchers. Although increasingly used, its application in spatial planning research is lagging behind other disciplines. We conducted a systematic literature review of QCA applications in spatial planning and related disciplines (SPARD), addressing two questions: when, where, and how is QCA used in SPARD and what are the main advantages of QCA for spatial planning research? We found that the main reasons why QCA is used in SPARD are its sensitivity to context, its ability to use small-/medium- n cases, and its attention to causal complexity.

APA, Harvard, Vancouver, ISO, and other styles

11

de Block, Debora, and Barbara Vis. "Addressing the Challenges Related to Transforming Qualitative Into Quantitative Data in Qualitative Comparative Analysis." Journal of Mixed Methods Research 13, no. 4 (May 8, 2018): 503–35. http://dx.doi.org/10.1177/1558689818770061.

Full text

Abstract:

The use of qualitative data has so far received relatively little attention in methodological discussions on qualitative comparative analysis (QCA). This article addresses this lacuna by discussing the challenges researchers face when transforming qualitative data into quantitative data in QCA. By reviewing 29 empirical studies using qualitative data for QCA, we explore common practices related to data calibration, data presentation, and sensitivity testing. Based on these three issues, we provide considerations when using qualitative data for QCA, which are relevant both for QCA scholars working with qualitative data and the wider mixed methods research community involved in quantitizing.

APA, Harvard, Vancouver, ISO, and other styles

12

Xiao, Lin Rong, Xiang Xu, and Shi Yan Ying. "Dual-Edge Triggered T Flip-Flop Structure Using Quantum-Dot Cellular Automata." Advanced Materials Research 662 (February 2013): 562–67. http://dx.doi.org/10.4028/www.scientific.net/amr.662.562.

Full text

Abstract:

As an emerging nanotechnology, quantum-dot cellular automata (QCA) has the potential to be used for next generation VLSI. Various designs of combinational logic circuits have been proposed for QCA implementation, but sequential circuit design is limited due to the lack of high-performance QCA flip-flops. After an introduction on QCA and dual-edge triggered (DET) flip-flops, a new QCA DET T flip-flop following a pulsed latch scheme is presented. The proposed T flip-flop is simulated using QCADesigner simulator and its logic functionality is verified. The same data throughput of the DET flip-flop can be achieved while operating at half the clock frequency of a single-edge triggered (SET) counterpart. The proposed flip-flop is promising in building QCA sequential circuits with low power and high performance.

APA, Harvard, Vancouver, ISO, and other styles

13

Devadoss, Rajeswari, Kolin Paul, and M. Balakrishnan. "p-QCA." ACM Journal on Emerging Technologies in Computing Systems 7, no. 3 (August 2011): 1–20. http://dx.doi.org/10.1145/2000502.2000506.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Costa, Ricardo A., and Johan H. C. Reiber. "QCA editorial." International Journal of Cardiovascular Imaging 27, no. 2 (February 2011): 155–56. http://dx.doi.org/10.1007/s10554-011-9827-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Stegehuis, Valerie, Jelmer Westra, Coen Boerhout, Martin Sejr-Hansen, Ashkan Eftekhari, Hernan Mejía-Renteria, Maribel Cambero-Madera, et al. "Three-Dimensional Angiographic Characteristics versus Functional Stenosis Severity in Fractional and Coronary Flow Reserve Discordance: A DEFINE FLOW Sub Study." Diagnostics 12, no. 7 (July 21, 2022): 1770. http://dx.doi.org/10.3390/diagnostics12071770.

Full text

Abstract:

Background: Coronary angiography alone is insufficient to identify lesions associated with myocardial ischemia that may benefit from revascularization. Coronary physiology parameters may improve clinical decision making in addition to coronary angiography, but the association between 2D and 3D qualitative coronary angiography (QCA) and invasive pressure and flow measurements is yet to be elucidated. Methods: We associated invasive fractional flow reserve (FFR), coronary flow reserve (CFR) and coronary flow capacity (CFC) with 2D- and 3D-QCA in 430 intermediate lesions of 366 patients. Results: Overall, 2D-QCA analysis resulted in less severe stenosis severity compared with 3D-QCA analysis. FFR+/CFR− lesions had similar 3D-QCA characteristics as FFR+/CFR+ lesions. In contrast, vessels with FFR−/CFR+ discordance had 3D-QCA characteristics similar to those of vessels with concordant FFR−/CFR−. Contrarily, FFR+/CFR− lesions had CFC similar to that of as FFR-/CFR- lesions. Conclusions: Non-flow-limiting lesions (FFR+/CFR−) have 3D-QCA characteristics similar to those of FFR+/CFR+, but the majority are not associated with inducible myocardial ischemia as determined by invasive CFC. FFR−/CFR+ lesions have 3D-QCA characteristics similar to those of FFR−/CFR− lesions but are more frequently associated with a moderately to severely reduced CFC, illustrating the angiographic–functional mismatch in discordant lesions.

APA, Harvard, Vancouver, ISO, and other styles

16

Schneider, Carsten Q. "Realists and Idealists in QCA." Political Analysis 26, no. 2 (March 19, 2018): 246–54. http://dx.doi.org/10.1017/pan.2017.45.

Full text

Abstract:

The sole purpose of the enhanced standard analysis (ESA) is to prevent so-called untenable assumptions in Qualitative Comparative Analysis (QCA). One source of such assumptions can be statements of necessity. QCA realists, the majority of QCA researchers, have elaborated a set of criteria for meaningful claims of necessity: empirical consistency, empirical relevance, and conceptual meaningfulness. I show that once Thiem’s (2017) data mining approach to detecting supersets is constrained by adhering to those standards, no CONSOL effect of Schneider and Wagemann’s ESA exists. QCA idealists, challenging most of QCA realists’ conventions, argue that separate searches for necessary conditions are futile because the most parsimonious solution formula reveals the minimally necessary disjunction of minimally sufficient conjunctions. Engaging with this perspective, I address several unresolved empirical and theoretical issues that seem to prevent the QCA idealist position from becoming mainstream.

APA, Harvard, Vancouver, ISO, and other styles

17

Verma, Vinay Kumar, and Neeraj Kumar Misra. "Study and Performance Analysis of MOS Technology and Nanocomputing QCA." SAMRIDDHI : A Journal of Physical Sciences, Engineering and Technology 9, no. 02 (December 25, 2017): 93–96. http://dx.doi.org/10.18090/samriddhi.v9i02.10868.

Full text

Abstract:

One of the critical issues in VLSI circuit is High Power dissipation. Quantumdot Cellular Automata (QCA) which is widely utilized in nanocomputing era. QCA has Landauer clocked based synthesis approach and it has clocked based information flow. This manuscript analysis and design a combinational digital circuits in an emerging QCA framework. The design is evaluated and formulated in terms of area, latency and power dissipation. QCA Designer tool has been taken for the design of quantum cell-based combinational circuits and simulation purpose. Moreover, it is believed based on experimental analysis that the QCA based combination circuits will make a contribution to high computing speed and low power paradigm.

APA, Harvard, Vancouver, ISO, and other styles

18

Waheed, Sajjad, and Md Golam Rasel. "Design and Implementation of New Feynman and Toffoli (NFT) Gates in Quantum-dot Cellular Automata (QCA)." Circulation in Computer Science 2, no. 4 (May 20, 2017): 64–67. http://dx.doi.org/10.22632/ccs-2017-252-10.

Full text

Abstract:

In this paper, New Feynman and Toffoli (NFT) gate is proposed based on QCA logic gates. The proposed circuit is a promising future in constructing of nano-scale low power consumption information processing system and can stimulate higher digital applications in QCA. QCA technology is a promising alternative to CMOS technology. It is attractive due to its fast speed, small area and low power consumption. A novel electronics paradigm for information processing and communication by QCA offers technology. QCA technology has the potential for attractive features such as faster speed, higher scale integration, higher switching frequency, smaller size and low power consumption than transistor based technology.

APA, Harvard, Vancouver, ISO, and other styles

19

Tatarczyk, Dawid. "Political Preferences of QCA Methods Institutes? A Comment on the Availability and Gender Gap Disparity Problems." Political Preferences, no. 28 (July 3, 2021): 23–31. http://dx.doi.org/10.31261/polpre.2021.28.23-31.

Full text

Abstract:

In this research note, I examine a set of two interrelated questions about the Qualitative Comparative Analysis (QCA) methods institutes. First, I assembled and analyzed a novel dataset that tracks every QCA related training worldwide from 2002 to 2018. My examination finds that although QCA trainings are becoming more popular in Europe, the US is still the single most frequent host country for such events. Secondly, I examine the extent to which gender gap exists among QCA instructors. My findings show that female QCA instructors are severely under-represented, which likely limits their academic and professional opportunities. Thus, the QCA research community appears to be marked by the same structural challenges to diversity and gender equality as other areas of political science. Overall, this paper should of interest to scholars interested in the impact of academic infrastructures on future research trajectories as well as those concerned about gender equality in academia.

APA, Harvard, Vancouver, ISO, and other styles

20

Zimborás, Zoltán, Terry Farrelly, Szilárd Farkas, and Lluis Masanes. "Does causal dynamics imply local interactions?" Quantum 6 (June 29, 2022): 748. http://dx.doi.org/10.22331/q-2022-06-29-748.

Full text

Abstract:

We consider quantum systems with causal dynamics in discrete spacetimes, also known as quantum cellular automata (QCA). Due to time-discreteness this type of dynamics is not characterized by a Hamiltonian but by a one-time-step unitary. This can be written as the exponential of a Hamiltonian but in a highly non-unique way. We ask if any of the Hamiltonians generating a QCA unitary is local in some sense, and we obtain two very different answers. On one hand, we present an example of QCA for which all generating Hamiltonians are fully non-local, in the sense that interactions do not decay with the distance. We expect this result to have relevant consequences for the classification of topological phases in Floquet systems, given that this relies on the effective Hamiltonian. On the other hand, we show that all one-dimensional quasi-free fermionic QCAs have quasi-local generating Hamiltonians, with interactions decaying exponentially in the massive case and algebraically in the critical case. We also prove that some integrable systems do not have local, quasi-local nor low-weight constants of motion; a result that challenges the standard definition of integrability.

APA, Harvard, Vancouver, ISO, and other styles

21

Vahabi, Mohsen, Ehsan Rahimi, Pavel Lyakhov, Ali Newaz Bahar, Khan A. Wahid, and Akira Otsuki. "Novel Quantum-Dot Cellular Automata-Based Gate Designs for Efficient Reversible Computing." Sustainability 15, no. 3 (January 26, 2023): 2265. http://dx.doi.org/10.3390/su15032265.

Full text

Abstract:

Reversible logic enables ultra-low power circuit design and quantum computation. Quantum-dot Cellular Automata (QCA) is the most promising technology considered to implement reversible circuits, mainly due to the correspondence between features of reversible and QCA circuits. This work aims to push forward the state-of-the-art of the QCA-based reversible circuits implementation by proposing a novel QCA design of a reversible full adder\full subtractor (FA\FS). At first, we consider an efficient XOR-gate, and based on this, new QCA circuit layouts of Feynman, Toffoli, Peres, PQR, TR, RUG, URG, RQCA, and RQG are proposed. The efficient XOR gate significantly reduces the required clock phases and circuit area. As a result, all the proposed reversible circuits are efficient regarding cell count, delay, and circuit area. Finally, based on the presented reversible gates, a novel QCA design of a reversible full adder\full subtractor (FA\FS) is proposed. Compared to the state-of-the-art circuits, the proposed QCA design of FA\FS reversible circuit achieved up to 57% area savings, with 46% and 29% reduction in cell number and delay, respectively.

APA, Harvard, Vancouver, ISO, and other styles

22

Chabi, Amir Mokhtar, Samira Sayedsalehi, Shaahin Angizi, and Keivan Navi. "Efficient QCA Exclusive-or and Multiplexer Circuits Based on a Nanoelectronic-Compatible Designing Approach." International Scholarly Research Notices 2014 (October 16, 2014): 1–9. http://dx.doi.org/10.1155/2014/463967.

Full text

Abstract:

Quantum-dot cellular automata (QCA) are a transistorless computation approach which encodes binary information via configuration of charges among quantum dots. The fundamental QCA logic primitives are majority and inverter gates which can be utilized to design various QCA circuits. This study presents a novel approach to designing efficient QCA-based circuits based on Boolean expressions achieved from reconfiguration of five-input and three-input majority gates. Whereas the multiplexer and Exclusive-or are the most important fundamental logical circuits in digital systems, designing efficient and single layer structures without coplanar cross-over wiring is advantageous in QCA technology. In order to demonstrate the efficiency and usefulness of the proposed approach, simple and dense multiplexer and Exclusive-or structures are implemented. The proposed designs have significant improvement in terms of area, complexity, latency, and gate count in comparison to previous designs. The correct logical functionalities of presented structures have been authenticated using QCA designer tool.

APA, Harvard, Vancouver, ISO, and other styles

23

Thomann, Eva, and Martino Maggetti. "Designing Research With Qualitative Comparative Analysis (QCA): Approaches, Challenges, and Tools." Sociological Methods & Research 49, no. 2 (October 3, 2017): 356–86. http://dx.doi.org/10.1177/0049124117729700.

Full text

Abstract:

Recent years have witnessed a host of innovations for conducting research with qualitative comparative analysis (QCA). Concurrently, important issues surrounding its uses have been highlighted. In this article, we seek to help users design QCA studies. We argue that establishing inference with QCA involves three intertwined design components: first, clarifying the question of external validity; second, ensuring internal validity; and third, explicitly adopting a specific mode of reasoning. We identify several emerging approaches to QCA rather than just one. Some approaches emphasize case knowledge, while others are condition oriented. Approaches emphasize either substantively interpretable or redundancy-free explanations, and some designs apply an inductive/explorative mode of reasoning, while others integrate deductive elements. Based on extant literature, we discuss issues surrounding inference with QCA and the tools available under different approaches to address these issues. We specify trade-offs and the importance of doing justice to the nature and goals of QCA in a specific research context.

APA, Harvard, Vancouver, ISO, and other styles

24

Waheed, Sajjad, Sharmin Aktar, and Ali Newaz Bahar. "A Novel Design and Implementation of New Double Feynman and Six-correction logic (DFSCL) gates in Quantum-dot Cellular Automata (QCA)." European Scientific Journal, ESJ 13, no. 15 (May 31, 2017): 265. http://dx.doi.org/10.19044/esj.2017.v13n15p265.

Full text

Abstract:

In recent years, quantum cellular automata (QCA) have been used widely to digital circuits and systems. QCA technology is a promising alternative to CMOS technology. It is attractive due to its fast speed, small area and low power consumption. The QCA offers a novel electronics paradigm for information processing and communication. It has the potential for attractive features such as faster speed, higher scale integration, higher switching frequency, smaller size and low power consumption than transistor based technology. In this paper, Double Feynman and Six-correction logic gate (DFSCL) is proposed based on QCA logic gates: MV gate and Inverter gate. The proposed circuit is a promising future in constructing of nano-scale low power consumption information processing system and can stimulate higher digital applications in QCA.

APA, Harvard, Vancouver, ISO, and other styles

25

Reis, Dayane Alfenas, and Frank Sill Torres. "A Defects Simulator for Robustness Analysis of QCA Circuits." Journal of Integrated Circuits and Systems 11, no. 2 (December 28, 2016): 86–96. http://dx.doi.org/10.29292/jics.v11i2.433.

Full text

Abstract:

Although QCA (Quantum-dot Cellular Automata) is a promising nanotechnology to replace CMOS (Complementary Metal-Oxide-Semiconductor), it has several known reliability problems. Consequently, the design of robust QCA structures is a mandatory step towards the consolidation of this new technology. This paper presents a novel methodology for error analysis of QCA structures based on deterministic and random insertion of possible defects to either the cells and to the phase shifts of the clocking circuit. Further features presented are an evaluation of structures robustness and identification of the design elements most susceptible to the defects. Simulation results obtained from the implemented QCA Defects Simulator indicate the feasibility of the proposed error exploration methodology, also revealing starting-points for robustness improvements of known QCA structures.

APA, Harvard, Vancouver, ISO, and other styles

26

Baumgartner, Michael, and Alrik Thiem. "Model Ambiguities in Configurational Comparative Research." Sociological Methods & Research 46, no. 4 (October 23, 2015): 954–87. http://dx.doi.org/10.1177/0049124115610351.

Full text

Abstract:

For many years, sociologists, political scientists, and management scholars have readily relied on Qualitative Comparative Analysis (QCA) for the purpose of configurational causal modeling. However, this article reveals that a severe problem in the application of QCA has gone unnoticed so far: model ambiguities. These arise when multiple causal models fare equally well in accounting for configurational data. Mainly due to the uncritical import of an algorithm that is unsuitable for causal modeling, researchers have typically been unaware of the whole model space. As a result, there exists an indeterminable risk for practically all QCA studies published in the last quarter century to have presented findings that their data did not warrant. Using hypothetical data, we first identify the algorithmic source of ambiguities and discuss to what extent they affect different methodological aspects of QCA. By reanalyzing a published QCA study from rural sociology, we then show that model ambiguities are not a mere theoretical possibility but a reality in applied research, which can assume such extreme proportions that no causal conclusions whatsoever are possible. Finally, the prevalence of model ambiguities is examined by performing a comprehensive analysis of 192 truth tables across 28 QCA studies published in applied sociology. In conclusion, we urge that future QCA practice ensures full transparency with respect to model ambiguities, both by informing readers of QCA-based research about their extent and by employing algorithms capable of revealing them.

APA, Harvard, Vancouver, ISO, and other styles

27

AlKaldy, Esam, Ali H. Majeed, Mohd Shamian Zainal, and Danial MD Nor. "Optimum multiplexer design in quantum-dot cellular automata." Indonesian Journal of Electrical Engineering and Computer Science 17, no. 1 (January 1, 2020): 148. http://dx.doi.org/10.11591/ijeecs.v17.i1.pp148-155.

Full text

Abstract:

<p>Quantum-dot Cellular Automata (QCA) is one of the most important computing technologies for the future and will be the alternative candidate for current CMOS technology. QCA is attracting a lot of researchers due to many features such as high speed, small size, and low power consumption. QCA has two main building blocks (majority gate and inverter) used for design any Boolean function. QCA also has an inherent capability that used to design many important gates such as XOR and Multiplexer in optimal form without following any Boolean function. This paper presents a novel design 2:1 QCA-Multiplexer in two forms. The proposed design is very simple, highly efficient and can be used to produce many logical functions. The proposed design output comes from the inherent capabilities of quantum technology. New 4:1 QCA-Multiplexer has been built using the proposed structure. The output waveforms showed the wonderful performance of the proposed design in terms of the number of cells, area, and latency.</p>

APA, Harvard, Vancouver, ISO, and other styles

28

Afrooz, Sonia, and Nima Jafari Navimipour. "Memory Designing Using Quantum-Dot Cellular Automata: Systematic Literature Review, Classification and Current Trends." Journal of Circuits, Systems and Computers 26, no. 12 (August 2017): 1730004. http://dx.doi.org/10.1142/s0218126617300045.

Full text

Abstract:

Quantum-dot cellular automata (QCA) has come out as one of the potential computational structures for the emerging nanocomputing systems. It has a large capacity in the development of circuits with high space density and dissipation of low heat and allows faster computers to develop with lower power consumption. The QCA is a new appliance to realize nanolevel digital devices and study and analyze their various parameters. It is also a potential technology for low force and high-density memory plans. Large memory designs in QCA show unique features because of their architectural structure. In QCA-based architectures, memory must be maintained in motion, i.e., the memory state has to be continuously moved through a set of QCA cells. These architectures have different features, such as the number of bits stored in a loop, access type (serial or parallel) and cell arrangement for the memory bank. However, the decisive features of the QCA memory cell design are the number of cells, to put off the use of energy. Although the review and study of the QCA-based memories are very important, there is no complete and systematic literature review about the systematical analyses of the state of the mechanisms in this field. Therefore, there are five main types to provide systematic reviews about the QCA-based memories; including read only memory (ROM), register, flip-flop, content addressable memory (CAM) and random access memory (RAM). Also, it has provided the advantages and disadvantages of the reviewed mechanisms and their important challenges so that some interesting lines for any coming research are provided.

APA, Harvard, Vancouver, ISO, and other styles

29

Schneider, Carsten Q., and Claudius Wagemann. "Standards of Good Practice in Qualitative Comparative Analysis (QCA) and Fuzzy-Sets." Comparative Sociology 9, no. 3 (2010): 397–418. http://dx.doi.org/10.1163/156913210x12493538729793.

Full text

Abstract:

AbstractAs a relatively new methodological tool, QCA is still a work in progress. Standards of good practice are needed in order to enhance the quality of its applications. We present a list from A to Z of twenty-six proposals regarding what a “good” QCA-based research entails, both with regard to QCA as a research approach and as an analytical technique. Our suggestions are subdivided into three categories: criteria referring to the research stages before, during, and after the analytical moment of data analysis. This listing can be read as a guideline for authors, reviewers, and readers of QCA.

APA, Harvard, Vancouver, ISO, and other styles

30

Ebaid, H. h., A. El-sehili, H. Rasheed, H. Ammar, and M. Mahrous. "Comparison of coronary vessel sizing using coronary angiography versus intravascular ultrasound in Egyptian patients." CARDIOMETRY, no. 20 (November 21, 2021): 185–90. http://dx.doi.org/10.18137/cardiometry.2021.20.184189.

Full text

Abstract:

Background: Coronary artery disease (CAD) is a leading causeof death worldwide. Intravascular imaging is an important toolin the arsenal of each interventional cardiologist. While angiographyprovides a two-dimensional image of a three-dimensionalstructure, intravascular imaging enhances understanding by providingdetailed cross-sectional images. This study aimed to investigatethe discrepancies in coronary vessel sizing between quantitativecoronary angiography (QCA) and intravascular ultrasound.Methods: This cohort study was conducted on 69 patients whowere referred for elective coronary angiography. Patients weresubjected to history taking, examination, blood samples, electrocardiogram(E.C.G.), and echocardiography. Then, a comparisonof each vessel’s luminal diameter by QCA and IVUS was done.Results: The study included 69 patients; The mean age was 54.7± 9.7. There was a statistically significant difference between thestudied vessels regarding the discrepancy between luminal diametersmeasured by IVUS and QCA. IVUS luminal diameter waslarger than QCA luminal diameter (the median difference in measuresof QCA and IVUS in the left main artery, LAD, LCX, and RCAwere -0.8, -0.55, -0.4, and -0.5 respectively). Furthermore, thereis a statistically significant difference between the studied vesselsregarding the presence of a difference >0.75 mm between theluminal diameters measured by IVUS and QCA (Difference >0.75mm in the left main artery, LAD, left circumflex and RCA were55.8%, 21.7%, 30.8%, and 15.4% respectively). Conclusion: Coronarylesions were underestimated by QCA in comparison to IVUSregarding luminal diameter, especially the left main (LM).

APA, Harvard, Vancouver, ISO, and other styles

31

Blair, Enrique, and Craig Lent. "Clock Topologies for Molecular Quantum-Dot Cellular Automata." Journal of Low Power Electronics and Applications 8, no. 3 (September 8, 2018): 31. http://dx.doi.org/10.3390/jlpea8030031.

Full text

Abstract:

Quantum-dot cellular automata (QCA) is a low-power, non-von-Neumann, general-purpose paradigm for classical computing using transistor-free logic. Here, classical bits are encoded on the charge configuration of individual computing primitives known as “cells.” A cell is a system of quantum dots with a few mobile charges. Device switching occurs through quantum mechanical inter-dot charge tunneling, and devices are interconnected via the electrostatic field. QCA devices are implemented using arrays of QCA cells. A molecular implementation of QCA may support THz-scale clocking or better at room temperature. Molecular QCA may be clocked using an applied electric field, known as a clocking field. A time-varying clocking field may be established using an array of conductors. The clocking field determines the flow of data and calculations. Various arrangements of clocking conductors are laid out, and the resulting electric field is simulated. It is shown that that control of molecular QCA can enable feedback loops, memories, planar circuit crossings, and versatile circuit grids that support feedback and memory, as well as data flow in any of the ordinal grid directions. Logic, interconnect and memory now become indistinguishable, and the von Neumann bottleneck is avoided.

APA, Harvard, Vancouver, ISO, and other styles

32

Sumana, G., and G. Anjan Babu. "Adder with Efficient Speed and Area by Using Quantum-Dot Cellular Automata Technology." Asian Journal of Computer Science and Technology 8, S3 (June 5, 2019): 109–13. http://dx.doi.org/10.51983/ajcst-2019.8.s3.2073.

Full text

Abstract:

The lessening in transistor estimate by following field’s law made chip unpredictability with more computational capacity. The present size of the transistor needs to decrease more, which prompts nanotechnology. The quantum-dot cell automata come extremely close to nanotechnology presents one of the conceivable arrangements in defeat this physical breaking point, even though the designs with QCA technology are not a fundamental basic. In this brief by considering quantum-dot cell automata (QCA) innovation idea a greater part door based adder is outlined. The effectiveness in territory and speed by larger part entryway idea based adders are executed and contrasted with beforehand technique plans by utilizing verilog coding mimicked in Xilinx. The proposed one-piece QCA viper depends on another calculation that requires just three larger part entryways and two inverters for the QCA expansion. Novel 128-bit adders designed in QCA become accomplished.

APA, Harvard, Vancouver, ISO, and other styles

33

MARDIRIS, VASILIOS A., and IOANNIS G. KARAFYLLIDIS. "DESIGN AND SIMULATION OF MODULAR QUANTUM-DOT CELLULAR AUTOMATA MULTIPLEXERS FOR MEMORY ACCESSING." Journal of Circuits, Systems and Computers 19, no. 02 (April 2010): 349–65. http://dx.doi.org/10.1142/s0218126610006104.

Full text

Abstract:

Multiplexers are extremely important parts of signal control systems. Some critical circuits of computing systems, like memories, use large multiplexers in order to present the value of a specific memory cell to their output. Several quantum-dot cellular automata (QCA) circuits have been designed and the need for a QCA memory access system becomes prominent. A modular 2n to 1 QCA multiplexer covering small area could reduce the size of such circuits and conclusively could increase circuit integration. In this paper we present a novel design of a small size, modular quantum-dot cellular automata (QCA) 2n to 1 multiplexer that can be used for memory addressing. The design objective is to develop a modular design methodology which can be used to implement 2n to 1 multiplexers using building blocks. For the QCA implementation a careful consideration is taken into account concerning the design in order to increase the circuit stability.

APA, Harvard, Vancouver, ISO, and other styles

34

Sen, Bibhash, Ayush Rajoria, and Biplab K. Sikdar. "Design of Efficient Full Adder in Quantum-Dot Cellular Automata." Scientific World Journal 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/250802.

Full text

Abstract:

Further downscaling of CMOS technology becomes challenging as it faces limitation of feature size reduction. Quantum-dot cellular automata (QCA), a potential alternative to CMOS, promises efficient digital design at nanoscale. Investigations on the reduction of QCA primitives (majority gates and inverters) for various adders are limited, and very few designs exist for reference. As a result, design of adders under QCA framework is gaining its importance in recent research. This work targets developing multi-layered full adder architecture in QCA framework based on five-input majority gate proposed here. A minimum clock zone (2 clock) with high compaction (0.01 μm2) for a full adder around QCA is achieved. Further, the usefulness of such design is established with the synthesis of high-level logic. Experimental results illustrate the significant improvements in design level in terms of circuit area, cell count, and clock compared to that of conventional design approaches.

APA, Harvard, Vancouver, ISO, and other styles

35

Safoev, Nuriddin, and Jun Cheol Jeon. "Coplanar Qca Adders for Arithmetic Circuits." International Journal of Engineering & Technology 7, no. 4.4 (September 15, 2018): 16. http://dx.doi.org/10.14419/ijet.v7i4.4.19597.

Full text

Abstract:

A quantum-dot cellular automaton (QCA) is one of the most perspective nanotechnologies for future computing paradigm. We propose low complexity QCA adders for arithmetic circuit design. The proposed majority-gate based full adder is coplanar layout, and on the basis of clock-phase crossover technique. The results of the proposed structures from the QCA simulator tool are analyzed and compared with previous works.

APA, Harvard, Vancouver, ISO, and other styles

36

Erniyazov, Sarvarbek, and Jun Cheol Jeon. "Implementation of Full Adder Using 5-Input Majority Gate." International Journal of Engineering & Technology 7, no. 4.4 (September 15, 2018): 17. http://dx.doi.org/10.14419/ijet.v7i4.4.19598.

Full text

Abstract:

In this paper full adder was created employing five-input majority gate according to Quantum-Dot Cellular Automata (QCA) innovation. We used the QCA logic in our modified structure to reduce the delay. That report details the structure furthermore investigate associated with QCA dependent 1-bit full adder design for minimal energy purposes. This method permits decreasing energy expenditure, delay, additionally location involving electronic circuits.

APA, Harvard, Vancouver, ISO, and other styles

37

Touil, Lamjed, Ismail Gassoumi, and Abdellatif Mtibaa. "Design and Implementation of Nanotechnology QCA Geometric Greedy Router." Journal of Electrical and Computer Engineering 2021 (September 14, 2021): 1–12. http://dx.doi.org/10.1155/2021/3935091.

Full text

Abstract:

This paper presents an optimized geometric greedy router (GGR) based on quantum dot cellular automata (QCA) technology. The proposed structure of GGR is based on a spanning tree of the network. This type of communication does not require an IP address. It uses only local information and can be used in many communication devices. In this paper, we first describe the principal components of the router and then we present their QCA architecture. The QCA technology is the most likely alternative to replace conventional circuits (CMOS) due to their very low power consumption and high processing speed. To consider integration with other complex circuit, we have utilized QCA clock-phase-based technique for the proposed design architecture. The results obtained using the QCA designer tool exhibit the superiority of the presented architecture over the existing designs. The proposed structure shows a reduction of 30% reduction in occupied space. The power dissipation rate of the proposed design is analyzed by QCAPro tool to approve its reliability.

APA, Harvard, Vancouver, ISO, and other styles

38

Cui, Huanqing, Li Cai, Sen Wang, Xiaoqiang Liu, and Xiaokuo Yang. "Accurate reliability analysis method for quantum-dot cellular automata circuits." International Journal of Modern Physics B 29, no. 29 (November 13, 2015): 1550203. http://dx.doi.org/10.1142/s0217979215502033.

Full text

Abstract:

Probabilistic transfer matrix (PTM) is a widely used model in the reliability research of circuits. However, PTM model cannot reflect the impact of input signals on reliability, so it does not completely conform to the mechanism of the novel field-coupled nanoelectronic device which is called quantum-dot cellular automata (QCA). It is difficult to get accurate results when PTM model is used to analyze the reliability of QCA circuits. To solve this problem, we present the fault tree models of QCA fundamental devices according to different input signals. After that, the binary decision diagram (BDD) is used to quantitatively investigate the reliability of two QCA XOR gates depending on the presented models. By employing the fault tree models, the impact of input signals on reliability can be identified clearly and the crucial components of a circuit can be found out precisely based on the importance values (IVs) of components. So this method is contributive to the construction of reliable QCA circuits.

APA, Harvard, Vancouver, ISO, and other styles

39

Sabbaghi-Nadooshan, Reza, Zahra Shahosseini, and Davood Rezaeipour. "Design of New QCA LFSR and NLFSR for Grain-128 Stream Cipher." Journal of Circuits, Systems and Computers 25, no. 02 (December 23, 2015): 1650005. http://dx.doi.org/10.1142/s0218126616500055.

Full text

Abstract:

The use of quantum-dot cellular automata (QCA) technology for the design of logic circuits has shown to increase data transfer rates up to 2 THz. In QCA technology, circuits are designed to have an ultra-small feature size as well as ultra-low power consumption. Grain-128 is one of the best stream ciphers in the final list of the eSTREAM project. In this paper, we have designed and simulated the main blocks of this algorithm including XOR gate, linear-feedback shift register (LFSR) and nonlinear-feedback shift register (NLFSR) using QCA technology. The designs of these blocks using the QCA Designer simulator are given and the main factors such as area, complexity and delay are estimated. Furthermore, ModelSim software is used to simulate HDLQ model of the QCA Grain-128 stream cipher algorithm. The results indicate that the main parameters of the proposed Grain-128, such as area and throughput, are improved as well.

APA, Harvard, Vancouver, ISO, and other styles

40

DAS, KUNAL, and DEBASHIS DE. "A STUDY ON DIVERSE NANOSTRUCTURE FOR IMPLEMENTING LOGIC GATE DESIGN FOR QCA." International Journal of Nanoscience 10, no. 01n02 (February 2011): 263–69. http://dx.doi.org/10.1142/s0219581x11007892.

Full text

Abstract:

Quantum dot cellular automata (QCA) define the nanostructure of basic computer. It is used as an alternative for designing high-speed computer over CMOS technology. The basic logic in QCA is the logic state that does not measure with voltage level; rather it measures the polarity of electrons in cell. The Majority Voter (MV) is first introduced to design the logic circuits, but only using MV, designing complex logic circuit became inefficient. Many proposals had been made for designing QCA logic gate. In this paper we focus on different useful nanostructures, reduced size and efficient design of Nand–Nor Inverter (NNI), 3 × 3 tile structures for implementing NNI, And–Or Logic, and AOI also present logic synthesis using proposed gates. We analyze QCA defect on proposed gates and describe its permissible defect tolerance. In QCA we describe application for implementing standard functions using proposed structures in this paper and describe effective area of proposed structures.

APA, Harvard, Vancouver, ISO, and other styles

41

Braumoeller, Bear F. "Guarding Against False Positives in Qualitative Comparative Analysis." Political Analysis 23, no. 4 (2015): 471–87. http://dx.doi.org/10.1093/pan/mpv017.

Full text

Abstract:

The various methodological techniques that fall under the umbrella description of qualitative comparative analysis (QCA) are increasingly popular for modeling causal complexity and necessary or sufficient conditions in medium-N settings. Because QCA methods are not designed as statistical techniques, however, there is no way to assess the probability that the patterns they uncover are the result of chance. Moreover, the implications of the multiple hypothesis tests inherent in these techniques for the false positive rate of the results are not widely understood. This article fills both gaps by tailoring a simple permutation test to the needs of QCA users and adjusting the Type I error rate of the test to take into account the multiple hypothesis tests inherent in QCA. An empirical application–a reexamination of a study of protest-movement success in the Arab Spring–highlights the need for such a test by showing that even very strong QCA results may plausibly be the result of chance.

APA, Harvard, Vancouver, ISO, and other styles

42

Potocki, Przemysław, and Izabela Lassota. "Jakościowa analiza porównawcza (QCA) jako nowa metoda badawcza w nauce o polityce: zarys zagadnienia." Studia Politologiczne, no. 59/2021 (March 31, 2021): 99–124. http://dx.doi.org/10.33896/spolit.2021.59.5.

Full text

Abstract:

The article presents main theoretical assumptions and empirical implementations of Qualitative Comparative Analysis (QCA). The main phases of this research method, as the alternative to the quantitative approach which is applied in political science are described. Strengths and weaknesses of this method are described from the perspective of epistemological value obtained by the user of QCA method. Some Polish and foreign examples of QCA implementation are also indicated.

APA, Harvard, Vancouver, ISO, and other styles

43

Cooper, Barry. "Applying Ragin's Crisp and Fuzzy Set QCA to Large Datasets: Social Class and Educational Achievement in the National Child Development Study." Sociological Research Online 10, no. 2 (July 2005): 1–20. http://dx.doi.org/10.5153/sro.1068.

Full text

Abstract:

The paper explores the use of Charles Ragin's Qualitative Comparative Analysis (QCA) in both its crisp and fuzzy set versions in the study of the relations between social class origin, sex, ‘ability’ and subsequent educational achievement. The work reported is part of a larger ongoing project which is employing QCA to compare these relations within two birth cohorts. Here data are used from the British National Child Development Study, i.e. from children born in 1958. The paper has a methodological focus, bringing out the strengths but also the difficulties that arise when employing QCA with a large dataset of this type. In particular, the problem of calibrating membership in fuzzy sets in a context where detailed case knowledge is not available is illustrated. It is also shown how the use of gradually increasing thresholds with Ragin's fs/QCA software can bring out the relative importance of various factors in accounting for achievement. The QCA-based analysis suggests that the processes of educational attainment can, at best, only be seen as partly falling under a ‘meritocratic’ description. It is also hoped that this paper will serve as a useful introduction to the potential of QCA for readers not yet familiar with it.

APA, Harvard, Vancouver, ISO, and other styles

44

Seyedi, Saeid, Nima Jafari Navimipour, and Akira Otsuki. "Design and Analysis of Fault-Tolerant 1:2 Demultiplexer Using Quantum-Dot Cellular Automata Nano-Technology." Electronics 10, no. 21 (October 20, 2021): 2565. http://dx.doi.org/10.3390/electronics10212565.

Full text

Abstract:

Quantum-dot Cellular Automata (QCA) is an innovative paradigm bringing hopeful applications in the perceptually novel computing layout in quantum electronics. The circuits manufactured by QCA technology can provide a notable decrease in size, rapid-switching velocity, and ultra-low power utilization. The demultiplexer is a beneficial component to optimize the whole process in any logical design, and therefore is very important in QCA. Moreover, fault-tolerant circuits can improve the reliability of digital circuits by redundancy. Hence, the present investigation illustrates a novel QCA-based fault-tolerant 1:2 demultiplexer construct that employs a two-input AND gate and inverter. The functionality of the suggested layout was executed and evaluated with the utilization of the QCADesigner 2.0.3 simulator. This paper utilizes cell redundancy on the wire, inverter, and AND gates for designing a fault-tolerant demultiplexer. Four components (i.e., missing cells, dislocation cells, extra cells, and misalignment) were analyzed by the QCADesigner simulator. The simulation results demonstrated that our proposed QCA-based fault-tolerant 1:2 demultiplexer acted more efficiently than prior constructs regarding delay and fault tolerance. The proposed fault-tolerant 1:2 demultiplexer could attain high fault-tolerance when single missing cell or extra cell faults exist in the QCA layout.

APA, Harvard, Vancouver, ISO, and other styles

45

Baumgartner, Michael, and Alrik Thiem. "Often Trusted but Never (Properly) Tested: Evaluating Qualitative Comparative Analysis." Sociological Methods & Research 49, no. 2 (May 3, 2017): 279–311. http://dx.doi.org/10.1177/0049124117701487.

Full text

Abstract:

To date, hundreds of researchers have employed the method of Qualitative Comparative Analysis (QCA) for the purpose of causal inference. In a recent series of simulation studies, however, several authors have questioned the correctness of QCA in this connection. Some prominent representatives of the method have replied in turn that simulations with artificial data are unsuited for assessing QCA. We take issue with either position in this impasse. On the one hand, we argue that data-driven evaluations of the correctness of a procedure of causal inference require artificial data. On the other hand, we prove all previous attempts in this direction to have been defective. For the first time in the literature on configurational comparative methods, we lay out a set of formal criteria for an adequate evaluation of QCA before implementing a battery of inverse-search trials to test how this method performs in different recovery contexts according to these criteria. While our results indicate that QCA is correct when generating the parsimonious solution type, they also demonstrate that the method is incorrect when generating the conservative and intermediate solution type. In consequence, researchers using QCA for causal inference, particularly in human-sensitive areas such as public health and medicine, should immediately discontinue employing the method’s conservative and intermediate search strategies.

APA, Harvard, Vancouver, ISO, and other styles

46

Bernstein, G. H., A. Imre, V. Metlushko, A. Orlov, L. Zhou, L. Ji, G. Csaba, and W. Porod. "Magnetic QCA systems." Microelectronics Journal 36, no. 7 (July 2005): 619–24. http://dx.doi.org/10.1016/j.mejo.2004.12.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Devadoss, R., K. Paul, and M. Balakrishnan. "Coplanar QCA crossovers." Electronics Letters 45, no. 24 (2009): 1234. http://dx.doi.org/10.1049/el.2009.2819.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Haruehanroengra, Sansiri, and Wei Wang. "Efficient Design of QCA Adder Structures." Solid State Phenomena 121-123 (March 2007): 553–56. http://dx.doi.org/10.4028/www.scientific.net/ssp.121-123.553.

Full text

Abstract:

Optimizing arithmetic primitives such as quantum-dot cellular automata (QCA) adders is important for investigating high-performance QCA computers in this emerging nano-technological paradigm. In this paper, we demonstrate that QCA ripple carry adder and bit-serial adder designs actually outperform carry-look-ahead and carry-select adder designs because of the increase in required interconnects. Simulation results obtained by using the QCADesigner tool for the proposed adder designs are also presented.

APA, Harvard, Vancouver, ISO, and other styles

49

Kim, Kyosun, Kaijie Wu, and Ramesh Karri. "The Robust QCA Adder Designs Using Composable QCA Building Blocks." IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 26, no. 1 (January 2007): 176–83. http://dx.doi.org/10.1109/tcad.2006.883921.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Farazkish, Razieh, Samira Sayedsalehi, and Keivan Navi. "Novel Design for Quantum Dots Cellular Automata to Obtain Fault-Tolerant Majority Gate." Journal of Nanotechnology 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/943406.

Full text

Abstract:

Quantum-dot Cellular Automata (QCA) is one of the most attractive technologies for computing at nanoscale. The principle element in QCA is majority gate. In this paper, fault-tolerance properties of the majority gate is analyzed. This component is suitable for designing fault-tolerant QCA circuits. We analyze fault-tolerance properties of three-input majority gate in terms of misalignment, missing, and dislocation cells. In order to verify the functionality of the proposed component some physical proofs using kink energy (the difference in electrostatic energy between the two polarization states) and computer simulations using QCA Designer tool are provided. Our results clearly demonstrate that the redundant version of the majority gate is more robust than the standard style for this gate.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'QCA'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles