Occupied Area Research Articles

Thermal–Mechanical and Signal Reliability of a New Differentiated TSV

The thermal–mechanical and signal reliability of through-silicon via (TSV) occupies an important position in three-dimensional integrated circuits (3D-ICs). However, few studies combined the thermal–mechanical and signal reliability are found. In the work, a new differentiated structure of TSV is proposed to decrease the peak thermal stress without affecting signal integrity. The effect of TSV diameter on the peak thermal stress and its location is deeply investigated to decrease the stress. Compared with regular TSV, the differentiated TSV can reduce 22% peak thermal stress and 68% occupied silicon area. More differentiated TSVs can be placed in the same Si substrate by considering the influence of thermal stress between TSVs. Meanwhile, the differentiated TSV can better shield crosstalk noise with ensuring signal integrity.

Toward quantum computers by designing a new nano-scale arithmetic & logic unit

Complementary metal-oxide-semiconductor (CMOS) technology is reaching its physical boundaries due to lithographic issues and diminishing scaling advantages. Options to conventional CMOS are becoming more popular, including quantum-dot cellular automata (QCA), nonmagnetic logic, tunneling phase logic, single-electron tunneling, etc. In actuality, QCA adheres to the logic of quantum computers; a quantum computer is a paradigm of how to build a computer. Quantum computers, according to the theory, can execute operations on data using quantum physics concepts such as superposition and entanglement. Quantum characteristics can be utilized to represent data and perform operations on it, which is the underlying premise of quantum computation. As a result, QCA has been proposed as a technology for building circuits at the nano-scale for quantum computing. This technique claims minimal power loss, fast velocity, low occupied area, and great density since the circuits have no electric flows. One of the most crucial and important parts of a microprocessor is the arithmetic logic unit (ALU), which is the key component of the central processing unit (CPU). A unique ALU based on QCA is proposed in this article. In this article, the best AND, OR, XOR, full-adder, and multiplexer circuit are used, which have been examined in detail. The QCADesigner-E program develops and simulates the structure of the recommended ALU. The recommended ALU was also investigated and contrasted with contemporary designs regarding cell counts, area, and temporal complexity. Exactly 185 cells and two clock periods are taken by this design. The number of cells has decreased by 26% in the suggested ALU.

Time-lagged effects of habitat fragmentation on terrestrial mammals in Madagascar.

Biodiversity is severely threatened by habitat destruction. As a consequence of habitat destruction, the remaining habitat becomes more fragmented. This results in time-lagged population extirpations in remaining fragments when these are too small to support populations in the long term. If these time-lagged effects are ignored, the long-term impacts of habitat loss and fragmentation will be underestimated. We quantified the magnitude of time-lagged effects of habitat fragmentation for 157 nonvolant terrestrial mammal species in Madagascar, one of the biodiversity hotspots with the highest rates of habitat loss and fragmentation. We refined species' geographic ranges based on habitat preferences and elevation limits and then estimated which habitat fragments were too small to support a population for at least 100 years given stochastic population fluctuations. We also evaluated whether time-lagged effects would change the threat status of species according to the International Union for the Conservation of Nature (IUCN) Red List assessment framework. We used allometric relationships to obtain the population parameters required to simulate the population dynamics of each species, and we quantified the consequences of uncertainty in these parameter estimates by repeating the analyses with a range of plausible parameter values. Based on the median outcomes, we found that for 34 species (22% of the 157 species) at least 10% of their current habitat contained unviable populations. Eight species (5%) had a higher threat status when accounting for time-lagged effects. Based on 0.95-quantile values, following a precautionary principle, for 108 species (69%) at least 10% of their habitat contained unviable populations, and 51 species (32%) had a higher threat status. Our results highlight the need to preserve continuous habitat and improve connectivity between habitat fragments. Moreover, our findings may help to identify species for which time-lagged effects are most severe and which may thus benefit the most from conservation actions.

Supply less sensitive ring voltage-controlled oscillator for microwave L-band frequencies

PurposeThe primary aim of this paper is to present a novel design approach for a ring voltage-controlled oscillator (VCO) suitable for L-band applications, whose oscillation frequency is less sensitive to power supply variations. In a few decades, with the advancement of modern wireless communication equipment, there has been an increasing demand for low-power and robust communication systems for longer battery life. A sudden drop in power significantly affects the performance of the VCO. Supply insensitive circuit design is the backbone of uninterrupted VCO performance. Because of their important roles in a variety of applications, VCOs and phase locked loops (PLLs) have been the subject of significant research for decades. For a few decades, the VCO has been one of the major components used to provide a local frequency signal to the PLL.Design/methodology/approachFirst, this paper chose to present recent developments on implemented techniques of ring VCO design for various applications. A complementary metal oxide semiconductor (CMOS)-based supply compensation technique is presented, which aims to reduce the change in oscillation frequency with the supply. The proposed circuit is designed and simulated on Cadence Virtuoso in 0.18 µm CMOS process under 1.8 V power supply. Active differential configuration with a cross-coupled NMOS structure is designed, which eliminates losses and negates supply noise. The proposed VCO is designed for excellent performance in many areas, including the L-band microwave frequency range, supply sensitivity, occupied area, power consumption and phase noise.FindingsThis work provides the complete design aspect of a novel ring VCO design for the L-band frequency range, low phase noise, low occupied area and low power applications. The maximum value of the supply sensitivity for the proposed ring VCO is 1.31, which is achieved by changing the VDD by ±0.5%. A tuning frequency range of 1.47–1.81 GHz is achieved, which falls within the L-band frequency range. This frequency range is achieved by varying the control voltage from 0.0 to 0.8 V, which shows that the proposed ring VCO is also suitable for low voltage regions. The total power consumed by the proposed ring VCO is 14.70 mW, a remarkably low value using this large transistor count. The achievable value of phase noise is −88.76 dBc/Hz @ 1 MHz offset frequency, which is a relatively small value. The performance of the proposed ring VCO is also evaluated by the figure of merit, achieving −163.13 dBc/Hz, which assures the specificity of the proposed design. The process and temperature variation simulations also validate the proposed design. The proposed oscillator occupied an extremely small area of only 0.00019 mm2 compared to contemporary designs.Originality/valueThe proposed CMOS-based supply compensation method is a unique design with the size and other parameters of the components used. All the data and results obtained show its originality in comparison with other designs. The obtained results are preserved to the fullest extent.

High-Isolated Coupling-Grounded Patch Antenna Pair With Shared Radiator for the Application of 5G Mobile Terminals

We propose a coupling-grounded patch (CGP) antenna pair for sharing the same radiator with the high isolation performance, where the two feeding ports are connected through such shared radiator with very close distance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.1 \lambda _{0}$ </tex-math></inline-formula> . More specifically, two coupling pins (C-pins) grounded on the symmetry plane of the radiator are shown to be capable of tuning the common mode (CM) impedance to be the same as the differential mode (DM) impedance, thus a very high isolation of such patch antenna pair is obtained. Both simulation and measurement results demonstrate that the isolation of the patch antenna pair could be greatly improved from the original 3 dB to approximately 25–50 dB in the N79 band (4.8–4.9 GHz). Furthermore, the extension to four-port antennas is also investigated. The proposed patch antenna pair with less occupied area provides significant promising application values for the multiple-input multiple-output (MIMO) systems, especially for the sophisticated fifth-generation (5G) mobile terminals.

Geographic information system as a tool for assessing ponds and the potential for environmental impact caused by fish farming

The hydrographic basin of Arroio Marreco (Paraná State) concentrates a productive chain of fish farming and great intensification of tilapia farming. In this study, we aimed to monitor the quality of effluent water and organic and inorganic elements released by fish farming in ponds, using geomorphological and land-use and occupation data. The Terrain Analysis Using Digital Elevation Models, Digital Elevation Model software was used to delimit watersheds in the software Quantum geographic information system version 3.6.3. A total of 1,457 production units (water slides) were identified across the study area. This represented an occupied area of 160.2 ha. Analyzing the sub-basins, it was found that High Marreco is the sub-basin with the most developed logistical chain. Low Marreco does not yet have an integration of its fish farming with the region’s logistics chain. Medium Marreco does not have fish farming as its main activity, only using it to reuse inputs from other agricultural activities. There is a large input of nutrients from aquaculture in all the sub-basins. To reduce them, it is recommended to implement decantation and/or reuse of wastewater systems. The results of this study show how important it is to know the dynamics of nutrients in the fish farms and the physical characteristics of the drainage basin to determine the support capacity of the environment, so as not to allow licenses that promote impacts above the self-cleaning capacity of the courses water.

Novel Reversible Comparator Design in Quantum Dot-Cellular Automata with Power Dissipation Analysis

In very large-scale integration (VLSI) circuits, a partial of energy lost leads to information loss in irreversible computing because, in conventional combinatorial circuits, each bit of information generates heat and power consumption, thus resulting in energy dissipation. When information is lost in conventional circuits, it will not be recoverable, as a result, the circuits are provided based on the reversible logic and according to reversible gates for data retrieval. Since comparators are one of the basic building blocks in digital logic design, in which they compare two numbers, the aim of this research is to design a 1-bit comparator building block based on reversible logic and implement it in the QCA with the minimum cell consumption, less occupied area, and lower latency, as well as to design it in a single layer. The proposed 1-bit reversible comparator is denser, cost-effective, and more efficient in quantum cost, power dissipation, and the main QCA parameters than that of previous works.

A 70-MS/s Vcm-free 10-bit-resolution SAR ADC with a novel DAC structure to reduce area andparasitic capacitance effect

A 10-bit-resolution successive approximation ADC with 70-Ms/s conversion rate and with a new configuration for capacitive DAC is represented in this paper. In the DAC structure proposed in this paper, the capacitors that form the Sub-DAC are smaller than the capacitors of the Sub-DAC of the other structures; therefore, the occupied area and the average switching energy in the proposed structure are less than in the other split-array structures, and the proposed structure is less susceptible to parasitic capacitance. Compared to the conventional split-array structure, the total capacitance and Sub-DAC parasitic capacitance are reduced by 15.87% and 46.87%, respectively. Also, the coupling capacitor is a unit capacitor, which improves the capacitor matching in the DAC array furthermore.To design and simulate the proposed 10-bit converter, 180-nm CMOS technology is used. Results of simulation prove that at 70 MS/s operating frequency, with a power supply equal to 1.8 V, and at Nyquist input frequency, SNDR of the proposed converter is 58.26 dB, that means ENOB is 9.39 bit, and SFDR is 64.87 dB. Consequently, the ADC FOM is equal to 123.5 fJ/conversion-step. Also, ramp-test simulation proves that INL and DNL are 0.53/+0.63 LSB and −0.6/+0.6 LSB, respectively. The proposed design consumes 5.8 mw at 70 MS/s operating frequency.

A new design for testability of the circuits based on quantum-dot cellular automata to reduce total consumption area

By inevitably reducing the transistor size of the semiconductors to the nano level, the current transistor-based technology has faced many challenges such as high chip temperature, reduced operating circuit accuracy, high current leakage, high power, etc. Therefore, several studies have been conducted to find an appropriate substitution for these circuits. One of the most important results of these studies is Quantum-Dot Cellular Automata (QCA), proposed as a possible replacement for conventional circuits. With the increasing volume of circuits, the complexity of designing and manufacturing circuits and the complexity of producing suitable test vectors for them increases, so producing and performing complete test operations on large circuits is very time-consuming and costly. Therefore, it is very important to find ways to produce circuits that can perform the test operation inside the circuit. This article gives a new design for testing circuits based on QCA to minimize overall consumption space. In this design, a linear transmission register circuit is provided to produce test patterns, and a serial signature register is presented to check the circuit's response to the test patterns. In designing these circuits, the minimum consumption of cells has been employed. Therefore, applying this design in QCA circuits increases the testability of circuits and self-test circuits. Besides, due to the minimum cell number used in the design of these circuits, the occupied area is reduced. The simulation outcomes illustrated that the suggested technique, compared to similar designs, gained significant improvement in terms of consumed area and cell.

Identification and Counting of European Souslik Burrows from UAV Images by Pixel-Based Image Analysis and Random Forest Classification: A Simple, Semi-Automated, yet Accurate Method for Estimating Population Size

Burrowing mammals such as European sousliks are widespread and contribute significantly to soil ecosystem services. However, they have declined across their range and the non-invasive estimation of their actual population size has remained a challenge. Results support that the number of burrow entrances is positively correlated with population abundance, and burrow locations indicate the occupied area. We present an imagery-based method to identify and count animals’ burrows semi-automatically by combining remotely recorded red, green, and blue (RGB) images, pixel-based imagery, and random forest (RF) classification. Field images were collected for four colonies, then combined and processed by histogram matching and spectral band normalization to improve the spectral distinctions among the categories BURROW, SOIL, TREE, and GRASS. The accuracy indexes of classification for BURROW kappa (κ) were 95% (precision) and 90% (sensitivity). A 10-iteration bootstrapping of the final model resulted in coefficients of variation (CV%) of BURROW κ for sensitivity and precision lower than 5%; moreover, CV% values were not significantly different between those scores. The consistency of classification and balanced precision and sensitivity confirmed the applicability of this approach. Our approach provides an accurate, user-friendly, and relatively simple approach to count the number of burrow openings, estimate population abundance, and delineate the areas of occupancy non-invasively.

Inventory of Water–Energy–Waste Resources in Rural Houses in Gran Canaria Island: Application and Potential of Renewable Resources and Mitigation of Carbon Footprint and GHG

The potential application of renewable energies is diverse, and they have demonstrated their suitability in their application to the size and operation of activities. Rural tourism is one of the products with the greatest potential for growth within the tourist offer of the island of Gran Canaria, as it combines sustainable development and respect for the natural environment. Among the renewable energies with high applicability in rural environments, we highlight photovoltaic solar, low-temperature solar thermal and the methanation of waste and wastewater generated in tourism. This article shows a methodology adapted and developed for the study of the water-energy-waste nexus, considering parameters of waste generation, water and energy consumption, the occupied area and potential renewable energy generation in rural houses in Gran Canaria and evaluates their environmental profitability. It has been concluded that applying these renewable technologies can significantly reduce the carbon and ecological footprint of the activity of rural houses based on the available surface. This contributes to achieving the energy and environmental objectives proposed by the EU to achieve decarbonization by 2050.

Localization and assessment of breakage defect in cables based on time–frequency domain reflectometry

Cables are very important in urban power system due to the small occupied area and excellent electrical properties. However, the breakage defect caused by manufacturing errors and improper installation can lead to great loss to the power system. Thus, the localization and assessment of breakage defect is necessary. In this paper, a non-destructive method based on time–frequency​ domain reflectometry is utilized, and the position and degree of breakage defect can be obtained by the peaks of the localization curve. Besides, pseudo Wigner–Ville distribution is proposed to avoid the cross-term interference problem in time–frequency domain reflectometry. In experiments, breakage defects of different degrees were caused to the same position of the target cable. The defects are localized accurately with errors less than 1% of the entire cable length, and as the degree of damage increases, the peak value of the assessment curve at the defect becomes larger accordingly.

Design of an Efficient Multilayer Hybrid Reversible Spintronic Ripple Carry Adder Using Quantum Cellular Automata Technique

Quantum-Dot-Cellular-Automata (QCA) using Spintronic electrons is a promising alternative to the traditional CMOS technology in this modern era to design any nano-sized electronic structure. The majority of the current digital components are being designed using QCA-cell-interaction. In some cases, reversible logic with the Spintronic-QCA-technique is also being explored to design various digital components. Because of this, the various aspects for the design of a novel hybrid QCA-based Spintronic advance reversible adder and its efficiency measures are presented in this research work by investigating area-occupation, temperature-tolerance, delay, power dissipation, and output strength. The results obtained in this work establish that the proposed design is more efficient in all respect compared to existing designs reported in recent literature. In this paper, 18nm quantum cells are used to design the proposed structure and when the power dissipation based on the total occupied cell area is calculated (100W/cm2), it is found that there is an assurance to get an adder structure with the less occupied area, less power dissipation and higher speed compared to previously published referred design. The temperature-tolerance and output-strength increment with layer separation gap reduction in multilayer platforms are also some additional advancements of the proposed structure, which are also clearly reflected. In this paper, QCA-based “Ripple-Carry-Adder (RCA)” is designed using Spintronic reversible logic in multilayer mode with different composite elements along with a “3-input-majority-voter-gate (MG)” to make the design more compact. QCADesigner 4.0 tool is used as widespread simulation trains to validate the design outcomes and measure different parameters individually.

Heritage conservation as a bridge to sustainability assessing thermal performance and the preservation of identity through heritage conservation in the Mediterranean city of Nablus

Heritage conservation can revive vernacular architectural methods of construction which naturally embody sustainable design concepts. This research investigates and highlights the intrinsic value of heritage conservation in building a sustainable society; from an environmental, economic, and social perspectives. This research is an evaluation of a unique case of heritage conservation in the city of Nablus, Palestine, at both architectural and urban scales. The investigation concluded that traditional passive design solutions have many advantages over modern ones. It was found that the thermal performance of a conserved traditional building was more effective, making it more sustainable than its modern counterpart with the same function. Further, the investigation concluded that heritage conservation is core to protecting identity in its preservation of the past for future generations, especially in an occupied area, such as Nablus. This study aims to highlight the vast scope and application of heritage conservation with regards to innovative and sustainable solutions in a modern urban society.

Miniaturized trisection BPF design using size-reduced substrate integrated coaxial resonators

The contribution of this work is to propose miniaturized trisection bandpass filters (BPFs) using size-reduced substrate integrated coaxial resonators (SICRs). The applied SICRs are operated under a coaxial mode. The occupied circuit area of the SICR developed from its structurally similar one, the substrate integrated waveguide (SIW) cavity, is only 6.2% that of the latter, corresponding to a circuit-area reduction rate of 93.8%. The cross-coupling between the input and output resonators can be either a magnetic or electric coupling for locating the transmission zero near either the upper or lower passband edge, respectively. Sample trisection BPFs with magnetic/electric cross-couplings are built for experimental verification. Agreements between measured and simulated data are observed. These miniaturized trisection BPFs with a freely switchable transmission zero are endowed with the advantage of an excellent circuit-area efficiency in the category of SICR and SIW cavity trisection BPFs.

Crosstalk Noise of Octagonal TSV Array Arrangement Based on Different Input Signal

This paper proposes an octagonal layout for enhancing the ability of resisting electromagnetic interference in Through Silicon Via (TSV) array. The influential factors of crosstalk noise between TSVs are investigated, including the TSV pitch, signal and ground TSVs location, and signal types (single-end and differential signal) by using a coplanar wave guide (CPW) testing structure. These results, based on traditional TSV arrays, show that a staggered TSV layout with differential signals had lower crosstalk noise. On this basis, the octagonal layout of TSV array is proposed and we show that it has obvious superiority in reducing occupied silicon area and crosstalk noise. Compared with traditional TSV arrays, the crosstalk noise is almost reduced by 44%. In order to further reduce the silicon area occupied by TSV without worsening crosstalk noise, the new division TSV structure is proposed in which a large TSV was substituted by four smaller TSVs. The area occupied by a single TSV and TSV array are both reduced by 60% without decreasing signal integrity when the regular TSV in the octagonal layout are replaced by a new TSV structure.

Retrodicting the rise, spread, and fall of large-scale states in the Old World.

Understanding the rise, spread, and fall of large-scale states in the ancient world has occupied thinkers for millennia. However, no comprehensive mechanistic model of state dynamics based on their insights has emerged, leaving it difficult to evaluate empirically or quantitatively the different explanations offered. Here I present a spatially- and temporally-resolved agent-based model incorporating several hypotheses about the behavior of large-scale (>200 thousand km2) agrarian states and steppe nomadic confederations in Afro-Eurasia between the late Bronze and the end of the Medieval era (1500 BCE to 1500 CE). The model tracks the spread of agrarian states as they expand, conquer the territory of other states or are themselves conquered, and, occasionally, collapse. To accurately retrodict the historical record, several key contingent regional technological advances in state military and agricultural efficiencies are identified. Modifying the location, scale, and timing of these contingent developments allows quantitative investigation of historically-plausible alternative trajectories of state growth, spread, and fragmentation, while demonstrating the operation and limits of the model. Under nominal assumptions, the rapid yet staggered increase of agrarian state sizes across Eurasia after 600 BCE occurs in response to intense military pressure from 'mirror' steppe nomadic confederations. Nevertheless, in spite of various technological advances throughout the period, the modeled creation and spread of new agrarian states is a fundamental consequence of state collapse and internal civil wars triggered by rising 'demographic-structural' pressures that occur when state territorial growth is checked yet (warrior elite) population growth continues. Together the model's underlying mechanisms substantially account for the number of states, their duration, location, spread rate, overall occupied area, and total population size for three thousand years.

Solar photovoltaic tree multi aspects analysis − a review

The generation of photovoltaic solar energy worldwide has increased significantly in recent years. This is mainly due to the growing demand of society for electricity, the need to reduce environmental impacts, and costs of such technology. The installation of a photovoltaic system with horizontally fixed panels requires a significant unshaded area, which has become increasingly scarce, especially in urban centers. The photovoltaic solar tree is a strategy used to increase the efficiency of photovoltaic systems by reducing the occupied area and optimizing the orientation angles of the panels. The originality of this work was that, through a literature review in different researches, seven relevant parameters related to solar photovoltaic trees were analyzed: (i) modeling and simulation, (ii) tree topology, (iii) orientation of the panels, (iv) constructive characteristics, (v) solar tracking, (vi) occupied area and (vii) site multiple uses. It was found that the photovoltaic solar tree is an interesting alternative to generate renewable energy for places without large enough areas, which can be used for other purposes, such as crop production and parking. Finally, it was concluded that, to date, there are no studies available in the literature on the optimization of photovoltaic generation per area for different topologies of known solar trees.

Testable MUXED-D Scan Cell in Quantum-dot Cellular Technology

Quantum-dot Cellular Automata (QCA) is one of the new nanoscale technologies which proposed for future circuits. This technology has been remarkable due to its faster speed, lower size and reduction in power consumption compared to CMOS technology. Many circuits have been implemented in this technology including shift registers, they are one of the most important digital circuits for many applications. With the development of QCA technology, it is important to provide testing methods for testing these circuits.4-Bit serial shift registers designed in previous research were not capable of testing their output. In this paper, MUXED-D scan cell concept helps to detect the errors before fabrication and reduce time and cost. The MUXED-D scan consists of a D flip-flop and a 2 to 1 multiplexer. Compared to the latest scan cell, we have seen a 25 % decrease in occupied area and 15.62 % decrease in the number of cells and latency from 1 to 0.75 clock cycle. In general, this scan cell circuit is made of 27 cells with an area of 0.03 µm2 and a latency of 3 clock cycles. The proposed shift register includes four scan cells with two inputs which includes main and test signals. In fact, the number of cells used for the last 4-bit serial testable shift register in this design is 324, 0.39µm2 occupied area and the corresponding delay is 6.75 clock cycles. In order to verify this performance, QCA simulator is used.

Representations of the use of psychoactive substances in the beliefs and rituals of ancient societies: between the sacred and the profane

The use of plants with psychoactive properties by ancient communities has been confirmed in numerous archaeological studies conducted in almost every place on earth. Many tribes used their own characteristic psychoactive potions and, according to researchers, their use fostered the integration of the members of a given community, facilitated their existence in an occupied area and could be of significant importance for its survival. Around the psychoactive plants and toxic secretions of some species of fauna a conglomerate of myths, cults and the properties attributed to them has developed. Permanent traces of their presence remain in both non-material and material culture. The aim of this article is to present the representations of psychoactive substances in the beliefs of ancient communities, their occurrence in myths, rock or sepulchral art, and to discuss the reasons for their use during rituals. The article presents also the main causes of the diffusion of the use of psychoactive plants from the sacred to the profane sphere.