Acceleration Demands Research Articles

Scalable and Conflict-Free NTT Hardware Accelerator Design: Methodology, Proof, and Implementation

Number Theoretic Transform (NTT) is useful for the acceleration of polynomial multiplication, which is the main performance bottleneck in the next-generation cryptographic schemes. Different NTT based cryptographic algorithms have different security settings. The diverse application scenarios introduce different cost-performance trade-offs and hardware constraints. Motivated by the emerging demand for more versatile NTT hardware accelerators, we propose a new design methodology that can generate area-efficient and high-performance NTT accelerators for any length and modulus of NTT polynomials and single processing element (PE) or PE array with a varying number of layers. The proposed NTT accelerator architecture pivots on a conflict-free memory access pattern for adaptation to different combinations of security and PE array configuration parameters. The proposed memory access pattern is formally proved to be conflict-free for any parametric configurations. The criterion for read-after-write conflict without pipeline stall is also established. Our proposed design methodology can produce NTT accelerators with single PE or multi-layer PE array for different polynomial size and modulus, with hardware area and computational efficiency comparable to accelerators customized for a fixed set of parameters. Our proposed methodology produces parameterized accelerator with higher scalability than the existing parameterized accelerator design. On average, the accelerators generated by our proposed method are 71.4% more area-time efficient. Up to 30.7% area-time reduction over the most area-time efficient state-of-the-art scalable NTT accelerator can be achieved for the same security parameters.

Influence of gravity connections and damper activation forces on the seismic behavior of steel CBF buildings with dissipative floor connectors

AbstractThis paper investigates the influence of typical gravity connections on the seismic demands of steel concentrically braced frame (CBF) buildings with friction dampers as dissipative floor connectors. The investigated connections include (i) typical shear tab, (ii) clip angle, (iii) flush end‐plate and (iv) shear tab connections with bottom T‐stub. It is shown that the seismic behavior of the gravity framing system (GFS) is practically insensitive to the gravity connection type because the supplemental damping provided by the dissipative floor connectors dominates the seismic response of the GFS. While flush end‐plate and shear tab connections with bottom T‐stub generally exhibit smaller rotational demands than more flexible gravity connections, the resultant lateral drift demands in the GFS are more‐or‐less identical in all cases due to the elastic contribution of the gravity columns. A simplified method is proposed to evaluate the influence of the damper activation forces on the seismic response of multi‐story CBF buildings equipped with floor sliding friction dampers. First, the building is transformed into an equivalent single‐degree‐of‐freedom system. Subsequently, dual graphics called P‐spectra are generated through nonlinear response history analysis. These graphics allow to estimate the peak floor absolute acceleration demands and peak/residual roof displacements of the GFS as a function of the activation forces of the sliding friction dampers. An application example demonstrates that the proposed method can be reliably employed in a pre‐design phase to identify the range of damper activation forces through which an optimal performance of the steel CBF building may be anticipated.

Assessment of seismic acceleration demands on nonstructural components in moderately ductile RC frame buildings designed according to NBC 2015

This paper presents an extensive investigation of the seismic demands on acceleration-sensitive nonstructural components (NSCs) attached to reinforced concrete moment-resisting frame buildings with limited ductility and designed according to the National Building Code of Canada. A total of four benchmark structures with varying heights are considered in this study. Linear and nonlinear time-history analyses were performed using artificial ground motions compatible with Montreal site Class C uniform hazard spectra having 2% and 10% probabilities of being exceeded in 50 years. Seismic acceleration demands on NSCs were evaluated by assessing the horizontal height factor Ax, the component dynamic amplification factor Ar, and the component force factor Sp compared with various building code provisions. The overall acceleration demands of NSCs are discussed, and a corresponding optimized Sp profile is proposed to improve the estimation of the seismic force demands on NSCs at the rooftops of buildings located in moderate seismic zones.

Peak match acceleration demands differentiate between elite youth and professional football players.

Youth footballers need to be developed to meet the technical, tactical, and physical demands of professional level competition, ensuring that the transition between competition levels is successful. To quantify the physical demands, peak match intensities have been measured across football competition tiers, with team formations and tactical approaches shown to influence these physical demands. To date, no research has directly compared the physical demands of elite youth and professional footballers from a single club utilising common formations and tactical approaches. The current study quantified the total match and peak match running demands of youth and professional footballers from a single Australian A-League club. GPS data were collected across a single season from both a professional (n = 19; total observations = 199; mean ± SD; 26.7 ± 4.0 years) and elite youth (n = 21; total observations = 59; 17.9 ± 1.3 years) team. Total match demands and peak match running demands (1-10 min) were quantified for measures of total distance, high-speed distance [>19.8 km·h-1] and average acceleration. Linear mixed models and effect sizes identified differences between competition levels. No differences existed between competition levels for any total match physical performance metric. Peak total and high-speed distances demands were similar between competitions for all moving average durations. Interestingly, peak average acceleration demands were lower (SMD = 0.63-0.69) in the youth players across all moving average durations. The data suggest that the development of acceleration and repeat effort capacities is crucial in youth players for them to transition into professional competition.

Respuesta sísmica para una edificación residencial de concreto armado acorde a las normas sudamericanas de la zona del Pacifico

En el presente trabajo se realizó la estimación de la respuesta sísmica de una edificación de concreto armado representativa de residencias multifamiliares modernas de mediana altura de la zona sur del Perú, en concordancia con las normas sísmicas de la zona del pacifico correspondientes a las directivas oficiales vigente del Perú (E.030,2018), Chile (NCh433, 2012) y Ecuador (NEC, 2015), empleando para ello el análisis modal espectral con el propósito de destacar los aspectos más relevantes en las normas e identificar posibles parámetros ausentes que influyen de forma destacada sobre la demanda estructural. El análisis contempló la estimación de las fuerzas cortantes, la aceleración espectral y el desplazamiento relativo de entrepiso abarcando variables cómo la zonificación sísmica, tipología de suelos, categoría de úso, sistema estructural, entre otros; contemplando el planteamiento de un esquema uniforme para la comparación de límites entre los desplazamientos relativos de entrepiso establecidos en cada norma. El proceso se realizó a partir de modelos numéricos de un edificio de concreto armado de 10 niveles constituido por pórticos y muros estructurales; encontrándose, entre otros, que la mayor demanda de aceleración a nivel de superficie en las regiones costeras para un suelo rocoso (Vs ≥ 900 m/s) corresponde al Perú, seguida de Ecuador y Chile. Se concluye en general, que las mayores demandas y los limites más restrictivos para las diferentes zonas sísmicas y diferentes condiciones de suelo corresponden a las disposiciones reglamentarias de Perú.

Acceleration demands in single-storey RC buildings with flexible diaphragms

This paper presents a study on acceleration demands in single-storey reinforced concrete (RC) buildings with flexible diaphragms, expressed through peak floor accelerations (PFAs) and floor response (acceleration) spectra (FRS). Firstly, an extensive parametric study was performed on idealized single-storey buildings for which geometrical parameters were varied for inducing different degrees of diaphragm flexibility. The influence of diaphragm flexibility was taken into account through the commonly used in-plane displacement ratio. To investigate acceleration demands, three sets of Eurocode 8 spectrum-compatible ground motion records were used as input, selected according to three different soil categories. RC buildings were considered as both linear elastic and nonlinear, whereas non-structural components (NSCs) were considered only as linear elastic. In all cases, it was observed that diaphragm flexibility significantly influences PFAs and FRS, which can both increase and decrease compared to buildings with rigid diaphragms. In the case of FRS, a shifting of peaks was observed as well. Despite the very complicated dependence between the diaphragm flexibility and PFAs and FRS, based on the obtained results, simple empirical formulas for the estimation of the ratios between PFAs and FRS in RC buildings with rigid and flexible diaphragms were proposed. Their accuracy was assessed through a case study example performed on an existing single-storey RC building.

A CNN Hardware Accelerator Using Triangle-based Convolution

Convolutional neural networks (CNNs) have gained a massive impression in the fields of computer vision and especially in the embedded applications because of their high accuracy and performance. However, high computational complexity and power consumption due to convolution operations causes a high demand for low-power accelerators. A 3D geometric optimization strategy is proposed to alleviate the area and power requirements of Multiply Accumulate operations prevalent in all spatial CNNs. The proposed technique is generic and may be easily scaled for accelerators performing spatial 2D convolution.

Effect of damping model and inelastic deformation on the prediction of vertical seismic acceleration demand on steel frames

This study addresses the modeling of different energy dissipation mechanisms for numerical prediction of the vertical acceleration demand in regular moment-resisting steel frame structures. One of the issues discussed is the consideration of viscous damping in the structural model. It is shown that well-established Rayleigh-damping may highly overestimate the damping of the vertical modes, resulting in much too low vertical acceleration response predictions. A study with different damping models provides an appropriate damping modeling strategy that leads to reasonable predictions of both horizontal and vertical frame acceleration demands. Another open question is the effect of inelastic material behavior on the vertical acceleration demand on the considered regular structures. The results of a shell model of a frame structure exposed to high intensity ground motion excitation demonstrate that inelastic material behavior has virtually no impact on the vertical acceleration demand, while structural inelasticity leaves the horizontal acceleration response significantly smaller compared to the elastic demand. This leads to the conclusion that common frame models that capture the inelastic horizontal response but behave elastic in the vertical direction are suitable for the computation of both the horizontal and vertical acceleration demand.

Seismic design and performance of steel concentrically braced frame buildings with dissipative floor connectors

AbstractThis paper explores the use of sliding friction dampers (SFDs) as dissipative floor connectors to mitigate higher mode effects and earthquake‐induced absolute acceleration demands on steel concentrically braced frame (CBF) buildings. The dampers connect each floor of the steel CBF system to the diaphragms of the gravity framing system (GFS) and they allow for a relative in‐plane movement between the two systems. For this purpose, a design methodology is first proposed to define the activation forces in the SFDs so as to ensure damage‐free seismic performance in the steel CBF and the diaphragms of the GFS. The efficiency of the design methodology is demonstrated through nonlinear response history analyses on a low‐ and high‐ductility six‐story steel CBF building. The simulation results suggest that (a) the determined activation forces of the SFDs are effective in mitigating higher mode effects and in preventing story drift concentrations regardless if capacity design is employed for the CBF system; (b) the absolute acceleration demands are reduced by approximately 50% relative to those in the rigid diaphragm counterpart. Similar reductions are achieved in the lateral drift demands of the GFS at seismic intensities with return periods of 475 and 2475 years. The reduction in the variability of seismic response, both in terms of absolute floor acceleration demands and story drift ratios (SDRs) in the CBF system, is noteworthy. Limitations as well as suggestions for future work are discussed.

Bridging Python to Silicon: The SODA Toolchain

Systems performing scientific computing, data analysis, and machine learning tasks have a growing demand for application-specific accelerators that can provide high computational performance while meeting strict size and power requirements. However, the algorithms and applications that need to be accelerated are evolving at a rate that is incompatible with manual design processes based on hardware description languages. Agile hardware design tools based on compiler techniques can help by quickly producing an application-specific integrated circuit (ASIC) accelerator starting from a high-level algorithmic description. We present the software-defined accelerator (SODA) synthesizer, a modular and open-source hardware compiler that provides automated end-to-end synthesis from high-level software frameworks to ASIC implementation, relying on multilevel representations to progressively lower and optimize the input code. Our approach does not require the application developer to write any register-transfer level code, and it is able to reach up to 364 giga floating point operations per second (GFLOPS)/W efficiency (32-bit precision) on typical convolutional neural network operators.

Advanced Thermal Management Systems for High-Power Lithium-Ion Capacitors: A Comprehensive Review

The acceleration demand from the driver in electric vehicles (EVs) should be supported by high-power energy storage systems (ESSs). In order to satisfy the driver’s request, the employed ESS should have high power densities. On the other hand, high energy densities are required at the same time for EVs’ traction to minimize the range anxiety. In this context, a novel ESS has emerged that can provide high power and energy densities at the same time. Such technology is called lithium-ion capacitor (LiC), which employs Li-doped carbon as negative electrode and activated carbon as positive electrode. However, high heat generation in high current applications is an issue that should be managed to extend the LiCs life span. Hence, a proper thermal management system (TMS) is mandatory for such a hybrid technology. Since this ESS is novel, there are only several TMSs addressed for LiCs. In this review article, a literature study regarding the developed TMSs for LiCs is presented. Since LiCs use Li-doped carbon in their negative electrodes, lithium-titanate oxide (LTO) batteries are the most similar lithium-ion batteries (LiBs) to LiCs. Therefore, the proposed TMSs for lithium-ion batteries, especially LTO batteries, have been explained as well. The investigated TMSs are active, passive, and hybrid cooling methods The proposed TMSs have been classified in three different sections, including active methods, passive methods, and hybrid methods.

Experimental testing on nonstructural continuous plasterboard suspended ceiling systems under shake table-generated motions

Three different continuous plasterboard suspended ceiling systems were experimentally investigated through shake table-generated motions: (1) vertical strut ceiling system with all edges fixed, (2) vertical strut and lateral brace ceiling system with all edges free, and (3) vertical strut ceiling system with all edges free. Dynamic behavior and performance of these ceiling systems were evaluated to understand the effect of various boundary conditions and lateral force-resisting mechanisms at increasing intensity levels of input motion. All the ceiling systems performed well up to floor accelerations ranging from 1.4 to 1.6 g without any visible damage. However, under sinusoidal excitation at the natural frequency of the ceiling systems, the strut system with free boundaries proved vulnerable as it slipped from the perimeter channel leading to major damage. This suggests that the vertical strut system with free edges is vulnerable for multistory buildings located in any seismic zone due to its poor performance observed under large acceleration demands.

Demands on acceleration-sensitive nonstructural components in special concentrically braced frame and special moment frame buildings

This study investigates demands on acceleration-sensitive nonstructural components (NSCs) in code-compliant Special Concentrically Braced Frame (SCBF) and Special Moment Frame (SMF) structures. Previous studies have highlighted that the assumption of ASCE 7-16 for the ratio of Peak Floor Acceleration (PFA) to Peak Ground Acceleration (PGA) is overly conservative. In most previous studies, the results were based on generic analytical models with non-deteriorating structural behavior or recorded data from instrumented buildings subjected to ground motions that were significantly weaker than the design-level earthquakes. This study evaluates the acceleration demands on NSCs in 11 archetype buildings modeled using advanced techniques. The ground motions used elicit inelastic response in the frames at the level expected by ASCE 7-16 compliant designs. The study examines the effect of the ratio of NSC period to structural period, NSC damping ratio, and NSC vertical location on these demands. Results of this investigation are compared with the provisions of ASCE 7-16 and the recommendations of the recently completed effort by the Applied Technology Council 120 project (ATC-120), which are the basis for the seismic design requirements for nonstructural components in the forthcoming ASCE 7-22 standard. Equations for the PFA/PGA ratio and NSC amplification factor, which account for the dynamic characteristics of the buildings, are developed based on regression analysis of the generated data. Results of the analyses indicate that the formula recommended by ATC-120 for estimating PFA/PGA along the height of the structure, which includes building nonlinearity effects through a constant building ductility reduction factor, overestimates floor accelerations at the top floors but underestimates them in the lower floors of the archetypes considered. At the same time, results show that the NSC seismic design force equation recommended by ATC-120 is conservative for the SCBF archetypes, while it underestimates the NSC force demands in the SMFs.

The Relationship Between Bureaucratic Leadership, Organizational Agility and Organizational Performance in the Tax Sector

The demands on public organizations increasingly place leaders in complex situations. Leaders are required to be able to unravel the complexity of the organization and deal with various problems, both internal and external. The leadership role necessitates responding and being proactive. The purpose of this research was to analyze the relationship between bureaucratic leadership, organizational agility and organizational performance in the tax sector. This research involved an explanatory survey by the SAMSAT office in Banten Province, conducted with 238 participants who were members of the public and regional tax officials who were randomly selected without differentiating positions in management. The variant SEM procedure was used for data analysis. The findings showed that the demands of bureaucratic leadership in the digital era are very high. Acceleration is an important aspect inherent in leadership in the digital era. Control over changes in local politics and administration, and demands for acceleration, necessitate leaders who have capacity. Bureaucratic leadership has an influence on organizational agility and organizational performance in the tax sector. Bureaucratic leadership influences organizational performance either directly or through organizational agility. The theoretical implication is the need to develop the concept of leadership in the context of the digital era in order to encourage public performance. The practical implication is the need for leadership that is agile in responding to public demands and acts quickly by integrating administrative orientation, understanding local political dynamics and being ready to face acceleration challenges.
 Keywords: bureaucratic leadership, organizational agility, organizational performance, the taxation sector

Impact and clutch nonlinearities in the seismic response of inerto-rocking systems

Rocking bodies can be found at all structural scales, from small museum exhibits to uplifting buildings. These structures, whose dynamic stability springs from the difficulty of mobilizing their rotational inertia, are ideal candidates for benefiting from the supplemental inertia provided by inerters. This benefit can be limited, however, if the inerter drives the structural response towards potentially undesirable motions by transferring back the kinetic energy accumulated within it at inconvenient times. To control this phenomenon, a clutching system can be employed to direct the interaction between the interter and the structure improving further its dynamic behaviour. To date, however, most of the studies dealing with clutching inerto-elastic or inerto-rocking systems under seismic excitation have adopted a rather simplistic idealisation of the clutch engagement-disengagement response. In this paper, we re-visit the impact effects on inerto-rocking structures and propose an improved mechanistic model of the clutching system. First, the effects of the inerter on the transition upon impact and the impact effects on the acceleration response of rocking blocks are analysed. Then, a set of original analytical expressions for rigid and flexible rocking structures equipped with a pair of clutched inerters are derived. The newly proposed models are used to examine the evolution of the energy dissipation in the device and the influence of key parameters like the clutch stiffness, gears play, viscous damping and dry friction on its response. We conclude by evaluating the behaviour of the detailed rocking model with clutched inerters to a set of realistic earthquake ground motions. Although important differences are observed in the evolution of energy dissipation and engagement response depending on the type and characteristics of the clutch model, largely comparable peak values of displacement are obtained. On the other hand, a more accurate representation of the clutch behaviour leads to potentially larger acceleration demands. Our analyses also show that, in general, the inclusion of the inerter results in higher coefficients of restitution, indicating lower energy dissipation during impact and that the infinite acceleration spikes predicted by Housner’s model can be ignored if impact forces are sufficiently distributed over time as to cause continuous velocity transitions, but sharp enough not to appreciably affect the rotation response.

Estimation of Floor Response Spectra for Self-Centering Structural Systems with Flag-Shaped Hysteretic Behavior

Spectral floor-acceleration demands are necessary for the seismic design of acceleration-sensitive non-structural components (NSCs). Existing studies to estimate floor response spectra (FRS) using empirical equations are based on elasto-plastic and stiffness degrading hysteretic behavior of the primary structure. In the present study, the FRS for self-centering (SC) structural systems with flag-shaped hysteretic behavior under far-fault ground motions are investigated. The FRS and dynamic amplification factor (DAF) are obtained from nonlinear response history analysis (NLRHA) of SC structural systems with flag-shaped hysteretic behavior. An equation to estimate the FRS is proposed and verified by carrying out NLRHA using a different set of far-fault ground motions. The equation to estimate FRS is shown to predict floor acceleration demands with very good accuracy.

Moving Toward a More Comprehensive Analysis of Acceleration Profiles in Elite Youth Football.

In football, having greater acceleration ability may decide the most important moments within matches. Up to now, commonly used acceleration variables have typically been investigated in isolation, with each variable suffering from unique limitations. Subsequently, any findings may provide a limited representation of what specific acceleration demands had actually occurred. Without gaining a comprehensive understanding of acceleration demands in football, it appears difficult to identify how to best monitor and maximize the long-term development of acceleration ability in footballers, all whilst doing so in a safe, sport-specific manner. Moving toward a more comprehensive analysis of acceleration profiles addresses this, as it can provide a more robust, informative understanding of the unique acceleration demands of competitive match-play. This perspective article aims to discuss the benefits of adopting a more comprehensive analysis of the acceleration demands during competitive matches for football players, by simultaneously analyzing high-intensity accelerations, repeated high acceleration ability (RHAA), and average acceleration. We discuss examples of the calculation and application of a more comprehensive acceleration profile at a team level throughout the course of an entire elite youth football season, as well as on an individual level. Monitoring acceleration profiles more comprehensively not only appears important from a training load/injury prevention perspective, but also, equips coaches and conditioning staff with the specific information necessary to develop and prescribe individualized, acceleration-emphasized training protocols that are replicable to the demands of match-play. Examples of such protocols are provided.

Barrier Lyapunov Function based Impact Time Guidance with Field-of-View and Input Constraints

This paper proposes a barrier Lyapunov function-based guidance scheme against stationary targets to achieve interception at a pre-specified impact time while satisflying the field-of-view constraint and the bounded lateral acceleration requirement for planar engagements. An approach that aids in satisflying the field-of-view constraint with a bounded interceptor lateral acceleration is first proposed using the conditions on time-to-go estimate of the engagement and extension of system states. Thereafter, the guidance command that constrains the time-to-go values and extended states within their bounds is obtained using the concept of the barrier Lyapunov function. The proposed approach also allows the designer to control the convergence rate and thereby the acceleration requirements, resulting in a trade-off between the rate of convergence of error and acceleration demand. Simulations are carried out to validate the effectiveness of the proposed schemes for different initial engagement geometries.

THE ESSENCE AND FEATURES OF SOCIAL COMMISSIONING IMPLEMENTATION IN UKRAINE

Relevance of the research problematics is proved by the social demand for acceleration of social commissioning implementation in Ukraine so as to respond to the ongoing pandemic COVID-19, armed conflict in Ukraine, long lasting tradition of institutional care for vulnerable people. The purpose of the article is to reveal the core of social commissioning linked to social work with families with children, to characterize dynamics of its implementation and development in Ukraine. Methods of research: the theoretical analysis of actual scientific sources, rated to the topic, is applied in the research together with desk review of a new international and national legislation. The methods of generalization and systematization were applied for definition of actual interpretation of “social commissioning” and its characteristics. The results of the research are as follows: The social commissioning is determined as an instrument for public regulation in the system of social service provision by means of contracting social service providers for satisfaction of social service needs identified within social service need assessment by entities of local self-government. Research attention is paid to the structure and key elements of social commissioning. Participants (сustomers, recipients and providers of social services), constituents (social character; contracting core and innovation value), and principles of social commissioning (result orientation; awareness; planning; priority to prevention and early intervention; partnership) are covered in the article. The procedural stages of social commissioning are also unpacked in the article (designing; implementation; monitoring and evaluation). Prospects for further research are the studies of barriers to the implementation of social commissioning and ways to overcome them, development and implementation of optimal algorithms for its implementation in a decentralized environment.

Deploying Multi-tenant FPGAs within Linux-based Cloud Infrastructure

Cloud deployments now increasingly exploit Field-Programmable Gate Array (FPGA) accelerators as part of virtual instances. While cloud FPGAs are still essentially single-tenant, the growing demand for efficient hardware acceleration paves the way to FPGA multi-tenancy. It then becomes necessary to explore architectures, design flows, and resource management features that aim at exposing multi-tenant FPGAs to the cloud users. In this article, we discuss a hardware/software architecture that supports provisioning space-shared FPGAs in Kernel-based Virtual Machine (KVM) clouds. The proposed hardware/software architecture introduces an FPGA organization that improves hardware consolidation and support hardware elasticity with minimal data movement overhead. It also relies on VirtIO to decrease communication latency between hardware and software domains. Prototyping the proposed architecture with a Virtex UltraScale+ FPGA demonstrated near specification maximum frequency for on-chip data movement and high throughput in virtual instance access to hardware accelerators. We demonstrate similar performance compared to single-tenant deployment while increasing FPGA utilization, which is one of the goals of virtualization. Overall, our FPGA design achieved about 2× higher maximum frequency than the state of the art and a bandwidth reaching up to 28 Gbps on 32-bit data width.