Search Results (8)

Maximal and explosive strength—defined as the ability to rapidly generate high levels of force—are widely recognized as critical for performance in strength–power sports such as track and field throwing. However, their interrelationship remains insufficiently examined, particularly in the upper body of elite athletes. This study examined the relationship between early force production (≤250 ms, subdivided into early phase: 0–100 ms; late phase: 100–250 ms) and peak isometric upper-body push and pull force in elite Swedish track and field throwers. A total of 30 athletes (17 females, 13 males; aged 18–34 years), all competing nationally or internationally in discus, hammer, shot put, or javelin, participated in a cross-sectional assessment. Isometric force was measured during bench press (push) and supine bench row (pull) using a custom-built device. Force output was recorded at 50, 100, 150, 200, and 250 ms, along with peak force. The results showed a progressive increase in the correlation between force at early time points and peak force. Associations were weak to moderate at 50–100 ms (r = 0.07–0.55) and became strong to very strong at 150–250 ms (r = 0.64–0.92). These patterns were consistent across sexes and test types. The findings suggest that maximal strength becomes increasingly important as force production time extends beyond 100 ms. Coaches may benefit from assessing both early and peak force characteristics to inform strength profiling and guide training focus, though further research is needed to determine their impact on performance. Full article

Experimental modal analysis has proven effective in damage identification of civil structures but has not been extensively applied to multi-leaf masonry structures, particularly in the context of wall tie inspection. This paper investigates the applicability of non-destructive, vibration-based damage identification methods to a one-storey masonry veneer wall to detect wall tie deterioration based on changes in modal parameters. An impact hammer was used to collect vibration data from eight different wall tie deterioration test cases by disconnecting the wall ties at various locations. The downshift of natural frequencies was recorded for all deterioration test cases, and a reduction of up to 38% was observed when the top row of wall ties was disconnected, highlighting the importance of wall ties to the overall stiffness of the masonry veneer wall system. In terms of damage localisation accuracy, the parameter-based method performed the best by successfully identifying seven out of eight damaged scenarios without additional noise. The findings show that the detection of wall tie deterioration using non-destructive, vibration-based damage identification methods is viable, providing an alternative wall tie inspection method with significant benefits to infrastructure management, thereby enhancing safety, efficiency, and sustainability in maintaining and preserving masonry veneer walls. Full article

This study investigates the impact of four parameters—gate angles, fin height controlled through gate overlaps and the distance from fin to source/drain, and substrate bottom doping concentration—on the row hammer effect (RHE) in DRAM cells. The influence of adjacent and passing gates on the DRAM cell body potential was identified as a key factor in D0 and D1 failures. The tolerance for D1 and D0 failures was analyzed, defined as the threshold number of pulses required to induce a 0.6 V change in the storage node voltage (from 1.2 V to 0.6 V for a D1 failure or from 0 V to 0.6 V for a D0 failure). D1 (D0) failure tolerances with the slope from the top of the top gate (θ_angle) of 3°, the height of the TiN gate covering the fin (H_{fin_overlap}) of 12.5 nm, and the height of the fin (H_fin) of 12.5 nm are 1.26 × 10⁶ (4.8 × 10⁶), 1.14 × 10⁶ (4 × 10⁷), and 7.5 × 10⁵ (4.8 × 10⁵), respectively. Higher θ_angles and smaller fin heights generally result in higher RHE tolerances. Although decreasing the fin height reduced the RHE, it also decreased the on-current and resulted in an increase in the threshold voltage (V_T) and the subthreshold swing (SS). In addition, by increasing the substrate bottom doping concentration (P_{dop_bot}), we improve RHE tolerance twice its original level without reducing the on-current. Therefore, designing a buried channel array transistor (BCAT) structure requires careful consideration of these trade-offs, and a thorough understanding of the underlying mechanism is crucial to devising strategies that reduce RHE tolerance. The findings of this study are expected to contribute significantly to the development of next-generation DRAM architectures, enhancing stability and performance. By addressing the reliability challenges posed by advanced scaling, this study paves the way for the ongoing advancement of DRAM technology for high-density and high-performance applications. Full article

Dynamic random-access memory (DRAM) is crucial for high-performance computing due to its speed and storage capacity. As the demand for high-capacity memory increases, DRAM has adopted a scaled-down approach for the next generation. However, the reduced distance between cells leads to electrical interference, known as the 1-row Hammer effect, which degrades DRAM performance and poses security risks. Therefore, the 1-row Hammer effect is a critical issue in current DRAM technology. In this study, we investigate the principles and impact of the 1-row Hammer phenomenon on DRAM. The 1-row Hammer effect can cause two types of failures: D0 and D1. We focus on D0 failures, which occur when stored data transition from 0 to 1 due to repeated accesses. This phenomenon involves the capture and diffusion of electrons, influenced by interfacial traps and device structures. To investigate the D0 failure, we simulated the 1-row Hammer effect using a mixed-mode approach to examine its effects on interfacial traps and device structure changes. This study aims to improve our understanding of row Hammer and suggests a mitigation strategy using buried oxide. The proposed structure mitigates the D0 failure by approximately 25%, effectively improving the security and reliability of DRAM. Full article

Data on the strength ratio between agonist and antagonist muscles are frequently examined in sports testing, given its correlation with athletic performance. The purpose of this study was to determine the agonist-to-antagonist ratio of upper body strength in female and male elite Swedish track and field throwers using a new push (bench press) and pull (supine bench row) test device, and to determine its reliability. The study involved eight female and nine male athletes, aged 19–29 years, engaging, respectively, in discus, hammer, and shot put competitions at both national and international levels. The athletes’ maximum isometric force was assessed during the bench press (push) and supine bench row (pull) exercises, respectively, using a custom-built test device. The test–retest reliability of the device was also examined. The total push-to-pull strength ratio for the female throwers was 1.15, whereas male throwers demonstrated a ratio of 1.22. Total push and pull force for the female throwers was significantly less than for the male throwers (5511 N vs. 8970 N, p < 0.001). Intraclass correlation coefficients ranged from 0.93 to 0.96 for the bench press and supine bench row exercise, indicating that the push and pull test device was highly reliable. The main findings of this study were that elite female and male discus, hammer, and shot put throwers exhibited 15% and 22% more pushing (bench press) than pulling (supine bench row) strength. Push and pull strength in the female throwers ranged from 47% to 71% of that of the male throwers. The push and pull test device is a reliable tool in establishing the agonist-to-antagonist ratio of upper body strength of athletes. Coaches and athletes may benefit from examining upper body push and pull strength ratios for training planning and prescription. Full article

The cells in dynamic random access memory (DRAM) degrade over time as a result of aging, leading to poor performance and potential security vulnerabilities. With a globalized horizontal supply chain, aged counterfeit DRAMs could end up on the market, posing a significant threat if employed in critical infrastructure. In this work, we look at the retention behavior of commercial DRAM chips from real-time silicon measurements and investigate how the reliability of DRAM cells degrade with accelerated aging. We analyze the retention-based errors at three different aging points to observe the design-induced variations, analyze the pattern dependency, and explore the impacts of accelerated aging for multiple DRAM vendors. We also investigate the DRAM chips’ statistical distribution to attribute the vital wear-out effects present in DRAM. We see a continuous increase in retention error as DRAM chips age and therefore infer that the aged retention signatures can be used to differentiate recycled DRAM chips in the supply chain. We also discuss the roles of device signature in DRAM aging and aging-related security implication on DRAM row-hammer error. Full article

Physical Unclonable Functions (PUFs) based on the retention times of the cells of a Dynamic Random Access Memory (DRAM) can be utilised for the implementation of cost-efficient and lightweight cryptographic protocols. However, as recent work has demonstrated, the times needed in order to generate their responses may prohibit their widespread usage. To address this issue, the Row Hammer PUF has been proposed by Schaller et al., which leverages the row hammer effect in DRAM modules to reduce the retention times of their cells and, therefore, significantly speed up the generation times for the responses of PUFs based on these retention times. In this work, we extend the work of Schaller et al. by presenting a run-time accessible implementation of this PUF and by further reducing the time required for the generation of its responses. Additionally, we also provide a more thorough investigation of the effects of temperature variations on the Row Hammer PUF and briefly discuss potential statistical relationships between the cells used to implement it. As our results prove, the Row Hammer PUF could potentially provide an adequate level of security for Commercial Off-The-Shelf (COTS) devices, if its dependency on temperature is mitigated, and, may therefore, be commercially adopted in the near future. Full article

The purpose of this study was to investigate the impact of ingesting an amino acid-electrolyte (AAE) beverage during upper body resistance exercise on transient muscle hypertrophy, exercise performance, markers of muscle damage, and recovery. Participants (n = 15) performed three sets of six repetitions—bench press, lat pull down, incline press, and seated row—followed by three sets of eight repetitions at 75% of the estimated 1 repetition maximum—triceps kickback, hammer curl, triceps push down, and preacher curl—with 90 s of rest between sets. The final set of the push down/preacher curl was performed to failure. Prior to and immediately post-exercise, as well as 24, 48, and 72 h post exercise, cross-sectional muscle thickness was measured. Blood samples were collected prior to exercise, as well as 24, 48, and 72 h post-exercise for serum creatine kinase (CK) analysis. No treatment effect was found for muscle cross-sectional area, repetitions to failure, or serum CK. A main effect (p < 0.001) was observed in the change in serum CK levels in the days following the resistance exercise session. The findings of this study suggest that the acute ingestion of a AAE beverage does not alter acute muscle thickness, performance, perceived soreness and weakness, or markers of muscle damage. Full article