Performance Slowdown Research Articles

Make or Break: The Influence of Expected Challenges and Rewards on the Motivation and Experience Associated with Cognitive Effort Exertion.

Challenging goals can induce harder work but also greater stress, in turn potentially undermining goal achievement. We sought to examine how mental effort and subjective experiences thereof interact as a function of the challenge level and the size of the incentives at stake. Participants performed a task that rewarded individual units of effort investment (correctly performed Stroop trials) but only if they met a threshold number of correct trials within a fixed time interval (challenge level). We varied this challenge level (Study 1, n = 40) and the rewards at stake (Study 2, n = 79) and measured variability in task performance and self-reported affect across task intervals. Greater challenge and higher rewards facilitated greater effort investment but also induced greater stress, whereas higher rewards (and lower challenge) simultaneously induced greater positive affect. Within intervals, we observed an initial speed up then slowdown in performance, which could reflect dynamic reconfiguration of control. Collectively, these findings further our understanding of the influence of task demands and incentives on mental effort exertion and well-being.

Ensuring data privacy in AC Optimal Power Flow with a distributed co-simulation framework

During the energy transition, the significance of collaborative management among institutions is rising, confronting challenges posed by data privacy concerns. Prevailing research on distributed approaches, as an alternative to centralized management, often lacks numerical convergence guarantees or is limited to single-machine numerical simulation. To address this, we present a distributed approach for solving AC Optimal Power Flow (OPF) problems within a geographically distributed environment. This involves integrating the energy system Co-Simulation (eCoSim) module in the eASiMOV framework with the convergence-guaranteed distributed optimization algorithm, i.e., the Augmented Lagrangian based Alternating Direction Inexact Newton method (aladin). Comprehensive evaluations across multiple system scenarios reveal a marginal performance slowdown compared to the centralized approach and the distributed approach executed on single machines—a justified trade-off for enhanced data privacy. This investigation serves as empirical validation of the successful execution of distributed AC OPF within a geographically distributed environment, highlighting potential directions for future research.

Aging-associated weakening of the action potential in fast-spiking interneurons in the human neocortex

Aging is associated with the slowdown of neuronal processing and cognitive performance in the brain; however, the exact cellular mechanisms behind this deterioration in humans are poorly elucidated. Recordings in human acute brain slices prepared from tissue resected during brain surgery enable the investigation of neuronal changes with age. Although neocortical fast-spiking cells are widely implicated in neuronal network activities underlying cognitive processes, they are vulnerable to neurodegeneration. Herein, we analyzed the electrical properties of 147 fast-spiking interneurons in neocortex samples resected in brain surgery from 106 patients aged 11–84 years. By studying the electrophysiological features of action potentials and passive membrane properties, we report that action potential overshoot significantly decreases and spike half-width increases with age. Moreover, the action potential maximum-rise speed (but not the repolarization speed or the afterhyperpolarization amplitude) significantly changed with age, suggesting a particular weakening of the sodium channel current generated in the soma. Cell passive membrane properties measured as the input resistance, membrane time constant, and cell capacitance remained unaffected by senescence. Thus, we conclude that the action potential in fast-spiking interneurons shows a significant weakening in the human neocortex with age. This may contribute to the deterioration of cortical functions by aging.

Impact of process interference on memory encoding and retrieval processes in dual-task situations

Dual-tasks at the memory encoding stage have been shown to decrease recall performance and impair concurrent task performance. In contrast, studies on the effect of dual-tasks at the memory retrieval stage observed mixed results. Which cognitive mechanisms are underlying this dual-task interference is still an unresolved question. In the present study, we investigated the influence of a concurrent reaction-time task on the performance in a long-term memory task in two experiments. In Experiment 1, participants performed an auditory-verbal free recall memory task and a visual-manual spatial Stroop task in a single or dual-task condition, either at the encoding or retrieval stage of the memory task. In Experiment 2, we examined the influence of processing conflicts in a concurrent RT task on memory encoding. Both experiments showed detrimental effects on recall accuracy and concurrent RT task performance in dual-task conditions at the encoding stage. Dual-task conditions at the retrieval stage led to a slowdown in recall latency and impaired concurrent RT task performance, but recall accuracy was maintained. In addition, we observed larger Stroop congruency effects in the dual-task conditions, indicating an increased processing conflict. However, in Experiment 2, we analyzed the effect of the processing conflict in a time-locked manner and could not find a significant influence on success of memory encoding. These findings suggest that processes in both tasks share the same limited capacity and are slowed down due to parallel processing, but we could not find evidence that this is further influenced by task-specific processing conflicts.

Effect of Aquatic Exercises on Strength and Quality of Life in Sarcopenia Older Individuals

Abstract There are various definitions of sarcopenia. Among them, the European Working Group on Sarcopenia in Older Persons (EWGSOP) has defined sarcopenia as "a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which carries the risk of unwanted consequences such as physical disability, poor quality of life and death". As a person ages, various changes occur in the skeletal muscle. Nutrition is one of the important factors affecting muscle mass and is a characteristic feature of the continuous loss of muscular mass in the aging process. However, sarcopenia, defined as age-related loss of skeletal muscle mass, leads to a deterioration in muscle quantity and quality, gradual slowdown in movements, decreased strength and performance, increased risk of fall-associated injury, and often a decrease in body weight. Treatment options for sarcopenia include lifestyle changes, including physical activity and exercise training, medical nutrition therapy, and pharmacological therapy. Aquatic exercises are a type of exercise that involves the use of all the muscles of the body in a vertical position in the water, opposing the resistance of the water to its own body weight, while cardio and strength training are performed in parallel. Eliminating the risk of falling in sarcopene individuals, working against their own body weight and water resistance can reduce muscle stress while increasing their strength. Healthy lifestyle patterns, proper nutrition and proper exercise programs are effective in preventing sarcopenia and at every stage of the treatment.

Neuromodulation of the Left Inferior Frontal Cortex Affects Social Monitoring during Motor Interactions.

Motor interactions require observing and monitoring a partner's performance as the interaction unfolds. Studies in monkeys suggest that this form of social monitoring might be mediated by the activity of the ventral premotor cortex (vPMc), a critical brain region in action observation and motor planning. Our previous fMRI studies in humans showed that the left vPMc is indeed recruited during social monitoring, but its causal role is unexplored. In three experiments, we applied online anodal or cathodal transcranial direct current stimulation over the left lateral frontal cortex during a music-like interactive task to test the hypothesis that neuromodulation of the left vPMc affects participants' performance when a partner violates the agent's expectations. Participants played short musical sequences together with a virtual partner by playing one note each in turn-taking. In 50% of the trials, the partner violated the participant's expectations by generating the correct note through an unexpected movement. During sham stimulation, the partner's unexpected behavior led to a slowdown in the participant's performance (observation-induced posterror slowing). A significant interaction with the stimulation type showed that cathodal and anodal transcranial direct current stimulation induced modulation of the observation-induced posterror slowing in opposite directions by reducing or enhancing it, respectively. Cathodal stimulation significantly reduced the effect compared to sham stimulation. No effect of neuromodulation was found when the partner behaved as expected or when the observed violation occurred within a context that was perceptually matched but noninteractive in nature. These results provide evidence for the critical causal role that the left vPMc might play in social monitoring during motor interactions, possibly through the interplay with other brain regions in the posterior medial frontal cortex.

MemPerf: Profiling Allocator-Induced Performance Slowdowns

The memory allocator plays a key role in the performance of applications, but none of the existing profilers can pinpoint performance slowdowns caused by a memory allocator. Consequently, programmers may spend time improving application code incorrectly or unnecessarily, achieving low or no performance improvement. This paper designs the first profiler—MemPerf—to identify allocator-induced performance slowdowns without comparing against another allocator. Based on the key observation that an allocator may impact the whole life-cycle of heap objects, including the accesses (or uses) of these objects, MemPerf proposes a life-cycle based detection to identify slowdowns caused by slow memory management operations and slow accesses separately. For the prior one, MemPerf proposes a thread-aware and type-aware performance modeling to identify slow management operations. For slow memory accesses, MemPerf utilizes a top-down approach to identify all possible reasons for slow memory accesses introduced by the allocator, mainly due to cache and TLB misses, and further proposes a unified method to identify them correctly and efficiently. Based on our extensive evaluation, MemPerf reports 98% medium and large allocator-reduced slowdowns (larger than 5%) correctly without reporting any false positives. MemPerf also pinpoints multiple known and unknown design issues in widely-used allocators.

Modeling 3D NAND Flash with Nonparametric Inference on Regression Coefficients for Reliable Solid-State Storage

Solid-state drives represent the preferred backbone storage solution thanks to their low latency and high throughput capabilities compared to mechanical hard disk drives. The performance of a drive is intertwined with the reliability of the memories; hence, modeling their reliability is an important task to be performed as a support for storage system designers. In the literature, storage developers devise dedicated parametric statistical approaches to model the evolution of the memory’s error distribution through well-known statistical frameworks. Some of these well-founded reliability models have a deep connection with the 3D NAND flash technology. In fact, the more precise and accurate the model, the less the probability of incurring storage performance slowdowns. In this work, to avoid some limitations of the parametric methods, a non-parametric approach to test the model goodness-of-fit based on combined permutation tests is carried out. The results show that the electrical characterization of different memory blocks and pages tested provides an FBC feature that can be well-modeled using a multiple regression analysis.

Bank Indonesia Syariah Certificate: Encouraging Economic Growth During The COVID-19 Pandemic

The Bank Indonesia Sharia Certificate (SBIS) is one of the sharia monetary instruments used by Bank Indonesia in formulating monetary policy. The development of SBIS is related to several factors: inflation growth, the economy, and the development of the gross domestic product. This study aims to determine how to implement the Bank Indonesia Sharia Certificate (SBIS) in encouraging monetary economic growth during the Covid-19 pandemic. The slowdown in economic growth and regional economic performance due to the impact of the Covid-19 virus outbreak that attacked the economy resulted in a decline in economic performance. The role of money market products (SBIS) can encourage economic growth and development through Islamic money market transactions. This research method uses descriptive qualitative research with a library research approach and interviews. In collecting interview data using the accidental sampling method conducted on Bank Indonesia staff directly at the research location and data on the growth, economy, and development of SBIS during the Covid-19 pandemic. Research results: The Bank Indonesia Sharia Certificate (SBIS) implementation has generally been carried out properly by Bank Indonesia. When Bank Indonesia issues SBIS and sells it to the public, this will cause the money supply in the community to decrease. When the money supply in society decreases, then inflation can be suppressed. When inflation can be suppressed, this will indirectly affect the increase in financing disbursements in Islamic banks. So, it can be concluded that SBIS significantly affects financing distribution in Islamic banking. When financing distribution increases, this will help MSME players affected by Covid-19 in terms of capital. The role of SBIS during the Covid-19 pandemic can stimulate and encourage economic growth performance.

The Earth system model CLIMBER-X v1.0 – Part 2: The global carbon cycle

Abstract. The carbon cycle component of the newly developed Earth system model of intermediate complexity CLIMBER-X is presented. The model represents the cycling of carbon through the atmosphere, vegetation, soils, seawater and marine sediments. Exchanges of carbon with geological reservoirs occur through sediment burial, rock weathering and volcanic degassing. The state-of-the-art HAMOCC6 model is employed to simulate ocean biogeochemistry and marine sediment processes. The land model PALADYN simulates the processes related to vegetation and soil carbon dynamics, including permafrost and peatlands. The dust cycle in the model allows for an interactive determination of the input of the micro-nutrient iron into the ocean. A rock weathering scheme is implemented in the model, with the weathering rate depending on lithology, runoff and soil temperature. CLIMBER-X includes a simple representation of the methane cycle, with explicitly modelled natural emissions from land and the assumption of a constant residence time of CH4 in the atmosphere. Carbon isotopes 13C and 14C are tracked through all model compartments and provide a useful diagnostic for model–data comparison. A comprehensive evaluation of the model performance for the present day and the historical period shows that CLIMBER-X is capable of realistically reproducing the historical evolution of atmospheric CO2 and CH4 but also the spatial distribution of carbon on land and the 3D structure of biogeochemical ocean tracers. The analysis of model performance is complemented by an assessment of carbon cycle feedbacks and model sensitivities compared to state-of-the-art Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Enabling an interactive carbon cycle in CLIMBER-X results in a relatively minor slow-down of model computational performance by ∼ 20 % compared to a throughput of ∼ 10 000 simulation years per day on a single node with 16 CPUs on a high-performance computer in a climate-only model set-up. CLIMBER-X is therefore well suited to investigating the feedbacks between climate and the carbon cycle on temporal scales ranging from decades to >100 000 years.

Disclosure: Improving Performance and Security of Web App Migration in Liquid Computing

Web app migration refers to capturing a snapshot of the execution state of a web app on a device and restoring it on another device to continue its execution for cross-device liquid computing. Although web apps are relatively easy to migrate due to their high portability, there is a JavaScript language feature called closure that complicates the migration since it requires migrating the variable states of already-finished outer functions. One approach to web app migration is to instrument the source code to trace the closure variables, yet this often suffers from performance slowdown, especially for multiple migrations. In this paper, we propose a new instrumentation-based technique called Disclosure, which moves the declarations of closure variables to a managed data structure and replaces the closure variables with the corresponding references to the data structure. This technique can improve runtime performance while enhancing security. We evaluated our work with eight Octane benchmarks and four real web apps. The runtime performance penalty due to Disclosure is 0–15%, which is a significant improvement over the results of the latest instrumentation-based work that supports similar deep closures and multiple migrations to Disclosure. Furthermore, real web apps are demonstrated to migrate seamlessly, even multiple times. Finally, Disclosure can hide data from exposure during migration with a secure migration technique using data encryption.

AEx: Automated High-Level Synthesis of Compiler Programmable Co-Processors

Modern High Level Synthesis (HLS) tools succeed well in their engineering productivity goal, but still require toolset and target technology specific modifications to the source code to guide the process towards an efficient implementation. Furthermore, their end result is a fixed function accelerator with limited field and runtime flexibility. In this paper we describe the status of AEx, a novel work-in-progress HLS tool developed in the FitOptiVis ECSEL JU project. AEx is based on automated exploration of architectures using a flexible and lightweight parallel co-processor template. We compare its current performance in CHStone C-language benchmarks to the state of the art FPGA HLS tool Vitis, provide ASIC implementation numbers, and identify the main remaining toolset features that are expected to dramatically further improve the performance. The potential is explored with a hand-optimized case study that shows only 1.64x performance slowdown with the programmable co-processor in comparison to the fixed function Vitis HLS result.

Cache-Based Side-Channel Attack Mitigation for Many-Core Distributed Systems via Dynamic Task Migration

Side-channel attacks (SCA) are a serious threat to cryptographic systems due to mostly unavoidable information leakage. Cache-based SCAs take advantage of cache inherent timing properties on shared memory systems to extract security-critical information. In this paper, we present a novel approach to mitigate cache-based SCAs on distributed many-core systems, based on a resource management technique. Our solution leverages dynamic task migration as a mechanism to ensure a secure execution scenario for security-critical applications. Additionally, we propose a resource-management-based mechanism to ensure a secure execution when migration is not possible due to a lack of available resources. We evaluate our solution in terms of gained security and performance impact using the Sniper simulator for different configurations. Results show that our technique effectively develops resilience against SCAs, while causing a low performance slowdown (1.6% on average, 9% worst case). For all tested benchmarks, our worst-case performance slowdown is 20% less than a state-of-the-art countermeasure. Moreover, our solution utilizes less than 1 ms of system run-time overhead for a 64 core platform with 100% utilization.

Age-related Deterioration of Alpha Power in Cortical Areas Slowing Motor Command Formation in Healthy Elderly Subjects.

The same neural processes may govern older people's motor and cognitive abilities since an inability to switch between actions develops with aging. In this study, a dexterity test was used to measure motor and cognitive perseverance, which required participants to move their fingers fast and correctly on hole boards. An electroencephalography (EEG) recording was used to evaluate how healthy young and older adults process brain signals when performing the test. A significant difference was found between the young and older groups in the average time taken to complete the test, with the older group taking 87.4 s and the young group taking 55.21 s. During motor movement, young participants showed alpha desynchronization over the cortex (Fz, Cz, Oz, Pz, T5, T6, P3, P4) in comparison to the resting state. However, compared to the younger group, no alpha desynchronization was found in the aging group during motor performance. It was noteworthy that alpha power (Pz, P3, and P4) in the parietal cortex was significantly lower in older compared to young adults. Age-related slowdown in motor performance may be caused by deteriorating alpha activity in the parietal cortex, which functions as a sensorimotor interface. This study provides new insights into how perception and action are distributed between brain regions.

DÜNYADA ORTA GELİR TUZAĞI, TÜRKİYE’NİN ORTA GELİR TUZAĞINA YAKALANMA NEDENLERİ VE ÇIKIŞI İÇİN ÖNERİLER

Orta gelir seviyesinde yer alan Türkiye ekonomisi, 1955 yılında alt-orta gelir grubuna yükselmiş ve 50 yıl boyunca bu grupta yer almıştır. Yıllar içinde birçok yönden gelişme gösteren Türkiye ekonomisinde 2005 yılında bir kırılma meydana gelmiş ve kişi başı gelir açısından incelendiğinde üst orta gelir seviyesine yükseldiği görülmüştür. Özellikle bu yükselme sonrasında Türkiye’nin yüksek gelirli ülkelerin kişi başı gelir düzeyine ulaşıp ulaşamayacağı tartışma konusu olmuştur. Yıllar itibariyle incelendiğinde dünya ekonomisindeki gelişmelere bağlı olarak 2012 yılından sonra Türkiye ekonomisinde büyüme performansının yavaşlamaya başlaması, orta gelir tuzağı yönündeki problemlerin güncel konular arasında yer almasına neden olmuştur. Dolayısıyla orta gelir tuzağına yakalanmadan yüksek gelirli ülkeler grubuna yükselen ülkeler ile üst-orta gelir grubundan yüksek gelirli ülkeler grubuna yükselen ülkelerin bu başarıyı nasıl sağladıkları, Türkiye ekonomisi açısından büyük önem taşımaktadır. Bu bağlamda Türkiye ekonomisinin orta gelir tuzağı riski altında olup olmadığı bir takım sosyal ve ekonomik veriler ışığında incelenecek, orta gelir tuzağı riskinden sakınmak için bazı stratejiler açıklanacaktır.

PowerMorph: QoS-Aware Server Power Reshaping for Data Center Regulation Service

Adoption of renewable energy in power grids introduces stability challenges in regulating the operation frequency of the electricity grid. Thus, electrical grid operators call for provisioning of frequency regulation services from end-user customers, such as data centers, to help balance the power grid’s stability by dynamically adjusting their energy consumption based on the power grid’s need. As renewable energy adoption grows, the average reward price of frequency regulation services has become much higher than that of the electricity cost. Therefore, there is a great cost incentive for data centers to provide frequency regulation service. Many existing techniques modulating data center power result in significant performance slowdown or provide a low amount of frequency regulation provision. We present PowerMorph , a tight QoS-aware data center power-reshaping framework, which enables commodity servers to provide practical frequency regulation service. The key behind PowerMorph is using “complementary workload” as an additional knob to modulate server power, which provides high provision capacity while satisfying tight QoS constraints of latency-critical workloads. We achieve up to 58% improvement to TCO under common conditions, and in certain cases can even completely eliminate the data center electricity bill and provide a net profit.

LMT: Accurate and Resource-Scalable Slowdown Prediction

Multi-core processors suffer from inter-application interference which makes the performance of an application depend on the behavior of the applications it happens to be co-scheduled with. This results in performance variability, which is undesirable, and researchers have hence proposed numerous schemes for predicting the performance slowdown caused by inter-application interference. While a slowdown predictor's primary objective is to achieve high accuracy, it must typically also respect resource constraints. It is hence beneficial to be able to scale the resource consumption of the predictor, but state-of-the-art slowdown predictors are not resource-scalable. We hence propose to construct predictors using Linear Model Trees (LMTs) which we show to be accurate <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">and</i> resource-scalable. More specifically, our 40-leaf-node LMT-40 predictor yields a 6.6% prediction error compared the 8.4% error of state-of-the-art GDP at similar storage overhead. In contrast, our LMT-10 predictor reduces storage overhead by 34.6% compared to GDP while only increasing prediction error to 9.4%.

Analisis Dampak Covid-19 terhadap Kinerja Perbankan

This study aimed to analyze the impact of the Corona Virus Disease-19 (Covid-19) pandemic on the performance of PT. Bank Pembangunan Daerah Jawa Timur Tbk. Cabang Magetan, and analyzed the scheme design which contains the most neededstrategic steps to correct the weakening of its performance. The method used in this research is descriptive statistics. The data used are financial statements in financial ratios, including BOPO, NIM, NPL, and CKPN. This study indicates that there has been a change and a slowdown in the financial performance of PT. Bank Pembangunan Daerah Jawa Timur Tbk. Cabang Magetan, both in terms of CKPN, NPL, BOPO, and NIM. Meanwhile, the policy that has been taken to correct these weaknesses is the implementation of a stress test preparation for the fixed effects industry level with the estimation of the ordinary least square model and the balance sheet approach, which can capture the dynamics of individual banks in surviving the shocks given in the stress test scenario (PD, LGD, and EAD) to see industrial resilience.&#x0D; Keywords: Covid-19; Banking; Financial Performance

Regional Bond as a Regional Development Resource (Case Study on the Bali Government)

The Province of Bali is a tourist area that is well known throughout the world, so that the issuance of regional bonds in the Province of Bali to develop the development of the tourism sector is the right step. Philosophically, the purpose of development carried out by the region has one goal, namely to create a prosperous life in accordance with the values of Pancasila. The emergence of bonds that refer to creative and constructive bonds that can provide added value and become a stimulus for regional economic development efforts through policies and further studies. The purpose of this study is to: (a) examine the nature of regional bonds in regional development (b) examine the regulation of the issuance of regional bonds as a resource for regional development in Bali. This research method uses normative legal law research type. The results of this study indicate that the Demand Side of Bali's Economic Construction in the first quarter of 2020 from the demand side stems from negative growth in the performance of foreign exports, investment and government consumption. Meanwhile, private consumption needs, the consumption component in the reporting period grew 2.25% (yoy), lower than the previous quarter's 6.58% (yoy), stemming from contraction in government consumption and slowing household consumption. In addition, the consumption performance of LNPRT also contracted during the quarter under review. The performance of private consumption, namely household consumption and LNPRT consumption, was restrained during the quarter under review. Household consumption grew by 2.90% (yoy) in the first quarter of 2020, lower than 5.70% (yoy) in the previous quarter. Meanwhile, the consumption performance of LNPRT decreased from 6.00% (yoy) to -4.67% (yoy). On the other hand, the slowdown in household consumption performance in the quarter under review was caused by restrained purchasing power in line with the decline in tourism performance in the midst of the COVID-19 pandemic. Keywords: Regional Bonds, Development Resources, Bali Province DOI: 10.7176/JLPG/117-05 Publication date: January 31 st 2022

DAMARU: A Denial-of-Service Attack on Randomized Last-Level Caches

Cross-core conflict-based timing attacks like Prime+Probe at the shared last-level cache (LLC) are practical and can cause information leakage. Cache address randomization is one of the techniques that claim to mitigate these attacks. CEASER, CEASER-S, and ScatterCache are the three recent randomized caches that use encryption engines to randomize the memory address mapping. CEASER and CEASER-S, along with encryption engines, remap the cache blocks periodically to break the static mapping of memory blocks into the LLC blocks. Encryption engine and remapping provide security to the randomized caches. However, access to encryption engines and the remapping of cache blocks are on the critical path of LLC accesses. We target encryption engine and remapping of randomized cache to mount a denial of service (DoS) attack named DAMARU. In DAMARU, the attacker frequently sends memory requests to the LLC that causes an increase in the victim's LLC access waiting time for the encryption engine. DAMARU is the first DoS attack on randomized caches where an attacker can cause a DoS even without thrashing the LLC. DAMARU provides a performance slowdown of up to 3.19X and 6X for 8-core and 16-core simulated systems, respectively. In terms of performance slowdown, the effectiveness of our DAMARU attack decreases with an increase in the number of encryption engines.