Provably correct, asymptotically efficient, higher-order reverse-mode automatic differentiation

In this paper, we give a simple and efficient implementation of reverse-mode automatic differentiation, which both extends easily to higher-order functions, and has run time and memory consumption linear in the run time of the original program. In addition to a formal description of the translation, we also describe an implementation of this algorithm, and prove its correctness by means of a logical relations argument.

Improving the time and space complexity of the WFA algorithm and generalizing its scoring

Modern genomic sequencing data is trending toward longer sequences with higher accuracy. Many analyses using these data will center on alignments, but classical exact alignment algorithms are infeasible for long sequences. The recently proposed WFA algorithm demonstrated how to perform exact alignment for long, similar sequences in O(sN) time and O(s2) memory, where s is a score that is low for similar sequences (Marco-Sola et al., 2021). However, this algorithm still has infeasible memory requirements for longer sequences. Also, it uses an alternate scoring system that is unfamiliar to many bioinformaticians. We describe variants of WFA that improve its asymptotic memory use from O(s2) to O(s3/2) and its asymptotic run time from O(sN) to O(s2 + N). We expect the reduction in memory use to be particularly impactful, as it makes it practical to perform highly multithreaded megabase-scale exact alignments in common compute environments. In addition, we show how to fold WFA's alternate scoring into the broader literature on alignment scores.

Liquidity connectedness in cryptocurrency market

We examine the dynamics of liquidity connectedness in the cryptocurrency market. We use the connectedness models of Diebold and Yilmaz (Int J Forecast 28(1):57–66, 2012) and Baruník and Křehlík (J Financ Econom 16(2):271–296, 2018) on a sample of six major cryptocurrencies, namely, Bitcoin (BTC), Litecoin (LTC), Ethereum (ETH), Ripple (XRP), Monero (XMR), and Dash. Our static analysis reveals a moderate liquidity connectedness among our sample cryptocurrencies, whereas BTC and LTC play a significant role in connectedness magnitude. A distinct liquidity cluster is observed for BTC, LTC, and XRP, and ETH, XMR, and Dash also form another distinct liquidity cluster. The frequency domain analysis reveals that liquidity connectedness is more pronounced in the short-run time horizon than the medium- and long-run time horizons. In the short run, BTC, LTC, and XRP are the leading contributor to liquidity shocks, whereas, in the long run, ETH assumes this role. Compared with the medium term, a tight liquidity clustering is found in the short and long terms. The time-varying analysis indicates that liquidity connectedness in the cryptocurrency market increases over time, pointing to the possible effect of rising demand and higher acceptability for this unique asset. Furthermore, more pronounced liquidity connectedness patterns are observed over the short and long run, reinforcing that liquidity connectedness in the cryptocurrency market is a phenomenon dependent on the time–frequency connectedness.

Cloud-Internet of Health Things (IOHT) Task Scheduling Using Hybrid Moth Flame Optimization with Deep Neural Network Algorithm for E Healthcare Systems

Considering task dependencies, the balancing of the Internet of Health Things (IoHT) scheduling is considered important to reduce the make span rate. In this paper, we developed a smart model approach for the best task schedule of Hybrid Moth Flame Optimization (HMFO) for cloud computing integrated in the IoHT environment over e-healthcare systems. The HMFO guarantees uniform resource assignment and enhanced quality of services (QoS). The model is trained with the Google cluster dataset such that it learns the instances of how a job is scheduled in cloud and the trained HMFO model is used to schedule the jobs in real time. The simulation is conducted on a CloudSim environment to test the scheduling efficacy of the model in hybrid cloud environment. The parameters used by this method for the performance assessment include the use of resources, response time, and energy utilization. In terms of response time, average run time, and lower costs, the hybrid HMFO approach has offered increased response rate with reduced cost and run time than other methods.

The Association of Smartphone Usage Duration with Physical Fitness among Chinese University Students

Background: The use of smartphones has become increasingly prevalent in recent years, especially among the youth. However, smartphone overuse has been reported to be related to several negative mental and physical health outcomes. Although the association between smartphone use and physical fitness has been investigated in several studies, these studies only focused on specific elements of physical fitness, such as grip strength. In addition, evidence on young adults is limited. Thus, this study aimed to examine the association between the duration of smartphone use and physical fitness among Chinese university students. Methods: A total of 11,242 university students volunteered to participate in the study. The duration of smartphone use was assessed using a self-reported questionnaire. Physical fitness tests consisted of a 50-m sprint and vital capacity tests for both sexes, a 1000-m run and pull-up test for male students, and an 800-m run and sit-up test for female students. Results: The duration of smartphone use among the participants was 5.4 h/day for male students and 6.1 h/day for female students on average. After adjusting for confounding factors, in male students, a long duration of smartphone use was significantly associated with a slow 50 m sprint and 1000 m run time, lower pull-up times, and poor vital capacity (p = 0.004, 0.002, 0.002 and 0.040, respectively). In female students, a long duration of smartphone use was associated with a slow 800 m run time (p < 0.001). Conclusion: This study found that longer duration of smartphone use was associated with lower physical fitness among Chinese university students. The duration of smartphone use may be an influencing factor for physical fitness.

DIGITAL SAFETY MANAGER: IOT SERVICE TO ASSURE THE SAFE BEHAVIOUR OF MACHINES AND CONTROLS IN THE DIGITAL INDUSTRY

The digital industry requires increasingly complex and reliable software systems. They need to control and make critical decisions at runtime. As a consequence, the verification and validation of these systems has become a major research challenge. At design and development time, model testing techniques are used while run-time verification aims at verifying that a system satisfies a given property. The latter technique complements the former. The solution presented in this paper targets embedded systems whose software components are designed by state machines defined by Unified Modelling Language (UML). The CRESCO (C++ REflective State-Machines based observable software COmponents) platform generates software components that provide internal information at runtime and the verifier uses this information to check system-level reliability/safety contracts. The verifier detects when a system contract is violated and initiates a safeState process to prevent dangerous scenarios. These contracts are defined by internal information from the software components that make up the system. Thus, as demonstrated in the tested experiment, the robustness of the system is increased. All software components (controllers), such as the verifier, have been deployed as services (producers/consumers) of the Arrowhead IoT platform: the controllers are deployed on local Arrowhead platforms (Edge) and the verifier (Safety Manager) is deployed on an Arrowhead platform (Cloud) that will consume controllers on the Edge and ensure the proper functioning of the plant controllers. Keywords: run-time monitoring, robustness, software components, contracts, software models, state machines

Analisa Performa RStudio Server Berbasis Cloud Menggunakan Elastic Stack sebagai Sistem Manajemen Metrik

Reliabilitas atau keandalan merupakan salah satu sifat penting pada sebuah server dalam melayani pengguna. Salah satu cara mengukurnya ialah dengan melakukan uji perfoma. Penelitian ini bertujuan untuk mengetahui kemampuan RStudio Server pada infrastruktur cloud saat digunakan oleh multiuser dengan Elastic Stack sebagai sistem yang menangani pengumpulan, penyimpanan dan visualisasi data metriknya. Tahapan dimulai dengan mengumpulkan data berupa metrik sistem oleh Metricbeat, lalu diproses Logstash dan disimpan menjadi index dalam Elasticsearch, visualisasi data ditampilkan oleh Kibana. Pengujian kinerja server dilakukan dengan menjalankan script R berdurasi 2 menit dan 7 menit secara simultan. Hasil pengujian berupa catatan CPU Usage, Memory Usage dan durasi penyelesaian script selanjutnya di plotting pada R. Hasil analisa dari plotting data menunjukkan jumlah user yang dapat menggunakan Rstudio Server dengan spesifikasi 2 CPU dan RAM 4GB secara optimal ialah maksimal 2 user pada script dengan run time 2 menit dan 7 menit, lebih dari jumlah user itu akan mempengaruhi waktu proses penyelesaian script menjadi tingkat performa sedang hingga berat.

Energy-Efficient Hybrid Unicore Architecture In Future Embedded Chip-Multiprocessor

Recently, technology scaling has enabled the placement of an increasing number of cores, in the form of chip-multiprocessors (CMPs) on a chip and continually shrinking transistor sizes to improve performance. In this context, power consumption has become the main constraint in designing CMPs. As a result, uncore components power consumption taking increasing portion from the on-chip power budget; therefore, designing power management techniques, particularly memory and network-on-chip (NoC) systems, has become an important issue to solve. Consequently, a considerable attention has been directed toward power management based on CMPs components, particularly shared caches and uncore interconnected structures, to overcome the challenges of limited chip power budget.<div>This work targets to design an energy-efficient uncore architecture by using heterogeneity in components (cache cells) and operational parameters (Voltage/Frequency). In order to ensure the minimum impact on the system performance, a run-time approach is investigated to assess the proposed method. An architecture is proposed where the cache layer contains the heterogenous cache banks in all placed in one frequency voltage domain. Average memory access time (AMAT) was selected as a network monitor to monitor the performance on the run-time. The appropriate size and type of the last level cache (LLC) and Voltage/Frequency for the uncore domain is adjusted according to the calculated AMAT which indicates the system demand from the uncore.<br></div><div>The proposed hybrid architecture was implemented, investigated and compared with the a baseline model where only SRAM banks were used in the last level cache. Experimental results on the Princeton Application Repository for Shared-Memory Computers (PARSEC) benchmark suit,show that the proposed architecture yields up to a 40% reduction in overall chip energy-delay product with a marginal performance degradation in average of -1.2% below the baseline one. The best energy saving was 55% and the worse degradation was only 15%.<br></div>