Content Formation Research Articles

CASHT: Contention Analysis in Shared Hierarchies with Thefts

Cache management policies should consider workloads’ contention behavior when managing a shared cache. Prior art makes estimates about shared cache behavior by adding extra logic or time to isolate per workload cache statistics. These approaches provide per-workload analysis but do not provide a holistic understanding of the utilization and effectiveness of caches under the ever-growing contention that comes standard with scaling cores. We present Contention Analysis in Shared Hierarchies using Thefts, or CASHT, 1 a framework for capturing cache contention information both offline and online. CASHT takes advantage of cache statistics made richer by observing a consequence of cache contention: inter-core evictions, or what we call THEFTS. We use thefts to complement more familiar cache statistics to train a learning model based on Gradient-boosting Trees (GBT) to predict the best ways to partition the last-level cache. GBT achieves 90+% accuracy with trained models as small as 100 B and at least 95% accuracy at 1 kB model size when predicting the best way to partition two workloads. CASHT employs a novel run-time framework for collecting thefts-based metrics despite partition intervention, and enables per-access sampling rather than set sampling that could add overhead but may not capture true workload behavior. Coupling CASHT and GBT for use as a dynamic policy results in a very lightweight and dynamic partitioning scheme that performs within a margin of error of Utility-based Cache Partitioning at a 1/8 the overhead.

ВИТОКИ ТА СТАНОВЛЕННЯ УКРАЇНСЬКОЇ ДЕРЖАВНОСТІ (III СТ. ДОН. Е. – IX СТ. Н. Е.): ІСТОРИКО-ПРАВОВА РЕКОНСТРУКЦІЯ

The actual problem of Ukrainian statehood commencement in the context of Ukrainian political and legal tradition of statehood is raised. The purpose of the article is to cover an in-depth development of the concept of formation's content of in the first historical forms of Ukrainian statehood by the autochthons of the Middle Dnieper region (ancestors of the Ukrainian people) in connection with various ethnic communities. Within the framework of socio-cultural and systemic approaches, it was proved by the method of logical analysis that the early historical forms of Ukrainian statehood arose without any significant borrowing from the state-building experience of other nations. The method of reconstruction highlighted the process of institutionalization of public power and confirmed the centuries-old continuity of the political and legal tradition in this area. Using the method of periodization, three periods of the process of the emergence and formation of early forms of Ukrainian statehood are distinguished: the Scythian era (VI-IV centuries BC); late antique times (II-IV centuries AD); the early Middle Ages, when Kyiv was founded and the state called Rus (Ukraine-Rus) was formed (VI-IX centuries AD). The proposition that the origins of the Russian state should be analyzed within the chronological limits of the second half of the 30s of the 9th century is substantiated. In connection with the conclusion of the first known treaty with Byzantium in Amastrid in 839, where it was first mentioned under its own name. It was found out that historically, the first forms of Ukrainian statehood were the Ante confederation and Rus. Subjects of the confederation retained territorial sovereignty with their own self-government, jurisdiction of local authorities within their territory and customary law. It is proved that within the framework of the confederation, the functions of princely governance were institutionalized, which took place in the streamlining and structuring of interaction with princes, tribal military leaders, tribal nobility, and self-governing territorial communities. The main result of the study is the conclusion that the first historical forms of Ukrainian statehood were the Ante confederation and Rus. They had all basic attributes of statehood in the legal plane: the people and the language of the people, as the most important marker of their ethnic self-identification; the motherland of the country with geographical, geospatial, and ethnographic characteristics; the continuity of the state values in the law that form a legal view of life through the prism of the mental representations of the people about truth, goodness, and justice. It was also emphasized that of all the characteristic features of the modern concept of the Ukrainian state, the legal power was historically the first to be formed, due to its mechanism, it was formed horizontally on the principle of equality and independence of all subjects of the confederation, united on a contractual basis; in the mechanism of the operation of law, the instrument of legal influence made norms of customary law, and the instrument of legal regulation was barbaric law. The links of legal influence and legal regulation were organically intertwined on the basis of legal tradition.

Optimal and near-optimal alpha-fair resource allocation algorithms based on traffic demand predictions for optical network planning

We examine proactive network optimization in reconfigurable optical networks based on traffic predictions. Specifically, the fair spectrum allocation (SA) problem is examined for a priori reserving resources aiming to achieve near-even minimum quality-of-service (QoS) guarantees for all contending connections. The fairness problem arises when greedy SA policies are followed, which are based on point-based maximum demand predictions, especially under congested networks, with some connections highly overprovisioned and others entirely blocked, resulting in highly uneven QoS connection guarantees. To address this problem, we consider predictive traffic distributions allowing the exploration of several combinations of possible SAs. To find a fair SA policy, we resort to an α -fairness scheme, while QoS fairness is evaluated according to a game-theoretic analysis based on the coefficient of variations of the connections’ unserved traffic metric, which measures the dispersion of unserved traffic for a connection around the mean of the unserved traffic over all connections. Non-contending (NC) and link-based contending (LBC) α -fair SA integer linear programming algorithms are proposed, where the optimal NC approach encompasses global network contention information, while the near-optimal LBC approach encompasses partial contention information to reduce problem complexity. We show that as parameter α increases, QoS fairness improves, along with connection blocking, resource utilization, and overprovisioning and underprovisioning. Further, LBC exhibits results close to the optimal, with a significant improvement in processing time.

Librarian 4.0 digital competency system

The article suggests the concept of the systematic approach to the formation of a list of the Bachelor's in Information, Library and Archives general and professional digital competencies. It grounds the model of their cross-platform (cross-platform) content's formation as well as the teaching methods formation of all library science graduate programs educational components. The study provides characteristics of the main types of the Library 4.0 digital technologies, identifies the modern trends of their development in the foreign practice of library and information services for users. The most developed among them are considered to be mobile library sites and other mobile applications, identification technologies, cloud and 3D technologies, augmented and virtual reality technologies, predictive analytics methods, the Internet of Things, robotics and cyber systems, artificial intelligence, Big Data, and paperless technologies. It is stated that in the conditions of the digital economy development, the criterion for the formation of a modern librarian digital competencies system is the “digital intelligence” to be the three basic components unity: "digital citizenship", "digital creativity", and "digital entrepreneurship". Regulated by the educational standard of Ukraine at the first (undergraduate / bachelor degree) level in specialty 029 "Information, Library and Archives", the digital competencies standard minimum is proved to be expanded and deepened in line with the international recommendations of the Organization for Economic Cooperation and Development, having developed the global competencies framework for the career to start in 2030.

Reordering Transaction Execution to Boost High-Frequency Trading Applications

High-frequency trading (HFT) has always been welcomed because it benefits not only personal benefits but also the whole social welfare. While the recent advance of portfolio selection in HFT market enables to bring about more profit, it yields much contended OLTP workloads. Featuring exploiting the abundant parallelism, transaction pipeline, the state-of-the-art concurrency control (CC) mechanism, however, suffers from limited concurrency confronted with HFT workloads. Its variants that enable more parallel execution by leveraging fine-grained contention information also take little effect. To solve this problem, we for the first time observe and formulate the source of restricted concurrency as harmful ordering of transaction statements. To resolve harmful ordering, we propose PARE, a pipeline-aware reordered execution, to improve application performance by rearranging statements in order of their degrees of contention. In concrete, two mechanisms are devised to ensure the correctness of statement rearrangement and identify the degrees of contention of statements, respectively. We also study the off-line reordering problem. We prove that this problem is NP-hard and present an off-line reordering approach to approximate the optimal reordering strategy. Experiment results show that PARE can improve transaction throughput and reduce transaction latency on HFT applications by up to an order of magnitude than the state-of-the-art CC mechanism.

Robust and dynamic data aggregation in wireless sensor networks: A cross-layer approach

In-network data aggregation is an effective technique to reduce communication cost in wireless sensor networks. Recent studies have focused on two issues respectively: dynamic aggregation to handle event triggered irregular traffic and robust aggregation to handle packet losses. However, how to achieve both the objectives simultaneously, i.e. dynamic and robust aggregation is still not considered. In this paper, by making use of direct support from MAC layer, we propose a cross-layer approach to realize robust and dynamic data aggregation. A new MAC protocol, DA-MAC is delicately designed to serve such purpose. With channel contention information obtained from DA-MAC, a node can dynamically determine where and when to do aggregation. To cope with packet losses, a virtual overlay, Rings is adopted to forward one packet to multiple nodes. We have conducted numerical analysis to optimize the key parameters and implemented our design in TinyOS based sensor networks. Performance evaluation though simulations and experiments shows that our approach can handle both traffic dynamics and packet losses, with less cost than similar solutions.

Runtime Contention and Bandwidth-Aware Adaptive Routing Selection Strategies for Networks-on-Chip

This paper presents adaptive routing selection strategies suitable for network-on-chip (NoC). The main prototype presented in this paper uses contention information and bandwidth space occupancy to make routing decision at runtime during application execution time. The performance of the NoC router is compared to other NoC routers with queue-length-oriented adaptive routing selection strategies. The evaluation results show that the contention- and bandwidth-aware adaptive routing selection strategies are better than the queue-length-oriented adaptive selection strategies. Messages in the NoC are switched with a wormhole cut-through switching method, where different messages can be interleaved at flit-level in the same communication link without using virtual channels. Hence, the head-of-line blocking problem can be solved effectively and efficiently. The routing control concept and the VLSI microarchitecture of the NoC routers are also presented in this paper.

Special Issue on Multimedia over Ad-Hoc and Sensor Networks

With the increased reliance of our modern society on communication infrastructures and the migration towards all-IP next generation networks, research and development activities must aim at providing stable and reliable broadband communication infrastructures and provisioning of new types of multimedia applications even under extreme situations. Existing wireless communication systems, such as 3G cellular networks and WLANs, are infrastructure based and often do not provide alternative communication paths, which instead are important in case the wireline/wireless infrastructure is damaged or heavily congested. Additionally, these solutions require increased capital investments and leading time for their deployment. These reasons gave birth to an increased interest for ad hoc and sensor networks, which represent network solutions that may be deployed in places where no any infrastructures are present but communications are required and the moving nodes may be considered as the “infrastructure” for these networks. The latest developments have increased the service retainability and accessibility in this type of networks, which represent now a viable solution for the deployment of networking services for data application at low costs and minimizing network installations. Yet, many efforts are still needed to make this technology workable for streaming applications where QoS (Quality of Service) requirements, in terms of packet losses, delay and jitter, are more stringent than those characterizing data applications. Provisioning of delay tolerant multimedia applications and location aware services is a challenging task. But more importantly, ad-hoc and sensor networks will provide a valuable communication tool for emergency cases (such as, flooding, earthquakes, large scale fire) when the infrastructure is not available or in cases that quick network deployment over an infrastructureless area is required. This Special Issue reports the results of recent advances in the field by presenting a collection of articles that address problems related to coding, signal processing, transmission, protocols, for robust and efficient multimedia communications in ad-hoc and sensor networks. Some of these papers are extensions of works that were presented at the Mobile Multimedia Communications Conference (MobiMedia 2007), which was held in Nafpaktos, Greece. An important issue addressed by the selected papers is related to the definition of new protocols aimed at improving the efficiency of the wireless links or increasing the end-to-end throughput. In particular, Navaratnam et al. investigate the impact of medium contention on transport layer performance and then propose a new transport protocol for supporting quality of service requirements in multi hop wireless networks. The proposed Link Adaptive Transport Protocol provides a systemic way of controlling the end-to-end rate for multimedia streaming applications, based on the degree of medium contention information received from the network. Link layer protocol performance is instead studied by Xylomenos and Makidis in their paper. Mobile Netw Appl (2008) 13:243–245 DOI 10.1007/s11036-008-0097-6

Identification of a chrysocolla amulet in an Early Dynastic child mummy

Two pyriform formations were identified within a bundle of linen bandages wrapping a 15–18 months old Early Dynastic mummy. The upper one was taken out of the bandages and examined to ascertain its nature. This formation showed to be a small bag closed by a knot containing an emerald-green mineral. For identification and with the aim of identifying the compound kept inside it, several different green minerals used for adornment in Ancient Egypt (from the Pre-dynastic period up to the Ptolemaic one) were examined by scanning electron microscope (SEM-EDX) followed by microanalysis. The pyriform formation's content is consistent, based on morphological and micro-analytical data, with the natural cryptocrystalline hydrated copper silicate identified as a bead of chrysocolla. The use of chrysocolla was less common than that of malachite as chrysocolla ores were rarer. To present days, only one other example of chrysocolla as a funerary equipment from an Ancient Egypt child burial can be traced. Since our archaeological finding indicates the presence of a chrysocolla bead in one other infant burial, it is possible that the use of this particular mineral was limited, in the Early Dynastic Period as a protective amulet for children.

A Hybrid Collision Avoidance Scheme for Ad Hoc Networks

A novel hybrid collision avoidance scheme that combines both sender-initiated and receiver-initiated collision-avoidance handshake is proposed for multi-hop ad hoc networks. The new scheme is compatible with the popular IEEE 802.11 MAC protocol and involves only some additional queue management and book-keeping work. Simulations of both UDP- and TCP-based applications are conducted with the IEEE 802.11 MAC protocol, a measurement-based fair scheme and the new scheme. It is shown that the new scheme can alleviate the fairness problem with almost no degradation in throughput. More importantly, it is shown that without explicit information exchange among nodes, the fairness problem cannot be solved conclusively if reasonable throughput is to be maintained. Hence it calls for further work to integrate the new collision avoidance scheme with other schemes that approximate fair queueing and use more contention information in channel access to achieve some QoS assurances in ad hoc networks.

System contention analysis— alternate approach to system tuning

In theory as well as in practice, contention analysis emerges as a new, interesting approach to both system and user tuning. The prototype was found to be low in cost and very simple both in its implementation and in its use. It provides affluent information that directly relates the users and resources associated at each contention point. The ability to provide contention information for each individual user in the system was found to be extremely valuable.

Statistical investigation of large volumes of data with respect to the biological activity of compounds III. Selection of a determinant for predicting biological activity

In p reced ing a r t i c l e s of the p re sen t s e r i e s , the pr inc ip les were p resen ted for cons t ruc t ion of a data bank for b iological ly act ive compounds containing informat ion on the i r s t ruc tu re and act ivi ty [1]. A method was also p roposed for using this bank to pred ic t the biological act ivi ty of chemica l compounds [2]. This method, based on subs t ruc tu re analys is [3], spec i f ies that for a new substance, an evaluat ion be made of the in format ion content Ij, the value cha rac t e r i z ing the degree of co r r e l a t i on of the subs t ruc tu re of a given c o m pound with the act ivi ty Aj being analyzed. In o rde r to make a decis ion on the b a s i s of the I.. value as to whether or not to t e s t a g iven compound for act ivi ty Aj, a threshold value 0j should be de te rmined ~or the evaluat ion of Ij, dividing all compounds analyzed for each type of act ivi ty into two c l a s s e s : those condit ionally act ive (Ij >0j) and those condit ionally inact ive (Ij -< 0j). The a im of the p re sen t pape r is to es tab l i sh a method for se lec t ing th resho ld va lues 0j to evaluate the r e su l t s of a predic t ion c a r r i e d out using these thresholds , and to d iscuss fu r the r means of developing this method.