Journal articles on the topic 'Prefetch techniques'

A major performance limiter in modern processors is the long latencies caused by data cache misses. Both compiler- and hardware-based prefetching schemes help hide these latencies and so improve performance. Compiler techniques infer memory access patterns through code analysis, and insert appropriate prefetch instructions. Hardware prefetching techniques work independently from the compiler by monitoring an access stream, detecting patterns in this stream and issuing prefetches based on these patterns. This paper looks at the interplay between compiler and hardware architecture-based prefetching techniques. Does either technique make the other one unnecessary? First, compilers' ability to achieve good results without extreme expertise is evaluated by preparing binaries with no prefetch, one-flag prefetch (no tuning), and expertly tuned prefetch. From runs of SPECcpu2006 binaries, we find that expertise avoids minor slowdown in a few benchmarks and provides substantial speedup in others. We compare software schemes to hardware prefetching schemes and our simulations show software alone substantially outperforms hardware alone on about half of a selection of benchmarks. While hardware matches or exceeds software in a few cases, software is better on average. Analysis reveals that in many cases hardware is not prefetching access patterns that it is capable of recognizing, due to some irregularities in the observed miss sequence. Hardware outperforms software on address sequences that the compiler would not guess. In general, while software is better at prefetching individual loads, hardware partly compensates for this by identifying more loads to prefetch. Using the two schemes together provides further benefits, but less than the sum of the contributions of each alone.

Achieving low load-to-use latency with low energy and storage overheads is critical for performance. Existing techniques either prefetch into the pipeline (via address prediction and validation) or provide data reuse in the pipeline (via register sharing or L0 caches). These techniques provide a range of tradeoffs between latency, reuse, and overhead. In this work, we present a pipeline prefetching technique that achieves state-of-the-art performance and data reuse without additional data storage, data movement, or validation overheads by adding address tags to the register file. Our addition of register file tags allows us to forward (reuse) load data from the register file with no additional data movement, keep the data alive in the register file beyond the instruction’s lifetime to increase temporal reuse, and coalesce prefetch requests to achieve spatial reuse. Further, we show that we can use the existing memory order violation detection hardware to validate prefetches and data forwards without additional overhead. Our design achieves the performance of existing pipeline prefetching while also forwarding 32% of the loads from the register file (compared to 15% in state-of-the-art register sharing), delivering a 16% reduction in L1 dynamic energy (1.6% total processor energy), with an area overhead of less than 0.5%.

Big data phenomenon refers to the practice of collection and processing of very large data sets and associated systems and algorithms used to analyze these massive data sets. Big data service is very attractive in the field of wireless communication environment, especially when we face the spatial applications, which are typical applications of big data. Because of the complexity to ingest, store and analyze geographical information data, this paper reflects on a few of the technical problems presented by the exploration of big data, and puts forward an effective storage method in wireless communication environment, which is based on the measurement of moving regularity through proposing three key techniques: partition technique, index technique and prefetch technique. Experimental results show that the performance of big data storage method using these new techniques is better than the other storage methods on managing a great capacity of big data in wireless communication environment.

Modern embedded systems are packed with dedicated Field Programmable Gate Arrays (FPGAs) to accelerate the overall system performance. However, the FPGAs are susceptible to reconfiguration overheads. The reconfiguration overheads are mainly because of the configuration data being fetched from the off-chip memory at run-time and also due to the improper management of tasks during execution. To reduce these overheads, our proposed methodology mainly focuses on the prefetch heuristic, reuse technique, and the available memory hierarchy to provide an efficient mapping of tasks over the available memories. Our paper includes a new replacement policy which reduces the overall time and energy reconfiguration overheads for static systems in their subsequent iterations. It is evident from the result that most of the reconfiguration overheads are eliminated when the applications are managed and executed based on our methodology.

Recording the frequency of items in highly skewed data streams is a fundamental and hot problem in recent years. The literature demonstrates that sketch is the most promising solution. The typical metrics to measure a sketch are accuracy and speed, but existing sketches make only trade-offs between the two dimensions. Our proposed solution is a new sketch framework called Stingy sketch with two key techniques: Bit-pinching Counter Tree ( BCTree ) and Prophet Queue ( PQueue ) which optimizes both the accuracy and speed. The key idea of BCTree is to split a large fixed-size counter into many small nodes of a tree structure, and to use a precise encoding to perform carry-in operations with low processing overhead. The key idea of PQueue is to use pipelined prefetch technique to make most memory accesses happen in L2 cache without losing precision. Importantly, the two techniques are cooperative so that Stingy sketch can improve accuracy and speed simultaneously. Extensive experimental results show that Stingy sketch is up to 50% more accurate than the SOTA of accuracy-oriented sketches and is up to 33% faster than the SOTA of speed-oriented sketches.

For today's increasingly power-constrained multicore systems, integrating simpler and more energy-efficient in-order cores becomes attractive. However, since in-order processors lack complex hardware support for tolerating long-latency memory accesses, developing compiler technologies to hide such latencies becomes critical. Compiler-directed prefetching has been demonstrated effective on some applications. On the application side, a large class of data centric applications has emerged to explore the underlying properties of the explosively growing data. These applications, in contrast to traditional benchmarks, are characterized by substantial thread-level parallelism, complex and unpredictable control flow, as well as intensive and irregular memory access patterns. These applications are expected to be the dominating workloads on future microprocessors. Thus, in this paper, we investigated the effectiveness of compiler-directed prefetching on data mining applications in in-order multicore systems. Our study reveals that although properly inserted prefetch instructions can often effectively reduce memory access latencies for data mining applications, the compiler is not always able to exploit this potential. Compiler-directed prefetching can become inefficient in the presence of complex control flow and memory access patterns; and architecture dependent behaviors. The integration of multithreaded execution onto a single die makes it even more difficult for the compiler to insert prefetch instructions, since optimizations that are effective for single-threaded execution may or may not be effective in multithreaded execution. Thus, compiler-directed prefetching must be judiciously deployed to avoid creating performance bottlenecks that otherwise do not exist. Our experiences suggest that dynamic performance tuning techniques that adjust to the behaviors of a program can potentially facilitate the deployment of aggressive optimizations in data mining applications.

Non-volatile memory technology is now available in commodity hardware. This technology can be used as a backup memory for an external dram cache memory without needing to modify the software. However, the higher read and write latencies of non-volatile memory may exacerbate the memory wall problem. In this work we present a novel off-chip prefetch technique based on a Hidden Markov Model that specifically deals with the latency problem caused by complexity of off-chip memory access patterns. Firstly, we present a thorough analysis of off-chip memory access patterns to identify its complexity in multicore processors. Based on this study, we propose a prefetching module located in the llc which uses two small tables, and where the computational complexity of which is linear with the number of computing threads. Our Markov-based technique is able to keep track and make clustering of several simultaneous groups of memory accesses coming from multiple simultaneous threads in a multicore processor. It can quickly identify complex address groups and trigger prefetch with very high accuracy. Our simulations show an improvement of up to 76% in the hit ratio of an off-chip dram cache for multicore architecture over the conventional prefetch technique (g/dc). Also, the overhead of prefetch requests (failed prefetches) is reduced by 48% in single core simulations and by 83% in multicore simulations.

One widely used metric that measures data locality is reuse distance —the number of unique memory locations that are accessed between two consecutive accesses to a particular memory location. State-of-the-art techniques that measure reuse distance in parallel applications rely on simulators or binary instrumentation tools that incur large performance and memory overheads. Moreover, the existing sampling-based tools are limited to measuring reuse distances of a single thread and discard interactions among threads in multi-threaded programs. In this work, we propose ReuseTracker —a fast and accurate reuse distance analyzer that leverages existing hardware features in commodity CPUs. ReuseTracker is designed for multi-threaded programs and takes cache-coherence effects into account. By utilizing hardware features like performance monitoring units and debug registers, ReuseTracker can accurately profile reuse distance in parallel applications with much lower overheads than existing tools. It introduces only 2.9× runtime and 2.8× memory overheads. Our tool achieves 92% accuracy when verified against a newly developed configurable benchmark that can generate a variety of different reuse distance patterns. We demonstrate the tool’s functionality with two use-case scenarios using PARSEC, Rodinia, and Synchrobench benchmark suites where ReuseTracker guides code refactoring in these benchmarks by detecting spatial reuses in shared caches that are also false sharing and successfully predicts whether some benchmarks in these suites can benefit from adjacent cache line prefetch optimization.

Prediction in web mining is one of the most complex tasks which will reduce web user latency. The main objective of this research work is to reduce web user latency by predicting and prefetching the users future request page. Web user activities were analyzed and monitored from the web server log file. The present work consists of two phases. In the first phase a directed graph is constructed for web user navigation with the reduction of repeated path. In the second phase, Monte Carlo search is applied on the constructed graph to predict the future request and prefetch the page. This work is successfully implemented and the prediction technique gives a better accuracy. This implementation paves a new way to prefetch the predicted pages at user end to reduce the user latency. Proposed Monte Carlo Prediction (MCP) Algorithm is compared with the existing algorithm Hidden Markov model. Proposed algorithm achieved better accuracy than the Hidden Markov Model. Accuracy is measured for the predicted web pages and achieved the optimal results.

Graphs have been utilized in various fields because of the development of social media and mobile devices. Various studies have also been conducted on caching techniques to reduce input and output costs when processing a large amount of graph data. In this paper, we propose a two-level caching scheme that considers the past usage pattern of subgraphs and graph connectivity, which are features of graph topology. The proposed caching is divided into a used cache and a prefetched cache to manage previously used subgraphs and subgraphs that will be used in the future. When the memory is full, a strategy that replaces a subgraph inside the memory with a new subgraph is needed. Subgraphs in the used cache are managed by a time-to-live (TTL) value, and subgraphs with a low TTL value are targeted for replacement. Subgraphs in the prefetched cache are managed by the queue structure. Thus, first-in subgraphs are targeted for replacement as a priority. When a cache hit occurs in the prefetched cache, the subgraphs are migrated and managed in the used cache. As a result of the performance evaluation, the proposed scheme takes into account subgraph usage patterns and graph connectivity, thus improving cache hit rates and data access speeds compared to conventional techniques. The proposed scheme can quickly process and analyze large graph queries in a computing environment with small memory. The proposed scheme can be used to speed up in-memory-based processing in applications where relationships between objects are complex, such as the Internet of Things and social networks.

<p>Theodor Kravina von Kronstein (1720-1789) was born in Slovenska Bistrica. As jesuit he became prefect and later rector of Vienna Military Academy, later general Academy Theresianum. The contribution deals with his work entitled <em>Entwurf der oekonomischen Kenntnisse</em>, published in 1773 representing systematic outline of economic sciences, tought at Theresianumu. It was predominantly about practical expertises in knowing the soil, plants, minerals and raw materials and techniques of their processing into final products. In this published monography Kravina described also the »Economic garden«, school agricultural enterprise and mineral collections, which all improved significantly under his leadership the quality of schooling process.</p>

Image stitching is an important technology to build a panorama image by combing several images with overlapped areas. In this study, we develop a image seamless mosaic and fusion technique to obtain a prefect panorama image after stitching. At first, it is usingspeeded-up robust features(SURF) algorithm to extract features form the images for stitching. Then,k-nearest neighbors(KNN) method is used to match the feature points andRandom sample consensus(RANSAC) algorithm is used to clear them. Thirdly, a method is improved to achieve seamless stitching based on optimal suture of the overlapped areas. Experimental results indicate that this method can eliminate cohesion gap of two stitching images very well.

In this paper, considering the stability and robustness of the aircraft, the flight control system is designed following the aspect of high flexibility and low cost. Comparing with the flight control system of super-size high-subsonic Unmanned Aerial Vehicle (UAV) in the world, the system presented in this paper has adopted the inimitable control technique of flying-off course、low-cost combinatorial navigation strategy and the advanced safety scheme, which can guarantee the performance, degrade the cost and extend the airspace and groundspace of the aircraft.Through quite a few simulations, the results show that this system can guarantee the attitude and altitude stable. The error between the flight path and programming path is very small. Flight curve is prefect; and the system performances can be achieved completely.

An important issue incurred by users that limits the use of internet is the long web access delays. Most efficient way to solve this problem is to use “Prefetching”. This paper is an attempt to dynamically monitor the network bandwidth for which a neural network-based model has been worked upon. Prefetching is an effective and efficient technique for reducing users perceived latency. It is a technique that predicts & fetches the web pages in advance corresponding to the clients’ request, that will be accessed in future. Generally, this prediction is based on the historical information that the sever maintains for each web page it serves in a chronological order. This is a speculative technique where if predictions are incorrect then prefetching adds extra traffic to the network, which is seriously negating the network performance. Therefore, there is critical need of a mechanism that could analyze the network bandwidth of the system before prefetching is done. Based on network conditions, this model not only guides if the prefetching should be done or not but also tells number of pages which are to be prefetched in advance so that network bandwidth can be effectively utilized. Proposed control mechanism has been validated using NS-2 simulator and thus various adverse effects of prefetching in terms of response time and bandwidth utilization have been reduced.

There is a memorable line at the end of the film classic, Casablanca. It is spoken by the Prefect of Police, Captain Renaud, to his men just after Rick (Humphrey Bogart) has shot Colonel Strasser. He says: “Colonel Strasser has been shot. Round up the usual suspects.” That rule or principle of action—of rounding up the usual suspects—writ large, captures the essence of the South African security system. The system may fairly be described as an elaborate mechanism designed to empower the security authorities to round up, or otherwise dispose of or deal with, suspects of their choice. The technique of empowerment is the conferment of statutory discretion upon some official or body to limit, suspend or terminate the basic liberties of any citizen or group of citizens. This discretion is usually couched in subjective terms.

Large-scale events, which are characterised by a dynamic complexity involving different national public administrations and institutional levels, require special attention in order to select adequate event management systems. Consequently, the analysis of a best practice event may be useful to identify the main variables, in terms of sustainable strategic planning, execution and control &ndash;required to achieve the greatest level of efficiency with regard to cost optimisation and quality of service delivery&ndash; along with exhorting the public sector to seek a structural renovation that makes better use of its available resources and fosters global sustainable growth. From this perspective, one such relevant experience has been the Italian case of the 2016 Extraordinary Jubilee of Mercy, coordinated by the Prefect of Rome. Indeed, the latter decided to adopt actions consistent with sustainability standards due to an inter-institutional network design and the engagement of institutions at different levels. Within a very short period, the Prefect of Rome achieved three main results: the coordination of the activities of the working groups, the integration of internal and external surveillance and communication systems, and collaboration with higher education institutions to acquire and disseminate knowledge. Accordingly, the aim of this paper is to describe and analyse this best practice event organised and managed by the Italian public administration with reference to the achievement of the UN&rsquo;s Sustainable Development Goals (SDGs). To systemise and combine the outcomes of these processes, as well as to evaluate whether they were consistent with sustainable development, the systems thinking technique was used. This paper explores the concept of sustainable development and focuses on its traditional social, environmental and economic pillars within the context of planned events such as the 2016 Extraordinary Jubilee of Mercy.

A novel phase-shifted Soft-switching converter is presented in this thesis，which is based on the Tou structural, groundwork of summarization of the development of lower Electronics in recent years and lucubration in theoretical basis of modern high frequency soft switching power convert technique and analysis of operation principle, characteristic of the circuit and inherent drawbacks of traditional phase-shifted Soft-switching converter. Explicit description of main circuit topology, operation principle, characteristic of the circuit of the novel phase-shifted Soft-switching converter as well as the simulation analysis with the PSPICE software is proposed. The main works that I did: The design involves calculation of transformer, inductor and capacitance in main circuit, parameter selection of each element and realization of control circuit. Electric circuit Tou structural is verified by emulation experiment. The electric circuit reduces availably switch exhaust of traditional soft switch transformation electric circuit. The experiment proved to the possibility of the reformed prefect. The experiment has important reference value to improved soft switch transformation.

This study sought to investigate the factors contributing to underrepresentation of female teachers in leadership positions in public secondary schools in Sumbawanga Municipality. The study employed the mixed research approach and convergent parallel research design. The Study sampled a total of 100 respondents out of a population of 687 educational stakeholders. These included 87 teachers, 5 heads of schools, 1 Municipality Executive Officer, 1 Regional Officer, 1 Municipality Education Officer and 5 head prefects. Purposive sampling technique was used to select students, heads of schools as well as all education officers while simple random sampling was used to select teachers. Questionnaire and interview guides were used to collect data. The study concludes that factors that hindered female teachers’ participation in school leadership was lack of consideration of gender when appointing school leaders and nothing else since all possible factors that were suggested in the questionnaire were denied by teachers of both genders. Therefore, gender biasness was a major factor that that brought about the gender imbalance in school leadership positions in the schools under investigation. The study therefore recommends that the appointing authorities should be guided by the affirmative action policy in the appointment of school heads. This will contribute to appointment of more women to leadership positions such as schools heads.

In carrying out its activities, PT. Regency Motor is assisted by employees who have a good work ethic. PT. Regency Motor selected the best employees who would later be given prizes as a result of the employee's hard work. This selection process often experiences several problems such as the calculation of employee criterion values that often experience similarities between one another. The best employee selection process involves all employees working at PT. Regency Motor. This process has several assessment stages which can take a long time in calculating the value of each employee. In these processes it is not uncommon for errors to occur in both the input of employee values and in the process of calculating those values. Therefore in this study the author tries to try to help the company to determine the best employees by using the Technique for Order Reference by Similarity to Ideal Solution (TOPSIS) method more effectively, because the TOPSIS method is one of the best alternatives that is able to produce employee data with using six criteria, namely discipline, loyalty, attitude, attendance, expertise and years of service, the final calculation result is obtained to determine the best employee obtained with the prefence value at the highest value, Alex Ryan with a value of 0.7592812

Pustakawan berprestasi terbaik adalah tenaga kerja perpustakaan yang memiliki prestasi unggul dalam bidang kepustakawanan. Salah satu upaya untuk meningkatkan kinerja pustakawan dalam mengolah perpustakaan adalah memberikan penghargaan melalui penyelenggaraan kegiatan Pemilihan Pustakawan Berprestasi Terbaik. Masalah yang dihadapi sampai saat ini adalah sulitnya menyatukan persepsi juri dalam melakukan penilaian terhadap peserta, kondisi ini terjadi karena ketiadaan sistem yang baku dalam melakukan proses pemilihan pustakawan berprestasi terbaik, yang tentunya menambah jam kerja tim juri dalam melakukan penilaian dan tidak objektif. Berdasarkan permasalahan tersebut dibutuhkan suatu Sistem Pendukung Keputusan Pemilihan Pustakawan Berprestasi Terbaik yang terkomputerisasi dalam mencari suatu keputusan yang tepat, efektif dan efisien. Sistem ini bertujuan membantu tim juri dalam menentukan pemenang pemilihan pustakawan berprestasi terbaik. Metode yang digunakan dalam Sistem Pendukung Keputusan Pemilihan Pustakawan Berprestasi Terbaik adalah menggunakan metode Techique For Other Reference by Similarity to Ideal Solution (TOPSIS). Data nilai yang telah dimasukkan ke dalam sistem akan dihitung menggunakan metode TOPSIS, dengan mencari jarak terjauh dan terdekat dari solusi ideal positif dan negatif. Peserta dengan nilai tertinggi akan menempati urutan teratas dalam sistem ini. Perbandingan terhadap data hasil dengan sistem yang telah dibuat menghasilkan akurasi 80%.

INTRODUCTIONAnal cleansing is the hygienic practice of cleaning the anal area after defecation. Inaccessibility to anal cleansing materials leads to inappropriate methods resulting in faecal hand contamination. This study assessed the accessibility of anal cleansing materials for public primary school pupils in Kajiado County, Kenya.MATERIALS AND METHODSThe researchers used a descriptive cross-sectional study approach, applying a cluster sampling technique to sample eighteen (18) schools to the study. Three hundred and eighty-four (384) pupils were selected from the schools using simple random sampling. The Headteacher and a teacher in charge of school health were purposively sampled due to their knowledge of school resources about hygiene. A total of thirty-six teachers participated in the key informant interviews.Data were analysed using SPSS version 21, and Chi-square was used to test the hypothesis at p<0.05 significance level.RESULTSAccessibility to anal cleansing materials was low at 22.9%. Pupils' class (p-value = 0.036) and level of material awareness (p-value <0.001) influenced accessibility. For Institutional factors, material sensitisation was associated with accessibility (p-value = 0.001). The following sustainability measures were proposed; sensitisation on anal cleansing materials, provision through cost sharing, management of the materials by class teachers and prefects, and continued support by government ministries of health and education.CONCLUSIONAnal cleansing materials access was low; pupils' predisposing characteristics and institutional factors influenced access.RECOMMENDATIONWe recommend that school management and ministries of health and education improve access to anal cleansing materials in schools and develop sustainability measures.

This study explores whether textual enhancement improves learners' acquisition of prefect tense structures in English. The perfect tense in English was taught explicitly in this study and then reinforced through input enhancement activity. The experiment involved 44 undergraduate students (experimental group 23, control group 21) taking practical English at a local four-year university in Korea. After explicit instruction, the two groups took a pretest, a reading comprehension activity, and then a post-test. After four weeks, the delayed test was conducted. In the experiment, the only difference between the two groups was whether the text was reinforced in the subsequent reading activity after the pretest. In online tests, participants were required to select the correct verb tense from multiple choice questions. The two groups had similar test scores, and there was no difference in the perfect tense acquisition between the two. However, when examining the differences within groups, the experimental group retained relatively high levels of perfect tense knowledge on the delayed posttest, whereas the control group did not. The results of the study demonstrated the synergistic effect of the textual enhancement technique when it is coupled with explicit grammar instruction. Furthermore, this study is important in that explicit grammar instruction is separated from input enforcement to allow the effects of it to be examined independently.

Aim: In this study, the ethical conflicts faced by the nurses working in the secondary health care facility in Eskişehir were investigated with the Nursing Ethical Dilemma Test .Method: It was a descriptive study. 233 nurses working in a secondary health care facility in Eskişehir were reached. The data were evaluated in the SPSS-21.00 statistical program,Pearson correlation and descriptive statistical techniques were used in the analysis.Findings: The average age is 32,53 ± 6,23. Nurses' Principle Thinking average point (17,64 ± 11,34); Practical Thinking average point (6,16± 5,07) ; acquaintance average point (13,86± 3,91) was determined that found to be well below the average in every three types of points.Conclusion: When the obtained data were analyzed,it was determined that the nurses frequently encountered situations with ethical problems during their professional lives,but they were nor sufficient to take ethical principles into account when deciding an ethical issues,and the most basic reason was not at the level of prefence with environmental factors. Extended English summary is in the end of Full Text PDF (TURKISH) file.ÖzetAmaç: Bu araştırmada Eskişehir ilinde İkinci basamak sağlık kurumunda çalışan hemşirelerin karşı karşıya kaldıkları etik ikilemlerin, “Hemşirelik Etik İkilem Testi’ile düzeylerinin incelenmesi amaçlanmıştır.Metod: Araştırmanın tipi tanımlayıcıdır. Eskişehir’de İkinci basamak sağlık kurumunda çalışan 233 hemşireye ulaşılmıştır. Veriler SPSS-21.00 istatistik programında değerlendirilmiş, analizinde Pearson korelasyonu ve tanımlayıcı istatistik teknikleri kullanılmıştır.Bulgular: Hemşirelerin Yaş ortalaması 32,53 ± 6,23’dir. Hemşirelerin İlkesel Düşünme (İD) puan ortalaması (17,64 ± 11,34) ; Pratik Düşünme (PD) puan ortalaması (6,16 ± 5,07);Aşinalık puan ortalaması (13,86± 3,91) olarak[N1] belirlenmiş, her üç puan türünde de ortalamanın çok altında puan aldıkları tespit edilmiştir.Sonuç: Elde edilen veriler analiz edildiğinde, hemşirelerin mesleki yaşantıları süresince sıklıkla etik sorun içeren durumlarla karşılaşmış olduğu, fakat etik sorunlara yönelik karar verirken etik ilkeleri göz önünde bulundurma konusunda oldukça yetersiz oldukları, bunun en temel nedenin çevresel faktörler etkisi ile istendik düzeyde olmadığı belirlenmiştir.

Amateur archaeologists in DenmarkThe article briefly sums up the history of amateur archaeology in Denmark and mentions the most renowned amateur archaeologists and collectors of artefacts, mainly from the island Fyn. Attention focuses on describing the close collaboration between amateur and profession al archaeologists, which has resulted in the institution of museums all over the country, often through donations of extensive artefact collections from skilful and wealthy amateur archaeologists.The first museum was established in Copenhagen by Ole Worm (1588-1654), who studied the Danish prehistory. The king, Frederik III (1609-1670), made the museum into a kunstkammer, which included not only archaeological artefacts but also curiosities. Later, the artefact collections were gathered in the Old Nordic Museum, which became the present National Museum in 1892.Ole Worm’s contemporary, the nobleman Jesper Friis (1593-1643) of Ørbæklunde on Fyn created an extensive and comprehensive kunstkammer including two Egyptian mummy coffins (fig. 1). Another native of Fyn, Professor Thomas Broder Bircherod (1661-1731) also had a collection of curios. In the 19th century, Lauritz Schebye Vedel Simonsen (1780-1858), the owner of the manor Elvedgård, and Niels Frederik Bernhard Sehested (1813-1882), owner of the manor Broholm, had large collections of artefacts. The latter was a talented amateur archaeologist, who undertook systematic excavations of almost 400 Iron Age graves on the Møllegårdsmarken site. The finds were published in well-illustrated books. Sehested had a small museum built in the manor garden, where he exhibited his finds. The museum still exists (fig. 2). He also experimented with the practical manufacturing and use of prehistoric tools – a novelty at the time (fig. 3). Even King Frederik VII (1808-1863), once the governor of Fyn, was a passionate collector, who undertook or initiated many excavations.The 20th century saw many wealthy amateur archaeologists, who built museums and issued archaeological publications, as for instance the prefect of the island Bornholm, Emil Vedel (1824-1909), who – assisted by the teacher, Johan Andreas Jørgensen (1840-1908) – made comprehensive investigations into several hundred graves at Lousgaard on Bornholm. Vedel initiated the horizontalstratigraphic excavation method, which resulted in the introduction of the Pre-Roman Iron Age in Danish archaeology. As an acknowledgement for this, Emil Vedel was appointed vice president of ”Det kongelige Nordiske Oldskriftselskab,” a credit to an amateur archaeologist!The chemists Christen Mikkelsen (1844-1924) and his son, Poul Helweg Mikkelsen (1876-1940) represented two generation s of very active amateur archaeologists on Fyn. Both left large private collections, which they willed to The National Museum and Fyns Stiftsmuseum (the museum of the diocese of Fyn) (fig. 4). Poul Helweg Mikkelsen is especially remembered for his excavation of the Ladby Viking ship. Out of his own pocket he paid for the building of a cupola covering the Viking ship, which was left in situ, thus making this Viking ship grave unique in Scandinavia.JensWinther (1863-1955), a grocer on the island of Langeland, paid a museum with his own money (fig. 5). He was a skilful amateur archaeologist, who carried out numerous excavations and introduced a new excavation technique, surface digging, involving the gradual exposure of the surface through the removal of thin successive earth layers – a technique that set a fashion. His excavations at the Troldebjerg site functioned as training excavations for future professional archaeologists. For instance, P.V. Glob, the later professor of archaeology and keeper of national antiquities, was one of Winther’s ”pupils”. Also Winther’s lifelong housekeeper, Miss Hornum, was a skilful amateur archaeologist – so skilful that she was invited to take part in the excavation of Inuit settlements in Greenland. Later she was admitted the second female member of ”Det kongelige Nordiske Oldskriftselskab,” following professor Brøndsted’s recommendation.Svend Dyhre Rasmussen (fig. 6), an amateur archaeologist from Sjælland, found the famous medieval high-backed fields and the adjoining village of Borup Ris. His fellow islander, Karl Kristian Nielsen (fig. 7) was a hardworking amateur archaeologist, who undertook both prehistoric and medieval excavations for forty years. He was a modest, self-taught man working as a charcoal burner and thus nicknamed ” the learned charcoal burner”. He was the first amateur archaeologist honoured with the membership of ”Det kongelige Nordiske Oldskriftselskab” (fig. 8).The article also mentions the wide section of the population – comprising all classes – that has contributed to collectin g and preserving our relics of the past in such a comprehensive manner. Another purpose of the article is to show the connection between important events in Danish history and the amateur archaeological initiatives that resulted from them. The article gives a survey of Danish amateur archaeology, which is organised in numerous associations that stimulate the public interest in this field.A new initiative was the founding of a countrywide organisation of amateur movements, the SDA, in 1990 (fig. 9).The SDA has initiated courses, publication of an amateur archaeological periodical and the ambitious project, ”Operation Golden Horn” aiming at a countrywide registration and mapping of finds and relics. The history of the amateur archaeologist associations on Fyn is described, including examples of the work of smaller groups (fig. 11). The cooperation between amateur archaeologists and museum employees on Fyn culminated in 1984 with the exhibition” Past time and spare time”.An important part of amateur archaeologists’ work is the participation in the annual excavation camps, where the amateurs enjoy the pleasure of finding artefacts and learn how to register them scholarly correctly. Cooperation on a Scandinavian level resulted in a Nordic Amateur Archaeologists’ Excavation Camp (the NAU) in connection with Odense’s 1000th anniversary in 1988 (fig. 12). Since then, similar excavation camps have been held in other Nordic countries, and in Estonia. The cooperation with Estonia has given a wider perspective, which includes international cooperation at different levels.The amateur archaeologists’ knowledge of their own neighbourhood has proved important, as they co nt act the profession al archaeologists when farming methods or public construction work is unexpectedly revealing archaeological finds. In such cases, retired and unemployed amateur archaeologists have made an ”ambulance service”, which offers assistance to museums at short notice. Another special initiative was taken by the amateur ar chaeologists on Bornholm, who created a special branch for detector amateurs. This has helped both Norwegian and Swedish museums investigating known sites and thus gain a more differentiated picture of Iron Age settlements. A third special branch of amateur work is the investigation of the submarine settlement of Tybrind Vig, which is an example of a well functioning coopertion with the marine-archaeological group in Fredericia.When in the 1991, Professor Henrik Thrane, Doctor of Philosophy, made the Hollufgård Museum on Fyn and its collection s more user-friendly and accessible to the public by creating ”open stores”, he also gave the amateur archaeologists the possibility of self-tuition. The publication of the archaeological journal ”Archaeology and the natives of Fyn” in 1979 was a result of cooperation between the museum and amateurs (fig. 13). Finally, in 1993, the SDA journal now carrying the name of” Archaeology for everyone” was published. To stimulate the interest in archaeology among the youth, so-called Hugin and Munin clubs have been started, with branches in Copenhagen, on Fyn and in Jutland.The Erik Westerby foundation (initiated by this famous amateur archaeologist) was created to support Danish archaeologists. In 1994, Axel Degn Johansson was the first amateur archaeologist to receive the price, along with 100.000 Dkr, and later another twelve amateur archaeologists have enjoyed grants and presents of money from the foundation.Finally, the importance of the amateur movement for the present and the future is mentioned, and it is stressed that good cooperation between amateurs and museum professionals is very important. Amateur archaeologists will also benefit from the new and refined methods of dating and analysing archaeological finds and – when detecting new finds in the field – of the exact position determination offered by the GPS system. The importance of publicattention on archaeology is stressed, and so the interest of amateur archaeologists is seen as a necessary part in the important and comprehensive task of preserving the past for the future.Jane Kjærgaard AndresenOdenseTranslated by Annette Lerche Trolle

This paper presents and evaluates a two-level web usage prediction technique, consisting of a neural network in the first level and contextual component predictors in the second level. We used Markov chains of different orders as contextual predictors to anticipate the next web access based on specific web access history. The role of the neural network is to decide, based on previous behaviour, whose predictor’s output to use. The predicted web resources are then prefetched into the cache of the browser. In this way, we considerably increase the hit rate of the web browser, which shortens the load times. We have determined the optimal configuration of the proposed hybrid predictor on a real dataset and compared it with other existing web prefetching techniques in terms of prediction accuracy. The best configuration of the proposed neural hybrid method provides an average web access prediction accuracy of 86.95%.

An important issue incurred by users that limits the use of internet is the long web access delays. Most efficient way to solve this problem is to use “Prefetching”. This paper is an attempt to dynamically monitor the network bandwidth for which a neural network-based model has been worked upon. Prefetching is an effective and efficient technique for reducing users perceived latency. It is a technique that predicts & fetches the web pages in advance corresponding to the clients’ request, that will be accessed in future. Generally, this prediction is based on the historical information that the sever maintains for each web page it serves in a chronological order. This is a speculative technique where if predictions are incorrect then prefetching adds extra traffic to the network, which is seriously negating the network performance. Therefore, there is critical need of a mechanism that could analyze the network bandwidth of the system before prefetching is done. Based on network conditions, this model not only guides if the prefetching should be done or not but also tells number of pages which are to be prefetched in advance so that network bandwidth can be effectively utilized. Proposed control mechanism has been validated using NS-2 simulator and thus various adverse effects of prefetching in terms of response time and bandwidth utilization have been reduced.

The study was designed to investigate the constraints to the effective discipline of secondary school students in Awka South Local Government Area of Anambra state. The survey design was adopted for the study. Five research questions guided the study. The population of the study comprised 1320 teachers. A simple random sampling technique was used to select 150 respondents for the study. The instrument for data collection was a structured questionnaire titled “Constraints to Effective Discipline of Secondary School Student Questionnaire (CEDSSSQ).” The instrument was face validated by three specialists, two from Educational Management and Policy and one from Educational Measurement and Evaluation, all in the Faculty of Education, Nnamdi Azikiwe University, Awka. The questionnaire was trail-tested using Pearson Product Moment Correlation and was used to determine the reliability coefficient of the instrument and this yielded a reliability coefficient (0.74). Data were analyzed using frequency means to answer the research questions. Based on the findings, it was revealed that discipline problems encountered in secondary schools include: Truancy, stealing, assault on school prefects, absenteeism, fighting, and examination malpractice, among others. It was recommended, among others, that in order to stem indiscipline, specific disciplinary actions should be meted out against undisciplined students to discourage others from being unruly.

WSN stands for Wireless Sensor Network it is an prefect models of the IoT or Internet of Things that gives checking administrations to catastrophic events, for example, volcanoes ejection and seismic tremor which can influence the life of person. All things considered, the QoS or Quality-of-Service it is a significant problem of the basic application so that it is adequate as well as heartiness is guaranteed. Other than this without a doubt administrations and commitments in checking frameworks, WSN's restricted assets can seriously corrupt the Quality-of-Service in the application of Internet of Things. There will be a decrease in the Quality-of-Service because of the blockage in the wireless service network in the application. For these situtations proficient utilization for the rare assets might be critical for guaranteeing consistent tramission of the information. Decreasing pace in the retransmission of the parcel that occurs due to the blockage diminishes sensor hubs power utilization. PDNC also known as Packet Discarding based Node Clustering that is a specific bundle disposing of technique is presented in this research paper. Every hubs conveyed will be bunched to a few gatherings that focuses on the zone and at once selection of a group head will be done. Parcel disposing of procedure will at that point be conveyed at every hub to diminish the quantity of bundles adding to blockage. Reenactment examination utilizing NS-2 demonstrates that the proposed method can lessen blockage along these lines improve the general execution.

This study investigated the relationship between computer literacy and teacher’s job effectiveness of secondary schools in Kwara State, Nigeria. The study was a correlation survey. Stratified random sampling technique was used to select 1800 respondents. The respondents were comprised of 40 principals, 80 vice principals, 120 heads of departments, 120 teachers, and 200 prefects totaling 600 respondents from each of the three senatorial districts in Kwara State. Five research hypotheses were generated for the study. Computer Literacy Questionnaire (CLQ) and Teacher’s Job Effectiveness Questionnaire (TJEQ) were used to collect relevant data. The instruments were validated and the reliability index of .63 and .69 was obtained for the (CLQ) and (TJEQ) respectively. The data obtained were analyzed using Pearson Product Moment Correlation statistic and t-test statistics and tested at .05 significance level. The findings revealed that computer literacy encourages appreciation and utilization of computers during teaching learning processes which invariably aid teachers’ job effectiveness, such as job performance, record keeping, school discipline, and supports students’ academic performance. It also revealed that computer literate teachers perform better in the schools than non-computer literate teachers in the schools by making use of computers during their teaching, the use of computers arouse students’ interest in the teachings which supports effective student academic performance. Those schools with non-computer literate teachers were never exposed to computers’ usage which detracted from effective teaching and learning in the schools. It was recommended that computer systems be supplied to every school for the teachers and students use by the government, nongovernmental agencies, and philanthropists. Also all teachers should be encouraged by the government through provision of in service computer training opportunities. In doing so, teachers’ job effectiveness in Kwara State secondary schools will improve.

Caching has received much attention as a promising technique to overcome high data rate and stringent latency requirements in the future wireless networks. The premise of caching technique is to prefetch most popular contents closer to end users in local cache of edge nodes, e.g., base station (BS). When a user requests a content that is available in the cache, it can be served directly without being sent from the core network. In this paper, we investigate the performance of hierarchical caching systems, in which both BS and end users are equipped with a storage memory. In particular, we propose a novel cooperative caching scheme that jointly optimizes the content placement at the BS’s and users’ caches. The proposed caching scheme is analytically shown to achieve a larger global caching gain than the reference in both uncoded – and coded caching strategies. Finally, numerical results are presented to demonstrate the effectiveness of our proposed caching algorithm. Keywords Hierarchical caching system, cooperative caching, caching gain, uncoded caching, coded caching References [1] D. Liu, B. Chen, C. Yang, A.F. Molisch, Caching at the Wireless Edge: Design Aspects, Challenges, and Future Directions, IEEE Communications Magazine 54 (2016) 22-28. https://doi.org/10.1109/MCOM.2016.7565183.[2] T.X. Vu, S. Chatzinotas, B. Ottersten, Edge-Caching Wireless Networks: Performance Analysis and Optimization, IEEE Transactions on Wireless Communications 17 (2018) 2827-2839. https://doi.org/10.1109/TWC.2018.2803816.[3] M.A. Maddah-Ali, U. Niesen, Fundamental Limits of Caching, IEEE Transactions on Information Theory 60 (2014) 2856-2867. https://doi.org/10.1109/TIT.2014.2306938.[4] M.A. Maddah-Ali, U. Niesen, Decentralized Coded Caching Attains Order-Optimal Memory-Rate Tradeoff, IEEE/ACM Transactions on Networking 23 (2015) 1029-1040. https://doi.org/10.1109/TNET.2014.2317316.[5] U. Niesen, M.A. Maddah-Ali, Coded Caching with Nonuniform Demands, IEEE Transactions on Information Theory 63 (2017) 1146-1158. https://doi.org/10.1109/TIT.2016.2639522.[6] Q. Yu, M.A. Maddah-Ali, A.S. Avestimehr, The exact rate-memory tradeoff for caching with uncoded prefetching, IEEE Transactions on Information Theory 64 (2018) 1281-1296. https://doi.org/10.1109/TIT.2017.2785237.[7] S.P. Shariatpanahi, H. Shah-Mansouri, B.H. Khalaj, Caching gain in interference-limited wireless networks, IET Communications 9 (2015) 1269-1277. https://doi.org/10.1049/iet-com.2014.0955.[8] N. Naderializadeh, M.A. Maddah-Ali, A.S. Avestimehr, Fundamental limits of cache-aided interference management, IEEE Transactions on Information Theory 63 (2017) 3092-3107. https://doi.org/10.1109/TIT.2017.2669942.[9] J. Hachem, U. Niesen, S. Diggavi, Energy-Efficiency Gains of Caching for Interference Channels, IEEE Communications Letters 22 (2018) 1434-1437. https://doi.org/10.1109/LCOMM.2018.2822694.[10] M.A. Maddah-Ali, U. Niesen, Cache-aided interference channels, IEEE International Symposium on Information Theory ISIT, 2015, pp. 809-813. https://doi.org/10.1109/ISIT.2015.7282567.[11] T.X. Vu, S. Chatzinotas, B. Ottersten, T.Q. Duong, Energy minimization for cache-assisted content delivery networks with wireless backhaul, IEEE Wireless Communications Letters 7 (2018) 332-335. https://doi.org/10.1109/LWC.2017.2776924.[12] S. Li, Q. Yu, M.A. Maddah-Ali, A.S. Avestimehr, Coded distributed computing: Fundamental limits and practical challenges, 50th Asilomar Conference on Signals, Systems and Computers (2016) 509-513. https://doi.org/ 10.1109/ACSSC.2016.7869092.[13] S. Li, M.A. Maddah-Ali, Q. Yu, A.S. Avestimehr, A fundamental tradeoff between computation and communication in distributed computing, IEEE Transactions on Information Theory 64 (2018) 109-128. https://doi.org/10.1109/TIT.2017.2756959.[14] S. Borst, V. Gupta, A. Walid, Distributed caching algorithms for content distribution networks, Proceedings IEEE INFOCOM. (2010) 1-9. https://doi.org/10.1109/INFCOM.2010.5461964.[15] N. Karamchandani, U. Niesen, M.A. Maddah-Ali, SN Diggavi, Hierarchical coded caching, IEEE Transactions on Information Theory 62 (2016) 3212-3229. https://doi.org/10.1109/TIT.2016.2557804.[16] S.P. Shariatpanahi, G. Caire, B. H. Khalaj, Multi-antenna coded caching, IEEE International Symposium on Information Theory ISIT, 2017, pp. 2113-2117. https://doi.org/10.1109/ISIT.2017.8006902.[17] R. Pedarsani, M.A. Maddah-Ali, U. Niesen, Online coded caching, IEEE/ACM Transactions on Networking 24 (2016) 836-845. https://doi.org/10.1109/TNET.2015.2394482.