191 research outputs found
Permutation Trellis Coded Multi-level FSK Signaling to Mitigate Primary User Interference in Cognitive Radio Networks
We employ Permutation Trellis Code (PTC) based multi-level Frequency Shift
Keying signaling to mitigate the impact of Primary Users (PUs) on the
performance of Secondary Users (SUs) in Cognitive Radio Networks (CRNs). The
PUs are assumed to be dynamic in that they appear intermittently and stay
active for an unknown duration. Our approach is based on the use of PTC
combined with multi-level FSK modulation so that an SU can improve its data
rate by increasing its transmission bandwidth while operating at low power and
not creating destructive interference for PUs. We evaluate system performance
by obtaining an approximation for the actual Bit Error Rate (BER) using
properties of the Viterbi decoder and carry out a thorough performance analysis
in terms of BER and throughput. The results show that the proposed coded system
achieves i) robustness by ensuring that SUs have stable throughput in the
presence of heavy PU interference and ii) improved resiliency of SU links to
interference in the presence of multiple dynamic PUs.Comment: 30 pages, 12 figure
An approach to represent time series forecasting via fuzzy numbers
This paper introduces a new approach for estimating the uncertainty in the forecast through the construction of Triangular Fuzzy Numbers (TFNs). The interval of the proposed TFN presentation is generated from a Fuzzy logic based Lower and Upper Bound Estimator (FLUBE). Here, instead of the representing the forecast with a crisp value with a Prediction Interval (PI), the level of uncertainty associated with the point forecasts will be quantified by defining TFNs (linguistic terms) within the uncertainty interval provided by the FLUBE. This will give the opportunity to handle the forecast as linguistic terms which will increase the interpretability. Moreover, the proposed approach will provide valuable information about the accuracy of the forecast by providing a relative membership degree. The demonstrated results indicate that the proposed FLUBE based TFN representation is an efficient and useful approach to represent the uncertainty and the quality of the forecast
Experimental characterization of the axial behavior of traditional masonry wall metal tie connections in cavity walls
In recent years, the number of human-induced earthquakes in Groningen, a large gas field in the north of the Netherlands, has increased. The majority of the buildings are built by using unreinforced masonry (URM), most of which consists of cavity (i.e. two-leaf) walls, and were not designed to withstand earthquakes. Efforts to define, test and standardize the metal ties, which do play an important role, are valuable also from the wider construction industry point of view. The presented study exhibits findings on the behavior of the metal tie connections between the masonry leaves often used in Dutch construction practice, but also elsewhere around the world. An experimental campaign has been carried out at Delft University of Technology to provide a complete characterization of the axial behavior of traditional connections in cavity walls. A large number of variations was considered in this research: two embedment lengths, four pre-compression levels, two different tie geometries, and five different testing protocols, including monotonic and cyclic loading. The experimental results showed that the capacity of the connection was strongly influenced by the embedment length and the geometry of the tie, whereas the applied pre-compression and the loading rate did not have a significant influence
Numerical modelling of cavity wall metal ties
The assessment of the out-of-plane response of unreinforced masonry (URM) buildings with cavity walls has been a popular topic in regions such as Central and Northern Europe, Australia, New Zealand, China and several other countries. Cavity walls are particularly vulnerable as the out-of-plane capacity of each individual leaf is significantly smaller than the one of a solid wall. In the Netherlands, cavity walls are characterized by an inner load-bearing leaf of calcium silicate bricks, and by an outer veneer of clay bricks that has only aesthetic and insulation functions. The two leaves are typically connected by means of metallic ties. This paper utilizes the results of an experimental campaign conducted by the authors to calibrate a hysteretic model that represents the axial cyclic response of cavity wall tie connections. The proposed numerical model uses zero-length elements implemented in OpenSees with the Pinching4 constitutive model to account for the compression-tension cyclic behaviour of the ties. The numerical model is able to capture important aspects of the tie response such as the strength degradation, the unloading stiffness degradation and the pinching behaviour. The numerical modelling approach in this paper can be easily adopted by practitioner engineers who aim to model the wall ties more accurately when assessing the structures against earthquakes
The effect of polyphonization of Hüseyni maqam melodies within modal jazz harmony and dorian scale on success in piano educationHüseyni makamı içerikli ezgilerin modal caz armonisi ve doryen dizi kapsamında çokseslendirilmesinin piyano eğitiminde başarıya etkisi
This research aims to determine effects of polyphonic performance of Turkish Music melodies containing Hüseyni maqam with modal jazz harmony on undergraduate piano students. Accordingly, “one group pretest-posttest pattern”,one of the weak experimental modals, has been used in the survey. In scope of the research, a piano curriculum based upon the components such as a general information about modal jazz harmony and chord setups has been applied to the students over two studies that are composed with dorian scale and two folk songs performed polyphonically in Hüseyni maqam. The effect of the applied piano curriculum on students’ piano performance has been analysed. As Hüseyni maqam in Turkish Music resembles dorian scale, the studies used for the curriculum have been made based on dorian scale. A six-week curriculum was applied to the students in the process level of the experimental period of the research. The pretest-posttest piano performance success of the students has been analysed by using piano performance rating form prepared pursuant to learned opinion. Wilcoxon Signed Rank Test and r effect size were calculated in the analysis process. As a result of the survey, it has been determined that the piano curriculum based on dorian scale and modal jazz harmony, enhances the piano performance success of the students noteworthily. Moreover, it has also been identified that the influence quantity is in a high level. ÖzetAraştırma ile Türkiye'de lisans düzeyinde piyano eğitimi gören öğrenciler için modal caz armonisi ile çokseslendirilen Hüseyni makamı içerikli Türk müziği ezgilerinin, öğrencilerin piyano performanslarına olan etkisinin belirlenmesi amaçlanmaktadır. Bu doğrultuda, araştırmada zayıf deneysel modellerden "tek grup ön test-son test desen" kullanılmıştır. Araştırma kapsamında, öğrencilere; doryen dizi ile bestelenmiş iki etüt ve çokseslendirilmiş iki hüseyni içerikli türkü üzerinden modal caz armonisine ilişkin genel bilgiler, akor kurulumları vb. öğelere dayanan bir piyano öğretim programı uygulanmıştır. Uygulanan piyano öğretim programının öğrenci piyano performanslarına olan etkisi incelenmiştir. Türk müziğindeki Hüseyni makamı dizisi ile doryen dizi benzerlik gösterdiği için öğretim programında kullanılan etütler, doryen dizi temel alınarak oluşturulmuştur. Araştırmanın deneysel sürecinin işlem evresinde öğrencilere altı haftalık piyano öğretim programı uygulanmıştır. Öğrencilerin öntest-sontest piyano performans başarıları, uzman görüşleri çerçevesinde oluşturulan piyano performans değerlendirme formu uygulanarak incelenmiştir. Analiz işlemlerinde Wilcoxon İşaretli Sıralar testi ve r etki büyüklüğü değerleri hesaplanmıştır. Araştırma sonucunda doryen dizi ile modal caz armonisine dayanan piyano öğretim programının, öğrencilerin piyano performans başarılarını anlamlı düzeyde arttırdığı tespit edilmiştir. Etki büyüklüklerinin ise yüksek düzeyde olduğu belirlenmiştir
An enhanced fuzzy linguistic term generation and representation for time series forecasting
This paper introduces an enhancement to linguistic forecast representation using Triangular Fuzzy Numbers (TFNs) called Enhanced Linguistic Generation and Representation Approach (ElinGRA). Since there is always an error margin in the predictions, there is a need to define error bounds in the forecast. The interval of the proposed presentation is generated from a Fuzzy logic based Lower and Upper Bound Estimator (FLUBE) by getting the models of forecast errors. Thus, instead of a classical statistical approaches, the level of uncertainty associated with the point forecasts will be defined within the FLUBE bounds and these bound can be used for defining fuzzy linguistic terms for the forecasts. Here, ElinGRA is proposed to generate triangular fuzzy numbers (TFNs) for the predictions. In addition to opportunity to handle the forecast as linguistic terms which will increase the interpretability, ElinGRA improved forecast accuracy of constructed TFNs by adding an extra correction term. The results of the experiments, which are conducted on two data sets, show the benefit of using ElinGRA to represent the uncertainty and the quality of the forecast
A General outlook to Turkish Musical institutions from republican period
Bu çalışmada, Cumhuriyetin ilanından itibaren kurulan, hattaevveliyatı Tanzimat devrine kadar uzanan resmî müzik müesseselerininkuruluş, muhteviyat ve değişimlerine temas edilmiştir. Bu kurumlar, tasnifedilirken kronolojik sıra ve bilhassa kurumların kendi içlerindekikategarizasyonuna dikkat edilmiştir. Buradan hareketle; askerî müzikkurumları, müzik öğretmeni yetiştiren lise, üniversite kurumları, devlet operave baleleri, her nevi konservatuvarlar, Kültür Bakanlığı’na ait birçok müzikorganizasyonları ve Türkiye Radyo Televizyon Kurumuna bağlı müzikkurumları başta olmak üzere birçok müessese; meydana gelişi, ihtiva ettikleriunsurlar ve Türk müzik eğitim-öğretim ve kültür hayatındaki rolü veehemmiyeti bakımından incelenmiştir. Bu inceleme neticesinde, iki asra yakınmazisi olan bu kurumların, birçok anlayış ve idare tarzı değişiklerineuğradığı, ülkenin siyasî, idarî kültür atmosferinin, bu kurumlarda icra edilen,öğretilen ve benimsetilmek istenen müzik türlerine büyük tesiri olduğugörülmüştür. Bu bakımdan, Tanzimat devrinden günümüz Türkiye’sine kadarresmî müzik kurumlarının birçoğuna temas edilen bu çalışmanın, bu devirlerarasındaki müzik kurumları tarih ve perspektifine genel manada bir çerçeveçizerek, ışık tutacağı düşünülmektedir.In this study, we aim to provide informations on self-evolution,development and also content-development of formal musical institutionssince Turkish Republican period which also dates back to the Tanzimat reform period. In reassortment of these institutions, we used chronologicalorder and also self-intra-categorisation of these institutions. Thus, weanalysed military music academies (specifically nco training schools), lyceesthat particularly educates music teacher candidates, state universities, alltypeconservatoires, state opera and ballet houses, musical organisationswhich hierarchically dependent on to the ministry of culture, organisationsthat dependent on to the Turkish Radio Corporation and many of themaccording to its foundational purposes, contents and its role in Turkish musiceducation and music cultural life. As a result, these institutions which alsodates back to approximately two century ago, has been reformed many timesaccording to political standpoint and the cultural perspective of rulers.Furthermore, the educational & teaching curricula and styles also have beeninfluenced due to above-mentioned manners. In this regard, since this studyencompasses a wide period from Tanzimat reform to the current TurkishRepublic, we believe this study will draw a frame and also shed a light on tohistory and official understanding of these music institutions
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