1,720,960 research outputs found
Spectrum Sensing berbasis Matriks Kovariansi Sinyal pada Cognitive Radio
Full text linkKetersediaan resource berupa alokasi spektrum frekuensi sudah sangat menurun. Spektrum frekuensi yang digunakan sebagai sarana transmisi data belum efektif dan efisien. Oleh karena itu, dikembangkan teknologi cognitive radio dengan fungsi spectrum sensing untuk mendeteksi spektrum yang tidak terpakai. Setelah itu, dapat digunakan untuk pengguna lain agar lebih efisien dan efektif. Algoritma sensing yang ada diantaranya adalah matched filter dan energy detector. Karena terdapat kekurangan pada energy detector (deteksi energi), yaitu sangat sensitif pada ketidakpastian noise power, maka dibentuk metode baru berdasarkan Matriks Kovariansi dari sinyal yang diterima. Matriks Kovariansi sinyal dan noise umumnya berbeda. Pada tulisan ini dilakukan analisis spectrum sensing pada cognitive radio menggunakan metode Matriks Kovariansi Sinyal dan Deteksi Energi. Sinyal space time block coding (STBC) sebagai sinyal primary user (PU) dibangkitkan secara random lalu ditransmisikan melalui kanal Geometrically-Based Single Bounce (GBSB). Setelah itu, dilakukan deteksi menggunakan kedua metode tersebut. Hasil simulasi memperlihatkan kelemahan Deteksi Energi dan keunggulan Matriks Kovariansi Sinyal saat noise power tidak tetap, atau mengalami ketidakpastian noise (uncertain noise
Energy saving on IoT using LoRa: a systematic literature review
No full textThe development of devices connected to the internet is very significant, encouraging the creation of the internet of things (IoT). With remote systems, IoT is not enough to use in case of internet instability. By using long range (LoRa), IoT systems can now solve this problem. Millions of data make IoT-LoRa have to spend a lot of energy. This paper helps discover where recent studies offer a broad perspective on energy savings using the systematic literature review (SLR). The paper extracted 252 articles from IEEE, ACM, MDPI, Springer, Hindawi, ScienceDirect, and IAES. 44 articles passed the specified inclusion and exclusion criteria. The article focuses on knowledge about IoT-Lora, energy saving needs, energy saving factors, and the paper demographics. The author synthesizes studies for that purpose on IoT applications using LoRa
Mountain Tourism Destination Website Interface Design Based on Classical Conditioning Theory of Persuasion
No full textMessage querying telemetry transfer on IoT applications to enhance technology: a systematic review
Get PDFMore things are connected to the Internet, making the internet of things (IoT) develop significantly. But IoT also has weaknesses in communication, one of which can be overcome by utilizing message querying telemetry transfer (MQTT) because there are too many benefits of MQTT. Because there have been many published studies regarding MQTT, this study aims to conduct a review utilizing preferred reporting items for systematic reviews and meta-analyses (PRISMA) on the application of MQTT in IoT applications to enhance technology. The results of using PRISMA were 57 papers selected from this process, which starts from the identification stage, screening, eligibility, and included. The last author found components that can be discussed to enhance technology. In this discussion, several topics will be used to enhance technology, such as; smart technology, security, MQTT performance for IoT, monitoring systems, MQTT comparison, enhancement or optimization. This paper is expected to help academia and industry related to MQTT research that can help IoT to enhance technology quality
Novel asymmetric space vector pulse width modulation for dead-time processing in three-phase power converters
Get PDFThis research analyzes the asymmetric control strategies in multilevel inverters, including asymmetric techniques in space vector modulation of power converters. Modulation parameters such as reference voltage vector (Vref), switching time, and duty cycle are derived in the three-dimensional spatial vector geometry formulation. Asymmetric space vector pulse width modulation (SVPWM) is unique in specifying modulation parameters, has unequal tetrahedron patterns, accompanied by application examples for the upper and lower sector pairs of a tetrahedron. The combination of the switch in the form of an inclined cylinder produces twelve pairs of asymmetric tetrahedrons where the voltage vector positions are in the other twenty-four tetrahedrons. The calculation shows processing dead-time in switching, which is used for current compensation in three-phase power converters
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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