1,720,982 research outputs found
Fractal Communication System Using Digital Signal Processing Starter Kit (DSK) TMS320c6713
Get PDFIn 1992, Wornell and Oppenheim did research on a modulation which is formed by using wavelet theory. In some other studies, proved that this modulation can survive on a few channels and has reliability in some applications. Because of this modulation using the concept of fractal, then it is called as fractal
modulation. Fractal modulation is formed by inserting information signal into fractal signals that are selffractal similary. This modulation technique has the potential to replace the OFDM (Orthogonal Frequency Division Multiplexing), which is currently used on some of the latest telecommunication technologies. The purpose of this research is to implement the fractal communication system using Digital Signal Processing Starter Kit (DSK) TMS320C6713 without using AWGN and Rayleigh channel in order to obtain the ideal performance of the system. From the simulation results using MATLAB7.4. it appears that this communication system has good performance on some channels than any other communication systems. While in terms of implementation by using (DSK) via TMS320C6713 Code Composer Studio (CCS), it can be concluded that the
fractal communication system has a better execution time on some tests
Perancangan Dan Implementasi Antena Yagi 2.4 GHz Pada Aplikasi WIFI (Wireless Fidelity)
No full textAbstrak Penggunaan teknologi komunikasi dengan menggunakan kabel kini sudah tergantikan oleh teknologi komunikasi tanpa kabel, dimana kebanyakan pengguna menggunakan perangkat access point yang memiliki jangkauan pancaran terbatas karena pola radiasi omnidirectional, sehingga diperlukan antena yang mempunyai pola radiasi directional untuk jangkauan pancaran yang lebih terarah. Antena yagi merupakan salah satu yang dapat digunakan untuk mengatasi masalah ini. Dalam penelitian ini, antena Yagi yang dirancang dapat diaplikasikan pada sistem WLAN. Hasil dari implementasi didapatkan bahwa antena Yagi dapat bekerja pada frekuensi kerja WLAN 2,4 GHz. Dan selainitudiperoleh level kuat medan dengan rata-rata peningkatan penguatan antena yagi terhadap antena omni sebesar 12,1 dB. Disamping itu diperoleh gain antena yagi sebesar 16 dB sedangkan hasil simulasi sebesar 10 dB, beamwidth vertikal 250 dan horizontal 260, dan bandwidth antena 150 MHz, Pada penelitian ini hasil yang didapatkan dibandingkan dengan hasil dari software vistumbler dan SuperNEC 2.9. Kata kunci : Access point, antenna yagi, directional, vistumbler, 2,4 GHz, SuperNEC 2.9 Abstract The use of communication technologies by using cable technology has now been replaced by wireless communication, whichmost usersuse theaccess point device that has a limited range due to beam omnidirectional radiation pattern, so that the required antenna that has a directional radiation pattern to reach a more focused beam. Yagi antenna is one that can be used to overcome this problem. In this study, Yagi antenna is designed to be applied in WLAN system. Results obtained from the implementations that Yagi antennas can work at the operating frequency of 2.4 GHz WLAN. And besides it is obtained strong level terrain with an average increase of the antenna yagi antenna gain of 12.1dB omni. Besides, obtained yagi antenna gai nof 16 dB, while the simulation result sat 10 dB, 250 vertical and horizontal beamwidth of 260, and a bandwidth of 150 MHz antennas, In this study,the results obtained are compared with the results of the software vistumbler and SupeNEC 2.9. Keywords: Accesspoint, yagi antennas, directional, vistumbler, 2.4 GHz, SuperNEC 2.9 </p
Light follower systems for visually impaired using visible light communication
No full textVisual impairment is the condition of someone who has a disorder or an obstacle in their vision. In this research, the implementation of light follower systems for visually impaired using visible light is proposed. This system can enable visually impaired people to determine orientation and support mobility, especially in an indoor situation, using visible light. The prototype of the visually impaired pathway was made as visible light communication (VLC) transmitter consisting of a 12 V power supply, light emitting diode (LED),
MPEG-1 Layer-3 (MP3), and band pass filter (BPF) filter circuit. The VLC receiver is made a prototype of a blind stick consisting of a photodiode, amplifier, buzzer, timer, and 9 V battery. The measurement of this system uses acrylic and color filters with system accuracy taking into account the angle and conditions when the fluorescent lights are turned on and off. This result showed the system could transmit audio signals at a frequency of 3000 Hz. Furthermore, the comparison results showed that the quality of measurements without using a filter is better than using a filter. The output voltage value without using a filter with an angle of 700 degree is 7.19 Vp-p, meanwhile using a filter with an angle of 700 degree is 6.48 Vp-p
Implementasi Visible Light Communication (VLC) Pada Sistem Komunikasi
No full textABSTRAKPerkembangan teknologi telah menunjukkan peningkatan yang cukup signifikan, terutama untuk bidang komunikasi. Hal ini terbukti dengan banyaknya media komunikasi baik itu nirkabel dan kabel. Pada penelitian ini dimanfaatkan cahaya tampak sebagai media dalam sistem komunikasi, dimana selama ini cahaya hanya digunakan sebagai penerangan saja. Visible Light Communication (VLC) adalah sebuah teknologi komunikasi yang memanfaatkan pancaran cahaya tampak dari lampu pada sistem komunikasi. Sistem komunikasi visible light ini terdiri dari pemancar dan penerima. Pemancar terdiri dari Light Emitting Dioda, audio transformator dan baterai, dan pada penerima terdiri dari solar cell dan photodioda, amplifier dan catu daya. Hal-hal yang dapat mempengaruhi hasil output sistem komunikasi adalah jarak, terang cahaya lampu pemancar dan cahaya luar. Pada penelitian ini, komunikasi menggunakan VLC dapat dilakukan pada jarak pengiriman data sebesar 2,5 m dan dengan range frekuensi 600 Hz sampai dengan 45 kHz dimana data dapat disalurkan dengan baik.
Kata kunci: Visible light, Sistem komunikasi, Light Emitting Dioda, solar cell, photodioda.
ABSTRACT
Technological developments have shown a significant increase, especially in the field of communication. This is proved by the many communications media using both wireless and wired. This study utilized the visible light as a medium of communication system, which has been used as an illumination light only. Visible Light Communication (VLC) is a communication technology which utilize visible light emitted from the lamp in the communication system. The visible light communication system consists of a transmitter and receiver. The transmitter consists of a Light Emitting Diode, audio transformer and battery, and the receiver consists of a solar cell and a photodiode, amplifier and power supply. Things that can affect the output of the communication system is the distance, bright light and outdoor light. In the research, the results that obtained from this study is the data transmission distance of 2.5 m and a frequency range of 600 Hz to 45 kHz data can be routed properly.
Keywords: Visible light, Communication systems, Light Emitting Dioda, solar cell, photodioda
Perancangan dan Implementasi Sistem Remote Tilting Antenna untuk Aplikasi Base Station
Get PDFABSTRAK
Pada kondisi pembangunan suatu jaringan seluler baru, permasalahan coverage area terkadang perlu penanganan khusus. Jika coverage area dari suatu base station terlalu besar maka dapat mengakibatkan saling tumpang tindih (overlap) dengan sel yang berdekatan. Hal ini akan meningkatkan interferensi daya antar sel, yang kemudian berakibat pada penurunan kualitas layanan. Salah satu bentuk solusi untuk dapat memenuhi persyaratan coverage area, kinerja jaringan seluler, dan juga memenuhi tingkat keselamatan engineer adalah dengan menggunakan metoda down tilting antenna melalui wireless. Penetapan metoda down tilting antenna dilakukan dengan membuat suatu peralatan yang dapat menggerakkan posisi antenna pada base station. Perangkat yang diimplementasikan terdiri atas Transmitter, Receiver, Motor DC, Driver Motor, Logam Pengait, dan Antena. Sinyal yang berfungsi sebagai pengendali masuk ke Transmitter dan selanjutnya diolah oleh Receiver. Sinyal keluaran dari Receiver digunakan untuk mengendalikan motor DC melalui driver motor yang mengendalikan pergerakan dari Antenna Base Station. Pada penelitian ini, sistem telah dapat diuji memalui pergerakan antenna sampai dengan jarak 10 m. Tingkat kemiringan antena dibandingkan dengan pergeseran logam berkait menunjukan hasil yang linear. Setiap pergeseran 0,5 cm akan menyebabkan perubahan kemiringan antenna sebesar 1 derajat.
Kata kunci: Remote Tilting, Motor DC, Transmitter, Receiver, Base Station
ABSTRACT
On the state of development of a new mobile network, problem coverage area sometimes need special handling. If the coverage area of a Base Station is too big then it may lead to overlap ( overlap ) with adjacent cells. This will improve inter- cell interference power, which then resulted in a decrease in the quality of service. One form of solutions to meet the requirements of the coverage area, the performance of cellular networks, and also meet the level of safety engineers is to use the method of tilting down through a wireless antenna. Determination method of antenna down tilting is done by creating a device that can move the position of the antenna on Base Station. The device is implemented consisting of Transmitter, Receiver, Motor DC Motor Driver, Metal Hook , and Base Station Antennas. Which serves as a signal controlling entry into Transmitter and subsequently processed by the Receiver. The output signal of the receiver is used to control a DC motor through a motor driver that controls the movement of Base Station Antenna. In this study, the system has to be tested memalui antenna movement up to a distance of 10 m. Levels compared to the friction slope antenna hooked metal has showed linear results. Each shift will lead to a change of 0.5 cm by 1 degree slope antenna.
Key words: Remote Tilting, DC Motor, Transmitter, Receiver, Base Statio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Implementasi Sistem Penyiaran Musik Digital di Kafe menggunakan Visible Light Communication
Get PDFABSTRAK
Teknologi penyiaran dengan frekuensi radio menggunakan teknik modulasi frekuensi (FM) telah dikenal sejak lama. Teknologi ini memfasilitasi pengiriman suara melalui sinyal analog dari pemancar kepada penerima. Pengembangan teknologi komunikasi menggunakan cahaya tampak yang memanfaatkan lampu LED sebagai pengirim informasi cukup banyak dilakukan. Pada penelitian ini diimplementasi sistem pengiriman dan penerimaaan siaran musik digital dengan memanfaatkan cahaya tampak yang berasal dari lampu penerangan di kafe. Sistem visible light communication (VLC) diimplementasikan dengan menggunakan metoda modulasi intensitas dan deteksi langsung (IM/DD). Dari hasil pengujian dapat ditunjukkan bahwa sistem ini dapat melewatkan siaran musik digital dengan redaman rata-rata 7,77 dB pada jarak maksimal adalah 3 meter. Hasil dari sistem yang telah dirancang dan diimplementasikan menunjukan hasil yang baik sehingga layak untuk diterapkan pada system penyiaran musik digital di kafe.
Kata kunci: Visible Light Communication, IM/DD, Sistem Penyiaran Musik Digital, Sistem Penerangan Kafe.
ABSTRACT
Broadcasting technology uses radio frequency and technique of frequency modulation (FM) has been known for a long time. This technology allows the transmission of voice through analog signals from transmitter to receiver. Currently, many research on visible light communication technology utilizes LED lights as the sender. In this paper presented the results of transmitter and receiver system implementation of digital musik broadcast for use in the cafe. Visible light communication (VLC) system is implemented using intensity modulation and direct detection (IM/DD) method. From the test results can be shown that this system can pass digital musik broadcast with an average attenuation of 7.77 dB at maximum distance is 3 meters. Results of the system that has been designed and implemented shows good results, so it deserves to be applied to the digital musik broadcasting system in the cafe.
Keywords: Visible Light Communication, IM/DD, Radio Broadcasting, Café Lighting
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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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