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"Bunyi dapat menjadi polusi suara terutama di kota besar seperti Jakarta dengan semakin banyaknya kendaraan dijalan, bunyi yang dihasilkan oleh mesin kendaraan bisa sangat mengganggu. Namun bunyi yang datang bisa kita redam dengan memilih material yang tepat di dalam rumah kita. Pada penelitian kali ini kami membuat rancang bangun yang dapat mengetahui nilai koefisiens transmisi dari suatu material. Komponen yang kami pakai dalam penelitian ini adalah XR 2206 sebagai pembangkit sinyal, power amplifier, Speaker, Arduino KY-038 sebagai sensor microphone, peak to peak detector, dan mikrokontroler. Kami menggunakan pipa paralon sepanjang 1 meter sebagai media perambatan gelombang. Pada bagian dalam pipa kami melapisinya dengan rockwool agar sistem kedap suara. Rentang frekuensi yang dipakai dalam penelitian ini adalah 100-9.000 Hz. Material uji yang digunakan adalah rockwool, gypsum, dan triplek. Dengan membandingkan amplitudo yang diterima sensor setelah dipasang material uji dan sebelum dipasang material uji kita dapat mengetahui koefisiens transmisi material tersebut. Setelah kita menguji ke-tiga material tersebut kami mendapatkan bahwa pada rentang frekuensi 600-2000 Hz nilai koefisiens transmisi selalu lebih besar dibandingkan titik frekuensi lainnya.

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The sound can be noise pollution especially in big cities such as Jakarta with the increasing number of vehicles in the streets the sound produced by the engine vehicles can be very disturbing. But the sound that comes can we asunder by selecting the right material in our houses. Research on this time we make the building blocks that can know the value of transmission koefisiens from a material. The components that we use in this research is the XR 1059 as power signal, Power Amplifier, Speaker, Arduino Judicial Commission-038 as a microphone sensor, peak to peak detector, and mikrokontroler. We use the tube paralon over 1 meter as media propagation waves. On the inside of the tube we overlaid them with rockwool so that the system is insulated from sound. The frequency range used in this research is 100-9,000 Hz. The test material used is rockwool, gypsum, and plywood. By comparing the received amplitudo after it is installed sensor test material and before the attached test material we can know the material transmission koefisiens. After we test to three of the material we get that at the frequency range from 600-2000 Hz the amplitude is always rise."

"This book puts the focus on serving human listeners in the sound field synthesis although the approach can be also exploited in other applications such as underwater acoustics or ultrasonics. The author derives a fundamental formulation based on standard integral equations and the single-layer potential approach is identified as a useful tool in order to derive a general solution. He also proposes extensions to the single-layer potential approach which allow for a derivation of explicit solutions for circular, planar, and linear distributions of secondary sources. Based on above described formulation it is shown that the two established analytical approaches of Wave Field Synthesis and Near-field Compensated Higher Order Ambisonics constitute specific solutions to the general problem which are covered by the single-layer potential solution and its extensions."

"This open access book provides a concise explanation of the fundamentals and background of the surround sound recording and playback technology Ambisonics. It equips readers with the psychoacoustical, signal processing, acoustical, and mathematical knowledge needed to understand the inner workings of modern processing utilities, special equipment for recording, manipulation, and reproduction in the higher-order Ambisonic format. The book comes with various practical examples based on free software tools and open scientific data for reproducible research.The books introductory section offers a perspective on Ambisonics spanning from the origins of coincident recordings in the 1930s to the Ambisonic concepts of the 1970s, as well as classical ways of applying Ambisonics in first-order coincident sound scene recording and reproduction that have been practiced since the 1980s. As, from time to time, the underlying mathematics become quite involved, but should be comprehensive without sacrificing readability, the book includes an extensive mathematical appendix. The book offers readers a deeper understanding of Ambisonic technologies, and will especially benefit scientists, audio-system and audio-recording engineers.In the advanced sections of the book, fundamentals and modern techniques as higher-order Ambisonic decoding, 3D audio effects, and higher-order recording are explained. Those techniques are shown to be suitable to supply audience areas ranging from studio-sized to hundreds of listeners, or headphone-based playback, regardless whether it is live, interactive, or studio-produced 3D audio material."

"Kelapa kopyor merupakan kelapa yang mengalami kelainan genetik sehingga daging buahnya tidak menempel pada tempurung kelapa. Hal tersebut diakibatkan oleh defisiensi enzim ?-D-galaktosidase yang menyebabkan tekstur dari daging kelapa kopyor unik. Keunikan tersebut menjadikannya memiliki banyak peminat sehingga harganya lebih tinggi, mencapai 4-5 kali lipat dari harga kelapa biasa. Dari penampakan luarnya kelapa kopyor tidak berbeda dibanding kelapa biasa. Selama ini petani maupun penjual menggunakan cara tradisional dengan mendengarkan suara guncangan dari kelapa kopyor untuk membedakannya. Sayangnya, cara tersebut sangat bergantung pada pengalaman dan keterampilan dari pemilahnya. Maka dari itu, pada penelitian ini diajukan metode deteksi kelapa kopyor berbasis pengenalan suara menggunakan Mel Frequency Cepstrum Coefficient MFCC sebagai metode ekstraksi fitur suara dan Dynamic Time Warping DTW sebagai metode pencocokan fitur suara. Objek yang akan dideteksi adalah kelapa kopyor dan kelapa biasa yang sudah tua. Dengan menggunakan kedua metode tersebut, sebuah program telah dibuat untuk dapat mendeteksi kelapa kopyor dengan akurasi sebesar 96.4.

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Kopyor coconut is a coconut that has genetic abnormalities which cause the coconut meat to not stick to the coconut shell. It is caused by deficiency of enzyme D galactosidase which causes the texture of kopyor coconut meat to become unique. Its uniqueness attracts many enthusiasts resulting in a high economic value, 4 5 times that of the ordinary coconut. From its external appearance, kopyor coconut does not differ with ordinary coconut. To date, both farmers and sellers use a traditional method by listening to the sound of whisk from kopyor coconut to detect them. Unfortunately, it relies heavily on experience and expertise of the person.

Therefore, a new detection method is proposed based on sound recognition using Mel Frequency Cepstrum Coefficient MFCC as the method for feature extraction and Dynamic Time Warping DTW as the method for feature matching. Objects that will be detected are kopyor coconuts and ordinary coconut which has grown mature. By using both methods, a program has been developed to detect kopyor coconut with an accuracy 96.4."

"Dengan kemajuan teknologi saat ini, perkembangan peralatan yang digunakan manusia dari segi informasi, komunikasi, produksi, transportasi, dan hiburan semakin pesat. Namun, sebagian besar peralatan ini menghasilkan suara yang tidak diinginkan, menyebabkan gangguan. Untuk mengatasi masalah ini, telah dikembangkan berbagai jenis bahan peredam suara. Meskipun kemajuan ini memberikan manfaat besar dalam meningkatkan efisiensi dan kenyamanan penggunaannya, tetapi juga memunculkan masalah baru terkait gangguan yang tidak diinginkan. Penelitian ini bertujuan untuk mengembangkan lembaran sandwich menggunakan SS Wire Mesh 8 sebagai inti dan SS 304 sebagai lapisan muka, dengan variasi filler glasswool dan rockwool untuk meningkatkan sifat mampu bentuk dan penyerapan suara. Evaluasi eksperimental dilakukan, termasuk pengujian regangan, perluasan lubang, regangan-bend, dan uji transmisi suara, untuk mengevaluasi sifat mampu bentuk komposit dan kemampuan peredam suaranya. Hasil penelitian menunjukkan peningkatan Batas Tinggi Kubah (LDH) sebesar 20,51% dan 8,46% dengan penggunaan filler rockwool dan glasswool, yang mengindikasikan peningkatan kemampuan regangan dari 3,90 mm menjadi 4,70 mm dan 4,23 mm, masing-masing. Rasio Ekspansi Lubang (HER) juga menunjukkan peningkatan signifikan sebesar 10,6% dan 19,6% untuk sampel dengan filler, dari 3,8%, karena pengaruh filler terhadap sifat penyerapan energi dan distribusi beban pada komposit sandwich. Namun, pengujian rentang tekuk menunjukkan bahwa peningkatan ketebalan sampel dengan filler menghasilkan Rasio Tekuk yang lebih rendah. Hasil pengujian pada sampel komponen peredam suara menunjukkan bahwa komposit sandwich dengan filler mampu menyerap suara lebih baik dibandingkan yang tanpa filler, dengan nilai kehilangan transmisi (TL) pada sampel filler glasswool dan rockwool masing-masing mencapai 4,41 dB dan 4,37 dB.

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The rapid advancement of technology has led to the increased development of tools across various sectors including information, communication, production, transportation, and entertainment. However, many of these tools generate unwanted noise, causing disturbances. To mitigate this issue, various sound-absorbing materials have been developed. While these technological advancements have significantly enhanced human efficiency and comfort, they have also introduced challenges related to unwanted disturbances. This study focuses on the development of sandwich sheets using SS Wire Mesh 8 as the core and SS 304 as the face, incorporating variations of glasswool and rockwool fillers to improve sound formation and absorption properties. Experimental evaluations included stretching, hole expansion, stretch-bend, and sound transmission tests were conducted to evaluate the formability and sound-damping characteristics of the composite. The findings revealed an increase in the Limiting Dome Height (LDH) by 20.51% and 8.46% with rockwool and glasswool fillers, respectively, indicating enhanced strain capacity from 3.90 mm to 4.70 mm and 4.23 mm, respectively. The Hole Expansion Ratio (HER) exhibited a notable increase of 10.6% and 19.6% for samples with fillers, compared to 3.8% without fillers, demonstrating the fillers' impact on energy absorption and load distribution in the sandwich composite. However, the stretch-bend tests indicated that increased sample thickness with fillers resulted in a lower Bend Ratio. Sound absorption tests on the composite samples for sound-damping components indicated superior performance of sandwich composites with fillers compared to those without fillers, achieving transmission loss (TL) values of 4.41 dB and 4.37 dB for glasswool and rockwool fillers, respectively."

"Dalam tesis ini diajukan sistem gabungan multicarrier code-division multiple-access (Multicarrier CDMA) dengan skema Pure Aloha (P-Aloha) dan Slotted Aloha (S-Aloha), yang disebut multicarrier CDMA P-Aloha dan multicarrier CDMA S-Aloha. Analisa terhadap kedua sistem dilakukan terhadap salah satu parameter kinerja sistem yaitu throughput.Dalam sistem multicarrier CDMA P-Aloha dan multicarrier CDMA S-Aloha, data mula-mula dikonversi dari serial menjadi paralel. Data tersebut kemudian dimodulasi dengan direct sequence spread-spectrum (DS-SS) menggunakan kode penyebar yang spesifik pada setiap user, dan semua sinyal DS tersebut ditransmisikan secara paralel pada subcarrier yang berbeda-beda. Setelah dikodekan, data dikirim secara acak untuk sistem multicarrier CDMA P-Aloha, sedangkan pada multicarrier CDMA S-Aloha data dikirim pada permulaan time-slot sesuai mekanisme sistem S-Aloha.Hasil penelitian menunjukkan bahwa kedua sistem memiliki throughput yang tinggi untuk transmisi sinyal dengan laju tinggi, dan multicarrier CDMA S-Aloha memiliki throughput yang lebih tinggi daripada multicarrier CDMA P-Aloha. Hasil penelitian juga menunjukkan bahwa throughput kedua sistem semakin tinggi dengan meningkatnya jumlah subcarrier dan panjang kode single-carrier yang digunakan, sementara peningkatan panjang subpaket menurunkan throughput kedua sistem. Multicarrier CDMA Aloha memiliki throughput yang lebih baik dari CDMA Aloha.

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This thesis proposes integrated systems consisting of multicarrier code-division multiple-access (Multicarrier CDMA) with Pure Aloha (P-Aloha) and Slotted Aloha (S-Aloha) schemes, named multicarrier CDMA P-Aloha and multicarrier CDMA S-Aloha, respectively. The performance analysis of both systems is stated as throughput, Multicarrier CDMA Aloha is proposed to improve the performance of CDMA Aloha.In multicarrier CDMA P-Aloha and multicarrier COMA S-Aloha the initial data is serial-to-parallel converted to a number of lower rate data streams. Each stream which consists of a part of the initial data called sub-packet will be then direct sequence spread-spectrum modulated using specific spreading code for each user, and all the DS-SS signals are transmitted in parallel on different subcarriers. The coded data is sent randomly in multicarrier CDMA P-Aloha system, whereas in multicarrier CDMA S-Aloha, the data is sent at the beginning of the time-slot according to the mechanism of S-Aloha system.Results show that both systems have high throughput for high bit rate signal transmission, and multicarrier CDMA S-Aloha outperforms multicarrier CDMA P-Aloha. It is also shown that the throughput of both systems improves as the number of subcarriers and the length of single-carrier code increase, while the increase of subpacket length degrades the throughput of both systems. Multicarrier CDMA Aloha has better performance compared to CDMA Aloha."