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"Teknik pengkodean suara digunakan dalam teknologi telekomunikasi untuk memanfaatkan informasi yang besar sehingga dapat meningkatkan efisiensi penggunaan kapasitas saluran. Akan tetapi pada teknik pengkodean suara masih dihadapkan kepada dilema antara besarnya laju bit yang dihasilkan dengan tingkat kualitas suara yang dihasilkan sebagai kompensasi dari penekanan laju bit ini. Mixed Excitation Linear Prediction (MELP) merupakan suatu metode pengkodean suara yang dikembangkan berdasarkan metode Linear Predictive Coding (LPC), yang menggunakan S4 bit untuk setiap frame suara selama 22,5 ms sehingga dihasilkan laju bit sebesar 2,4 kbps. Metode MELP ini memperbaiki kualitas sintesa ucapan hasil pengkodean dengan penambahan empat parameter baru, yaitu: pencampuran eksilasi pulsa dan derau, pulsa-pulsa aperiodik, filter Adaptive Spectral Enhancement, dan filter Pulse Dispersion. Pada skripsi ini dianalisis unjuk kerja dari metode MELP dilihat dari kualitas suara sintesis yang dihasilkan ditinjau dari segi SNRR, perbandingan spektral, dan penilaian subyektif oleh 40 orang pendengar. Hasil yang didapat menunjukkan bahwa suara sintesis hasil kompresi MELP masih dapat jelas diterima oleh telinga manusia dalam arti bahwa informasi masih dapat diterima dengan baik dengan kualitas suara yang cukup baik."

"In electric power systems that consist of some generators, electric power stability in supplies sidebecomes the most important problems, which must be paid attention. In the interconnection system, ifthere are some troubles in transmission, generator or load will cause another generators feel theexistence of instability condition. For instability condition which not too serious, system can overcomethe fault and will not influence stability of system as a whole. However, for in big scale of fault andhappened in a long duration can be ejected system becoming unstable and will result hampered ofelectrics energy supply to the load For the worst condition could be blackout condition.This article studies about improvement of the stability of the system by using excitation current andthe prime mover of generators, which is coordinated fuzzy logic control in synchronize generator. Byusing annexation from three methods above, the condition of stability of the power system can attain thestability. The transient stability needed control in order that system with good stability can return tonormal condition. Faulted electric power system often caused by failure in controlling the transientstability. It is because in transient stability forms critical condition for electrical power system. By controlling the level of excitation current and mechanical energy from the prime mover ofgenerators which controlled by fuzzy logic when the fault is happened will make acceleration areabecome decreasing and deceleration area become increasing with the result that system can be stablequickly. It visible that from result of simulation obtained if using generator oscillation of fuzzy logiccontrol, transient period becoming shorter and amplitude of oscillation wave is smaller compare by usingwithout fuzzy logic. Likewise, this method is able loo to overcome transient condition at starting period ofa generator."

"Sistem tenaga listrik modem menggunakan pengatur tegangan dan sistem penguatan medan, untuk menjaga kestabilan sistem terhadap ganggguan. Pada suatu sistem penguatan medan dapat ditambahkan Pembatas Eksitasi Kurang (Under Excitation Limiter). Fungsi Pembatas Eksitasi Kurang (PEK) adalah menjaga kestabilan generator terhadap panas pada inti jangkar, mencegah kehilangan eksitasi oleh gangguan yang cukup ekstrim. PEK bekerja berdasarkan galat pengatur tegangan dan tegangan acuan. Setelah diolah PEK, sinyal ini diteruskan ke medan generator untuk mengembalikan tegangan medan pada nilai yang diinginkan.Simulasi dalam tesis ini memerlukan kurva kemampulan generator. Generator diberi nilai daya yang berada di luar kurva, yang memisalkan keadaan tidak stabil. Hasil simulasi menunjukkan bahwa tegangan terminal dikembalikan kepada nilai keadaan stabil. Tanggapan tegangan medan mirip dengan tanggapan fungsi orde satu dengan masukan fungsi undak.Parameter PEK harus disesuaikan dengan batas kestabilan generator. Batas kerja PEK didasarkan pada kurva kemampuan generator. Simulasi meninjau sistem satu pembangkit dengan daya 2 KW dan satu bus tak terhingga (infinite bus). Namun hasilnya dapat diterapkan pada sistem dengan daya lebih besar. Untuk pengembangan studi tentang PEK, dapat diteliti penggunaannya bersama Pembatas Eksitasi Lebih (Over Excitation Limiter), dan pada sistem dengan banyak bus tak terhingga.

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Modem power systems apply voltage controller and excitation systems to keep their stability against disturbance. To the excitation system can be added an under excitation limiter (UEL}. UEL functions to keep generator's stability against armature core overheating, and loss of excitation due to relatively big disturbances. UEL operates by using the error between controller's output and reference voltage. After being processed by the UEL, the signal is passed to the generator's field to return the field voltage to its desired value.

Simulation in this thesis needs generator capability curve. The generator was given a power value outside the curve. The value reflected an instable condition. The results of the simulation showed that terminal voltage was brought back to a value in the stable region. The field voltage response is similar to a first order response with step function input.

UEL parameters should be adjusted to the generator's stability limits. UEL's limit is based on generator capability curve. The simulation observed a 2 KW generator system connected to an infinite bus. However the results can be applicable to bigger systems. Continuing the study on UEL, further UEL experiments together with over excitation limiters (OEL), and its use on an many infinite buses can be conducted."

"Skripsi ini membahas mengenai pemodelan dan simulasi rangkaian enkoder pada teknik pengkodean suara VSELP. VSELP merupakan suatu teknik pengkodean suara atau kompresi pada komunikasi selular yang memberikan tingkat kompresi sebesar delapan kilo bit persekon. Bagian Enkoder VSELP melakukan kompresi dengan metode Linear Prediction Coding dan memodelkan nilai eksitasi dengan kode buku adaptif dan kode buku eksitasi.Bagian Enkoder ini akan disimulasikan dan dibuktikan tingkat kompresi suaranya. Simulasi dilakukan dengan secara offline yang berarti suara direkam terlebih dahulu dan kemudian diproses secara terpisah. Simulasi tersebut akan menghasilkan sebuah bentuk dokumen dari data asli yang akan memberikan tingkat kompresi sebesar delapan kilo bit perdetik.

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This final project discusses designing and simulating encoder part of VSELP sound compression. Vector Sum Excitation Linear Prediction is one of the technique of sound compression or sound coding on cellular communication that give compression into eight kilo bit per second. VSELP Encoder compressed sound data with linear prediction coding and model the excitation with adaptive codebook and excitation codebook This Encoder part will be simulated to prove the compression level of it. Simulation done in offline condition whereas the data recorded and processed separately. Simulation will give a new file from the origin data that give the eight kilo bit persecond compression."

"Nanopartikel emas (AuNPs) merupakan suatu bahan yang mulai marak digunakan dalam bioimaging. AuNPs yang digunakan dalam bioimaging umumnya disintesis menggunakan metode kimiawi. Salah satu teknik pencitraan yang memakai AuNPs sebagai medium adalah Two photon microscopy. Teknik ini memanfaatkan eksitasi two photon pada AuNPs untuk memberikan label pada sampel-sampel biologis. Pada penelitian ini, telah disintesis AuNPs menggunakan metode ablasi laser menggunakan laser Nd:YAG dengan panjang gelombang 1064 nm selama 5 menit. Tiga jenis pelarut (aqueous, polyvinyl alcohol dan polyethylene glycol) digunakan untuk memodifikasi diameter AuNPs. Masing-masing AuNPs ini menunjukkan puncak absorbsi yang berbeda pada spektrometri UV-Vis. Spektrum ini kemudian dibandingkan dengan sebuah alat simulasi pada MATLAB. Didapatkan besar diameter AuNPs untuk masing-masing parameter adalah 16,2 nm, 16,7 nm, dan 15,9 nm secara berurutan. Telah dibuat pula setup optik untuk melakukan uji eksitasi two photon (TPE) pada AuNPs memvariasikan daya dari laser femtosecond. Didapatkan bahwa TPE terjadi pada rentang panjang gelombang ~490 sampai ~500 nm dengan daya laser sebear 1,2 W sampai 1,8 W.

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Gold nanoparticles (AuNPs) is a material that has been gaining attraction in bioimaging. AuNPs that used in bioimaging usually shynthetized using chemmicals method. An example of imaging techniques that use AuNPs as medium is Two photon microscopy. This technique use two photon excitation on AuNPs to dye or labels biological samples. Ini this experiment, AuNPs have been successfully fabricated using laser ablation method by Nd:YAG lser with 1064 nm wavelength for 5 minute. Three different solution (aqueous, polyvinyl alcohol and polyethylene glycol) was applied to modify AuNPs diameter. Each of these AuNPs was observed by mean UV-Vis spectroscopy exhibit different absorption peak. This spectrum then was compared to simulation tool on MATLAB. The measured AuNPs’ diameters was 16,2 nm, 16,7 nm, dan 15,9 nm repectively. An optical setup for two photon excitation (TPE) experiment on AuNPs has also been made by varying the power of femtosecond laser. TPE was detected at ~490 to ~500 nm range with laser power about 1,2 W to 1,8 W."

"The work presented in this thesis is divided two subjects. First, devoted to the behavior, mechanic model, simulation and analysis of plate tectonics under excitation force approximated. Approach of an Earthquake are assumptions on the nature of the rupture process, review the evidence for the essential importance of the flow under plate with the modes of deformations.

Earthquake is primarily a mechanical process which appears as genuire rupture of crust and the earth behaves as an elastic body during the short time span of the phenomena. The friction has probably a fundamental role in the mechanics of the earthquakes. Rock mechanicians consider an earthquake as a stick-slip event controlled by the friction properties of the fault.

During an earthquake, on the nature of the fault and on the effect of trapped fluids within the crust at seismogenic depth, fault zone head seismic waves are generated by a shear-dislocation source and then propagated through the modeled earth medium. Wave propagation theory is used to solve the problem at hand for wave motion response, which is found as the superposition of the mean and scattered wave response.

Second, devoted model of the wave propagation, an important modeling tool of fault zone properties at depth can be provided by accurate simulations of seismic fault zone head and trapped waves for realistic structures. Analytical solutions for seismic wave fields generated by double-couple sources at material discontinuities in plane-parallel structures. Extensive 2D studies of the dependency of fault zone wave motion on basic media properties and source receiver geometries show that there are significant trade offs between propagation distances along the structure, fault zone width, impedance contrasts, source location within.

And the most important applications of the theory of structural dynamics is in analyzing the response of the structures to ground shaking caused by an earthquake. The study for earthquake response of linear SDF systems to earthquake motions concerned the displacement, velocity and acceleration. Then we introduced the response spectrum concept, which is central to earthquake engineering, together with procedures to determine the peak response of systems directly from the response spectrum."

"Tujuan dari penulisan skripsi ini adalah untuk menganalisis respons dari struktur portal tiga dimensi (3D) yang memiliki peredam geser akibat dari eksitasi seismik. Respons yang dimaksud adalah respons kinematik yaitu lendutan, kecepatan dan percepatan serta respons mekanik berupa gaya dalam dan reaksi perletakan dari struktur yang ditinjau. Struktur portal tiga dimensi dimodelkan sebagai struktur portal lima lantai untuk bangunan perbankan dengan vaultroom sebagai ruang penyimpanan. Vaultroom dibentuk dari tembok beton dengan ketebalan mininum 30 cm, sehingga memiliki kekakuan yang sangat besar dibandingkan dengan kekakuan bangunan. Penempatan vaultroom pada bagian tertentu dari struktur akan mengakibatkan eksentrisitas pusat massa dan pusat rotasi struktur sehingga menimbulkan efek torsi pada saat pembebanan dinamik. Peredam geser akan diletakan di antara vaultroom dan pelat vaultroom. Peredam geser yang digunakan diharapkan dapat menreduksi respons dari struktur akibat kekakuan eksentris struktur saat gempa.

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The aim of this research is to analyze the responses of eccentric structure with friction damper. The responses are kinematic and mechanic responses of the structure. The kinematic and mechanic responses consist of deflection, velocity, acceleration, element force, and base reaction. The three dimensional frame is modeled as a five-story building for a bank with vault. The room is made from 30 cm-thick mass concrete as a wall. Vaultroom will stiffen some part of structure. Eccentricity of center of mass and center of rotation will then occur. This will emerge torsion effect when dynamic excitation is applied to the building. Friction damper will placed between vaultroom and vaultroom plate. Seismic responses of structure are expected to be reduced by using this friction damper."

"Untuk meningkatkan keandalan sistem tenaga listrik dengan tenaga mikrohidro, salah satu caranya yaitu memparalelkan generator induksi dengan generator sinkron. Dalam beroperasi sendiri, generator induksi tidak mampu mempertahankan frekuensi dan tegangannya, sehingga belum dapat dilakukan operasi paralel. Dengan menggunakan kompensator statis, tegangan terminal generator induksi lebih cepat stabil pada nilai 1 pu selama 0,3 detik dan frekuensi kerja dijaga stabil dalam rentang 49,6 ? 50,6 Hz. Selain itu, nilai eror tegangan dan frekuensi generator induksi berkurang dari 10,63% menjadi 3,48% dan 13,9% menjadi 0,01%. Kondisi saat operasi paralel yaitu, perbedaan sudut fasa tegangan dari generator sinkron dan generator induksi sebesar 0,71°, tegangan antar fasa dan frekuensi kerja masing-masing generator berada dalam range 0,9 ? 1,1 pu dan 49 ? 51 Hz, serta urutan fasa yang sama. Dari kondisi tersebut, operasi paralel generator sinkron dan generator induksi dengan menggunakan kompensator statis dapat dicapai dan masih dalam standar yang ditetapkan.

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To improve the reliability of micro hydro power systems, one way is to parallel induction generator and synchronous generator. When induction generator stands alone, it can?t maintain the frequency and terminal voltage, so that parallel operation can?t be performed. By using static compensator, terminal voltage of induction generator is stable at value of 1 pu after 0.3 seconds and operating frequency is maintained in the range 49.6 to 50.6 Hz. In addition, error value of voltage and frequency of the induction generator is reduced from 10.63% to 3.48% and 13.9% to 0.01%. The terms of parallel operation are, voltage phase angle difference of synchronous generators and induction generators is 0.71 °, voltage magnitude and operating frequency of each generator is in the range of 0,9 ? 1,1 pu and 49 - 51 Hz, and the same phase sequence. From these conditions, parallel operation of synchronous generators and induction generators using a static compensator can be achieved and still within the set standards."

"Pembangkit Listrik Tenaga Mikro Hidro (PLTMH) merupakan salah satu topik yang menarik untuk dilakukan terutama di Indonesia. Dalam skripsi ini akan dibahas mengenai analisa kestabilan sistem pengendalian tegangan eksitasi pada PLTMH. Pengendalian tegangan eksitasi pada sistem ini dapat dilakukan dengan cara mengendalikan Mesin Sinkron Magnet Permanen (PMSM) dengan algoritma tertentu sehingga tegangan pada DC-link sistem dapat terkendali. Tanpa mengetahui spesifikasi dari parameter sistem yang tepat, maka kemungkinan besar akan terjadi ketidakstabilan. Oleh karena itu pada kesempatan ini akan dilakukan permodelan, simulasi, serta analisa kestabilan sistem secara matematis sehingga bisa didapat spesifikasi parameter agar sistem tetap stabil.

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Micro Hydro Power Plant is one of the interesting topic to be researched especially in Indonesia. This final project will be discussing about the stability analysis on control system of excitation voltage on Micro Hydro Power Plant. The control of this voltage can be achieved by controlling the Permanent Magnet Synchronous Machine (PMSM) with particular algorithm so the voltage on DC-link part of the system can be controlled. Without knowing the exact specification of system parameters, the system will be most likely unstable. Therefore, on this occasion the system stability will be modelled, simulated, and mathematically analyzed so the parameter specification for the stable system can be obtained."

"This book discusses the problem of electromagnetic wave excitation in spatial regions with spherical boundaries and the accurate mathematical modeling based on numerical and analytical methods to significantly reduce the time required for developing new antenna devices. It particularly focuses on elements and systems on mobile objects of complex shape that are made of new technological materials. The experimental development of such devices and systems is an extremely time-consuming, lengthy, and expensive process. The book is intended for senior and postgraduate students and researchers working in the fields of radiophysics, radio engineering and antenna design. The authors assume that readers understand the basics of vector and tensor analysis, as well as the general theory of electrodynamics. The original results presented can be directly used in the development of spherical antennas and antenna systems for the mobile objects."