1,727,881 research outputs found
A Command Line Tool for Generating Charged Patchy Particle Models (CPPMs)
No full textThis is a single command-line tool that generates spherical Charged Patchy Particle Models (CPPM) which mimic bio-colloidal particles, e.g. globular proteins. The tool, `cppm-generator`, generates CPPMs by placing neutral, positive, and negative particles on the surface of a sphere, and minimise the (free) energy using Metropolis-Hastings Monte Carlo sampling
Key-Assignment Strategies for CPPM
No full textCSS, the first system to protect multimedia content on the new DVD medium failed badly, because both its encryption algorithm and its key management could easily be broken. A new industry initiative, the 4C Entity, LLC (founded by IBM, Intel, Matsushita and Toshiba), presents a more mature approach, called “Copy Protection for Prerecorded Media ” (CPPM), which has already been adopted in DVD-Audio. A key-feature of CPPM is its advanced key-management, which allows for system renewability by revoking compromised devices. Renewability means that content provider can encrypt the content, such that compromised devices cannot decrypt it, whereas noncompromised devices still can. In this paper, we review the basic concepts of CPPM and propose a framework to study its cryptographic strengths based on the published specifications. We will focus our assessment especially on CPPM’s key-management scheme, which, unfortunately, is not completely specified in the official publicly available specification. As a consequence, it is currently unknown, how the 4C Entity selects the device keys that are assigned to devices. As a main contribution we propose several suitable key-assignment strategies based on finite geometric structures and study their security
Compartmental modeling of an industrial column
Get PDFThe industrial production of refined sodium bicarbonate is realized in large-scale bubble columns, called the BIR columns. Several complex phenomena exist in these columns, such as three-phase flow, gas-liquid mass transfer of CO2, and crystallization. This work deals with the development of an operational BIR column model using the compartmental modeling approach. It is fed by previous works and current studies. A parametric sensitivity analysis is realized to identify the more important modeling parameters and to point the future research that have to be performed. Some simulations results are presented for typical operating conditions of an industrial column.Available at: http://www.bepress.com/cppm/vol4/iss5/16info:eu-repo/semantics/publishe
Performance Analysis of CPPM using Simplified Coherent Receiver
No full text[[abstract]]連續性的數位化調相調變(PM)，又名為連續相位調相調變(CPPM)，是一種新穎的固定包絡調變，它與傳統上以數位調頻(FM)實現之連續相位調變(CPM)一樣具有很好的功率與頻寬效益，甚至在相同的接收機複雜度下，最小歐氏距離更勝於傳統的CPM，為了進一步簡化它的接收機設計，在本論文中，我們利用最近完成之連續相位調相調變的脈波振幅調變(PAM)分解模型[6]，研究簡化接收機的設計。
我們針對簡化後的接收機做廣泛的分析，包括誤碼率的理論值與模擬。我們以具有良好編碼增益的連續相位調相調變器為例子，將接收機的複雜度與效能做一個最佳的權衡，並且找出複雜度簡化後的接收機誤碼率之理論值。[[abstract]]Continuous-Phase Phase Modulation (CPPM) is a novel constant envelope modulation. It has excellent power and spectral efficient properties as the conventional Continuous Phase Modulation (CPM) that is usually implemented in the form of digital frequency modulation. Nevertheless, the complexity of CPM, no matter it is conventional CPM or CPPM, is much too high, as compared to the phase-shift keying. In this thesis, we employed recent results of decomposing CPPM as a combination of pulse amplitude modulation (PAM) pulses [6], the complexity of CPPM can be simplified.
Error performance of the simplified CPPM receivers using the PAM decomposition model are analyzed and simulated, trade-off between complexity and performance are discussed, and theoretical bit error performance are given
A simple spectra computing approach for continuous-phase phase modulation (CPPM)
No full textDigital Modulation TechniqueRecently, we have developed a special class of continuous-phase modulation (CPM) scheme, called the continuous-phase phase modulation (CPPM); it transmits the PAM information sequences using time-limited phase shaping pulses. In this paper, the power spectra for this novel CPM are investigated. We employ autocorrelation function approach to modify the CPM spectra computing formula for time-limited phase shaping pulse. Since CPPM is a CPM modulator with time-limited phase shaping function, previous research believed that such modulator will have data-independent spectral lines and suggested to be avoided. However, we show that the spectral lines can be diminished by choosing appropriate modulation index, modulation level and phase shaping pulse. Spectra for two classes of CPPM schemes are given. It is shown that the bandwidth of CPPM scheme can be effectively reduced by using smaller modulation index andlor increasing the correlative length and modulation level. The resultant CPPM schemes have attractive spectral occupancy as compared to conventional CPM.國際20111207~2011120
PAM Decompositions Of CPPM Signals With Separable Phase
No full text[[abstract]]連續相位調變 (Continuous Phase Modulation，CPM) 訊號具有固定的波封、頻寬效益、功率效益以及低旁波帶的特性，可適應於非線性放大器之操作。由於訊號本身具有記憶的特性，使得接收端在解調訊號時複雜性提高。因此，國外學者 Laurent[5]透過脈衝振幅調變 (Pulse Amplitude Modulation，PAM) 的方式將CPM的訊號進行分解，便於簡化接收機的複雜度。其後學者 Cariolaro[9, 10]則是利用某些CPM具有相位可分離的特性，將CPM的訊號再進行簡化。
在本篇論文中，將討論如何對同樣具有固定波封、連續相位且複雜度比CPM低，新近所架構的連續相位調相調變[1] (Continuous-Phase Phase Modulation，CPPM)訊號進行相位分解。 Yang[3]發現可對一個相位塑形脈波長度為偶數的M-ary CPPM，利用相位分離的方式，使其等效於一個M'-ary(M'>M) 與脈波長度縮小為 2 的CPPM，我們甚至可進一步將其等效於一個特殊的連續相位頻移鍵 (CPFSK) 。透過這樣的概念，我們達到降低接收機複雜度的目的。最後，我們將顯示相位分離後，發射端與接收端的結構，並用電腦模擬驗證其正確性。[[abstract]]Continuous phase modulation (Continuous Phase Modulation，CPM) signals have the properties of constant envelope, bandwidth efficiency, power efficiency and low side-lobe, which can be adaptable in the non-linear amplifires. It makes high complexity due to signal is memory when it is demodulated in receiver. Therefore, the foreign savant Laurent[5] decomposed the signal of CPM by pulse amplitude modulation (Pulse Amplitude Modulation，PAM) for the convenience of simplifing complexity of receiver. Later, savant Cariolaro[9, 10] utilized some signals of CPM which have properties of separable phase, and simplified them again.
In this thesis, we will discuss how to decompose the new structure of continuous phase phase modulation[1] (Continuous-Phase Phase Modulation，CPPM) signals which also have the properties of constant envelope, continuous phase and lower complexity than CPM. Yang[3] finds that we can shape the pulse which are even number duration of M-ary CPPM phase, with the separable phase, let them be equivalent to a CPPM which isM'-ary(M'>M) and pulse duration is 2 , even we can let them be equivalent to a special continuous phase frequency shift keying (CPFSK). With this idea, we achieve reduction in complexity of receiver. Finally, we will show the structure of transmitter and receiver which are after separating phase, and verify the truth by simulation
Launch of The AfCFTA-anchored Pharmaceutical Initiative’s Centralized Pooled Procurement Mechanism(CPPM)
No full textThe United Nations Economic Commission for Africa (ECA)’s led AfCFTA-anchored Pharmaceutical Initiative will launch the Centralized Pooled Procurement Mechanism (CPPM). The objective of the launch is to solicit buy-in from pilot countries on the proposed CPPM and its work program, time frames and expected objectives, as well as the establishment of necessary institutional arrangements for successful implementation of the mechanism. Furthermore, it will showcase health business opportunities for private sector investment contributing towards creation of jobs, cost savings and productivity gains leveraging on the AfCFTA and the Africa Medicines Agency (AMA) for sustainable and inclusive development in Africa
PAM-based receiver design for CPPM with phase-separable property
No full text[[abstract]]連續相位調變 (Continuous Phase Modulation，CPM) 訊號具有固定的包絡、頻寬效益、功率效益以及低旁波帶的特性，因此可適應於非線性放大器之操作，但是MLSE ( Maximum Likelihood Sequence Estimation ) 接收機的複雜度也相對提高。因此，於1986年，國外學者 Laurent[4]提出了一個方法，將傳統的Binary CPM訊號用一組脈衝振幅調變 ( Pulse Amplitude Modulation，PAM ) 形式表示，由於經過PAM分解的CPM訊號，訊號能量較集中於幾個脈波上，因此接收機則可選擇能量較大的脈波作為匹配濾波器( Matched Filters )之偵測，以達到簡化接收機的功效。近年來，Yang, Lee and Chern[1]提出了一個新穎的調變器，稱為連續相位調相調變( Continuous-Phase Phase Modulation，CPPM )，是將CPM訊號運用在數位PM的一種調變技術，在許多情況下，它的效能上更勝於傳統的CPM，接收機複雜度也同樣可以利用PAM的分解方式達到簡化。在本篇論文中，我們將討論如何對新式的連續相位調相調變[1] CPPM訊號進行相位分解。針對一個相位塑形脈波長度為偶數的 CPPM，利用相位分離的方式，使其等效於一個 ( ) 的完全響應( Full response )之CPM，之後再利用PAM分解的方式，達到降低接收機複雜度的目的。最後，我們將分析並顯示相位分離前與相位分離後，發射端與接收端的結構，並用電腦模擬驗證其正確性。[[abstract]]Continuous phase modulation (CPM) signals have the properties of constant envelope, bandwidth efficiency, power efficiency and fast roll-off side-lobe, which can be adaptable in the non-linear amplifiers. However, CPM with excellent spectral and power efficiency usually accompanies with large complexity in the MLSE (Maximum Likelihood Sequence Estimation) receiver. In 1986, Laurent suggested an approach to represent the binary CPM signal with a set of PAM (Pulse Amplitude Modulation) waveforms. It was also found that the energy of PAM pulses are not evenly distributed and most of the energy is concentrated in a few pulses. Therefore, one can employ the significant pulses to design PAM-based receiver such that the complexity can be reduced. Recently, Yang, Lee and Chern [1] suggest a novel modulator, called continuous-phase phase modulation (CPPM), which transmits a CPM signal in the form of digital PM. It outperforms the conventional CPM in many cases and the receiver complexity also can also be reduced by using the PAM-based receiver.In this thesis, we further reduce the number of PAM pulses using a concept called separable phase. With that concept, we found that CPPM with an LTRI shaping pulse, where L is an even number, is equivalence to an ( ) full response CPM. In this manner, it can reduce the receiver complexity significantly. The structure of the transmitter and receiver is analyzed and the performance of this novel scheme is simulated by computer
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