Framework for Speech Enhancement and Recognition

Framework for Speech Enhancement and Recognition A Generalized Framework for Speech Enhancement and Recognition with Special Focus On Patients with Speech Disorders Literature Review Kumara Sharma et.al. have proposed Harmonics-to-Noise Ratio and Critical-Band Energy Spectrum of speech as Acoustic Indicators of Laryngeal and Voice Pathology [8]. Acoustic analysis of speech signals is a noninvasive technique that has been proved to be an effective tool for the objective support of vocal and voice disease screening. In the present study acoustic analysis of sustained vowels is considered. A simple k-means nearest neighbor classifier is designed to test the efficacy of a harmonics-to-noise ratio (HNR) measure and the critical-band energy spectrum of the voiced speech signal as tools for the detection of laryngeal pathologies [12]. It groups the given voice signal sample into pathologic and normal. The voiced speech signal is decomposed into harmonic and noise components using an iterative signal extrapolation algorithm. The HNRs at four different frequency bands are estimated and used as features. Voiced speech is also filtered with 21 critical-band pass filters tha t mimic the human auditory neurons. Normalized energies of these filter outputs are used as another set of features. The HNR and the critical-band energy spectrum can be used to correlate laryngeal pathology and voice alteration, using previously classified voice samples. This method could be an additional acoustic indicator that supplements the clinical diagnostic features for voice evaluation [42]. Cepstral-based estimation is used to provide a baseline estimate of the noise level in the logarithmic spectrum for voiced speech. A theoretical description of Cepstral processing of voiced speech containing aspiration noise, together with supporting empirical data, is provided in order to illustrate the nature of the noise baseline estimation process. Taking the Fourier transform of the liftered (filtered in the Cepstral domain) cepstrum produces a noise baseline estimate. It is shown that Fourier transforming the low-pass liftered cepstrum is comparable to applying a moving average (MA) filter to the logarithmic spectrum and hence the baseline receives contributions from the glottal source excited vocal tract and the noise excited vocal tract[43]. Because the estimation process resembles the action of a MA filter, the resulting noise baseline is determined by the harmonic resolution as determined by the temporal analysis window length and the glottal source spectral tilt. On select ing an appropriate temporal analysis window length the estimated baseline is shown to lie halfway between the glottal excited vocal tract and the noise excited vocal tract. This information is employed in a new harmonics-to-noise (HNR) estimation technique, which is shown to provide accurate HNR estimates when tested on synthetically generated voice signals. HNR is defined as the ratio between the energy of the periodic component to the energy of the aperiodic component in the signal. As such it is sensitive to all forms of waveform aperiodicity [8],[12]. It only specifically reflects a signal to aspiration noise ratio when other aperiodicities in the signal are comparatively low. Validation of a HNR method requires testing the technique against synthesis data with a priori knowledge of the HNR. Time-domain methods that require individual period detection for HNR estimation can be problematic because of the difficulty in estimating the period markers for pathological voiced speech. Frequency domain methods encounter the problem of estimating noise at harmonic locations .Cepstral techniques have been introduced to supply noise estimates at all frequency locations in the spectrum (the Cepstral processing removes the harmonics from the spectrum).It is shown that the cepstrum-based noise baseline estimation process is comparable to applying a moving average MA filter to the power spectrum and hence the baseline receives contributions from the glottal source excited vocal tract and the noise excited vocal tract. Two important issues need to be considered with respect to HNR estimation for sustained vowel phonation when inferring glottal noise levels: HNR is a global indicator of voice periodicity.HNR is indirectly related to the noise level of the glottal source .HNR provides a g lobal estimate of signal periodicity. Hence a low value of HNR can arise from any form of aperiodicity, for example, from aspiration noise, jitter, shimmer, nonstationarity of the vocal tract, or other waveform anomalies [43]. Daryush Mehta has discussed about Aspiration Noise during Phonation: Synthesis, Analysis, and Pitch-Scale Modification. The current study investigates the synthesis and analysis of aspiration noise in synthesized and spoken vowels. Based on the linear source-filter model of speech production, author has implemented a vowel synthesizer in which the aspiration noise source is temporally modulated by the periodic source waveform. Modulations in the noise source waveform and their synchronism with the periodic source are shown to be salient for natural-sounding vowel synthesis. The accurate estimation of the aspiration noise component that contains energy across the frequency spectrum and temporal characteristics due to modulations in the noise source was a challenging task for the author. Spectral harmonic/noise component analysis of spoken vowels shows evidence of noise modulations with peaks in the estimated noise source component synchronous with both the open phase of the periodic s ource and with time instants of glottal closure [39]. Due to natural modulations in the aspiration noise source, author has developed an alternate approach to the speech signal processing with the aim of accurate pitch-scale modification. The proposed strategy takes a dual processing approach, in which the periodic and noise components of the speech signal are separately analyzed, modified, and re-synthesized. The periodic component is modified using our implementation of time-domain pitch-synchronous overlap-add, and the noise component is handled by modifying characteristics of its source waveform. Author has modeled an inherent coupling between the original periodic and aspiration noise sources; the modification algorithm is designed to preserve the synchronism between temporal modulations of the two sources [44]. The reconstructed modified signal is perceived to be natural-sounding and generally reduces artifacts. Arpit Mathur et.al. have discussed about the significance of parametric spectral ratio methods in detection and recognit ion of whispered speech [45]. Other References Kaladhar developed confusion matrix which is a matrix for a two-class classifier, contains information about actual and predicted classifications done by a classification system. The accuracy obtained by training the probabilistic neural network using Parkinson disease dataset got 100% as positives, predictions that an instance is positive, using WEKA 3 and Matlab v7. The data explored in this research was obtained from the Oxford Parkinsons Disease Detection Dataset. Data mining is the process of extracting patterns from data. Data mining is an important tool to transform this data into information. Authors present results with accuracy obtained by training the probabilistic neural network using the above dataset [46]. Xiao Li et.al. proposed a technique to reduce the likelihood computation in ASR systems that use continuous density HMMs. Based on the nature of dynamic features and the numerical properties of Gaussian mixture distributions, the observation likelihood computation is approximated to achieve a speedup. Although the technique does not show appreciable benefit in an isolated word task, it yields significant improvements in continuous speech recognition. For example, 50% of the computation can be saved on the TIMIT database with only a negligible degradation in system performance [47]. Authors analyze the case with only static features and their deltas and focus on achieving computational saving by partially computing the observation probability in a Gaussian component. It ignores computing the dynamic-feature part of an observation vector when its static-feature part already falls in the tail of a Gaussian. This technique doesnt require a complicated training procedure and brings almost no overhead to the decoding process. It is effective on both isolated word and connected word speech tasks, but works especially well on connected word recognition with high-dimensional dynamic features [47]. Elisabeth Ahlsà ©n has discussed different types of communication disorders. In case of Global aphasia there is nil or almost no linguistic communication. In case of Broca’s aphasia there is slow, effortful speech, telegram style, word finding problems known as anomia, relatively good comprehension. In case of Wernicke’s aphasia there is fluent verbose speech, w ord finding difficulties known as anomia, substitutions of words and sounds, impaired comprehension. In case of Anomic aphasia there are only word finding problems [49]. Kristen Jacobson explains about auditory and language processing disorders as follows. There are three general levels that speech sounds travel through while we are â€Å"listening†. The first level refers to the reception of sounds that occurs within our ears. A person who is diagnosed with a hearing impairment has difficulties perceiving sounds at this level. This problem is not referred to as a processing disorder. Central auditory processing disorders (CAPD) refer to difficulties discriminating, identifying and retaining sounds after the ears have heard the sounds. Individuals who experience difficulties attaching meaning to sound groups that form words, sentences and stories are often diagnosed with language processing disorders. They may also experience similar difficulties processing and organizing language for meaning during reading. Similar sounding words are often confused and some individuals may experience sensitivity to specific sounds. Reduced recognition of stre ss patterns and word boundaries within sentences is often present, especially during rapid speech or listening without visual cues. At times, only parts of messages are received accurately, so that messages and directions often appear incomplete. Specific language processing deficits are often reflected in delayed responses, the need to rehearse statements, and/or the need for frequent reviews while learning new information [50]. There are various types of speech disorders in children described as follows. Articulation: There is difficulty in the production of individual or sequenced sounds. The speakers exhibit substitutions, omissions, additions, and distortions of syllables or words. The Motor or Neurogenic speech disorders result into speech difficulties and affect the planning, coordination, timing, and execution of speech movements. Apraxia of speech is neurogenic motor speech disorder affecting the planning of speech. There is difficulty with the voluntary, purposeful movement of speech .The causes are stroke, tumor, head injury, and developmental disorders. The speakers can produce individual sounds but cannot produce them in longer words or sentences. Voice disorders affect pitch, duration, intensity, resonance, and vocal quality parameters. Fluency disorders produce interruptions in the flow of speaking. It is also known as stuttering. It means frequent repetition and/or prolongation of words or sounds [51]. Treatment of children with Speech Oral Placement Disorders (OPD)s needs various types of speech oral placement therapy (OPT) .Children with speech OPDs may have typical or a typical oral structures. The key to the definition of OPD lies in the child’s ability or inability to imitate auditory-visual stimuli and follow verbal oral placement instructions. Children with OPD cannot imitate targeted speech sounds using auditory and visual stimuli .They also cannot follow specific instructions to produce targeted speech sounds [52]. Thomas Dubuisson et.al. described an analysis system aiming at discriminating between normal and pathological voices. Based on the normal and pathological samples included the MEEI database, it has been found that using two features (spectral decrease and first spectral tristimuli in the Bark scale). Music Information Retrieval (MIR) aims at extracting information from music in order to build classification system of music. Temporal Domain features are Energy, mean, standard deviation. Spectral features are spectral Delta, Spectral Mean Value, Spectral Standard Deviation, Spectral Center of Gravity known as spectral centroid, Spectral Moments. The first four moments of the power spectrum M1, M2, M3, M4 . M3 is used to compute the skewness defining the orientation of the PSD around its first moment. If it is positive, the PSD is more oriented to the right and to the left if is negative. The skewness is computed as Skewness = M3/(M2)3/2 . The fourth moment is used to compute the kurtos is defining the acuity of the PSD around its first moment. A Gaussian distribution is having a kurtosis equal to 3, a distribution with a higher kurtosis is more acute than a Gaussian one while a distribution with a lower kurtosis is more flat than a Gaussian distribution. The kurtosis is computed as Kurtosis = M4/(M2)2. The Soft Phonation Index is defined for the (0–1000 Hz) and (0–8000 Hz) frequency bands [54]. Behnaz Ghoraani et.al. proposed a novel methodology for automatic pattern classification of pathological voices. The main contribution of this paper is extraction of meaningful and unique features using Adaptive time-frequency distribution (TFD) and nonnegative matrix factorization (NMF). The proposed method extracts meaningful and unique features from the joint TFD of the speech, and automatically identifies and measures the abnormality of the signal. The proposed method is applied on the Massachusetts Eye and Ear Infirmary (MEEI) voice disorders database. As a matter of fact from the TFD of abnormal speech it is evident that there are more transients in the abnormal signals, and the formants in pathological speech are more spread and are less structured [55]. Corinne Fredouille et.al. have addressed voice disorder assessment. The goal of this methodology is to bring a better understanding of acoustic phenomena related to dysphonia. The automatic system was validated on dysphonic corpus (80) female voices. These observations led to a manual analysis of unvoiced plosives, which highlighted a lengthening of VOT according to the dysphonia severity validated by a preliminary statistical analysis. The feature vectors issued from this analysis, at a 10 millisecond rate, are finally normalized to fit a 0-mean and 1-variance distribution. The LFSC/MFSC computation is done by using the (GPL) SPRO toolkit. Finally, the feature vectors can be augmented by adding dynamic information representing the way these vectors vary in time. Here, first and second derivatives of static coefficients are considered (also named Δ and ΔΔ coefficients) resulting in 72 coefficients [56]. Younggwan Kim et.al. discussed the role of the statistical model-based voice activity detector (SMVAD) to detect speech regions from input signals using the statistical models of noise and noisy speech. The LRT-based decision rule may cause detection errors because of statistical properties of noise and speech signals[57]. Wiqas Ghai et.al. described automatic speech recognition system as comprised of modules Speech Signal acquisition ,Feature extraction, using MFCC is done . Acoustic Modeling is done for expected phonetics of the hypothesis word/sentence. For generating mapping between the basic speech units such as phones, tri-phones syllables, a rigorous training is carried. During training, a pattern representative for the features of a class using one or more patterns corresponding to speech sounds of the same class. Language Lexical Modeling is done with the help of Text Corpus, Pronunciation Dictionary and Language Model [59]. Lucas Leon Oller presents analysis of voice signals for the Harmonics-to-Noise crossover frequency .The harmonics-to-noise ratio (HNR) has been used to assess the behavior of the vocal fold closure. The objective is to find a particular harmonics-to-noise crossover frequency (HNF) where the harmonic components of the voice drop below the noise floor, and use it as an indicator of the vocal fold insufficiency. . As the range used for the calculation of the cepstrum approaches the lowest octaves, the growth of the rahmonics should accelerate at some point, the range is going to contain harmonics that are above the noise floor level, and then the energy of the rahmonics will start to faster. That point would be the harmonics-to-noise crossover frequency [60]. Daryl Ning has developed an Isolated Word Recognition System in MATLAB. A robust speech-recognition system combines accuracy of identification with the ability to filter out noise and adapt to other acoustic conditions, such as the speaker’s speech rate and accent. It requires detailed knowledge of signal processing and statistical modeling [61]. Phonetic Concepts Daniel Jurafsky et.al. presented a case study of Star trek where robots converse with humans in natural Dialogue system with language conversational agents. Various components that make up modern conversational agents, including language input and language output dialogue ,automatic speech recognition, natural language understanding ,response planning , speech synthesis systems and the goal of machine translation which leads to automatic translation of a document from one language to another is explained here [62]. Steven Pruett describes speech as the motor act of communicating by articulating verbal expression and Language as the knowledge of a symbol system used for interpersonal communication. Mary Planchart has explained four domains of language namely Phonology, Grammar , Morphology ,Syntax , and Pragmatics [63], [64]. Eric J. Hunter has presented a case study of a 5 year old healthy male child. He has analyzed comparison of the child’s fundamental frequencies in structured elicited vocalizations versus unstructured natural vocalizations. The child also wore a National Center for Voice and Speech voice dosimeter, a device that collects voice data over the course of an entire day, during all activities for 34 hours over 4 days. It was observed that the child’s long-term F0 distribution is not normal. If this distribution is consistent in long-term, unstructured natural vocalization patterns of children, statistical mean would not be a valid measure. Author has suggested mode and median as two parameters which convey more accurate information about typical F0 usage [65].

Alien And Sedition Acts :: essays research papers

ALIEN AND SEDITION ACTS   Ã‚  Ã‚  Ã‚  Ã‚  In 1798, when Congress passed both the Alien and Sedition Acts, it was very much constitutional. These acts were definitely in the best interest of America. America was a significantly young nation, at the time, and could not afford to create problems caused by foreigners coming to America. They did not have enough national power to sustain order if everyone was attacking the newly created laws, and many of those rebels being citizens from foreign countries, nevertheless.   Ã‚  Ã‚  Ã‚  Ã‚  These acts were, of no questions asked, surly constitutional. The Federalist Party presented these acts, later consequently passed by Congress, because they were and fair and just laws in accordance to the nation at that time. For the sake of argument, the nation and government was very inexperienced, and did not know what to expect in their near future. John Adams became the second president of the United States of America, subsequently, having to accept many challenges and responsibilities to fulfill the job in office. He had the task of making sure that the newly founded nation kept running smooth. That is a big burden if there are activities going on in the country that one has no control, nor knowledge of (i.e. foreigners coming into the nation and starting trouble by disrupting the form of government, or having radicals trying to protest and perturb the running government in office-Federalists, at this time). John Adams was smart enough to realize the signif icance of these factors. Thus, taking his duty of President of USA seriously, he, along with the Federalist-controlled Congress, took action to protect the new country. Hence, were the creation and passing of the four, debate-causing laws (Naturalization, Alien, Alien Enemies, and Sedition Acts).   Ã‚  Ã‚  Ã‚  Ã‚  These all made sense to be in effect for the time and date because many of the immigrants coming to the USA were Irish exiles (for plotting against British rule), British radicals, and French people (wanting to rebel against Adams). On these grounds, and many more, President Adams and the Federalist-controlled Congress had reason to believe that they had to protect their country from stirring troubles. In view of that, the government was permitted to the authority of deporting or imprisoning any foreigner that he saw fit. This is a very sensible power that the president ought to have had back then, given the particular situation. They also were entitled to enforce such laws to protect against from just any, unintelligent foreigners from intruding in their country to vote and such for legally binding decisions of the nation.

Stress in the life of young people today Essay

Stress can sometimes be good but if it lasts for a long time it can have negative effects on us, like lack of concentration, tiredness and headaches. The sources of stress are different for everyone but among young people, there are still some main causes that affect almost everyone. To begin with, one of the main sources of stress among adolescents is school. Not only homework, tests and exams cause stress but also the pressure of being successful and comparing themselves to other people make them feel insecure. In addition, parents can put a lot of pressure on their kids so they would get better grades. As a result, children may feel that however hard they try, they are still not good enough. Therefore, I believe it is important to take a break every once in a while and have fun (e.g. read, go to cinema, spend time with friends). Furthermore, thinking about future causes a lot of anxiety for youngsters. Most people want to be successful and have a bright future ahead of them so they are constantly worrying about how to make their dreams come true. I’ve come to the conclusion that everything will eventually work out, wether I worry or not. It is important to stay positive and do things today. To sum up, stress is an inseparable part of our lives and we need to learn how to cope with it. It is essential to relax and maintain a positive attitude. Stress can sometimes be good but if it lasts for a long time it can have negative effects on us, like lack of concentration, tiredness and headaches. The sources of stress are different for everyone but among young people, there are still some main causes that affect almost everyone. To begin with, one of the main sources of stress among adolescents is school. Not only homework, tests and exams cause stress but also the pressure of being successful and comparing themselves to other people make them feel insecure. In addition, parents can put a lot of pressure on their kids so they would get better grades. As a result, children may feel that however hard they try, they are still not good enough. Therefore, I believe it is important to take a break every once in a while and have fun (e.g. read, go to cinema, spend time with friends). Furthermore, thinking about future causes a lot of anxiety for youngsters. Most people want to be successful and have a bright future ahead of them so they are constantly worrying about how to make their dreams come true. I’ve come to the conclusion that everything will eventually work out, wether I  worry or not. It is important to stay positive and do things today. To sum up, stress is an inseparable part of our lives and we need to learn how to cope with it. It is essential to relax and maintain a positive attitude. Stress can sometimes be good but if it lasts for a long time it can have negative effects on us, like lack of concentration, tiredness and headaches. The sources of stress are different for everyone but among young people, there are still some main causes that affect almost everyone. To begin with, one of the main sources of stress among adolescents is school. Not only homework, tests and exams cause stress but also the pressure of being successful and comparing themselves to other people make them feel insecure. In addition, parents can put a lot of pressure on their kids so they would get better grades. As a result, children may feel that however hard they try, they are still not good enough. Therefore, I believe it is important to take a break every once in a while and have fun (e.g. read, go to cinema, spend time with friends). Furthermore, thinking about future causes a lot of anxiety for youngsters. Most people want to be successful and have a bright future ahead of them so they are constantly worrying about how to make their dreams come true. I’ve come to the conclusion that everything will eventually work out, wether I worry or not. It is important to stay positive and do things today. To sum up, stress is an inseparable part of our lives and we need to learn how to cope with it. It is essential to relax and maintain a positive attitude. Stress can sometimes be good but if it lasts for a long time it can have negative effects on us, like lack of concentration, tiredness and headaches. The sources of stress are different for everyone but among young people, there are still some main causes that affect almost everyone. To begin with, one of the main sources of stress among adolescents is school. Not only homework, tests and exams cause stress but also the pressure of being successful and comparing themselves to other people make them feel insecure. In addition, parents can put a lot of pressure on their kids so they would get better grades. As a result, children may feel that however hard they try, they are still no t good enough. Therefore, I believe it is important to take a break every once in a while and have fun (e.g. read, go to cinema, spend time with friends). Furthermore, thinking about future causes a lot of anxiety for youngsters. Most people want to be successful and have a bright future ahead of them so  they are constantly worrying about how to make their dreams come true. I’ve come to the conclusion that everything will eventually work out, wether I worry or not. It is important to stay positive and do things today. To sum up, stress is an inseparable part of our lives and we need to learn how to cope with it. It is essential to relax and maintain a positive attitude. Stress can sometimes be good but if it lasts for a long time it can have negative effects on us, like lack of concentration, tiredness and headaches. The sources of stress are different for everyone but among young people, there are still some main causes that affect almost everyone. To begin with, one of the main sources of stress among adolescents is school. Not only homework, tests and exams cause stress but also the pressure of being successful and comparing themselves to other people make them feel insecure. In addition, parents can put a lot of pressure on their kids so they would get better grades. As a result, children may feel that however hard they try, they are still not good enough. Therefore, I believe it is important to take a break every once in a while and have fun (e.g. read, go to cinema, spend time with friends). Furthermore, thinking about future causes a lot of anxiety for youngsters. Most people want to be successful and have a bright future ahead of them so they are constantly worrying about how to make their dreams come true. I’ve come to the conclusion that everything will eventually work out, wether I worry or not. It is important to stay positive and do things today. To sum up, stress is an inseparable part of our lives and we ne ed to learn how to cope with it. It is essential to relax and maintain a positive attitude.

Irish Immigrants essays

Irish Immigrants essays The Irish first arrived in Canada nearly 400 years ago, and to this day they have almost been fully integrated into our Canadian society. Years ago, they tended to move to large American cities, however they also moved to Canada and spread into the Canadian countryside. They have made a significant influence on the history of this country and they have very much became a part of the Canadian identity today. The Irish first came to Canada due to dire economic conditions in their homelands, and due to the lack of jobs. Some also came because of poverty, and others because the British wanted to get ride of Irish troublemakers who rebelled against the British rule in Ireland. The first Irishman settled in Canada near Newfoundland in 1622. Later that century, the Irish began to settle in Newfoundland in larger numbers. Most of them came on English fishing vessels, however they planned on returning in a few years. Most stayed and established Canada as they new home. By the 1830s, Newfoundland, Nova Scotia, New Brunswick, Prince Edward Island and Upper and Lower Canada contained significant Irish populations. Though the Atlantic Provinces have strong links to Ireland, the strongest Irish-Canadian connections are in Quebec, where 40 per cent of the population are of Irish ancestry. Canadas port of entry was Quebec City and many immigrants settled in the area. They were able to bridge the cu ltural gaps between the French majority, whose religion they shared, and the English minority, whose language they spoke. The Great Famine struck Ireland in the 1840s and this drove approximately two million people out of Ireland, hundreds of thousands of them to British North America. However most of the Irish preferred America, and thousands left by the 1860s. Most of Canadas Irish communities were established before the famine. Unfortunately most of the Irish who came during the famine did not survive because thou ...

Cam Profile Essays

Cam Profile Essays Cam Profile Paper Cam Profile Paper {text:bookmark-start} {draw:frame} TERMPAPER of PRODUCTION TECHNOLOGY SUBMITTED By- Name- Gurpreet Singh Class- Mech. Diploma {B-Tech 6yrs} Section- Rj0708 Roll No. Rj0708x30 Reg. No. 4180070122 INRIDUCTION {text:bookmark-start} A Simple Experiment: What is a Cam? {text:bookmark-end} {draw:frame} Simple Cam experiment Take a pencil and a book to do an experiment as shown above. Make the book an inclined plane and use the pencil as a slider (use your hand as a guide). When you move the book smoothly upward, what happens to the pencil? It will be pushed up along the guide. By this method, you have transformed one motion into another motion by a very simple device. This is the basic idea of a cam. By rotating the cams in the figure below, the bars will have either translational or oscillatory motion. Task Basic Principle Graphical Layout of Cam Profiles Simulation Task The task is too determining the exact shape of the cam. Surface required to dwliver a specified follower motion, we assume here that the reqired motion has been completely determine,,,, graphically as well as analytically. We will only address the case of plate cams. Basic principle In constructing the cam profile, we employ the principle of kinematic inversion, imagining the cam to be stationary and allowing the follower to rotate apposite to the direction of cam rotation. Talking the cam with knife-edge follower for example, the locus generated by the trace point as the follower moves relative to the cam is identical to cam surface. By this way cam surface can be figured out. GRAPHICAL LAYOUT OF CAM PROFILE For the case of reciprocating knife-edge follower {draw:frame} As shown in figure the displacement diagram of follower is given s=s. onstruct the plate cam profile. For the case of reciprocating knife-edge follower {draw:frame} Step 1; divide the displacement-diagram abscissa into a number of segments. Step 2:- divide the prime circle into corresponding segments. Step 3:- transfer distances, by means of dividers, from the displacement diagram directly onto the Cam layout to locate the corresponding positions of the trace point. For the case of reciprocating knife-edge follower {draw:frame} Step 4:- draw the smooth curve through these points. The curve is just the required cam profile. For the case of reciprocating offset roller follower {draw:frame} As shown in figure, the displacement diagram of the follower is given S=S. For the case of reciprocating offset roller follower Construct the plate cam profile. {draw:frame} Step 1:- construct the prime circle with radius ro. step 2 ;- construct the offset circle with radius equal to the amount of offset e. For the case of reciprocating offset roller follower {draw:frame} Step 3:- Divide the displacement-diagram abscissa into a number of segments. Srep4: Divide the offset circle into corresponding segments and assign station number to the boundaries of these segments. Step 5:- Construct lines tangent to the offset circle from these station, dividing the prime circle into corresponding segments Step 6:- Transfer distances, by mean of dividers, from the displacement diagram directoly onto the cam layout to locate the corresponding positions of the trace point, always measuring outward from the prime circle. For the reciprocating flat-face follower {draw:frame} As shown in figure, the displacement diagram of the follower is given, S=S. Construct the plate cam profile Step 1; Divide the displacement-diagram abscissa into a number of segments. Step 2:- Divide the prime circle into corresponding segments. Step 3:- Transfer distances from the from the displacements diagram directly onto the cam layout. Step 4:- Construct a line representing the flat face of the follower in each position. Step 5:- construct a smooth curve tangent to all follower positions. This curve is required cam profile For the case of oscillating follower As shown in figure, the displacement diagram of the follower, radious of prime circle, and follower length are given. draw:frame} Construct the plate cam profile Step 1:- Divide the displacement-diagram abscissa into a number of segment. Seep 2:- Draw a circle about camshaft center O with radius OA. Step 3:- Divide the circle and give the station number correspond to the displacement diagram. {draw:frame} Step 4; Draw arcs about each of these centers, all with equal radial corresponding to the l ength of follower. Step 5:- Calculate the angular displacement at each station traveled by the follower. Step 6; Measure outward along the arc from the prime circle to locate trace point at each Station. draw:frame} Step 7:- construct a smooth curve through these points. The curve is just the required cam profile. For the case of reciprocating offset roller follower As shown in figure, the displacement diagram of the follower is given. S=S. The offset distances e, radius of prime r, are also known. Formulate the equation of plate cam profile. {draw:frame} Step 1:- Equation prime curve circle, offset circle, and the initial position of the follower. Draw prime circle, offset circle, and the initial position of the follower. Define the Cartesian coordinate system O-xy. Rotate the follower backward arbitrary angle around the camshaft center O. {draw:frame} Determine the coordinate (x,y) of trace point B. The synthesis results can be validated by simulation. Here is an example. The simulation is done with software ADAMS/VIEW. Example : Design a plate cam profile, as shown in below. {draw:frame} Knowing: the cam profile rotates with constant angular velocity in clockwise. The radius prome circle ro=30mm. the knife-edge follower rises with uniform motion, and the lift is 50mm during which the rotates 180’. Then the follower dwells during which the cam rotates 60’. With cam rotating 120’ to complete the work cycle, the follower returns to its initial position with paraboric motion. {draw:frame} Follower displacement: Solid dark line- actual displacement Dash linegiven displacement {draw:frame} Simulation shows that the error b/w the actual follower displacement and given follower displacement varies, but the maximum absolute error is 0. 3747mm. The error is brought by step lenth of programming and simulation and is accepatable. Therefore the the synthesis result is proved to be correct.

The Main Development of e Marketing and its Effect on Tourism Essay

The Main Development of e Marketing and its Effect on Tourism - Essay Example This essay will seek to address some of the major developments of e marketing and their effects on tourism. Additionally, it will also look at the major issues related to technology and innovation as well as their impacts on global tourism. Understanding and managing technological change and innovation To begin with, the recent advances and developments in connectivity and power processing facilitated by Information Communication Technology are undeniable. It is also agreeable and true that the expansion of broadband is part of the greatest challenges of the 21st century, which, once the world overcomes it, will witness the end of the ‘plague of distance’ that exists globally. Simultaneously, the ‘smart world’ in which are living in whose landscape albeit experiencing a permanent process of evolution is offering clearer, becoming friendlier, and presenting solutions that serve in reducing money and time and opening new paths towards the personalization of pr oducts and services. At this point, it is understandable that, in this world, in spite of its tones of inequalities offers an immense space to increase travel, because many barriers that once prevented or slowed global travel are gradually declining (Alipour, 2011:1). As of today, combination of technology and price comparison is increasingly shaping the activities of tourism. Experts are developing new applications for mobiles that offer a wide range of opportunities, social networks are consolidating themselves within a more transparent market where citizens are in a position to develop and provide services together, and changes in the concept of the value chain are producing new business models. In other words, change is becoming more constant and obvious, just as the opportunities that it is creating and presenting. However, technological advancements are presenting a challenge for the tourism industry. It is therefore vital understand the main trends that are influencing supply and demand, to know what is managing the change in the external environment while evolving at the same rate (McMaster, Kato, and Khan, 2005:12). Moreover, it is congruent to converse with the improved capacity for tourism organizations to respond via policies that can better integrate diverse interests, taking into account the whole range of potential of a destination. Business analysts recognize the internet as a widely and extremely valuable tool of marketing. This is because; the internet gives substantial merits over traditional methods of communication. The offers increased customer involvement in controlling transactions, increases the speed of transferring and retrieving information, and reduces the costs involved in communication. The internet is offering the tourism industry a greater flexibility of using the marketing mix (Kim, 2004:5). As such, it increases internal and external communications as well as facilitates market research. Tourism industry depends highly on int ernet in intensifying and improving customer services, product development, market penetration, cost saving via reengineering, product delivering, and in direct marketing. The use of internet transformed the tourism indus

In-house production Article Example | Topics and Well Written Essays - 2000 words

In-house production - Article Example Globalization is both a cause and a result of the modern information revolution. It is driven by dramatic improvements in telecommunications, incredible increases in computing power, and the development of information networks, such as the Internet. These technologies are helping to overcome the barriers of physical distance. With what results' According to its proponents, globalization can be a whirlwind of trade and investment that builds economies and spurs development in even the world's poorest countries. For example, during the 1990's alone, foreign investors have poured one'trillion dollars into developing economies. This phenomenal increase in international investment has made the building of roads, airports, and factories possible in poorer nations. Globalization has indeed been a force that has raised living standards for some across the world. Peter Sutherland, chairman of the Overseas Development Council, says that "until recently, it took at least two generations for living standards to double, but in China, living standards now double every 10 years" (as quoted by Bendor-Samuel, 24). Globalization is perceived as bringing unprecedented opportunities to billions of people. The staggering expansion of world trade has induced a wave of productivity and efficiency and has created new'jobs. Its critics,Its critics, however, counter that globalization can also bring down economies overnight. A few clicks of a computer mouse can devalue a national currency very quickly, washing away the life savings of millions of breadwinners. Ominous words from the mouth of an influential Wall Street analyst can instantly cause a herd of panicked investors to sell their stocks in Asia, creating a huge capital vacuum that could eventually drive millions into poverty. A board of directors can decide to close a plant in Mexico and open up one in Thailand instead-creating jobs in Asia while condemning hundreds of families in Latin America to destitution. Certainly, as governments from different countries try to get into the bandwagon of globalization, outsourcing has been the main focus of many government officials when it comes to the shift of industrial culture that their own countries have to take. However, outsourcing has not been so much of an accepted agreement for everyone, especially for the local workers in the United States. What are the reasons behind this' What really is outsourcing and how does this economic strategy affect the whole working force of the business industries' The Truth behind Outsourcing Strategies Universally, globalization has placed great pressure on working people as governments force down wages and labor standards in an attempt to attract foreign investment with the promise of low costs. While some newly industrialized countries have profited from increased exports as a result of freer global trade, poorer nations have been largely excluded from the feast. Along with this, the economic enthusiasts saw the possibilities of using the low-cost options of taking the skills of other poorer countries in becoming a part of the work force of their growing economies. It all seemed so practical at first; however, some considerations placed some pressures on the matter. True, the skills of the third world communities are