Recurrence Quantification Analysis of System Signals for Detecting Tool and Chatter in Turning

In this thesis, the applications of the recurrence quantification analysis in metal cutting operation in a lathe, with specific objective to detect tool wear and chatter, are presented.This study is based on the discovery that process dynamics in a lathe is low dimensional chaotic. It implies that the machine dynamics is controllable using principles of chaos theory. This understanding is to revolutionize the feature extraction methodologies used in condition monitoring systems as conventional linear methods or models are incapable of capturing the critical and strange behaviors associated with the metal cutting process.As sensor based approaches provide an automated and cost effective way to monitor and control, an efficient feature extraction methodology based on nonlinear time series analysis is much more demanding. The task here is more complex when the information has to be deduced solely from sensor signals since traditional methods do not address the issue of how to treat noise present in real-world processes and its non-stationarity. In an effort to get over these two issues to the maximum possible, this thesis adopts the recurrence quantification analysis methodology in the study since this feature extraction technique is found to be robust against noise and stationarity in the signals.The work consists of two different sets of experiments in a lathe; set-I and set-2. The experiment, set-I, study the influence of tool wear on the RQA variables whereas the set-2 is carried out to identify the sensitive RQA variables to machine tool chatter followed by its validation in actual cutting. To obtain the bounds of the spectrum of the significant RQA variable values, in set-i, a fresh tool and a worn tool are used for cutting. The first part of the set-2 experiments uses a stepped shaft in order to create chatter at a known location. And the second part uses a conical section having a uniform taper along the axis for creating chatter to onset at some distance from the smaller end by gradually increasing the depth of cut while keeping the spindle speed and feed rate constant.The study concludes by revealing the dependence of certain RQA variables; percent determinism, percent recurrence and entropy, to tool wear and chatter unambiguously. The performances of the results establish this methodology to be viable for detection of tool wear and chatter in metal cutting operation in a lathe. The key reason is that the dynamics of the system under study have been nonlinear and the recurrence quantification analysis can characterize them adequately.This work establishes that principles and practice of machining can be considerably benefited and advanced from using nonlinear dynamics and chaos theory.

E-marketing motivators,inhibitors and critical success factors: A study of small and medium tourism enterprises (SMTES) in Mauritius and Andaman islands, India

Information and Communication Technologies (ICTs) have a dramatic impact on the tourism industry because they force this sector as a whole to rethink the way in which it organises its business . In the light of such rethinking within the tourism industry, this study has focussed on the Small and Medium Tourism Enterprises (SMTEs) in two island destinations, namely Mauritius and Andaman Islands, India.Suggestions. The findings conceming SMTEs in Mauritius and Andaman Islands have been compared to make some destination-specific inferences. The relevance of the findings has been discussed with reference to the SMTEs in the two destinations as well as the possible acceptability in other comparable settings. Suggestions have been made for further research in SMTEs’ use of the Internet for marketing function.

Disorder-induced critical phenomena in magnetically glassy Cu-Al-Mn alloys

Measurements of magnetic hysteresis loops in Cu-Al-Mn alloys of different Mn content at low temperatures are presented. The loops are smooth and continuous above a certain temperature, but exhibit a magnetization discontinuity below that temperature. Scaling analysis suggest that this system displays a disorder-induced phase transition line. Measurements allow one to determine the critical exponents ß=0.03±0.01 and ß¿=0.4±0.1, which coincide with those reported recently in a different system, thus supporting the existence of universality for disorder-induced critical points.

A critical study of major construction projects in kerala vis-a-vis effectiveness in project implementation

Chapter 1 presents a brief note on the state at which the construction industry stands at present, bringing into focus the significance of the critical study. Relevance of the study, area of investigation and objectives of the study are outlined in this chapter. The 2nd chapter presents a review of the literature on the relevant areas. In the third chapter an analysis on time and cost overrun in construction highlighting the major factors responsible for it has been done. A couple of case studies to estimate loss to the nation on account of delay in construction have been presented in the chapter. The need for an appropriate estimate and a competent contractor has been emphasised for improving effectiveness in the project implementation. Certain useful equations and thoughts have been formulated on this area in this chapter that can be followed in State PWD and other Govt. organisations. Case studies on project implementation of major projects undertaken by Government sponsored/supported organizations in Kerala have been dealt with in Chapter 4. A detailed description of the project of Kerala Legislature Complex with a critical analysis has been given in this chapter. A detailed account of the investigations carried out on the construction of International Stadium, a sports project of Greater Cochin Development Authority is included here. The project details of Cochin International Airport at Nedumbassery, its promoters and contractors are also discussed in Chapter 4. Various aspects of implementation which led the above projects successful have been discussed in chapter 5. The data collected were analysed through discussion and perceptions to arrive at certain conclusions. The emergence of front-loaded contract and its impact on economics of the project execution are dealt with in this chapter. Analysis of delays in respect of the various project narrated in chapter 3 has been done here. The root causes of the project time and overrun and its remedial measures are also enlisted in this chapter. Study of cost and time overrun of any construction project IS a part of construction management. Under the present environment of heavy investment on construction activities in India, the consequences of mismanagement many a time lead to excessive expenditure which are not be avoidable. Cost consciousness, therefore has to be keener than ever before. Optimization in investment can be achieved by improved dynamism in construction management. The successful completion of coristruction projects within the specified programme, optimizing three major attributes of the process - quality, schedule and costs - has become the most valuable and challenging task for the engineer - managers to perform. So, the various aspects of construction management such as cost control, schedule control, quality assurance, management techniques etc. have also been discussed in this fifth chapter. Chapter 6 summarises the conclusions drawn from the above criticalr1 of rhajor construction projects in Kerala.

IA Critical Study of the Impact of Institutional Finance on Agriculture in Selected Villages of Ernakulam Revenue District

Vast changes have taken place in the field of institutional rural credit in India since the nationalisation of nineteen commercial banks in 1969. The supply of institutional finance to cultivators amounted to 63.2 percent of the total credit in 1981 compared to 31.2 percent in 1971. Insti tutionalisation of agricultural credit envisaged two objectives in general. One was to emancipate cultivators and farmers from the clutches of indigenous financiers and money lenders. The second was to make farmers financially capable of adopting the new technology or improved practices in agriculture so as to increase their agricultural production and thereby contributing to the development of agriculture in India. Though vast literature on Institutional Credi t and agriculture is available, no indepth and serious work examining thoroughly the cause of credit diversion has been undertaken so far. The present study is an attempt to fill up this gap. The study will be helpful to lending insti tutions, viz. Co-ope:r-atives, Commercial banks and various other insti tutional agencies in connection with their lending activity_ Also, the study will help government in .formulating proper policies that will insure a preferential treatment in favour of the most needy category of farmers and cultivators with respect to agricultural credit disbursement

Criminal justice system in pondicherry - a comparative critical study of the past and the presen

The Union Territory of Pondicherry prior to its merger with the Indian Union was a French Colony. The erstwhile territory of Pondicherry along with its hamlets, namely, KARAIKKAL, MAHE and YANAM was administered by the French Regime. Before it was established by French in 1 6 74 A.D. it was part of Vijayanagara Empire. Prior to this, Pondicherry was a part of the Kingdom of Chola and Pallava Kings. During French Regime, the laws which were in force in France in relation to administration of civil and criminal justice were extended to the erstwhile Territory of Pondicherry. Thus while Pondicherry stood influenced by the Inquisitorial system since the beginning of the 18th century, the neighboring states forming part of the Indian Union since Independence came under the Influence of the British system, viz. accusatorial system. The territory of Pondicherry, for administrative reasons, came to be merged with the Indian Union in the early 60's. Following the merger, the Indian administration sought to extent its own laws from time to time replacing erstwhile French Laws, however, subject to certain savings. Thus the transitional period witnessed consequential changes in the administration of the territory, including the sphere of judicial system. Since I 963, the Union Territory of Pondicherry was brought under the spell of the Indian Legal System The people in Pondicherry ' thus have had the benefit of experiencing both the svstems. Their experiences will be of much help to those who undertake comparative studies in law. The plus and minus points of the respective systems help one to develop a detachment that helps independent evaluation of the svstents. The result of these studies could be relevant in revitalising our criminal systems.The present system is evaluated in the light of the past system. New dimensions are added by way' of an empirical study also.

Quantum critical effects in mean-field glassy systems

We consider the effects of quantum fluctuations in mean-field quantum spin-glass models with pairwise interactions. We examine the nature of the quantum glass transition at zero temperature in a transverse field. In models (such as the random orthogonal model) where the classical phase transition is discontinuous an analysis using the static approximation reveals that the transition becomes continuous at zero temperature.

Evidence of a critical time in constrained Kinetic Ising models

We study the relaxational dynamics of the one-spin facilitated Ising model introduced by Fredrickson and Andersen. We show the existence of a critical time which separates an initial regime in which the relaxation is exponentially fast and aging is absent from a regime in which relaxation becomes slow and aging effects are present. The presence of this fast exponential process and its associated critical time is in agreement with some recent experimental results on fragile glasses.

Critical behavior in nonequilibrium phase transitions

The nonequilibrium phase transitions occurring in a fast-ionic-conductor model and in a reaction-diffusion Ising model are studied by Monte Carlo finite-size scaling to reveal nonclassical critical behavior; our results are compared with those in related models.

Right to Maintenance Under Criminal Law - A Critical Study

Some study has been made earlier, but no attempt has ever been made to make the study comprehensive and comparative. There exists also no information as to the working of the system. Hence the work is undertaken to provide first hand knowledge of the legal institutions that had handled and now handles annually large masses of deprived and neglected population. An investigation is also necessary to know the legal and social characteristics of the jurisdiction enjoined on the court so that this will help compare the law in the statute with the law and practice. The evaluation of the working system in the changed social atmosphere is also an urgent need of the hour

Anomaly Detection Using System Call Sequence Sets.

This paper discusses our research in developing a generalized and systematic method for anomaly detection. The key ideas are to represent normal program behaviour using system call frequencies and to incorporate probabilistic techniques for classification to detect anomalies and intrusions. Using experiments on the sendmail system call data, we demonstrate that concise and accurate classifiers can be constructed to detect anomalies. An overview of the approach that we have implemented is provided.

Dose/frequency: A critical factor in the administration of glucan as immunostimulant to Indian white shrimp Fenneropenaeus indicus

The immunostimulatory effect of an alkali insoluble glucan extracted from marine yeast isolate Candida sake S165 was tested in Fenneropenaeus indicus. Post larvae (PL) of F. indicus, fed glucan incorporated diet at varying concentrations (0.05, 0.1, 0.2, 0.3, 0.4 g glucan/100 g feed) for 21 days were challenged orally with white spot syndrome virus (WSSV). Maximum survival was observed in PL fed the 0.2% glucan incorporated diet. Subsequently the feed incorporated with 0.2% glucan was fed to F. indicus post larvae at different feeding intervals, i.e. daily, once every two days, once every five days, once every seven days and once every ten days. After 40 days, the prawns were challenged orally with WSSV and post challenge survival was recorded. Shrimp feed containing 0.2% glucan when administered once every seven days gave maximum survival. This was supported by haematological data obtained from adult F. indicus, i.e. total haemocyte count, phenoloxidase activity and nitroblue tetrazolium reduction (NBT). The present observation confirms the importance of dose and frequency of administration of immunostimulants in shrimp health management

Computing median and antimedian sets in median graphs

The median (antimedian) set of a profile π = (u1, . . . , uk) of vertices of a graphG is the set of vertices x that minimize (maximize) the remoteness i d(x,ui ). Two algorithms for median graphs G of complexity O(nidim(G)) are designed, where n is the order and idim(G) the isometric dimension of G. The first algorithm computes median sets of profiles and will be in practice often faster than the other algorithm which in addition computes antimedian sets and remoteness functions and works in all partial cubes