The Weibull distribution is a popular and widely used distribution in reliability and in lifetime data analysis. Since 1958, the Weibull distribution has been modified by many researchers to allow for non-monotonic hazard functions. Many modifications of the Weibull distribution have achieved the above purpose. On the other hand, the number of parameters has increased, the forms of the survival and hazard functions have become more complicated and the estimation problems have risen. This thesis provides an extensive review of some discrete and continuous versions of the modifications of the Weibull distribution, which could serve as an important reference and encourage further modifications of the Weibull distribution. Four different modifications of the Weibull distribution are proposed to address some of the above problems using different techniques. First model, with five parameters, is constructed by considering a two-component serial system with one component following a Weibull distribution and another following a modified Weibull distribution. A new method has been proposed to reduce the number of parameters of the new modified Weibull distribution from five to three parameters to simplify the distribution and address the estimation problems. The reduced version has the same desirable properties of the original distribution in spite of having two less parameters. It can be an alternative distribution for all modifications of the Weibull distribution with bathtub shaped hazard rate functions. To deal with unimodal shaped hazard rates, the third model with four parameters, named as the exponentiated reduced modified Weibull distribution is introduced. This model is flexible, has a nice physical interpretation and has the ability to capture monotonically increasing, unimodal and bathtub shaped hazard rates. It is a generalization of the reduced modified Weibull distribution. The proposed distribution gives the best fit comparing to other modifications of the Weibull distribution including those having similar properties. A three-parameter discrete distribution is introduced based on the reduced distribution. It is one of only three discrete distributions allowing for bathtub shaped hazard rate functions. Four real data sets have applied to this distribution. The new distribution is shown to outperform at least three other models including the ones allowing for bathtub shaped hazard rate functions. The new models show flexibility and can be used to model different kinds of real data sets better than other modified versions of Weibull distribution including those having the same number of parameters. The mathematical properties and statistical inferences of the new models are studied. Based on a simulation study the performances of the MLEs of each model are assessed with respect to sample size n. We find no evidence that the generalized modified Weibull distribution can provide a better fit than the exponentiated Weibull distributionfor data sets exhibiting the modified unimodal hazard function.

A review of the literature revealed that various scholars on the subject of customer relationship management hold divergent views on the exact domain of CRM because of its multi-faceted nature. Furthermore, CRM remains vague in terms of its impact on firm performance because the generative mechanisms have not been fully considered. In response, a theoretical framework of CRM as the underpinning foundation which establishes the linkages between CRM and the firm's performance is proposed, which synthesizes different perspectives of key constructs of CRM and thus seeks to incorporate them into a practical and coherent framework that can be universally used. Therefore, the central aim of this thesis is to develop an empirically based conceptual model of the process that has the potential for crossing cultural and sectoral boundaries and highlights the potential link between CRM and the establishment of long term customer value. This thesis presents and discusses empirical findings from a survey of 226 senior managers and 584 customers in the Taiwanese banking sector who are examined from their perspectives by using structural equation modeling. From the perspective of managers, the findings largely supported the proposed hypotheses. Customer interaction and customisation, but not customer knowledge and customer knowledge management (CKM) capability, are significantly and positively related to customer value. CKM capability and customization are crucial in affecting customer satisfaction. The results also provided strong evidence of customer values' impact on customer satisfaction, which in turn is necessary determinant of customer loyalty. Furthermore, the relationship between customer loyalty and CLV is positive. Consequently, it has been found that customer benefits play significant mediating roles between CRM and firm performance. On the other hand, from the perspective of customers, the results showed that managerial perceptions of CRM practice have no relationships with the customer value and customer satisfaction as perceived by customers. This thesis contributes to academic and managerial knowledge by providing alternative insights into CRM's influences on the customer's benefits and the firm's performance from a dyadic perspective in one single model. Particularly, the inclusion of customer value and customer satisfaction constructs as key consequences of CRM is suggested to contribute additionally to provide a more complete model of a CRM-performance relationship within the banking setting. Therefore, the framework as a diagnostic tool can be used to identify where specific improvements are needed and where certain aspects of the organizational operations could be improved in CRM for pursuing their competitive advantage and long-term profit.

This study examined the customer asset management and the relationship between various constructs and firm characteristics on customer lifetime value(CLV).The relationship between marketing actions such as loyalty programs and the level of commitment and specifically the type of commitment and the type of loyalty that may be influenced by such a program were investigated.The main focus of the study was on the relationship between commitment and loyalty.Additional investigations were done on the impact that this may have on customer lifetime value.In terms of commitment,many researchers regard this as an important antecedent to customer retention but there have been conflicting or ambiguous empirical findings from various studies.In terms of loyalty ,many studies have similarly found that this concept is necessary for retention as well.This study examined the effects of the two dimensions of commitment on the two dimensions of loyalty.A survey was administered and a sample of 152 informants was analyzed using SEM with PLS-Graph 3.0 Build 1130 for inferential analysis and SPSS version 16.0 for descriptive analysis.The results show a significant relationship between affective commitment and attitudinal loyalty and behavioral loyalty and that continuance commitment is not significantly related to loyalty.In addition,the results indicate that affective commitment has a greater impact on loyalty than calculative commitment;however there was no significant relationship between attitudinal loyalty and CLV or between behavioral loyalty and CLV.

All-optical time-resolved measurement techniques provide a powerful tool for investigating critical parameters that determine the performance of infrared photodetector and emitter semiconductor materials. Narrow-bandgap InAs/GaSb type-II superlattices (T2SLs) have shown great promise as next generation materials, due to superior intrinsic properties and versatility. Unfortunately, InAs/GaSb T2SLs are plagued by parasitic Shockley-Read-Hall recombination centers that shorten the carrier lifetime and limit device performance. Ultrafast pump-probe techniques and time-resolved differential-transmission measurements are used here to demonstrate that "Ga-free" InAs/InAs₁₋xSbx T2SLs and InAsSb alloys do not have this same limitation and thus have significantly longer carrier lifetimes. Measurements of unintentionally doped MWIR and LWIR InAs/InAs₁₋xSbx T2SLs demonstrate minority carrier (MC) lifetimes of 18.4 µs and 4.5 µs at 77 K, respectively. This represents a more than two order of magnitude increase compared to the 90 ns MC lifetime measured in a comparable MWIR and LWIR InAs/GaSb T2SL. Through temperature-dependent differential-transmission measurements, the various carrier recombination processes are differentiated and the dominant recombination mechanisms identified for InAs/InAs₁₋xSbx T2SLs. These results demonstrate that these Ga-free materials are viable options over InAs/GaSb T2SLs and potentially bulk Hg₁₋xCdxTe photodetectors. In addition to carrier lifetimes, the drift and diusion of excited charge carriers through the superlattice layers (i.e. in-plane transport) directly aects the performance of photo-detectors and emitters. All-optical ultrafast techniques were successfully used for a direct measure of in-plane diffusion coeffcients in MWIR InAs/InAsSb T2SLs using a photo-generated transient grating technique at various temperatures. Ambipolar diffusion coefficients of approximately 60 cm²/s were reported for MWIR InAs/InAs₁₋xSbxT2SLs at 293 K.

Organic-inorganic hybrid perovskites (OIHPs), which are promising materials for electronic and optoelectronic applications (1-10), have made into layered organic-inorganic hybrid perovskites (LOIHPs). These LOIHPs have been applied to thin-film transistors, solar cells and tunable wavelength phosphors (11-18). It is known that devices fabricated with single crystal exhibit the superior performance, which makes the growth of large-sized single crystals critical for future device applications (19-23). However, the difficulty in growing large-sized LOIHPs single crystal with superior electrical properties limits their practical applications. Here, we report a method to grow the centimeter-scaled LOIHP single crystal of [(HOC2H4NH3)2PbI4], demonstrating the potentials in mass production. After that, we reveal anisotropic electrical and optoelectronic properties which proved the carrier propagating along inorganic framework. The carrier mobility of in-inorganic-plane (in-plane) devices shows the average value of 45 cm2 V–1 s–1 which is about 100 times greater than the record of LOIHP devices (15), showing the importance of single crystal in device application. Moreover, the LOIHP single crystals show its ultra-short carrier lifetime of 42.7 ps and photoluminescence quantum efficiency (PLQE) of 25.4 %. We expect this report to be a start of LOIHPs for advanced applications in which the anisotropic properties are needed (24-25), and meets the demand of high-speed applications and fast-response applications.

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This thesis studies the lifetime of the PE pipes materials. For determination of the lifetime one of the standard accelerated tests (Full Notch Creep test) was used. The main goal is to assess the influence of different types of detergents on lifetime. Specimen preparation and measurement procedure corresponding to the relevant ISO standard (ISO 16770: Plastics - Determination of environmental stress cracking (ESC) of Polyethylene (PE) - Full Notch Creep Test (FNCT)). Air, distilled water, Arkopal N 090 and Arkopal N 110 were used as detergents.

This thesis focuses on the study of the life of a fluorescent dye. It also examines changes in its emission spectrum determined with the aid of development of fluorescence intensity over the long term sensing in several kinds if of cella. The general part of the thesis with the issues of confocal microscopy, fluorescent radiation and maks. Furthermorer, an analysis of methods for measuring fluorescence lifetime is done. In the thesis there is elaborated a description of the program, whitch was designed for the analysis of the collected output of the used confocal microscope. Sebsequently, the results are evaluated.

This dissertation treats of the influence of PVD coats to a change of tool lifetime. The theoretical part of the dissertation describes the adjustment of tools before the process of coating. Following part describes the specific properties of deposited layers of the coating and its measuring. There is also the enumeration and specification of selected ways of depositing PVD coats and brief description of its advantages and disadvantages. Second part of the dissertation is focused on an experiment with measuring of the tool force loading and its change depending to the tool wear. There are compared four short four-edged milling cutters with a coat and as well without it. Those tools were made of high speed steel by the conventional way and also by the powder metallurgy. Milling operation was done by down and up milling technique. The evaluation of the experimental results for powder metallurgy tools confirmed that these tools are advantageous compared to the standard high speed steel tools.

<p>Accelerated life testing (ALT) is commonly used to obtain the reliability (lifetime) of a system in a short period by applying severe stress factors (i.e. temperature, humidity, chemical etc.,) to the system. Accelerated life testing was done on 2N3904 N-P-N bipolar junction transistor. After accelerated life testing, the acceleration factor is calculated through statistical analysis to predict the lifetime of a system at a certain operating condition. Multiple temperature and water immersed experiments were conducted on transistors at various temperatures. With the obtained results, analysis was done on the data to predict lifetime of transistors at different environmental conditions. Effects of the environmental conditions on the transistors were also discussed. Corrosion effects on transistors were studied. ALTA software is used to analyze the experimental data and to calculate the lifetime of the transistors. From the obtained failure data prediction of mean time to failure at various temperatures was done. </p>