When a reliability experiment is used, practitioners can understand better what lifetimes to expect of a product under different operating conditions and what factors are important to designing reliability into a product. Reliability experiments, however, can be very challenging to analyze because often the reliability or lifetime data tend to follow distinctly non-normal distributions and the experiments typically involve censoring. Time and cost constraints may also lead to reliability experiments with experimental protocols that are not completely randomized. In many industrial experiments, for example, the split-plot structure arises when the randomization of the experimental runs is restricted. Additionally, for many reliability experiments, it is often cost effective to apply a treatment combination to a stand with multiple units on it as opposed to each unit individually, which introduces subsampling. The analysis of lifetime data assuming a completely randomized design has been well studied, but until recently analysis methodologies for more complex experimental designs with multiple error terms have not been a focus of the reliability field. This dissertation provides two analysis methods for analyzing right-censored Weibull distributed lifetime data from a split-plot experiment with subsampling. We evaluate the proposed methods through a simulation study. Companies also routinely perform life tests on their products to ensure that products meet requirements. Each of these life tests typically involves testing several units simultaneously with interest in the times to failure. Again, the fact that lifetime data tend to be nonnormally distributed and censored make the development of a control charting procedure more demanding. In this dissertation, one-sided lower and upper likelihood ratio based cumulative sum (CUSUM) control charting procedures are developed for right-censored Weibull lifetime data to monitor changes in the scale parameter, also known as the characteristic life, for a fixed value of the Weibull shape parameter. Because a decrease in the characteristic life indicates a decrease in the mean lifetime of a product, a one-sided lower CUSUM chart is the main focus. We illustrate the development and implementation of the chart and evaluate the properties through a simulation study. / Ph. D.

Proton exchange membrane fuel cells typically consist of stacks of membrane electrode assemblies sandwiched between bipolar plates, effectively combining the individual cells in series to achieve the desired voltage levels. Elastomeric gaskets are commonly used between each cell to insure that the reactant gases are isolated; any failure of a fuel cell gasket can cause the reactants to mix, which may lead to failure of the fuel cell. An investigation of the durability of these fuel cell seals was performed by using accelerated characterization methods. A hydrocarbon sealant was tested in five different environments to simulate fuel cell conditions. Viscoelastic properties of these seals were analyzed using momentary and relaxation compressive stress tests. Material properties such as secant modulus at 100% strain, tensile strength, and strain at failure were determined using dog-bone samples aged at several different imposed strains and aging times in environments of interest. Tearing energy was evaluated using trouser test samples tested under different rates and temperatures after various environmental aging conditions. Additionally, tearing tests were conducted on samples tested in liquid environment. A viscoelastic and mechanical property characterization of these elastomeric seals under accelerated aging conditions could help understand the behavior and predict durability in the presence of mechanical and environmental loading. Additionally, the effects of confinement have been evaluated for a bonded joint with varying thickness along the bonded direction. The Dreaming project is a glass art project in Fredrick, MD which incorporates such a varying thickness joint where thermal expansion of the adhesive has caused the glass adherend to break and debonding of the sealant. To examine this joint design, finite element analysis has been used to determine the effects of thermal expansion on such a complex geometry. Nine different test geometries have been evaluated to determine the effect of confinement coupled with thermal expansion on joint design with an elastomeric adhesive. Once evaluated, design changes were performed to try to reduce the loading while maintaining the general joint design. Results of this analysis can be used to determine the effects of confinement on a complex elastomeric joint. / Master of Science

No / In the past, marketing researchers have proposed the use of simple net present value analyses to assess customer lifetime values (CLVs). However, simple net present values disregard two important aspects: (1) environmental risks affecting customer cash flows and (2) a firm's flexibility in reacting to these risks. Consequently, they are inappropriate for assessing CLVs in relationships, in which risks affect customer cash flows and suppliers are able to react. This paper suggests a typology of CLV models in accordance with the degree of environmental risk and the supplier's flexibility. The paper thus contributes to a more differentiated customer lifetime valuation and, consequently, to a more accurate basis for decision making in relationships. The use of real options analysis is recommended for relationships which are affected by environmental risks and in which suppliers are flexible. By applying real options analysis to customer lifetime valuation, the paper offers a new methodological approach, thus merging financial valuation methods with key marketing concepts.

No / In rehydroxylation (RHX) dating, the activation energy of the rehydroxylation reaction is required first in the estimate of a material's effective lifetime temperature (ELT), and second to correct the RHX rate constant obtained at a given measurement temperature to that at the ELT. Measurement of the activation energy is thus integral to the RHX methodology. In this paper, we report a temperature-step method for the measurement of activation energy and develop fully the underlying theoretical basis. In contrast to obtaining the activation energy from a series of separate experiments (each of which requires the sample to be dehydroxylated prior to measuring the RHX rate constant), the temperature-step method not only requires a single dehydroxylation at 500°C but also eliminates repeated acquisition of Stage I data, which are not required for dating purposes. Since the first temperature step is set to correspond to the temperature at which a dating determination is carried out, the measurement of rate constants at higher temperatures simply becomes an extension of dating. Consequently, the logistics of obtaining the activation energy of rehydroxylation are greatly simplified.

在以往探討非財務性績效指標與財務績效指標關係的相關文獻中，大多以品質、顧客滿意度、瑕疵率及準時送達率為主，甚少討論顧客生命週期時間（customer lifetime）。本研究主要探索顧客生命週期時間與顧客獲利力的關係、顧客生命週期時間的影響因素與多重通路的相關議題。 本文以一家大型電視購物業的公司為個案，64,632名顧客30個月的交易資料為樣本，實證結果發現：（一） 顧客生命週期時間與顧客獲利力的關係為正向關係。（二）顧客的交易金額與顧客生命週期時間呈正向關係；平均間隔購買時間、自有品牌與耐久財對顧客生命週期時間的關係為反向關係；退貨次數與顧客生命週期時間是U字形關係。（三）自電視購物通路所取得的顧客，未來的顧客生命週期時間會較短，但自型錄通路所取得的顧客則會較長；來自電視通路的顧客利潤顯著高於其它通路。（四）使用多重通路的顧客其顧客生命週期時間顯著高於單一通路的使用者，但顧客利潤則顯著低於單一通路的使用者。 / Non-financial measures have been widely advocated and adopted, such as quality, customer satisfaction, defective rate, and on-time delivery rate. However, empirical research has little focus on customer lifetime. This study explores (1) the relationship between customer lifetime and customer profitability; (2) the determinants of customer lifetime; (3) the impact of multi-channel shopping on customer profitability and customer lifetime. Using 64,632 customers level data (30 months) from a large TV Shopping company, this study finds: (1) the relationship between customer lifetime and customer profitability is positive; (2) customer transaction amount is positively related to customer lifetime duration; average interpurchase time, private brand, and durable goods are negatively related to customer lifetime duration; the relationship between customer’s return frequency and customer lifetime is U shape; (3) the customer lifetime duration of TV channel customers is shorter than that of other channel customers, but the customer profitability of TV channel customers is larger than that of other channel customers; (4) the customer lifetime duration of multi-channel customers is longer than that of single channel shoppers, but the customer profitability of multi-channel customers is less than that of single channel customers.

Atomic parity violation measurements provide a way to probe physics beyond the Standard Model. They can provide constraints on conjectures of a massive Z′ bosonor a light boson, or searches of dark energy. Using the two-pathway coherent control technique, our group plans to make a new measurement of the weak interaction induced parity non-conservation (PNC) transition moment (<i>E_PNC</i>) on the cesium 6S→7S transition. We will coherently interfere a 2-photon transition with the Stark and PNC transitions to amplify and extract the PNC amplitude. Previously, our lab has measured the magnetic dipole transition moment on the same 6S→7S transition to about 0.4% uncertainty using this technique. In this dissertation, I discuss improvements made to the system, and review what future upgrades are needed for a new<i> E</i>_{<i>PNC </i>}measurement. Key systematics are also described. For an accurate determination of <i>E_PNC</i>, properties of cesium such as the scalar (<i>α</i>) and vector (<i>β</i>) transition polarizabilities are needed. I present improved determinations of keyelectric dipole matrix elements, and calculate new high precision determinations of <i>α</i> and <i>β</i>. Finally, using <i>β</i> and the previously measured value of <i>E_PNC/β</i>, I calculate new values for the weak charge of the cesium nucleus Q_w.<br>

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17581号 / 工博第3740号 / 新制||工||1570(附属図書館) / 30347 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 木本 恒暢, 教授 藤田 静雄, 准教授 浅野 卓 / 学位規則第4条第1項該当

Cette thèse est consacrée à l’optimisation des sources de lumière synchrotron. La dynamique de faisceau non linéaire de l'anneau de stockage du synchrotron SOLEIL est optimisée à l’aide d’algorithmes génétiques multiobjectifs (MOGA-ELEGANT). Le code ELEGANT est d’abord comparé avec le code étalon de SOLEIL, TRACY3. Le code MOGA est ensuite utilisé pour obtenir les meilleures configurations possible en termes d’ouvertures dynamiques et d’acceptances en énergie, qui sont fortement en rapport avec la durée de vie Touschek et l'efficacité d'injection respecti-vement. Après 1 mois de calcul sur le cluster de calcul de haute performance de SOLEIL en utilisant 200 CPU, un ensemble de solutions est trouvé. Elles sont testées expérimentalement dans la salle de contrôle du SOLEIL. L'amélioration de la durée de vie Touschek obtenue est confirmée par les mesures : la durée de vie du faisceau de l'anneau de stockage de SOLEIL est accrue de 50 à 60%. La deuxième partie de ce travail de thèse présente une étude expérimentale de la durée de vie du faisceau de l'anneau de stockage de SOLEIL. En particulier les contributions de la durée de vie Touschek et la durée de vie de gaz sont étudiées. La durée de vie du faisceau est mesurée en fonction de paramètres importants tels que le couplage, racleurs horizontaux et verticaux, et le courant. Les résultats expérimentaux sont comparés avec les durées de vie Touschek calculées par la formule Piwinski mise en œuvre dans le code TRACY3 et la durée de vie du gaz calculée analytiquement. Cette étude permet de montrer que la composition du gaz résiduel et la pression locale varient de manière importante le long de toute la machine: l’effet des ondulateurs sous-vide est dominant. Des nombres atomiques effectifs sont obtenus. La forme des courbes expérimentales est proche des courbes simulées et est compatible avec un nombre atomique effectif proche de 7. / This thesis is dedicated to the optimization of the nonlinear beam dynamics of synchrotron radiation light sources using Multi-objective Genetic Algorithms (MOGA-ELEGANT). In the first part the ELEGANT code is benchmarked against TRACY3; then MOGA is tuned and used to find the best settings of quadrupole and sextupole magnets in order to maximize the dynamic and momentum apertures, strongly related with the Touschek lifetime and the injection efficiency respectively. Solutions obtained after one month of computation in the high level computational cluster of SOLEIL using 200 CPUs are analyzed. The improvement of the Touschek lifetime obtained with MOGA is confirmed by the beam-based experiments. The beam lifetime of the SOLEIL storage ring is increased 50-60 % .The second part this PhD work is devoted to study experimentally the beam lifetime of the SOLEIL storage ring to improve the understanding of the beam lifetime and its contributions: the Touschek and gas lifetimes. The beam lifetime is measured in function of important parameters as coupling, horizontal and vertical scrapers, and bunch current. The experimental results are compared with the simulated ones. The Piwinski formula is implemented in the tracking code TRACY3 to replace Bruck approximation. The gas lifetimes were computed using analytical models. This study allows understanding that the composition of the residual gas and the local pressure along all the machine vary significantly between the arcs and the in-vacuum insertion devices: new effective atomic number are obtained. This type of measurement remains difficult to analyze without a large error margin; in-vacuum insertions have a dominant contribution. The shape of the experimental curves is closed to the expected ones and compatible with an effective atomic number of about 7.

Polymer brushes, consisting of densely end-tethered polymers to a surface, can exhibit rapid and sharp conformational transitions due to specific stimuli, which offer intriguing possibilities for surface-based sensing of the stimuli. The key toward unlocking these possibilities is the development of methods to readily transduce signals from polymer conformational changes. Herein, we report on single-fluorophore integrated ultrathin (<40 nm) polymer brush surfaces that exhibit changing fluorescence properties based on polymer conformation. The basis of our methods is the change in occupied volume as the polymer brush undergoes a collapse transition, which enhances the effective concentration and aggregation of the integrated fluorophores, leading to a self-quenching of the fluorophores’ fluorescence and thereby reduced fluorescence lifetimes. By using fluorescence lifetime imaging microscopy, we reveal spatial details on polymer brush conformational transitions across complex interfaces, including at the air–water–solid interface and at the interface of immiscible liquids that solvate the surface. Furthermore, our method identifies the swelling of polymer brushes from outside of a direct droplet (i.e., the polymer phase with vapor above), which is controlled by humidity. These solvation-sensitive surfaces offer a strong potential for surface-based sensing of stimuli-induced phase transitions of polymer brushes with spatially resolved output in high resolution.

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