• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1356
  • 457
  • 203
  • 190
  • 170
  • 120
  • 102
  • 97
  • 94
  • 55
  • 32
  • 23
  • 14
  • 12
  • 10
  • Tagged with
  • 3376
  • 338
  • 243
  • 214
  • 213
  • 203
  • 178
  • 173
  • 162
  • 151
  • 146
  • 137
  • 136
  • 135
  • 125
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Comparison of Managerial Model with the Concepts of Innovation and traditions: Micro-Cell Technology Co.

Lin, Chien-cheng 20 August 2009 (has links)
It is a ring of the whole business activity that enterprise manages. The mode of managing, the method of managing and the efficiency of managing all are enough to influence the surviving and developing of the enterprise. Many influence the whole commercial ecology too. All emphasize the important method bringing forth new ideas to bring forth new ideas mostly on the documents which manages the tactics. But, in the managing actually of the enterprise, and, what is the different between the tradition and innovate? How to operate the manage model of the tradition and innovate? What the influences for the achievement result which enterprise manage? The person who manages enterprises is for real operation, how to choice and apply the tradition model and innovate model? This report is the investigation that the different for the tradition and innovate. Also supply the simple and easy method to analyze for the people who manage enterprises. Make the enterprise able to adjust the mode that the enterprises manage according to different situation. This report use the angle that industry analysed to collect all kinds of reports about industry analysed and KFS and core ability. Build the analysis model of enterprises manages. And, use this model to prove the real case. Finally, the best method developed between the tradition and innovation.
72

Cenozoic Extensional Tectonics Revealed Through Seismic Reflection Imaging, SE Arizona

Wagner, Frank Henry January 2005 (has links)
The Basin and Range province of western North America is a broad region of irregular topographic expression characterized by various styles of Cenozoic extension. Recent reprocessing and interpretation of a regional suite of industry seismic reflection profiles in southern Arizona, in the southern Basin and Range province of southwestern North America, have illuminated subsurface features related to Cenozoic crustal extension and show a detailed view of extensional processes in the southern Basin and Range. Seismic stratigraphic investigations on these profiles suggest a two-phase model for the evolution of the Catalina-Rincon metamorphic core complex, with an initial stage of isostatic core complex emplacement during detachment faulting that resulted in little topographic expression. This was followed, after a significant tectonic hiatus, by late-stage exhumation and flexural uplift of the metamorphic core complex controlled by younger high-angle faulting. Along-strike, upper-plate deformation in response to core complex emplacement was accommodated by the Santa Rita fault, south of the Catalina-Rincon metamorphic core complex. Finite-element models predicts early mechanical failure of the upper-plate of the detachment system to the south of the Catalina core complex. These models suggest that the Santa Rita fault is the result of a perturbation in the regional stress field caused by the Catalina detachment and the associated brittle failure of the upper plate from the extreme crustal extension associated with core-complex emplacement. These profiles, coupled with geologic and well control, indicate that the southwest-dipping Catalina detachment, the northwest-dipping Santa Rita fault, the east dipping Altar Valley fault, and the highly dissected Sierrita Mountains are all aspects of the same extensional event in the middle-Tertiary. These features all appear to merge into a broad zone of middle-crustal deformation and likely represent heterogeneous upper-crustal deformation in response to middle-to-lower crustal homogeneous deformation.
73

Matrix Acidizing Parallel Core Flooding Apparatus

Ghosh, Vivek 16 December 2013 (has links)
Matrix acidizing is a well stimulation procedure where acid is injected down the wellbore or coil tubing and into the reservoir near the wellbore region. Wellbore damage is a common issue in the oil field. The primary goal of matrix acidizing in carbonate reservoirs is to bypass wellbore damage by creating highly conductive channels that go several feet into the formation, known as wormholes. The goal of laboratory experiments is to find an optimum injection rate to create dominant wormholes and provide this information to the field. To conduct various experiments, core flooding setups are created. The setup consists of a core holder, accumulator, overburden pump, injection pump, accumulator, pressure sensors, and a back pressure regulator. Results from matrix acidizing core flooding in laboratory conditions provide an understand for wormhole growth, acid diversion, injection rates, and adds a variety of liquid chemicals for testing at reservoir pressures and temperatures. The first objective was to design, assemble, and test a matrix acidizing parallel core flooding apparatus. The apparatus was rated for 5,000 psi and 250 ºF. Combinations of the various mechanical components were chosen appropriately to meet the requirements. Electrical wiring and data acquisition hardware was assembled. LabVIEW software code was written for controlling temperature and recording data. The second objective was to create a documented method for conducting experiments.
74

In-situ stress magnitude and core disking

Lim, Seong Sik Unknown Date
No description available.
75

Photoelastic stress analysis of the end of a borehole.

Talapatra, Dipak Chandra. January 1968 (has links)
No description available.
76

Trainability of Core Stiffness: Studies of Core Training Methods on Naive and Savvy Populations

Lee, Benjamin January 2014 (has links)
Core exercise is a staple of many physical training regimens with goals ranging from improving athletic performance to rehabilitation of spine and knee injuries. Traditionally, dynamic movements such as flexion, lateral bending and twisting core exercise maneuvers are used in training programs; an approach consistent with training the distal limbs where muscular effort is mostly devoted to creating motion. However, knowledge of the functional anatomy of core musculature and spine injury mechanisms questions the use of these types of exercises. Alternative core exercises make use of isometric postures and static bracing to create muscular activation while minimizing spine loads and injury mechanisms linked with movement. This study aims to quantify the effect of various core training programs on the change of passive and active stiffness properties of the torso. This study was driven by several curiosities: 1) Isometric core exercises are reported to help some people who have low back pain. Is there a short lasting ???enhanced stiffness??? after performing these exercises? 2) Core training regimens use Isometric and Dynamic core exercises to enhance core bracing properties. Is one method superior to the other in terms of enhancing core stiffness? 3) If adaptations to core stiffness can be achieved with core exercise, do these adaptations differ between beginners and trained individuals? Twenty four healthy male subjects (22.9 ?? 2.7 years, 1.79 ?? 0.06 m, 77.5 ?? 10.8 kg) were recruited for short and long term core training. Of the overall population, twelve subjects (21.7 ?? 1.89 years, 1.80 ?? 0.076 m, 78.3 ?? 12.3 kg) were University students with little to no experience in performing regular core exercise. The other twelve subjects (24.2 ?? 2.89 years, 1.79 ?? 0.047 m, 76.8 ?? 9.71 kg) were athletically trained with at least one year of experience performing regular core exercise (minimum three times per week). This study was a repeated measures design examining short and long term core stiffness (active and passive) and range of motion before and after a single fifteen minute bout of isometric core exercise and a six week core training program. The long term training groups were divided evenly into isometric, dynamic and control groups. The Isometric group received a six week training program consisting of core bracing exercises ranging from basic static bodyweight exercises to weighted exercises with additional challenge of distal limb mobility while maintaining a braced core, while dynamic group exercises consisted of movement and speed based core exercises. The Control group received no further training during this period. All subjects were asked to refrain from any extra core demands not given by the researchers. After the training period was complete all subjects were retested for stiffness and range of motion. Passive stiffness tests were performed using a frictionless bending apparatus for flexion, extension, left and right lateral bend and left and right axial twist directions. Active stiffness was assessed via a ???quick release??? mechanism, preloaded with a 16 kg mass and randomly released to assess active extension. Participants were instrumented with unilateral electromyography (EMG) of selected core musculature and electromagnetic signals for motion capture for lumbar kinematics. To determine if training had an effect on dependent variables a series of repeated measures ANOVAs were performed; short term training utilized a 2x2 Repeated Measures ANOVA using the pre/post condition and training experience (na??ve vs. savvy) as factors. Long term training utilized a 3x2x2 Repeated Measures ANOVA using training group (Isometric vs. Dynamic vs. Control), training experience (na??ve vs. savvy) and pre/post condition as factors. In general, short term isometric core training increased core stiffness in all directions for na??ve and savvy subjects. Comparisons between these two subject groups did not yield any significant differences. After long term training stiffness was increased the greatest in the Isometric training group with both na??ve and savvy subjects. Dynamic training yielded significant increases in stiffness but for only one direction in each subject group (right lateral bend in na??ve subjects and left axial twist in savvy subjects). The Control group did not show any significant changes in stiffness. Comparisons between training groups and training experience did not yield any significant differences. Isometric training lead to significant stiffness increases in all test except for passive and active extension in na??ve subjects, and similar results were found for savvy subjects except for right lateral bend not showing any significant changes. Researchers believe reasons for insignificant changes are related to high variances which may be due to inadequate statistical power and a wide variety of responses within each subject group. Though some analyses showed inadequate statistical power due to small sample sizes it should be noted that this research is the first of its kind investigating the trainability of core stiffness in the short and long term, and thus difficult to establish sample sizes without any baseline values. The findings of this study can be directly applied to core training for rehabilitation and athletic function. Enhancements in core stiffness are thought to subsequently enhance traits such as load bearing ability, pain management and athletic function. The results of short term training give insight into how a short training session performed prior to a load bearing task can make the task safer and easier to perform. The results of long term training show that Isometric training performed over a long duration may induce more permanent enhancements to stiffness and core function.
77

The influence of topography upon rotating magnetoconvection

Coffey, Paul Anthony January 1996 (has links)
Aspects of thermal convection in the Earth's fluid core in the presence of a strong azimuthal magnetic field may be understood by considering a horizontal plane layer, rotating about the vertical z axis, with gravity acting downwards and containing an applied magnetic field aligned in the y (azimuthal) direction. Since the OMB is not smooth, the effects of adding bumps (with axes perpendicular to the applied magnetic field) to the top boundary of the layer are investigated in the magnetogeostrophic limit. The arbitrary geostrophic flow that arises under this limit is evaluated using a modified Taylor constraint. The bumps distort the isotherms so that they are not aligned with equipotential surfaces, leading to an imperfect configuration. This means that a hydrostatic balance is not possible, and motion ensues. This motion takes the form of a steady transverse convection roll, with axis parallel to the bumps. The roll exists for all values of the Rayleigh number, except that value for which the corresponding homogeneous problem in the standard plane layer has a solution. The roll obeys Taylor's constraint, and has no associated geostrophic flow. The stability of this roll to perturbation by oblique rolls (which are preferred for 0(1) values of the Elsasser number) is considered. It is found that the most unstable linear mode consists of a pair of these oblique rolls, aligned so that no geostrophic flow is accelerated by their interaction with the basic state. Hence, the stability results obtained here are identical to those found by perturbing the hydrostatic conduction solution with oblique rolls in the standard layer. Finally, the nonlinear evolution through the Ekman regime of these linear instabilities is considered. It is found that the nonlinear convection behaves similarly to mean field dynamo models which incorporate a geostrophic nonlinearity. Various types of Ekman solution are found, and evolution to Taylor states is observed.
78

Experimental Investigation for the Effect of the Core Length on the Optimum Acid Flux in Carbonate Acidizing

Dong, Kai 2012 August 1900 (has links)
Matrix acidizing is commonly used to stimulate wells in carbonate reservoirs. Large amounts of lab tests indicate an optimum acid interstitial velocity (Vi-opt, injection rate over flow area and porosity) exists, which results in the minimum volume of acid required for wormhole propagation and best stimulation results. Previous tests showed that the Vi-opt increased with increasing core length, but it is not clear if the Vi-opt can be independent of the core length when the core length reaches a certain value. In this work, a series of core flood experiments with different core lengths was carried out to determine the Vi-opt. Results showed that the Vi-opt became a constant when the core length reached a certain length. The finding of this study can guide lab researchers to use proper core lengths when determining the Vi-opt.
79

Metadata for user-centred, inclusive access to digital resources: realising the theory of AccessForAll accessibility

Nevile, Elizabeth, liddy@sunriseresearch.org January 2010 (has links)
To be inclusive, the Web needs published resources to be matched to individual users' needs and preferences for their perception and control. In a decade, this has not been achieved and many cannot make use of resources despite having appropriate facilities. This thesis argues that the necessary management of resources can be achieved with well-designed metadata. Demonstration and explanation of the accessibility problems, efforts to solve them and the current state of inaccessibility of Web resources, any resource that is available through the World Wide Web, is fundamental to the research. The author relies heavily on Dublin Core metadata as it is relatively easy to use; is probably the most populous metadata; can be managed with free software systems, and for commercial reasons. The research investigated what makes DC metadata, so apparently simple, powerful enough to be the most popular metadata because there is very little available that explains this. The thesis then documents the scientific view of metadata upon which effective use of metadata can be based in the context of accessibility. It argues, at a practical level, that metadata is essential and integral to any shift to an on-going process approach to accessibility. It contributes to the science of metadata in as much as it analyses, synthesizes, and articulates the characteristics of an essential infrastructure for a new approach to accessibility. The author argues in favour of an on-going process approach to accessibility of resources that supports continuous improvement of any given resource, not necessarily by the author of the resource, and not necessarily by design or with knowledge of the original author, by contributors who may be distributed globally. The thesis argues that the current dependence on production guidelines and post-production evaluation of resources as either universally accessible or otherwise, does not adequately provide for either the accessibility necessary for individuals or the continuous or evolutionary approach possible within the current Web environment. It argues that a distributed, social-networking view of the Web as interactive, combined with a social model of disability, given the management tools of machine-readable, interoperable AccessForAll metadata, as developed, can achieve the desired goals. It raises issues regarding its implementation in the distributed environment of the Web. Please note: The thesis is archived in a format that is not accessible to all and for this reason, the author may be contacted for alternative versions (liddy@sunriseresearch.org; liddy.nevile@gmail.com).
80

The Influence of Human Resource Management Practices on the Retention of Core Employees of Australian Organisations: An Empirical Study

Janet.Chew@cbs.curtin.edu.au, Janet Cheng Lian Chew January 2004 (has links)
Employee retention is one of the challenges facing many business organisations today. For many organisations, strategic staffing has become a concern because the ability to hold on to highly talented core employees can be crucial to future survival. This empirical study examined the current human resource management (HRM) practices of Australian organisations in the retention of their core employees. In particular, the research identified the core elements of HRM practices, which strongly influence the decision for core employees to stay. The study comprise three phases: (1) a preliminary investigation, utilising the Delphi Technique to obtain the opinions of an expert panel of thirteen, (2) in-depth interviews, involving twelve human resource managers of Australian organisations and (3) a quantitative survey of 800 employees from nine Australian organisations. The findings revealed greater insights into the HRM-retention relationship and provided empirical validation of the relationship. More specifically, the research identified eight retention factors that influence the decision of core employees to stay. These specific factors consisted of two bundles of practices: HR factors (e.g., person organisational fit, remuneration, reward and recognition, training and career development, challenging job opportunities) and Organisational factors (e.g., leadership behaviour, company culture and policies, teamwork relationship and satisfactory work environment). The outcome of the HRM-retention relationship was examined through organisational commitment and turnover intention using multiple regression analysis. The findings of this study revealed positive significant co-relationships between the eight factors and organisational commitment. Moreover, it was highlighted that commitment acted as a partial mediator of remuneration, recognition and reward, training and career development and work environment on intent to stay. Commitment fully mediated the relationship person organisational fit, teamwork relationship, culture and policies and intention to stay. The study produced a model suitable for use by human resource practitioners as a guide in determining what initiatives an organisation should adopt to retain their critical employees. This research has also made a contribution by illuminating the current employment relationships in Australian organisations and providing relevant empirical evidence to support the theoretical model of Human Resource Architecture, developed by Lepak and Snell (1999) and, as a result, creating a configuration for an Australian Human Resource Architecture model.

Page generated in 0.0371 seconds