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  • 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.
1

Development of On-Line Inspection System on Bare Fiber Polishing Machine

Huang, Fu-Pin 13 August 2004 (has links)
For the requirements of high-speed signal transmission has been increasing. Optical communication system is the way to solve the demands. The 980-nm high-power laser modules are used for optical communication system as the power of the amplifier for long distance communication. The QPSFE is used for coupling between the high-power 980nm laser diodes and the single mode fiber. This research established an on-line inspection system to inspect the fiber endface during the polishing process which is applied on a bare fiber polishing machine. The system we developed is to detect the fiber endface for QPSFE fabrication process. In this paper, we simply use couple charge device (CCD) as a position sensor to detect the grinding situation. The system had been successfully achieved on-inspection purpose, therefore; it will be the key technique toward the automatic bare fiber polishing system.
2

Development of a Force Sensor Mechanism for the Bare Fiber Polishing Machine

Chang, Chung-heng 17 February 2005 (has links)
Because the need of high speed data transmission is increasing day by day, fiber optic communication have played an important role. However, with increasing of the data transmission distance, the loss of the power is a series problem. To solve this problem, the power of the signal must be amplified in a fixed distance to keep the signal reality. In the optic amplified system, the pump laser is always a 980nm high-power laser. Because of the high aspect ratio of this laser, the quadrangular- pyramid-shaped fiber endface(QPSFE) lensed fiber is needed in order to increase the coupling efficiency. There is no standard process to fabricate QPSFE now. The experiment method is as follow. The first procedure is to polish the flat-end fiber to become the QPSFE, then melt the fiber by electric arc, the QPSFE lensed fiber is formed finally. In the polishing step, the bare fiber polishing machine is used. But, the polished quantity is unavailable during polishing, so the yield of the well-polished fibers is poor, only 20%. In this research, the force sensing mechanism mounted in the polishing machine is proposed to measure the force between the fiber and the polish disk. By mounting the mechanism, there are several advantages, such as operating conveniently, increasing the polishing speed, and making the polished quantity available during polishing. Using this force sensing mechanism to develop a polish rule will improve the yield of the well-polished fibers. The strain gauge method is used to design the force sensing mechanism. Using this mechanism and taking the force analysis of the fiber polishing will make the force information between the fiber and the polish disk available. By design the parameters of this mechanism advisably, it will reach the expected purpose in this research. A 0.5
3

Survival and growth of three oak planting stocks on Hurricane Katrina disturbed lands

Hollis, Damon 06 August 2011 (has links)
Three types of oak planting stock were evaluated to determine their influence on survival and initial growth. Planting stocks utilized include conventional containerized seedlings with a 240 cm3 container, 1-0, bare-root seedlings, and Root Production Method (RPM™) seedlings with a 11.4 L container. Initially after outplanting and at the conclusion of the first and second growing seasons, height, groundline diameter (GLD), and survival were assessed. Study sites are located in southern Mississippi on lands disturbed by Hurricane Katrina. Species planted were swamp chestnut oak (Quercus michauxii Nutt.) and Nuttall oak (Q. texana Palmer). A total of 3,600 seedlings were planted in this study: 300 seedlings for each of the six planting stock/species combinations per site. Statistical comparisons of growth and survival among species and planting stock types were performed. RPM™ and bare-root planting stocks exhibited similar growth and survival, while the conventional container stock had significantly lower growth and survival.
4

Assessment of FLUENT CFD code as an analysis tool for SCW applications

Farah, Amjad 01 August 2012 (has links)
Chosen as one of six Generation‒IV nuclear-reactor concepts, SuperCritical Water-cooled Reactors (SCWRs) are expected to have high thermal efficiencies within the range of 45 ‒ 50% owing to the reactor‟s high pressures and outlet temperatures. The behaviour of supercritical water however, is not well understood and most of the methods available to predict the effects of the heat transfer phenomena within the pseudocritical region are based on empirical one-directional correlations which do not capture the multi-dimensional effects and do not provide accurate results in regions such as the deteriorated heat transfer regime. Computational Fluid Dynamics (CFD) is a numerical approach to model fluids in multidimensional space using the Navier-Stokes equations and databases of fluid properties to arrive at a full simulation of a fluid dynamics and heat transfer system. In this work, the CFD code, FLUENT-12, is used with associated software such as Gambit and NIST REFPROP to predict the Heat Transfer Coefficients at the wall and corresponding wall temperature profiles inside vertical bare tubes with SuperCritical Water (SCW) as the cooling medium. The numerical results are compared with experimental data and 1-D models represented by existing empirical correlations. Analysis of the individual heat-transfer regimes is conducted using an axisymmetric 2-D model of tubes of various lengths and composed of different nodes count along the heated length. Wall temperatures and heat transfer coefficients were analyzed to select the best model for each region (below, at and above the pseudocritical region). To neutralize effects of the rest of the tube on that region, smaller meshes were used were possible. Two turbulent models were used in the process: k-ε and k-ω, with many variations in the sub-model parameters such as viscous heating, thermal effects, and low-Reynolds number correction. Results of the analysis show a fit of ±10% for the wall temperatures using the SST k-ω model in the deteriorated heat transfer regime and less than ±5% for the normal heat transfer regime. The accuracy of the model is higher than any empirical correlation tested in the mentioned regimes, and provides additional information about the multidimensional effects between the bulk-fluid and wall temperatures. Despite the improved prediction capability, the numerical solutions indicate that further work is necessary. Each region has a different numerical model and the CFD code cannot cover the entire range in one comprehensive model. Additionally, some of the trends and transitions predicted are difficult to accept as representation of the true physics of SCW flow conditions. While CFD can be used to develop preliminary design solutions for SCW type reactors, a significant effort in experimental work to measure the actual phenomena is important to make further advancements in CFD based analysis of SCW fluid behaviour. / UOIT
5

Simulated vs. Actual Landsat Reflectance Spectra of Bare Soils

Chavda, Chandrapalsinh Ghanshyamsinh 06 August 2005 (has links)
Simulated Landsat reflectance spectra of soil samples were compared to actual Landsat radiance values of soils in two fields (1 and 3) near Vance, Mississippi. The simulated reflectance spectra were calculated by combining Landsat spectral sensitivity with laboratory-based spectrophotometer reflectance values. The actual radiance data were obtained by extracting pixel values from Landsat images. Simple linear regression (SLR) yielded significant linear relationships for 1997 field-1 and 2001 field-3 data. Multiple linear regression (MLR) and weighted linear regression (WLR), which indirectly accounted for moisture content and spatial resolution, respectively, yielded improvement in R2 for most of the studied bands. The analyses generally satisfied the normality and constant variance assumptions, and removal of outliers improved the validity of the assumptions and R2. It was concluded that indirect measures of soil moisture content and spatial uncertainty can substantially improve the relationship between remotely sensed bare-soil spectra and laboratory spectra.
6

Monitoring and Analysis of CPU Utilization, Disk Throughput and Latency in servers running Cassandra database : An Experimental Investigation

Chekkilla, Avinash Goud January 2017 (has links)
Context Light weight process virtualization has been used in the past e.g., Solaris zones, jails in Free BSD and Linux’s containers (LXC). But only since 2013 is there a kernel support for user namespace and process grouping control that make the use of lightweight virtualization interesting to create virtual environments comparable to virtual machines. Telecom providers have to handle the massive growth of information due to the growing number of customers and devices. Traditional databases are not designed to handle such massive data ballooning. NoSQL databases were developed for this purpose. Cassandra, with its high read and write throughputs, is a popular NoSQL database to handle this kind of data. Running the database using operating system virtualization or containerization would offer a significant performance gain when compared to that of virtual machines and also gives the benefits of migration, fast boot up and shut down times, lower latency and less use of physical resources of the servers. Objectives This thesis aims to investigate the trade-off in performance while loading a Cassandra cluster in bare-metal and containerized environments. A detailed study of the effect of loading the cluster in each individual node in terms of Latency, CPU and Disk throughput will be analyzed. Method We implement the physical model of the Cassandra cluster based on realistic and commonly used scenarios or database analysis for our experiment. We generate different load cases on the cluster for Bare-Metal and Docker and see the values of CPU utilization, Disk throughput and latency using standard tools like sar and iostat. Statistical analysis (Mean value analysis, higher moment analysis and confidence intervals) are done on measurements on specific interfaces in order to show the reliability of the results. Results Experimental results show a quantitative analysis of measurements consisting Latency, CPU and Disk throughput while running a Cassandra cluster in Bare Metal and Container Environments. A statistical analysis summarizing the performance of Cassandra cluster while running single Cassandra is surveyed. Conclusions With the detailed analysis, the resource utilization of the database was similar in both the bare-metal and container scenarios. From the results the CPU utilization for the bare-metal servers is equivalent in the case of mixed, read and write loads. The latency values inside the container are slightly higher for all the cases. The mean value analysis and higher moment analysis helps us in doing a finer analysis of the results. The confidence intervals calculated show that there is a lot of variation in the disk performance which might be due to compactions happening randomly. Further work can be done by configuring the compaction strategies, memory, read and write rates.
7

Efficient Bare Metal Backup and Restore in OpenStack Based Cloud InfrastructureDesign : Implementation and Testing of a Prototype

TADESSE, ADDISHIWOT January 2016 (has links)
No description available.
8

Cosmic Racial Holy War:Biopolitics and Bare-Life from the Creativity Movement to the War on Terror

Berry, Damon T. 10 September 2009 (has links)
No description available.
9

On the form and meaning of Chinese bare conditionals : not just "whatever"

Huang, Yahui, 1973- 10 February 2011 (has links)
The syntactic and semantic treatment of Chinese Bare Conditionals is a topic of much debate (Cheng and Huang 1996; Lin 1996; Chierchia 2000). This dissertation investigates the nature of Chinese Bare Conditionals in three aspects: quantification and modal implications as compared to English free relatives with –ever, and pronoun occurrence. With regard to quantification, I propose to treat the anteceding wh-phrase and its anaphoric element (pronoun/wh-word) uniformly as a definite description denoting a maximal plural entity similar to Jacobson (1995). This entity can be an atomic entity resulting in a singular definite reading, or an entity consisting of more than one atom deriving a universal-like reading. Concerning modal implication, I propose to capture the agent’s/speaker’s indifference reading of bare conditionals with von Fintel (2000). Indifference reading in his analysis is interpreted against a counterfactual modal base which predicts a causal link. His analysis is needed for the interpretation of Chinese bare conditionals but may not be applied directly to whatever, given that a causal link is necessarily present in a bare conditional, but not required in an English whatever-sentence. I argue that the use of a pronoun in a bare conditional is not subject to a uniqueness and existence condition as claimed in Lin (1996). Although bare conditionals typically contain two identical wh-words, they may occur naturally with a pronoun that links bare conditionals with other sentences into a piece of coherent discourse. This account bears an important implication for the study of Chinese wh-phrases and third person pronouns in being able to predict the existence of anaphoric definite wh-phrases and bound-variable pronouns in the language. It also improves on existing accounts of Chinese bare conditionals in being able to capture the details of the form and meaning of this construction. Chinese bare conditionals are structurally related to ruguo ‘if’-conditionals and Hindi left-adjoined correlatives and their meaning is similar to, and yet not quite the same as that of whatever. / text
10

Sexuella övergrepp i en kontext av mänsklig säkerhet och biopolitiskt maktutövande : En diskursanalys om inverkan av mänsklig säkerhet på sexuella övergrepp i fredsbevarande operationer

Högman, Elisa January 2017 (has links)
United Nations peacekeeping has been distinguished as a bringer of peace and stability to countries plagued by war and insecurity. However, reports since the 1990s of sexual exploitations by peacekeeping personnel have tainted these accomplishments. At the same time as these reports started to surface there was an internal development within the UN where the security discourse went from being state focused to being focused on securing the population’s security and health. This new trend was established in the United Nations Development Programme in 1994 as Human Security and laid the ground for the structure of the peacekeeping operations. This study asks the question how these exploits can occur in a discursive context where the population’s welfare and health is the reference of intervention. By examining the following representative cases: the Democratic Republic of Congo (DRC) and the Central African Republic (CAR), it can be seen how human security expresses a discursive reproduction of two different kinds of power: biopower and sovereign power. Through an analysis of the discourse in documents relating to the interventions it can be seen how these expressions of power creates a contextual environment where the sexual exploitations can take place.

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