• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 49
  • 39
  • 16
  • 11
  • 8
  • 8
  • 5
  • 2
  • 1
  • 1
  • Tagged with
  • 143
  • 143
  • 50
  • 49
  • 47
  • 32
  • 31
  • 28
  • 26
  • 23
  • 22
  • 17
  • 16
  • 16
  • 16
  • 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

Working time in Great Britain and Australia : an economic analysis

Dawkins, Peter J. January 1986 (has links)
The subject of this thesis is the economics of working time in Great Britain and Australia, with special reference to the length and timing of working hours. First, the incidence of and trends in work patterns, in Great Britain and Australia, are examined. The incidence of and trends in, normal hours, actual hours, overtime and part-time work in Britain and Australia, show a great deal of similarity. It is more difficult to compare "non-standard working hours" (hours outside of the normal spread of hours, e.g. shift work) because of problems with the data. It is clear, however, that non-standard hours of work are important in both countries.
2

A Data Analysis Software Architecture for Parallel and Distributed Computation

Brockett, D. M. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / Real-time high-volume telemetry data analysts have needs which require access to ever-increasing amounts of data, which must be processed in a seamless and coherent manner. BBN has developed a data analysis software architecture for use in distributed- and parallel-processing environments which is particularly well-suited for telemetry streams. BBN is currently using this software at two Navy sites to do realtime data analysis. The architecture provides data-source management, data-stream fusion, and data extraction all in a modular, scalable framework. Because of the scalable nature of the software, it can easily accommodate high data rates.
3

Lead time analysis from order to delivery : A study of lead time in the material flow and the information flow for the aftermarket at Siemens Industrial Turbomachinery AB

Zetterström, Filippa, Ek, Niklas January 2015 (has links)
Siemens Industrial Turbomachinery AB (SIT) is a company that produces and delivers medium sized industrial gas turbines to customers all over the world and is located in Finspång. The Service section of SIT handles the aftermarket of turbines with both planned and unplanned inspections/repairs. SIT-Service experience that their lead time to customers is too long and a yearly survey with customers confirmed this. Service strives for a higher customer service and since the company suspect that internal processes have safety time built into can time quickly build up. Service has different service lines depending on what kind of maintenance needed and if planned/unplanned. Different options in a combination with several departments involved in these big projects make the flow hard to visualize and makes it complex.This report has studied how SIT-Service can enable a lead time reduction from order to delivery where the flow for Parts was chosen to be mapped and analyzed for one of the service lines. This orientation of the study was partly based on directions from the company and partly delimitations by the writers of the report. Directions from the company were for example to investigate a standard scope and to visualize the flow by mapping it, all with a focus on lead time. Delimitations developed to exclude sales and transportations as well as to only investigate one turbine type and one service line. To be able to follow the flow was a decision made to investigate the flow for Parts.The study has mapped times and activities in the Parts flow from received purchase order (PO) from customer to when parts are ready to leave SIT Finspång. This mapping includes several departments and several transactions in the ERP-system, activities, tasks, queues and uncertainties. The mapping investigated how the lead time was built up by the system and one angle of the mapping was to investigate if the times in the system were consistent with the matching times in reality. To be able to suggest any changes in the Parts flow regarding lead time, the mapping was classified based on value-adding/non-value-adding, wastes, critical chain and bottlenecks. This was followed by a use of different principles in how to enable lead time reduction. These principles were: elimination, simplification, parallelization and a combination of critical chain and bottlenecks.The results and conclusions based on the two analysis parts have been divided into two parts where suggestions in the first one are believed to have a larger impact on the total lead time. This part consists of five big areas of time with several suggestions, from concrete to more general. One of the most important areas is that SIT needs to improve how the company uses the Planned delivery time; to standardize and to make sure that it is used in the same way by all involved which could eliminate unnecessary times built in. Another important area is that the Goods receiving process time could be reduced for a majority of material in the ERP-system since this differs today even if material is handled the same in reality. The second part consisting of 14 smaller areas of suggestions are believed to have a smaller impact on the total lead time but are still considered to be important to implement. All suggestions have an order of implementation which recommends what should be done first for SIT-Service. If the suggestions are implemented is it believed that SIT-Service can shorten the lead time in the Parts flow and also to get a more efficient organization.
4

Real-Time Communication over Switched Ethernet with Resource Reservation

Ashjaei, Mohammad January 2016 (has links)
Due to the need for advanced computer-controlled functionality in distributed embedded systems the requirements on network communication are becoming overly intricate. This dissertation targets the requirements that are concerned with real-time guarantees, run-time adaptation, resource utilization and flexibility during the development. The Flexible Time-Triggered Switched Ethernet (FTT-SE) and Hard Real-Time Ethernet Switching (HaRTES) network architectures have emerged as two promising solutions that can cater for these requirements. However, these architectures do not support multi-hop communication as they are originally developed for single-switch networks. This dissertation presents a fundamental contribution in multi-hop real-time communication over the FTT-SE and HaRTES architectures targeting the above mentioned requirements. It proposes and evaluates various solutions for scheduling and forwarding the traffic through multiple switches in these architectures. These solutions preserve the ability of dynamic adaptation without jeopardizing real-time properties of the architectures. Moreover, the dissertation presents schedulability analyses for the timeliness verification and evaluation of the proposed solutions as well as several protocols to support run-time adaptation in the multi-hop communication. Finally, the work led to an end-to-end resource reservation framework, based on the proposed multi-hop architectures, to support flexibility during the development of the systems. The efficiency of the proposed solutions is evaluated on various case studies that are inspired from industrial systems.
5

Execution time analysis for dynamic real-time systems

Zhou, Yongjun January 2002 (has links)
No description available.
6

Real Time Analysis of Protein Adsorption

Cornelius, Rena Marie 09 1900 (has links)
<p> An experimental method for monitoring the adsorption of proteins in real time has been developed and is the topic of this thesis.</p> <p> Proteins were radioactively labeled using 125I and injected at a constant flow rate into a well stirred glass cell containing buffer and the adsorbing surface in particle form. The buffer contained in the cell was gradually displaced by the protein solution. NaI(TI) detectors, coupled to a multichannel analyzer and high voltage power supply, were placed at the exit of the cell to monitor the radioactivity of the bulk solution. Adsorption of the protein was determined by depletion of protein in the bulk solution.</p> <p> A process to treat the surface of the cell and the glass tubing so as to prevent adsorption was developed and implemented prior to the flow experiments. This procedure involved exposing the cell and glass tubing to a 1 mg/mL fibrinogen solution for two hours at room temperature. The cell and tubing were then placed in an oven for 10 minutes at 70° C. This procedure (referred to as the thermal treatment procedure) resulted in a non-adsorbing protein layer that appeared, from extensive experiments, to be irreversibly attached to the surface of the cell and tubing.</p> <p> The adsorption of fibrinogen from a single component system, as well as from plasma, was studied using the experimental arrangement described above. Concentrations of fibrinogen in isotonic Tris, for the single component system, ranged from 40 mg/mL to 300 mg/mL. It was found from these experiments that an initial, fairly rapid, adsorption of protein took place. Later the adsorption of protein slowed significantly.</p> <p> The adsorption and subsequent desorption of fibrinogen from diluted plasma was also studied. Dilutions ranged from 1% to 20%. The results from these experiments are consistent with the model proposed by Vroman for plasma surface interactions.</p> / Thesis / Master of Engineering (MEngr)
7

REAL-TIME RECOGNITION OF TIME-SERIES PATTERNS

Morrill, Jeffrey P., Delatizky, Jonathan 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes a real-time implementation of the pattern recognition technology originally developed by BBN [Delatizky et al] for post-processing of time-sampled telemetry data. This makes it possible to monitor a data stream for a characteristic shape, such as an arrhythmic heartbeat or a step-response whose overshoot is unacceptably large. Once programmed to recognize patterns of interest, it generates a symbolic description of a time-series signal in intuitive, object-oriented terms. The basic technique is to decompose the signal into a hierarchy of simpler components using rules of grammar, analogous to the process of decomposing a sentence into phrases and words. This paper describes the basic technique used for pattern recognition of time-series signals and the problems that must be solved to apply the techniques in real time. We present experimental results for an unoptimized prototype demonstrating that 4000 samples per second can be handled easily on conventional hardware.
8

Estudo das variabilidades espectroscópicas da estrela &eta; Centauri / Study of spectroscopic variabilities of star &eta; Centauri

Levenhagen, Ronaldo Savarino 14 August 2000 (has links)
A espectrocopia de estrelas Be realizada com alta resolução e alta relação sinal/ruído permite investigar variações temporais rápidas nos perfis de linhas de absorção, usualmente atribuidas às pulsações não radiais, entre outros mecanismos. O fenômeno Be é transitorio para esse tipo de estrelas. Com efeito, seus espectros podem apresentar as características de uma estrela B normal, ou então de uma estrela com envelope circunstelar "frio" (presença de linhas finas de emissão e absorção no espectro visível). Essas estrelas se caracterizam por apresentarem altas velocidades de rotação, entretanto insuficientes para explicar as altas taxas de perda de massa, cujos mecanismos permanecem ainda incompreendicos. Neste trabalho, adotamos o modelo de pulsações não radiais (PNR) para tentar explicar as variações temporais presentes nos perfis de linha centrados em Hel &lambda; 667.8nm. Para este fim, foi utilizado o método CLEANEST para efetuar a determinação de periodicidades, após alguns testes de comparação prévios entre o desempenho desse método e o CLEAN. Ambos os métodos possuem grande eficiência em análises temporais, entre tanto na média o método CLEANEST se sobressaiu tanto na determinação de freqüências como de amplitudes. Além disso, foram estudados outros tipos de variabilidades também presentes nesses perfis, como as variabilidades nas intensidades relativas das asas da linha e a variabilidade na posição de um pico central em quase emissão. Os dados espectroscópicos analisados constituem quatro conjuntos de espectros obtidos nos anos 1995, 1996, 1997 e 1998 no MCT/LNA. Há ainda um conjunto de dados fotométricos proveniente do satélite HIPPARCOS relativo aos anos de 1990, 1991 e 1992. As análises dos dados espectroscópicos e fotométricos forneceram resultados que concordam com outros trabalhos sobre &eta; Centauri. / The spectroscopy of Be stars carried out with high resolution and signal to noise relation allows to investigate quick time variations in line absorption profiles, usually due to non radial pulsations, among other mechanisms. The Be phenomenon is transitory for such stars. Indeed, their spectra may show characteristics of a normal B star, or a star with a "cold" circumstellar envelope (presence of sharp emission and absorption lines in visible spectrum). These stars are characterized by high speed rotation, however insufficient to explain high mass loss rates, whose mechanisms still remains misunderstood. In this work, we adopted the non-radial pulsation model (NRP) in order to explain the observed time series variations present in line profiles centered in HeI &lambda; 667.8 nm. For this sake, it was used the CLEANEST method to carry out periodicity determinations, after some previous comparative tests of performance between this method and CLEAN. Both of them possess great efficiency in time analysis, however in average the CLEANEST method stood out both in determining frequencies and amplitudes. Besides, it were studied also other kinds of variability also present in these profiles, such as relative intensity variations in the wings of the profile and the variability in position of the central quasi-emission peak. The analyzed spectroscopic data constitute four sets of spectra obtained in 1995, 1996, 1997 and 1998 at the MCT/LNA. There is still one photometric data set coming from HIPPARCOS satellite spanning from 1990 to 1992. The spectroscopic and photometric data analysis have furnished results that agree with other works on &eta; Centauri
9

Response time analysis for implementation of distributed control systems

Redell, Ola January 2003 (has links)
Methods for performing response time analysis of real-timesystems are important, not only for their use in traditionalschedulability testing, but also for deriving bounds on outputtiming variations in control applications. Automatic controlsystems are inherently sensitive to variations in periodicityand end-to-end delays. Therefore, real-time performance needsto be considered during control design. For this purpose, anyreal-time analysis of a potential control implementation shouldproduce results that can easily be used to examine how theimplementation affects control performance. To find the maximumresponse time variation for a task, bounds on both minimum andmaximum response times are needed. A tight bound on thismaximum variation is useful in the analysis of controlperformance and can also be used to improve the results of someiterative response time analysis methods. In this thesis, threemethods for response time analysis are developed. While earlier research has focused on bounding maximumresponse times, one of the analysis methods in this thesisallows a computation of the minimum response times ofindependent fixed priority scheduled tasks. The analysis findsthe largest lower bound of response times for such tasks, whichleads to a tighter bound on the response time variations. Asecond analysis method allows exact computation of maximumresponse times for tasks whose arrival times are related byoffsets. The method is a complement to schedule simulationbased analysis, which it outperforms for systems with tasksthat may experience release jitter. A common design principle for distributed real-time systemsis to let the completion of one task trigger the start of oneor more successors. A third method supporting the analysis oftasks in such systems is described. The method extends andimproves earlier methods as it allows a generalized systemmodel and also results in tighter bounds than the originalmethods. This method has been implemented as part of a toolsetthat enables an integrated approach to the design and analysisof control systems and their implementation as distributedreal-time systems. As part of the thesis, models for describingdistributed control systems have been developed. The toolset,which is based on these models, uses the derived response timebounds in a control system performance analysis based onsimulation. The use of the toolset is exemplified in a smallcase study. <b>Keywords:</b>real-time systems, scheduling, response time,fixed priority, control, jitter, offset, schedulabilityanalysis
10

Response time analysis for implementation of distributed control systems

Redell, Ola January 2003 (has links)
<p>Methods for performing response time analysis of real-timesystems are important, not only for their use in traditionalschedulability testing, but also for deriving bounds on outputtiming variations in control applications. Automatic controlsystems are inherently sensitive to variations in periodicityand end-to-end delays. Therefore, real-time performance needsto be considered during control design. For this purpose, anyreal-time analysis of a potential control implementation shouldproduce results that can easily be used to examine how theimplementation affects control performance. To find the maximumresponse time variation for a task, bounds on both minimum andmaximum response times are needed. A tight bound on thismaximum variation is useful in the analysis of controlperformance and can also be used to improve the results of someiterative response time analysis methods. In this thesis, threemethods for response time analysis are developed.</p><p>While earlier research has focused on bounding maximumresponse times, one of the analysis methods in this thesisallows a computation of the minimum response times ofindependent fixed priority scheduled tasks. The analysis findsthe largest lower bound of response times for such tasks, whichleads to a tighter bound on the response time variations. Asecond analysis method allows exact computation of maximumresponse times for tasks whose arrival times are related byoffsets. The method is a complement to schedule simulationbased analysis, which it outperforms for systems with tasksthat may experience release jitter.</p><p>A common design principle for distributed real-time systemsis to let the completion of one task trigger the start of oneor more successors. A third method supporting the analysis oftasks in such systems is described. The method extends andimproves earlier methods as it allows a generalized systemmodel and also results in tighter bounds than the originalmethods. This method has been implemented as part of a toolsetthat enables an integrated approach to the design and analysisof control systems and their implementation as distributedreal-time systems. As part of the thesis, models for describingdistributed control systems have been developed. The toolset,which is based on these models, uses the derived response timebounds in a control system performance analysis based onsimulation. The use of the toolset is exemplified in a smallcase study.</p><p><b>Keywords:</b>real-time systems, scheduling, response time,fixed priority, control, jitter, offset, schedulabilityanalysis</p>

Page generated in 0.0702 seconds