1,357 research outputs found
The Effects Of Human Resource Management Practices (Hrm) On Service Innovation In Malaysian Islamic Banks
Objektif kajian ini adalah untuk mengkaji kesan amalan sumber manusia pada inovasi perkhidmatan dalam konteks bank-bank Islam dan secara praktik kajian ini meneliti tiga dimensi amalan HRM: pampasan, prestasi penilaian dan penyertaan.
The objective of this study is to examine the effect of human resource practices on service innovation in the context of Islamic banks. This study examines three dimensions of HRM practices: compensation, performance appraisal and participation
Design of Air-conditioning System for an Office Building
This study was performed in order to .Design the air conditioning system for assignedThis study was performed in order to .Design the air conditioning system for assigne
Septic shock: targeting evaluation and treatment; halting the progression to multiple organ failure
Shock may be defined in physiologic terms as a state in which the circulatory system is unable to meet the cellular needs for perfusion to maintain tissue homeostasis. Septic shock is defined as a state of tissue hypoperfusion arising from a documented infection or the infection-induced release of inflammatory mediators. Successful resuscitation depends on careful patient assessment to determine the causal organisms of infection and appropriate antibiotic therapy targeting the key pathogens. In many cases, where high cardiac output is opposed by reduced left ventricular filling pressure despite fluid loading, administration of inotropic agents may be warranted to alleviate myocardial dysfunction. Septic shock requires rapid intervention to stop the downward spiral to multiple organ failure and death. (J Crit Illness. 2002; 17(9):357-363
High spectral purity microwave sources based on optical resonators
L'optique constitue aujourd'hui une solution performante pour la réalisation de sources très pures en hyperfréquences, en particulier grâce à l'approche de l'oscillateur électro-optique (OEO). La pureté spectrale de ces sources est essentielle pour les applications spatiales, militaires et pour la métrologie du temps et des fréquences. Durant cette thèse, nous avons réalisé et étudié différents types d'OEO à résonateur optique en vue d'optimiser le bruit de phase de ce système. Nous avons en particulier orienté nos travaux vers une approche originale utilisant un anneau résonant fibré (ARF) passif. Ce type de résonateur présente en effet des coefficients de qualité optiques supérieurs à 109 pour des longueurs de fibre restant relativement faibles (L ~ 10 m) et facilement intégrables dans un support planaire. En parallèle, nous avons mené un travail important sur les oscillateurs à base de résonateurs optiques 3D. Concernant l'OEO à ARF, des progrès spectaculaires ont pu être obtenus grâce à une meilleure compréhension des phénomènes de bruit intrinsèques à ce système. Les deux types de bruit prépondérants étaient la conversion du bruit du laser (FM et AM) en bruit de phase RF par différentes non-linéarités (dont la photodiode) et le déclenchement d'effets non-linéaires optiques à l'intérieur du résonateur. Le contrôle de ces effets a permis en particulier d'éliminer des remontées importantes de bruit sur le spectre de l'oscillateur, et d'atteindre un niveau de bruit de phase de -128 dBc/Hz à 10 kHz de la porteuse à 10.2 GHz en utilisant un OEO à base d'un ARF passif de 100 mètres de longueur, optimisé et immunisé contre les effets non-linéaires optiques.Optics represents an elegant and reliable solution to generate high spectral purity microwave signals, especially the approach using the optoelectronic oscillator (OEO). The spectral purity of these sources is very important for space and military applications and also for time and frequency domain metrology. During this thesis, we have fabricated and studied many types of resonator based OEO in order to optimize the system phase noise. We have especially investigated an original approach using a passive fiber ring resonator (FRR). This resonator type can feature optical quality factors higher than 109 when only few meters of optical fibers are used (L ~ 10 m) and it can be easily integrated in a planar setup. Moreover, we have performed an important work on 3D WGM resonators based oscillators. In the FRR based OEO, spectacular progresses have been achieved thanks to a good understanding of the system intrinsic noise phenomena. Actually, we have found that the most important noise parameters were the laser FM and AM noise conversion into RF phase noise by means of different nonlinearities in the system (like the photodiode nonlinearity), but also by the generation of nonlinear optical effects inside the resonator. By controlling these effects, we have been able to reduce the OEO phase noise level and to reach a -128 dBc/Hz noise level at 10 kHz offset frequency from a 10.2 GHz carrier. This has been achieved using an OEO based on a 100m-long passive FRR, which has been optimized and immunized against different nonlinear optical effects
Mechanisms of Seed Discrimination and Selective Seed Foraging in Carabid Weed Seed Predators
Ground (carabid) beetles (Coleoptera: Carabidae) are among the most prevalent biological agents in temperate agroecosystems, with numerous species functioning as predators of both insect pests and weed seeds. Several carabid species are omnivorous, and the diversity and complexity of their feeding habits makes it difficult to predict the magnitude of population suppression they impose on pest and weed species. Thus, it remains unclear why omnivorous carabid beetles choose to feed on seed species when alternative food sources are available. It was first thought that seed feeding in carabids was driven by chance alone and hence, take place upon random encounter. Recent lines of evidence show that carabid predators can be quite choosy or selective about the seeds they consume when seeds of different species are offered in laboratory or field feeding experiments. Seed feeding habits in carabids thus seem driven by active seed discrimination and selection behaviors. Yet, little is known about the sensory, behavioral, nutritional, and biophysical mechanisms that underlie seed preferences in carabid seed predators.
In this thesis I explore the feeding ecology of omnivorous carabid species and describe aspects of the sensory, behavioral, nutritional, and biophysical ecology involved in their seed feeding habits. Multiple-choice feeding bioassays coupled with sensory manipulations of carabid predators showed that carabids rely on their olfactory system to detect seeds of different species and identify the suitable seed species among them. Seed choice was driven by the perception of long chain volatile chemicals derived from the epicuticular lipids located on the seed coat surface. Seed surface volatiles seemed to encode information about the nutritional quality of seed species, especially their fatty acid content. Experiments with synthetic diets showed that omnivorous carabids potentially seek seed consumption to overcome the scarcity of some lipids in their diets.
Carabids most likely choose seed species based on desirable lipid content if the physical properties of seed species in the environment pose no challenges to efficient seed handling. However, if physical seed traits such as mass or size are highly variable among seed species, seed handling costs are likely to vary widely among seed species and thus, constrain the active selection of nutritious seeds. Carabids would more preferably select seed species that are easier to handle in such a case, irrespective of their nutritional quality. The findings of this thesis bridge important knowledge gaps in the seed feeding ecology of carabid species as the sensory basis of seed perception and discrimination is elucidated, and some of the key factors that render seed of certain species more vulnerable to elevated carabid attacks are identified
Assessing the Performance of Different Large Format Digital Cameras by Investigating the Geometric Accuracy and Camera Calibration
This paper provides an independent investigation on the geometric accuracy and camera calibration of the new photogrammetric digital airborne camera systems, undertaken as a part of the German Society of Photogrammetry, Remote Sensing and Geoinfirmation (DGPF) project for investigating large format digital cameras (Vexcel Imaging UltraCamX, Z/I Imaging DMC and Z/I Imaging RMC Top 15). This paper presents results from the imaging data on 6 different flight days flown over a test site in Germany during a 10 week time window starting at the beginning of July till the middle of September 2008. Most of the sensors were flown at two different flying heights, resulting in two blocks with different Ground Sampling Distances (GSD); namely GSD 20cm and GSD 8cm. In this paper, the digital camera calibration was assessed through analyzing and identifying any systematic patterns in the image residuals. A new calibration method was undertaken in this paper based on analyzing the systematic errors of the high and low flown residuals. The bundle adjustment will be re-computed based on the analysis of the systematic residual patterns. This approach is based on analyzing the systematic errors of the high flown residuals and re-computing the bundle adjustment of the low flown images based on the residual corrections of the high flown images. These corrections were computed from a block triangulation and applied because the systematic patterns were considered similar for all images. The bundle adjustment will be re-computed based on the analysis of the systematic residual patterns. This approach is based on analyzing the systematic errors of the high flown residuals and re-computing the bundle adjustment of the low flown images based on the residual corrections of the high flown images. The results introduced in this paper were significantly improved by using the traditional existing selfcalibration method and the new calibration approac
On Optimality of Myopic Policy for Restless Multi-armed Bandit Problem with Non i.i.d. Arms and Imperfect Detection
We consider the channel access problem in a multi-channel opportunistic
communication system with imperfect channel sensing, where the state of each
channel evolves as a non independent and identically distributed Markov
process. This problem can be cast into a restless multi-armed bandit (RMAB)
problem that is intractable for its exponential computation complexity. A
natural alternative is to consider the easily implementable myopic policy that
maximizes the immediate reward but ignores the impact of the current strategy
on the future reward. In particular, we develop three axioms characterizing a
family of generic and practically important functions termed as -regular
functions which includes a wide spectrum of utility functions in engineering.
By pursuing a mathematical analysis based on the axioms, we establish a set of
closed-form structural conditions for the optimality of myopic policy.Comment: Second version, 16 page
On Optimality of Myopic Sensing Policy with Imperfect Sensing in Multi-channel Opportunistic Access
We consider the channel access problem under imperfect sensing of channel
state in a multi-channel opportunistic communication system, where the state of
each channel evolves as an independent and identically distributed Markov
process. The considered problem can be cast into a restless multi-armed bandit
(RMAB) problem that is of fundamental importance in decision theory. It is
well-known that solving the RMAB problem is PSPACE-hard, with the optimal
policy usually intractable due to the exponential computation complexity. A
natural alternative is to consider the easily implementable myopic policy that
maximizes the immediate reward but ignores the impact of the current strategy
on the future reward. In this paper, we perform an analytical study on the
optimality of the myopic policy under imperfect sensing for the considered RMAB
problem. Specifically, for a family of generic and practically important
utility functions, we establish the closed-form conditions under which the
myopic policy is guaranteed to be optimal even under imperfect sensing. Despite
our focus on the opportunistic channel access, the obtained results are generic
in nature and are widely applicable in a wide range of engineering domains.Comment: 21 pages regular pape
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