Many-Sources Large Deviations for Max-Weight Scheduling

In this paper, a many-sources large deviations principle (LDP) for the transient workload of a multi-queue single-server system is established where the service rates are chosen from a compact, convex and coordinate-convex rate region and where the service discipline is the max-weight policy. Under the assumption that the arrival processes satisfy a many-sources LDP, this is accomplished by employing Garcia's extended contraction principle that is applicable to quasi-continuous mappings. For the simplex rate-region, an LDP for the stationary workload is also established under the additional requirements that the scheduling policy be work-conserving and that the arrival processes satisfy certain mixing conditions. The LDP results can be used to calculate asymptotic buffer overflow probabilities accounting for the multiplexing gain, when the arrival process is an average of \emph{i.i.d.} processes. The rate function for the stationary workload is expressed in term of the rate functions of the finite-horizon workloads when the arrival processes have \emph{i.i.d.} increments.Comment: 44 page

Aquaculture development in Thailand

Aquaculture practised in Thailand is in the form of pond culture and cage culture in freshwater, brackishwater and coastal areas. The main species cultured include freshwater prawns, brackishwater shrimp, cockles, mussels, and various freshwater and marine finfishes. There is good potential for increased production from freshwater, brackishwater and marine aquaculture. However, the 1983 production of 145 000 mt represents only about 6% of Thailand's total fish production and production in this subsector has fluctuated widely. It will be several years before aquaculture production will contribute substantially to total production. Nonetheless, the culture of high value species of shrimp and fish could contribute significantly to export earnings during the next 5 to 10 years. Conducted primarily by government agencies, research and development are along the lines of increasing seed supply, establishing new culture techniques or improving older ones. The Department of Fisheries (DOF) together with some private companies have ventured into the development and testing of artificial diets for the various cultured species using a variety of indigenous feed stuffs. It is estimated that with adequate investments and appropriate support, aquaculture production will increase from 145 000 mt in 1983 to 378 000 mt in 1991, showing an annual increase of about 13% over this period. Major increases would come from bivalve mariculture (131 000 mt), brackishwater ponds (36 000 mt) freshwater ponds (46 000 mt) and brackishwater cage culture (20 000 mt)

Water Resource Management Options in the Seawater Irrigation Project in Kung Krabaen, Thailand

The purpose of this study was fourfold as follows: Firstly, to elucidate problems related to shrimp culture in Kung Krabaen Bay. Secondly, to study trends in water quality in the Kung Krabaen Bay. Thirdly, to determine the perception of the shrimp farmers on a number of matters about the Seawater Irrigation Project, and finally to determine the most appropriate methods for managing the new water resource associated with the Seawater Irrigation Project. The methodology for the study consisted of field observations, questionnaire surveys, sampling and analysis of water and wastewater, and discussions with some relevant authorities and NGOs connected with the study. The field work was carried out from September 1996 to September 1997 in Kung Krabaen Bay. Sampling of water in the shrimp ponds was carried out over two cropping seasons with each crop consisting of ten ponds. Each water sample was analysed for Dissolved Oxygen, Biochemical Oxygen Demand, Nitrite, Nitrate, Ammonia, pH, Salinity, Water Temperature and Suspended Solids. The interview form was pretested in October 1996, improved, and real data was gathered beginning February 1997. A total of 88 respondents were used in the social survey. All data were then analysed for frequencies, means, standard deviation, and percentage. In addition, the t-test and one-way ANOVA were employed to compare water quality values

Tsunami impacts and mitigation plans for the Khoa Lak (Andaman Sea), coastal areas of Thailand

To build a tsunami-resilient coastal community it is fundamental to understand the characteristics of past tsunami patterns and likely impact of possible future events. The MOST model (Method of Splitting Tsunami) and ComMIT (Community Model Interface for Tsunami) were used to model patterns of water levels, wave speed and direction, and inundation distances resulting from the 2004 Indian Ocean tsunami on the Khao Lak coast of Thailand. The model of the 2004 tsunami was calibrated against estimates of water depths made along the coast in early 2005; an M, = 9.3 earthquake in the model was found to best match observations. The model was verified against a variety of other evidence, including digital photographs and video clips taken on the day of the tsunami, mainly from two sites along the Khao Lak coast at Nang Thong and Bang Niang beaches, together with aerial surveys and a tide-gauge record. The timing and extent of water recession prior to the arrival of the first wave, the heights and number of the subsequent waves, and the inundation distances corresponded well providing confidence in the application of the MOST model to this coastal region. Historical evidence suggest that tsunami of the magnitude of 2004 are rare (200-700 y) so for mitigation planning in the Khao Lak area a smaller tsunami genic-earthquake (M; =8.9) was chosen (l00-500 y). Sensitivity to the choice of M, was also considered. The tsunami from such an event is similar in its character to the 2004 event, less extreme but still highly destructive, reaching the Khao Lak coast in ~ 2 h 15 min, and preceded by receding water levels. The first wave (5.0-6.5 m high) arrives 2h 25 min after the earthquake travelling at 6-8 mls at the coastline.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Separation of PVC from PET/PVC Mixtures Using Flotation by Calcium Lignosulfonate Depressant

Recycling is an important activity in the minimization of waste that results from human activities. In the United States, 103.2 billion pounds of plastic are produced in 2011. Unfortunately, the majority of this plastic ends up in landfills where its decomposition process can take anywhere from 10 to 30 years. In this work, froth flotation was used to treat PVC (polyvinyl chloride) and PET (polyethylene terephthalate) mixtures. The parameters studied are fed mixtures component ratios, concentration of Calcium Lignosulfonate as wetting reagent and a number of cleaning flotation. The results show a yield of 100% pure PVC separated from PET

Quantum Nanostructures by Droplet Epitaxy

Droplet epitaxy is an alternative growth technique for several quantum nanostructures. Indium droplets are distributed randomly on GaAs substrates at low temperatures (120 - 350oC). Under background pressure of group V elements, Arsenic and Phosphorous, InAs and InP nanostructures are created. Quantum rings with isotropic shape are obtained at low temperature range. When the growth thickness is increased, quantum rings are transformed to quantum dot rings. At high temperature range, anisotropic strain gives rise to quantum rings with square holes and non-uniform ring stripe. Regrowth of quantum dots on these anisotropic quantum rings, Quadra-Quantum Dots (QQDs) could be realized. Potential applications of these quantum nanostructures are also discussed

Quadra-Quantum Dots and Related Patterns of Quantum Dot Molecules: Basic Nanostructures for Quantum Dot Cellular Automata Application

Laterally close-packed quantum dots (QDs) called quantum dot molecules (QDMs) are grown by modified molecular beam epitaxy (MBE). Quantum dots could be aligned and cross hatched. Quantum rings (QRs) created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs) and quantum dot rings (QDRs).
 Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA) is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs). Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits.
 Molecular Beam Epitaxial growth technique called 'Droplet Epitaxy' has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85) droplets deposited on a GaAs substrate at 390'C with a droplet growth rate of 1ML/s. Arsenic flux (7'8'10-6Torr) is then exposed for InGaAs crystallization at 200'C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or, which are preferable crystallographic directions of quantum dot alignment in general

Analysis of Two-Layer Protocols: DCCP Simultaneous-Open and Hole Punching Procedures

The simultaneous-open procedure of the Datagram Congestion Control Protocol (DCCP), RFC 5596, was published in September 2009. Its design aims to overcome DCCP weaknesses when the Server is behind a middle box, such as Network Address Translators or firewalls. The original DCCP specification, RFC 4340, only allows the Client to initiate the call. The call request cannot reach the Server behind the middle box. A widely used solution to address this problem is called the hole punching technique. This technique requires the Server to initiate sending packets. Using Coloured Petri Nets (CPN) this paper models and analyses the DCCP procedure specified in RFC 5596. However, the difficulty is that detailed modelling of the address translation is also required. This causes state space explosion. We alleviate the state explosion using prioritized transitions and the sweep-line technique. Modelling and analysis approaches are discussed in the hope that it is helpful for others who wish to analyse similar protocols. Analysis results are also obtained for the simultaneous-open procedure specified in RFC 5596

Power and Reader-Writer Relationship : EFL Writing Assessment

EFL writing assessment in Thailand relies to a great extent on rapidity and reliabilityin order to match teachersû workloads and studentsû English language competence. †As a result,rubrics usually include criteria such as ideas, organization, sentence structure, mechanics,wording, and verbal facility, in other words, those that make grading quick and easilyexplainable. †One important effect of this traditional method of assessment is that teachers payless attention to other qualities that truly reflect the function and nature of writing. †This paperpresents power and reader-writer relationship as two possible criteria that may expand thecurrent limited writing assessment method into other realms and give teachers more insight intohow one should assess and research in the field of EFL writing. †This paper suggests that otherelements of writing such as imagination, metaphor, ideology, ethos, and pathos should alsobe taken into consideration along with the assessment of power or reader-writerrelationship.Key words : writing assessment, EFL writing assessment, grading criteria, power, reader-writerrelationshi