202 research outputs found
The Relationship between Language Games in Discourse Interactions in Classroom and Strengthening and Developing Vocabularies of Grade Two Male Students in Primary School
The purpose of the present research is evaluating the effect of teaching method based on language games on development of students’ language and discourse. The main hypothesis of the research is based on effect of language games on development of students’ vocabularies. The participants of the research included 44 second grade male students in primary school who were studying at 2015-2016 in Qarchak of Varamin in schools which the researcher teaches in them. Sample for study was divided into two groups of experimental and control though simple random. Initially, pretest was taken from the both groups in order to obtain full confidence of their integration and awareness about vocabularies of the lesson. Then the experimental group was educated for 6 months means from October 2015 to April 2016 for 3 hours per week through method based on language game and the control group was educated based on traditional method at the same period through the usual method with the same teacher and training book. At the end of the treatment, posttest was taken from the both group. Results indicated a considerable difference has been made between the experiment and the control groups
Reducing Consumed Energy while Drilling an Oil Well through a Deep Rig Time Analysis
As time goes by, increase in world energy demand forces oil and gas companies to drill deeper in order to produce more oil and gas for balancing world’s offer and demand. This requires drilling layers with various characteristics and dealing with more drilling problems as drilling progresses. Reduction of drilling problems can help drillers to reduce their cost effectively. Rig time break down of more than 300 wells in one south west Iranian oil field has been analysed to determine effective parameters on non-productive time amount. Results show that the most common drilling problems always have been experienced by drilling engineers are Equipment failure, stuck pipe and lost circulation which expose huge expenses to the oil companies. Several factors while drilling will govern how severe mud loss and stuck pipe would occur. These actually make analytical modelling of lost circulation or pipe sticking to somehow complicated. Hereby, employing artificial intelligence can be a leeway with proven capability and accuracy. In this research, operational parameters in Maroun oilfields are introduced to artificial neural networks to predict lost circulation severity, stuck pipe position and stuck pipe severity before happening. Results are well-matched with reality. Key words: Energy; Drilling problems; Lost circulation; Stuck pipe; Rig time analysi
Toward the implementation of analog LDPC decoders for long codewords
Error control codes are used in virtually every digital communication system. Traditionally, decoders have been implemented digitally. Analog decoders have been recently shown to have the potential to outperform digital decoders in terms of area and power/speed ratio. Analog designers have attempted to fully understand and exploit this potential for large decoders. However, large codes are generally still implemented with digital circuits. Nevertheless, in this thesis a number of aspects of analog decoder implementation are investigated with the hope of enabling the design of large analog decoders. In this thesis, we study and modify analog circuits used in a decoding algorithm known as the sum-product algorithm for implementation in a CMOS 90 nm technology. We apply a current-mode approach at the input nodes of these circuits and show through simulations that the power/speed ratio will be improved. Interested in studying the dynamics of decoders, we model an LDPC code in MATLAB's Simulink. We then apply the linearization technique on the modeled LDPC code in order to linearize the decoder about an initial state as its solution point. Challenges associated with decoder linearization are discussed. We also design and implement a chip comprised of the sum-product circuits with different configurations and sizes in order to study the effect of mismatch on the accuracy of the outputs. Unfortunately, testing of the chip fails as a result of errors in either the packaging process or fabrication
Resilient Digital Supply Chain Twins Modelling: Simulation-based Analysis on the COVID-19 Pandemic Outbreak
Over the past few years, Supply Chains (SC) have expanded rapidly in terms of dimensions and complexity (e.g., globalization, outsourcing, etc.). Besides, numerous practitioners and researchers proposed models mainly focused on minimizing SC’s total cost. Consequently, the potential financial advantages of reduced stock levels and inventory buffers have made SCs more vulnerable to local and global Low-Frequency High-Impact disruption risks which have long-term destructive effects. For instance, the COVID-19 pandemic outbreak has severely disturbed SCs, especially for essential products, by a sharp increase in demand and raw material supply failure. During this challenging situation, the focus should be shifted from cost minimization to SC’s survival, maximizing demand satisfaction, and minimizing delivery time. Consequently, these emerging issues have put forth the need for greater emphasis to develop resilient supply chains.
This study presents a methodological SC simulation modelling framework that enables visualizing the SC and making quick decisions by SC managers in near real-time to ensure resiliency during the disruption. The solution approach is applied as a case study in Luxxeen Co., a Canadian manufacturer of green disposable products, i.e. Toilet Tissues, which is considered an essential product.
First, we develop SC’s structural and behavioral conceptual model by customizing the SCOR reference model. Afterwards, we translate it to Discrete Event Simulation formalist and implement it using the “Arena simulation software” platform. Next, we design three COVID-19 pandemic outbreak disruption scenarios in suppliers, transportation networks, and retailers. Finally, three risk mitigation strategies (i.e., Multiple Sourcing, Changing Inventory Control Policy and Buffering) are suggested to ensure SC resiliency in terms of reliability and responsiveness performance metrics. Moreover, by conducting a comparison analysis using “Process Analyzer” and “Optquest” between these scenarios, the best set of actions are proposed for each disruption scenario
Flow rate measurement in a high temperature, radioactive, and corrosive environment
Accurate measurement of coolant flow rate is essential for determining the maximum power required by the nuclear plant operation and critical for monitoring its operation safety. However, no practical off-the-shelf flowmeter is available to satisfy all the pressing multidimensional operation requirements (i. e., high temperature, high irradiation, and high corrosion). This work thus deals with the development of a new flowmeter for nuclear power plant/reactor process-monitoring and real time analysis; this proposed flowmeter shall be able to continuously conduct robust measurements under extremely harsh environment with high irradiation, high pressure, high temperature and corrosive media. We investigate a transit-time based flow rate measurement which is used in such environment. The transit time of a thermal signal travels along with a liquid flow can be obtained using a cross correlation method. This transit-time-based flowmeter using thermocouples with grounded stainless steel shielding is by far the most robust and reliable solution to measure the flow rate in a harsh environment typically seen in a nuclear reactor. In practice, cross correlation calculation tends to produce flat peak plateau or multiple peaks, leading to a significant error in peak detection. To overcome this problem, in this work, an Auto-Adaptive Impulse Response Function estimation (AAIRF) technique is introduced and a significantly narrower peak is shown theoretically and also verified experimentally. In addition, we show that more accurate results can be obtained if moving average filter based cross correlation function (MAFCCF) is combined with AAIRF. Also in this work, we investigate a few important practical problems related to negative delays and sampling frequencies of the data acquisition. The second part of this work deals with the calibration of the developed flowmeter which was mentioned above. To commission the flowmeter, calibration process is applied by comparing the reading measurements with a standard flowmeter measurement. In this work, this process is performed in an in house developed water-based test apparatus with a developed transit-time based flowmeter based on the measurement and processing of correlated thermal signals. In this system, we have observed that the accuracy of the measured flow is restricted to the time response of the thermocouples. In addition, since the flow rate is inversely proportional to estimated time delay, high flow rates measurement like 5 gpm (gallon per minute) requires large transit-time span that can not be achieved from a limited physical system dimensions. These problems are investigated through this work.
In the final part of this work, as the ultrasonic flow measurement technologies including transit-time and Doppler effect technologies are usually used in harsh environments, we study these methods with intensive simulations
In vivo effects of calcitriol on phenotypic and functional properties of Dendritic cells
Background: Dendritic cells (DCs) play a central role in the initiation and expansion of T cell mediated immune responses with potential immunotherapy application. The compounds which have the ability to induce immunomodulatory effects on DCs may be employed for the treatment of immunopathologic conditions such as autoimmune diseases. Objective: The aim of this study was to investigate the in vivo effects of calcitriol (active form of vitamin D3) on DCs. Methods: 0.1 microgram calcitriol was injected intra-peritoneally into C57BL/6 mice every other day within 3 weeks, and spleen DCs were extracted by magnetic beads. The phenotypic and functional properties of DCs were studied by flow cytometry and mixed lymphocyte reaction (MLR), respectively. Results: The expression of CD86 and MHC II, as maturation markers and costimulatory molecules were significantly decreased (p=0.028 and p=0.047, respectively) while CD11b expression, as a marker of mice myeloid DCs which mostly induces Th2 cytokine profile, was significantly increased (p=0.011). Allogeneic T cell stimulation in MLR was also significantly inhibited in comparison with the control groups (p<0.05). Conclusion: Our data indicate that in vivo calcitriol administration inhibits maturation and activation of DCs in the same manner as in vitro conditions
Diversificação de símile no estilo e estrutura de Gilani 'diwan A'li (suprema corte)
Simile has always been the subject of attention by poets and writers and it has a unique place. The uniqueness of this beautiful art attracts the imaginative element of poetry and readership, and the owners of style and writers that can't be easily remove this elegant and functional instrument. Poets and peoples use their efforts to bring their writings with a variety of similes. A poet is capable that use these imaginative designs in the most beautiful way. In this article, we examine the types of simile in the poem of Gilani Supreme Court. The provided table helps the reader to understand hidden sides of the poet's thoughts. Among the used similes, topic is the praise, Image is around subjects. A'li used composite, sensory, wisdom simile and the supposed syntax has the highest repetition among the poet's poetry. A'li used simile more than any other instrument in his poem.El símil siempre ha sido el tema de atención de poetas y escritores y tiene un lugar único. La singularidad de este bello arte atrae el elemento imaginativo de la poesía y los lectores, y los propietarios de estilo y escritores que no pueden eliminar fácilmente este instrumento elegante y funcional. Los poetas y los pueblos usan sus esfuerzos para llevar sus escritos con una variedad de símiles. Un poeta es capaz de utilizar estos diseños imaginativos de la manera más bella. En este artículo, examinamos los tipos de símil en el poema de la Corte Suprema de Gilani. La tabla proporcionada ayuda al lector a comprender los lados ocultos de los pensamientos del poeta. Entre los símiles usados, el tema es el elogio, la imagen está alrededor de los sujetos. A'li utilizó un símil compuesto, sensorial, de sabiduría y la supuesta sintaxis tiene la mayor repetición entre la poesía del poeta. A'li usó símil más que cualquier otro instrumento en su poema.Simile sempre foi objeto de atenção de poetas e escritores e tem um lugar único. A singularidade desta bela arte atrai o elemento imaginativo de poesia e leitura, e os donos de estilo e escritores que não podem facilmente remover este instrumento elegante e funcional. Poetas e povos usam seus esforços para trazer seus escritos com uma variedade de símiles. Um poeta é capaz de usar esses desenhos imaginativos da maneira mais bonita. Neste artigo, examinamos os tipos de símile no poema da Suprema Corte de Gilani.
A tabela fornecida ajuda o leitor a entender os lados ocultos dos pensamentos do poeta. Entre os símiles usados, tópico é o elogio, Imag em é em torno de assuntos. A'li usou compósitos, sensorial, simile de sabedoria e a suposta sintaxe tem a mais alta repetição entre a poesia do poeta. A'li usou símile mais do que qualquer outro instrumento em seu poema
Analytical Models for Distribution of the Envelope and Phase of Linearly Modulated Signals in AWGN Channel
In this paper, analytical expressions for the distribution of the envelope and phase of linearly modulated signals such as BPSK, M-PSK, and M-QAM in AWGN are presented. We perform numerical simulations for different orders of signal constellations. The results show that the proposed theoretical models are in excellent agreement with the estimated distributions from various numerical experiments
Energy-Efficient Wake-up Receivers for 915-MHz ISM Band Applications
Wake-up receiver (WuRx) is a well-known approach for optimizing the latency and power consumption of ultra-low power transceivers in wireless sensor nodes.
Tuned RF (TRF) or Envelope Detection architecture is an appropriate topology for short-range Wireless Body Area Network (WBAN) applications, where achieving a very high sensitivity is not a priority. However, the demand for an improved sensitivity gets emphasized for longer transmission ranges. Regardless of the application, considering the existing trade-off between the power and sensitivity, design techniques and novel architectures are usually employed to optimize the power-sensitivity product. Moreover, considering the negative impact of higher data rate on the sensitivity, the energy-sensitivity product can be a more reasonable figure of merit when comparing WuRx designs.
In this thesis, the RF-subsampling architecture has been combined with the TRF receiver architecture as a first approach for improving the power-sensitivity product. The overall power consumption is reduced as a result of employing the subsampling topology with a low-frequency local oscillator (LO). Post layout simulations show that the proposed WuRx draws only 56 μA from a 0.5 V supply and exhibits an input sensitivity of -70 dBm for a data rate of 100 kbps. The chip occupies an area of 0.15 mm2 and is fabricated with TSMC 90nm CMOS technology.
Another major contribution of this work is to propose and implement a novel dual-mode ultra-low-power WuRx based on the subsampling topology, which not only reduces the overall power consumption but also optimizes the energy-sensitivity product of the receiver. During the typical mode of operation known as the Monitoring (MO) mode, the start frame bits are received at a rate of as low as 10 kbps. Having received the true preamble bits in the MO mode, the remaining wake-up pattern bits are received at a higher rate of 200 kbps during the Identifier (ID) mode. By lowering the gain of the front-end amplifier in the MO mode, the power dissipation is reduced, which in turn causes an increase in the overall noise figure of the receiver. However, adequate sensitivity and hence an optimized energy-sensitivity product is maintained by intentionally lowering the data rate as well as the detection bandwidth of the receiver in the MO mode.
The proposed wake-up receiver has been designed and fabricated in IBM 130 nm technology with a core size of about 0.2 mm2 for the target frequency range of 902-928 MHz. The measured results show that the proposed dual-mode receiver achieves a sensitivity of -78.5 dBm and -75 dBm while dissipating an average power of 16.4 µW and 22.9 µW during MO and ID modes, respectively
Multi-objective sustainable location-districting for the collection of municipal solid waste : two case studies
This paper presents a multi-objective location-districting optimization model for sustainable collection of municipal solid waste, motivated by strategic waste management decisions in Iran. The model aims to design an efficient system for providing municipal services by integrating the decisions regarding urban area districting and the location of waste collection centers. Three objectives are minimized, given as 1) the cost of establishing collection centers and collecting waste, 2) a measure of destructive environmental consequences, and 3) a measure of social dissatisfaction. Constraints are formulated to enforce an exclusive assignment of urban areas to districts and that the created districts are contiguous. In addition, constraints make sure that districts are compact and that they are balanced in terms of the amount of waste collected. A multi-objective local search heuristic using the farthest-candidate method is implemented to solve medium and large-scale numerical instances, while small instances can be solved directly by commercial software. A set of randomly generated test instances is used to test the effectiveness of the heuristic. The model and the heuristic are then applied to two case studies from Iran. The obtained results indicate that waste collection costs can be reduced by an estimated 20-30 %, while significantly improving the performance with respect to environmental and social criteria. Thus, the provided approach can provide important decision support for making strategic choices in municipal solid waste management. Keywords: multi-objective optimization, local search, best-worst methodpublishedVersio
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