Search results for: discrete event simulation (DES)

Authors: Abeer F. Almarzouki, Christopher A. Brown, Richard J. Brown, Anthony K. P. Jones

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Although relief is commonly assumed to be a direct reflection of pain reduction, it seems to be driven by complex emotional interactions in which pain reduction is only one component. For example, termination of a painful/aversive event may be relieving and rewarding. Accordingly, in this study, whether terminating an aversive negative prediction of pain would be reflected in a greater relief experience was investigated, with a view to separating apart the effects of the manipulation on pain and relief. We use aversive conditioning paradigm to investigate the perception of relief in an aversive (threat) vs. positive context. Participants received positive predictors of a non-painful outcome which were presented within either a congruent positive (non-painful) context or an incongruent threat (painful) context that had been previously conditioned; trials followed by identical laser stimuli on both conditions. Participants were asked to rate the perceived intensity of pain as well as their perception of relief in response to the cue predicting the outcome. Results demonstrated that participants reported more pain in the aversive context compared to the positive context. Conversely, participants reported more relief in the aversive context compares to the neutral context. The rating of relief in the threat context was not correlated with pain reports. The results suggest that relief is not dependant on pain intensity. Consistent with this, relief in the threat context was greater than that in the positive expectancy condition, while the opposite pattern was obtained for the pain ratings. The value of relief in this study is better appreciated in the context of an impending negative threat, which is apparent in the higher pain ratings in the prior negative expectancy compared to the positive expectancy condition. Moreover, the more threatening the context (as manifested by higher unpleasantness/higher state anxiety scores), the more the relief is appreciated. The importance of the study highlights the importance of exploring relief and pain intensity in monitoring separately or evaluating pain-related suffering. The results also illustrate that the perception of painful input may largely be shaped by the context and not necessarily stimulus-related.

Keywords: aversive context, pain, predictions, relief

Procedia PDF Downloads 134

Authors: Siwar Fadhel, Imen Bahri, Man Zhang

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The switched reluctance machine (SRM) has undeniable qualities in terms of low cost and mechanical robustness. However, its highly nonlinear character and its uncertain parameters justify the development of complicated controls. In this paper, authors present the design of a robust H-infinity current controller for an 8/6 SRM with taking into account the nonlinearity of the SRM and with rejection of disturbances. The electromagnetic torque is indirectly regulated through the current controller. To show the performances of this control, a robustness analysis is performed by comparing the H-infinity and PI controller simulation results. This comparison demonstrates better performances for the presented controller. The effectiveness and robustness of the presented controller are also demonstrated by experimental tests.

Keywords: current regulation, experimentation, robust H-infinity control, switched reluctance machine

Procedia PDF Downloads 307

Authors: Ruth Manzanares, Victor Honores, Hugo Zapata, Javier Cansaya, Deivid Yavar, Junior Meza

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LogiSum is a robot focused on education like a solution to the ecological crisis. This robot allows reducing the pollution on the beaches by stimulating environmental awareness of not contaminating through the collection of waste. Through the use of the methodology of design thinking, it is intended to reinforce values in adults and with a greater focus on children, so as not to contaminate the beaches. The goal is to encourage the use of the container of the robot LogiSum to put the garbage, with visual interaction and simulation of dialogue with the function of the robot. The results obtained of the testings of the interaction of children with the robot showed an encouraging behavior. With the robot, children left the waste in the right places and not bury it in the sand or in the floor.

Keywords: interaction human-robot, pollution reduction, social robot, robot container, beach pollution

Procedia PDF Downloads 257

Authors: Dawit Hailekrios Hailu

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The main objective of this study is to predict the sediment yield of the Jido River Watershed. Jido River is the largest tributary and covers around 50% of the total catchment area of Lake Shala. This research is undertaken to analyze the sediment yield of the catchments, transport capacity of the streams and sediment deposition rates of Jido River, which is located in the Sub-basin of Shala Lake, Rift Valley Basin of Ethiopia. The input data were Meteorological, Hydrological, land use/land cover maps and soil maps collected from concerned government offices. The sediment yield of Jido River and sediment change of the streams discharging into the Shala Lake were modeled.

Keywords: sediment yield, watershed, simulation, calibration

Procedia PDF Downloads 62

Authors: Olomon Wu, Hung Lu, Nick Wilkins, Daniel Kerr, Zekeriya Aliyazicioglu, H. K. Hwang

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Multiple Input Multiple Output (MIMO) radar has received increasing attention in recent years. MIMO radar has many advantages over conventional phased array radar such as target detection, resolution enhancement, and interference suppression. In this paper, the results are presented from a simulation study of MIMO Uniformly-Spaced Linear Array (ULA) antennas. The performance is investigated under varied parameters, including varied array size, Pseudo Random (PN) sequence length, number of snapshots, and Signal to Noise Ratio (SNR). The results of MIMO are compared to a traditional array antenna.

Keywords: MIMO radar, phased array antenna, target detection, radar signal processing

Procedia PDF Downloads 536

Authors: Zhijie Li, Wenhui Peng, Zelong Yuan, Jianchun Wang

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Turbulence is a complex phenomenon that plays a crucial role in various fields, such as engineering, atmospheric science, and fluid dynamics. Predicting and understanding its behavior over long time scales have been challenging tasks. Traditional methods, such as large-eddy simulation (LES), have provided valuable insights but are computationally expensive. In the past few years, machine learning methods have experienced rapid development, leading to significant improvements in computational speed. However, ensuring stable and accurate long-term predictions remains a challenging task for these methods. In this study, we introduce the implicit U-net enhanced Fourier neural operator (IU-FNO) as a solution for stable and efficient long-term predictions of the nonlinear dynamics in three-dimensional (3D) turbulence. The IU-FNO model combines implicit re-current Fourier layers to deepen the network and incorporates the U-Net architecture to accurately capture small-scale flow structures. We evaluate the performance of the IU-FNO model through extensive large-eddy simulations of three types of 3D turbulence: forced homogeneous isotropic turbulence (HIT), temporally evolving turbulent mixing layer, and decaying homogeneous isotropic turbulence. The results demonstrate that the IU-FNO model outperforms other FNO-based models, including vanilla FNO, implicit FNO (IFNO), and U-net enhanced FNO (U-FNO), as well as the dynamic Smagorinsky model (DSM), in predicting various turbulence statistics. Specifically, the IU-FNO model exhibits improved accuracy in predicting the velocity spectrum, probability density functions (PDFs) of vorticity and velocity increments, and instantaneous spatial structures of the flow field. Furthermore, the IU-FNO model addresses the stability issues encountered in long-term predictions, which were limitations of previous FNO models. In addition to its superior performance, the IU-FNO model offers faster computational speed compared to traditional large-eddy simulations using the DSM model. It also demonstrates generalization capabilities to higher Taylor-Reynolds numbers and unseen flow regimes, such as decaying turbulence. Overall, the IU-FNO model presents a promising approach for long-term dynamics prediction in 3D turbulence, providing improved accuracy, stability, and computational efficiency compared to existing methods.

Keywords: data-driven, Fourier neural operator, large eddy simulation, fluid dynamics

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Authors: San-Yih Lin, Hsien-Hao Teng

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In this research, we use commercial software, ANSYS CFX, to carry on the simulation the F16 aerodynamics performance flow field. The flight with a modified Leading Edge Extension (LEX) is proposed to increase the lift/drag ratio. The Shear Stress Transport turbulent model is used. The unstructured grid system is generated by the ICEM CFD. The prism grid around the wall surface is generated to simulate boundary layer viscosity flow field and Tetrahedron Mesh is used for the other computation domain. The lift, drag, and pitch moment are computed. The strong vortex structures upper the wing and vortex bursts under different sweep angle of LEX are investigated.

Keywords: LEX, lift/drag ratio, pitch moment, vortex burst

Procedia PDF Downloads 319

Authors: Soulayma Smirani, Mourad Aidi, Taoufik Aguili

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Energy harvesting has arisen as a prominent research area for low power delivery to RF devices. Rectennas have become a key element in this technology. In this paper, electromagnetic modeling of a rectenna system is presented. In our approach, a hybrid technique was demonstrated to associate both the method of auxiliary sources (MAS) and MoM-GEC (the method of moments combined with the generalized equivalent circuit technique). Auxiliary sources were used in order to substitute specific electronic devices. Therefore, a simple and controllable model is obtained. Also, it can easily be interconnected to form different topologies of rectenna arrays for more energy harvesting. At last, simulation results show the feasibility and simplicity of the proposed rectenna model with high precision and computation efficiency.

Keywords: computational electromagnetics, MoM-GEC method, rectennas, RF energy harvesting

Procedia PDF Downloads 164

Authors: Paivi Hietanen

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At family with children, divorce is a risk for a child to lose the relationship to the parent with whom the child doesn't live. A child has the right to the get care from both parents after the divorce. Even though your ex-spouse isn’t longer your companion, to the child he or she is still unique as a parent and parents must cooperate and support their child in the new family situation. To divorcee, it's necessary to understand the difference between the intimate relationship that ends and parenthood that continues. Cooperative parenting takes a lot of effort and flexibility for the parents to make joint custody work well. It is vital that parents get help to understand the situation from child points of view. When parent is facing divorce, and all the emotions that it brings along, can the child easily be forgotten. To help children, we must help parents to understand, that a relationship can end, parenthood cannot. As professionals, we should help the parents to see the significance and value of both parents to the child and try to support and protect parenthood-relationship between parents. The Federation of Mother and Child Homes and Shelters have developed group models to work with parents during or after divorce. These support groups are led by professionals, but peer support is also used. These support groups have been held over 10 years and there are found from 20 different cities in Finland. Eroneuvo event (divorce advice) service is intended for parents who are considering or have already divorced. The Vanhemman neuvo (parents' council) is a peer support group that helps parents with post-divorce parenting issues. From these groups, parents receive information and peer support for matters related to divorcing and how to support the child and do co-parenting. At the groups and in given information for divorced parents, is used a method called the 'Irreversible triangle'. It's a way to picture the intimate relationship and parenthood after the divorce and what is the difference between these two things. 'Irreversible triangle' is used to help parents and professionals to understand, what happens if a child loses the relationship to the other parent or if parents co-parenting doesn't work well. From the largely collected feedback, group members tell that they feel themselves relieved after taking part of the group. Parents also experience that talking with other parents helps to survive. Group members learn to co-operate with the other parent, and they'll also learn to see the best interest of the child after the divorce. Parents would highly recommend these groups to other parents.

Keywords: child's right, co-parenting, parenthood after the divorce, peer support

Procedia PDF Downloads 161

Authors: Suparman

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This paper addresses the problem of the signal segmentation within a Bayesian framework by using reversible jump MCMC algorithm. The signal is modelled by piecewise constant Moving-Average (MA) model where the numbers of segments, the position of change-point, the order and the coefficient of the MA model for each segment are unknown. The reversible jump MCMC algorithm is then used to generate samples distributed according to the joint posterior distribution of the unknown parameters. These samples allow calculating some interesting features of the posterior distribution. The performance of the methodology is illustrated via several simulation results.

Keywords: piecewise, moving-average model, reversible jump MCMC, signal segmentation

Procedia PDF Downloads 221

Authors: Hee-Guk Chae, Bo-Bae Song, Kyoung-Il Do, Jeong-Yun Seo, Yong-Seo Koo

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In this study, an improved Electrostatic Discharge (ESD) protection circuit with low trigger voltage and high holding voltage is proposed. ESD has become a serious problem in the semiconductor process because the semiconductor density has become very high these days. Therefore, much research has been done to prevent ESD. The proposed circuit is a stacked structure of the new unit structure combined by the Zener Triggering (SCR ZTSCR) and the High Holding Voltage SCR (HHVSCR). The simulation results show that the proposed circuit has low trigger voltage and high holding voltage. And the stack technology is applied to adjust the various operating voltage. As the results, the holding voltage is 7.7 V for 2-stack and 10.7 V for 3-stack.

Keywords: ESD, SCR, latch-up, power clamp, holding voltage

Procedia PDF Downloads 541

Authors: Encarnación Álvarez, Rosa M. García-Fernández, Juan F. Muñoz, Francisco J. Blanco-Encomienda

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The problem of estimating a proportion has important applications in the field of economics, and in general, in many areas such as social sciences. A common application in economics is the estimation of the headcount index. In this paper, we define the general headcount index as a proportion. Furthermore, we introduce a new quantitative method for estimating the headcount index. In particular, we suggest to use the logistic regression estimator for the problem of estimating the headcount index. Assuming a real data set, results derived from Monte Carlo simulation studies indicate that the logistic regression estimator can be more accurate than the traditional estimator of the headcount index.

Keywords: poverty line, poor, risk of poverty, Monte Carlo simulations, sample

Procedia PDF Downloads 417

Authors: Elmo Thiago Lins Cöuras Ford, Valentina Alessandra Carvalho do Vale

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The simulation in wind tunnel is used thoroughly to model real situations of drainages of air. Besides the automotive industry, a great number of applications can be numbered: dispersion of pollutant, studies of pedestrians comfort and dispersion of particles. This work had the objective of visualizing the characteristics aerodynamics of two automobiles in different ways. To accomplish that drainage of air a fan that generated a speed exists (measured with anemometer of hot thread) of 4,1m/s and 4,95m/s. To visualize the path of the air through the cars, in the wind tunnel, smoke was used, obtained with it burns of vegetable oil. For “to do smoke” vegetable oil was used, that was burned for a tension of 20 V generated by a thread of 2,5 mm. The cars were placed inside of the wind tunnel with the drainage of “air-smoke” and photographed, registering like this the path lines around them, in the 3 different speeds.

Keywords: aerodynamics, vehicle drag, vegetable oil, wind tunnel

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Authors: Han Bing, Yin Zhenjie

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In order to analyze the status of a diesel engine, as well as conduct fault prediction, a new prediction model based on a gray system is proposed in this paper, which takes advantage of the neural network and the genetic algorithm. The proposed GBPGA prediction model builds on the GM (1.5) model and uses a neural network, which is optimized by a genetic algorithm to construct the error compensator. We verify our proposed model on the diesel faulty simulation data and the experimental results show that GBPGA has the potential to employ fault prediction on diesel.

Keywords: fault prediction, neural network, GM(1, 5) genetic algorithm, GBPGA

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Authors: Xiaoyun Li, Suoang Longzhou

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This paper derives the analytical solution of stellar distance according to its redshift based on the photon-dominated universe expansion model. Firstly, it calculates stellar separation speed and the farthest distance of observable stars via simulation. Then the analytical solution of stellar distance according to its redshift is derived. It shows that when the redshift is large, the stellar distance (and its separation speed) is not proportional to its redshift due to the relativity effect. It also reveals the relationship between stellar age and its redshift. The correctness of the analytical solution is verified by the latest astronomic observations of Ia supernovas in 2020.

Keywords: redshift, cosmic expansion model, analytical solution, stellar distance

Procedia PDF Downloads 156

Authors: Mohd Ali Abbas Zaidi, Meenu Sachdeva, Jonaki Sen

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In the vertebrate embryo, the forebrain anlagen develops from the anterior-most region of the neural tube which is the precursor of the central nervous system (CNS). The roof plate located at the dorsal midline region of the forebrain anlagen, acts as a source of several secreted molecules involved in patterning and morphogenesis of the forebrain. One such key morphogenetic event is the invagination of the forebrain roof plate which results in separation of the single forebrain vesicle into two cerebral hemispheres. Retinoic acid (RA) signaling plays a key role in this process. Blocking RA signaling at the dorsal forebrain midline inhibits dorsal invagination and results in the absence of certain key features of this region, such as thinning of the neuroepithelium and a lowering of cell proliferation. At present we are investigating the possibility of other signaling pathways acting in concert with RA signaling to regulate this process. We have focused on BMP signaling, which we found to be active in a mutually exclusive domain to that of RA signaling within the roof plate. We have also observed that there is a change in BMP signaling activity on modulation of RA signaling indicating an antagonistic relationship between the two. Moreover, constitutive activation of BMP signaling seems to completely inhibit thinning and partially affect invagination, leaving the lowering of cell proliferation in the midline unaffected. We are employing in-silico modeling as well as molecular manipulations to investigate the relative contribution if any, of regional differences in rates of cell proliferation and thinning of the neuroepithelium towards the process of invagination. We have found expression of certain cell adhesion molecules in forebrain roof-plate whose mRNA localization across the thickness of neuroepithelium is influenced by Bmp and RA signaling, giving regional rigidity to roof plate and assisting invagination. We also found expression of certain cytoskeleton modifiers in a localized small domains in invaginating forebrain roof plate suggesting that midline invagination is under control of many factors.

Keywords: bone morphogenetic signaling, cytoskeleton, cell adhesion molecules, forebrain roof plate, retinoic acid signaling

Procedia PDF Downloads 151

Authors: Ararat Khachatryan, Davit Mirzoyan

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In sub micrometer technology, the aging phenomenon starts to have a significant impact on the reliability of integrated circuits by bringing performance degradation. For that reason, it is important to have a capability to evaluate the aging effects accurately. This paper presents an accurate aging measurement approach based on phase-locked loop (PLL) and voltage-controlled oscillator (VCO) circuit. The architecture is rejecting the circuit self-aging effect from the characteristics of PLL, which is generating the frequency without any aging phenomena affects. The aging monitor is implemented in low power 32 nm CMOS technology, and occupies a pretty small area. Aging simulation results show that the proposed aging measurement circuit improves accuracy by about 2.8% at high temperature and 19.6% at high voltage.

Keywords: aging effect, HCI, NBTI, nanoscale

Procedia PDF Downloads 353

Authors: Selma Bouasria, Mahi Abdelkader, Abbès Azzi, Herouz Keltoum

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This paper reports concept was used into the computational fluid dynamics (CFD) code cfx through user-defined functions to assess ventilation efficiency inside (forced-ventilation local). CFX is a simulation tool which uses powerful computer and applied mathematics, to model fluid flow situations for the prediction of heat, mass and momentum transfer and optimal design in various heat transfer and fluid flow processes to evaluate thermal comfort in a room ventilated (highly-glazed). The quality of the solutions obtained from CFD simulations is an effective tool for predicting the behavior and performance indoor thermo-aéraulique comfort.

Keywords: ventilation, thermal comfort, CFD, indoor environment, solar air heater

Procedia PDF Downloads 626

Authors: Baluku Nathan

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Infection prevention and control (IPC) is a practical, evidence-based approach that prevents patients and emergency health workers from being harmed by avoidable infections as a result of antimicrobial resistance; all hospital infection control programs put together various practices which, when used appropriately, restrict the spread of infection. A breach in these control practices facilitates the transmission of infections from patients to health workers, other patients and attendants. It is, therefore, important for all EMTs and patients to adhere to them strictly. It is also imperative for administrators to ensure the implementation of the infection control program for their facilities. Purpose: The purpose of this study was to investigate the influencing factors of prevention practices against Infection exposure among emergency medical technicians (EMTs) in the emergency department at Mbarara hospital. Methodology: This was a descriptive cross-sectional study that employed a self-reported questionnaire that was filled out by 32 EMTs in the emergency department from 12th February to 3rd march 2022. The questionnaire consisted of items concerning the defensive environment and other Factors influencing Infection prevention and control practices in the accident and emergency department of Mbarara hospital. Results: From the findings, majority16(50%) always used protective gear when doing clinical work,14 (43.8%) didn’t use protective gear, citing they were only assisting those performing resuscitations, gumboots were the least used protective gear with only3(9.4%) usage. Regarding disposal techniques of specific products like blood and sharps, results showed 10 (31.3%) said blood is disposed of in red buckets, 5(15.6%) in yellow buckets and only5(15.6%) in black buckets and 12(37.5%) didn’t respond. However, 28(87.5%) said sharps were disposed of in a sharps container. The majority, 17(53.1%), were not aware of the infection control guidelines even though they were pinned on walls of the emergency rooms,15(46.9%) said they had never had quality assurance monitoring events,14(43.8%) said monitoring was continuous while15(46.9 %) said it was discrete. Conclusions: The infection control practices at the emergency department were inadequate in view of less than 100% of the EMTs observing the five principles of infection prevention, such as the use of personal protective equipment and proper waste disposal in appropriate color-coded bins. Dysfunctional infection prevention and control committees accompanied by inadequate supervision to ensure infection control remained a big challenge.

Keywords: infection prevention, influencing factors, emergency medical technician (EMT), emergency unit

Procedia PDF Downloads 109

Authors: Baluku Nathan

Abstract:

Infection prevention and control (IPC) is a practical, evidence-based approach that prevents patients and emergency health workers from being harmed by avoidable infections as a result of antimicrobial resistance; all hospital infection control programs put together various practices which, when used appropriately, restrict the spread of infection. A breach in these control practices facilitates the transmission of infections from patients to health workers, other patients, and attendants. It is, therefore important for all emergency medical technicians (EMTs) and patients to strictly adhere to them. It is also imperative for administrators to ensure the implementation of the infection control programme for their facilities. Purpose: The purpose of this study was to investigate the influencing factors of prevention practices against infection exposure among emergency medical technicians (EMTs) in the emergency department at Mbarara hospital. Methodology: This was a descriptive cross-sectional study that employed a self-reported questionnaire that was filled out by 32 EMTs in the emergency department from 12th February to 3rd march 2022. The questionnaire consisted of items concerning the defensive environment and other factors influencing infection prevention and control practices in the accident and emergency department of Mbarara hospital. Results: From the findings, the majority 16 (50%) always used protective gear when doing clinical work, 14 (43.8%) didn’t use protective gear, citing they were only assisting those performing resuscitations, gumboots were the least used protective gear with only3(9.4%) usage. About disposal techniques of specific products like blood and sharps, results showed 10 (31.3%) said blood is disposed of in red buckets, 5 (15.6%) in yellow buckets, and only 5(15.6%) in black buckets, and 12(37.5%) didn’t respond, however, 28(87.5%) said sharps were disposed of in a sharps container. The majority, 17 (53.1%), were not aware of the infection control guidelines even though they were pinned on walls of the emergency rooms, 15(46.9%) said they have never had quality assurance monitoring events, 14(43.8%) said monitoring was continuous while 15(46.9 %) said it was discrete. Conclusions: The infection control practices at the emergency department were inadequate in view of less than 100% of the EMTs observing the five principles of infection prevention, such as the use of personal protective equipment and proper waste disposal in appropriate color-coded bins. Dysfunctional infection prevention and control committees accompanied by inadequate supervision to ensure infection control remained a big challenge.

Keywords: emergency medical technician, infection prevention, influencing factors, infection control

Procedia PDF Downloads 102

Authors: Yoonsuh Jung, Steven N. MacEachern

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Check loss function is used to define quantile regression. In the prospect of cross validation, it is also employed as a validation function when underlying truth is unknown. However, our empirical study indicates that the validation with check loss often leads to choosing an over estimated fits. In this work, we suggest a modified or L2-adjusted check loss which rounds the sharp corner in the middle of check loss. It has a large effect of guarding against over fitted model in some extent. Through various simulation settings of linear and non-linear regressions, the improvement of check loss by L2 adjustment is empirically examined. This adjustment is devised to shrink to zero as sample size grows.

Keywords: cross-validation, model selection, quantile regression, tuning parameter selection

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Authors: Rabbia Tariq, Hannan Sajjad, Mehreen Sirshar

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Design patterns are widely used to make the process of development easier as they greatly help the developers to develop the software. Different design patterns have been introduced till now but the behavior of same design pattern may differ in different domains that can lead to the wrong selection of the design pattern. The paper aims to discover the design patterns that suits best with respect to their domain thereby helping the developers to choose an effective design pattern. It presents the comprehensive analysis of design patterns based on different methodologies that include simulation, case study and comparison of various algorithms. Due to the difference of the domain the methodology used in one domain may be inapplicable to the other domain. The paper draws a conclusion based on strength and limitation of each design pattern in their respective domain.

Keywords: design patterns, evaluation, quality assurance, software domains

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Authors: Nuo Xu, Sijing Chen

Abstract:

Background: Childbirth is considered a critical traumatic event throughout our lives, positively or negatively impacting the mother's physiology, psychology, and even the whole family. Adverse birth experiences, such as labor pain, anxiety, and fear can negatively impact the mother. Studies had shown that the immersive nature of VR can distract attention from pain and increase focus on interventions for pain relief. However, the existing studies that applied VR to maternal delivery were still in their infancy and showed disparate results, and the small sample size is not representative, so this review analyzed the effects of VR in labor, such as on maternal pain and anxiety, with a view to providing a basis for future applications. Search strategy: We searched Pubmed, Embase, Web of Science, the Cochrane Library, CINAHL, China National Knowledge Infrastructure, Wan-Fang database from the building to November 17, 2021. Selection Criteria: Randomized controlled trials (RCTs) that intervened the pregnant women aged 18-35 years with gestational >34 weeks and without complications with VR technology were contained within this review. Data Collection and Analysis: Two researchers completed the study selection, data extraction, and assessment of study quality. For quantitative data we used MD or SMD, and RR (risk ratio) for qualitative data. Random-effects model and 95% confidence interval (95% CI) were used. Main Results: 12 studies were included. Using VR could relieve pain during labor (MD=-1.81, 95% CI (-2.04, -1.57), P< 0.00001) and active period (SMD=-0.41, 95% CI (-0.68, -0.14), P= 0.003), reduce anxiety (SMD=-1.39, 95% CI (-1.99, -0.78), P< 0.00001) and improve satisfaction (RR = 1.32; 95% CI (1.10, 1.59); P = 0.003), but the effect on the duration of first (SMD=-1.12, 95% CI (-2.38, 0.13), P=0.08) and second (SMD=-0.22, 95% CI (-0.67, 0.24), P=0.35) stage of labor was not statistically significant. Conclusions: Compared with conventional care, VR technology can relieve labor pain and anxiety and improve satisfaction. However, extensive experimental validation is still needed.

Keywords: virtual reality, delivery, labor pain, anxiety, meta-analysis, systematic review

Procedia PDF Downloads 88

Authors: Simona Capossela, Ramona Schaniel, Singer Franziska, Aquino Fournier Catharine, Daniel Stekhoven, Jivko Stoyanov

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A spinal cord injury (SCI) is a traumatic life event that often results in ageing associated health conditions such as muscle mass decline, adipose tissue increase, decline in immune function, frailty, systemic chronic inflammation, and psychological distress and depression. Psychological, oxidative, and metabolic stressors may facilitate accelerated ageing in the SCI population with reduced life expectancy. Research designs using biomarkers of aging and stress are needed to elucidate the role of psychological distress in accelerated aging. The aim of this project is a feasibility pilot study to observe changes in stress biomarkers and correlate them with aging markers in SCI patients during their first rehabilitation (longitudinal cohort study). Biological samples were collected in the SwiSCI (Swiss Spinal Cord Injury Cohort Study) Biobank in Nottwil at 4 weeks±12 days after the injury (T1) and at the end of the first rehabilitation (discharge, T4). The "distress thermometer" is used as a selfassessment tool for psychological distress. Stress biomarkers, as cortisol and protein carbonyl content (PCC), and markers of cellular aging, such as telomere lengths, will be measured. 2 Preliminary results showed that SCI patients (N= 129) are still generally distressed at end of rehabilitation, however we found a statistically significant (p< 0.001) median decrease in distress from 6 (T1) to 5 (T4) during the rehabilitation. In addition, an explorative transcriptomics will be conducted on N=50 SCI patients to compare groups of persons with SCI who have different trajectories of selfreported distress at the beginning and end of the first rehabilitation after the trauma. We identified 4 groups: very high chronic stress (stress thermometer values above 7 at T1 and T4; n=14); transient stress (high to low; n=14), low stress (values below 5 at T1 and T4; n=14), increasing stress (low to high; n=8). The study will attempt to identify and address issues that may occur in relation to the design and conceptualization of future study on stress and aging in the SCI population.

Keywords: stress, aging, spinal cord injury, biomarkers

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Authors: Afiq Mohd Fahmi, Tony Gutierrez, Sebastian Hennige

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Increasing amounts of CO₂ entering the marine environment, also known as ocean acidification, is documented as having harmful impacts on a variety of marine organisms. When considering the future risk of hydrocarbon pollution, which is generally detrimental to marine life as well, this needs to consider how OA-induced changes to microbial communities will compound this since hydrocarbon degradation is influenced by the community-level microbial response. This study aims to evaluate the effects of increased atmospheric CO₂ conditions and oil enrichment on the phytoplankton-associated bacterial communities. Faroe Shetland Channel (FSC) is a subarctic region in the northeast Atlantic where crude oil extraction has recently been expanded. In the event of a major oil spill in this region, it is vital that we understand the response of the bacterial community and its consequence on primary production within this region—some phytoplankton communities found in the ocean harbor hydrocarbon-degrading bacteria that are associated with its psychosphere. Surface water containing phytoplankton and bacteria from FSC were cultured in ambient and elevated atmospheric CO₂ conditions for 4 days of acclimation in microcosms before introducing 1% (v/v) of crude oil into the microcosms to simulate oil spill conditions at sea. It was found that elevated CO₂ conditions do not significantly affect the chl a concentration, and exposure to crude oil detrimentally affected chl a concentration up to 10 days after exposure to crude oil. The diversity and richness of the bacterial community were not significantly affected by both CO₂ treatment and oil enrichment. The increase in the relative abundance of known hydrocarbon degraders such as Oleispira, Marinobacter and Halomonas indicates potential for biodegradation of crude oil, while the resilience of dominant taxa Colwellia, unclassified Gammaproteobacteria, unclassified Rnodobacteria and unclassified Halomonadaceae could be associated with the recovery of microalgal community 13 days after oil exposure. Therefore, the microbial community from the subsurface of FSC has the potential to recover from crude oil pollution even under elevated CO₂ (750 ppm) conditions.

Keywords: phytoplankton, bacteria, crude oil, ocean acidification

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Authors: Min L. Stewart, Patrick Johnston

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Predictive coding has been proposed as a general explanatory framework for understanding the neural mechanisms of perception. As such, an underweighting of perceptual priors has been hypothesised to underpin a range of differences in inferential and sensory processing in autism spectrum disorders. However, empirical evidence to support this has not been well established. The present study uses an electroencephalography paradigm involving changes of facial identity and person category (actors etc.) to explore how levels of autistic traits (AT) affect predictive coding at multiple stages in the visual processing hierarchy. The study uses a rapid serial presentation of faces, with hierarchically structured sequences involving both periodic and aperiodic repetitions of different stimulus attributes (i.e., person identity and person category) in order to induce contextual expectations relating to these attributes. It investigates two main predictions: (1) significantly larger and late neural responses to change of expected visual sequences in high-relative to low-AT, and (2) significantly reduced neural responses to violations of contextually induced expectation in high- relative to low-AT. Preliminary frequency analysis data comparing high and low-AT show greater and later event-related-potentials (ERPs) in occipitotemporal areas and prefrontal areas in high-AT than in low-AT for periodic changes of facial identity and person category but smaller ERPs over the same areas in response to aperiodic changes of identity and category. The research advances our understanding of how abnormalities in predictive coding might underpin aberrant perceptual experience in autism spectrum. This is the first stage of a research project that will inform clinical practitioners in developing better diagnostic tests and interventions for people with autism.

Keywords: hierarchical visual processing, face processing, perceptual hierarchy, prediction error, predictive coding

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Authors: Ping-Ben Liu, Chien-Chou Tseng

Abstract:

The objective of this study is to investigate the relationship between the lift coefficient and dynamic behaviors of cavitating flow around a two-dimensional Clark Y hydrofoil at 8° angle of attack, cavitation number of 0.8, and Reynolds number of 7.10⁵. The flow field is investigated numerically by using a vapor transfer equation and a modified turbulence model which applies the filter and local density correction. The results including time-averaged lift/drag coefficient and shedding frequency agree well with experimental observations, which confirmed the reliability of this simulation. According to the variation of lift coefficient, the cycle which consists of growth and shedding of cavitation can be divided into three stages, and the lift coefficient at each stage behaves similarly due to the formation and shedding of the cavity around the trailing edge.

Keywords: Computational Fluid Dynamics, cavitation, turbulence, lift coefficient

Procedia PDF Downloads 343

Authors: Abdelghafour Galadi

Abstract:

In this paper, accurate power MOSFET models including quasi-saturation effect are presented. These models have no internal node voltages determined by the circuit simulator and use one JFET or one depletion mode MOSFET transistors controlled by an “effective” gate voltage taking into account the quasi-saturation effect. The proposed models achieve accurate simulation results with an average error percentage less than 9%, which is an improvement of 21 percentage points compared to the commonly used standard power MOSFET model. In addition, the models can be integrated in any available commercial circuit simulators by using their analytical equations. A description of the models will be provided along with the parameter extraction procedure.

Keywords: power MOSFET, drift layer, quasi-saturation effect, SPICE model

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Authors: Hamed Alipour-Banaei, Farhad Mehdizadeh

Abstract:

We report the design and characterization of ultra high quality factor filter based on one-dimensional photonic-crystal Thue-Morse sequence structure. The behavior of aperiodic array of photonic crystal structure is numerically investigated and we show that by changing the angle of incident wave, desired wavelengths could be tuned and a tunable filter is realized. Also it is shown that high quality factor filter be achieved in the telecommunication window around 1550 nm, with a device based on Thue-Morse structure. Simulation results show that the proposed structure has a quality factor more than 100000 and it is suitable for DWDM communication applications.

Keywords: Thue-Morse, filter, quality factor, photonic

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Authors: Rishabh Sharma

Abstract:

The main design parameter of WSN (wireless sensor network) is the energy consumption. To compensate this parameter, hierarchical clustering is a technique that assists in extending duration of the networks life by efficiently consuming the energy. This paper focuses on dealing with the WSNs and the FIS (fuzzy interface system) which are deployed to enhance the BEENISH protocol. The node energy, mobility, pause time and density are considered for the selection of CH (cluster head). The simulation outcomes exhibited that the projected system outperforms the traditional system with regard to the energy utilization and number of packets transmitted to sink.

Keywords: wireless sensor network, sink, sensor node, routing protocol, fuzzy rule, fuzzy inference system

Procedia PDF Downloads 98