Practical Scheduling Research Articles

Energy-Efficient Scheduling for Multiple Latency-Sensitive Bluetooth Low Energy Nodes

Energy-efficient scheduling in wireless embedded devices is a critical consideration due to limited energy supplies and the latency constraint of sensory data processing. Bluetooth low energy (BLE) is a low power solution that provides a user-defined connection interval parameter for extending the sleep time of BLE nodes. Instead of minimizing the values for this connection parameter to minimize latency, which can lead to excessive energy consumption, this paper presents a practical energy-efficient scheduling framework for multiple BLE devices having applications with latency constraints. First, we determine the required connection interval for a single BLE node with multi-rate sensing applications. Then, considering the scheduling issues caused by non-preemptive data transmission, we present an energy-efficient connection interval assignment for a sensor network with multiple BLE nodes to meet the latency constraints of sensing applications. Finally, based on the proposed connection interval determination, we propose a priority inversion awareness scheduler for the BLE master node to schedule all slave node transmissions in the network. Extensive experiments show that the proposed algorithms prolonged network lifetime by 235% compared with a simple pessimistic setting.

Channel transmission strategy for mmWave hybrid UAV communications with blockage

The blockage is a tough hurdle for millimetre-wave (mmWave) unmanned aerial vehicle (UAV) communications. In this Letter, the authors propose an angle domain channel transmission scheme for mmWave hybrid UAV communication with blockage. Firstly, they investigate the angle domain channel transmission of mmWave UAV communication systems with massive array antennas. Then, they solve the blockage problem through the multi-UAV coordination. Specially, they provide a practical user scheduling algorithm to maximize the achievable sum rates. Finally, simulation results are provided to show the effectiveness of the proposed method.

Practical Production Scheduling for Hot Metal Pretreatment-Steelmaking-Continuous Casting Process Involving Preventive Maintenance Consideration

Preventive maintenance is significant for health management of production system, while the maintenance plan is seldom simultaneously considered in the decision-making process of production scheduling. This paper studies a practical production scheduling problem for the hot metal pretreatment-steelmaking-continuous casting process involving preventive maintenance consideration (denoted as PSCCPM scheduling). A mathematical programming model is designed for the PSCCPM scheduling by considering constraints related to the maintenance plan and other production process requirements. An effective heuristic containing a machine allocation procedure and a conflict eliminate procedure is developed first to obtain a good feasible schedule of this model. Subsequently, by using the heuristic as a decoding algorithm, an adaptive genetic algorithm (AGA) featuring a novel adaptive evolutionary strategy is presented to obtain a suboptimal solution. Experimental results based on instances generated from a realistic steel plant show the effectiveness of the proposed AGA for solving PSCCPM scheduling problems.

Influence of Random and Blocked Practice Schedules on Motor Learning in Children Aged 6–12 Years

Influence of Random and Blocked Practice Schedules on Motor Learning in Children Aged 6–12 Years

Skinny blues: Karen Carpenter, anorexia nervosa and popular music

AbstractThis article discusses an extraordinary body in popular music, that belonging to the person with anorexia which is also usually a gendered body – female – and that of the singer or frontperson. I explore the relation between the anorexic body and popular music, which is more than simply looking at constructions of anorexia in pop. It involves contextually thinking about the (medical) history and the critical reception and representation, the place of anorexia across the creative industries more widely, and a particular moment when pop played a role in the public awareness of anorexia. Following such context the article looks in more detail at a small number of popular music artists who had experience of anorexia, their stage and media presentations (of it), and how they did or apparently did not explore their experience of it in their own work and public appearances. This close discussion is framed within thinking about the popular music industry's capacity for carelessness, its schedule of pressure and practice of destruction on its own stars, particularly in this instance its female artists. This is an article about a condition and an industry. At its heart is the American singer and drummer Karen Carpenter (1950–1983), a major international pop star in the 1970s, in the Carpenters duo with her brother Richard; the other figures discussed are Scottish child pop star Lena Zavaroni (1963–1999), and the Welsh rock lyricist, stylist and erstwhile guitarist of the Manic Street Preachers, Richey Edwards (1967–1995 missing/2008 officially presumed dead).

Efficient scheduling and power allocation for multiuser decoding receivers in OFDMA networks with minimum rate requirements

In recent years, techniques for exploiting interference on the receiver side to improve the performance of future cellular networks have been of interest. Due to the dominance of data in network traffic, user rate demands are becoming crucial for resource allocation of cells in the network.We propose an efficient transmission scheme for the downlink of an OFDMA multicell multiuser system with multiuser decoding (successive interference cancellation (SIC), joint decoding (JD), single decoding (SD)) capable receivers. We define a marginal rate maximization problem taking into account minimum rate demands of users and develop a practical scheduling (subchannel assignment) and power allocation algorithm using Lagrangian dual decomposition and gradient (ellipsoid and projected subgradient) methods. In the subchannel assignment, we propose the ratio of direct-to-cross channel strengths and multiuser rate regions different than the studies in the literature. Through Lagrangian dual decomposition, we derive the optimal power allocation rule using multiuser decoding modes for a given subchannel assignment.We observe that the method proposed here has low computational complexity and can be easily integrated to next generation networks as well as achieving high performance in practical scenarios.

Opposition multiple objective symbiotic organisms search (OMOSOS) for time, cost, quality and work continuity tradeoff in repetitive projects

AbstractConstruction managers often face with projects containing multiple units wherein activities repeat from unit to unit. Therefore effective resource management is crucial in terms of project duration, cost and quality. Accordingly, researchers have developed several models to aid planners in developing practical and near-optimal schedules for repetitive projects. Despite their undeniable benefits, such models lack the ability of pure simultaneous optimization because existing methodologies optimize the schedule with respect to a single factor, to achieve minimum duration, total cost, resource work breaks or various combinations, respectively. This study introduces a novel approach called “opposition multiple objective symbiotic organisms search” (OMOSOS) for scheduling repetitive projects. The proposed algorithm used an opposition-based learning technique for population initialization and for generation jumping. Further, this study integrated a scheduling module (M1) to determine all project objectives including time, cost, quality and interruption. The proposed algorithm was implemented on two application examples in order to demonstrate its capabilities in optimizing the scheduling of repetitive construction projects. The results indicate that the OMOSOS approach is a powerful optimization technique and can assist project managers in selecting appropriate plan for project.Highlights This study presents an advanced multiple optimization algorithm OMOSOS. Opposition technique is utilized to spreading the initial population and generation jumping. OMOSOS is applied to solve time, cost, quality and work continuity tradeoff problem. The model performance is demonstrated in the experimental results.

Task engagement and mental workload involved in variation and repetition of a motor skill

Explanatory hypotheses proposed in behavioral studies assumed that less repetitive practice schedules, such as random practice, seem to demand greater cognitive effort than more repetitive types of practice organization, such as constant. All of these hypotheses emphasize the enhanced demand to memory processes promoted by less repetitive practice schedules. In the present study, we investigated the cognitive effort involved in random and constant practice schedules with an electrophysiological approach. Twenty-one male participants practiced a sequential key-pressing task with two goals: learning the relative timing dimension and learning the absolute timing dimension. Sixty trials were performed in a constant practice schedule (only one absolute timing goal), and sixty trials were performed in random order (three absolute timing goals). Two electroencephalography based measures of cognitive states were used: (a) task engagement (sensory processing and attention resources) and (b) mental workload (working memory load). The results showed that random practice induced greater cognitive effort than constant practice when task engagement was analyzed. Throughout practice, both task engagement and mental workload decreased more in the constant practice condition than in the random practice condition. The increased demand for sensory processing observed in random practice opens a new exciting field of study in practice organization.

Cyclic Scheduling of Multi-Cluster Tools Based on Mixed Integer Programming

Multi-cluster tools are automated equipment which is increasingly used in semiconductor manufacturing. The scheduling of multi-cluster tools is much more challenging than single-cluster tools due to multi-robot coordination and increasing chambers. In this paper, we develop a mixed integer programming (MIP) model which manages to formulate the multi-robot coordination for cyclic scheduling of multi-cluster tools. Three reformulations of the model are implemented: 1) linearization; 2) eliminating integer variables; and 3) tightening constraints. The first reformulation is designed to make the MIP model solvable by commercial solvers while the other two are intended for promoting computational efficiency which is critical when chambers increase. The proposed model can meet various practical scheduling requirements such as dual-armed robots, wafer residency time constraints, parallel and reentrant processes in multi-cluster tools. Experimental results demonstrate the efficiency of the proposed method.

Cellular-D2D resource reuse algorithms based on proportional fairness

Device-to-device (D2D) communication can improve coverage, spectrum efficiency, and energy efficiency based on the current cellular network architecture. The fair scheduling for D2D communication in the orthogonal frequency division multiple access-based cellular network is studied in this paper. Based on the proportional fairness criteria, the optimization objective is formulated to maximize the sum of the relative achievable rate of both cellular users (CUs) and D2D pairs. It is a hybrid optimization problem since it involves in both the resource reuse and the transmit power control. A practical proportional fairness scheduling (PFS) algorithm is proposed. Firstly, the admissible area is decided according to the transmit power limitation of terminals and the quality of service (QoS) requirement. Next, we seek the optimal transmit power combination for the CU and D2D pair in the admissible area and it is demonstrated that the optimal value can be selected from several points on the border of the admissible area. Lastly, when multiple subchannels can be employed for scheduling, based on the generated bipartite graph, Hungarian algorithm is adopted to realize maximum matching, i.e., select reusable CUs and D2D pairs to maximize the sum of the relative achievable rates. The simulation results show that PFS algorithm can guarantee the excellent performance of both throughput and fairness.

Status and Countermeasure Study on Physical Education Teaching Practice

Objective: Teaching practice is an organic part in the process of physical education, is the only way to foster a qualified sports teacher, and a main way to evaluate quality of talents cultivated by universities in an all-round manner. Method: In the paper, literature consultation, questionnaire survey and other methods were applied to investigate on physical education teaching practice status, and countermeasure study was made on problems in practice process and suggestions were put forward accordingly. Process: We conducted exploration from physical education teaching practice’s trial teaching, practice preparation, practice school’s basic information, practice schedule, practice location and advisors status, intern students’ status as well as feedback by the end of practice in accordance with time sequence that intern students participated in teaching practice. Results: We found that there are some problems, such as low satisfaction with trial teaching, single way of intern students’ practice units’ selection, excessive concentrated practice bases, insufficient intern class hour for intern students, incomplete implementation of probation stage in teaching practice, irresponsible advisors and so on. By doing so, we would provide specific practice experience and theoretical evidence for standardizing and effectively promoting physical education teaching practice, and offer reference data for the progress of Chinese physical education.

Dyad Practice Impacts Self-Directed Practice Behaviors and Motor Learning Outcomes in a Contextual Interference Paradigm

ABSTRACTWe studied dyad practice to determine whether and how alternating practice blocks with a partner impacts self-directed practice scheduling, learning, and perceptions of practice. Participants were assigned to be Partner 1 (P1) or 2 (P2). P1s had a blocked, random, or self-directed schedule, while all P2s self-directed practice of 3, differently-timed keystroke-sequences. P2s showed both own error-dependent practice (switching sequences following better performance) and partner-dependent practice, with the partner's schedule impacting sequence selection and switching frequency. A partner's schedule also impacted learning. Random practice resulted in better timing accuracy than blocked practice for both partners in an immediate and delayed retention test. These data give evidence that self-directed practice behaviors and learning outcomes are modulated by a partner's practice schedule.

Developing the National Family Medicine Graduate Survey.

Developing the National Family Medicine Graduate Survey.

Utility of Automated Calls for Filling Care Gaps in Medical Practice: A 1-Year Initial Experience: 2017 Presidential Poster Award

Introduction: Automated outreach systems have been used in several clinical settings to reduce readmission rates, improve outcomes for chronic illness and reduce health-care utilization. To assess the potential for automated post-encounter calls to close common care gaps and those caused by service disruptions in an outpatient clinical practice, we reviewed the first full-year experience in a single-specialty gastroenterology practice. Methods: Automated post-encounter phone calls were made to all patients seen in the clinic during 2016. After confirming the identity of the patient accepting the call, the system asked four questions to identify care gaps related to instructions received during the visit, prescriptions, additional scheduling needs, and overall patient satisfaction. Data collected through an integrated dashboard was reviewed and analyzed for reach rates, issues opened for further staff action, types of care gaps identified, issue resolution rates, and staff actions taken. The practice schedule was examined to identify events during the year that might have disrupted service in the practice. Results: The system performed outreach in the form of automated telephone calls for 9,593 clinic visits, with a success rate of 82% (7,853 patients reached regarding their visit). Of these, 1,677 calls resulted in an issue opened for a staff response (21.4% of patients reached) in 55 different identified categories. A large number of issues opened were attributable to patient mistakes or improper documentation by staff. Patient satisfaction concerns resulted in 170 issues (2.1% of patients reached). Clinically important care gaps were identified in 462 issues (5.9% of patients reached). The ten most frequent issues comprised 474 (75.0%) of the 632 clinical or satisfaction issues opened. Of these, the most frequent issues were triggered by patient questions about instructions (187), prescription medications (120) and care coordination (105). When these issues were compared against known service disruption events that affected the practice during the year, the patterns detected suggest correlations. Conclusion: The automated outreach system resulted in a high reach rate and identified many clinically important service gaps for corrective actions. With small adjustments in the implementation process this type of hybrid-automated outreach system may improve care and mitigate the negative impact of service disruptions in outpatient clinical practice.Figure: Post-Visit Automated Call Engagement Metrics by Month.Figure: Most Frequent (“Top 10”) Actions Taken by Wichita Falls GI Associates Staff in 2016 by Month.Figure: WFGIA Care Gap Documentation and Key Service Disruptions by Month.

A dispatching rule and a random iterated greedy metaheuristic for identical parallel machine scheduling to minimize total tardiness

This paper addresses a real-life production scheduling problem with identical parallel machines, originating from a plant producing Acrylonitrile-Butadiene-Styrene (ABS) plate products. In the considered practical scheduling problem, ABS plate has some specific specifications and each specification has several different levels. Because there is at least one different level of specification between two ABS plate products, it is necessary to make a set-up adjustment on each machine whenever a switch occurs from processing one ABS plate product to another product. As tardiness leads to extra penalty costs and opportunity losses, the objective of minimising total tardiness has become one of the most important tasks for the schedule manager in the plant. The problem can be classified as an identical parallel machine scheduling problem to minimise the total tardiness. A dispatching rule is proposed for this problem and evaluated by comparing it with the current scheduling method and several existing approaches. Moreover, an iterated greedy-based metaheuristic is developed to further improve the initial solution. The experimental results show that the proposed metaheuristic can perform better than an existing tabu search algorithm, and obtain the optimal solution for small-sized problems and significantly improve the initial solutions for large-sized problems.

An innovative artificial bee colony algorithm and its application to a practical intercell scheduling problem

ABSTRACTIn this article, an innovative artificial bee colony (IABC) algorithm is proposed, which incorporates two mechanisms. On the one hand, to provide the evolutionary process with a higher starting level, genetic programming (GP) is used to generate heuristic rules by exploiting the elements that constitute the problem. On the other hand, to achieve a better balance between exploration and exploitation, a leading mechanism is proposed to attract individuals towards a promising region. To evaluate the performance of IABC in solving practical and complex problems, it is applied to the intercell scheduling problem with limited transportation capacity. It is observed that the GP-generated rules incorporate the elements of the most competing human-designed rules, and they are more effective than the human-designed ones. Regarding the leading mechanism, the strategies of the ageing leader and multiple challengers make the algorithm less likely to be trapped in local optima.

Effects of practice schedule and task specificity on the adaptive process of motor learning

This study investigated the effects of practice schedule and task specificity based on the perspective of adaptive process of motor learning. For this purpose, tasks with temporal and force control learning requirements were manipulated in experiments 1 and 2, respectively. Specifically, the task consisted of touching with the dominant hand the three sequential targets with specific movement time or force for each touch. Participants were children (N=120), both boys and girls, with an average age of 11.2years (SD=1.0). The design in both experiments involved four practice groups (constant, random, constant–random, and random–constant) and two phases (stabilisation and adaptation). The dependent variables included measures related to the task goal (accuracy and variability of error of the overall movement and force patterns) and movement pattern (macro- and microstructures). Results revealed a similar error of the overall patterns for all groups in both experiments and that they adapted themselves differently in terms of the macro- and microstructures of movement patterns. The study concludes that the effects of practice schedules on the adaptive process of motor learning were both general and specific to the task. That is, they were general to the task goal performance and specific regarding the movement pattern.

Investigating Optimal Memory Enhancement Procedures in Foreign Language Learning

SummaryWe investigated the effects of learning schedule and multi‐modality stimulus presentation on foreign language vocabulary learning. In Experiment 1, participants learned German vocabulary words utilizing three learning methods that were organized either in a blocked or interleaved fashion. We found interleaving with the keyword mnemonic and rote study advantageous over blocking, but retrieval practice was better served in a blocked schedule. It is likely that the excessively delayed feedback for the retrieval practice in the interleaved practice schedule impeded learning while the spacing involved in the interleaved schedule enhanced learning in the keyword mnemonic and rote study. In Experiment 2, we examined whether a multi‐modality stimulus presentation from visual and auditory channels is better suited for aiding learning over a visual presentation condition. We found benefits of multi‐modality presentation only for the keyword mnemonic condition, presumably because the nature of the keyword mnemonic involving sound and visualization was particularly relevant with the multi‐modality presentation. The present study suggests that optimal foreign language learning environments should incorporate learning schedules and multimedia presentations based on specific learning methods and materials. Copyright © 2017 John Wiley & Sons, Ltd.

Procedural Memory Consolidation in Attention-Deficit/Hyperactivity Disorder Is Promoted by Scheduling of Practice to Evening Hours.

In young adults without attention-deficit/hyperactivity disorder (ADHD) training on a novel movement sequence results not only in large within-session (online) gains in task performance but also in additional (delayed, off-line) gains in the performance, expressed after an interval of sleep. In contrast, young people with ADHD, given an identical practice, were shown to improve online but expressed much smaller delayed gains overnight. As delayed gains in performance are taken to reflect procedural (“how to”) memory consolidation processes, this may explain skill learning deficits in persons with ADHD. However, motor training is usually provided in morning sessions, and, given that persons with ADHD are often evening types, chronobiological constraints may constitute a hidden factor. Here, we tested the hypothesis that evening training, compared to morning training, would result in larger overnight consolidation gains following practice on a novel motor task in young women with ADHD. Participants with (N = 25) and without (N = 24) ADHD were given training on a finger opposition sequence tapping task, either in the morning or at evening. Performance was assessed before and immediately after training, overnight, and at 2 weeks post-training. Individuals with ADHD reported a general preference for evening hours. Evening training was equally effective in participants with and without ADHD, both groups showing robust consolidation gains in task performance overnight. However, the ability to express delayed gains overnight was significantly reduced in participants with ADHD if trained in the morning. Typical peers were as effective in expressing overnight consolidation phase gains irrespective of the time-of-day wherein the training session was afforded. Nevertheless, even after morning training, participants with ADHD fully retained the gains acquired within the first 24 h over an interval of about 2 weeks. Our results suggest that procedural memory consolidation processes are extant and effective in ADHD, but require that specific biobehavioral conditions be met. The affordance of training in the evening hours can relax some of the constraints on these processes in ADHD. The current results are in line with the notion that the control of what is to be retained in procedural memory is atypical or more stringent in ADHD.

Evaluating the effect of instruction and practice schedule on the acquisition of ECG interpretation skills.

IntroductionEvidence of the benefit of distributed instruction and interleaved practice comes from studies using simple materials (e. g. word pairs). Furthermore, there is currently no evidence of the combined impact of these strategies in undergraduate medical education. The present study evaluated the impact of varying both instruction and practice schedules for the acquisition of ECG interpretation skills.MethodsWe conducted a 2 × 2 factorial study with two levels of instruction (massed and distributed) and two levels of practice (interleaved and blocked). A three-module introductory course in ECG interpretation was delivered to 80 first year medical undergraduate students. Students were assigned to one of four Instruction-Practice conditions: Massed-Interleaved, Massed-Blocked, Distributed-Interleaved and Distributed-Blocked. Learning was evaluated by a multiple choice quiz at the end of each module and a final multiple choice quiz at the end of the course.ResultsEnd of module mean scores showed that distributed instruction was consistently superior to massed instruction (52% vs 42%, p < 0.01). However, there was no effect of practice and no interaction between teaching and practice methods. The delayed final test scores revealed an advantage for blocked over mixed practice (34% vs 24%, p < 0.05) and distributed over massed instruction (34% vs 24%, p < 0.05).DiscussionThese results suggest that these popular strategies may have varying effects with complex learning materials. Further research is required to understand how these strategies affect the learning of simple and very complex skills.Electronic supplementary materialThe online version of this article (doi: 10.1007/s40037-017-0365-x) contains supplementary material, which is available to authorized users.