Scheduling Software Research Articles

A two-stage stochastic programming approach to employee scheduling in retail outlets with uncertain demand

This paper describes an employee scheduling system for retail outlets; it is a constraint-based system that exploits forecasts and stochastic techniques to generate schedules meeting the demand for sales personnel. Uncertain scenarios due to fluctuating demand are taken into account to develop a stochastic operational optimization of staffing levels. Mathematically, the problem is stated as a mixed-integer linear programming problem. Simulations with store data belonging to a major Swiss retailer show the effective performance of the proposed approach. The schedule quality is assessed through comparison with a deterministic scheduling package, which has been used at several outlets in Switzerland.

A Genetic Algorithm for Optimal Resource-driven Project Scheduling

Resource allocation optimization is one of the most challenging problems in project management. It is a combinatorial problem with multiple objectives (project duration confinement, resource-constrained allocation, resource leveling) and its size and complexity grows exponentially as the number of activities, resource types, and execution modes increase. Existing studies bound the analysis on specific aspects of the problem or include simplifying assumptions which may not adequately represent actual (construction) projects. They typically incorporate only a few alternative activity execution modes while it is known (and also handled by popular project management software) that activities can be frequently executed in several arrangements by simply adjusting their gang size and duration. In this work, an optimization method for multi-objective resource-constrained scheduling is developed which evaluates several resource-duration alternatives within each activity. The current optimization aims at minimizing the total cost that results from (a) resource overallocation, (b) project deadline exceedance, and (c) day-by- day resource fluctuations. All three sub-objectives are represented by cost functions after assigning unit cost values to each deviation from the corresponding goal. As a result, the whole optimization parameter is a pure cost variable avoiding thus the need for subjectively setting importance weights among dissimilar parameters (as, for instance, the standard deviation of the resource histogram as a means to determine the resource levelling success). Due to the large number of activity execution alternatives, a genetic algorithm has been employed for the optimization. The algorithm has been tested with several test cases and the results were compared to those developed by the Microsoft Project. The evaluation indicates that the proposed algorithm can provide adequate and balanced solutions with regard to the three objectives and that these solutions are better than those provided by commercial project scheduling software.

Deployment of query plans on multicores

Efficient resource scheduling of multithreaded software on multicore hardware is difficult given the many parameters involved and the hardware heterogeneity of existing systems. In this paper we explore the efficient deployment of query plans over a multicore machine. We focus on shared query systems, and implement the proposed ideas using SharedDB. The goal of the paper is to explore how to deliver maximum performance and predictability, while minimizing resource utilization when deploying query plans on multicore machines. We propose to use resource activity vectors to characterize the behavior of individual database operators. We then present a novel deployment algorithm which uses these vectors together with dataflow information from the query plan to optimally assign relational operators to physical cores. Experiments demonstrate that this approach significantly reduces resource requirements while preserving performance and is robust across different server architectures.

System Application of Genetic Algorithm for Scheduling Optimization Study Using Java (Case Study : Department of Computer System UNTAN)

cheduling of lecture in a university is a college activities into the work place and time that there is room in such a way so as to minimize the violation of the scheduling problems of a lecture. Problems that are often referred to as the University timetabling problem ( UTP ) is, requires a lot of consideration include the number of students, number of teachers who are not proportional to the number of courses, the amount of space used, as well as lecture predetermined time. Scheduling lectures with the automation system is very important because it can save you hours of work and provide optimum solutions in a short time, which can increase productivity, the quality of teaching and learning, and quality of service. One method that can be used to complete the course scheduling problem is a genetic algorithm approach. Genetic algorithm is an optimization tool that models the principles of evolution. Genetic algorithm is able to find a globally optimum solution in the search space is very complex. By using an initial population of solutions is encoded and selected based on its quality, and then used to create a new population using crossbreeding and mutation process of the initial individuals. Evaluation function is used to calculate the hard constraints and soft constraints can be met. This study discusses the scheduling college located in Department of Computer Systems Untan. The purpose of study is to optimize the college scheduling and to make easier the scheduling job with make a college scheduling software

BDM기법에 의한 LOB와 TACT기법 통합

Controversies over that the scheduling practices for the construction projects in Korea are unsystematic, illogical, and less advanced still continue. One of the main controversial issues is that the existing scheduling techniques does not satisfy the scheduling requirements of construction site. Because most construction personnel prefer a good-looking and easy understanding schedule, LOB and TACT techniques although those are not formal CPM technique have been applying overwhelmingly in the construction projects. Moreover, LOB and TACT techniques can be quickly and conveniently established by Excel or word-processor familiar with most people. Since Excel is not a formal scheduling software, however, it can not provide formal CPM scheduling practices. The purpose of this study is to propose the method that can satisfy visual schedule format as well as perform formal CPM scheduling practices by integration of LOB and TACT techniques by BDM technique.

Features of RadioAstron Mission Control

Support means of the Spektr-R spacecraft flight and features of the Mission Control Center operation and spacecraft control are considered. Software for scheduling and preparing sessions of controlling and simulating for the spacecraft operation are considered. The problems of ballistic navigation support of the spacecraft flight are presented. Ground spacecraft control segment and software for analyzing and imaging telemetric information are considered.

Continuous interprofessional coordination in perioperative work: an exploratory study

Coordination of perioperative work is challenging. Advancements in diagnostic and therapeutic possibilities have not been followed by similar advancements in the ability to coordinate care. In this paper, we report on a study that explored the nature of continuous coordination as practiced by perioperative staff in order to coordinate their own activities with respect to those of their colleagues. We conducted in-depth interviews (n = 14), and combined observations and focused interviews (n = 31) with perioperative staff (physicians, nurses, technicians, and cleaners) at a major university hospital in Norway. Data were analysed qualitatively with systematic text condensation. The results indicated that a surgical schedule was important for informing staff members about the cases and tasks they had been assigned. Staff also depended on ad hoc, explicit communication to ensure timeliness of particular perioperative activities. This, however, left little room for adjustments of other activities. Hence, to be able to proactively coordinate their own work some staff tried to predict future perioperative activities by observing the workplace, monitoring the surgical scheduling software for changes, and sharing their colleagues' progress updates and predictions. These findings could be important for those developing support for perioperative coordination.

IPR Beamline for Macromolecular Assemblies at SPring-8 (BL44XU)

Biological macromolecular assemblies play significant roles in many biological reaction systems, including energy transfer, protein synthesis, protein degradation and signal transduction. A detailed understanding of the functions of the macromolecular assemblies requires information derived from three-dimensional atomic structures. X-ray crystal structure analysis is one of the most powerful methods to determine the three-dimensional structures of macromolecular assemblies at atomic level. Since features of crystals of biological macromolecular assemblies are extremely weak diffraction power and narrow space between the diffraction spots, it is essential to use high brilliance and high paralleled synchrotron radiation for diffraction data collection from crystals of biological macromolecular assemblies. The Institute for Protein Research (IPR) of Osaka University is operating a beamline for crystal structure analysis of biological macromolecular assemblies at SPring-8 (BL44XU). This beamline is designed to collect high quality diffraction data from biological macromolecular assembly crystals with large unit cells. The light source of this beamline is a SPring-8 standard type in-vacuum undulator. Liquid nitrogen cooled double crystal monochromator and horizontal focusing mirror are used as the optical components. BSS (Beamline Scheduling Software), which is SPring-8 protein crystallography beamline standard GUI, is installed to unify user operation throughout protein crystallography beamlines in the SPring-8. We have recently upgraded to a high speed air-bearing goniostat and installed a high performance CCD detector, MX-300HE. Present status and future plan of the beamline will be presented.

A Schedule Optimization Tool for Destructive and Non-Destructive Vehicle Tests

Whenever an auto manufacturer refreshes an existing car or truck model or builds a new one, the model will undergo hundreds if not thousands of tests before the factory line and tooling is finished and vehicle production beings. These tests are generally carried out on expensive, custom-made vehicles because the new factory lines for the model do not exist yet. The work presented in this paper describes how an existing intelligent scheduling software framework was modified to include domain-specific heuristics used in the vehicle test planning process. The result of this work is a prototype scheduling tool that optimizes the overall given test schedule in order to complete the work in a given time window while minimizing the total number of vehicles required for the test schedule. Initial results are presented that show a reduction in required test vehicles compared to manual scheduling of the same tasks as well as increased capability to ask “what-if” questions to further improve the schedule.

Automated safety planning approach for residential construction sites in Malaysia

Construction continues to be considered as one of the most dangerous industries in the world, in particular residential building construction. This paper aims at proposing an automated safety planning plug-in (ASPP) for project scheduling software applications to mitigate the occurrence of construction accidents. To achieve this aim, frequency and severity of the common construction safety hazards in residential buildings were investigated by distributing a questionnaire among various safety managers and construction managers in Malaysia. A total of 106 completed responses were received. The risk level associated to each hazard was calculated based on the relevant risk matrix. The ASPP extracts current construction activities from any computer-based schedule (Microsoft Project® in this paper) and identifies their risk levels as well as safety regulations and hazards related to each activity as a report. The reliability and usability of ASPP was tested in a case study. The ASPP was found to be efficient and helpful for rigorously complying with safety regulations and control potential hazards. The practical implication of this study is to improve construction safety by promoting the project managers' awareness of safety hazards and relevant risks as well as essential safety measures provided through a comprehensive report from which managers can review essential safety measures to prevent possible construction accidents.

Abstract 265: TeleStroke: Expanding Access and Coordination of Care from Acute Stroke to Follow-up

Background: The University of Utah Medical Center (UUMC) serves a wide geographical area, encompassing 10% of the continental US landmass. Stroke patients are often transported from remote facilities for specialty care. The UUMC Telestroke Center routinely provides acute care, but has only rarely been used for outpatient follow-up. The objective of this study was to develop a novel pathway for follow-up care after inpatient admissions for acute ischemic stroke (AIS) utilizing the existing telestroke infrastructure, with the goals of improving quality outcomes, reducing patient costs, and increasing access to care. Methods: Utilizing LEAN methodology, the existing care model was process-mapped to assess for potential areas of improvement. Over one month in 2013, a convenience sample of 27 inpatients admitted with AIS were surveyed to assess for potential barriers associated with travel to appointments, as well as for attitudes towards utilizing tele-health technologies for follow-up care. We analyzed primary residence patient zip-codes to determine which communities might be optimal for tele-health follow-up visits. Results: Ten patients (37%) lived ≤50 miles from UUMC; 7 (26%) 51-100 miles; 8 (30%)101-500 miles; and 2 (7.4%) > 500 miles away. Patients estimated the costs associated with a visit (excluding appointment fees) as: $0-9 (3.8%), $10-100 (42.3%), $101-500 (38.5%), $501-1000 (11.5%), and >$1000 (3.8%). Twenty-two patients (88%) said they would be interested in a tele-followup visit if it were closer to home and/or reduced travel time, and 59% of respondents said they would actually prefer this option to an in-office visit. Due to these results, an ideal community clinic partner was identified based upon geographic patient demographics, existing tele-health infrastructure, university-based scheduling, shared billing and meaningful-use software, and an expressed interest in collaboration. Follow-up tele-visits will link a stroke specialist physician at UUMC with a patient at the community clinic via 2-way audio-video telehealth equipment. A medical assistant with additional training in the neurologic exam will help facilitate the visit. Clinic training and coordination has already occurred, and a go-live date is anticipated for late February 2014. Discussion: A proof-of-concept health care model has been established at UUMC to provide tele-health follow-up after AIS admission to reduce significant barriers to follow-up care. Outcome metrics will include patient satisfaction, stroke and all cause readmission rates, medication compliance, and outpatient follow-up rates. Beyond increasing access to care, we hope that utilizing remote sites for follow-up will increase communication and coordination with primary care providers at these sites, in essence building a remote care “neighborhood” for our patients and optimizing care after discharge.

Prediction Model for Object Oriented Software Development Effort Estimation Using One Hidden Layer Feed Forward Neural Network with Genetic Algorithm

The budget computation for software development is affected by the prediction of software development effort and schedule. Software development effort and schedule can be predicted precisely on the basis of past software project data sets. In this paper, a model for object-oriented software development effort estimation using one hidden layer feed forward neural network (OHFNN) has been developed. The model has been further optimized with the help of genetic algorithm by taking weight vector obtained from OHFNN as initial population for the genetic algorithm. Convergence has been obtained by minimizing the sum of squared errors of each input vector and optimal weight vector has been determined to predict the software development effort. The model has been empirically validated on the PROMISE software engineering repository dataset. Performance of the model is more accurate than the well-established constructive cost model (COCOMO).

When Does the Devil Make Work? An Empirical Study of the Impact of Workload on Worker Productivity

We analyze a large, detailed operational data set from a restaurant chain to shed new light on how workload (defined as the number of tables or diners that a server simultaneously handles) affects servers' performance (measured as sales and meal duration). We use an exogenous shock—the implementation of labor scheduling software—and time-lagged instrumental variables to disentangle the endogeneity between demand and supply in this setting. We show that servers strive to maximize sales and speed efforts simultaneously, depending on the relative values of sales and speed. As a result, we find that, when the overall workload is small, servers expend more and more sales efforts with the increase in workload at a cost of slower service speed. However, above a certain workload threshold, servers start to reduce their sales efforts and work more promptly with the further rise in workload. In the focal restaurant chain, we find that this saturation point is currently not reached and, counterintuitively, the chain can reduce the staffing level and achieve both significantly higher sales (an estimated 3% increase) and lower labor costs (an estimated 17% decrease). This paper was accepted by Noah Gans, special issue on business analytics.

Simulation on the Optimized Scheduling of Multi-Tenant Software under Cloud Computing Environment

Multi-tenant software scheduling strategy based on hybrid genetic algorithm and ant colony algorithm was proposed, scheduling resource and scheduling tasks were dispersed into multiple resource nodes and task nodes, encoded on the chromosome through natural number, the fitness function was utilized to assess the quality of chromosomes, according to fitness value to the individual offspring obtained by genetic algorithms, in order to get the best individual as initial value. Experimental results show that the proposed method using multi-tenant software scheduling are better than traditional methods on run-time, the performance of resource utilization, with a stronger multi-tenant software scheduling capability.

A New Multi-Tiered Solid State Disk Using Slc/Mlc Combined Flash Memory

Storing digital information, ensuring the accuracy, steady and uninterrupted access to the data are considered as fundamental challenges in enterprise -class organizations and companies. In recentyears, new types of storage systems such as solid state disks (SSD) have been introduced. Unlike hard disks that have mechanical structure, SSDs are based on flash memory and thus have electronic structure. Generally a SSD consists of a number of flash mem ory chips, some buffers of the volatile memory type, and an embedded microprocessor, which have been interconnected by a port. This microprocessor run a small file system which called flash translation layer (FTL). This software controls and schedules buff ers, data transfers and all flash memory tasks. SSDs have some advantages over hard disks such as high speed, low energy consumption, lower heat and noise, resistance against damage, and smaller size. Besides, some disadvantages such as limited endurance a nd high price are still challenging. In this study, the effort is to combine two common technologies- SLC and MLC chips- used in the manufacture of SSDs in a single SSD to decrease the side effects of current SSDs. The idea of using multi -layer SSD is regarded as an efficient solution in this field.

Annual coordinated generation and transmission maintenance scheduling considering network constraints and energy not supplied

Summary Most generation and transmission maintenance scheduling (GTMS) packages consider preventive maintenance scheduling over a 1- or 2-year time horizon to lessen the total operation costs while fulfilling system energy requirements. This paper proposes a security-constrained model for the GTMS problem. For a more realistic study, system reliability indices such as amount of not supplied energy are taken into account. The impact of load curve on the GTMS problem is investigated by a penalty factor. Unlike some previous studies that consider a fixed period for all unit maintenance windows, here various maintenance windows are considered for the system that is more realistic. Considering the problem that contains integer variables and taking into account the proposed model that is based on optimal generation and maintenance costs, mixed integer programming is employed to obtain the most accurate results by branch-and-bound algorithm. An IEEE 24-bus reliability test system is employed for simulation and to show the accuracy of results. As demonstrated, system's security and reliability constraints like penalty factor, transmission safety, and energy not supplied may affect GTMS and alter system maintenance and operation costs. These strategies may lead to increases in unit operation or maintenance costs while varying units and transmission maintenance scheduling. Copyright © 2014 John Wiley & Sons, Ltd.

HARS

The current trend in embedded computing consists in increasing the number of processing resources on a chip. Following this paradigm, cluster-based many-core accelerators with a shared hierarchical memory have emerged. Handling synchronizations on these architectures is critical since parallel implementations speed-ups of embedded applications strongly depend on the ability to exploit the largest possible number of cores while limiting task management overhead. This article presents the combination of a low-overhead complete runtime software and a flexible hardware accelerator for synchronizations called HARS (Hardware-Assisted Runtime Software). Experiments on a multicore test chip showed that the hardware accelerator for synchronizations has less than 1% area overhead compared to a cluster of the chip while reducing synchronization latencies (up to 2.8 times compared to a test-and-set implementation) and contentions. The runtime software part offers basic features like memory management but also optimized execution engines to allow the easy and efficient extraction of the parallelism in applications with multiple programming models. By using the hardware acceleration as well as a very low overhead task scheduling software technique, we show that HARS outperforms an optimized state-of-the-art task scheduler by 13% for the execution of a parallel application.

New VLBI2010 scheduling strategies and implications on the terrestrial reference frames.

In connection with the work for the next generation VLBI2010 Global Observing System (VGOS) of the International VLBI Service for Geodesy and Astrometry, a new scheduling package (Vie_Sched) has been developed at the Vienna University of Technology as a part of the Vienna VLBI Software. In addition to the classical station-based approach it is equipped with a new scheduling strategy based on the radio sources to be observed. We introduce different configurations of source-based scheduling options and investigate the implications on present and future VLBI2010 geodetic schedules. By comparison to existing VLBI schedules of the continuous campaign CONT11, we find that the source-based approach with two sources has a performance similar to the station-based approach in terms of number of observations, sky coverage, and geodetic parameters. For an artificial 16 station VLBI2010 network, the source-based approach with four sources provides an improved distribution of source observations on the celestial sphere. Monte Carlo simulations yield slightly better repeatabilities of station coordinates with the source-based approach with two sources or four sources than the classical strategy. The new VLBI scheduling software with its alternative scheduling strategy offers a promising option with respect to applications of the VGOS.

Implementation of Energy Storage System with Fleet Management on Electric Shuttle Buses

Electric public bus scheduling problem is studied for the service in Chulalongkorn university campus. This paper presents an integrated bus scheduling simulation combined with options of energy storage system with the target to minimize the wait time. The bus system is simulated by Arena software for the bus scheduling. The solution dictates the change of the bus schedule; the resulting change of wait time is then observed. Lead-acid equipped with supercapacitor and lithium-ion batteries were compared in this study to exhibit the improved performance. The supercapacitor hybrid and lithium-ion battery provides an improvement of 14% and 45.7% in discharge energy, respectively. The supercapacitor hybrid was shown to reduce battery stress as well as improved driving dynamics. The optimized lead-acid case can reduce the waiting time significantly and at the similar level to the supercapacitor hybrid. With much higher cost, the lithium-ion battery reduce the waiting time the most by 25% due to its superior energy efficiency as well as shorter charging period.

Using Object-Relational Mapping to Create the Distributed Databases in a Hybrid Cloud Infrastructure

One of the challenges currently problems in the use of cloud services is the task of designing of data management systems. This is especially important for hybrid systems in which the data are located in public and private clouds. Implementation monitoring functions querying, scheduling and processing software must be properly implemented and is an integral part of the system. To provide these functions is proposed to use an object-relational mapping (ORM). The article devoted to presenting the approach of designing databases for information systems hosted in a hybrid cloud infrastructure. It also provides an example of the development of ORM library.