Schedule Delays Research Articles

Resource Allocation in 5G Platoon Communication: Modeling, Analysis and Optimization

New features brought by 5 G New Radio V2X (NR-V2X) support multiple vehicular communication types (unicast, groupcast, and broadcast) to coexist in road scenarios. However, the current standard does not specify the resource scheduling approach for groupcast to support such a new feature, which may severely degrade its packet delivery performance impacted by other communication types. In this paper, we investigate the scheduling and resource allocation approaches for a groupcast-based application, vehicle platooning, under the environment characterizing this new feature. We first analyze two baseline resource allocation approaches, i.e., Semi-persistent Scheduling (SPS) stated in the 3 rd generation partnership project (3GPP) and Random Selection (RS), based on the metric of packet collision probability. Subsequently, considering the issues from baseline approaches, we develop an Improved Random Selection (IRS) scheme to decrease the collision probability. We further propose to employ Deep Deterministic Policy Gradient (DDPG) algorithm to overcome the impact of inter-vehicle collaboration in the platoon based on local information. A Monte Carlo simulator is then used to verify the analytical models' results. The numerical results show that IRS significantly mitigates the packet collision probability compared with the baselines. Meanwhile, DDPG outperforms IRS in terms of the packet collision probability as well as average scheduled delay and is more robust to the change in the environment.

TEBAS: A Time-Efficient Balance-Aware Scheduling Strategy for Batch Processing Jobs

Common schedulers for long-term running services that perform task-level optimization fail to accommodate short-living batch processing (BP) jobs. Thus, many efficient job-level scheduling strategies are proposed for BP jobs. However, the existing scheduling strategies perform time-consuming objective optimization which yields non-negligible scheduling delay. Moreover, they tend to assign BP jobs in a centralized manner to reduce monetary cost and synchronization overhead, which can easily cause resource contention due to the task co-location. To address these problems, this paper proposes TEBAS, a time-efficient balance-aware scheduling strategy, which spreads all tasks of a BP job into the cluster according to the resource specifications of a single task based on the observation that computing tasks of a BP job commonly possess similar features. The experimental results show the effectiveness of TEBAS in terms of scheduling efficiency and load balancing performance.

Controversy in wind energy construction projects: How social systems impact project performance

The energy industry strives to address a number of challenges—satisfy increasing energy demands, fulfill renewable energy policy requirements, and update aging infrastructure. Complicating energy projects are the controversies they can stir among stakeholders, sparking disagreements about environmental, economic, and aesthetic outcomes. Conflicts such as protests, petitions, or lawsuits can lead to schedule delays and cost overruns, which are difficult for project sponsors to predict. Using literature and news media, this study aims to identify trends in project controversies across energy projects. The study uses a mixed deductive and inductive content analysis to determine which actions, project phases, and stakeholders are discussed most frequently within both academic literature and news media. Using code cooccurrences, the study evaluates which stakeholders take specific actions at different project phases. Results show that the most active opposing stakeholders to energy development projects are community members, and actions opposing a project most frequently occur in the proposal phase. These results highlight the importance of engaging with communities early in project lifecycles. Opposition typically includes dissemination of information within communities, including letters to editors, internet newsletters, and public meetings. From this analysis, policy recommendations are provided for energy project sponsors to better anticipate and mitigate conflict.

A fine-grained task scheduling mechanism for digital economy services based on intelligent edge and cloud computing

Digital economy is regarded countries as an inevitable choice to promote economic growth and provides new opportunities and new paths for the high-quality development of economy. For the Chinese market, the strong base behind cloud computing is the unstoppable development trend of the digital economy. In digital economy, the cloud as infrastructure becomes the base of the pyramid to build the digital economy. To relieve the pressure on the servers of the digital economy and develop a reasonable scheduling scheme, this paper proposes a fine-grained task scheduling method for cloud and edge computing based on a hybrid ant colony optimization algorithm. The edge computing task scheduling problem is described, and assumptions are set to simplify the difficulty of a scheduling solution. The multi-objective function is solved by using a hybrid ant colony optimization algorithm which solves computational problems by finding the optimal solution with the help of graphs. Ant colony optimization algorithm is easy to use and effective in scheduling problems. The proposed scheduling model includes an end-device layer and an edge layer. A terminal device layer consists of devices used by the clients that may generate computationally intensive tasks and are sometime uncapable to complete the tasks. The proposed scheduling policy migrates these tasks to a suitable place where they can be completed while meeting the latency requirements. The CPUs of the idle users on the end-device layer are used for other CPU-overloaded terminals. The simulation results, in terms of energy consumptions, and task scheduling delays, show that the task scheduling performance is better under the application of this method and the obtained scheduling scheme is more reasonable.

Analisis Sistem Pengendalian Intern Pemerintah (SPIP) terhadap Pendistribusian Bantuan Sosial Covid-19 di Dinas Sosial Provinsi DKI Jakarta Tahun 2020


 The aim of the study was to find out how the Government Internal Control System (SPIP) performs in the implementation of Covid-19 income assistance at the DKI Jakarta Provincial Social Service according to the Elements of Internal Control based on PP No. 60 of 2008 concerning the Government Internal Control System (SPIP). This study uses a qualitative method with an interpretive paradigm and an ethnomethodological approach. Data collection techniques for this study were through interviewing key informants and supporting informants, observation and documentation. Based on the results of this study, the implementation of the SPIP in the implementation of income assistance in the implementation of the Covid-19 countermeasures has generally been effective and sufficient in accordance with Government Regulation No. 60 of 2008. Therefore, additional and evaluation is still needed. Implementation, such as discussing ethics and ethics training, assessing the role of assistants and social workers and identifying risks, was not carried out due to the risk of delays in the distribution schedule.
 Keywords: Government Internal Control System, Covid-19 Social Assistance, SPIP

Packet scheduling in rechargeable wireless sensor networks under SINR model

Two packet scheduling algorithms for rechargeable sensor networks are proposed based on the signal to interference plus noise ratio model. They allocate different transmission slots to conflicting packets and overcome the challenges caused by the fact that the channel state changes quickly and is uncontrollable. The first algorithm proposes a priority-based framework for packet scheduling in rechargeable sensor networks. Every packet is assigned a priority related to the transmission delay and the remaining energy of rechargeable batteries, and the packets with higher priority are scheduled first. The second algorithm mainly focuses on the energy efficiency of batteries. The priorities are related to the transmission distance of packets, and the packets with short transmission distance are scheduled first. The sensors are equipped with low-capacity rechargeable batteries, and the harvest-store-use model is used. We consider imperfect batteries. That is, the battery capacity is limited, and battery energy leaks over time. The energy harvesting rate, energy retention rate and transmission power are known. Extensive simulation results indicate that the battery capacity has little effect on the packet scheduling delay. Therefore, the algorithms proposed in this paper are very suitable for wireless sensor networks with low-capacity batteries.

Optimal variable vehicle scheduling strategy for a network of electric buses with fast opportunity charging

The introduction of battery-powered electric buses (EBs) presents promising prospects for greener and more sustainable public transit. However, recharging activities of EBs to extend the total daily operation range, enabled by fast opportunity charging approach, create a significant challenge for attaining better, or equivalent, operational efficiency than conventional diesel buses. We propose a novel variable vehicle scheduling strategy of a transit EB network with multiple depots to meet this challenge by right shifting trip departure times. A numerical example is used as an expository device to illustrate the variable EB-scheduling methodology, followed by an empirical case study in the city of Dalian, China. The results show how the optimised variable EB scheduling strategy can reduce the impact of recharging activities on the operation’s efficiency. It has been found that by inserting a small schedule delay it is possible to save operational costs, especially through a reduction of the fleet size.

Implementation Guideline to Solve Obstacles in Construction Delay Analysis: An Empirical Study of Indonesia

Construction project commonly suffers schedule delays and consequent claims. To overcome schedule delay difficulties, certain schedule delay analysis methodologies have been developed, but project practitioners are habitually not familiar with conducting required data collation and delay analysis. This research aims to provide an implementation guideline of using schedule delay analysis approaches to solve the obstacles of the analysis and uses Indonesia construction practitioners as an example to examine the proposed guideline. Interviews were performed with domain experts in Indonesia to collect existing obstacles, suggestions, and opinions to create an implementation guideline. The proposed guideline with the required documents is suitable for solving the obstacles identified in Indonesia. The proposed guideline covers three implementation phases; before, during, and during/after construction. Before construction, the guideline helps to identify key issues in a contract. During construction, identifying and categorizing schedule delay types are strongly suggested. Besides that, arranging the schedules (as-planned and as-built) and delaying time types to one comparison table is necessary during or after the construction. The proposed guideline with required documents is expected to be a reference for project practitioners in performing delay analysis systemically.

Estimating the Value of Airport Access Time in Developing Countries with a Case Study of Nanjing, China

The valuation of time is one of the most important public policy issues in project cost-benefit analysis. This paper estimates the value of airport access time and time variability in developing countries with a case study of Nanjing, China. An international meta-analysis is being used to identify the factors that may affect heterogeneity in the value of travel time. Regression models are then established for the prediction of the value of travel time. The results provide some new insights into the impacts of survey region, traffic mode, and trip purpose on the value of travel time. Considering the significant influencing factors that were obtained, stated preference surveys are designed and used to collect data on preferred arrival time and decision choice under various hypothetical situations. A multivariate regression model is used with the data to explore the significant factors that influence the travelers’ preferred arrival time. Mixed logit models are developed to estimate the value of airport access time, value of schedule delay early, and value of schedule delay late by incorporating the effects of travel delay variability on users’ scheduling costs. The tax system is being used to illustrate the contribution of different income groups to social funds, which also calculates the social value of airport access time, social value of schedule delay early, and social value of schedule delay late. The results identify the significant factors that may affect the valuation of airport access time and provide reasonable estimates for these values. The findings also bring new enlightenment on the effects of the variation of airport access time.

Safety, tolerability, and preliminary efficacy of TAR-200 in patients with intermediate risk non–muscle-invasive bladder cancer: A phase 1 study.

505 Background: TAR-200 is a novel intravesical drug delivery system designed to provide a continuous, slow release of gemcitabine within the bladder. Prolonged gemcitabine exposure over days, instead of hours, such as with current standard intravesical installations, may achieve more efficient and effective tumor response. We report on the safety and tolerability of TAR-200 in patients with non-muscle–invasive bladder cancer (NMIBC). Methods: In this phase 1b, open-label, prospective study, patients with a papillary recurrence after prior histologically proven, intermediate risk (IR)-NMIBC received two 1-week TAR-200 dosing cycles over a 4- to 6-week period. The study used a marker lesion/ablation design. Cystoscopy was performed to assess for recurrent papillary disease and for complete transurethral resection of the residual bladder tumor. The primary outcome was safety of TAR-200. Secondary outcomes were tolerability, pharmacokinetics, preliminary efficacy, and immunohistochemistry. Results: In total, 12 patients received TAR-200 treatment. Insertion and removal of TAR-200 was uneventful. No TAR-200-related serious adverse events (AEs) occurred. Four patients had no TAR-200-associated AEs; the remainder had varying degrees of AEs (all grade ≤2 [CTCAEv4.0]), mainly consisting of low-grade urinary urgency, urinary frequency, and dysuria, with no delay in the treatment schedule. Two patients refused a second dosing cycle due to urinary urgency and frequency. Plasma gemcitabine concentrations remained below the lower limit of detection. Five of 12 patients (42%) had complete response (CR); of these, 4 had a pathologic CR and 1 had CR based on visual assessment (with no biopsy available for pathologic assessment). Conclusions: In this small, phase 1 series, TAR-200 appears to be safe and well tolerated in patients with IR-NMIBC. Clinical trial information: NCT02720367 .

Why are the Frequently Reported Delay Factors in Construction Projects Recurring?: A Qualitative Study

Since a construction project involves a huge amount of resources, delays in construction have an unfavorable impact on all stakeholders. Due to the large-scale, specialization, and complexity of construction projects, construction delaysare reported globally. Previous quantitative studies mainly through questionnaires have focused on identifying delay factors. However, the identified delay factors show little difference regardless of time and region, thus, a more fundamental study on theroot causes of the delay is needed. Therefore, this study intends to discuss in depth the causes of delay factors identified in previous studies from professionals’ point of view. According to the interview with the experts, schedule delays are caused by factors such as short initial construction periods, errors in design documents, and rework. The effect of construction delays includes not only work quality degradation and increased risk of workplace accidents, but also the professional ethical dilemma ofmanagers. The experts mention that the construction delay can be alleviated with basic measures such as estimating spare construction period, reviewing design documents before work, and thorough quality control. This paper helps in understanding of the identified construction delays and can provide valuable insights in formulating effective strategies to avoid delays in construction projects.

An Estimation of the Safety Risk Factors Encountered During Tower Crane Installation and Dismantling on Construction Sites in Vietnam

The construction field has an important and meaningful role in the economy of any nation, especially developing nations. However, construction is one of the most dangerous fields and has the highest rate of accidents, including deaths and disabling injuries in the world. The construction field uses many tower cranes, especiallyfor constructing multi-storey buildings, factories, or in urban areas, and requires an increasing number of tower cranes. Tower cranes certainly contribute to the high rate of construction injuries and fatalities, in which tower crane installation and dismantling take a high rate. Accidents during tower crane installation and dismantling can killpeople (workers and citizens) as well as delays in construction schedules of project and/or damage to buildings and machines under construction. As a result, the cost of costruction projects can increase. In this paper, safety risk factors during tower crane installation and dismantling on construction sites in Vietnam are estimated byshowing their likelihood of occurrence, degree of influence, and risk levels. A suitable-structured questionnaire was produced and sent to get data that had their likelihood of occurrence and degree of influence by applying a five-point Likert scale. The results showed that “Time constraints are requested by investor, principal contractor or employer” is the most likely factor with a mean value of 3.60 and “Break of a wire rope occurring on dismantling” has the highest degree of influence, with a mean valueof4.18. The result also showed that there are 15/21 factors with a moderate risk level that is acceptable but, requires suitable controls to maintain a safe working condition of tower crane installation and dismantling. The results of the paper may help managers as well as practicians with good understandings of how to advance the safety of tower crane installation and dismantling on construction sites in Vietnam.

A data-driven support system for the efficient schedule delay management of the ultra-high-voltage projects considering subjective risk preferences

Renewable generation technologies are thriving due to sustainable transformation of the whole society, while there exists a general gap between large-scale renewable energy sources and loads in major cities which could be addressed by Ultra-high voltage (UHV) transmission projects. This paper proposes a data-driven support system for schedule delays of UHV projects. The system is composed of three modules. Firstly, general project schedule routines are interpreted by logistic curves. Classical earned values are measured by trapezoidal fuzzy numbers which are used for subjective judgement of project managers. These measures serve as the system input. Then, combined objective schedule delay and subjective severity judgement are analyzed by least square support vector regression. Enhanced particle swarm optimization is applied to determine optimal parameter combinations according to the structure of trained data. Next, delay prediction results combining subjective and objective information are divided into three severity degrees by an enhanced K-means algorithm and finally, integrated prevention measures are raised for project managers. The proposed system is validated by a real case study and results indicate good performance and reliability. The system could be integrated into the daily workflow of project managers and constantly provides references that facilitate efficient schedule management.

Association between emergency department sepsis order set design and delay to second dose piperacillin-tazobactam administration

BackgroundDelay to first antibiotic dose in patients with sepsis has been associated with increased mortality. Second dose antibiotic delay has also been linked to worsened patient outcomes. Optimal methods to decrease second dose delay are currently unclear. The primary objective of this study was to evaluate the association between updating an emergency department (ED) sepsis order set design from one-time doses to scheduled antibiotic frequencies and delay to administration of second piperacillin-tazobactam dose. MethodsThis retrospective cohort study was conducted at eleven hospitals in a large, integrated health system and included adult patients treated in the ED with at least one dose of piperacillin-tazobactam ordered through an ED sepsis order set over a two year period. Patients were excluded if they received less than two doses of piperacillin-tazobactam. Midway through the study period, the enterprise-wide ED sepsis order set was updated to include scheduled antibiotic frequencies. Two patient cohorts receiving piperacillin-tazobactam were compared: those in the year before the order set update and those in the year post-update. The primary outcome was major delay, defined as an administration delay >25% of the recommended dosing interval, which was evaluated with multivariable logistic regression and interrupted time series analysis. Results3219 patients were included: 1222 in the pre-update group and 1997 in the post-update group. The proportion of patients who experienced major second dose delay was significantly lower in the post-update group (32.7% vs 25.6%, p < 0.01; adjusted OR 0.64, 95% CI 0.52 to 0.78). No between-group difference was detected in the slope of monthly major delay frequency, but there was a significant level change (post-update change −10%, 95% CI −17.9% to −1.9%). ConclusionsIncluding scheduled antibiotic frequencies in ED sepsis order sets is a pragmatic mechanism to decrease delays in second antibiotic doses.

Uncertainty Analysis of Key Schedule Performance Indicators in Design, Procurement, and Construction Phases of Heavy Industrial Projects

Construction is a dynamic industry due to the existence of uncertainties surrounding evolving technologies, budgets, resources, and the development process. Because construction environments are relatively complicated, project managers may face significant challenges in delivering timely and effective project outcomes. Delays may occur throughout the design, procurement, and construction (DPC) phases of all construction projects, including those involving heavy industry; however, indicators of schedule delays can be identified early in a project’s life cycle, and appropriate strategies can be applied. This purpose of this study was to identify indicators that lead to the poor schedule performance of a project during the DPC phases and to examine the robustness of each schedule performance indicator. To accomplish this objective, a survey questionnaire was designed and sent to a diverse group of experienced construction professionals. Statistical methods, such as the chi-squared test, the two-sample t-test, and the Kruskal-Wallis test, were employed to evaluate and screen the DPC schedule performance indicators of heavy industrial projects, and a list of schedule delay indicators was developed using the all-possible combination regression analysis approach. The extreme bound analysis (EBA) technique was used to determine the robustness of each indicator’s relationship to the model. The results revealed nine robust schedule performance indicators in each of the DPC phases. The findings of this study can be used by the decision makers in construction projects to emphasize more reliable factors and minimize the number of revisions required during a project’s execution.

Analysis Performance for Evaluation of Schedule Irregularities on Bore Pile Foundation with FTA

Purpose: In construction projects, delays are disruptive and expensive. Therefore, the reason for the schedule delay needs to be identied. The delay factors determined in previous research were predominantly studied through surveys. In these studies, the participants were a stakeholder in construction projects, and the reason for schedule lateness was identied through their point of view.&#x0D; Design/methodology/approach: This research is conducted at a bored pile project in Opus Apartment, Batam, Indonesia. The studies are done through the Fault Tree Analysis method to find the root causes of the delay.&#x0D; Findings: Causes of delay in construction to prevent lateness on future construction projects.&#x0D; Research limitations/implications: Evaluation of delay causes on the bore pile foundation project in Opus Apartment. &#x0D; Practical implications: Evaluation of lateness in construction project through Fault Tree Analysis &#x0D; Paper type: Case Study

The effect of physician density on colorectal cancer stage at diagnosis: causal inference methods for spatial data applied on regional-level data

BackgroundThe early detection of colorectal cancer (CRC) through regular screening decreases its incidence and mortality rates and improves survival rates. Norway has an extremely high percentage of CRC cases diagnosed at late stages, with large variations across municipalities and hospital catchment areas. This study examined whether the availability of physicians related to CRC primary diagnosis and preoperative investigations, or physician density, contributes to the observed geographical differences in late-stage incidence rates.MethodMunicipality-level data on CRC stage at diagnosis were obtained from the Cancer Registry of Norway for the period 2012–2020. Physician density was calculated as the number of physicians related to CRC investigations, general practitioners (GPs) and specialists per 10,000 people, using physician counts per municipality and hospital areas from Statistics Norway. The relationship was examined using a novel causal inference method for spatial data—neighbourhood adjustment method via spatial smoothing (NA approach)—which allowed for studying the region-level effect of physician supply on CRC outcome by using spatially referenced data and still providing causal relationships.ResultsAccording to the NA approach, an increase in one general practitioner per 10,000 people will result in a 3.6% (CI −0.064 to −0.008) decrease in late-stage CRC rates. For specialists, there was no evidence of a significant correlation with late-stage CRC distribution, while for both groups, GPs and specialists combined, an increase of 1 physician per 10,000 people would be equal to an average decrease in late-stage incidence rates by 2.79% (CI −0.055 to −0.001).ConclusionThe study confirmed previous findings that an increase in GP supply will significantly improve CRC outcomes. In contrast to previous research, this study identified the importance of accessibility to both groups of physicians—GPs and specialists. If GPs encounter insufficient workforces in hospitals and long delays in colonoscopy scheduling, they will less often recommend colonoscopy examinations to patients. This study also highlighted the efficiency of the novel methodology for spatially referenced data, which allowed us to study the effect of physician density on cancer outcomes within a causal inference framework.

Analyzing of Project Delivery Risks in Highway Construction During the Covid-19 Pandemic

The Covid-19 pandemic has hit all sectors of the business world, and the construction sector is no exception, resulting in delays, loss of efficiency, and cost impacts due to Covid-19 and the response to related government regulations, there is little or no precedent to help contractor companies understand what the potential impacts are. Covid-19 in the future and construction program when the lockdown begins. However it is very likely that work will need to be stopped due to health and safety concerns. Even if the project does not stop altogether, it is likely to be more expensive and take more time. This study attempts to conduct a risk assessment of project delivery with the most popular system, to see risk factors and then analyze risk factor ratings at all stages of project implementation until construction handover. The Covid-19 pandemic can be said to be a new phenomenon that has not much literature, so the identification of risk factors using a literature review was validated by expert discussion method, assessment by probability and impact, while the analytical method used the Analytical Hierarchy Process (AHP) approach. The results of dominant and major priority of risks including construction work health and safety, delay in delivery schedule, delays in procuring materials, labor, and equipment and delay in certification of bills. Keywords: Pandemic Covid-19 · Risk · Project · Highway Construction

The Day-to-Day Departure Time Choice of Heterogeneous Commuters Under an Anonymous Toll Charge for System Optimum

We consider a bottleneck system in a state of disequilibrium, in which commuters are heterogeneous in the values of travel time and schedule delays. Three representative dynamical systems are used to formulate the day-to-day departure time choice of commuters, and a Walrasian toll charge scheme is utilized to control the evolutionary process of traffic flows. The toll charge scheme is anonymous; that is, toll charges are identical for all user classes, and the scheme’s implementation does not need to resort to information on the values of travel time and schedule delays. We find that the system optimum (SO) flow pattern can be achieved at the stationary state under the implementation of the toll charge scheme. The equivalence between the stationary state and the SO, the existence of the toll charge for achieving the SO, and the convergence of day-to-day traffic flows to the SO under the implementation of the toll charge scheme are theoretically proved. The distributions of traffic flows and toll charges at the SO state during morning rush hour are analytically shown. The application of the toll charge scheme to a network with multiple trip origins is presented. The effectiveness of the toll charge scheme for achieving the SO is also examined by numerical analyses. Funding: This work was supported by the National Natural Science Foundation of China [Grants 72171007, 71890972/71890970, and 72021001]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/trsc.2022.1191 .

Combination of Throughput-optimal Scheduling and Network Utility Maximization in NOMA Systems with Flow-Level Dynamics

In wireless networks, the network queue stability (throughput-optimality) and the network utility maximization are two crucial tasks for network operators. Besides, new techniques of mobile communications, e.g. the non-orthogonal multiple access (NOMA), have emerged endlessly to meet coming challenges. In this paper, we for the first time, investigate a downlink NOMA system with flow-level dynamics, where long-lived flows and short-lived flows exist simultaneously, and formulate an optimization problem of user selection and power allocation. We aim to maximize the network utility at each time slot and simultaneously guarantee the throughput-optimality, under the quality of service (QoS) constraints. Considering the practicability of algorithm, the suboptimal algorithm containing two stages, is proposed. And we analyze the complexity of proposed algorithm. In the performance evaluation, the benchmark algorithm is provided for comparison. And we take the energy efficiency (EE) as an example of the network utility and define the scheduling delay (SD). Simulation results show that the suboptimal algorithm is throughput-optimal, and understandably, its performances could be better than those in the benchmark algorithm in terms of EE and SD, as long as the appropriate parameter is set.