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A hybrid solution approach for the Integrated Healthcare Timetabling Competition 2024

arXiv.org Artificial Intelligence

Our healthcare systems are struggling with the ageing population resulting in an increasing demand and rising expenditures while facing a shortage of healthcare professionals at the same time [7, 12]. When a system is under stress and demand exceeds supply, among other strategies, scheduling resources efficiently and planning becomes important [8]. Hospitals are a critical component of the healthcare system, playing a vital role in care coordination, system development, and supporting population health needs [11]. Efficient planning in hospitals is important to utilized the limited resources in the best possible manner. Here approaches from Operations Research can be of benefit to optimize planning problems such as admission planning, bed allocation, nurse scheduling and surgery scheduling [6, 10]. It has been recognized in the past that resources should be planned in an integrated manner to improve the overall outcomes instead of focusing on individual departments or resources [10].


I2I-STRADA -- Information to Insights via Structured Reasoning Agent for Data Analysis

arXiv.org Artificial Intelligence

Recent advances in agentic systems for data analysis have emphasized automation of insight generation through multi-agent frameworks, and orchestration layers. While these systems effectively manage tasks like query translation, data transformation, and visualization, they often overlook the structured reasoning process underlying analytical thinking. Reasoning large language models (LLMs) used for multi-step problem solving are trained as general-purpose problem solvers. As a result, their reasoning or thinking steps do not adhere to fixed processes for specific tasks. Real-world data analysis requires a consistent cognitive workflow: interpreting vague goals, grounding them in contextual knowledge, constructing abstract plans, and adapting execution based on intermediate outcomes. We introduce I2I-STRADA (Information-to-Insight via Structured Reasoning Agent for Data Analysis), an agentic architecture designed to formalize this reasoning process. I2I-STRADA focuses on modeling how analysis unfolds via modular sub-tasks that reflect the cognitive steps of analytical reasoning. Evaluations on the DABstep and DABench benchmarks show that I2I-STRADA outperforms prior systems in planning coherence and insight alignment, highlighting the importance of structured cognitive workflows in agent design for data analysis.


Fairness Driven Slot Allocation Problem in Billboard Advertisement

arXiv.org Artificial Intelligence

In billboard advertisement, a number of digital billboards are owned by an influence provider, and several commercial houses (which we call advertisers) approach the influence provider for a specific number of views of their advertisement content on a payment basis. Though the billboard slot allocation problem has been studied in the literature, this problem still needs to be addressed from a fairness point of view. In this paper, we introduce the Fair Billboard Slot Allocation Problem, where the objective is to allocate a given set of billboard slots among a group of advertisers based on their demands fairly and efficiently. As fairness criteria, we consider the maximin fair share, which ensures that each advertiser will receive a subset of slots that maximizes the minimum share for all the advertisers. We have proposed a solution approach that generates an allocation and provides an approximate maximum fair share. The proposed methodology has been analyzed to understand its time and space requirements and a performance guarantee. It has been implemented with real-world trajectory and billboard datasets, and the results have been reported. The results show that the proposed approach leads to a balanced allocation by satisfying the maximin fairness criteria.


From approximation error to optimality gap -- Explaining the performance impact of opportunity cost approximation in integrated demand management and vehicle routing

arXiv.org Artificial Intelligence

Prominent examples of these services are attended home delivery (AHD), same-day delivery (SDD), or mobility-on-demand (MOD). These business models have in common that customers expect a very high service level, e.g., in terms of the deviation from their desired service time (Amorim et al. (2024)). Meeting these expectations makes demand consolidation challenging, which entails high fulfillment cost (Ulmer (2020)). To still operate profitably, operational planning for these business models has evolved: Instead of optimizing the associated vehicle routing alone, providers additionally apply demand management to achieve efficient fulfillment operations. The resulting integrated demand management and vehicle routing problems (i-DMVRPs) are stochastic and dynamic with two types of integrated decisions: For each dynamically arriving customer request, the provider integratively makes a demand control decision and a vehicle routing decision with the overall objective of maximizing the expected profit, i.e., revenue net of operational fulfillment cost. Such an i-DMVRP can be modeled as a Markov decision process (MDP) and, theoretically, be solved by evaluating the well-known Bellman equation (Puterman (2014)). Practically, however, i-DMVRPs suffer from the curses of dimensionality ((Powell (2011)) such that this is not tractable for realistic-sized instances. Consequently, in literature, demand control decisions for i-DMVRPs are often optimized with a decomposition-based solution approach. More precisely, two subproblems are solved sequentially for every incoming customer request (Fleckenstein, Klein, and Steinhardt (2023), Ulmer (2020), Gallego and Topaloglu (2019), p. 25, Klein et al. (2018)): 1.) Approximating opportunity cost (OC) for each potential fulfillment option (e.g., different time windows) to measure the expected profit impact assuming the current customer chooses the respective option, given the state of the system.


Deduplicating and Ranking Solution Programs for Suggesting Reference Solutions

arXiv.org Artificial Intelligence

Referring to solution programs written by other users is helpful for learners in programming education. However, current online judge systems just list all solution programs submitted by users for references, and the programs are sorted based on the submission date and time, execution time, or user rating, ignoring to what extent the programs can be helpful to be referenced. In addition, users struggle to refer to a variety of solution approaches since there are too many duplicated and near-duplicated programs. To motivate learners to refer to various solutions to learn better solution approaches, in this paper, we propose an approach to deduplicate and rank common solution programs in each programming problem. Inspired by the nature that the many-duplicated program adopts a more common approach and can be a general reference, we remove the near-duplicated solution programs and rank the unique programs based on the duplicate count. The experiments on the solution programs submitted to a real-world online judge system demonstrate that the number of programs is reduced by 60.20%, whereas the baseline only reduces by 29.59% after the deduplication, meaning that users only need to refer to 39.80% of programs on average. Furthermore, our analysis shows that top-10 ranked programs cover 29.95% of programs on average, indicating that users can grasp 29.95% of solution approaches by referring to only 10 programs. The proposed approach shows the potential of reducing the learners' burden of referring to too many solutions and motivating them to learn a variety of solution approaches.


A Semi-Automated Solution Approach Selection Tool for Any Use Case via Scopus and OpenAI: a Case Study for AI/ML in Oncology

arXiv.org Artificial Intelligence

In today's vast literature landscape, a manual review is very time-consuming. To address this challenge, this paper proposes a semi-automated tool for solution method review and selection. It caters to researchers, practitioners, and decision-makers while serving as a benchmark for future work. The tool comprises three modules: (1) paper selection and scoring, using a keyword selection scheme to query Scopus API and compute relevancy; (2) solution method extraction in papers utilizing OpenAI API; (3) sensitivity analysis and post-analyzes. It reveals trends, relevant papers, and methods. AI in the oncology case study and several use cases are presented with promising results, comparing the tool to manual ground truth.


Kinematic Orienteering Problem With Time-Optimal Trajectories for Multirotor UAVs

arXiv.org Artificial Intelligence

In many unmanned aerial vehicle (UAV) applications for surveillance and data collection, it is not possible to reach all requested locations due to the given maximum flight time. Hence, the requested locations must be prioritized and the problem of selecting the most important locations is modeled as an Orienteering Problem (OP). To fully exploit the kinematic properties of the UAV in such scenarios, we combine the OP with the generation of time-optimal trajectories with bounds on velocity and acceleration. We define the resulting problem as the Kinematic Orienteering Problem (KOP) and propose an exact mixed-integer formulation together with a Large Neighborhood Search (LNS) as a heuristic solution method. We demonstrate the effectiveness of our approach based on Orienteering instances from the literature and benchmark against optimal solutions of the Dubins Orienteering Problem (DOP) as the state-of-the-art. Additionally, we show by simulation \color{black} that the resulting solutions can be tracked precisely by a modern MPC-based flight controller. Since we demonstrate that the state-of-the-art in generating time-optimal trajectories in multiple dimensions is not generally correct, we further present an improved analytical method for time-optimal trajectory generation.


Dynamic Unicast-Multicast Scheduling for Age-Optimal Information Dissemination in Vehicular Networks

arXiv.org Artificial Intelligence

This paper investigates the problem of minimizing the age-of-information (AoI) and transmit power consumption in a vehicular network, where a roadside unit (RSU) provides timely updates about a set of physical processes to vehicles. Each vehicle is interested in maintaining the freshness of its information status about one or more physical processes. A framework is proposed to optimize the decisions to unicast, multicast, broadcast, or not transmit updates to vehicles as well as power allocations to minimize the AoI and the RSU's power consumption over a time horizon. The formulated problem is a mixed-integer nonlinear programming problem (MINLP), thus a global optimal solution is difficult to achieve. In this context, we first develop an ant colony optimization (ACO) solution which provides near-optimal performance and thus serves as an efficient benchmark. Then, for real-time implementation, we develop a deep reinforcement learning (DRL) framework that captures the vehicles' demands and channel conditions in the state space and assigns processes to vehicles through dynamic unicast-multicast scheduling actions. Complexity analysis of the proposed algorithms is presented. Simulation results depict interesting trade-offs between AoI and power consumption as a function of the network parameters.


The Solution Approach Of The Great Indian Hiring Hackathon: Winners' Take

#artificialintelligence

MachineHack has successfully concluded The Great Indian Hiring Hackathon on 23rd of November 2020, where it collaborated for the first time with 12 companies to help data science professionals land up in a rewarding career. In this hackathon, the MachineHack community was asked to come up with an algorithm to predict the price of retail items belonging to different categories. In participation with companies like -- Aditya Birla Group, Bridgei2i, Concentrix, Fractal, Genpact, Lowe's, MiQ, Piramal, Scienaptic, Vmware, WellsFargo, and Zycus, the hackathon has witnessed an active attendance of whooping 5655 practitioners. Foretelling the retail price can be a daunting task due to the huge datasets with a variety of attributes ranging from text, numbers (floats, integers), as well as date and time. Also, outliers can be a big problem when dealing with unit prices. Thus this hackathon asked the participants to come out with a solution to forecast retail prices of items of different categories.


Metaheuristics for the operating theater planning and scheduling: A systematic review

arXiv.org Artificial Intelligence

Healthcare expenses represent a large share of most developing countries' GDP. Operational theatres make up the majority of these costs in hospitals. There are found a vast number of papers studying the problem of operating theater planning and scheduling. Different variants of this problem are generally recognized to be NPcomplete; thus, several solution approaches have been utilized in the literature to confront with these complicated problems. The lack of a thorough review of the main characteristics of solution approaches is tangible in the literature (reviewing them separately and with regards to the characteristics of studied problems), which can provide pragmatic guidelines for practitioners and future research projects. This paper aims to address this issue. Since different types of solution approaches usually have different characteristics, this paper focuses only on metaheuristic algorithms. Through both automatic and manual search methods, we have selected and reviewed 28 papers with respect to their main problem and solution approach features. Finally, some directions are introduced for future research.