708 research outputs found
An ASP-Based Approach to Scheduling Pre-operative Assessment Clinic
The problem of scheduling Pre-Operative Assessment Clinic (PAC) consists of assigning patients to a day for the exams needed before a surgical procedure, taking into account patients with different priority levels, due dates, and operators availability. Realizing a satisfying schedule is of upmost importance for a clinic, since delay in PAC can cause delay in the subsequent phases, causing a decrease in patients’ satisfaction. In this paper, we divide the problem in two sub-problems: In the first sub-problem patients are assigned to a day taking into account a default list of exams; then, in the second sub-problem, having the actual list of exams needed by each patient, we use the results of the first sub-problem to assign a starting time to each exam. We first present a mathematical formulation for both problems. Then, we present solutions based on Answer Set Programming (ASP): The first solution is a genuine ASP encoding of the sub-problems, while the second introduces domain-specific optimizations. Experiments show that both solutions provide satisfying results in short time, while the second is able to prove optimality faster
Mobilidade de camponeses entre assentamentos de reforma agrária: territorialidades em cheque no desenvolvimento local da Transamazônica, Pará, Brasil.
O artigo trata do papel da mobilidade espacial de famílias camponesas entre assentamentos da chamada reforma agrária no desenvolvimento local da região Transamazônica, Estado do Pará. A análise das práticas e narrativas de sujeitos locais no contexto de políticas públicas fundiárias e ambientais evidencia que essa execução vigente não se coaduna com os processos de territorialização concebidos pelos chamados beneficiários de reforma agrária
Recommended from our members
Summary of activities at the Engineered Barriers Test Facility, October 1, 1995 to January 31, 1997, and initial data
Replicates of two engineered barrier designs (a thick soil barrier and a bio/capillary barrier) were constructed in the test plots of the facility. Prior to placement of any soil in the test plots, instruments were calibrated and attached to plot instrument towers, which were then installed in the test plots. Soil from Spreading Area B was installed in the test plots in lifts and compacted. Instruments attached to the instrument tower were placed in shallow trenches dug in the lifts and buried. Each instrument was checked to make sure it functioned prior to installation of the next lift. Soil samples were collected from each lift in one plot during construction for later determination of physical and hydraulic properties. After completion of the test plots, the data acquisition system was finalized, and data collection began. Appropriate instrument calibration equations and equation coefficients are presented, and data reduction techniques are described. Initial data show test plot soils drying throughout the summer and early fall. This corresponds to low rainfall during this period. Infiltration of water into the test plots was first detected around mid-November with several subsequent episodes in December. Infiltration was verified by corresponding measurements from several different instruments [time domain reflectometry (TDR), neutron probe, thermocouple psychrometers, and heat dissipation sensors]. Tensiometer data does not appear to corroborate data from the other instruments. Test plots were warmer on the side closest to the access trench indicating a temperature effect from the trench. This resulted in greater soil moisture freezing with less and shallower infiltration on the far side of the plots than on the side closest to the trench. At the end of this monitoring period, infiltration in all but two of the test plots has reached the 155-cm depth. Infiltration in test plots B2 and S3 has reached only the 140-cm depth. The monitored infiltration events have not resulted in drainage from the bottom of the test plots
Operating Room (Re)Scheduling with Bed Management via ASP
The Operating Room Scheduling (ORS) problem is the task of assigning patients to operating rooms (ORs), taking into account different specialties, lengths, and priority scores of each planned surgery, OR session durations, and the availability of beds for the entire length of stay (LOS) both in the Intensive Care Unit (ICU) and in the wards. A proper solution to the ORS problem is of primary importance for the healthcare service quality and the satisfaction of patients in hospital environments. In this paper we first present a solution to the problem based on Answer Set Programming (ASP). The solution is tested on benchmarks with realistic sizes and parameters, on three scenarios for the target length on 5-day scheduling, common in small-medium-sized hospitals, and results show that ASP is a suitable solving methodology for the ORS problem in such setting. Then, we also performed a scalability analysis on the schedule length up to 15 days, which still shows the suitability of our solution also on longer plan horizons. Moreover, we also present an ASP solution for the rescheduling problem, that is, when the offline schedule cannot be completed for some reason. Finally, we introduce a web framework for managing ORS problems via ASP that allows a user to insert the main parameters of the problem, solve a specific instance, and show results graphically in real time
Solving Operating Room Scheduling Problems with Surgical Teams via Answer Set Programming
The optimization of daily operating room surgery schedule can be problematic because of many constraints, like to determine the starting time of different surgeries and allocating the required resources, including the availability of surgical teams for complete surgical procedures. Recently, Answer Set Programming (ASP) has been successfully employed for addressing and solving real-life scheduling and planning problems in the healthcare domain. In this paper we present an enhanced solution using ASP for scheduling operating rooms taking explicitly into consideration availability of surgical teams, that include a surgeon and an anesthetist in different specialties for the entire duration of the surgery. We tested our solution on different benchmarks with realistic parameters for schedule’s length up to the target 5-days planning. The results of our experiments show that ASP is a suitable methodology for solving also such enhanced problem
An ASP-based Solution to the Chemotherapy Treatment Scheduling problem
The problem of scheduling chemotherapy treatments in oncology clinics is a complex problem, given that the solution has to satisfy (as much as possible) several requirements such as the cyclic nature of chemotherapy treatment plans, maintaining a constant number of patients, and the availability of resources, for example, treatment time, nurses, and drugs. At the same time, realizing a satisfying schedule is of upmost importance for obtaining the best health outcomes. In this paper we first consider a specific instance of the problem which is employed in the San Martino Hospital in Genova, Italy, and present a solution to the problem based on Answer Set Programming (ASP). Then, we enrich the problem and the related ASP encoding considering further features often employed in other hospitals, desirable also in S. Martino, and/or considered in related papers. Results of an experimental analysis, conducted on the real data provided by the San Martino Hospital, show that ASP is an effective solving methodology also for this important scheduling problem
Augmented Reality to Engage Visitors of Science Museums through Interactive Experiences
In the last years, interactive exhibitions based on digital technologies have become widely common, thanks to their flexibility and effectiveness in engaging visitors and creating memorable experiences. One of the topics in which digital technologies can be particularly effective is the communication of abstract concepts that are difficult for the human mind to imagine. An emblematic example is the astronomy discipline, which requires us to imagine and understand phenomena far away from our everyday life. In this paper, the authors present a research project, MARSS, in which digital technologies are used effectively to enhance the Users' Experience of the Museo Astronomico di Brera located in Milan. Specifically, the MARSS project aims at designing and developing a new digital journey inside the museum to allow different categories of visitors to enjoy the exhibition in an engaging and interactive way. The paper presents the design and development phases of the experience and its evaluation with users. The results of the evaluation indicate that the digital interactive experience is appreciated by users and is successful in translating the content of high scientific value into more engaging and easily understandable elements
Telematic integration of health data: the INTESA project
Following an approach based on the methods of basic research, the INTESA project has developed a complete architecture of health information system, capable to guarantee a smart and safe storing of the essential information, an effective and personalized retrieval of data, and some innovative models to compare the results of clinical and medical activities of all the "actors" of the health care process. Together with other metropolitan repositories based on HL7 messages and applications able to examine the data stored, the developed archive will contribute to keep a check on every citizen's health history, clinical examinations and cure therapies, but, above all, it will allow to verify the efficacy and efficiency of the health care processes related to particular pathologies.Non present
Denitrogenation process in ThMn12 nitride by in situ neutron powder diffraction
ThMn12 nitrides are good candidates for high performance permanent magnets. However, one of the remaining challenges is to transfer the good properties of the powder into a useful bulk magnet. Thus, understanding the denitrogenation process of this phase is of key importance. In this study, we investigate the magnetic and structural stability of the (Nd0.75, Pr0.25)1.2Fe10.5Mo1.5Nx compound (x=0 and 0.85) as function of temperature by means of neutron powder diffraction. Thermal dependence of the lattice parameters, formation of a-(Fe, Mo), as well as the nitrogen content in the nitrides are investigated by heating the compounds up to 1010 K. The decomposition takes place mainly via the formation of the a-(Fe, Mo) phase, which starts at around 900 K, whereas the nitrogen remains stable in the lattice. Additionally, we show that the magnetic properties of the nitrides [M(4T)=90 Am2/kg and Hc=0.55 T] are maintained after the thermal treatments up to 900 K. This study demonstrates that the ThMn12 nitrides with the Mo stabilizing element offer good prospects for a bulk magnet provided an adequate processing route is found
A Two-Phase ASP Encoding for Solving Rehabilitation Scheduling
The rehabilitation scheduling process consists of planning rehabilitation physiotherapy sessions for patients, by assigning proper operators to them in a certain time slot of a given day, taking into account several requirements and optimizations, e.g., patient’s preferences and operator’s work balancing. Being able to efficiently solve such problem is of upmost importance, in particular after the COVID-19 pandemic that significantly increased rehabilitation’s needs. In this paper, we present a solution to rehabilitation scheduling based on Answer Set Programming (ASP), which proved to be an effective tool for solving practical scheduling problems. Results of experiments performed on both synthetic and real benchmarks, the latter provided by ICS Maugeri, show the effectiveness of our solution
- …