8 resultados para p-median problem
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The decrease in crime is one of the core issues that cause concern in society today. This study aims to propose improvements to public safety from the choice of points to the location of police units, ie the points which support the car and the police. For this, three models were developed in order to assist decision making regarding the best placement of these bases. The Model of Police Units Routing has the intention to analyze the current configuration of a given region and develop optimal routes for round preventative. The Model of Allocation and Routing for New Police Units (MARNUP) used the model of facility location called p-median weighted and traveling salesman problem (TSP) combined aiming an ideal setting for regions that do not yet have support points or to assess how far the distribution is present in relation to that found in solution. The Model Redefinition and Routing Unit Police (MRRUP) seek to change the current positioning taking into account the budgetary constraints of the decision maker. To verify the applicability of these models we used data from 602 points to instances of police command that is responsible for the capital city of Natal. The city currently has 31 police units for 36 of these 19 districts and police have some assistance. This reality can lead to higher costs and higher response times for answering emergency calls. The results of the models showed that in an ideal situation it is possible to define a distance of 500 km/round, whereas in this 900 km are covered by approximately round. However, a change from three-point lead reduced to 700 km / round which represents a decrease of 22% in the route. This reduction should help improve response time to emergency care, improving the level of service provided by the increase of solved cases, reducing police shifts and routing preventive patrols
Resumo:
This work presents a new model for the Heterogeneous p-median Problem (HPM), proposed to recover the hidden category structures present in the data provided by a sorting task procedure, a popular approach to understand heterogeneous individual’s perception of products and brands. This new model is named as the Penalty-free Heterogeneous p-median Problem (PFHPM), a single-objective version of the original problem, the HPM. The main parameter in the HPM is also eliminated, the penalty factor. It is responsible for the weighting of the objective function terms. The adjusting of this parameter controls the way that the model recovers the hidden category structures present in data, and depends on a broad knowledge of the problem. Additionally, two complementary formulations for the PFHPM are shown, both mixed integer linear programming problems. From these additional formulations lower-bounds were obtained for the PFHPM. These values were used to validate a specialized Variable Neighborhood Search (VNS) algorithm, proposed to solve the PFHPM. This algorithm provided good quality solutions for the PFHPM, solving artificial generated instances from a Monte Carlo Simulation and real data instances, even with limited computational resources. Statistical analyses presented in this work suggest that the new algorithm and model, the PFHPM, can recover more accurately the original category structures related to heterogeneous individual’s perceptions than the original model and algorithm, the HPM. Finally, an illustrative application of the PFHPM is presented, as well as some insights about some new possibilities for it, extending the new model to fuzzy environments
Resumo:
The increasing of pollution in aquatic ecosystems in the last decades has caused an expansion of eutrophication and loss of water quality for human consumption. The increase of frequency and intensity of cyanobacteria blooms have been recognized as a major problem connected to water quality and eutrophication. The knowledge of environmental factors controlling these blooms is a key step towards the management for recovering aquatic ecosystems from eutrophic conditions. Primary productivity in aquatic ecosystems is dependent on light and nutrients availability. In the present work we evaluated the relative importance of the concentration of major nutrients, such as phosphorus and nitrogen, and light for phytoplankton growth in the main water reservoir of Rio Grande do Norte State, named Engenheiro Armando Ribeiro Gonçalves (EARG), which is an eutrophic system, dominated by potentially toxic cyanobacteria populations. Limitation of phytoplankton growth was evaluated through bioassays using differential enrichment of nutrients (N and/or P) under two light conditions (low light and high light) and monthly monitoring of chlorophyll-a and nutrients (total nitrogen and phosphorus) concentrations, and water transparency (Secchi depth) at the pelagic region. Our results confirm that EARG reservoir is an eutrophic system with a low water quality. Results of bioassays on the growth of phytoplankton limitation (N or P) were conflicting with the results predicted by the TN:TP ratios, which indicates that these ratios were not a good indicator of algal growth limitation. Nitrogen was the limiting nutrient, considering both frequency and magnitude. Light and hidrology affected phytoplankton response to nutrient enrichment. The extreme eutrophic conditions of this reservoir, dominated by cyanobacteria blooms, demand urgent managing strategies in order to guarantee the multiple uses for this system, including water supply for human population. Although nitrogen is the limiting nutrient, an effective management program must focus on the reduction of both phosphorus and nitrogen input
Resumo:
The venous ulcer is an epidemiological problem of high prevalence, causing disability and dependence. Assess the tissue impairment level of patients with venous lesions, within a nursing referential, is relevant for the implementation of a directed assistance to specific clientele. Thus, this work aims to characterize the health status regarding the integrity the lower limbs skin of patients with venous ulcers, according to the of tissue integrity outcome indicators from the Nursing Outcomes Classification. A cross-sectional study conducted in a university hospital in Natal - Rio Grande do Norte. The sample consisted of 50 participants, selected through consecutive sampling. Data collection occurred through a interview and physical examination form and a operational definitions tool for indicators of the nursing Tissue Integrity outcome directed to patients with venous ulcer, applied from February to June 2012. Data analysis was done by descriptive statistics and nonparametric tests (Spearman, Kruskal-Wallis and Mann-Whitney tests). The project was approved by the Research Ethics Committee with protocol 608/11 and Presentation Certificate to Ethical Consideration No. 0038.0.294.000-11. The results were presented using three scientific articles derivatives of research. It was found that the indicators show moderate impairment, light and not impaired, as the median. The respondents had an average of 59.72 years, 66% female, 50% were retired, 60% with a partner, 44% had arterial hypertension, 26% allergies, 20% diabetes mellitus, 96% were sedentary, 14% drank alcohol and 6% were smokers. There was a statistically significant correlation of low intensity between age and hydration (p=0.032; rs=-0.304) and skin desquamation (p=0.026; rs=-0.316), family income and necrosis (p=0.012; rs=-0.353); Ankle Brachial Index and tissue perfusion (p=0,044; rs=-0,329); Diabetes Mellitus and texture (p=0.015) and tissue perfusion (p=0.026); allergy and texture (p=0.034), physical activity and hydration (p=0.034), smoking and thickness (p=0.018), and alcohol consumption and exudate (p=0.045). We conclude that the patients had light to moderate impairment, indicating a good state of health on the integrity of the skin of the lower limbs, according to the indicators of the outcome of tissue integrity Classification Nursing Outcomes valued in the present study. It is believed that the evaluation of impairment tissue using a self-nursing system and its relation with socioeconomic, clinical and risk factors are unique tools in the care planning and in the wound healing
Resumo:
The therapeutic adherence is still a big problem among people with venous ulcers (VU) because the treatment is long, expensive and demand changes in lifestyle. In this context, this study aims to examine treatment adherence and quality of life (QOL) of people with VU assisted at primary health care. This is an analytical, cross-sectional study with a quantitative approach to treatment and data analysis. The study had the scenario 13 Family Health Units and 02 Units Mixed of Natal. The target population consisted of 44 persons with UV indicated by the teams of the Family Health Strategy between February and April 2014. Three instruments were used: an instrument to characterize the sociodemographic, health and care aspects, the Multidimensional Scale of Adherence Therapy composed of the dimensions: healthy lifestyle, compressive therapy and neurovascular monitoring and the Charing Cross Venous Ulcer Questionnaire (CCVUQ) that evaluates QOL in persons with VU composed by the domains: Total Score, Social Interaction, Domestic Activities, Aesthetics and Emotional State. The study was approved by the Ethics Committee in Research of the Federal University of Rio Grande do Norte, CAAE: 07556312.0.0000.5537. The data concerning the sociodemographic characteristics showed that there was a predominance of females (65.9%), age range as of 60 years (59.1%) and income of up to 1 minimum wage (81.8%). With the characterization of health, it was evident that most people reported chronic diseases (63.6%), sleep more than 6 hours (81.8%), present pain (81.8%), denying alcoholism (86 4%) and smoking (77.3%) and showed a number greater than or equal to 1 (77.3%) recurrences. Concerning the therapeutic adherence was found that in the dimension compressive therapy there poor adherence. No associations between the domains of adherence and sociodemographic and health variables were found. Was observed, however, better adherence among individuals without pain and with higher schooling. When analyzed the averages of the dimensions of therapeutic adherence with the care characteristics there was statistical significance between: adherence to compression therapy and guidance for use of compressive therapy (p = 0.002) and guidance for regular exercise (p = 0.026). Considering the mean of total score of CCVUQ (mean 51.47, SD 18.33) it is observed that the overall QOL of respondents has approximate value of the median of the scale (50). The mean of the domain Social Interaction (mean 44.23, SD 21.38) and Domestic Activities (mean 45.70, SD 23.21) were those who reported better QOL. There were weak correlations but significant between adherence to healthy lifestyle and Domains Total Score (p = 0.012), social interaction (p-value = 0.048), Aesthetics (p-value = 0.025) and Emotional State (0.017) of CCVUQ. From the data analysis it is concluded that among people with UV, there poor adherence to compressive therapy. Furthermore, we found no statistically significant association between treatment adherence and sociodemographic and health characteristics. It is added that there was a correlation between the healthy lifestyle dimension and domains CCVUQ
Resumo:
Launching centers are designed for scientific and commercial activities with aerospace vehicles. Rockets Tracking Systems (RTS) are part of the infrastructure of these centers and they are responsible for collecting and processing the data trajectory of vehicles. Generally, Parabolic Reflector Radars (PRRs) are used in RTS. However, it is possible to use radars with antenna arrays, or Phased Arrays (PAs), so called Phased Arrays Radars (PARs). Thus, the excitation signal of each radiating element of the array can be adjusted to perform electronic control of the radiation pattern in order to improve functionality and maintenance of the system. Therefore, in the implementation and reuse projects of PARs, modeling is subject to various combinations of excitation signals, producing a complex optimization problem due to the large number of available solutions. In this case, it is possible to use offline optimization methods, such as Genetic Algorithms (GAs), to calculate the problem solutions, which are stored for online applications. Hence, the Genetic Algorithm with Maximum-Minimum Crossover (GAMMC) optimization method was used to develop the GAMMC-P algorithm that optimizes the modeling step of radiation pattern control from planar PAs. Compared with a conventional crossover GA, the GAMMC has a different approach from the conventional one, because it performs the crossover of the fittest individuals with the least fit individuals in order to enhance the genetic diversity. Thus, the GAMMC prevents premature convergence, increases population fitness and reduces the processing time. Therefore, the GAMMC-P uses a reconfigurable algorithm with multiple objectives, different coding and genetic operator MMC. The test results show that GAMMC-P reached the proposed requirements for different operating conditions of a planar RAV.
Resumo:
Ceramic materials alumina basis have been widely used in structural components, mainly because owning properties such as high hardness, chemical inertness and good wear resistance, however, the low toughness is a factor that compromises its use in many other applications, featuring the addition of nickel as a possible solution to this problem, in this context, this work aims to study the addition of nickel alumina using the route of powder metallurgy processing of the material. The percentage of nickel were added 2, 4 and 6 wt%; and each composition to high energy milling in a planetary mill was performed for 2, 4, 9 and 16h. Subsequently, the samples were compacted at 300 MPa and sintered in a vacuum oven at 1400⁰C for 2h. The samples were characterized as the physical and mechanical properties, observing, in general, an improvement in sinterability of the material with increasing grinding time and nickel content, and mixing with a decrease of porosity and increase of hardness, density values above 80% of theoretical were obtained. The milling time of 4 hours and addition of 2% nickel, particularly if achieved higher hardness (HV 1068.7 +/- 32.6) and density of about 99% theoretical density.
Resumo:
Ceramic materials alumina basis have been widely used in structural components, mainly because owning properties such as high hardness, chemical inertness and good wear resistance, however, the low toughness is a factor that compromises its use in many other applications, featuring the addition of nickel as a possible solution to this problem, in this context, this work aims to study the addition of nickel alumina using the route of powder metallurgy processing of the material. The percentage of nickel were added 2, 4 and 6 wt%; and each composition to high energy milling in a planetary mill was performed for 2, 4, 9 and 16h. Subsequently, the samples were compacted at 300 MPa and sintered in a vacuum oven at 1400⁰C for 2h. The samples were characterized as the physical and mechanical properties, observing, in general, an improvement in sinterability of the material with increasing grinding time and nickel content, and mixing with a decrease of porosity and increase of hardness, density values above 80% of theoretical were obtained. The milling time of 4 hours and addition of 2% nickel, particularly if achieved higher hardness (HV 1068.7 +/- 32.6) and density of about 99% theoretical density.