60 research outputs found

    Proposing a Hybrid Approach to Predict, Schedule and Select the Most Robust Project Portfolio under Uncertainty

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    Suitable project portfolio selection in inconsistent economy that can reduce the portfolio risks and increasing utilities for investors has gained significant research attentions.   This article addresses the project portfolio selection in which conventional certain (1) prediction, (2) optimization and (3) clustering approaches cannot be used to face uncertainty. To predict the real value of affecting project risk parameters, neural network has been used; Then to determine the optimized sequences and procedures, the proposed model have been evaluated using the multi-objective shuffle frog leaping algorithm (SFLA) by robust optimization approach; To suggest different risk criteria, K-means algorithm utilized to categorize the candidate projects and differentiating the clusters.  As the proposed hybrid methodology is studied on 420 different construction projects in an Iranian construction company in two economic stable years and an instable year in Iran real estate market. The results show 96 percent prediction-optimization capability due to different desired criteria

    Lymphatic mapping and sentinel node biopsy in endometrial cancer — a feasibility study using cervical injection of radiotracer and blue dye

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    BACKGROUND: The aim of this study was to evaluate the feasibility and accuracy of sentinel lymph node (SLN) detection using preoperative lymphoscintigraphy and intra-operative gamma probe/blue dye for endometrial cancer patients. MATERIAL AND METHODS: Twenty four consecutive patients with endometrial cancer were recruited. All patients underwent lymphatic mapping and sentinel node biopsy using combined intracervical radiotracer and blue dye injections. Pelvic lymph node dissection was performed for all patients. Para-aortic lymphadenectomy was done in high risk patients. All SLNs were examined by frozen section and Hematoxylin and Eosin (H&E) permanent sections. RESULTS: Pre-operative lymphoscintigraphy showed at least one SLN in 21/24 patients. Intra-operatively, at least one SLN could be harvested by gamma probe and/or blue dye methods. A total of 95 SLNs were detected. Four SLNs were detected only by blue dye, 42 only by radiotracer, and 49 were hot/blue. Median number of SLN per patient was 3. Three patients had positive pelvic lymph nodes. All of them had positive SLN (no false negative case). Frozen section could identify SLN involvement in two of three patients with positive pathology. CONCLUSION: Lymphatic mapping and sentinel node biopsy is feasible and accurate in endometrial cancer patients using combined radiotracer and blue dye methods. Frozen section accuracy was lower and underscores the importance of expert pathologists for SLN mapping technique.

    Cathodic synthesis of Al-Ce-Mn Oxide nanohybride powder with improved surface for effective removal of fluoride from aqueous media

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    Al-Ce-Mn oxide samples were synthesized by the cathodic electrochemical method at current densities of 5, 15, and 35 mAcm-2. The XRD, SEM, and EDX techniques were used for the characterization of samples. The SEM images show that at high current density the one-dimensional(nanowire) structure and at low current density two-dimensional (nanosheet) structure were obtained. Moreover, the particle sizes are decreased with increasing the current density. The samples were applied for the uptake of fluorine (F-) ions from solutions. The influence of the contact time, initial fluoride concentration, and solution pH on the adsorption was investigated. The results showed more than 80 % of F-  ions were uptake from solution during the three hours initial contact times and the uptake capacity has little change at pH below 6 and it has a sharp decline with increasing solution pH. The kinetic data were well fitted to the pseudo-second-order model and the equilibrium adsorption data was well described by the Langmuir isotherm model.  The adsorption capacity was 48 mg/g at pH 6 and room temperature

    GNN-GMVO: Graph Neural Networks for Optimizing Gross Merchandise Value in Similar Item Recommendation

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    Similar item recommendation is a critical task in the e-Commerce industry, which helps customers explore similar and relevant alternatives based on their interested products. Despite the traditional machine learning models, Graph Neural Networks (GNNs), by design, can understand complex relations like similarity between products. However, in contrast to their wide usage in retrieval tasks and their focus on optimizing the relevance, the current GNN architectures are not tailored toward maximizing revenue-related objectives such as Gross Merchandise Value (GMV), which is one of the major business metrics for e-Commerce companies. In addition, defining accurate edge relations in GNNs is non-trivial in large-scale e-Commerce systems, due to the heterogeneity nature of the item-item relationships. This work aims to address these issues by designing a new GNN architecture called GNN-GMVO (Graph Neural Network - Gross Merchandise Value Optimizer). This model directly optimizes GMV while considering the complex relations between items. In addition, we propose a customized edge construction method to tailor the model toward similar item recommendation task and alleviate the noisy and complex item-item relations. In our comprehensive experiments on three real-world datasets, we show higher prediction performance and expected GMV for top ranked items recommended by our model when compared with selected state-of-the-art benchmark models.Comment: 9 pages, 3 figures, 43 citation

    Immobilized nickel hexacyanoferrate nano particles on graphen for effective removal of Cs(I) ions from radionuclide wastes

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    In the current work synthesis and modification of graphene oxide with Nickel Hexa Ferrocyanide (NiHCF) nanoparticles has been reported. The Graphene oxide- Nickel Hexa Ferrocyanide (GO-NiHCF) was used as an adsorbent to remove Cesium (Cs) ions from a simulated solution. The obtained product was characterized with XRD, SEM, TGA, FTIR, and BET techniques. The SEM images and XRD pattern confirms the successful immobilization of Nickel Hexa Ferrocyanide on graphene oxide sheet. The cesium removal ability of GO-NiHCF was evaluated in batch mode. Effect of various parameters such as pH, initial concentration, contact time, and interferences ions were studied. The results cleared that the maximum adsorption for Cs removal was 240 mg g-1. Equilibrium modeling studies suggest that the data are reasonably and relatively fitted well to the Langmuir adsorption isotherm. Kinetic studies show that sorption process is fairly rapid and the kinetic data are fitted well to the pseudo-second order rate model. This composite offers strong potential in the field of elimination of Cs that requires rapid and complete decontamination

    New metal organic framework (MOF) nanoparticle for gas separation by matrix membranes

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    {[Dy(BTC)(H2O)]•DMF}n metal organic framework nanoparticles was synthezed through solvthermal method. The product was characterized by XRD, TG, BET, and SEM techniques. SEM images showed that the synthesized sample has semi-cubic particles with average size of 70 nm in length.For improve the gas separation performance,the MOF nano particles were dispersed in polydimethylsiloxane (PDMS) for preparation of mixed matrix membrane (MMM) on support of polyethersulphone (PES). The performance of obtained MMM in separation of NO, N2 and O2 gas were investigated, and the effect of MOF nanoparticles (5, 10, and 15% wt)and feed pressure (100-250 kPa) on permeability and selectivity were studied. It was found that the membrane performance is evaluated by addition of MOF nano particles in membrane (polymeric matrix), and the feed pressure have not important effect on separation. The performance (NO/N2 and NO/O2 selectivity) increased as the loading of MOF particles (up to 15% wt) being dispersed within the polymer matrices

    The association of cardio-metabolic risk factors and history of falling in men with osteosarcopenia: a cross-sectional analysis of Bushehr Elderly Health (BEH) program

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    Osteosarcopenia, defined as sarcopenia plus osteopenia/osteoporosis, may increase the risk of fractures and affects morbidity and mortality in the older population. Falling is also common in the elderly and increases the risk of fractures and mortality. We examined the association of cardio-metabolic risk factors with a history of falling in osteosarcopenic men. Methods We used the baseline data of the Bushehr Elderly Health (BEH) program. Osteosarcopenia was defined as having both sarcopenia (reduced skeletal muscle mass plus low physical performance and/or low muscle strength) and osteopenia/osteoporosis (T-score ≤ − 1.0). Falling was defined as a self-reported history of an unintentional down on the ground during the previous year before the study. We used logistic regression analysis to estimate the adjusted odds ratio (AOR) with a 95% Confidence Interval (CI) to quantify the associations. Results All elderly men diagnosed with osteosarcopenia (n = 341), with a mean age of 73.3(±7.4) years, were included. Almost 50(14.7%) participants reported falling. Age showed a positive association with falling (AOR: 1.09, 95%CI: 1.04–1.14). An increase of 10 mmHg in systolic blood pressure(SBP), reduces the odds of falling by 26%(AOR:0.74, 95%CI:0.62–0.89), while a positive association was detected for fasting plasma glucose (FPG), as 10 mg/dl increase in the FPG, raises the chance of falling by 14%(AOR = 1.14, 95%CI:1.06,1.23). Hypertriglyceridemia was inversely associated with falling (AOR = 0.33, 95% CI: 0.12, 0.89). Conclusions Falling is a major public health problem in rapidly aging countries, especially in individuals with a higher risk of fragility fractures. Older age-raised fasting plasma glucose and low SBP are associated with falling in osteosarcopenic patients. Considering the higher risk of fracture in osteosarcopenic men, comprehensive strategies are needed to prevent fall-related injuries in this high-risk population
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