Integration of strategic and tactical decisions for vendor selection under capacity constraints

We examine a generalized vendor selection problem of a multi-store firm where the goal is the simultaneous determination of (i) the set of vendors the firm should work with and (ii) how much each store should order from the selected vendors. In addition to the typical costs associated with vendor selection and delivery between the vendors and their assigned stores, we explicitly consider the inventory-related costs and decisions of the stores. We emphasize the relationship between facility location applications and the problem at hand, and we propose an integrated vendor selection and inventory optimization model. Also, arguing that our model creates a venue for precise incorporation of realistic capacity constraints, we model throughput and dispatch capacities, explicitly. The model is a challenging mixed integer nonlinear program for which we propose an efficient solution approach that relies on Generalized Benders Decomposition (GBD).     

Fall detection using single-tree complex wavelet transform

The goal of Ambient Assisted Living (AAL) research is to improve the quality of life of the elderly and handicapped people and help them maintain an independent lifestyle with the use of sensors, signal processing and telecommunications infrastructure. Unusual human activity detection such as fall detection has important applications. In this paper, a fall detection algorithm for a low cost AAL system using vibration and passive infrared (PIR) sensors is proposed. The single-tree complex wavelet transform (ST-C$\mathbb{C}$WT) is used for feature extraction from vibration sensor signal. The proposed feature extraction scheme is compared to discrete Fourier transform and mel-frequency cepstrum coefficients based feature extraction methods. Vibration signal features are classified into “fall” and “ordinary activity” classes using Euclidean distance, Mahalanobis distance, and support vector machine (SVM) classifiers, and they are compared to each other. The PIR sensor is used for the detection of a moving person in a region of interest. The proposed system works in real-time on a standard personal computer.     

A hybrid named entity recognizer for Turkish

Named entity recognition is an important subfield of the broader research area of information extraction from textual data. Yet, named entity recognition research conducted on Turkish texts is still rare as compared to related research carried out on other languages such as English, Spanish, Chinese, and Japanese. In this study, we present a hybrid named entity recognizer for Turkish, which is based on a manually engineered rule based recognizer that we have proposed. Since rule based systems for specific domains require their knowledge sources to be manually revised when ported to other domains, we enrich our rule based recognizer and turn it into a hybrid recognizer so that it learns from annotated data when available and improves its knowledge sources accordingly. The hybrid recognizer is originally engineered for generic news texts, but with its learning capability, it is improved to be applicable to that of financial news texts, historical texts, and child stories as well, without human intervention. Both the hybrid recognizer and its rule based predecessor are evaluated on the same corpora and the hybrid recognizer achieves better results as compared to its predecessor. The proposed hybrid named entity recognizer is significant since it is the first hybrid recognizer proposal for Turkish addressing the above porting problem considering that Turkish possesses different structural properties compared to widely studied languages such as English and there is very limited information extraction research conducted on Turkish texts. Moreover, the employment of the proposed hybrid recognizer for semantic video indexing is shown as a case study on Turkish news videos. The genuine textual and video corpora utilized throughout the paper are compiled and annotated by the authors due to the lack of publicly available annotated corpora for information extraction research on Turkish texts.     

Poly(methyl methacrylate) hybrid syntactic foams with hollow glass microspheres and polyhedral oligomeric silsesquioxanes

The study aims to produce poly(methyl methacrylate) (PMMA)-based lower density syntactic foams with hollow glass microspheres (HGMs) and to improve their mechanical properties by the addition of polyhedral oligomeric silsesquioxanes (POSSs) while maintaining the thermal properties of the neat polymer. First to understand the effect of POSS addition, PMMA–POSS composites with octaisobutyl and octaphenyl POSS were produced through extrusion. Higher relative flexural and impact strengths were obtained with POSS addition to PMMA. Obtaining more enhanced properties with octaphenyl POSS, PMMA-HGM-POSS hybrid syntactic foams were prepared with this additive. In general, the specific flexural strength and modulus of the PMMA syntactic foams were improved with the POSS loading, while the lower density and thermal properties of the PMMA syntactic foams were maintained. PMMA hybrid syntactic foams with 15 wt % HGMs and 0.25 wt % POSS exhibited 37.6% improvement in the specific flexural modulus with respect to the neat PMMA. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48368.     

Fatty acid and 3‐hydroxy fatty acid composition of two Hypericum species from Turkey

The fatty acid compositions of flowering tops of Hypericum perforatum L. and Hypericum retusum Aucher (Guttiferae) were analyzed by gas chromatography and gas chromatography‐mass spectrometry. The major components were C16:0 (24.87%), C18:3 n‐3 (21.94%), 3‐OH‐C18:0 (18.46%) and 3‐OH‐C14:0 (14.22%) for H. perforatumL. and 3‐OH‐C14:0 (28.29%), C18:0 (16.47%) and C16:0 (14.17%) for H. retusum Aucher. Besides widespread plant fatty acids, 3‐hydroxy fatty acids, namely 3‐hydroxytetradecanoic acid (3‐OH‐C14:0) and 3‐hydroxyoctadecanoic acid (3‐OH‐C18:0) were also obtained.     

GIS based statistical and physical approaches to landslide susceptibility mapping (Sebinkarahisar,Turkey)

The case study presents GIS-aided statistically and physically based landslide susceptibility mapping in the landslide-prone Avutmus district of Sebinkarahisar (Giresun, Turkey). Field investigations, analysis of geological data and laboratory tests suggested that two important factors have acted together to cause sliding: ground water pressures and toe erosion. Frequency ratio (FR) and stability index mapping (SINMAP) were used to create the landslide susceptibility maps based on a landslide inventory; distance from drainage systems, faults and roads; slope angle and aspect; topographic elevation and topographical wetness index; and vegetation cover. Validation of the models indicated high quality susceptibility maps with the more realistic results were obtained from the statistically based FR model.     

Determination of antimicrobial effect of mint and basil essential oils on survival of E. coli O157:H7 and S. typhimurium in fresh-cut lettuce and purslane

In this research, mint and basil essential oils at concentrations of 0.01 ml/L, 0.032 ml/L or 0.08 ml/L were used for disinfection treatments of fresh-cut lettuce and purslane samples inoculated with Salmonella typhimurium or Escherichia coli 0157:H7. Disinfection treatment time was applied as 10 min (short) or 15 min (long). Disinfected samples were packaged aerobically and stored at refrigerator +4 °C for 7 days. It was observed that mint and basil essential oils showed antimicrobial effect on the survival of E. coli O157:H7 and S. typhimurium inoculated into lettuce and purslane samples during refrigerated storage. Mint essential oil showed higher antimicrobial effect on pathogens when compared to basil essential oil. Mint and basil essential oils at concentration of 0.08 ml/L were the most effective antimicrobial treatment against pathogens in two different vegetable. S. typhimurium was more resistant against basil oil in lettuce samples when compared to its resistance against basil oil in purslane samples, whereas E. coli O157:H7 was more resistant to mint oil in purslane samples when compared to its resistance against mint oil in lettuce samples.     

Can primary failure of arteriovenous fistulas be anticipated?

Primary failure, early thrombosis, and inadequate maturation are the main complications encountered in arteriovenous fistulas. Doppler ultrasonographic assessment of flow‐mediated dilatation (FMD) is currently used for the early diagnosis of atherosclerosis. Clinical experience in the use of FMD for preoperative assessment of vasculature is rather limited; therefore, we sought to elucidate the relationship between preoperative FMD and primary failure of the fistula. Thirty‐three patients with end‐stage renal disease who were admitted to our hospital between January and July 2005 were included in our study. Medical histories were established and the internal diameter, wall thickness, peak systolic flow rate, and resistive index (RI) were measured in the cephalic vein and radial and brachial arteries. Flow‐mediated dilatation and nitrate‐mediated dilatation (NMD) of the brachial artery were assessed. Fistulas were evaluated 48 hours and 30 days postoperatively. Brachial arterial internal diameter was lower in all fistulas that developed primary failure in 48 hours (0.4 ± 0.07 cm vs. 0.35 ± 0.07 cm, P = 0.016). The radial artery RI was found to be significantly elevated in fistulas with both early (48‐hour) and late‐term (30‐day) failure (0.9 ± 0.08 vs. 0.68 ± 0.3, P = 0.01, and 0.86 ± 0.8 vs. 0.67 ± 0.3, P = 0.038, respectively). The brachial artery peak systolic flow rate was significantly reduced in patients in the radiocephalic fistula group that developed early and late‐term failure (42.9 ± 12 cm/sec vs. 68.4 ± 10 cm/sec, P = 0.01, and 44.1 ± 13 cm/sec vs. 57.7 ± 16 cm/sec, P = 0.038, respectively). Our study, constrained by a smaller, older patient group, was unable to show a statistically significant correlation between FMD, NMD, and fistula success. Any single parameter may not be sufficient to assess vascular health preoperatively. A multifactorial approach incorporating parameters evaluating arterial and venous function might be more effective in predicting fistula success. Further studies on larger patient groups may indeed demonstrate the value of these assessments.     

Corn gluten hydrolysis by Alcalase: Calibration of pH-stat

In the present study, pH-stat method was calibrated by TNBS and OPA reactions for control of hydrolysis of corn gluten by Alcalase. Hydrolysis experiments were conducted in a batch reactor at the temperature of 50 °C for various pH values, and at pH 7 for 40 and 60 °C. The calibration was characterized by good linear correlations for both methods. The mean pK values of corn gluten hydrolysates were obtained as 6.83, 6.59 and 6.36 for 40, 50 and 60 °C, respectively.