Prediction of MOR and MOE of structural plywood board using an artificial neural network and comparison with a multivariate regression model

The structural application of plywood boards has increased considerably in recent years. In this context, determining plywood mechanical properties such as bending strength and modulus of elasticity through predictive models using more-easily obtained properties is a very useful tool for in-factory quality control. Artificial neural networks have demonstrated their high capacity for modelling complex relations between variables, considerably improving on results obtained through regression techniques. Four neural networks were developed to obtain these mechanical properties by determining board thickness, moisture content, specific gravity, bending strength and modulus of elasticity of test pieces of small dimensions. The results were compared with those of a regression model and in all cases the results of the present study were better.     

Joint spectrum and power optimization in the design of the UMTS satellite component

The paper provides a power and spectrum joint analysis of the universal mobile telecommunications system (UMTS) satellite component, based on the wideband code division multiple access (W‐CDMA) air interface. In fact, power and spectral efficiency may become highly conflicting requirements in a satellite system and a trade‐off analysis is needed to drive a proper dimensioning of the satellite. The proposed approach allows a dimensioning of the satellite component either in terms of orbit and power budget or in terms of additional capacity for the terrestrial section, for specified orbit and power limitations. The impact of candidate frequency bands, orbit type and diversity on both spectral and power requirements of the satellite component is evaluated. For given traffic requirements, power‐vs‐spectrum trade‐off is proposed which ensures a proper resources utilization. The efficiency evaluation accounts for: beams overlapping, ortho gonality, voice activity factor, diversity and cross‐polarization frequency reuse. Perfect power control is assumed and the effect of the excess power required by the shadowed users is accounted for in the interference calculation. Furthermore, still in the frame of a proper resource exploitation, a possible optimization of capacity through the use of unpaired bands in the two link directions is analysed. Copyright © 2001 John Wiley & Sons, Ltd.     

Improving antioxidant activity and nutritional components of Philippine salt-fermented shrimp paste through prolonged fermentation

The antioxidant activity and nutritional components of Philippine salt-fermented shrimp paste were improved through prolonged fermentation (90, 180, and 360 days). The antioxidant ability against 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, hydrogen peroxide, and lipid peroxidation increased significantly with prolonged fermentation and were suggested to be related with the Maillard reaction products formed, as measured by the characteristic browning and fluorescent developments. Polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the shrimp paste were not substantially damaged for 360 days, while free amino acid content dramatically increased at 90 days. However, excessive fermentation showed slight but significant decrease in free amino acids and increase in ammonia. These results suggest that properly prolonged fermentation would improve antioxidant ability and some nutritional value in the salt-fermented shrimp paste.     

FM-UWB for Communications and Radar in Medical Applications

UWB technology is a useful and safe new technology in the area of wireless body area network. There are many advantages of using UWB as a communication standard for biomedical applications. Due to very low radiated power (−41.3 dBm/MHz), low power consumption, good coexistence with the other existing instruments, Robustness to interference and multipath. Moreover, one specific UWB technology, namely Frequency Modulated (FM)-UWB, has also an important advantage, which make it even more convenient for medical applications, such as simple low cost design (FM, no receive LO, no carrier synchronization as in IR-UWB). UWB technology has been also proposed radar applications such as: Non-Invasive Heart and Respiration Rate Monitoring; Detection of Cardiac Arrhythmias; Detection of Pathological Respiratory Patterns, particularly in Sudden Infant Death Syndrome (SIDS) and Sleep Apnea; Multi-Patient Monitoring; Detection and Non-Invasive Imaging of Breast Tumors. However, pulsed radar are mainly used for these applications. The main issue that is addressed in this paper is the integration of sensing and communication using FM-UWB and radar technology so that a single device can be obtained for two different operational mode. We have show that FM-UWB as radar can meet the requirements of typical biomedical applications such as Non-Invasive Heart and Respiration Rate Monitoring. Advantages and challenges of this integration are shown. Future perspectives of this novel activity will be drawn.     

SOMAR: A SOcial Mobile Activity Recommender

A 2010 survey (Nielsen) showed that 22.7% of the time spent on the Internet is on a social network. Moreover, there is an increasing demand to access social networks by mobile phones, i.e., around 30% globally. Social networking has become a reality, and it generates an incredible amount of information that is sometimes difficult for users to process, especially from mobile phones. Several links, activities, and recommendations are proposed by networked friends every hour, which together are nearly impossible to manage. There is a need to filter and make accessible such information to users, which is the motivation behind developing a mobile recommender that exploits social network information. Thus, in this paper, we propose the design and the implementation of a SOcial Mobile Activity Recommender (SOMAR) that can integrate Facebook social network mobile data and sensor data to propose activities to the user (e.g., concert or computer science seminar). The recommendations are completely calculated in situ in the mobile device with an embedded data mining component. We analyze how to compute and update the social graph in case of changes in social relationships or user context. The paper also presents a case study to analyze the performance of the method.     

Near infrared (NIR) spectroscopy as a tool for monitoring blueberry osmo-air dehydration process

Osmo-air dehydration treatments are widely applied to fruits in order to prolong shelf-life, reduce packaging and logistic costs, and improve both sensory and nutritional quality of the end products. In this work osmo-air dehydration was applied to blueberries (Vaccinium corymbosum), a fruit that is gaining increasing attention due to its high content of dietary antioxidants. In particular, the aim of this study was to investigate the performance of near infrared (NIR) spectroscopy as a tool for monitoring blueberry osmo and air dehydration processes.Blanched blueberries were dipped in sucrose and fructose + glucose osmotic solutions for 24 h, and the osmotic exchanges were determined by mass balances (water loss, solid gain, sugar intake, changes in total phenolics and anthocyanins); NIR spectra were collected in order to study modifications due to the osmotic treatments. Untreated and infused berries were subsequently air-dried at 70 °C to final moisture content of 10-14%. During drying chemical, nutritional and structural changes were monitored and NIR spectra were acquired on whole berries, using an optic probe working in diffuse reflectance. Spectral data were standardized, transformed into first derivative and processed by Principal Component Analysis. Results show that NIR spectroscopy was able to follow the osmotic and the air-drying processes and to discriminate untreated and osmo-dehydrated berries. Spectral differences reflect the main molecular modifications associated with water absorption bands due to OH stretch + OH bending and sugar absorption bands due to CH stretch + CH bending and OH stretch + OH bending. In order to investigate the variation of main constituents (sugars and water) involved in the osmo-dehydration process, two-dimensional correlation analysis of spectral data was also carried out.     

A Lesson on Unpredictable Future

This paper presents the main conclusions that can be drawn by the discussions on future communication systems addressed in details in the papers published in this issue of the journal and the lessons on unpredictable future of wireless communications.     

Diversity of virulence profiles of Shiga toxin-producing Escherichia coli serotypes in food-producing animals in Brazil

The prevalence, serotypes and virulence profiles of Shiga toxin-producing Escherichia coli (STEC) were investigated in 205 healthy beef and dairy cattle, and 106 goats reared in the southeastern region of Minas Gerais State, Brazil. The prevalence of STEC was 57.5% (61/106) in goats, 39.2%, (40/102) in beef cattle and 17.5% (18/103) in dairy cattle. Among the 514 STEC isolates, 40 different serotypes were found and some of them were identified in a specific host. STEC isolates harboring stx(1) corresponded to 15.6% (28/180), 26.7% (16/60) and 24.1% (66/274) in beef cattle, dairy cattle and goats, respectively. stx(2) was found in 30% (54/180), 53.3% (32/60) and 34.7% (95/274) of beef and dairy cattle, and goats. stx(1) plus stx(2) sequences were harbored by 54.4% (98/180), 20% (12/60) and 41.2% (113/274) of beef cattle, dairy cattle and goats, respectively. The eae sequence was found in 15% (9/60) and 0.6% (1/180) of STEC isolates from dairy and beef cattle, respectively, and the toxB gene was found only in one O157:H7 strain isolated from beef cattle. Strains with the genetic profiles stx(2) ehxA iha saa and stx(1) stx(2) ehxA iha saa were the most prevalent among STEC isolates from cattle. Profiles stx(1) stx(2) ehxA iha, stx(2), and stx(1) iha accounted for 75.5% (207 /274) of the STEC isolates from goats. While STEC strains carrying either stx(2) alone or associated with stx(1) were found more frequently in cattle, those harboring sequences stx(1c) and stx(2d) alone or associated with stx(1c) predominated in goats. Our data show a diversity of STEC strains in food-producing animals, most of them carrying genes linked to severe forms of human diseases.     

Structural features of native cellulose gels and films from their susceptibility to enzymic attack

The reaction of enzymic hydrolysis has been used as a probe to evidence the different structural features of bacterial native cellulose gels and films synthesized from different carbon sources. The gels were found to be more hydrolyzable than were the films, both in terms of reaction extent and of initial reaction rate, by factors increasing with temperature. For instance, a cellulose gel synthesized from glucose showed at 50°C a hydrolysis yield twice as much as that of the corresponding film, thus revealing, in the former case, a higher level of substrate accessibility and enzyme penetrability. It has been suggested that the increase of gel accessibility with temperature can be associated with a corresponding lowering of the amount of structured water close to the polymer chains in the gel. The significant decrease of susceptibility to enzymic attack observed in going from the cellulose film obtained from glucose to that obtained from xylose has been related to the markedly lower value of specific surface area estimated in the latter case. Likely, in the film obtained from xylose, densely packed microfibrils occur that are scarcely accessible to enzyme. In some cases, the reaction progress has been followed by SEM analysis. Microcrystalline cellulose has been also considered for comparison.