Intelligent control system simulation of an agricultural robot

An intelligent control system for an agricultural robot which performs in an uncertain and unstructured environment was modelled as distributed, autonomous computing modules that communicate through globally accessible blackboard structures. The control architecture was implemented for a robotic harvester of melons. A CAD workstation was used to plan, model, simulate and evaluate the robot and gripper motions using 3-D, real-time animation. The intelligent control structure was verified by simulating the dynamic data flow scenarios of melon harvesting. Control algorithms were evaluated on measured melon locations.Picking time was reduced by 49% by applying the traveling salesman algorithm to define the picking sequence. Picking speeds can be increased by a continuous mode of operation. However, this decreases harvest efficiency. Therefore, an algorithm was developed to attain 100% harvest efficiency by varying the vehicle's forward speed. By comparing different motion control algorithms through animated visual simulation, the best was selected and thereby the performance improved.Journal Paper No. 13043, Agricultural Experiment Station, Purdue University, W. Lafayette, IN 47907, U.S.A. This research was supported by Grants No. US-1254-87 and US-1682-89 from BARD, the United States-Israel Binational Agricultural Research and Development Fund.     

Calculation of quantitative shunt values using photoluminescence imaging

A proof of concept study for a method of determining quantitative shunt values in silicon solar cells from photoluminescence images is presented. The method is based on interpretation of the luminescence intensity around a local shunt or recombination‐active defect in terms of the extracted current. The theoretical relationship between the photoluminescence signal and the shunt current is derived. Experimental results on specifically prepared test structures show good agreement with known shunt resistance values. Experimental data on diffused wafers are presented. The effect of the front metallisation in complete cells on the appearance and interpretation of shunts in photoluminescence images is investigated experimentally. The limitations of the method are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Extended shelf life of soy bread using modified atmosphere packaging

This study investigated the use of modified atmosphere packaging (MAP) to extend the shelf life of soy bread with and without calcium propionate as a chemical preservative. The bread samples were packaged in pouches made from low-density polyethylene (LDPE) as the control (film 1), high-barrier laminated linear low-density polyethylene (LLDPE)-nylon-ethylene vinyl alcohol-nylon-LLDPE (film 2), and medium-barrier laminated LLDPE-nylon-LLDPE (film 3). The headspace gases used were atmosphere (air) as control, 50% CO2-50% N2, or 20% CO2-80% N2. The shelf life was determined by monitoring mold and yeast (M+Y) and aerobic plate counts (APC) in soy bread samples stored at 21 degrees C +/- 3 degrees C and 38% +/- 2% relative humidity. At 0, 2, 4, 6, 8, 10, and 12 days of storage, soy bread samples were removed, and the M+Y and APC were determined. The preservative, the films, and the headspace gases had significant effects on both the M+Y counts and the APC of soy bread samples. The combination of film 2 in the 50% CO2-50% N2 or 20% CO2-80% N2 headspace gases without calcium propionate as the preservative inhibited the M+Y growth by 6 days and the APC by 4 days. It was thus concluded that MAP using film 2 with either the 50% CO2-50% N2 or 20% CO2-80% N2 was the best combination for shelf-life extension of the soy bread without the need for a chemical preservative. These MAP treatments extended the shelf life by at least 200%.     

Dynamic repair priority for a transfer line with a finite buffer

We formulate a continuous-time Markov chain model of a transfer line in which there are two unreliable machines separated by a finite buffer. Due to limited repair resources, simultaneous repairs are not possible in cases where both machines fail, and therefore we develop a repair priority rule that depends on the number of work-pieces present in the buffer. Each machine is characterized by three exponentially distributed random variables: processing time, time to failure, and time to repair. We provide a stochastic model for finding an optimal repair priority rule and an efficient algorithm accompanied by easy-to-use Matlab software. An extensive numerical study is performed to test the sensitivity of the proposed dynamic repair priority rule. While in previous studies repair priority was given to the bottleneck machine, we show that there are situations in which priority should be given to the non-bottleneck machine. Finally, we identify conditions in which adding a second technician is economically advisable.     

On the equivalence of some transductions involving letter to letter morphisms on regular languages

Summary Equivalence problems of some transductions involving letter to letter morphisms on regular languages are discussed. In particular, we deal with finite substitutions and inverses of finite substitutions. Our main results are the following: (i) The equivalence problem of inverses of finite substitutions on regular languages is undecidable, (ii) The existential equivalence problem of finite substitutions on regular languages is undecidable, and (iii) The length-equivalence problem of finite substitutions on regular languages is decidable.     

Mother-Infant Interactions in Rats Lacking CCKA Receptors.

Mediation of mother-infant interactions by the brain-gut peptide cholecystokinin (CCK) was examined by observing behavior of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which lack functional CCKA receptors because of a genetic abnormality. OLETF (n = 10) and control (Long-Evans Tokushima Otsuka [LETO] n = 10) dams interacted with 1 pup of each line on Postpartum Days 6-9. OLETF pups received more body and anogenital licking and emitted substantially more ultrasonic vocalizations than LETO pups. OLETF dams carried pups less frequently and showed a nursing position more frequently than LETO dams. No significant Pup X Dam Line interactions or line differences in dams' activity were detected. The results provide convergent validity to previous pharmacological studies implicating CCK mediation of both infant and maternal behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical Activity and Psychological Well-Being in Advanced Age: A Meta-Analysis of Intervention Studies.

A meta-analysis examined data from 36 studies linking physical activity to well-being in older adults without clinical disorders. The weighted mean-change effect size for treatment groups (dC. = 0.24) was almost 3 times the mean for control groups (dC. = 0.09). Aerobic training was most beneficial (dC. = 0.29), and moderate intensity activity was the most beneficial activity level (dC. = 0.34). Longer exercise duration was less beneficial for several types of well-being, though findings are inconclusive. Physical activity had the strongest effects on self-efficacy (dC.= 0.38), and improvements in cardiovascular status, strength, and functional capacity were linked to well-being improvement overall. Social-cognitive theory is used to explain the effect of physical activity on well-being. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Array-based binary analysis for bacterial typing

An allele-specific oligonucleotide microarray was developed for rapid typing of pathogens based on analysis of genomic variations. Using a panel of Escherichia coli strains as a model system, selected loci were sequenced to uncover differences, such as single- or multiple-nucleotide polymorphisms as well as insertion/deletions (indels). While typical genomic profiling experiments employ specific sequences targeted to genomic DNA unique to a single strain or virulent gene, the present array is designed to type bacteria based on a patterned signature response across multiple loci. In the signature concept, all strains are interrogated by hybridizing their amplified DNA to an array containing multiple probe sequences. Allele-specific oligonucleotide probe sequences targeting each of these variable regions were synthesized and included in a custom fiber-optic array. For each locus, a set of specific probe sequences is selected, such that hybridization gives a binary signal/no signal response to each of the probes. Using this strategy for multiple loci, many pathogens or microorganisms could be classified using a limited number of probes. Because of the advantages of the fiber-optic array platform over other array formats, including sensitivity and speed, the platform described in this paper is capable of supporting a high-throughput diagnostic strategy.     

Nonchronological video synopsis and indexing

The amount of captured video is growing with the increased numbers of video cameras, especially the increase of millions of surveillance cameras that operate 24 hours a day. Since video browsing and retrieval is time consuming, most captured video is never watched or examined. Video synopsis is an effective tool for browsing and indexing of such a video. It provides a short video representation, while preserving the essential activities of the original video. The activity in the video is condensed into a shorter period by simultaneously showing multiple activities, even when they originally occurred at different times. The synopsis video is also an index into the original video by pointing to the original time of each activity. Video Synopsis can be applied to create a synopsis of an endless video streams, as generated by webcams and by surveillance cameras. It can address queries like "Show in one minute the synopsis of this camera broadcast during the past day'. This process includes two major phases: (i) An online conversion of the endless video stream into a database of objects and activities (rather than frames). (ii) A response phase, generating the video synopsis as a response to the user's query.     

Factors Influencing Perceived Benefits and User Satisfaction in Knowledge Management Systems

This study offers a model for predicting users’ perceived benefits and user satisfaction in organizational knowledge management systems. Four constructs are theorized to influence the dependent variables: system quality, knowledge quality, user IS competence, and organizational attitude to knowledge management. The model was empirically tested among 100 respondents working in the knowledge-intensive software industry. The results suggest that knowledge management systems hold certain characteristics to be considered when evaluating technical and socio-psychological factors of users’ perceptions and attitudes toward the systems.