58 research outputs found
Multi-Objective Multi-Agent Planning for Jointly Discovering and Tracking Mobile Object
We consider the challenging problem of online planning for a team of agents
to autonomously search and track a time-varying number of mobile objects under
the practical constraint of detection range limited onboard sensors. A standard
POMDP with a value function that either encourages discovery or accurate
tracking of mobile objects is inadequate to simultaneously meet the conflicting
goals of searching for undiscovered mobile objects whilst keeping track of
discovered objects. The planning problem is further complicated by
misdetections or false detections of objects caused by range limited sensors
and noise inherent to sensor measurements. We formulate a novel multi-objective
POMDP based on information theoretic criteria, and an online multi-object
tracking filter for the problem. Since controlling multi-agent is a well known
combinatorial optimization problem, assigning control actions to agents
necessitates a greedy algorithm. We prove that our proposed multi-objective
value function is a monotone submodular set function; consequently, the greedy
algorithm can achieve a (1-1/e) approximation for maximizing the submodular
multi-objective function.Comment: Accepted for publication to the Thirty-Fourth AAAI Conference on
Artificial Intelligence (AAAI-20). Added algorithm 1, background on MPOMDP
and OSP
Experiment and FEM Modelling of Bond Behaviors between Pre-stressing Strands and Ultra–High–Performance Concrete
The objective of this paper is to investigate the bond properties of prestressing strands embedded in Ultra–High–Performance Concrete (UHPC).The UHPC was made in laboratory using local materials in Vietnam.Its mixture contains: silica aggregates, portland cement PC40, fly ash, silica fume, polycarboxylate superplasticizer and the micro steel fibers.The experimental process is realized on a pull-out test. The volume fraction of micro steel fibers in UHPC was 2%. The prestressing strand with diameters of 15.2mm was considered. The interface shear strength between strand and UHPC is identified based on the results of force and displacement obtained during the pull-out test. The Cohesive Zone Model (CZM) is implemented in finite element model to study this interface behavior. This model described by a piecewise linear elastic law. The CZM’s parameters are identified based on experimental results of pull-out test.The numerical studies are used the CZM in ANSYS software. Two numerical tests are realized and compared with experimental results: pull-out test and other test to verify the deflection of I girder due to prestressing force
Experiment and FEM Modelling of Bond Behaviors between Pre-stressing Strands and Ultra–High–Performance Concrete
The objective of this paper is to investigate the bond properties of prestressing strands embedded in Ultra–High–Performance Concrete (UHPC).The UHPC was made in laboratory using local materials in Vietnam.Its mixture contains: silica aggregates, portland cement PC40, fly ash, silica fume, polycarboxylate superplasticizer and the micro steel fibers.The experimental process is realized on a pull-out test. The volume fraction of micro steel fibers in UHPC was 2%. The prestressing strand with diameters of 15.2mm was considered. The interface shear strength between strand and UHPC is identified based on the results of force and displacement obtained during the pull-out test. The Cohesive Zone Model (CZM) is implemented in finite element model to study this interface behavior. This model described by a piecewise linear elastic law. The CZM’s parameters are identified based on experimental results of pull-out test.The numerical studies are used the CZM in ANSYS software. Two numerical tests are realized and compared with experimental results: pull-out test and other test to verify the deflection of I girder due to prestressing force
The Impact of Ripening Time on Technological Quality Traits, Chemical Change and Sensory Characteristics of Dry-cured Loin
The effect of ripening time on the technological quality traits, fatty acid compositions and sensory characteristics of dry-cured loin was studied. Pork loins (n = 102) at 24 h post-mortem were used to produce dry-cured loins. The dry-cured loins were assessed at 30, 60, and 90 days of ripening for the aforementioned characteristics. Our results showed that the water activity (aw) decreased (p<0.05) up to 60 days and did not change thereafter. The lipid oxidation and weight loss levels significantly (p<0.05) increased with increased ripening time. The Commission Internationale de l’Eclairage (CIE) L* decreased for 90 days while CIE a* increased for 60 days and did not increase thereafter. More noticeably, the levels of most of unsaturated fatty acids and total polyunsaturated fatty acids significantly decreased as increasing ripening time up to 90 days. The 30 days-ripened loins had lower (p<0.05) color, flavor and overall acceptability scores than the loins ripened for 60 and 90 days, however, no differences in sensory traits occurred between the 60 and 90 day-ripened samples. Based on the results obtained in the present study, it is suggested that the ripening duration between 30 and 60 days could be more appropriate for producing dry-cured loin product with higher quality and economic benefits
Beneficial Effects of Traditional Seasonings on Quality Characteristics of Fermented Sausages
Though traditional seasonings are widely used in many dishes, however, no attention has been paid to the investigation of their effects on quality characteristics of food products. The present investigation was undertaken to study the effects of incorporating several traditional seasonings including doenjang (fermented soybean paste), gochu-jang (red pepper paste), fresh medium-hot, and hot peppers, and fresh garlic on the lipid oxidation, cholesterol content and sensory characteristics of fermented sausages. Six fermented sausage treatments (5 with 1% (w/w) each test seasoning and 1 without added test seasoning (control) were prepared. The addition of seasonings generally had beneficial effects on the improvement of fermented sausage’s quality however the effects differed depending on the each type of seasonings added. Significant lower pH values were found in all fermented sausages made with the seasonings while, lower levels of lipid oxidation were found in the treatments with hot peppers and garlic as compared with the control (p<0.05). The treatment with seasonings did not cause color or texture defects in the products whereas the sausages made with gochu-jang had significantly higher Commission International de l’Eclairagea* (redness) value in comparison with the control. Noticeably, incorporating doenjang, medium-hot peppers, hot peppers and garlic resulted in reduction of 26.50, 32.54, 47.04, and 48.54 mg cholesterol/100 g samples, respectively (p<0.05). Higher scores for the sensory traits such as aroma, taste, color and acceptability were also given for the sausages made with seasonings. The current work demonstrates that the test seasonings represent potentially natural ingredients to be used for producing healthier fermented sausages
Effect of coating with combined chitosan and gallic acid on shelf-life stability of Jeju black cattle beef
Objective Beef of Jeju black cattle (JBC) is considered as a healthy meat type due to its significantly higher unsaturated fatty acids (UFA). Lipid (e.g., UFA) is highly susceptible to oxidizing agents, which results in the quality deterioration and economic value loss of meat products. Therefore, development and application of novel preservative techniques is necessary to improve the shelf-life stability of high-UFA beef. The objective of this study was to assess the applicability of chitosan-based coatings in preservation of JBC beef. Methods Different coating solutions: 2% chitosan alone, and 2% chitosan containing 0.1% or 0.3% gallic acid were prepared to investigate their applicability in preservation of fresh beef during storage. Jeju black cattle beef (2-cm thick steaks) were non-coated (control) or coated with the above coating solutions, placed on trays, over-wrapped with plastic film and stored at 4°C. The microbiological indices, color, total volatile basic nitrogen (TVBN) and lipid oxidation of the beef were investigated after 1, 10, and 21 days of storage. Results Coating with 2% chitosan alone reduced the spoilage bacteria count, TVBN and thiobarbituric acid reactive substances levels in the beef compared with control during storage (p<0.05). Noticeably, coating with 2% chitosan containing 0.1% or 0.3% gallic acid was more effective on retardation of spoilage bacteria growth, lipid oxidation and discoloration in the beef compared to the chitosan coating alone over the storage period (21 days) (p<0.05). Conclusion Taken together, the combined chitosan and gallic acid coating could be used as a bio-preservative technique in the meat industry
Effect of Particular Breed on the Chemical Composition, Texture, Color, and Sensorial Characteristics of Dry-cured Ham
The present study demonstrates the impact of specific breed on the characteristics of dry-cured ham. Eighty thighs from Korean native pig (KNP), crossbreed (Landrace×Yorkshire)♀×Duroc♂ (LYD), Berkshire (Ber), and Duroc (Du) pig breeds (n = 10 for each breed) were used for processing of dry-cured ham. The thighs were salted with 6% NaCl (w/w) and 100 ppm NaNO2, and total processing time was 413 days. The effects of breed on the physicochemical composition, texture, color and sensory characteristics were assessed on the biceps femoris muscle of the hams. The results revealed that the highest weight loss was found in the dry-cured ham of LYD breed and the lowest weight loss was found in Ber dry-cured ham. The KNP dry-cured ham contain higher intramuscular fat level than other breed hams (p<0.05). It was observed that the dry-cured ham made from KNP breed had the lowest water activity value and highest salt content, while the LYD dry-cure ham had higher total volatile basic nitrogen content than the Ber and Du hams (p<0.05). Zinc, iron and total monounsaturated fatty acids levels were higher in KNP ham while polyunsaturated fatty acids levels were higher in Du ham when compared to other breed hams (p<0.05). Additionally, the KNP dry-cured ham possessed higher Commission International de l’Eclairage (CIE) a* value, while the Du dry-cured ham had higher L*, CIE b* and hue angle values (p<0.05). Furthermore, breed significantly affected the sensory attributes of dry-cured hams with higher scores for color, aroma and taste found in KNP dry-cured ham as compared to other breed hams (p<0.05). The overall outcome of the study is that the breed has a potential effect on the specific chemical composition, texture, color and sensorial properties of dry-cured hams. These data could be useful for meat processors to select the suitable breeds for economical manufacturing of high quality dry-cured hams
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