Control of free-ranging automated guided vehicles in container terminals

Container terminal automation has come to the fore during the last 20 years to improve their efficiency. Whereas a high level of automation has already been achieved in vertical handling operations (stacking cranes), horizontal container transport still has disincentives to the adoption of automated guided vehicles (AGVs) due to a high degree of operational complexity of vehicles. This feature has led to the employment of simple AGV control techniques while hindering the vehicles to utilise their maximum operational capability. In AGV dispatching, vehicles cannot amend ongoing delivery assignments although they have yet to receive the corresponding containers. Therefore, better AGV allocation plans would be discarded that can only be achieved by task reassignment. Also, because of the adoption of predetermined guide paths, AGVs are forced to deploy a highly limited range of their movement abilities while increasing required travel distances for handling container delivery jobs. To handle the two main issues, an AGV dispatching model and a fleet trajectory planning algorithm are proposed. The dispatcher achieves job assignment flexibility by allowing AGVs towards to container origins to abandon their current duty and receive new tasks. The trajectory planner advances Dubins curves to suggest diverse optional paths per origin-destination pair. It also amends vehicular acceleration rates for resolving conflicts between AGVs. In both of the models, the framework of simulated annealing was applied to resolve inherent time complexity. To test and evaluate the sophisticated AGV control models for vehicle dispatching and fleet trajectory planning, a bespoke simulation model is also proposed. A series of simulation tests were performed based on a real container terminal with several performance indicators, and it is identified that the presented dispatcher outperforms conventional vehicle dispatching heuristics in AGV arrival delay time and setup travel time, and the fleet trajectory planner can suggest shorter paths than the corresponding Manhattan distances, especially with fewer AGVs.Open Acces

Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines.

Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1) expression resulting in decreased proliferation and increased S-G(2)/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma

Observation of enhanced superconductivity in the vicinity of Ar-induced nano-cavities in Pb(111)

Local variations of superconductivity have been studied using scanning tunneling microscopy around nano-cavities formed by Ar ions embedded in Pb(111). Various factors including the density of states at Fermi energy, electron-phonon couplings, and quantum well states, which are known to affect superconductivity, have been examined. We show that the superconductivity is enhanced near the nano-cavities and propose that quantum effects such as quantum confinement, proximity effect and multi-gap effect are possibly involved in determining the superconducting gap of this system. These results have important implications for the characterization and understanding of superconductivity at a nanometer scale. © 2017 The Author(s).1

Changes in activity and isozyme patterns of peroxidase and chitinase in kiwifruit pollen

In this study, changes in activity and isozyme patterns of peroxidase (POD) and chitinase in kiwifruit (Actinidia chinensis) pollen were investigated under different storage conditions. Although residual activity was detected in heat-treated pollen, changes in POD activity were observed due to difference in storage conditions as revealed by preliminary studies in which pollen germination varied with different storage conditions. POD activity of kiwifruit pollen increased as proportions of viable pollen increased, indicating a positive correlation (R2=0.993) between pollen viability and POD activity. There was a detectable difference in the relative activity of POD enzyme between heat-treated and viable pollen. Decoloration of Congo Red was observed in germination medium which fresh pollen was cultured. The activity of individual chitinase isozymes present in kiwifruit pollen differed depending on storage conditions, which had a direct impact on pollen vigor. Although direct evidence showing that chitinase isozymes are implicated in pollen vigor is still uncertain, distinction of isozymes may facilitate more precise identification of viable pollen which possesses germination potential from non-viable pollen. Taken together, these results suggest that monitoring the activity of POD and chitinase can be an attractive alternative to evaluate pollen vigor in kiwifruit

An Angiotensin I Converting Enzyme Polymorphism Is Associated with Clinical Phenotype When Using Differentiation-Syndrome to Categorize Korean Bronchial Asthma Patients

In this study, genetic analysis was conducted to investigate the association of angiotensin I converting enzyme (ACE) gene polymorphism with clinical phenotype based on differentiation-syndrome of bronchial asthma patients. Differentiation-syndrome is a traditional Korean medicine (TKM) theory in which patients are classified into a Deficiency Syndrome Group (DSG) and an Excess Syndrome Group (ESG) according to their symptomatic classification. For this study, 110 participants were evaluated by pulmonary function test. Among them, 39 patients were excluded because they refused genotyping. Of the remaining patients, 52 with DSG of asthma (DSGA) and 29 with ESG of asthma (ESGA), as determined by the differentiation-syndrome techniques were assessed by genetic analysis. ACE insertion/deletion (I/D) polymorphism analysis was conducted using polymerase chain reaction (PCR). Student's t, chi-square, Fisher and Hardy-Weinberg equilibrium tests were used to compare groups. No significant differences in pulmonary function were observed between DSGA and ESGA. The genotypic frequency of ACE I/D polymorphism was found to differ slightly between DSGA and ESGA (P = .0495). However, there were no significant differences in allelic frequency observed between DSGA and ESGA (P = .7006, OR = 1.1223). Interestingly, the allelic (P = .0043, OR = 3.4545) and genotypic (P = .0126) frequencies of the ACE I/D polymorphism in female patients differed significantly between DSGA and ESGA. Taken together, the results presented here indicate that the symptomatic classification of DSGA and ESGA by differentiation-syndrome in Korean asthma patients could be useful in evaluation of the pathogenesis of bronchial asthma

GAS AND SOLID MIXING IN A THREE PARTITIONED FLUIDIZED BED

There are many gas-solid reaction systems which take place simultaneously in a single reactor, such as coal gasification. By splitting the reactions, high concentrated gases can be obtained without separation processes. Dual fluidized bed was proposed for this purpose. Similarly, simultaneous adsorption/desorption systems with dry sorbent for CO2 capture and the gasification reaction system with a char combustor and a gasifier separately were developed. For improving gas and solid mixing efficiencies of the dual fluidized beds, a hitherto unknown partitioned fluidized bed (PFB) is proposed. A basic concept of PFB is that lower parts between two separated fluidized beds are linked (opened), whereas upper parts are blocked by walls. Solid mixing occurs in lower parts with preventing gas mixing. The solid residence time becomes longer than that of dual fluidized bed and the high conversion of solid can be obtained. In this study, the gas and the solid mixing behaviors were investigated in three partitioned fluidized beds (left, center and right). The size of each fluidized bed is 7 cm (w) X 7 cm (d) X 30 cm (h) and partitioned above the 7 cm of distributor. Air and CO2-air mixture were used as fluidizing gas in each partitioned fluidized bed. For the gas mixing experiments, glass bead particles with 150 micron and density of 2.5g/cm3 were introduced. Outlet gas concentrations of each fluidized bed were analyzed by IR and then the gas exchanges between the reactors were calculated. For the solid mixing experiments, the polypropylene particles with 1000 micron and the density of 0.883 g/cm3 were continuously fed into the reactor. The gas mixing percentages were 0.4 ~ 16.0% of input gas amounts with varying gas velocities. The solid discharge rates in center and right side can be controlled by operating conditions