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- Anh-Tuan Le (12)
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- Truong V. Vu (8)
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We present a numerical investigation of the breakup and freezing of a pendant hollow water drop beneath a cold curved surface. The drop contains a bubble surrounded by a shell of water that forms at an outer wetting angle of θo with the surface. The freezing begins on the cold curved surface and evolves in the direction of gravity. As it freezes, the water accumulates and forms a bulbous end at the bottom of the drop. Breakup can occur, inducing a daughter water drop. As a result, the freezing process of the remaining hollow drop attached to the surface takes less time, and the frozen drop shrinks. However, this breakup has no effect on the bubble. The various parameters under consideration include the Bond number Bo, the Stefan number St, the size of the bubble, and the angle θo. I... |
In this paper, we present exact methods for solving the Time Dependent Minimum Tour Duration Problem (TD-MTDP) and the Time Dependent Delivery Man Problem (TD-DMP). Both methods are based on a Dynamic Discretization Discovery (DDD) approach for solving the Time Dependent Traveling Salesman Problem with Time Windows (TD-TSPTW). Unlike the TD-TSPTW, these problems involve objective functions that depend in part on the time at which the vehicle departs the depot. As such, optimizing these problems adds a scheduling dimension to the problem. We present multiple enhancements to the DDD method, including enabling it to dynamically determine which waiting opportunities at the depot to model. With an extensive computational study we demonstrate that the resulting methods outperform all know... |
The book examines the psycho-religious mechanism behind the violent extremism of suicide attacks in the post-9/11 world. It employs the mindsponge concept, an original dataset, and original research results obtained from the authors' statistical investigations using the Hamiltonian Markov chain Monte Carlo technique. It provides insights and implications for policymakers and strategists in their efforts to engage in peace talks and reduce violent conflicts worldwide. |
This study aims at improving the control quality of parallel robot, where Rostock Delta robot is the main object. This study proves stability of the sliding mode control method when the dynamic parameters of Rostock Delta robot are uncertain. Numerical simulation is then performed for trajectory tracking problem of Rostock Delta robot using sliding mode control method, where the dynamic parameters are assumed in case to be precise and in case to be uncertain. The obtained results show agreement with the established theory. |
Compound droplets with different sizes are increasingly used in industrial production and academic research. This study aims to improve understanding of the dynamical behaviors of the compound droplet moving in microchannels. The compound droplet consisting of one inner core is initially concentric and placed at the entrance of a circular channel with a cone at the downstream region. Following this primary channel is a secondary channel that is circular and straight. Manipulation of the droplet is assisted by a flow introduced via the gap between two channels. The numerical results show that when passing through these confined channels, the droplet experiences a finite deformation or breakup mode. In each mode, the deformation or breakup of the compound droplet is also different whe... |
The rapid post-millennial internationalisation of Japan’s tourism sector and the influx of international visi-tors have quickly increased visitor motivations’ heterogeneity, thereby posing challenges for management. Given the lack of prior research, we aimed to identify nature-based tourism (NBT) push-factor motivation domains of visitors in a Japanese national park and segment domestic and international visitors based on their motivations, demographics and trip profiles. Primary data collection of 137 responses took place in November 2019 through an on-site self-admin-istered questionnaire. From 11 push-factor statements, the principal component analysis yielded a four-factor solution: ‘enjoying nature with family or friends’, ‘improving physical health’, ‘discovering and learning’... |
A forward error correction (FEC) and unity-rate coded (URC) autoencoder (AE)-assisted communication system is proposed for the first time, which relies on soft iterative decoding for attaining a vanishingly low error probability. The AE-demapper is specifically designed for directly calculating the extrinsic logarithmic likelihood ratios (LLRs), which can be directly entered into the URC decoder for soft iterative decoding. This avoids the potential degradation due to the conversion of symbol probabilities to bit LLRs. A comprehensive capacity analysis of the AE is performed, which demonstrates the capacity advantage of the AE-aided constellation design over its conventional quadrature amplitude modulation (QAM)/ phase shift keying (PSK) counterpart. Furthermore, we carry out its EX... |
Tin selenide (SnSe) is considered a robust candidate for thermoelectric applications due to its very high thermoelectric figure of merit, ZT, with values of 2.6 in p-type and 2.8 in n-type single crystals. Sn has been replaced with various lower group dopants to achieve successful p-type doping in SnSe with high ZT values. A known, facile, and powerful alternative way to introduce a hole carrier is to use a natural single Sn vacancy, VSn. Through transport and scanning tunneling microscopy studies, we discovered that VSn are dominant in high-quality (slow cooling rate) SnSe single crystals, while multiple vacancies, Vmulti, are dominant in low-quality (high cooling rate) single crystals. Surprisingly, both VSn and Vmulti help to increase the power factors of SnSe, whereas samples wi... |
Multiphase Al2O3 samples are simulated using molecular dynamics method. These samples consist of γ-Al2O3 and α-Al2O3 crystals embedded in a disordered phase matrix. The stress–strain curves of these samples show elastic and plastic deformation. Structural analysis indicates that the AlO bond lengths are stretched and the geometries of the AlOx (x = 4, 5, and 6) units are distorted during tensile deformation. AlO bond breakage causes the transformation of AlOx units; AlO4 increases while AlO6 decreases with increasing strain. The γ-Al2O3 and α-Al2O3 crystals transfer into the disordered phase, while a small number of atoms recrystallize under tensile loads. In plastic deformation, large simplexes with radii above 1.958 Å increase rapidly with increasing strains above 0.116, with th... |
One important requirement of modern supply chain management is the frequent exchange of containers via multiple cross-docks which requires spatial and time synchronisations between different types of vehicle. Moreover, as collaborations in logistics between several companies become popular, more flexible and extended models must be solved to consider the different needs of the companies. This is of high importance in a new logistics concept, the Physical Internet, which is expected to considerably improve the way logistics are handled in the current supply chain management.
To optimise the aforementioned requirements, a rich vehicle routing problem with pickup and delivery including numerous attributes is modelled and solved. A mathematical formulation is proposed and implemented... |
