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In the digital era, major shipping lines are developing instant quote and online booking platforms. In one of the first attempts to investigate the post-event effects of this trend, we evaluate how a shipping line's online quote platform impacts its shipper portfolio and the ordered container volume. In order to control for unobserved, time-varying effects that could be correlated with the platform's implementation, we apply the regression discontinuity design (RDD) method to the import trade data from 2016 to 2019 of a top shipping line that released its platform in August 2018. We also adopt global polynomial regression and local liner regression so as to control for the effects of different polynomial time trends. We find the container volume assigned to the shipping line declined slightly after the online platform was launched. The container orders of small shippers increase by 3.97 TEU on average after online platform adoption. The volume of assigned containers from other shippersdeclines. These findings hold fruitful implications for shipping lines. A significant increase in the number of small shippers and their container volumes demonstrate administrative cost saving and risk mitigation for a shipping line. However, it also leads to possible loss of large customers. [ABSTRACT FROM AUTHOR]

This study takes stock of business and economics research on Artificial Intelligence (AI) and provides a dynamic panorama of the overall knowledge structure of this ever-growing body of work ever since its inception in 1966. Our bibliometric analysis based on the full archive of 1024 studies identifies the main trends of and the major intellectual contributors to the extant knowledge of AI in business and economics research. Specifically, our results show that (1) AI-focused business and economics research wintnessed growth over three stages, particularly with a sharp increase after 2017. (2) While this body of research has gained tremendous momentum across the globe, the United States is by far the center of knowledge generation. (3) Research collaborations are still limited in this area. (4) Research topics flourished, ranging from early decision support systems, neural networks, and scheduling methods to more recent machine learning, automation, and big data. This study also identifies fruitful avenues for further business and economics research with an AI focus. [ABSTRACT FROM AUTHOR]

This article presents an analysis of the competitiveness of Brazilian container port terminals and discusses the implications for the sustainable development of this sector in Brazil in the context of container ship size maximization. A cluster analysis was developed. Thirteen criteria were selected in the analysis taking into consideration both the previous literature and the characteristic of Brazilian ports. The classification shows that the third group of terminals (Santos Brasil, BTP and Paranaguá) has the highest average values in eleven out of the thirteen criteria, standing out mainly in annual capacity, number of plugs, and GDP hinterland. This is the most competitive group with the highest frequency of ship visits. It is also interesting to find that this group of terminals has a limitation regarding the operational draft that limits the port sector when receiving large ships. Considering the expected inclusion of New Panamax-class ships operating on the Brazilian coast, container terminals have restrictions due to the limited operational draft. Conclusions are drawn regarding the potential for implementing strategies and policy interventions. The study represents an application inspired by the current debate in the Brazilian port sector, which presents the country's urgent problem of receiving large capacity ships. [ABSTRACT FROM AUTHOR]

A novel broadband circularly polarized square-slot antenna with parasitic elements is presented in this article. The proposed antenna with dimensions of 77.6 × 77.6 × 1.6 mm3 is composed of a L-shaped strip, a pair of rectangular slots, a L-shaped branch, and an inverted L-shaped feeding line. First, a pair of rectangular slots are used to excite an impedance resonance point that appears near 4.8 GHz and improve the axial ratio bandwidth (ARBW). Second, a L-shaped strip etched into the square-slot ground plane is used to enhance the ARBW. Third, a L-shaped branch is inserted into the inverted L-shaped feeding line to improve the impedance matching at high frequencies. At a result, the multiple circularly polarized (CP) resonant points could be excited by using these slot and strips as perturbation elements to alter the surface current distribution of the antenna. To demonstrate the design rationality, a designed antenna model is simulated, manufactured, and measured. The tested results show the proposed antenna has a wider −10-dB impedance bandwidth from 2.6 to 6.6 GHz (86.9%) and a broad 3-dB ARBW from 2.35 to 5.80 GHz (84.7%). In addition, the measured peak gain of the antenna is 4.8 dBi. The presented antenna has a potential application value in C band wireless communication. [ABSTRACT FROM AUTHOR]

The heat transfer characteristic of supercritical water is one of the crucial issues in SuperCritical Water-Cooled Reactors (SCWRs). The efficiency and safety of the SCWR system are largely dependent on the local heat transfer performance. This paper establishes the numerical model for supercritical water in a long vertical circular loop (inside diameter = 10 mm) and analyzes the flow and heat transfer mechanism during the transition process from subcritical to supercritical states under various heat fluxes (uniform and nonuniform). The results reveal that the difference in thermophysical properties between the boundary layer and the core region is the main reason for the heat transfer behavior, especially during the transition from subcritical to supercritical and liquidlike to gaslike. The flow structure on the buffer layer is a dominating factor for heat transfer deterioration. The cases under variable nonuniform heat fluxes have a higher heat transfer coefficient compared with uniform heat fluxes. But, this will cause large changes of the parameter locally. The dominating factors of heat transfer deterioration under these conditions are also identified. [ABSTRACT FROM AUTHOR]

We explore the influence of absorption, anisotropy and unstable layered turbulence on the channel capacity of horizontal seawater link. By developing the spectrum average coherence length of collimated beam wave in the absorptive seawater turbulence, we propose a model of the channel capacity of links with carrier Bessel-Gaussian vortex localized wave. Our model shows that the capacity of links increases with the increasing of the half-modulated pulse width of the input pulse, the rate of dissipation of kinetic energy per unit mass of fluid and the anisotropic factor of turbulence, but it decreases with the increasing of the Bessel cone angle and the dissipation rate of the mean-squared temperature. We also find that there is a maximum effective beam waist for a given receiving aperture, the channel capacity is more sensitive to salinity fluctuations than to temperature fluctuations in turbulence, and the influences of the inner scale and outer scale of turbulence on channel capacity of links in anisotropic turbulence and isotropic turbulence are different. [ABSTRACT FROM AUTHOR]

Rhein is a key ingredient in many herbal remedies and is widely used. However, herbs containing rhein are frequently associated with poisoning incidents, especially in elderly subjects. Acute and subchronic toxicity of rhein in Kunming mice (KM) was investigated in this experiment. Acute toxicity tests showed a 40% lethality at a given rhein dose of 4000 mg/kg, and the LD50 of rhein was calculated by the bliss method to be greater than 2185.6 mg/kg. In subchronic toxicity, d-gal-induced aged and immature animals were randomized into three groups that were exposed to rhein of 0, 175, and 375 mg/kg/d for 75 days, respectively. No mortality was observed in immature mice group, whereas 55.5% (5/9) subjects in aged mice groups died in the high dosage group. AST, ALT, IL-6, TNF-α levels and typical histopathological changes indicate that rhein causes liver injury. In addition, our investigation explored possible hepatotoxic mechanisms of rhein and experimental results showed increased ROS production, NRF-2 and MDA levels and decreased SOD levels, demonstrating that rhein causes oxidative stress. MMP and mitochondrial swelling levels were able to assess the impact of rhein on mitochondrial function. Furthermore, the effect of rhein on apoptosis can be detected by flow cytometry. Our studies suggested that rhein induces oxidative stress leading to mitochondria dysfunction and apoptotic activation. Multidrug resistance protein (MRP) is an efflux transporter protein and is capable of transporting cellular oxidative stress-related substances. To further clarify the role of MRP in rhein induced oxidative stress, we examined MRP expression in the liver. However, the expression of MRP has no statistical significance. [ABSTRACT FROM AUTHOR]

This article aims to present the steady-state analysis in finite-buffer M/G/1 queues with starting failures under a randomized control of N-policy. When the system empties, the server is turned off. If the system size reaches the threshold N, the server is turned on with probability p or turned off with probability 1 − p. The server needs a startup time before providing service. If the server is started successfully (with probability θ), customers are served immediately. When the server is started unsuccessfully, he is started again. It is assumed that the restart is always successful. Using the supplementary variable method, we obtain the stationary distribution of the number of customers in the system. We develop a number of performance measures. A cost model is constructed, and we then determine numerical values of the optimal service rate to minimize the average cost per unit time. Finally, numerical examples are provided to show the effects of system parameters on performance measures and the optimal service rate. [ABSTRACT FROM AUTHOR]

Two new unsymmetrical ligands, namely, 2-(pyridin-3-yl)-5-(quinolin-2-yl)-1,3,4-oxadiazole (L1) and 2-(pyridin-4-yl)-5-(quinolin-2-yl)-1,3,4-oxadiazole (L2), have been synthesized and their self-assembly reactions with Co(NO3)2 and Co(ClO4)2 have been investigated for the rational construction of coordination polymers (CPs). It was found that the counter-anion plays an important role in the structural assemblies. Their anti-ovarian cancer activity was evaluated and the related mechanism was explored at the same time. Firstly, the proliferation of the ovarian cancer cells was measured with CCK-8 detection kit. Then, the real time RT-PCR was used to evaluate the relative expression levels of the ROS related genes in the ovarian cancer cells after compounds treatment. [ABSTRACT FROM AUTHOR]

This paper focus on passivity and passive control for a cascade nonlinear system consisting of two switched systems. The asymptotic stability criterion for the cascade system is developed without requiring passivity of subsystem in the whole state interval. Passivity and stabilisation of the closed-loop system are achieved by co-designing an output feedback control law and a state-dependent switching signal if the full output information is measurable. While the output information of the first switched system are not available, the sampled integral stabilisation (SIS) technique which only adopts the output information and common energy function of the second one, is exploited to achieve passive control of two switched systems connected in a cascade way. Then, a particular case of cascade system where only one passive switched system exists is stabilised via SIS technique. Finally, the validity of the developed results is demonstrated via a plane articulation arm example. [ABSTRACT FROM AUTHOR]

It is significant to identify the moldy status of stored maize by fungi infection in the early stage. Hyperspectral imaging (HSI) combined with the sparse auto-encoders (SAE) and convolutional neural network (CNN) algorithms was used to classify the moldy grades of maize kernels. The HSI data were obtained in the range of 400–1000 nm, and four grades from health to heavy mildew were distinguished using the measured fungal spores of maize. The depth spectral features were represented using SAE and the image features were extracted by CNN. K nearest neighbors, support vector machine (SVM), and partial least squares discriminant analysis classifiers were combined with the spectral and image features to establish classification models to identify the different moldy grades of maize kernels. The comparison results indicated that the fusion of SAE and CNN combined with the SVM classifier to construct the SAE-CNN-SVM model had the most satisfactory identification result with high correct recognition rates of 99.47% and 98.94% for the training and testing sets, respectively, and the values of sensitivity and specificity were 0.95–1. The moldy grades were presented intuitively on the maize image based on pixels or kernel-wise. Therefore, the HSI with the SAE-CNN-SVM model had good recognition ability for the early detection of moldy maize kernels, which could potentially provide technical support for the development of online detection of moldy maize kernels during storage. [ABSTRACT FROM AUTHOR]

In this paper, the image space analysis is applied to investigate a vector equilibrium problem using improvement sets and with matrix inequality constraints. First, a nonlinear scalar regular weak separation function is constructed by using the oriented distance function and the norm function. Then, a global saddle-point condition for a generalized Lagrange function is investigated. It is shown that the existence of a saddle point is equivalent to a nonlinear separation of two suitable subsets in the image space. Furthermore, a gap function and an error bound are obtained in terms of the nonlinear scalar regular weak separation function under suitable assumptions. As applications, an optimality condition, a gap function and an error bound for a strategic game with vector payoffs are also given. [ABSTRACT FROM AUTHOR]

It is a common practice to promote highly discounted fares by cruise companies to enlarge the market share, ignoring economically sustainable development. In some regions, the continuous discounted fares leading to the unsatisfying revenue may be the main cause of decline in ports calls. Cruise companies have learned that dynamic pricing would be much more advantageous at revenue management instead of blindly lowering fares. This paper illustrates such an attempt. We try to dynamically price multiple types of staterooms with various occupancies and evaluate the effect on demand and revenue from different discount and refund policies. We first formulate the cruise pricing problem as Markov Decision Process and Reinforcement Learning (RL), more specifically, state-action-reward-state-action (SARSA) algorithm, is applied to solve it. We then use empirical data to validate the feasibility of RL. Results show that both revenue and demand could be improved under reasonable discount policies. In addition, we demonstrate that reasonable refund policies can also facilitate revenue growth. Finally, a comparison between SARSA algorithm and Q-learning algorithm is discussed. Our finding suggests that SARSA results in higher revenues but takes more time to converge. [ABSTRACT FROM AUTHOR]

A new boundary-type meshfree collection method, namely the virtual boundary element-free Galerkin method (VBEFGM), is demonstrated for three-dimension (3-D) multi-domain steady-state heat conduction problems. The virtual source functions of the virtual nodes are constructed by the radial basis function interpolation. And the virtual and real boundaries are discreted into the virtual and real nodes. 3-D multi-domain steady-state heat conduction problems are solved without the background integral element by VBEFGM. Using the Galerkin method to obtain the formula of VBEFGM, the proposed method has the advantages of the virtual boundary element-free method, the meshfree collection method and the Galerkin method. It is easily programed and extended to solve other more complicated 3-D heat conduction problems, since the detailed calculation scheme is deduced and shown. Two numerical examples of the boundary conditions varying with the space are computed. The computational results are compared with other numerical methods. The accuracy and stability of the proposed method are validated for 3-D multi-domain steady-state heat conduction problems. [ABSTRACT FROM AUTHOR]

This article focuses on a new approach to investigate the Hölder continuity for the solution mapping of a parametric non-convex strong generalized Ky Fan inequality. Based on a non-convex separation theorem, the union relation between the solution set of the parametric non-convex strong generalized Ky Fan inequality and the solution sets of a series of Ky Fan inequalities, is established. Without density results and any information on the solution mapping, a sufficient condition for the Hölder continuity of the solution mapping to the parametric non-convex strong generalized Ky Fan inequality is given by using the key union relation. Our method does not impose any convexity, monotonicity, and the single-valuedness of the solution mapping. [ABSTRACT FROM AUTHOR]

Lotus II, a randomized, open-label, multicenter, international study compared the efficacy and safety of oral dydrogesterone versus micronized vaginal progesterone (MVP) gel for luteal support in IVF. A prespecified subgroup analysis was performed on 239 Chinese mainland subjects from the overall study population (n = 1034), who were randomized to oral dydrogesterone 30 mg or 8% MVP gel 90 mg daily from the day of oocyte retrieval until 12 weeks of gestation. The aim was to demonstrate non-inferiority of oral dydrogesterone to MVP gel, assessed by the presence of a fetal heartbeat at 12 weeks of gestation. In the Chinese mainland subpopulation, there was a numerical difference of 9.4% in favor of oral dydrogesterone, with ongoing pregnancy rates at 12 weeks of gestation of 61.4% and 51.9% in the oral dydrogesterone and MVP gel groups, respectively (adjusted difference, 9.4%; 95% CI: −3.4 to 22.1); in the overall population, these were 38.7% and 35%, respectively (adjusted difference, 3.7%; 95% CI: −2.3 to 9.7). In both the Chinese mainland subpopulation and the overall population, dydrogesterone had similar efficacy and safety to MVP gel. With convenient oral administration, dydrogesterone has potential to transform luteal support treatment. [ABSTRACT FROM AUTHOR]

The virtual boundary meshfree Galerkin method (VBMGM) is further developed to compute three-dimensional single-domain steady-state heat conduction problem. Using VBMGM, three-dimensional problem is reduced into two-dimensional boundary, whose element information can be obtained by the meshing software, namely ANSYS software. It greatly facilitates the programing implementation of the proposed method that ANSYS Parametric Design Language (APDL) is demonstrated for the element information acquisition of the curved surface. The virtual source function on the virtual boundary element method (VBEM) is interpolated by the radial basis function interpolation (RBFI) of the meshfree method. The calculation equation of three-dimensional single-domain steady-state heat conduction problem by VBMGM is constructed by the Galerkin method of the weighted residual method. Therefore, it has the advantages of the VBEM, the meshfree method and the Galerkin method that the proposed method is employed to computed three-dimensional single-domain steady-state heat conduction problem. It is beneficial to further popularize the proposed method to solve other three-dimensional heat conduction problems that the detailed numerical discrete formula of the proposed method for three-dimensional single-domain steady-state heat conduction problem is obtained. The numerical results of two numerical examples are computed and compared with the other numerical method and the extract solutions. The accuracy and stability of VBMGM for three-dimensional single-domain steady-state heat conduction problem are verified. [ABSTRACT FROM AUTHOR]

Meteorological elements are important for various fields related to human activities, including scientific research. Using the Tibetan Areas of West Sichuan Province (TAOWS) as an example, this study examined the estimation methods for near-surface air temperature (Ta), vapour pressure deficit (VPD), and atmospheric pressure (P) and their distribution characteristics in areas with complex terrains and sparse stations. An improved satellite-based approach, combining an artificial neural network and inverse distance weighting (ANN-IDW), is proposed for estimating Ta and VPD with high-accuracy under all weather conditions from Moderate Resolution Imaging Spectroradiometer (MODIS) data. The data of 41 meteorological stations in TAOWS and its adjacent areas were used for the training and validation of the ANN-IDW. For Ta and VPD, the mean absolute errors (MAEs) of the ANN-IDW are 1.45°C to 2.15°C and 0.54 hPa to 0.87 hPa, respectively. Also, the detailed features of the distribution of the estimated Ta and VPD are prominent and closely related to the terrain. The accuracy of the method was also verified indirectly. In addition, the improved method based on the existing method was applied for estimating P. The results confirm that (1) the ANN-IDW is suitable for estimating Ta and VPD in areas with complex terrain and sparse stations under all weather conditions; (2) the improved method is more suitable for estimating P at high-elevation. Moreover, the distribution characteristics of meteorological elements in TAOWS were also analysed. These elements influence agricultural production and animal husbandry and have a high application value. The results further show that topography is the most important factor affecting the spatial distribution and complexity of meteorological elements over complex terrains, but the degree of influence of topography varies greatly across different seasons. [ABSTRACT FROM AUTHOR]

The information-rich vessel movement data provided by the Automatic Identification System (AIS) has gained much popularity over the past decade, during which the employment of satellite-based receivers has enabled wide coverage and improved data quality. The application of AIS data has developed from simply navigation-oriented research to now include trade flow estimation, emission accounting, and vessel performance monitoring. The AIS now provides high frequency, real-time positioning and sailing patterns for almost the whole world's commercial fleet, and therefore, in combination with supplementary databases and analyses, AIS data has arguably kickstarted the era of digitisation in the shipping industry. In this study, we conduct a comprehensive review of the literature regarding AIS applications by dividing it into three development stages, namely, basic application, extended application, and advanced application. Each stage contains two to three application fields, and in total we identified seven application fields, including (1) AIS data mining, (2) navigation safety, (3) ship behaviour analysis, (4) environmental evaluation, (5) trade analysis, (6) ship and port performance, and (7) Arctic shipping. We found that the original application of AIS data to navigation safety has, with the improvement of data accessibility, evolved into diverse applications in various directions. Moreover, we summarised the major methodologies in the literature into four categories, these being (1) data processing and mining, (2) index measurement, (3) causality analysis, and (4) operational research. Undoubtedly, the applications of AIS data will be further expanded in the foreseeable future. This will not only provide a more comprehensive understanding of voyage performance and allow researchers to examine shipping market dynamics from the micro level, but also the abundance of AIS data may also open up the rather opaque aspect of how shipping companies release information to external authorities, including the International Maritime Organization, port states, scientists and researchers. It is expected that more multi-disciplinary AIS studies will emerge in the coming years. We believe that this study will shed further light on the future development of AIS studies. [ABSTRACT FROM AUTHOR]

This paper presents a steady-state analysis of an M/M/1 retrial queue with working vacations, in which the server is subject to starting failures. The proposed queueing model is described in terms of the quasi-birth-death (QBD) process. We first derive the system stability condition. We then use the matrix-geometric method to compute the stationary probability distribution of the orbit size. Some performance measures for the system are developed. We construct a cost model, and our objective is to determine the optimal service rates during normal and vacation periods that minimize the expected cost per unit time. The canonical particle swarm optimization (CPSO) algorithm is employed to deal with the cost optimization problem. Numerical results are provided to illustrate the effects of system parameters on the performance measures and the optimal service rates. These results depict the system behaviour and show how the CPSO algorithm can be used to find numerical solutions for optimal service rates. [ABSTRACT FROM AUTHOR]

In this paper, the approach of the control bumps limitation is generalised and applied to the problem of H∞ bumpless transfer for a class of switched linear parameter-varying (LPV) systems. The H∞ bumpless transfer problem is to design a controller with the amplitude limitation and a parameter and modes-dependent switching law to reduce control bumps of the switched LPV systems and satisfy an H∞ performance index. The key point is to guarantee the bumps limitation constraint of the switched LPV systems by dual design of controllers and a switching law, even though the constraint for each subsystem is unsatisfied. First, a set of switching signals depending on parameters and modes are designed, and a family of switched LPV controllers with the bumps limitation objective are developed via multiple parameter-dependent Lyapunov functions. Then, a sufficient condition ensuring the H∞ bumpless transfer performance for a switched LPV system is presented in the format of numerically tractable conditions. Finally, the effectiveness of the proposed control design scheme is illustrated by its application to the control design of an aero-engine. [ABSTRACT FROM AUTHOR]

The promoter of prosocial behavior in fighting against the COVID-19 pandemic needs to be examined. Here, we examined the effect of experienced awe through cross-sectional (Study 1), a 3-wave longitudinal (Study 2) and experimental (Study 3–4) approaches. Study 1 showed that dispositional awe positively predicted one's prosocial behavior in the pandemic (N = 1281). Study 2 (N = 332) observed that experienced awe predicted higher prosociality, and this relationship was serially mediated by connectedness and empathy. Study 3 (N = 153) and 4 (N = 156) confirmed that elicited awe, compared to that of amusement and neutrality, promoted multiple types of prosociality (Study 3) and willingness of blood donation (Study 4) via serial mediation of connectedness and empathy. These findings suggest that the experience of awe increases one's connectedness to the world, which in turn enhances empathic concern and prosociality in pandemic fighting. [ABSTRACT FROM AUTHOR]

The traditional estimation of higher order co-moments of non-normal random variables by the sample analog of the expectation faces a curse of dimensionality, as the number of parameters increases steeply when the dimension increases. Imposing a factor structure on the process solves this problem; however, it leads to the challenging task of selecting an appropriate factor model. This paper contributes by proposing a test that exploits the following feature: when the factor model is correctly specified, the higher order co-moments of the unexplained return variation are sparse. It recommends a general to specific approach for selecting the factor model by choosing the most parsimonious specification for which the sparsity assumption is satisfied. This approach uses a Wald or Gumbel test statistic for testing the joint statistical significance of the co-moments that are zero when the factor model is correctly specified. The asymptotic distribution of the test is derived. An extensive simulation study confirms the good finite sample properties of the approach. This paper illustrates the practical usefulness of factor selection on daily returns of random subsets of S&P 100 constituents. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of the horizontal projection on the spill flame ejected from an enclosure. Experiments were carried out in a reduced-scale enclosure and a horizontal projection was installed above the opening. The spill flame beneath a horizontal projection is composed of a horizontal momentum-dominated rectangle region and a buoyancy-dominated semicircle region. The overall averaged excess air ratio and the averaged entrainment coefficient of the spill flame beneath a horizontal projection were investigated. A theoretical model for the total flame length was developed. The model predictions agree well with the measured values. [ABSTRACT FROM AUTHOR]

This study develops a generalized F distribution model with random parameters to estimate the ship property damage cost in maritime traffic accidents with 10 years’ shipping accident data in the Fujian waters. Model results show that sinking and capsizing can incur the largest property damage cost, followed by collisions, contact, grounding and fire/explosion. There is a smaller ship property damage cost when the ship is moored or docked. The poor visibility has the least impact on the increment of ship property damage cost. Results reveal that the bigger property damage cost is associated with maritime accidents occurring in the Straits/sea areas and under the strong wind/wave condition and nighttime periods. It is also found that the lookout failure exhibits a bigger effect than the operation error. These results are helpful for policy makers to make efficient strategies for reducing property damage cost in maritime accidents. The developed model is useful for insurance companies in determining the appropriate ship insurance rates. [ABSTRACT FROM AUTHOR]

A recently developed infrared (IR) local heating method is fairly effective to reduce springback of advanced high strength steel in manufacturing processes of car chassis. Although parabolic heaters, consisting of an IR lamp located on the focus of a parabolic reflector, can reduce springback in stamping processes, non-negligible temperature changes are generated in the heated area. For this reason, an improved heater has been required for the IR heating method. In this work, an overlapping heater array is designed to solve the problem of the parabolic heater for the IR local heating method. The overlapping heater array can reduce the temperature change in the heated area. In the overlapping heater array, the parabolic heaters are connected in series. The connected parabolic heaters are then placed on both sides of a thin sheet metal and intersected to reduce the temperature change. In order to design a more efficient overlapping heater array, a simple design parameter was employed. The numerical and experimental verifications have shown that the overlapping heater array drastically reduces the temperature change in the heated area. [ABSTRACT FROM AUTHOR]

In this paper, we propose a machine repair problem with constant retrial policy, wherein if a failed machine finds the repairman busy upon arrival, it enters into an orbit. The machines in the orbit form a single waiting line, and only the one at the head of the orbit repeats its request for repair. The failure times of operating machines and the repair times of failed machines follow exponential distributions. It is assumed that retrial times are generally distributed. We used the supplementary variable technique to obtain explicit expressions for the steady-state probabilities of the number of failed machines in the orbit. We performed sensitivity analysis of the machine availability and operative efficiency with respect to system parameters and the number of machines in operation. The analysis of the busy period and the waiting time were also presented. Finally, we developed a cost model and formulated a cost minimization problem. [ABSTRACT FROM AUTHOR]

The wideband radar transmitting the linear frequency modulation signal often processes its echoes by the stretched processing. This paper deals with the range-spread target detection in white complex Gaussian noise. Here, we propose a new detection method for the range-spread target based on sparse representation, which selects the time-frequency feature to realise the target detection. It can be simply described as follows: first, the sketched signal is reconstructed from its noisy measurements by basis pursuit de-noising (BPDN); scatterers on the target are determined by its reconstruction and used to calculate the Wigner distribution; for the target embedded in noise, the time-frequency feature in its power-density spectrum is compared with the decision threshold. Meanwhile, the median absolute deviation (MAD) is adopted to estimate the noise variance. The mainly novelties can be concluded as follows: the Fourier matrix is selected to sparsely represent the sketched signal; the sparsity is used to improve the SNR of the received echoes; the Wigner transform is utilised to acquire the time-frequency feature of the range-spread target. Both the optimisation theory and time-frequency representation are introduced to solve the target detection problem. Experimental results on the raw data show that the proposed detector outperforms the conventional methods. [ABSTRACT FROM AUTHOR]

This study proposes high-frequency container port congestion measures based on Automatic Identification System (AIS) data. Vessel movement information of 3,957 container ships from March 2017 to April 2017 is included. The world top 20 container ports' berth and anchorage areas are identified through Density Based Spatial Clustering of Applications with Noise (DBSCAN) and convex hull methods, and their hourly port congestion statuses are depicted in terms of the traffic volume and turnaround time. The constructed congestion measures overcome the disadvantages of the traditionally used port or industry data, which is heterogenous, behind the time and not easy to obtain publicly. The higher frequency (hourly) of the proposed measures can effectively monitor any slight change in port performance. A Long Short-Term Memory (LSTM) neural network model is then proposed for congestion prediction using constructed congestion measures. Point prediction and sequence prediction are both performed. We innovatively introduce congestion propagation effects into the prediction model as input features. Using Shanghai, Singapore and Ningbo ports as case studies, results show that the inclusion of congestion propagation effect can improve the prediction performance especially for sequence prediction. This study provides significant implications and decision support for container shipping market participants. [ABSTRACT FROM AUTHOR]

An ultra-low specific on-resistance (Ron,sp) trench silicon-on-insulator (SOI) LDMOS is proposed in this paper. In this novel structure, a floating lateral metal field plate (FLFP) is introduced into the oxide trench of the conventional SOI LDMOS (con-TLDMOS) and connected to the gate outside the device working region. The oxide trench causes multidirectional depletion, which leads to electric field reshaping. The FLFP causes an assistant depletion effect especially for the trench surface regions, which significantly increases the doping concentration of the drift region (Nd). Therefore, a novel structure (FLFP-TLDMOS) with a breakdown voltage (BV) of 188 V and an Ron,sp of 1.05 mΩ·cm2 is obtained on a 4.8-μm-long drift region. Compared with the con-TLDMOS, the Ron,sp of the FLFP-TLDMOS can be reduced by about 54.3%; furthermore, its BV is maintained the same class with the con-TLDMOS, and the figure of merit is increased by 118%. Furthermore, the dynamic performance and self-heating effect of the novel structure are slightly improved compared with the conventional trench structure. [ABSTRACT FROM AUTHOR]

The focus of this paper is the selection of paths for the maritime transportation of crude oil. In addition to transportation cost, the nodes in a maritime transportation network are always affected by extreme events. Therefore, connectivity reliability must be considered during path selection. In this paper, uncertainty variables are introduced to describe the connectivity reliability of nodes under the influence of extreme events, and an uncertain bi-objective programming model with connectivity reliability maximization and transportation cost minimization as objectives is established for path selection. China’s maritime transportation network for crude oil imports is used as a case study to validate the model, the effects of variations in the model parameters on path selection, transportation cost and connectivity reliability are discussed in the case study. The research results provide a basis on which for government decision makers to better plan crude oil transportation strategies. [ABSTRACT FROM AUTHOR]

The virtual boundary meshfree Galerkin method (VBMGM) is given to calculate the multi-domain transient heat conduction with heat source problem. The radial basis function interpolation is used to obtain the virtual source function on the virtual boundary, the heat source, the particular solutions of the temperature, and the heat flux in the computational domain. The formula of the proposed method is gotten by the Galerkin method and the control equations of the multi-domain transient heat conduction with heat source. Therefore, there are the advantages of the Galerkin method, the boundary element method, and the meshfree method for the multi-domain transient heat conduction with heat source problem by VBMGM. The numerical meaning of the weighted values are definite for the multi-domain transient heat conduction with heat source problem through VBMGM, such as the partial derivatives of the temperature, the heat flux, the heat source, and the continuity conditions on the public boundary at time. The detailed calculation scheme of VBMGM is deducted for the multi-domain transient heat conduction with heat source problem. Two numerical examples, four subdomains with the time-dependent heat source problem and two subdomains with the constant heat source and mixed boundary condition problem, are computed. The accuracy and the stability of VBMGM for the multi-domain transient heat conduction with heat source problem are verified. [ABSTRACT FROM AUTHOR]

The trend towards global warming and the rapid decline in the extent of summer Arctic sea ice over recent years has increased the feasibility of international Arctic shipping. In this study we propose a seasonal NSR (North Sea Route)/SCR (Suez Canal Route)-combined shipping service linking Shanghai and Rotterdam, using the Northern Sea Route during the economical navigable window but using the traditional Suez Canal Route at other times. Different from the previous literatures, this paper dynamically considers the sea ice extent in the model, which is more reasonable for the assessment of Arctic container shipping, because fuel consumption is highly related to ship speed, while ship speed is determined by the relative distances of ice-covered and ice-free route stages. A new approach is developed to predict the time points at which the ship enters and exits the ice-covered stage, given that both the ship position and the extent of sea ice are constantly changing. The results show that the NSR/SCR-combined Arctic container service can be more economical than the SCR, given lower NSR tariffs. [ABSTRACT FROM AUTHOR]

This paper presents major element, trace element, and new zircon Hf isotopic data for the Early Mesozoic intrusive rocks in the south Hunchun, Yanbian area, Northeast China. These data are used to constrain the petrogenesis of these intrusive rocks and their implications for the Phanerozoic continental growth of the Central Asian Orogenic Belt (CAOB). Combining geology, geochronology, and whole-rock geochemistry, we identify three distinct episodes of magmatism as Early-Middle Triassic (249-237 Ma), Late Triassic (224-206 Ma), and Early Jurassic (200-187 Ma). The Early-Middle Triassic (249-237 Ma) adakitic tonalite and granodiorite were produced by the partial melting of subducted oceanic slabs, and the melts were contaminated by mantle peridotite during their ascent, whereas the coeval non-adakitic diorite and monzogranite were most likely derived from partial melting of crustal material. The remarkably high zircon Hf isotopic signature (εHf(t) = + 9.4 - +18.9), the enrichment in large-ion lithophile element and light rare earth elements, and the depletion in high field strength element suggest that these 224 Ma gabbros were derived from the partial melting of depleted mantle modified by subduction-related fluids. The 212 Ma monzogranite was most likely derived from juvenile material mixed with old crustal material as evidenced by their high SiO2, low MgO, and low Cr concentrations and variable εHf(t) values (-4.6 to +10.0). Except for the 197 Ma tonalites with affinity to the high silica adakites, the overall geochemical evolution of Early Jurassic (200-187 Ma) rocks was consistent with fractional crystallization from quartz diorite, granodiorite, and monzogranite to syenogranite. Both the Early Jurassic syn-subduction lateral continental growth by accretion of arc complexes and the Late Triassic post-collisional vertical continental growth by accretion of mantle-derived material played an important role in the Phanerozoic continental growth of the CAOB. [ABSTRACT FROM AUTHOR]

This paper considers an M/M/1 queue with second optional service, in which the server is subject to working breakdowns and repairs. All arriving customers require the first essential service, whereas only a portion of them require a second optional service. In case where the server may break down while providing the first (essential) or second (optional) service, the server continues operation at a reduced level rather than ceasing service entirely. The stability condition for this queue is derived in explicit form. The matrix-geometric method is used to compute the stationary probability distribution of the system size and various system performance measures. The genetic algorithm is applied to a cost optimization problem with the aim of optimizing service rates by minimizing the expected cost per unit time. Finally, a numerical example is presented for illustrative purposes. [ABSTRACT FROM AUTHOR]

In the past decades, a multilayer transshipment network of bulk shipping has been formed along the Yangtze River so as to support the fast development of Chinese iron and steel industry. Yet with the decrease of iron ore trade in China since 2014, the bulk port system on Yangtze River probably will be subject to change in the future. Under this background, this paper aims to analyze the development potential of Yangtze River bulk ports system with a focus on iron ore transshipment. To realize this objective, we firstly sort out the main transshipment patterns of bulk shipping, and optimize the bulk-shipping network with an optimization model. Several scenarios are then proposed and examined in the model by changing corresponding parameters. Cooperation among ports as one scenario is analyzed by applying core theory in cooperative game. Based on the changes of transshipment plans observed under the various scenarios, we finally ascertain the different development potentials of the system, and provide suggestions to the port operators and local maritime authorities. [ABSTRACT FROM PUBLISHER]

A new high-precision boundary meshfree method, namely virtual boundary meshfree Galerkin method (VBMGM), for calculating the multi-domain constant coefficient heat conduction with a heat source problem is given. In the paper, the radial basis function interpolation is used to solve the virtual source function of virtual boundary and the heat source within each subdomain. Simultaneously, the equation of VBMGM for multi-domain constant coefficient heat conduction with a heat source problem is obtained by the Galerkin method. Therefore, the proposed method has common advantages of the boundary element method, meshfree method, and Galerkin method. Coefficient matrix of this specific expression is symmetrical and the specific expression of VBMGM for the multi-domain constant coefficient heat conduction with a heat source problem is given. Two numerical examples are given. The numerical results are also compared with other numerical methods. The accuracy and feasibility of the method for the multi-domain constant coefficient heat conduction with a heat source problem are proved. [ABSTRACT FROM PUBLISHER]

Central serous chorioretinopathy (CSCR) is a challenging disease characterized by subretinal serous fluid accumulation. The complex pathogenesis is still not fully understood, but is thought to be multifactorial and involves exogenous and endogenous factors affecting the choroid and retinal pigment epithelium. The involvement of corticosteroids is undisputed, while the contribution of mineralocorticoid pathways is under investigation. This review addresses the proposed pathogenesis models and the evidence for systemic treatment of CSCR with mineralocorticoid antagonists. [ABSTRACT FROM AUTHOR]

To accommodate the structural changes in logistics, competitions along a maritime supply chain are more intensive than before. This paper adopts a two-stage noncooperative game-theoretical approach to model the horizontal and vertical interactions among liners and ports. In the first stage, Bertrand game is applied to model the interactions between two liners. When the shipping line decides which port to call, a multinomial Logit model is applied. In the second stage, Bertrand game is applied to model the competitions between two ports. Nash equilibrium is derived by solving the Bertrand games. A numerical example is provided as a case study. [ABSTRACT FROM AUTHOR]

This paper deals with the issue of observer-basedH∞resilient control for a class of switched linear parameter-varying (LPV) systems by utilising a multiple parameter-dependent Lyapunov functions method. First, attention is focused upon the design of a resilient observer, an observer-based resilient controller and a parameter and estimate state-dependent switching signal, which can stabilise and achieve the disturbance attenuation for the given systems. Then, a solvability condition of theH∞resilient control problem is given in terms of matrix inequality for the switched LPV systems. This condition allows theH∞resilient control problem for each individual subsystem to be unsolvable. The observer, controller, and switching signal are explicitly computed by solving linear matrix inequalities (LMIs). Finally, the effectiveness of the proposed control scheme is illustrated by its application to a turbofan engine, which can hardly be handled by the existing approaches. [ABSTRACT FROM AUTHOR]

Esophageal post-reflux swallow-induced peristaltic wave index (PSPWI) and mean nocturnal baseline impedance (MNBI), novel impedance-based markers of reflux burden, are associated with esophageal dynamics. We aim to investigate the characteristics of PSPWI and MNBI in Chinese refractory gastroesophageal reflux disease (RGERD) patients with different esophageal dynamic changes. 201 RGERD and 76 functional heartburn patients, undergone off-PPI endoscopy, esophageal manometry and impedance-pH monitoring, were included. Comparisons of conventional and novel impedance-pH metrics were made among different esophageal dynamics groups. Receiver operating-characteristic analyses were utilized to evaluate the diagnostic efficacy of PSPWI and MNBI in differentiating abnormal esophageal dynamics. Correlations were used to investigate their associated factors. PSPWI and MNBI of RGERD with esophagogastric junction (EGJ) injury and esophageal dysmotility were lower than EGJ injury alone or normal dynamics (p < 0.05 for both comparisons). PSPWI with esophageal peristalsis abnormality was lower than EGJ injury (p = 0.049), while MNBI showed no statistical difference. PSPWI, MNBI and their combination have auxiliary diagnostic values for esophageal peristalsis [area under the curves (AUCs): 0.683, 0.656, 0.708)] while only their combination for EGJ injury (AUC: 0.610). And they positively correlated with esophageal motility while negatively correlated with ineffective swallows and acid reflux events. PSPWI and MNBI, indicating impairment of esophageal chemical clearance and mucosa integrity, were lower in RGERD patients with multiple esophageal dynamic injuries than single injuries or normal dynamics. Moreover, they provided useful contributing information for potential dynamic injuries if manometry has already been found normal or marginal. [ABSTRACT FROM AUTHOR]

We consider the distributions of operating characteristics of an M[x]/G/1 queue under vacation policies, where the first customer of each busy period receives an exceptional service. When all the customers are served in the system exhaustively, the server deactivates and operates one of two vacation policies: (1) multiple vacation policy and (2) single vacation policy. We develop the performance measures for both systems. Finally, some numerical illustrations are also given. These two vacation models have potential applications in day-to-day life, such as post offices, banks, hospitals, etc. [ABSTRACT FROM AUTHOR]

In this article, a new high-precision boundary-type mesh-free method, called the virtual boundary mesh-free Galerkin method (VBMGM), is given for analyzing the heat conduction problem consisting of multiple media. A control equation of the proposed method is established by the the Galerkin method of the weighted residual methods. The virtual source function is approached through the radial basis function interpolation in the mesh-free method. Thus, the main feature of the proposed technique has the advantages of the mesh-free method, the boundary-element method, and the Galerkin method, a symmetrical coefficient matrix. The numerical meanings of the weighted values in the VBMGM equation, such as the partial derivatives the temperature, the heat flux, the temperature connection condition, and the heat flux connection condition, are clear. Numerical examples of a thick-walled cylinder consisting of two media and a two-layered rectangular plate are provided. The feasibility and the accuracy of the proposed technique are proved. [ABSTRACT FROM AUTHOR]

This article presents a virtual boundary meshless with Trefftz method for calculation of the two-dimensional steady-state heat conduction crack problem, which is based on the idea of multidomain combination. The virtual source function is constructed by the radial basis functions approximation in the subdomain not containing the crack. The temperature or heat flux is calculated by crack special solution of Trefftz function in the crack subdomain. Thus, the proposed method has the advantages of both the boundary-type meshless method and the Trefftz method. No nodes or elements are distributed on the crack, because the boundary condition of the crack is automatically satisfied by employing the crack special solution of the Trefftz function. The heat stress intensity factor is simply and directly calculated. [ABSTRACT FROM PUBLISHER]

Conclusions: The vascular endothelial growth factor (VEGF)-mediated mechanism of endothelial progenitor cell (EPC) mobilization, migration, and differentiation may occur in response to noise-induced acoustic trauma of the cochlea, leading to the protection of cochlear function. Objective: The purpose of this study was to analyze changes in the cochlear vessel under an intensive noise environment. Methods: Sixty male Sprague-Dawley rats were randomly divided into six groups. Acoustic trauma was induced by 120 dB SPL white noise for 4 h. Auditory function was evaluated by the auditory brainstem response threshold. Morphological changes of the cochleae, the expression of VEGF, and the circulation of EPCs in the peripheral blood were studied by immunohistochemistry, Western blotting analysis, scanning electron microscopy, and flow cytometry. Results: Vascular recovery of the cochlea began after noise exposure. The change in the number of EPCs was consistent with the expression of VEGF at different time points after noise exposure. We propose that VEGF evokes specific permeable and chemotactic effects on the vascular endothelial cells. These effects can mobilize EPCs into the peripheral blood, leading the EPCs to target damaged sites and to exert a neoangiogenic effect. [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed analysis of a multi-server retrial queue with Bernoulli feedback, where the servers are subject to starting failures. Upon completion of a service, a customer would decide either to leave the system with probabilitypor to join the retrial orbit again for another service with complementary probability 1−p. We analyse this queueing system as a quasi-birth–death process. Specifically, the equilibrium condition of the system is given for the existence of the steady-state analysis. Applying the matrix-geometric method, the formulae for computing the rate matrix and stationary probabilities are obtained. We further develop the matrix-form expressions for various system performance measures. A cost model is constructed to determine the optimal number of servers, the optimal mean service rate and the optimal mean repair rate subject to the stability condition. Finally, we give a practical example to illustrate the potential applicability of this model. [ABSTRACT FROM PUBLISHER]

This paper investigates theF-policy queue using fuzzy parameters, in which the arrival rate, service rate, and start-up rate are all fuzzy numbers. TheF-policy deals with the control of arrivals in a queueing system, in which the server requires a start-up time before allowing customers to enter. A crispF-policy queueing system generalised to a fuzzy environment would be widely applicable; therefore, we apply the α-cuts approach and Zadeh's extension principle to transform fuzzyF-policy queues into a family of crispF-policy queues. This study presents a mathematical programming approach applicable to the construction of membership functions for the expected number of customers in the system. Furthermore, we propose an efficient solution procedure to compute the membership function of the expected number of customers in the system under different levels of α. Finally, we give an example of the proposed system as applied to a case in the automotive industry to demonstrate its practicality. [ABSTRACT FROM PUBLISHER]

Objective: To examine the relationship between country of birth and the utilization of coronary angiography, percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) after a first-time myocardial infarction (MI). Design, setting and patients: 117 494 MI patients of all ages who were admitted to coronary care units between 2001 and 2009 in Sweden were followed-up for three months after admission. Main outcome measures: Undergoing coronary angiography, PCI or CABG after first-time MI. Results: proportion of patients undergoing angiography and PCI increased whereas proportion of patients undergoing CABG also delay time for all three procedures decreased over the study period. The proportion of women undergoing any of the three procedures was markedly lower and delay time longer than those of men regardless of study period and migration background. Overall foreign-born first MI patients had higher rate of angiography (HR = 1.30, 95% CI: 1.27-1.33), PCI (HR = 1.27, 95% CI: 1.24-1.30) and CABG (HR = 1.21, 95% CI: 1.15-1.28) compared with Sweden born first MI patients. After controlling for potential confounding factors in multivariable models, the overall differences vanished for angiography and reduced markedly for PCI and CABG. However, multivariable stratified analysis by specific country of birth yielded higher rate of angiography among men born in Uganda (HR = 2.11, 95% CI: 1.00-4.43) and Peru (HR = 1.98, 95% CI: 1.07-3.68) and lower rate among men born in Croatia (HR = 0.71, 95% CI: 0.52-0.99) and women born in Thailand (HR = 0.49, 95% CI: 0.35-0.94). PCI adjusted rates were higher among women born in Palestine state (HR = 2.44, 95% CI: 1.15-5.16), Iraq (HR = 1.34, 95% CI: 1.04-1.74) and Poland (HR = 1.21, 95% CI: 1.02-1.44) and rate of CABG was higher among immigrants from some parts of Asia, including men born in Sri Lanka (HR = 3.19, 95% CI: 1.43-7.12), India (HR = 1.95, 95% CI: 1.21-3.14), Vietnam (HR = 2.65, 95% CI: 1.32-5.33), Palestine State (HR = 2.11, 95% CI: 1.06-4.24), and women born in Syria (HR = 2.36, 95% CI: 1.25-4.45), Iraq (HR = 1.74, 95% CI: 1.02-2.94), and Turkey (HR = 1.70, 95% CI: 1.03-2.79). Conclusions: The observed high rate of CABG for immigrants and particularly those born in some Asian countries was not explained by the potential confounding factors. A more severe coronary disease in this population might explain this high rate but needs further research. Awareness and subsequent intervention at earlier stage of coronary disease among immigrants could prolong their life and reduce the healthcare costs. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the association between serum high-sensitivity C-reactive protein (hs-CRP) and incident hypertension. Study subjects were 452 Koreans who were enrolled in a cohort study. Log-transformed hs-CRP (odds ratio, 1.89; 95% confidence interval, 1.05-3.39; p = 0.035) was an independent predictor of incident hypertension. Inclusion of hs-CRP showed significant increase in the area under the curve from 0.697 to 0.720 ( p = 0.042), the net reclassification improvement (0.394, p < 0.001) and integrated discrimination improvement (0.0111, p = 0.045). The hs-CRP added incremental value to the combination of systolic blood pressure and conventional risk factors in predicting incident hypertension. [ABSTRACT FROM AUTHOR]