This article examines whether the likelihood and amount of firm charitable giving in response to catastrophic events are related to firm advertising intensity, and whether industry competition level moderates this relationship. Using data on Chinese firms’ philanthropic response to the 2008 Sichuan earthquake, we find that firm advertising intensity is positively associated with both the probability and the amount of corporate giving. The results also indicate that this positive advertising intensity-philanthropic giving relationship is stronger in competitive industries, and firms in (...) competitive industries are more likely to donate. This study thus provides evidence suggesting that even in the wake of catastrophic events, corporate philanthropic giving is strategic. (shrink)

A stochastic prey-predator system in a polluted environment with Beddington-DeAngelis functional response is proposed and analyzed. Firstly, for the system with white noise perturbation, by analyzing the limit system, the existence of boundary periodic solutions and positive periodic solutions is proved and the sufficient conditions for the existence of boundary periodic solutions and positive periodic solutions are derived. And then for the stochastic system, by introducing Markov regime switching, the sufficient conditions for extinction or persistence of such system are obtained. (...) Furthermore, we proved that the system is ergodic and has a stationary distribution when the concentration of toxicant is a positive constant. Finally, two examples with numerical simulations are carried out in order to illustrate the theoretical results. (shrink)

ABSTRACTThis study adapted a questionnaire design to survey six identified core dimensions of twenty-first-century learning among China high school students. The core dimensions are learning proces...

The point bar is one of the most important reservoirs in a meandering depositional system, and accurately building a 3D architecture model for point bars is crucial to predict hydrocarbon distribution within the reservoir. Unfortunately, we can only obtain a qualitative description about the internal architecture of the point bar due to the limited information or the low resolution of available data. To build a 3D prototype point bar reservoir model, we analyze the architecture of point bars by integrating high-resolution (...) ground penetrating radar data and modern deposition. We found that our GPR data have five main reflection patterns, and GPR facies can be used to relate with architectural elements. The concave-down GPR facies is usually related to the abandoned channel. The continuous, subhorizontal, subparallel GPR facies is commonly related with lateral-accretion sand bodies within the point bar. The multiple stacked small-scale, discontinuous reflections GPR facies is interpreted to be shale drapes within the point bar. We further analyzed the geometry parameters of the identified channels. We found that the nonsymmetric [Formula: see text] of abandoned channel near the channel axis is related to the ratio between the curvature of channel radius [Formula: see text] and channel width [Formula: see text]. Finally, we built two 3D channel reservoir models and our models could provide useful guidance for the architecture analysis of buried meandering fluvial reservoirs. (shrink)

Quantitative characterization of pore structure in shale can provide basic parameters for evaluation of the shale-gas reservoir quality. However, it is difficult to use conventional methods to accurately and comprehensively characterize the pore structure parameters. We take shale samples from the Longmaxi Formation in the Sichuan Basin as the study object, and we use the high-pressure mercury intrusion, nitrogen adsorption, and carbon dioxide adsorption methods to characterize the whole aperture distribution. We found that the pore size in shale is positively (...) related to the transverse relaxation time and there exists a conversion coefficient. We have developed a new method combining nuclear magnetic resonance with hybrid detection methods for testing the pore size distribution, and we optimized the conversion coefficient between pore size obtained by a hybrid detection method and the [Formula: see text] value. NMR can then characterize the pore size distribution by conversion coefficient. This method can effectively make up for the deficiency of conventional methods for pore size distribution characterization by a single method. Our results indicate that the macropore, mesopore, and micropore in shale are very developed, and the pore shapes are ink bottle and slit-like. Shale pores mainly consist of mesopore and micropore, contributing to approximately 74.33% of pore volume, whereas micropore contributes approximately 70.18% of specific surface area. Therefore, the macropore has a limited effect on the pore volume and SSA. In addition, the establishment of whole aperture distribution characterization by the new method can more comprehensively reflect the actual pore distribution in shale. (shrink)

Diagenesis is one of the most important factors impacting the performance of many reservoirs and is perhaps the most important factor impacting the performance of tight sandstone reservoirs, such as those of the Sulige gas field in the Ordos Basin of China. However, the relationship between diagenesis and related parameters determining reservoir physical properties remains unclear. Therefore, we have analyzed experimental data from high-pressure mercury intrusion porosimetry, scanning electron microscopy, and thin sections in addition to using a porosity recovery calculation (...) model to investigate microscopic characteristics, diagenesis, and pore-evolution processes of the low-permeability tight gas reservoir of the He-8 unit of the Sulige gas field in the Ordos Basin. In addition, we have identified the impacts of diagenesis on reservoir characteristics and established the relationship between diagenesis and reservoir quality evolution. We also used the Beard primary porosity model to recover the primary porosity, and to built the reducing and enhancing calculation models for intergranular pore, dissolution pore, and intercrystalline pore during diagenesis. Based on the quantitative relationship between diagenesis processes and porosity evolution, we found that the results of simulation calculation and experimental works were in close agreement with minimal error. (shrink)

A novel iterative learning control algorithm for a two-wheeled self-balancing mobile robot with time-varying, nonlinear, and strong-coupling dynamics properties is presented to resolve the trajectory tracking problem in this research. A kinematics model and dynamic model of a two-wheeled self-balancing mobile robot are deduced in this paper, and the combination of an open-closed-loop PD-ILC law and a variable forgetting factor is presented. The open-closed-loop PD-ILC algorithm adopts current and past learning items to drive the state variables and input variables, and (...) the output variables converge to the bounded scope of their desired values. In addition, introducing a variable forgetting factor can enhance the robustness and stability of ILC. Numerous simulation and experimental data demonstrate that the proposed control scheme has better feasibility and effectiveness than the traditional control algorithm. (shrink)

How to aggregate decision information in heterogeneous multiattribute group decision making is vital. The aim of this paper is to develop an approach to aggregating decision data into intuitionistic triangular fuzzy numbers for heterogeneous MAGDM problems with real numbers, interval numbers, triangular fuzzy numbers, trapezoidal fuzzy numbers, and triangular intuitionistic fuzzy number. Using the relative closeness of technique for order preference by similarity to ideal solution and geometry entropy method, we first present a general approach to aggregating heterogeneous information into (...) ITFNs, which takes the group consistency of experts into account. Based on the collective intuitionistic triangular fuzzy decision matrix and extended TOPSIS, a multiple objective mathematical program is constructed to determine the optimal attribute weights. Subsequently, a new method to solve HMAGDM problems is presented based on the aforementioned discussion. A trustworthy service selection example is provided to verify the practicality and effectiveness of the proposed method. (shrink)

As an important variant of membrane computing models, fuzzy reasoning spiking neural P systems were introduced to build a link between P systems and fault diagnosis applications. An FRSN P system offers an intuitive illustration based on a strictly mathematical expression, a good fault-tolerant capacity, a good description for the relationships between protective devices and faults, and an understandable diagnosis model-building process. However, the implementation of FRSN P systems is still at a manual process, which is a time-consuming and hard (...) labor work, especially impossible to perform on large-scale complex power systems. This manual process seriously limits the use of FRSN P systems to diagnose faults in large-scale complex power systems and has always been a challenging and ongoing task for many years. In this work we develop an automatic implementation method for automatically fulfilling the hard task, named membrane computing fault diagnosis method. This is a very significant attempt in the development of FRSN P systems and even of the membrane computing applications. MCFD is realized by automating input and output, and diagnosis processes consists of network topology analysis, suspicious fault component analysis, construction of FRSN P systems for suspicious fault components, and fuzzy inference. Also, the feasibility of the FRSN P system is verified on the IEEE14, IEEE 39, and IEEE 118 node systems. (shrink)

Controversy persists over the ethics of compensating research participants and providing posttrial benefits to communities in developing countries. Little is known about residents' views on these subjects. In this study, interviews about compensation and posttrial benefits from a hypothetical HIV vaccine trial were conducted in Uganda’s Rakai District. Most respondents said researchers owed the community posttrial benefits and research compensation, but opinions differed as to what these should be. Debates about posttrial benefits and compensation rarely include residents' views like these, (...) but future ones should. (shrink)

Group conflict is one of the main human conflicts in the history of human development and results in various forms such as competition, fight, riot, or war in extreme cases and compromise, negotiation, or cooperation in other cases. The inner essence of the group conflict is competitors vying for resource control. If the conflict ends up at a situation where one party overwhelms the other, it will actually bring destructive results to both sides. Is there a solution to avoid fierce (...) conflicts and to achieve a win-win situation? Is there a unified model by which different forms of conflicts can be interpreted and studied? The purpose of this paper was to address these problems and attempt to establish such a unified model and to use it to analyze the dynamic relationship between the employees and their employers in the viewpoint of group conflict and symbiosis. By changing coefficients of the unified model, the two sides, employers and employees, could be in different situations such as employer win, employee win, lose-lose, and win-win. Keeping other coefficients unchanged, we found and proved that there is a win-win strategy space of the payoff rate. Two parties chose strategy within the space can achieve optimal status in long run. (shrink)

In this paper, by means of the Hirota bilinear method, a dimensionally reduced nonlinear evolution equation is investigated. Through its bilinear form, lump solutions are obtained. We construct interaction solutions between lump solutions and one soliton solution by choosing quadratic functions and exponential function. Interaction solutions with the combinations of exponential functions and sine function are also given. Meanwhile, the figures of these solutions are plotted. The dynamical characteristics and properties of obtained solutions are discussed, respectively. The results show that (...) the corresponding physical quantities and properties of nonlinear waves are associated with the values of the parameters. (shrink)