Parallel Processing Strategies for Geospatial Data in a Cloud Computing Infrastructure

This paper is on the optimization of computing resources to process geospatial image data in a cloud computing infrastructure. Parallelization was tested by combining two different strategies: image tiling and multi-threading. The objective here was to get insight on the optimal use of available processing resources in order to minimize the processing time. Maximum speedup was obtained when combining tiling and multi-threading techniques. Both techniques are complementary, but a trade-off also exists. Speedup is improved with tiling, as parts of the image can run in parallel. But reading part of the image introduces an overhead and increases the relative part of the program that can only run in serial. This limits speedup that can be achieved via multi-threading. The optimal strategy of tiling and multi-threading that maximizes speedup depends on the scale of the application (global or local processing area), the implementation of the algorithm (processing libraries), and on the available computing resources (amount of memory and cores). A medium-sized virtual server that has been obtained from a cloud service provider has rather limited computing resources. Tiling will not only improve speedup but can be necessary to reduce the memory footprint. However, a tiling scheme with many small tiles increases overhead and can introduce extra latency due to queued tiles that are waiting to be processed. In a high-throughput computing cluster with hundreds of physical processing cores, more tiles can be processed in parallel, and the optimal strategy will be different. A quantitative assessment of the speedup was performed in this study, based on a number of experiments for different computing environments. The potential and limitations of parallel processing by tiling and multi-threading were hereby assessed. Experiments were based on an implementation that relies on an application programming interface (API) abstracting any platform-specific details, such as those related to data access.

The Optimal Strategy of China’s Plastic Drinking Straws Ban Based on Consumer Heterogeneity and Retailer Competition

The Chinese government has issued a new “Plastic Restriction Ban” requiring that, by the end of 2020, the food and beverage industry across the country bans the use of single-use, nondegradable plastic drinking straws. The governance of plastic drinking straws is a multi-dimensional and complex process. Therefore, based on the heterogeneity of consumers, this paper constructs a tripartite game model (the government, retailers, and consumers) for the governance of plastic drinking straws in China. Under this model, this research derives an optimal strategy in both monopoly and competitive markets, assuming the government has access to two policy tools, fines and subsidies. The research results suggest the following. (1) In monopoly markets, when (a) the fine or subsidy fee is high or (b) the fine or subsidy fee is low and the number of environment-conscious consumers is high, retailers are more inclined to provide biodegradable drinking straws. (2) Consumer heterogeneity has a certain impact on policy results; when there are enough environment-conscious consumers, policy costs can be reduced. (3) For high-quality products, the policy costs in competitive markets is lower than in monopoly markets; for low-quality products, the policy costs in competitive markets is higher than in monopoly markets. Based on the conclusions, this work suggests the government should focus on cultivating consumers’ environmental awareness and tighter control of products quality, in addition to the two policy tools, i.e., fines and subsidies, because these can reduce policy costs. Consumers should be aware of their own importance to China’s Plastic Drinking Straws Ban and adopt a refusal to accept plastic drinking straws and reduce the consumption of disposable plastics to support the policy. Retailers should also realize that proactively catering to consumer and government expectations can bring higher benefits to themselves; this can be achieved by providing high-quality biodegradable straws to support China’s Plastic Drinking Straws Ban. The model of this work could be applied to other corporate activities related to sustainability, such as plastic bags, plastic bottles, etc., and their connection to government policies.

Passenger Behavior Simulation in Congested Urban Rail Transit System: A Capacity-Limited Optimal Strategy Model for Passenger Assignment

Optimal strategy, one of the main transit assignment models, can better demonstrate the flexibility for passengers using routes in a transit network. According to the basic optimal strategy model, passengers can board trains based on their frequency without any capacity limitation. In the metropolitan cities such as Beijing, Shanghai, and Hong Kong, morning commuters face huge transit problems. Especially for the metro system, there is heavy rush in metro stations. Owing to the limited train capacity, some passengers cannot board the first coming train and need to wait for the next one. To better demonstrate the behavior of passengers pertaining to the limited train capacity, we consider capacity constraints for the basic optimal strategy model to represent the real situation. We have proposed a simulation-based algorithm to solve the model and apply it to the Beijing Subway to demonstrate the feasibility of the model. The application of the proposed approach has been demonstrated using the computational results for transit networks originating from practice.

Characteristics of Parent-Teacher Communication in Romanian Primary Education During the COVID-19 Pandemic

The COVID-19 pandemic has influenced the manner in which school activities are organized and the way that interactions occur between all educational actors. According to both teacher and parent opinion, the quality of cooperation and communication between the school and the families has not been affected. The use of modern means of communication is considered by both parents and primary school teachers as an optimal strategy for strengthening the school-family partnership. This study presents several types of activities that parents have enjoyed and which could be organized in the online environment. The authors of the study have discovered that for some parents it was very comfortable to interact with the teacher in the online environment. For these parents, the main advantage of using communication platforms or applications refers to economy of time; thus, travel from their home or job to the school was avoided.

CHOICE OF LOCOMOTIVE PARK MAINTENANCE STRATEGY WHEN INTRODUCING THE SERVICE

In operation, sometimes there are situations of uncertainty in assessing the technical condition of locomotive equipment and at the same time choosing the optimal strategy for its maintenance, including the possibility of using the service. Application of the concept of service gives the chance to stimulate work of all divisions of locomotive economy, to save all kinds of resources for operation of locomotives. According to this, the article substantiates the choice of strategy for maintaining the locomotive fleet using the provisions of the theory of statistical solutions. Game theory approaches were used to theoretically substantiate the transition to a service for decision-making in conflict situations and to determine the optimal strategy of behavior of each of the participants in this situation. Approaches to the choice of strategy for the maintenance of the locomotive fleet during the introduction of the service on the basis of the provisions of the theory of strategic games on the criterion of maximum efficiency were considered. It is shown on examples of the decision of some problems of a choice of maintenance strategy of locomotives for various industrial situations. It is concluded that a mixed strategy describes different situations best and allows to made rational decisions. It is also noted that the most effective approach to concretize the algorithm of actions is the complex application of the theory of strategic decisions, the theory of fuzzy sets, the theory of pattern recognition.

Reply to Jubouri and Abdelhaliem

We present a reply to the invited commentary by Jubouri and Abdelhaliem published in response to our original article titled: Prevention vs Cure: is BioGlue priming the optimal strategy against E-Vita Neo graft oozing? The authors highlight key issues associated with the E-Vita Open NEO aortic arch prosthesis, chiefly, the propensity for the prosthesis to exhibit post-anastomotic oozing. We read with great interest their commentary and concur that the issues highlighted therein are significant and warrant discussion.

THE VERTICAL LAND USE ZONING FOR UNDERGROUND SPACE DEVELOPMENT IN MALAYSIA

There is a demand for the development of underground space beneath alienated land by a third party other than the surface landowner. Arguments frequently arise because the surface landowner asserts that his rights extend to ownership extension, while the other party wishes to develop the underground space without interfering with the rights of others. Due to Malaysia's absent of land use zoning for underground space, the rights to develop underground space are ambiguous. Using a qualitative approach, this study will examine the role of land use zoning in assisting the development of underground spaces. Thematic analyses revealed three interconnected elements: underground land use zoning, standardisation of land category depths, and a buffer zone for surface and underground space ownership. Additionally, a comparative study was conducted between Malaysia, Hong Kong, China, Japan, and Finland in order to determine the optimal strategy for zoning underground space land uses. At the conclusion of this paper, verticalland use zoning was also proposed.