197 research outputs found
Risk Decision for Dual-Channel Supply Chain of Agricultural Products Under Disturbance
This paper presents a decision analysis model for the dual-channel supply chain of agricultural products under the disturbance of emergency. Mean variance analysis tool and utility function risk tool are used to describe risk indicators in supply chain. In this study, retailer plays a leading role in agricultural supply chain. By means of the Kuhn-Tucker condition of the retailer’s maximum utility, the optimal price and optimal demand are obtained. The study also shows that risk averse retailer has higher wholesale price, lower retail price and greater supply as well as the demand for the pursuit of greater utility; Supplier has a certain robustness to the sudden event disturbance, when the disturbance is large, the quantity of initial supply quantity will be adjusted. The relationship between the demand change rate of the two channels and the market share of the channel is found. Finally, some numerical examples are presented to illustrate the results. The study provides a possible way of thinking in emergency decision analysis
Performance Limits of Monolayer Transition Metal Dichalcogenide Transistors
The performance limits of monolayer transition metal dichalcogenide
transistors are examined with a ballistic MOSFET model. Using ab-initio theory,
we calculate the band structures of two-dimensional (2D) transition metal
dichalco-genide (MX2). We find the lattice structures of monolayer MX2 remain
the same as the bulk MX2. Within the ballistic regime, the performances of
monolayer MX2 transistors are better compared to the silicon transistors if
thin high-{\kappa} gate insulator is used. This makes monolayer MX2 promising
2D materials for future nanoelectronic device applications
Normal-mode splitting in the optomechanical system with an optical parametric amplifier and coherent feedback
Strong coupling in optomechanical systems is the basic condition for
observing many quantum phenomena such as optomechanical squeezing and
entanglement. Normal-mode splitting (NMS) is the most evident signature of
strong coupling systems. Here we show the NMS in the spectra of the movable
mirror and the output field in an optomechanical system can be flexibly
engineered by a combination of optical parametric amplifier (OPA) and coherent
feedback (CF). Moreover, the NMS could be enhanced by optimizing the parameters
such as input optical power, OPA gain and phase, CF strength in terms of
amplitude reflectivity of beam splitter.Comment: 8 pages, 7 figure
Some Essential Issues and Outlook for Industrialization of Cu-III-VI2 Thin-Film Solar Cells
The concept and method of in-line sputtering and selenization become the industrial standard for Cu-III-VI2 solar cell fabrication, but it is a difficult work to control and predict the electrical and optical performances, which are closely related to the chemical composition of the film. This chapter addresses the material design, device design, and process design using chemical compositions relating parameters. Compositional variation leads to change in the poisson equation, current equation and continuity equation governing the device design. To make the device design much realistic and meaningful, we have to build a model that relates the opto-electrical performance to the chemical composition of the film. The material and device structural parameters are input into the process simulation to give a complete process control parameters and method. We calculated neutral defect concentrations of non-stoichiometric CuMSe2 (M-In, Ga) under the specific atomic chemical potential conditions. The electrical and optical performance has also been investigated for the development of full function analytical solar cell simulator. Module instability and their origins are listed. After that progress of CZTS (Cu2ZnS4) is briefed on the future work of CIGS (CuInGaSe2). The future prospects regarding the development of CIGS thin-film solar cells (TFSCs) have also been discussed
Data Management in Microservices: State of the Practice, Challenges, and Research Directions
We are recently witnessing an increased adoption of microservice
architectures by the industry for achieving scalability by functional
decomposition, fault-tolerance by deployment of small and independent services,
and polyglot persistence by the adoption of different database technologies
specific to the needs of each service. Despite the accelerating industrial
adoption and the extensive research on microservices, there is a lack of
thorough investigation on the state of the practice and the major challenges
faced by practitioners with regard to data management. To bridge this gap, this
paper presents a detailed investigation of data management in microservices.
Our exploratory study is based on the following methodology: we conducted a
systematic literature review of articles reporting the adoption of
microservices in industry, where more than 300 articles were filtered down to
11 representative studies; we analyzed a set of 9 popular open-source
microservice-based applications, selected out of more than 20 open-source
projects; furthermore, to strengthen our evidence, we conducted an online
survey that we then used to cross-validate the findings of the previous steps
with the perceptions and experiences of over 120 practitioners and researchers.
Through this process, we were able to categorize the state of practice and
reveal several principled challenges that cannot be solved by software
engineering practices, but rather need system-level support to alleviate the
burden of practitioners. Based on the observations we also identified a series
of research directions to achieve this goal. Fundamentally, novel database
systems and data management tools that support isolation for microservices,
which include fault isolation, performance isolation, data ownership, and
independent schema evolution across microservices must be built to address the
needs of this growing architectural style
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