Improved cultural algorithms for job shop scheduling problem

This paper presents a new cultural algorithm for job shop scheduling problem. Unlike the canonical genetic algorithm, in which random elitist selection and mutational genetics is assumed. The proposed cultural algorithm extract the useful knowledge from the population space of genetic algorithm to form belief space, and utilize it to guide the genetic operator of selection and mutation. The different sizes of the benchmark data taken from literature are used to analyze the efficacy of this algorithm. Experimental results indicate that it outperforms current approaches using canonical genetic algorithms in computational time and quality of the solutions

Effects of government subsidies on production and emissions reduction decisions under carbon tax regulation and consumer low‐carbon awareness

To promote low-carbon production, the government simultaneously provides some subsidies under carbon tax regulations. Two government subsidies are widely adopted: one is based on emissions reduction quantity and the other is based on emissions reduction investment cost. Additionally, consumer low-carbon awareness has also been enhanced. Considering the aforementioned circumstances, this paper investigates the effects of different government subsidies on production and emissions reduction decisions under a carbon tax regulation by formulating three decision-making optimization models. The results show that (1) although the carbon tax regulation cannot guarantee further improvement of emissions reduction levels, government subsidies could make the corresponding conditions of improving emissions reduction investments wider; (2) a heavy carbon tax or stronger consumer low-carbon awareness would make the positive effect of government subsidies more apparent; and (3) subsidy policies may also be selected by the government from different perspectives, such as manufacturer development, consumer surplus, environmental damage and social welfare. Especially, from the perspective of maximizing social welfare, investment cost (IC) subsidy is not always advantageous, while emissions reduction (ER) subsidy can always bring higher social welfare compared with the case under no government subsidy

Exploring the Process of Fresh Produce Supply Within a Platform Ecosystem During City Lockdown Period

While the existing literature focusing on how organizations collaborate within ecosystems to overcome institutional logic conflicts and the information systems enabled inter-organizational cooperation, less is known on how information systems develop during crises and enable effective collaboration among stakeholders. Through an in-depth case study of Shenzhen Company H (pseudonym) platform ecosystem, we present an IT-enabled fresh produce supply process. Our findings reveal that this process unfolds across four dimensions - iterative IT tailoring, progressive system synergy, facilitative IT confluence, and user-attuned technological adaptation. Based on these dimensions, we propose an IT-enabled platform ecosystem orchestration mechanism in crisis situations. These mechanisms also offer practical implications not only for organizations\u27 strategies when facing crises but also for the enhancement of their daily operational competence

Effect of 5-aminolevulinic acid on yield and quality of lettuce in sunlit greenhouse

The role of 5-aminolevulinic acid (ALA) as a precursor of chlorophyll and heme is well documented. Low concentration of exogenous ALA has been found to regulate plant growth and increase crop yield, but there is little information on how ALA influences the yield and quality of lettuce in sunlit greenhouse. Here, we report the effects of ALA on photosynthetic rate, yield and quality of lettuce in sunlit greenhouse.5-aminolevulinic acid and 5-aminolevulinic acid with nitrogen fertilizer (ALA+N) were applied by foliage and soil. The results showed that application of ALA improved the photosynthetic rate of lettuce leaves by 23.9 to 34.7% and by 35.3 to 41.6%. Moreover, exogenous ALA increased vitamin C and soluble sugar content, reduced nitrate and crude fiber content and lead to better quality and taste of lettuce.Keywords: 5-aminolevulinic acid, lettuce, plant growth, promotive effects, yield, vegetable qualit

Multi-scale Modelling for Materials Design in Additive Manufacturing

Additively manufactured (AMed) austenitic stainless steels (SSs) possess exceptional properties like high strength and toughness. However, it is unclear how they perform under long-term exposure to high-temperature conditions, such as those found in nuclear reactors. These properties arise due to complex microstructures that develop during additive manufacturing (AM), including nanoscale dislocation cellular structures, microscale sub-grains with a high density of low-angle grain boundaries (LAGBs), and high dislocation density. Although the quasi-static mechanical properties of AM austenitic SSs, such as 316L SS, have been systematically investigated, the creep behaviour of such alloys is still a new area of research, with some experimental studies conducted in recent years. Additionally, the mechanical properties of most AMed alloys are anisotropic due to texture formation, and creep behaviour can be significantly influenced by microstructural differences in various building directions. Furthermore, the presence of AM-characterised microstructure is a notable feature of AM materials, and the size and shape of the pores can greatly influence stress concentration during loading. Thus, it is critical to quantify the effects of AM-characterised microstructure on the mechanical properties of materials. As experimental methods have limitations for studying material properties, it is necessary to use computational modelling to extrapolate existing experimental data, especially for highly time-consuming experiments such as creep testing. This study aims to provide a modelling framework for characterizing the evolution of microstructure and high-temperature creep behaviour in AM and wrought austenitic SSs, considering the impact of the initial microstructure. For AM materials, there are two types of samples: horizontally-built samples (loading direction parallel to the building direction) and vertically-built samples (loading direction vertical to the building direction). The choice of AM materials with different built directions is for studying the effect of the relative loading direction to the building direction on material creep behaviour. The materials strengthening mechanisms, including lattice friction, solid solution strengthening, dislocation hardening, and precipitation hardening, are quantified in detail. In addition to data from literature and experiments used to evaluate each strengthening mechanism, the precipitation evolution during the creep process is simulated through the thermokinetics calculation using Thermo-Calc software. Differently fabricated materials are originally simulated under the visco-plasticity self-consistent (VPSC) framework, using the materials' own characteristics as input. The creep mechanical responses of AM and wrought materials are compared, and the dominant deformation mechanisms are revealed and quantitatively compared. Due to the limitations of the VPSC, only the primary stage and secondary stage of creep behaviour are captured. Based on this, the same physics-based model is employed under the crystal plasticity finite element method (CP-FEM) framework, which is full-field, and combined with the Gurson-Tvergaard-Needleman (GTN) damage model to capture the tertiary stage creep deformation. The original crystal plasticity model is highly microstructure-sensitive, and the detailed local structure can be analyzed through the finite element method. Therefore, the original electron backscatter diffraction (EBSD) information is pictured by MATLAB and used for materials input under the CP-FEM framework. In addition, DREAM3D software is used to extract microstructure information from raw EBSD data. The tertiary creep stages of horizontally-built and vertically-built AMed samples are simulated and compared, revealing that damage tends to accumulate on grain boundaries that are perpendicular to the loading direction. Additionally, the effects of AM-induced pores on creep deformation are evaluated by introducing them into the CP-FEM input. As selecting a specific region on the original EBSD data cannot summarize the overall AM materials characteristics, an artificial input is randomly generated through a Voronoi diagram by MATLAB with assigned grain orientation. The artificial input is characterized by AM-induced elongated grain structure to study the effects of high-angle grain boundaries (HAGBs) on materials creep behaviour, especially the damage evolution

User Motivation to Explore Enterprise System Features: An Exploratory Study of Its Organizational Antecedents and Consequences

To attain the strategic goal of deriving competitive advantage from Enterprise System (ES) adoption, organizations rely on users’ exploration of the system features and eventually integrating the system application tightly with job tasks. Research on how to align users’ interest with the organization’s strategic goal and enhance user motivation to explore ES features is of great significance but lacking. Drawing upon organizational psychology and information systems theories, this paper investigates the organizational mechanisms (i.e., reward system, autonomy job design, and socialization tactics) enhancing user motivation (i.e., extrinsic, intrinsic and normative motivation) to explore ES features, the moderating effect of individual motivational system (prevention focus in particular) on the association between organizational mechanisms and motivation, and how different types of motivation affect cognitive and affective exploration outcomes. Our research model is tested by data collected from individual users through a longitudinal two-wave survey. Theoretical contributions and managerial implication of this study are discussed

The Role of Long Noncoding RNAs in Gene Expression Regulation

Accumulating evidence highlights that noncoding RNAs, especially the long noncoding RNAs (lncRNAs), are critical regulators of gene expression in development, differentiation, and human diseases, such as cancers and heart diseases. The regulatory mechanisms of lncRNAs have been categorized into four major archetypes: signals, decoys, scaffolds, and guides. Increasing evidence points that lncRNAs are able to regulate almost every cellular process by their binding to proteins, mRNAs, miRNA, and/or DNAs. In this review, we present the recent research advances about the regulatory mechanisms of lncRNA in gene expression at various levels, including pretranscription, transcription regulation, and posttranscription regulation. We also introduce the interaction between lncRNA and DNA, RNA and protein, and the bioinformatics applications on lncRNA research

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques