Hybrid Variable Neighborhood Search for Solving School Bus-Driver Problem with Resource Constraints

The School Bus-Driver Problem with Resource Constraints (SBDP-RC) is an optimization problem with many practical applications. In the problem, the number of vehicles is prepared to pick a number of pupils, in which the total resource of all vehicles is less than a predefined value. The aim is to find a tour minimizing the sum of pupils’ waiting times. The problem is NP-hard in the general case. In many cases, reaching a feasible solution becomes an NP-hard problem. To solve the large-sized problem, a metaheuristic approach is a suitable approach. The first phase creates an initial solution by the construction heuristic based on Insertion Heuristic. After that, the post phase improves the solution by the General Variable Neighborhood Search (GVNS) with Random Neighborhood Search combined with Shaking Technique. The hybridization ensures the balance between exploitation and exploration. Therefore, the proposed algorithm can escape from local optimal solutions. The proposed metaheuristic algorithm is tested on a benchmark to show the efficiency of the algorithm. The results show that the algorithm receives good feasible solutions fast. Additionally, in many cases, better solutions can be found in comparison with the previous metaheuristic algorithms

Emotional Regulation in Synchronous Online Collaborative Learning: A Facial Expression Recognition Study

Emotional regulation in learning has been recognised as a critical factor for collaborative learning success. However, the “unobservable” processes of emotion and motivation at the core of learning regulation have challenged the methodological progress to examine and support learners’ regulation. Artificial intelligence (AI) and learning analytics have recently brought novel opportunities for investigating the learning processes. This multidisciplinary study proposes a novel fine-grained approach to provide empirical evidence on the application of these advanced technologies in assessing emotional regulation in synchronous computer-support collaborative learning (CSCL). The study involved eighteen university students (N=18) working collaboratively in groups of three. The process mining analysis was adopted to explore the patterns of emotional regulation in synchronous CSCL, while AI facial expression recognition was used for examining learners’ associated emotions and emotional synchrony in regulatory activities. Our findings establish a foundation for further design of human-centred AI-enhanced support for collaborative learning regulation

Revealing the Hidden Structure of Affective States During Emotion Regulation in Synchronous Online Collaborative Learning

This study aims to explore the use of advanced technologies such as artificial intelligence (AI) to reveal learners' emotion regulation. In particular, this study attempts to discover the hidden structure of affective states associated with facial expression during challenges, interactions, and strategies for emotion regulation in the context of synchronous online collaborative learning. The participants consist of 18 higher education students (N=18) who collaboratively worked in groups. The Hidden Markov Model (HMM) results indicated interesting transition patterns of latent state of emotion and provided insights into how learners engage in the emotion regulation process. This study demonstrates a new opportunity for theoretical and methodology advancement in the exploration of AI in researching socially shared regulation in collaborative learning

EXTRACTION AND PROPERTY STUDIES OF COENZYME Q10 FROM RECOMBINANT AGROBACTERIUM TUMEFACIENS

In this report, some results of extraction and characterization of CoQ10 from recombinant A. tumefaciens are presented. Four different cell breaking methods (sonication, acidic treatment, ethanol treatment, and enzymatic lysis) in combination with the extracting steps were carried out to extract CoQ10 and the results showed that ethanol treatment was the most efficient method. Appropriate conditions for CoQ10 extraction were 25 oC, 24 hours incubation and ethanol solvent/biomass ratio of 10:1 (ml/g). Characterization of extracted CoQ10 showed that CoQ10 was sensitive to light, but stable in the temperature ranges of 4 – 60 oC and the pH range of 6.0 – 9.0. Obtained results in present study should be applied in the large scale for CoQ10 extraction, providing the CoQ10 product for testing production of functional foods

Selection and identification of thermophilic yeast strains in leachate from the organic waste heap in Phu Luong district, Thai Nguyen province, Vietnam

The study was carried out to isolate and select useful thermophilic yeast strains in the process of organic domestic waste treatment in Phu Luong - Thai Nguyen. Research results from 23 samples of rust have isolated 10 strains of yeast on YPG medium at 40 oC. Among them, 6 strains of yeast were selected with the ability to grow and develop in a wide temperature range from 20-45 oC. The results of identification combined with morphological, physiological, and biochemical characteristics of yeast strains showed that, out of 6 selected strains, there were 3 strains belonging to the genus Saccharomyces (Saccharomyces sp. TNY13.01, Saccharomyces sp. TNY22.01), Saccharomyces cerevisiae TNY13.09), 2 strains of the genus Candida (Candida sp. TNY23.01, Candida tropicalis TNY23.126) and 1 strain of the genus Papiliotrema (Papiliotrema laurentii TNY23.127). Among them, the identified strain Saccharomyces cerevisiae TNY13.09 has the ability to grow at 45, tolerates a wide pH range of 4.0– 8.5, has a positive catalase reaction, is capable of using a variety of carbon sources, and belongs to class I biosafety group. On that basis, Saccharomyces cerevisiae TNY13.09 has the potential to be further researched and applied as additional microbial inoculants to the organic waste heap

Fragmented understanding: exploring the practice and meaning of informed consent in clinical trials in Ho Chi Minh City, Vietnam

Background The informed consent process in clinical trials has been extensively studied to inform the development processes which protect research participants and encourage their autonomy. However, ensuring a meaningful informed consent process is still of great concern in many research settings due to its complexity in practice and interwined socio-cultural factors. Objectives This study explored the practices and meaning of the informed consent process in two clinial trials conducted by Oxford University Clinical Research Unit in collaboration with the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Methods We used multiple data collection methods including direct observervations, in-depth interviews with study physicians and trial participants, review of informed consent documents from 2009 to 2018, and participant observation with patients’ family members. We recruited seven physicians and twenty-five trial participants into the study, of whom five physicians and thirteen trial participants completed in-depth interviews, and we held twenty-two direct observation sessions. Results We use the concept “fragmented understanding” to describe the nuances of understanding about the consent process and unpack underlying reasons for differing understandings. Conclusions Our findings show how practices of informed consent and different understanding of the trial information are shaped by trial participants’ characteristics and the socio-cultural context in which the trials take place

NONLINEAR CHARACTERISTICS OF SQUARE SOLID-CORE PHOTONIC CRYSTAL FIBERS WITH VARIOUS LATTICE PARAMETERS IN THE CLADDING

Nonlinear characteristics of fused silica, solid-core photonic crystal fibers (PCFs) with a square array of air holes are studied numerically. We present a novel design that emphasizes the difference in air hole diameters in the photonic cladding. These PCFs have the advantages of flat dispersion, high nonlinearity, and low attenuation. Based on simulation results, three optimal structures, denoted #F1, #F2, and #F3, having anomalous and all-normal dispersions in the near-infrared range are selected to investigate characteristic properties at the pump wavelength. Such PCFs open up many possibilities for nonlinear optical applications, especially supercontinuum generation