The bees algorithm: Modelling nature to solve complex optimisation problems

The Bees Algorithm models the foraging behaviour of honey bees in order to solve optimisation problems. The algorithm performs a kind of exploitative neighbourhood search combined with random explorative search. This paper describes the Bees Algorithm and presents two application examples: the training of neural networks to predict the energy efficiency of buildings, and the solution of the protein folding problem. The Bees Algorithm proved its effectiveness and speed, and obtained very competitive modelling accuracies compared with other state-of-the-art methods

FINITE ELEMENT MODELING FOR ANALYSIS VIBRATION OF LARGE TURBO MACHINERY

Recently, finite elements method (FEM) has been used most popular for analysis of stress, vibration, heat flow and many other phenomena. With the increase in computing power, FEM is wider used for the static and dynamic analysis of rotor bearing system. In this paper, the lateral vibration of large turbo machinery is studied. The FEM model is created and the eigenvalues and eigenvectors are calculated and analyzed to find natural frequencies, critical speeds, mode shapes and unbalance responses. Then critical and mode shapes are determined. Finally, responses of unbalance force are analyzed and compared in case of isotropic bearings and anisotropic bearings

Estimates for the elastic moduli of 2D aggregate of hexagonal-shape orthorhombic crystals with in-plane random crystalline orientations

Numerical finite element simulations on the homogenization problem for large samples of particular 2D hexagonal-shape-geometry random orientation aggregates from the base crystals of orthorhombic symmetry have been performed. At sufficiently large random-aggregate samples, the scatter intervals of the macroscopic 2D bulk and shear elastic moduli converge toward the Voigt-Reuss-Hill bounds, and then our recently constructed theoretical estimates, which have been specified for the aggregates

Theoretical Framework on the Role of Knowledge Management for Students on Academic Performance

Knowledge management is a developing sector that has received lots of consideration and support from the community which is industrial. Knowledge management is a young academic field which has not been built up a systematized and unified framework. This paper reviews the role of knowledge management for students on academic performance by using the structural equation modeling. Through applying knowledge management in the study process can help students to gain better results. As a result, it can be expected to shed light on the relative importance of knowledge management on students’ academic performance. Keywords: Knowledge management, Academic performance, digital economy DOI: 10.7176/IKM/11-2-05 Publication date:March 31st 202

Interaction Between Two Charged-Hardcore Soft Particles

During two last decades, theories of soft-particles has been introduced and developed in order to describe the behavior of bacteria and virus which can be considered as the bio-colloid particles. Soft particles are assumed to be consist of a rigid core inside an ion-permeable shell. The outer layer is always negatively charged while the core can be neutral or charged. In this paper, we investigate the interaction between two identical soft-particles with charged core. We derived the analytic formula for the interaction energy in a compact form. We showed that this interaction energy involving a screened Coulomb-like interaction term with a distance-independent coefficient. The numerical calculations showed that the interaction energy has very small amplitude and exponentially decay on the distance between the soft particles. The results indicate that it is possible to measure this kind of interaction energy when the system is put into a salt solution with the concentration low enough

The validation of organisational culture assessment instrument in healthcare setting: results from a cross-sectional study in Vietnam

BACKGROUND: Organisational culture (OC) has increasingly become a crucial factor in defining healthcare practice and management. However, there has been little research validating and adapting OCAI (organisational culture assessment instrument) to assess OC in healthcare settings in developing countries, including Vietnam. The purpose of this study is to validate the OCAI in a hospital setting using key psychometric tests and confirmatory factor analysis (CFA). METHODS: This is a cross-sectional study. Self-administered structured questionnaire was completed by 566 health professionals from a Vietnamese national general hospital, the General Hospital of Quang Nam province. The psychometric tests and CFA were utilized to detect internal reliability and construct validity of the instrument. RESULTS: The Cronbach\u27s alpha coefficients (alpha-reliability statistic) ranged from 0.6 to 0.8. In current culture, the coefficient was 0.80 for clan and 0.60 for adhocracy, hierarchy and market dimension, while in expected culture, the coefficient for clan, adhocracy, hierarchy, and market dimension was 0.70, 0.70, 0.70 and 0.60, respectively. The CFA indicated that most factor loading coefficients were of moderate values ranging from 0.30 to 0.60 in both current and expected culture model. These models are of marginal good fit. CONCLUSIONS: The study findings suggest that the OCAI be of fairly good reliability and construct validity in measuring four types of organisational culture in healthcare setting in resource-constrained countries such as Vietnam. This result is a first step towards developing a valid Vietnamese version of the OCAI which can also provide a strong case for future research in the field of measuring and managing organisational culture

Human Centered Development of SAE-2 Automation for Truck Driving

Compared with passenger cars, automating driving functions for trucks and understanding related driver behaviour are considerably less advanced, potentially due to difficulties accessing relevant technology and subject matter experts (SMEs). Project HALC's (HighwayAssist with Lane Change) first objective was to develop the HALC system, which is an automation assisting truck drivers on highways. The system performs longitudinal and lateral control of commercial trucks, including lane changes. To optimally support truck drivers' interactions with the HALC system, we developed its functionality and human-machine interface (HMI) in close cooperation with SMEs. As an SAE level 2 (SAE International, 2014) type automation, the system may require drivers to resume control anytime. Thus, the second objective was to develop a monitoring system to ensure drivers' takeover readiness. The project's third objective was to understand better truck driver behaviour based on data collected within the project. This knowledge was then used to inform the HALC system's design and implementation

Biological activities of essential oil extracted from leaves of Atalantia sessiflora Guillauminin Vietnam

Introduction: The present study aimed to determine the chemical compositions and bioactivities of the essential oil of Atalantia sessifloraGuillaumin (A. sessiflora), including antibacterial, antimycotic, antitrichomonas, anti-inflammatory and antiviral effects. Methodology: The essential oil from leaves of A. sessiflora was extracted by hydrodistillation using a Clevenger apparatus. Chemical compositions of oil were identified by GC/MS. Antimicrobial and antitrichomonas activity were determined by the microdilution method; anti-inflammatory and antiviral were determined by the MTT method. Results: The average yield of oil was 0.46 ± 0.01% (v/w, dry leaves). A number of 45 constituents were identified by GC/MS. The essential oil comprised four main components. The oil showed antimicrobial activities against Gram-positive strains as Staphylococcus; Gram-negative bacteria such as Klebsiella pneumoniae and Escherichia coli; and finally four Candidaspecies. Enterococcus faecalis and Pseudomonas aeruginosawere least susceptible to the oil of A. sessiflora, as seen in their MIC and MLC values over 16% (v/v). Activity against Trichomonas vaginalis was also undertaken, showing IC50, IC90 and MLC values of 0.016, 0.03 and 0.06% (v/v) respectively, after 48 hours of incubation. The oil of A. sessiflora displayed activity against the nitric oxide generation with the IC50 of 95.94 ± 6.18 μg/mL. The oil was completely ineffective against tested viruses, ssRNA+, ssRNA-, dsRNA, and dsDNA viruses. Conclusions: This is the first yet comprehensive scientific report about the chemical compositions and pharmacological properties of the essential oil of A. sessiflora. Further studies should be done to evaluate the safety and toxicity of A. sessiflora oil

HỢP CHẤT STEROID VÀ FLAVONE TỪ THÂN RỄ THIÊN NIÊN KIỆN LÁ LỚN (Homalomena pendula)

Phytochemical investigation of the rhizomes of Homalomena pendula resulted in the isolation of one flavone and three steroids. These compounds were determined as tangeretin (1), ergosterol peroxide (2), sitoindoside I (3), and stigmasterol (4) on the basis of 1D and 2D NMR data and in comparison with the available data in the literature. Compounds 1‒3 were found for the first time from the genus Homamomena. The n-hexane and ethyl acetate extracts show NO production inhibitory activity in RAW 264.7 macrophage cells with IC50 values of 46.8 and 75.52 µg·mL–1.Hợp chất flavone, tangeretin (1), và ba hợp chất steroid: ergosterol peroxide (2), sitoindoside I (3) và stigmasterol (4) đã được phân lập từ thân rễ của cây thiên niên kiện lá lớn (Homalomena pendula). Cấu trúc hóa học của chúng được xác định dựa trên phân tích dữ liệu phổ cộng hưởng từ hạt nhân (1D và 2D NMR) và so sánh với các tài liệu đã công bố. Các hợp chất (1-3) được phân lập lần đầu tiên từ chi Homalomena. Cao chiết n-hexane và ethyl acetate của cây này có hoạt tính ức chế sản sinh NO trên đại thực bào RAW 264.7 kích thích bằng lipopolysaccharide với các giá trị IC50 là 46,80 và 75,52 µg·mL–1