241 research outputs found

    EVALUATING BARRIERS TO INDUSTRY 4.0 ADOPTION IN ASIAN MANUFACTURING ENTERPRISES: A FUNNEL PLOT ANALYSIS APPROACH

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    Industry 4.0 (I4.0) has attracted significant attention in manufacturing fields, but its implementation success rate remains low, particularly among Asian countries facing barriers. This study synthesizes key challenges to I4.0 adoption in Asian manufacturing, drawing on funnel plot analysis and a systematic review of Scopus database entries to evaluate reliability and publication bias. The study’s validity is reinforced by a systematic review process, while its reliability is established through the rigorous application of funnel plot analysis to evaluate publication bias, thereby providing a comprehensive understanding of these barriers. Important barriers identified include a lack of technical skills, high implementation costs, limited IT literacy, concerns around data security, and unclear returns on investment (ROI), among others. These findings offer actionable insights for addressing I4.0 implementation challenges and support successful adoption across diverse manufacturing contexts in Asia. While some barriers receive less immediate attention, they act as underlying causes that trigger other, more critical barriers, creating a compound effect on I4.0 adoption. Exploring the interconnections among barriers through advanced analytical methods is crucial to uncovering their cascading effects and developing integrated strategies to address them. In addition, future research should include country-specific empirical studies to further understand regional variations and unique factors impacting I4.0 adoption

    TRENDS IN THE SCIENTIFIC LITERATURE ON THE LEAGILE SUPPLY CHAIN: BIBLIOMETRIC AND CITATION CONTEXT ANALYSES

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    Leagile is a hybrid of conventional lean and agile approaches intended to eliminate specific constraints and capacity limitations and enable agility in highly competitive business environments. Interest in incorporating lean and agile into the supply chain has grown in recent years, as shown by the growing number of scientific publications on this topic. This topic has garnered significant interest across a wide range of academic disciplines; however, a comprehensive study of the literature in this field has not yet been conducted. Therefore, the present study aims to provide a state-of-the-art summary of leagile supply chain issues that concern researchers. To do so, we use a bibliometric method, combined with citation context analysis, to evaluate data extracted from Scopus peer-reviewed articles published between 1999 and March 2023. Data analytic techniques, including citation analysis, co-citation analysis, and co-word (co-occurrence) analysis, are used. Using rigorous bibliometric and visualization tools, the results show the current status of the research problem, its impact, and suggestions for future work to address research gaps, such as a problem in an area of research that has been answered incompletely or insufficiently. The findings suggest that researchers in unexplored research areas in the ASEAN region include green supply chain strategies, supply chain risk management influenced by lean and agile strategies, and comparative analyses among ASEAN countries. These areas offer promising avenues for future research, contributing to regional competitiveness and performance enhancement

    Performance Evaluation of Pre-foamed Ultra-lightweight Composites Incorporating Various Proportions of Slag

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    This research examines the feasibility of using a mixture of cement, fly ash, ground granulated blast-furnace slag, and river sand to manufacture pre-foamed ultra-lightweight composite (PULC). Four PULC specimens were prepared with the substitution of cement by slag at 0, 10, 20, and 30 % by weight. The engineering properties of PULC samples were evaluated through the tests of compressive strength, dry density, water absorption, drying shrinkage, and thermal conductivity. Besides, numerical simulation of heat transfer through the PULC brick wall and the microstructure observation were performed. The performance of PULC mixtures incorporating slag showed higher effectiveness than merely used cement. The substitution of 20 % cement by slag resulted in the highest compressive strength as well as the lowest value of water absorption of the PULC samples. Also, the efficiency of the thermal conductivity was in inverse proportion with the density of PULC specimens and it was right for water absorption and drying shrinkage. Moreover, numerical simulations showed that the temperature distribution values in the wall made by PULC material were smaller than in the wall made by the normal clay brick in the same position. Besides, the microstructure analysis revealed that the existence of slag generated a more dense structure of PULC samples with the addition of calcium-silicate-hydrate (C-S-H) gel, especially for a mix containing 20 % slag. Thus, the results of this study further demonstrated that a 20 % slag was the optimal content for the good engineering properties of the PULC samples

    Jellyfish search algorithm for economic load dispatch under the considerations of prohibited operation zones, load demand variations, and renewable energy sources

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    This paper suggests a modified version of the former economic load dispatch (MELD) problem with the integration of wind power plant (WPP) and solar power plants (SPP) into thermal units (TUs). The target of the whole study is to cut the total producing electricity cost (TPEC) as much as possible. Three meta-heuristic algorithms, including particle swarm optimization (PSO), jellyfish search (JS) and salp swarm algorithm (SSA), are applied to solve the MELD. The real performance of these optimization tools is tested on the first system with six thermal units considering prohibited zones, and the second system with the combination of the first system and one solar, and two WPPs. In addition, the variation of load demand in 24 hours per day is also taken into account in the second system. JS is proved to be the most effective method for dealing with MELD. Furthermore, JS can also reach lower or the same TPEC as other previous algorithms. Hence, JS is a recommended to be a strong computing method for dealing with the MELD problem.

    Single phase second order sliding mode controller for complex interconnected systems with extended disturbances and unknown time-varying delays

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    Novel results on complex interconnected time-delay systems with single phase second order sliding mode control is investigated. First, a reaching phase in traditional sliding mode control (TSMC) is removed by using a novel single phase switching manifold function. Next, a novel reduced order sliding mode observer (ROSMO) with lower dimension is suggested to estimate the unmeasurable variables of the plant. Then, a new single phase second order sliding mode controller (SPSOSMC) is established based on ROSMO tool to drive the state variables into the specified switching manifold from beginning of the motion and reduce the chattering in control input. Then, a stability condition is suggested based on the well-known linear matrix inequality (LMI) method to ensure the asymptotical stability of the whole plant. Finally, an illustrated example is simulated to validate the feasible application of the suggested technique

    Observer-based single-phase robustness sliding mode controller for the pitch control of a variable speed wind turbine

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    In this paper, a new observer-based single-phase robustness sliding mode controller (SPRSMC) is proposed for the pitch control of a variable speed wind turbine (VSWT) systems. The finding of this research includes two tasks: i) to ensure a global stability of the VSWT plant, the reaching phase in traditional sliding mode control (TSMC) technique is eliminated and ii) to guess the immeasurable variables of VSWT plants, a novel pitch angle output feedback controller is constructed based on the estimator tool and output information only. Firstly, a single-phase switching function is determined to eject the reaching phase in TSMC. Moreover, an immeasurable variable of the VSWT system is estimated by employing the suggested estimator tool. Next, a SPRSMC for VSWT plant is built based on the support of the estimator instrument and output data only. Furthermore, an appropriate requirement is founded by utilizing the linear matrix inequality (LMI) method for ensuring the robust stability of motion dynamics in sliding mode. Finally, the solution of the suggested control is confirmed the three-blade wind turbine with a 5-MW utilizing the wind turbine simulator fatigue, aerodynamics, structures, and turbulence (FAST) code and the National Renewable Energy Laboratory (NREL)

    Triolein from Coix Lacryma-Jobi Induces Cell Cycle Arrest through P53/P21Signaling Pathway

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    The Relationship between Online Learning and Student Satisfaction with Training Quality in Private Universities during the COVID-19 Pandemic

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    This study aims to explore the relationship between the influential factors of online learning and the satisfaction of economics and business majors with the quality of their training in the context of the Covid-19 pandemic. A total of 900 students in private universities completed a questionnaire. The principal findings of this research are that the students are satisfied with their online learning and that learning conferencing software is the most important driving factor leading to the students’ satisfaction when compared with learning conditions and learning devices. Another interesting finding is that the experience of using learning conferencing software results in a slight difference in the students’ perceived level of satisfaction, adding that users with more than two years’ experience are more satisfied with their training quality than users with less than one year’s experience. However, the results also show that students want to switch to offline learning when the pandemic is over. This study should, therefore, be of value to higher education authorities wishing to understand their students’ perceptions of online learning. In addition, results from the study suggest more managerial approaches as well as improve the online teaching quality during the pandemic

    The cryomechanical design of MUSIC: a novel imaging instrument for millimeter-wave astrophysics at the Caltech Submillimeter Observatory

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    MUSIC (Multicolor Submillimeter kinetic Inductance Camera) is a new facility instrument for the Caltech Submillimeter Observatory (Mauna Kea, Hawaii) developed as a collaborative effect of Caltech, JPL, the University of Colorado at Boulder and UC Santa Barbara, and is due for initial commissioning in early 2011. MUSIC utilizes a new class of superconducting photon detectors known as microwave kinetic inductance detectors (MKIDs), an emergent technology that offers considerable advantages over current types of detectors for submillimeter and millimeter direct detection. MUSIC will operate a focal plane of 576 spatial pixels, where each pixel is a slot line antenna coupled to multiple detectors through on-chip, lumped-element filters, allowing simultaneously imaging in four bands at 0.86, 1.02, 1.33 and 2.00 mm. The MUSIC instrument is designed for closed-cycle operation, combining a pulse tube cooler with a two-stage Helium-3 adsorption refrigerator, providing a focal plane temperature of 0.25 K with intermediate temperature stages at approximately 50, 4 and 0.4 K for buffering heat loads and heat sinking of optical filters. Detector readout is achieved using semi-rigid coaxial cables from room temperature to the focal plane, with cryogenic HEMT amplifiers operating at 4 K. Several hundred detectors may be multiplexed in frequency space through one signal line and amplifier. This paper discusses the design of the instrument cryogenic hardware, including a number of features unique to the implementation of superconducting detectors. Predicted performance data for the instrument system will also be presented and discussed
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