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Factors that affect the technological transition of firms toward the industry 4.0 technologies
Get PDFThis research identifies factors that affect the technological transition of firms toward industry 4.0 (IT) technologies focusing on capabilities and policy impacts using relatedness and complexity measures. For the analysis, a unique dataset was used of Korean manufacturing firms??? patents and their financial and market information. Following the Principle of Relatedness, which is a recently shaped empirical principle in the field of economic complexity, economic geography, and regional studies, a technology space is built, and each firm???s footprint in the space is traced. Using the firms??? technology space can identify those firms that successfully develop new I4 technologies and can examine whether their accumulated capabilities in their previous technology domains positively affect their technological diversification and which factors play a critical role in their transition towards I4. In addition, combining data on whether the firms received government support for R&D activities can help further analyze the role of government policy in supporting firms??? knowledge activities in new I4 technologies. Firms with higher related technologies and more government support are more likely to engage in new I4 technologies. This research is expected to inform policymakers who intend to diversify firms??? technological capabilities towards I4 technologies
Development of clothing-type platforms considering pressure and user satisfaction: focusing on industrial workers who tend to lift loads
No full textThe purpose of this study was to develop a clothing-type platform of wearable robots for industrial workers who usually lift loads to prevent accidents and increase their work efficiency. First, fabrics were selected through test analyses of the elongation recovery rate and tensile strength. Second, a suit-type platform embedded with electrostatic clutch band actuators was prototyped and measured the friction force, and a washing dimension change rate of the test with the platform was conducted. Third, clothing pressures were measured after the developed prototype was worn, using an air injection sensor system at nine points and with four motions. Next, subjective clothing pressure and satisfaction surveys were conducted. The study produced four major results: (a) the selected fabrics and the prototype with the electrostatic clutch actuator met the performance requirements; (b) the greatest clothing pressure occurred at the back, back waist, and back knee, where actuators were connected, and the clothing pressure was sufficient for positional stability; (c) the subjective pressure was different in each section from the actual clothing pressure measurement; and (d) participants were satisfied with the developed prototypes, and they showed willingness to purchase them. The results can help developers of wearable robots increase comfort and user satisfaction
Effects of emission trading scheme (ETS) on change rate of carbon emission
Get PDFThis paper investigates the effects of Emission Trading Scheme (ETS) adoption on the country-level reduction rate of carbon emission. We first used Environmental Kuznets Curve (EKC) tests to group countries into three categories: inverse U-shaped and gamma-shaped EKC for decoupled countries, and a positive linear EKC for non-decoupled countries. We then examined the effectiveness of ETS adoption. We found ETS was effective for both post-industrial and pre-industrial economies. Compared to countries that have not adopted ETS, the carbon emission reduction (increment) rate of decoupled (non-decoupled) countries that have adopted ETS is faster (slower). Furthermore, ETS adoption significantly reduces overall carbon emissions per capita compared to other global events, such as oil crises. The results imply that a market-based mechanism is an effective strategy for achieving sustainable development, thus, providing insights for policymakers and governments to design effective carbon neutrality policies to achieve sustainable development
East Asian VLBI Network astrometry toward the extreme outer Galaxy: Kinematic distance with the proper motion of G034.84-00.95
No full textWe aim to reveal the structure and kinematics of the Outer Scutum-Centaurus (OSC) arm located on the far side of the Milky Way through very long baseline interferometry (VLBI) astrometry using KaVA, which is composed of KVN (the Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). We report the proper motion of a 22 GHz H2O maser source, which is associated with the star-forming region G034.84-00.95, to be (mu(alpha)cos delta, mu(delta)) = (-1.61 & PLUSMN; 0.18, -4.29 & PLUSMN; 0.16) mas yr(-1) in equatorial coordinates (J2000.0). We estimate the 2D kinematic distance to the source to be 18.6 & PLUSMN; 1.0 kpc, which is derived from the variance weighted average of kinematic distances with local standard of rest velocity and the galactic-longitude component of the measured proper motion. Our result places the source in the OSC arm and implies that G034.84-00.95 is moving away from the Galactic plane with a vertical velocity of -38 & PLUSMN; 16 km s(-1). Since the H i supershell GS033+06-49 is located at a kinematic distance roughly equal to that of G034.84-00.95, it is expected that gas circulation occurs between the outer Galactic disk around G034.84-00.95 with a Galactocentric distance of 12.8<^>{+1.0}_{-0.9}\:kpc and the halo. We evaluate possible origins of the fast vertical motion of G034.84-00.95, which are (1) supernova explosions and (2) cloud collisions with the Galactic disk. However, neither of these possibilities are matched with the results of VLBI astrometry or the spatial distributions of H ii regions and H i gas
Vacuum pressure swing adsorption for efficient off-gas recycling: Techno-economic and CO2 abatement study
No full textWe suggest a vacuum pressure swing adsorption that uses CuCl/Boehmite adsorbent as a novel material to efficiently recycle a blast furnace gas into the blast furnace and discuss the techno-economic and CO2 abatement impact. To identify the crucial factors of the separation, five cases are simulated: three adsorption pressures at moderate CO purity, and three purity levels at moderate adsorption pressure. Also, the coke-replacement effects are estimated through the blast furnace simulation to consider the economic benefits. The result shows that the energy efficiency of the separation process varied 72-82%, and injection of highly purified off-gas (99% purity) was the most economically profitable, giving 86.7 US-MM$ of net present value. Cost sensitivity showed that the coke price is the most influential, but the adsorbent cost and carbon taxes have relatively little effect. In the best case, the coke-replacement ratio is 0.26kgCoke m(gas)(-3). The suggested process reduces net emission by 0.19tCO(2)-eq t(HM)(-1) , and this corresponds to the 10% of net reduction which is the competitive strategy compared with the renewable hydrogen blast furnace. This study broadened the understanding of the separation process for off-gas recycling, and optimization of the process should be studied further
Bona fide stochastic resonance under nonGaussian active fluctuations
No full textWe report on the experimental observation of stochastic resonance (SR) in a nonGaussian active bath without any periodic modulation. A Brownian particle hopping in a nanoscale double-well potential under the influence of nonGaussian correlated noise, with mean interval tau(P) and correlation time tau(c), shows a series of equally-spaced peaks in the residence time distribution at integral multiples of tau(P). The strength of the first peak is found to be maximum when the mean residence time (tau)(d) matches the double condition, 4 tau(c) asymptotic to tau(P) asymptotic to(tau)(d)/2, demonstrating a new type of bona fide SR. The experimental findings agree with a simple model that explains the emergence of SR without periodic modulation of the double-well potential. Additionally, we show that generic SR under periodic modulation, known to degrade in strongly correlated continuous noise, is recovered by the discrete nonGaussian kicks
Theoretical Studies on Thermally Activated Delayed Fluorescence Mechanism of Au(III) Complexes in Films: Insights from Quantum Mechanics/Molecular Mechanics Simulations
No full textOrganometallic complexes usually exhibit thermally activated delayed fluorescence (TADF) emission in films. However, the surrounding effects on TADF have not been explored and the underlying photophysical mechanism remains elusive. In this study, we have investigated structures, spectroscopic characteristics, radiative and nonradiative rates, and luminescence mechanisms of three Au(III) complexes in films using DFT and time-dependent DFT approaches combined with molecular dynamics and quantum mechanics/molecular mechanics simulations. The results show that the S1 and T1 states are of ligand-toligand charge transfer character owing to the efficient separation of the HOMO and the LUMO. Proper spin-orbit couplings and small energy gaps between the S1 and T1 states benefit the reverse intersystem crossing process enabling TADF. Moreover, the film environments play key roles in regulating geometric structures, electronic properties, and thereto luminescence. These results provide insights into understanding the TADF mechanism of organometallic complexes in films
Effective and Efficient Core Computation in Signed Networks
No full textWith the proliferation of mobile technology and IT development, people can use social network services anywhere and anytime. Among many social network mining problems, identifying cohesive subgraphs has attracted extensive atten-tion from different fields due to its numerous applications. The most widely used among many cohesive subgraph models is k-core, because of its simple and intuitive structure. In this paper, we formulate (p, n)-core in signed networks by extending the k-core model. (p, n)-core is designed to guarantee sufficient internal positive edges and deficient internal negative edges. We formally prove that finding an exact (p, n)-core is NP-hard. Hence, we propose three efficient and effective algorithms to find a solution. We demonstrate the superiority of our proposed algorithms using real-world and synthetic networks
Diffusion-Limited Accepter Alloy Enables Highly Efficient and Stable Organic Solar Cells
No full textOrganic solar cells (OSCs) are designed based on a blend of polymer donor and small molecular acceptor whereby the thermodynamic relaxation of the morphology raises the concerns related to operational stability. Herein, it is demonstrated that the classical Y6-based binary device can be stabilized by using its derivative of ZCCF3 as the third component, which is designed with the replacing of the thiadiazole group on Y6 with the trifluoromethyl substituted diazepine unit. ZCCF3 delivers not only higher glass transition temperature (T-g) than Y6 but also have hyper-miscibility with Y6, contributing to a favorable diffusion-limited Y6:ZCCF3 alloy when blended with polymer donor. Consequently, a champion power conversion efficiency of 18.54% is achieved in the optimal PM6: Y6: ZCCF3 devices, which can retain their 80% initial efficiency of up to 360 h. This study highlights the importance of high T-g of the third component and its derived hyper-miscible accepter alloys in achieving highly efficient and stable OSCs