304 research outputs found

    The impact of China's Indigenous innovation strategy on the innovation behaviour of automobile enterprises in China

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    China's indigenous innovation strategy is a government-led innovation strategy in the term of pushing forward the technology development both in the state-owned enterprises and in the private enterprises. It was codified in the "Medium- and Long-Term National Science and Technology development Plan (2006-2020)" which was officially announced in 2006. There are several policy tools as the support to the indigenous innovation strategy. ļ¬ R&D funding ļ¬ Mega projects sponsored by government ļ¬ Public procurement ļ¬ Tax reduction ļ¬ Standards and patents Automobile industry is normally regarded as the pillar of the economy as it is both labor intensive and capital intensive. It combines a lot of industries like steel industry, chemical industry, electronics industry, etc. Before 1980s, Chinese automobile industry concentrated on the commercial vehicle manufacture. Since 1980 the government started to be aware of the passenger car industry. Because of shortage of capital and technology, joint-venture was regarded as the only choice to get a rapid development for the passenger car industry at the cost of opening the market to the foreign automobile enterprises. This is a case of the famous "exchange market for technology" strategy, which is generally regarded as an aborted strategy 30 years later even though the Chinese government never officially acknowledges. In the beginning of 2000s, more than half of the Chinese passenger car market was occupied by the China-made foreign brand cars. Before the year of 2000, there are two types of automobile manufactures in China, one is state-owned enterprises, the other is the joint-ventures set up by the state-owned enterprises and their foreign partners most of which were the top automobile enterprises in the world like Volkswagen, GM, Toyota, etc. From 2000, the private capital was permitted to enter the automobile industry and became the third type of automobile enterprises in China. Not only in automobile industry, but also in many other industries, the failure of the "exchange market for technology" happened. Even more is that the advantage of low labor cost is losing under the competition from the emerging countries like India, Vietnam, etc. The Chinese government has the willing to turn from "world factory" to an innovation-driven country for the economic development in the future. The indigenous innovation strategy is put forward to try to solve those problems. After the indigenous innovation strategy being push forward, the new innovation system is emerging. This thesis is to research on the change of the innovation behavior both in industry level and enterprise level under the impact of the indigenous innovation strategy. Key words: indigenous innovation strategy, IPR strategy, patent applications, automobile industr

    A Wireless Covert Channel Based on Constellation Shaping Modulation

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    Wireless covert channel is an emerging covert communication technique which conceals the very existence of secret information in wireless signal including GSM, CDMA, and LTE. The secret message bits are always modulated into artificial noise superposed with cover signal, which is then demodulated with the shared codebook at the receiver. In this paper, we first extend the traditional KS test and regularity test in covert timing channel detection into wireless covert channel, which can be used to reveal the very existence of secret data in wireless covert channel from the aspect of multiorder statistics. In order to improve the undetectability, a wireless covert channel for OFDM-based communication system based on constellation shaping modulation is proposed, which generates additional constellation points around the standard points in normal constellations. The carrier signal is then modulated with the dirty constellation and the secret message bits are represented by the selection mode of the additional constellation points; shaping modulation is employed to keep the distribution of constellation errors unchanged. Experimental results show that the proposed wireless covert channel scheme can resist various statistical detections. The communication reliability under typical interference is also proved

    Shaking Table Test and Time-history Analysis of High-rise Diagrid Tube Structure

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    As a new type of high-rise building structure system, diagridtube in tube structure is increasingly applied in high-rise building.Guangzhou West tower is the first high-rise diagrid tube intube structure in China. To study seismic performance of thestructure, elastic time-history analysis and shaking table testwere conducted. The results of elastic time-history analysis andshaking table test were in a good agreement, which verified thevalidity of the elastic time-history analysis. Dynamic characteristicsand responses of the model structureā€™s acceleration,displacement and strain under different intensity earthquakeaction were obtained through analysis and test. Dynamicresponses of prototype structure were deduced based on similaritylaw and shaking table test results. Research shows thatdiagrid tube structure has a small deformation under earthquakeactions; the main vibration mode is translation, whiletorsional effect is not obvious; whiplash effect has less influenceon the structure; diagrid members, diagrid nodes andshear walls at the bottom of the structure are weak parts

    Unsupervised Skin Lesion Segmentation via Structural Entropy Minimization on Multi-Scale Superpixel Graphs

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    Skin lesion segmentation is a fundamental task in dermoscopic image analysis. The complex features of pixels in the lesion region impede the lesion segmentation accuracy, and existing deep learning-based methods often lack interpretability to this problem. In this work, we propose a novel unsupervised Skin Lesion sEgmentation framework based on structural entropy and isolation forest outlier Detection, namely SLED. Specifically, skin lesions are segmented by minimizing the structural entropy of a superpixel graph constructed from the dermoscopic image. Then, we characterize the consistency of healthy skin features and devise a novel multi-scale segmentation mechanism by outlier detection, which enhances the segmentation accuracy by leveraging the superpixel features from multiple scales. We conduct experiments on four skin lesion benchmarks and compare SLED with nine representative unsupervised segmentation methods. Experimental results demonstrate the superiority of the proposed framework. Additionally, some case studies are analyzed to demonstrate the effectiveness of SLED.Comment: 10 pages, 8 figures, conference. Accepted by IEEE ICDM 202

    A Tough Metalā€Coordinated Elastomer: A Fatigueā€Resistant, Notchā€Insensitive Material with an Excellent Selfā€Healing Capacity

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    Self-healing materials can prolong device life, but their relatively weak mechanical strength limits their applications. Introducing tunable metal-ligand interactions into self-healing systems can improve their mechanical strength. However, applying this concept to solid elastomers is a challenge. To address this need, polyurethane-containing metal complexes were fabricated by introduction of a pyridine-containing ligand into polyurethane, and subsequent coordination with Fe2+. The strong reversible coordination bond provides mechanical strength and self-healing ability. By optimizing the monomer ratio and Fe2+ content, the resulting complex possesses a very high tensile strength of 4.6MPa at strain of around 498% and a high Young's modulus (3.2MPa). Importantly, the metal complex exhibits an extremely high self-healing efficiency of approximately 96% of tensile strength at room temperature and around 30% at 5 degrees C. The complex is notch-insensitive and the fracture energy is 76186J/m(2), which is among the highest reported values for self-healing systems

    Preparation of graphene/aligned carbon nanotube array composite films for thermal packaging applications

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    Vertically aligned carbon nanotube arrays (VACNTs) have been successfully achieved by CVD. The carbon nanotubes were almost triple-walled. Furthermore, the graphene/VACNT composite films have been prepared as thermal interface materials, using photolithographic and densification processes. Compared with pure epoxy resin, the longitudinal thermal conductivity of the composite films was obviously improved, which confirmed that VACNTs provided additional longitudinal heat transfer channels in the films. Furthermore, their longitudinal thermal conductivity was largely dependent on the distribution of VACNTs. The transversal thermal conductivity of the composite film with a pattern size of 300 mu m was about seven times higher than that of pure epoxy resin. This indicated that graphene provided additional horizontal heat transfer channels to achieve the enhancement of transversal thermal conductivity in composite films. (C) 2019 The Japan Society of Applied Physic

    Effects of Musical Tempo on Musiciansā€™ and Non-musiciansā€™ Emotional Experience When Listening to Music

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    Tempo is an important musical element that affects humanā€™s emotional processes when listening to music. However, it remains unclear how tempo and training affect individualsā€™ emotional experience of music. To explore the neural underpinnings of the effects of tempo on music-evoked emotion, music with fast, medium, and slow tempi were collected to compare differences in emotional responses using functional magnetic resonance imaging (fMRI) of neural activity between musicians and non-musicians. Behaviorally, musicians perceived higher valence in fast music than did non-musicians. The main effects of musicians and non-musicians and tempo were significant, and a near significant interaction between group and tempo was found. In the arousal dimension, the mean score of medium-tempo music was the highest among the three kinds; in the valence dimension, the mean scores decreased in order from fast music, medium music, to slow music. Functional analyses revealed that the neural activation of musicians was stronger than those of non-musicians in the left inferior parietal lobe (IPL). A comparison of tempi showed a stronger activation from fast music than slow music in the bilateral superior temporal gyrus (STG), which provided corresponding neural evidence for the highest valence reported by participants for fast music. Medium music showed stronger activation than slow music in the right Heschlā€™s gyrus (HG), right middle temporal gyrus (MTG), right posterior cingulate cortex (PCC), right precuneus, right IPL, and left STG. Importantly, this study confirmed and explained the connection between music tempo and emotional experiences, and their interaction with individualsā€™ musical training
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