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- 摘要
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- 实验方案
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[IEEE 2019 International 3D Systems Integration Conference (3DIC) - Sendai, Japan (2019.10.8-2019.10.10)] 2019 International 3D Systems Integration Conference (3DIC) - Development of Laser-Assisted Bonding with Compression (LABC) Process for 3D IC Integration
摘要： Laser-Assisted Bonding with Compression (LABC) technology with NCF was proposed to accomplish the productivity and process reliability at the same time. A quartz block as a header was used to deliver a pressure to the devices because of its extremely low absorption of the laser during the bonding process. Newly developed NCF for LABC was designed to have stability on a hot stage and to show solder wetting and fast curing with no void and optimal fillet during the LABC bonding process. As the laser is used as a heat source, the uniform heat should be provided on each interconnection without any damages on chip or a substrate. 780μm-thick daisy chain top and bottom chips with the minimum pitch of 30μm and bump number of about 27,000 were successfully bonded using the LABC and NCF film.
关键词： throughput,non-conductive film,laser-assisted bonding,bonding performance,TCB,thermal compression bonding,NCF,LABC,compression
更新于2025-09-23 15:21:01
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A Single-Stage Low-Power AC-DC RGB-LED Driver with Switching Capacitor Control Scheme
摘要： The High Efficiency Video Coding (HEVC) standard (ITU-T H.265 and ISO/IEC 23008-2) has been developed with the main goal of providing significantly improved video compression compared with its predecessors. In order to evaluate this goal, verification tests were conducted by the Joint Collaborative Team on Video Coding of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29. This paper presents the subjective and objective results of a verification test in which the performance of the new standard is compared with its highly successful predecessor, the Advanced Video Coding (AVC) video compression standard (ITU-T H.264 and ISO/IEC 14496-10). The test used video sequences with resolutions ranging from 480p up to ultra-high definition, encoded at various quality levels using the HEVC Main profile and the AVC High profile. In order to provide a clear evaluation, this paper also discusses various aspects for the analysis of the test results. The tests showed that bit rate savings of 59% on average can be achieved by HEVC for the same perceived video quality, which is higher than a bit rate saving of 44% demonstrated with the PSNR objective quality metric. However, it has been shown that the bit rates required to achieve good quality of compressed content, as well as the bit rate savings relative to AVC, are highly dependent on the characteristics of the tested content.
关键词： Moving Picture Experts Group (MPEG),H.265,MPEG-H Part 2,Video Coding Experts Group (VCEG),High Efficiency Video Coding (HEVC),video compression,Advanced Video Coding (AVC),Joint Collaborative Team on Video Coding (JCT-VC),standards
更新于2025-09-23 15:21:01
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SBS pulse compression using bulk fused silica by diode-pumped solid-state lasers at 1??kHz repetition rate
摘要： This study is focused on constructing a highly stable diode-pumped solid-state laser system by conducting experiments on high-repetition-rate SBS pulse compression using bulk fused silica. A multi-rod serial-connection structure is adopted for SBS expriments by comparing K8 glass and fused silica medium at a 10 Hz repetition rate. The optimized structure is obtained according to variation of the pump power density. Based on the optimized structure, fused silica-based SBS pulse compression is carried out in the range of 100–1000 Hz and the parameter performance of laser system after compression is also evaluated by comparing a HT270 liquid medium. Experimental results indicate that the energy e?ciency of fused silica-based SBS is improved by approximately 40% compared with that of K8 glass. Further, the energy relative standard deviation of fused silica-based SBS is reduced by approximately 88% compared with HT270 medium, indicating that bulk fused silica is advantageous for high-repetition-rate SBS pulse compression because of its un-?uidity, high thermal conductivity and power-load ability. In addition, a 1 kHz highly-stable sub-nanosecond compressed pulse is achieved using bulk fused silica medium at a pump energy of 50 mJ. Furthermore, the SBS energy e?ciency can be further improved by increasing the input energy.
关键词： Pulse compression,High repetition rate,Solid-state lasers,Sub-nanosecond pulse,Stimulated Brillouin scattering (SBS)
更新于2025-09-23 15:21:01
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Increasing Fracture Toughness and Transmittance of Transparent Ceramics using Functional Low-Thermal Expansion Coatings
摘要： Transparent polycrystalline ceramics have the potential to enable applications no other materials can, but to do so their strength and toughness must be improved. However, surface strengthening treatments like those used for glasses have so far remained elusive. Here for the first time, we report on engineering unprecedented surface compression, of the magnitude achieved for ion-exchange strengthened glasses (~750 MPa) in transparent ceramics. This was achieved by applying functional, low thermal-expansion yttria coatings onto yttria-stabilized zirconia substrates and thermally treating. In some instances, the treatment more than doubled the fracture toughness while simultaneously increasing light transmittance.
关键词： surface compression,transparent ceramics,fracture toughness,thermal-expansion mismatch,yttria coatings
更新于2025-09-23 15:21:01
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Secure Image Compression Approach based on Fusion of 3D Chaotic Maps and Arithmetic Coding
摘要： The advances in digital image processing and communications have created a great demand for real–time secure image transmission over the networks. However, the development of effective, fast and secure dependent image compression encryption systems are still a research problem as the intrinsic features of images such as bulk data capacity and high correlation among pixels hinds the use of the traditional joint encryption compression methods. A new approach is suggested in this paper for partial image encryption compression that adopts chaotic 3D cat map to de-correlate relations among pixels in conjunction with an adaptive thresholding technique that is utilized as a lossy compression technique instead of using complex quantization techniques and also as a substitution technique to increase the security of the cipher image. The proposed scheme is based on employing both of lossless compression with encryption on the most significant part of the image after contourlet transform. However the least significant parts are lossy compressed by employing a simple thresholding rule and arithmetic coding to render the image totally unrecognizable. Due to the weakness of 3D cat map to chosen plain text attack, the suggested scheme incorporates a mechanism to generate random key depending on the contents of the image (context key). Several experiments were done on benchmark images to insure the validity of the proposed technique. The compression analysis and security outcomes indicate that the suggested technique is an efficacious and safe for real time image’s applications.
关键词： Cryptography,Chaotic maps,Joint compression encryption,Contourlet transform,Thresholding,Arithmetic coding
更新于2025-09-23 15:21:01
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Joint Image Compression and Encryption Using IWT with SPIHT, Kd-Tree and Chaotic Maps
摘要： Confidentiality and efficient bandwidth utilization require a combination of compression and encryption of digital images. In this paper, a new method for joint image compression and encryption based on set partitioning in hierarchical trees (SPIHT) with optimized Kd-tree and multiple chaotic maps was proposed. First, the lossless compression and encryption of the original images were performed based on integer wavelet transform (IWT) with SPIHT. Wavelet coefficients undergo diffusions and permutations before encoded through SPIHT. Second, maximum confusion, diffusion and compression of the SPIHT output were performed via the modified Kd-tree, wavelet tree and Huffman coding. Finally, the compressed output was further encrypted with varying parameter logistic maps and modified quadratic chaotic maps. The performance of the proposed technique was evaluated through compression ratio (CR) and peak-signal-to-noise ratio (PSNR), key space and histogram analyses. Moreover, this scheme passes several security tests, such as sensitivity, entropy and differential analysis tests. According to the theoretical analysis and experimental results, the proposed method is more secure and decreases the redundant information of the image more than the existing techniques for hybrid compression and encryption.
关键词： k-dimensional tree,chaotic maps,set partition in hierarchical trees,integer wavelet transform,encryption,image compression
更新于2025-09-23 15:21:01
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Ytterbium laser system for studying parametric amplification of femtosecond pulses with a centre wavelength of a??2 ??m
摘要： A laser system is developed with an optical synchronisation of a femtosecond signal with a pump channel. The signal of a driving ytterbium fibre laser with a 60 MHz repetition rate of stretched femtosecond pulses is amplified in energy from several nanojoules to 0.4 mJ at a pulse repetition rate of 3 kHz in a wide-band amplifier and then is compressed in time to 250 fs. The obtained radiation is used for generating femtosecond laser pulses with a centre wavelength of ~2 mm, pulse energy of above 20 mJ, duration of several field oscillations, and phase stabilisation between the electromagnetic field and envelope. The other pulse of the driving fibre laser provides optical synchronisation and a minimal time delay and is directed to a regenerative Yb : YAG disk amplifier for amplification to an energy of 4 mJ at a pulse repetition rate of 3 kHz and duration of 20 ps. A multipass disk amplifier is developed for further increasing the energy of pump chirped pulses to an energy of 70 mJ at a pulse repetition rate of 10 Hz and duration of 400 ps for studying parametric amplification under sub-nanosecond pumping.
关键词： parametric amplification,Yb :YAG disk amplifier,ytterbium fibre laser,femtosecond pulses,pulse compression
更新于2025-09-23 15:19:57
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[IEEE 2019 Sixth Iranian Conference on Radar and Surveillance Systems - Isfahan, Iran (2019.12.4-2019.12.6)] 2019 Sixth Iranian Conference on Radar and Surveillance Systems - A Novel Two-Way Gysel Power Divider Based on Ridge-Gap Waveguide Technology
摘要： An iterative turbo decoder-based cross layer error recovery scheme for compressed video is presented in this paper. The soft information exchanged between two convolutional decoders is reinforced both by channel coded parity and video compression syntactical information. An algorithm to identify the video frame boundaries in corrupted compressed sequences is formulated. This paper continues to propose algorithms to deduce the correct values for selected fields in the compressed stream. Modifying the turbo extrinsic information using these corrections acts as reinforcements in the turbo decoding iterative process. The optimal number of turbo iterations suitable for the proposed system model is derived using EXIT charts. Simulation results reveal that a transmission power saving of 2.28% can be achieved using the proposed methodology. Contrary to typical joint cross layer decoding schemes, the additional resource requirement is minimal, since the proposed decoding cycle does not involve the decompression function.
关键词： EXIT charts,mobile communication,iterative decoding,video compression,Combined source channel coding,turbo codes
更新于2025-09-23 15:19:57
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Radiative and Nonradiative Tunneling in Nanowire Light-Emitting Diodes
摘要： This paper aims to highlight distinctive features of the SP theory of intelligence, realized in the SP computer model, and its apparent advantages compared with some AI-related alternatives. Perhaps most importantly, the theory simplifies and integrates observations and concepts in AI-related areas, and has potential to simplify and integrate of structures and processes in computing systems. Unlike most other AI-related theories, the SP theory is itself a theory of computing, which can be the basis for new architectures for computers. Fundamental in the theory is information compression via the matching and unification of patterns and, more specifically, via a concept of multiple alignment. The theory promotes transparency in the representation and processing of knowledge, and unsupervised learning of natural structures via information compression. It provides an interpretation of aspects of mathematics and an interpretation of phenomena in human perception and cognition. Abstract concepts in the theory may be realized in terms of neurons and their inter-connections (SP-neural). These features and advantages of the SP system are discussed in relation to AI-related alternatives: the concept of minimum length encoding and related concepts, how computational and energy efficiency in computing may be achieved, deep learning in neural networks, unified theories of cognition and related research, universal search, Bayesian networks and some other models for AI, IBM’s Watson, solving problems associated with big data and in the development of intelligence in autonomous robots, pattern recognition and vision, the learning and processing of natural language, exact and inexact forms of reasoning, representation and processing of diverse forms of knowledge, and software engineering. In conclusion, the SP system can provide a firm foundation for the long-term development of AI and related areas, and at the same time, it may deliver useful results on relatively short timescales.
关键词： information compression,unsupervised learning,perception,reasoning,multiple alignment,cognition,deep learning,mathematics,neural networks,Artificial intelligence
更新于2025-09-23 15:19:57
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Research on Synchronous Control Method for Suppressing Nonlinear Impulse Perturbation of Photovoltaic Grid-Connected Inverter
摘要： We study universal compression of sequences generated by monotonic distributions. We show that for a monotonic distribution over an alphabet of size , each probability parameter costs essentially bits, where is the coded sequence length, as long as . Otherwise, for , the total average sequence redundancy is bits overall. We then show that there exists a sub-class of monotonic distributions over infinite alphabets for which redundancy of bits overall is still achievable. This class contains fast decaying distributions, including many distributions over the integers such as the family of Zipf distributions and geometric distributions. For some slower decays, including other distributions over the integers, redundancy of bits overall is achievable. A method to compute specific redundancy rates for such distributions is derived. The results are specifically true for finite entropy monotonic distributions. Finally, we study individual sequence redundancy behavior assuming a sequence is governed by a monotonic distribution. We show that for sequences whose empirical distributions are monotonic, individual redundancy bounds even tighter than those in the average case can be obtained. The relation of universal compression with monotonic distributions to universal compression of patterns of sequences is demonstrated.
关键词： large alphabets,universal compression,individual redundancy,monotonic distributions,Average redundancy,patterns
更新于2025-09-23 15:19:57