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Evolution of technology management system based on self-organization theory

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Journal of Systems Engineering and Electronics 2021年第6期32卷 1439-1449页

作者： wu weiwei MA Qian LIU Yexin YANG Ying YUE Suzhen School of Management Harbin Institute of TechnologyHarbin 150006China Beijing Institute of Aerospace Information Beijing 100854China School of Economics and Management Harbin Institute of Technology at WeihaiWeihai 264209China School of Finance and Economics Shenzhen Institute of Information TechnologyShenzhen 518172China

Industrial and academic interest in how to effectively manage technology resources is increasing as it becomes more and more *** managing of technology resources depends on technology management system,and thus understanding how such system evolves becomes an ongoing research *** on the self-organization theory,this paper constructs an evolution model of technology management *** simulation results show that the evolution of each of the technology management subsystem is affected by the knowledge growth rate of its own,and it is also affected by the coupling and synergy relationship with other ***,the coupling and synergy relationship can make the speed of evolution higher than the knowledge growth rate of the subsystem itself.

关键词： technology management technology management system self-organization

Highly efficient and stable perovskite solar cells with strong hydrophobic barrier via introducing poly(vinylidene fluoride)additive

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Journal of Energy Chemistry 2021年第6期30卷 593-600,I0014页

作者： Haiying Zheng Guozhen Liu weiwei wu Huifen Xu Xu Pan Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601AnhuiChina Key Laboratory of Photovoltaic and Energy Conservation Materials Institute of Solid State PhysicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031AnhuiChina

Perovskite solar cells(PSCs)have become the promising next-generation photovoltaic devices due to their excellent photoelectric performances,and the power conversion efficiencies(PCEs)have experienced unprecedented rapid increase in recent ***,to realize the practical application of PSCs,high performance and long-term stability are required and the preparation of high-quality perovskite film is the ***,we adopt a simple and effective method to prepare high-quality perovskite films by introducing the poly(vinylidene fluoride)(PVDF)polymer additive with abundant hydrophobic *** the growth template,the PVDF promotes the growth of perovskite crystal,improves the crystallinity and film morphology,thus reducing defect density and inhibiting carrier *** results show that the photovoltaic performances of the perovskite device with PVDF are meaningfully improved,and a high PCE of 21.42%is achieved with an improvement of 10.87%,More importantly,the PVDF-based perovskites display greatly enhanced humidity and heat stability due to the protection of strong hydrophobic barrier from F and PVDF long *** at 45%±5%relative humidity(RH)for 2400 h and 850 C for300 h,respectively,the unsealed PVDF devices can maintain over 90%of the initial *** indicates that suitable polymer additives can improve the film quality to acquire high-performance and stable PSCs and lay a foundation to design new perovskite light absorption layer with different polymers for the further development of PSCs.

关键词： Perovskite solar cells Poly(vinylidene fluoride) Polymer additive Hydrophobic barrier Long-term stability

Impact of the synergy between technology management and technological capability on new product development:a system dynamics approach

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Journal of Systems Engineering and Electronics 2022年第1期33卷 105-119页

作者： MA Qian wu weiwei LIU Yexin LIANG Zhou KOU Lingzhi School of Management Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Aerospace Information Beijing 100854China School of Economics and Management Harbin Institute of Technology at WeihaiWeihai 264209China

This paper employs system dynamics to explore how the synergy between technology management and technological capability affects new product *** results show that the synergy between technology management and technological capability has positive impact on new product ***, the leading synergy processes between technology management and technological capability in different new product development stages are *** paper deepens the theoretical understanding of how to achieve new product development, and also provides useful guidance for firms to implement new product development.

关键词： technology management technological capability new product development system dynamics

SWG: an architecture for sparse weight gradient computation

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Science China(Information Sciences) 2024年第2期67卷 302-321页

作者： weiwei wu Fengbin TU Xiangyu LI Shaojun WEI Shouyi YIN School of Integrated Circuits Tsinghua University Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology

On-device training for deep neural networks(DNN) has become a trend due to various user preferences and scenarios. The DNN training process consists of three phases, feedforward(FF), backpropagation(BP), and weight gradient(WG) update. WG takes about one-third of the computation in the whole training process. Current training accelerators usually ignore the special computation property of WG and process it in a way similar to FF/BP. Besides, the extensive data sparsity existing in WG, which brings opportunities to save computation, is not well explored. Nevertheless, exploiting the optimization opportunities would meet three underutilization problems, which are caused by(1) the mismatch between WG data dimensions and hardware parallelism,(2) the full sparsity, i.e., the sparsity of feature map(Fmap),error map(Emap), and gradient, and(3) the workload imbalance resulting from irregular sparsity. In this paper, we propose a specific architecture for sparse weight gradient(SWG) computation. The architecture is designed based on hierarchical unrolling and sparsity-aware(HUSA) dataflow to exploit the optimization opportunities of the special computation property and full data sparsity. In HUSA dataflow, the data dimensions are unrolled hierarchically on the hardware architecture. A valid-data trace(VDT) mechanism is embedded in the dataflow to avoid the underutilization caused by the two-sided input sparsity. The gradient is unrolled in PE to alleviate the underutilization induced by output sparsity while maintaining the data reuse opportunities. Besides, we design an intra-and inter-column balancer(IIBLC) to dynamically tackle the workload imbalance problem resulting from the irregular sparsity. Experimental results show that with HUSA dataflow exploiting the full sparsity, SWG achieves a speedup of 12.23× over state-of-the-art gradient computation architecture, Train Ware. SWG helps to improve the energy efficiency of the state-of-the-art training accelerator LNPU from

关键词： CNN training gradient computation sparsity architecture

A transceiver frequency conversion module based on 3D micropackaging technology

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Journal of Systems Engineering and Electronics 2020年第5期31卷 899-907页

作者： LIU Boyuan WANG Qingping wu weiwei YUAN Naichang School of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China

The idea of Ku-band transceiver frequency conversion module design based on 3D micropackaging technology is proposed. By using the double frequency conversion technology,the dual transceiver circuit from Ku-band to L-band is realized by combining with the local oscillator and the power control circuit to complete functions such as amplification, filtering and gain. In order to achieve the performance optimization and a high level of integration of the Ku-band monolithic microwave integrated circuits(MMIC) operating chip, the 3 D vertical interconnection micro-assembly technology is used. By stacking solder balls on the printed circuit board(PCB), the technology decreases the volume of the original transceiver to a miniaturized module. The module has a good electromagnetic compatibility through special structure designs. This module has the characteristics of miniaturization, low power consumption and high density, which is suitable for popularization in practical application.

关键词： Ku-band frequency conversion 3D packaging chip electromagnetic compatibility

Ultrastable and ultrasensitive pH-switchable carbon dots with high quantum yield for water quality identification,glucose detection,and two starch-based solid-state fluorescence materials

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Nano Research 2020年第11期13卷 3012-3018页

作者： Daiyong Chao Jinxing Chen Qing Dong weiwei wu Desheng Qi Shaojun Dong College of Chemistry Jilin UniversityChangchun130012China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

It is attractive and encouraging to develop new fluorescent carbon dots(CDs)with excellent optical properties and promising applications ***,highly-efficient green emissive CDs(m-CDs)with a high quantum yield(QY)of 71.7%in water are prepared through a facile solvothermal ***,the m-CDs exhibit excellent fluorescence stability in the pH range of 1–***,the fluorescence intensity of the m-CDs is almost completely quenched as the pH is increased from 9 to *** mechanism of the unique pH-responsive behavior is discussed in detail and a plausible mechanism is *** to the unique pH-responsive behavior,the m-CDs are used as a on-off fluorescent probe for water quality *** combining the reversible pH-ultrasensitive optical properties of the m-CDs in the pH range of 9–10 with the glucose oxidase-mimicking(GOx-mimicking)ability of Au nanoparticles(AuNPs),glucose can be quantitatively ***,two environment-friendly starch-based solid-state fluorescence materials(powder and film)are developed through green preparation routes.

关键词： carbon dot high quantum yield pH-ultrasensitive optical properties water quality identification glucose detection solid-state fluorescence materials

Variations in China's terrestrial water storage over the past decade using GRACE data

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Geodesy and Geodynamics 2015年第3期6卷 187-193页

作者： Zhao Qian wu weiwei wu Yunlong Institute of Earthquake Science China Earthquake Administration College of Surveying and Geo-Informatics Engineering Tongji University Key Laboratory of Earthquake Geodesy Institute of Seismology China Earthquake Administration

Variations in China’s terrestrial water storage from March 2003 to February 2013 were determined using data from the Gravity Recovery and Climate Experiment(GRACE)monthly gravity field model provided by the Center for Space Research. The results were compared with the variations in surface water estimated using the Global Land Data Assimilation System(GLDAS) hydrological model. The results indicated a decline in terrestrial water storage in the Shanxi and Xinjiang Tianshan regions over the past decade with a downward trend that reached 7.76 ± 0.71 mm/a and 5.8 ± 0.67 mm/a, respectively. Anthropogenic activities were considered to be the major cause of this terrestrial water loss(especially groundwater) in these regions. In contrast, the intersection of the Xinjiang and Tibet Autonomous Regions and the Qinghai Province showed an upward trend in the terrestrial water storage at a rate of 9.06 ± 0.37 mm/a, which is closely related to the high-quality local ecological environment and lack of human activities. At the intersections between the Chongqing, Guizhou, and Hunan Provinces and between the Jiangxi, Zhejiang, and Fujian Provinces, the terrestrial water storage increased at rates of7.86 ± 0.9 and 8.68 ± 0.8 mm/a, respectively. These two regions received abundant annual precipitation; moreover, there was no considerable variation in the amount of groundwater storage over the past decade. In addition, the empirical orthogonal function(EOF) method used in this study could eliminate correlated errors in the GRACE monthly gravity field model more effectively than the traditional polynomial fitting method, and it did not generate false signals.

关键词： EOF(Empirical orthogonal function) GRACE(Gravity R

Effectiveness of empirical orthogonal function used in decorrelation of GRACE time-variable gravity field

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Geodesy and Geodynamics 2015年第5期6卷 324-332页

作者： Zhao Qian wu Yunlong wu weiwei Institute of Earthquake Science China Earthquake Administration Key Laboratory of Earthquake Geodesy Institute of Seismology China Earthquake Administration College of Surveying and Geo-Informatics Engineering Tongji University

Empirical orthogonal function （EOF） was used to process the spherical harmonic coefficient （SHC） of 115 Gravity Recovery and Climate Experiment （GRACE） RL05 monthly gravity field models from March 2003 to February 2013 released by CSR （Center for Space Research）. We analyzed the effectiveness of EOF in decorrelation of gravity field. Results show that only a small Gaussian smoothing radius was needed by EOF to significantly weaken the north -south stripes compared with the empirical moving-window filtering algorithm. The comparative experiments with a Global Land Data Assimilation System （GLDAS） hydrological model also show that EOF did not much affect the real geophysical signals, and that the removed signals were nearly uncorrelated with the real geophysical signals. As the Gravity Recovery and Climate Experiment （GRACE） missions continue, EOF can be used to significantly remove the correlated errors from monthly gravity fields and reserve rich effective signals.

关键词： Empirical orthogonal functionGravity recovery and climateexperiment (GRACE) gravity fieldDeeorrelationTerrestrial water storageGlobal Land Data AssimilationSystem (GLDAS)

Study of a New Type of SIW End Slot Antenna at X-Band

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Chinese Journal of Electronics 2014年第4期23卷 862-865页

作者： wu weiwei ZHAO Hongyu HUANG Jingjian FENG Qi WANG Chao Department of Electronic Science and Engineering National University of Defense Technology

A new type of Substrate integrated waveguide end slot antenna(SIWESA) radiating from the waveguide end of a Substrate integrated waveguide(SIW) at Xband is investigated with simulation and experiment in this paper. A novel SIW transmission line and a SIWTL end matching network are developed to transfer the energy from the coaxial line to the SIW end radiating slot. This whole antenna is fabricated on a microwave substrate with standard PCB process. The simulated results of a single SIWESA are in good agreement with the experiment ***, a 4-element array are fabricated and measured. The good tested results and the low-cost PCB process fabrication technology demonstrate that SIWESA is a new candidate for the phased arrays.

关键词： Slot antenna Substrate integrated waveguide(SIW) SIW transmission line Matching network