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Secure beamforming and deployment design for rate-splitting multiple access-based UAV communications

Science China(Information Sciences) 2025年第1期68卷 342-356页

作者： Bing WANG Xiaofeng TAO Shujun HAN Huici WU Kai YANG Zhu HAN National Engineering Research Center of Mobile Network Technologies Beijing University of Posts and Telecommunications Peng cheng Laboratory Department of Electrical and Computer Engineering University of Houston

Rate-splitting multiple access(RSMA) has recently gained attention as a potential robust multiple access(MA)scheme for upcoming wireless networks. Given its ability to efficiently utilize wireless resources and design interference management strategies, it can be applied to unmanned aerial vehicle(UAV) networks to provide convenient services for large-scale access ground users. However, due to the line-of-sight(LoS) broadcast nature of UAV transmission, information is susceptible to eavesdropping in RSMA-based UAV networks. Moreover, the superposition of signals at the receiver in such networks becomes complicated. To cope with the challenge, we propose a two-user multi-input single-output(MISO) RSMA-based UAV secure transmission framework in downlink communication networks. In a passive eavesdropping scenario, our goal is to maximize the sum secrecy rate by optimizing the transmit beamforming and deployment location of the UAV-base station(UAV-BS),while considering quality-of-service(QoS) constraints, maximum transmit power, and flight space limitations. To address the non-convexity of the proposed problem, the optimization problem is first decoupled into two subproblems. Then, the successive convex approximation(SCA) method is employed to solve each subproblem using different propositions. In addition, an alternating optimization(AO)-based location RSMA(L-RSMA) beamforming algorithm is developed to implement joint optimization to obtain the suboptimal solution. Numerical results demonstrate that(1) the proposed L-RSMA scheme yields a28.97% higher sum secrecy rate than the baseline L-space division multiple access(SDMA) scheme;(2) the proposed L-RSMA scheme improves the security performance by 42.61% compared to the L-non-orthogonal multiple access(NOMA) scheme.

关键词： rate-splitting multiple access UAV communication precoding optimization deployment location physical layer security

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Examination of DMT-based methods for evaluating the liquefaction potential of soils

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2011年第11期12卷 807-817页

作者： Gordon Tung-Chin kung Der-Her LEE Pai-Hsiang TSAI Sustainable Environment Research Center National Cheng Kung University Department of Civil Engineering National Cheng Kung University

The flat dilatometer test （DMT） has the potential to be a useful tool in the evaluation of liquefaction potential of soils. In practice, it is necessary to carefully examine existing DMT-based methods for evaluating liquefaction potential. We con- ducted the DMT and cone penetration test （CPT） in high liquefaction potential areas to examine the existing DMT-based methods for liquefaction potential evaluation. Specifically, the DMT and CPT were conducted side-by-side at each of six in-situ sites, and thus it is feasible to utilize those test results to validate the existing DMT-based methods. The DMT parameter, horizontal stress index （KD）, is used as an indicator for estimating liquefaction resistance of soils in terms of cyclic resistance ratio （CRR）. The analysis results revealed that the existing KD-based liquefaction evaluation methods would overestimate the CRR of soils, which leads to overestimation of the factor of safety against liquefaction. Also, the estimations of DMT-KI~ values by using the CPT-qc as well as the correlation between DMT-KD and CPT-qc proposed by the previous studies would be significantly smaller than field measurements. The results reflected that further validation of the existing DMT-based methods for liquefaction evaluation is desirable.

关键词： Liquefaction Flat dilatometer test (DMT) Horizontal stress index Earthquake

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NUMERICAL SIMULATION OF SOLITARY WAVE RUN-UP AND OVER-TOPPING USING BOUSSINESQ-TYPE MODEL

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Journal of Hydrodynamics 2012年第6期24卷 899-913页

作者： TSUNG Wen-Shuo HSIAO Shih-Chun LIN Ting-Chieh Department of Hydraulic and Ocean Engineering National Cheng Kung University Tainan Hydraulics Laboratory National Cheng Kung University

In this article, the use of a high-order Boussinesq-type model and sets of laboratory experiments in a large scale flume of breaking solitary waves climbing up slopes with two inclinations are presented to study the shoreline behavior of breaking and non-breaking solitary waves on plane slopes. The scale effect on run-up height is briefly discussed. The model simulation capability is well validated against the available laboratory data and present experiments. Then, serial numerical tests are conducted to study the shoreline motion correlated with the effects of beach slope and wave nonlinearity for breaking and non-breaking waves. The empirical formula proposed by Hsiao et al. for predicting the maximum run-up height of a breaking solitary wave on plane slopes with a wide range of slope inclinations is confirmed to be cautious. Furthermore, solitary waves impacting and overtopping an impermeable sloping seawall at various water depths are investigated. Laboratory data of run-up height, shoreline motion, free surface elevation and overtopping discharge are presented. Comparisons of run-up, run-down, shoreline trajectory and wave overtopping discharge are made. A fairly good agreement is seen between numerical results and experimental data. It elucidates that the present depth-integrated model can be used as an efficient tool for predicting a wide spectrum of coastal problems.

关键词： Boussinesq equations solitary wave run-up shoreline scale effect overtopping

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Solution Combustion Synthesis of TiO_2 and Its Use for Fabrication of Photoelectrode for Dye-sensitized Solar Cell

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Journal of Materials Science & Technology 2012年第8期28卷 713-722页

作者： Shyan-Lung Chung Ching-Mei Wang Department of Chemical Engineering National Cheng Kung University Advanced Optoelectronic Technology Center National Cheng Kung University

Three different types of TiO2 nano powders were synthesized by a solution combustion synthesis （SCS） method using three different fuels and for comparison, another type of Ti2 nano powder was synthesized by calcination of titanyl hydroxide. These TiO2 nano powders were used to fabricate photoelectrodes for the dye-sensitized solar cell （DSSC） and their performance was compared to that of the DSSC fabricated with Degussa P25 TiO2. The results showed that the SCS TiO2 could work well as photoelectrode for DSSC. The SCS TiO2 contained impurities of C and/or S, thus exhibiting visible light absorption and reduced band gap. The open circuit voltage and the fill factor both varied little among the various TiO2 and thus both had little effect on the photoelectrical conversion efficiency （η）. However, the variation of r/was seen to be in quite a good agreement with that of the short circuit current （Isc）, suggesting that r/was dominated by Isc. lsc was found to be enhanced by light scattering effect due to the presence of large particles but reduced by high impurity content due to an increase in electron transfer resistance. In addition, the specific surface area of the powders was found to be an important factor affecting the Isc and thus the η.

关键词： TiO2 Combustion synthesis Dye-sensitized solar cells

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Features associated with progression of small pancreatic cystic lesions: A retrospective study

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World Journal of Gastroenterology 2015年第47期21卷 13309-13315页

作者： Hong-Ming Tsai Chiao-Hsiung Chuang Yan-Shen Shan Yi-Sheng Liu Chiung-Yu Chen Department of Radiology National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Internal Medicine National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Surgery National Cheng Kung University Hospital College of Medicine National Cheng Kung University

AIM: To investigate the progression rate of small pancreatic cystic lesions and identify characteristics associated with their ***: Patients with pancreatic cystic lesions with at least 1-year of follow-up were evaluated retrospectively. We excluded patients with cysts larger than 3 cm or with features that were a concern for malignancy. In total, 135 patients were evaluated. The interval progression of the cysts was examined. Characteristics were compared between patients with and without ***: The pancreatic cysts ranged from 3 to 29 mm. The mean follow-up period was 4.5 ± 2.3 years and the mean progression rate was 1.0 ± 1.3 mm/year. Ninety patients showed interval progression and were divided into two groups; the minimal-change group(n = 41), who had cyst progression at less than 1 mm/year, and the progression group(n = 49), who had a progression rate of more than 1 mm/year. Compared with the cysts without progression, the lesions of the progression group were more frequently associated with tubular cyst, septation or a prominent pancreatic duct(P < 0.05). The odds ratio for progression was 5.318 for septation and 4.582 for tubular ***: Small pancreatic cysts progress slowly. Lesions with tubular shape, septa, or prominent pancreatic duct were more likely to progress, and required further diagnostic intervention or shorter surveillance interval.

关键词： Pancreas Cystic lesion Progression Imaging features Observation

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Infra-Gravity Wave Generation by the Shoaling Wave Groups over Beaches

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China Ocean Engineering 2012年第1期26卷 1-18页

作者： LIN Yu-Hsien HWUNG Hwung-Hweng Fishing Boat and Marine Engineering Research Center National Cheng-Kung University National cheng-kung university

A physical parameter, fib, which was used to meet the forcing of primary short waves to be off-resonant before wave breaking, has been considered as an applicable parameter in the infra-gravity wave generation. Since a series of modulating wave groups for different wave conditions are perfonned to proceed with the resonant mechanism of infra- gravity waves prior to wave breaking, the amplitude growth of incident bound long wave is assumed to be simply controlled by the normalized bed slope, fib. The results appear a large dependence of the growth rate, a, of incident bound long wave, separated by the three-array method, on the normalized bed slope, fib. High spatial resolution of wave records enables identification of the cross-correlation between squared short-wave envelopes and infra-gravity waves. The cross- shore structure of infra-gravity waves over beaches presents the mechanics of incident bound- and outgoing free long waves with the formation of free standing long waves in the nearshore region. The wave run-up and amplification of infra-gravity waves in the swash zone appear that the additional long waves generated by the breaking process would modify the cross-shore structure of free standing long waves. Finally, this paper would further discuss the contribution of long wave breaking and bottom friction to the energy dissipation of infra-gravity waves based on different slope conditions.

关键词： infra-gravity wave low-frequency wave surf zone swash zone

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Progesterone receptor membrane component 1 as a potential prognostic biomarker for hepatocellular carcinoma

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World Journal of Gastroenterology 2018年第10期24卷 1152-1166页

作者： Hung-Wen Tsai Chung-Liang Ho Shu-Wen cheng Yih-Jyh Lin Chou-cheng Chen Pin-Nan cheng Chia-Jui Yen Ting-Tsung Chang Po-Min Chiang Shih-Huang Chan cheng-Hsun Ho Shu-Hui Chen Yi-Wen Wang Nan-Haw Chow Jou-Chun Lin Institute of Clinical Medicine National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Pathology National Cheng Kung University Hospital College of Medicine National Cheng Kung University Institute of Basic Medical Sciences College of Medicine National Cheng Kung University Center of Infectious Disease and Signaling Research College of Medicine National Cheng Kung University Department of Surgery National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Internal Medicine National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Statistics College of Management National Cheng Kung University Research Center of Clinical Medicine National Cheng Kung University Hospital College of Medicine National Cheng Kung University Department of Chemistry College of Sciences National Cheng Kung University

AIM To investigate the clinicopathological significance of progesterone receptor membrane component 1(PGRMC1) and PGRMC2 in hepatocellular carcinoma(HCC). METHODS We performed immunohistochemical staining to evaluate the estrogen receptor(ER), progesterone receptor(PR), PGRMC1, and PGRMC2 in a clinical cohort consisting of 89 paired HCC and non-tumor liver samples. We also analyzed HCC data(n = 373) from The Cancer Genome Atlas(TCGA). We correlated the expression status of PGRMC1 and PGRMC2 with clinicopathological indicators and the clinical outcomes of the HCC patients. We knocked down or overexpressed PGRMC1 in HCC cell lines to evaluate its biological significance in HCC cell proliferation, differentiation, migration, and invasion. RESULTS We found that few HCC cases expressed ER(5.6%) and PR(4.5%). In contrast, most HCC cases expressed PGRMC1(89.9%) and PGRMC2(100%). PGRMC1 and PGRMC2 exhibited significantly lower expression in tumor tissue than in non-tumor tissue(P < 0.001). Lower PGRMC1 expression in HCC was significantly associated with higher serum alpha-fetoprotein expression(P = 0.004), poorer tumor differentiation(P = 0.045) and liver capsule penetration(P = 0.038). Low PGRMC1 expression was an independent predictor for worse disease-free survival(P = 0.002, HR = 2.384,CI: 1.377-4.128) in our cases, as well as in the TCGA cohort(P < 0.001, HR = 2.857, CI: 1.781-4.584). The expression of PGRMC2 did not relate to patient outcome. PGRMC1 knockdown promoted a poorly differentiated phenotype and proliferation of HCC cells in vitro, while PGRMC1 overexpression caused the opposite *** PGRMC1 is a non-classical hormonal receptor that negatively regulates hepatocarcinogenesis. PGRMC1 down-regulation is associated with progression of HCC and is a poor prognostic indicator.

关键词： progesterone receptor membrane component 1 hormonal receptor proliferation hepatocellular carcinoma prognosis

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Analysis of Wave Directional Spreading by Bayesian Parameter Estimation

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China Ocean Engineering 2002年第1期17卷 89-105页

作者：钱桦莊士贤高家俊 Institute of Hydraulic and Ocean Engineering Cheng Kung University Coastal Ocean Montioring Center Cheng Kung University

A spatial array of wave gauges installed on an observatoion platform has been designed and arranged to measure the local features of winter monsoon directional waves off Taishi coast of Taiwan. A new method, named the Bayesian Parameter Estimation Method(BPEM), is developed and adopted to determine the main direction and the directional spreading parameter of directional spectra. ne BPEM could be considered as a regression analysis to find the maximum joint probability of parameters, which best approximates the observed data from the Bayesian viewpoint. The result of the analysis of field wave data demonstrates the highly dependency of the characteristics of normalized directional spreading on the wave age. The Mitsuyasu type empirical formula of directional spectrum is therefore modified to be representative of monsoon wave field. Moreover, it is suggested that S-max could be expressed as a function of wave steepness. The values of S-max decrease with increasing steepness. Finally, a local directional spreading model, which is simple to be utilized in engineering practice, is proposed.

关键词： directional wave spectrum Bayesian theorem wave age

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Constitutive modelling of composite laminates under uniaxial compression

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Chinese Journal of Aeronautics 2019年第4期32卷 938-947页

作者： Hsuan-Teh HU Lung-Shen KE Department of Civil Engineering ‘‘National" Cheng Kung University

A nonlinear constitutive model for a single lamina is proposed for the failure analysis of composite laminates. In the material model, both fiber and matrix are assumed to behave elasticplastically and the in-plane shear is assumed to behave nonlinearly with a variable shear *** damage onset for individual lamina is detected by a mixed failure criterion, composed of the Tsai-Wu criterion and the maximum stress criterion. After damage takes place within the lamina,the fiber and in-plane shear are assumed to exhibit brittle behavior, and the matrix is assumed to exhibit degrading behavior. The proposed nonlinear material model is tested against experimental data of composite laminates subjected to uniaxial compressive loads, and good agreement is obtained.

关键词： Composite laminates Constitutive model Finite element analysis Nonlinearity Uniaxial compression

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Detecting changes in long-period site responses after the M_w 7.6 Chi-Chi earthquake, Taiwan, using strong motion records

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Earthquake Engineering and Engineering Vibration 2015年第2期14卷 217-228页

作者： Teng-To Yu Chi-Shin Wu Youg-Sin cheng Department of Resources Engineering Cheng Kung University (NCKU)

Temporal changes in site effects are obtained using the HVSR(horizontal-to-vertical spectral ratio) method and strong motion records after the M w 7.6 Chi-Chi earthquake, Taiwan. Seismic data recorded between 1995 and 2010 are used, comprising 3,708 data from 15 stations adjacent to the Chelungpu fault. Temporal fl uctuations are determined by analyzing the site effect variation using a time–frequency variation(TFV) diagram based on these seismic data. Stations adjacent to the fault show signifi cant disturbances in the resonance frequency at 16–26 Hz. Station TCU129 shows a 40% drop in fundamental frequency after the main shock, and a gradual return to the original state over nine years. For stations located farther from the fault zone, sudden changes in tectonic stress play a dominant role in temporal changes to the HVSR. An impact analysis of the directional factor confi rms our fi nding that the proximity of the fault to seismic stations has the most infl uence on data.

关键词： Chi-Chi earthquake horizontal-to-vertical spectral

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