Cross-Layer Resource Allocation in Multi-interface Multi-channel Wireless Multi-hop Networks

Wei Feng,Suili Feng,Yongzhong Zhang3,Xiaowei Xia 한국전자통신연구원 2014 ETRI Journal Vol.36 No.6

In this paper, an analytical framework is proposed forthe optimization of network performance through jointcongestion control, channel allocation, rate allocation,power control, scheduling, and routing with theconsideration of fairness in multi-channel wireless multihopnetworks. More specifically, the framework modelsthe network by a generalized network utilitymaximization (NUM) problem under an elastic link datarate and power constraints. Using the dual decompositiontechnique, the NUM problem is decomposed into foursubproblems — flow control; next-hop routing; rateallocation and scheduling; power control; and channelallocation — and finally solved by a low-complexitydistributed method. Simulation results show that theproposed distributed algorithm significantly improves thenetwork throughput and energy efficiency compared withprevious algorithms.

Comprehensive review on physical properties of supercritical carbon dioxide calculated by molecular simulation

Gaoliang Liao,Yuntao Du,Feng Zhang,Jiaqiang E 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.1

The applications of molecular simulation in supercritical carbon dioxide (S-CO2) and its mixtures are reviewed. First, an overview of physical properties of S-CO2 and CO2 models is given. Secondly, the accuracy of S-CO2 thermodynamic and transport properties calculated by different models is compared. It shows that Zhang’s model has relatively better global accuracy in calculating thermodynamic properties. EPM2, Zhang and Cygan models have similar accuracy when calculating transport properties based on equilibrium molecular simulation (EMD) method, but generally have higher deviations when calculating thermal conductivity. Therefore, EMD and non-equilibrium molecular simulation (NEMD) methods have been compared in calculating thermal conductivity. The results show that NEMD is better than EMD but the process is complicated. The structural properties are also discussed in this part. Thirdly, the applications of molecular simulation in S-CO2 binary organic, binary inorganic and multiple mixtures are reviewed. Finally, the summary and the prospect of future works are given.

Determination of Survival of Gastric Cancer Patients With Distant Lymph Node Metastasis Using Prealbumin Level and Prothrombin Time: Contour Plots Based on Random Survival Forest Algorithm on High-Dimensionality Clinical and Laboratory Datasets

Zhang, Cheng,Xie, Minmin,Zhang, Yi,Zhang, Xiaopeng,Feng, Chong,Wu, Zhijun,Feng, Ying,Yang, Yahui,Xu, Hui,Ma, Tai The Korean Gastric Cancer Association 2022 Journal of gastric cancer Vol.22 No.2

Purpose: This study aimed to identify prognostic factors for patients with distant lymph node-involved gastric cancer (GC) using a machine learning algorithm, a method that offers considerable advantages and new prospects for high-dimensional biomedical data exploration. Materials and Methods: This study employed 79 features of clinical pathology, laboratory tests, and therapeutic details from 289 GC patients whose distant lymphadenopathy was presented as the first episode of recurrence or metastasis. Outcomes were measured as any-cause death events and survival months after distant lymph node metastasis. A prediction model was built based on possible outcome predictors using a random survival forest algorithm and confirmed by 5×5 nested cross-validation. The effects of single variables were interpreted using partial dependence plots. A contour plot was used to visually represent survival prediction based on 2 predictive features. Results: The median survival time of patients with GC with distant nodal metastasis was 9.2 months. The optimal model incorporated the prealbumin level and the prothrombin time (PT), and yielded a prediction error of 0.353. The inclusion of other variables resulted in poorer model performance. Patients with higher serum prealbumin levels or shorter PTs had a significantly better prognosis. The predicted one-year survival rate was stratified and illustrated as a contour plot based on the combined effect the prealbumin level and the PT. Conclusions: Machine learning is useful for identifying the important determinants of cancer survival using high-dimensional datasets. The prealbumin level and the PT on distant lymph node metastasis are the 2 most crucial factors in predicting the subsequent survival time of advanced GC.

NUMERICAL MODELING OF VERTICAL-2D UNSTEADY FLOW AND SUSPENDED MATERIAL DISTRIBUTION

ZHANG XIAO-FENG,FENG XIAO-XIANG,CUI ZHAN-FENG 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Enhancement of transglutaminase production in Streptomyces mobaraensis DSM 40587 by non-nutritional stress conditions: Effects of heat shock, alcohols, and salt treatments

Lili Zhang,Lanwei Zhang,Huaxi Yi,Ming Du,Yingchun Zhang,Xue Han,Zhen Feng,Jingyan Li,Yuehua Jiao,Yanhe Zhang,Chunfeng Guo 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.7

Stress-mediated bioprocess is a strategy designed to enhance biological target productivity. In this study,an attempt was made to enhance transglutaminase (TGase) production by Streptomyces mobaraensis by using different stress conditions including heat shock, alcohols and salt stress. Results showed that the effects of stress on TGase production depended on the type applied. For heat shock, TGase production (1.32 U/ml) was recorded maximum in the culture treated at 48 h post inoculation in water bath at 60 oC for 1 min. For alcohols treatment, the maximum activity of TGase (1.77 and 1.75 U/ml) was obtained when 3% methanol was added into the medium at 0 or 24 h of fermentation. However, a 3.5-fold increased production of TGase (3.8 U/ml) was observed in the medium supplemented with 0.2mol/l MgCl2 compared with the basic medium at the beginning of fermentation. In conclusion, TGase production from S. mobaraensis was improved by heat shock, methanol and salt stress treatments, MgCl2 stress was the most effective.

Numerical Investigation and Design of Cold-formed Steel Angle Columns with Complex Edges under Axial Compression

Jun-Feng Zhang,Mengmeng Feng,En-Feng Deng,Shiyun Pang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

Currently, cold-formed steel (CFS) is widely used in fabricated steel structures for high strength-to-weight ratio and ease for installation. However, limited research is available in the literature on the CFS angle columns with complex edges under axial compression. In this paper, the axial compressive capacity of the CFS angle columns with complex edges was numerically studied. The distortional buckling characteristics of 1008 CFS angle sections with complex edges were analyzed by finite strip software CUFSM. Detailed non-linear finite element model (FEM) was developed based on finite element program ABAQUS and verified by comparing with test results. The verification indicated that the developed FEM could well predict the ultimate strength and failure model of the specimens. Using the validated FEM, an extensive parametric study comprised of 330 models was conducted. The influences of the specimen length, the edge ratio and the limb-width ratio of the angle section on the axial compressive capacity of CFS angle columns with complex edges were evaluated. Then an improved direct strength method (DSM) was proposed based on the existing DSM. The evaluations based on tests and FEA results showed that using the modified DSM to predict the load-bearing capacity of the CFS angle columns with complex edges was feasible.

Novel AgCl/Ag2SO3 Hybrids as a Visible-Light-driven Photocatalyst: Preparation, Characterization, and Degradation of Rhodamine-B and Methyl Orange

Xiang-Feng Wu,Yi-Jin Wang,Zuo-Lin Cao,Yan-Mei Feng,Hui Li,Chen-Xu Zhang,Jun-Zhang Su,Jia-Rui Zhang,Yi-Wei Wang,Kai-Yuan Wang,Guo-Wen Sun 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.7

The novel AgCl/Ag2SO3 hybrids as an efficient photocatalyst had been fabricated by an in situ synthetic method. The correlations between the structure and the photocatalytic properties of the as-fabricated hybrids were analyzed. Experimental results exhibited that with increasing the amount of Ag2SO3, the degradation rate of the as-obtained samples was firstly increased and then decreased under the visible light irradiation. When the mass ratio of AgCl to Ag2SO3 was 1:2, in 30?min, it displayed the highest degradation rate of 99.2% for rhodamine-B, which was obviously higher than 46.1, 60.5, and 14.6% of pure AgCl, Ag2SO3, and TiO2 (P25), respectively. Similar results could be found in degradation of methyl orange. It had the maximum of 97.4% in 90?min, which was higher than 55.2, 48.7, and 12.7% of pure AgCl, Ag2SO3, and P25, respectively. Moreover, the as-prepared hybrids possessed the enhanced separation and transfer of photo-generated electron?hole pairs compared to the pure samples. In addition, the holes and superoxide radicals played the dominant role and the hydroxyl radicals played the secondary role during the process of photocatalytic degradation.

Electro-chemical Preparation of TiO₂/CNT Electrodes with TNB Electrolyte and Their Photoelectrocatalytic Effect

Zhang, Feng-Jun,Chen, Ming-Liang,Oh, Won-Chun The Korean Ceramic Society 2009 한국세라믹학회지 Vol.46 No.6

We investigate a method for the electrochemical preparation of titanium dioxide/carbon nanotube ($TiO_2$/CNT) composites involving the electroplating of Ti in a titanium n-butoxide (TNB) electrolyte into a CNT matrix. The Brunauer-Emmett-Teller (BET) surface areas of $TiO_2$/CNT composites decrease as the electrochemical operating time increases. Changes in XRD patterns show a typical anatase type on the $TiO_2$/CNT composite prepared with a CNT matrix by the electroplating method in a TNB solution. In SEM micrographs, the titanium complex particles are uniformly distributed on the CNT surface. The results of chemical elemental analysis for the $TiO_2$/CNT composites show that most of the spectra for these samples produce stronger peaks for carbon and Ti metal than for any other element. Finally, the prominent photoelectrocatalytic activities of the $TiO_2$/CNT composites can be attributed to the combined effects of photodegradation of $TiO_2$, electron assistance of CNT, and the application of a sufficient voltage.

IL-24 Contributes to Neutrophilic Asthma in an IL-17A-Dependent Manner and Is Suppressed by IL-37

Feng Kang-ni,Meng Ping,Zhang Min,Zou Xiao-ling,Li Shuang,Huang Chu-qin,Lai Ke-fang,Li Hong-tao,Zhang Tian-tuo 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.5

Purpose: Neutrophilic asthma is associated with asthma exacerbation, steroid insensitivity, and severe asthma. Interleukin (IL)-24 is overexpressed in asthma and is involved in the pathogenesis of several allergic inflammatory diseases. However, the role and specific mechanism of IL-24 in neutrophilic asthma are unclear. We aimed to elucidate the roles of IL-24 and IL-37 in neutrophilic asthma, the relationships with IL-17A and the mechanisms regulating neutrophilic asthma progression. Methods: Purified human neutrophils were isolated from healthy volunteers, and a cell coculture system was used to evaluate the function of IL-24 in epithelium-derived IL-17A-dependent neutrophil migration. IL-37 or a small interfering RNA (siRNA) targeting IL-24 was delivered intranasally to verify the effect in a murine model of house dust mite (HDM)/lipopolysaccharide (LPS)-induced neutrophilic asthma. Results: IL-24 enhanced IL-17A production in bronchial epithelial cells via the STAT3 and ERK1/2 signaling pathways; this effect was reversed by exogenous IL-37. Anti-IL-17A monoclonal antibodies reduced neutrophil chemotaxis induced by IL-24-treated epithelial cells in vitro. Increased IL-24 and IL-17A expression in the airway epithelium was observed in HDM/LPS-induced neutrophilic asthma. IL-37 administration or IL-24 silencing attenuated neutrophilic asthma, reducing IL-17A levels and decreasing neutrophil airway infiltration, airway hyperresponsiveness, and goblet cell metaplasia. Silencing IL-24 inhibited T-helper 17 (Th17) immune responses, but not Th1 or Th2 immune responses, in the lungs of a neutrophilic asthma model. Conclusions: IL-24 aggravated neutrophilic airway inflammation by increasing epithelium-derived IL-17A production, which could be suppressed by IL-37. Targeting the IL-24/IL-17A signaling axis is a potential strategy, and IL-37 is a potential candidate agent for alleviating neutrophilic airway inflammation in asthma.

Joint Estimation of Vehicle State and Parameter Based on Maximum Correntropy Adaptive Unscented Kalman Filter

Zhang Feng,Feng Jingan,Qi Dengliang,Liu Ya,Shao Wenping,Qi Jiaao,Lin Yuangang 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.6

To address the problem of poor robustness and accuracy of vehicle state and parameter estimation by conventional Kalman filter in the non-Gaussian environments, a three-degree-of-freedom vehicle model with an improved Dugoff tire model is established and a joint estimator of vehicle state and parameter is designed using the Maximum Correntropy (MC) adaptive unscented Kalman filter (AUKF) algorithm in order to simultaneously estimate and identify the yaw rate, longitudinal vehicle speed, lateral vehicle speed, vehicle mass and rotational inertia. The proposed joint estimator algorithm was validated by Simulink/CarSim simulation testbed under Double Lane Change and Sine Wave Steering Input conditions. The results show that MC combined with AUKF (MCAUKF) algorithm has higher estimation accuracy and better convergence compared to the unscented Kalman filter (UKF) and the MC combined with UKF (MCUKF) in non-Gaussian environments, and the MCAUKF estimator is more suitable for state estimation and parameter identification of real vehicles.