Precoding design for space-time codes and relay selection with a novel scheme for multiple relay systems

Abstract In this paper, we consider the joint design of precoding matrices at both the source and relay nodes in a multi-relay system based on perfect and imperfect channel information, and propose the novel relay selection scheme based on log-likelihood ratio (LLR). Moreover, the symbol error rate (SER) for relay selection system based on proposed scheme is analyzed. At first, we design the combined precoding matrices based on respectively the maximum signal-to-noise ratio (SNR) with perfect channel state information (CSI) and the minimum SER of the single-relay system with imperfect CSI. Using decomposition of matrices, the joint design problems are solved with a two-step method, i.e., the first step is to determine the optimal direction of the precoding matrices, and the second step is to transform the optimization problem into two kinds of independent sub-problems which can be solved in lower complexity. Then, different from traditional relay selection based on signal-to-noise ratio, the relay node with the maximum LLR is chosen. Simulation results show the proposed selection scheme based on LLR is superior to the scheme based on SNR in the SER performance. Furthermore, the multi-relay system using the precoding matrices joint space-time coding technology can improve SER performance of the system effectively compared with only space-time coding or only precoding system

Characterizing Preferential Flow Paths in Texturally Similar Soils under Different Land Uses by Combining Drainage and Dye-Staining Methods

Preferential flow paths have been widely characterized by many visualization methods. However, the differences in preferential flow paths under various land uses and their relationships to hydraulic properties remain uncertain. The objectives of this study are to (1) characterize preferential flow paths under various land uses (forest and orchard) by combining drainage and dye-staining methods and to (2) build a connection between preferential flow paths and hydraulic-related parameters and extract the proportion of preferential flow paths from the compounding effects of matrix flow and preferential flow. The dye-staining experiments were conducted in five sandy soils and one sandy clay loam in situ, including four soils from forest and two soils from orchards. A total of 47 soil cores, 4 cm in height and 9 cm in diameter, were collected in each layer of the dye-stained soils for drainage experiments in the laboratory. Dye coverage and hydraulically equivalent macropore parameters (macroporosity, pore size distribution, and number of macropores) and their relationships were analyzed. The results show that the volume of preferential flow is partly affected by the total macropore volume. The effect of macropores on preferential flow varies by macropore size distribution. Dye coverage exhibited a significant (P < 0.01) correlation with macroporosity (correlation coefficient 0.83). Based on the value of macroporosity or steady effluent rates, the part of the dye coverage that was due to preferential flow on the surface dye-stained soil (resulting from both matrix and preferential flow) could be identified in this study. Compared with orchards, forestland has more preferential flow paths in both surface soil and subsoil. Further studies are needed to quantify the 3-D preferential flow paths and build a connection between preferential flow paths and hydraulic properties

Modeling the Effect of Different Forest Types on Water Balance in the Three Gorges Reservoir Area in China, with CoupModel

Precipitation, throughfall, stemflow, and soil water content were measured, whereas interception, transpiration, evaporation, deep percolation, and soil water recharge were estimated in three plots, including oak (Lithocarpus glaber), Chinese fir (Cunninghamia lanceolata) forestlands, and maize (Zea mays) farmland in the Three Gorges Reservoir in China. A physical process-based model (CoupModel) was set up with climatic measurements as input and was calibrated with throughfall and vertical frequency domain reflectometry measurements from January 2018 to December 2019. Simulated values of soil moisture were fairly consistent with measured ones, with a determination coefficient (R2) of 0.73–0.91. Evapotranspiration was the main output of water balance, with a percentage of up to 61%, and such output was ranked as follows: oak forest (720 mm/y) &gt; Chinese fir forest (700 mm/y) &gt; maize farmland (600 mm/y). Afforestation influenced water balance, and water recharge was generally less significant in oak forestland than in Chinese fir forestland. Annual simulated deep percolation decreased by 60 mm for oak and 47 mm for Chinese fir compared with that for farmland (452 mm/y) and even more significantly in wet years. This decrease was mainly attributed to increased interception (122–159 mm/y) and transpiration (49–84 mm/y) after afforestation. Simulations indicated that vegetation species significantly influenced the magnitude of water balance components, calling for further attention to the selection of regrown tree species in the planning for afforestation projects, particularly for such projects that aim to improve the quantity of water infiltrating groundwater. Soil and water conservation measures should also be applied scientifically when converting farmland to forest in this area, particularly in the oak forest stand

Characterizing Preferential Flow Paths in Texturally Similar Soils under Different Land Uses by Combining Drainage and Dye-Staining Methods

Preferential flow paths have been widely characterized by many visualization methods. However, the differences in preferential flow paths under various land uses and their relationships to hydraulic properties remain uncertain. The objectives of this study are to (1) characterize preferential flow paths under various land uses (forest and orchard) by combining drainage and dye-staining methods and to (2) build a connection between preferential flow paths and hydraulic-related parameters and extract the proportion of preferential flow paths from the compounding effects of matrix flow and preferential flow. The dye-staining experiments were conducted in five sandy soils and one sandy clay loam in situ, including four soils from forest and two soils from orchards. A total of 47 soil cores, 4 cm in height and 9 cm in diameter, were collected in each layer of the dye-stained soils for drainage experiments in the laboratory. Dye coverage and hydraulically equivalent macropore parameters (macroporosity, pore size distribution, and number of macropores) and their relationships were analyzed. The results show that the volume of preferential flow is partly affected by the total macropore volume. The effect of macropores on preferential flow varies by macropore size distribution. Dye coverage exhibited a significant (P &lt; 0.01) correlation with macroporosity (correlation coefficient 0.83). Based on the value of macroporosity or steady effluent rates, the part of the dye coverage that was due to preferential flow on the surface dye-stained soil (resulting from both matrix and preferential flow) could be identified in this study. Compared with orchards, forestland has more preferential flow paths in both surface soil and subsoil. Further studies are needed to quantify the 3-D preferential flow paths and build a connection between preferential flow paths and hydraulic properties

Modeling the Effect of Different Forest Types on Water Balance in the Three Gorges Reservoir Area in China, with CoupModel

Precipitation, throughfall, stemflow, and soil water content were measured, whereas interception, transpiration, evaporation, deep percolation, and soil water recharge were estimated in three plots, including oak (Lithocarpus glaber), Chinese fir (Cunninghamia lanceolata) forestlands, and maize (Zea mays) farmland in the Three Gorges Reservoir in China. A physical process-based model (CoupModel) was set up with climatic measurements as input and was calibrated with throughfall and vertical frequency domain reflectometry measurements from January 2018 to December 2019. Simulated values of soil moisture were fairly consistent with measured ones, with a determination coefficient (R2) of 0.73–0.91. Evapotranspiration was the main output of water balance, with a percentage of up to 61%, and such output was ranked as follows: oak forest (720 mm/y) > Chinese fir forest (700 mm/y) > maize farmland (600 mm/y). Afforestation influenced water balance, and water recharge was generally less significant in oak forestland than in Chinese fir forestland. Annual simulated deep percolation decreased by 60 mm for oak and 47 mm for Chinese fir compared with that for farmland (452 mm/y) and even more significantly in wet years. This decrease was mainly attributed to increased interception (122–159 mm/y) and transpiration (49–84 mm/y) after afforestation. Simulations indicated that vegetation species significantly influenced the magnitude of water balance components, calling for further attention to the selection of regrown tree species in the planning for afforestation projects, particularly for such projects that aim to improve the quantity of water infiltrating groundwater. Soil and water conservation measures should also be applied scientifically when converting farmland to forest in this area, particularly in the oak forest stand

Soybean oil-based shape-memory polyurethanes: Synthesis and characterization

Shape-memory polymers (SMPs) have wide range of applications due to their ability to sense environmental stimuli and reshape from a temporary shape to a permanent shape. Plant oil-based polymeric materials are highly concerned in recent years in consideration of petroleum depletion and environmental pollution. However, plant oil-based polymers are rarely investigated regarding their shape-memory characteristics though bio-based SMPs are highly desired nowadays. In this study, a series of soybean oil-based shape-memory polyurethanes (SSMPUs) are prepared through a mild chemo-enzymatic synthetic route, and their properties are fully characterized with tensile testing, DSC, dynamic mechanical analysis (DMA), and shape-memory testing. Results show that SSMPUs are soft rubbers with tensile strength in the range of 1.92.2?MPa and glass transition temperature in the range of 25 degrees C, and possess good shape recoveries at RT when stretching ratio is 10, 20, and 30%, respectively. This work would promote the development of high-value-added plant oil-based shape-memory polyurethanes

Quantitative effects of Nf1 inactivation on in vivo hematopoiesis

The NF1 tumor-suppressor gene is frequently inactivated in juvenile myelomonocytic leukemia, and Nf1 mutant mice model this myeloproliferative disorder (MPD). Competitive repopulation assays were performed to quantify the proliferative advantage of Nf1(–/–) hematopoietic cells in vivo. Nf1 mutant stem cells demonstrated a growth advantage that was greatest in myeloid lineage cells and least pronounced in T lymphocytes. Surprisingly, although low numbers of Nf1-deficient cells consistently outcompeted wild-type cells, levels of chimerism were stable over months of observation, and MPD was not observed unless threshold numbers of mutant cells were injected. These data showing that normal competitor cells can strongly modulate the growth of mutant populations in vivo have general implications for modeling cancer in the mouse. In particular, strains in which cancer-associated mutations are expressed in fields of target cells may not accurately model early events in tumorigenesis because they eliminate the requirement for a mutant clone to outcompete resident normal cells

Analysis of Prognostic Risk Factors and Establishment of Prognostic Scoring System for Secondary Adult Hemophagocytic Syndrome

Introduction: The objective of this paper is to identify the prognostic risk factors of secondary adult hemophagocytic syndrome (HLH) in hospitalized patients and establish a simple and convenient prognostic scoring system. Method:We reviewed 162 adult patients secondary with HLH treated in Zhejiang Cancer Hospital and the First Affiliated Hospital of Medical College of Zhejiang University from January 2014 to December 2018 were enrolled to form the test group; from January 2019 to February 2021, 162 adult patients in the hospitals constituted the validation group. The HLH prognosis scoring system was constructed according to the risk factors, and the patients were divided into three risk groups: low risk, medium risk, and high risk. The scoring system was verified by Kaplan&ndash;Meier method and log rank test survival analysis. The discrimination ability was evaluated according to the receiver operating characteristic (ROC) curve. Results: Univariate and multivariate analysis showed that the independent risk factors for the prognosis of HLH were male sex, activated partial prothrombin time (APTT) greater than 36 s, lactate dehydrogenase (LDH) greater than 1000 U/L, and C-reactive protein (CRP) greater than 100 mg/L. The area under the ROC curve was 0.754 (95% Cl: 0.678&ndash;0.829). The patients were divided into a low-risk group (0&ndash;1), a medium-risk group (2&ndash;4), and a high-risk group (5&ndash;6). The 5-year overall survival (OS) rate were 87.5%, 41.8% and 12.8%, respectively (p &lt; 0.001). The area under ROC curve was 0.736 (95% Cl: 0.660&ndash;0.813) in the validation group, and the 2-year OS of patients in low-risk, medium-risk and high-risk groups were 88.0%, 45.1% and 16.7%, respectively (p &lt; 0.001). Conclusion:The new prognostic scoring system can accurately predict the prognosis of secondary adult HLH and can further provide basis for the accurate treatment of secondary adult HLH

Soybean Oil-Based Polyurethane Networks: Shape-Memory Effects and Surface Morphologies

Vegetable oil-based shape-memory polyurethane networks are an emerging class of bio-based functional materials with great potential applications. In this study, a series of different structural soybean oil polyols were synthesized, and utilized to fabricate polyurethane networks by reacting with 1,6-diisocyanatohexane. The soybean oil-based polyurethanes (SOPUs) were characterized with differential scanning calorimetry (DSC), dynamic mechanical tests (DMA), tensile testing, shape-memory testing, and atomic force microscopy (AFM). It was found that SOPUs with a preserved triglyceride structure were fixed in a temporary shape at -20 A degrees C, while others were fixed in temporary shapes at 4 A degrees C. Although the recovery speeds were different, all the samples could completely regain their permanent shapes at 37 A degrees C (human body temperature). Furthermore, different SOPUs exhibited different surface structures, which might provide the materials with additional values

Enzymatic synthesis of oleic acid-based epoxy monomer for the production of value added polymers

An oleic acid-based epoxy monomer was synthesized by reacting 2-hydroxyethyl acrylate with epoxy stearic acid and an immobilized lipase. NMR, electrospray ionization mass spectrometry and gel permeation chromatography were used to characterize the intermediates and products. 2-(Acryloyloxy) ethyl epoxy stearate was synthesized with a yield of 87 % w/w. After free radical polymerization, epoxy stearic acid-grafted epoxy polymer with molecular weight of 15,150 g/mol was obtained; the final yield was 81 % w/w