Flexural Strength Reliability of Visually Graded Southern Pine Dimensional Lumber

The reference design values published in the National Design Specification (NDS) for Wood Construction are derived from full-scale testing of lumber samples performed in the 1980s. This testing program is commonly known as the In-GradeTest Program. Selective annual sample tests of visually graded Southern Pine lumber from 1994 to 2010 revealed an overall decreasing trend in the mechanical properties. Because of this alarming observation, a new round of full-scale In-Grade test of visually graded Southern Pine was initiated in 2010. The new test data indicated significant reductions in certain design values published in the current design code (2005 NDS). The new reference design values have been adopted by the 2012 NDS. Compared to the 2005 NDS, the 2012 NDS reference design values for modulus of elasticity (MOE) and modulus of rupture (MOR) were reduced by approximately 0.0 to 14.3% and 11.4 to 41.7%, respectively. This suggests that the underlying reliability of structures constructed recently using Southern Pine might not meet the minimum target flexural reliability speculated in the design code. The main goal of this study was to assess the reliability of flexural members constructed using visually graded Southern Pine lumber and designed using the 2005 NDS design values to determine if they meet the minimum target reliability of wood construction. The new MOE and MOR data were obtained from the Southern Pine Inspection Bureau (SPIB). Probability distribution fitting was performed to determine the best-fit statistical distributions for the new MOE and MOR data. Five distributions were considered: Normal, Lognormal, Gumbel, Frechet and Weibull distributions. The fitted distribution parameters were used to assess the reliability of visually graded Southern Pine floor joists subjected to uniformly distributed dead and live loads. Two scenarios were considered in the reliability analyses conducted in this study. The first scenario assessed the reliability of flexural members designed using the 2005 NDS reference design values which are derived from the 1978 In-Grade test data. The second scenario assessed the reliability of flexural members designed using the new reference design values for visually graded Southern Pine lumber which are derived from the new (2010) In-Grade test data. The analysis results showed that the reliability of Scenario 1 designs (i.e. designs based on the 2005 NDS values) are lower than that of Scenario 2. However, the overall influence of reductions in new reference design values of visually graded Southern Pine on the reliability or safety of bending members is not as significant as expected. This is because the design of flexural members, in particular for No. 2 and better grades, often is controlled by the serviceability limit state (deflection) and not the strength level limit state. Using both the 2005 NDS and 2012 NDS design values, maximum span lengths for floor joists for common ranges of live load-to-dead load ratios, joist spacings and joist dimensions were computed and tabulated in a series of tables. These tables can be used by practitioners as design guides to quickly determine if the floor joists designed based on the 2005 NDS are at-risk or required rectification. Since shear failure usually does not control in the design of floor joists, only the bending strength and serviceability (deflection) limit states were considered in the maximum span tables. Comparison between the maximum span lengths determined from the 2005 NDS and 2012 NDS revealed that the reduction in allowable span lengths is a function of lumber grade, in which the reductions in maximum span lengths for lower grade lumbers are more significant than that of higher grade lumbers. There are no reductions for the maximum span lengths of Select Structural (SS) grade lumber while the maximum span lengths of No. 3 & Stud grade floor joists are reduced by 7.7 to 13.4%

A Scheduling Strategy of Mobile Parcel Lockers for the Last Mile Delivery Problem

In the form of unattended Collection-and-Delivery Points (CDP), the fixed parcel lockers can save courier miles and improve the delivery efficiency. However, due to the fixed location and combination, the fixed parcel locker cannot accommodate the change of demands effectively. In this paper, an approach to supplementing fixed lockers by mobile parcel lockers to meet the demands of the last mile delivery has been proposed. With the goal of minimizing the operating cost, the location and route optimization problems of mobile parcel lockers are integrated into a non-linear integer programming model. An embedded GA has been developed to optimally determine the locations of distribution points, the number of mobile parcel lockers needed by each distribution point and the schedules and routes of mobile parcel lockers, simultaneously. Finally, a numerical example is given to compare the optimization results of the schemes with and without the aggregation problem. The results show that the scheme with the aggregation problem can greatly save the delivery time. However, for the scheme without the aggregation problem, time windows are more continuous, so it saves the number of vehicles

Technology-driven energy revolution: the impact of digital technology on energy efficiency and its mechanism

Introduction: Improving energy efficiency is significant for achieving carbon emission reduction and promoting the transformation of green economic development. In the sustainable development framework set out in the 2030 Agenda for Sustainable Development, Goal 7.3 explicitly aims to double the global rate of energy efficiency improvement by 2030. The rapid development of digital technology, along with its universality and penetrative characteristics, has provide a feasible solution for improving energy efficiency and environmental conditions. However, the theoretical understanding of the impact and underlying logic of digital technology on energy efficiency remains unclear.Methods: Based on the panel data of 30 provinces in China from 2006 to 2021, this paper adopts econometric methods, including two-way fixed effect, instrumental variable method, and Driscoll-Kraay standard error. It investigates the influence of digital technology on energy efficiency and its internal mechanism from single factor and all factor levels.Result: The results show that Digital technology, represented by industrial robots, significantly improves energy efficiency, whether measured by the energy consumption intensity of GDP or the total-factor energy efficiency estimated using the SBM-GML model. The results still hold even after conducting endogeneity tests and robustness tests. Digital technology can improve energy efficiency by increasing virtual industrial agglomeration and promoting outward foreign direct investment.Discussion: In addition to promoting the theoretical understanding of the impact of digital technology on energy efficiency and exploring its mechanism, this paper also provides empirical evidence for policy makers and enterprises to formulate effective measures and strategies to improve energy efficiency under the background of digital economy

The impact of land use/cover change on extreme temperatures on the Yangtze River Delta, China

The contribution from land use/cover change (LUCC) toward temperature in recent decades is of great concern across the globe. Although there have been many studies, most of them focus on the discussion of average temperature and lack a discussion of extreme temperatures. In this study, we first investigated the spatio-temporal changes in extreme temperatures in the Yangtze River Delta during 1980–2020 using the ensemble empirical mode decomposition (EEMD) method. Then, we explored the impact of LUCC on extreme temperatures using the observation minus reanalysis (OMR) method. Finally, the relationship between the normalized difference vegetation index (NDVI) and extreme temperatures was analyzed using the correlation analysis method. We found that: (1) extreme temperatures have a nonlinear variation characteristics on different time scales. Extremely high temperatures (EHT) clearly exhibited a monthly time scale (quasi-3-month), an interannual time scale (quasi-1-year, quasi-2-year, quasi-3-year and quasi-5-year), and an interdecadal time scale (quasi-10-year and quasi-35-year). Extremely low temperatures (ELT) also clearly exhibited a monthly time scale (quasi-3-month), an interannual scale (quasi-1-year, quasi-2-year, quasi-3-year and quasi-6-year), and an interdecadal scale (quasi-10-year and quasi-20-year). (2) EHT showed an east–middle–west staggered phase and ELT showed a southeast–northwest anti-phase characteristic in spatial distribution. (3) The contribution rates of LUCC on EHT and ELT are 53.6% and 92.4%, respectively, which are higher than for the average temperature (40%). (4) The monthly time scale response of the NDVI to extreme temperatures is more regionally concentrated and significant than that on the interannual time scale in spatial distribution. This paper makes up for the insufficiency of the impact of land use/cover changes on extreme temperature changes at multiple time scales and enriches our understanding of climate change

RNAi-based Gene Therapy for Blood Genetic Diseases

Therapies for blood genetic diseases can be divided into different categories, including chemotherapy, radiotherapy, gene therapy, and hematopoietic stem cell transplantation. Among these treatments, gene targeting is progressively becoming a therapeutic alternative that offers the possibility of a permanent cure for certain blood genetic diseases. In recent years, gene therapy has played a more important role in curing genetic blood disorders. RNA interference (RNAi) is one of the directions for gene therapy, which was intensively studied in the past decades for its potentials in the treatment of diseases. In order to provide useful references and prospective directions for further studies concerning RNAi-based gene therapy for blood genetic diseases, current RNAi-based gene therapies for several typical blood genetic diseases have been summarized and discussed in this chapter

The Impacts of Social Security Expenditure on Rural Residents' Medical Consumption in Hubei Province

This paper analyzes the effect ofSocial Security Expenditure issued by Hubei Province on health services for the peasantry, and provides the evidences towards the integration process regarding medical insurances of the urban and the countryside.Based on the related economical data collected from countrysides area of Hubei province from 2003-2019, this paper utilizes the outcome of Cointegration and Granger Casual Relation Test to prove the relation from social security and employment fiscal expenditures and rural households’ annual per capita net income.Then the research adds the control variables to perform the examination on robustness. The study shows that the social security expenditure has a significant impact on rural residents' medical consumption.Considering that medical insurance is an important part of social security,we should ensure the steadiness of the further improvement achieved by system of health insurance,increase government financial investment and strengthen the construction of rural basic health and medical facilities.Hubei Province should improve the level of rural medical and health security, strengthen management, improve efficiency and improve mechanisms, and deepen the reform of the medical and health system.Therefore, the economical burden of rural residents brought by seeking medical treatment will be reduced in order to narrow the difference between the urban and the countryside which will further promote the equality in medical system

Comparative analysis of phosphoproteomic in the intestine of Sepia lycidas under different salinity environments

Cuttlefish are sensitive to the breeding environment, and the low-salinity environment significantly impacts their growth and immunity. So far, it is difficult to breed this species artificially. This study was conducted in Sepia lycidas. And the aim was to investigate the differences in protein phosphorylation in the intestine of S. lycidas under different salinity conditions. Firstly, 999 phosphoproteins (specific peptide ≥ 1), 1928 phosphopeptides, and 2727 phosphorylation sites were identified. Among them were 284 down-regulated expression phosphorylation sites (corresponding to 115 phosphoproteins) and 674 up-regulated expression phosphorylation sites (corresponding to 408 phosphoproteins) in the intestine under a low salinity environment compared with that under a natural salinity environment. Next, GO analysis found that more phosphoproteins corresponding to differentially expressed phosphorylation sites were related to anatomical structure development, multicellular organism development, regulation of the cellular process, etc. The molecular functions of these proteins mainly contain protein binding, transferase activity, catalytic activity, and heterocyclic compound binding. And they are mainly involved in the cellular components of intracellular anatomical structure, organelle, and cytoplasm. KEGG enrichment analysis of the differential phosphoproteins suggested that many significantly enriched pathways were related to the phosphatidylinositol signaling system, cell junction (adherens junction and tight junction), and inositol phosphate metabolism. Finally, changes in environmental salinity can affect the intestinal structure, metabolism, and immune homeostasis of S. lycidas

MC-MLP:Multiple Coordinate Frames in all-MLP Architecture for Vision

In deep learning, Multi-Layer Perceptrons (MLPs) have once again garnered attention from researchers. This paper introduces MC-MLP, a general MLP-like backbone for computer vision that is composed of a series of fully-connected (FC) layers. In MC-MLP, we propose that the same semantic information has varying levels of difficulty in learning, depending on the coordinate frame of features. To address this, we perform an orthogonal transform on the feature information, equivalent to changing the coordinate frame of features. Through this design, MC-MLP is equipped with multi-coordinate frame receptive fields and the ability to learn information across different coordinate frames. Experiments demonstrate that MC-MLP outperforms most MLPs in image classification tasks, achieving better performance at the same parameter level. The code will be available at: https://github.com/ZZM11/MC-MLP

副甲状腺ホルモンによる Leptin 受容体陽性間葉系幹細胞の骨芽細胞分化機構の解析

松本歯科大学大学院歯学独立研究科博士（歯学）学位申請論文;硬組織疾患制御再建学講座（主指導教員:宇田川　信之教授