A set-covering model for a bidirectional multi-shift full truckload vehicle routing problem

This paper introduces a bidirectional multi-shift full truckload transportation problem with operation dependent service times. The problem is different from the previous container transport problems and the existing approaches for container transport problems and vehicle routing pickup and delivery are either not suitable or inefficient. In this paper, a set covering model is developed for the problem based on a novel route representation and a container-flow mapping. It was demonstrated that the model can be applied to solve real-life, medium sized instances of the container transport problem at a large international port. A lower bound of the problem is also obtained by relaxing the time window constraints to the nearest shifts and transforming the problem into a service network design problem. Implications and managerial insights of the results by the lower bound results are also provided

Decision analysis of slope ecological restoration based on AHP

The serious deterioration of the ecological environment comes from a large number of geological disasters. These disasters were caused by a number of engineering activities. Ecological restoration is an important measure to reduce geological disasters and protect the ecological environment. On the basis of the introduction of cast-in-situ grids technology, external-soil spray seeding technology and vegetation bag technology, according to the ecological restoration experiment of the road slope attach to the Three Gorges Pumped-Storage Power Station in Hohhot, decision analysis of slope ecological restoration is done with AHP. It is shown that in arid and semi-arid area, selection of slope ecological restoration scheme mainly needs considering the ecological effect and stability. The major factor of ecological effects is survival rate of vegetation. The major factor of stability is the stability in a whole. Cast-in-situ grids technology will be the first choice for ecological restoration of road slope in arid and semi-arid area. This study provides reference for decision of the slope ecological restoration in arid and semi-arid region

A dynamic truck dispatching problem in marine container terminal

In this paper, a dynamic truck dispatching problem of a marine container terminal is described and discussed. In this problem, a few containers, encoded as work instructions, need to be transferred between yard blocks and vessels by a fleet of trucks. Both the yard blocks and the quay are equipped with cranes to support loading/unloading operations. In order to service more vessels, any unnecessary idle time between quay crane (QC) operations need to be minimised to speed up the container transfer process. Due to the unpredictable port situations that can affect routing plans and the short calculation time allowed to generate one, static solution methods are not suitable for this problem. In this paper, we introduce a new mathematical model that minimises both the QC makespan and the truck travelling time. Three dynamic heuristics are proposed and a genetic algorithm hyperheuristic (GAHH) under development is also described. Experiment results show promising capabilities the GAHH may offer

Vitamin D status in tuberculosis patients with diabetes, prediabetes and normal blood glucose in China: a cross-sectional study.

OBJECTIVE: The association between tuberculosis (TB), diabetes mellitus (DM) and vitamin D status is poorly characterised. We therefore: (1) determined vitamin D status in patients with TB in relation to whether they had normal fasting blood glucose (FBG), pre-DM or DM and (2) assessed whether baseline characteristics in patients with TB, including their DM status, were associated with vitamin D deficiency. METHODS: In patients with TB consecutively attending six clinics or hospitals in China, we measured 25-hydroxycholecalciferol (25-(OH)D3) at the time of registration using electrochemiluminescence in a COBASE 601 Roche analyser by chemiluminescence immunoassay. Data analysis was performed using the χ2 test, ORs and multivariate logistic regression. RESULTS: There were 306 eligible patients with TB, including 96 with smear positive pulmonary TB, 187 with smear negative pulmonary TB and 23 with extrapulmonary TB. Of these, 95 (31%) had normal blood glucose, 83 (27%) had pre-DM and 128 (42%) had DM. Median serum vitamin D levels were 16.1 ng/mL in patients with TB with normal FBG, 12.6 ng/mL in patients with TB with pre-DM and 12.1 ng/mL in patients with TB with DM (p<0.001). The study highlighted certain baseline characteristics associated with vitamin D deficiency (25-(OH)D3<20 ng/mL). After adjusting for confounders, serum vitamin D deficiency was significantly more common in patients being registered in the cold season (November to April) (p=0.006) and in those with DM (p=0.003). CONCLUSION: Vitamin D levels are lower in patients with TB with pre-DM and DM and are also affected by certain baseline characteristics that include being registered in the cold season and having DM. TB programmes need to pay more attention to vitamin D status in their patients, especially if there is coexisting pre-DM or DM

Current situation and trend of cardiovascular disease burden in China from a global perspective

Objective: Based on the global burden of disease (GBD) 2019 study, to analyze the epidemic trend and risk factors of cardiovascular disease (CVD) in China by comparing the world, the United States, Japan and India. Methods data were obtained from the global health data exchange (ghdx) database. The prevalence, morbidity, mortality, disability adjusted life year (DALY) and other disease burden status and main risk factors of CVD in China were analyzed by sex and age; the age standardized rate was used to compare the change trend of CVD disease burden in China, the United States, Japan and India from 1990 to 2019. Results: In 2019, the number of CVD patients in China was 12 billion, with 123.41 million new cases and 458.43 million deaths; the prevalence, incidence rate, mortality and Daly rates increased from 423,543/100,000, 44,781/100,000, 20,475/100,000 and 509,103/100,000 in 1990 to 84,608/100,000, 86,765/100,000, 32,230/100,000 and 646,347/100,000 in 2019 respectively. The prevalence, incidence rate, mortality and Daly rate increased with age, and the burden of CVD in men was higher than that in women. In addition, the top 4 risk factors for CVD in China in 2019 are hypertension, diet, air pollution and tobacco, which lead to higher CVD disease burden than the global average. Conclusion: due to hypertension, dietary factors, air pollution, tobacco and other reasons, coupled with the rapid aging of the population, the disease burden of CVD in China is still very serious, which needs to be paid attention to by relevant departments

Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context

Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.

Towards Effective Network Intrusion Detection: A Hybrid Model Integrating Gini Index and GBDT with PSO

In order to protect computing systems from malicious attacks, network intrusion detection systems have become an important part in the security infrastructure. Recently, hybrid models that integrating several machine learning techniques have captured more attention of researchers. In this paper, a novel hybrid model was proposed with the purpose of detecting network intrusion effectively. In the proposed model, Gini index is used to select the optimal subset of features, the gradient boosted decision tree (GBDT) algorithm is adopted to detect network attacks, and the particle swarm optimization (PSO) algorithm is utilized to optimize the parameters of GBDT. The performance of the proposed model is experimentally evaluated in terms of accuracy, detection rate, precision, F1-score, and false alarm rate using the NSL-KDD dataset. Experimental results show that the proposed model is superior to the compared methods