Comprehensive Reliability Allocation Method for CNC Lathes Based on Cubic Transformed Functions of Failure Mode and Effects Analysis

Reliability allocation of computerized numerical controlled（CNC）lathes is very important in industry.Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components,which is not applicable in some conditions.Aiming at solving the problem of CNC lathes reliability allocating,a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis（FMEA）is presented.Firstly,conventional reliability allocation methods are introduced.Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated.Subsequently,a cubic transformed function is established in order to overcome these limitations.Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence.Designers can choose appropriate transform amplitudes according to their requirements.Finally,a CNC lathe and a spindle system are used as an example to verify the new allocation method.Seven criteria are considered to compare the results of the new method with traditional methods.The allocation results indicate that the new method is more flexible than traditional methods.By employing the new cubic transformed function,the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

Comprehensive therapeutic effect of the stroke rehabilitation unit in a medium-sized comprehensive community hospital

BACKGROUND： Acute stroke unit （stroke care unit） is developing in some domestic large-sized hospitals, but most stroke patients need stroke rehabilitation unit therapy, so setting stroke rehabilitation unit in medium-sized comprehensive community hospital （secondary hospital）, where medical facility is relatively insufficient, is a new pathway to satisfy stroke patients. OBJECTIVE： To observe the comprehensive effect of developing stroke rehabilitation unit based on the facility of secondary hospital and its feasibility. DESIGN： Non-randomized concurrent controlled observation SETTING： Department of Neurology, Beijing Longfu Hospital PARTICIPANTS： Totally 264 stroke reconvalescents who suffered stroke for 7 days and received treatment in the Department of Neurology, Beijing Longfu Hospital during June 2003 to June 2005 were involved in the study. All the involved patients were confirmed by CT or MRI. The patients were scored by using Modified Edinbergh-Scandinavia stroke scale （SSS） 〉 16 points. Written informed consents were obtained from all the patients. The patients were assigned into 2 groups according to the willing of patients and their relatives： （1）treatment group, in which, there were 134 patients, 76 males and 58 females, aged 43 to 74 years; cerebral infarction was found in 116 cases and cerebral hemorrhage in 18 cases;（2） control group, in which, there were 130 patients, 66 males and 64 females, aged 45 to 77 years, cerebral infarction was found in 115 cases and cerebral hemorrhage in 15 cases. There were significant differences in baseline data of the patients between two groups. METHODS： A same basic treatment was conducted in the patients of the two groups. （1） Patients in the treatment group admitted to stroke rehabilitation unit and received comprehensive rehabilitation treatment. The rehabilitation flow-sheet： randomization-letting the patients of treatment group go into the unit-making comprehensive assessment in the initial stage-making therapy plan-talking with patients and their other family members-general rehabilitation-making metaphase assessment-adjusting therapy plan-making final assessment-letting the patients discharge and doing follow-up visits. （2） The patients in the control group admitted to common wards, and they were encouraged to do activities by themselves in the early stage, but did not receive rehabilitation training under the instructions from professional physicians. MAIN OUTCOME MEASURES： The following assessments were conducted on admission and 7 and 28 days after admission： （1） Severity of stroke and motor function： scored as 0 to 45 points by SSS, the higher points, the severer damage. （2）Activities of daily living： Evaluated by Barthel index, 110 points in total, 110 points meant normal, 0 point meant extremely poor. （3）Mental status： evaluated by Hopkin＇s symptom scale with a 5-point scoring. The symptom was scored with low to high points. （4）Cognitive function： Quantification measurement was conducted with LOTCA method. The higher points, the better therapeutic effects. RESULTS： （1） Three cases dropped out and one died in the treatment group, 11 cases dropped out and 4 died in the control group. （2）The neurologic impairment points on 7 and 28 days after therapy in the treatment group were lower than those in the control group separately [7 days：（9.73±6.43） points vs. （12.63± 7.87） points, t =2.28, P〈 0.05;28 days：（7.88±4.81） points vs. （9.84±7.03）points, t =2.04, P〈 0.05]. Barthel index on 7 and 28 days after therapy in the treatment group were higher than those in the control group separately [7 days：（54.28±8.38） points vs. （39.76±7.31） points, t =2.206, P 〈 0.05; 28 days： （89.72±7.94） points vs. （67.34±8.63） points, t =2.812, P 〈 0.01]. （4） Patients were allocated into different age groups based on age and evaluated with LOTCA. Results showed that there were no significant differences among different age groups （P 〉 0.05）. （5） Totally 160 patients in the two groups accomplished the Hopkin＇s test, among them, 94 （58.7%） had different mental disorders; Among the patients with mental disorder, depression, obsessive-compulsive and anxiety were found mostly, being 53.8%, 52.5% and 46.2%, respectively. CONCLUSION： （1） Developing stroke rehabilitation unit therapy in the secondary hospital can obviously improve the motor function and activities of daily living of stroke reconvalescents. （2） More than half of the stroke reconvalescents accompany the symptoms of depression, obsessive-compulsive, anxiety and other mental disorders. （3） The cognitive function of stroke reconvalescents is not related to age.

Notable effects on comprehensive techniques of man-made biosphere in rice fields

Studied by Mr. LIU Zhongzhu, ex Chairman of Fujian Academy of Agri Sciences, a combined technique of man—made biosphere in rice fields deserves notice. The research indicated that using man—made biosphere in rice fields can enrich soil, reduce the infects of diseases, insects and weeds, economize the use of pesticide and herbicide, decrease green house effect, and improve atmosphere. As tested, the yield for rice is usually 10500—12000 kg/ha, for fish is usually 2250—3250 kg/ha. Again, about 50%—60% fertilizer and 30%—50% pesticide can be saved. The net income increased $ 1,080—1,800 per ha.

Oasis cold island effect and its influence on air temperature: a case study of Tarim Basin, Northwest China

Oasis effect can improve the regional climate and habitability of an arid region. In this study, we explored the cold island effects of oases distributed along the edge of Tarim Basin by analyzing the oasis cold island effect （OCIE） intensity, spatial-temporal variation of OCIE, factors influencing the OCIE and impacts of OCIE on air temperature using geographical statistics and GIS methods based on the MODIS land surface temperature, land use/cover change （LUCC） and observed air temperature data. Results showed that all the oases in the Tarim Basin exhibited cold island effects, with the OCIE intensity highest in summer （-9.08℃）, followed by autumn （-4.24℃） and spring （-3.85℃）. The total area of oasis cold island （OCI） and the comprehensive OCIE index showed the same seasonal change trend as the OCIE intensity. However, the changing trends in areas of OCI with strong, medium and weak OCIEs were inconsistent across different seasons. Farmland and water areas were found to be the key contributors that affected the OCIE, and the area and aggregation metrics of these two land use/cover types directly contributed to the OCIE. By contrast, natural vegetation, such as forest and grassland, almost had no contribution to the OCIE. Simulation of observed air temperature data showed that if farmland is replaced by forest or grassland in the oasis, the mean, maximum and minimum air temperatures will increase significantly. This heating effect will be higher in summer （reaching 1.14℃ to 2.08℃） and lower in spring and autumn. Moreover, the heating effect of farmland being replaced by forest will be higher than that of farmland being replaced by grassland. These results can provide a basis for understanding the cold island effect of oases in arid regions.

A RESEARCH INTO THE EFFECT OF BACKGROUND KNOWLEDGE ON BUSINESS ENGLISH READING COMPREHENSION

With the arrival of the new millennium,the demand fortalented people with both professional knowledge and excellentlanguage abilities is getting stronger and stronger.For business major students,reading is paramount inBusiness English teaching and learning.And their reading abilityis often assessed by a text of reading comprehension.However,from my experience as a college teacher ofBusiness English,I have noticed some problems among studentswho have little knowledge of business.They seem to readBusiness English materials at a slower rate and with lessunderstanding than general English materials.Then there is the question:is Business English reading"simply"a problem of language competence? Or are there anyother more important factors?This article is an investigation into the effect of backgroundknowledge on Business English reading comprehension.Thestudy attempts to assess to what extent L2 readers might beaffected because of their lack of a background schematapresupposed by the author by comparing the test results of twopassages comparable in language lightness or heaviness.Morecomparable passages like these can be used in investigating intothe rival effects of background knowledge and linguisticcompetence.The implications of comprehension theory for L2pedagogy are discussed and suggestions for Business Englishteaching is put forward.

A novel stacking-based ensemble learning model for drilling efficiency prediction in earth-rock excavation

Accurate prediction of drilling efficiency is critical for developing the earth-rock excavation schedule.The single machine learning(ML)prediction models usually suffer from problems including parameter sensitivity and overfitting.In addition,the influence of environmental and operational factors is often ignored.In response,a novel stacking-based ensemble learning method taking into account the combined effects of those factors is proposed.Through multiple comparison tests,four models,e Xtreme gradient boosting(XGBoost),random forest(RF),back propagation neural network(BPNN)as the base learners,and support vector regression(SVR)as the meta-learner,are selected for stacking.Furthermore,an improved cuckoo search optimization(ICSO)algorithm is developed for hyper-parameter optimization of the ensemble model.The application to a real-world project demonstrates that the proposed method outperforms the popular single ML method XGBoost and the ensemble model optimized by particle swarm optimization(PSO),with 16.43%and 4.88%improvements of mean absolute percentage error(MAPE),respectively.

Molecular Modification of Benzophenone Derivatives for Lower Bioenrichment and Toxicity Through the Pharmacophore Model

In this study,we used the improved extreme-difference normalization method to calculate the comprehensive evaluation values of bioenrichment and toxicity of benzophenone UV light absor-bers(BPs).Based on this parameter,a 3D-QSAR(QSAR=quantitative structure activity relationship)pharmacophore model was constructed using Discovery Studio software and applied to the mole-cular modification of BPs.With three commonly used ingredients in sunscreen 2-hydroxy-4-methoxybenzophenone(BP-3),2,2'-dihydroxy-4,4'-dimethoxybenzophenone(BP-6)and 2,2'-dihydroxy-4-methoxybenzophenone(BP-8)as target molecules,we performed BPs substitution reaction based on the binding positions of characteristic elements of the pharmacophore model and designed BP derivatives with reduced bioenrichment and toxicity.Stability and function evaluation showed that while the stability of 6 BP derivatives was enhanced,the light absorption capacity was also significantly enhanced(from 9.16%to 43.16%).Molecular dynamics simulation results showed that the binding ability of BP-609 molecule with serum albumin was reduced by 16.37%compared with BP-6,and the binding with collagen could not occur spontaneously,which could be used as an explanation for the simultaneous reduction of its bioenrichment and toxicity.Besides,through the simulation of human metabolism,it was found that the liver metabolites of BP-609 were less toxic,which reduced the potential risk of human metabolism.It proved that the molecular modification scheme of BPs was environment-friendly.