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A Tool Path Re-generation Algorithm for Die & Mold Machining

厦门大学学报（自然科学版） 2002年第S1期41卷 101-102页

作者： L P Zhang j Y H Fuh A Y C Nee Department of Mechanical Engineering National University of SingaporeDepartment of Mechanical Engineering National University of SingaporeDepartment of Mechanical Engineering National University of Singapore SingaporeSingaporeSingapore

Facing the challenges of a shorter product design a nd manufacturing lead-time, many mold companies are using 3-D CAD/CAM software s ystems in design and manufacturing. A new product file is often issued to the mo ld design department before it is completely finalized and the design may have t o be iterated many times during the mold design and making processes. In practic e, if a mold has been modified, all the tool paths that cover the modified regio n must be re-generated, no matter how small the modified region may be. With th e available tool path generation systems, if a tool path needs to be re-generat ed, all the cutter location (CL) points must be re-calculated, and none of the original CL points can be re-used. It would require as much time to re-gen erate the modified tool path as in the original case. On the other hand, the mod ified region is usually quite small compared with the entire mold. The complete re-generation process is therefore highly unproductive and time-consuming. This paper proposes an efficient tool path re-generation approach for 3-axis d ie and mold machining. It is assumed in this research that a gouge-free too l path has been generated for the original mold and the same ball end-mill is to be used to generate the tool path for the modified mold. It is shown in th is work that if the boundary of the modified region is interference-free, the a ffected CL points are enclosed by a set of CL points which correspond to the poi nts on the boundary of the modified region. An efficient tool path re-generatio n algorithm was developed in this research. With this algorithm, a closed CL cur ve is first generated from the boundary of the affected region. The CL points fo r the original mold are then analyzed by comparing the x and y values with the b oundary of the affected CL points. If the CL points are not affected by the modi fication, they are output to the new CL file directly. Otherwise, they are remov ed and replaced by the new CL points

关键词： A Tool Path Re-generation Algorithm for Die Mold Machining

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Living Earth:Implementing national standardised land cover classification systems for Earth Observation in support of sustainable development

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Big Earth Data 2021年第3期5卷 368-390页

作者： Christopher j.Owers Richard M.Lucas Daniel Clewley Carole Planque Suvarna Punalekar Belle Tissott Sean M.T.Chua Pete Bunting Norman Mueller Graciela Metternicht Department of Geography and Earth Sciences Aberystwyth UniversityAberystwythCeredigionWalesUK Centre for Geospatial Applications Plymouth Marine LaboratoryPlymouthDevonEnglandUK Geoscience Australia SymonstonACTAustralia Earth and Sustainability Science Research Centre School of BiologicalEarth and Environmental SciencesUniversity of New South WalesSydneyAustralia

Earth Observation(EO)has been recognised as a key data source for supporting the United Nations Sustainable Development Goals(SDGs).Advances in data availability and analytical capabilities have provided a wide range of users access to global coverage analysis-ready data(ard).However,ard does not provide the information required by national agencies tasked with coordinating the implementation of ***,standardised,scalable mapping of land cover and its change over time and space facilitates informed deci-sion making,providing cohesive methods for target setting and reporting of *** aim of this study was to implement a global framework for classifying land *** Food and Agriculture Organisation’s Land Cover Classification System(FAO LCCS)provides a global land cover taxonomy suitable to comprehensively support SDG target setting and *** present a fully implemented FAO LCCS optimised for EO data;Living Earth,an open-source software package that can be readily applied using existing national EO infrastructure and satellite *** resolve several semantic challenges of LCCS for consistent EO implementation,including modifications to environmental descriptors,inter-dependency within the mod-ular-hierarchical framework,and increased flexibility associated with limited data *** ensure easy adoption of Living Earth for SDG reporting,we identified key environmental descriptors to provide resource allocation recommendations for generating routinely retrieved input *** Earth provides an optimal platform for global adoption of EO4SDGs ensuring a transparent methodology that allows monitoring to be standardised for all countries.

关键词： Land cover FAO LCCS open data cube sustainable development goals environmental descriptors

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活动性炎症性肠病患者缺乏未成熟的外周血浆细胞样和髓样树突状细胞

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世界核心医学期刊文摘（胃肠病学分册） 2005年第7期1卷 28-29页

作者： Baumgart D.C. Metzke D. Schmitz j. 陈云茹 Char. Med. Centre-Virchow Hospital Med. Sch. of the Humboldt- UniversityDepartment of Medicine D- 13344 Berlin Germany Dr.

Background: Breakdown of tolerance against the commensal microflora is believ ed to be a major factor in the pathogenesis of inflammatory bowel disease (IBD). Dendritic cells (DC) have been implicated in this process in various animal mod els, but data on human DC in IBD are very limited. Aim: To characterise plasmacy toid DC (PDC) and myeloid DC (MDC) in patients with active versus inactive IBD a nd healthy controls. Patients and Methods: Peripheral blood was obtained from 10 6 patients (Crohn’ s disease (CD) n = 49, ulcerative colitis (UC) n = 57) and h ealthy controls (n = 19). Disease activity was scored using themodified Truelove Witts (MTWSI) for UC and the Harvey Bradshaw severity indices (HBSI) for CD. Fo ur colour flow cytometric analysis was used to identify, enumerate, and phenotyp e DC. DC from patients with acute flare ups and healthy controls were cultured a nd stimulated with CpG ODN 2006 or lipopolysaccharide (LPS). Results: IBD patien ts in remission (PDC UC, 0.39% ; CD, 0.35% ; MDC- 1 UC, 0.23% ; CD, 0.22% of PBMC) have slightly lower numbers of circulating DC compared with healthy con trols (PDC 0.41% , MDC- 1 0.25% of PBMC). In acute flare ups IBD patients ex perience a significant drop of DC (PDC UC, 0.04% ; CD, 0.11% ; MDC- 1 UC, 0.1 1% ; CD, 0.14% of PBMC) that correlates with disease activity (correlation co efficients: PDC MTWSI, 0.93; HBSI, 0.79; MDC- 1 MTWSI, 0.75; HBSI, 0.81). Moreo ver, both express α l4β 7 integrin and display an immature phenotype. Freshly isolated PDC and MDC- 1 from untreated flaring IBD patients express higher base line levels of CD86 which increases further in culture and upon stimulation comp ared with healthy controls. Conclusion: IBD patients lack immature blood DC duri ng flare ups which possibly migrate to the gut. An aberrant response to microbia l surrogate stimuli suggests a disturbed interaction with commensals.

关键词：炎症性肠病髓样树突状细胞浆细胞样疾病活动度克罗恩病严重度溃疡性结肠炎动物模型微生物类循环血

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肥胖与新发房颤危险之间的关系

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世界核心医学期刊文摘（心脏病学分册） 2005年第4期1卷 20-21页

作者： Parise H. Levy D. E. j. Benjamin 王亭忠 Framingham Heart Study 73 Mount Wayte Ave Framingham MA 01702-5827 United States Dr.

Context: Obesity is associated with atrial enlargement and ventricular diastol ic dysfunction, both known predictors of atrial fibrillation(AF). However, it is unclear whether obesity is a risk factor for AF. Objective: To examine the asso ciation between body mass index(BMI) and the risk of developing AF. Design, Sett ing, and Participants: Prospective, communitybased observational cohort in Fra mingham, Mass. We studied 5282 participants(mean age, 57[SD, 13] years; 2898 wom en[55%]) without baseline AF(electrocardiographic AF or arterial flutter). Body mass index(calculated as weight in kilograms divided by square of height in met ers) was evaluated as both a continuous and a categorical variable(normal define d as ju sting for clinical confounders by multivariable techniques, we also examined mod els including echocardiographic left atrial diameter to examine whether the infl uence of obesity was mediated by changes in left atrial dimensions. Main Outcome Measure: Association between BMI or BMI category and risk of developing newon set AF. Results: During a mean followup of 13.7 years, 526 participants(234 wo men) developed AF. Age adjusted incidence rates for AF increased across the 3 BM I categories in men(9.7, 10.7, and 14.3 per 1000 personyears) and women(5.1, 8 .6, and 9.9 per 1000 personyears). In multivariable models adjusted for cardio vascular risk factors and interim myocardial infarction or heart failure, a 4%i ncrease in AF risk per 1-unit increase in BMI was observed in men(95%confidenc e interval[CI], 1%-7%; P=.02) and in women(95%CI, 1%-7%; P=.009). Adjuste d hazard ratios for AF associated with obesity were 1.52(95%CI, 1.09-2.13; P=. 02) and 1.46(95%CI, 1.03-2.07; P=.03) for men and women, respectively, compare d with individuals with normal BMI. After adjustment for echocardiographic left atrial diameter in addition to clinical risk factors, BMI was no longer associat ed

关键词：舒张功能不全房扑左房扩大临床危险因素连续变量队列研究马萨诸塞州血管危险因素多变量模型混杂因素

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