COMPUTATION OF MAXIMUM LIKELIHOOD ESTIMATES OF GRAVITY MODEL PARAMETERS*

ABSTRACT. This paper presents the derivations of several new algorithms for the computation of maximum likelihood estimates of the parameters of a very general form of the gravity model. The algorithms are then compared with previously available algorithms including GLIM and that given in Sen (1986). One of the new algorithms emerges as far superior in just about every way to its competitors. In particular, it is usually much more than an order of magnitude faster than the GLIM procedure and that given in Sen (1986). It is also not substantially affected by pitfalls such as multicollinearity and (unlike the GLIM procedure) is capable of comfortably handling large O-D matrices.     

GRAVITY MODEL APPLICATIONS IN HEALTH PLANNING: ANALYSIS OF AN URBAN HOSPITAL MARKET*

ABSTRACT. In this paper a gravity model is formulated to model a hospital patient flow system. Both spatial and nonspatial measures of separation are used to estimate the model. Travel time was found to provide improved fits over linear distance in modeling patient flow behavior. Transformations of travel time (square root and log) were found to improve model performance further. Model diagnostics suggested additional spatial separation measurw, separation measure parameters demonstrated stability over time. The model is used to forecast the effects of health care financing reform and hospital closure on patient flows in an urban hospital market. Universal health coverage was found to dramatically improve access to hospital services for lower income patient populations. Hospitals at risk for closure were forecast to receive increased patient flows. Medical school hospitals are expected to lose patients after implementation of health reform, with important implications for graduate medical education. Hospital closures were shown to have negative effects on access to services in poor neighborhoods, but relatively little effect on access in the system as a whole.     

陕西子洲出土商代青铜容器铸造工艺观察分析

2010年11月,陕西省子洲县裴家湾镇关王岔村出土了6件青铜容器,包括尊、瓿、盘、觚、鼎、提梁卣各1件。本文通过对铜器上遗留的工艺痕迹进行肉眼观察,对铜器的铸型设计、芯撑情况、浇注位置等铸造工艺环节以及铸后加工的细节进行了初步的判断和复原,指出该批铜器的铸造工艺与安阳出土的殷墟前期同类器物基本相同,这一结果对认识和揭示这批青铜器的学术价值具有重要的意义。     

宋钱版别研究珍贵史料——读叶适《淮西论铁钱五事状》

叶适（1150～1223）,字正则,学者称水心先生,浙江永嘉（今浙江温州）人,为南宋著名思想家、文学家、政论家,是与朱熹的道学派、陆九渊的心学派并列为南宋三大学派的永嘉学派的集大成者和主要代表。南宋淳熙五年（1178）,叶适以进士第二名及第,后历任吏部员外郎、吏部侍郎、江东安抚使兼沿江制置使等职,官至宝文阁学士、光禄大夫。     

社会史:新的史学范式与新的通史观念--评赵世瑜著《狂欢与日常--明清以来的庙会与民间社会》

赵世瑜教授是当代中国社会史研究的积极倡导者和实践者之一,所著《狂欢与日常——明清以来的庙会与民间社会》一书,探讨了当代中国社会史研究力图形成的新的历史解释思路、新的通史意识及其发展态势与存在的问题。     

《古代的交互作用:欧亚大陆的东部与西部》述评

最近 ,英国剑桥大学麦克唐纳研究所出版《古代的交互作用 :欧亚大陆的东部与西部》文集 ,它集中展示了欧亚大陆的考古及东西文化交流的最新成果。 1998年以来 ,剑桥大学举办了 3次大型国际会议 ,内容涉及欧亚大陆史前学、人类学、语言和文化。本书为 2 0 0 0年“史前后期欧亚草原的开发”会议文集。由著名考古学家伦福儒教授作序 ,收入不同国家学者的文章 2 1篇 ,全面介绍了欧亚草原新石器晚期至铁器时代初的考古发现和的研究成果 ;另有部分文章涉及该区域内的植物考古学与人种学的Y染色体DNA分析     

伪华北政务委员会教育总署施政纪要

该施政纪要从总务事项、文化事项、教育事项、保健事项等四个方面介绍了1943年2月1日——1944年1月31日伪华北政务委员会教育总署的文化教育情况,反映了伪华北政务委员会教育总署在华北推行奴化教育的基本状况,可与本刊2005年第3期所刊《伪华北政务委员会教育总署教育行政报告书》(1938至1943年初)形成完整之报告。     

中国传统文化与环境保护关系初探

加强环境保护是世界各国面临的一项迫切任务。中国传统文化中"天人合一"的观点促进了环境的保护,但"多子多福"、"不孝有三、无后为大"等观念又强烈统治着人们的思想,人口的膨胀导致人们不得不以牺牲环境为代价来满足生活的基本需求。因此,正确认识和评价传统文化对环境保护正反两方面的影响,吸收古文化的精髓,剔除糟粕,对我国环境保护的改善有重要意义。     

胡适的容忍论

胡适的自由思想中容忍具有极为重要的地位.胡适认为容忍既是一种自由的精神,又是一种民主的精神,是自由的根本.一个社会缺乏容忍,自由就不会有保障.社会只有容忍不同的思想存在,容忍有不同的声音,才能使人人都有思想的自由.胡适极力反对不容忍,主张容忍异己,容忍反对党.胡适还强调,一个社会缺少容忍精神,必定会产生唯我主义,走向极权专制.胡适终身奉行容忍,在朋友中倡导互相容忍,反对各种不容忍.