从江南私家园林看中国传统景观观念

该文通过对江南私家园林造园艺术与景观观念的分析,提出了对中国传统景观观念在当代的合理继承与批判性思考。     

The Impossibility of Basing One-Way Permutations on Central Cryptographic Primitives

We know that trapdoor permutations can be used to construct all kinds of basic cryptographic primitives, including trapdoor functions, public-key encryption, private information retrieval, oblivious transfer, key agreement, and those known to be equivalent to one-way functions such as digital signature, private-key encryption, bit commitment, pseudo-random generator and pseudo-random functions. On the other hand, trapdoor functions are not as powerful as trapdoor permutations, so the structural property of permutations seems to be something special that deserves a more careful study. In this paper we investigate the relationships between one-way permutations and all these basic cryptographic primitives. Following previous works, we focus on an important type of reductions called black-box reductions. We prove that no such reductions exist from one-way permutations to either trapdoor functions or private information retrieval. Together with previous results, all the relationships with one-way permutations have now been established, and we know that no such reductions exist from one-way permutations to any of these primitives except trapdoor permutations. This may have the following meaning, with respect to black-box reductions. We know that one-way permutations imply none of the primitives in "public cryptography," where additional properties are required on top of "one-wayness" \cite{IR89}, so permutations cannot be traded for any of these additional properties. On the other hand, we now know that none of these additional properties can be traded for permutations either. Thus, being a permutation seems to be something orthogonal to those additional properties on top of one-wayness. Like previous non-reducibility results, our proofs follow the oracle separation paradigm of Impagliazzo and Rudich.     

鲁宾逊能有一门语言吗?

私人语言问题是维特根斯坦后期哲学中的主要论题之一 ,本文对这一问题中的一个重要论点—即终生孤居者能否拥有语言问题进行探讨 ,并在考察有关研究者的论述的基础上 ,提出一些新的观点     

Governance choices and policy outcomes in the Latin American and caribbean electricity sector

The paper first provides, for Latin America and the Caribbean, country-specific synthetic quantitative measures of the degree of adoption of governance reforms in the electricity sector, focusing on four key dimensions (market structure, private sector participation (PSP), regulatory autonomy and operational organization). These measures are then correlated with standard policy performance outcomes measures. The findings suggest that, the reforms, considered jointly, were statistically significantly associated with higher technical and process quality but not with social or service improvements. Considered individually, increased regulatory autonomy enjoyed the highest positive correlation with desirable outcomes, but PSP has no significant correlation with any of the outcomes. In sum, as of 2018, governance reforms, considered jointly, had still not delivered on some promised payoffs, notably in addressing energy poverty, although the sensitivity analysis suggests that, for some indicators, the relationships are stronger for larger than for smaller countries.     

From smart cities to smart social urbanism: A framework for shaping the socio-technological ecosystems in cities

Advocated mostly by technology companies, the smart city concept promises participation, democratization and innovative urbanism. Tracking these promises and ideas, this paper explores “smart urbanism” in ten cities from all over Israel. Based on interviews with leading figures in municipalities, smart city consultants and key figures in technological companies (n = 40), the aims of this paper are to assess the efforts of cities to become smart by responding to the following questions: 1. What is guiding the decision-making process in developing technological initiatives? 2. Does context play a role in implementing technological initiatives? 3. How are the residents perceived, and what tools are being used to address residents' digital differences? The key argument of this paper is threefold: first, in the process of becoming a smart city, the roles of public and private actors are blurred, influencing the process of decision making. Second, despite contextual differences, cities adopt similar digital initiatives. Third, technological initiatives that focus on social needs and address inequality in the digital age are still at the margins. The final discussion suggests that most municipalities are still at an early stage of digitization implementation and have the ability to shape and form a vision for the cities as socio-technological ecosystems in a way that will serve their publics as a whole. The paper ends with a call for shifting the focus from the city to society in developing digital initiatives and cultivating smart social urbanism.     

民营水泥企业面临的困境及对策研究

民营经济作为我国经济的重要组成部分,其地位和作用日益突出。但是,目前水泥行业竞争激烈、生产成本上升,民营水泥企业的发展仍面临融资困难、人才匮乏、管理模式落后等问题。因此,只有通过提高企业自主创新能力、建立科学管理体系,并且利用有利的国家政策扶植,才能使企业在竞争中占据一定优势,获得可持续发展。     

民营制造业信息化现状及发展策略研究

通过对民营制造业信息化现状的分析，指出了民营制造业信息化工程中存在的问题，明确了民营制造业进一步发展的必然选择，提出了民营制造业信息化实施的策略。     

We House

四位来自英国、日本、西班牙和中国香港的建筑师带来的不仅仅是建筑的新形态，别墅的新空间，还带来了与北京西区气质相同又有新意的独特风情。     

基础设施项目开发的PFI模式的探讨

主要介绍了PFI模式的概念、分类以及优点,分析了我国基础设施项目开发引进PFI模式的可行性,并且针对我国的现状提出了引进PFI模式需要解决的几个问题,以促进PFI模式的发展,从而促进我国基础设施建设的发展。     

北京私家园林的理水艺术

北京相对缺水,但元明清以来也出现了很多以水景见长的私家园林,一些水源丰富的大型园林拥有大面积的水面,而一些无法引取活水的宅园则通过打井和收集雨水的方法来获得水源。其理水手法十分丰富,能够形成池塘、湖泊、河流、泉水、瀑布等各种摹拟自然的水体形态,既受到江南园林的影响,也能够因地制宜,体现出鲜明的地方特色。结合大量文献描述和实例调研,对北京私家园林的理水手法进行了探讨和总结。