自然资源资产负债表中的负债问题研究

自然资源负债核算是自然资源资产负债核算中难度最大的问题,也是目前编制自然资源资产负债表亟需攻关的重点。本文探讨了自然资源负债确认的理论契合点,搭建了自然资源负债确认与经典资产负债核算不能匹配的桥梁,从资源配置原理角度探讨了自然资源负债确认的条件、计量及责任分摊,并通过包含资产负债变动的自然资源资产负债表将其予以披露,整体上实现了自然资源负债的确认、计量和披露三大关键性问题与经典资产负债核算理论一脉相承的要求。     

江苏省经济增长与能源消费关系的实证研究

近年国内大量关于经济增长与能源发展关系的研究大多着眼于宏观或表面现象,没有挖掘深层次关系。通过江苏省经济增长和能源消费的实证研究,运用协整和误差修正模型,建立了江苏省经济增长和能源消费的关系模型,找出特定地区特定经济发展阶段经济增长与能源消费的“真实”关系,为政府制定相应的政策提供依据。     

资源耗减及其对宏观经济总量调整的思考

本文通过对几大类自然资源在经济活动中的不同耗减方式的描述,分析了各种资源耗减在国民经济核算中所产生的不同影响,以及由此而对宏观经济总量进行调整的可行性和可能存在的问题。     

中国水资源核算中的混合账户与经济账户

为研究资源环境与经济活动之间的关系,加强水资源综合管理,水利部与国家统计局在联合国统计署的技术援助下,于2006年开始进行水资源核算体系研究。水资源核算体系包括实物量供给使用表、排放账户、混合账户、水资源资产账户和水质账户等。本文介绍其中的混合账户与经济账户,包括编制账户的目的、编制方法、账户的核算表式,以及所需的数据来源等。     

中国西部地区石油天然气产业集聚水平测度的实证研究

文章利用CRn指数、H指数、Ellison-Glaeser指数等指标,对西部地区石油天然气产业的产业集聚程度进行了实证研究,并对石油天然气产业的上、下游环节进行了细化研究。通过研究得出结论:西部地区石油天然气产业的上游已显现出较强的集群性,但是石油天然气产业的下游并没有体现出相应的集群性。中国西部地区的石油天然气产业的产业链布局存在以上缺陷,这是导致西部地区的资源禀赋优势没有得到充分发挥的主要原因。     

Two-stage cluster sampling with hybrid ranked set sampling in the secondary sampling frame

In surveys of natural resources in agriculture, ecology, fisheries, forestry, environmental management, etc., cost-effective sampling methods are of major concern. In this paper, we propose a two-stage cluster sampling (TSCS) in integration with the hybrid ranked set sampling (HRSS)—named TSCS-HRSS—in the second stage of sampling for estimating the population mean. The TSCS-HRSS scheme encompasses several existing ranked set sampling (RSS) schemes and may help in selecting a smaller number of units to rank. It is shown both theoretically and numerically that the TSCS-HRSS provides an unbiased estimator of the population mean and it is more precise than the mean estimators based on TSCS with SRS and RSS schemes. An unbiased estimator of the variance of the proposed mean estimator is also derived. A similar trend is observed when studying the impact of imperfect rankings on the performance of the TSCS-HRSS based mean estimator.     

Spatially correlated Poisson sampling

A new method for sampling from a finite population that is spread in one, two or more dimensions is presented. Weights are used to create strong negative correlations between the inclusion indicators of nearby units. The method can be used to produce unequal probability samples that are well spread over the population in every dimension, without any spatial stratification. Since the method is very general there are numerous possible applications, especially in sampling of natural resources where spatially balanced sampling has proven to be efficient. Two examples show that the method gives better estimates than other commonly used designs.     

Scientific Periodicals in Iran: A Systems Approach

Scientific periodicals fulfill a significant role in the communication, exchange, and sharing of scientific findings. In recent years, the Iranian Ministry of Science, Research, and Technology (MSRT) has concentrated on non-medical, scientific periodicals. The present paper offers a short history of scientific periodicals and their role in Iran. The authors further examine the current status in the Iranian Ministry of Science, Research, and Technology by using a systems approach. Scientific periodicals in Iran involve four external entities and six major subsystems, including resources, format, content, publication, refereeing, and structure. Investigation of the current failings of the periodicals in the MSRT reveals that the main orientation of the system does not facilitate scientific communication, ease of starting new periodicals, and promotion of natural development of these periodicals. The authors suggest ways to improve the status of scholarly periodicals in Iran.     

长株潭城市群水资源承载力的实证研究

在界定水资源承载力概念的基础上,构建了长株潭城市群水资源承载能力的指标体系,采用基于遗传算法的投影寻踪聚类模型对长株潭城市群水资源承载能力进行了实证分析,提出了提高长株潭城市群水资源承载能力水平的几点应对措施。     

基于模糊物元的天然气汽车项目后评价

鉴于天然气汽车项目后评价中各指标的不确定性和模糊性，结合模糊物元分析法建立天然气汽车项目后评价模型，并以海南省天然气汽车项目为例验证了该评价方法的合理性。最后，通过对评价结果和主要影响因素的分析，发现国家政策导向及资源限制对天然气汽车项目的影响最大，投资者需要在国家政策支持的前提下与天然气开采商建立多方的、持久的天然气资源供应机制。     

Ascent-based Monte Carlo expectation– maximization

Summary.  The expectation–maximization (EM) algorithm is a popular tool for maximizing likelihood functions in the presence of missing data. Unfortunately, EM often requires the evaluation of analytically intractable and high dimensional integrals. The Monte Carlo EM (MCEM) algorithm is the natural extension of EM that employs Monte Carlo methods to estimate the relevant integrals. Typically, a very large Monte Carlo sample size is required to estimate these integrals within an acceptable tolerance when the algorithm is near convergence. Even if this sample size were known at the onset of implementation of MCEM, its use throughout all iterations is wasteful, especially when accurate starting values are not available. We propose a data-driven strategy for controlling Monte Carlo resources in MCEM. The algorithm proposed improves on similar existing methods by recovering EM's ascent (i.e. likelihood increasing) property with high probability, being more robust to the effect of user-defined inputs and handling classical Monte Carlo and Markov chain Monte Carlo methods within a common framework. Because of the first of these properties we refer to the algorithm as 'ascent-based MCEM'. We apply ascent-based MCEM to a variety of examples, including one where it is used to accelerate the convergence of deterministic EM dramatically.     

Experimental designs for open pollination in polycross trials

A polycross is the pollination by natural hybridization of a group of genotypes, generally selected, grown in isolation from other compatible genotypes in such a way to promote random open pollination. A particular practical application of the polycross method occurs in the production of a synthetic variety resulting from cross-pollinated plants. Laying out these experiments in appropriate designs, known as polycross designs, would not only save experimental resources but also gather more information from the experiment. Different situations may arise in polycross nurseries where accordingly different polycross designs may be used. For situations in which some genotypes interfere in the growth or production of other genotypes, but have to be grown together, neighbour-restricted design is a better option. Furthermore, when the topography of the nursery is such that a known wind system in a certain direction may prevail, then designs balanced for neighbour effects of genotypes only in the direction of wind are appropriate which may help in saving experimental resources to a great extent. Also, when genotypes are planted in a small area without leaving much space between rows, designs balanced for neighbour effects from all possible eight directions are useful to have equal chance of pollinating and being pollinated by every other genotype. Here, polycross designs have been obtained to match above-mentioned three situations. SAS Macros have also been developed to generate these proposed designs.     

中国油砂富集区域资源勘探开发序列研究——基于探索性空间数据分析

以中国油砂资源富集的省域为研究对象,综合运用SPSS和GeoDA软件,对中国区域油砂资源丰度和投资环境的空间差异分析后发现:中国油砂富集区域的资源丰度与投资环境差异较大,资源丰度较高的区域主要集中于西部,而投资环境较优的区域则主要集中于东部和中部;资源丰度的全局自相关特征明显,存在着相似值的空间集聚特征;依据油砂资源丰度与区域投资环境组合类型的空间特征,可以规划出中国区域油砂资源的勘探开发序列。     

生产性服务资源环节错配对高技术产品出口的影响分析

本文以修正Antràs et al（2012）模型为切入点，首次构建了生产性服务资源环节错配的测度方法，进而以WIOD数据库中发展中国家为样本首次细致分析了生产性服务资源环节错配对高技术产品出口的作用机理。研究发现：首先生产性服务资源环节错配系数对发展中国家高技术产品出口的作用力呈现倒U型，生产性服务资源环节错配不利于发展中国家高技术产品的出口，这一结论在分位数回归、控制内生性、分时间段和分产业等条件下依然稳健；其次中国生产性服务资源环节错配系数在所有样本国中最高，中国生产性服务资源过于偏向上游原料环节导致了上述现象的出现，这使得中国生产性服务资源处于“偏离最优值较远的低效扭曲使用”状态；最后高等教育、企业经营环境和经济效率均对高技术产品出口具有较为显著的促进效应，而“资源诅咒”使得丰裕的资源禀赋对高技术产品出口表现出一定的负效应，空间型贸易地理优势和契约型贸易地理优势均有助于高技术产品的出口，金融危机则对高技术产品出口产生了较为显著的负向冲击。     

Developing a Freely Accessible/Open Access Resource Management Policy at Duke University Libraries: A Case Study

Abstract

Freely accessible and open access resources present unique challenges for librarians working with electronic resources. Due to the fact that many of these resources lack high-quality metadata or the technical support provided by traditional publishers, making them discoverable and maintaining access over time can be tricky. Creating a policy allows for a systematic approach to the management of freely accessible/open access (OA) resources, alleviating problems surrounding lack of staff time or expertise. Many of these resources are already important parts of collections and will only continue to grow in importance. Freely accessible/OA resources allow for a more diverse representation of content, both by subject and format type, and allow a wider array of authors to have their work appear in library collections. This case study will provide a review of freely accessible/OA policies in other libraries, describe why these resources are important to add to our collections, discuss challenges libraries face with managing these resources, and explain how Duke University Libraries is addressing some of these challenges through the development of a policy.     

Algorithmic and analytical construction of efficient designs in small blocks for comparing consecutive pairs of treatments

Optimal block designs in small blocks are explored under the A-, E- and D-criteria when the treatments have a natural ordering and interest lies in comparing consecutive pairs of treatments. We first formulate the problem via approximate theory which leads to a convenient multiplicative algorithm for obtaining A-optimal design measures. This, in turn, yields highly efficient exact designs, under the A-criterion, even when the number of blocks is rather small. Moreover, our approach is seen to allow nesting of such efficient exact designs which is an advantage when the resources for the experiment are available in possibly several stages. Illustrative examples are given and tables of A-optimal design measures are provided. Approximate theory is also seen to yield analytical results on E- and D-optimal design measures.     

Modeling and predicting extreme cyber attack rates via marked point processes

Cyber attacks have become a problem that is threatening the economy, human privacy, and even national security. Before we can adequately address the problem, we need to have a crystal clear understanding about cyber attacks from various perspectives. This is a challenge because the Internet is a large-scale complex system with humans in the loop. In this paper, we investigate a particular perspective of the problem, namely the extreme value phenomenon that is exhibited by cyber attack rates, which are the numbers of attacks against a system of interest per time unit. It is important to explore this perspective because understanding the statistical properties of extreme cyber attack rates will pave the way for cost-effective, if not optimal, allocation of resources in real-life cyber defense operations. Specifically, we propose modeling and predicting extreme cyber attack rates via marked point processes, while using the Value-at-Risk as a natural measure of intense cyber attacks. The point processes are then applied to analyze some real data sets. Our analysis shows that the point processes can describe and predict extreme cyber attack rates at a very satisfactory accuracy.     

环境约束下的化石能源跨期开采路径比较研究

考虑化石能源开发和使用的环境外部性与代际外部性,在动态最优开采模型基础上构建含有环境污染因子的跨期配置模型,比较考虑环境制约因素前后的开采路径,证明环境约束对化石能源消耗有复杂影响,环境作为政策工具可以调节化石能源开采强度,在一定程度上缓解了资源的稀缺性和延长了资源耗竭时间,为具有经济价值的可再生能源的出现赢得时间。应用中国相关历史数据,发现实际上环境约束没有抑制化石能源消耗,偏离了理论分析预期目标。据此提出加快矿产资源税费改革、加大环境污染治理投资、优化投资结构、建立科学环境补偿制度、促进技术进步的政策建议。     

中国三次产业间劳动力资源优化配置及转移分析

本文依据以Cobb-Douglas生产函数为基础建立的三次产业资源优化配置模型,给出了劳动力资源合理配置的估算方法,并利用中国三次产业的相关数据对该方法进行了实证分析。通过实证分析,本文得出了在产出和资本投入给定情况下,三次产业劳动力资源的最优配置数量,并使用三次产业的实际劳动力数据以及农民工流动数据估算了我国劳动力资源配置偏差情况,最后提出了相应的政策建议。     

近年来我国国民经济核算的改革与实践

党的十八届三中全会以来,国家统计局在国民经济核算方面进行了一系列改革,制定新的国民经济核算标准,完善国内生产总值(GDP)核算方法,细化账户内容,多项核算工作取得重要进展。本文全面梳理了近年来国家统计局在国民经济核算方面开展的各项工作,系统总结国民经济核算取得的新进展,介绍《中国国民经济核算体系(2016)》的变化以及组织实施情况,总结地区生产总值统一核算、编制全国和地方资产负债表、探索编制自然资源资产负债表、GDP核算、投入产出核算、资金流量核算、派生产业核算等方面开展的改革工作,并结合继续完善我国国民经济核算工作要求,提出政策建议。本文对于有关学者进一步开展国民经济核算研究,以及广大用户正确使用和解读国民经济核算数据具有重要的参考意义。