Displacement-Controlled Behavior of Asymmetrical Single-Story Building Models

Displacement controlled behavior is a feature of low to moderate seismicity areas where the peak displacement demand on structures could be limited despite significant structural strength and stiffness degradation. In this article, the extension of the displacement controlled phenomenon to torsionally unbalanced framing systems is investigated. It is shown that the displacement demand of critical elements within a building can be insensitive to changes in eccentricity and torsional stiffness properties. While torsional actions is a well-researched topic, the incorporation of displacement controlled phenomenon into the analysis is original and represents a new development.     

Testing Policy Theory with Statistical Models of Networks

This article presents a conceptual framework for clarifying the network hypotheses embedded in policy theories and how they relate to macrolevel political institutions and microlevel political behavior. We then describe the role of statistical models of networks for testing these hypotheses, including the problem of operationalizing theoretical concepts with the parameters of statistical models. Examples from existing theories of the policy process and empirical research are provided and potential extensions are discussed.     

Modeling and Control of the CSCEC Multi-Function Testing System

In order to promote the research and development on evaluating the seismic performance of structures, China State Construction Engineering Corporation (CSCEC) planned to construct a large-scale loading testing facility, the Multi-Function Testing System (MFTS). This facility can perform full-scale, real-time, 6-degree-of-freedom static and dynamic testing of rubber bearings and many types of structural components including long columns, shear walls and cross shape joints. The basic performances of the MFTS are a clearance of 9.1 m × 6.6 m × 10 m for specimen installation, maximum x-directional displacement 1500 mm, maximum y-directional velocity 1570 mm/s and maximum z-directional compressive load 108 MN. The system configuration and performance specifications of the MFTS are presented in this paper. The inverse kinematics model and the nonlinear model of the hydraulic servosystem of the MFTS are built. A modified feedback forward kinematics algorithm is developed for real-time control of the MFTS. Internal force characteristics of the loading system are analyzed. The internal force control method based on real-time solution of basis of internal force space is proposed for the system with large motion ranges. The motion controller combining position control loop and internal force control loop is developed. To meet the requirement of simultaneously imposing vertical compressive load and horizontal displacement, a mixed load and displacement controller is designed, where a direct force control loop is used to improve the response speed of the force control and reduce spatial dynamic coupling effects. Finally, a dynamic bearing testing is performed. The test results demonstrate that the system using the proposed controller has good abilities on position tracking, force balance, and load following.     

Stability in a Spatial Production and Trade System

Basic properties of the production and trade system for sulfur in the North Atlantic sphere are studied. Oligopolistic competition produces a more stable system than polypoly. Occasional exceptions, difficult to anticipate theoretically, are possible, however. When subjected to realistic exogenous shocks in consumption (demand), the system is less stable than if the shocks appear in supply.     

The Dynamic Behavior of the Basilica of San Francesco in Assisi Using Simplified Analytical Models

The Basilica of San Francesco in Assisi endured stronger earthquakes for centuries before 1997 earthquake, which generated the collapse of the two vaults. Experts blame as possible reasons of collapse the damage cumulated from previous earthquakes and/or the retrofitting made to the structure over its lifetime. This article presents the history of the retrofit interventions of the Basilica through the centuries, focusing mainly on the roof, which has been subjected to three major restorations through its life. It is shown using simple analytical models that the cumulative effects of the changes made to the roof of the Basilica affected the structure’s dynamic behavior in a negative manner, increasing the seismic loads on the existing structural members. In particular, the numerical results show that the 1958 roof intervention has stiffened the structure, redistributing the seismic loads on the façade and the transept. This overload might explain the collapse of the two Gothic vaults during 1997 earthquake.     

Trees or Chains, Links or Branches: Conceptual Alternatives for Consideration of Stone Tool Production and Other Sequential Activities

Archaeologists construct sequence models to describe the operation of past activities such as production of stone tools. As developed in Japan, France, and North American, such models summarize processes, present intermediate steps, and link formally diverse materials. Some sequence models are teleological in that they present actions as predetermined patterns. Others can be considered evolutionary in that they describe results produced by selected interaction between conditions and variables. With separate strengths and different goals, both approaches to sequence modeling have archaeological utility.     

商代分封制的产生与发展

关于商代分封制的问题,学者有不同意见,有的学者认为商代存在分封制,也有的学者认为商代没有分封制,分封制是周代才确定的制度。     

日本庄园制产生的制度分析

日本的封建化过程是在深受中国唐朝封建制度的影响下完成的。但是,由于生产力水平低下、土地国有制度脆弱,封建化之后的日本在并未与西欧建立任何联系的前提下,却形成了与西欧十分相似的封建社会模式。其中,庄园制的产生最能反映日本封建化过程的这一特征。具体表现为：一、剥削方式在落后的生产力的作用下由实物地租向劳役地租的回归;二、土地国有制在私有传统和庞大官僚队伍的鲸吞下向土地私有制转化。中国唐朝先进的封建因素与日本本土落后的前封建因素相互接触、融合,最后产生了日本的封建庄园制。     

Chemical Variability in Clays and Pottery from a Traditional Cooking Pot Production Village: Testing Assumptions in Pereruela*

This paper explores analytically the contemporary pottery‐making community of Pereruela (north‐west Spain) that produces cooking pots from a mixture of red clay and kaolin. Analyses by different techniques (XRF, NAA, XRD, SEM and petrography) showed an extremely high variability for cooking ware pottery produced in a single production centre, by the same technology and using local clays. The main source of chemical variation is related to the use of different red clays and the presence of non‐normally distributed inclusions of monazite. These two factors induce a high chemical variability, not only in the output of a single production centre, but even in the paste of a single pot, to an extent to which chemical compositions from one ‘workshop’, or even one ‘pot’, could be classified as having different provenances. The implications for the chemical characterization and for provenance studies of archaeological ceramics are addressed.     

Building an Automated Modeling System to Explore a Universe of Spatial Interaction Models

A methodology is described for harnessing the power of supercomputer hardware to build an automated modeling system. The problems of applying this new approach to mathematical modeling in geography are discussed by reference to the design of better performing spatial interaction models. It is also possible that the results may provide clues about new theories and knowledge.     

Measuring Impacts of Condition Variables in Rule‐Based Models of Space‐Time Choice Behavior: Method and Empirical Illustration

The use of rule‐based systems for modeling space‐time choice has gained increasing research interests over the last years. The potential advantage of the rule‐based approach is that it can handle interactions between a large set of predictors. Decision tree induction methods are available and have been explored for deriving rules from data. However, the complexity of the structures that are generated by such knowledge discovery methods hampers an interpretation of the rule‐set in behavioral terms with as a consequence that the models typically remain a black box. To solve this problem, this paper develops a method for measuring the size and direction of the impact of condition variables on the choice variable as predicted by the model. The paper illustrates the method based on location and transport‐mode choice models that are part of Albatross model—an activity‐based model of space‐time choice.     

Models and Metadata: The Ethics of Sharing Bioarchaeological 3D Models Online

Digital 3D modelling is increasingly common in archaeological recording, but building the models is only part of the story. Sharing and interacting with these digital representations is essential in fostering engagement and ensuring that research is relevant to the broader community. Projects and institutions understand that much of their communication and outreach now take place via digital platforms. However, archaeologists are faced with a variety of challenges when sharing 3D models of human remains online, including metadata curation, accessibility, openness, copyright as well as the ethical implications of sharing digital bioarchaeological data and long-term storage requirements. In this research, metadata from a collection of 3D models of human remains were extracted from SketchFab and analysed to understand how users share 3D models of human remains via online social platforms. The results were contrasted with a critical review of current ethical and technical guidelines, indicating potentially ethically compromising practices, particularly the lack of contextualising metadata for some models. This article proposes and discusses recommendations for developing more strategic approaches to the sharing of 3D data on human remains online, such as assessing and agreeing hosting, licensing and metadata management during project design. Frameworks are provided to support these approaches and make decisions on how to share data openly.     

“后发优势”与中国改革的时序安排

“后发优势”,实质上是由“时间差”而形成的一种“优势”。中国改革在时序安排上很好地考虑并利用了改革中的各种“时间差”,形成了一系列“后发优势”,大大简化了改革的难度,降低了改革的成本和风险,使得改革进展顺利并且取得很大的成功。     

Decision-Making on Transport Infrastructure and Contested Information: A Critical Analysis of Three Approaches

Information is highly contested in virtually all decision-making processes on large infrastructure projects, leading to the delay or cancellation of projects. Contested information has two characteristics: uncertainty and ambiguity. The uncertainty of information refers to the lack of reliable knowledge about the characteristics and future effects of infrastructure projects. The ambiguity of information means that different actors have different (legitimate and valid) perspectives on the characteristics and effects of infrastructure projects. Information is contested if both uncertainty and ambiguity apply. In this paper, we develop a theoretical framework based on different perspectives on rationality and the role ascribed to information in decision-making. We then use this framework to analyse three approaches aiming to deal with the contested nature of information. The analysis shows that none of the approaches can fully deal with the contested nature of information, because no practically feasible approach has yet been developed to effectively address the ambiguity of information. We end with a brief discussion of the possible responses to this finding.     

汉代大铁官管理职官的再研究

本文通过对汉代铁官铭的系统研究,总结出铁官铭及职官的规律。同时根据铁官的省称与编号的规律,推论出未曾发现铁官铭的铁官作坊的职官形式,进而从具体作坊职官形式,推论汉代整个大铁官体系。