386 research outputs found
Living heritage conservation
Living Heritage is characterized by ‘continuity’, in particular those historic places that are still a ‘living’ part of their community. In China, the mainstream of living heritage conservation is shifting from commodity-oriented renewal to culture-oriented and people-centred revival, which has obviously displayed in many planning practices. This paper centres on the connotation of living heritage and explores its applications approaches through two conservation practices in Nanjing, China. In the first project, the author conceived a brand-new way of protecting and revealing historic streets, named ‘Reflection Alley’. It treats the street as an open museum, utilizing current semi-dismantled remains, providing a stage for dialogues between history and modernity, endowing the historic legacy with a sustainable future. In the second project, a ‘Five-stakeholder Platform’ is set up to support the progressive revitalization of a historic district. Through in-depth community engagement, the design team have developed a three-phase planning guide helping locals to protect and repair their residences thus stimulating the vitality of community life. The paper provides solutions for the implementation of culture-oriented and people-centred revival through the interaction between tangible and intangible parts and the connections to community
Marginal Structural Illness-Death Models for Semi-Competing Risks Data
The three-state illness death model has been established as a general
approach for regression analysis of semi-competing risks data. For
observational data the marginal structural models (MSM) are a useful tool,
under the potential outcomes framework to define and estimate parameters with
causal interpretations. In this paper we introduce a class of marginal
structural illness death models for the analysis of observational semi
competing risks data. We consider two specific such models, the usual Markov
illness death MSM and the general Markov illness death MSM where the latter
incorporates a frailty term. For interpretation purposes, risk contrasts under
the MSMs are defined. Inference under the usual Markov MSM can be carried out
using estimating equations with inverse probability weighting, while inference
under the general Markov MSM requires a weighted EM algorithm. We study the
inference procedures under both MSMs using extensive simulations, and apply
them to the analysis of mid-life alcohol exposure on late life cognitive
impairment as well as mortality using the Honolulu-Asia Aging Study data set.
The R codes developed in this work have been implemented in the R package
semicmprskcoxmsm that is publicly available on CRAN
Optimal Battery Energy Storage Placement for Transient Voltage Stability Enhancement
A placement problem for multiple Battery Energy Storage System (BESS) units
is formulated towards power system transient voltage stability enhancement in
this paper. The problem is solved by the Cross-Entropy (CE) optimization
method. A simulation-based approach is adopted to incorporate higher-order
dynamics and nonlinearities of generators and loads. The objective is to
maximize the voltage stability index, which is set up based on certain
grid-codes. Formulations of the optimization problem are then discussed.
Finally, the proposed approach is implemented in MATLAB/DIgSILENT and tested on
the New England 39-Bus system. Results indicate that installing BESS units at
the optimized location can alleviate transient voltage instability issue
compared with the original system with no BESS. The CE placement algorithm is
also compared with the classic PSO (Particle Swarm Optimization) method, and
its superiority is demonstrated in terms of fewer iterations for convergence
with better solution qualities.Comment: This paper has been accepted by the 2019 IEEE PES General Meeting at
Atlanta, GA in August 201
Multi-category Comparative Analysis of Factors Affecting E-commerce Sales
With the continuous development of e-commerce, more and more types of goods are sold online, so merchants should develop different sales strategies for different types of goods. This paper firstly selects 15 variables to build a stepwise regression model. In the analysis of influencing factors on sales of products in different categories, we find that there are significant differences in the impact of the number of appended reviews and pictures reviews on the sales of utilitarian and hedonic products. In the analysis of influencing factors on sales of products in the same category, we find that the factors influencing the sales of different clothing products are also different to some extent. At last, we put forward some suggestions on adjusting price and title length, and writing product details. This paper is more detailed in variable selection and product classification than some previous studies. It is meaningful for merchants to optimize sales plans and improve product sales
Submodular Load Clustering with Robust Principal Component Analysis
Traditional load analysis is facing challenges with the new electricity usage
patterns due to demand response as well as increasing deployment of distributed
generations, including photovoltaics (PV), electric vehicles (EV), and energy
storage systems (ESS). At the transmission system, despite of irregular load
behaviors at different areas, highly aggregated load shapes still share similar
characteristics. Load clustering is to discover such intrinsic patterns and
provide useful information to other load applications, such as load forecasting
and load modeling. This paper proposes an efficient submodular load clustering
method for transmission-level load areas. Robust principal component analysis
(R-PCA) firstly decomposes the annual load profiles into low-rank components
and sparse components to extract key features. A novel submodular cluster
center selection technique is then applied to determine the optimal cluster
centers through constructed similarity graph. Following the selection results,
load areas are efficiently assigned to different clusters for further load
analysis and applications. Numerical results obtained from PJM load demonstrate
the effectiveness of the proposed approach.Comment: Accepted by 2019 IEEE PES General Meeting, Atlanta, G
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