Matching Items (3)
Description
Social media has become popular in the past decade. Facebook for example has 1.59 billion active users monthly. With such massive social networks generating lot of data, everyone is constantly looking for ways of leveraging the knowledge from social networks to make their systems more personalized to their end users. And with rapid increase in the usage of mobile phones and wearables, social media data is being tied to spatial networks. This research document proposes an efficient technique that answers socially k-Nearest Neighbors with Spatial Range Filter. The proposed approach performs a joint search on both the social and spatial domains which radically improves the performance compared to straight forward solutions. The research document proposes a novel index that combines social and spatial indexes. In other words, graph data is stored in an organized manner to filter it based on spatial (region of interest) and social constraints (top-k closest vertices) at query time. That leads to pruning necessary paths during the social graph traversal procedure, and only returns the top-K social close venues. The research document then experimentally proves how the proposed approach outperforms existing baseline approaches by at least three times and also compare how each of our algorithms perform under various conditions on a real geo-social dataset extracted from Yelp.
ContributorsPasumarthy, Nitin (Author) / Sarwat, Mohamed (Thesis advisor) / Papotti, Paolo (Committee member) / Sen, Arunabha (Committee member) / Arizona State University (Publisher)
Created2016
Description
The Gulf of Mexico (or “Gulf”) is of critical significance to the oil and gas industries’ offshore production, but the potential for accidental petrochemical influx into the Gulf due to such processes is high; two of the largest marine oil spills in history, Pemex's Ixtoc I spill (1979) and British Petroleum's (BP) Deepwater Horizon (2010), have occurred in the region. However, the Gulf is also of critical significance to thousands of unique species, many of which may be irreparably harmed by accidental petrochemical exposure. To better manage the conservation and recovery of marine species in the Gulf ecosystem, a Petrochemical Vulnerability Index was developed to determine the potential impact of a petrochemical influx on Gulf marine fishes, therein providing an objective framework with which to determine the best immediate and long term management strategies for resource managers and decision-makers. The resulting Petrochemical Vulnerability Index (PVI) was developed and applied to all bony fishes and shark/ray species in the Gulf of Mexico (1,670 spp), based on a theoretical petrochemical vulnerability framework developed by peer review. The PVI for fishes embodies three key facets of species vulnerability: likelihood of exposure, individual sensitivity, and population resilience, and comprised of 11 total metrics (Distribution, Longevity, Mobility, Habitat, Pre-Adult Stage Length, Pre-Adult Exposure; Increased Adult Sensitivity Due to UV Light, Increased Pre-Adult Sensitivity Due to UV Light; and Abundance, Reproductive Turnover Rate, Diet/Habitat Specialization). The resulting PVI can be used to guide attention to the species potentially most in need of immediate attention in the event of an oil spill or other petrochemical influx, as well as those species that may require intensive long-term recovery. The scored relative vulnerability rankings can also provide information on species that ought to be the focus of future toxicological research, by indicating which species lack toxicological data, and may potentially experience significant impacts.
ContributorsWoodyard, Megan (Author) / Polidoro, Beth (Thesis advisor) / Saul, Steven (Thesis advisor) / Matson, Cole (Committee member) / Arizona State University (Publisher)
Created2020
Description本文是针对A股上市公司的社会价值所进行的模型开发与量化评估研究。
公司的社会价值，在本文中界定为公司所实现的经济、社会和环境等方面的综合贡献。随着全球和中国越来越重视可持续发展，公司的社会价值也越来越引起资本市场投资者的关注。
研究以具有原创性的“上市公司社会价值评估模型”为工具，以沪深300成分股为对象，以上市公司的经济、社会和环境的综合贡献为内容，筛选出社会价值量化得分居前99位的公司，形成义利99榜单和指数。
基于该模型和义利99榜单，博时基金已经发布了“博时中证可持续发展100指数”ETF产品（515090），标志着“义利99”从一项研究变成了可交易的基金产品。
“上市公司社会价值评估模型” ，将公司的社会价值分为三个方面，即目标、方式和效益。 “目标” （AIM）是建设更高质量、更有效率、更加公平和更可持续的美好未来，这是公司社会价值的驱动力； “方式” （APPROACH）是指创新的生产技术、运营模式和管理机制，这是公司社会价值的创新力； “效益” （ACTION）是指公司的经济、社会和环境的贡献，这是公司社会价值的转化力。该模型也称 “社会价值三A三力三合一模型” ，简称3A模型。
通过义利99指数和博时中证可持续发展100指数长达五年以上的回测分析发现，这些公司有相对更好、更平稳的市场表现，这两个指数存在Fama-French因子不能解释的超额收益率，即具有显著的正α。回归分析还显示，义利两个属性的因子都能贡献超额收益，但股票月收益率与利的指标成显著正向线性相关，与义的指标成正向线性相关但关系较弱。
“义利99” 是将上市公司对经济、社会和环境的贡献纳入模型进行量化评估的探索，有利于资本市场更好地关注上市公司的社会价值，并促进上市公司将社会价值纳入长期战略安排。
随着更多上市公司更好地承担起信息披露的责任，“义利99”未来将不会局限于沪深300，会有更广泛的应用。中国上市公司终将成为推动世界可持续发展的新动力。
公司的社会价值，在本文中界定为公司所实现的经济、社会和环境等方面的综合贡献。随着全球和中国越来越重视可持续发展，公司的社会价值也越来越引起资本市场投资者的关注。
研究以具有原创性的“上市公司社会价值评估模型”为工具，以沪深300成分股为对象，以上市公司的经济、社会和环境的综合贡献为内容，筛选出社会价值量化得分居前99位的公司，形成义利99榜单和指数。
基于该模型和义利99榜单，博时基金已经发布了“博时中证可持续发展100指数”ETF产品（515090），标志着“义利99”从一项研究变成了可交易的基金产品。
“上市公司社会价值评估模型” ，将公司的社会价值分为三个方面，即目标、方式和效益。 “目标” （AIM）是建设更高质量、更有效率、更加公平和更可持续的美好未来，这是公司社会价值的驱动力； “方式” （APPROACH）是指创新的生产技术、运营模式和管理机制，这是公司社会价值的创新力； “效益” （ACTION）是指公司的经济、社会和环境的贡献，这是公司社会价值的转化力。该模型也称 “社会价值三A三力三合一模型” ，简称3A模型。
通过义利99指数和博时中证可持续发展100指数长达五年以上的回测分析发现，这些公司有相对更好、更平稳的市场表现，这两个指数存在Fama-French因子不能解释的超额收益率，即具有显著的正α。回归分析还显示，义利两个属性的因子都能贡献超额收益，但股票月收益率与利的指标成显著正向线性相关，与义的指标成正向线性相关但关系较弱。
“义利99” 是将上市公司对经济、社会和环境的贡献纳入模型进行量化评估的探索，有利于资本市场更好地关注上市公司的社会价值，并促进上市公司将社会价值纳入长期战略安排。
随着更多上市公司更好地承担起信息披露的责任，“义利99”未来将不会局限于沪深300，会有更广泛的应用。中国上市公司终将成为推动世界可持续发展的新动力。
ContributorsQin, Shuo (Author) / Zhu, Hongquan (Thesis advisor) / Yan, Hong (Thesis advisor) / Gu, Bin (Committee member) / Arizona State University (Publisher)
Created2020