基于回归树和AdaBoost方法的刀具磨损评估

本文利用高速数控铣刀铣削中不同侧面方向的切削力和振动信号以及声发射信号均方根值,以数据驱动的形式对刀具磨损进行了拟合评估. 在本次研究中,分别从时域、频域和时频联合域上探索与刀具磨损相关的敏感特征,具体特征提取方法包括时域统计分析、频域上的快速傅里叶变换（FFT）和时频联合分析的小波变换（WT）. 本文中,决策树被用于回归问题而非分类问题,用于评估刀具磨损值. 同时,引入AdaBoost算法对回归树模型进行提升,并从模型的准确性、稳定性和适用性三个方面上综合对比了提升的决策树回归模型和原模型的性能. 研究表明,AdaBoost算法提升的回归决策树模型在预测的准确性和稳定性上都有一定程度上提高,并且在面向全新刀具磨损预测的适用性上也取得了不错的提升效果.     

多元因子分析模型在河流健康评价中的应用——以苏子河水质特性研究为例

为顺应河流生态可持续发展,提出健康河流、生命河流等概念,维持河流生态系统健康已经成为流域综合管理的必然趋势。综合运用水文学、水力学、泥沙地貌学和水生生态学的基本理论和方法研究河流生态健康的表征因子,确定各因子的阈值,建立流域性水体水质可续发展评价体系。以河流可持续发展为基础,引用代表性的相关指标进行筛选,对流域水质指标进行数值化分析,以苏子河流域水质特性为研究对象,选取出评估河流健康状况的环境因子,客观反映出中小河流域健康状况,为河流的可持续管理和生态环境建设提供参考。     

Broadband, red-edge information from satellites improves early stress detection in a New Mexico conifer woodland

Multiple plant stresses can affect the health, esthetic condition, and timber harvest value of conifer forests. To monitor spatial and temporal dynamic forest stress conditions, timely, accurate, and cost-effective information is needed that could be provided by remote sensing. Recently, satellite imagery has become available via the RapidEye satellite constellation to provide spectral information in five broad bands, including the red-edge region (690-730 nm) of the electromagnetic spectrum. We tested the hypothesis that broadband, red-edge satellite information improves early detection of stress (as manifest by shifts in foliar chlorophyll a + b) in a woodland ecosystem relative to other more commonly utilized band combinations of red, green, blue, and near infrared band reflectance spectra. We analyzed a temporally dense time series of 22 RapidEye scenes of a piñon-juniper woodland in central New Mexico acquired before and after stress was induced by girdling. We found that the Normalized Difference Red-Edge index (NDRE) allowed stress to be detected 13 days after girdling — between and 16 days earlier than broadband spectral indices such as the Normalized Difference Vegetation Index (NDVI) and Green NDVI traditionally used for satellite based forest health monitoring. We conclude that red-edge information has the potential to considerably improve forest stress monitoring from satellites and warrants further investigation in other forested ecosystems.     

Efficient key management for preserving HIPAA regulations

The protection of patients’ health information is a very important issue in the information age. Health Insurance Portability and Accountability Act (HIPAA) of privacy and security regulations are two crucial provisions in the protection of healthcare privacy, especially electronic medical information. For the quality and efficiency of the electronic services, it is necessary to construct better performance for the user and the trusted party. Based on elliptic curve cryptography (ECC) and complying with HIPAA regulations, this article presents an efficient key management scheme to facilitate inter-operations among the applied cryptographic mechanisms. In addition, the proposed scheme can achieve the complete functionality which includes: (1) a dictionary of key tables is not required for users and other units; (2) users can freely choose their own passwords; (3) users can freely update their passwords after the registration phase; (4) the computational cost is very low for users and the trusted center or server; (5) users are able to access their individual medical information through the authorization process; (6) case of consent exceptions intended to facilitate emergency applications or other possible exceptions can also be dealt with easier.     

膜法富氧技术及其应用研究

介绍了作者在膜法富氧技术方面的研究进展，并将膜法与其他制氧方法进行了比较，最后讨论了膜法富氧技术目前的有关应用，着重研究了膜法富氧在有色金属冶炼，硅酸盐窑炉，化铁炉，加热炉，医疗保健和柴油机增氧等方面的典型应用。     

城市人居环境评价指标及其多元统计分析

为了优化城市居民的生活环境,利用被称为主成分分析的多元统计方法,建立了城市人居环境评价 模型．以哈尔滨市为例,对其1995 - 2009年居民生活环境状况进行了研究．结果表明：受绿化和教育水平、社 会治安、医疗卫生和食品供应等主成分的影响,1995 - 2009年哈尔滨市人居环境发展大致经历了两个阶段, 即1995 - 2003年人居环境明显改善阶段和2003 - 2009年人居环境平稳发展阶段．最后,针对哈尔滨市人居 环境的发展提出了相应的建议．本研究成果将为城市人居环境问题的优化研究奠定基础     

多不饱和脂肪酸对人体神经系统保健作用研究进展

多不饱和脂肪酸,特别是ω-3系列的多不饱和脂肪酸对神经系统有着极其重要的作用,能够保护多巴胺能神经元、增强大脑活力、提高学习能力,尤其对胎儿及婴幼儿的大脑发育有很强的促进作用.多不饱和脂肪酸对视神经有保健作用,对神经系统肿瘤、精神性疾病也有较好的预防和治疗作用.     

Evaluation of a workplace technology for mental health assessment: A meaning-making process

This paper describes the results of a summative evaluation conducted to explore the usability and acceptability of an automated telephone-based technology, designed and developed as a screening tool for mental health disorders in the workplace. The system screens employees for symptoms and subsequently provides educational information and referrals to improve mental health and enhance productivity. The qualitative evaluation was a sub-study of a larger randomized controlled trial (RCT). We conducted in-depth interviews with 15 individuals who participated in the RCT and had used the system. A phenomenological theoretical framework was utilized to analyze the narrative data. Results indicated that participants had mostly positive experience with the system and perceived it as a confidential program that allowed them to reflect on their symptoms without inhibition, fear of judgment or embarrassment. We also learned that asking mere questions about mental health symptoms can be a positive, instructive and possibly a restorative experience. There is a likelihood that for many participants, exposure to questions about their emotional and mental distress validated their feelings about their symptoms and was sufficiently compelling to promote help-seeking behavior. This evaluation study demonstrates that computers can be utilized in the workplace as effective screening and educational tools to improve employees’ mental health.     

Internet pornography exposure and risky sexual behavior among adult males in the United States

Sexually transmitted infections (STIs) continue to pose a threat to the public health in the United States. Many sexual behaviors increase an individual’s risk of STI contraction. Chief among these are having unprotected sex, having sex with multiple partners, and either paying for sex or having sex for pay. The present study used General Social Survey (GSS) data from 2000, 2002, and 2004 to explore the association between exposure to internet pornography and these STI risk behaviors among adult US males. After controlling for demographic and individual difference covariates, internet pornography consumption was positively associated with having sex with multiple partners, engaging in paid sex, and having had extramarital sex. Internet pornography consumption was unrelated to having unprotected sex. Subsequent GSSs have not asked participants about exposure to internet pornography. As the GSS is the only ongoing, full-probability, national survey assessing social beliefs and behaviors, the present report provides unique insight into the risky sexual behavior patterns of adult male internet pornography consumers in the United States.     

Denotation and connotation in the human – computer interface: The ‘Save as …’ command

This paper presents a semiotic technique as a means of exploring meaning and understanding in interface design and use. This is examined through a study of the interaction between the ‘file’ metaphor and ‘save as’ command metaphor. The behaviour of these (from a functional or computational basis) do not exactly match, or map onto, the meaning of the metaphor. We examine both the denotation of a term to the user, i.e. its literal meaning to that person, and the term's connotations, i.e. any other meanings associated with the term. We suggest that the technique applied is useful in predicting future problems with understanding the use of metaphor at the interface and with designing appropriate signification for human-computer interaction. Variation in connotation was expected but a more fundamental difference in denotation was also uncovered. Moreover, the results clearly demonstrate that consistency in the denotation of a term is critical in achieving a good user understanding of the command.