A review of digital twin in product design and development

In the era of digitalization, there are many emerging technologies, such as the Internet of Things (IoT), Digital Twin (DT), Cloud Computing and Artificial Intelligence (AI), which are quickly developped and used in product design and development. Among those technologies, DT is one promising technology which has been widely used in different industries, especially manufacturing, to monitor the performance, optimize the progresses, simulate the results and predict the potential errors. DT also plays various roles within the whole product lifecycle from design, manufacturing, delivery, use and end-of-life. With the growing demands of individualized products and implementation of Industry 4.0, DT can provide an effective solution for future product design, development and innovation. This paper aims to figure out the current states of DT research focusing on product design and development through summarizing typical industrial cases. Challenges and potential applications of DT in product design and development are also discussed to inspire future studies.     

Does placebo effect exist in contact lens discomfort management?

PurposeTo study the effect of daily disposable contact lens (DDCL) refitting in monthly contact lens (CL) wearers suffering from contact lens discomfort (CLD), and to assess if there is a placebo effect associated with this CLD intervention.MethodsSymptomatic CL wearers, according to the Contact Lens Dry Eye Questionnaire 8 (CLDEQ-8 ≥ 12 points), were divided into two groups. The study group was provided with DDCLs (delefilcon A) and the control group with a masked pair of their habitual monthly CLs (placebo effect) and were assessed after one month. Then, the control group was provided with the same DDCLs and evaluated one month later. The symptoms were recorded with the CLDEQ-8 and global rating of change scale (GRCS). Non-invasive tear break-up time (NITBUT), conjunctival hyperaemia, fluorescein staining, and lid wiper epitheliopathy (LWE) were evaluated. Changes between visits, groups, and the effect of each intervention were analysed.ResultsThirty-one participants (mean age: 23.2 ± 5.3 years) were recruited. The study group (n = 14) showed an improvement of -39.6 ± 25.8 % (p < 0.001) in CLDEQ-8 and 31.3 ± 14.6 points in GRCS (p < 0.001) after one month of DDCL use, while no changes in clinical tests were found. In the control group (n = 17), symptoms improved significantly after wearing the masked monthly CL (CLDEQ-8: -26.1 ± 31.0 %, p = 0.03; GRCS: 14.9 ± 17.0, p = 0.002), however a worsening in bulbar (26.5 ± 40.0 %; p = 0.02) and limbal hyperaemia (21.6 ± 34.7 %, p = 0.02) and an improvement of -19.1 ± 37.0 % (p = 0.049) in LWE was found. When the control group was fitted with the DDCL, improvements in GRCS (20.5 ± 25.5, p = 0.02), NITBUT (37.9 ± 42.3 %, p = 0.002), and conjunctival staining (-47.1 ± 59.9 %, p = 0.005) were noted.ConclusionsRefitting symptomatic monthly CL wearers with Delefilcon A DDCL is effective in reducing symptoms related to CLD. However, clinicians and researchers must be aware of the existence of a placebo effect when assessing the effectiveness of any CL refitting.     

基于XGBoost算法的垃圾短信分层分级治理体系

为有效整治垃圾短信,不断提升不良信息治理的精准性,文章基于XGBoost算法构建了一套科学的分层分级垃圾短信治理体系。通过对用户入网、消费、通信行为等特征进行建模与运算,识别出用户发送垃圾短信的风险系数,并定义了六级用户。分级名单生成后,依托于垃圾短信拦截系统的分级策略管理功能,分别设置相匹配的拦截策略。在加大对中高危用户的识别和拦截力度的同时,有效降低了高价值用户因不良信息治理导致被误拦截的风险。该治理体系应用于辽宁移动管理实际以来,垃圾短信平均投诉量降幅34.82%。误关停投诉率稳定在0.1%以内。一至三级高价值客户群关停投诉量降幅27.43%。     

浅析项目业主对交通噪声污染防治的管理责任

交通噪声是交通建设项目的重点污染源,近年来有关的投诉和诉讼越来越频繁,本文通过对现行法律条款的分析,结合典型诉讼案例,剖析了项目业主对交通噪声污染防治的法定责任。为履行好项目业主的管理责任,提出了从环境影响评价、工程设计、工程监理、环境监理和环境保护验收等方面入手,进行全过程综合管理的建议。     

对风景名胜区和自然保护区实行特许经营的讨论

介绍了国外国家公园实行特许经营的经验,阐述特许经营的基本特征和实行特许经营的一些基本原则。揭示在我国的一些风景名胜区和自然保护区实行的“特许经营”所具有的整体性、垄断性和不公开、不透明等缺陷,分析了以经营等同于管理、以经营取代管理给国家级风景名胜区和自然保护区资源保护管理带来的种种弊端。风景名胜区和自然保护区的特许经营问题,需要进一步的理论研究、个案调查,从而推动立法进程。     

地下商场空调节能设计与管理

结合地下商场的特点，从空调设计和运行管理两方面提出了节能措施，并应用在上海某地下商场工程中，取得了较好的节能效果。     

论监理工程师的安全责任

在充分研究国内外建设工程相关法律法规、合同文本及实际案例的基础上,详细分析了监理工程师承担安全责任的原因,总结了监理工程师对建设工程的安全承担责任的前提条件,并针对性地提出了监理企业和监理工程师避免安全责任的具体措施。     

风景园林之于自然重建的意义

21世纪以来,世界人口的增长要求风景园林做出积极的贡献。生态系统服务概念为我们提供了一个框架,使我们理解风景园林对人类活动有着重大意义,并且呼吁在风景园林采取可靠的措施适应紧迫的人口增长。由于在人类交互作用、生态溢流和环境体制等方面受过专门的训练,风景园林师完全胜任引领这些景观设施的发展。     

施工企业加强工程项目成本管理的若干思考

工程项目是施工企业的“窗口”,生产和管理的基点,经济效益的源泉。以工程项目管理为中心,提高项目的运作质量,是施工企业生存和发展永恒的主题。本文结合工程项目管理的实践,就加强工程项目成本管理问题,阐述自己的一些初步认识,共同探讨。     

Communicative Approaches to Restoration Ecology: a case study from Dovre Mountain and Svalbard, Norway

Extensive damage to the vegetation cover in arctic and alpine landscapes has raised the question of restoration as a possible management strategy. Restoration is a goal-oriented activity, a technological undertaking wider than its parent science of ecology. Social science and planning concepts and methods are necessary to handle the value judgements implicit in restoration. It is argued that the notion of 'desired state' is a better reference point in defining restoration goals than the notion of 'original state'. Using qualitative methods, two areas with vulnerable arctic/alpine vegetation are investigated. Based on participants' statements, four possible scenarios or desired states for future management are constructed. The main focus in the scenarios is on participants' attitudes to restoration activity, and it is shown how these are influenced by participants' attachment to the area and their view of nature.