The evaluation of Istanbul airspace design from the perspective of complexity and safety

The approach, descent, and climb phases of flights in terminal maneuvering areas (TMAs) are some of the critical parts of a flight in which more than half of accidents happen. For an ANSP (Air Navigation Service Provider), to fulfill the responsibility with a high-quality service degree while maintaining safety, these difficult areas should be designed carefully and equipped with the most efficient procedures. Point merge system (PMS), which is defined as a systemized method for sequencing arrival flows, is launched in Istanbul's new TMA (LTFM TMA) being designed by DHMI (Devlet Hava Meydanları Isletmesi) to improve safety and efficiency. In this paper, the airspace complexity is based on adjusted density and structural index, and safety indicators. To investigate the effects of the radical changes made in re-organized LTFM TMA on the safety issue in comparison with the previous terminal maneuvering area, LTBA TMA, six months' data consisting of 75215 arrival and departure flights are used. Results reflect that the LTFM TMA, one of the world's busiest terminal airspaces, has statistically significantly lower scores in terms of conflict numbers per aircraft, complexity metrics, adjusted density, the hour of interactions, and flight hours than LTBA TMA. Lastly, there exists no longer a significant relationship between conflict types and complexity after launching the new design and structure.     

离心式血液泵水力特性设计及其试验研究

借助商业软件NREC开展离心式血液泵的水力特性设计,其设计流量为5 L/min,设计转速为5000 r/min,得到离心叶轮和蜗壳的三维结构设计方案,并针对其全通道网格进行设计工况下三维流场的定常数值模拟研究.对其溶血性指标进行分析,发现离心式血液泵中95％ 区域切应力小于150 Pa,最大切应力小于500 Pa,满足人体对血液泵溶血性的要求.搭建离心式血液泵流量-压升特性试验测试平台,以质量分数为0.06％ 的黄原胶溶液为流动介质进行试验研究,试验结果显示在设计转速下的实际体积流量偏大于设计流量,整体压升在6550 Pa左右.     

Some issues in blockchain for accounting and the supply chain,with an application of distributed databases to virtual organizations

This paper reviews some recent blockchain‐based applications for information capture, distribution and preservation. As part of that review, this paper examines two key concerns with current blockchain designs for accounting and supply chain transactions: data independence and multiple semantic models for the same information distribution problem. Blockchain applications typically integrate database, application and presentation tiers all in the same ledger. This results in a general inability to query information in the ledger and other concerns. Further, since most applications appear to be private blockchain applications, there is a concern of agents needing to accommodate multiple blockchains depending on who their trading partners are and what they request. Finally, this paper uses a distributed database to design a ‘blockchain‐like’ system for virtual organizations.     

Fluctuating levels of personal role engagement within the working day: A multilevel study

In this diary study, we examined a theoretical model in which the psychological conditions of meaningfulness, availability, and safety serve as mechanisms through which the work context during discrete situations within the workday influences “state” engagement. We further theorised that a person's “trait” level of engagement would exert cross‐level effects on the state level relationships. Multilevel analyses based on a sample of 124 individuals in six organisations and 1,446 situational observations revealed that meaningfulness and availability (but not safety) mediated the relationships between perceptions of the work context and state engagement. High levels of trait engagement strengthened the within‐person relation between availability and state engagement, yet weakened the within‐person relation between meaningfulness and state engagement, suggesting two different processes may be at play. Overall, the findings advance our understanding of engagement as a multilevel and temporally dynamic psychological phenomenon and promote a contextually based HRM approach to facilitating engagement.     

基于模态应变能密度理论的网架结构损伤识别方法

为了研究网架结构的损伤检测方法,根据应变能密度理论,提出采用单元模态应变能密度差值作为网架结构损伤识别指标的方法,以损伤单元模态应变能密度差值的大小初步确定单元的损伤程度。分析了5种具有代表性的损伤工况,并在数值计算结果中引入了白噪声。结果显示,在一阶模态下,针对单损伤、多损伤和轻微损伤、严重损伤等不同损伤工况,损伤杆件的模态应变能密度差值均为高值。因此,该方法可以有效识别出网架结构的损伤位置,根据损伤单元的模态应变能密度差值大小初步确定单元的损伤程度,且在一定的噪声水平下具有较强的鲁棒性,对网架结构损伤识别具有参考价值。     

食品安全规制能提高生产者福利吗？——基于不同规制强度的检验

食品安全规制涉及政府、生产者和消费者三方利益主体的博弈。已有文献主要关注政府规制对减少生产者违规概率、提升食品安全水平和消费者福利所产生的作用。本文从生产者福利视角考察企业参与食品安全规制是否存在“收益率溢价”效应，以此对中国食品安全规制的间接效果进行实证检验。首先采用倾向得分匹配模型考察食品安全规制对企业资产收益率的平均影响效应，然后采用广义倾向得分匹配模型和门槛模型进一步考察不同规制强度与企业资产收益率的非线性关系。研究表明，当前食品安全规制对参与规制企业产生了“收益率溢价”的间接效果,但随着规制强度的扩展，企业资产收益率呈现先上升后下降的“倒U型”变化，具有显著的双重门槛特征，当企业持有4项质量认证证书时为“最优规制强度”。最后结合当前中国实际，解释了上述结论产生的原因及政策含义。     

政府投资工程总承包项目设计优化认定与收益归属研究

工程总承包模式以设计与施工的高度融合,日益在建筑业受到青睐。但由于政府投资项目中存在有关结余资金上缴国库等规定,容易导致政府投资工程总承包项目下设计优化产生的成果是进行分成或作为结余资金上缴界定不清。鉴于此,本文通过政策文件,并结合政府投资项目特点,分析政府投资工程总承包项目设计优化的情形认定以及在不同结算依据和合同计价方式下设计优化收益归属的界定,为有效激励总承包单位积极进行设计优化奠定基础。     

Examining the change in wellbeing following a holiday

Building on existing evidence that tourism contributes to wellbeing, this study aims to investigate how both hedonic and eudaimonic wellbeing changes after a holiday. A longitudinal inquiry involving three waves of observation (during, the fourth week, and the eighth week following a holiday) was carried out in five tourism cities in China, using Latent Growth Curve models to analyze change. Results suggest that life satisfaction – an indicator of hedonic wellbeing – does not decline as expected whereas other indicators of hedonic wellbeing declined dramatically in the first month and then mildly in the second month following a holiday. Comparatively, eudaimonic wellbeing declined gradually and mildly during the same two-month intervals. Higher levels of optimal tourism experiences predicted slower declines of both hedonic and eudaimonic wellbeing. Theoretical, methodological, and practical implications are discussed.     

关于民用气瓶动态监管的研究

民用气瓶也就是我们常说的液化气瓶,属于移动式高危产品,在人们日常生活中是必不可少的东西,因监管不完善导致每年发生的民用气瓶爆炸事件次数呈上升的状态,气瓶成了埋伏在我们周围的一个隐形“杀手”,严重威胁到人们的生命及财产安全,所以液化气市场需及时采取有效监管方案,彻底消除气瓶所带来的安全隐患。     

西餐牛肉类初加工与食品安全控制分析

牛肉是西餐主要的食材之一。本文通过对牛肉的初加工技术进行分析,探究对西餐牛肉类进行食品安全控制的措施,以提高牛肉类产品的整体质量,使西餐牛肉类产品能够达到我国食品安全的标准。