共查询到20条相似文献，搜索用时 31 毫秒
1.
John Monberg 《The Information Society》2013,29(4):281-284
The field of science and technology studies provides three landmarks useful for orienting the loose constellation of intellectual projects pursued under the rubric of Internet research. Interdisciplinarity, networks, and politics offer a foundation from which social change and progress can be assessed. These landmarks can help to examine the rapid change, the micro and macro connections, the constraints and possibilities for self-organization that stand to reconfigure the substance of power, class, and culture associated with the adoption of new communication technologies. 相似文献
2.
与传统的车辆定位导航系统不同,面向个人的定位业务需求往往是偶发的,并且更注重导航设备的便携性、易用性。分析了基于GPS技术并结合Google Earth地标显示功能的手持式GPS定位系统,可以普及用于家庭监护。 相似文献
3.
《国际创新研究学报(英文)》2022,6(3):196-215
This study examines technological capability accumulation and the Brazilian rice industry's technological trajectory. Multiple case design was chosen, with an analysis of seven firms involved in the Brazilian rice industry. The results indicate three factors: The first was the identification of technological landmarks for firms in this sector (peeling and polishing, electronic grain selection, electronic packaging, use of forklifts and palletizers, and Industry 4.0). The second is related to the fact that different firms implemented innovative activities and technologies at different speeds, originating from the sector's different technological trajectories. The third is associated with identifying activities within the Brazilian rice industry that can be generalized to other food industries. These results have implications for formulating public policies in the sector, such as creating producer support mechanisms (research and technology transfer institutions), qualification of professionals, and encouragement for economic efficiency and competition. 相似文献
4.
Vladimir Macias Israel Becerra Edgar Martinez Rafael Murrieta-Cid Hector M. Becerrra 《Journal of The Franklin Institute》2021,358(9):4761-4792
In this paper, we propose a feedback-based control approach to execute the time optimal motion trajectories for a differential drive robot. These trajectories are composed of straight lines and rotations in place. We show that the evolution of the position of a single landmark over time, in a local reference frame, makes it possible to track a prescribed time-optimal robot’s trajectory, based on feedback of the landmark’s position. We also show that the closed-loop system is an exponentially stable one with a nonvanishing perturbation, and that globally uniformly ultimately boundedness of the tracking errors can be achieved. The two main results of this work are: 1) Our approach leverages visual servo control type of methods with tools from optimal control for executing time-optimal trajectories in the state space based on feedback information. 2) The approach is able to work with the minimum number of landmarks–only one–this represents a necessary and sufficientcondition for landmark-based navigation. Experiments in a physical robot, a nonholonomic differential drive system equipped with an omnidirectional laser sensor, are shown, which validate the proposed theoretical modelling. 相似文献
5.
王江荔 《科学技术与辩证法》2011,28(1):100-104
历史上,＂冲突与对立＂曾被认为概括了科学与宗教、神学的关系。在科学与神学的关系史上有三个重要的里程碑：新的天文学革命、机械论的宇宙观和达尔文的人类起源说。近年来,人们认识到,科学与神学之间的冲突是由于二者对科学知识和神学知识的本质和范围作出了言过其实的断言。科学方法的成功、神学的新境遇以及自然科学的新发展推动了科学与神学的交流与对话。 相似文献
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7.
面向小班对象的森林资源变化遥感监测方法——以福建省厦门市为例 总被引：2，自引：0，他引：2
快速、客观、有效的森林资源变化监测技术是林业资源管理部门迫切需要解决的技术难题.本研究基于面向对象影像分析的思想,提出面向小班对象的森林资源变化遥感监测方法.首先,通过结合森林小班图层的大尺度影像分割,得到小班影像对象;其次,在森林小班专题对象内部,进行小尺度分割,自动提取变化图斑边界,得到变化与未变化小班影像对象;最后,通过对每一林地专题内部变化小班的分类解译,直接获得森林资源的地类变化信息.该方法可以根据影像分辨率的高低和森林小班图的尺度,满足不同比例尺森林覆盖变化监测的精度要求.以福建省厦门市为例,选用2011年RapidEye卫星影像和2007年森林小班图层进行森林覆盖变化信息提取.结果表明,所提出的方法在确保精度的同时,时间效率提高1～2倍,满足林业部门对森林覆盖变化信息快速准确获取的要求. 相似文献
8.
《Research Policy》2023,52(2):104697
Climate change represents a significant problem to the planet which raises concerns from stakeholder groups about corporate commitment to climate change issues. In this paper, we explore the effect of eco-innovation and climate governance on corporate commitment to climate change. We develop a unique measure for climate change commitment by considering four components, viz. whether a company supports the Sustainable Development Goal 13 on climate action, whether a company is aware that climate change can represent commercial risks or opportunities, whether a company reports Scope 3 CO2 emissions and whether a company sets a target for emission reduction. We measure eco-innovation by using a score collected from the Eikon database that reflects a company's capacity to reduce environmental costs, eco-innovation intensity measured as environmental expenditures over revenues. We also create an index computed as a composite score by totalling five eco-innovation proxies collected from the Eikon database that reflect companies' efforts to reduce environmental impact. Concerning climate governance, we focus on three proxies, namely the existence of an environmental committee, climate incentives and the existence of sustainability reports. Based on a sample of companies listed on the London Stock Exchange for the period of 2014–2020, we find that corporate eco-innovation is positively associated with climate change commitment. We argue that firms that adopt innovative approaches to efficiently control pollution and resource use and reduce their environmental impact are more committed to climate change. We also find that climate governance is positively associated with climate change commitment. We claim that companies that integrate climate change issues in governance can help address climate change risks and opportunities. Our empirical evidence provides recommendations for managers and policymakers to promote the adoption of eco-innovative technologies and integrate climate change issues in governance, which can contribute to corporate commitment to climate change. 相似文献
9.
《International Journal of Information Management》2017,37(6):505-519
With this work, we propose and validate a new service system in the context of Wayfinding services to improve the SmartCities mechanism: smart mobility, smart people, smart governance and smart living services. Steering and navigation tasks through an environment constitute an essential activity in our daily lives. They have a high degree of practical value in a variety of domains, such as public area design, architectural Wayfinding, geo-positioning and navigation, as well as urban planning and environmental design. At times, people with a visual impairment may also have problems in navigating autonomously and without personal assistance, especially in unknown environments (outdoor and indoor) using a smartphone. There could also be emergency situations in which the receiving of information in real time could be crucial. People with motor disabilities usually need information to avoid environments with obstacles, to arrive at a target or to manage touchscreens in daily activities and different environments. The use of landmarks is therefore vitally important in human navigation. Wayfinding systems must change, given that according to the United Nations (UN) Development Program, people with a disability represent around 10% of the world’s population, which is approximately 650 million people. Additionally, according to the World Health Organization, the world’s population of people 60 years of age and older has doubled since 1980 and is predicted to reach 2 billion by 2050. Most Wayfinding applications in the Smartphone market suffer from at least one of the following problems: the information is not dynamic, the design is not universal or the interface is not adapted to different users and preferences. Accordingly, apps do not currently have a universal design. The GAWA platform provides a universal and accessible solution to manage Wayfinding applications that focuses on people with a disability in outdoor and indoor environments in Smartcities. According to the results, the platform could be used for performing activities in their daily lives. 相似文献
10.
测定条件对旋光方向的影响 总被引：1，自引：0，他引：1
有些光学活性分子因测定条件不同而改变旋光方向,因为不同条件下,分子构象发生了变化。构象改变后,分子结构内的螺旋方向改变,其旋光方向随之改变。测定条件变化,若不影响化合物构象,则其旋光方向不改变。 相似文献
11.
技术变革次序双元与后发企业追赶 《科学学研究》2019,37(11):2016-2025
双元性对后发企业追赶具有重要的作用,但后发企业如何通过次序双元实现技术追赶的过程机制仍不清楚。慈星1988~2018年的纵向案例研究发现,后发企业在技术追赶过程中可根据行业技术变革性质开展不同的组织学习,技术范式发生转变的根本性变革期以探索性学习为主导,可由独立的自治机构负责,技术范式趋于稳定的收敛性变革期则以利用性为主导,可在主流机构内完成,同时随着追赶技术难度的增加,企业研发团队由轻量级升级为重量级。技术变革性质、组织学习类型与企业内部要素三者之间的动态匹配,使后发企业有节奏地在探索与利用之间进行转换,形成了次序双元,进而实现了对国际领先企业的技术追赶。本文研究结论对技术追赶和双元学习研究都具有一定的理论贡献。 相似文献
12.
对流换热边界条件下球体内固液相变过程移动热源法求解 总被引：1，自引：0，他引：1
应用移动热源法求解了对流换热条件下球体内具有明显相变界面的固液相变问题,分析了球体半径、相变材料潜热、外界对流换热条件对相变过程的影响,并进一步考虑实际相变过程存在的变对流边界条件,构造了一实用解法.为求解相变问题的数值方法提供了一校核其可靠性的新途径,还为实验结果提供了相互比较的数据.该方法及其结果对相变材料的分析与设计具有重要的实用价值 相似文献
13.
基于转移矩阵的土地利用变化信息挖掘方法探讨 总被引：28，自引：0，他引：28
土地利用变化是全球变化中的重要组成部分。本文以土地利用转移矩阵为基础,构建了土地利用净变化量、交换变化量、总变化量的计算方法,并计算了随机状态下各地类间相互转换的理论频数,通过实际转换量与理论转换量进行对比,构建判断土地利用转换规则的方法,从而能够更加清晰地判断土地利用变化的系统过程。应用上述方法对山东省德州市临邑县土地利用变化进行了实证分析,结果显示:临邑县耕地总变化量最大,其次是园林地和未利用地,最后是建设用地和其他土地,其中耕地几乎全部都是交换变化,而未利用地则相反,园林地和其他土地以交换变化为主,建设用地以净变化为主;从新增的角度来说,未利用地转化为其他土地最具有转换优势,其次是未利用地转换为园林地;从流失的去向看,其他土地转换为园林地最具转换优势,其次是耕地转换为园林地。结果表明该方法可以有效获取各土地利用类型动态变化信息,更清晰地辨别土地利用类型间的转换规则,能够为土地利用空间分析和建模提供更有用的信息。 相似文献
14.
绩效评价系统的内在驱动机制及其影响效应研究 总被引：2，自引：0，他引：2
摘要：本文系统地分析了绩效评价的内在驱动机制及其影响效应。验证性因子分析和探索性因子分析验证了学者Latham的开创性结论：有效的绩效评价系统构筑在正规化、目标导向以及组织公平三大基石之上。进一步研究表明,正规化与员工绩效之间存在“倒U型”关系;随着员工人力资本独特性提升,严格的绩效控制会降低工作绩效,而提高公平感知则会显著提升工作绩效,设置有挑战性的绩效目标对工作绩效有正向影响。但是在人力资本独特性低的情形下目标设置的激励效应与员工绩效呈现“S型”关系。本研究揭示,绩效评价应该从注重对员工行为结果的评估转向对员工自主管理能力的评估,从绩效行为管理转向对员工价值观的深层管理。 相似文献
15.
用方程解决问题,是思维方式的重要转折。小学生初学方程解决问题,情感上不认同,不愿积极主动运用方程;由于改变了已有的思维习惯,出现较大的认知障碍;缺少步骤方法的指导训练,解决问题时,或急于列方程或存在随意性,降低了正确率,无法体现方程思想的优越性。通过介绍方程的产生及其作用,帮助学生转变态度,主动学习运用;让学生在解决问题的过程中,经历、体验、试误,掌握用方程解决问题的步骤方法;通过设元、找等式等专项训练,提高用方程解决问题的能力。 相似文献
16.
Feng Li 《International Journal of Information Management》1997,17(6):451-464
Using the evidence gathered from 22 large firms in the UK since 1990, this paper highlights a radical change in a basic rule of organisational design: “from compromise to harmony”. Most existing organisational designs are based on a series of compromises (for instance, between central control and empowerment, or between spatial separation and process integration). Conventional organisational reforms have tended to change the balance between these compromises, and the improvement of one aspect often happens at the expense of the other. However, some recent evidence suggests that information and communication technologies (ICTs) can be used to resolve such compromises, and an organisation today can become more decentralised with improved central control, for example. This change can have profound implications for the future form of organisations. The paper goes on to argue that organisational redesign through ICTs should be treated explicitly as an emerging field of inquiry, and it will provide the basis for a new generation of organisational theories for the information economy. To fulfil this challenging task, at least three types of research are needed. 相似文献
17.
利用区域气候模式RegCM3模拟了2000年-2009年全国的气温及其变化,并通过地面气象观测资料对模拟结果进行了初步检验和分析。结果表明：模式总体上能模拟出全国的气温分布、梯度变化以及较为明显的高温中心,对中东部地区的模拟效果优于西部的青藏高原、新疆等地区。代表性气象站点2005年-2009年较2000年-2004年气温变化趋势的观测结果与模拟一致,模式具有一定的区域气候变化模拟能力。利用各区域气象站观测资料对模拟结果进行检验,进一步模拟出气温的年度和季节变化,对东北和华北的模拟效果优于其它地区,但模式对气温的模拟存在系统性偏低现象,特别是北方地区的高温季节、西南-长江流域一线的低温季节气温偏低较为明显。在全球气候变化背景下极端气候事件频繁发生,因此未来对模式模拟性能会有更高要求,在提高模式分辨率、改进模式物理化学机制,以及使用更多的地面观测资料等方面需要进一步深入研究。 相似文献
18.
Improving how knowledge is leveraged in organizations for improved business performance is today considered as a major organizational change. Knowledge management (KM) projects are stigmatized as demanding, fuzzy and complex, with questionable outcomes—more than 70% of them do not deliver what they promised. A case of Samsung Electronics mobile branch we present shows how KM projects can be more successful if they are treated as business process-oriented organizational change projects. Both organizations and academia can stand on the shoulders of giants as previous experience and research in that area is rich. Adding the KM flavor to such organizational change is the goal of this case study; the learning outcomes include a six-step KM solution design method, a justification for the business process level of analysis and managerial action, and the need for modest and just-do-it approach when introducing KM-related organizational interventions. 相似文献
19.
Research into the role of routine change has been conducted in relatively stable and structured organizational settings. This study extends the current understanding of routine change to more fluid organizational forms. Drawing on the literature in organizational routines and routine change, we develop and test a model that captures the dynamic relationships among routine change, routine diversity, and project performance in the context of open-source software development. By sequence-mining the digital trace data of OSS projects, we show that routine change reduces project popularity; however, this effect is mitigated as routine diversity increases. Thus, routine diversity provides a coping mechanism for participants to adapt to changing routines. This study reveals the dynamics in open-source development routines and their effects on project popularity, which can apply to various other fluid organizational forms. 相似文献
20.
《Research Policy》2019,48(10):103555
Understanding how policymaking processes can influence the rate and direction of socio-technical change towards sustainability is an important, yet underexplored research agenda in the field of sustainability transitions. Some studies have sought to explain how individual policy instruments can influence transitions, and the politics surrounding this process. We argue that such individual policy instruments can cause wider feedback mechanisms that influence not only their own future development, but also other instruments in the same area. Consequently, by extending the scope of analysis to that of a policy mix allows us to account for multiple policy effects on socio-technical change and resultant feedback mechanisms influencing the policy processes that underpin further policy mix change. This paper takes a first step in this regard by combining policy studies and innovation studies literatures to conceptualise the co-evolutionary dynamics of policy mixes and socio-technical systems. We focus on policy processes to help explain how policy mixes influence socio-technical change, and how changes in the socio-technical system also shape the evolution of the policy mix. To do so we draw on insights from the policy feedback literature, and propose a novel conceptual framework. The framework highlights that policy mixes aiming to foster sustainability transitions need to be designed to create incentives for beneficiaries to mobilise further support, while overcoming a number of prevailing challenges which may undermine political support over time. In the paper, we illustrate the framework using the example of the zero carbon homes policy mix in the UK. We conclude with deriving research and policy implications for analysing and designing dynamic policy mixes for sustainability transitions. 相似文献