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41.
Orsenigo Luigi Pammolli Fabio Riccaboni Massimo Bonaccorsi Andrea Turchetti Giuseppe 《Journal of Management and Governance》1997,1(2):147-175
The paper moves a step forward in the direction of establishing a connection between the structure and evolution of knowledge
bases and the structure and evolution of organizational forms in innovative activities in a science-intensive industry. The
paper has an explicit focus on the dynamics of the network of collaborative agreements in R&D in the pharma/biotech industry
after the “molecular biology revolution”. Using a comprehensive dataset, built by the authors integrating several sources
in the industry, the dynamics of the network over time is extensively analyzed. With regards to network structure, it is found
that, while the size of the network increases over time due to net flows of entry, its topological properties remain relatively
unchanged. The evolution of the network has occurred without relevant deformations in the core-periphery profile. With regards
to age-dependent propensity to collaborate, the paper finds that the extent of inter-generational collaboration is much more
significant than intra-generational collaboration. In addition, the propensity of firms of a given generation to enter into
collaboration with firms of a different generation increases with the distance between the two, while the total number of
intra-generational collaborations decreases over time and, moreover, tends to decrease for most recent generations. In the
paper a unitary and coherent explanation of the evidence is developed, coming to reveal the existence of a striking isomorphism
between structural properties of the dynamics of knowledge and of the evolution of network structure.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
42.
Effective supply chain management (SCM) has become a potentially valuable way of securing competitive advantage and improving organizational performance since competition is no longer between organizations, but among supply chains. This research conceptualizes and develops five dimensions of SCM practice (strategic supplier partnership, customer relationship, level of information sharing, quality of information sharing, and postponement) and tests the relationships between SCM practices, competitive advantage, and organizational performance. Data for the study were collected from 196 organizations and the relationships proposed in the framework were tested using structural equation modeling. The results indicate that higher levels of SCM practice can lead to enhanced competitive advantage and improved organizational performance. Also, competitive advantage can have a direct, positive impact on organizational performance. 相似文献
43.
对大数据和企业精准营销相关性的分析能够为精准营销的实施提供基础和技术平台,为企业对大数据的管理提供一定的方向,将很大程度影响企业的竞争力和发展。在拟定大数据和精准营销指标体系基础上,通过对黑龙江省服务业、商业企业、制造业和现代农业企业进行问卷调查,运用结构方程模型分析其相关性。分析结果显示,大数据与精准营销具有显著相关性,客户数据挖掘对大数据具有显著影响,精准广告投放对精准营销具有显著影响。据此指出,企业应当充分利用大数据技术,注重客户数据挖掘,提高营销的精准性,使其能适应市场竞争带来的机遇与挑战。 相似文献
44.
45.
煤矿瓦斯爆炸事故单危险源风险度量模型研究 总被引:1,自引:0,他引:1
本文研究了煤矿瓦斯爆炸事故危险源的分类,把危险源划分为人的不安全行为、机器设备不安全状态、环境不安全特征和管理缺陷四大类,并根据煤矿现场调查各类危险源的数据以及相应数学方法的特点,提出煤矿瓦斯爆炸事故人、机器设备(物)、环境、管理四类危险源的风险度量方法,在此基础上构建四类危险源的风险度量模型。研究表明,危险源的风险度量模型由风险发生的可能性、危险源重要度以及事故导致的损失构成;危险源风险发生的可能性,在具体应用中可以采用各类危险源的不可靠度、故障率等来衡量;危险源在事故中的重要度可以通过分析事故故障树种要素结构重要性获取。根据风险评价的结果,可以对危险源进行分级排序,从而为煤矿事故单危险源的控制提供依据。 相似文献
46.
《Journal of Statistical Computation and Simulation》2012,82(2):145-187
This paper studies the effects of non-normality and autocorrelation on the performances of various individuals control charts for monitoring the process mean and/or variance. The traditional Shewhart X chart and moving range (MR) chart are investigated as well as several types of exponentially weighted moving average (EWMA) charts and combinations of control charts involving these EWMA charts. It is shown that the combination of the X and MR charts will not detect small and moderate parameter shifts as fast as combinations involving the EWMA charts, and that the performana of the X and MR charts is very sensitive to the normality assumption. It is also shown that certain combinations of EWMA charts can be designed to be robust to non-normality and very effective at detecting small and moderate shifts in the process mean and/or variance. Although autocorrelation can have a significant effect on the in-control performances of these combinations of EWMA charts, their relative out-of-control performances under independence are generally maintained for low to moderate levels of autocorrelation. 相似文献
47.
The amount of radon in natural gas varies with its source. Little has been published about the radon from shale gas to date, making estimates of its impact on radon‐induced lung cancer speculative. We measured radon in natural gas pipelines carrying gas from the Marcellus Shale in Pennsylvania and West Virginia. Radon concentrations ranged from 1,520 to 2,750 Bq/m3 (41–74 pCi/L), and the throughput‐weighted average was 1,983 Bq/m3 (54 pCi/L). Potential radon exposure due to the use of Marcellus Shale gas for cooking and space heating using vent‐free heaters or gas ranges in northeastern U.S. homes and apartments was assessed. Though the measured radon concentrations are higher than what has been previously reported, it is unlikely that exposure from natural gas cooking would exceed 1.2 Bq/m3 (<1% of the U.S. Environmental Protection Agency's action level). Using worst‐case assumptions, we estimate the excess lifetime (70 years) lung cancer risk associated with cooking to be 1.8×10?4 (interval spanning 95% of simulation results: 8.5×10?5, 3.4×10?4). The risk profile for supplemental heating with unvented gas appliances is similar. Individuals using unvented gas appliances to provide primary heating may face lifetime risks as high as 3.9×10?3. Under current housing stock and gas consumption assumptions, expected levels of residential radon exposure due to unvented combustion of Marcellus Shale natural gas in the Northeast United States do not result in a detectable change in the lung cancer death rates. 相似文献
48.
Zahra Mansourvar Torben Martinussen Thomas H. Scheike 《Scandinavian Journal of Statistics》2016,43(2):487-504
The mean residual life measures the expected remaining life of a subject who has survived up to a particular time. When survival time distribution is highly skewed or heavy tailed, the restricted mean residual life must be considered. In this paper, we propose an additive–multiplicative restricted mean residual life model to study the association between the restricted mean residual life function and potential regression covariates in the presence of right censoring. This model extends the proportional mean residual life model using an additive model as its covariate dependent baseline. For the suggested model, some covariate effects are allowed to be time‐varying. To estimate the model parameters, martingale estimating equations are developed, and the large sample properties of the resulting estimators are established. In addition, to assess the adequacy of the model, we investigate a goodness of fit test that is asymptotically justified. The proposed methodology is evaluated via simulation studies and further applied to a kidney cancer data set collected from a clinical trial. 相似文献
49.
人口空间动态与区域经济发展的耦合关系是同城化区域间共同面对的重要课题。本文在解构人口空间动态维度主体的基础上,将人口空间动态的诉求机制与动因机理架构于更低交易费用的利益诉求之上,解析人口空间动态的模式选择,深入探讨人口空间动态与区域经济发展的耦合关联性。在此基础上,提出引导人口流动与合理分布的策略。研究成果将有助于更好地理解同城化态势下人口空间演变的动因机理,为同城区域的经济发展、城市规划、文化交融等方面的科学设计提供重要参考。 相似文献
50.
《Journal of Social Work Practice》2012,26(1):81-90
This paper arises out of psychoanalytically oriented consultancy to teams of staff in the helping professions where there is a statutory 'duty to care'. It takes as its premise the seemingly paradoxical hypothesis that workers may need to split off part of their emotional experience in order to preserve their own mental health and provide reliable services to their clients. I argue that while a professional 'duty to care' requires us to be emotionally 'in touch', the demands of our clients together with the demands of the institutional response to the 'duty to care' cause us to split off parts of our awareness. I also argue that provided the splitting does not become extreme we are doing no more or less than the rest of society. In other words, there is a degree of 'normal splitting' which numbs our awareness of danger and destructiveness and seeks to protect us from too much anxiety and pain. Yet if professional workers are charged with the responsibility of assessing risk and acting accordingly for the protection of all concerned they need ways of being 'in touch' (re-integrating the splits) for some or enough of the time. Finally, I will describe ways of being 'in touch', illustrating the difficulty and the pain of re-integrating the splits and some of the insights that can arise out of this work with examples from my consultancy work. 相似文献