521 research outputs found
Enhancing the learnability of Chinese–English dictionaries for Chinese as a foreign language learners: the neglected legacy of Robert Morrison in his compilation of Wuche Yunfu (1819)
In previous studies on learner lexicography, design features of both the content and presentation of learner's dictionaries are the two major research concerns. The quality assessment of learner's dictionaries also covers the two dimensions. Terms used for evaluating them are respectively "usability" or "availability" for the former and "findability" or "accessibility" for the latter. However, the lexicographical construction of "learnability", which takes into account the users' reference and learning needs, remains virtually unexplored either theoretically or practically. Compared to the features of dictionary design mentioned above, "learnability" as the design phi-losophy of learner lexicography is worth more serious consideration. The present paper aims at exploring the lexicographical notion of "learnability" by way of introducing the neglected legacy of Robert Morrison in his compilation of Wuche Yunfu (五车韵府) (1819)1, which is characterized by a high degree of learnability illustrated in the dictionary entries. Morrison's pioneering efforts may help with the conceptual clarification of "learnability" in compiling learner's dictionaries, bilingual ones in particular. Moreover, it is hoped that the recognition of Morrison's lexicographical practice will be beneficial to the future production of better Chinese–English dictionaries for non-native Chinese learners.Keywords: learnerability, learner lexicography, Chinese as a for foreign language learners, Wuche Yunfu, Chinese–English dictionaries, bilingua
Price competition model in decentralized and centralized supply chains with demand disruption
Purpose: The paper studies the price competition of a supply chain with one supplier and two competing retailers under occasional demand disruption.
Design/methodology/approach: The supply chain is either decentralized or centralized. The demand disruption for two retailers occurs with different probability. We analyze the effect of occurrence probability of demand disruption on the optimal prices of the supplier and two retailers.
Findings: We find that the profits of supplier, retailers and supply chain are decreasing with the occurrence probability of demand disruption.
Originality/value: It is helpful for supply chain members to adjust the original contracts to demand disruption.Peer Reviewe
Influential factors on water footprint: A focus on wheat production and consumption in virtual water import and export regions
Agriculture is a key sector and a major consumer of water resources; therefore, a clear understanding of the agricultural water demand for crop production and consumption is imperative for addressing water scarcity problems, particularly in water export regions. This study provides new insights into the influential factors driving the changes in the agricultural production water footprint (WFprod) and consumption water footprint (WFcon) in the net water import and net water export regions. The WFprod and WFcon of wheat are evaluated in Beijing city (the net water import region) and Heilongjiang province (the net water export region) over the period 1996–2015. The statistical significances of the influential factors, i.e., climate change, gross domestic product, population, dietary demand and technology update are determined using a multivariate linear regression model (LRM) and nonlinear regression model (NLRM). The results indicate that the gross domestic product and population were the dominant positive influential factors, whereas technology update and dietary demand were the dominant negative influential factors affecting the changes in the WFprod and WFcon in the net water import region. In the net water export region, technology update was the dominant negative influential factor affecting the changes in the WFprod and WFcon. Climate change did not contribute significantly to the changes in the WFprod and WFcon of wheat; however, it was an important factor (especially precipitation for the green WF with an average relative importance of more than 22% and the blue WF with an average relative importance of more than 15%) affecting the changes in the WFprod and WFcon of the crop. An in-depth analysis of the influential factors that contribute to the changes in the WFs is fundamentally important for decision-makers to develop countermeasures and strategic planning implementations to mitigate water resource pressure in China
Reduction of DC-link ripples for SiC-based three-phase four-wire inverters with unbalanced loads
Three-phase inverters are widely used in the smart
grid to integrate renewable energy resources. When the inverters
are used to feed the unbalanced three-phase loads, the threephase
four-wire inverters are usually required to provide the
current path for neutral currents. However, unbalanced loads will
cause undesirable second-order ripples on DC bus. Conventional
three-phase four-wire inverters with neutral legs can not address
this challenge. Bulky capacitors or extra active circuits are still
required to reduce the ripples. This inevitably leads to increased
size and cost of the system. Although SiC-based converters
have the advantage of achieving high power density, the DCbus
capacitance can not be reduced by simply replacing Si
IGBTs with SiC MOSFETs. In this paper, a new topology of
SiC-based three-phase four-wire inverters is proposed to reduce
the DC-bus ripples without adding any additional hardware
components. With the reduction of DC-bus ripples, the DC-bus
capacitance can be reduced to achieve high power density. The
equivalent circuit is analyzed and the control strategy for the
proposed topology is designed. The proposed topology is built in
Matlab/Simulink and simulation results are presented to verify
the proposed topology
- …