Carbon-Neutralized Joint User Association and Base Station Switching for Green Cellular Networks

Mitigating climate change and its impacts is one of the sustainable development goals (SDGs) required by United Nations for an urgent action. Increasing carbon emissions due to human activities is the root cause to climate change. Telecommunication networks that provide service connectivity to mobile users contribute great amount of carbon emissions by consuming lots of non-renewable energy sources. Beyond the improvement on energy efficiency, to reduce the carbon footprint, telecom operators are increasing their adoption of renewable energy (e.g., wind power). The high variability of renewable energy in time and location; however, creates difficulties for operators when utilizing renewables for the reduction of carbon emissions. In this paper, we consider a heterogeneous network consisted of one macro base station (MBS) and multiple small base stations (SBSs) where each base station (BS) is powered by both of renewable and non-renewable energy. Different from the prior works that target on the total power consumption, we propose a novel scheme to minimize the carbon footprint of networks by dynamically switching the ON/OFF modes of SBSs and adjusting the association between users and BSs to access renewables as much as possible. Our numerical analysis shows that the proposed scheme significantly reduces up to 86% of the nonrenewable energy consumption compared to two representative baselines.Comment: To appear in IEEE International Conference on Communications (ICC) 202

Characterization of the Antheraea pernyi abnormal wing disc gene that may contribute to its temperature tolerance

It has been known that the abnormal wing disc (awd) gene encodes a nucleoside diphosphate kinase and is closely related to wing development in Drosophila melanogaster and Bombyx mori. In the present study, the awd gene was isolated and characterized from Antheraea pernyi, a well-known wild silkmoth. The isolated cDNA sequence is 666 bp in length with an open reading frame of 462 bp encoding a polypeptide of 153 amino acids, which contains a putative nucleoside diphosphate kinases active site motif and conserved multimer interface. The deduced A. pernyi awd protein sequence reveals 75, 82 and 96% identity with its homologue of Homo sapiens, D. melanogaster, and B. mori, respectively. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that the awd gene was transcribed during all four developmental stages (egg, larva, pupa, and moth), and present in all tissues tested (blood, midgut, silk glands, Malpighian tublues, spermaries, ovaries, brain, muscle, fat body and body wall), with the highest abundance in Malpighian tubules. Interestingly, mRNA expression level in pupal fat body was significantly down-regulated after cold shock (4°C) compared with the control (26°C) and significantly up-regulated after heat shock (46°C). The results indicated that the A. pernyi awd gene is inducible, and that its expression effect is different after cold stress and heat stress. Consequently, we refer that the product of the awd gene may contribute to its temperature tolerance.Key words: Antheraea pernyi, abnormal wing disc gene, cloning, expression pattern, temperature stress

Resource Slack, Innovation Ambidexterity, and Quality Performance: Knowledge Heterogeneity Perspective

Abstract. Resource slack and innovation ambidexterity can both be represented and connected conceptually with heterogeneous knowledge structure. Hypothesizing with the logic of knowledge heterogeneity, the present study empirically examined ambidexterity’s mediation effect in the relationship between two forms of resource slacks (i.e., human and financial resources) and product quality. Companies in Taiwanese manufacturing industry were located based on the random inspection conducted by the Department of Budget, Accounting and Statistics of the Government in 2011, and surveyed. Our findings demonstrated that slack resource is only an indirect factor for product quality evaluated by internal developers and producers (i.e. development and delivery processes) and external customers (product-specific quality). Specifically, first, different resource slacks influence differently on ambidexterity; second, both exploration and exploitation positively influence quality of innovation; third, ambidexterity plays a significant mediator’s role that may strategically alter the relationship between slack and quality. Research has paid increasing attention to ambidexterity (i.e., exploration and exploitation) in organizational innovation. Mostly, however, focus on the influencing factors leading to possible ambidextrous design or implementation of innovation. Few have examined ambidexterity’s effects on specific dimensions of innovation as outcomes.Keywords. Resource slacks, Ambidexterity, Quality, Knowledge heterogeneity.JEL. M10; M11; M14

Investigating the Knowledge-Sharing Behavior ina Professional Virtual Community

This research aims at investigating the knowledge sharing-behaviors in a teachers’ professional virtual community. Logs data in the entire community and in special interest groups (SIGs) were analyzed. Some typical behaviors were identified by the clustering analysis in this study. The largest group of member belongs to inactive users. They rarely log in the system, are passive in uploading or downloading teaching materials, and almost never post or reply messages. Another group is active in receiving knowledge while reluctant to give knowledge or to respond. The third group frequently login the system, is the most active in sharing knowledge, and actively searching knowledge. However, the third group contains only a small number of members. Furthermore, fifty-five members of the knowledge-sharing group were interviewed using focus group technique to find out qualitative information as to why they are willing to share information and what are their concerns in sharing information. The results indicated that knowledge sharing is not a common behavior in professional virtual community, and knowledge-sharing culture is difficult to promote even in non-competitive professional communities. Secondly, knowledge cannot flow easily throughout the community even when certain knowledge flow promoting mechanism is provided. Thirdly, professional autonomy may hinder the frequency of interactions with others in professional virtual community. Fourthly, attitudes regarding information ownership are important factors in knowledge sharing of a professional virtual community. Finally, teaching and IT usage experiences are not major factors affecting knowledge-sharing behavior in pro fessional virtual communities

A Follow-up Study of Neonatal Interatrial Shunt with Echocardiography until Twelve to Fifteen Months of Age

ObjectiveTo assess the incidence and natural history of full-term neonates with interatrial shunt (IAS).MethodsA follow-up study of 1389 neonates who received screening echocardiography between 2003 and 2006. Babies with IAS at 2 to 4 days of life underwent follow-up echocardiography at 2 to 4 months, 6 to 9 months and 12 to 15 months of age until closure of IAS.ResultsThe ratio of IAS was 68.3% initially. No significant demographic differences were identified between infants with and without initial IAS. Among 949 neonates with initial IAS, 84.5% infants had a left-to-right interatrial shunt, 13.5% had bidirectional shunt and 2% had predominantly right-to-left shunt. The persistence rate of IAS at 12 to 15 months of age was 3.8% (44/1166). The initial size of IAS ranged from 1.2 to 7.7 mm (4.3 ± 1.1 mm) detected by color Doppler flow mapping and cases were divided into three groups: small (≦5 mm), medium (5 to 8 mm) and large group (≧8 mm). There were 74.6% infants in the small group and 25.4% in the medium group initially. The neonates in the initial small group would always see their IAS close or else they would remain in the small group. Those in the final medium and large size groups always came from the initial medium group. The late closure rate of IAS was 93.9% of infants with initial IAS. The closure curves of initial small and medium sized groups were significantly different, and their late closure rates were 95.1% and 90.4%, respectively.ConclusionsIAS was very common during early neonatal stage, but most cases would close after 1 year. The late closure rate of initial IAS was different if using a cutpoint of 5 mm