Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is ...Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is well known that routing is a challenging problem in VANETs due to the fast-changing network typology caused by high mobility at both ends of transmission. Moreover, under urban environment, there are two non-negligible factors in routing protocol design, the non-uniform vehicle distribution caused by traffic lights, and the network congestion due to high traffic demand in rush hours. In this paper, we propose a greedy traffic light and queue aware routing protocol(GTLQR) which jointly considers the street connectivity, channel quality, relative distance, and queuing delay to alleviate the packet loss caused by vehicle clustering at the intersection and balance the traffic load among vehicles. Through performance evaluation, we show that our proposed protocol outperforms both TLRC and GLSR-L in terms of packet delivery ratio and end-to-end delay.展开更多
In this study, we propose the use of the Degree of Alignment(DOA) in engineering applications for evaluating the precision of and identifying the transfer alignment on a moving base. First, we derive the statistical f...In this study, we propose the use of the Degree of Alignment(DOA) in engineering applications for evaluating the precision of and identifying the transfer alignment on a moving base. First, we derive the statistical formula on the basis of estimations. Next, we design a scheme for evaluating the transfer alignment on a moving base, for which the attitude error cannot be directly measured. Then, we build a mathematic estimation model and discuss Fixed Point Smoothing(FPS), Returns to Scale(RTS), Inverted Sequence Recursive Estimation(ISRE), and Kalman filter estimation methods, which can be used when evaluating alignment accuracy. Our theoretical calculations and simulated analyses show that the DOA reflects not only the alignment time and accuracy but also differences in the maneuver schemes, and is suitable for use as an integrated evaluation index. Furthermore, all four of these algorithms can be used to identify the transfer alignment and evaluate its accuracy. We recommend RTS in particular for engineering applications. Generalized DOAs should be calculated according to the tactical requirements.展开更多
In this paper, we derive a general formula of the flow equtions for the Harry-Dym hierarchy. And three applications in n-reduction, （2 ＋ 1）-dimensional generalization, and Kupershmidt reduction, are considered.
In case of the failure of Automatic Train Control （ATC）, it is necessary to organize the train by Telephone Block System. In this paper, the APP system is built on the basis of local area network, which is focus on ...In case of the failure of Automatic Train Control （ATC）, it is necessary to organize the train by Telephone Block System. In this paper, the APP system is built on the basis of local area network, which is focus on the simulation station map of Telephone Block System, Wain operation, equipment failure. This APP can vividly simulate the application of Telephone Block System in train urban transit organization.展开更多
Abstract： The main purpose of the research was to study a role and place of managers in maintaining staff policy at pharmaceutical companies. It was interesting to see how Georgian pharmaceutical companies are gettin...Abstract： The main purpose of the research was to study a role and place of managers in maintaining staff policy at pharmaceutical companies. It was interesting to see how Georgian pharmaceutical companies are getting new employees at work, what is the priority of the new recruits？ What methods are used for selection and recruitment？ There were made inquiries by the way of filling applications, which （the applications） were given to the managers ofAversi, PSP, GPC, Pharmadepot and Pharmaceutical House. 50 managers were interviewed totally. It was established that pharmaceutical company management appoints people on the position of pharmacist-managers mainly on the basis of contract （90%）. At present, the pharmacist education does not comply with the competence, so 55% of interviewed managers are bachelors, 45% are masters. In order to increase the management＇s qualifications, pharmaceutical companies are conducting seminars （50%）, trainings （30%）, and testing （20%）. Staff administration in the pharmacies is mainly carried out by the company administration （75%）, rarely by managers （25%）, but very often the administration takes into consideration the manager＇s opinion; employees are accepted by testing-interview （70%） or CV （30%）. Professional career and experience of the newly employed staff are not highly important （50/50）, and the company prefers to educate and share practice to the personnel itself. It is possible to conclude that today the pharmacist-managers of the pharmacies are working in accordance with the contractual fights and obligations signed with the employers and pharmaceutical activities regulated under non-governmental institutes. As a result, it is important to be included special features of pharmaceutical management and the recommendations offered by the World Health Organization and the International Pharmaceutical Federation in the articles of regulatory laws.展开更多
基金supported by the Beijing University of Posts and Telecommunications project No.500418759the State Key Laboratory of Networking and Switching Technology project No.600118124
文摘Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is well known that routing is a challenging problem in VANETs due to the fast-changing network typology caused by high mobility at both ends of transmission. Moreover, under urban environment, there are two non-negligible factors in routing protocol design, the non-uniform vehicle distribution caused by traffic lights, and the network congestion due to high traffic demand in rush hours. In this paper, we propose a greedy traffic light and queue aware routing protocol(GTLQR) which jointly considers the street connectivity, channel quality, relative distance, and queuing delay to alleviate the packet loss caused by vehicle clustering at the intersection and balance the traffic load among vehicles. Through performance evaluation, we show that our proposed protocol outperforms both TLRC and GLSR-L in terms of packet delivery ratio and end-to-end delay.
基金Supported by the National Natural Science Foundation of China （61633008）, the National Natural Science Foundation of China （61203225）, the Natural Science Foundation of Heilongjiang Province of China（QC2014C069）, the Special fund for the Central Universities （HEUCF160401）, and Provincial Postdoctoral Scientific Research Foundation （LBH-Q 15032）.
文摘In this study, we propose the use of the Degree of Alignment(DOA) in engineering applications for evaluating the precision of and identifying the transfer alignment on a moving base. First, we derive the statistical formula on the basis of estimations. Next, we design a scheme for evaluating the transfer alignment on a moving base, for which the attitude error cannot be directly measured. Then, we build a mathematic estimation model and discuss Fixed Point Smoothing(FPS), Returns to Scale(RTS), Inverted Sequence Recursive Estimation(ISRE), and Kalman filter estimation methods, which can be used when evaluating alignment accuracy. Our theoretical calculations and simulated analyses show that the DOA reflects not only the alignment time and accuracy but also differences in the maneuver schemes, and is suitable for use as an integrated evaluation index. Furthermore, all four of these algorithms can be used to identify the transfer alignment and evaluate its accuracy. We recommend RTS in particular for engineering applications. Generalized DOAs should be calculated according to the tactical requirements.
基金Supported by the Natural Science Foundation of China under Grant Nos.10671187 and 10971 109Supported by Program for New Century Excellent Talents in Universities under Grant No.NECT-08-0515
文摘In this paper, we derive a general formula of the flow equtions for the Harry-Dym hierarchy. And three applications in n-reduction, （2 ＋ 1）-dimensional generalization, and Kupershmidt reduction, are considered.
文摘In case of the failure of Automatic Train Control （ATC）, it is necessary to organize the train by Telephone Block System. In this paper, the APP system is built on the basis of local area network, which is focus on the simulation station map of Telephone Block System, Wain operation, equipment failure. This APP can vividly simulate the application of Telephone Block System in train urban transit organization.
文摘Abstract： The main purpose of the research was to study a role and place of managers in maintaining staff policy at pharmaceutical companies. It was interesting to see how Georgian pharmaceutical companies are getting new employees at work, what is the priority of the new recruits？ What methods are used for selection and recruitment？ There were made inquiries by the way of filling applications, which （the applications） were given to the managers ofAversi, PSP, GPC, Pharmadepot and Pharmaceutical House. 50 managers were interviewed totally. It was established that pharmaceutical company management appoints people on the position of pharmacist-managers mainly on the basis of contract （90%）. At present, the pharmacist education does not comply with the competence, so 55% of interviewed managers are bachelors, 45% are masters. In order to increase the management＇s qualifications, pharmaceutical companies are conducting seminars （50%）, trainings （30%）, and testing （20%）. Staff administration in the pharmacies is mainly carried out by the company administration （75%）, rarely by managers （25%）, but very often the administration takes into consideration the manager＇s opinion; employees are accepted by testing-interview （70%） or CV （30%）. Professional career and experience of the newly employed staff are not highly important （50/50）, and the company prefers to educate and share practice to the personnel itself. It is possible to conclude that today the pharmacist-managers of the pharmacies are working in accordance with the contractual fights and obligations signed with the employers and pharmaceutical activities regulated under non-governmental institutes. As a result, it is important to be included special features of pharmaceutical management and the recommendations offered by the World Health Organization and the International Pharmaceutical Federation in the articles of regulatory laws.
