The Globalization Practices of Chinese Telecom Operators

The telecommunications industry is one of the mosttypically globalized industries. Chinese telecom operatorscarry out the globalization practices in theirown ways. This paper sums up the characters of theChinese operators’ globalization based on a reviewof the recent efforts of Chinese operators. Fourmodes of globalization are pointed out undertakenby Chinese operators: Business Cooperation andAlliance, Branch and Subsidiary Company, Merge& Acquisition and Foreign Direct Investment andExportation of Expertise. And the behaviors of Chineseoperators are categorized into two dimensions:the target customer and the destination region. It isindicated that Chinese operators focus more on thedomestic customers when extending their servicesglobally, especially toward the developed countriesand regions. However, when they intend to graspnew market opportunities, they tend to aim at developingcountries.

An elastic-plastic analysis of short-leg shear wall structures during earthquakes

Short-leg shear wall structures are a new form of building structure that combine the merits of both frame and shear wall structures. Its architectural features, structure bearing and engineering cost are reasonable. To analyze the elastic-plastic response of a short-leg shear wall structure during an earthquake, this study modified the multiple-vertical-rod element model of the shear wall, considered the shear lag effect and proposed a multiple-vertical-rod element coupling beam model with a new local stiffness domain. Based on the principle of minimum potential energy and the variational principle, the stiffness matrixes of a short-leg shear wall and a coupling beam are derived in this study. Furthermore, the bending shear correlation for the analysis of different parameters to describe the structure, such as the beam height to span ratio, short-leg shear wall height to thickness ratio, and steel ratio are introduced. The results show that the height to span ratio directly affects the structural integrity; and the short-leg shear wall height to thickness ratio should be limited to a range of approximately 6.0 to 7.0. The design of short-leg shear walls should be in accordance with the ＂strong wall and weak beam＂ principle.

MULTI-CHANNEL TRANSMISSION STRATEGY FOR DYNAMIC SPECTRUM ACCESS

Cognitive radio is a promising technology that deals with the scarcity of radio spectrum. In this paper, we propose a new multi-channel transmission strategy for dynamic spectrum access in cognitive radio network. Starting with the model of spectrum activities, we present the multi-channel transmission strategy which has primary user's protection mechanism to improve the spectrum efficiency and study its performance under perfect and imperfect sensing. Numerical example results reveal that the performance of the proposed strategy has the superiority with respect to capacity performance of cognitive users and the protection of primary users.

Vertical shaking table tests on the structure with viscoelastic multi-dimensional earthquake isolation and mitigation devices

The viscoelastic multi-dimensional earthquake isolation and mitigation device is a new kind of passive control device, which can perform its "name-giving" task of earthquake isolation and earthquake mitigation simultaneously. In order to quantify its vertical earthquake isolation and mitigation effect on structures, firstly, shaking table tests on steel frame structures with and without the devices were carried out; secondly, analysis on dynamic characteristics and dynamic responses of the structures was also performed; furthermore, the finite element analytical results and the experimental results were compared. It can be shown from the analytical and experimental results that the devices have noticeable earthquake isolation and mitigation effect in the vertical direction.

Establishment and Analysis of the Fault Tree for the Oil Transfer Pump System in CNPC Work Zone

The reliability of the equipment is very important for the large petrochemical industry, especially for oil pump as the core component of driving equipment. In order to reduce the loss of the enterprise brought by equipment failure, it is need to find those reasons which may lead to equipment failure and take some preventive measures as early as possible. This article analyzes the failure of the oil transfer pump system in CNPC work zone systematically, qualitatively and quantitatively, using the fault tree analysis method. Then 105 groups of minimal cut sets are found, and the probability of system failure after a certain time operation is calculated by using Weibull distribution. Combined with specific requirements of reliability, the work zone may make a scientific decision of plant maintenance cycle according to the conclusion.

Device authentication for 5G terminals via Radio Frequency

The development of wireless communication network technology has provided people with diversified and convenient services.However,with the expansion of network scale and the increase in the number of devices,malicious attacks on wireless communication are becoming increasingly prevalent,causing significant losses.Currently,wireless communication systems authenticate identities through certain data identifiers.However,this software-based data information can be forged or replicated.This article proposes the authentication of device identity using the hardware fingerprint of the terminal’s Radio Frequency(RF)components,which possesses properties of being genuine,unique,and stable,holding significant implications for wireless communication security.Through the collection and processing of raw data,extraction of various features including time-domain and frequency-domain features,and utilizing machine learning algorithms for training and constructing a legal fingerprint database,it is possible to achieve close to a 97%recognition accuracy for Fifth Generation(5G)terminals of the same model.This provides an additional and robust hardware-based security layer for 5G communication security,enhancing monitoring capability and reliability.