In this paper the authors explore the Global Positioning System （GPS） signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the perf...In this paper the authors explore the Global Positioning System （GPS） signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the performance of a software GPS receiver in terms of its speed. A trade-off study is done to seek a good balance between the acquisition accuracy and the processing time. The frequency-domain acquisition method by circular correlation, used in a software GPS receiver, has been improved by studying the power spectrum of the Coarse Acquisition （C/A） code alone. The analysis of C/A code reveals that its power spectrum is symmetrical; hence only half the points are required to perform circular correlation. Besides, either half of the spectrum is asymmetrical where a larger amount of power is concentrated in almost one-quarter of the spectrum on its either sides. This further reduces the number of points used to perform correlation. Comparative results of MATLAB simulation of full-size, half-size and quarter-size circular correlation done on actual data stored on hard disk are provided, and they agree with those obtained using GPS receiver. Further reduction in acquisition time has been achieved by investigating the effect of length of the noncoherent pre-integration period. The improved acquisition methods pave way for further development of new algorithms to enhance software GPS receiver performance.展开更多
This paper investigates social dimensions in the Libyan family and their relationship to the common practice of bribery. In Libya, bribery is most noticeable in administrative contexts where other practices such as fa...This paper investigates social dimensions in the Libyan family and their relationship to the common practice of bribery. In Libya, bribery is most noticeable in administrative contexts where other practices such as favouritism, fraud and forgery are also found. The paper aims to make an original contribution to knowledge in a little-researched area by examining social dimensions and cultural practices. The paper is based on the basic assumption that there is a relationship between accepting bribes and social dimensions surrounding the family in Libya and will thus also examine bribery as a social culture, by means of a set of variables such as gifts, promises, assistance and loans. The study took place in Benghazi, Libya, where the number of employees exceeded 200. The study was conducted using an interpretative epistemology and a quantitative method. Data were collected using quantitative research instruments and the Statistical Package for the Social Sciences （SPSS） was used to analyse the data. The findings of the study suggest that there is a relationship between family relationships, social status and the commission of the crime of bribery except for variables of social status and cultural background, in addition to the social relationship＇s effect on administration.展开更多
The technology innovation cooperation relationship of enterprises has evolved into the representation of complicated network. MATLAB software is used for computer simulation on network evolution process of technology ...The technology innovation cooperation relationship of enterprises has evolved into the representation of complicated network. MATLAB software is used for computer simulation on network evolution process of technology innovation cooperation, and Ucinet characterization analysis software is used to compute characteristic values of simulation network such as power law index of network, average route length and accumulation coefficients. It is compared with the actual network, and the simulation results are analyzed to verify the rationality of the constructed evolution model.展开更多
The purpose of this study was to explore the triphasic mechanical properties of osteoarthritic cartilage with different pathological grades.First,samples of cartilage from rabbits with different stages of osteoarthrit...The purpose of this study was to explore the triphasic mechanical properties of osteoarthritic cartilage with different pathological grades.First,samples of cartilage from rabbits with different stages of osteoarthritis (OA) were graded.Following this,the cartilage was strained by a swelling experiment,and changes were measured using a high-frequency ultrasound system.The result,together with fixed charge density and water volume fraction of cartilage samples,was used to estimate the uniaxial modulus of the cartilage tissue,based on a triphasic model.For the control cartilage samples,the uniaxial elastic modulus on the cartilage surface was lower than those in the middle and deep layers.With an increase in the OA grade,the uniaxial elastic modulus of the surface,middle and deep layers decreased.A significant difference was found in the surface elastic modulus of different OA grades (P<0.01),while no significant differences were identified for OA cartilages of Grades 1 and 2 in the middle and deep layers (P<0.01).Compared with Grades 1 and 2,there was a significant reduction in the elastic modulus in the middle and deep layers of Grade 3 OA cartilage (P<0.05).Overall,this study may provide a new quantitative method to evaluate the severity of OA using the mechanical properties of cartilage tissue.展开更多
文摘In this paper the authors explore the Global Positioning System （GPS） signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the performance of a software GPS receiver in terms of its speed. A trade-off study is done to seek a good balance between the acquisition accuracy and the processing time. The frequency-domain acquisition method by circular correlation, used in a software GPS receiver, has been improved by studying the power spectrum of the Coarse Acquisition （C/A） code alone. The analysis of C/A code reveals that its power spectrum is symmetrical; hence only half the points are required to perform circular correlation. Besides, either half of the spectrum is asymmetrical where a larger amount of power is concentrated in almost one-quarter of the spectrum on its either sides. This further reduces the number of points used to perform correlation. Comparative results of MATLAB simulation of full-size, half-size and quarter-size circular correlation done on actual data stored on hard disk are provided, and they agree with those obtained using GPS receiver. Further reduction in acquisition time has been achieved by investigating the effect of length of the noncoherent pre-integration period. The improved acquisition methods pave way for further development of new algorithms to enhance software GPS receiver performance.
文摘This paper investigates social dimensions in the Libyan family and their relationship to the common practice of bribery. In Libya, bribery is most noticeable in administrative contexts where other practices such as favouritism, fraud and forgery are also found. The paper aims to make an original contribution to knowledge in a little-researched area by examining social dimensions and cultural practices. The paper is based on the basic assumption that there is a relationship between accepting bribes and social dimensions surrounding the family in Libya and will thus also examine bribery as a social culture, by means of a set of variables such as gifts, promises, assistance and loans. The study took place in Benghazi, Libya, where the number of employees exceeded 200. The study was conducted using an interpretative epistemology and a quantitative method. Data were collected using quantitative research instruments and the Statistical Package for the Social Sciences （SPSS） was used to analyse the data. The findings of the study suggest that there is a relationship between family relationships, social status and the commission of the crime of bribery except for variables of social status and cultural background, in addition to the social relationship＇s effect on administration.
文摘The technology innovation cooperation relationship of enterprises has evolved into the representation of complicated network. MATLAB software is used for computer simulation on network evolution process of technology innovation cooperation, and Ucinet characterization analysis software is used to compute characteristic values of simulation network such as power law index of network, average route length and accumulation coefficients. It is compared with the actual network, and the simulation results are analyzed to verify the rationality of the constructed evolution model.
基金supported by the National Natural Science Foundation of China (Grant No.31170896)Natural Science Foundation of Shandong Province (Grant No.ZR2009CMO32)
文摘The purpose of this study was to explore the triphasic mechanical properties of osteoarthritic cartilage with different pathological grades.First,samples of cartilage from rabbits with different stages of osteoarthritis (OA) were graded.Following this,the cartilage was strained by a swelling experiment,and changes were measured using a high-frequency ultrasound system.The result,together with fixed charge density and water volume fraction of cartilage samples,was used to estimate the uniaxial modulus of the cartilage tissue,based on a triphasic model.For the control cartilage samples,the uniaxial elastic modulus on the cartilage surface was lower than those in the middle and deep layers.With an increase in the OA grade,the uniaxial elastic modulus of the surface,middle and deep layers decreased.A significant difference was found in the surface elastic modulus of different OA grades (P<0.01),while no significant differences were identified for OA cartilages of Grades 1 and 2 in the middle and deep layers (P<0.01).Compared with Grades 1 and 2,there was a significant reduction in the elastic modulus in the middle and deep layers of Grade 3 OA cartilage (P<0.05).Overall,this study may provide a new quantitative method to evaluate the severity of OA using the mechanical properties of cartilage tissue.
