This research focused on the social concern of college students5 participation in physical exercise and mobile phone dependence.The research model and hypotheses in this study were constructed based on the self-contro...This research focused on the social concern of college students5 participation in physical exercise and mobile phone dependence.The research model and hypotheses in this study were constructed based on the self-control theory and by reviewing previous research.This research distributed questionnaires to 207 college students from a university in Guangzhou,China to obtain relevant data.Mediation analysis was employed to test the four hypotheses drawn from empirical and conceptual research.The results of this research showed that first,the longer the exercise duration of college students,the higher the level of their self-control,thus exercise duration has a significant positive impact on self-control.Second,increasing the exercise duration of college students had no effect on their mobile phone dependence.Third,the higher the level of selfcontrol,the lower the dependence on mobile phones,thus signifying that self-control has significantly negative impact on mobile phone dependence.Fourth,self-control plays a mediating role in the effect of exercise duration on mobile phone dependence.In conclusion,the longer the exercise duration of college students,the higher the level of self-control,in which it is able to significantly reduce the dependence on mobile phones.展开更多
We investigated factors contributing to mobile phone dependence. To 139 medical students, we administered a self-reporting questionnaire designed to evaluate mobile phone dependence, health-related lifestyle, patterns...We investigated factors contributing to mobile phone dependence. To 139 medical students, we administered a self-reporting questionnaire designed to evaluate mobile phone dependence, health-related lifestyle, patterns of behavior, and depressive state. Multivariate logistic regression analysis revealed that scores for poor health-related lifestyle, Type A behavior pattern, and presence of depression are independently associated with degree of mobile phone dependency. These findings suggest that persons with an unhealthy lifestyle, Type A behavior traits, or depression might benefit from mobile phone use guidance.展开更多
We investigated factors contributing to Internet addiction in 105 Japanese medical students. The subjects were administered by a self-reporting questionnaire designed to evaluate demographic factors, Internet addictio...We investigated factors contributing to Internet addiction in 105 Japanese medical students. The subjects were administered by a self-reporting questionnaire designed to evaluate demographic factors, Internet addiction, loneliness, health-related lifestyle factors, depressive state, patterns of behavior, and mobile phone dependence. Results of multivariate logistic regression analysis indicated that loneliness and mobile phone dependence were positively related to degree of addiction. Our findings suggest that Internet addiction is associated with loneliness and mobile phone dependence in Japanese students.展开更多
Urban traffic volume detection is an essential part of trafficplanning in terms of urban planning in China. To improve the statisticsefficiency of road traffic volume, this thesis proposes a method for predictingmotor...Urban traffic volume detection is an essential part of trafficplanning in terms of urban planning in China. To improve the statisticsefficiency of road traffic volume, this thesis proposes a method for predictingmotor vehicle traffic volume on urban roads in small and medium-sizedcities during the traffic peak hour by using mobile signal technology. Themethod is verified through simulation experiments, and the limitations andthe improvement methods are discussed. This research can be divided intothree parts: Firstly, the traffic patterns of small and medium-sized cities areobtained through a questionnaire survey. A total of 19745 residents weresurveyed in Luohe, a medium-sized city in China and five travel modes oflocal people were obtained. Secondly, after the characteristics of residents’rest and working time are investigated, a method is proposed in this studyfor the distribution of urban residential and working places based on mobilephone signaling technology. Finally, methods for predicting traffic volume ofthese travel modes are proposed after the characteristics of these travel modesand methods for the distribution of urban residential and working placesare analyzed. Based on the actual traffic volume data observed at offlineintersections, the project team takes Luohe city as the research object and itverifies the accuracy of the prediction method by comparing the predictiondata. The prediction simulation results of traffic volume show that the averageerror rate of traffic volume is unstable. The error rate ranges from 10% to 30%.In this thesis, simulation experiments and field investigations are adopted toanalyze why these errors occur.展开更多
Mobile phone addiction is a growing concern among college students, with significant implications for their mental health. This study examines the complex relationship between mobile phone addiction and its impact on ...Mobile phone addiction is a growing concern among college students, with significant implications for their mental health. This study examines the complex relationship between mobile phone addiction and its impact on college students’ insomnia, symptoms of depression, and anxiety. A sample of 399 college students from traditional Chinese medicine colleges in Guangxi, China, completed the Mobile Phone Addiction Tendency Scale questionnaire. Among them, 155 students with high Mobile Phone Addiction Tendency scores were selected for the correlation study. The analysis revealed a strong association between mobile phone addiction and insomnia. Furthermore, mobile phone addiction was significantly associated with symptoms of depression, including feelings of sadness, worthlessness, and hopelessness, as well as heightened anxiety symptoms, such as excessive worry and restlessness. These findings emphasized the importance of targeted interventions and preventive measures to address the negative impact of mobile phone addiction on college students’ mental health.展开更多
More and more problems have been arisen from higher social development level and more and more terminal devices,especially addictive devices have been exposed to the education field during the constant development of ...More and more problems have been arisen from higher social development level and more and more terminal devices,especially addictive devices have been exposed to the education field during the constant development of cutting-edge techniques,thus making students more and more dependent on mobile phones and other terminal devices.In this process,students tend to more depend on mobile phones,which will make students sort out the exchange and communication with other persons by taking mobile phones as the core and be lonely.It is very important for the current vocational education to research the dependence of students on mobile phones and their loneliness,and break the deadlock.Therefore,in this paper,the online education is researched,and the dependence of vocational students on mobile phones as well as their loneliness are solved based on online education.展开更多
The electronic waste (e-waste) is increasingly flooding Asia,especially China.E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly.This makes the evaluation ...The electronic waste (e-waste) is increasingly flooding Asia,especially China.E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly.This makes the evaluation of environmental impact from electronics an essentially important task for the life cycle assessment (LCA) and the end-of-life management of electronic products.This study presented a quantitative investigation on the environmental performance of typical electronics.Two types of disposed mobile phones (MPs),as a representative of consumer electronics,were evaluated in terms of toxicity potential indicator (TPI) with an assumption of worst-case scenario.It is found that the composition and the percentages of constituents in MPs are similar.More than 20 metallic elements make up 35 wt.%-40 wt.% of the total weight,of which 12 elements are identified to be highly hazardous and 12 are less harmful.With the TPI technique,the environmental performance of Pb is attributed to be 20.8 mg-1.The total TPIs of metallic elements in the old and new type MP is 255,403 and 127,639 units,respectively,which is equivalent to the effect of releasing 6.14 and 12.28 g Pb into the environment.The average TPI of the old and new type MP is 4.1 and 4.5 mg-1,respectively,which suggests a similar eco-effciency per unit mass.The new model of MP is more eco-effective than the old one,which is not due to a reduction in the type of hazardous elements,but rather due to a significant miniaturization of the package with less weight.A single MP can have a considerable toxicity to the environment as referred to Pb,which suggests a major concern for the environmental impact of the total e-waste with a huge quantity and a heavy mass in China.展开更多
The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phon...The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phone data,for instance,are found to be a useful data source for extracting diurnal human mobility patterns and for understanding urban dynamics.While previous studies often use call detail record(CDR)data,this study deploys aggregated network-driven mobile phone data that may reveal human mobility patterns more comprehensively and can mitigate some of the privacy concerns raised by mobile phone data usage.We first propose an analytical framework for characterizing and classifying urban areas based on their temporal activity patterns extracted from mobile phone data.Specifically,urban areas’diurnal spatiotemporal signatures of human mobility patterns are obtained through longitudinal mobile phone data.Urban areas are then classified based on the obtained signatures.The classification provides insights into city planning and development.Using the proposed framework,a case study was implemented in the city of Wuhu,China to understand its urban dynamics.The empirical study suggests that human activities in the city of Wuhu are highly concentrated at the Traffic Analysis Zone(TAZ)level.This large portion of local activities suggests that development and planning strategies that are different from those used by metropolitan Chinese cities should be applied in the city of Wuhu.This article concludes with discussions on several common challenges associated with using network-driven mobile phone data,which should be addressed in future studies.展开更多
This paper presents a microscopic traffic simulation-based method for urban traffic state estimation using Assisted Global Positioning System (A-GPS) mobile phones. In this approach, real-time location data are collec...This paper presents a microscopic traffic simulation-based method for urban traffic state estimation using Assisted Global Positioning System (A-GPS) mobile phones. In this approach, real-time location data are collected by A-GPS mobile phones to track vehicles traveling on urban roads. In addition, tracking data obtained from individual mobile probes are aggregated to provide estimations of average road link speeds along rolling time periods. Moreover, the estimated average speeds are classified to different traffic condition levels, which are prepared for displaying a real-time traffic map on mobile phones. Simulation results demonstrate the effectiveness of the proposed method, which are fundamental for the subsequent development of a system demonstrator.展开更多
In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8...In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8 hours to mobile phone microwaves at 900 MHz at a magnetic field intensity around 16 mA/m. The relative effects on the secondary structure of the proteins were studied by means of Fourier Transform Infrared Spectroscopy. An increase of the amide I band intensity in the secondary structure of the proteins was observed after the microwaves exposure. Furthermore, a weak shift of the amide I mode of bovine serum albumin and a heavier shift of the amide I of myoglobin occurred after the exposure. In addition, a clear increasing of the β-sheet components with respect to the α-helix content was observed in the spectra of bovine serum albumin and myoglobin after the exposure, suggesting the hypothesis of the formation of aggregates.展开更多
Recently, use of mobile communicational devices in field data collection is increasing such as smart phones and cellular phones due to emergence of embedded Global Position System GPS and Wi-Fi Internet access. Accura...Recently, use of mobile communicational devices in field data collection is increasing such as smart phones and cellular phones due to emergence of embedded Global Position System GPS and Wi-Fi Internet access. Accurate timely and handy field data collection is required for disaster management and emergency quick responses. In this article, we introduce web-based GIS system to collect the field data by personal mobile phone through Post Office Protocol POP3 mail server. The main objective of this work is to demonstrate real-time field data collection method to the students using their mobile phone to collect field data by timely and handy manners, either individual or group survey in local or global scale research.展开更多
This paper seeks to examine the awareness of potential health hazards by using mobile phone among AIMST (Asian Institute of Medical science and technology) University students. This is a cross-sectional survey conduct...This paper seeks to examine the awareness of potential health hazards by using mobile phone among AIMST (Asian Institute of Medical science and technology) University students. This is a cross-sectional survey conducted by distributing ‘perception questionnaire’. Perception of health hazards and outcomes were compared by gender, age, course of study, preferred ear, number of calls and SMS daily, the brand of mobile phone and use of mobile phone accessory (Bluetooth and hands free). The overall perception of mobile phone hazard in AIMST university student was 62%.Most subjects agreed that mobile phone usage can cause headache, loss of mental attention and sleeping disturbances and most disagree that mobile phone usage can cause constipation and diarrhea. Out of the 124 subjects who were aware of the side effects, 5% of the males and 10% of the females felt that there was no need to minimize the unwanted effects. The paper is useful to the general population particularly to the students as the perceived health risk did not significantly deter students from using mobile phone. The reasons given by students for the continued usage of mobile phone in spite of their awareness of the associated hazards have been discussed. This study offers new insight into level of awareness and perception of mobile phone hazard among University students.展开更多
Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in ...Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.展开更多
Recent advances in information and communication technologies, such as mobile Internet and smartphones, have created new paradigms for participatory environment monitoring. The ubiquitous mobile phones with capabiliti...Recent advances in information and communication technologies, such as mobile Internet and smartphones, have created new paradigms for participatory environment monitoring. The ubiquitous mobile phones with capabilities such as a global positioning system,camera, and network access, offer opportunities to establish distributed monitoring networks that can perform a wide range of measurements for a landscape. This study examined the potential of mobile phone-based community monitoring of fall webworm(Hyphantria cunea Drury).We built a prototype of a participatory fall webworm monitoring system based on mobile devices that streamlined data collection, transmission, and visualization. We also assessed the accuracy and reliability of the data collected by the local community. The system performance was evaluated at the Ziya commune of Tianjin municipality in northern China, where fall webworm infestation has occurred. The local community provided data with accuracy comparable to expert measurements(Willmott's index of agreement>0.85). Measurements by the local community effectively complemented remote sensing images in both temporal and spatial resolution.展开更多
Two waves of technology are dramatically changing daily life: cloud computing and mobile phones. New cloud computing services such as webmail and content rich data search have emerged. However, in order to use these s...Two waves of technology are dramatically changing daily life: cloud computing and mobile phones. New cloud computing services such as webmail and content rich data search have emerged. However, in order to use these services, a mobile phone must be able to run new applications and handle high network bandwidth. Worldwide, about 3.45 billion mobile phones are low end phones; they have low bandwidth and cannot run new applications. Because of this technology gap, most mobile users are unable to experience cloud computing services with their thumbs. In this paper, a novel platform, Thumb-in-Cloud, is proposed to bridge this gap. Thumb-in-Cloud consists of two subsystems: Thumb-Machine and Thumb-Gateways. Thumb-Machine is a virtual machine built into a low end phone to enable it to run new applications. Thumb-Gateways can tailor cloud computing services by reformatting and compressing the service to fit the phone's profile.展开更多
Location Based Navigation System (LBNS) is a specific Location Based Service (LBS) purely for navigational purpose. These systems resolve position of a user by using GNSS/GPS positioning technologies, to which supplem...Location Based Navigation System (LBNS) is a specific Location Based Service (LBS) purely for navigational purpose. These systems resolve position of a user by using GNSS/GPS positioning technologies, to which supplementary information on goods and services are tagged. The navigation services have become popular and can be installed on mobile phones to provide route information, location of points of interest and user’s current location. LBS has continued to face challenges which include “communication” process towards user reference. Location Based Service System conveys suitable information through a mobile device for effective decision making and reaction within a given time span. This research was geared at understanding the state of LBS technology acceptance and adoption by users in Nairobi Kenya. To do this a quantitative study was carried out through a questionnaire, to investigate mobile phone users’ response on awareness and use of LBS technology. Testing the growth of this technology in this region compared to predictions in previous studies using Technology Acceptance Model (TAM), it is evident that many users may be aware of GPS functionality in mobile phones but are certainly yet to fully embrace the technology as they rarely use it. This points to some underlying challenges towards this technology within this part of the World, thereby recommending for deliberate monitoring and evaluation of LBS technology for sustenance growth based on user satisfaction and acceptance for improved usability.展开更多
To enhance the security of user data in the clouds,we present an adaptive and dynamic data encryption method to encrypt user data in the mobile phone before it is uploaded.Firstly,the adopted data encryption algorithm...To enhance the security of user data in the clouds,we present an adaptive and dynamic data encryption method to encrypt user data in the mobile phone before it is uploaded.Firstly,the adopted data encryption algorithm is not static and uniform.For each encryption,this algorithm is adaptively and dynamically selected from the algorithm set in the mobile phone encryption system.From the mobile phone's character,the detail encryption algorithm selection strategy is confirmed based on the user's mobile phone hardware information,personalization information and a pseudo-random number.Secondly,the data is rearranged with a randomly selected start position in the data before being encrypted.The start position's randomness makes the mobile phone data encryption safer.Thirdly,the rearranged data is encrypted by the selected algorithm and generated key.Finally,the analysis shows this method possesses the higher security because the more dynamics and randomness are adaptively added into the encryption process.展开更多
Objective: To study the impacts of exposure to electromagnetic radiation(EMR) on liver function in rats. Methods: Twenty adult male Sprague-Dawley rats were randomly divided into normal group and radiated group. The r...Objective: To study the impacts of exposure to electromagnetic radiation(EMR) on liver function in rats. Methods: Twenty adult male Sprague-Dawley rats were randomly divided into normal group and radiated group. The rats in normal group were not radiated, those in radiated group were exposed to EMR 4 h/d for 18 consecutive days. Rats were sacrificed immediately after the end of the experiment. The serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST), and those of malondialdehyde(MDA) and glutathione(GSH) in liver tissue were evaluated by colorimetric method. The liver histopathological changes were observed by hematoxylin and eosin staining and the protein expression of bax and bcl-2 in liver tissue were detected by immunohistochemical method. Terminal-deoxynucleotidyl transferase mediated nick and labelling(TUNEL) method was used for analysis of apoptosis in liver. Results: Compared with the normal rats, the serum levels of ALT and AST in the radiated group had no obvious changes(P>0.05), while the contents of MDA increased(P<0.01) and those of GSH decreased(P<0.01) in liver tissues. The histopathology examination showed diffuse hepatocyte swelling and vacuolation, small pieces and focal necrosis. The immunohistochemical results displayed that the expression of the bax protein was higher and that of bcl-2 protein was lower in radiated group. The hepatocyte apoptosis rates in radiated group was higher than that in normal group(all P<0.01). Conclusion: The exposure to 900 MHz mobile phone 4 h/d for 18 days could induce the liver histological changes, which may be partly due to the apoptosis and oxidative stress induced in liver tissue by electromagnetic radiation.展开更多
In order to improve the performance of the antenna at low frequency,short circuit branch and coupling feed structure are introduced into the folded broadband single antenna in this paper,then resonant frequency is mer...In order to improve the performance of the antenna at low frequency,short circuit branch and coupling feed structure are introduced into the folded broadband single antenna in this paper,then resonant frequency is merged into the antenna using method of stagger tuning,finally,a UWB antenna is designed to w ork betw een 800 MHz ~ 2700 MHz. Analysis are conducted to determine the antenna's properties. The short-circuit w ire location,feeding point location and the length of folded strip are discussed in detail. The SAR is calculated by HFSS simulation softw are w hile the antenna is close to a 3D human head model. The research results show that the antenna can cover eight commonly used commercial frequency bands at present,and electromagnetic radiation of the antenna has tiny influence on the human head model.展开更多
文摘This research focused on the social concern of college students5 participation in physical exercise and mobile phone dependence.The research model and hypotheses in this study were constructed based on the self-control theory and by reviewing previous research.This research distributed questionnaires to 207 college students from a university in Guangzhou,China to obtain relevant data.Mediation analysis was employed to test the four hypotheses drawn from empirical and conceptual research.The results of this research showed that first,the longer the exercise duration of college students,the higher the level of their self-control,thus exercise duration has a significant positive impact on self-control.Second,increasing the exercise duration of college students had no effect on their mobile phone dependence.Third,the higher the level of selfcontrol,the lower the dependence on mobile phones,thus signifying that self-control has significantly negative impact on mobile phone dependence.Fourth,self-control plays a mediating role in the effect of exercise duration on mobile phone dependence.In conclusion,the longer the exercise duration of college students,the higher the level of self-control,in which it is able to significantly reduce the dependence on mobile phones.
文摘We investigated factors contributing to mobile phone dependence. To 139 medical students, we administered a self-reporting questionnaire designed to evaluate mobile phone dependence, health-related lifestyle, patterns of behavior, and depressive state. Multivariate logistic regression analysis revealed that scores for poor health-related lifestyle, Type A behavior pattern, and presence of depression are independently associated with degree of mobile phone dependency. These findings suggest that persons with an unhealthy lifestyle, Type A behavior traits, or depression might benefit from mobile phone use guidance.
文摘We investigated factors contributing to Internet addiction in 105 Japanese medical students. The subjects were administered by a self-reporting questionnaire designed to evaluate demographic factors, Internet addiction, loneliness, health-related lifestyle factors, depressive state, patterns of behavior, and mobile phone dependence. Results of multivariate logistic regression analysis indicated that loneliness and mobile phone dependence were positively related to degree of addiction. Our findings suggest that Internet addiction is associated with loneliness and mobile phone dependence in Japanese students.
文摘Urban traffic volume detection is an essential part of trafficplanning in terms of urban planning in China. To improve the statisticsefficiency of road traffic volume, this thesis proposes a method for predictingmotor vehicle traffic volume on urban roads in small and medium-sizedcities during the traffic peak hour by using mobile signal technology. Themethod is verified through simulation experiments, and the limitations andthe improvement methods are discussed. This research can be divided intothree parts: Firstly, the traffic patterns of small and medium-sized cities areobtained through a questionnaire survey. A total of 19745 residents weresurveyed in Luohe, a medium-sized city in China and five travel modes oflocal people were obtained. Secondly, after the characteristics of residents’rest and working time are investigated, a method is proposed in this studyfor the distribution of urban residential and working places based on mobilephone signaling technology. Finally, methods for predicting traffic volume ofthese travel modes are proposed after the characteristics of these travel modesand methods for the distribution of urban residential and working placesare analyzed. Based on the actual traffic volume data observed at offlineintersections, the project team takes Luohe city as the research object and itverifies the accuracy of the prediction method by comparing the predictiondata. The prediction simulation results of traffic volume show that the averageerror rate of traffic volume is unstable. The error rate ranges from 10% to 30%.In this thesis, simulation experiments and field investigations are adopted toanalyze why these errors occur.
文摘Mobile phone addiction is a growing concern among college students, with significant implications for their mental health. This study examines the complex relationship between mobile phone addiction and its impact on college students’ insomnia, symptoms of depression, and anxiety. A sample of 399 college students from traditional Chinese medicine colleges in Guangxi, China, completed the Mobile Phone Addiction Tendency Scale questionnaire. Among them, 155 students with high Mobile Phone Addiction Tendency scores were selected for the correlation study. The analysis revealed a strong association between mobile phone addiction and insomnia. Furthermore, mobile phone addiction was significantly associated with symptoms of depression, including feelings of sadness, worthlessness, and hopelessness, as well as heightened anxiety symptoms, such as excessive worry and restlessness. These findings emphasized the importance of targeted interventions and preventive measures to address the negative impact of mobile phone addiction on college students’ mental health.
文摘More and more problems have been arisen from higher social development level and more and more terminal devices,especially addictive devices have been exposed to the education field during the constant development of cutting-edge techniques,thus making students more and more dependent on mobile phones and other terminal devices.In this process,students tend to more depend on mobile phones,which will make students sort out the exchange and communication with other persons by taking mobile phones as the core and be lonely.It is very important for the current vocational education to research the dependence of students on mobile phones and their loneliness,and break the deadlock.Therefore,in this paper,the online education is researched,and the dependence of vocational students on mobile phones as well as their loneliness are solved based on online education.
文摘The electronic waste (e-waste) is increasingly flooding Asia,especially China.E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly.This makes the evaluation of environmental impact from electronics an essentially important task for the life cycle assessment (LCA) and the end-of-life management of electronic products.This study presented a quantitative investigation on the environmental performance of typical electronics.Two types of disposed mobile phones (MPs),as a representative of consumer electronics,were evaluated in terms of toxicity potential indicator (TPI) with an assumption of worst-case scenario.It is found that the composition and the percentages of constituents in MPs are similar.More than 20 metallic elements make up 35 wt.%-40 wt.% of the total weight,of which 12 elements are identified to be highly hazardous and 12 are less harmful.With the TPI technique,the environmental performance of Pb is attributed to be 20.8 mg-1.The total TPIs of metallic elements in the old and new type MP is 255,403 and 127,639 units,respectively,which is equivalent to the effect of releasing 6.14 and 12.28 g Pb into the environment.The average TPI of the old and new type MP is 4.1 and 4.5 mg-1,respectively,which suggests a similar eco-effciency per unit mass.The new model of MP is more eco-effective than the old one,which is not due to a reduction in the type of hazardous elements,but rather due to a significant miniaturization of the package with less weight.A single MP can have a considerable toxicity to the environment as referred to Pb,which suggests a major concern for the environmental impact of the total e-waste with a huge quantity and a heavy mass in China.
基金Under the auspices of the National Natural Science Foundation of China(No.41571146)China Postdoctoral Science Foundation(No.2019M651784)。
文摘The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phone data,for instance,are found to be a useful data source for extracting diurnal human mobility patterns and for understanding urban dynamics.While previous studies often use call detail record(CDR)data,this study deploys aggregated network-driven mobile phone data that may reveal human mobility patterns more comprehensively and can mitigate some of the privacy concerns raised by mobile phone data usage.We first propose an analytical framework for characterizing and classifying urban areas based on their temporal activity patterns extracted from mobile phone data.Specifically,urban areas’diurnal spatiotemporal signatures of human mobility patterns are obtained through longitudinal mobile phone data.Urban areas are then classified based on the obtained signatures.The classification provides insights into city planning and development.Using the proposed framework,a case study was implemented in the city of Wuhu,China to understand its urban dynamics.The empirical study suggests that human activities in the city of Wuhu are highly concentrated at the Traffic Analysis Zone(TAZ)level.This large portion of local activities suggests that development and planning strategies that are different from those used by metropolitan Chinese cities should be applied in the city of Wuhu.This article concludes with discussions on several common challenges associated with using network-driven mobile phone data,which should be addressed in future studies.
文摘This paper presents a microscopic traffic simulation-based method for urban traffic state estimation using Assisted Global Positioning System (A-GPS) mobile phones. In this approach, real-time location data are collected by A-GPS mobile phones to track vehicles traveling on urban roads. In addition, tracking data obtained from individual mobile probes are aggregated to provide estimations of average road link speeds along rolling time periods. Moreover, the estimated average speeds are classified to different traffic condition levels, which are prepared for displaying a real-time traffic map on mobile phones. Simulation results demonstrate the effectiveness of the proposed method, which are fundamental for the subsequent development of a system demonstrator.
文摘In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8 hours to mobile phone microwaves at 900 MHz at a magnetic field intensity around 16 mA/m. The relative effects on the secondary structure of the proteins were studied by means of Fourier Transform Infrared Spectroscopy. An increase of the amide I band intensity in the secondary structure of the proteins was observed after the microwaves exposure. Furthermore, a weak shift of the amide I mode of bovine serum albumin and a heavier shift of the amide I of myoglobin occurred after the exposure. In addition, a clear increasing of the β-sheet components with respect to the α-helix content was observed in the spectra of bovine serum albumin and myoglobin after the exposure, suggesting the hypothesis of the formation of aggregates.
文摘Recently, use of mobile communicational devices in field data collection is increasing such as smart phones and cellular phones due to emergence of embedded Global Position System GPS and Wi-Fi Internet access. Accurate timely and handy field data collection is required for disaster management and emergency quick responses. In this article, we introduce web-based GIS system to collect the field data by personal mobile phone through Post Office Protocol POP3 mail server. The main objective of this work is to demonstrate real-time field data collection method to the students using their mobile phone to collect field data by timely and handy manners, either individual or group survey in local or global scale research.
文摘This paper seeks to examine the awareness of potential health hazards by using mobile phone among AIMST (Asian Institute of Medical science and technology) University students. This is a cross-sectional survey conducted by distributing ‘perception questionnaire’. Perception of health hazards and outcomes were compared by gender, age, course of study, preferred ear, number of calls and SMS daily, the brand of mobile phone and use of mobile phone accessory (Bluetooth and hands free). The overall perception of mobile phone hazard in AIMST university student was 62%.Most subjects agreed that mobile phone usage can cause headache, loss of mental attention and sleeping disturbances and most disagree that mobile phone usage can cause constipation and diarrhea. Out of the 124 subjects who were aware of the side effects, 5% of the males and 10% of the females felt that there was no need to minimize the unwanted effects. The paper is useful to the general population particularly to the students as the perceived health risk did not significantly deter students from using mobile phone. The reasons given by students for the continued usage of mobile phone in spite of their awareness of the associated hazards have been discussed. This study offers new insight into level of awareness and perception of mobile phone hazard among University students.
基金The National Natural Science Foundation of China(Grant No.11274172)supported this work.
文摘Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.
基金supported by National Science and Technology Major Projects of China(21-Y30B05-9001-13/15)
文摘Recent advances in information and communication technologies, such as mobile Internet and smartphones, have created new paradigms for participatory environment monitoring. The ubiquitous mobile phones with capabilities such as a global positioning system,camera, and network access, offer opportunities to establish distributed monitoring networks that can perform a wide range of measurements for a landscape. This study examined the potential of mobile phone-based community monitoring of fall webworm(Hyphantria cunea Drury).We built a prototype of a participatory fall webworm monitoring system based on mobile devices that streamlined data collection, transmission, and visualization. We also assessed the accuracy and reliability of the data collected by the local community. The system performance was evaluated at the Ziya commune of Tianjin municipality in northern China, where fall webworm infestation has occurred. The local community provided data with accuracy comparable to expert measurements(Willmott's index of agreement>0.85). Measurements by the local community effectively complemented remote sensing images in both temporal and spatial resolution.
基金supported by CityU Applied Research Grant (ARG) under Grant No. 9667033Shenzhen Basic Research Grant under No. JC200903170456A+3 种基金Shenzhen-HK Innovation Cycle Grant under No. ZYB200907080078ARGC General Research Fund (GRF), HK SAR under Grant No. CityU 114609CityU Applied R & D Centre (ARD (Ctr)) under Grant No. 9681001China NSF under Grant No. 61070222/F020802
文摘Two waves of technology are dramatically changing daily life: cloud computing and mobile phones. New cloud computing services such as webmail and content rich data search have emerged. However, in order to use these services, a mobile phone must be able to run new applications and handle high network bandwidth. Worldwide, about 3.45 billion mobile phones are low end phones; they have low bandwidth and cannot run new applications. Because of this technology gap, most mobile users are unable to experience cloud computing services with their thumbs. In this paper, a novel platform, Thumb-in-Cloud, is proposed to bridge this gap. Thumb-in-Cloud consists of two subsystems: Thumb-Machine and Thumb-Gateways. Thumb-Machine is a virtual machine built into a low end phone to enable it to run new applications. Thumb-Gateways can tailor cloud computing services by reformatting and compressing the service to fit the phone's profile.
文摘Location Based Navigation System (LBNS) is a specific Location Based Service (LBS) purely for navigational purpose. These systems resolve position of a user by using GNSS/GPS positioning technologies, to which supplementary information on goods and services are tagged. The navigation services have become popular and can be installed on mobile phones to provide route information, location of points of interest and user’s current location. LBS has continued to face challenges which include “communication” process towards user reference. Location Based Service System conveys suitable information through a mobile device for effective decision making and reaction within a given time span. This research was geared at understanding the state of LBS technology acceptance and adoption by users in Nairobi Kenya. To do this a quantitative study was carried out through a questionnaire, to investigate mobile phone users’ response on awareness and use of LBS technology. Testing the growth of this technology in this region compared to predictions in previous studies using Technology Acceptance Model (TAM), it is evident that many users may be aware of GPS functionality in mobile phones but are certainly yet to fully embrace the technology as they rarely use it. This points to some underlying challenges towards this technology within this part of the World, thereby recommending for deliberate monitoring and evaluation of LBS technology for sustenance growth based on user satisfaction and acceptance for improved usability.
文摘To enhance the security of user data in the clouds,we present an adaptive and dynamic data encryption method to encrypt user data in the mobile phone before it is uploaded.Firstly,the adopted data encryption algorithm is not static and uniform.For each encryption,this algorithm is adaptively and dynamically selected from the algorithm set in the mobile phone encryption system.From the mobile phone's character,the detail encryption algorithm selection strategy is confirmed based on the user's mobile phone hardware information,personalization information and a pseudo-random number.Secondly,the data is rearranged with a randomly selected start position in the data before being encrypted.The start position's randomness makes the mobile phone data encryption safer.Thirdly,the rearranged data is encrypted by the selected algorithm and generated key.Finally,the analysis shows this method possesses the higher security because the more dynamics and randomness are adaptively added into the encryption process.
基金supported by the Natural Science Foundation of Hebei Province(201220123)Youth Fund Project of He Bei University of Chinese Medicine(QNZ2014015)
文摘Objective: To study the impacts of exposure to electromagnetic radiation(EMR) on liver function in rats. Methods: Twenty adult male Sprague-Dawley rats were randomly divided into normal group and radiated group. The rats in normal group were not radiated, those in radiated group were exposed to EMR 4 h/d for 18 consecutive days. Rats were sacrificed immediately after the end of the experiment. The serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST), and those of malondialdehyde(MDA) and glutathione(GSH) in liver tissue were evaluated by colorimetric method. The liver histopathological changes were observed by hematoxylin and eosin staining and the protein expression of bax and bcl-2 in liver tissue were detected by immunohistochemical method. Terminal-deoxynucleotidyl transferase mediated nick and labelling(TUNEL) method was used for analysis of apoptosis in liver. Results: Compared with the normal rats, the serum levels of ALT and AST in the radiated group had no obvious changes(P>0.05), while the contents of MDA increased(P<0.01) and those of GSH decreased(P<0.01) in liver tissues. The histopathology examination showed diffuse hepatocyte swelling and vacuolation, small pieces and focal necrosis. The immunohistochemical results displayed that the expression of the bax protein was higher and that of bcl-2 protein was lower in radiated group. The hepatocyte apoptosis rates in radiated group was higher than that in normal group(all P<0.01). Conclusion: The exposure to 900 MHz mobile phone 4 h/d for 18 days could induce the liver histological changes, which may be partly due to the apoptosis and oxidative stress induced in liver tissue by electromagnetic radiation.
基金supported by National Natural Science Foundation of China(grant No.61471002)The Natural Science Foundation of Higher Education of Anhui Province,China(grant No.KJ2016JD11)
文摘In order to improve the performance of the antenna at low frequency,short circuit branch and coupling feed structure are introduced into the folded broadband single antenna in this paper,then resonant frequency is merged into the antenna using method of stagger tuning,finally,a UWB antenna is designed to w ork betw een 800 MHz ~ 2700 MHz. Analysis are conducted to determine the antenna's properties. The short-circuit w ire location,feeding point location and the length of folded strip are discussed in detail. The SAR is calculated by HFSS simulation softw are w hile the antenna is close to a 3D human head model. The research results show that the antenna can cover eight commonly used commercial frequency bands at present,and electromagnetic radiation of the antenna has tiny influence on the human head model.
