Denial of Service Distributed Denial of Service (DOS) attack, especially (DDoS) attack, is one of the greatest threats to Internet. Much research has been done for it by now, however, it is always concentrated in ...Denial of Service Distributed Denial of Service (DOS) attack, especially (DDoS) attack, is one of the greatest threats to Internet. Much research has been done for it by now, however, it is always concentrated in the behaviors of the network and can not deal with the problem exactly. In this paper, we start from the security of the protocol, then we propose a novel theory for security protocol analysis of Denial of Service in order to deal with the DoS attack. We first introduce the conception of weighted graph to extend the strand space model, then we extend the penetrator model and define the goal of anti-DoS attack through the conception of the DoS-stop protocol, finally we propose two kinds of DoS test model and erect the novel formal theory for security protocol analysis of Denial of Service. Our new formal theory is applied in two example protocols. It is proved that the Internet key exchange (IKE) easily suffers from the DoS attacks, and the efficient DoS- resistant secure key exchange protocol (JFK) is resistant against DoS attack for the server, respectively.展开更多
Blogs have permeated into our daily lives at a fast speed, and various kinds of blog spaces have attracted our attention. However, little effort has been made on studying the users' motivation to participate in bl...Blogs have permeated into our daily lives at a fast speed, and various kinds of blog spaces have attracted our attention. However, little effort has been made on studying the users' motivation to participate in blog activities. This paper aims to construct a theoretical model about the blog adoption based on technology acceptance model(TAM theory), social capital theory and social exchange theory, and put forward 18 related hypotheses. Then the survey method is adopted to analyze the data from 208 questionnaires using the SPSS and LISREL tools, and to examine the theoretical model and hypotheses. Finally, the paper makes a discussion from five aspects due to the results of data analysis, including individual driving factors, group driving factors, community driving factors, technology acceptance factors and moderating variables. The results show that curiosity/enjoyment, user's experience, social interaction and social identification will greatly affect users' motivation to accept a blog; meanwhile, perceived ease of use, exchange cost and trust will partially influence users' intention to participate in blog activities. The results also suggest that age and education degrees have significant moderating effects on users' acceptance and updating of blogs.展开更多
This study examines how and when authoritarian leadership affects subordinates’task performance.Using social exchange theory and power dependence theory,this study proposes that authoritarian leadership negatively in...This study examines how and when authoritarian leadership affects subordinates’task performance.Using social exchange theory and power dependence theory,this study proposes that authoritarian leadership negatively influences task performance through leader-member exchange(LMX).This study further proposes that the effect of authoritarian leadership on LMX is stronger when a subordinate has less dependence on a leader.A two-wave survey was conducted in a large electronics and information enterprise group in China.These hypotheses are supported by results based on 219 supervisor-subordinate dyads.The results reveal that authoritarian leadership negatively affects subordinates’task performance via LMX.Dependence on leader buffers the negative effect of authoritarian leadership on LMX and mitigates the indirect effect of authoritarian leadership on employee task performance through LMX.Theoretical contributions and practical implications are discussed.展开更多
As the rate-determining step in native chemical ligation reactions, the thiol–thioester exchange step is important in determining the efficiency of the ligations of peptides. In the present study, systematic theoreti...As the rate-determining step in native chemical ligation reactions, the thiol–thioester exchange step is important in determining the efficiency of the ligations of peptides. In the present study, systematic theoretical calculations were carried out on the relationships between the structure of different thioesters and the free energy barriers of the thiol–thioester exchange step. According to the calculation results, the thiol–thioester exchange step is disfavored by the steric hindrance around the carbonyl center, while the electronic effect(i.e. conjugation and hyper-conjugation effects) becomes important when the steric hindrance is insignificant.展开更多
This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and C...This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and Communication Technology(ICT)sector in Jordan.Employing the Social Exchange Theory(SET)as a guiding framework,this study explored how employee psychological empowerment and innovative work behavior mediated the influence of HR practices on a firm’s innovative capabilities.Drawing on extensive data collected from ICT organizations in Jordan,our analysis had several key findings.A significant positive correlation between HR practices and psychological empowerment was observed.Job design emerged as the most influential factor affecting psychological empowerment,whereas compensation had a weaker impact.Furthermore,we established that psychological empowerment significantly enhanced innovative work behavior,underscoring its role as a catalyst for innovative work behavior within the sector.Finally,our study supported the theory that psychological empowerment influenced a firms’innovation capabilities,emphasizing the pivotal role of employee empowerment in driving firm-level innovation in the Jordanian ICT sector.These findings provide insights for academic and practical audiences,clarifying how HR practices,employee psychological empowerment,and innovative work behavior collectively influenced firm innovation capability within the unique context of the Jordanian ICT sector.展开更多
Drawing upon the conservation of resources theory (Hobfoll, Am Psychol 44:513- 524, 1989), social exchange theory (Blau, Exchange and power in social life, 1964) and the job demand-control model (Karasek, Adm Sc...Drawing upon the conservation of resources theory (Hobfoll, Am Psychol 44:513- 524, 1989), social exchange theory (Blau, Exchange and power in social life, 1964) and the job demand-control model (Karasek, Adm Sci Q 24:285-308, 1979), this study uncovers the theoretical mechanism that explains the relationship between work- family conflict and organizational citizenship behavior (OCB). First, this study focuses on how employee job satisfaction mediates the relationship. Then, we investigate the moderating role of decision authority in, the mediated relationsip. We employ three-wave data collected from 324 employees in 102 teams to test our hypotheses. Aesults of hierarchical linear modeling (HLM) first shows that job satisfaction mediates the relationship between work interference with family (WIF) and OCB. In addition, employees' decision authority moderates the direct effect of WlF on OCB. Specifically, the negative relationship between WlF and OCB is stronger when employees' decision authority is high. Moreover, decision authority moderates the indirect effect of WIF on OCB via job satisfaction. Specifically, the negative relationship between WlE and job satisfaction is weaker when employees' decision authority is high. The results suggest that organizations should give employees enough decision authority over their work, as a high level of decision authority may act as a double-edged sword regarding critical organizational outcomes.展开更多
Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we a...Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we are unaware of the psychological mechanism and boundary conditions underlying leader humility and employees’negative behaviors toward leaders.Drawing on social exchange theory and using a multistage sample including 273 employees and 55 supervisors in China,we demonstrated a negative indirect effect between leader humility and subordinates’counterproductive work behaviors toward supervisors(CWB-S)via interpersonal justice and trust in supervisor.Furthermore,we find that leader political skill moderates the effect of leader humility on interpersonal justice and trust in supervisor.The indirect effect of leader humility on subordinates’CWB-S through interpersonal justice is stronger when leader political skill is high,suggesting a moderated mediation model.Finally,we discuss the theoretical contributions and practical implications of this study,and highlight future directions for research on leader humility.展开更多
The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation. In this paper, the suspended droplets' evaporation character wa...The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation. In this paper, the suspended droplets' evaporation character was measured in a quiescent high-temperature environment by micro high-speed camera system. The gasoline and kerosene experimental results are consistent with the reference data. Methanol, common kerosene and aviation kerosene droplet evaporation characteristics, as well as their evaporation rate changing with temperature, were obtained. The evaporation rate experimental data were compared with the prediction result of Ranz-Marshall boiling temperature model(RMB), Ranz-Marshall low-temperature model(RML), drift flux model(DFM), mass analogy model(MAM), and stagnant film model(SFM). The disparity between the experimental data and the model prediction results was mainly caused by the neglect of the natural convection effect, which was never introduced into the droplet evaporation concept. A new droplet evaporation model with consideration of natural convection buoyancy force effect was proposed in this paper. Under the experimental conditions in this paper, the calculation results of the new droplet evaporation model were agreed with the experimental data for kerosene, methanol and other fuels, with less than 20% relative deviations. The relative deviations between the new evaporation model predictions for kerosene and the experimental data from the references were within 10%.展开更多
基金This work is supported by National Natural Science Foundation of China under contract 60902008.
文摘Denial of Service Distributed Denial of Service (DOS) attack, especially (DDoS) attack, is one of the greatest threats to Internet. Much research has been done for it by now, however, it is always concentrated in the behaviors of the network and can not deal with the problem exactly. In this paper, we start from the security of the protocol, then we propose a novel theory for security protocol analysis of Denial of Service in order to deal with the DoS attack. We first introduce the conception of weighted graph to extend the strand space model, then we extend the penetrator model and define the goal of anti-DoS attack through the conception of the DoS-stop protocol, finally we propose two kinds of DoS test model and erect the novel formal theory for security protocol analysis of Denial of Service. Our new formal theory is applied in two example protocols. It is proved that the Internet key exchange (IKE) easily suffers from the DoS attacks, and the efficient DoS- resistant secure key exchange protocol (JFK) is resistant against DoS attack for the server, respectively.
文摘Blogs have permeated into our daily lives at a fast speed, and various kinds of blog spaces have attracted our attention. However, little effort has been made on studying the users' motivation to participate in blog activities. This paper aims to construct a theoretical model about the blog adoption based on technology acceptance model(TAM theory), social capital theory and social exchange theory, and put forward 18 related hypotheses. Then the survey method is adopted to analyze the data from 208 questionnaires using the SPSS and LISREL tools, and to examine the theoretical model and hypotheses. Finally, the paper makes a discussion from five aspects due to the results of data analysis, including individual driving factors, group driving factors, community driving factors, technology acceptance factors and moderating variables. The results show that curiosity/enjoyment, user's experience, social interaction and social identification will greatly affect users' motivation to accept a blog; meanwhile, perceived ease of use, exchange cost and trust will partially influence users' intention to participate in blog activities. The results also suggest that age and education degrees have significant moderating effects on users' acceptance and updating of blogs.
基金the National Natural Science Foundation of China(No.71971211)the Humanity and Social Science Youth Foundation of Ministry of Education of China(18YJC630192).
文摘This study examines how and when authoritarian leadership affects subordinates’task performance.Using social exchange theory and power dependence theory,this study proposes that authoritarian leadership negatively influences task performance through leader-member exchange(LMX).This study further proposes that the effect of authoritarian leadership on LMX is stronger when a subordinate has less dependence on a leader.A two-wave survey was conducted in a large electronics and information enterprise group in China.These hypotheses are supported by results based on 219 supervisor-subordinate dyads.The results reveal that authoritarian leadership negatively affects subordinates’task performance via LMX.Dependence on leader buffers the negative effect of authoritarian leadership on LMX and mitigates the indirect effect of authoritarian leadership on employee task performance through LMX.Theoretical contributions and practical implications are discussed.
基金NSFC (No. 21202006)FRFCU (No. FRF-TP14-015A2) for financial supports and Super-computer Center of Shanghai and Shenzhen for technical supports
文摘As the rate-determining step in native chemical ligation reactions, the thiol–thioester exchange step is important in determining the efficiency of the ligations of peptides. In the present study, systematic theoretical calculations were carried out on the relationships between the structure of different thioesters and the free energy barriers of the thiol–thioester exchange step. According to the calculation results, the thiol–thioester exchange step is disfavored by the steric hindrance around the carbonyl center, while the electronic effect(i.e. conjugation and hyper-conjugation effects) becomes important when the steric hindrance is insignificant.
文摘This study investigated the relationships between human resource(HR)practices,employee psychological empowerment,employee innovative work behavior,and firm innovation capability in the context of the Information and Communication Technology(ICT)sector in Jordan.Employing the Social Exchange Theory(SET)as a guiding framework,this study explored how employee psychological empowerment and innovative work behavior mediated the influence of HR practices on a firm’s innovative capabilities.Drawing on extensive data collected from ICT organizations in Jordan,our analysis had several key findings.A significant positive correlation between HR practices and psychological empowerment was observed.Job design emerged as the most influential factor affecting psychological empowerment,whereas compensation had a weaker impact.Furthermore,we established that psychological empowerment significantly enhanced innovative work behavior,underscoring its role as a catalyst for innovative work behavior within the sector.Finally,our study supported the theory that psychological empowerment influenced a firms’innovation capabilities,emphasizing the pivotal role of employee empowerment in driving firm-level innovation in the Jordanian ICT sector.These findings provide insights for academic and practical audiences,clarifying how HR practices,employee psychological empowerment,and innovative work behavior collectively influenced firm innovation capability within the unique context of the Jordanian ICT sector.
基金This article was funded by National Natural Science Foundation of China (Nos. 71101148 and 71702184).
文摘Drawing upon the conservation of resources theory (Hobfoll, Am Psychol 44:513- 524, 1989), social exchange theory (Blau, Exchange and power in social life, 1964) and the job demand-control model (Karasek, Adm Sci Q 24:285-308, 1979), this study uncovers the theoretical mechanism that explains the relationship between work- family conflict and organizational citizenship behavior (OCB). First, this study focuses on how employee job satisfaction mediates the relationship. Then, we investigate the moderating role of decision authority in, the mediated relationsip. We employ three-wave data collected from 324 employees in 102 teams to test our hypotheses. Aesults of hierarchical linear modeling (HLM) first shows that job satisfaction mediates the relationship between work interference with family (WIF) and OCB. In addition, employees' decision authority moderates the direct effect of WlF on OCB. Specifically, the negative relationship between WlF and OCB is stronger when employees' decision authority is high. Moreover, decision authority moderates the indirect effect of WIF on OCB via job satisfaction. Specifically, the negative relationship between WlE and job satisfaction is weaker when employees' decision authority is high. The results suggest that organizations should give employees enough decision authority over their work, as a high level of decision authority may act as a double-edged sword regarding critical organizational outcomes.
基金National Natural Science Foundation of China(project code:7164001571772176)Yuyou Talent Program of NCUT,and the 2019 PhD Joint Training Scholarship of Renmin Business School.
文摘Leader humility has emerged as an important topic in understanding the role of leadership in organizations in recent years.Though it was found to enhance subordinates’work performance and positive work behaviors,we are unaware of the psychological mechanism and boundary conditions underlying leader humility and employees’negative behaviors toward leaders.Drawing on social exchange theory and using a multistage sample including 273 employees and 55 supervisors in China,we demonstrated a negative indirect effect between leader humility and subordinates’counterproductive work behaviors toward supervisors(CWB-S)via interpersonal justice and trust in supervisor.Furthermore,we find that leader political skill moderates the effect of leader humility on interpersonal justice and trust in supervisor.The indirect effect of leader humility on subordinates’CWB-S through interpersonal justice is stronger when leader political skill is high,suggesting a moderated mediation model.Finally,we discuss the theoretical contributions and practical implications of this study,and highlight future directions for research on leader humility.
基金supported by the National Natural Science Foundation of China (No. 51106006)
文摘The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation. In this paper, the suspended droplets' evaporation character was measured in a quiescent high-temperature environment by micro high-speed camera system. The gasoline and kerosene experimental results are consistent with the reference data. Methanol, common kerosene and aviation kerosene droplet evaporation characteristics, as well as their evaporation rate changing with temperature, were obtained. The evaporation rate experimental data were compared with the prediction result of Ranz-Marshall boiling temperature model(RMB), Ranz-Marshall low-temperature model(RML), drift flux model(DFM), mass analogy model(MAM), and stagnant film model(SFM). The disparity between the experimental data and the model prediction results was mainly caused by the neglect of the natural convection effect, which was never introduced into the droplet evaporation concept. A new droplet evaporation model with consideration of natural convection buoyancy force effect was proposed in this paper. Under the experimental conditions in this paper, the calculation results of the new droplet evaporation model were agreed with the experimental data for kerosene, methanol and other fuels, with less than 20% relative deviations. The relative deviations between the new evaporation model predictions for kerosene and the experimental data from the references were within 10%.