Search

PurposeUnsafe behavior is a major cause of safety accidents, while in most management measures for unsafe behavior, the construction workers are generally managed as a whole. Therefore, this study aims to propose group management of construction workers' unsafe behavior considering individual characteristics.Design/methodology/approachA cognitive process model with ten cognitive factors was constructed based on cognitive safety theory. The questionnaire was developed and validated based on the cognitive model, and the results showed that the questionnaire had good reliability and validity, and the cognitive model fitted well. Latent class analysis was used to classify the unsafe behaviors of construction workers.FindingsFour categories of cognitive excellent type, cognitive failure type, no fear type and knowingly offending type were obtained. Workers of cognitive excellent type have good cognitive ability and a small tendency for unsafe behaviors. Workers of cognitive failure type have poor cognitive ability and the potential for cognitive failure in all four cognitive links. Workers of no fear type have weak cognitive ability, and cognitive failure may occur in discovering information and choosing coping links. Workers of knowingly offending type have certain cognitive abilities, but cognitive failure may occur in choosing coping link.Originality/valueThis study formulates targeted management measures according to the potential characteristics of these four types and provides scientific theoretical support for the personalized management of unsafe behavior.

The accidental fatality rate of the construction industry is one of the highest areas with occupational accidents in all workplaces. To investigate the most common and direct cause of hazardous accidental incidents, the unsafe behaviors of construction workers would be the answer. In order to reduce occupational accidents, an assessable questionnaire is urgently needed for measuring the potential unsafe behaviors of construction workers. Considering that safety climate research and behavior safety research barely explained the causes of unsafe behavior, this research was conducted from a cognitive model-based perspective. A new questionnaire was designed to evaluate the potentially unsafe behaviors, and a cognitive model with 11 factors was adopted. After verification by exploratory factor analysis, confirmatory factor analysis, and reliability analysis, the new questionnaire showed good validity (content validity index 0.42, average variance extracted > 0.5) and reliability (Cronbach's α > 0.7, composite reliability > 0.7), and the cognitive model fitted well. Therefore, the new questionnaire is effective and reliable in assessing the causes of unsafe behaviors of construction workers.

We provide a justification of why social networks boost knowledge exchange.We propose a set of measurable outcome indicators for knowledge exchange research.We justify the investment on social networking for virtual community of practice.We verify the impact of social networking support on knowledge exchange. Virtual community of practice (VCoP) is an important form of knowledge management systems. Would the integration of social networking support into traditional forum-based VCoP benefit knowledge exchange in the community? If so, why? Based on social capital theory and transactive memory system research, this study suggests that social networking support will enhance knowledge exchange in VCoP. In a field study, this study found that social networking support intensifies dyadic knowledge exchange among friends and reduces the probability that dyads stop knowledge exchange. These findings empirically confirm the effect of social networking support integration in VCoP, offering an investment justification for practitioners.

Based on the DNA sequence of ACS9, two produced fragments were subcloned into binary vector pCAMBIA1300 in antisense and sense orientations, and the generated RNA interference (RNAi) vector was then transformed into Arabidopsis thaliana. The stress resistance function of ACS9 gene in Arabidopsis thaliana was researched by determination of stress resistance physiologic indexes, NaCl and PEG6000 resistance. The results showed that the inhibition of ACS9 expression enhanced the sensitivity to high concentration NaCl (150 mmol/L) and PEG6000 (7%) in Arabidopsis thaliana seeding stage. The proline contents and water loss rates in transgenic plants were 0.68 and 1.4 times higher than those in the wild-type leaves, respectively, indicating that the inhibition of ACS9 expression due to salt and drought resistant was reduced and suggested that ACS9 gene played important roles in plant salt and drought tolerance.

This paper focuses on impacts of switching capacitors on dynamic power quality in diverse situations, based on collecting data on site from Recorder and Real-Time Digital Dynamic Simulation System (RTDS). Some regularities of bus dynamic voltage fluctuation caused by switching capacitors are obtained by the research for factors of system, switching angles, capacitor capacities, loads, series reactor configurations and so on.

Shanghai Pudong Maglev is the first commercial Maglev application in the world. Maglev is the typical fast-varying nonlinear load due to its AC-DC-AC-driven feature. This paper summarizes harmonic models and power changes for Maglev in operation. Power system harmonic computation program is employed for elaborate evaluation of harmonic current injected into the grid and the voltage surge at the power supply bus due to Maglev operation. The computational results may help the power supply company to provide reasonable suggestions for the customer. (4 pages)

An overall analysis is presented based on harmonics measurement data at the substations of Subway NO.l, NO.2 and Mingzhu Line (No.3)in Shanghai. Combined with the power supply mechanism of subway transportation, the variation principles of the active and reactive power are developed for the subway load. The load frequency characteristics are retrieved. In terms of various subway operation modes in 2005, further harmonics analysis is performed according to the fundamental data of harmonics pollution after subway being connected into Shanghai Grid. Harmonics pollution brought to Shanghai Grid is evaluated in 2005. The analysis shows that serious harmonic distortion will be brought to Shanghai Grid after the fundamental subway transportation network is formed. (6 pages)

The charge storage properties of amorphous silicon nitride (Si/sub 3/N/sub 4/) film deposited by LPCVD on silicon substrate and double layer of Si/sub 3/N/sub 4//SiO/sub 2/ on silicon substrate have been investigated. Because the double layer of Si/sub 3/N/sub 4//SiO/sub 2/ has more outstanding charge storage stability than single layer silicon dioxide, people are very interested in the charge storage mechanism of Si/sub 3/N/sub 4//SiO/sub 2/. In this paper, a revised formula for calculating the mean charge depth of the double layer system for inorganic dielectric films was introduced based on Guenther and Sessler's method (1991). Space charge storage characteristics and the shift of the mean charge depth under different conditions were investigated by means of corona charging, TSD (thermal stimulated discharge), capacitance-voltage (C-V) analysis method and chemical surface modification, etc.

Amorphous silicon nitride (Si/sub 3/N/sub 4/) film has outstanding electret properties and it is compatible with micromachining technology. Therefore, it is expected to be used as an electret vibrating membrane in miniature microphones. One of the most important parameters of characterizing electret-vibrating membranes is flexibility. So the reduction of internal stress due to boron ion implantation for the LPCVD Si/sub 3/N/sub 4/ film on silicon substrate is discussed first. The charge storage ability for the Si/sub 3/N/sub 4/ films B+ implanted by various doses and energies are investigated by means of negative corona charging, the isothermal surface potential decay measurements and open-circuit thermally stimulated discharge (TSD) current spectrum analysis.

Amorphous silicon nitride (Si/sub 3/N/sub 4/) film has outstanding electret properties and it is compatible to the micromachining technology. Therefore, it is expected to find use as an electret membrane or vibrating membrane in miniature microphones. Both sensitivity and stability are very important parameters in miniature microphones. So high internal stress in Si/sub 3/N/sub 4/ film should be eliminated. In this paper, the reduction of internal stress due to boron ion implantation for the LPCVD Si/sub 3/N/sub 4/ film on silicon substrate and the influence of boron ion implantation on the mechanics and electret properties of Si/sub 3/N/sub 4/ films are discussed. The results show boron ion implantation reduces the internal stress of the Si/sub 3/N/sub 4/ film effectively and the charge storage of a Si/sub 3/N/sub 4/ film with implanted B ions is worse than for an unimplanted one. The authors conclude that the Si/sub 3/N/sub 4/ film is more suitable for use as a vibrating membrane than as a single electret membrane in electret miniature microphones.