Objective:Cardiopulmonary resuscitation(CPR)is one of the most important life-saving procedures in the hospital.Contrary to medical guidelines,family presence during CPR is still not accepted in some countries.Family ...Objective:Cardiopulmonary resuscitation(CPR)is one of the most important life-saving procedures in the hospital.Contrary to medical guidelines,family presence during CPR is still not accepted in some countries.Family presence during CPR depends on the nurses’attitude,which is influenced by various factors.Emotional intelligence(EI)helps nurses make wise decisions and display responsible behavior,which is necessary for proper and good performance in nursing.The study’s purpose was to determine the attitude of acute care nurses toward family presence during CPR and its relationship with EI.Methods:The descriptive-analytical study was conducted among the nurses of acute care units(intensive care unit[ICU],critical care unit,and emergency department)in teaching hospitals of Qazvin University of Medical Sciences,Iran,in 2022-2023.A total of 186 nurses were included in the study using convenience sampling.The data collection tools were a checklist of demographic characteristics,nurses’attitude toward the presence of family scale,and Siberia Schering’s EI questionnaire.The collected data were analyzed using descriptive and analytical statistics and SPSS software.Results:The mean age of the participants was(32.05±6.93)years.Of 186 nurses participating in the study,127(68.3%)were women and the rest were men.The mean score of attitude was 47.41±9.41(the minimum score of the nurses was 19 and the maximum score was 95).The mean score of EI was 99.27±8.86(the minimum score was 69 and the maximum score was 128).The results of Pearson’s correlation coefficient showed no significant relationship between the total score of attitude and EI of the participants(P=0.588).Data analysis showed that only the self-arousal dimension of EI has a significant relationship with the range of family self-control behaviors in attitude(P=0.037).Conclusions:The results showed that the nurses of acute care units have a positive attitude toward the presence of the family during CPR and have high EI.Although no significant relationship was observed between the 2 variables,paying attention to the influencing factors on the attitude of the nurse toward family presence during CPR in different societies needs more research and investigation.展开更多
This study investigated the relationship between college students’awe and depression,along with the mediating roles of future self-continuity and presence of meaning.891 Chinese college students(570 female;mean age 1...This study investigated the relationship between college students’awe and depression,along with the mediating roles of future self-continuity and presence of meaning.891 Chinese college students(570 female;mean age 18.59;SD 1.34)from one university completed four surveys:Dispositional Awe Subscale,Future self-continuity Scale,Meaning in Life Scale and Depression Scale.Using structural equation modelling and the bootstrap method,the results delineated that awe negatively related to depression,and future self-continuity and presence of meaning had a serial mediation effect,reducing depression.The study implies educational institutions should foster a positive mental health education environment,urging students to develop positive traits,enhancing well-being and resilience,and facilitating psychological development.展开更多
BACKGROUND Parental presence in neonatal units(NUs)is essential for infant development and family well-being.A deeper understanding of the factors influencing parental presence is vital and will contribute to the deve...BACKGROUND Parental presence in neonatal units(NUs)is essential for infant development and family well-being.A deeper understanding of the factors influencing parental presence is vital and will contribute to the development of targeted interventions and policies that enhance parental engagement in neonatal care,thereby improving outcomes for infants and their families.AIM To identify and analyze primary factors influencing parental involvement in their child’s care in a neonatal intensive care unit(NICU).METHODS A literature search was conducted using the PubMed,MEDLINE,and Cochrane Library for systematic reviews databases,with the following search terms:“parental presence neonatology”,“couplet care”,“zero separation neonatal care”,“family integrated care”,“couplet care intervention”,“mother-child separation”,“parents newborn togetherness”,“mother-baby care”,“closeness and separation NICU”,“mother-infant interaction NICU”,“kangaroo care”,“dyad mother-infant”,and“newborn integrated care”.The database search for this literature review began on December 10,2024,with the final search conducted on April 10,2025.RESULTS The literature search yielded 281 articles,out of which 23 were selected for a detailed review.The factors associated with parental presence in NUs were grouped into five main categories:Parents’socio-demographic and cultural traits;the physical layout and care model of the NUs;the quality of parents’relationships with the healthcare staff;their active involvement in neonatal care;and the newborn’s health status.CONCLUSION The identification of factors that affect parental presence in NUs is critical for developing effective strategies aimed at encouraging increased parental involvement and ultimately improving neonatal and family outcomes.展开更多
We study the average rate of change of energy of two accelerated entangled atoms coupled to electromagnetic fields in the presence of a reflecting boundary,which according to the Dalibard,Dupont-Roc and Cohen-Tannoudj...We study the average rate of change of energy of two accelerated entangled atoms coupled to electromagnetic fields in the presence of a reflecting boundary,which according to the Dalibard,Dupont-Roc and Cohen-Tannoudji formalism is only attributed to the contribution of the radiative reaction of atoms.When the boundary is present,this result can be expressed as the sum of the free-space result and the boundary-induced modifications,and it generally depends on the two-atom initial state,the orientations of atomic dipole moments,as well as the relative scales among atom-boundary distance,interatomic separation and the inverse of atomic acceleration.When the two atoms are vertically aligned and one atom is very close to the boundary,we find that the terms only related to the closer atom are zero for the symmetric state but double the free-space counterpart for the antisymmetric state,if the atom is polarizable parallel to the boundary.However,for the atom polarizable vertically to the boundary,these terms vanish for the antisymmetric state but are twice the free-space counterpart for the symmetric state.Moreover,the terms related to the farther atom exhibit obviously oscillatory behavior,and the terms related to both atoms are vanishing unless the dipole moments of two atoms both have their components vertical to the boundary.When the two atoms are aligned parallel to and very close to the boundary,the terms related to one atom are interatomicseparation-independent and only influenced by the atomic dipole moments.The terms related to both atoms are actually consistent with the counterpart in the vertical-alignment case.In addition,when the two atoms are polarizable along the direction parallel to the boundary,the average rate of change of energy of two parallel-aligned and symmetric entangled atoms vanishes as if the two atoms were a closed system.展开更多
A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of ...A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of the plant.At low temperature,LTIA1 and LTIA2 redundantly affect chlorophyll levels,non-photochemical quenching,photosynthetic quantum yield of PSⅡand seedling growth.LTIA1 and LTIA2 proteins are involved in splicing of atp F and the biogenesis of 16S and 23S rRNA in chloroplasts.Presence/absence variation of LTIA1,the ancestral copy,was found only in japonica but that of LTIA2 in all rice subgroups.Accessions with LTIA2 presence tended to be distributed more remote from the equator compared to those with LTIA2 absence.LTIA2 duplicated from LTIA1 at the early stage of divergence of the AA genome Oryza species but deleted againin O.nivara.In cultivated rice,absence of LTIA2 is derived from O.nivara.LTIA1 absence occurred more recently in japonica.展开更多
Over the past few years,China’s higher education institutions have experienced remarkable growth in online teaching.However,it remains uncertain whether and how the sense of presence perceived by students affects the...Over the past few years,China’s higher education institutions have experienced remarkable growth in online teaching.However,it remains uncertain whether and how the sense of presence perceived by students affects their online learning outcomes when teachers use online teaching media for communication.This sense specifically pertains to the extent to which students perceive themselves as“real persons”and establish connections with others.Therefore,this study constructs a conceptual model elucidating the impact of presence on students’online learning outcomes and empirically examines the mechanism through which three types of presence influence students’online learning.The test results of the structural equation modeling(SEM)indicate that:(a)teaching presence,social presence,and cognitive presence all exhibit significantly positive outcomes on students’online learning outcomes;(b)these three types of presence can also indirectly and positively influence students’online learning outcomes through the mediating effect of flow experience and learning satisfaction;and(c)flow experience and learning satisfaction play a sequential mediating role in the process by which presence impacts students’online learning outcomes.We hope that the relevant research findings may contribute to unveiling the“black box”of the impact of presence on students’online learning outcomes and offer valuable insights for college educators to overcome online teaching constraints and enhance online teaching quality.展开更多
Enhancing the sense of presence of participants is an important issue in terms of security awareness for remote collaboration in extended reality.However,conventional methods are insufficient to be aware of remote sit...Enhancing the sense of presence of participants is an important issue in terms of security awareness for remote collaboration in extended reality.However,conventional methods are insufficient to be aware of remote situations and to search for and control remote workspaces.This study pro-poses a spatial multi-presence system that simultaneously provides multiple spaces while rapidly exploring these spaces as users perform collaborative work in an extended reality environment.The proposed system provides methods for arranging and manipulating remote and personal spaces by creating an annular screen that is invisible to the user.The user can freely arrange remote participants and their workspaces on the annular screen.Because users can simultaneously view various spaces arranged on the annular screen,they can perform collaborative work while simultaneously feeling the presence of multiple spaces and can be fully immersed in a specific space.In addition,the personal spaces where users work can also be arranged through the annular screen.According to the results of the performance evaluations,users participating in remote collaborative works can visualize the spaces of multiple users simultaneously and feel their presence,thereby increasing their understanding of the spaces.Moreover,the proposed system reduces the time to perform tasks and gain awareness of the emergency in remote workspaces.展开更多
The Conservation Voltage Reduction (CVR) is a technique that aims to achieve the decrease of power consumption as a result of voltage reduction. The customer is supplied with the lowest possible voltage level compatib...The Conservation Voltage Reduction (CVR) is a technique that aims to achieve the decrease of power consumption as a result of voltage reduction. The customer is supplied with the lowest possible voltage level compatible with the stipulated level by the regulatory agency. International Standards ANSI C84.1-2006 and IEEE std 1250-1995 specify the range of supply voltage to electronics equipment from 0.9 to 1.05 pu of nominal voltage. To analyse the CVR effect in distribution systems with different load characteristics (residential, commercial, industrial or a combination of these), mathematical load models are used. Typically, these equipment/load models are used to analyse load aggregation without any consideration of its nonlinearity characteristics. Aiming to analyse the nonlinear characteristics and its consequences, this paper presents a discussion of the neglected variables as well as the results of a set of measurements of nonlinear loads. Different mathematical models are applied to obtain them for each load. Using these models the load aggregation is evaluated. It is presented that although the models show adequate results for individual loads, the same does not occur for aggregated models if the harmonic contribution is not considered. Consequently, to apply the load model in CVR it is necessary to consider the harmonics presence and the model has to be done using only the fundamental frequency data. The discussion about the causes is done and the models are compared with the measurements.展开更多
Progress is described regarding the development of a new electrotactile feedback glove designed for application to dexterous robot. The sensitivity of operator's finger against electrical stimulus pulse is conside...Progress is described regarding the development of a new electrotactile feedback glove designed for application to dexterous robot. The sensitivity of operator's finger against electrical stimulus pulse is considered. It is found that frequency, duty ratio, and voltage amplitude of electrical stimulus pulse determine the sensitivity of finger. The effects of materials, sizes, arrangements and shapes of electrodes on sensitivity of finger are analyzed. Finally, the tactile tele presence system is designed to experimentally confirm that the robot with electrotactile feedback glove can manipulate dexterous robotic multi fingered hand and identify and classify three sorts of objects.展开更多
We extend Bespalov-Talanov (B-T) theory on small-scale self-focusing (SSSF) to include vector effect of a very narrow intense laser beam with application of the vector self-focusing model. The gain spectrum for pertur...We extend Bespalov-Talanov (B-T) theory on small-scale self-focusing (SSSF) to include vector effect of a very narrow intense laser beam with application of the vector self-focusing model. The gain spectrum for perturbations is obtained by using the standard linear instability analysis. It is shown that the influence on SSSF of vector effect is closely related to the beam width. For a very narrow beam, the role played by vector effect becomes significant, it reduces the fastest growing frequency and the maximum growth rate, and shortens the frequency range for perturbation growing, and thus deviates the gain spectrum from that of B-T theory.展开更多
Antibodies to the ubiquitous group of stress proteins known as heat shock proteins (Hsps) have been found to be associated with a number of diseases in humans. Hsps are known to be induced by certain xenobiotics, some...Antibodies to the ubiquitous group of stress proteins known as heat shock proteins (Hsps) have been found to be associated with a number of diseases in humans. Hsps are known to be induced by certain xenobiotics, some of which are common in the working environment. The biological significance of the presence of such autoantibodies is presently unclear. In the present study, we used immunoblotting to investigate the presence of antibodies against the different stress proteins, Hsp27, Hsp60, Hsp71, Hse (heat shock cognate ) 73 and Hsp89a and D in groups of workers exposed to high temperature or carbon monoxide. These data were related to a detailed clinical evaluation and to various laboratory measurements including electrocardiogram (ECG), B echogram, white blood cell counts and typing, the activity of alanine aminotransferase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) and lymphocyte DNA damage. Antibodies to Hsp27 and Hsp71 were found more frequently in the high temperature and carbon monoxide-exposed groups than in controls (P (0.05 ). The carbon monoxide-exposed group showed the highest incidence of anti-Hsp antibodies. Anti-Hsp60 antibodies were only detected in workers exposed to high temperature or carbon monoxide. The percentage of workers with abnormal ECG, B echogram changes and displaying hepatitis B antigen (HBsAg ) was higher in the carbon monoxide group than in the control group (P＜0.05 ).There was a significant inerease in the activity of ALT in the high temperature and carbon monoxide groups and in the activities of ACP and ALP in the carbon monoxide group (P＜0.05 ). The extent of DNA damage measured in lymphoeytes was higher in workers from the high temperature and carbon monoxide-cxposed groups. We suggest that the increased frequeney of antibodies to Hsps is the result of these damages, of the release of denatured Hsps and of a decrease in the phagocytic ability of macrophages in these workers. The data gathered in the present study show a statistical relation between the occurrence of antibodies against Hsps and the frequency of health problems in workers and suggest a potential role for the antibodies as useful biomarkers to assess whether workers are experieneing environmental stress展开更多
A microstructural analysis was performed to determine the presence of oxygen in a wire rod section of AISI 1008 steel with a surface mechanical failure produced during wire drawing.The failure zone was analyzed by com...A microstructural analysis was performed to determine the presence of oxygen in a wire rod section of AISI 1008 steel with a surface mechanical failure produced during wire drawing.The failure zone was analyzed by comparison using three different attack reagents:alkaline sodium chromate(ASC),ASC with hydrogen peroxide and amyl alcohol,and a solution of nitric acid in ethyl alcohol.The reagents were applied in samples in the failure zone,showing different types of zones in regions with internal and superficial defects such as carbides,pores,cracks,deformation,and detachment zones,indicating the possible presence of oxygen.The areas identified were observed by means of an optical microscope and were correlated with the content of elements that were present in the region using a scanning electron microscope and a scattered X-ray energy spectrometer,which determined that the areas identified by chromate sodium correspond to regions with a high concentration of oxygen and slag-forming elements such as silicon,aluminum,and iron;this is associated with the presence of oxygen in the oxide form.It was also observed that the ASC and the modified ASC solution with hydrogen peroxide and amyl alcohol could identify areas with a high presence of oxides,while the nitric acid solution only identified the steel microstructure.The modified ASC solution is an alternative to identify the presence of chemical variants of oxygen because the conventional formulation is unstable and has a too short shelf life,and therefore,its application must be carried out at the time of preparation.展开更多
The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in the presence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BS powder quantity...The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in the presence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BS powder quantity,initiator concentration and reaction temperature.Experimental results showed that the rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of the initiator concentration.There is a linear relationship of 2/3-power for the conversion and time.A process for the polymerization is propose to explain the experimental results.展开更多
This study aimed at comparing the level of social presence generated in a voice-based chat room and a text-based forum when learners tried to build personal relationships and form an online community for learning on a...This study aimed at comparing the level of social presence generated in a voice-based chat room and a text-based forum when learners tried to build personal relationships and form an online community for learning on an online language course in China. A mixed-method approach was taken for the study, drawing on data from questionnaires to find out about student perception of social presence, and postings of text messages and audio messages in the communication of the student learning process to search for students’ projected social presence in terms of affective, interactive and cohesive features. Interviews were also conducted to supplement additional information with the hope of forming a complete picture of social presence in the reality of an online learning environment. The text-based forum and the voice-based chat room were found to have a different impact on student social presence. In terms of student perception, most of them were more likely to get to know peers in the text-based forum and thus developed a sense of community in their learning process of the online course. Yet they believed that the voice-based chat room had the advantage of helping them with course learning. In the actual interaction, the voice-based chat room was more interactive although the text-based forum was more affective and cohesive. But in terms of the affective category, the problem with the existing framework in literature was that there were no prosodic features included. Therefore, in future more research is needed to probe for the relationship between prosodic sound features and social presence, and the present theoretic framework must be extended. In interviews, students explained that in the voice-based chat room prosodic features led to higher peer awareness, which further reinforced this need.展开更多
文摘Objective:Cardiopulmonary resuscitation(CPR)is one of the most important life-saving procedures in the hospital.Contrary to medical guidelines,family presence during CPR is still not accepted in some countries.Family presence during CPR depends on the nurses’attitude,which is influenced by various factors.Emotional intelligence(EI)helps nurses make wise decisions and display responsible behavior,which is necessary for proper and good performance in nursing.The study’s purpose was to determine the attitude of acute care nurses toward family presence during CPR and its relationship with EI.Methods:The descriptive-analytical study was conducted among the nurses of acute care units(intensive care unit[ICU],critical care unit,and emergency department)in teaching hospitals of Qazvin University of Medical Sciences,Iran,in 2022-2023.A total of 186 nurses were included in the study using convenience sampling.The data collection tools were a checklist of demographic characteristics,nurses’attitude toward the presence of family scale,and Siberia Schering’s EI questionnaire.The collected data were analyzed using descriptive and analytical statistics and SPSS software.Results:The mean age of the participants was(32.05±6.93)years.Of 186 nurses participating in the study,127(68.3%)were women and the rest were men.The mean score of attitude was 47.41±9.41(the minimum score of the nurses was 19 and the maximum score was 95).The mean score of EI was 99.27±8.86(the minimum score was 69 and the maximum score was 128).The results of Pearson’s correlation coefficient showed no significant relationship between the total score of attitude and EI of the participants(P=0.588).Data analysis showed that only the self-arousal dimension of EI has a significant relationship with the range of family self-control behaviors in attitude(P=0.037).Conclusions:The results showed that the nurses of acute care units have a positive attitude toward the presence of the family during CPR and have high EI.Although no significant relationship was observed between the 2 variables,paying attention to the influencing factors on the attitude of the nurse toward family presence during CPR in different societies needs more research and investigation.
基金supported by the Fundamental Research Funds for the Central Universities,and the Research Funds of Civil Aviation University of China,No.3122024012.
文摘This study investigated the relationship between college students’awe and depression,along with the mediating roles of future self-continuity and presence of meaning.891 Chinese college students(570 female;mean age 18.59;SD 1.34)from one university completed four surveys:Dispositional Awe Subscale,Future self-continuity Scale,Meaning in Life Scale and Depression Scale.Using structural equation modelling and the bootstrap method,the results delineated that awe negatively related to depression,and future self-continuity and presence of meaning had a serial mediation effect,reducing depression.The study implies educational institutions should foster a positive mental health education environment,urging students to develop positive traits,enhancing well-being and resilience,and facilitating psychological development.
文摘BACKGROUND Parental presence in neonatal units(NUs)is essential for infant development and family well-being.A deeper understanding of the factors influencing parental presence is vital and will contribute to the development of targeted interventions and policies that enhance parental engagement in neonatal care,thereby improving outcomes for infants and their families.AIM To identify and analyze primary factors influencing parental involvement in their child’s care in a neonatal intensive care unit(NICU).METHODS A literature search was conducted using the PubMed,MEDLINE,and Cochrane Library for systematic reviews databases,with the following search terms:“parental presence neonatology”,“couplet care”,“zero separation neonatal care”,“family integrated care”,“couplet care intervention”,“mother-child separation”,“parents newborn togetherness”,“mother-baby care”,“closeness and separation NICU”,“mother-infant interaction NICU”,“kangaroo care”,“dyad mother-infant”,and“newborn integrated care”.The database search for this literature review began on December 10,2024,with the final search conducted on April 10,2025.RESULTS The literature search yielded 281 articles,out of which 23 were selected for a detailed review.The factors associated with parental presence in NUs were grouped into five main categories:Parents’socio-demographic and cultural traits;the physical layout and care model of the NUs;the quality of parents’relationships with the healthcare staff;their active involvement in neonatal care;and the newborn’s health status.CONCLUSION The identification of factors that affect parental presence in NUs is critical for developing effective strategies aimed at encouraging increased parental involvement and ultimately improving neonatal and family outcomes.
基金supported in part by the NSFC under Grant Nos.12047551 and 12105061the Graduate Innovation Project of Shanxi Normal University under Grant No.2023XSY041。
文摘We study the average rate of change of energy of two accelerated entangled atoms coupled to electromagnetic fields in the presence of a reflecting boundary,which according to the Dalibard,Dupont-Roc and Cohen-Tannoudji formalism is only attributed to the contribution of the radiative reaction of atoms.When the boundary is present,this result can be expressed as the sum of the free-space result and the boundary-induced modifications,and it generally depends on the two-atom initial state,the orientations of atomic dipole moments,as well as the relative scales among atom-boundary distance,interatomic separation and the inverse of atomic acceleration.When the two atoms are vertically aligned and one atom is very close to the boundary,we find that the terms only related to the closer atom are zero for the symmetric state but double the free-space counterpart for the antisymmetric state,if the atom is polarizable parallel to the boundary.However,for the atom polarizable vertically to the boundary,these terms vanish for the antisymmetric state but are twice the free-space counterpart for the symmetric state.Moreover,the terms related to the farther atom exhibit obviously oscillatory behavior,and the terms related to both atoms are vanishing unless the dipole moments of two atoms both have their components vertical to the boundary.When the two atoms are aligned parallel to and very close to the boundary,the terms related to one atom are interatomicseparation-independent and only influenced by the atomic dipole moments.The terms related to both atoms are actually consistent with the counterpart in the vertical-alignment case.In addition,when the two atoms are polarizable along the direction parallel to the boundary,the average rate of change of energy of two parallel-aligned and symmetric entangled atoms vanishes as if the two atoms were a closed system.
基金supported by Zhejiang Provincial Natural Science Foundation of China (LD24C130002)Scientific Research Foundation of China Jiliang University。
文摘A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of the plant.At low temperature,LTIA1 and LTIA2 redundantly affect chlorophyll levels,non-photochemical quenching,photosynthetic quantum yield of PSⅡand seedling growth.LTIA1 and LTIA2 proteins are involved in splicing of atp F and the biogenesis of 16S and 23S rRNA in chloroplasts.Presence/absence variation of LTIA1,the ancestral copy,was found only in japonica but that of LTIA2 in all rice subgroups.Accessions with LTIA2 presence tended to be distributed more remote from the equator compared to those with LTIA2 absence.LTIA2 duplicated from LTIA1 at the early stage of divergence of the AA genome Oryza species but deleted againin O.nivara.In cultivated rice,absence of LTIA2 is derived from O.nivara.LTIA1 absence occurred more recently in japonica.
基金the project“Research on the Evaluation Mechanism of College Ideological and Political Education:A Perspective on Teacher-Student Development,”funded by Zhejiang Provincial College Ideological and Political Education Research Project.
文摘Over the past few years,China’s higher education institutions have experienced remarkable growth in online teaching.However,it remains uncertain whether and how the sense of presence perceived by students affects their online learning outcomes when teachers use online teaching media for communication.This sense specifically pertains to the extent to which students perceive themselves as“real persons”and establish connections with others.Therefore,this study constructs a conceptual model elucidating the impact of presence on students’online learning outcomes and empirically examines the mechanism through which three types of presence influence students’online learning.The test results of the structural equation modeling(SEM)indicate that:(a)teaching presence,social presence,and cognitive presence all exhibit significantly positive outcomes on students’online learning outcomes;(b)these three types of presence can also indirectly and positively influence students’online learning outcomes through the mediating effect of flow experience and learning satisfaction;and(c)flow experience and learning satisfaction play a sequential mediating role in the process by which presence impacts students’online learning outcomes.We hope that the relevant research findings may contribute to unveiling the“black box”of the impact of presence on students’online learning outcomes and offer valuable insights for college educators to overcome online teaching constraints and enhance online teaching quality.
基金supported by“Regional Innovation Strategy(RIS)”through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(2021RIS-004).
文摘Enhancing the sense of presence of participants is an important issue in terms of security awareness for remote collaboration in extended reality.However,conventional methods are insufficient to be aware of remote situations and to search for and control remote workspaces.This study pro-poses a spatial multi-presence system that simultaneously provides multiple spaces while rapidly exploring these spaces as users perform collaborative work in an extended reality environment.The proposed system provides methods for arranging and manipulating remote and personal spaces by creating an annular screen that is invisible to the user.The user can freely arrange remote participants and their workspaces on the annular screen.Because users can simultaneously view various spaces arranged on the annular screen,they can perform collaborative work while simultaneously feeling the presence of multiple spaces and can be fully immersed in a specific space.In addition,the personal spaces where users work can also be arranged through the annular screen.According to the results of the performance evaluations,users participating in remote collaborative works can visualize the spaces of multiple users simultaneously and feel their presence,thereby increasing their understanding of the spaces.Moreover,the proposed system reduces the time to perform tasks and gain awareness of the emergency in remote workspaces.
文摘The Conservation Voltage Reduction (CVR) is a technique that aims to achieve the decrease of power consumption as a result of voltage reduction. The customer is supplied with the lowest possible voltage level compatible with the stipulated level by the regulatory agency. International Standards ANSI C84.1-2006 and IEEE std 1250-1995 specify the range of supply voltage to electronics equipment from 0.9 to 1.05 pu of nominal voltage. To analyse the CVR effect in distribution systems with different load characteristics (residential, commercial, industrial or a combination of these), mathematical load models are used. Typically, these equipment/load models are used to analyse load aggregation without any consideration of its nonlinearity characteristics. Aiming to analyse the nonlinear characteristics and its consequences, this paper presents a discussion of the neglected variables as well as the results of a set of measurements of nonlinear loads. Different mathematical models are applied to obtain them for each load. Using these models the load aggregation is evaluated. It is presented that although the models show adequate results for individual loads, the same does not occur for aggregated models if the harmonic contribution is not considered. Consequently, to apply the load model in CVR it is necessary to consider the harmonics presence and the model has to be done using only the fundamental frequency data. The discussion about the causes is done and the models are compared with the measurements.
文摘Progress is described regarding the development of a new electrotactile feedback glove designed for application to dexterous robot. The sensitivity of operator's finger against electrical stimulus pulse is considered. It is found that frequency, duty ratio, and voltage amplitude of electrical stimulus pulse determine the sensitivity of finger. The effects of materials, sizes, arrangements and shapes of electrodes on sensitivity of finger are analyzed. Finally, the tactile tele presence system is designed to experimentally confirm that the robot with electrotactile feedback glove can manipulate dexterous robotic multi fingered hand and identify and classify three sorts of objects.
基金Supported by the High Technology Research and Development Program of China(Grant No.863-416-5).
文摘We extend Bespalov-Talanov (B-T) theory on small-scale self-focusing (SSSF) to include vector effect of a very narrow intense laser beam with application of the vector self-focusing model. The gain spectrum for perturbations is obtained by using the standard linear instability analysis. It is shown that the influence on SSSF of vector effect is closely related to the beam width. For a very narrow beam, the role played by vector effect becomes significant, it reduces the fastest growing frequency and the maximum growth rate, and shortens the frequency range for perturbation growing, and thus deviates the gain spectrum from that of B-T theory.
文摘Antibodies to the ubiquitous group of stress proteins known as heat shock proteins (Hsps) have been found to be associated with a number of diseases in humans. Hsps are known to be induced by certain xenobiotics, some of which are common in the working environment. The biological significance of the presence of such autoantibodies is presently unclear. In the present study, we used immunoblotting to investigate the presence of antibodies against the different stress proteins, Hsp27, Hsp60, Hsp71, Hse (heat shock cognate ) 73 and Hsp89a and D in groups of workers exposed to high temperature or carbon monoxide. These data were related to a detailed clinical evaluation and to various laboratory measurements including electrocardiogram (ECG), B echogram, white blood cell counts and typing, the activity of alanine aminotransferase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) and lymphocyte DNA damage. Antibodies to Hsp27 and Hsp71 were found more frequently in the high temperature and carbon monoxide-exposed groups than in controls (P (0.05 ). The carbon monoxide-exposed group showed the highest incidence of anti-Hsp antibodies. Anti-Hsp60 antibodies were only detected in workers exposed to high temperature or carbon monoxide. The percentage of workers with abnormal ECG, B echogram changes and displaying hepatitis B antigen (HBsAg ) was higher in the carbon monoxide group than in the control group (P＜0.05 ).There was a significant inerease in the activity of ALT in the high temperature and carbon monoxide groups and in the activities of ACP and ALP in the carbon monoxide group (P＜0.05 ). The extent of DNA damage measured in lymphoeytes was higher in workers from the high temperature and carbon monoxide-cxposed groups. We suggest that the increased frequeney of antibodies to Hsps is the result of these damages, of the release of denatured Hsps and of a decrease in the phagocytic ability of macrophages in these workers. The data gathered in the present study show a statistical relation between the occurrence of antibodies against Hsps and the frequency of health problems in workers and suggest a potential role for the antibodies as useful biomarkers to assess whether workers are experieneing environmental stress
基金the National Council of Science and Technology of Mexico(CONACYT)for the Ph.D.scholarship(No.788678)receivedthe use of the equipment acquired with the support for projects Nos.235780,271878,and 282357 of the National Laboratory SEDEAM-CONACYT.
文摘A microstructural analysis was performed to determine the presence of oxygen in a wire rod section of AISI 1008 steel with a surface mechanical failure produced during wire drawing.The failure zone was analyzed by comparison using three different attack reagents:alkaline sodium chromate(ASC),ASC with hydrogen peroxide and amyl alcohol,and a solution of nitric acid in ethyl alcohol.The reagents were applied in samples in the failure zone,showing different types of zones in regions with internal and superficial defects such as carbides,pores,cracks,deformation,and detachment zones,indicating the possible presence of oxygen.The areas identified were observed by means of an optical microscope and were correlated with the content of elements that were present in the region using a scanning electron microscope and a scattered X-ray energy spectrometer,which determined that the areas identified by chromate sodium correspond to regions with a high concentration of oxygen and slag-forming elements such as silicon,aluminum,and iron;this is associated with the presence of oxygen in the oxide form.It was also observed that the ASC and the modified ASC solution with hydrogen peroxide and amyl alcohol could identify areas with a high presence of oxides,while the nitric acid solution only identified the steel microstructure.The modified ASC solution is an alternative to identify the presence of chemical variants of oxygen because the conventional formulation is unstable and has a too short shelf life,and therefore,its application must be carried out at the time of preparation.
文摘The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in the presence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BS powder quantity,initiator concentration and reaction temperature.Experimental results showed that the rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of the initiator concentration.There is a linear relationship of 2/3-power for the conversion and time.A process for the polymerization is propose to explain the experimental results.
文摘This study aimed at comparing the level of social presence generated in a voice-based chat room and a text-based forum when learners tried to build personal relationships and form an online community for learning on an online language course in China. A mixed-method approach was taken for the study, drawing on data from questionnaires to find out about student perception of social presence, and postings of text messages and audio messages in the communication of the student learning process to search for students’ projected social presence in terms of affective, interactive and cohesive features. Interviews were also conducted to supplement additional information with the hope of forming a complete picture of social presence in the reality of an online learning environment. The text-based forum and the voice-based chat room were found to have a different impact on student social presence. In terms of student perception, most of them were more likely to get to know peers in the text-based forum and thus developed a sense of community in their learning process of the online course. Yet they believed that the voice-based chat room had the advantage of helping them with course learning. In the actual interaction, the voice-based chat room was more interactive although the text-based forum was more affective and cohesive. But in terms of the affective category, the problem with the existing framework in literature was that there were no prosodic features included. Therefore, in future more research is needed to probe for the relationship between prosodic sound features and social presence, and the present theoretic framework must be extended. In interviews, students explained that in the voice-based chat room prosodic features led to higher peer awareness, which further reinforced this need.
