Water-borne disaster debris can exacerbate the damage on the built-environment through debris impact and debris damming loads and by decreasing the functionality of infrastructure systems after these ...events. Therefore, an understanding of disaster debris transport is essential for disaster management. In this paper, an experimental study of tsunami-driven debris spreading over a flat testbed was conducted considering different density conditions of debris elements. Debris elements of two different materials (densities) were considered various debris groups and starting orientation. The final dislocations and local velocity of debris elements were measured optically and compared to flow velocity. Among two debris elements in a debris group, it was found that debris elements of higher density affected the mean longitudinal displacement of the less dense debris, but the less dense debris did not affect the displacement of higher density debris. Also, it was found that the initial orientations of the debris groups had no measurable impact on the final displacement. The effects of obstacles on the passage of debris and the probability of collision to obstacles were examined and the process of debris-debris and debris-obstacle interactions from debris entrainment to final dislocation was studied. It was found that the less dense debris had a higher probability of collision with the obstacles compared to the more dense debris case. However, when the debris types were mixed, the less dense debris had a lower probability of collision. Finally, the characteristics of debris dislocation and velocity fields under various density conditions as a group were also evaluated. The reflected wave and interaction among different debris play a role in the probability of collision. However, the density of each debris element was a dominant factor in determining the collision probability.
•An experimental study of tsunami-driven debris transportation is performed.•The less-dense debris group moved further and had less spread.•The less-dense debris has a lower probability of collision to obstacles.•The debris velocity varied spatially and is sensitive to the depth and obstacles.
Thermal comfort is an essential environmental factor related to quality of life and work effectiveness. We assessed the feasibility of wrist skin temperature monitoring for estimating subjective ...thermal sensation. We invented a wrist band that simultaneously monitors skin temperatures from the wrist (i.e., the radial artery and ulnar artery regions, and upper wrist) and the fingertip. Skin temperatures from eight healthy subjects were acquired while thermal sensation varied. To develop a thermal sensation estimation model, the mean skin temperature, temperature gradient, time differential of the temperatures, and average power of frequency band were calculated. A thermal sensation estimation model using temperatures of the fingertip and wrist showed the highest accuracy (mean root mean square error RMSE: 1.26 ± 0.31). An estimation model based on the three wrist skin temperatures showed a slightly better result to the model that used a single fingertip skin temperature (mean RMSE: 1.39 ± 0.18). When a personalized thermal sensation estimation model based on three wrist skin temperatures was used, the mean RMSE was 1.06 ± 0.29, and the correlation coefficient was 0.89. Thermal sensation estimation technology based on wrist skin temperatures, and combined with wearable devices may facilitate intelligent control of one's thermal environment.
The aim of this study was to evaluate the effect of simulation-based learning using standardized patients (SPs) on cognitive, affective, and psychomotor domain outcomes of learning in nursing ...students.
MEDLINE via PubMed, Cochrane Library CENTRAL, EMBASE, CINAHL, and several Korean electronic databases (to June 2014) were searched. The RevMan 5.3 program of the Cochrane library was used for data analysis.
A meta-analysis was conducted of 18 controlled trials (4 randomized and 14 non-randomized designs), with a total of 1326 nursing students. Overall, simulation-based learning using SPs appeared to have beneficial effects on the cognitive, affective, and psychomotor domains of learning. In subgroup analysis, use of SPs showed significant effects on knowledge acquisition (d=0.38, p=.05, I2=42%), communication skill (d=1.86, p<.001, I2=15%), self-efficacy (d=0.61, p<.001, I2=6%), learning motivation (d=0.77, p<.001, I2=0%) and clinical competence (d=0.72, p<.001, I2=0%). Treatment effects on critical thinking (p=.75) and learning satisfaction (p=.43) were not significant.
The findings of the current study suggest that simulation-based learning using SPs might have a positive impact on self efficacy and learning motivation that affects knowledge and clinical skill acquisition. Therefore, these findings demonstrate that, if integrated appropriately, an SP educational approach can be used in academic settings as an active learning methodology.
The International Electrotechnical Commission (IEC) 62351-6 standard prescribes provisions to secure IEC 61850-8-1 generic object-oriented substation events (GOOSE) communications from cyber threats. ...The GOOSE authentication schemes recommended by IEC 62351-6 have shortcomings, such as long authentication-value computation times, large signature lengths, the usage of symmetric keys, and susceptibility to quantum computer attacks. To overcome these, this paper proposes the usage of the rainbow signature scheme (RSS), a quantum cryptographic method to secure GOOSE messages. The RSS offers fast signature generation and verification using asymmetric keys, making it very attractive to meet the time-latency and security requirements of the GOOSE protocol. The adaptation of the RSS cryptography method for its application to the GOOSE protocol is presented in this paper. The algorithms for key generation, signature computation and message verification are discussed in detail. A first-of-its-kind C library that incorporates security features within the GOOSE protocol in compliance with the IEC 62351-6-stipulated format, is developed. The superior features of the RSS in comparison with the other IEC 62351-6 security schemes are demonstrated.
The protective effects of vitamin D and calcium on colorectal neoplasms are known. Bone mineral density (BMD) may be a reliable biomarker that reflects the long-term anticancer effect of vitamin D ...and calcium. This study aimed to evaluate the association between BMD and colorectal adenomas including high-risk adenoma.
A multicenter, cross-sectional, case-control study was conducted among participants with average risk of colorectal cancer who underwent BMD and screening colonoscopy between 2015 and 2019. The main outcome was the detection of colorectal neoplasms. The variable under consideration was low BMD (osteopenia/osteoporosis). The logistic regression model included baseline demographics, components of metabolic syndrome, fatty liver disease status, and aspirin and multivitamin use.
A total of 2,109 subjects were enrolled. The mean age was 52.1±10.8 years and 42.6% were male. The adenoma detection rate was 43%. Colorectal adenoma and high-risk adenoma were both more prevalent in subjects with low BMD than those with normal BMD (48.2% vs 38.8% and 12.1% vs 9.1%). In the univariate analysis, old age, male sex, smoking, metabolic components, fatty liver, and osteoporosis were significantly associated with the risk of adenoma and high-risk adenoma. In the multivariate analysis, osteoporosis was independently associated with risk of colorectal adenoma (odds ratio OR, 1.65; 95% confidence interval CI, 1.11 to 2.46; p=0.014) and high-risk adenoma (OR, 1.94; 95% CI, 1.14 to 3.29; p=0.014).
Osteoporosis is an independent risk factor of colorectal adenoma and high-risk adenoma.
Background/Aims: The protective effects of vitamin D and calcium on colorectal neoplasms are known. Bone mineral density (BMD) may be a reliable biomarker that reflects the long-term anticancer ...effect of vitamin D and calcium. This study aimed to evaluate the association between BMD and colorectal adenomas including high-risk adenoma.
Methods: A multicenter, cross-sectional, case-control study was conducted among participants with average risk of colorectal cancer who underwent BMD and screening colonoscopy between 2015 and 2019. The main outcome was the detection of colorectal neoplasms. The variable under consideration was low BMD (osteopenia/osteoporosis). The logistic regression model included baseline demographics, components of metabolic syndrome, fatty liver disease status, and aspirin and multivitamin use.
Results: A total of 2,109 subjects were enrolled. The mean age was 52.1±10.8 years and 42.6% were male. The adenoma detection rate was 43%. Colorectal adenoma and high-risk adenoma were both more prevalent in subjects with low BMD than those with normal BMD (48.2% vs 38.8% and 12.1% vs 9.1%). In the univariate analysis, old age, male sex, smoking, metabolic components, fatty liver, and osteoporosis were significantly associated with the risk of adenoma and high-risk adenoma. In the multivariate analysis, osteoporosis was independently associated with risk of colorectal adenoma (odds ratio OR, 1.65; 95% confidence interval CI, 1.11 to 2.46; p=0.014) and high-risk adenoma (OR, 1.94; 95% CI, 1.14 to 3.29; p=0.014).
Conclusions: Osteoporosis is an independent risk factor of colorectal adenoma and high-risk adenoma. (Gut Liver 2022;16:269-276)
Online courses and programs continue to grow in higher education settings. Students are increasingly demanding online access, and universities and colleges are working to meet the demands. Yet many ...questions remain re: the viability and veracity of online learning, particularly from the learner perspective. The purpose of this study was to gain insights into learners' perceptions of online learning. Seventy-six (76) graduate students were surveyed to identify helpful components and perceived challenges based on their online learning experiences. Results of the study indicated that most learners agreed that course design, learner motivation, time management, and comfortableness with online technologies impact the success of an online learning experience. Participants indicated that technical problems, a perceived lack of sense of community, time constraints, and the difficulty in understanding the objectives of the online courses as challenges. Suggestions for addressing the challenges are provided.
Online groupwork is becoming an increasingly popular instructional strategy. Although researchers have questioned the benefits of groupwork in online learning environments, little empirical research ...has examined the challenges it presents. The purpose of this study was to investigate the experience of students involved in online groupwork to find strategies that could be implemented to assist students in completing online groupwork. The findings indicated that the strategies for the instructors included two areas: course design and groupwork process. The course design strategies include 1) providing multiple communication methods; 2) providing an overall plan for the class; 3) preparing for technology; and 4) building virtual team skills. The groupwork process strategies include 1) assisting group formation; 2) building a sense of connection; 3) being involved in group processes; and 4) evaluating group processes. Finally, this study suggested future research is needed in the conditions that facilitate effective group composition.
American education has been threatened by low student achievement, high teacher attrition, and proficient teacher shortages for decades. Disruptive classroom behaviors are the primary contributor to ...teacher attrition and the interlinked dichotomy, but relative to special education, general education lacks both competent teacher preparation and constructive behavior remediation. The study found K-12 students with and without disabilities to exhibit different behavior profiles, but the quantity and quality of both profiles warrant the need for proper teacher preparation and implementation of structured behavior intervention systems. Study implications regarding public schools' systematic challenges were discussed extensively with recommended next steps.
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