Public randomization in the repeated prisoner's dilemma game with local interaction

We consider a situation in which each agent observes only their neighbor's actions and locally interacts with them by playing prisoner's dilemma games. Introducing a public randomization, we construct an equilibrium which sustains cooperation and in which cooperation eventually resumes after any history.Repeated prisoner's dilemma game Local interaction Public randomization Network

Efficient structure of organization with heterogeneous workers

Abstract This paper studies the problem of organizational design in a setting where workers differ in their abilities and every worker has to be monitored to prevent shirking. The need for monitoring workers generates a hierarchical structure in an organization, which can be represented as a rooted tree. The value of an organization is determined by the wage cost, the total number of productive tasks carried out, and the length of the chain of supervision in the organizational hierarchy. In this setting, we construct and characterize an efficient structure of hierarchy which maximizes the value of the organization. In addition, we show that a hierarchy with an optimal size has the form of a balanced rooted tree.Organization Hierarchy Rooted tree Structure rule

Value of Online Videos as a Shoulder Injection Training Tool for Physicians and Usability of Current Video Evaluation Tools

This study aimed to evaluate the reliability, overall quality, and educational value of online videos for learning the techniques related to shoulder injection treatments and analyzing the usability of video evaluation tools for musculoskeletal injections. Online video searches were performed in February 2022 using the terms “shoulder injection”, “glenohumeral joint injection”, “acromioclavicular joint injection”, and “subacromial bursa injection.” Included videos were scored by modified DISCERN (mDISCERN), global quality score (GQS), and shoulder injection score (SIS). Correlations between scoring systems were analyzed. Of the 150 videos, 49 (32.67%) contained highly reliable information. Regarding the assessment of overall quality by the GQS, 109 (72.67%) videos were of low quality. Regarding SIS, 114 (76.00%) scored not >5, of which 77 (51.33%) scored <3. Most of the SIS domains were fully explained in <40% of the included videos. A weak positive relationship was noted between the mDISCERN and SIS (r2 = 0.38), while a moderately positive relationship was observed between the GQS and SIS (r2 = 0.49). The majority of online videos about shoulder injection treatment showed low reliability, overall quality, and educational value. Additionally, a new scoring system is required to accurately evaluate musculoskeletal injection videos for educational purposes

Mobile applications for cognitive training: Content analysis and quality review

Background: As the number of individuals suffering from cognitive diseases continues to rise, dealing with the diminished cognitive function that comes with age has become a serious public health concern. While the use of mobile applications (apps) as digital treatments for cognitive training shows promise, the analysis of their content and quality remains unclear. Objective: The aim of this study was to systematically search and assess cognitive training apps using the multidimensional mobile app rating scale (MARS) to rate objective quality and identify critical points. Methods: A search was conducted on the Google Play Store and Apple App Store in February 2022 using the terms “cognitive training” and “cognitive rehabilitation.” The cognitive domains provided by each app were analyzed, and the frequency and percentage according to the apps were obtained. The MARS, a mHealth app quality rating tool including multidimensional measures, was used to analyze the quality of the apps. The relationship between the MARS score, the number of reviews, and 5-star ratings were examined. Results: Of the 53 apps, 52 (98 %) included memory function, 48 (91 %) included attention function, 24 (45 %) included executive function, and 19 (36 %) included visuospatial function. The mean (SD) scores of MARS, 5-star ratings, and reviews of 53 apps were 3.09 (0.61), 4.33 (0.30), and 62,415.43 (121,578.77). From the between-section comparison, engagement (mean 2.97, SD 0.68) obtained lower scores than functionality (mean 3.18, SD 0.62), aesthetics (mean 3.13, SD 0.72), and information (mean 3.11, SD 0.54). The mean quality score and reviews showed a statistically significant association (r = 0.447 and P = .001*). As the number of domains increased, the mean quality score showed a statistically significant increasing trend (P = .002*). Conclusions: Most apps provided training for the memory and attention domains, but few apps included executive function or visuospatial domains. The quality of the apps improved significantly when more domains were provided, and was positively associated with the number of reviews received. These results could be useful for the future development of mobile apps for cognitive training

Efficient and Stable Fiber Dye-Sensitized Solar Cells Based on Solid-State Li-TFSI Electrolytes with 4-Oxo-TEMPO Derivatives

Fiber-shaped dye-sensitized solar cells (FDSSCs) with flexibility, weavablity, and wearability have attracted intense scientific interest and development in recent years due to their low cost, simple fabrication, and environmentally friendly operation. Since the Grätzel group used the organic radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as the redox system in dye-sensitized solar cells (DSSCs) in 2008, TEMPO has been utilized as an electrolyte to further improve power conversion efficiency (PCE) of solar cells. Hence, the TEMPO with high catalyst oxidant characteristics was developed as a hybrid solid-state electrolyte having high conductivity and stability structure by being integrated with a lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) film for FDSSCs. The optimized 4-Oxo TEMPO (OX) based solid-state FDSSC (SS-FDSSC) showed the PCE of up to 6%, which was improved by 34.2% compared to that of the reference device with 4.47%. The OX-enhanced SS-FDSSCs reduced a series resistance (Rs) resulting in effective electron extraction with improved short-circuit current density (JSC), while increasing a shunt resistance (Rsh) to prevent the recombination of photo-excited electrons. The result is an improvement in a fill factor (FF) and consequently a higher value for the PCE