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The procedural justice theory of police legitimacy has been examined extensively by previous scholars; yet more expansion of the legitimacy literature is warranted. Specifically, the current study examines the effects of institutional trust and obligation to obey as mediators between procedural justice and perceived legitimacy.

The current study uses structural equation modeling (SEM) to test our hypotheses. Convenience sampling of South Korean university students (N = 2,188) was used to investigate our inquiry.

The results support our hypotheses in that while procedural justice was the primary predictor of legitimacy, institutional trust and obligation to obey were also significant mediators of procedural justice and perceived legitimacy.

A multitude of research examining various predictors of police legitimacy exists (e.g. Baker and Gau, 2018; Boateng and Buckner, 2019; Boateng et al., 2022; Lee and Lee, 2021; Lee et al., 2022, 2024; Lee and Kim, 2023; Nagin and Telep, 2017). More importantly, various researchers have concluded that procedural justice does in fact have a positive impact on the public’s perception of governmental institutions (Hough et al., 2010; Mazerolle et al., 2013a; Murphy and Cherney, 2012; Sunshine and Tyler, 2003). A few research have directly examined institutional trust in the policing context (e.g. Boateng, 2018; Camp et al., 2021). Specifically, Boateng (2018) examined institutional trust and its relationship to police performance, and Camp et al. (2021) examined police officers’ prosody and its impact on the citizens’ institutional trust in police. However, the objective of the current research is to examine the relationship between procedural justice and legitimacy through the double mediating role of the public’s perception of institutional trust and obligation to obey.

The study aims to show the influence of selected mechanical parameters of the rotor on the maximum speed and parameters of the electric motor.

A simplified mechanical analysis of the rotor of the electric motor was conducted, determining the safety factor of the motor. An analysis of the impact of key rotor parameters (significant from the mechanical strength perspective) on the electromagnetic parameters and the safety factor of the selected high-speed electric motor was carried out. The influence of changes in the rotor’s geometrical dimensions (centrifugal force) on the electromagnetic parameters of the electric motor was shown.

The study shows the impact of changes in selected rotor parameters on electromagnetic parameters and the safety factor of a high-speed electric motor (at its required operating point of 45,000 rpm). The dependence of the safety factor as a function of the maximum motor speed was determined for the proposed rotor modifications.

The proposed modifications can be used in larger drive systems. They have practically no impact on increasing the value of the motor’s moment of inertia (they do not degrade the dynamics of the motor’s operation).

It was proposed to use a new design coefficient which is in relation to the motor’s safety coefficient. It has been shown that a minimal modification of the motor rotor allows to increase its maximum speed by several dozen per cent (while maintaining the safety factor). It has also been shown that when operating at maximum speed within the safe range, the change in the geometrical dimensions of the rotor hardly influences the change in the value of the centrifugal force.

This paper investigates a retrospective on the Journal of Derivatives and Quantitative Studies (JDQS) on its 30th anniversary based on bibliometric. JDQSs yearly publications, citations, impact factors, and centrality indices grew up in early 2010s, and diminished in 2020. Keyword network analysis reveals the JDQS's main keywords including behavioral finance, implied volatility, information asymmetry, price discovery, KOSPI200 futures, volatility, and KOSPI200 options. Citations of JDQS articles are mainly driven by article age, demeaned age squared, conference, nonacademic authors and language. In comparison between number of views and downloads for JDQS articles, we find that recent changes in publisher and editorial and publishing policies have increased visibility of JDQS.

In the past several years, CH₃NH₃PbI₃ perovskite material has been extensively evaluated as an absorber layer of perovskite solar cells due to its excellent structural and optical properties, and greater than 22% conversion efficiency. However, improvement and future commercialization of solar cells based on CH₃NH₃PbI₃ encountered restrictions due to toxicity and instability of the lead element. Recently, studies on properties of lead-free and mixture of lead with other cations perovskite thin films as light absorber materials have been reported. The purpose of this paper was the fabrication of CH₃NH₃Sn₁-xPbxI₃ thin films with different SnI₂ concentrations in ambient condition, and study on the structural, morphological, optical, and photovoltaic performance of the studied solar cells. The X-ray diffraction studies revealed the formation of both CH₃NH₃PbI₃ and CH₃NH₃SnI₃ phases with increasing the Sn concentration, and improvement in crystallinity and morphology was also observed. All perovskite layers had a relatively high absorption coefficient >104 cm⁻¹ in the visible wavelengths, and the bandgap values varied in the range from 1.46 to 1.63 eV. Perovskite solar cells based on these thin films have been fabricated, and device performance was investigated. Results showed that photo-conversion efficiency (PCE) for the pure CH₃NH₃PbI₃sample was 1.20%. With adding SnI₂, PCE was increased to 4.48%.

In this work, the author mixed tin and lead with different percentages in the perovskite thin film. Also, the preparation of these layers and also other layers to fabricate solar cells based on them were conducted in an open and non-glove box environment. Finally, the effect of [Sn/Pb] ratio in the CH₃NH₃Sn₁-xPbxI₃ layers on the structural, morphological, optical, electrical and photovoltaic performance have been investigated.

CH₃NH₃Sn₁-xPbxI₃ (x = 0.0, 0.25, 0.50, 0.75, 1.0) perovskite thin films have been grown by a spin-coating technique. It was found that as tin concentration increases, the X-ray diffraction and FESEM images studies revealed the formation of both CH₃NH₃PbI₃ and CH₃NH₃SnI₃ phases, and improvement in crystallinity, and morphology; all thin films had high absorption coefficient values close to 104 cm⁻¹ in the visible region, and the direct optical bandgap in the layers decreases from 1.63 eV in pure CH₃NH₃SnI₃ to 1.46 eV for CH₃NH₃Sn0.0.25Pb0.75I3 samples; all thin films had p-type conductivity, and mobility and carrier density increased; perovskite solar cells based on these thin films have been fabricated, and device performance was investigated. Results showed that photo-conversion efficiency (PCE) for the pure CH₃NH₃PbI₃sample was 1.20%. With adding SnI2, PCE was increased to 4.48%.

The preparation method seems to be interesting as it is in an ambient environment without the protection of nitrogen or argon gas.

While conceived to examine key factors affecting post-retirement career advancement of retired elite athletes in South Korea, the purpose of this paper is to report how English, as a de facto global lingua franca, functions as a powerful gatekeeper in the sports administration field.

Interpreted through the lens of Bourdieu’s linguistic capital and Gramsci’s hegemony of language, the present study draws on content analysis of semi-structured individual interviews, as well as focus group interviews, conducted with thirty former South Korean elite athletes.

Based on the data analysis, systematic bias toward athletes was uncovered, privileging English as the single determining factor for employment. Furthermore, the educational implications for adult learners of English as a Foreign or English an Additional Language reveal unrealistic expectations of top–down language policies.

Perspectives of athlete participants, an underrepresented group in educational research, within the South Korean globalization context shed critical light on the pervasive aspects of English hegemony and its unexamined dimensions.

As the number of users on social network services (SNSs) continues to increase at a remarkable rate, privacy and security issues are consistently arising. Although users may not want to disclose their private attributes, these can be inferred from their public behavior on social media. In order to investigate the severity of the leakage of private information in this manner, the purpose of this paper is to present a method to infer undisclosed personal attributes of users based only on the data available on their public profiles on Facebook.

Facebook profile data consisting of 32 attributes were collected for 111,123 Korean users. Inferences were made for four private attributes (gender, age, marital status, and relationship status) based on five machine learning-based classification algorithms and three regression algorithms.

Experimental results showed that users’ gender can be inferred very accurately, whereas marital status and relationship status can be predicted more accurately with the authors’ algorithms than with a random model. Moreover, the average difference between the actual and predicted ages of users was only 0.5 years. The results show that some private attributes can be easily inferred from only a few pieces of user profile information, which can jeopardize personal information and may increase the risk to dignity.

In this paper, the authors’ only utilized each user’s own profile data, especially text information. Since users in SNSs are directly or indirectly connected, inference performance can be improved if the profile data of the friends of a given user are additionally considered. Moreover, utilizing non-text profile information, such as profile images, can help increase inference accuracy. The authors’ can also provide a more generalized inference performance if a larger data set of Facebook users is available.

A private attribute leakage alarm system based on the inference model would be helpful for users not desirous of the disclosure of their private attributes on SNSs. SNS service providers can measure and monitor the risk of privacy leakage in their system to protect their users and optimize the target marketing based on the inferred information if users agree to use it.

This paper investigates whether private attributes of SNS users can be inferred with a few pieces of publicly available information although users are not willing to disclose them. The experimental results showed that gender, age, marital status, and relationship status, can be inferred by machine-learning algorithms. Based on these results, an early warning system was designed to help both service providers and users to protect the users’ privacy.