• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1951-1975
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• 2023

Recent advances in Cognitive Radio Networks (CRN) have elevated them to the status of a critical instrument for overcoming spectrum limits and achieving severe future wireless communication requirements. Collaborative spectrum sensing is presented for efficient channel selection because spectrum sensing is an essential part of CRNs. This study presents an innovative cooperative spectrum sensing (CSS) model that is built on the Firefly Algorithm (FA), as well as machine learning artificial neural networks (ANN). This system makes use of user grouping strategies to improve detection performance dramatically while lowering collaboration costs. Cooperative sensing wasn't used until after cognitive radio users had been correctly identified using energy data samples and an ANN model. Cooperative sensing strategies produce a user base that is either secure, requires less effort, or is faultless. The suggested method's purpose is to choose the best transmission channel. Clustering is utilized by the suggested ANN-FA model to reduce spectrum sensing inaccuracy. The transmission channel that has the highest weight is chosen by employing the method that has been provided for computing channel weight. The proposed ANN-FA model computes channel weight based on three sets of input parameters: PU utilization, CR count, and channel capacity. Using an improved evolutionary algorithm, the key principles of the ANN-FA scheme are optimized to boost the overall efficiency of the CRN channel selection technique. This study proposes the Artificial Neural Network with Firefly Algorithm (ANN-FA) for cognitive radio networks to overcome the obstacles. This proposed work focuses primarily on sensing the optimal secondary user channel and reducing the spectrum handoff delay in wireless networks. Several benchmark functions are utilized We analyze the efficacy of this innovative strategy by evaluating its performance. The performance of ANN-FA is 22.72 percent more robust and effective than that of the other metaheuristic algorithm, according to experimental findings. The proposed ANN-FA model is simulated using the NS2 simulator, The results are evaluated in terms of average interference ratio, spectrum opportunity utilization, three metrics are measured: packet delivery ratio (PDR), end-to-end delay, and end-to-average throughput for a variety of different CRs found in the network.

• Journal of Service Research and Studies
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• v.11 no.1
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• pp.59-79
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• 2021

Service-related research in accordance with the transition to the service economy era has been conducted in a wide variety of ways, but the development of a service-related scale suitable for the present time is still insignificant. The purpose of this study is to define the nature of services and to develop measurement items for them. First, four categories of service nature were adopted in the previous study. The four categories are 'relationship', 'interactivity', 'horizontality', and 'harmony'. In this study, sub-factors and specific items of each of these four service essences were extracted and developed as measurable items. As a qualitative study, the four categories of sub-factors were extracted, and a mixed study was adopted to prove the reliability and validity of the extracted factors through quantitative studies. The scale items were identified through literature study, free response method, and Delphi technique, and the measurement items were refined through a second questionnaire of 30 Delphi panels composed of experts. As a result of the study, 15 out of 52 questions for relationship, 11 out of 45 questions for bilateral direction, 9 out of 33 questions for horizontality, and 17 out of 61 questions for harmonization were derived after secondary refining. Through this study, it was possible to uncover new essential items suitable for the service economy era. SNS, network, synergy, platform, system, real name, and breakthrough are concepts that have not been obtained in previous studies, and can be seen as contributions of this study. However, due to various limitations, this study did not cover all aspects of the service, but mainly dealt with people-centered services, which are part of the service. In the future, it is necessary to study the development of service essence measurement items for the overall aspect of services developed according to the evolution of the service economy era.

• 대한상한금궤의학회지
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• v.14 no.1
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• pp.1-26
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• 2022

Objectives: We aimed to confirm the safety and effectiveness of the decoction of Sibjo-tang, which is a powder type purgative. In addition, we checked whether the '發作' of 『Shanghanlun』 can be interpreted to have the same meaning as "seizure" in English. By confirming these objectives, we intend to lead the progress in the application of Sibjo-tang and to expand the clinical application of the 152nd provision and Sibjo-tang. Methods: We analyzed the medical records of patients who visited Apgujeongjeongin Oriental Clinic and Almyeon Oriental Clinic for seizures. We confirmed side effects in patients who took Sibjo-tang for a long time. Sibjo-tang was prepared as a hot water extract by using 5 g each of Euphorbiae Pekinensis Radix, Eurphobiae Kansui Radix, and Genkwae Flos and 15 g of Zizyphi Fructus. The "seizure" recorded in the 152nd provision was interpreted through the shape analysis of Oracle bone scripts. The seizure frequency of patients diagnosed with epilepsy after taking Sibjo-tang was compared, and we analyzed other symptoms and psychosocial conditions associated with seizures at the first episode. Results: No side effects were found in 7 patients who took Sibjo-tang for 16.57 ± 14.10 months. Seizures were eliminated in 6 cases while taking Sibjo-tang and significantly decreased in 1 case. Frequent indigestion (in 7 cases), mild exhaustion (in 5 cases), and inferiority complex (in 5 cases) were identified as accompanying pathogenic conditions. The "seizure" in the 152nd provision was interpreted as "a state of being stabbed by a sharp substance in clothes", confirming a deep connection with epileptic seizures. Conclusions: The results suggest that using a decoction of Sibjo-tang is safe and efficacious. In addition, the necessity of conducting an advanced study on epileptic seizures accompanied by frequent indigestion using Sibjo-tang was confirmed.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.889-897
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• 2023

This study attempted to examine how participation in a cooperative learning extracurricular program affects the improvement of college students' self-directed learning abilities. In order to operate a cooperative learning extracurricular program, students were recruited voluntarily through the school system. A total of 128 students were selected. They formed groups according to the number of participants and participated in the cooperative learning extracurricular program for 9 weeks. Before the program was implemented and after the program was terminated, a survey was conducted on the self-directed learning ability of participating students through a questionnaire. The effectiveness of the program was examined through pre-post tests of the experimental group. The results are as follow. First, the self-directed learning ability scores of students who participated in the cooperative learning extracurricular program significantly improved. Second, in order to closely analyze self-directed learning ability, the sub-elements of self-directed learning ability were examined, and the scores of self-awareness and learning strategy, which are sub-elements of self-directed learning ability, were found to have significantly increased. However, although scores for learning motivation and learning situations improved, the levels were not found to be statistically significant. Based on these results, we presented discussions for improving college students' self-directed learning ability and ways to revitalize cooperative learning in universities.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.207-228
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• 2023

After COVID-19, organizations have widely adopted platforms such as zoom or developed their proprietary online real-time systems for remote work, with recent forays into incorporating the metaverse for meetings and publicity. While ongoing studies investigate the impact of avatar customization, expansive virtual environments, and past virtual experiences on participant satisfaction within virtual reality or metaverse settings, the utilization of the metaverse as a dedicated workspace is still an evolving area. There exists a notable gap in research concerning the factors influencing the performance of the metaverse as a workspace, particularly in non-immersive work-type metaverses. Unlike studies focusing on immersive virtual reality or metaverses emphasizing immersion and presence, the majority of contemporary work-oriented metaverses tend to be non-immersive. As such, understanding the factors that contribute to the success of these existing non-immersive metaverses becomes crucial. Hence, this paper aims to empirically analyze the factors impacting personal outcomes in the non-immersive metaverse workspace and derive implications from the results. To achieve this, the study adopts the Embodied Social Presence (ESP) model as a theoretical foundation, modifying and proposing a research model tailored to the non-immersive metaverse workspace. The findings validate that the impact of presence on task engagement and task involvement exhibits a moderating effect based on the metaverse platform used. Following interviews with participants engaged in non-immersive metaverse workplaces (specifically Gather Town and Ifland), a survey was conducted to gather comprehensive insights.

• Korean Journal of Radiology
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• v.22 no.8
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• pp.1240-1252
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• 2021

Objective: To compare the accuracy for detecting breast cancer in the diagnostic setting between the use of digital breast tomosynthesis (DBT), defined as DBT alone or combined DBT and digital mammography (DM), and the use of DM alone through a systematic review and meta-analysis. Materials and Methods: Ovid-MEDLINE, Ovid-Embase, Cochrane Library and five Korean local databases were searched for articles published until March 25, 2020. We selected studies that reported diagnostic accuracy in women who were recalled after screening or symptomatic. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random effects model was used to estimate pooled sensitivity and specificity. We compared the diagnostic accuracy between DBT and DM alone using meta-regression and subgroup analyses by modality of intervention, country, existence of calcifications, breast density, Breast Imaging Reporting and Data System category threshold, study design, protocol for participant sampling, sample size, reason for diagnostic examination, and number of readers who interpreted the studies. Results: Twenty studies (n = 44513) that compared DBT and DM alone were included. The pooled sensitivity and specificity were 0.90 (95% confidence interval [CI] 0.86-0.93) and 0.90 (95% CI 0.84-0.94), respectively, for DBT, which were higher than 0.76 (95% CI 0.68-0.83) and 0.83 (95% CI 0.73-0.89), respectively, for DM alone (p < 0.001). The area under the summary receiver operating characteristics curve was 0.95 (95% CI 0.93-0.97) for DBT and 0.86 (95% CI 0.82-0.88) for DM alone. The higher sensitivity and specificity of DBT than DM alone were consistently noted in most subgroup and meta-regression analyses. Conclusion: Use of DBT was more accurate than DM alone for the diagnosis of breast cancer. Women with clinical symptoms or abnormal screening findings could be more effectively evaluated for breast cancer using DBT, which has a superior diagnostic performance compared to DM alone.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.54-69
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• 2022

Early detection of potential asymptomatic coronary artery disease is very important, as patients with sudden cardiac death often do not show symptoms such as chest pain or motor dyspnea. Coronary CT angiography (CCTA) has long been unjustified as a screening tool for asymptomatic patients because of the risks posed by radiation exposure. However, there are still various opinions regarding the usefulness of CCTA for screening for coronary artery disease (CAD) in asymptomatic healthy individuals or patients. This review investigated the usefulness of coronary artery calcium score and CCTA as screening tests for CAD in asymptomatic healthy individuals or patients through various literature reviews. With the development of CT technology, recent studies have been conducted in asymptomatic CAD patients with a reduced radiation dose of less than 1 mSv. A total of 2.6% of asymptomatic subjects on CCTA found significant CAD over 70%, and it was concluded that screening CCTA for CAD showed prognostic power in predicting the future occurrence of CAD in asymptomatic people. However, after the completion of the current NIH SCOT-HEART 2 study, it may be possible to determine whether CCTA is appropriate as a screening tool for CAD in asymptomatic healthy individuals.

• The Korean Society of Law and Medicine
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• v.24 no.4
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• pp.37-63
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• 2023

In medical litigation, there are various cases where a doctor's 'explanation' of a patient becomes problematic. Medical explanations and guidance are required from the doctor, starting from the beginning of diagnosis, through treatment processes such as surgery, when hospitalization is necessary for treatment, during hospitalization, upon discharge, and after discharge. Furthermore, notification from the doctor or medical institution may be requested regarding the economic costs that will be incurred due to medical treatment. South Korea's judiciary has been developing legal principles regarding such doctor's explanations by distinguishing between explanations for obtaining consent for medical treatment and medical explanations related to guidance on patient treatment methods, taking into account related laws such as the stage of treatment and the Medical Service Act. Additionally, the Constitutional Court recently ruled on the non-benefit cost notification system linked to the explanation of economic costs. However, holding a doctor accountable solely because the doctor's explanation was insufficient has aspects that do not correspond to the actual situation in clinical reality, and may have a reflexive disadvantage that results in a decline in legal rights. Therefore, the doctor's explanation needs to be examined from both perspectives: guaranteeing the patient's right to self-determination and protecting his or her right to decision.

• Journal of Service Research and Studies
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• v.14 no.1
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• pp.1-12
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• 2024

As the service robot market grows among the food technology industry, the quality of robot service that affects consumer behavioral intentions in the restaurant industry has become important. Serving robots, which are common in restaurants, reduce employee work through order and delivery, but because they do not respond to service failures, they increase customer dissatisfaction as well as increase employee work. In order to improve the quality of service beyond the simple function of receiving and serving orders, functions of recovery effort, fairness, empathy, responsiveness, and certainty of the process after service failure, such as serving employees, are also required. Accordingly, we assumed the type of failure of restaurant serving service as two internal and external factors, and developed a serving robot with a vocational ethics module to respond with a professional ethical attitude when the restaurant serving service fails. At this time, the expression and action of the serving robot were developed by adding a failure mode reflecting failure recovery efforts and empathy to the normal service mode. And by recruiting college students, we tested whether the service robot's response to two types of service failures had a significant effect on evaluating the robot. Participants responded that they were more uncomfortable with service failures caused by other customers' mistakes than robot mistakes, and that the serving robot's professional ethical empathy and response were appropriate. In addition, unlike the robot's favorability, the evaluation of the safety of the robot had a significant difference depending on whether or not a professional ethical empathy module was installed. A professional ethical empathy response module for natural service failure recovery using generative artificial intelligence should be developed and mounted, and the domestic serving robot industry and market are expected to grow more rapidly if the Korean serving robot certification system is introduced.

• Journal of Korean Home Economics Education Association
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• v.35 no.4
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• pp.33-45
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• 2023

The purpose of this study is to investigate the association between dietary behavior and related factors according to the generalized anxiety disorder (GAD) in adolescents. The results of analyzing demographic characteristics according to the GAD showed that gender, age, BMI, type of school, residence type, father's nationality, smoking and drinking experience, perceived health status, perception of body shape, economic status, academic achievement, physical activity, sedentary time and smartphone usage time were related to the GAD (p<0.01). The results of analyzing dietary behavior according to the GAD showed that the frequency of water intake, sweetened beverage intake, fast food intake, fruit intake and breakfast intake were related to the GAD (p<0.001). The results of analyzing depression and suicidality according to the GAD showed that depression, suicidal ideation, planning, and attempts were all related to the GAD (p<0.001). Even after adjusting for factors corresponding to demographic characteristics, it was confirmed that the level of GAD had a significant effect on depression and suicidality. This study is significant in that it provided basic data on adolescent mental health problems by analyzing dietary behavior and related factors according to the level of GAD.