• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.149-156
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• 2011

In the recent years, power analysis attacks were widely investigated, and so various countermeasures have been proposed. In the case of block ciphers, masking methods that blind the intermediate values in the en/decryption computations are well-known among these countermeasures. But the cost of non-linear part is extremely high in the masking method of block cipher, and so the countermeasure for S-box must be efficiently constructed in the case of AES, ARIA and SEED. Existing countermeasures for S-box use the masked S-box table to require 256 bytes RAM corresponding to one S-box. But, the usage of the these countermeasures is not adequate in the lightweight security devices having the small size of RAM. In this paper, we propose the new countermeasure not using the masked S-box table to make up for this weak point. Also, the new countermeasure reduces time-complexity as well as the usage of RAM because this does not consume the time for generating masked S-box table.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.21-28
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• 2009

In the recent years, power attacks were widely investigated, and so various countermeasures have been proposed, In the case of block ciphers, masking methods that blind the intermediate values in the algorithm computations(encryption, decryption, and key-schedule) are well-known among these countermeasures. But the cost of non-linear part is extremely high in the masking method of block cipher, and so the inversion of S-box is the most significant part in the case of AES. This fact make various countermeasures be proposed for reducing the cost of masking inversion and Zakeri's method using normal bases over the composite field is known to be most efficient algorithm among these masking method. We rearrange the masking inversion operation over the composite field and so can find duplicated multiplications. Because of these duplicated multiplications, our method can reduce about 10.5% gates in comparison with Zakeri's method.

• Clinics in Shoulder and Elbow
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• v.24 no.1
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• pp.4-8
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• 2021

Background: As nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids have similar effects, steroids can be avoided to reduce adverse effects. This study aimed to compare the differences in symptom improvement after subacromial injection of steroids or NSAIDs. Methods: Sixty patients with rotator cuff syndrome for at least 3 months were enrolled and divided into steroid and NSAID groups. The steroid group received a mixture of 1 mL of triamcinolone acetonide (40 mg/mL) and 1 mL of lidocaine hydrochloride 2%, while the NSAID group received a mixture of 1 mL of Ketorolac Tromethamine (30 mg/mL) and 1 mL of lidocaine hydrochloride 2%. The patients were assessed before and at 3, 6, and 12 weeks after the procedure. Shoulder scores from visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES), and University of California Los Angeles (UCLA) were used for evaluation. Results: Both groups showed improvements in the clinical outcomes. Overall VAS, ASES, and UCLA scores improved from 6.9, 32.7, and 16.0 before the procedure to 2.0, 1.2, and 1.1; 81.5, 87.6, and 88.5; and 29.7, 31.8, and 32.0 at weeks 3, 6, and 12 weeks after the procedure, respectively. Twenty-six patients (86.7%) in the steroid group and 28 (93.3%) in the NSAID group reported satisfactory treatment outcomes. There were no significant differences in the outcomes between the two groups (p=0.671). Conclusions: Subacromial injection of NSAIDs for rotator cuff tendinitis with shoulder pain had equivalent outcomes with those of steroid injection at the 12-week follow-up.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.318-326
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• 2021

This study aims to the effectiveness of physical examination using VR contents to solve problems such as the increase in chronic diseases and shortage of professional manpower in the health care field according to the aging and low birth rate, and to provide efficient healthcare. Therefore, this study implemented a one-stop VR content physical examination system by wearing HTC VIVE Pro VR and a stick controller. The system is from step 1 to step 5, and the final body age is determined and a simple solution is provided through five steps sequentially: color blind test, memory test, audiogram test, reaction speed test, and instantaneous cognitive ability test. In addition, for the one-stop VR content physical examination system developed by this study, as a result of verifying the user satisfaction for normal people who visited the health examination center and VR/AR clinical trial center of certified tertiary hospital in Daejeon, the overall satisfaction and the intention to reuse Was high, and according to gender, there was a significant difference in the 5-step test, and according to the age, there were significant differences in the 4-step test and the 5-step test.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.480-493
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• 2021

In this paper, we attempt to empirically explain the process by which fandom performs social participation using digital media. To do this, we utilize the concept of identification and the Situational Theory of Publics in a theoretical framework, and study ARMY, BTS fandom. We confirmed a positive association between communication behavior and social participation, and verified a mediating effect of the identification as well. Interestingly, horizontal identification, a fan-to-star friendly relationship, had a greater effect on moving toward social participation than did vertical identification, a fan's blind worship of a star. This study has significance in that it has figured out the relationship of personal feelings to public participation by mobilizing achievements in various research fields.

• The Korean Journal of Pain
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• v.34 no.3
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• pp.315-321
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• 2021

Background: Pillar pain may develop after carpal tunnel release surgery (CTRS). This prospective double-blinded randomized trial investigated the effectiveness of extracorporeal shock wave therapy (ESWT) in pillar pain relief and hand function improvement. Methods: The sample consisted of 60 patients with post-CTRS pillar pain, randomized into two groups. The ESWT group (experimental) received three sessions of ESWT, while the control group received three sessions of sham ESWT, one session per week. Participants were evaluated before treatment, and three weeks, three months, and six months after treatment. The pain was assessed using the visual analogue scale (VAS). Hand functions were assessed using the Michigan hand outcomes questionnaire (MHQ). Results: The ESWT group showed significant improvement in VAS and MHQ scores after treatment at all time points compared to the control group (P < 0.001). Before treatment, the ESWT and control groups had a VAS score of 6.8 ± 1.3 and 6.7 ± 1.0, respectively. Three weeks after treatment, they had a VAS score of 2.8 ± 1.1 and 6.1 ± 1.0, respectively. Six months after treatment, the VAS score was reduced to 1.9 ± 0.9 and 5.1 ± 1.0, respectively. The ESWT group had a MHQ score of 54.4 ± 7.7 before treatment and 73.3 ± 6.8 six months after. The control group had a MHQ score of 54.2 ± 7.1 before treatment and 57.8 ± 4.4 six months after. Conclusions: ESWT is an effective and a safe non-invasive treatment option for pain management and hand functionality in pillar pain.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.258-268
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• 2021

Online learning systems are becoming an effective educational medium for many universities. The accessibility of online learning system in universities means that every student, including the visually impaired, is able use all the site's services. This research focuses on investigating the accessibility of online learning systems for visually impaired users. The paper purpose is to understand the perception of visually impaired undergraduate students towards Blackboard's accessibility and to make recommendations for a new Blackboard design with accessible features that support their needs. Impact of a new Blackboard design with accessible features on visually impaired students, using Taif University students as a case study is evaluated in this paper, as it is similar to most learning systems used by Saudi universities. A study on Taif University's utilization of Blackboard was conducted using mixed method approaches (an automatic tool and a user study). In the first phase, Taif's use of Blackboard was evaluated by the web accessibility tool called AChecker. In the second phase, we conducted a user study to verify previously discovered accessibility challenges to fully assess them according to the accessibility and usability guidelines. In this study, the accessibility of Taif University's Blackboard was evaluated by thirteen visually impaired undergraduate students. The results of the study show that Blackboard has accessibility issues, which are confusing navigation, incompatibility with assistive technologies, untitled pages or parts, unclear identification for visual elements, and inaccessible PDF files. This paper also introduces a set of recommendations that aim to improve the accessibility of Blackboard and other educational websites developed for this population. It also highlights the serious need for universities to enhance web accessibility for online learning systems for students with disabilities.

• Journal of the Korea Society of Computer and Information
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• v.26 no.3
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• pp.19-28
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• 2021

Esophagogastroduodenoscopy is a method commonly used for early diagnosis of upper gastrointestinal lesions. However, 10-20 percent of the gastric lesions are reported to be missed, due to human error. And countries including the US, the UK, and Japan, the World Endoscopy Organization (WEO) suggested guidelines about essential gastrointestinal parts to take pictures of so that all gastric lesions are observed. In this paper, we propose deep learning techniques for classification of anatomical sites, aiming for the system that informs practitioners whether they successfully did the gastroscopy without blind spots. The proposed model uses pre-processing modules and data augmentation techniques suitable for gastroscopy images. Not only does the experiment result with a maximum F1 score of 99.6%, but it also shows a error rate of less than 4% based on the actual data. Given the performance results, we found the model to be explainable with the potential to be utilized in the clinical area.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.191-198
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• 2021

Background: Most clinical studies of immune responses activated by Korean Red Ginseng (KRG) have been conducted exclusively in patients. However, there is still a lack of clinical research on immune-boosting benefits of KRG for healthy persons. This study aims to confirm how KRG boosts the immune system of healthy subjects. Methods: A total of 100 healthy adult subjects were randomly divided into two groups that took either a 2 g KRG tablet or a placebo per day for 8 weeks. The primary efficacy evaluation variables included changes in T cells, B cells, and white blood cells (WBCs) before and after eight weeks of KRG ingestion. Cytokines (TNF-α, INF-γ, IL-2 and IL-4), WBC differential count, and incidence of colds were measured in the secondary efficacy evaluation variables. Safety evaluation variables were used to identify changes in laboratory test results that incorporated adverse reactions, vital signs, hematological tests, blood chemistry tests, and urinalysis. Results: Compared to the placebo group, the KRG intake group showed a significant increase in the number of T cells (CD3) and its subtypes (CD4 and CD8), B cells, and the WBC count before and after eight weeks of the intake. There were no clinically significant adverse reactions or other notable results in the safety evaluation factors observed. Conclusion: This study has proven through its eight-week intake test and subsequent analysis that KRG boosts the immune system through an increase in T cells, B cells, and WBCs, and that it is safe according to the study's safety evaluation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1666-1672
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• 2019

A closed loop wireless transmission method adaptive to mobile unit speed is proposed in this paper. A mobile communication node measures the mobile speed based on the transmitted pilot signals through Doppler frequency estimation, and it changes the transmission period of pilot signals as per estimated mobile speed adaptively. The pilot signals with the different transmission periods are transmitted using the different PN sequences with the previous ones without any explicit information about the new period. The corresponding receiver node can detect and extract the transmitted pilot signals through blind search of the transmitted PN sequences of the pilot signals, and it can demodulate and decode the transmitted information using the channel estimation results based on the detected pilot signals. The performance of the proposed method had been analyzed through the simulation under the fading channel environments and compared with the previous methods. The simulation results showed performance improvement of the proposed method over the existing ones.