• Journal of Pharmacopuncture
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• v.26 no.1
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• pp.27-37
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• 2023

Objectives: Moroccan Arbutus unedo is an essential medicinal plant; however, little is known about the biological properties of its leaves mentioned in Moroccan traditional medicine. Methods: Various standard experiments were performed to evaluate the phytochemical, antidiabetic, antioxidant, antibacterial, and acute and sub-chronic toxicity characteristics of A. unedo leaves. Results: Phytochemical screening led to the identification of several phytochemical classes, including tannins, flavonoids, terpenoids, and anthraquinones, with high concentrations of polyphenols (31.83 ± 0.29 mg GAEs/g extract) and flavonoids (16.66 ± 1.47 mg REs/g extract). Further, the mineral analysis revealed high levels of calcium and potassium. A. unedo extract demonstrated significant antioxidant and anti-diabetic activities by inhibiting α-amylase (1.350 ± 0.32 g/mL) and α-glucosidase (0.099 ± 1.21 g/mL) compared to the reference drug Acarbose. Also, the methanolic extract of the plant exhibited significantly higher antibacterial activity than the aqueous extract. Precisely, three of the four examined bacterial strains exhibited substantial susceptibility to the methanolic extract . Minimum bactericidal concentration (MBC)/minimum inhibitory concentration (MIC) values indicated that A. unedo harbor abundant bactericidal compounds. For toxicological studies, mice were administered with A. unedo aqueous extract at single doses of 2,000 and 5,000 mg/kg. They did not exhibit significant abnormal behavior, toxic symptoms, or death during the 14-day acute toxicity test and the 90-day sub-chronic toxicity test periods. The general behavior, body weight, and hematological and biochemical status of the rats were assessed, revealing no toxicological symptoms or clinically significant changes in biological markers observed in the mice models, except hypoglycemia, after 90 days of daily dose administration. Conclusion: The study highlighted several biological advantages of A. unedo leaves without toxic effects in short-term application. Our findings suggest that conducting more comprehensive and extensive in vivo investigations is of utmost importance to identify molecules that can be formulated into pharmaceuticals in the future.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.52-60
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• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.179-186
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• 2010

The present study is a partial extension of the Duncan-Johnson and Donchin (1979) and Soskins, Rosenfeld, and Niendam (2001) studies that found some effects of high pass filter (HPF) setting on P300 waveform. EEGs were recorded while the subjects performed a visual three-stimulus oddball task, and the Fz and Pz EEG signals were passed through 0.01 Hz, 0.3 Hz, and 1.0 Hz HPFs. P300 amplitudes at Fz and Pz were reduced at 1.0 Hz HPF compared to 0.01 Hz and 0.3 Hz HPFs. The negative peaks post P300 at Fz and Pz were not observed at 0.01 Hz HPF, but observed at 0.3 Hz and 1.0 Hz HPFs. The combination of 0.3 Hz HPF and peak-to-peak P300 measures was more useful than that of 0.01 Hz, 0.3 Hz, or 1.0 Hz HPF and baseline-to-peak P300 measures to discriminate between non-target and standard stimuli. The peak-to-peak P300 measures were more useful than the baseline-topeak P300 measures at 1.0 Hz HPF setting.

• Asia Marketing Journal
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• v.13 no.4
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• pp.213-226
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• 2012

As the Korean rental car industry turned into a mature stage, the competition level has become stronger than ever. In 2006, AJ Rent a Car declared customer satisfaction management as its vision to make a breakthrough. Through various service innovation efforts, AJ has been successfully offering meaningful and differentiated values to the customers. As results, the complaints rate has decreased, while service quality index has significantly increased. These service quality indicators have led to improved customer satisfaction level which was measured by re-purchase intention and customer satisfaction index, and AJ outran its major competitors in these dimensions of competition. The first key success factor of AJ is its effective service system. AJ manages the VOC, ERP, and CRM system in a well organized manner. AJ's another key success factor is a effective service process, which helps the organization share and respond to customer complaints in an efficient way. Finally, the management communicates the clear vision and strategic direction not only with the customers but also with the entire organization. With these three factors combined, AJ has created the service oriented corporate culture. Based on the culture. AJ has been able to develop a strong and sustainable competitive advantage in customer satisfaction management.

• Information Systems Review
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• v.7 no.2
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• pp.257-276
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• 2005

The most distinctive characteristic in Maeil's outsourcing strategy was the rapid decision process done by CEO. At first, Maeil made a contract with a outsourcing vendor based on 50% investment for 5 years. However, 3 years later Maeil changed their outsourcing strategy from 10% share to 100% outsourcing. This is for the efficiency improvement and cost reduction. Also, Maeil organized separate TFT which could control IS quality. This TFT reviewed the feasibility of requirement analysis and IS planning process. Through this cooperation between TFT and the outsourcing vendor, Maeil could get the stable IT development and operation. During last 5 years, Maeil achieved great performance in the area of IT development and operation from the outsourcing. The present issue related to outsourcing strategy is whether Maeil will continue the current contract or change the vendor due to the anxiety of becoming a captive customer.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.501-509
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• 2017

The purpose of this study was to review the effects of the physical fatigue induced by overtraining on cognitive information processing and emotional change of athletes by neurophysiologic study. And to provide basic data for the athletes and coaches in the sports field to improve understanding of the overtraining symptoms from the brain physiological point of view. We reviewed the domestic and international academic materials and research reports published in the last 20 years using electronic databases and examined the literature that is consistent with the purpose of this study among the retrieved documents. Based on the reviewed literature, we examined the cognitive information processing and emotional change of the athlete according to the training, and overtraining can accumulate the fatigue of the body, which can cause severe side effects in terms of cognitive ability and emotional ability of athletes as well as deterioration of performance. The study using P300 and EEG cerebral hemispheric asymmetry difference indices also confirmed the possibility of a new approach to understand psychological and physiological effects of overtraining on information processing and emotional changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3184-3190
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• 2013

These days, the great part of design processes in the field of ship or offshore manufacturing are planed and implemented using the customized CAD system for each ship-building companies. It means that all information for design and production could be extracted and reused at the useful other area cost considerable time and efforts. The representative example is the estimation of welding length and material amount which is demanded during the construction of ship or offshore structures. The proper estimation of welding material to be used and the usage of them at the stage of schedule planning is mostly important to achieve the seamless process of production and expect the costing in advance. This study is related to the calculation of welding length and needed material amount at the stage of design complete utilizing the CAD system. The calculated amount are classified according to welding position, stage, block, bevel and welding type. Moreover it is possible to predict the working time for welding operation and could be used efficiently for the cost management using the results of this research.

• Information Systems Review
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• v.11 no.1
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• pp.19-47
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• 2009

Many products today tend to adopt a convergence approach by adding new features or functionalities to the existing products. The convergence, however, results in both positive and negative effects on usage of products, and thus demonstrates the characteristics called "paradox of technology." On the one hand, the added functionalities or features will increase the usefulness of the products. On the other hand, the convergence increases complexity of learning and usage of products and may decrease satisfaction or user evaluations. This study provides an empirical evidence of this paradox through investigation of telematics, one of the exemplary products of convergence services. Our research model is designed to test the existence of the "paradox of technology" and includes variables such as variety of functions, complexity of usage, perceived usefulness, service evaluation, and service fit. The proposed research model and subsequent hypotheses are empirically tested using 149 survey responses from telematics users. We have found that the variety of functions is positively associated with perceived usefulness, but is negatively associated with the complexity of usage. The data analysis reveals that the perceived usefulness has more significant impacts on service evaluation than the complexity of usage does. Furthermore, the strength of causal relationships among these variables is partially moderated by the degree of service fit. This study thus highlights the paradox of technology in explaining user attitudes and beliefs associated with convergence services.

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.91-100
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• 2014

This study was to examine how visual angle of matrix corresponding to the physical properties of P300 speller and eye gaze corresponding to the user's personal characteristics influence on the accuracy of P300. Visual angle of the matrix was operated as the distance between the user and the matrix and three groups were composed: 60 cm group, 100 cm groups, and 150 cm group. Eye gaze methods was consisted three conditions. Head moving condition was putting eye gaze using head, pupil moving condition was moving pupil with the head fixed, while the eye fixed condition is to fix the eye gaze at the center of the matrix. The results showed that there was significant difference in the accuracy of P300 speller according to the eye gaze method. The accuracy of the head moving condition was higher than the accuracy of pupil moving conditions, accuracy of pupil moving conditions was higher than the accuracy of the eye fixed conditions. However, the effect of visual angle of matrix and interaction effect were not significant. When P300 amplitude of target character was measured depending on how you stare at the target character, P300 amplitude of the head moving condition was greater than P300 amplitude of the pupil moving condition. There was no significant difference in the error distribution in head moving condition and pupil moving condition, while there was a significant difference between two eye gaze conditions and fixed gaze condition. The error was located at the neighboring characters of the target character in head moving condition and pupil moving condition, while the error was relatively distributed widely in fixed eye condition, error was occurred with high rate in characters far away from the center of matrix.

• Sleep Medicine and Psychophysiology
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• v.1 no.1
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• pp.76-86
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• 1994

Objectives: This research was performed in order to observe the neuropsychological implication and functional anatomical source of event related potentials(ERP) by studying of correlations between event related potentials and neuropsychological tests. Methods: The latency and voltage of P100 of visual evoked potential (VEP), and N120 and P300 of event related potentials were studied in 56 patients and their correlations with neuropsychological tests were computed. Results: The tests showing significant correlation with latency P100 were visual continous performance test(VCPT) and contingent continous performance test(CCPT) without any significant correlation with voltage of P100. In latency of N120 category test and verbal IQ of KWIS showed significant correlation, and in voltage of N120, finger tapping test, VCPT, CCPT and digit symbol test displayed significant correlations. The latency of P300 had significant correlation with trail making A test and Stroop test. In the voltage of P300 significant correlations were shown with trail making B test, digit symbol test and Wechsler memory scale, finger tapping test, stroop test, VCPT and CCPT. Conclusion : N120 may be considered to reflect the function of medial frontal lobe and P300 may be considered to be developed from the subcortical connection of medial temporal lobe, hippocampus, thalamus, basal ganglia and medial frontal lobe.