• Imaging Science in Dentistry
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• 제52권1호
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• pp.93-101
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• 2022

Purpose: This study compared the effectiveness of complementary metal-oxide semiconductors (CMOS) and photostimulable phosphor (PSP) plates as intraoral imaging systems in terms of time efficacy, patient comfort, and subjective image quality assessment in real clinical settings. Materials and Methods: Fifty-eight patients (25 women and 33 men) were included. Patients were referred for a full-mouth radiological examination including 1 bitewing radiograph (left and right) and 8 periapical radiographs for each side (left maxilla/mandible and right maxilla/mandible). For each patient, 1 side of the dental arch was radiographed using a CMOS detector, whereas the other side was radiographed using a PSP detector, ensuring an equal number of left and right arches imaged by each detector. Clinical application time, comfort/pain, and subjective image quality were assessed for each detector. Continuous variables were summarized as mean±standard deviation. Differences between detectors were evaluated using repeated-measures analysis of variance. P<0.05 was accepted as significant. Results: The mean total time required for all imaging procedures with the CMOS detector was significantly lower than the mean total time required for imaging procedures with PSP (P<0.05). The overall mean patient comfort scores for the CMOS and PSP detectors were 4.57 and 4.48, respectively, without a statistically significant difference (P>0.05). The performance of both observers in subjectively assessing structures was significantly higher when using CMOS images than when using PSP images for all regions (P<0.05). Conclusion: The CMOS detector was found to be superior to the PSP detector in terms of clinical time efficacy and subjective image quality.

• Journal of Ginseng Research
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• 제47권6호
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• pp.735-742
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• 2023

Background: Gintonin is a new material of ginseng that acts through the ginseng-derived lysophosphatidic acid (LPA) receptor ligand. The gintonin-enriched fraction (GEF) inhibits amyloid plaque accumulation in the cortex and hippocampus, improves cognitive dysfunction by increasing acetylcholine levels, and promoted hippocampal neurogenesis in an animal model of Alzheimer's disease. We evaluated the effect of the GEF on the cognitive performance of subjects with subjective memory impairment (SMI). Methods: In this eight-week, randomized, assessor- and participant-blinded, placebo-controlled study, participants with SMI were assigned to three groups receiving placebo, GEF 300 mg/day or GEF 600 mg/day. The Korean versions of the Alzheimer's Disease Assessment Scale (K-ADAS), Mini-Mental State Examination (K-MMSE), and Stroop color-word test (K-SCWT) were also evaluated along with the safety profiles. Results: One hundred thirty-six participants completed the study. After eight weeks, we analyzed intergroup differences in primary or secondary outcome score changes. When we compared the GEF group with the placebo group, we observed significant improvements in the K-ADAS and K-SCWT scores. The GEF group did not show a significant improvement in K-MMSE and BDI scores compared to the placebo group. No adverse events were observed in the gintonin and placebo groups for eight weeks. Conclusion: The GEF is safe and effective in improving subjective cognitive impairment related to both the K-ADAS and K-SCWT in this study. However, further large-scale and randomized controlled studies are warranted to secure other cognitive function tests besides the K-ADAS and K-SCWT, and to confirm the findings of the current study.

• The Korean journal of internal medicine
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• 제39권1호
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• pp.86-94
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• 2024

Background/Aims: A catheter is inserted through the nasal cavity during high-resolution esophageal manometry (HRM), which may cause adverse events such as pain or epistaxis. Despite these possible safety considerations, studies on this subject are very limited. We aimed to investigate the usefulness of nasal cavity evaluation before HRM to reduce the risk of adverse events and test failure. Methods: Patients who underwent HRM after consultation with the ear-nose-throat department for nasal evaluation were retrospectively enrolled between December 2021 and May 2022. The included patients had a previous history of sinonasal disease or surgery or had subjective nasal discomfort. All patients answered the Sino-Nasal Outcome Test (SNOT-22) questionnaire, and subjective nasal discomfort was scored using a visual analog scale. Nasal endoscopy and acoustic rhinometry were performed for disease evaluation and volumetric assessment. Results: The analysis included 22 patients with a mean age of 58.9 years. The mean SNOT-22 score was 24.2, and 16 patients (72.7%) complained of subjective nasal obstruction. The HRM catheter was successfully inserted in 20 patients (90.9%), without any significant adverse events. The objective measurement outcomes of acoustic rhinometry and sinus endoscopy did not always correspond to subjective symptoms. Narrowed nasal airways unresponsive to decongestants were observed in two patients with failed catheter insertion. Conclusions: To reduce the risk of adverse events and test failure during HRM, a site-specific questionnaire to evaluate nasal obstruction might be helpful. When nasal obstruction is suspected, objective nasal cavity evaluation could be recommended for the safe and successful performance of HRM.

• 대한산업공학회지
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• 제42권5호
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• pp.352-359
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• 2016

The soft keyboard with touch interaction is universally available on mobile phone, a variety of previous studies with respect to the soft keyboard on smart devices had been conducted. However, previous studies of cursor control for text entry on smart devices such as smartphone did not performed. In this study, we compared three types of cursor controls (Default, 3D touch, Slide) in smartphone using Fitts' law and C-D ratio. Then we performed a laboratory experiment with three cursor control types and evaluated using cursor movement time as a quantitative evaluation and 8 subjective metrics for usability as a qualitative evaluation. Then, we discussed what types of cursor control showed better performance and subjective satisfaction through their results. From these results, this study recommended the design guidelines for cursor control on smartphones and developed its study methods as our contributions.

• The Journal of the Acoustical Society of Korea
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• 제22권3E호
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• pp.110-112
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• 2003

There have been numerous studies on the enhancement of the noisy speech signal. In this paper, we propose a completely new speech enhancement scheme, that is, a filtering of a dissonant frequency (especially F# in each octave of the tempered scale) based on the fundamental frequency which is developed in frequency domain. In order to evaluate the performance of the proposed enhancement scheme, subjective tests (MOS tests) were conducted. The subjective test results indicate that the proposed method provides a significant gain in audible improvement especially for speech contaminated by colored noise and speaking in a husky voice. Therefore when the filter is employed as a pre-filter for speech enhancement, the output speech quality and intelligibility is greatly enhanced.

• 대한전자공학회논문지
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• 제27권5호
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• pp.784-792
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• 1990

In this paper, attempts have been made to compare the subjective performance of sub-band coding (SBC) techniques incorporating four representative modulation transfer functions (MTF's) of th human visual system(HVS): Sakrison, Nill, Ngan, and Rao. In SBC, the frequency band of input signal is split into 16 equal sub-bands. In addition, 28 sub-band splitting schemd which splits more sub-bands in low spatial frequency is considered to compare the 4 MTF's effectively. In encoding of each sub-band, the weight of each sub-band obtained from the MTF of HVS is applied to bit allocation process which minimize the weighted mean square error (WMSE). The differential pulse code modulation(DPCM) coder is used to encode the lowest sub-band and the pulse code modulation(PCM) coder is used for the rest of sub-bands. It is found that the images incorporating the MTF of Rao yields the best results in subjective criteria, followed by Ngan, Nill, Sakrison, and the images not employing the HVS.

• 대한산업공학회지
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• 제26권2호
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• pp.146-154
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• 2000

This study showed a way to develop web site of shopping mall through systematic identification of the interface elements affecting user's performance and subjective sensibility for Internet shopping mall. To quantify the effects of factors, simulators were designed and used in experiments. It was shown that location of 'Table of Contents'(left > right = up = down) and 'Menu' type(non_Drop down and page Movement = Drop down and page Movement > Drop down and non_age Movement) were the significant factors. However, whether 'Frame' was used or not, there was no significant difference. Also, in the evaluation of subjective sensibility, 'Background color' was a significant factor. And for 'Header & Scanning Column color', yellow color had a tendency to enhance satisfaction for 'simplicity', while green or blue color strengthened 'balance' feeling. But 'text style' was not significant.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.250-253
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• 2009

This paper presents NR (No Reference) Quality assessment method for IPTV or mobile IPTV. Because No Reference quality assessment method does not access the original signal so it is suitable for the real-time streaming service. Our proposed method use decoding parameters, such as quantization parameter, motion vector, and packet loss as a major network parameter. To evaluate performance of the proposed algorithm, we carried out subjective test of video quality with the ITU-T P.910 ACR (Absolute Category Rating) method and obtained the mean opinion score (MOS) value for QVGA 180 video sequence coded by H.264/AVC encoder. Experimental results show the proposed quality metric has a high correlation (84%) to subjective quality.

• 산업경영시스템학회지
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• 제22권50호
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• pp.91-103
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• 1999

This paper deals with effectiveness of Object-Oriented Modeling and Design(OOMD) through GroupSystems V which is a typical groupware or group decision support system(GDSS) to aid group work. Objective and subjective evaluations between traditional non-GDSS face-to-face group and GDSS-supported group have been performed in terms of modeling accuracy and subjective ratings, respectively. Experimental results indicate that the GDSS group shows much better performance than the traditional group in the realm of OOMD. In particular, when a modeling task is not simple or not structured, the former outperforms the latter. Based on the questionaire, the GDSS group feel more equal status and have less dominant voices than do the non-GDSS group. These facts show that GDSS can be used effectively for OOMD under Korean cultures.

• 대한인간공학회지
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• 제19권3호
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• pp.61-75
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• 2000

To enhance web site's usability, it has been suggested that the depth of tree structured menus should be minimized. In this research, experimental results are reported to quantitatively compare the methods currently used for reducing the depth of menus in web sites. 25 popular web sites were selected and their menu types were categorized into four types: top menu, drop-down menu, boolean menu, and table of contents. The four types of menu were then sub-categorized into 15 different types according to their sub-menu type, existence of menu colors, and the event occurring after mouse activation. Performance tests and subjective evaluation were carried out. The results showed that there were no significant differences in terms of response time among the 15 menu types, while table of contents and drop-down in which the first and second level of menus were visible induced the least number of errors. In the subjective test, the top-menu structure with colors and presentation of its sub-menu without clicking mouse were preferred.