• ETRI Journal
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• 제45권1호
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• pp.75-92
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• 2023

Level 3 autonomous vehicles require conditional autonomous driving in which autonomous and manual driving are alternately performed; whether the driver can resume manual driving within a limited time should be examined. This study investigates whether the demographics and subjective driving tendencies of drivers affect the take-over performance. We measured and analyzed the reengagement and stabilization time after a take-over request from the autonomous driving system to manual driving using a vehicle simulator that supports the driver's take-over mechanism. We discovered that the driver's reengagement and stabilization time correlated with the speeding and wild driving tendency as well as driving workload questionnaires. To verify the efficiency of subjective questionnaire information, we tested whether the driver with slow or fast reengagement and stabilization time can be detected based on machine learning techniques and obtained results. We expect to apply these results to training programs for autonomous vehicles' users and personalized human-vehicle interfaces for future autonomous vehicles.

• 말소리와 음성과학
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• 제4권3호
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• pp.111-117
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• 2012

In this paper, we compare the performance of several speaker adaptation methods for a HMM-based Korean speech synthesis system with small amounts of adaptation data. According to objective and subjective evaluations, a hybrid method of constrained structural maximum a posteriori linear regression (CSMAPLR) and maximum a posteriori (MAP) adaptation shows better performance than other methods, when only five minutes of adaptation data are available for the target speaker. During the objective evaluation, we find that the duration models are insufficiently adapted to the target speaker as the spectral envelope and pitch models. To alleviate the problem, we propose the duration rectification method and the duration interpolation method. Both the objective and subjective evaluations reveal that the incorporation of the proposed two methods into the conventional speaker adaptation method is effective in improving the performance of the duration model adaptation.

• 한국생활과학회지
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• 제19권4호
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• pp.667-674
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• 2010

This study evaluated the convenience and heating performance of 4 heated vests on the market through a trial of the vests. Participants were four healthy men who wore the garments outside in cold temperatures typical of the garments' real conditions of use. As the results, all the participants preferred the product, having an easily operable controller in ergonomic aspects and the good insulation for keeping the body temperature. The heating performance of vests was the most important factor in selecting the best product in this test. Indeed, the vests themselves found not to be sufficiently warm in the experimental condition. Thus, heated vests with the enhanced heating performance should be developed so that temperatures in the allowed range can be safely accessed.

• 경영정보학연구
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• 제3권1호
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• pp.31-46
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• 2001

• 한국통신학회논문지
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• 제17권8호
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• pp.881-890
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• 1992

본 논문은 음성 시스템과 통신망에서 이용되는 음성 품질 평가 모델의 구축을 위한 기본 연구로서, 음성 부호화 평가 방법 중 주관적 평가에서 발생되는 여러 문제점을 해결하여 안정된 객관적 평가값을 얻기위해서, 여러 객관적 평가량과 주관적 평가량을 상호 비교한 후, 주관적 평가값에 적합한 객관적 평가량을 검토하였다.

• 생물정신의학
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• 제6권2호
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• pp.176-188
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• 1999

Objective : The purpose of this study was to evaluate the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. Method : A total of 24 males, half with active $ALDH2^*1/2^*1$ and the other with inactive $ALDH2^*1/2^*2$, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time (CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. Results : The major results are as follows. 1) BACs in the inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. Conclusions : These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

• 한국콘텐츠학회논문지
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• 제11권8호
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• pp.68-76
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• 2011

최근 소비자의 화질에 대한 높은 관심으로 관련 시장 경쟁력이 가열되었으며, 이에 따라 제조사는 고객만족을 위한 제품을 개발하는 방향으로 진보하고 있다. 그러나 제품의 객관적 성능 향상이 실제 소비자가 인지하는 화질의 선호도에 항상 긍정적인 영향을 미친다고 단정하기 어렵다. 또한 선행연구를 통해 객관적 성능 평가 방법과 주관적 화질 평가 결과 간의 상관관계를 찾기 어려웠다. 그러므로 객관적 화질 재현 성능이 이미지 선호도에 미치는 영향을 파악하여 감상자가 선호하는 화질에 대해 분석할 필요가 있다. 따라서 본 논문에서는 객관적 화질 평가 요소들을 측정하고 이러한 수치들이 이미지 선호도와 어떠한 관계를 갖고 있는지 분석하고자 하였다. 이와 같은 연구를 위해 ISO에서 규정하고 있는 화질 평가 방법을 사용하여 이미지의 선호도를 측정하였으며 이러한 결과가 객관적 화질 평가 요소들과 어떠한 상관관계를 갖고 있는지 통계적으로 분석하였다. 이와 같은 결과는 화질을 향상시키는 요소를 분석할 수 있으며 단순한 고화질 추구를 위한 성능 개발뿐만 아니라 감상자가 선호하는 화질을 파악하여 개발에 도움이 될 수 있는 실질적인 연구로 기대된다.

• 생물정신의학
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• 제22권2호
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• pp.63-77
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• 2015

Objectives The combination extract of four kinds of herbs, Gastrodia elata, Liriope platyphylla, Dimocarpus longan, and Salvia miltiorrhiza, has shown to have memory improving effects in mice. The aim of this study was to investigate the efficacy and safety of the herbal mixture for improving working memory as well as microstructural changes in white matter integrity in individuals with subjective memory complaints. Methods Seventy-five individuals with subjective memory complaints were assigned to receive either placebo (n = 15) or herbal mixture (low-dose group, n = 30 and high-dose group, n = 30) supplementation in an 8-week, randomized, double-blind, placebo-controlled clinical trial. Changes in working memory performance and fractional anisotropy (FA) values reflecting white matter integrity from baseline to 8-week endpoint were assessed. Results The herbal mixture group showed an increase in working memory performance compared to the placebo group (p for interaction = 0.001). In addition, the herbal mixture group showed an increase in FA values in the temporo-parietal regions (corrected p < 0.05), which are crucially involved in working memory function and are among the most affected regions in patients with cognitive impairments. Conclusions Findings from this study indicate that the herbal mixture may be a promising therapeutic option for individuals with subjective memory complaints.

• Journal of Periodontal and Implant Science
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• 제43권6호
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• pp.308-314
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• 2013

Purpose: The purposes of this study were to assess the dentists' subjective satisfaction with the crestal approach sinus (CAS) kit, a device for maxillary sinus membrane elevation by the crestal approach using a special drilling system and hydraulic pressure, and to summarize the subjective satisfaction of dental implants placed after a sinus lift procedure with the CAS kit. Methods: Thirty dental clinicians who had experience with dental implant placement after a sinus lift procedure with the CAS kit from June 2010 to May 2012 were included in this study. The questionnaire for the evaluation of the dentists' subjective satisfaction with the CAS kit was sent to the respondents and returned. The questionnaire was composed of two main parts. The first part was related to the sinus membrane perforation rate. The second part was related to the dentists' subjective satisfaction with the CAS kit. Results: A total of 28 dentists answered the questionnaire. Among 924 implant cases, sinus membrane perforation occurred in 38 cases (4.1%). Among the 28 dentists, 26 dentists (92.9%) were satisfied or very satisfied with the CAS kit. In particular, 24 dentists (85.7%) reported that safety, cutting performance, and user-friendliness of the CAS drill were advantages of the CAS kit. However, 7 dentists (25%) did not routinely use the hydraulic lifter for sinus membrane elevation. Conclusions: From the survey, it was shown that the respondents were generally satisfied with the CAS kit and that the cutting performance and safety of the drill component were considered strengths of the CAS kit.

• 한국치위생학회지
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• 제17권5호
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• pp.827-840
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• 2017

Objectives: The purpose of this study was to investigate the relationship between demographic characteristics, health factors, oral health factors and subjective body shape perception of adolescents in order to provide basic data for adolescents health management. Methods: This study was analyzed using Korea Youth Risk Behavior Web-Based Survey in 2015, where 68,043 adolescents in total participated. Data were analyzed by SPSS Ver. 21.0. Multiple regression analysis was used to analyze the relationships among health factors and oral health factors related to subjective body shape perception. Results: The analysis of the factors influencing the body shape perception of male adolescents showed that they tend to be low in school performance, low in family economic level, and high school students. The worse they perceive their subjective health to be, the more they feel stress, and the less frequently they brush their teeth per day. They had bad breath. The analysis of the factors influencing the body shape perception of female adolescents showed that they tend to be low in school performance, low in family economic level, and high school students. The worse they feel their subjective health is, the more they feel unhappy, and stressful, and the less frequently they brush their teeth per day. They feel pain during chewing, and have bad breath. Conclusions: In conclusion, it is necessary to consider educational intervention in adolescent life that will make them have proper perception of their body shape for proper health management of it. To make the intervention effective, we need to consider various factors such as health factors and oral health factors.