• 전기학회논문지P
• /
• 제66권2호
• /
• pp.58-62
• /
• 2017

This paper presents a novel prototype of the resonant AC link snubber circuit for the three-phase sinwave soft-switching PWM inverter. In principle, its operating principle is described, and the performance evaluations of the specific instantaneous space voltage modulated three-phase sinewave soft switching PWM inverter incorporating a resonant AC link snubber is illustrated, and evaluated, introducing the specific space voltage vector modulation implementation. It is conferred that the validity of three-phase soft-switching inverter treated here in setup experiment.

• 음성과학
• /
• 제11권4호
• /
• pp.173-184
• /
• 2004

This study aims to discuss the test methodologies that evaluate the speech intelligibility of hearing-impaired adults using various contexts. Seven adults with severe hearing loss participated in the experiment. The context of the speech intelligibility consists of 77 pairs of one-syllable words with phonemic contrasts, 30 two-syllable words and the list of each 12 and 10 sentences. The speech intelligibility of various contexts had significant correlation, and both one-syllable words with phonemic contrasts and the sentence 1 had higher correlation than other tests. The one-syllable words with phonemic contrasts took longer to test than others, and it demanded more effort to select the pair of words. However, from the point of view of the identification of segmental difficulties, the one-syllable words with phonemic contrasts that reflected segmental factors contributing to the intelligibility was useful.

• 조명전기설비학회논문지
• /
• 제24권11호
• /
• pp.1-8
• /
• 2010

This study analyzes whether a person's visual perception differs according to the kinds of light source. Evaluations of the effects of space, color-tone and texture perception revealed that different kinds of light sources change the perception of finishing material. The perception from directly attached lamps was compared to an environment with both directly attached lamps and supplemental lighting. We found the perception changed with changes in the types of supplemental light source We compared the mean value of each perception and found that perceptions change most when incandescent lights were followed by halogen. Thus, one should account for the changes in perception that occur as a result of these changes.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
• /
• pp.76-79
• /
• 2009

This paper presents analyses and performance evaluations of a PWM inverter for a permanent magnet synchronous motor drive under open fault conditions caused by the open fault in one switching device or isolation between the inverter and motor terminal. A fault model for a PWM inverter is derived and experiment is carried out by using DSP TMS320F28335 to provide the basis of fault diagnosis for such a case.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1092-1094
• /
• 2005

This paper deal with the efficiency evaluations in a Synchronous reluctance motor(SynRM) Vs. PMASynRM using a coupled transient finite element method(FEM) and preisach modeling, which is presented to analyze the characteristics under the effect of saturation and hysteresis loss. The focus of this paper is the efficiency evaluation relative to hysteresis loss, copper loss, etc. on the basis of load condition in a SynRM and PMASynRM. Computer simulation and experiment at result for the efficiency using dynamometer shoe the propriety of the proposed method.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송∙미디어공학회 2018년도 하계학술대회
• /
• pp.63-66
• /
• 2018

Recently, a convolutional neural network (CNN) models at single image super-resolution have been very successful. Residual learning improves training stability and network performance in CNN. In this paper, we compare four convolutional neural network models for super-resolution (SR) to learn nonlinear mapping from low-resolution (LR) input image to high-resolution (HR) target image. Four models include general CNN model, global residual learning CNN model, local residual learning CNN model, and the CNN model with global and local residual learning. Experiment results show that the results are greatly affected by how skip connections are connected at the basic CNN network, and network trained with only global residual learning generates highest performance among four models at objective and subjective evaluations.

• 국제초고층학회논문집
• /
• 제11권3호
• /
• pp.145-156
• /
• 2022

Application examples of computational fluid dynamics (CFD) in the planning stage of high-rise buildings are introduced. First, we introduce examples of applications in the environmental field. The pedestrian wind environment was one of the earliest practical examples of CFD. CFD was also employed to validate the heat island mitigation measures proposed as part of the new construction plan. Second, application examples of wind-force evaluations are introduced. Prediction examples are presented for the peak wind pressure around a complex-shaped building and the wind force evaluation for a base-isolated building. The results prove that the results of the proper execution of CFD are equivalent to those of the wind tunnel experiment. As examples of CFD applications of other issues related to high-rise building planning, we introduce snow accretion on outer walls and high-temperature exhaust from emergency generators. Finally, the future prospects for the use of CFD are discussed.

• Toxicological Research
• /
• 제35권4호
• /
• pp.371-387
• /
• 2019

Although the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae) is a popular medicinal plant in East Asia, there has been no systemic toxicological evaluation of a water extract of Saposhnikoviae Radix (SRE). In this experiment, an oral acute and 13-week subchronic toxicological evaluations of SRE (500-5,000 mg/kg body weight) were performed in both sexes of Crl:CD(SD) rats. Based on the results from mortality, clinical signs, effects on body weight and organ weight, clinical biochemistry, hematology, urinalysis, and histopathology, significant acute, 4-week repeated dose range finding (DRF) and 13-week subchronic toxicity of SRE was not observed in either sex of rats; thus, the no observed adverse effect level (NOAEL) was 5,000 mg (kg/day). To identify anti-hyperuricemia potential of SRE, the suppressive effect of SRE was determined in mice challenged with potassium oxonate (PO; 250 mg/kg) via intraperitoneal injection for 8 days (each group; n = 7). SRE supplementation suppressed the uric acid level in urine through significant xanthine oxidase (XO) inhibitory activity. Kidney dysfunctions were observed in PO-challenged mice as evidenced by an increase in serum creatinine level. Whereas, SRE supplementation suppressed it in a dose-dependent manner. Collectively, SRE was safe up to 5,000 mg (kg/day) based on NOAEL found from acute and 13-week subchronic toxicological evaluations. SRE had anti-hyperuricemia effect and lowered the excessive level of uric acid, a potential factor for gout and kidney failure.

• 동의생리병리학회지
• /
• 제35권5호
• /
• pp.162-168
• /
• 2021

This study was conducted to investigate the current status of online classes and evaluations during the COVID-19 pandemic and the satisfaction of students attending the College of Korean Medicine. A survey was conducted with students enrolled in Dongguk University's College of Korean Medicine. The questionnaire was divided into four areas asking about online lectures, laboratory practice, clinical practice, and evaluation experience. The items were composed of multiple-choice, a 5-point scale, and subjective type. After distributing the Google form address through SNS and LMS, only those who agreed to the questionnaire were responded anonymously. 149 out of 457 enrolled students responded. 98.7% of students experienced online lectures, and more frequently experienced real-time online lectures (98.6%) than recorded lectures (43.5%). Overall satisfaction with online lectures was 3.99 on average. 80.5% of the students experienced the online experiment and practice class, and the overall satisfaction with it was 3.29 on average. 1.3% of students experienced online clinical practice. 86.6% of students experienced online evaluation, and when asked about the fairness of the test, the average score was 3.99. Satisfaction with online lectures and evaluations is generally high, so it is expected to be used as an effective learning tool in the future. However, it seems that facility improvement and technical training of instructors are necessary. In experimental and practical education, the satisfaction level is lower than that of online lectures, so it seems necessary to develop a new online program and to prepare a safe offline education system.

• 방사선산업학회지
• /
• 제17권4호
• /
• pp.385-390
• /
• 2023

The uterus, one of women's reproductive organs, is also closely related to women's health. Among them, hemorrhagic luteal cysts, one of the causes of pelvic pain that women often experience, were observed through CT and ultrasound, and the quality of images was evaluated through quantitative and qualitative evaluations. This study sought to find out whether the test method is more helpful to patients during CT and ultrasound. This study was conducted on 15 adolescent women and 15 adult women(21.31±3.45 average age). The equipment used for filming used EC3-10X (3~10 MHZ) and Philips Mx8000 iCT 256 among Endocavity Probes among Ecube Platinum. After setting a constant ROI on the cyst and the interface as a quantitative analysis method, SNR and CNR values were measured on a 5-point scale based on image quality, lesion clarity, image distortion, clarity of the interface, and motion artifacts (p<0.05). Independent t-test and Mann Whiteny U were performed, and the statistical program used was noted when SPSS (Version 22.0 for windows software package, Chicago, IL, USA) was statistically less than 0.05. Comparing the SNR and CNR values for this experiment, it can be seen that the SNR value was higher in the case of CT images(p<0.05). As a result of the qualitative evaluation, the quality of the image, the clarity of the lesion, the distortion of the image, the clarity of the interface, and the clarity of the boundary were measured on a 5-point scale based on the movement artifact. Comparing each score, CT images scored higher with a finer difference than ultrasound images(p<0.05). In conclusion, both test methods showed excellent results in finding the patient's lesions. However, in quantitative and qualitative evaluations, CT produced higher results in detecting lesions than ultrasound. However, for cyst tests that require continuous observation, ultrasonography, a non-invasive method that is advantageous for patients, will be clinically useful. Therefore, observing the patient's lesions by appropriately distributing these two test methods will provide optimal diagnostic information. These results will be useful for providing clinical basic data and educational materials to CT and US users in the future.