• 한국물환경학회지
• /
• 제38권1호
• /
• pp.1-9
• /
• 2022

The Yeongsan River, one of the four major rivers in Korea, shows the highest degree of water pollution compared to the other major rivers. The construction and opening of two weirs, Seungchon and Juksan, induced fluctuations in the hydrologic conditions and water quality of the river. To investigate the water quality changes caused by the opening of the weir in 2017, this study analyzed the water quality data using the non-parametric Wilcoxon signed-rank test and the three-dimensional spatiotemporal plots. The non-parametric statistical test results showed that the concentration of all parameters has increased after 2017 at a significance level of 0.05. For the parameters that showed the highest degree of change, chlorophyll-a and suspended solids, the median values have increased by more than 30% after weir opening. Visual analysis additionally showed the spatial changes in the Yeongsan River. Generally, the sites above the Seungchon weir showed higher pollution levels than those above the Juksan weir. In time series, visual analysis results also showed the trend of rising concentration for all water quality parameters, indicating that the opening of two weirs had a significant effect on the change in water quality of the Yeongsan River.

• 한국식품영양과학회지
• /
• 제30권2호
• /
• pp.283-287
• /
• 2001

Persimmon vinegar was clarified with 400mg/L chitosans of two different molecular weights (MW 150 and 37 kDa), and its quality changes were investigated during storage at room temperature for 6 months. No significant changes in pH, acidity, and tannin content were observed. However, turbidity and browning slightly increased while protein content slightly decreased. Soluble solids content slightly decreased when treated with high MW chitosan. Color L* value decreased while a* and b* values increased with storage periods. The major organic acid in the persimmon vinegar after 6 months storage was acetic acid with minor lactic, malic, tartaric, galacturonic, and succinic acids. Overall, the quality of persimmon vinegar clarified by chitosan treatment, irrespective of molecular weight, was more stable without noticeable changes during storage than that of control group without chitosan treatment.

• Journal of Korea Trade
• /
• 제23권3호
• /
• pp.20-37
• /
• 2019

Purpose - The purpose of this paper is to analyze the trade structure and competitiveness of China's information technology (IT) industry in comparison to that of Korea and the United States, particularly in terms of quality. Design/methodology/approach - Indices such as trade specialization index (TSI), Revealed Comparative Advantage (RCA), and Market Comparative Advantage (MCA) are used. Further, an Intra-industry Trade (IIT) index is used to analyze qualitative changes in horizontal intra-industry trade and intra-industry trade of high- and low-quality goods. Findings - China's IT industry has a comparative competitive advantage over that of Korea and the United States, and mainly exports goods of inferior quality and imports goods of superior quality. Further, China's horizontal intra-industry trade has been decreasing, while its vertical intra-industry trade has been increasing and vertical trade of inferior quality goods outweighs that of superior quality goods. This shows that China is rapidly catching up with Korea and the United States, even though its qualitative competitiveness has not significantly improved. Research limitations/implication - This study has academic and political implications, as it analyzes changes in China's IT trade competitiveness. However, it is somewhat limited as factors determining qualitative aspects has not been considered. Originality/value - Most studies aggregate analyses of export competitiveness using methodologies such as TSI, RCA, and market share. However, the focus of these methods is price competitiveness. Hence, an examination of the objective and qualitative trade competitiveness of China's IT industry is necessary. this study the trade structure and quantitative competitiveness of the industry by analyzing intra-industry trade focusing on the quality of competitiveness. Therefore, the changes in China's IT industry in the USA and Korea and in foreign trade competitiveness and quality competitiveness are clarified. The results show that the academic and policy implications of these changes in the IT industry will be a useful resource. This is the first study in Korea to attempt such an analysis. This is the first study in Korea to attempt such an analysis.

• 한국주거학회논문집
• /
• 제7권1호
• /
• pp.1-13
• /
• 1996

The objective of this study was to investigate changes in housing quality and residential satisfaction among the New Town movers. Numerous literatures pertaning to the subject were thoroughly reviewed, and a set of hypotheses was drawn therefrom. Methodology applied to the study included bivariate and multivariate analyses for both derivation of descriptive statistics and hypotheses testing. SPSS PC+ for window(version 6.2) was used to analyze the data collected by Korea Research Institute for Human Settlements(KRIHS) in 1993. The major findings are highlited as follows : 1) Regardless of the household income level and other characteristics housing quality has improved substantially by moving to new towns. 2) The level of residential satisfaction is increased as a result of moving to new towns. 3) Upward changes in housing quality strongly influence the change in residential satisfaction. Both variables to be highly correlated. 4) These most satisfied residents are those who moved to the large size of dwellings and they are mostly high income families.

• 품질경영학회지
• /
• 제25권2호
• /
• pp.189-196
• /
• 1997

When proferssors teach an introductory statistics course to undergraduate students, they have given unilateral lecture to the students. It is emphasized that the changes are necessary in teaching the introductory statistics course. Some effective and diverse methods are introduced to teach students.

• 대한물리의학회지
• /
• 제10권4호
• /
• pp.123-131
• /
• 2015

PURPOSE: This study attempts to examine the impact of respiratory muscle exercises on the respiratory function and quality of sleep among stroke patients. METHODS: A total of 20 stroke patients were randomly divided into a breathing-exercise training group(n=10) and a breathing-device-training group(n=10). Changes in pulmonary function, as well as the quality, were measured before and after the intervention. The breathing exercise was performed three times a week for a total of eight weeks. Breathing-device exercises made use of a lung-capacity-strengthening device and were performed for three times a week for eight weeks. One Flow FVC was used as a measurement tool for the pulmonary function test. The Pittsburgh Sleep Quality Index(PSQI) and a sleep measurement tool were used for sleep evaluation. RESULTS: In a comparison of changes in pulmonary function before and after the training, the breathing-exercise group and the breathing-device-training group showed a significant difference. In changes of sleeping measure and PSQI, the breathing-exercise group and the breathing-device-training group also showed significant differences. CONCLUSION: Diverse index analyses confirmed that breathing exercises and exercises using a lung-capacity-strengthening device, were effective in improving respiratory function and quality of sleep among stroke patients experiencing respiratory function disorders and sleep disorders.

• 정보과학회 논문지
• /
• 제44권4호
• /
• pp.423-432
• /
• 2017

최근 HTTP 적응적 스트리밍 서비스의 표준인 DASH(Dynamic Adaptive Streaming over HTTP)를 기반으로 하는 비디오 스트리밍 서비스의 QoE(Quality of Experience) 향상을 위해 비디오 품질 조절 기법들이 연구되고 있다. 그러나 기존 기법들은 비디오의 VBR(Variable Bitrate) 특성에 대한 고려가 부족하여 불필요한 품질 변화로 인해 QoE가 저하되는 문제를 발생시킨다. 본 논문에서는 세그먼트 특성을 기반으로 품질을 조절하는 SC-DASH(Segment Characteristics-based DASH)를 제안한다. SC-DASH는 다음에 요청할 세그먼트의 크기, 세그먼트 처리량, 그리고 버퍼 점유율을 기반으로 비디오 품질을 조절하여 불필요한 품질 변화가 발생하는 것을 방지한다. 실험 결과를 통해 SC-DASH가 기존 기법보다 불필요한 품질 변화를 감소시킴으로써 QoE를 향상시키는 것을 확인하였다.

• 한국응급구조학회지
• /
• 제17권1호
• /
• pp.9-19
• /
• 2013

Purpose : The purpose of this study was to investigate the variation of elapsed time in the cardiopulmonary resuscitation (CPR) quality and the fatigue in continuous CPR by single rescuer. This study will provide basic data about the time for the alternation of the CPR providers. Methods : The volunteer students having healthcare provider certification were recruited from the department of emergency medical service. The students performed 30:2 CPR for 20 minutes, and the data were recorded and analyzed. Metrics were based on the 2010 American Heart Association (AHA) Guidelines, and the CPR continued without any feedback. Results : Among the indicators of CPR, the accuracy and the depth of chest compressions decreased after about 5.3 minutes, and the rate increased approximately after 6.8 minutes. Changes in clinical indicators appeared, and fatigue increased after about 3 minutes. According to the increase in fatigue level, the changes in the CPR indicators and clinical indicators showed up, and these results proved to be statistically significant. However, there were no associations among the time, fatigue, and gender. Conclusion : Even though the times of changes in the indicators appeared differently, the times of changes in fatigue and CPR quality were able to be confirmed.

• 음성과학
• /
• 제9권3호
• /
• pp.133-140
• /
• 2002

The purpose of this study was to investigate any changes in acoustic qualities of voice as ,a function of nasalance, in order to determine the relationship between vocal quality and nasalance. Twenty normal subjects (10 males and 10 females) vocalized /a/, /$\tilde{a}$/, and /a $\eta$/. The changes in nasalance and acoustic characteristics of the voice were analyzed by Nasometer (Model 6200-3, Kay Elemetrics, co) and Dr, Speech 4.0 (Tiger Electronics, Co), respectively. One-way ANOVA was used to examine any changes in jitter, shimmer, harmonics-to-noise ratio, and normalized noise energy relative to the nasalance in 3 types of vocalization. The Person r correlation coefficient was used to identify the relationship between the nasalance and the vocal quality. There was no statistically significant changes in jitter, shimmer, HNR and NNE. The jitter, however, tended to increase as the nasalance socre increased, compared to the other vocal parameters. In addition, the NNE showed an increase on / $\tilde{a}$/, and /a $\eta$/, more on the /a $\eta$/. Thus, it was speculated that NNE could be used to identify or screen resonant disorders with hypernasality

• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.1611-1611
• /
• 2001

The main selection parameters used by forage grass (rye and Italian rye grass) breeders are dry-matter yield, seasonal growth, persistency, disease resistance, heading date, and heading. These characteristics can all be identified usually in the segregating F2 population, however characteristics such as soluble carbohydrate level, protein, lipid and digestibility cannot be identified. The emphasis of this work is to introduce a quantitative selection process for characterization of herbage quality e.g. protein, water-soluble carbohydrates, fiber fractions, dry matter digestibility. NIRS calibrations are currently being developed for identifying grass genotypes to assist the selection process, thereby allowing the opportunity to actively breed improved herbage quality. The changes in fibre fractions, associated components and digestibility of a number of grass clones at different growth stages are being assessed changes taking place during a growing season. This will provide a database of the major changes taking place during a growing season. Attempts to classify quality differences between genotypes will be carried out using multivariate analysis of the spectral data. I addition changes associated with maturity of grass will be considered in order to develop robust calibrations.