• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.404-406
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• 1996

The objective of this paper is to present a new feature-vector extraction method for the automatic detection and classification of power quality(PQ) disturbances, where FFT, DWT(Discrete Wavelet Transform), and data compression are utilized to extract an appropriate feature vector. In particular, the proposed classifier consists of three parts: i.e., (i) automatic detection of PQ disturbances, where the wavelet transform and signal power estimation method are utilized to detect each disturbance, (ii) feature vector extraction from the detected disturbance, and (iii) automatic classification, where Multi-Layer Perceptron(MLP) is used to classify each disturbance from the corresponding extracted feature vector. To demonstrate the performance and applicability of the proposed classification algorithm, some test results obtained by analyzing 7-class power quality disturbances generated by the EMTP are also provided.

• Journal of Korean Clinical Nursing Research
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• v.17 no.3
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• pp.421-432
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• 2011

Purpose: The purpose of this study was to investigate the sleep patterns and the factors related to sleep disturbance in mechanically ventilated patients in intensive care units (ICUs). Sleep patterns in this study included both quality and quantity of sleep. Methods: Forty-four subjects were recruited in ICUs at a tertiary university hospital in D city. Data were collected using questionnaires, observation, and medical record from June, 2008 to May, 2009. Results: The total mean of sleep quality was $1.99{\pm}1.68$. The mean of total sleep time per 24-hour period was $3.75{\pm}1.94$hour (range 1-7.25) in mechanically ventilated ICU patients. The main sleep disturbance factors were listed as frequent nursing activities, attachment of medical appliances, and noise. All these factors were also significantly related to the sleep quality. Conclusion: These results indicated that mechanically ventilated patients were both qualitatively and quantitatively deprived of sleep far more than other ICU patients. In summary, a deeper understanding of sleep characteristics in mechanically ventilated ICU patients could help nurses to improve sleep derangements and patient outcome.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1904-1913
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• 2021

With the proliferation of smart phones and the development of IoT technology, it has become possible to collect personal data for public purposes. However, users are afraid of voluntarily providing their private data due to privacy issues. To remedy this problem, mainly three techniques have been studied: data disturbance, traditional encryption, and homomorphic encryption. In this work, we perform simulations to compare them in terms of accuracy, message length, and computation delay. Experiment results show that the data disturbance method is fast and inaccurate while the traditional encryption method is accurate and slow. Similar to traditional encryption algorithms, the homomorphic encryption algorithm is relatively effective in privacy preserving because it allows computing encrypted data without decryption, but it requires high computation costs as well. However, its main cost, arithmetic operations, can be processed in parallel. Also, data analysis using the homomorphic encryption needs to do decryption only once at any number of data.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.172-177
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• 2007

Wavelet transforms provide basis functions for time-frequency analysis and have properties that are particularly useful for the compression of analogue point on wave transient and disturbance power system signals. This paper evaluates the compression properties of the discrete wavelet transform using actual power system data. The results presented in the paper indicate that reduction ratios up to 10:1 with acceptable distortion are achievable. The paper discusses the application of the reduction method for expedient fault analysis and protection assessment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1152-1160
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• 2007

In this paper we deal with a design of integral sliding mode controller to reject the disturbance force acting on the suspension system in the magnetically levitated system which is propelled by the linear induction motor. The control scheme comprises an integral controller which is designed for achieving zero steady-state error under step disturbances, and a sliding mode controller which is designed for enhancing robustness under plant uncertainties. A proper continuous design signal is introduced to overcome the chattering problem. The disturbance force produced by the linear motor is formularized by using a curve fitting of the experimental raw data. Computer simulations show the effectiveness of the designed integral sliding mode controller to reject the disturbance force.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.257-269
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• 2017

The study has piloted to find the Pattern of species distribution along environmental variables and disturbance in Raghunandan Reserve Forest. Shaltila and Shahapur beat of Raghunandan Hill Reserve Forest are situated in Chunarughat sub-district of Habiganj district between $24^{\circ}5^{\prime}-24^{\circ}10^{\prime}N$ and $91^{\circ}25^{\prime}-91^{\circ}30^{\prime}E$ under the Sylhet Forest Division. The Environmental variable and vegetation data were collected from 30 sample plots from each forest beat by using arbitrary sampling without preconceived bias. 51 species were found from Shaltila and 34 species found in Shahapur forest beat. Thus the dataset continued with total 85 species in 60 samples. To determine the relationships between tree species distribution and environmental variables, Canonical Correspondence Analysis (CCA) ordination method were performed separately for two forest beat. In CCA ordination, tree species showed significant variation along environmental gradients in terms of soil organic matter and disturbances (p<0.05) in the case of Shaltila forest. Potassium has a significant relationship with axis 1 and axis 2 in this forest. But Shahapur forest showed no significant relationship between species and environmental variables. Phosphorus has a significantly negative relationship with axis 2 in this forest. Disturbance played as a critical role of this forest thus influencing the distribution of species. The study showed that the distributions of tree species are strongly influenced by disturbance and organic matter in Shaltila and Shahapur forest beat showed no significant relationship between species and environmental variables. Future research should be included more environmental variables with larger study area that identify the most important environmental forces which will drive by species distribution findings in this forest.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.2
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• pp.365-372
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• 2011

The purpose of this study was to identify the effects of aroma hand massage and hand massage on sleep disturbance and depression in hospitalized elderly patients. The study was performed using a nonequivalent control group pretest-posttest design. The data was collected by using questionnaires and the measured values from 1 June to 31 August, 2006. The subjects who were admitted to the B Medical Center Hospital in Busan. A total of 40 subjects were selected : 20 in the experimental group and 20 in the control group. The aroma hand massage was administered to the experimental group, and hand massage was given to the control group. The experimental group were applied the aroma hand massage executed by methods such as effleurage, circling, pressing, etc. to both hands using a solution diluting six drops of lavender oil, and bergamot oil, 3% in jojoba oil 20 cc. In the experimental group, aroma hand massage was given for 10 minutes, three times a week, during 2 weeks. The control group receiving the hand massage was given the massage for 10 minutes every two days for 2 weeks. The result of the study are as follows : 1) The first hypothesis : "The Experimental group would have a higher degree of sleep score than the control group" was supported(F=31.798, p=p<0.001). 2) The second hypothesis : "The Experimental group would have a lower degree of depression score than the control group" was supported(F=21.743, p<0.001). Aroma hand massage is an effective nursing intervention for decreased sleep disturbance and depression. Therefore, aroma hand massage by nursing intervention is strongly recommended for improving psychological and physiological functions in hospitalized elderly patients.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.203-211
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• 2021

The purpose of this study is to analyze the effects of disturbance factors of exercise on leisure satisfaction and health-related quality of life in the era of COVID-19 in club members participating in sports for all and use for basic data for continuous exercise to keep and improve health. 353 sports for all club members who consented to the study participated in the study after the purposes and methods of the study were explained. The following conclusions were drawn. The disturbance factors of exercise had significant effects on leisure satisfaction and health-related quality of life in sports for all club members. Moreover, leisure satisfaction had significant effects on health-related quality of life. Although we hope to end COVID-19, we should prepare with Corona. Sports facilities should strive for quarantine and personal hygiene to help sports for all club members' continuous participation in exercise for their healthy life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5882-5892
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• 2012

This study was performed to examine the effects of Dan Jeon Breathing on stress, sleep disturbance and self-esteem of hemodialysis patients. This study used the nonequivalent control group pretest-posttest design. Before applying the Dan Jeon Breathing program, the patients were divided into the experimental group and the control group, respectively, and were requested to report their self-ratings to measure their stress, sleep disturbance and self-esteem. The Dan Jeon Breathing program was given to experimental groups for 60 minutes a day and 2 times a week for 12 weeks. The data collected from the program were analyzed by means of ${\chi}^2$ test, Fisher's exact probability test, Shapiro-Wilk and t-test. The analyses revealed that the stress(t=-2.95, p=.006) and sleep disturbance(t=-2.13, p=.041) levels of the experimental group decreased after Dan Jeon Breathing compared to those of the control group. The difference in self-esteem(t=2.44, p=.020) level was statistically significant. From the above results, it was verified that Dan Jeon Breathing could be used as nursing intervention for hemodialysis patients to mitigate their stress, sleep disturbance and to improve their self-esteem.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.43-60
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• 2019

Background: Tropical montane forests played an important role in the provision of ecosystem services. The intense degradation and deforestation for the need of agricultural land expansion result in a significant decline of forest cover. However, the expansion of agricultural land did not completely destruct natural forests. There remain forests inaccessible for agricultural and grazing purpose. Studies on these forests remained scant, motivating to investigate biomass and soil carbon stocks. Data of biomass and soils were collected in 80 quadrats ($400m^2$) systematically in 5 forests. Biomass and disturbance gradients were determined using allometric equation and disturbance index, respectively. The regression modeling is employed to explore the spatial distribution of carbon stock along disturbance and environmental gradients. Correlation analysis is also employed to identify the relation between site factors and carbon stocks. Results: The result revealed that a total of 1655 individuals with a diameter of ${\geq}5cm$, representing 38 species, were measured in 5 forests. The mean aboveground biomass carbon stocks (AGB CS) and soil organic carbon (SOC) stocks at 5 forests were $191.6{\pm}19.7$ and $149.32{\pm}6.8Mg\;C\;ha^{-1}$, respectively. The AGB CS exhibited significant (P < 0.05) positive correlation with SOC and total nitrogen (TN) stocks, reflecting that biomass seems to be a general predictor of SOCs. AGB CS between highly and least-disturbed forests was significantly different (P < 0.05). This disturbance level equates to a decrease in AGB CS of 36.8% in the highly disturbed compared with the least-disturbed forest. In all forests, dominant species sequestrated more than 58% of carbon. The AGB CS in response to elevation and disturbance index and SOC stocks in response to soil pH attained unimodal pattern. The stand structures, such as canopy cover and basal area, had significant positive relation with AGB CS. Conclusions: Study results confirmed that carbon stocks of studied forests were comparable to carbon stocks of protected forests. The biotic, edaphic, topographic, and disturbance factors played a significant variation in carbon stocks of forests. Further study should be conducted to quantify carbon stocks of herbaceous, litter, and soil microbes to account the role of the whole forest ecosystem.