• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제17권10호
• /
• pp.2627-2642
• /
• 2023

Parkinson's disease (PD) is a typical, chronic neurodegenerative disease involving the concentration of dopamine, which can disrupt motor activity and cause different degrees of gait disturbance relevant to PD severity in patients. As current clinical PD diagnosis is a complex, time-consuming, and challenging task that relays on physicians' subjective evaluation of visual observations, gait disturbance has been extensively explored to make automatic detection of PD diagnosis and severity rating and provides auxiliary information for physicians' decisions using gait data from various acquisition devices. Among them, wearable sensors have the advantage of flexibility since they do not limit the wearers' activity sphere in this application scenario. In this paper, an attention-based temporal network (ATN) is designed for the time series structure of gait data (vertical ground reaction force signals) from foot sensor systems, to learn the discriminative differences related to PD severity levels hidden in sequential data. The structure of the proposed method is illuminated by Transformer Network for its success in excavating temporal information, containing three modules: a preprocessing module to map intra-moment features, a feature extractor computing complicated gait characteristic of the whole signal sequence in the temporal dimension, and a classifier for the final decision-making about PD severity assessment. The experiment is conducted on the public dataset PDgait of VGRF signals to verify the proposed model's validity and show promising classification performance compared with several existing methods.

• Communications for Statistical Applications and Methods
• /
• 제16권4호
• /
• pp.659-667
• /
• 2009

Recently Song and Cheon (2006) and Cheon and Lim (2009) developed the generalized maximum entropy(GME) estimator to solve ill-posed problems for the regression coefficients in the simple panel model. The models discussed consider the individual and a spatial autoregressive disturbance effects. However, in many application in economics the data may contain nested groupings. This paper considers a two-way error component model with nested groupings for the ill-posed data and proposes the GME estimator of the unknown parameters. The performance of this estimator is compared with the existing methods on the simulated dataset. The results indicate that the GME method performs the best in estimating the unknown parameters in terms of its quality when the data are ill-posed.

• The Korean Journal of Ecology
• /
• 제16권1호
• /
• pp.75-91
• /
• 1993

Structure and dynamics of Abies koreana community in Mt. Gaya were studied to provide the basic data for conservation of Abies koreana community, an endemic species in Korea. A. koreana community of this study site was composed of tree layer (4~7m), subtree layer (2~4m), shrub layer (1~2m), and herb layer (below 1m). The heights of tree and subtree layers were low. Floristic composition showed that this study site was subalpine and dry site. In frequency distribution diagram of diameter classes of major species consisting of A. koreana community, those of both A. koreana and other species showed reverse J-shaped types. From these results, it was estimated that A. koreana community of this site might be maintained continuously as a stable climax state like present state. In the spatal distribution diagram of major species, saplings of A. koreana were established under the canopy of A. koreana and Pinus koraiensis and under the dead tree of A. koreana. From these results, it was known that A. koreana saplings were recruited before the community was disturbed and regeneration was accomplished by advance regeneration pattern, in which these saplings established before occurrence of disturbance fill with open site originated from death of mature tree. Growth of annual rings was variable among individuals, it was estimated that such variation was originated in that growth of each individual relates to microclimatic conditions rather than macroclimatic ones. Ecological longevity of A. koreana in this study site estimated by disturbance types and age of dead trees was about 120 years.

• 한국환경과학회지
• /
• 제13권2호
• /
• pp.117-127
• /
• 2004

The purpose of this study is to present the conditions and methods for keeping the sustainability of the landscape resources of the East Coast of Gangwon province, the Republic of Korea by investigating the landscape resources management in the area and pointing out its problems. The unit of analysis in this study is four cities and two counties located along the national road route seven in Gangwon province. The classification and characteristics of the landscape resources in this area was analyzed by a literature review, and we surveyed the tourists visiting the area and statistically analyzed the data in order to examine their satisfaction with the landscape resources management and make recommendations. The problems of the landscape resources management are: 1) the disturbance of the persistence of life by reclamation, the population reduction in the ecosystem due to the overload in environmental capacity, and the severance of space between land and water. 2) the reduction of the benefits from indirect experience by interfering with the conservation of fluxes --- the manipulation of horizontal arrangement of the landscape resource, the visual disturbance by the construction of high-storied buildings, and the disharmony between the color/image and the environment. The means for keeping sustainability of the landscape resources include the regulations of development and use, the change in the recognition of the value of landscape resources and the moral system, and the improvement of resource management skills.

• The Korean Journal of Ecology
• /
• 제24권6호
• /
• pp.341-348
• /
• 2001

Population dynamics of the oldest relic stand of Pinus densiflora for. erecta which remains as a status of patch in Sokwang-Ri area, Uljin-Gun, was studied to provide the basic data for conservation of the oldest pine stand in Korea. The upper slope site and ridge site including total 12 plots mainly represented Pinus densiflora for. erecta and Quercus mongolica. These two tree species showed reverse J-shaped distribution. From this information, it was concluded that intensive interspecific competition between two species could be occurring. Age distribution of P. densiflora for. erecta on the sites above middle slope area was indicated bi-modal type or tri-modal type which was known as an age structure of climax forest. Therefore, it was estimated that Pinus densiflora for. erecta population could be continuously maintained in the each patch above middle slope area. In the valley sites, hardwood species such as Q. mongolica, Q. variabilis, Styrax obassia and Acer pseudosieboldianum occupied most part of the under crown-cover area and their seedlings and saplings were developing into the closed upper layer crown because the height of upper layer crown reached about 35 meters and such a high crown height was more suitable for light utilization by plants of under layer. The growth patterns were mainly fluctuated for the entire life time of the oldest tree caused by frequent disturbance. And the initial growth curves of the mature trees and suppressed juvenile trees showed different tendencies along the sites.

• 한국간호교육학회지
• /
• 제3권2호
• /
• pp.214-225
• /
• 1997

Sleep is an inevitable part of human existence and a part of the dynamic quality of life. The purpose of this study is to explore sleep pattern changes and related factors of patients hospitalized. The participants are 158 patients hospitalized in one general hospital. The questionnaire was developed by modification of VSH sleep scale (1987). Open question was used for research of related factors. $SPSS/PC^+$ are utilized for data analysis. The results are as follows ; There is significant difference before and after admission in the sleep disturbance. There is retroverse significant difference before and after admission in the sleep effectiveness. There is no significant difference between two groups in the nap supplementation. The patients reported pain by reason of sleep latency and mid-sleep awakening and noise due to early awakening. The reasons for lack of sleep were pain and noise. The method for overcoming their sleep disturbance, most of the subjects waited with closed eyes, imaged by themselved and took medicate sleeping pills. Discomfort manifested in the case of insufficient steepness was fatigue, headache and aggressiveness.

• 대한예방한의학회지
• /
• 제13권3호
• /
• pp.73-85
• /
• 2009

Objectives : To evaluate the effects of aroma hand massage on sleep disturbance and depression in hospitalized elderly patients. Methods : The data was collected using questionnaires from the subjects who were admitted to the G Medical Hospital in Daegu from 7 July to 12 July, 2008. A total of 23 subjects were selected. The subjects were applied with the aroma hand massage to both hands using a solution diluting four drops of lavender oil in jojoba oil 10cc. Aroma hand massage was given for 10 minutes, one time a day, during 5 days. Results : There was statistically significant improvement on the Korean sleep scale(t=-7.614, p=0.000) and on the Geriatric Depression Scale Short Korea Version(GDSSF-K)(t=3.444, p=0.002). Conclusions : aroma hand massage is an effective therapeutic intervention for decreased sleep disturbance and depression. Therefore, aroma therapy and hand massage by therapeutic intervention is recommended for improving psychological and physiological functions in hospitalized elderly patients.

• International Journal of Automotive Technology
• /
• 제8권3호
• /
• pp.383-394
• /
• 2007

Due to the clutch's non-linear dynamics, time-delays, external disturbance and parameter uncertainty, the automated clutch is difficult to control precisely during the launch process or automatic mechanical transmission (AMT) vehicles. In this paper, an enhanced fuzzy sliding mode controller (EFSMC) is proposed to control the automated clutch. The sliding and global stability conditions are formulated and analyzed in terms of the Lyapunov full quadratic form. The chattering phenomenon is handled by using a saturation function to replace the pure sign function and fuzzy logic adaptation system in the control law. To meet the real-time requirement of the automated clutch, the region-wise linear technology s adopted to reduce the fuzzy rules of the EFSMC. The simulation results have shown hat the proposed controller can achieve a higher performance with minimum reaching time and smooth control actions. In addition, our data also show that the controller is effective and robust to the parametric variation and external disturbance.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권9호
• /
• pp.425-432
• /
• 2000

Wavelet transform is a new method fro electric power quality analysis. Several types of mother wavelets are compared using voltage sag data. Investigations on the use of some mother wavelets, namely Daubechies, Symlets, Coiflets, Biorthogonal, are carried out. On the basis of extensive investigations, optimal mother wavelets for the detection of voltage sag are chosen. The recommended mother wavelet is 'Daubechies 4(db4)' wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, can be used most properly in disturbance phenomena which occurs rapidly for a short time. This paper presents a discrete wavelet transform approach for determining the beginning time and end time of voltage sags. The technique is based on utilising the maximum value of d1(at scale 1) coefficients in multiresolution analysis(MRA) based on the discrete wavelet transform. The procedure is fully described, and the results are compared with other methods for determining voltage sag duration, such as the RMS voltage and STFT(Short-Time Fourier Transform) methods. As a result, the voltage sag detection using wavelet transform appears to be a reliable method for detecting and measuring voltage sags in power quality disturbance analysis.

• 근관절건강학회지
• /
• 제27권2호
• /
• pp.169-176
• /
• 2020

Purpose: This study aims to investigate the factors affecting fatigue of care helpers in long-term care facilities. Methods: The subjects consisted of 131 care helpers at six long-term care facilities in Chungcheongnam-do. A survey was conducted between July and September 2019 to collect data, which were analyzed using t-test, ANOVA, Pearson's correlation coefficients, and multiple regression analysis.Results: An increase in fatigue of care helpers owing to taking care of over 10 patients a day, increase in emotional labor and sleep disturbance, and a decrease in economic status was observed. Their fatigue decreased when there was an increase in their subjective health status and job satisfaction. Work-related stress (β=.37, p<.001), emotional labor (β=.21, p=.014), and sleep disturbance (β=.18, p=.026) significantly predicted fatigue. These factors explained 37% of the total variance in fatigue (F=10.48, p<.001).Conclusion: In addition to improving the work environment, interventions that alleviate emotional labor and improve sleep quality, are needed to lower the fatigue of care helpers.