• Sleep Medicine and Psychophysiology
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• v.4 no.2
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• pp.191-200
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• 1997

Objectives : Periodic limb movements during sleep (PLMS) may cause arousals that may lead to non-restorative sleep. PLMS is characterized by long sleep latency, sleep fragmentation, frequent stage shifts, and rarity of stages 3/4 NREM sleep on polysomnography. However, controversies have existed and it still remains to be elaborated whether PLMS actually causes insomnia, since normal persons happen to have PLMS. Clinically, it would be crucial to know factors which might disturb sleep in PLMS. We became interested in Coleman's theory(1980) that invariant periodic movements disturb patients' sleep less. Though, Coleman's study seems to have been confounded by including PLMS patients with various co-morbid sleep disorders. Therefore, we attempted to study in patients only with PLMS the effects of movement patterns on sleep architecture. Methods : In 27 patients diagnosed as having PLMS only with clinical interview and nocturnal polysomnography, we studied the relationship between the movement patterns such as mean duration and variability of periodic limb movement's interval and the sleep architecture variables. Results : The shorter and the more regular the limb movement intervals were, the fewer arousals followed. The movement intervals of the older patients were shorter and more regular than the younger patients. The probability of the accompanying arousal with each limb movement increased as the duration and variance of the movement intervals increased. It decreased as the age and the frequency of limb movements increased. Among these factors the most significant one was the mean duration of the movement intervals. In other words, the shorter the movement intervals were, the less disturbed sleep was. Conclusion : PLMS frequency increases with aging but the probability of the accompanying arousal with each movement decreases with aging. Sleep-disturbing effects of PLMS depends more on the duration and variability of movement intervals than the PLMS frequency.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.191-198
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• 2006

In this paper, we focus on a question. Which is better between time-based location update method and movement-based location update method? Or, does any other method combining the two methods show better performance? For the question, we propose a hybrid location update scheme, which integrates the time-based and the movement-based methods. In the proposed scheme, a mobile terminal updates its location after n cell boundary crossing and a time interval of T, or the inverse. We derive an analytical solution for the performance of the hybrid scheme with exponential cell resident time. From the numerical analysis, we conclude that the movement-based method seems to have better performance than the time-based and hybrid methods, that is the optimal costs occur at T=0.

• Journal of Korea Multimedia Society
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• v.17 no.4
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• pp.433-440
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• 2014

Wireless communication offers the flexibility to the node movement at the spatial dimension more than the wire communication not only in IP architecture but also in Content-Centric Networking. Although it gives such advantage, the intra-domain movement of a node especially the data source node affects the communication to the access point node which in the end affects the acceptance ratio of the client node that requests the data packets from the data source node. In this paper, we use time-division access method to maintain the acceptance ratio of the client node as the effect of the intra-domain data source node movement in Content-Centric Networking. The simulation result shows that the acceptance ratio of the client node can be maintained using the time-division access method as long as the interval access time is less than the coherence time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.1013-1019
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• 2016

This paper describes a novel Context-awareness Markov Chain Prediction (CMCP) algorithm based on movement prediction using Markov chain in Delay Tolerant Network (DTN). The existing prediction models require additional information such as a node's schedule and delivery predictability. However, network reliability is lowered when additional information is unknown. To solve this problem, we propose a CMCP model based on node behaviour movement that can predict the mobility without requiring additional information such as a node's schedule or connectivity between nodes in periodic interval node behavior. The main contribution of this paper is the definition of approximate speed and direction for prediction scheme. The prediction of node movement forwarding path is made by manipulating the transition probability matrix based on Markov chain models including buffer availability and given interval time. We present simulation results indicating that such a scheme can be beneficial effects that increased the delivery ratio and decreased the transmission delay time of predicting movement path of the node in DTN.

• Journal of Sleep Medicine
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• v.15 no.2
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• pp.68-73
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• 2018

Objectives: Periodic leg movements in sleep (PLMS) are associated with arousals and autonomic activation, which may contribute to higher cardiovascular disease risk in patients with restless legs syndrome (RLS). Non-periodic leg movements in sleep (NPLM) are leg jerks in sleep that does not satisfy standard criteria of PLMS. The aim of this study was to evaluate impact of short-interval leg movements in sleep (SILMS) and isolated leg movements in sleep (ILMS) in comparison to PLMS on heart rate in both patients with RLS and healthy controls. Methods: Seven idiopathic RLS patients and 9 controls were enrolled in this study. Polysomnographic studies were analyzed and leg movements (LM) were automatically detected. NPLM can be classified as SILMS and ILMS. SILMS are LM separated by an inter-movement interval (IMI) shorter than 10 s, and ILMS are LM with IMI longer than 90 s. Frequency and heart rate associated with SILMS, ILMS, and PLMS in RLS patients were compared to those in controls. Heart rate change associated with LM were determined for a fixed time window. Results: Frequencies of SILMS and ILMS of patients with RLS were not significantly different to those of controls. RLS patients presented higher heart rate change associated with SILMS than PLMS before movement onset, while heart rate change associated with SILMS, ILMS, and PLMS were not different in the controls. Conclusions: Although the number of SILMS is not higher than PLMS, SILMS may have closely associated with higher cardiac activation of RLS than PLMS. Therefore, SILMS might be an important treatment target for patients with RLS to reduce long-term cardiovascular risk. Long-term prospective studies are needed to evaluate the relationship between NPLM and cardiovascular disease in patients with RLS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.515-522
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• 2018

The purpose of this study was to determine the effect of gait training based on the way in a speed pattern on the respiratory function of general adults. A total of 37 people were divided into three groups to conduct fast, standard, and interval gait training. For gait training, a treadmill was used. Three groups were trained for 60 minutes, three times per week, for a period of 6 weeks. Inspiration pressure, maximum inspiration volume, and the size of diaphragm movement were measured. Repeated Measures ANOVA was used to compare times, groups, and interactions. For inspiratory pressure, maximum inspiration volume, and size changes in diaphragm movement, there were significant differences depending on the time and interaction between times and groups. For size changes in diaphragm's movement, there was a significant difference between interval gait training group and standard gait training group. Therefore, interval gait training had effects on size changes in diaphragm movement.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.493-501
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• 2016

Objective: This study analyzes the effect of angle conditions of rehabilitation equipment used for supporting hemiplegic patients on their rehabilitation training for standing action. The study was performed by adjusting the rear angle of seat inclination through a motion analysis. Background: Owing to a loss of muscle rigidity and degradation of muscle control ability, hemiplegic stroke patients suffer from asymmetrical posture, abnormal body balance, and degraded balance abilities due to poor weight-shifting capacity. The ability to shift and maintain one's weight is extremely essential for mobility, which plays an important role in our daily life. Thus, to improve patients' ability to maintain weight evenly and move normally, they need to undergo orthostatic and ambulatory training. Method: Using a motion analysis system, knee movements on both hemiplegic side and non-hemiplegic side were measured and analyzed in five angles ($0^{\circ}$, $10^{\circ}$, $30^{\circ}$, $50^{\circ}$, $70^{\circ}$) while supported by the sit-to-stand rehabilitation equipment. Results: The knee movements on both sides increased as the angle increased in angle support interval to support a hemiplegic patient's standing up position. In standing up interval, a hemiplegic patient's knee movement deviations on both sides decreased, and the movement differences between hemiplegic and non-hemiplegic legs also decreased as the angle increased. Conclusion: The results of this study showed that the rehabilitation effectiveness increases as the angle increases, leading to a balanced standing posture through the decrease of movement difference between hemiplegic and non-hemiplegic sides and an improved standing up ability through the increase of knee movement on both sides. However, angles higher than $50^{\circ}$ didn't provide a significant effect. Therefore, a support angle under $50^{\circ}$ was proposed in this study. Application: The results of this study are expected to be applicable to the design of sit-to-stand support equipment to improve the effectiveness of the rehabilitation process of hemiplegic patients.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.86-91
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• 2001

In lateral ground flow, slope stability, and land slide problems, H-piles have been often used for a horizontally deforming ground to prevent the failure of mass of soil in a downward and outward movement of a slope. Here, Theoretical equations are derived to estimate the lateral force, assuming that the Mohr-coulomb's Plastic states occures in the ground just around H-piles. In this study, the mechanism of lateral force acting on passive pile that is in a row, situated in the ground undergoing plastic deformation was discussed, and its theoretical analysis was carried out considering the interval between H-piles. The solution of the theoretical equation derived from here showed resonable characteristic for constants of soil as well as for the interval, widths, and heights of H-pile.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.111-124
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• 2011

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight by opening/closing of a blind. In previous researches on blind controls, major problem is that the time interval and amount of blind movement do not meet the control objective at the inflected zone of solar profile curve. To overcome these limitations revealed in theprevious researches, following tasks were performed in this study. i)To establish the control objective to accomplish the goal of this study. ii)To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various solar profile angle curves. This study proposed the control strategy and method that define the base control section implying the inflection point within the control objective zone and subsequently, divide the control sections for the residual time zones. The proposed strategy and method are found to increase the incoming daylight and solar irradiation by 0 to 15 %.

• Korean Institute of Interior Design Journal
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• v.26 no.1
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• pp.63-74
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• 2017

This study is for the characteristic of expression of exhibition presentation in 'The Korean peninsula' which is the Golden Lion Winner at the Venice Biennale in 2014. The Korean peninsula provides two opposite political and economic systems and adaptations of modernism through various multi media images. The curator, Minsuk Cho, presented cinema montage image of Collision for analyzing dynamic exhibition organization and provides the foundation of his theory from Bergson's image and duration to Deleuze's movement-image and time-image which is mentioned from Deleuze's book "cinema 1" and "cinema 2". Furthermore, the Korean peninsula has showed perception-image and affection-image from Eisenstein & Vertov's cinemathology and systemized exhibition presentation. The montage of Collision has maximized the movement from the variety and complexity in a collision and it made difference between information images which are space, time, emotion, intelligence, the tumult between subjectivity and objectivity, fragments from reorganizing itself, and distribution and art images. The limit of montage of Collision's dialectic is not only visual but also space from organic organization but the Korean peninsula overcomes its limit and shows leap of tactile perception and time-reflection from the montage of Collision's dialectic. Therefore, the exhibition of the Korean peninsula presents the conviction of adaptations of modernism.