• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.218-230
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• 1999

Background: Craniofacial anatomic abnormalities related to structural narrowing of the upper airway have been reported in patients with obstructive sleep apnea syndrome. In this study, we evaluated the craniofacial anatomic characteristics of Korean patients with obstructive sleep apnea syndrome, and the role of cephalometric analysis in the prediction of abnormal breathing during sleep. Methods: Thirty-nine patients with obstructive sleep apnea syndrome(OSAS), 39 simple snorers(simple snorers) and 20 controls(control) had cephalometric analysis using the technique of Riley et al, and underwent standardized polysomnographic recordings. Different variables, including sex, body mass index, cephalometric and polysomnographic data, were statistically analyzed. Results: Pm-UPW and V-LPW distances were significantly shorter in OSAS when compared with simple snorers or control. PAS in simple snorers was shorter than in control. ANS-Gn distance in OSAS was significantly longer than in control. PNS-P distance in OSAS or simple snorers was significantly longer than in control. MP-H distance in OSAS was significantly longer than in simple snorers or control and MP-H distance in simple snorers was also longer than in control. NL/Pm-P angle in OSAS was lesser than in control. MP-H distance in OSAS or in the combined groups of OSAS and simple snorers was significantly correlated with apneahypopnea index(AHI). PNS-P distance in the combined groups of OSAS and simple snorers was correlated with AHI. In male of all subjects, body mass index was significantly correlated with PNS-P or MP-H distance. Conclusion: Cephalometric analysis can be useful tool in determining the craniofacial anatomic abnormalities in patients with obstructive sleep apnea syndrome. Cephalometric parameters, especially MP-H distance, can be useful for predicting frequency of narrowing or obstruction of upper airway during sleep.

• The Journal of Korean Physical Therapy
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• v.29 no.5
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• pp.281-286
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• 2017

Purpose: The purpose of this study was to examine the correlations among the resting physical factors related to a six-minute walk test (6MWT) and to determine the effects of the resting physical factors on the distance and intensity related to the 6MWT in healthy female subjects. Methods: A total of 43 healthy female subjects ($22.84{\pm}3.90yrs$) participated in this study. They performed the 6MWT, and the physical factors related to the 6MWT were assessed. SPSS 20.0 was used to analyze the data, and the mean and standard deviation were calculated, and the collected data were analyzed by the Pearson's correlation coefficient (among physical factors related to 6MWT) and independent t-test (between six-minute walk distance [6MWD] groups and six-minute walk intensity [6MWI] groups). Results: The 6MWD had a significant negative correlation with the resting HR (beat/min) in healthy female subjects (r=-0.49, p<0.05). The 6MWI had a significant negative correlation with the resting systolic blood pressure (SBP) (r=-0.45, p<0.01). A comparison of the 6MWD revealed the long distance group (LDG, 700-799 m) to be significantly higher than the middle distance group (MDG, 600-699 m) in the 6MWI (%), %predicted distance (%), predicted VO2max (mL/kg/min), resting HR (beat/min), and resting SBP (mmHg)(p<0.05). In the comparison of 6MWI, the moderate intensity group (MIG, 64-75%HRmax) was significantly lower than the low intensity group (LIG, 50-63%HRmax) in the resting SBP (mmHg) (p<0.05). Conclusion: These results suggest that the resting physical factors are related to the 6MWD and 6MWI of the 6MWT in healthy females. In particular, SBP is associated with not only the 6MWD but also the 6MWI in 6MWT.

• East Asian mathematical journal
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• v.16 no.2
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• pp.169-174
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• 2000

We give an easy proof that ${\phi}(z)=\frac{z^2_1}{1-z^2_2}$ induces the bounded composition operator $C_{\phi}:\mathcal{B}{\rightarrow}{\bigcap}H^p(B_2)$ defined by $C_{\phi}f=f\;o\;{\phi}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1621-1630
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• 2009

There is a lot of recent research to provide services of dynamic distributed contents in P2P-based distributed environment. Distributed services of contents objects, however, have problems in QoS and dynamic management of segments. This paper proposed a new segment management method for the service of P2P-based distributed contents. The proposed method manages groups by the SGM(Segment Group Manager). The SGM manages streaming efficiently by the grouping of segments to be served in P2P environment. The segments in the same group cooperate for improved QoS using the management structure based on the distance and relationship. The distance-based management structure is for the improvement of retrieval efficiency while the relationship-based management structure is for the improvement of service ratio. The simulation results of the proposed method showed improvements in average transmission efficiency and average service rate. The improvement is 8% - 30% in average transmission efficiency and 10% - 30% in average service rate.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.149-155
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• 2015

Purpose : Recently, many researchers and golf coachers demonstrated that X-factor and X-factor stretch had a co-relationship with driving distance. However, its relationship is still controversial and ambiguous. Thus, the aim of this study was to examine the relationship among X-factor, X-factor stretch and swing-related factors, including driving distance in elite golfers. Method : Seventeen male elite golfers (handicap: ${\leq}4$) with no history of musculo-skeletal injuries participated in the study. Thirty spherical retro-reflective markers were placed on including the middle point of PSIS, the right/left ASIS, the right/left lateral acromion of the scapula, driver head and shaft grip. All motion capture data was collected at 100Hz using 6 infrared cameras. Carry distance, club speed, ball speed, smash factor, launch angle, and spin rate were collected from radar-based device, TrackMan. Results : Pearson's correlation coefficient method was used to find the correlations among X-factor, X-factor stretch and swing-related factors. Positive correlations between driving distance and other swing-related factors which include club speed(r=.798, p<.001), and ball speed(r=.948, p<.001) were observed. In contrast to the swing-related factors, X-factor and X-factor stretch had no relationship to driving distance. Conclusion : These results indicate that X-factor and X-factor stretch are not key regulators in driving distance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9C
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• pp.846-852
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• 2006

The ${\kappa}$-error linear complexity is a ky measure of the stability of the sequences used in the areas of communication systems, stream ciphers in cryptology and so on. This paper introduces an efficient algorithm to determine the ${\kappa}$-error linear complexity and the corresponding error vectors of $p^m$-periodic binary sequences, where : is a prime and 2 is a primitive root modulo $p^2$. We also give a new sense about the ${\kappa}$-error linear complexity in viewpoint of coding theory instead of cryptographic results. We present an efficient algorithm for decoding binary cyclic codes of length $p^m$ and derive key properties of the minimum distance of these codes.

• Korean Journal of Plant Resources
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• v.25 no.3
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• pp.308-316
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• 2012

The purpose of this study was to identify the variant of Platanus occidentalis, whose bark looks white, also can be classified as P. occidentalis and to examine its genetic difference from the general P. occidentalis. For the variant identification of P. occidentalis, SNP and ISSR analysis were used in this study. Thirteen samples of P. occidentalis white variant were collected in Cheongju and 24 samples of normal P. occidentalis obtained in Cheongju, Pyongtaek, Ansan, Suwon, Osan and Jincheon area. ITS 1 and ITS 2 sequences of white variants were identical with those of P. occidentalis. We could not find any sequence difference between normal and white P. occidentalis. So we concluded that the white variant belongs to normal P. occidentalis even their bark is white and peeled easily. By ISSR test, 98 amplicons were acquired using 10 primers. P. occidentalis and white P. occidentalis showed different band patterns from the UBC #834. According to the result of Nei (1979)'s genetic distance analysis, the members of white P. occidentalis were grouped more tightly than the members of normal P. occidentalis. The UPGMA dendrogram shows that the variant and P. occidentalis divided widely into two groups. These results show that the phenotype of P. occidentalis white variant is caused by genetic factors rather than by environmental factors.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.89-96
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• 2017

This study developed a method which recognizes emotional interactions from the social distance by a beacon wearable device. The recognized interaction was evaluated by comparing with the cardiovascular synchrony from photoplethysmogram (PPG). The interaction was recognized when social distance was maintained for a certain period of time. The cardiovascular synchrony was estimated by correlation anaysis between beat per minute (BPM) from PPG. The maintenance time was determined by Mann-Whitney U test between the cardiovascular synchrony of interaction and non-interaction groups. Fifteen groups (2 persons per a group) participated in the experiment and they were asked to wear the beacon and PPG wearable devices in daily life. Experimental results showed that the interaction groups had more higher cardiovascular synchrony than non-interaction groups and the significant interaction time was determined to be 11 seconds (p=.045). Consequently, the real-time measurement and evaluation of the social network in real space was expected to be improved.

• The Korean Journal of Emergency Medical Services
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• v.18 no.1
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• pp.7-15
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• 2014

Purpose: The purpose of the study is to evaluate the distance and location of the rescuer to patient for the effective chest compressions qualities. Methods: The subjects were 42 students who earned the basic lifesaving technique and had informed consents to participate in the study from May 1 to 20 in 2013. The position of the rescuers included model-0(reference point), model-1(10 cm distance), model-2(20 cm distance), and model-kn(kneeling up). Results: The mean depth of compression was $50.6{\pm}6.6mm$ in Model-0, $48.7{\pm}8.2mm$ in Model-1, $44.2{\pm}10.4mm$ in Model-2, and $51.8{\pm}6.0mm$ in Model-kn. There were statistically significant differences between each Model(p<.001). Conclusion: The closer distance between rescuer and patient could provide more effective chest compressions. Kneeling on the bed stance provided the deeper chest compression consistently than the stool stance.