• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.85.2-86
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• 2015

The YORP effect is non-gravitational force that changes the spin-status of asteroid. So far this effect has been directly detected only from the Near-Earth asteroids (Taylor et al. 2007; Lowry et al. 2007, 2014; Breiter et al. 2011; Durech et al. 2008, 2012). Pravec at el. 2008 found the evidences for changing spin rate of small asteroids (3 - 15 km) by the YORP effect in the Main-Belt and Mars-crossing asteroids. The Mars-crossing asteroids (1.3 < q < 1.66 AU) are objects that cross orbit of the Mars. The Mars-crossing asteroids are regarded as one of the main sources for the Near-Earth asteroids. We expect that rotation of Mars-crossing asteroids would be influenced by the YORP effect. We try to search observational evidence of the YORP effect for the Mars-crossing asteroid. Our target 2078 Nanking is a population of the Mars-crossing asteroid. First light-curve of 2078 Nanking was obtained from Mohamed et al. 1994, and Warner et al. 2015 recently published new observational data. We observed this asteroid on 26th Nov. 2014 and 17th Jan. 2015 using SOAO (Sobaeksan Optical Astronomy Observatory) 0.61 m telescope with 4K CCD. Using light-curve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we try to determine the pole orientation and shape model of this asteroid based on the combination of our light-curve and literature photometric data. Knowing spin parameters, such as rotational period and spin axis, are essential for studying the YORP effect. In this presentation, we provide some preliminary results of our recent study: light-curve and processing of shape modeling of 2078 Nanking. We plan to find observational clue for the YORP effect on the Mars-crossing asteroids.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.244-255
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• 1998

The purpose of this study was to verify the reliability and validity of the Rosenbaum self-control schedule (SCS) for assessing resourcefulness in Korea and to explore the simplified scale. The study subjects consisted of 787 adults in a community. The data was collected during the period from Oct. to Dec., 1995 and analyzed as Cronbach α, item correlation with total, Pearson correlation and factor analysis with varimax rotation using SAS. Results were as follows : The mean SCS score for this sample was 17.2 and there were statistical differences for gender(men, 13.1 ; women, 20.0) on the SCS scores. The cronbachα of SCS with 36 items was .74 and when simplified with 30 items, it's coefficient alpha was .78. The translated content of the SCS was validated by two nursing faculty members and one professor of psychology. Factor analysis revealed the most parsimonious structure was obtained when six factors were extracted and subsequently rotated via the varimax criterion. There was 40.2% of total communality variance in the SCS with 36 items. The total communality variance was slightly increased to 43.4% with 30 items of the SCS. In order to reduce from 36 items to 30 items, the process excepted 6 items having low item correlation with total and low MSA(means of sampling adequacy) of factor analysis. According to factor analysis, there are six factors such as emotion control, impulse control, self-efficacy, coping with problems, pain control and satisfaction control, The SCS was found to have low, but statistically significant, correlations with social desirability and helplessness. From the above results, it can be concluded that the reliability of the SCS(inherent and simplified) was a acceptable level and its validity was reasonable when comparing it with other validity studies. To determine the usefulness the simplified scale, further study is necessary to simultaneously compare and analyze both scales for stability.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.4
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• pp.53-63
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• 2007

Seismic design codes are developed mainly based on the observation of the behavior of structures in the high seismicity regions where structures may experience significant amount of inelastic deformations and major earthquakes may result in structural damages in a vast area. Therefore, seismic loads are reduced in current design codes for building structures using response modification factors which depend on the ductility capacity and overstrength of a structural system. However, structures in low seismicity regions, subjected to a minor earthquake, will behave almost elastically because of the larger overstrength of structures in low seismicity regions such as Korea. Structures in low seismicity regions may have longer periods since they are designed to smaller seismic loads and main target of design will be minor or moderate earthquakes occurring nearby. Ground accelerations recorded at stations near the epicenter may have somewhat different response spectra from those of distant station records. Therefore, it is necessary to verify if the seismic design methods based on high seismicity would he applicable to low seismicity regions. In this study, the adequacy of design spectra, period estimation and response modification factors are discussed for the seismic design in low seismicity regions. The response modification factors are verified based on the ductility and overstrength of building structures estimated from the farce-displacement relationship. For the same response modification factor, the ductility demand in low seismicity regions may be smaller than that of high seismicity regions because the overstrength of structures may be larger in low seismicity regions. The ductility demands in example structures designed to UBC97 for high, moderate and low seismicity regions were compared. Demands of plastic rotation in connections were much lower in low seismicity regions compared to those of high seismicity regions when the structures are designed with the same response modification factor. Therefore, in low seismicity regions, it would be not required to use connection details with large ductility capacity even for structures designed with a large response modification factor.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.419-426
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• 2017

This paper describes an acoustic echo canceller with double-talk using BSS(: Blind Signal Separation) based on the geometric concept. The acoustic echo canceller may be deteriorated or diverged during the double-talk period. So we use the blind signal separation to detect the double talking by separating the near-end speech signal from the mixed microphone signal. In the closed reverberation environment, the blind signal separation extracts the near-end signal from unknown signals with the transformation and rotation based on the geometric concept. By this method, the acoustic echo canceller operates irrespective of double-talking. We verified performances of the proposed acoustic echo canceller by computer simulations. The results show that the acoustic echo canceller with this algorithm detects the double-talk periods thoroughly, and operates stably in the normal state without diverging of coefficients after ending the double-talking.

• The Journal of Korean Physical Therapy
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• v.29 no.4
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• pp.223-226
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• 2017

Purpose: This study examined two trunk strategies - medio-lateral ramp and anterior-posterior ram - and their effects on pelvis and trunk movements, providing basic material for safe ramp utilization. Methods: The present study included 20 asymptomatic males recruited from a local university. Participants were asked to stand with their feet shoulder-width apart. Their dorsal side faced the camera, and measurements were performed while standing in a neutral double stance, one leg stance, $15^{\circ}$ of medial and lateral ramp, and $15^{\circ}$ of anterior and posterior ramp. Participants were allowed to practice for 3 minutes, and each participant had a 30 seconds rest between the two ramp conditions. One-way repeated measures analysis of variance was used to determine the effects the ramp conditions on spinal alignment. In all analyses, p<0.05 was used to indicate statistical significance. Results: The trunk-inclination angle on the posterior ramp was significantly lower than that of the double stance position (p<0.05). The trunk imbalance angle was significantly higher on the medial ramp, than that on the double stance position (p<0.05). The pelvic position and pelvic torsion angles were significantly higher in the medial, lateral, and anterior ramp positions than that of the double stance position (p<0.05). The pelvic rotation angles on the medial, lateral, and anterior ramps were significantly lower than that of the double stance position (p<0.05). Conclusion: These findings suggest that when people are exposed to the same form of ramp for an extended period, posture modifications may be triggered.

• Clinics in Shoulder and Elbow
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• v.18 no.4
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• pp.242-247
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• 2015

Background: The size of the baseplate used in reverse total shoulder arthroplasty (RTSA) tends to be larger than the average size of the glenoid in the Korean population. The mismatch between the sizes of the baseplate and the patient's glenoid may result in improper fixation of the glenoid baseplate. This in turn may lead to the premature loosening of the glenoid component. Thus, we evaluated the short-term results of using a 25-mm baseplate in RTSA. Methods: Seventeen patients with cuff tear arthropathy underwent RTSA with a 25-mm baseplate. The mean age of the patients was 70.1 years, and the mean follow-up period was 14.0 months. We evaluated clinical outcomes preoperatively and postoperatively: the range of shoulder motion, the American Shoulder and Elbow Surgeons (ASES) score, and the Korean Shoulder Society (KSS) score. Results: We found that the mean ASES score and KSS improved from 35.0 to 74.4 (p<0.001) and from 46.9 to 71.8 (p<0.001) with RTSA. The mean forward elevation and abduction, external rotation also improved from $78.6^{\circ}$ to $134.3^{\circ}$ (p<0.05) and from $66.6^{\circ}$ to $125.0^{\circ}$ (p<0.05), from $20.2^{\circ}$ to $28.4^{\circ}$ (p=0.43). Postoperative complications were seen in 12% of patients, but neither the loosening of the glenoid baseplate nor inferior scapular notching were observed. Conclusions: In sum, the results of using a 25-mm baseplate in RTSA were similar to those of previous reports. Even though the outcomes are those of a short-term follow-up, neither the loosening of the glenoid baseplate nor the scapular notching were observed.

• Development and Reproduction
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• v.7 no.1
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• pp.1-7
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• 2003

Most animals, including human beings, live in a cyclic pattern of lift that is influenced by the ambient changes of environment. The regular changes occurred by rotation of the Earth itself its revolving around the Sun, and the local environment, are reflected by the distinct behavior in the living organisms. These regular changes of environment have been imprinted into the genes within the living organisms through the evolutionary process over a long period of time. The genes are expressed by rhythms during the process of fetal development followed by growth. The environmental modifications ultimately are settled in genes, serving as a biological clock that is located putatively in the hypothalamus. Thus the biological clock governs a large number of rhythms and affects the time of birth and death lift expectancy, behavior, physiology, cell division, biochemical reaction, etc. The rhythms are readjusted to the changes of environmental cues. The biological clock has the great advantage of predicting and preparing the regular changes of environment.

• Journal of the Korean Home Economics Association
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• v.47 no.9
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• pp.15-26
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• 2009

The main purpose of this study was to speculate how psychological state of adolescent students has changed their school uniform style. For the study, the distinctive characteristics during adolescence stage were theoretically examined. Through the examination, this study found four interests in fashions and school uniforms. For the purpose, this study conducted interviews with grade 2 students in a total of six coeducation secondary schools in Seoul, Gyeongki and Gwangju using a questionnaire. The survey period ranged from December 15 2008 to December 24 2008 and a total of 1196 were used for a final analysis. This study extracted factors as Principal Components Analysis and used Varimax for orthogonal rotation analysis. To measure confidence, it used Cronbach's a test to item internal consistency. For data analysis, it used SPSS WIN 12.0 and for hypothesis analysis, frequency analysis, cross analysis, independent t-test, and one-way ANOVA were conducted. For posterior analysis, it used Sheffe test. The results are as follows: First, the interests in fashion and school uniforms differed depending on their own tastes, but these interests were more influenced by environment around school. Secondly, the boy subjects were more aggressive towards repairs their uniforms than the girls, which suggested that boys had stronger desire to show themselves to others and more satisfaction from repairs their uniforms than the girls. Based on the results, this study concluded as follows: We should pay attention to preventing deformation in original design of school uniforms while expanding options to have variable designs or to change detailed part of design. So, there will be no additional uniform mending expense and financial loss to parents, and students will be more satisfied with their school uniforms.

• Journal of Korean Foot and Ankle Society
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• v.15 no.1
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• pp.13-17
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• 2011

Purpose: To evaluate the clinical results of anteroinferior tibiofibular ligament avulsion fracture accompanied ankle fractures treated with anatomical reduction and internal fixation. Materials and Methods: From January 2007 to April 2010, 30 cases with anteroinferior tibiofibular ligament avulsion fracture that treated with anatomical reduction and internal fixation were analyzed. The average follow-up period was 26 months (minimum 6 months). We have reviewed the bony union, complication and subjective satisfaction according to the fracture classification and method of internal fixation. Results: Among 30 cases, 28 cases were occurred in Lauge-Hansen classification supination-external rotation type, one case was fracture-dislocation and one case was Maisonneuve fracture. We have performed internal fixation with Mini screw in 11 cases, K-wire in 10 cases, repair in six cases and Mini screw & K-wire in three cases. In all cases bony union was completed. two cases in Mini screw, one case in K-wire, two cases in repair and one case in Mini screw & K-wire revealed LOM of ankle joint. Skin irritation and superficial peroneal nerve irritation happened in one case each. Other cases show good subjective satisfaction. Conclusion: Anteroinferior tibiofibular ligament avulsion fracture accompanied with ankle fracture is a good clinical outcome with internal fixation. So we should not miss out the anteroinferior tibiofibular ligament avulsion fracture in radiologic evaluation or operation room.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.26.3-27
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• 2011

Formation of a steep plasma density gradient in the middle-latitude ionosphere during geomagnetic storms and the latitudinal migration of its location depending on the storm phase are suggested to be associated with the ionospheric signature of the plasmapause. We test this idea by using the satellite and ground observation data during the 11 April 2001 storm. The locations of the steep plasma density gradient identified by TOPEX/Poseidon (2001 LT) and DMSP (1800 and 2130 LT) satellites coincide with the ionospheric footprints of the plasmapause identified by the IMAGE satellite. This observation may support the dependence of the middle-latitude plasma density gradient location on the plasmapause motion, but does not explain why the steep density gradient whose morphology is largely different from the morphology of the middle-latitude ionization trough during quiet period is formed in association with the plasmapause. The ionospheric disturbances in the total electron content (TEC) maps shows that the steep TEC gradient is formed at the boundary of the positive ionospheric storm in low-middle latitudes and the negative ionospheric storm in middle-high latitudes. We interpret that the thermospheric neutral composition disturbance in the dayside is confined within the middle-high latitude ionospheric convection zone. The neutral composition latitudes and, therefore, the locations of the steep plasma density gradient coincide with the footprints of the plasmapause. The TEC maps show that the appearance of the steep plasma density gradient in the pre-midnight sector during the recovery phase is related to the co-rotation of the gradient that is created during the main phase.