• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.38.3-39
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• 2010

While major solar proton events (SPEs) come from the coronal mass eject (CME)-driven shocks in solar wind, there are many evidences that potentiality of CMEs to generate SPEs depends on its early evolution near the Sun and on different solar activities observed around the CME liftoff time. To decipher origin of SPE release, we have investigated onset time comparison of the SPE with CME, metric type II radio burst, and hard X-ray flare. For this, we select 30 SPEs observed from 1997 to 2006 by using the particle instrument ERNE onboard SOHO, which allows proton flux anisotropy measurement in the energy range ~10 - 50MeV. Onset time of the SPEs is inferred by considering the energy-dependent proton transport time. As results, we found that (1) SPE onset time is comparable to that of type II but later than type III onset time and HXR start time, (2) SPE onset time is mostly later than the peak time of HXR flare, (3) almost half of the SPE onsets occurred after the HXR emission, and (4) there are two groups of CME height at the onset time of SPE; one is the height below 5 Rs (low corona) and the other is above 5Rs (high corona). In this talk, we will present the onset time comparison and discuss about the origin of the SPE onset.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.1
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• pp.19-26
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• 2019

Purpose : The aim of this study was to investigate the effects of the abdominal draw-in (ADI) exercise on the onset times of the gluteus maximus (GM) and erector spinae (ES) as well as the pelvic anterior tilt angle during prone hip extension (PHE). Methods : A total of 24 female adults were divided into two groups: those with normal abdominal muscles (n=12) and those with weak abdominal muscles (WAM; n=12). Before the intervention, the onset times of the GM and ES along with the pelvic angle during PHE were measured. Subsequently, the participants conducted the ADI exercise for 10 minutes. After conducting the ADI exercise, the onset times and the pelvic angle were re-measured. Results : In the pre-intervention comparison between the two groups, the WAM group showed faster ES onset times and higher pelvic angle than the normal group (p<0.05). In the WAM group, the ES onset times were significantly delayed after the ADI exercise (p<0.05). In both groups, the pelvic angle was significantly decreased after the ADI exercise (p<0.05). The decrease in the pelvic angle was significantly greater in the WAM group than in the normal group (p<0.05). The GM onset time was found to be not significant in all comparisons (p>0.05). Conclusion : Therefore, it can be concluded that after performing the ADI exercise, the pelvic anterior tilt during PHE is decreased in normal women and those with WAM, especially in the WAM group, suggesting that the ADI exercise can reduce the compensatory pelvic anterior tilt more effectively by delaying the ES onset times.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.1
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• pp.81-88
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• 2019

Purpose : The purpose of this study was to examine if there is any correlation between pelvic tilt angle and trunk motion and trunk extensor during trunk forward flexion and to measure trunk motion, onset time of trunk motion, and onset time of trunk extensor activation. Methods : The subjects of this study were 42 healthy adults. The subjects had no back pain due to neurological disease and no experience of back surgery. After pelvic tilt angle was measured, each trunk forward flexion was performed three times. Trunk motion and onset time of trunk motion were measured using Myomotion. Four sensors were used, with one located at the upper thoracic (below $C_7$), the lower thoracic ($T_{12}-L_1$), the sacrum ($S_1$), and at the center of the anterior femur. Onset time of trunk extensors (spinalis, longissimus, gluteus medius, gluteus maximus, biceps femoris, and gastrocnemius) activation was measured using a wireless surface EMG. The EMG amplitude was normalized by using the reference voluntary contraction (RVC). The statistical significance of the results were evaluated using Pearson's correlation test. Results : The correlation between pelvic tilt angle and lumbar motion, onset time of pelvis motion, and onset time of gluteus medius activation was statistically significant in a positive direction (p<.05). The correlation between pelvic tilt angle with pelvis motion, onset time of lumbar motion, and onset time of longissimus activation showed a statistically significant negative correlation (p<.05). Conclusion : The study results provide a significant contribution to our understanding of the lumbar load at the initial stage of trunk flexion. Therefore, it may be possible to provide basic data for evaluation and treatment, such as orthodontic treatment for alignment of the spine and back pain. In addition, it is necessary to focus on normal exercise pattern reeducation as well as pelvic correction during exercise in daily life or in industrial fields.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.153-159
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• 2008

The timing of the canopy phenology onset (CPO hereafter) indicates the initiation of the growing season, with rapid increases in exchange rates of carbon dioxide and water vapor between vegetation and atmosphere. The CPO is regarded as a potential indicator of ecosystem responses to global warming, but the CPO shows considerable spatial variation depending on the species composition and local temperature regime. at a given geographic location. In this study, we evaluated the utility of satellite observation data for detection of the timing of the CPO. Leaf area indices (LAI) obtained from the Moderate Resolution Imaging Spectrora-diometer (MODIS) were utilized to detect and map the onset dates from 2001 to 2006. The reliability of MODIS-based onset dates was evaluated with ground measured cherry blossom flowering data from national weather stations. The MODIS onset dates preceded the observed flowering dates by 8 days and were linearly related with a correlation coefficient of 0.58 (p < 0.05). In spite of the coarse spatial (1 km) and temporal (8 days) resolutions of MODIS LAI, the MODIS-based onset dates showed reasonable ability to predict flowering dates.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.295-301
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• 2020

Purpose: The purpose of this study was to compare the electromyographic activity and onset time of the gluteus maximus (GM) and hamstring (HAM), lumbopelvic kinematics during three different prone table hip extension exercises in healthy individuals. Methods: Twenty subjects were participated. Electromyography device was used to measure the muscle activities and onset time of the GM and HAM muscles. An electromagnetic tracking motion device was used to measure lumbopelvic compensations. The subjects were asked to perform three different prone table hip extension [Prone table hip extension with the abdominal drawing-in maneuver on a chair (PTHEA), PTHEA with the ipsilateral knee flexion (PTHEAF), PTHEAF with hip 30 abduction (PTHEAFA)]. One-way repeated measures analysis of the variance and a Bonferroni post hoc test were used. Results: The electromyographic activity and onset time were significantly different among three conditions (PTHEA vs. PTHEAF vs. PTHEAFA)(p<0.01). The GM muscle activity and onset time were significantly greater and reduced during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). However, The HAM muscle activity and onset time were significantly smaller and delayed during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). Conclusions: PTHEAFA exercise can be recommended to facilitate the muscle activity and efficient muscle firing time of GM without HAM dominance.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.757-772
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• 2003

We simulate the geographical effects on the onset time of sea breeze at Suyoung and Haeundae districts by using the LCM (Local Circulation Model). The following can be found out from the numerical simulation on Case I (real terrain) which considered the real geography of Busan metropolitan area. Especially, as a result of analyzing the land breeze path, it could be found along the coastline as it flows out through low land coastal area. To find out more about the effects of terrain and geography on the onset time of sea breeze, the results of numerical simulation of virtual geography are as follows. In Case II (flat terrain), to find out how the terrain slope affects the onset of sea breeze, flat land and the ocean was considered. As a result, convergence of nighttime air mass at a Suyoung area and nighttime strong wind speed phenomenon was not shown. In Case III (modified flat terrain), to find out the effects of the irregularity of coastline affecting the onset of sea breeze, numerical simulation was carried out by simplifying the complex coastline into segments of straight coastline. So land breeze system and changing process of sea breeze after sunrise at Suyoung and Haeundae was simulated almost in a similar manner. Through this we could find the effects of coastal irregularities on onset of sea breeze.

• Physical Therapy Korea
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• v.14 no.2
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• pp.68-75
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• 2007

Reductions in strength and range of motion in older persons have been associated with decreased functional mobility and risk of falls. The purpose of this research was to investigate the effect of intensive dynamic balance exercise (DBE) during 8 weeks on onset time of medial gastrocnemius and tibialis anterior muscle contraction after perturbation in older women. Thirty subjects were randomly assigned into DBE group or control group. The DBE group participated in 50 minutes 3 days a week for 8 weeks. Surface electromyography (EMG) activity was recorded from the medial gastrocnemius and tibialis anterior muscles of left side. Outcome data were collected both groups at the pre-exercise and post-exercise. Independent t-test and paired t-test were used to determine the statistical difference. Results showed that the passive range of motion and functional reach test were significantly increased in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles and discrepancy of onset time significantly reduced in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles were significantly reduced in the post-exercise than the pre-exercise in the DBE group (p<.05). The discrepancy of onset time in the DBE group was significantly reduced in the post-exercise than the pre-exercise (p<.05). These findings suggest that intensive dynamic balance exercise for the eight weeks was effective in improving the postural control with older persons.

• PNF and Movement
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• v.20 no.3
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• pp.331-340
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• 2022

Purpose: Thisstudy aimed to identify the effect of varying the expansibility of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. Methods: Forty-five young adults with forward head posture syndrome volunteered to participate and were randomly assigned to one of three groups according to the expansibility of the elastic tape (25%, 50%, 75%). The onset time of muscle contraction for the neck extensor during neck extension was measured using an electromyographic system (Free EMG, BTS, Italy). Multivariate analysis of variance was employed to determine the effect of different expansibilities of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. When there was a statistically significant difference by MANOVA, Scheffe was used as a post-hoc test. The level of significance was set at α=0.05. Results: In the comparison of the onset time of muscle contraction of varying elastic tape expansibilities and measurement times, there was a significant difference between the groups (Lt. UT, Lt. SCM, Rt. SCM) (p < 0.05), but there was no significant difference in the interaction between the measurement time and the group, between the measurement time (p > 0.05). Conclusion: In the neck extension, 75% of the tape extensibility in the Lt. UT and both SCM shortened the muscle contraction onset time.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.762-765
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• 2010

특정 시간에 동시 연주된 다수 음원의 onset 을 검출하기 위해서는 음원 분리 문제가 선결되어야 한다. 특히, 드럼과 같은 조음(?音) 악기 신호 검출 문제를 해결하기 위해서는 음원 분리 방법의 성능이 중요하다. 이에 본 연구에서는 효과적인 음원 분리 방법으로 알려진 확률적 은닉 성분 분석(PLCA) 방법에 기반한 주요 악기 신호의 onset 검출 방법을 제안한다. 효과적인 onset 검출을 위해, 첫째, 확률적 은닉 성분 분석으로 훈련 된 비음수 주파수 성분 중 최적의 성분을 선택하는 방법을 적용하고, 둘째, 드럼 악기 신호의 정확한 onset 검출을 위해 고안된 비음수 시계열 신호 threshold 방법을 적용한다. 실험에서는 제시된 방법을 이용하여 드럼의 주요 악기 신호 onset 검출 성능이 향상됨을 보인다.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.771-774
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• 1999

This study was carried out to quantitatively investigate the amount of corrosion at the time of onset of cracks in cover concrete due to rebar corrosion. In this experiments, the accelerated galvanostatic corrosion method was carried out. FEM analyses were also conducted to investigate the expansive behaviors due to rebar corrosion and the mechanical properties of corrosion products. As a result, it was concluded that the corrosion ratio at the time of onset of cracks in cover concrete was 3% by weight. The onset of cracks in cover concrete due to rebar corrosion could be analyzed by the finite element method.