• Physical Therapy Korea
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• v.23 no.1
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• pp.80-86
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• 2016

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

• The Journal of Korean Physical Therapy
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• v.18 no.4
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• pp.51-60
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• 2006

Purpose: This study was to compare the effect of center of pressure(COP) displacement and muscle activation onset during expected and unexpected sudden limb loading in subjects with low back pain and healthy control subjects. Most studies of COP displacement and muscle activation onset on postural task focused on sudden trunk loading or gross limb movements. Investigation of the COP displacement and muscle activation onset during expected and unexpected sudden upper limb loading deserves similar attention. Methods: For this study, 14 subjects with low back pain and 12 healthy control subjects are participated. Force plate and surface EMG measures were used to determine COP displacement and muscle activation onset under expected and unexpected sudden upper limb loading. Results: COP displacement and muscle activation onset under unexpected sudden upper limb loading were similar in subjects with low back pain and healthy control subjects. However, COP displacement and muscle activation onset under expected sudden upper limb loading were shortened in healthy control subject but not among the subjects with low back pain. Conclusion: The results provide evidence for impaired feed-forward control in subjects with low back pain.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.223-229
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• 2017

When concrete is exposed to neutron rays for a long time, the concrete tends to become activated. If activated, it is classified as middle or low level radioactive waste. However, the great amount of the activated concrete is hard to dispose. In this study, low-activation cement was developed for decreasing the activated waste from shielding concrete around nuclear reactor. Furthermore, the manufactured low-activation was analyzed with activation nuclide Eu, Co. The low-activation cement showed great advantage for low-activation with detecting none of Eu and 3.75ppm of Co while ordinary portland cement showed 0.4~0.9ppm of Eu, 5.5~19.8ppm of Co content. As the results of physical properties of the low-activation cement, it is similar to type 1 ordinary portland cement and accords with type 4 low heat portland cement. Meanwhile, as for the chemical properties of the cement, it accords wite type 1 and 4 at the same time.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.323-330
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• 2010

Purpose : The purpose of this study was to evaluate the effects of muscle activation of neck, lumbar and low limb by using baby carrier with arms during walking. Methods : Twenty healthy and young females who brought up infants and had no musculoskeletal disorders of neck, lumbar and low limb were recruited for this study. They were instructed to perform muscle activation of neck, lumbar and low limb using the baby carrier with and without arms during walking. ProComp $infiniti^{TM}$ (Thought Technology Ltd., Canada) was used to measure the muscle activity of neck, lumbar and lower extremity muscles. Results : Activation of neck paraspinalis muscle was significantly increased using baby carrier with arms and there was a significant increase on erector spinae muscle activation by using anterior baby carrier. Conclusion : These results indicate that the muscle activation was changed by arms assist and the position of using baby carrier. Therefore, it could be considered relationship of muscle activation and musculoskeletal demage as carrying baby.

• Journal of Korean Physical Therapy Science
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• v.18 no.3
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• pp.63-69
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• 2011

Purpose : The purpose of study is activation of lumbar multifidus muscle by needle EMG during shoulder flexion in chronic low back pain patients. The subject were consisted of 10 women patients with chronic low back pain and healthy asymtomatic subject 10 women. Methods : 10 women patients with chronic low back pain and healthy asymptomatic subject 10 women is voluntary participated for the research. Subjects were positioned in standing. The needle EMG were measured activation of multifidus. Needle electrode was used to 28 gauge. The shoulder flexion movement used to activate the multifidus was then measured. Results : Results of the analysis showed that asymptomatic subjects had significantly larger multifidus muscle activation compared with CLBP subjects during shoulder flexion. Conclusion : This study will be used as multifidus measurement method of patient with chronic LBP. The multifidus muscle in chronic LBP patient clinical significance. Most of chronic LBP patients have multifidus contraction pattern. Therefore chronic LBP patients necessary multifidus activation measurement with needle EMG.

• ETRI Journal
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• v.38 no.5
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• pp.885-895
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• 2016

The lowest power mode (passive-standby mode) was proposed for reducing the power consumption of set-top boxes in a standby state when not receiving content. However, low-power set-top boxes equipped with the lowest power mode have been rarely commercialized because of their low-quality user experience. In the lowest power mode, they deactivates almost all of operational modules and processes, and thus require dozens of seconds for activation latency (that is, the latency for activating all modules of the set-top boxes in a standby state). They are not even updated in a standby state because they deactivate their network interfaces in a standby state. This paper proposes an adaptive standby mode scheduling method for improving the user experience of such boxes. Set-top boxes using the proposed method can analyze the activation pattern and find the frequently used time period (that is, when the set-top boxes are frequently activated). They prepare for their activation during this frequently used time period, thereby reducing the activation latency and enabling their update in a standby state.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.45-53
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• 2019

This study is a neutron activation for concrete that shields medical linear accelerator facilities. Comparison of general concrete and low activation concrete. The simulation method was simulated using MCNPX (Ver. 2.5.0) and FISPACT-2010, and the shielding ability for photon and neutron beams was calculated and neutron activation evaluation was carried out. As a result, the shielding capacity was 20 ~ 50 cm efficient in general concrete, and activate evaluation in low activation concrete was calculated to be low in radioactivity concrete, but all were estimated to not exceed their own allowable concentration in self - disposal. As a result of the comprehensive analysis, it is considered effective to use ordinary concrete.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.5
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• pp.45-51
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• 1997

Low temperature activation of dopants which were doped using ion mass doping system in amorphous silicon(a-Si) thin films was investigated. With a 20.angs.-thick Ni film on top of the a-Si thin film, the activation temperature of dopants lowered to 500.deg. C. When the doping was performaed after the deposition of Ni thin film on the a-Si thin films (post-doping), the activation time was shorter than that of dopants mass, the activation time of the dopants doped by pre-doping method increased. It turned NiSi2 formation, while the decrease of activation time was mainly due to the enhancement of the NiSi2 formation by mixing of Ni and a-Si at the interface of Ni and a -Si thin during the ion doping process.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.182-189
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• 2018

A neutron generation system was developed to induce fissile fission in a lead slowing down spectrometer (LSDS) system. The source neutron is one of the key factors for LSDS system work. The LSDS was developed to quantify the isotopic contents of fissile materials in spent nuclear fuel and recycled fuel. The source neutron is produced at a multilayered target by the (e,${\gamma}$)(${\gamma}$,n) reaction and slowed down at the lead medium. Activation analysis of the target materials is necessary to estimate the lifetime, durability, and safety of the target system. The CINDER90 code was used for the activation analysis, and it can involve three-dimensional geometry, position dependent neutron flux, and multigroup cross-section libraries. Several sensitivity calculations for a metal target with different geometries, materials, and coolants were done to achieve a high neutron generation rate and a low activation characteristic. Based on the results of the activation analysis, tantalum was chosen as a target material due to its better activation characteristics, and helium gas was suggested as a coolant. In addition, activation in a lead medium was performed. After a distance of 55 cm from the lead surface to the neutron incidence, the neutron intensity dramatically decreased; this result indicates very low activation.

• Journal of Korean Vacuum Science & Technology
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• v.2 no.2
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• pp.97-100
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• 1998

We have investigated the effects of crystalline activation on solid phase crystallization (SPC) of amorphous silicon (a-Si) thin films. Wet blasting and self ion implantation were employed as the activation treatments to induce macro or micro crystalline damages on deposited a-Si films. Low temperature and larger grain crystallization were obtained by the applied two-step activation. High degree of crystallinity was also observed on both furnace and rapid SPC. crystalline activations showed the promotion of nucleation on the activated regions and the retardation of growth in an amorphous matrix in SPC. The observed behavior of two-step SPC was strongly dependent on the applied activation and annealing processes. It was also found that the diversified effects by macro and micro activations on the SPC were virtually diminished as the annealing temperature increased.