• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.99-104
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• 2012

The United States will proceed with the effort to modernize the GPS system, and one of its main content is to provide L5 signal. L5 will be transmitted in a radio band reserved exclusively for aviation safety services. And, L5, in combination with L1, will improve the position accuracy via ionospheric correction and robustness via signal redundancy. However, The acquisition processing time of L5 takes longer than that of L1 as the code length of L5 is 10 times longer than that of L1. To reduce this acquisition processing time, a higher number of correlators in the aquisition module should be used. However, there is a problem that this causes increase in the complexity of the correlator configuration and the computation power. So, in this paper, we propose L5 signal tracking scheme using tracking results in the GPS L1/L5 receiver. The proposed scheme could reduce the hardware complexity as the GPS L5 signal acquisition module is not needed, and provide fast and stable tracking of L5 signal by aiding L1 tracking results such as PRN, the code phase synchronization, and the Doppler frequency. The feasibility of the proposed scheme is demonstrated through simulation results.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.471-480
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• 2019

L-spine 3~4, L-spine 4~5, and L-spine 5~Sacrum 1 intervertebral disc(IVD) angle according to gender, age, body mass index(BMI), lumbar lordosis angle(LLA) were compared and analyzed. The anteriorposterior incidence angle of L-spine 3 ~ 4, L-spine 4 ~ 5 and L-spine 5~Sacrum 1 in body mass index were 5.66, 13.23 and 29.13 degrees in the head direction and L-spine 3 4, L-spine 4 ~ 5, L-spine 5~Sacrum 1 had 6.32 degrees, 16.09 degrees and 35.36 degrees in the head direction. The distortion area ratio comparison was performed with the phantom image using the proposed incidence angle. There was a significant difference in L-spine 4~5 and L-spine 5~Sacrum 1 IVD angle relative to body mass index and LLA(p<0.05), IVD angle and LLA were positively correlated(p<0.05).As a result of evaluating the usefulness of the image by applying the incidence angles of the disc angles according to the phantom angle of deviation to the head direction as 11 degrees for L4 and 26 degrees for L5, the distortion ratio area decreased from 14.90% to 12.11% in L4, And from 15.25% to 13.72% in L5. In anteriorposterior image of the Lumbar spine applying the incidence angle according to the measured disc angle, it is possible to reduce the distortion to purpose L4, L5. And improved the quality and diagnostic information of the target site.

• Asian Spine Journal
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• v.12 no.6
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• pp.1037-1042
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• 2018

Study Design: Retrospective study. Purpose: This study aimed to investigate whether segmental lumbar hyperlordosis of the affected vertebra in patients with spondylolysis occurs only at L5 or also occurs at L4. Overview of Literature: To the best of our knowledge, increase in segmental lordosis of the spondylolytic vertebrae has only been investigated in bilateral L5 spondylolysis; it has not been examined at different levels of bilateral spondylolysis. According to the characteristics of segmental lordosis in bilateral L5 spondylolysis, patients with bilateral L4 spondylolysis may also have increased segmental lordosis of the L4 vertebra. Methods: Patients with bilateral spondylolysis of the L5 or L4 vertebra in 2013-2015 were retrospectively identified from the hospital database. Standing lateral lumbar radiographs were assessed for the angle of segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis. The differences in segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis were determined using non-paired Student t-test. Results: Overall, 15 cases of bilateral L4 spondylolysis and 41 cases of bilateral L5 spondylolysis satisfied the inclusion and exclusion criteria. Lordosis of the L4 vertebra was significantly greater in the bilateral L4 spondylolysis group ($24.2^{\circ}{\pm}7.0^{\circ}$) than that in the L5 spondylolysis group ($20.3^{\circ}{\pm}6.1^{\circ}$, p=0.047). Lordosis of the L5 vertebra was significantly lower in the L4 spondylolysis group ($27.7^{\circ}{\pm}8.2^{\circ}$) than that in the L5 spondylolysis group ($32.5^{\circ}{\pm}7.3^{\circ}$, p=0.040). The sacral slope and lumbar lordosis did not significantly differ between the groups. Conclusions: Adolescent patients with bilateral spondylolysis have segmental hyperlordosis of the affected vertebra not only at the L5 level but also at the L4 level.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.283-288
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• 2011

In this paper, an adaptive signal tracking loop for a GPS L1/L2C/L5 receiver is designed. The design parameters is adjusted according to the receiver's operating conditions such as the signal strength and the receiver dynamics by using the different characteristics of GPS L1, L2C and L5 signal. Simulation results show that the tracking accuracy of the proposed signal tracking loop is better than those of L1, L2C and L5 only signal tracking loop.

• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.81-84
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• 2009

Objective : Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. Methods : The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Results : Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. Conclusion : If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.134-139
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• 1990

The hydrogenation catalyst precursors $[(L-L)Rh(NBD)]ClO_4\;(L-L=Fe({\eta}^5-C_5H_4PBu^t\;_2)_2,\;Fe({\eta}^5-C_5H_4PPhBu^t)_2$; NBD = norbornadiene) react with $H_2(1\;atm,\;30^{\circ}C$, MeOH) to yield $[(L-L)HRh({\mu}-H)_3RhH(L-L)]ClO_4$. These hydrido species are fluxional, and variable temperature NMR studies show the existence of a number of equilibria involving both fluxional and non-fluxional species. The synthesis, solution structures, and fluxional behaviors of these hydrides are described.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.263-266
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• 1998

Flowergenic callus was induced from the ovary surface of Allium fistulosum L. cultured on MS medium containing 0.5mg/L NAA and 0.5mg/L BA or 0.5mg/L kinetin. After 3-4 weeks of culture, the flower buds were developed from flowergenic callus. The continuous production of flowergenic callus was proliferated, when subcultured on the medium containing 0.5mg/L NAA and 0.5mg/L kinetin. However, frequency of flower bud formation from flowergenic callus was decreased as the subculture was repeated. Histological observation reveals that the developmental pattern of flower bud from flowergenic callus was closely similar to that of natural flowers.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.3
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• pp.1-7
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• 2022

Background: Manual traction with a belt is a physiotherapy treatment method that reduces disk pressure and widens the disk space. In clinical settings, it is applied to numerous patients with herniated intervertebral disk (HIVD). This study aimed to identify the effects of manual traction with a belt on the intervertebral space in patients with lumbar HIVDs. Methods: The intervention was performed on 17 patients with lumbar HIVDs who were divided into two groups: one with eight patients having HIVD at L4~L5 and another group with nine patients having HIVD at L5~S1. The participants received manual traction with a belt twice a week for 12 weeks, and radiographic imaging was used to visualize the intervertebral space and compare it before and after treatment. Results: Manual traction with a belt increased the lumbar intervertebral space at L4~L5 and L5~S1 in patients with L4~L5 HIVD. A significant difference was observed in the L4-L5 distance (p<.01); however, no significant difference was observed in the L5~S1 distance (p>.05). The intervertebral space significantly increased at both L4~L5 and L5~S1 in patients with L5~S1 HIVD (p<.05). Conclusion: Thus, manual traction with a belt increased the intervertebral space in patients with L4~L5 and L5~S1 HIVDs. These results are expected to guide studies on manual traction with belts in clinical settings in the future. Further studies using the present research as an objective study method are anticipated.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.230-235
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• 2009

The effect of auxin transport inhibitor (TIBA and PCIB) or auxin synergist (phloroglucinol) on somatic embryo maturation and germination in Japanese larch (Larix leptolepis) was examined. The addition of 15.8 mg/L ABA+5.0 mg/L PCIB showed most promoted the maturation of cotyledon -staged somatic embryos (177.7/90 mg ESM). In contrast, with treatment of 5.0 mg/L PCIB or 5.0 mg/L TIBA, no somatic embryos were obtained. Considering from this result, PCIB or TIBA alone could not substitute for exogenously supplied ABA for maturation of somatic embryos. In the test of below concentration of 5.0 mg/L PCIB, the highest results were recorded in 15.8 mg/L ABA+2.0 mg/L PCIB (109.3/90 mg ESM) or 15.8 mg/L ABA+5.0 mg/L PCIB (103.7/90 mg ESM). However, 5.0 mg/L phloroglucinol (0/90 mg ESM) or no ABA addition (3/90 mg ESM) had little influence on somatic embryos maturation. In germination study, the highest frequency of plantlet regeneration obtained from the somatic embryos which had matured on 15.8 mg/L ABA+5.0 mg/L PCIB (67.9%). However, either 5.0 mg/L PCIB nor 5.0 mg/L TIBA resulted in obtained from plantlets.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.685-693
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• 2020

This study was performed to compare the differences between total fat area, subcutaneous fat area and visceral fat area according to L1-S1 inter vertebral disc level in asymptomatic Korean patients with non-contrast abdominal CT scan. The location of the maximum fat ratio of the total fat area is the total fat area measured in male L2-3, L3-4, L4-5, female L4-5, and L5-S1. The location showing the maximum fat ratio of the subcutaneous fat area is the subcutaneous fat area measured in male L4-5, and the woman is the subcutaneous fat area measured in L4-5 and L5-S1. The location of the maximum fat ratio of visceral fat area was the visceral fat area measured in L1-2 and L2-3 males, and there was no difference in visceral fat area according to the measured position in females. Although abdominal fat measurement is common at the L4-5 inter vertebral disc level, fat distribution varies widely depending on nationality, race, and gender. Therefore, it is necessary to analyze through the research data which location to choose according to the research purpose, and to mention why the location is appropriate.