• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1553-1561
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• 2024

Nondestructive radiography using cosmic ray muons has been used for decades to monitor nuclear reactor and spent nuclear fuel storage. Because nuclear fuel assemblies are highly dense and large, typical radiation probes such as x-rays cannot penetrate these target imaging objects. Although cosmic ray muons are highly penetrative for nuclear fuels as a result of their relatively high energy, the wide application of muon tomography is limited because of naturally low cosmic ray muon flux. This work presents a new image reconstruction algorithm to maximize the utility of cosmic ray muon in tomography applications. Muon momentum information is used to improve imaging resolution, as well as muon scattering angle. In this work, a new convolution was introduced known as M-value, which is a mathematical integration of two measured quantities: scattering angle and momentum. It captures the objects' quantity and density in a way that is easy to use with image reconstruction algorithms. The results demonstrate how to reconstruct images when muon momentum measurements are included in a typical muon scattering tomography algorithm. Using M-value improves muon tomography image resolution by replacing the scattering angle value without increasing computation costs. This new algorithm is projected to be a standard nondestructive radiography technique for spent nuclear fuel and nuclear material management.

• The Journal of Korean Physical Therapy
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• 제29권4호
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• pp.158-163
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• 2017

Purpose: The purpose of this study was to investigate the relationship among pain, range of motion of the neck, neck disability index and grip strength after thoracic manipulation and cervical stabilization training in patients with chronic neck pain. Methods: In this study, twelve subjects with chronic neck pain were included. All participants had thoracic manipulation and cervical stabilization training. Intervention was conducted three times per a week, for 4 weeks. The visual analogue scale (VAS), range of motion of neck, neck disability index (NDI), as well as the grip strength before and after intervention were measured in all participants. Paired t-test was used to compare variables before and after intervention. Pearson correlation analysis was used to identify the correlations between the variables. Results: All variables after the intervention were significantly improved. There was a significant negative correlation between VAS and flexion angle of the neck (r=-0.669, p<0.05). Moreover, there was a significant positive correlation between NDI and VAS (r=0.636, p<0.05), and a significant negative correlation between NDI and flexion angle of the neck (r=-0.692, p<0.05). Conclusion: Patients with reduced pain following therapeutic intervention illustrated that there would be an improvement in the flexion angle rather than the extension angle of the neck, and that those with increased flexion angle would have less restriction of activities in daily living.

• 대한물리치료과학회지
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• 제24권3호
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• pp.56-63
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• 2017

Purpose: This study aimed to investigate the effects of sitting posture on cervical flexion angle and pain during smart phone use. Method: This research was performed on 10 adult female students who use smart phones regularly, Each of the two groups of participants used the provided smart phone for 20 minutes while maintaining the given default posture. The evaluation order was randomly selected and the two groups were photographed twice before and after the experiment and were asked to answer if they felt pain during or after the experiment. Result: First, both upright sitting position and vertebra bent position pre and post experiment readings showed significant statistical difference (p<.05). And it is shown to be a factor that induces pain around the neck via increase in neck flexion angle. Second, although there were no significant statistical difference between the pre and post experiment readings of the upright sitting position results and the vertebra bent position results, the vertebra bent position readings showed bigger changes to the neck flexion angle then the upright sitting position readings. Third, all participants from both groups claimed pain in all the tested postures of smart phone usage. Conclusion: Smart phone usage for an extended amount of time in all body postures may prove to have a negative effect making the "optimal" smart phone usage position as a controlled time with neck stretches included in between short sessions.

• 한국항공우주학회지
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• 제30권4호
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• pp.1-9
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• 2002

항공기 동체에 널리 사용되고 있는 기계적 체결은 응력집중 및 접촉압력 등으로 인해 체결부로부터의 균열발생 가능성이 상대적으로 높다. 본 연구에서는 가중함수법을 적용하여 기계적 체결부에 존재하는 경사진 타원형 모서리균열의 표면점과 최심점에서의 혼합모드 응력확대계수 해석을 수행하였다. 가중함수에 포함된 미정계수들은 기준하중에 대한 유한 요소해석으로부터 구하였다. 경사각에 따른 응력확대계수의 변화를 해석하여 모드 I 응력 확대계수가 최대가 되는 임계 경사각을 결정하였고, 간극의 크기와 균열깊이가 임계 경사각에 미치는 영향을 조사하였다.

• 대한족부족관절학회지
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• 제8권2호
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• pp.117-120
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• 2004

저자에 의해 개선된 변형 Mau 절골술은 우수한 교정력과 견고한 고정이 가능하면서도 술기가 간단하고 중족골두의 상하 전위가 없고 조기 보행이 가능한 안전한 방법이라 할 수 있었다. 따라서 향후 장기 추시가 필요하긴 하지만 중족골간각이 큰 중증의 무지외반증에서 추천할만한 좋은 방법으로 사료된다.

• Journal of Korean Neurosurgical Society
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• 제58권5호
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• pp.454-461
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• 2015

Objective : In this study, we aimed to investigate the underlying ethiological factors in chiari malformation (CM) type-I (CMI) via performing volumetric and morphometric length-angle measurements. Methods : A total of 66 individuals [33 patients (20-65 years) with CMI and 33 control subjects] were included in this study. In sagittal MR images, tonsillar herniation length and concurrent anomalies were evaluated. Supratentorial, infratentorial, and total intracranial volumes were measured using Cavalieri method. Various cranial distances and angles were used to evaluate the platybasia and posterior cranial fossa (PCF) development. Results : Tonsillar herniation length was measured $9.09{\pm}3.39mm$ below foramen magnum in CM group. Tonsillar herniation/concurrent syringomyelia, concavity/defect of clivus, herniation of bulbus and fourth ventricle, basilar invagination and craniovertebral junction abnormality rates were 30.3, 27, 18, 2, 3, and 3 percent, respectively. Absence of cisterna magna was encountered in 87.9% of the patients. Total, IT and ST volumes and distance between Chamberlain line and tip of dens axis, Klaus index, clivus length, distance between internal occipital protuberance and opisthion were significantly decreased in patient group. Also in patient group, it was found that Welcher basal angle/Boogard angle increased and tentorial slope angle decreased. Conclusion : Mean cranial volume and length-angle measurement values significantly decreased and there was a congenital abnormality association in nearly 81.5 percent of the CM cases. As a result, it was concluded that CM ethiology can be attributed to multifactorial causes. Moreover, congenital defects can also give rise to this condition.

• The Journal of Korean Physical Therapy
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• 제26권2호
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• pp.56-61
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• 2014

Purpose: The aim of this study was to investigate relationship between the angle of the first metatarsophalangeal joint (1st MPJ) and the dimensions of the abductor hallucis; dorso-plantar (DP) thickness, medio-lateral (ML) width, and cross-sectional area (CSA), in subjects with and without hallux valgus. Methods: Sixty feet, mean (SD) age of 22.5 (2.1) years old, were included in this study (hallux valgus = 30; control = 30). An X-ray device was used for measurement of the angle of the 1st MPJ, and an ultrasound system was used for determination of mean (SD) DP thickness, ML width, and CSA of the abductor hallucis muscle in each foot from three trials. Results: The results showed the DP thickness, ML width, and CSA of the abductor hallucis did not differ significantly between subjects with and without hallux valgus. In addition, the correlations between the angle of the 1st MPJ and DP thickness, ML width, and CSA of the abductor hallucis showed poor correlation (Pearson r=-0.09, -0.20, and -0.18, respectively). Conclusion: Based on these findings, we speculate that morphological changes to the abductor hallucis muscle cannot be representative of the angle of the 1st MPJ, and also cannot be used in differentiation between subjects with and without hallux valgus.

• 대한통합의학회지
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• 제7권3호
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• pp.109-115
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• 2019

Purpose : The purpose of this study was to investigate the activity of muscles around the scapulothoracic muscles according to the angle of shoulder joint abduction in the prone position. Methods : The participants included 15 adult males who had not undergone orthopedic surgery and did not have shoulder joint impairments. We measured the muscle activity of the upper trapezius, middle trapezius, lower trapezius, and serratus anterior at $120^{\circ}$, $90^{\circ}$, and $60^{\circ}$ shoulder joint abduction angles. Results : There was a significant difference in the comparison of muscle activity in the upper trapezius, middle trapezius, and serratus anterior muscles according to the shoulder joint abduction angle (p<.05). The results of the post test showed that the upper trapezius was significantly different between $120^{\circ}$ and $60^{\circ}$ (p<.01), and the middle trapezius was significantly different between $90^{\circ}$ and $120^{\circ}$, and between $90^{\circ}$ and $60^{\circ}$ (p<.05). There was a significant difference in the serratus anterior between $120^{\circ}$ and $90^{\circ}$ (p<.01), and $120^{\circ}$ and $60^{\circ}$ (p<.01). Conclusion : The results of this study could be used to determine an effective shoulder joint abduction angle to reduce muscle activity of the upper trapezius and increase muscle activity of the middle trapezius, lower trapezius, and serratus anterior.

• 한국분말재료학회지
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• 제28권4호
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• pp.310-316
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• 2021

The effects of different spray angles (90°, 85°, 80°) on the microstructure and mechanical properties of a Y₂O₃ coating layer prepared using the atmospheric plasma spray (APS) process were studied. The powders employed in this study had a spherical shape and included a cubic Y₂O₃ phase. The APS coating layer exhibited the same phase as the powders. Thickness values of the coating layers were 90°: 203.7 ± 8.5 ㎛, 85°: 196.4 ± 9.6 ㎛, and 80°: 208.8 ± 10.2 ㎛, and it was confirmed that the effect of the spray angle on the thickness was insignificant. The porosities were measured as 90°: 3.9 ± 0.85%, 85°: 11.4 ± 2.3%, and 80°: 12.7 ± 0.5%, and the surface roughness values were 90°: 5.9 ± 0.3 ㎛, 85°: 8.5 ± 1.1 ㎛, and 80°: 8.5 ± 0.4 ㎛. As the spray angle decreased, the porosity increased, but the surface roughness did not show a significant difference. Vickers hardness measurements revealed values of 90°: 369.2 ± 22.3, 85°: 315.8 ± 31.4, and 80°: 267.1 ± 45.1 HV. It was found that under the condition of a 90° angle with the lowest porosity exhibited the best hardness value. Based on the aforementioned results, an improved method for the APS Y₂O₃ coating layer was also discussed.

• 한방재활의학과학회지
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• 제32권1호
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• pp.63-72
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• 2022

Objectives This study was conducted to characterize scoliosis patients visiting Korean medicine hospital and to analyze the demands and factors affecting discomfort. Methods This retrospective study analyzed 33 scoliosis patients who visited Korean medicine hospital from March, 2021 to October, 2021. The data analysis consisted of three factors: (1) demographic characteristics, (2) characteristics of demands on Korean medicine (reasons for choosing Korean medical treatment, preferred treatment methods, most uncomfortable part, treatment priorities) and (3) discomfort factors (treatment experiences, diagnosed age and Cobb's angle). Statistical analyses were performed and a p-value≤0.05 was considered to be statistically significant. Results 43.75% of the patients chose 'effectiveness' for the reason why they preferred Korean medicine treatment. 'Chuna treatment' was the most preferred treatment method. The patients chose 'lower back' for the most uncomfortable part and 'pain' for the highest priority of improvement. The Cobb's angle of included patients was 16.02±7.65° and it is not much differ to average of Cobb's angle in Korean. Discomfort was more severe in the patients with treatment-experienced than treatment-naive. The score of discomfort in appearance and psychological were higher in the patients diagnosed in childhood or adolescent period than who were diagnosed after adult. Classification based on Cobb's angle showed no statistical difference. Conclusions Not only Cobb's angle but also other clinical factors should be considered for effective treatment in scoliosis. Also, It is necessary to pay attention to adult scoliosis patients.