• 한국융합학회논문지
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• 제12권2호
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• pp.29-34
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• 2021

본 논문에서는 중심에 동공을 갖는 원통형태 광결정 도파로가 제안되어지고, 이 전송로의 도파 특성에 대한 분석이 수행되어진다. 여기서 동공은 일반적인 공기이거나 임의의 액체나 고체 물질들에 의한 저지수 유전체로써 형성되게 된다. 베셀 함수를 이용한 분석적 방법으로 전자장에 대한 엄밀한 해를 구하기 위하여, 행렬 기법이 고유치 방정식의 유도에 사용되고, 실효 굴절률, 분산, 전자장 분포 등의 기본 모드의 중요한 전송 성질들이 조사된다. 또한 분석 결과 정확도의 검증을 위하여 엄밀한 완전 벡터 유한 차분법을 적용해보고, 광결정 도파로의 설계와 제조 상의 문제를 해결하는데 용이하게 활용하고자 한다. 설계된 중심-동공 광도파관의 실효 모드 면적이 2.6056 ㎛2에서 5.9673 ㎛2까지 동작 파장에 따라 다양하게 변하며, 일반적으로 광도파로의 중심으로부터 바깥쪽으로 원통형의 층수가 적을수록 그리고 굴절률 n1이 약간 큰 저지수일수록 실효 면적은 작아지므로, 비선형 소자 응용의 관점에서 훨씬 더 최적화된 결과를 나타낸다.

• 한국컴퓨터정보학회논문지
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• 제27권4호
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• pp.193-203
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• 2022

본 연구는 앱을 이용한 홈 트레이닝이 비만중년여성의 대사증후군 위험이자 및 동맥경화지수 변화를 분석하여 COVID-19의 펜데믹 시대에 비만 개선의 하나의 중재방법으로 제시하고자 실시되었다. 연구의 대상자는 비만중년여성 33명을 대상으로 앱 홈트레이닝 그룹(AHTG) 15명, 통제그룹 (CG) 18명을 모집하여 8주간의 앱을 이용한 홈트레이닝을 주 3회 실시하였다. 이 연구 결과 AHTG의 대사증후군 위험요인 중 WC(p<.001)는 유의하게 감소하고 HDL-C(p<.05)는 유의하게 증가하였으며, 동맥경화지수는 LDL-C/HDL-C(p<.01) 유의하게 증가하였다. 따라서 COVID-19 펜데믹 시대에 PA는 여러 만성질환에 대한 개선 효과 외에도 심각한 COVID-19 대유행을 완화 하는데 중요한 역할을 하며 앱을 이용한 홈트레이닝이 비만 및 대사증후군을 예방에 효율적인 중재 방법이 될 수 있는 가능성을 확인하였다.

• Earthquakes and Structures
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• 제25권2호
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• pp.125-134
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• 2023

In the present work, a new global damage index is proposed for the seismic performance and failure analysis of concrete gravity dams. Unlike the existing indices of concrete structures, this index doesn't need scaling with an ultimate or an upper value. For this purpose, the Beni-Haroun dam in north-eastern Algeria, is considered as a case study, for which an average seismic capacity curve is first evaluated by performing several incremental dynamic analyses. The seismic performance point of the dam is then determined using the N2 method, considering multiple modes and taking into account the stiffness degradation. The seismic demand is obtained from the design spectrum of the Algerian seismic regulations. A series of recorded and artificial accelerograms are used as dynamic loads to evaluate the nonlinear responses of the dam. The nonlinear behaviour of the concrete mass is modelled by using continuum damage mechanics, where material damage is represented by a scalar field damage variable. This modelling, which is suitable for cyclic loading, uses only a single damage parameter to describe the stiffness degradation of the concrete. The hydrodynamic and the sediment pressures are included in the analyses. The obtained results show that the proposed damage index faithfully describes the successive brittle failures of the dam which increase with increasing applied ground accelerations. It is found that minor damage can occur for ground accelerations less than 0.3 g, and complete failure can be caused by accelerations greater than 0.45 g.

• 대한정형도수물리치료학회지
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• 제29권3호
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• pp.31-42
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• 2023

Background: This study aimed to investigate the effects of combining the lumbar stabilization exercise with the gluteal muscle strength exercise on pain, the dysfunction index, and postnatal depression in women experiencing chronic low back pain after a cesarean section. Methods: The study used a randomized design with two groups: one group (n=15) performed the lumbar stabilization exercise along with the gluteal muscle strength exercise, while the other group (n=15) only did the lumbar stabilization exercise. The intervention consisted of 30 minute exercise sessions, twice a week, for 6 weeks. The pain was assessed using the visual analog scale (VAS), the dysfunction index with the Oswestry disability index (ODI), and postnatal depression using the edinburgh postnatal depression scale-Korean version (EPDS-K). Results: Both groups showed significant improvements in their VAS, ODI, and EPDS-K scores within their respective groups (p<.05). Additionally, the between-group analysis revealed significant differences in post-test results (p<.05). Conclusion: The combination of the lumbar stabilization exercise and the gluteal muscle strength exercise proved to be more effective in reducing pain, improving the dysfunction index, and alleviating postnatal depression in women with chronic low back pain after a cesarean section. Therefore, incorporating these exercises could be beneficial as an intervention program for women experiencing chronic low back pain after a cesarean section.

• Physical Therapy Rehabilitation Science
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• 제13권1호
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• pp.36-42
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• 2024

Objective: The aim of this study is to investigate the effect of hamstring eccentric exercise on pain and functional activity in patients with chronic low back pain. Design: Randomized controlled trial Methods: Participants comprised 27 subjects with back pain persisting for 3 months. They were randomly assigned to the experimental group (Eccentric exercise: n=13) and the control group (Stretching: n=14). The experimental group performed gastrocnemius, iliopsoas, and quadratus lumborum stretching along with hamstring eccentric exercise, while the control group engaged in the same stretches along with hamstring stretching. The eccentric exercise for the hamstrings was Nordic curl exercise. Each group practiced for 1 hour a day, 3 times a week, for 4 weeks. Pain, disability index, balance, and hamstring length were measured. Results: Significant differences were observed in the comparison of changes in back pain, back disability index, and hamstring length before and after exercise within each group (p<0.05). The balance ability of the experimental group showed a difference before and after exercise (p<0.05), whereas no significant difference in the control group. There were no significant differences in back pain and hamstring length between the groups. Changes in back disability index and balance ability significantly increased in the experimental group compared to the control group (p<0.05). Conclusion: Hamstring eccentric exercise using Nordic curls has a positive effect on back pain, back disability index, balance ability, and hamstring length changes.

• Journal of Astronomy and Space Sciences
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• 제25권4호
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• pp.383-394
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• 2008

코로나질량방출(CMEs)의 지구영향도를 효율적으로 예측하기 위해 속도가 빠른 CMEs의 방향지시 매개인수(parameter)를 조사하여 Dst 지수 최소값과의 상관관계를 비교하였다. 그리고 이 매개인수 중 어떤 매개인수가 예측 효율성이 높은지 알아보았다. 이를 위해 SOHO/LASCO 목록에서 CMEs의 속도가 1000km/s 이상, CMEs발생 위치가 태양 중심에서 ${\pm}30^{\circ}$ 이내에 위치한 혜일로(halo) CMEs를 사용하였다. 이 CMEs가 태양에서 발생하여 지구에 도착하는 시각을 모델을 이용하여 예측한 뒤 이 시각에 가장 가까운(24시간 이내) Dst 지수 최소값을 구하였다. 이를 통해 CMEs의 지구 영향도를 판별하였다. 전체 30개의 사건 중 22개(73%)가 지자기 폭풍을 일으켰다. 우리는 CMEs의 지구 영향도를 예측하기 위해 기존의 방향 매개인수와 이번 연구에서 새롭게 제안한 이심을, 이동거리, 중심각 매개인수를 사용하였다. 이들 매개인수와 Dst 지수 최소값의 상관관계 분석을 통해 상관계수 값을 알아보고 그 결과를 통해 어떤 매개인수가 CMEs의 지구 영향도 예측 효율이 높은지 비교하였다. 그 결과 이심율 매개인수가 가장 좋은 상관관계를 보였고, 방향 매개인수는 비교적 좋은 상관관계를 보였다. 이동거리와 중심각 매개인수는 이심율과 방향 매개인수보다 낮은 상관관계를 보였다. 하지만 이들 역시 강한 지자기 폭풍(Dst 지수 ${\leq}$-200nT)의 경우에는 좋은 상관관계를 보였다. 방향 매개인수 값이 0.6 이상이고 이심율 매개인수 값이 0.4 이하이며 이동거리, 중심각 매개인수 값이 0.2 이하인 경우에는 강한 지자기 폭풍(Dst 지수 ${\leq}$-200nT)이 일어날 확률이 아주 높음을 알 수 있었다. CMEs의 방향을 지시하는 매개인수는 CMEs의 지구 영향도를 판별하는데 유용하고 이를 복합적으로 고려한다면 예측의 효율성을 높일 수 있다.

• PNF and Movement
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• 제14권3호
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• pp.185-193
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• 2016

Purpose: The purpose of this study was to investigate the effects of neck patterns in proprioceptive neuromuscular facilitation (PNF) for neck movement and the neck disability index (NDI) among adults with forward head posture. Methods: Thirty-nine subjects were randomly assigned into two groups. Subjects in the proprioceptive neuromuscular facilitation exercise group (PNFG, n = 20) received 20 minutes of PNF neck pattern (flexion-Rt. lateral flexion-Rt. rotation followed by extension-Lt. lateral flexion-Lt. rotation) 3 times weekly for 4 weeks. Outcomes were measured using absolute rotation angle (ARA), anterior weight bearing (AWB), range of flexion and extension motions (RFEM), and neck disability index (NDI) methods before and after the 4-week intervention period. Results: There were significant effects for the PNFG, pre- and post-intervention, in ARA, AWB, RFEM, and NDI. There were significant differences in ARA, AWB, RFEM, and NDI compared with CG. Conclusion: The results of this study suggest the PNF neck pattern could be beneficial for adults with forward head posture.Purpose: This study investigates how abdominal muscular exercise based on proprioceptive neuromuscular facilitation (PNF) can affect chronic low back pain patients in terms of their pulmonary function, pain, and functional disability indexes. Methods: Fourteen target subjects with chronic low back were randomly assigned to the control group (n = 7) that performed abdominal muscle exercises and the experimental group (n = 7) that performed PNF abdominal muscular exercises. The exercises were performed five times a week for six weeks. To check the change in pulmonary function, the forced expiratory volume at one second (FEV1) and visible analogue scale (VAS) were measured to check the pain level. The disability level caused by back pain was measured by the Oswestry Disability Index (ODI). A paired t-test was applied to compare the differences between the groups before and after the intervention, and an independent t-test was used to compare the differences between the groups. The level of statistical significance was set as ${\alpha}=0.05$. Results: Before and after the intervention, the experimental group showed a significant change in FEV1 (p < 0.01), and both the experimental and the control groups showed significant changes in VAS and ODI (p < 0.01). A comparison of the differences between the groups indicated that the experimental group showed more significant changes in FEV1 (p < 0.05). Conclusion: According to the study results, PNF abdominal muscular exercise effectively improved pulmonary function, pain, and functional disability indexes in subjects with chronic back pain. The proposed program can be applied to chronic back pain patients as a useful therapy.

• Pediatric Infection and Vaccine
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• 제24권1호
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• pp.1-6
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• 2017

목적: 본 연구에서는 delta neutrophil index (DNI)가 신생아 균혈증을 예측하는 지표로서의 효용성을 다른 지표들과의 비교를 통해 알아보고자 하였다. 방법: 원주세브란스 기독병원 신생아 중환자실에 발열을 주소로 입원한 환아들과 입원 중 발열이 있었던 생후 31일 미만 환아 146명을 대상으로 혈액배양검사와 동시에 시행한 총 백혈구 수, 절대호중구수, DNI, 혈소판 수, C-반응단백(C-reactive protein, CRP)에 대하여 분석하였다. 결과: 균혈증이 있었던 환아 77명의 평균 재태주수는 38.74주, 출생 체중은 3.20 kg였다. 대조군의 평균 재태주수는 33.34주, 출생 체중은 2.20 kg였다. 균혈증의 원인은 Staphylococcus aureus (22명), Staphylococcus epidermidis (18명), Streptococcus agalactiae (8명) 등이었다. DNI와 CRP만이 재태주수와 출생 체중 보정 후 균혈증과 연관성을 보여 area under the ROC curve를 조사하였고 DNI 0.70, CRP 0.68이었다. 결론: DNI는 신생아 균혈증을 예측하는 데 효과적인 지표이다. 다른 인자들과 함께 고려한다면 균혈증을 예측하는 데 더 도움이 될 것이다.

• 대한통합의학회지
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• 제9권4호
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• pp.271-281
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• 2021

Purpose : This study aimed to apply muscle relaxation exercise and ultrasound therapy as an effective treatment method for tension headache patients by comparatively analyzing the muscle mechanical properties, neck disorder index, and headache impact test. Method : The subjects were classified into three groups based on the intervention received: the therapeutic ultrasound (n=15, group I), placebo therapeutic ultrasound combined with the suboccipital release (n=15, group II), and therapeutic ultrasound combined with suboccipital release (n=15, group III) groups. The intragroup and intergroup differences in muscle mechanical properties, neck disability index, and headache impact test were compared and analyzed. Result : The comparison and analyses of the changes in muscle tone and post hoc analysis revealed statistically significant intragroup decreases in the suboccipitalis and upper trapezius in groups I and III. Furthermore, statistically significant intergroup differences in the upper trapezius with a greater change in group III than in group II and suboccipitalis with greater changes in group III than in groups I and II were observed. The comparison and analyses of the changes in muscle stiffness and post hoc analysis revealed statistically significant intragroup decreases in the upper trapezius in group I and suboccipitalis in group III. Moreover, statistically significant intergroup differences in both muscles with greater changes in group III than in group II for both cases were observed. The comparison and analyses of the changes in the neck disability index and post hoc analysis revealed statistically significant intragroup decreases in all three groups and statistically significant intergroup differences with greater changes in group III than in groups I and II. The comparison and analyses of the changes in the headache impact test and post hoc analysis revealed statistically significant intragroup decreases in all three groups and a statistically significant intergroup difference with greater changes in group III than in groups I and II. Conclusion : The therapeutic ultrasound and suboccipital muscle release exercise effectively increased the flexibility of the muscles around the cervical vertebrae and reduced muscle tension and stiffness in tension-type headache patients.

• Journal of Information Display
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• 제12권3호
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• pp.145-152
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• 2011

Since the discovery of fullerenes as a class of nanostructure compounds, many potential applications have been suggested for their unusual structures and properties. The isolated pentagon rule (IPR) states that all pentagonal carbon rings are isolated in the most stable fullerene. Fullerenes $C_n$ are a class of spherical carbon allotrope group with unique properties. Electron transfer between fullerenes and other molecules is thought to involve the transfer of electrons between the molecules surrounding the fullerene cage. One class of electron transfer molecules is the methanofullerene derivatives ([6,6]-phenyl $C_{61}$-butyric acid methyl ester (PCBM), 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid methyl ester (p-EHO-PCBM), and 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid (p-EHO-PCBA), 10-12). It has been determined that $C_{60}$ does not obey IPR. Supramolecular complexes 1-9 and 10-12 are shown to possess a previously unreported host.guest interaction for electron transfer processes. The unsaturated, cis-geometry, thiocrown ethers, (1-9) (described as [X-UT-Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively), are a group of crown ethers that display interesting physiochemical properties in the light of their conformational restriction compared with a corresponding saturated system, as well as the sizes of their cavities. Topological indices have been successfully used to construct mathematical methods that relate structural data to various chemical and physical properties. To establish a good relationship between the structures of 1-9 with 10-12, a new index is introduced, ${\mu}_{cs}$. This index is the ratio of the sum of the number of carbon atoms ($n_c$) and the number of sulfur atoms ($n_s$) to the product of these two numbers for 1-9. In this study, the relationships between this index and oxidation potential ($^{ox}E_1$) of 1-9, as well as the first to third free energies of electron transfer (${\Delta}G_{et(n)}$, for n = 1-3, which is given by the Rehm-Weller equation) between 1-9 and PCBM, p-EHO-PCBM, and p-EHO-PCBA (10-12) as [X-UT-Y]@R(where R is the adduct PCBM, p-EHO-PCBM, and p-EHO-PCBA group) (13-15) supramolecular complexes are presented and investigated.