• Title/Summary/Keyword: Effect of Curvature

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Clinical Comparison Study on 40 Cases of Temporomandibular Disorder Patients with Idiopathic Scoliosis Treated by Chuna & General Oriental Method (추나치료를 병행한 척추측만증을 동반한 악관절장애환자 40례에 대한 임상적 비교 고찰)

  • Heo, Yoon-Kyoung;Choi, Ka-Won;Kang, Min-Wan;Kim, Sung-Lae;Kim, Jeong-Ho;Kim, Young-Il;Hong, Kwon-Eui;Lee, Hyun;Lim, Yun-Kyoung;Song, Min-Sic
    • Journal of Acupuncture Research
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    • v.22 no.5
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    • pp.133-140
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    • 2005
  • Objectives : This study was to evaluate the effect of Chuna on Temporomandibular Disorder Patients with idiopathic Scoliosis, utilizing Cobb's angle to determine the degree of curvature progression in the thoracic and lumbar regions. Methods: From October 1st 2004 to June 31st 2005, the clinical comparison study was carried out 40 cases of Temporomandibular Disorder Patients with idiopathic Scoliosis treated by both Chuna and General oriental method(Experimental Group) & only General oriental method(Control Group), who had been treated at Dept. of Acupuncture and Moxibustion Daejon Oriental Medical Hospital. Results : The results obtained as follows; 1. The facial pain of Experimental Group and Control Group was improved significantly. but the difference of two groups is not significant.(p<0.05) 2. The function of Temporomandibular joint of Experimental Group and Control Group was improved significantly. Experimental Group is more effective than Control Group significantly.(p<0.05) 3. The limitation of activity of Temporomandibular joint of Experimental Group and Control Group was improved significantly. Experimental Group is more effective than Control Group significantly. (p<0.05) Conclusion : This result sugests that the Chuna be effective treatment modality on Temporomandibular Disorder Patients with idiopathic Scoliosis. So further research is needed continuously.

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Effects of Corrugated Webs on the Ultimate Behavior of Horizontally Curved I-shaped Girders (파형 복부판이 수평 곡선 I형 거더의 극한 거동에 미치는 영향)

  • Kim, Seungjun;Han, Taek Hee;Won, Deok Hee;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1327-1336
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    • 2013
  • In this study, the effects of corrugated webs on the ultimate behavior of horizontally curved I-shaped girders are investigated. Because of the geometric characteristics of corrugated plates, corrugated webs can be used for enhancing torsional and warping stiffness of plate girders. Many researches have been conducted to study the effects of corrugated webs on the ultimate behavior of straight girders. But, the studies of the ultimate behavior of horizontally curved girders with corrugated webs, which generally show out-of plane behavior manly, have been rarely performed so far. By performing inelastic-nonlinear analysis, the ultimate behavior of curved girders with corrugated webs is studied in this paper. Laterally unsupported length and subtended angle of girders, and length of height of corrugation of webs are considered as the geometric parameters which would be expected to affect the ultimate behavior. By this analytical study with considering the geometric parameters, the changes of ultimate behavior and load carrying capacity of curved girders with corrugated webs are investigated. Also, the effects of corrugated webs on the increase of load carrying capacity for curved girders are studied with comparing to the capacity of general curved girders with flat webs. According to the analytical results, corrugated webs can be used to increase the ultimate load carrying capacity of curved girders, because of their high torsional and warping stiffness. But, it is also indicated that they may decrease the load carrying capacity of curved girders which have relatively small subtended angle or initial curvature, because of an accordion effect.

C7 Fracture as a Complication of C7 Dome-Like Laminectomy : Impact on Clinical and Radiological Outcomes and Evaluation of the Risk Factors

  • Yang, Seung Heon;Kim, Chi Heon;Lee, Chang Hyun;Ko, Young San;Won, Youngil;Chung, Chun Kee
    • Journal of Korean Neurosurgical Society
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    • v.64 no.4
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    • pp.575-584
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    • 2021
  • Objective : Cervical expansive laminoplasty is an effective surgical method to address multilevel cervical spinal stenosis. During surgery, the spinous processes of C2 and C7 are usually preserved to keep the insertion points of the cervical musculature and nuchal ligament intact. In this regard, dome-like laminectomy (undercutting of C7 lamina) instead of laminoplasty is performed on C7 in selected cases. However, resection of the lamina can weaken the C7 lamina, and stress fractures may occur, but this complication has not been characterized in the literature. The objective of the present study was to investigate the incidence and risk factors for C7 laminar fracture after C7 dome-like laminectomy and its impact on clinical and radiological outcomes. Methods : Patients who underwent cervical open-door laminoplasty combined with C7 dome-like laminectomy (n=123) were classified according to the presence of C7 laminar fracture. Clinical parameters (neck/arm pain score and neck disability index) and radiologic parameters (C2-7 angle, C2-7 sagittal vertical axis, and C7-T1 angle) were compared between the groups preoperatively and at postoperatively at 3, 6, 12, and 24 months. Risk factors for complications were evaluated, and a formula estimating C7 fracture risk was suggested. Results : C7 lamina fracture occurred in 32/123 (26%) patients and occurred at the bilateral isthmus in 29 patients and at the spinolaminar junction in three patients. All fractures appeared on X-ray within 3 months postoperatively, but patients did not present any neurological deterioration. The fracture spontaneously healed in 27/32 (84%) patients at 1 year and in 29/32 (91%) at 2 years. During follow-up, clinical outcomes were not significantly different between the groups. However, patients with C7 fractures showed a more lordotic C2-7 angle and kyphotic C7-T1 angle than patients without C7 fractures. C7 fracture was significantly associated with the extent of bone removal. By incorporating significant factors, the probability of C7 laminar fracture could be assessed with the formula 'Risk score = 1.08 × depth (%) + 1.03 × length (%, of the posterior height of C7 vertebral body)', and a cut-off value of 167.9% demonstrated a sensitivity of 90.3% and a specificity of 65.1% (area under the curve, 0.81). Conclusion : C7 laminar fracture can occur after C7 dome-like laminectomy when a substantial amount of lamina is resected. Although C7 fractures may not cause deleterious clinical outcomes, they can lead to an unharmonized cervical curvature. The chance of C7 fracture should be discussed in the shared decision-making process.

Absorbable Guided Bone Regeneration Membrane Fabricated from Dehydrothermal Treated Porcine Collagen (Dehydrothermal Treatment로 제작한 흡수성 콜라겐 골유도재생술 차단막)

  • Pang, Kang-Mi;Choung, Han-Wool;Kim, Sung-Po;Yang, Eun-Kyung;Kim, Ki-Ho;Kim, Soung-Min;Kim, Myung-Jin;Jahng, Jeong-Won;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.33 no.2
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    • pp.112-119
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    • 2011
  • Purpose: Collagen membranes are used extensively as bioabsorbable barriers in guided bone regeneration. However, collagen has different effects on tissue restoration depending on the type, structure, degree of cross-linking and chemical treatment. The purpose of this study was to evaluate the inflammatory reaction, bone formation, and degradation of dehydrothermal treated porcine type I atelocollagen (CollaGuide$^{(R)}$) compared to of the non-crosslinked porcine type I, III collagen (BioGide$^{(R)}$) and the glutaldehyde cross-linked bovine type I collagen (BioMend$^{(R)}$) in surgically created bone defects in rat mandible. Methods: Bone defect model was based upon 3 mm sized full-thickness transcortical bone defects in the mandibular ramus of Sprague-Dawley rats. The defects were covered bucolingually with CollaGuide$^{(R)}$, BioMend$^{(R)}$, or BioGide$^{(R)}$ (n=12). For control, the defects were not covered by any membrane. Lymphocyte, multinucleated giant cell infiltration, bone formation over the defect area and membrane absorption were evaluated at 4 weeks postimplantation. For comparison of the membrane effect over the bone augmentation, rats received a bone graft plus different covering of membrane. A $3{\times}4$ mm sized block graft was harvested from the mandibular angle and was laid and stabilized with a microscrew on the naturally existing curvature of mandibular inferior border. After 10 weeks postimplantation, same histologic analysis were done. Results: In the defect model at 4 weeks post-implantation, the amount of new bone formed in defects was similar for all types of membrane. Bio-Gide$^{(R)}$ membranes induced significantly greater inflammatory response and membrane resorption than other two membranes; characterized by lymphocytes and multinucleated giant cells. At 10 weeks postoperatively, all membranes were completely resorbed. Conclusion: Dehydrotheramal treated cross-linked collagen was safe and effective in guiding bone regeneration in alveolar ridge defects and bone augmentation in rats, similar to BioGide$^{(R)}$ and BioMend$^{(R)}$, thus, could be clinically useful.

Strength and Lateral Torsional Behavior of Horizontally Curved Steel I-Girders Subjected to Equal End Moments (양단 균일 모멘트를 받는 수평곡선 I형 강재 거더의 횡-비틀림 거동 및 강도 산정 방안)

  • Lee, Keesei;Lee, Manseop;Choi, Junho;Kang, Youngjong
    • Journal of Korean Society of Steel Construction
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    • v.30 no.1
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    • pp.1-12
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    • 2018
  • A curved member should resist bending and torsional moments simultaneously even though the primary load is usually supposed to be gravitational load. The torsional moment causes complicate stress state and also can result in early yielding of material to reduce member strength. According to analysis results, the strength of a curved member that has 45 degrees of subtended angle could decrease more than 50% compare to straight girder. Nevertheless, there have been very few of researches related with ultimate strength of curved girders. In this study, various kinds of stiffness about bending, pure torsion and warping were considered with a number of models in order to verify the main factor that affects ultimate behavior of curved girder. Lateral and rotational displacement of curved member were introduced as lateral-torsional-vertical behavior and bending-torsional moment interaction curve was derived. Finally, a strength equation for ultimate moment of horizontally curved steel I-girders subjected to equal end moments based on the interaction curves. The equation could take account of the effect of curvature, unbraced length and sectional properties.

A Numerical Analysis on the Diaphragm Structures for Improving Fatigue Performance in Orthotropic Steel Decks (강바닥판의 피로성능 향상을 위한 다이아프램 구조상세)

  • Shin, Jae Choul;An, Zu Og;Yoon, Tae Yang
    • Journal of Korean Society of Steel Construction
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    • v.19 no.6
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    • pp.559-573
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    • 2007
  • Orthotropic steel decks are manufactured by welding thin plates therefore it is inevitable that there are abundant works of welding process. On connection of transverse rib web, crossing point of longitudinal rib, transverse rib and deck plate and cut-out parts of transverse rib are the significant position of stress concentration because of out of plane and oil-canning deformation caused by longitudinal rib distortion with shear force and distortion. At the current research, the crossing point where the orthotropic steel decks's effect of improving fatigue performance are high, not placing scallop and diaphragm which have same plane with transverse rib placed inside of longitudinal rib at the same time, the reduce effects of stress concentration at the cut-out section and the crossing are high. Especially the installation of the diaphragm causing great effects based on research results to stress concentration appearance reduce effects at the cut-out section, putting radius of curvature of the diaphragm's top and bottom as a target, as a result of carrying out the parametric analysis an optimal diaphragm form that has great effects in fatigue performance came to a conclusion. Also based on optimal diaphragm form, an advantage of the diaphragm optimal setting position for improvement of the fatigue performance came to a conclusion.

Undifferentiated Adenocarcinoma with Rhabdoid Features in the Stomach: A Case Report (횡문근양 미분화 위선암 1예 보고)

  • Im, Myoung-Goo;Jun, Kyong-Hwa;Won, Yong-Sung;Jung, Ji-Han;Chin, Hyung-Min;Park, Woo-Bae;Chun, Chung-Soo
    • Journal of Gastric Cancer
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    • v.7 no.2
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    • pp.107-112
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    • 2007
  • Rhabdoid tumor has been considered to be a rare subtype of Wilm's tumor with Rhabdomyoma features. Since rhabdoid tumor that developed in the kidney was described for the first time in 1989, it has been reported in the gastrointestinal tract, although this is rare. The appropriate treatment is radical resection, and the effect of adjuvant chemotherapy has not yet been reported on. The outcome of extra-renal rhabdoid tumor is different from renal rhabdoid tumor and the former shows a poor prognosis. Among extra-renal rhabdoid tumors, undifferentiated gastric adenocarcinoma with rhabdoid features is very rare and its prognosis is poor. A 63 years old male patient underwent total gastrectomy for a tumor that developed in the greater curvature of the gastric body and this was diagnosed as undifferentiated gastric adenocarcinoma with rhabdoid features, according to the histopathology. We experienced an undifferentiated gastric adenocarcinoma with rhabdoid features that was diagnosed by immunohistochemical staining and we report here on this case.

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Study on the Fairway Used by Coastal Passenger Ship at Mokpo Port (목포항 입출항 연안여객선의 이용 항로에 관한 고찰)

  • Lee, Li-Na;Lee, Hong-Hoon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.4
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    • pp.525-532
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    • 2022
  • The port of Mokpo operates the largest number of coastal passenger ships and routes in Korea. These coastal passenger ships pass through narrow channels in the south-west coast of Korea owing to the geographical effect. It is difficult to find a research for the safety of the marine traffic environment in the narrow channel used by coastal passenger ship. Therefore, in this study, the navigation safety of the target coastal passenger ship was analyzed in the narrow channel near the port of Mokpo using the Korea design standard for port and harbour facilities. As a result of the analysis, the width of the narrow channel between Maek-island and Dali-island is narrower than 1.5 times of the target ship's length over all, the degree of curvature of the narrow channel exceeds the standard value of 30°, and several fishing gears exist near the narrow channel. Finally, the following were suggested to improve the safety of navigation on the narrow channel: keeping one-way traffic during the day-time, and navigating through the designated fairway during night·visibility restriction·low tide.

Fragility Analysis Method Based on Seismic Performance of Bridge Structure considering Earthquake Frequencies (지진 진동수에 따른 교량의 내진성능기반 취약도 해석 방법)

  • Lee, Dae-Hyoung;Chung, Young-Soo;Yang, Dong-Wook
    • Journal of the Korea Concrete Institute
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    • v.21 no.2
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    • pp.187-197
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    • 2009
  • This paper presents a systematic approach for estimating fragility curves and damage probability matrices for different frequencies. Fragility curves and damage probability indicate the probabilities that a structure will sustain different degrees of damage at different ground motion levels. The seismic damages are to achieved by probabilistic evaluation because of uncertainty of earthquakes. In contrast to previous approaches, this paper presents a method that is based on nonlinear dynamic analysis of the structure using empirical data. This paper presents the probability of damage as a function of peak ground acceleration and estimates the probability of five damage levels for prestressed concrete (PSC) bridge pier subjected to given ground acceleration. At each level, 100 artificial earthquake motions were generated in terms of soil conditions, and nonlinear time domain analyses was performed for the damage states of PSC bridge pier structures. These damage states are described by displacement ductility resulting from seismic performance based on existing research results. Using the damage states and ground motion parameters, five fragility curves for PSC bridge pier with five types of dominant frequencies were constructed assuming a log-normal distribution. The effect of dominant frequences was found to be significant on fragility curves.

Spacing of Intermediate Diaphragms Horizontally Curved Steel Box Girder Bridges considering Bending-distortional Warping Normal Stress Ratio (곡선 강박스 거더의 휨-뒤틀림 응력비에 따른 중간 다이아프램 간격)

  • Lee, Jeong-Hwa;Lee, Kee-Sei;Lim, Jeong-Hyun;Choi, Jun-Ho;Kang, Young-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6325-6332
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    • 2015
  • Although distortions of horizontally curved box girder are more susceptible than which of the straight girder due to curvature effect, current domestic design standards does not present spacing of intermediate diaphragms for the curved box girder. In this study, parametric studies for straight and curved box girder considering distortional warping normal stresses based on linear finite element analysis were carried out. Single span curved girders were chosen for analysis based on current domestic bridge data with 1-6 of solid intermediate diaphragms, 0-30 degree of subtended angle, 30m and 60m of span length and 2-3m of flange width and web height. The adequate spacing of diaphragms for the box girder were suggested considering subtended angles and bending and distortional warping normal stress ratios with 5%, 10%, 15% and 20%. The analysis results were also compared to a current design standard and suggested spacing of diaphragm were evaluated.