• Childhood Kidney Diseases
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• 제8권2호
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• pp.244-249
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• 2004

비만성 사구체경화증(obesity-associated focal segmental glomerulosclerosis)은 비만과 부종이 없는 신증후군 범위의 단백뇨, 사구체 비대 및 경화 등의 임상상을 보이는 질환으로, 다수의 환자에서 신부전으로 진행되는 것으로 알려져 있다. 연구자들은 부종 없이 심한 단백뇨와 저알부민혈증을 보인 14세의 Prader-Willi 증후군 여아에서 신생검을 통하여 사구체비후와 메산지움 증식이 동반된 국소성 분절성 사구체경화 소견을 관찰하였다 이로써 소아의 Prader-Willi 증후군에서도 비만성 사구체경화증에 의한 신부전으로의 진행 위험이 있음을 알리는 바이다.

• Journal of Chest Surgery
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• 제51권5호
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• pp.338-343
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• 2018

Background: This study examined the role of superficial vein surgery in patients with combined superficial venous reflux and segmental popliteal vein reflux. Methods: We retrospectively reviewed 42 limbs in 38 patients with combined superficial venous reflux and segmental popliteal vein reflux who underwent saphenous vein ablation between January 2014 and February 2017. Patients underwent outpatient follow-up duplex ultrasonography at 3, 6, and 12 months postoperatively. Resolution of deep vein reflux was defined as reversed blood flow in a popliteal segment for less than 1.0 second and a decrease in the reflux time of more than 20% of the preoperative reflux time. Results: The mean follow-up period was 9 months (range, 3-23 months). Saphenous vein ablations were performed by stripping in 24 limbs and radiofrequency ablation in 18 limbs. Preoperative segmental popliteal vein reflux resolved in 21 of the 42 limbs (50%). Conclusion: This study demonstrated that superficial venous surgery corrected segmental popliteal vein reflux in 50% of limbs with combined superficial venous reflux and segmental popliteal vein reflux. Other prospective studies are necessary to elucidate the etiology of the non-reversible cases.

• Earthquakes and Structures
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• 제8권6호
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• pp.1277-1297
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• 2015

Post-tensioned precast segmental bridge columns have shown high level of strength and ductility, and low residual displacement, which makes them suffer minor damage after earthquake loading; however, there is still lack of confidence on their lateral response against severe seismic loading due in part to their low energy dissipation capacity. This study investigates the influence of major design factors such as post-tensioning force level, strands position, columns aspect ratio, steel jacket and mild steel ratio on seismic performance of self-centring segmental bridge columns in terms of lateral strength, residual displacement and lateral peak displacement. Seismic analyses show that increasing the continuous mild steel ratio improves the lateral peak displacement of the self-centring columns at different levels of post-tensioning (PT) forces. Such an increase in steel ratio reduces the residual drift in segmental columns with higher aspect ratio more considerably. Suggestions are proposed for the design of self-centring segmental columns with various aspect ratios at different target drifts.

• 한국지진공학회논문집
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• 제20권1호
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• pp.33-43
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• 2016

This study investigates the performance of hollow precast segmental bridge columns with reinforcement details for material quantity reduction. The proposed triangular reinforcement details are economically feasible and rational, and facilitate shorter construction periods. The precast segmental bridge columns provides an alternative to current cast-in-place systems. We tested a model of hollow precast segmental bridge columns under a constant axial load and a quasi-static, cyclically reversed horizontal load. We used a computer program, Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST), for analysis of reinforced concrete structures. The used numerical method gives a realistic prediction of performance throughout the loading cycles for hollow precast segmental bridge column specimens investigated. As a result, proposed reinforcement details for material quantity reduction was equal to existing reinforcement details in terms of required performance.

• 전력전자학회논문지
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• 제21권1호
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• pp.1-9
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• 2016

In this study, two types of switched reluctance motors (SRMs) with segmental rotors are presented in detail. The first is a 6/5 segmental rotor type, whereas the second is a 12/8 segmental rotor type. Both motor types have the same stator, rotor, and winding configurations. The stator is constructed with special stator poles, namely, exclusively designed exciting and auxiliary poles. The rotor is constructed from a series of discrete segments, each of which is embedded into the nonmagnetic isolator. The windings are only wound on the exciting poles, and no winding is wound on the auxiliary poles. Given these configurations, short flux paths and high flux-linkage utilization rate are achieved in the proposed motors, which may reduce the magnetomotive force requirement and increase the electrical utilization of a machine. To verify the effectiveness of the proposed motors, their characteristics, such as magnetic flux distribution, flux-linkage, torque, radial force, and efficiency, are analyzed and compared with those of a conventional 12/8 SRM. Meanwhile, two prototypes, one for each proposed segmental rotor type, are also designed and manufactured. Finally, the validity of the proposed motors is further verified by test results.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권5호
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• pp.329-334
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• 2009

Objective: To evaluate the ratio between bone-contact length and inter-segmental length of the rigid fixation screw used in bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback. Material and Methods: Records of 40 patients with Class III malocclusion were selected. 20 of them had BSSRO, while the other 20 had BSSRO with maxillary LeFort I osteotomy. All of the patients had three noncompressive bicortical screws inserted at the gonial angle through transcutaneous approach. Two screws were inserted antero-posteriorly above inferior alveolar nerve and one screw was inserted below. The lengths of bone-contact and that of inter-segmental part were measured using cone-beam computed tomography. Ratio between these two measured lengths was calculated. Results: Both bone-contact and inter-segmental lengths were longer in BSSRO group than in BSSRO with maxillary LeFort I osteotomy group. Ratio of bone-contact to inter-segmental length was lower in BSSRO group than in BSSRO with Lefort I group. Both bone-contact and inter-segmental lengths were longer at the antero-superior position than at the inferior position. However, their ratio showed little difference. Conclusion: This study suggest that stability of screws in BSSRO group was greater than in BSSRO with Lefort I group. Stability of screws at the antero-superior position was greater than at the inferior position. Ratio of bone-contact to inter-segmental lengths was 0.2 in average.

• 대한지역사회영양학회지
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• 제2권2호
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• pp.179-186
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• 1997

A new bioelectrical impedance method has been developed and evaluated. The electrodes; were made of stainless steel and electrical interfaces were created by an upright subject gripping hand electrodes and stepping onto foot electrodes. Eight tactile electrodes were in contact with surfaces of both hands and feet; thumb, palm and fingers, front sole, and rear sole. Automatic on-off switches were used to change current pathways and to measure voltage differences for target segments. Segmental body resistances and whole body resistance(RWHOLE)were measured in 60 healthy subjects. Segmental resistances of right arm(RRA), left arm(RLA), trunk(RT), right leg(RRL) and left leg(RLL)were310.0$\pm$61.6$\Omega$, 316.9$\pm$64.6$\Omega$, 25.1$\pm$3.4$\Omega$, 236.8$\pm$31.2$\Omega$ and 237.6$\pm$30.4$\Omega$, respectively. Individual segmental impedance indexes(Ht2/RRA, Ht2/RT, and Ht2 /RLA) were closely related to lean body mass(LBM)as measured by densitometry ranged from r=0.925 to 0.960. Ht2/(RRA+RT+RLA) predicted LBM slightly better(r=0.969) than the traditional index, Ht2/RWHOLE(r=0.964), supporting the accuracy of the segmental measurement. A multiple regression equation utilizing Ht2/RRA, Ht2/RT and Ht2/RRL predicted LBM with r=0.971. Ht2/RRA term of the regression contributed to more than 40$\%$ of the LBM prediction, indicating that lean mass of arm represented whole body LBM more closely than other body segments. The new bioimpedance method was characterized by upright posture, eight tactile electrodes, segmental measurements and utilization of electronic switches in comparison with the traditional method. The measurement with this new method was extremely reproducible, quick and easy to use.

• 한국운동역학회지
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• 제24권4호
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• pp.375-383
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• 2014

The purpose of this study was to assess the inter-segmental trunk motion during which multi-segmental movements of the spinal column was designed to interpret the effect of segmentation on the total measured spine motion. Also it analyzed the relative motion at three types of the spine models in drop landing. A secondary goal was to determine the intrinsic algorithmic errors of spine motion and the usefulness of such an approach as a tool to assess spinal motions. College students in the soccer team were selected the ten males with no history of spine symptoms or injuries. Each subject was given a fifteen minute adaptation period of drop landing on the 30cm height box. Inter-segmental spine motion were collected Vicon Motion Capture System (250 Hz) and synchronized with GRF data (1000 Hz). The result shows that Model III has a more increased range of motion (ROM) than Model I and Model II. And the Lagrange energy has significant difference of at E3 and E4 (p<.05). This study can be concluded that there are differences in the three models of algorithm during the phase of load absorption. Especially, Model III shows proper spine motion for the inter-segmental joint motion with the interaction effects using the seven segments. Model III shows more proper observed values about dynamic equilibrium than Model I & Model II. The findings have shown that the dynamic stability strategy of Model III toward multi-directional spinal motion supports for better function of the inter-segmental motor-control than the Model I and Model II.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 토목섬유 학술발표회 논문집
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• pp.1-20
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• 1997

• 한국구조물진단유지관리공학회 논문집
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• 제23권3호
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• pp.9-16
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• 2019

최근 프리캐스트 PSC 거더 형식의 교량이 널리 시공되고 있으며, 거더의 경간과 운송제한을 극복하기 위하여 분절거더의 시공이 증가하고 있다. 분절 공법을 적용한 세그먼트 간의 접합면에는 불연속면이 존재할 수 있으므로 교량의 건전성에 있어 접합부의 일체거동이 매우 중요하다. 분절 접합부는 접합부의 형태, 전단키 유무, 구속력의 크기에 따라 거동차이를 보이기 때문에 이러한 영향인자를 변수로 한 접합부 거동 연구가 필요하다. 본 연구에서는 프리캐스트 PSC 거더교의 접합부 거동을 평가하기 위하여 전단키의 형상, 구속력 도입여부를 변수로 한 전단키 유한요소해석과 축소모형시험을 실시하고, 그 결과를 비교하여 전단키와 구속력 효과를 평가하였으며, 접합부에 1/2~1/3의 돌출높이비를 갖는 전단키를 설치하고 콘크리트 강도의 1/2 수준의 구속력을 도입하는 것이 분절 접합부 거동향상에 효과적이라는 것을 확인하였다. 또한, 분절 공법으로 시공된 실제 프리캐스트 PSC 거더 교량의 재하시험을 실시하고 접합부 세그먼트 간의 처짐차이를 측정하여 분절부 거동을 평가하는 방법을 제안하였다.