• Investigative Magnetic Resonance Imaging
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• 제21권3호
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• pp.187-191
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• 2017

Bone marrow aspirates concentrate (BMAC) transplantation is a well-known technique for cartilage regeneration with good clinical outcomes for symptoms in patients with osteoarthritis (OA). Magnetic resonance imaging (MRI) has an important role in evaluating the degree of cartilage repair in cartilage regeneration therapy instead of a second assessment via an arthroscopy. We experienced a case of hypertrophic regeneration of the cartilage and a presumed simultaneous regeneration of the posterior horn of the lateral meniscus after BMAC transplantation for a cartilage defect at the lateral tibial and femoral condyle. This report provides the details of a case of an unusual treatment response after a BMAC transplant. This report is the first of its kind to demonstrate a MR image that displays the simultaneous regeneration of the cartilage and meniscus with a differentiation ability of the mesenchymal stem cell to the desired cell lineage.

• Steel and Composite Structures
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• 제37권1호
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• pp.51-73
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• 2020

The present paper investigates the simultaneous resonance behavior of spiral stiffened multilayer functionally graded (SSMFG) cylindrical shells with internal and external functionally graded stiffeners under the two-term large amplitude excitations. The structure is embedded within a generalized nonlinear viscoelastic foundation which is composed of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness. The cylindrical shell has three layers consist of ceramic, FGM, and metal. The exterior layer of the cylindrical shell is rich ceramic while the interior layer is rich metal and the functionally graded material layer is located between these layers. With regard to classical shells theory, von-Kármán equation, and Hook law, the relations of stress-strain are derived for shell and stiffeners. The spiral stiffeners of the cylindrical shell are modeled according to the smeared stiffener technique. According to the Galerkin method, the discretized motion equation is obtained. The simultaneous resonance is obtained using the multiple scales method. Finally, the influences of different material and geometrical parameters on the system resonances are investigated comprehensively.

• Journal of Korean Neurosurgical Society
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• 제58권4호
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• pp.397-400
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• 2015

The simultaneous occurrence of an intracranial and a spinal subdural hematoma (SDH) is rare. We describe a case of cranial SDH with a simultaneous spinal SDH. An 82-year-old woman visited the emergency room because of drowsiness and not being able to walk 6 weeks after falling down. A neurological examination showed a drowsy mentality. Brain computed tomography showed bilateral chronic SDH with an acute component. The patient underwent an emergency burr-hole trephination and hematoma removal. She exhibited good recovery after the operation. On the fourth postoperative day, she complained of low-back pain radiating to both lower limbs, and subjective weakness of the lower limbs. Spine magnetic resonance imaging revealed a thoracolumbosacral SDH. A follow-up spinal magnetic resonance imaging study that was performed 16 days later showed a significant decrease in the size of the spinal SDH. We discuss the pathogenesis of this simultaneous occurrence of spinal and cranial SDH.

• ETRI Journal
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• 제31권2호
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• pp.201-208
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• 2009

This paper proposes a spiral-shaped power island structure that can effectively suppress simultaneous switching noise (SSN) when the power plane drives high-speed integrated circuits in a small area. In addition, a new technique is presented which greatly improves the resonance peaks in a stopband by utilizing ${\lambda}$/4 open stubs on a conventional periodic electromagnetic bandgap (EBG) power plane. Both proposed structures are simulated numerically and experimentally verified using commercially available 3D electromagnetic field simulation software. The results demonstrate that they achieve better SSN suppression performance than conventional periodic EBG structures.

• 마이크로전자및패키징학회지
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• 제6권4호
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• pp.9-14
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• 1999

본 논문에서는 고속 디지털 회로에서 발생하는 Simultaneous Switching Noise (SSN)를 감소하기 위한 다층 기판 구조를 제안하고 시간 영역 시간 차분법 (Finite Difference Time Domain Method)을 이용하여 그 효과를 확인하였다. 제안된 구조는 전원 평면과 접지 평면사이에 전도성 유전체를 전체 또는 부분적으로 삽입한 구조로 혼신 전압파의 크기를 각각 최대 85%, 55% 까지 줄일 수 있어 고속 고성능 디지털 시스템 구현에 효과적으로 적용될 수 있다.

• Investigative Magnetic Resonance Imaging
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• 제16권2호
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• pp.169-172
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• 2012

양측 대퇴사두건의 동시성 파열은 매우 드물며 몇 개의 증례만이 문헌에 보고되어 있다. 정확한 병인은 아직까지 알려지지 않았다. 그러나 만성신부전에 의한 이차성 부갑상선기능항진증과 같은 만성 대사성 질환을 앓고 있는 환자들에게 드물게 발생한다. 저자들은 만성신부전에 의한 이차성부갑상선기능항진증 환자에서 대퇴사두건이 양측 동시 파열된 1예를 경험하였기에 문헌고찰과 함께 보고하고자 한다.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2006년도 제11차 학술대회
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• pp.32-32
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• 2006

• ETRI Journal
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• 제23권3호
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• pp.106-110
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• 2001

Subpicosecond all-optical switching method based on the simultaneous two-photon coherence exchange is proposed and numerically demonstrated. The optical switching mechanism is based on the optical field induced dark resonance swapping via nondegenerate four-wave mixing processes. For potential applications of ultrafast all-optical switching in fiber-optic communications, 10-THz channel number independent quantum router is discussed.

• 대한관절경학회지
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• 제10권1호
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• pp.95-98
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• 2006

원판형 연골은 주로 슬관절의 외측에 발생하는 것이 보통이며 드물게 내측에도 발생하는 것으로 알려져 있다. 그러나 내측 및 외측에 동시에 발생한 원판형 연골은 보고된 바가 없다. 저자들은 슬관절 동통을 주소로 내원한 15세 남자에서 자기 공명 영상 및 관절경을 이용하여 한쪽 슬관절에서 내측 및 외측에 동시에 발생한 원판형 연골을 진단하고 양측 모두에 대해 관절경하 부분 절제술로 치료하였기에 보고하고자 한다.

• Investigative Magnetic Resonance Imaging
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• 제21권4호
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• pp.210-222
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• 2017

Purpose: To develop a novel combination of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) with integrated SSFP (CAIPI-iSSFP) for accelerated SSFP imaging without banding artifacts at 3T. Materials and Methods: CAIPI-iSSFP was developed by adding a dephasing gradient to the balanced SSFP (bSSFP) pulse sequence with a gradient area that results in $2{\pi}$ dephasing across a single pixel. Extended phase graph (EPG) simulations were performed to show the signal behaviors of iSSFP, bSSFP, and RF-spoiled gradient echo (SPGR) sequences. In vivo experiments were performed for brain and abdominal imaging at 3T with simultaneous multi-slice (SMS) acceleration factors of 2, 3 and 4 with CAIPI-iSSFP and CAIPI-bSSFP. The image quality was evaluated by measuring the relative contrast-to-noise ratio (CNR) and by qualitatively assessing banding artifact removal in the brain. Results: Banding artifacts were removed using CAIPI-iSSFP compared to CAIPI-bSSFP up to an SMS factor of 4 and 3 on brain and liver imaging, respectively. The relative CNRs between gray and white matter were on average 18% lower in CAIPI-iSSFP compared to that of CAIPI-bSSFP. Conclusion: This study demonstrated that CAIPI-iSSFP provides up to a factor of four acceleration, while minimizing the banding artifacts with up to a 20% decrease in the relative CNR.