Biomechanical analysis of lumbar decompression surgery in relation to degenerative changes in the lumbar spine – Validated finite element analysis

Li, Quan You,Kim, Ho-Joong,Son, Juhyun,Kang, Kyoung-Tak,Chang, Bong-Soon,Lee, Choon-Ki,Seok, Hyun Sik,Yeom, Jin S. Elsevier 2017 Computers in biology and medicine Vol.89 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>There are no studies about the biomechanical analysis of lumbar decompression surgery in relation to degenerative changes of the lumbar spine. Therefore, the purpose of this study was to compare, by using finite element (FE) analysis, the biomechanical changes of the lumbar spine in terms of annulus stress and nucleus pressure after two different kinds of lumbar decompression surgery in relation to disc degenerative changes.</P> <P><B>Methods</B></P> <P>The validated intact and degenerated FE models (L2-5) were used in this study. In these two models, two different decompression surgical scenarios at L3-4, including conventional laminectomy (ConLa) and the spinous process osteotomy (SpinO), were simulated. Therefore, a total of six models were simulated. Under preloading, 7.5 Nm moments of flexion, extension, lateral bending, and torsion were imposed. In each model, the maximal von Mises stress on the annulus fibrosus and nucleus pressure at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) were analyzed.</P> <P><B>Results</B></P> <P>The ConLa model and disc degeneration model demonstrated a larger annulus stress at the decompression level (L3-4) under all four moments than were seen in the SpinO model and healthy disc model, respectively. Therefore, the ConLa model with moderate disc degeneration showed the highest annulus stress at the decompression level (L3-4). However, the percent change of annulus stress at L3-4 from the intact model to the matched decompression model was less in the moderate disc degeneration model than in the healthy disc model.</P> <P><B>Conclusions</B></P> <P>Although the ConLa model with moderate disc degeneration showed the highest annulus stress, the degenerative models would be less influenced by the decompression technique.</P>

급성 심근 경색중 후 추적 관찰에 관한 연구

박영배,이영우,오동진,고창순,서정돈,서봉관,오병회 대한내과학회 1986 대한내과학회지 Vol.31 No.5

To assess the change in left ventricular function after hospital discharge, 57 patients with acute myocardial infarction were studied before discharge and 26 of them after discharge as well with either or both of treadmill test and radionuclide ventriculography(RNV). Follow-up study patients were 2g men with mean age of 53.1. Their infarct locations were anterior in 16 cases, inferior in 8 cases and anterior and inferior in 2 cases; 21 cases were in Killip class I, 3 cases in II, and 2 cases in III. Follow-up study was performed 2~19 months(mean 7.3 months) after acute myocardial infarction. The results were as follows: 1) Predischarge study showed that a relationship is present between regional wall motion abnormality, Killip class, peak serum CK and left ventricular ejection fraction(LVEF). 2) Predischarge and follow-up treadmill tests showed no significant change. 3) Follow-up RNV showed worsening of regional wall motion only in 1 case: Other cases showed either improvement or no change in regional wall motion. 4) Overall patients showed a significant increase in LVEF on follow-up. By location, only anterior infarction showed a significant increase in LVEF. 5) Killip class I patients showed a significant increase in LVEF on follow-up. 6) Most cases in this study were uncomplicated myocardial infarction and they showed improved LV function(suggested by RNV) on follow-up. Treadmill test also seems to be valuable for evaluationg improvement in exercise capacity on follow-up. So it is recomended that treadmill test or RNV be performed after discharge to evaluate change in LV function objectively.

배지의 무기염류와 sucrose 농도가 감자의 기내 shoot 증식과 기내경 삽목묘의 생존율에 미치는 영향

김희곤,임순희,안장순,송창길,박미경,강봉균 全南大學校 農業科學技術硏究所 1999 農業科學技術硏究 Vol.34 No.-

감자의 virus-free 기내경 삽목묘의 효율적인 대량 생산 체계의 확립을 위하여 생장점 배양으로 얻어진 감자의 기내경의 증식과 기내경의 순화삽목을 실시한 결과는 다음과 같다. 초대배양에서는 염류농도와 sucrose 농도가 높을수록 양호하였다. 즉, MS나 2MS에 sucrose를 6% 첨가한 배지에서 튼튼한 기내경이 생산되었다. 계대배양에서는 sucrose 농도가 높을수록 줄기의 길이는 단축되고 굵기는 커졌으며 생체중은 염류농도와 관계없이 3%의 sucrose가 첨가된 배지에서 무거웠다. 이들 유식물체의 경절을 삽목한 결과 계대배양 배지의 sucrose농도가 6%인 배지에서 생존율이 높은 경향이었다. In order to establish a mass propagation system of potato planting material, in vitro multiplication of virus-free shoot originated from meristem culture and sucrose concentrations on survival of cutting of the in vitro stem tried with various media containing different levels of MS salts(0.5x, 1x and 2x) and sucrose(1.0, 3.0, 6.0%), and the effects of MS salts elements were evaluated. Higher level of sucrose in the initial culture media favored the shoot growth, that is, both of 1MS and 2MS media containing 6.0% sugar produced stouter shoots. Higher level of sucrose in the subculture media also favored the development of compact stout shoots, but biomass production in terms of fresh weight was high on the media containing 3.0%sucrose, regardless of MS salts concentration. The survival rate of cuttings made of the in vitro stem segments tended to be higher in those obtained from subculture media containg 6.0%sucrose.

IEEE 802.11a OFDM System을 위한 파이프라인 구조인 R4SDC와 R2²SDF IFFT/FFT 모듈의 설계 비교

이창훈,곽성민,강봉순 동아대학교 정보기술연구소 2003 情報技術硏究所論文誌 Vol.11 No.1

The IFFT/FFT module takes charge of modulation and demodulation part and is critical to performance of the OFDM system, that is, error from the IFFT/FFT module is very critical to the whole system. Therefore, when implementing the hardware, minimizing error of the IFFTEFT module is essential. In this paper, we design this IFFT/FFT. The designed IFFT/FFT is the 64-point FFT to be compatible the IEEE 802.11a standard and the pipeline architecture which needs no serial-to-parallel and parallel-to-serial converter. The design methods are the R22SDF (Radix-22 Single-path Delay Feedback) and R4SDC (Radix-4 Single-path Delay Commutator) architecture. We are focusing on the hardware structure considering the OFDM and errors that occur in the IFFT/FFT design step, such as Scaling, Coefficient and Round-off error.

금호타이어의 경영혁신활동 : 균형성과표와 6시그마를 중심으로 Balanced Scorecard and 6-σ

김순기,김봉기,이창대 서강대학교 경영학연구원 2004 서강경영논총 Vol.14 No.2

1비트 직렬통신에서 헤드정보 검출 기능을 가진 회전기용 리시버의 FPGA 구현

이창훈,이상진,하주영,강봉순 東亞大學校附設 情報技術硏究所 2004 情報技術硏究所論文誌 Vol.12 No.1

This paper presents the design and implementation of a receiver operating between a rotary machine encoder and DSP. The receiver connects with the encoder using 1 bit serial data and DSP using 16 bits bus line. The receiver and encoder use the different operating frequency each other. We suggest a new apparatus and method of synchronized code for header detection in 1bit serial communication. The system operating frequency can be changed into 20MHz or 60MHz by using the external port such as 'clk_select'.

지상파 디지털 멀티미디어 방송 시스템을 위한 파이프라인 구조의 IFFT/FFT 모듈

이창훈,하주영,강봉순 東亞大學校附設 情報技術硏究所 2004 情報技術硏究所論文誌 Vol.12 No.1

In this paper, we propose an implementation result for Multi complex point pipelined IFFT/FFT(Inverse Fast Fourier Transform/Fast Fourier Transform) in terms of sequential data processing. We compared four types of IFFT/FFT modules for the hardware complexity and operation for IEEE 802.11a-1999. In order to minimize the error, we design the IFFT/FFT module to operate with additional decimal parts after butterfly operation. In case of the R22SDF(Radix-2 Single-path Delay Feedback), the IFFT/FFT module has low gate counts excluding RAMs and the minimized error rate as compared with other types. Therefore we choose the pipelined R22SDF architecture IFFT/FFT for DAB(Digital Audio Broadcasting) System.

흰쥐 숨뇌의 맨아래구역에서 Phenylalanine처리에 따른 Monosodium Glutamate의 효과

이창헌,고병문,김명순,정옥봉 대한췌담도연구회 2000 대한췌담도연구회지 Vol.5 No.2

出生前 MAM(methylazoxymehtanol) 投與가 逃避不可能한 衝擊에 의해 生成되는 도피수행결손에 미치는 效果

鄭奉敎,朴淳權,張鉉甲 嶺南大學校附設 基礎科學硏究所 1987 基礎科學硏究 Vol.7 No.-

본 연구는 임신중에 MAM이 투여된 어미에서 태어난 새끼들이 도피검사에서 수행장애를 나타내는가를 검토해 보고자 하였다. 피험동물의 반수는 변동간격계획 60초에 따라 6초간 지속되는 60회의 도피불가능한 전기충격(1.0mA-900V, DC)을 받았고, 나머지 동물들은 충격을 받지 않았다. 도피검사는 최초의 스트레스회기가 종료된 24시간 후에 실시되었다. 도피불가한 전기충격에 대한 노출경험은 전기충격을 도피하는 과제에서 반응시간의 증가를 초래했다. 그러나 이런 충격효과는 MAM 처치동물에서는 현저하지 않았다. 단순구금된 MAM 처치흰뒤들도 전기충격을 받은 MAM처치 흰쥐와 통제군의 흰쥐만큼 도피수행의 결함을 나타내었다. 이런 결과는 MAM처치동물들이 비교적 정도가 낮은 스트레스에 대해서도 민감하게 반능할 가능성을 시사해 준다. The effect of prenatal treament of rats with methylazowymethanol(MAM) on the deficits of escape behavior was evaluated. Half the rats received 60 inescapable shocks of 1.0mA (900V, DC) of 6s duration at variable intervals of 60s. The other restrained animals did not receive any shock. Escape testeing was conducted 24h after termination of the initial stress session. The exposure to inescapable shock subsequently increased the latency to escape from shock, but the degree of icrease was less prounced in MAM-treated animals than in saline treated controls. The performance of nonshock rats with MAM treatment exhibited escape deficits comparable to preshocked rats. This results suggested that the MAM rats are sensitive to the moderate levels of stress.

방카슈랑스 도입이 금융겸업화 효율성에 미치는 영향

이봉주(Bong Joo Lee),이순재(Soon Jae Lee),정세창(Se Chang Jung) 한국경영학회 2004 經營學硏究 Vol.33 No.2

The purpose of this paper is to reveal the effects of integration when banks and insurers combine and to examine which types of financial firms are appropriate for a bancassurance partner in terms of the cost, revenue, and profit efficiency. The thick frontier and scenario analysis are employed to measure the efficiency change. We find that, while foreign and small- and medium-sized insurers can gain cost and profit efficiency through financial convergence, they lose revenue efficiency. On the other hand, large insurers can realize cost efficiency, but lose revenue and profit efficiency. Banks as a whole can realize revenue and profit efficiency, but lose cost efficiency. As a bancassurance partner for banks, large insurers are most suitable due to their related product portfolio and good reputation. Banks partnering with small- and medium-sized insurers results in a gain in revenue efficiency, but a loss in profit efficiency.