• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.247-256
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• 2007

In this paper we introduced GB-SAR focusing algorithms for image formation and suggested an optimized solution. We compared the characteristics, advantages, and limitations of the Deramp-FFT (DF) algorithm and the Range-Doppler (RD) algorithm in terms of their image formation principles, memory usage and processing time. We found that DF algorithm is efficient in memory and processing time but can not focus the near range. The RD algorithm can focus the entire range but, considering the refinement on the rail length, it has much redundancy in memory and processing time. In conclusion, we optimized the GB-SAR focusing by using the DF algorithm for a far-range case and the RD algorithm for a near-range case separately.

• Journal of Chest Surgery
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• v.57 no.2
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• pp.195-204
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• 2024

Background: Extracorporeal membrane oxygenation (ECMO) is an intervention for severe heart and lung failure; however, it poses the risk of complications, including gastrointestinal bleeding (GIB). Comprehensive analyses of GIB in patients undergoing ECMO are limited, and its impact on clinical outcomes remains unclear. Methods: This retrospective study included 484 patients who received venovenous and venoarterial ECMO between January 2015 and December 2022. Data collected included patient characteristics, laboratory results, GIB details, and interventions. Statistical analyses were performed to identify risk factors and assess the outcomes. Results: GIB occurred in 44 of 484 patients (9.1%) who received ECMO. Multivariable analysis revealed that older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01-1.06; p=0.0130) and need to change the ECMO mode (OR, 3.74; 95% CI, 1.75-7.96; p=0.0006) were significant risk factors for GIB, whereas no association was found with antiplatelet or systemic anticoagulation therapies during ECMO management. Half of the patients with GIB (22/44, 50%) underwent intervention, with endoscopy as the primary modality (19/22, 86.4%). Patients who underwent ECMO and developed GIB had higher rates of mortality (40/44 [90.9%] vs. 262/440 [59.5%]) and ECMO weaning failure (38/44 [86.4%] vs. 208/440 [47.3%]). Conclusion: GIB in patients undergoing ECMO is associated with adverse outcomes, including increased risks of mortality and weaning failure. Even in seemingly uncomplicated cases, it is crucial to avoid underestimating the significance of GIB.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.2
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• pp.223-226
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• 2024

Percutaneous techniques for femoral arterial access are increasingly being performed due to advances in endovascular cerebral procedures, as they provide a less morbid and minimally invasive approach than open procedures. Common complications associated with this peripheral puncture include hematoma, bleeding, pseudoaneurysm, arteriovenous fistula, retroperitoneal bleeding, inadvertent venous puncture, dissection, etc. The retrograde femoral access is currently the most frequently used arterial access as it is technically straightforward, allows for the use of larger size sheaths and catheters, allows repeated attempts, etc. Although being technically less challenging, grave complications can occur due to hardware failure. Here, we present a case of unruptured posterior inferior cerebellar artery (PICA) aneurysm, who underwent uneventful diagnostic cerebral digital substraction angiography (DSA) via right femoral artery route on first attempt, but on second attempt for therapeutic intervention, landed up with stuck guide wire and faced decannulation difficulty due to unravelling of guide wire and multiple knot formation, which was finally removed after multiple attempts at pulling and improvised manoeuvres. Such cannulation and decannulation difficulties have been reported multiple times for central venous access, but extremely rarely for femoral routes, making this case a rarity and worth reporting.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.25-30
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• 2007

In this paper, we proposed a new burst-mode optical transmitter structure which is suitable for high data rate operation such as Gb/s operation. With this structure we made a 1.25Gb/s burst-mode optical transmitter including a digitally controlled APC circuit for EPON systems using commercial 0.8m BiCMOS technology. It well functioned at 1.25Gb/s and showed good eye patterns with 53.3ps jitter, 191ps rise time and 258ps fall time. To characterize the APC function we measured optical output power as increasing external voltage VREF. The optical power is linearlyproportional to VREF at the rate of 0.293mW/V.

• Earthquakes and Structures
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• v.22 no.3
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• pp.319-330
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• 2022

Retrofit of soft-story buildings due to seismic loads using Gap-Inclined-Brace (GIB) system is considered a new retrofit technique that aims to maintain both strength and stiffness of structure. In addition, it provides more ductility and less P-delta effect, and subsequently better performance is observed. In this paper, the effect of the eccentricity between GIB and the retrofitted column due to installation on the efficiency of the retrofitting system is studied. In addition, a modification in the determination method of GIB properties is introduced to reduce the eccentricity effect. Also, the effect of GIB system on the seismic response of mid-rise buildings with different heights considering soft-story at various heights has been studied. A numerical model is developed to study the impact of such system on the response of retrofitted soft-story buildings under the action of seismic loads. To achieve that goal, this model is used to perform a numerical investigation, by considering five case study scenarios represent several locations of soft-story of two mid-rise reinforced concrete buildings. At first, Non-linear static pushover analysis was carried out to develop the capacity curves for case studies. Then, Non-linear time history analyses using ten earthquake records with five peak ground accelerations is performed for each case study scenario before and after retrofitting with GIB. The results show that large GIB eccentricity reduce the ultimate lateral resistance and deformation capacity of the retrofitting system. Moreover, the higher the retrofitted building, the more deformation capacity is observed but without significant increase in ultimate lateral resistance.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.267-274
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• 2006

The evaluation of GB stones with ultrasound has proved to be useful procedure in patient with symptoms of cholelithiasis. GB is evaluated for size, wall thickness, presence of internal reflections within the lumen and posterior acoustic shadowing or enhancement in Ultrsonography. The patient position should be shifted during procedure to demonstrate further the presence of stone within the GB. Patient scanned at the Rt. subcostal region in supine, right lateral, Lt. down decubitus, and upright sitting position. So GB stone should shift to dependent area of GB. Often, GB is not markedly distended in the presence of cholethiasis, and so the diagnosis becomes more difficult. One of the more difficult areas for detection of a GB stones are embeded in the cystic duct region. And since the GB is adjacent to the duodenum and hepatic flexure, its may be difficult to visualizing a GB stone. When patient study position changes frome supine to other position, stones displaced the site. But if its are polyps, not changes the site whatever patient positions. It is very important to what make different GB stones or polyps. We have studied about mobility of GB stones according to the patients position(supine, Lt. down decubitus, $30^{\circ} LAO. sitting and hand-knee). So we have a result, stones wherever localized within the GB, changed 100% its position in the hand-knee position and the others appeared at least 90%. In this study, when a large stones are located through fundus-body and body-neck, does not changing the stones position in spite of varied patient's positions. But hand-knee positions can identified GB stones, because its make changed the position of stons from posterior wall to anterior wall within the GB. We recommend the hand-knee position for differentiation GB stones from polyps.

• Molecules and Cells
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• v.26 no.6
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• pp.536-547
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• 2008

Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.

• The Magazine of the IEIE
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• v.29 no.10
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• pp.1175-1175
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• 2002

2002년 6월, IEEE 802.3ae 10Gb/s 이더넷이 표준으로 승인되었다. 10 Gb/s 이더넷은 MAC 부계층과 물리계층을 통합한 규격으로 전이중 방식 및 광섬유 매체만을 제공한다. 기존 이더넷과 동일한 프레임 형식을 사용하고, LAN 물리계층과 WAN 물리계층까지 지원하고 있다. 따라서 LAN, MAN, WAN 영역에서 10Gb/s의 높은 속도를 제공할 수 있으며, 기존의 이더넷과 투명하게 통합할 수 있다. 본 논문에서는 10 기가비트 이더넷의 MAC 부계층과 물리계층 및 최근 기술 동향을 살펴본다.

• The Magazine of the IEIE
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• v.29 no.10
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• pp.29-38
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• 2002

2002년 6월, IEEE 802.3ae 10Gb/s 이더넷이 표준으로 승인되었다. 10 Gb/s 이더넷은 MAC 부계층과 물리계층을 통합한 규격으로 전이중 방식 및 광섬유 매체만을 제공한다.기존 이더넷과 동일한 프레임 형식을 사용하고, LAN 물리계층과 WAN 물리계층까지 지원하고 있다. 따라서 LAN, MAN, WAN 영역에서 10Gb/s의 높은 속도를 제공할 수 있으며, 기존의 이더넷과 투명하게 통합할 수 있다. 본 논문에서는 10 기가비트 이더넷의 MAC 부계층과 물리계층 및 최근 기술 동향을 살펴본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.96-103
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• 1997

We developed the prototype of 4-channel WDM link with erbium-doped fiber amplifiers. Bit rate of each channel was 2.5Gb/s. The unrepeatered transmission over 120km with DSF was achieved and the transmission length was extended to 240km using two EDFAs.