• Journal of Korean Neurosurgical Society
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• v.38 no.5
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• pp.399-402
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• 2005

Direct anterior approach for lesions located anterior to the thecal sac is definitely superior to lateral or posterior approach in many respects. However, various anatomical obstacles and technical difficulties often hinder direct anterior approach. Thanks to ripe experience of retroperitoneal approach to the lumbar spine for anterior lumbar interbody fusion and total disc replacement, the authors could perform lumbar corpectomy and reconstruction by using midline retroperitoneal approach recently. During this approach, we repaired anterior longitudinal ligament also to reduce the risk of graft extrusion and to prevent erosion of vascular wall due to direct contact between metallic hardware, which was used for reconstruction of vertebral body, and major vessels.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.848-855
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• 1989

By structural comparison of process optimization strategies based on Simultaneous Modular Approach, they can be classified into two groups : the Sequential Module Based Approach and the Two-Tier Approach. The Sequential Module Based Approach needs rigorous models and a set of accurate solutions are guranteed. However, it requires large amount of computation time. In the Two-Tier Approach composed of rigorous and simplified models, optimization calculation uses simplified models, therefore comparatively smaller amount of computation time is required but the obtained solutions may not be accurate. These optimization problems were somewhat improved by the alternate application of the two strategies. In this study, improved optimization strategy is suggested, in which Jacobian Matrix is modified to accomodate the strong points of above mentioned strategies. The results of case study show that this approach is superior to the other strategies.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.28 no.1
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• pp.59-69
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• 2024

Backgrounds/Aims: Pancreaticoduodenectomy (PD) is the only radical treatment for periampullary malignancies. Superior mesenteric artery (SMA) first approach combined with total meso-pancreas (MP) excision was conducted to improve the oncological results. There has not been any previous research of a technique that combines the SMA first approach and total MP excision with a detailed description of the MP macroscopical shape. Methods: We prospectively assessed 77 patients with periampullary malignancies between October 2020 and March 2022 (18 months). All patients had undergone PD with SMA first approach combined total MP excision. The perioperative indications, clinical data, intra-operative index, R0 resection rate of postoperative pathological specimens (especially mesopancreatic margin), postoperative complications, and follow-up results were evaluated. Results: The median operative time was 289.6 min (178-540 min), the median intraoperative blood loss was 209 mL (30-1,600 mL). Microscopically, there were 19 (24.7%) cases with metastatic MP, and five cases (6.5%) with R1-resection of the MP. The number of lymph nodes (LNs) harvested and metastatic LNs were 27.2 (maximum was 74) and 1.8 (maximum was 16), respectively. Some (46.8%) patients had pancreatic fistula, but mostly in grade A, with 7 patients (9.1%) who required re-operations. Some 18.2% of cases developed postoperative refractory diarrhea. The rate of in-hospital mortality was 1.3%. Conclusions: The PD with SMA first approach combined TMpE for periampullary malignancies was effective in achieving superior oncological statistics (rate of MP R0-resection and number of total resected LNs) with non-inferior short-term outcomes. It is necessary to evaluate survival outcomes with long-term follow-up.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.222-225
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• 2011

Superior petrosal sinus (SPS) dural arteriovenous fistula (DAVF) is one of tentorial DAVFs with significant morbidity, which usually drains into the petrosal vein and its tributaries. Unless there is a connection with venous sinus, surgical obliteration is required. We present two cases of SPS DAVF which were successfully treated with the presigmold retrolabyrinthine approach.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.297-313
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• 2012

This paper is intended to show the robustness and capabilities of a coupled boundary element-finite element technique for the analysis of vibrations generated by high-speed trains under different geometrical, mechanical and operation conditions. The approach has been developed by the authors and some results have already been presented. Nevertheless, a more comprehensive study is presented in this paper to show the relevance and robustness of the method which is able to predict vibrations due to train passage at the vehicle, the track, the free-field and any structure close to the track. Local soil discontinuities, underground constructions such as underpasses, and coupling with nearby structures that break the uniformity of the geometry along the track line can be represented by the model. Non-linear behaviour of the structures can be also considered. Results concerning the excitation mechanisms, track behaviour and sub-Rayleigh and super-Rayleigh train speed are summarized in this work.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.868-874
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• 1990

A singular value approach is presented in order to determine the number of multiple sinusoids from the finite noisy data. Simulations are conducted for Akaike's information criterion (AIC), Rissanen's shortest data description (MDL) and a singular value approach, for various examples with different SNR's and methods of estimating frequencies. And then the performances are compared. Simulation results that the singular value approach is superior to AIC and MDL for FBLP, HOYW and covariance matrix based methods are investigated. The approach with contribute to the frequency estimation of multiple sinusoids from the finite noisy data. Furthermore, this will be applied to the DSPs of communication and bio-medical engineering.

• ETRI Journal
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• v.41 no.4
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• pp.452-464
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• 2019

The use of wireless body area networks (WBANs) in healthcare applications has made it convenient to monitor both health personnel and patient status continuously in real time through wearable wireless sensor nodes. However, the heterogeneous and complex network structure of WBANs has some disadvantages in terms of control and management. The software-defined network (SDN) approach is a promising technology that defines a new design and management approach for network communications. In order to create more flexible and dynamic network structures in WBANs, this study uses the SDN approach. For this, a WBAN architecture based on the SDN approach with a new energy-aware routing algorithm for healthcare architecture is proposed. To develop a more flexible architecture, a controller that manages all HUBs is designed. The proposed architecture is modeled using the Riverbed Modeler software for performance analysis. The simulation results show that the SDN-based structure meets the service quality requirements and shows superior performance in terms of energy consumption, throughput, successful transmission rate, and delay parameters according to the traditional routing approach.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2787-2790
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• 2003

In this paper, we predict tracking performance of the multiple hypothesis tracking (MHT) algorithm. The MHT algorithm is known to be an optimal Bayesian approach and is superior to asly other tracking filters because it takes into account the events that the measurements can be originated from new targets and false alarms 3s well as interesting targets. In the MHT algorithm, a number of candidate hypotheses are generated and evaluated later as more data are received. The probability of each candidate hypotheses is approximately evaluated by using the hybrid conditional average approach (HYCA). We performed numerical experiments to show the validity of our performance prediction.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.585-588
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• 1999

This paper concentrates on an experimental results on visual only recognition tasks using an image transform approach and HMM based recognition system. There are two approaches for extracting features of lipreading, a lip contour based approach and an image transform based one. The latter obtains a compressed representation of the image pixel values that contain the speaker's mouth results in superior lipreading performance. In addition, PCA(Principal component analysis) is used for fast algorithm. Finally, HMM recognition tasks are compared with the another.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1087-1099
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• 2021

MRI has become important for the detection of prostate cancer. MRI-guided biopsy is superior to conventional systematic biopsy in patients suspected with prostate cancer. MRI is also increasingly used for monitoring patients with low-risk prostate cancer during active surveillance. It improves patient selection for active surveillance at diagnosis, although its role during follow-up is unclear. We aim to review existing evidence and propose a practical approach for incorporating MRI into active surveillance protocols.