• Archives of Plastic Surgery
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• v.49 no.4
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• pp.543-548
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• 2022

Microvascular reconstruction frequently requires anastomosis outside of the zone of injury for successful reconstruction. Multiple options exist for pedicle lengthening including vein grafts, arteriovenous loops, and arteriovenous bundle interposition grafts. The authors performed a systematic review of arteriovenous bundle interposition grafts to elucidate indications and outcomes of arteriovenous grafts in microvascular reconstruction. A systematic review of the literature was performed using targeted keywords. Data extraction was performed by two independent authors, and descriptive statistics were used to analyze pooled data. Forty-four patients underwent pedicle lengthening with an arteriovenous graft from the descending branch of the lateral circumflex femoral artery. Most common indications for flap reconstruction were malignancy (n = 12), trauma (n = 7), and diabetic ulceration (n = 4). The most commonly used free flap was the anterolateral thigh flap (n = 18). There were five complications, with one resulting in flap loss. Arteriovenous bundle interposition grafts are a viable option for pedicle lengthening when free flap distant anastomosis is required. The descending branch of the lateral circumflex femoral artery may be used for a variety of defects and can be used in conjunction with fasciocutaneous, osteocutaneous, muscle, and chimeric free flaps.

• Archives of Plastic Surgery
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• v.39 no.3
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• pp.222-226
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• 2012

Background : Immediate breast reconstruction after mastectomy and delayed breast reconstruction with post-supplementary treatment are the two types of breast reconstruction currently performed when treating breast cancer. Post-mastectomy radiation therapy (PMRT) not only reduces local recurrence but also improves overall survival. However, the complications and survival rates associated with PMRT need to be clear when determining the timing of breast reconstruction. Accordingly, we investigated the optimal timing of breast reconstruction by observing patients who underwent mastectomy followed by PMRT, based on their overall health and aesthetic satisfaction. Methods : We retrospectively reviewed 21 patients who underwent breast reconstruction with PMRT between November 2004 and November 2010. We collected data regarding the various methods of mastectomy, and the modality of adjuvant therapy, such as chemotherapy, hormone therapy, and radiotherapy. Telephone interviews were conducted to study the general and aesthetic satisfaction. Results : Patients who received PMRT after breast reconstruction showed a greater complication rate than those undergoing breast reconstruction after PMRT (P=0.02). Aesthetic satisfaction was significantly higher in the groups undergoing breast reconstruction after PMRT (P=0.03). Patients who underwent breast reconstruction before PMRT developed complications more frequently, but they expressed greater aesthetic satisfaction with the treatment. Conclusions : It is recommended that the complication rates and aesthetic satisfaction after breast reconstruction be carefully considered when determining the optimal timing for radiotherapy.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.3
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• pp.143-151
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• 2024

In this study, we present a mapping framework for 3D spatial reconstruction of digital twin model using navigation and perception sensors mounted on an Autonomous Surface Vehicle (ASV). For improving the level of realism of digital twin models, 3D spatial information should be reconstructed as a digitalized spatial model and integrated with the components and system models of the ASV. In particular, for the 3D spatial reconstruction, color and 3D point cloud data which acquired from a camera and a LiDAR sensors corresponding to the navigation information at the specific time are required to map without minimizing the noise. To ensure clear and accurate reconstruction of the acquired data in the proposed mapping framework, a image preprocessing was designed to enhance the brightness of low-light images, and a preprocessing for 3D point cloud data was included to filter out unnecessary data. Subsequently, a point matching process between consecutive 3D point cloud data was conducted using the Generalized Iterative Closest Point (G-ICP) approach, and the color information was mapped with the matched 3D point cloud data. The feasibility of the proposed mapping framework was validated through a field data set acquired from field experiments in a inland water environment, and its results were described.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.204-211
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• 2010

Background and Objectives : Boundary detection and drawing are essential in 3D reconstruction of neck mass. Manual tracing methods are popular for drawing head and neck tumor. To improve manual tracing, circular boundaries overlapping was tried. Materials and Methods : Twenty patients with neck tumors were recruited for study. Representative frames were examined for shapes of outline. They were all single closed curves. Circular boundaries were added to fill the outlines of the tumors. Inserted circles were merged to form single closed curves(Circular boundary overlapping, CBO). After surface rendering, 3 dimensional images with volumes and area data were made. Same procedures were performed with manual tracing from same cases. 3D images were compared with surgical photographs of tumors for shape similarity by 2 doctors. All data were evaluated with Mann-Whitney test(p<0.05). Results : Shapes of boundaries from CBO were similar with boundaries from manual tracing. Tumor outlines could be filled with multiple circular boundaries., While both boundary tracing gave same results in small tumors, the bigger tumors showed different data. Two raters gave the similar high scores for both manual and CBO methods. Conclusion : Circular boundary overlapping is time saver in 3 dimensional reconstruction of CT images.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.225-230
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• 1997

Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that tile signal compression using wavelet is very effective to reduce the data saving spaces.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.183-186
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• 2003

A vision sensor should be calibrated prior to infer a Euclidian shape reconstruction. A point to point calibration. also referred to as a hard calibration, estimates calibration parameters by means of a set of 3D to 2D point pairs. We proposed a new method for determining a set of 3D to 2D pairs for the structured light hard calibration. It is simply determined based on epipolar geometry between camera image plane and projector plane, and a projector calibrating grid pattern. The projector calibration is divided two stages; world 3D data acquisition Stage and corresponding 2D data acquisition stage. After 3D data points are derived using cross ratio, corresponding 2D point in the projector plane can be determined by the fundamental matrix and horizontal grid ID of a projector calibrating pattern. Euclidian reconstruction can be achieved by linear triangulation. and experimental results from simulation are presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1747-1751
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• 2000

It is well known that acoustic signals, even measured in an anechoic chamber, can be contaminated due to the wall interference. Therefore, it is necessary to reconstruct the original signal from the measured data, which is very critical for the case of measurement of source signal in a water tunnel. In this thesis, new methods for the reconstruction of sound sources are proposed and validated by using Boundary Element Method from measured data in a closed space. The inverse Helmholtz integral equation and its normal derivative are used for the reconstruction of sound sources in a closed space. An arbitrary Kirchhoff surface over the sources is proposed to solve the surface information instead of direct solution for the source. Although sound sources are not directly known by the inverse Helmholtz equation, the original sound source of pressure-field outside of the wall can be indirectly obtained by using this new method.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.4
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• pp.294-301
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• 2016

In this paper, we present methods to efficiently parallelize iterative 3D image reconstruction by exploiting trigeneous devices (three different types of device) at the same time: a CPU, an integrated GPU, and a discrete GPU. We first present a technique that exploits single instruction multiple data (SIMD) architectures in GPUs. Then, we propose a performance estimation model, based on which we can easily find the optimal data partitioning on trigeneous devices. We found that the performance significantly varies by up to 6.23 times, depending on how SIMD units in GPUs are accessed. Then, by using trigeneous devices and the proposed estimation models, we achieve optimal partitioning and throughput, which corresponds to a 9.4% further improvement, compared to discrete GPU-only execution.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.232-235
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• 1988

Recently, an iterative reconstruction-reprojection (IRR) algorithm has been suggested for application to incomplete data computed tomography (CT). In the IRR, the interpolation operation is performed in the image space during reconstruction-reprojection. The errors associated with the interpolation degrade the reconstructed image and may cause divergence unless a large number of rays is used. In this paper, we propose an improved IRR algorithm which eliminates the need for interpolation. The proposed algorithm adopts a new sampling scheme in which samples (projection data) is taken in phase with the samples of the Cartesian grid.

• Korean Journal of Remote Sensing
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• v.10 no.2
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• pp.63-82
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• 1994

Multitemporal analysis with remotely sensed data is complicated by numerous intervening factors, including atmospheric attenuation and occurrence of clouds that obscure the relationship between ground and satellite observed spectral measurements. A reconstruction system was developed to increase the discrimination capability for imagery that has been modified by residual dffects resulting from imperfect sensing of the target and by atmospheric attenuation of the signal. Utilizing temporal information based on an adaptive timporal filter, it recovers missing measurements resulting from cloud cover and sensor noise and enhances the imagery. The temporal filter effectively tracks a systematic trend in remote sensing data by using a polynomial model. The reconstruction system were applied to the AVHRR data collected over Korean Peninsula. The results show that missing measurements are typically recovered successfully and the temporal trend in vegetation change is exposed clearly in the reconstructed series.