• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.279-282
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• 1997

Bayesian reconstruction methods for emission computed tomography have been a topic of interest in recent years, partly because they allow for the introduction of prior information into the reconstruction problem. Early formulations incorporated priors that imposed simple spatial smoothness constraints on the underlying object using Gibbs priors in the form of four-nearest or eight-nearest neighbors. While these types of priors, known as "membrane" priors, are useful as stabilizers in otherwise unstable ML-EM reconstructions, more sophisticated prior models are needed to model underlying source distributions more accurately. In this work, we investigate whether the "thin plate" model has advantages over the simple Gibbs smoothing priors mentioned above. To test and compare quantitative performance of the reconstruction algorithms, we use Monte Carlo noise trials and calculate bias and variance images of reconstruction estimates. The conclusion is that the thin plate prior outperforms the membrane prior in terms of bias and variance.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.118-126
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• 2008

Statistical image reconstruction methods have played an important role in emission computed tomography (ECT) since they accurately model the statistical noise associated with gamma-ray projection data. Although the use of statistical methods in clinical practice in early days was of a difficult problem due to high per-iteration costs and large numbers of iterations, with the development of fast algorithms and dramatically improved speed of computers, it is now inevitably becoming more practical. Some statistical methods are indeed commonly available from nuclear medicine equipment suppliers. In this paper, we first describe a mathematical background for statistical reconstruction methods, which includes assumptions underlying the Poisson statistical model, maximum likelihood and maximum a posteriori approaches, and prior models in the context of a Bayesian framework. We then review a recent progress in developing fast iterative algorithms.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.913-916
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• 2005

This paper presents the development of Artificial Neural Network models for forecasting the cost and contract duration of school reconstruction projects to assist the planners' decision-making in the early stage of the projects. 132 schools reconstruction projects in central Taiwan, which received the most serious damage from the Chi-Chi Earthquake, were collected. The developed Artificial Neural Network prediction models demonstrate good prediction abilities with average error rates under 10% for school reconstruction projects. The analytical results indicate that the Artificial Neural Network model with back-propagation learning is a feasible method to produce accurate prediction results to assist planners' decision-making process.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.157-162
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• 2010

Purpose: Free flap reconstruction in the pediatric population is difficult. However, microsurgery has had remarkable success rates in children. The aim of study is to present our clinical experience using free flap for reconstruction of soft tissue defects in children and to describe long-term follow-up results. Methods: Between June 2002 and July 2010, 30 cases of pediatric reconstruction were performed with free flap. The authors analyzed several items, such as the kind of flap, associated complications, and growth problems. Results: Among the 30 cases, 21 cases were due to traffic accidents, 5 to cancer, and 4 to falls and other soft tissue defects. The lower leg and foot were the most common sites of the lesion. In the free flap operations we have done, 20 cases involved an anterolateral thigh perforator free flap, 6 a superficial circumflex iliac perforator free flap, and 4 an upper medial thigh perforator free flap. In early postoperative complications, partial necrosis was seen in 2 cases, infection in 1 case, and the hematoma in 1 case. A satisfactory success rate and functional results were achieved. Conclusion: Free flap reconstruction in children allows satisfactory function with no significant effect on growth. Free flaps are regarded as the primary choice for selective pediatric reconstructive cases.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.31-35
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• 2012

Background : Orbital roof fractures are frequently associated with a high energy impact to the craniofacial region, and displaced orbital roof fractures can cause ophthalmic and neurologic complications and occasionally require open surgical intervention. The purpose of this article was to investigate the clinical features and treatment outcomes of orbital root fractures combined with neurologic injuries after early reconstruction. Methods : Between January 2006 and December 2008, 45 patients with orbital roof fractures were admitted; among them, 37 patients were treated conservatively and 8 patients underwent early surgical intervention for orbital roof fractures. The type of injuries that caused the fractures, patient characteristics, associated fractures, ocular and neurological injuries, patient management, and treatment outcomes were investigated. Results : The patients underwent frontal craniotomy and free bone fragment removal, their orbital roofs were reconstructed with titanium micromesh, and associated fractures were repaired. The mean follow up period was 11 months. There were no postoperative neurologic sequelae. Postoperative computed tomography scans showed anatomically reconstructed orbital roofs. Two of the five patients with traumatic optic neuropathy achieved full visual acuity recovery, one patient showed decreased visual acuity, and the other two patients completely lost their vision due to traumatic optic neuropathy. Preoperative ophthalmic symptoms, such as proptosis, diplopia, upper eyelid ptosis, and enophthalmos were corrected. Conclusions : Early recognition and treatment of orbital roof fractures can reduce intracranial and ocular complications. A coronal flap with frontal craniotomy and orbital roof reconstruction using titanium mesh provides a versatile method and provides good functional and cosmetic results.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.590-596
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• 2020

Background The introduction of the partial second toe pulp free flap has enabled superior aesthetic and functional results for fingertip reconstruction in adults. Children undergoing fingertip amputation for various reasons have limited options for reconstruction. Conventional treatment could shorten the finger, leading to poor cosmesis and function. We report 18 years of our experiences with fingertip reconstruction using partial second toe pulp free flaps in patients in early childhood. Methods Medical charts of children who had undergone fingertip reconstruction using partial second toe pulp free flaps from 2001 to 2018 were retrospectively reviewed. The surgical procedures were identical to those for adults, except for the usage of 11-0 nylon sutures. Patients' demographic data, vessel size, flap dimensions, length of the distal phalanx, and functional outcomes over the course of long-term follow-up were documented. The statistical analysis was performed with the Student t-test, the Mann-Whitney U test, and Pearson correlation analysis. Results Eighteen toe pulp flaps in 17 patients (mean age, 3.0 years) were identified. All the flaps survived without any major complications. In long-term follow-up, the flap-covered distal phalanges showed growth in line with regular development. There was no donor-site morbidity, and all children adapted to daily life without any problems. In two-point discrimination tests, the fingertip sensation recovered to almost the same level as that in the contralateral finger. Conclusions Partial second toe pulp free flaps are an excellent option for fingertip reconstruction in young children, as well as in adults.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.42.1-42.5
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• 2018

Background: Fractures of the orbital wall are mainly caused by traffic accidents, assaults, and falls and generally occur in men aged between 20 and 40 years. Complications that may occur after an orbital fracture include diplopia and decreased visual acuity due to changes in orbital volume, ocular depression due to changes in orbital floor height, and exophthalmos. If surgery is delayed too long, tissue adhesion will occur, making it difficult to improve ophthalmologic symptoms. Thus, early diagnosis and treatment are important. Fractures of the superior orbital wall are often accompanied by skull fractures. Most of these patients are unable to perform an early ocular evaluation due to neurosurgery and treatment. These patients are more likely to show tissue adhesion, making it difficult to properly dissect the tissue for wall reconstruction during surgery. Case presentation: This report details a case of superior orbital wall reconstruction using superior orbital rim osteotomy in a patient with a superior orbital wall fracture involving severe tissue adhesion. Three months after reconstruction, there were no significant complications. Conclusion: In a patient with a superior orbital wall fracture, our procedure is helpful in securing the visual field and in delamination of the surrounding tissue.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.555-558
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• 2009

Purpose: The high success rate of free flap transfers is well documented in previous literature, and is possible due to the early detection of vascular compromise and timely reoperation. We specifically analyzed the operative results of immediate and delayed reconstruction with free transverse rectus abdominis musculocutaneous(TRAM) flap respectively in order to reveal its distinctive features on timing and causes of vascular compromise. Methods: The senior author operated on 158 patients, 161 cases of free TRAM flap for breast reconstruction. 51 patients underwent delayed reconstruction, whilst immediate reconstruction was performed in the other 107 patients. All patients were monitored every 3 hours for the first 3 days. We reviewed medical records of all patients, and tested statistical significance with the Fisher's test. Results: Reoperation was performed in 20 cases, but the cases include hematoma with bleeding focus and arterial anastomosis site rupture due to abrupt arm abduction. We performed reoperation in 15 cases of suspicious vascular compromise. Flap compromise was noticed mostly within 24 hours, but not longer than 72 hours. Venous compromise was dominant by 11 cases (73.3%). There was difference in the timing of flap compromise between immediate and delayed reconstruction. All the cases of delayed reconstruction did not show signs of vascular compromise after 12 hours postoperatively. On the other hand, cases of vascular compromise were observed until 72 hours postoperatively in cases of immediate reconstruction. Conclusion: Delayed reconstruction showed vascular compromise within 12 hours postoperatively, while immediate reconstruction showed compromised until the 3rd postoperative day. If more aggressive monitoring is maintained during this period, we believe salvage of flaps may be increased with more efficiency.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1059-1066
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• 2022

In 2020, it was estimated that more than 2.4 million households in South Korea are over 30 years old. That is, more than 40% of all houses in Korea are old and that they require proper rehabilitation. The two options to improve poor living conditions are reconstruction and remodeling. Compared to reconstruction, remodeling has advantages in terms of the construction period, cost, and environmental impact. As such, the current Korean regulations are more favorable for remodeling than reconstruction. Typically, several candidate floor plans are presented in the early stages of an apartment remodeling project. Extracting information about bearing walls and other structural elements from the multiple plans to compare those plans quantitatively is one of the essential tasks during the early stage of a project. To cope with this task, an automated data extraction method for walls and slabs from before and after remodeling plans is developed. Through the developed program, load-bearing walls, non-bearing walls, slabs, and weight changes after remodeling can be analyzed and visualized in a fast and automated manner.

• Journal of the Korean Professional Engineers Association
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• v.22 no.2
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• pp.61-67
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• 1989

The writer, a member of the Society of Vertebrate Paleontology(SVP), succeeds in making the miniatured dinosaur mcdels from the Early Cretaceous dinosaur remains of Korea. The dinosaur species of reconstruction models this time are the Ultrasaurus tabriensis KIM, the Iguanodon kimi KIM, and the Deinonychus koreanesis KIM. Those are reconstructed for the first time in Korea since the first discovery of dinosaur skeletons in 1973 from the country. The miniature models of dinosaurs reconstructed are exhibited by the photographs from lateral, frontal, and dorsal views.