• Korean Journal of Radiology
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• v.23 no.1
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• pp.139-149
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• 2022

Objective: To compare the effects of bone suppression imaging using deep learning (BSp-DL) based on a generative adversarial network (GAN) and bone subtraction imaging using a dual energy technique (BSt-DE) on radiologists' performance for pulmonary nodule detection on chest radiographs (CXRs). Materials and Methods: A total of 111 adults, including 49 patients with 83 pulmonary nodules, who underwent both CXR using the dual energy technique and chest CT, were enrolled. Using CT as a reference, two independent radiologists evaluated CXR images for the presence or absence of pulmonary nodules in three reading sessions (standard CXR, BSt-DE CXR, and BSp-DL CXR). Person-wise and nodule-wise performances were assessed using receiver-operating characteristic (ROC) and alternative free-response ROC (AFROC) curve analyses, respectively. Subgroup analyses based on nodule size, location, and the presence of overlapping bones were performed. Results: BSt-DE with an area under the AFROC curve (AUAFROC) of 0.996 and 0.976 for readers 1 and 2, respectively, and BSp-DL with AUAFROC of 0.981 and 0.958, respectively, showed better nodule-wise performance than standard CXR (AUAFROC of 0.907 and 0.808, respectively; p ≤ 0.005). In the person-wise analysis, BSp-DL with an area under the ROC curve (AUROC) of 0.984 and 0.931 for readers 1 and 2, respectively, showed better performance than standard CXR (AUROC of 0.915 and 0.798, respectively; p ≤ 0.011) and comparable performance to BSt-DE (AUROC of 0.988 and 0.974; p ≥ 0.064). BSt-DE and BSp-DL were superior to standard CXR for detecting nodules overlapping with bones (p < 0.017) or in the upper/middle lung zone (p < 0.017). BSt-DE was superior (p < 0.017) to BSp-DL in detecting peripheral and sub-centimeter nodules. Conclusion: BSp-DL (GAN-based bone suppression) showed comparable performance to BSt-DE and can improve radiologists' performance in detecting pulmonary nodules on CXRs. Nevertheless, for better delineation of small and peripheral nodules, further technical improvements are required.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.691-696
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• 1999

Epithelioid hemangioendothelioma(EH) is a rare pulmonary vascular malignancy. Clinically, EH has been considered as an indolent, generally non-aggressive tumor. We report a case of EH which was confirmed by open lung biopsy. A 34-year-old woman was admitted for further evaluation of multiple small(less than 2cm in size) nodules, incidentally detected on screening chest radiograph. The chest CT showed multiple, relatively well-marginated, variable sized nodules at both whole lung. Transbronchial lung biopsy and transthoracic needle aspiration were nondiagnostic and open lung biopsy was performed from right middle lobe of lung. On light-microscopic examination, the nodules were composed of a poorly cellular hyaline core and a more cellular peripheral zone which extended into air space in a micropolypoid fashion and obliterated blood vessels. The tumor cells at the peripheral zone had intracytoplasmic vacuoles which suggested primitive, vascular differentiation. Immuno-histochemical study revealed the cellular area which gave positive reaction to factor VIII-related antigen. She received no specific therapy after open lung biopsy and chest X-ray films had showed no change for about two years.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5_2
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• pp.186-193
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• 2010

The purpose of this study was to survey the citizens for their satisfaction with the outdoor landscape lighting in Gyeongju Historic Areas registered as UNESCO World Cultural Heritage in November 2000 and thereupon, provide for some basic data useful to the design of the outdoor landscape lighting for the cultural properties. As a result of examining the conditions of the outdoor landscape lighting in Wolseong Zone of Anapji, Banwolseong, Dongbu Sajeokji, Cheomseongdae and Gyerim, there were found 391 lighting fixtures of 12 types in Anapji, 138 lightings of 4 types in Banwolseong, 38 lightings of 6 types in Cheomseongdae, 28 lightings of 3 types in Dongbu Sajeokji and 54 lightings of 5 types in Gyerim. As a result of analyzing citizens' satisfaction with the outdoor landscape lighting, it was found that citizens were satisfied more or less with the nightscape image changed by the outdoor landscape lighting; their satisfaction scored 3.836 on average for Anapji on a 5-point Likert type scale, 3.516 for Banwolseong, 3.446 for Dongbu Sajeokji, 3.650 for Cheomseongdae and 3.479 for Gyerim. However, citizens' satisfaction with the originality of the nightscape was generally low: 3.055 for Anapji, 2.914 for Cheomseongdae, 2.877 for Banwolseong, 2.847 for Gyerim and 2.665 for Dongbu Sajeokji. On the other hand, since most of the lighting fixtures were installed as inserted lights or floodlights, the color tones of light source were relatively highly distinctive, but the peripheral spaces around the cultural properties were rather dark, which means that citizens were feeling inconvenient more or less for using the amenities such as bench or waste box. All in all, their satisfaction with the outdoor landscape at the sample zone at night scored 2.981, lower than the normal level.

• Journal of Korean Neurosurgical Society
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• v.46 no.4
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• pp.340-345
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• 2009

Objective : We investigated the locations of compressing vessels in hemifacial spasm. To approach compression sites, we described and evaluated the efficacy of the infranuchal infrafloccular (INIF) approach. Methods : A retrospective review of 31 consecutive patients who underwent microvascular decompression (MVD) through INIF with a minimum follow-up of 1 year was performed. Along the intracranial facial nerve, we classified the compression sites into the transitional zone (TRZ), the central nervous system (CNS) segment and the peripheral nervous system (PNS) segment. The INIF approach was used to inspect the CNS segment and the TRZ. Subdural patch graft technique was used in order to achieve watertight dural closure. The cranioplasty was performed using polymethylmethacrylate. The outcome and procedure-related morbidities were evaluated. Results : Twenty-nine patients (93%) showed complete disappearance of spasm. In two patients, the spasm was resolved gradually in 2 and 4 weeks, respectively. Late recurrence was noted in one patient (3%). The TRZ has been identified as the only compression site in 19 cases (61.3%), both the TRZ and CNS segment in 11 (35.5%) and the CNS segment only in 1 (3.2%). There was no patient having a compressing vessel in the PNS segment. Infection as a result of cerebrospinal fluid leak occurred in one patient (3%). Delayed transient facial weakness occurred in one patient. Conclusion : The TRZ and the CNS segment were more vulnerable area to the compression of vessels. We suggest that surgical avenue with the INIF approach provides early identification of this area.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.29-32
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• 2008

Although various criteria on the diagnosis of diabetic neuropathy are applied from trial to trial, being tailored in concert with its purpose, the utmost evidences of the diagnosis are subjective symptoms and objective signs of neurologic deficit. The application and interpretation of auxiliary electrophysiological test including nerve conduction study (NCS) should be made on the context of clinical pictures. The evaluation of the functions of small, thinly myelinated or unmyelinated nerve fibers has been increasingly stressed recently with the advent of newer techniques, e.g., measurement of intraepidermal fiber density, quantitative sensory testing, and autonomic function test. And the studies with those techniques have shed light to the nature of the evolution of diabetic neuropathy. The practical application of these techniques to the diagnosis of diabetic neuropathy in the individual patients, however, should be made cautiously due to several shortcomings: limited accessibility, wide overlapping zone between norm and abnormality with resultant unsatisfactory sensitivity and specificity, difficulty in performing subsequent tests, unproven quantitative correlation with clinical deficit, and invasiveness of some technique. NCS, as an extension of clinical examination, is still the most reliable electrophysiological test in evaluating neuropathy and gives the invaluable information about the nature of neuropathy, whereas the newer techniques need more refinement of the procedure and interpretation, and the accumulation of large scaled data of application to be considered as established diagnostic tools of peripheral neuropathy.

• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.183-194
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• 2014

Recently, a CANDU digital reactivity computer system (CDRCS) to measure the worth of the liquid zone controller in a CANDU-6 was developed and successfully applied to a physics test of refurbished Wolsong Unit 1. In advance of using the CDRCS, its measureable reactivity range should be investigated and confirmed. There are two reasons for this investigation. First, the CANDU-6 has a larger reactor and smaller excore detectors than a general PWR and consequently the measured reactivity is likely to reflect the peripheral power variation only, not the whole core. The second reason is photo neutrons generated from the interaction of the moderator and gamma-rays, which are never considered in a PWR. To evaluate the limitations of the CDRCS, several tens of three-dimensional steady and transient simulations were performed. The simulated detector signals were used to obtain the dynamic reactivity. The difference between the dynamic reactivity and the static worth increases in line with the water level changes. The maximum allowable reactivity was determined to be 1.4 mk in the case of CANDU-6 by confining the difference to less than 1%.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.8
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• pp.713-717
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• 2015

In this paper, we propose camber monitoring system which is using on hot rolling process. In roughing mill which is one of the rolling part in hot rolling process, steel plate can be bended in width direction under the imbalance of rolling condition. This bending of steel plate in width direction is called as camber. In order to measure the camber, first, cameras which are installed over transport pathway of steel plate take pictures of whole shape of steel plate. And location value of steel plate edge is extrated from these pictures by edge detection algorithm. But, there are a lot of noises which are generated by such as water sprays, dusts, peripheral equipments in these pictures, and these noises make edge detection difficult. In order to solve this kind of problem, we developed a direction selective edge detection algorithm, and applicated in our camber monitoring system. As a result, we got stable results in spite of process noises.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.414-417
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• 2011

On the basis of the paper described herein, rotor blade failure in the compressor, gas generator turbine, and power turbine and the resulting internal damage is contained within the peripheral hardware and engine casings. For the safety reason, the blade containment was regulated by aviation authority. For reducing the weight of the case, a heaviest single component of a jet engine, the blade containment capability was analyzed by engine manufacturer. The procedure established for containment design involves an energy balance method based on the comparison of the kinetic energy of released blade and the strain energy of the containment zone. The LS-DYNA simulation can also be introduced to predict behavior of released blade and case. All of the analytic and numerical result are described ${\ldots}$.

• Korean Journal of Head & Neck Oncology
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• v.39 no.1
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• pp.33-36
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• 2023

Malignant lymphoma rarely occurs in the larynx and hypopharynx. Few cases of malignant lymphoma in the larynx were reported in Korea. However, malignant lymphoma in the hypopharynx had been not reported in Korea. A 68-year-old woman came to the outpatient clinic with a foreign body sensation in her throat. A round, smooth margin, bright pink-colored mass was confirmed by the laryngoscopy. The patient took neck computer tomography. A small bulging of mucosa was observed, but there was no peripheral infiltration or abnormally enlarged lymph nodes. We did excision using CO2 LASER. She was finally diagnosed with mucosa-associated lymphoid tissue lymphoma (MALT lymphoma). After diagnosis, several image studies confirmed that there was no metastatic lesion. She got only radiotherapy after that and kept a complete response state for over 2 years.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.112-123
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• 2011

This study focused on developing strategies of cyber-compact city, combining compact city with information and communications technologies(ICTs), in order to enhance sustainable transportation. The cyber-compact city development is defined as a development that is able to reduce travel by ICTs and encourage people to use transit or non-motorized vehicles such as bicycles for ICT-induced travel (especially, discretionary travel) by compact and mixed land use. It can be achieved with combining cyber and compact strategies with respect to network, node, and area. For example, ICT network may use transit network facility, a transfer station may be a hub of ICTs, and transit influenced zone may work with ICT service area. We proposed three cohesive strategies for the cyber-compact city based on literature review and case studies on cyber and compact cities. The first strategy is a cohesion between public transportation and telecommunication network by centering on the two for national and urban spatial linkage structure. That is, cities or urban centers and its peripheral areas can be connected by rail network, and extra space of railway network can be used for constructing telecommunication network infrastructure. The second strategy is a cohesion between public transportation node and telecommunication node by building up regional and urban telecommunication centers near to or at main railway stations. For this strategy, telework centers and communication service centers should be established mainly at transfer stations. The third strategy is a cohesion between public transportation impact zone and telecommunication impact zone as transit oriented development.