• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1294-1300
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• 2013

The purpose of this study is to increase contrast to noise ratio(CNR) in myocardial viability test by using contrast agent which highly content gadolinium(1mmol/mL) maximizing diagnostic value. This research method that four hundred four patients were underwent the MRI scanning two hundred eighty four of them were injected commercial contrast media which have 0.5mmol/L and the rest of them were injected new contrast media(gadobutrol) which have 1mmol/mL of molarity to study the contrast difference depending on the molarity of the contrast agent signal intensities of normal ventricle and left ventricle were measured to compare and evaluate signal to noise ratio(SNR) and CNR of the images. As result, 1mmol/mL contrast agent showed higher SNR by 25.13% in myocardium and 30.74% in left ventricle. CNR was proved to be better in 1mmol/mL contrast agent by 31.29%. The results above were all statistically meaningful. Therefore, contrast agent contenting more gadolinium which was 1mmol/mL in this study, could more effectively shorten T1 relaxation time, increase the signal intensity and at the same time maximize CNR and diagnostic value. This study firstly report the usefulness of 1mmol/mL contrast agent in patients allegedly suffering cardiac diseases and it is considered to increase diagnostic value.

• Tunnel and Underground Space
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• v.30 no.1
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• pp.29-38
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• 2020

Recent research trend of North Korean mining and rock engineering in the past 10 years was analyzed by a literature review of mining and rock engineering papers published in North Korean major mining journals, 'mining engineering', 'geological and geographical science' and 'technology innovation' published in 2008-2017. Basic database was established by organizing bibliographic information and abstract data of research papers in each journal. For each journal, paper submission trend classified by research field was analyzed using the basic database. And further study was conducted to the papers which showed distinguishing methodology and result, to analyze the trend of North Korean mining and rock engineering. The literature study showed a recent trend of quantification and automation in mining and rock engineering researches in North Korea, which seems due to recent changes in North Korea's science and technology policy and deterioration of the mining conditions. The results of this study can be applied in the feasibility studies of North Korea's mineral resource development projects. Future inter-Korean technical cooperation and site survey on North Korean field can secure complement the reliability of this study.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.11-17
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• 2013

Currently, there are many studies being conducted around the world to reduce exposure dose to radiation for patients to receive medical treatments in a safe environment. We developed and fabricated of this shield that the patients are protected from the radiation and are need of safety control during breast imaging. In this study, for breast imaging, GE Senography 2000D were used and set at SID 65cm, 28kVp, and 63mAs. The measuring instrument was Fluke's Victoreen 6000-529. And we performed Face Block on with 30 patients. The chamber on the actual thyroid glands to take CC and MLO and measure the dosage before and after wearing the Face Block. For the results, after wearing the Face Block, exposure was decreased by 53.8%-100% and 65.8% in average in CC View and by 50%-100% and 60.7% in average in MLO View. The development of the Face Block that practically decreased the exposure dose of thyroid glands, crystalline eyes during breast imaging and reduced the patients' anxiety during breast imaging. The Face Block is expected to improve patients' satisfaction and contribute to reducing patients' exposure dose, but more efforts should be made to reduce exposure dose to medical radiation.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.544-547
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• 2015

An 11-year-old, intact male Pekingese was brought to the Veterinary Teaching Hospital of Kangwon National University with a 10-day history of seizures. Fifteen days before coming to Kangwon National University, the dog had visited a local animal hospital for lameness, and non-steroidal anti-inflammatory drugs were prescribed to treat this symptom. However, 10 days before coming to our hospital, the dog experienced generalized seizures. Two days before his arrival, generalized ataxia and mental dullness also occurred. Our examinations revealed no remarkable findings on a routine blood test or X-ray. However, the neurological examinations confirmed mental dullness, generalized ataxia, and a lack of menace response and pupillary light reflexes. Nine hours later, dyspnea occurred, and 12 hours after that, the patient was euthanized per the client's request. A necropsy of transverse sections confirmed the presence of a prominent midline shift due to extended tumor growth. On histopathological analyses, pseudopalisading necrosis of the glial cells and microvascular proliferation were observed. In immunohistochemical analysis, glial fibrillary acidic protein, proliferating cell nuclear antigens, and ionized calcium binding adaptor molecule 1 immunoreactive cells were observed in the tumor area. Based on the results, the tumor was confirmed to be a glioblastoma. Primary intracranial tumors are rare in the veterinary field. This case report describes the clinical and histopathological findings of glioblastoma in a Pekingese.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.215-222
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• 2016

X-ray mammography is the most effective method for the diagnosis of calcified lesions of various breast diseases. To reduce patient dose and to obtain optimal image required for diagnosis, the performance of the mammography system should be maintained continuously. Because the target (anode) angle of the X-ray tube is measured from the central X-ray, the effective angle can be slightly different in view of the position on the detector, which can result in degrading spatial resolution of the imaging within the field of view. In this study, we measured the MTF to examine spatial resolution for positions on the detector in the digital mammography system. For a tungsten wire of $50{\mu}m$ diameter, the highest spatial frequency was obtained. It meant that a wire diameter for measuring MTF through LSF should be small compared to the pixel size of the detector used in the mammography system. The spatial resolution showed slightly different performance according to positions on the detector. The center position gave the best spatial resolution and positions away from the center showed the degraded performance although the difference of the spatial resolution was small. The effective focal spot size of the full width at half maximum also showed similar result. It concluded that the slightly increase of the effective focal spot size gave the degradation of the spatial resolution for positions on the detector.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.268-278
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• 2004

In this paper, we describe our experience in the design and implementation of the SMART file system to handle multimedia workload. Our work has three design objectives: (ⅰ) efficient support for sequential workload, (ⅱ) avoiding disk fragmentation, (ⅲ) logical unit based file access. To achieve these three objectives, we develop a file system where a file consists of linked list of Data Unit Group. Instead of tree like structure of the legacy Unix file system, we use single level file structure. Our file system can also access the file based upon the logical unit which can be video frame or audio samples. Data Unit Group is a group of logical data units which is allocated continuous disk blocks. At the beginning of each Data Unit Group, there exists an index array. Each index points to the beginning of logical data units, e.g. frames in the Data Unit Group. This index array enables the random access and sequencial access of semantic data units. SMART file system is elaborately tailored to effectively support multimedia workload. We perform physical experiments and compare the performance of SMART file system with EXT2 file system and SGI XFS file system. In this experiment, SMART file system exhibits superior performance under streaming workload.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1099-1103
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• 2007

TFT's have been intensively researched for possible electronic and display applications. Through tremendous engineering and scientific efforts, a-Si:H TFT fabrication process was greatly improved. In this paper, the reason on defects occurring at a-Si:H TFT fabrication process is analyzed and solved, so a-Si:H TFT's yield is increased and reliability is improved. The a-Si:H TFT of this paper is inverted staggered type TFT. The gate electrode is formed by patterning with length of $8{\mu}m{\sim}16{\mu}m$ and width of $80{\sim}200{\mu}m$ after depositing with gate electrode (Cr). We have fabricated a-SiN:H, conductor, etch-stopper and photo-resistor on gate electrode in sequence, respectively. We have deposited n+a-Si:H, NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-slower pattern. The NPR layer by inverting pattern of upper Sate electrode is patterned and the n+a-Si:H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. The a-Si:H TFT made like this has problems at photo-lithography process caused by remains of PR. When sample is cleaned, this remains of PR makes thin chemical film on surface and damages device. Therefor, in order to improve this problem we added ashing process and cleaning process was enforced strictly. We can estimate that this method stabilizes fabrication process and makes to increase a-Si:H TFT's yield.

• (The) Research of the performance art and culture
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• no.33
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• pp.223-242
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• 2016

The Korean $taeg{\breve{u}}m$, a horizontal bamboo flute, is considered a representative wind instrument of Korean traditional music. Symbolized by its unique timbre and diverse techniques, this instrument transmits the beauty of Korea, and has become acknowledged even in international music scenes. Being a $taeg{\breve{u}}m$ player, composer, and ethnomusicology researcher, I have developed creative collaborations with musicians from Asian, electro-acoustic, jazz, and Western art music traditions developed outside my country of origin and tried to overcome musical boundaries through the 'intercultural performances' (after Turner 1988). Zooming in one collaboration, I detail the process of music creation and performance, collaborating with prominent Korean composer Kim $Taes{\breve{o}}ng$ (b.1967), who was commissioned by myself to write two compositions for the $taeg{\breve{u}}m$ and Western art music. The purpose is twofold: firstly, the modernization and appropriation of the Korean flute is briefly tracked down within the context of Western Art music. Secondly, a performance project is illustrated with the support of technical apparatuses such as DVD and CD recordings and delves further into the question of the 'cultural relativism' (Michael Tenzer, 2006: 7) through the interactive process. The performance-as-research, as a tool 'actualizing' (Richard Schechner 2003: 32) the hybridity, touches on critical domains in Ethnomusicology. The corresponding two parts discover, as Alan Merriam's(1964) 'tripartite model' suggests, the 'context' of Korean and Western cultures, the 'behaviour' of collaborating and performing and the 'sound' of improvised and composed productions in the course of music making.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1669-1683
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• 2021

AI intelligent agriculture and digital agriculture are important for the science of agriculture. Leaf chlorophyll contents(LCC) are one of the most important indicators to determine the growth status of vegetable crops. In this study, a support vector machine (SVM) regression model was produced using an unmanned aerial vehicle-based RGB camera and a multispectral (MSP) sensor for onions and garlic, and the LCC estimation applicability of the RGB camera was reviewed by comparing it with the MSP sensor. As a result of this study, the RGB-based LCC model showed lower results than the MSP-based LCC model with an average R² of 0.09, RMSE 18.66, and nRMSE 3.46%. However, the difference in accuracy between the two sensors was not large, and the accuracy did not drop significantly when compared with previous studies using various sensors and algorithms. In addition, the RGB-based LCC model reflects the field LCC trend well when compared with the actual measured value, but it tends to be underestimated at high chlorophyll concentrations. It was possible to confirm the applicability of the LCC estimation with RGB considering the economic feasibility and versatility of the RGB camera. The results obtained from this study are expected to be usefully utilized in digital agriculture as AI intelligent agriculture technology that applies artificial intelligence and big data convergence technology.

• The Journal of Bigdata
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• v.6 no.1
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• pp.37-49
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• 2021

The number of dementia patients in Korea is estimated to be over 800,000, and the severity of dementia is becoming a social problem. However, no treatment or drug has yet been developed to cure dementia worldwide. The number of dementia patients is expected to increase further due to the rapid aging of the population. Currently, early detection of dementia and delaying the course of dementia symptoms is the best alternative. This study presented a methodology for early diagnosis of dementia by measuring and analyzing amyloid plaques. This vital protein can most clearly and early diagnose dementia in the retina through AI-based image analysis. We performed binary classification and multi-classification learning based on CNN on retina data. We also developed a deep learning algorithm that can diagnose dementia early based on pre-processed retinal data. Accuracy and recall of the deep learning model were verified, and as a result of the verification, and derived results that satisfy both recall and accuracy. In the future, we plan to continue the study based on clinical data of actual dementia patients, and the results of this study are expected to solve the dementia problem.