• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.911-917
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• 2023

The method of observing nodular changes on the liver surface using clinical ultrasonography is useful for diagnosing cirrhosis. However, the speckle noise that inevitably occurs in ultrasound images makes it difficult to identify changes in the liver surface and echo patterns, which has a negative impact on the diagnosis of cirrhosis. The purpose of this study is to model the median modified Wiener filter (MMWF), which can efficiently reduce noise in cirrhotic ultrasound images, and confirm its applicability. Ultrasound images were acquired using an ACR phantom and an actual cirrhotic patient, and the proposed MMWF algorithm and conventional noise reduction algorithm were applied to each image. Coefficient of variation (COV) and edge rise distance (ERD) were used as quantitative image quality evaluation factors for the acquired ultrasound images. We confirmed that the MMWF algorithm improved both COV and ERD values compared to the conventional noise reduction algorithm in both ACR phantom and real ultrasound images of cirrhotic patients. In conclusion, the proposed MMWF algorithm is expected to contribute to improving the diagnosis rate of cirrhosis patients by reducing the noise level and improving spatial resolution at the same time.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.427-436
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• 1997

데이터베이스 설계에서 개념적 모델링 단계에서는 논리적 설계가 효율적으로 수행 되도록 하기 위하여 현실 세계를 보다 정확하게 표현할 수 있도록 다양한 의미 표현 도구를 제공해야 한다. 본 연구에서는 데이터베이스 개념 설계에 가장 널리 사용되는 실체 관계 모 델(ERD)을 기반으로 데이터의 표현 능력을 향상시키고자 한다. 특히 데이터의 표현을 확장 하려는 연구들을 정리하고 통합적인 데이터 모델링 방법의 개발 필요성을 제시한다.

• Korean Journal of Mathematics
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• v.16 no.4
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• pp.495-498
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• 2008

Every totally disconnected space is hereditarily disconnected. In this note, we provide an example of a hereditarily disconnected which is not a totally disconnected space. We further provide an example that not homogeneous space is the product of a totally disconnected and a connected.

• Journal of Information Technology Applications and Management
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• v.17 no.3
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• pp.1-24
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• 2010

Most of enterprises depend on a data modeler during developing their management information systems. In formulating business requirements for information systems, they widely and naturally use the interview method between a data modeler and a field worker. But, the discrepancy between both parties would certainly cause information loss and distortion that lead to let the systems not faithful to real business works. To improve or avoid modeler-dependant data modeling process, many automated data design CASE tools have been introduced. However, since most of traditional CASE tools just support drawing works for conceptual data design, a data modeler could not generate an ERD faithful to real business works and a user could not use them without any knowledge on database. Although some CASE tools supported conceptual data design, they still required too much preliminary database knowledge for a user. Against these traditional CASE tools, we proposed a Requirement-Oriented Entity Relationship Model for automated data design tool, called ROERM. Based on Non-Stop Methodology, ROERM adopts inner systematic modules for complete and sound ERD that is faithful to real field works, where modules are composed of interaction modules with a user, rules of schema operations and sentence translations. In addition to structure design of ROERM, we also devise detailed algorithms and perform an experiment for a case study.

• Korean Journal of Pharmacognosy
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• v.7 no.1
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• pp.55-57
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• 1976

The callus formation of Glycyrrhiza glabra L. var. $glandulifera\;R_{EG}.\;et\;H_{ERD}$. in tissue culture was promoted on Murashige and Skoog's basal solution supplemented with 40g/l of sucrose, 1mg/l of kinetin and 5mg/l of 2, 4-D. The fresh and dry weights of callus and glycyrrhizin contents in callus of the Glycyrrhiza glabra L. var. $glandulifera\;R_{EG}.\;et\;H_{ERD}$. were determined monthly up to 12 months and obtained the results as follows: 1.The fresh weight of formed callus was increased rapidly from 2 to 4 months but growing rate of callus was slow from 4 to 6 months. This indicates that the cell division of callus was most active during the first $2{\sim}3$ months. 2. Glycyrrhizin contents in callus were also increased but the contents were not related to the increased weight of callus.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.228-231
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• 2002

We report the effect of density of thin films on moisture adsorption and hydration of MgO thin film, usually used as a protective layer in AC-PDP After hydration, lots of hemispherical shaped clusters, $Mg(OH)_2$, formed on the surface of MgO thin films. However clusters formed on low-density thin films were bigger than those on high-density films. From ERD spectra, it seemed that the concentration of hydrogen was very high in the region 20 nm from the surface of MgO thin film. The low-density thin film had more hydrogen than high-density thin film. From simulation results of ERD and RBS it was found that hydration reaction also occurred in the inner part of the film. So diffusion of Mg atoms from the inner part of the film to the surface and $H_2O$ molecules from the surface to the inner part of the film is important. And because low density thin film has many short paths for diffusion of Mg atoms and $H_2O$ molecules, low-density thin film is more hydrated. So to suppress hydration of MgO thin films, high-density thin film is needed.

• Journal of the Korean Vacuum Society
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• v.5 no.1
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• pp.25-32
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• 1996

An ERD-TOF system is constructed for the nondestructive depth profiling of light elements in thin films in the range of several thousand angstroms. The particles, recoiled by 10 $MeV^{35}Cl$ projectiles, were detected by a Time-Of-Flight spectrometer composed of a MCP (Micro Channel Plate) and a SSB (Silicon Surface Barrier) detector. A two parameter data acquisition system composed of two PC's was constructed for registering simultaneous time and energy signals. A $Si_3N_4$/poly-Si/$SiO_2$/Si sample was anlayzed and the result is compared with RBS. The detection limit, maximum probable depth and depth resolution for light elements in silicon are about $4\times10^{14}atoms/\textrm{cm}^2$, 5, 000$\AA$ and 100$\AA$, respectively.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.306-311
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• 2007

Proper management of construction productivity is one of the main drivers of project success. This research focuses on the development of a construction productivity analysis system based on Web and OLAP in order to effectively manage construction productivity. Throughout the research effort, a construction productivity analysis system was modeled using IDEFO & ERD techniques and was deployed on the WWW(World Wide Web). Based on the system modeling, this research studies the methodology for system development of construction productivity that can consult the decision of managers on job site.

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.593-602
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• 2018

Background/Aims The different clinical manifestations of gastroesophageal reflux disease (GERD) may be influenced by associated psychological factors. We evaluated the psychological status (anxiety and depression) according to each subtype of GERD. Methods Subjects who underwent esophagogastroduodenoscopy and completed a symptom questionnaire between January 2008 and December 2011 were analyzed. The subjects were classified into the following groups: erosive reflux disease (ERD), non-erosive reflux disease (NERD), asymptomatic erosive esophagitis (AEE), and controls. Anxiety and depression were assessed using the State-Trait Anxiety Inventory and Beck Depression Inventory, respectively. Results We analyzed 19 099 subjects: 16 157 (84.6%), 176 (0.9%), 1398 (7.3%), and 1368 (7.2%) in the control, ERD, NERD, and AEE groups, respectively. Multiple multinomial logistic regression revealed a significant association of increased state (adjusted OR, 1.89; 95% CI, 1.53-2.33) and trait anxiety (adjusted OR, 1.78; 95% CI, 1.34-2.35) and depression (adjusted OR, 2.21; 95% CI, 1.75-2.80) with NERD. ERD group showed a significant association only with state anxiety (adjusted OR, 2.20; 95% CI, 1.27-3.81) and depression (adjusted OR, 2.23; 95% CI, 1.18-4.22). The AEE group, however, did not show any significant association with psychological factors. Conclusion This cross-sectional study revealed that anxiety and depression levels were significantly higher in subjects with GERD (notably in the NERD) than in controls.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1850-1857
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• 2021

Objective: The purpose of this study was to assess whether a deep learning (DL) algorithm could enable simultaneous noise reduction and edge sharpening in low-dose lumbar spine CT. Materials and Methods: This retrospective study included 52 patients (26 male and 26 female; median age, 60.5 years) who had undergone CT-guided lumbar bone biopsy between October 2015 and April 2020. Initial 100-mAs survey images and 50-mAs intraprocedural images were reconstructed by filtered back projection. Denoising was performed using a vendor-agnostic DL model (ClariCT.AI^TM, ClariPI) for the 50-mAS images, and the 50-mAs, denoised 50-mAs, and 100-mAs CT images were compared. Noise, signal-to-noise ratio (SNR), and edge rise distance (ERD) for image sharpness were measured. The data were summarized as the mean ± standard deviation for these parameters. Two musculoskeletal radiologists assessed the visibility of the normal anatomical structures. Results: Noise was lower in the denoised 50-mAs images (36.38 ± 7.03 Hounsfield unit [HU]) than the 50-mAs (93.33 ± 25.36 HU) and 100-mAs (63.33 ± 16.09 HU) images (p < 0.001). The SNRs for the images in descending order were as follows: denoised 50-mAs (1.46 ± 0.54), 100-mAs (0.99 ± 0.34), and 50-mAs (0.58 ± 0.18) images (p < 0.001). The denoised 50-mAs images had better edge sharpness than the 100-mAs images at the vertebral body (ERD; 0.94 ± 0.2 mm vs. 1.05 ± 0.24 mm, p = 0.036) and the psoas (ERD; 0.42 ± 0.09 mm vs. 0.50 ± 0.12 mm, p = 0.002). The denoised 50-mAs images significantly improved the visualization of the normal anatomical structures (p < 0.001). Conclusion: DL-based reconstruction may enable simultaneous noise reduction and improvement in image quality with the preservation of edge sharpness on low-dose lumbar spine CT. Investigations on further radiation dose reduction and the clinical applicability of this technique are warranted.