• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.791-807
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• 2021

Vasculitis is a systemic disease, characterized by inflammation of the vascular wall. Although rare, it is sometimes life-threatening due to diffuse pulmonary hemorrhage or acute glomerulonephritis. Besides primary vasculitis, whose cause is unknown, numerous conditions such as autoimmune diseases, drugs, infections, and tumors can cause secondary vasculitis. Vasculitis displays various non-specific symptoms, signs, and laboratory findings; hence, diagnosis of the disease requires integration of various results including clinical features, imaging findings, autoantibody tests, and pathological findings. In this review, we have discussed the clinical, radiologic, and pathological features of vasculitis. Further, we elaborated the imaging findings and differential diagnosis of typical vasculitis that frequently involves the lung and introduced a new international classification of vasculitis, the Diagnostic and Classification Criteria in Vasculitis.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.851-861
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• 2021

Liver injury is a common consequence of blunt abdominopelvic trauma. Contrast-enhanced CT allows for the rapid detection and evaluation of liver injury. The treatment strategy for blunt liver injury has shifted from surgical to nonoperative management, which has been widely complemented by interventional management to treat both liver injury and its complications. In this article, we review the major imaging features of liver injury and the role of interventional management for the treatment of liver injury.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1134-1139
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• 2023

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor primarily located in the head and neck. We report the imaging features of pathologically confirmed MCC in the trunk. On US, MCC showed heterogeneous echogenicity with perpendicular hypoechoic linear bands that resembled "columns of smoke" in the skin and subcutaneous layers as well as prominent vascularity. On MRI, the tumor showed hypointensity on T1-weighted images and hyperintensity on proton density and T2-weighted images with linear low-signal bands in the skin and subcutaneous layers as well as intense enhancement on T1-enhanced images. Although MCC has nonspecific imaging features, these characteristics may be helpful for the early diagnosis of this disease.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.550-564
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• 2023

MRI is currently the imaging modality of choice to evaluate rectal cancer after neoadjuvant treatment. The purposes of restaging MRI are to assess the resectability of rectal cancer and to decide whether organ preservation strategies can be applied in patients with a complete clinical response. This review article indicates the key MRI features needed to evaluate rectal cancer after neoadjuvant treatment using a systematic approach. Assessment of primary tumor response including MRI findings to predict a complete response is discussed. Additionally, MRI evaluation of the relationship between the primary tumor and adjacent structures, lymph node response, extramural venous invasion, and tumor deposits after neoadjuvant treatment is presented. Knowledge of these imaging features and their clinical relevance may help radiologists provide an accurate and clinically valuable interpretation of restaging rectal MRI.

• Current Photovoltaic Research
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• v.8 no.3
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• pp.67-78
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• 2020

A novel energy production system which has fascinated a wide consideration because of its several benefits that are called floating photovoltaic technology (FPVT). The FPVT system that helps to minimize the evaporation of water as well as an increase in energy production. For the research purposes, both electrical and mechanical structure requires studying of these systems for the development of FPVT power plants. From different points of views, numerous researches have been directed on FPVT systems that have evaluated these systems. The present research article give a logical investigation and up to date review that shows the different features and components of FPVT systems as an energy production system is offered. This articles reviewing the FPVT that gets the attention of the scientists who have the investigational stage and involuntary inspection of FPVT systems in addition to influence of implementing these systems on the water surface. Also, a comprehensive comparison has been constructed that shows the cons and pros of various types of solar systems that could be installed in various locations. In this review, it has been found that solar energy on the roof of a dwelling house generally has a power of 5 to 20 kW, while the inhabitants of commercial buildings generally have a power of 100 kW or more. The average power capacity of a floating solar panel is 11% more of the average capacity of a solar panel installed on the ground. Studies show that 40% of the water in open reservoirs is lost through evaporation. By covering only 30% of the water surface, evaporation can be reduced by 49%. The global solar panel market exceeds 100 GW and the capacity of 104 GW will bring the annual growth rate to 6%. In 2018, the world's total photovoltaic capacity reached 512 GW, an increase of 27% compared to the total capacity and about 55% of the renewable resources newly created that come from photovoltaic systems. It has been also predicted by this review that in 2025 the Solar technology including the FPVT system will increase by 7.38% that is 485.4 GW more of today installed power worldwide.

• Journal of Information Technology and Architecture
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• v.11 no.1
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• pp.63-73
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• 2014

As the advance of WWW, unstructured data including texts are taking users' interests more and more. These unstructured data created by WWW users represent users' subjective opinions thus we can get very useful information such as users' personal tastes or perspectives from them if we analyze appropriately. In this paper, we provide various analysis efficiently for unstructured text documents by taking advantage of OLAP (On-Line Analytical Processing) multidimensional cube technology. OLAP cubes have been widely used for the multidimensional analysis for structured data such as simple alphabetic and numberic data but they didn't have used for unstructured data consisting of long texts. In order to provide multidimensional analysis for unstructured text data, however, Text Cube model has been proposed precently. It incorporates term frequency and inverted index as measurements to search and analyze text databases which play key roles in information retrieval. The primary goal of this paper is to apply this text cube model to a real data set from in an Internet site sharing hotel information and to provide multidimensional analysis for users' reviews on hotels written in texts. To achieve this goal, we first build text cubes for the hotel review data. By using the text cubes, we design and implement the system which provides multidimensional keyword search features to search and to analyze review texts on various dimensions. This system will be able to help users to get valuable guest-subjective summary information easily. Furthermore, this paper evaluats the proposed systems through various experiments and it reveals the effectiveness of the system.

• Journal of Korea Trade
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• v.24 no.7
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• pp.1-28
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• 2020

Purpose - This paper empirically investigates the predictors and main determinants of consumers' ratings of mobile applications in the Google Play Store. Using a linear and nonlinear model comparison to identify the function of users' review, in determining application rating across countries, this study estimates the direct effects of users' reviews on the application rating. In addition, extending our modelling into a sentimental analysis, this paper also aims to explore the effects of review polarity and subjectivity on the application rating, followed by an examination of the moderating effect of user reviews on the polarity-rating and subjectivity-rating relationships. Design/methodology - Our empirical model considers nonlinear association as well as linear causality between features and targets. This study employs competing theoretical frameworks - multiple regression, decision-tree and neural network models - to identify the predictors and main determinants of app ratings, using data from the Google Play Store. Using a cross-validation method, our analysis investigates the direct and moderating effects of predictors and main determinants of application ratings in a global app market. Findings - The main findings of this study can be summarized as follows: the number of user's review is positively associated with the ratings of a given app and it positively moderates the polarity-rating relationship. Applying the review polarity measured by a sentimental analysis to the modelling, it was found that the polarity is not significantly associated with the rating. This result best applies to the function of both positive and negative reviews in playing a word-of-mouth role, as well as serving as a channel for communication, leading to product innovation. Originality/value - Applying a proxy measured by binomial figures, previous studies have predominantly focused on positive and negative sentiment in examining the determinants of app ratings, assuming that they are significantly associated. Given the constraints to measurement of sentiment in current research, this paper employs sentimental analysis to measure the real integer for users' polarity and subjectivity. This paper also seeks to compare the suitability of three distinct models - linear regression, decision-tree and neural network models. Although a comparison between methodologies has long been considered important to the empirical approach, it has hitherto been underexplored in studies on the app market.

• Particle and aerosol research
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• v.13 no.1
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• pp.1-10
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• 2017

Accurate prediction of size, shape and velocity of a bubble rising through a liquid pool is very important for predicting the particulate removal efficiency in pool scrubbing, for designing engineering safety features to prepare for severe accidents in nuclear power plants, and for predicting the emission of fission products from MCCI (molten core-concrete interaction) process during severe accidents. In this review article, previous studies on the determination of the size, shape and rising velocity of a bubble in liquid are reviewed. Various theoretical and parameterization formulas calculating the bubble size, shape and velocity from physical properties of liquid and gas flowrate are compared. Recent studies tend to suggest simple parameterizations that can easily determine the bubble shape and rising velocity without iteration, whereas iteration has to be performed to determine the bubble shape and velocity in old theories. The recent parameterizations show good agreement with measured data obtained from experiments conducted using different liquid materials with very diverse physical properties, proving themselves to be very useful tools for researchers in related fields.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.517-528
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• 2016

This study attempted to explore and examine a new user experience (UX) research method for IoT products which are becoming widely used but lack practical user research. While user experience research has been traditionally opted for survey or observation methods, this paper utilized big data analysis method for user online reviews on an intelligent agent IoT product, Amazon's Echo. The results of topic modelling analysis extracted user experience elements such as features, conversational interaction, and updates. In addition, regression analysis showed that the topic of updates was the most influential determinant of user satisfaction. The main implication of this study is the new introduction of big data analysis method into the user experience research for the intelligent agent IoT products.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.221-228
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• 2018

Since the discovery that Mycobacterium aviumsubsp. paratuberculosis (Map) is the causative agent of Johne's disease (JD) in cattle at the end of the nineteenth century, movement of livestock latently infected with Map has led to the spread of JD throughout the world. A new form of enteritis with clinical features of JD in cattle appeared in humans concurrent with the appearance of Map as a disease problem in livestock. The demonstration that Map is a zoonotic pathogen and the causative agent of the new form of enteritis in humans, however, wasn't recognized until late in the twentieth century when methods were developed to detect the presence Map in tissues from patients with the new form of clinical enteritis. The objective of this short review is to provide a brief history explaining how Map has become a major disease problem in livestock and humans and then provide a review of the progress that has been made in treating patients with an enteritis caused by Map and the strategies underway to develop a vaccine to control infection in livestock.