• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1103-1107
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• 2001

Objective : Atypical and malignant meningiomas(AM, MM) are known to be rare and show aggressive behavior. Limited data are available concerning the clinical features, effectiveness of surgical removal and role of radiation therapy with AM, MM. The authors report our experience of AM, MM, with respect to clinical features. Methods : Twenty-four cases of AM and 28 cases of MM, who were operated between 1988 and 1999 were retro-spectively studied review of medical records and radiological findings. These were compared with control group of 24 cases of menigiomas manifestating usual clinical course, which are selected arbitrarily among operative cases between Apr. 1999 and Dec. 1999. Mean follow-up periods were 26(1-91) months for AM and 23(1-62) for MM. Authors analyzed the prognostic factors for survival, and statistical analysis were accomplished by Kaplan-Meier method and log-rank test. Results : Differences of clinical features between control groups and these atypical and malignant meningioma group were not significant. However, the location of MM was frequent in non-basal area(p<0.01). In AM, there were 4 patients of recurrence, and 3 patients of mortality. Among mortality cases, only one patient died of tumor progression, the other patients died of other causes. The survival at 2 year and 5 year in this group were 88% and 74% respectively, and in MM, 11 patients died due to tumor progression and 2 had spinal metastasis. The survival at 2 year and 5 year were 72% and 20%, respectively. For extent of resection, total removal(Simpson grade 1 or 2) was less often achieved in MM compared with AM(50% vs. 83%). Extent of resection of tumor and postoperative radiation therapy did not affect survival in both AM, MM. Conclusions : Clinical behavior of AM showed more benign than that of MM. Prognostic factor for survival is not related extent of resection of tumor and postoperative radiation therapy. However, further investigation with long-term follow-up and additional cases is mandatory.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.3 no.1
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• pp.147-157
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• 1992

The fragile X syndrome, which is considered to be synonymous with the Martin-Bell syndrome, is a relatively common form of X-linked mental retardation. The syndrome seems to occure in many different ethnic groups and its prevalence among mentally retarded males has been estimated to be in the order of 2 to 6%. The karyotypic hallmark of the syndrome is made up with a pronounced constriction near each tip of the long arm of the X chromosome(fragile site), shown in vitro only under conditions in which thymidylate production is blocked(lowered folate levels). Special culture media are needed to demonstrate this constriction site. Major clinical features associated with the syndrome include macroorchidism, large or prominent ears, significant emotional and behavioral dysfunctions such as hyperactivity, self-injury, lack of eye contact and social interaction, schizophrenia, autism, etc., and speech and language dysfunctions ranging from nonverbal to verbal speech with moderate to severe expressive language delays. Some have minor clinical features in common such as an increase in birth weight high forehead, prognathism, increased head circumference in infancy and childhood which did not persist into adult life. The recent research findings have shown that the fragile X syndrome is associated with infantile autism. Many patients with the fragile X syndrome fulfill the diagnostic criteria for infantile autism. Therefore it is recommendable that any patient with developmental delays and autism or autistic manifestations should have a chromosomal analysis, including fragile X examination. In the present review, historical aspects, incidence, and clinical features are presented. Recent anecdotal reports of the association with autism and the clinical improvement following high dose folic acid treatment will be discussed.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.787-797
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• 2017

In this study, we investigated the features of using smart devices in socioscientific issues (SSI) debate classes. Twenty-seven high school students in Gyeonggi-do participated in this study. The processes of the SSI debate classes with smart devices were classified into five stages: data searching, data sharing, summary and organization of data, debate in the classroom, and online debate. Then some features at each stage were identified. It was found that they collected self-directed and in-depth data while reflecting their knowledge and experience, and selected data which were easy to understand at the stage of data searching. The specificity and validity of the evidences gathered and the clarity of the sources were improved at the stage of data sharing, although they shared more data offline than online. They organized their data by using paper rather than smart devices at the stage of summary and organization of data. Most of them failed to use the summary in debate. They argued and refuted based on concrete grounds at the stage of debate in the classroom, which raised students' interest in debate and led students to participate actively. At the stage of online debate, they were able to rearrange and review the arguments of both sides, and the participation of the students who were passive in classroom debate was enhanced. Based on these results, we suggest some effective teaching methods for SSI debate classes using smart devices.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.876-882
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• 2001

Objectives : Meningeal hemangiopericytoma is a rare tumor. Clinical and radiological features are similar to those of an ordinary meningioma. But its biological behavior is quite different from those of a meningioma as it brings profuse bleeding in the operation field, frequent recurrence and metastasis to other systemic organs even in the case of gross total resection. In order to find out the prognostic factors and to compare longterm outcome after various treatment modalities, the authors reviewed consecutive 20 operated cases of meningeal hemangiopericytoma to characterize their clinical features, surgical outcomes and effectiveness of the radiation therapy. Methods : Twenty patients with a hemangiopericytoma were treated between 1982 and 1999 in our department. They are composed of 13 patients of hemangiopericytoma and 7 patients who were initially diagnosed as angioblastic type meningioma and then confirmed as a hemangiopericytoma after review of their previous histopathology slides. The mean follow-up period was 99 months(1-256 months). The long-term outcomes after various treatment modalities were evaluated according to recurrence-free survival and image follow-up. Recurrence-free survival curves are compared between the patient groups according to the extent of removal and radiation therapy. Results : There were 10 cases of recurrence and 4 cases of distant metastases ; lung, liver and femur(2 cases) respectively. The 5-year recurrence rate was 37%, while the 10-year recurrence rose to 77%. There was also statistically significant difference of median recurrence-free survival between the completely-resected group(Simpson grade 1 or 2) and partially-resected group(Simpson grade 3 or 4 or 5) ; 137 months compared to 47 months, respectively(p=0.009). The median recurrence-free period after subtotal resection of tumor and postoperative radiotherapy was 47 months compared to 117 months of the patients who underwent gross total resection of tumor and did not receive radiotherapy. But radiation therapy alone did not show significant difference in recurrence-free survival. Marked tumor volume reduction and easy removal of tumors without bleeding were found in 2 recurred cases. Conclusion : The extent of tumor resection and presence of metastasis are the most important factors related to long-term outcome of the patients with hemangiopericytoma. Radiation therapy after the first operation did not have a role in extending the recurrence-free survival, but it affected favorably to decrease the size of residual mass and intraoperative bleeding during the second operation.

• Korea Trade Review
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• v.42 no.1
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• pp.141-163
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• 2017

The purpose of this study to analyze the relationship among three characteristics of O2O commerce and extended goal-directed behavior(EGB) model(trust, desire and intention to use). From June to July in 2015, the questionnaires were sent to Chinese customers using O2O commerce. Among 494 questionnaires gathered, 433 valid ones are analyzed using SPSS and AMOS. Among ten research hypotheses derived from prior research and the research model, eight hypotheses are tenable, while the rest hypotheses are untenable. Online features of mobility and Offline features of service quality. The Online features of mobility bring consumers convenience but also has some latent customer privacy issue. On other hand, because of the untenable hypothesis, there is inconformity between online service and offline service, and customer have distrust on the O2O commerce. To achieve continuous online consumption, offline businesses need to improve their service. The perceived quality of selling company exerts a significant effect on the customers' reliability for the brand equity of open market company and selling company, such as the brand awareness of the open market, open market image, brand awareness of selling company, and the perceived quality of selling company. Thus, selling company should improve self-brand service and quality in order to improve customers' reliability. In addition, the consumer characteristics of attitude, subjective norm, and perceived behavioral control are all tenable. These results mean that O2O commerce is a favorite way of consumption by Chinese consumers.

• Information Systems Review
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• v.22 no.3
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• pp.119-142
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• 2020

This study aims to examine the role of IT features as heuristic cues in choosing a content on YouTube. According to the heuristic-systematic model, people tend to rely on heuristic cues when they have to choose and process useful information quickly so that they could save time and reduce demands for thinking. Based on this line of reasoning, this study posits that YouTube users rely on certain IT features as heuristic cues in choosing contents before they actually watch them. Based on the prior literature and interviews with YouTube users, we develop a research model in which social endorsement, self-presentation, and interactivity are identified as potential determinants of users' attitude toward contents, which in turn influence their intention to watch them. To empirically test the research model, we conduct a laboratory experiment and a follow-up survey. The results of data analysis show that social endorsement for the content, YouTube creator's self-presentation, and interactivity have significant and positive effects on their attitude toward the content, leading to their intention to watch it. This study suggests that IT features on YouTube could be wisely utilized to increase the chance that users choose a particular content out of many competing contents when they search certain information on YouTube.

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.99-115
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• 2021

Various sequences have been developed for MRI to aid in the radiologic diagnosis. Among the various MR sequences, susceptibility-weighted imaging (SWI) is a high-spatial-resolution, three-dimensional gradient-echo MR sequence, which is very sensitive in detecting deoxyhemoglobin, ferritin, hemosiderin, and bone minerals through local magnetic field distortion. In this regard, SWI has been used for the diagnosis and treatment of various neurologic disorders, and the improved image quality has enabled to acquire more useful information for radiologists. Here, we explain the principle of various signals on SWI arising in neurological disorders and provide a retrospective review of many cases of clinically or pathologically proven disease or components with distinctive imaging features of various neurological diseases. Additionally, we outline a short and condensed overview of principles of SWI in relation to neurological disorders and describe various cases with characteristic imaging features on SWI. There are many different types diseases involving the brain parenchyma, and they have distinct SWI features. SWI is an effective imaging tool that provides complementary information for the diagnosis of various diseases.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1029-1036
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• 2024

Drawing on the deep experience and understanding of the principles of nuclear safety, as well as many years of nuclear power plant design and operation, the EDF led NUWARD SMR Project is developing a design for a Small Modular Reactor (SMR) of 340 MWe composed of two 170 MWe independent units, that will supplement the offering of high-output nuclear reactors, especially in response to specific needs such as replacement of fossil-fuelled power plants. NUWARD SMR is a mix of proven and innovative design features that will make it more commercially competitive, while integrating safety features that comply with the highest international standards. Following the principles of redundancy and diversity and rigorous application of Defence in Depth (DID), with an international view on nuclear safety licensing, the Project also incorporates new safety approaches into its design development. The NUWARD SMR Project has been in development for a number of years, it entered conceptual design formally in mid-2019 and entered Basic Design in 2023. The objective of the concept design phase was to confirm the project technological choices and to define the first design configuration of the NUWARD SMR product, to document it, in order to launch pre-licensing with the French Safety Authority (ASN) and to define its estimated cost and its subsequent development and construction schedules. As a delivery milestone the Safety Options file (called the Dossier d'Options de Sûreté (DOS)) has been submitted to ASN in July 2023 for their opinion. An integral part of the NUWARD SMR Project, is not only to deliver a design suitable for France and to satisfy French regulation, but to develop a product suitable and indeed desirable, for the international market, with a first focus in Europe. In order to achieve its objectives and realise its market potential, the NUWARD SMR Project needs to define and realise its safety approach within an international environment and that is the key subject of this paper. The following paper: • Summarises the foundation principles and technological background which underpin the design; • Contextualises the key design features with regard to the international safety regulatory framework with particular emphasis on innovative passive safety aspects; • Illustrates the Project activities in preparation for first licensing in France, and also a wider international view via the ASN led Joint Early Review of the NUWARD SMR design, including Finnish and Czech Republic regulators, recently joined by the Swedish, Polish and Dutch regulators; • Articulates the collaborative approach to design development from involvement with the Project partners (the Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Naval Group, TechnicAtome, Framatome and Tractebel) to the establishment of the International NUWARD Advisory Board (INAB), to gain greater international insight and advice; • Concludes with the focus on next steps into detailed design development, standardisation of the design and its simplification to enhance its commercial competitiveness in a context of further harmonisation of the nuclear safety and licensing requirements and aspirations.

• Information Systems Review
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• v.25 no.2
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• pp.77-101
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• 2023

Due to COVID-19, paid virtual live-stream concerts have emerged as an alternative format and a new revenue model for in-person live concerts. Despite the increasing scholarly and practical interest in how participants experience paid virtual live-stream concerts, few studies examined participants' consumption and participation experiences. Thus, this study aims to provide insights into consumers' virtual live-stream concert experience by employing social representations theory (SRT). We explore the features of paid virtual live-stream concerts based on the C-P-N-D (Content-Platform-Network-Device) framework and the consumers' cognitive and affective perception. To this end, an SRT-based core-periphery analysis was conducted based on 239 responses to the open-ended survey questions. The results show that network-and device-level features of virtual live concerts and participants' overall perception are presented as core elements of paid virtual live-stream concerts, whereas content- and platform-level features are peripheral elements. This finding provides an in-depth understanding of the emergence of paid virtual live-stream concerts as an alternative concert format, thereby providing an invaluable understanding of a virtual live concert experience and theoretical and practical insights.

• The Korean Journal of Cytopathology
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• v.1 no.1
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• pp.18-26
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• 1990

CT guided percutaneous fine-needle aspiration (FNA) of the liver for both cytologic and histologic examination has great value in diagnosing liver malignancy. From March, 1986 to April, 1990, 62 patients with the clinical impression of liver malignancy underwent CT guided percutaneous FNA biopsy. Of these, 43 cases were reviewed for this study, 19 were reported to be liver cell carcinoma, 2 were adenocarcinoma, 11 were reported as anaplastic cell present, and the rest (11 cases) were negative (9) or necrotic (2). Among the 11 cases of the last group, 9 were diagnosed as liver cell carcinoma and 2 were necrotic histologically. Retrospective review, in order to clarify the cause of cytologic diagnostic error, of both cytologic and histologic slides of all cases showed discordance of 23% between these diagnoses and sensitivity is 93.9% and specificity is 90.9%. The reasons were as follows ; 1) the lack of awareness of tumor cells of well differentiated liver cell carcinoma (4 cases), 2) missed tumor cells due to too scanty cellularity (1 case), 3) improper smear (2 cases) and no tumor cell In the cytologic smears (3 cases). In such cases, at the initiation of FNA, a correct diagnosis of liver malignancy could only be made by a combination of cytologic and histologic examinations. However after three years' experience we can conclude that cytomorphologic features of liver cell carcinoma are sufficiently distinctive from other liver malignancies to be diagnostic.