• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.753-760
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• 2018

Objective : We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs). Methods : We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans ($CK_{original}$) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at low-isodose levels (10-30% of prescription dose) for dose spillage. In each case, a modified CK plan ($CK_{modified}$) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared. Results : There were no differences in the conformity indices among the $CK_{original}$, $CK_{modified}$, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the $CK_{modified}$ plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the $CK_{original}$ plans (p<0.001), with no statistical differences in those volumes compared with GK plans (p=0.345). Conclusion : These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

• Journal of the Korea Institute of Building Construction
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• v.20 no.3
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• pp.269-278
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• 2020

In this study, we analyzed the safety accidents that occurred in the apartment construction site and the correlations between the victims according to the type of work accidents through multiple correspondence analysis. There is a lack of disaster-related studies on apartment construction sites, the third most frequent building type in Korea, and most of them have used survey techniques. Therefore, the exploratory data analysis was conducted in industrial accident cause data, and derived the correlation analysis between each disaster victim through multiple correspondence analysis. The results of the study are summarized in two as follows. First, as the number of heights increased due to the high rise and complexity of apartments, the fall rate and mortality rate were high. In addition, deaths are mostly caused by very few experienced workers or those with more than 10 years of experience, resulting from safety training, lack of experience, and insensitivity to safety. Second, multi-correspondence analysis showed that most safety accidents can be prevented by wearing safety equipment, and following proper work process and its safety action. The key factors derived from this study can be used for safety education, supervision, and management in apartment construction sites.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.57-67
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• 2012

There is much confusion with the relationship between character and actor. Under the pressure of 'becoming' a character, the actor tends to begin his work apart from his own senses, imagination and memory, and is most likely to fall into the trap of artificiality and clich$\acute{e}$. Like every other art, the actor has to begin honestly with himself who, in nature, has unfathomable possibilities. To be and live as a character, the actor has to experience. To experience, to react. To react, to see with all the senses. Like ours, each character's life goes on from reaction to reaction, reacting to the images from the imagination and the memory. "You are what you see." The actor is put into the extremely unfamiliar circumstances of drama, given only with his own senses, imagination and memory. Fear comes in. However, fear cannot stop the actor's challenging journey to self-discoveries. The actor does and acts, not because he is certain but because he is not. The actor challenges himself to go beyond the limit and uncertainty, so that he will finally come to know and truly understand human beings from the challenges of his own. In a nutshell, acting is a journey to the unknown and the unfamiliar in which the actor unceasingly discover new 'I's.

• Informatization Policy
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• v.28 no.3
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• pp.3-22
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• 2021

This article reviews previous literature on the metaverse and attempts to provide a refined definition for this phenomenon. Metaverse has recently been in the spotlight among discussions by the industry and the media while a consensus on the exact definition of metaverse is yet to be determined. Since Neal Stephenson first coined the term metaverse in his novel "Snow Crash" in 1992, the Acceleration Studies Foundation (ASF) was the first to analyze the concept of metaverse in 2007. While ASF's effort did not receive much spotlight it may have deserved, metaverse gained much attention in the fall of 2020 when NVIDIA announced its real-time simulation and collaboration platform for 3D production named "Omniverse" as a next-generation alternative for the Internet along with Roblox defining its service as metaverse during its IPO. Since then, metaverse has been commonly recognized as a world where we can cross over reality and virtuality. Based on the two axes and four scenarios proposed by the ASF, we review the literature across four realms as follows - virtual reality, mirror world, augmented reality, and lifelogging. Then, we examine the issues with the existing definition of metaverse and propose an alternative explanation by focusing on human behavior and user experience. Finally, we reassess the concept of metaverse and incorporate human communication, reality-based and virtual-based activities, and eXtended reality as elements to properly define metaverse.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.633-642
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• 2021

This study explores the online learning experiences of Chinese foreign students in Korea by using the CQR process and method. To gather data, researchers conducted online, in-depth interviews with 15 Chinese university students in Korea who were enrolled in the spring and fall semesters in 2020. After compiling the research, the data were segmented into four domains and 13 categories, with 36 subcategories identified from among foreign students' online learning experiences. The results show that Chinese students perceived the convenience of online classes and personalized learning as its strength, but considered lowered motivation and lack of concentration as weaknesses. Also, they experienced an increase in the amount of learning, spending more time studying online, using personal learning strategies, and getting help from friends and the university's online learning system. Moreover, they experienced difficulties related to class notifications, guidance, and interactions with the instructors. Foreign students studying in Korea need their instructor's facilitation in order to understand and participate in online classes, reinforcing a student's self-directed learning ability, and need appropriate guidance and support in terms of the online class environment.

• Clinical and Experimental Pediatrics
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• v.51 no.2
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• pp.122-128
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• 2008

Roughly one third of medical problems in children are related to the musculoskeletal system. Most of these problems are common and can be precisely diagnosed. For these problems, nonoperative treatment or reassurance can be given by the pediatrician. Occasionally, a problem needs surgical treatment, but a precise diagnosis must be made. There is little agreement about what types of orthopedic problems a primary care pediatrician should understand in order to effectively care for children. Many pediatric residencies lack an organized teaching curriculum that effectively covers these topics or that includes a required pediatric orthopedic rotation. In this article the authors delineate pediatric orthopedic problems that require recognition and urgent surgical treatment and are relatively common, but have different treatment options (observation, conservative treatment, and surgery) depending on their natural history. Whenever possible, the diagnosis should be made before a decision to refer is made. An accurate diagnosis allows the pediatrician to discuss the natural history of the condition properly. Referral to the wrong specialty can needlessly generate expensive tests and further delay in treatment or generate inappropriate treatment. The parents can be reassured rather than waiting to hear the same information from another physician. In particular, orthopedic problems are known to generate pressure from the parents to seek specialty consultation for reassurance. It is important to communicate to the specialist that the reason for the referral is for parental reassurance rather than for further work-up or treatment. After a proper diagnosis, communication directly between the pediatrician and the appropriate specialist can often avoid an unnecessary referral, and avoid unnecessary tests. The authors reviewed our experience at our outpatient clinic over last 1 year and found that it is useful to classify conditions as common or uncommon, and whether they require surgical or nonsurgical treatment. Many conditions fall in between. The following is a discussion of some of these more important or common conditions.

• Health Policy and Management
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• v.13 no.3
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• pp.52-70
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• 2003

The rate of conversion to Medical-juridical-persons' ownership of medical institutions has increased rapidly since its start in 1970s in Korea. The most sensitive issue to introduce for-profit medical institutions, ignited particularly by the WTO/DDA negotiations, has sparked considerable debate, stemming largely from conflicting views on the theoretical effects of ownership status on organizational behavior. This study surveyed health-related experts' opinions on allowing for for-profit-firms-owned medical institutions. Some fear that the obligation to maximize the share-holders' return on their investment will cause the medical institutions to eliminate necessary but less lucrative services. They may easily fall under more pressure to generate income, and respond more aggressively than not-for-profit medical institutions to financial pressures. Advocates of for-profit ownership of medical institutions argue that greater responsiveness to the demands of the marketplace will lead to larger investment, higher quality and lower costs to consumers. Referring to both foreign countries' experience and domestic experts' opinions, this study suggests for reform of the current Korean Medical-Juridical-Person(MJP) System. Introduction of so-called “Capital-investment” MJPs is recommended where the properties left in case of their dissolution can be distributed to original investors according to the procedures stipulated in their statutes. However, their annual profits are not allowed to be allocated to investors, but should be reinvested for their medical institutions, as is the case in current MJPs. Their legal aspects are also reviewed in this study.

• The Korean Journal of Emergency Medical Services
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• v.17 no.3
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• pp.9-20
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• 2013

Purpose: This research project addressed the need to designing more safe and efficient interior of the future ambulance in Korea. Methods: The study sample contained 760 paramedics in 4 districts. Data was collected by using a revised and complemented questionnaire based on literature review. Results: In relation to the efficacy and safety of work, answers related to storage closet showed to be the highest, and the most difficult part of paramedic work in an ambulance was lurching. CPR is the most frequently used emergency care inside an ambulance, but 66% of the paramedics responded that accurate CPR is not possible during vehicle transfer. Safety belts are not worn for 82.8% of the time, because of discomfort (51.3%). 13.8% of the paramedics responded that stretchers are unstable, 29.5% had an experience of having patients fall off the stretcher inside an ambulance. There were comments on installing equipments to prevent noise, and assist communication. Conclusion: The suggested practical layout contains five main modifications 1. Developing specially designed belt is needed for paramedic safety & efficient work. 2. The seats are molded to be ergonomically friendly. 3. Equipments to secure the body and safety devices for CPR are needed. 4. System improvement for communication between the driver seat and paramedics is needed. 5. The stretchers are molded to be maximize efficiency and minimize injury.

• Journal of Trauma and Injury
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• v.30 no.2
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• pp.33-40
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• 2017

Purpose: The role for minimally invasive surgery in chest trauma is vague, one that recently is more frequently performed, and one attractive option to be considered. Thoracoscopic surgery may improve morbidity, mortality, hasten recovery and shorten hospital stay. Methods: A total of 31 patients underwent video assisted thoracoscopic surgery for the treatment of blunt and penetrating chest trauma from June 9th, 2013 to March 21st, 2016 in Jeju, South Korea. Results: Twenty-three patients were males and eight patients were females. Their ages ranged from 23 to 81 years. The cause of injury was due to traffic accident in 17 patients, fall down in 5 patients, bicycle accident in 2 patients, battery in 2 patients, crushing injury in 2 patients, and slip down, kicked by horse, and stab wound in one patient each. Video assisted thoracoscopic exploration was performed in the 18 patients with flail chest or greater than 3 displaced ribs. The thoracoscopic procedures done were hematoma evacuation in 13 patients, partial rib fragment excision in 9 patients, lung suture in 5 patients, bleeding control (ligation or electrocautery) in 3 patients with massive hemothorax, diaphragmatic repair in two patients, wedge resection in two patients and decortication in 1 patient. There was only one patient with conversion to open thoracotomy. Conclusion: There is a broad range of procedures that can be done by thoracoscopic surgery and a painful thoracotomy incision can be avoided. Thoracoscopic surgery can be done safely and swiftly in the trauma patient.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.560-564
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• 2008

Purpose: Because of traffic accidents and many criminal violences, the incidence of facial trauma has been increasing not only in adults but also in children. We planed this study to introduce our experience about pediatric blow out fracture and provide more information. Methods: We made retrospective study in 76 children with blow out fracture from January 2001 to September 2005 by retrospective chart review including detailed preoperative and postoperative evaluations, age, sex, cause, symptom and sign, and their post-operative complications. Results: Among our patients, 69 were male and 7 were female. The ages ranged from 7 to 18 years, which shows the greatest incidence of blow out fracture. Physical violence(46%) was the most common cause in this group and was followed by vehicle accident(28%), and fall down accident(17%). Left side(64%) showed slightly more incidence than right side(36%), but there were no statistical importance. Ecchymosis(88%) was the most common symptom and followed by periorbital swelling(68%) and diplopia(30%). 30 patients was diagnosed with another facial bone fracture and nasal bone(51%) was the most common associated facial bone fracture. Fourty four Patients(60%) got an orbital wall reconstruction in 7 days after trauma. After the operation, only 3 patients(4%) suffered from diplopia postoperative 3 month, and resolved in 4 years. Conclusion: The incidence of blow out fracture in children has been increasing every year, and violence has become more important etiology of pediatric blow out fracture and public and private education institutions were the most common place that blow out fracture originated. Accurate diagnosis and careful treatment plans are important in pediatric blow out fracture.