• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.4-31
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• 2018

The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.67-86
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• 2020

Recommender Systems have been huge influence users and business more and more. Recently the importance of E-commerce has been reached rapid growth greatly in world-wide COVID-19 pandemic. Recommender system is the center of E-commerce lively. Top ranked E-commerce managers mentioned that recommender systems have a major influence on customer's purchase such as about 50% of Netflix, Amazon sales from their recommender systems. Most algorithms have been focused on improving accuracy of recommender system regardless of novelty, diversity, serendipity etc. Recommender systems with only high accuracy cannot satisfy business long-term profit because of generating sales polarization. In addition, customers do not experience enjoyment of shopping from only focusing accuracy recommender system because customer's preference is changed constantly. Therefore, recommender systems with various values need to be developed for user's high satisfaction. Reranking is the most useful methodology to realize diversity of recommender system. In this paper, diversity of recommender system is represented through constructing high similarity with users who have different preference using each user's purchased item's category algorithm. It is distinguished from past research approach which is changing the algorithm of recommender system without user's diversity preference level. We tried to discover user's diversity preference level and observed the results how the effect was different according to user's diversity preference level. In addition, graph-based recommender system was used to show diversity through user's network, not collaborative filtering. In this paper, Amazon Grocery and Gourmet Food data was used because the low-involvement product, such as habitual product, foods, low-priced goods etc., had high probability to show customer's diversity. First, a bipartite graph with users and items simultaneously is constructed to make graph-based recommender system. However, each users and items unipartite graph also need to be established to show diversity of recommender system. The weight of each unipartite graph has played crucial role changing Jaccard Distance of item's category. We can observe two important results from the user's unipartite network. First, the user's diversity preference level is observed from the network and second, dissimilar users can be discovered in the user's network. Through the research process, diversity of recommender system is presented highly with small accuracy loss and optimalization for higher accuracy is possible controlling diversity ratio. This paper has three important theoretical points. First, this research expands recommender system research for user's satisfaction with various values. Second, the graph-based recommender system is developed newly. Third, the evaluation indicator of diversity is made for diversity. In addition, recommender systems are useful for corporate profit practically and this paper has contribution on business closely. Above all, business long-term profit can be improved using recommender system with diversity and the recommender system can provide right service according to user's diversity level. Lastly, the corporate selling low-involvement products have great effect based on the results.

• Journal of Popular Narrative
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• v.26 no.3
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• pp.123-160
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• 2020

Manga develops by reflecting a change of society, reader's needs, and their thoughts and changes of tastes, sensitively. Shojo manga and Jyosei manga also do. We can find several kinds of meaningful changes in Japanese Jyosei manga in the 2010s. The works which represent preciousness of daily life, women's narrative and self-realization are gradually increasing. In addition, the works that deal with very touchy issues such as sex discrimination at work, sexual harassment begin to emerge. It has never been found in the manga of the former era. While this paper analyzes the social and cultural causes of these changes of the works that exclude romance and treat gender issues focusing on recent works, it examines changes of Japanese Jyosei manga in the 2010s and their meanings. I investigate the current trends of Japanese Jyosei manga in the 2010s through Umimachi Diary that represents a precious everyday life with woman-centered narrative, Metamorphose no engawa that deals with women's story from a new perspective, Good-bye My Miniskirt that tackles gender issues. Furthermore I intensively analyze how Nagi's Long Vacation and Darucyan, which win popularity from women in their 20s~30, represent lives and troubles of contemporary Japanese women. Nagi's Long Vacation represents the heroine's quest for a self throwing everything out. While Darucyan deals with self-realization, it forms of a bond of sympathy of readers by representing the heroine who suffers sexual harassment and inequal conditions very realistically. Nagi's Long Vacation and Darucyan have something in common with portraying troubles and self-realization of the working women in their 20s based on a indigenous reality to Japanese society very realistically. However they are unusual in that it is different from the manga of the former era in dealing with heroine's troubles and their solutions. The most distinctive changes of Jyosei manga since 2010 are that real issues surfaced with social changes. In addition, these social contradictions result from irrational discriminations and old customs of Japanese society for a long time. Manga reflects subtly the portraits of the times, their images of women, and their values. These changes of Jyosei manga also show the concerns of readers at that time, and it means that women began to be aware of the issues.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.152-161
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• 2023

In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.285-294
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• 2014

This study investigates the effects of formative assessment utilizing mobile applications on interest and self-directedness in science instruction. The study subjects are two 6th grade classes from H elementary school located in Incheon, and the experimental group and the comparative group are composed of 21 students, respectively. The students from the experimental group have been taught with mobile devices while the comparative group has been taught in methods consistent with the current teaching standards. For the sake of research, the results of the method applied to the mobile device focus group have been edited using Google Drive Forms, entered as QR codes and stored in order for them to later be utilized for teaching and learning process. In the process, the teacher has provided the students with feedback based on their answers. The students of comparative group are to solve the same formative assessment in paper. As a result, the teacher of the mobile device focus group has been able to go through twenty-nine questions on formative assessment in the teaching and learning process, confirm the correct answers five times and provide feedback twenty-five times for additional explanation. In the inquiry about interest, the mobile device group scored 4.64 points and the standard one scored just 1.99 points (p<0.01). Fifteen students answered in the interview that and the major reason why they scored high has been because it was fun to study with mobile devices. When it comes to self-directedness over the process of teaching and learning, the mobile device focus group has answered positively but the standard group has scored relatively low (p<0.01).

• Neonatal Medicine
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• v.18 no.2
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• pp.257-264
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• 2011

Purpose: The development of postnatal pneumothorax and its common causes and clinical aspects were studied to promote early diagnosis and proper management. Methods: A retrospective study of neonates who were hospitalized in the neonatal intensive care unit at Soonchunhyang University Bucheon Hospital from 2001 to 2010 was performed. Term neonates were divided into a spontaneous pneumothorax group and a secondary pneumothorax group. The secondary group was divided into term and preterm groups. Results: Of 4,414 inpatients, 57 (1.3%) were diagnosed with pneumothorax. Of term newborn patients, 28 (80%) had a secondary pneumothorax, and seven (20%) had a spontaneous pneumothorax. No differences were observed for gender, birth weight, resuscitation, or duration of admission between the spontaneous and control groups. The duration of treatment with a thoracostomy (20 patients, 57%) was longer in the spontaneous group (5.4${\pm}$2.9 days vs. 2.7${\pm}$2.0 days) than that in the control group. Patients with respiratory distress syndrome (RDS) developed a pneumothorax 22.8 hours after surfactant treatment, whereas patients with transient tachypnea of the newborn (TTN), pneumonia, and meconium aspiration syndrome (MAS) developed pneumothorax after 16.6 hours. Of 50 patients with a secondary pneumothorax, 19 (38%) had RDS, 11 (22%) had MAS, 7 (14%) had TTN, and six (12%) had pneumonia. Among term newborns, 42.9% were treated only with 100% oxygen. Among preterm newborns, 72.6% and 27.3% needed a thoracostomy or ventilator care, respectively. Conclusion: A pneumothorax is likely to develop when pulmonary disease occurs in neonates. Therefore, it is important to carefully identify pneumothorax and provide appropriate treatment.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.409-415
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• 2018

The development of smart devices has brought about significant changes in daily life and one of the most significant changes is the virtual reality zone. Virtual reality is a technology that creates the illusion that a 3D high-resolution image has already been created using a display device just like it does in itself. Unrealized subjects are forced to rely on audiovisual materials, resulting in a decline in the concentration of practices and the quality of classes. It used virtual reality to develop effective teaching materials for radiology students. In order to produce a video clip bridge using virtual reality, a radiology clinic was selected to conduct two exposures from July to September 2017. The video was produced taking into account the radiology and work flow chart and filming was carried out in two separate locations : in the computerized tomography unit and in the LINAC room. Prior to filming the scenario and the filming route were checked in advance to facilitate editing of the video. Modeling and mapping was performed in a PC environment using the Window XP operating system. Using two leading virtual reality camera Gopro Hero, CC pixels were produced using a 4K UHD, Adobe, followed by an 8 megapixel resolution of $3,840{\times}2,160/4,096{\times}2,160$. Total regeneration time was performed in about 5 minutes during the production of using virtual reality to prevent vomiting and dizziness. Currently developed virtual reality radiation and educational contents are being used to secure the market and extend the promotion process to be used by various institutions. The researchers will investigate the satisfaction level of radiation and educational contents using virtual reality and carry out supplementary tasks depending on the results.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.1
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• pp.1-8
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• 2013

This study was conducted to compare the local climate conditions and growth periods for the apple (Malus domestica 'Borkh') orchards at different altitudes (330, 500, and 670 m) in Jangsu-Gun, Korea. Observation data for the growth period show that the monthly mean air temperatures at the 'Hongro' apple orchard sites decrease with height at the rate of 1.0 to $3.0^{\circ}C$/100 m. The monthly minimum temperatures in April (blooming period for 'Hongro' apple) were 4.3, 2.9, and $0.4^{\circ}C$ at 330, 500, and 670 m, respectively. The monthly mean temperatures in September (i.e., the coloration and maturation period) were 20.6, 18.7, and $14.5^{\circ}C$, respectively. The annual precipitation range varied from 1,234 to 1,439 mm, which tended to increase with height. The heavy rainfall occurred in summer (June to August) and amounted to 827-933 mm. No significant differences in the duration of sunshine were observed amongst the orchards at three different altitudes. The earliest bud break was observed at the 330 m altitude (18 March 2009), which was 4 and 11 days earlier in comparison to those at 500 and 670 m, respectively. The time of full bloom at 330 m was 12 days ahead of that at 670 m. The optimal maturation of fruit (based on skin redness > 80%) was observed between 7 and 10 September at 330 m, 15 and 18 September at 500 m, and 21 and 23 September at 670 m.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.224-237
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• 1988

To determine the causes of and related factors to childhood injuries, the emergency room records and inpatient medical records were reviewed for 4,849 injured children out of 15,790 pediatric patients(<15 years old) who visited the emergency rooms of 3 university hospitals and 2 general hospitals in Taegu from 1 January to 31 December 1987. Out of total injured children, 54.675 were 3-8 years old and the male to female ratio of the total injured children was about 2:1. The leading causes of injury were falls and slips (29.1%) and traffic accident(28.2%). The frequency of injury was higher in May-October than the rest of months and 51.6% of the injuries occurred between 15 and 20 o'clock. Falls and slips took place most frequently at the stairway(25.7%). The most common interpersonal violence was inflicted injuries(85.6%) and there were 11 child rapes. Dog bites accounted for 67.6% of all biting injuries and it occured 2.9 times more in male than in female. CO intoxication was the most common cause of poisoning (45.3%) and scalding accounted for 85.2% of all burns. Common places of drownings were river (32.2%), swimming pool (22.6%) and construction site(19.3%). To prevent childhood injuries, it is recommended to eliminate the hazardous environmental factors, to provide safe playgrounds, to educate the children for safety from kindergarten and the general public through mass communication, to establish a strict safety standard for houses, public buildings and facilities, and playgrounds.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.826-830
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• 2002

Prosthetic valve thrombosis(PVT) may be a life-threatening complication requiring prompt intervention. This is a case report of thrombolytic therapy for thrombosis of prosthetic mitral valve. A 47 year-old male admitted to the emergency room for abrupt onset of dyspnea. He had undergone mitral valve replacement(On-Ⅹ valve, 29mm) for mitral stenosis 8 months ago. The patient's international normalized ratio(INR) on admission was 1.09. The mechanical clicks were muffled and rales were heard in both lung fields. A transesophageal echocardiography(TEE) revealed prosthetic valve thrombosis with increased transvalvular pressure gradient(34 mmHg). The patient's condition needed to intubation for mechanical ventilation due to hemodynamic compromise, however his wife and relatives refused the surgical intervention due to financial problems. The patient was transferred to the cardiac care unit and we decided to perform thrombolytic therapy. A bolus of 1,500,000 IU of urokinase was given, followed by a drip of 1,500,000 IU for 1 hour. The patient did not improved hemodynamically; therefore, we gave 100 mg of tissue plasminogen activator(t-PA) for over 2 hours. During that time mechanical clicks were audible and hemodynamics of the patient improved progressively. A TEE showed disappearance of thrombus and decreased pressure gradient(1.7 mmHg) after 6 hours of thrombolytic therapy. The patient was recovered without any neurologic sequale and was discharged with administration of warfarin.