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A Study on Major Safety Problems and Improvement Measures of Personal Mobility (개인형 이동장치의 안전 주요 문제점 및 개선방안 연구)

  • Kang, Seung Shik;Kang, Seong Kyung
    • Journal of the Society of Disaster Information
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    • v.18 no.1
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    • pp.202-217
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    • 2022
  • Purpose: The recent increased use of Personal Mobility (PM) has been accompanied by a rise in the annual number of accidents. Accordingly, the safety requirements for PM use are being strengthened, but the laws/systems, infrastructure, and management systems remain insufficient for fostering a safe environment. Therefore, this study comprehensively searches the main problems and improvement methods through a review of previous studies that are related to PM. Then the priorities according to the importance of the improvement methods are presented through the Delphi survey. Method: The research method is mainly composed of a literature study and an expert survey (Delphi survey). Prior research and improvement cases (local governments, government departments, companies, etc.) are reviewed to derive problems and improvements, and a problem/improvement classification table is created based on keywords. Based on the classification contents, an expert survey is conducted to derive a priority improvement plan. Result: The PM-related problems were in 'non-compliance with traffic laws, lack of knowledge, inexperienced operation, and lack of safety awareness' in relation to human factors, and 'device characteristics, road-drivable space, road facilities, parking facilities' in relation to physical factors. 'Management/supervision, product management, user management, education/training' as administrative factors and legal factors are divided into 'absence/sufficiency of law, confusion/duplication, reduced effectiveness'. Improvement tasks related to this include 'PM education/public relations, parking/return, road improvement, PM registration/management, insurance, safety standards, traffic standards, PM device safety, PM supplementary facilities, enforcement/management, dedicated organization, service providers, management system, and related laws/institutional improvement', and 42 detailed tasks are derived for these 14 core tasks. The results for the importance evaluation of detailed tasks show that the tasks with a high overall average for the evaluation items of cost, time, effect, urgency, and feasibility were 'strengthening crackdown/instruction activities, education publicity/campaign, truancy PM management, and clarification of traffic rules'. Conclusion: The PM market is experiencing gradual growth based on shared services and a safe environment for PM use must be ensured along with industrial revitalization. In this respect, this study seeks out the major problems and improvement plans related to PM from a comprehensive point of view and prioritizes the necessary improvement measures. Therefore, it can serve as a basis of data for future policy establishment. In the future, in-depth data supplementation will be required for each key improvement area for practical policy application.

Study on Manufacturing Techniques and Conservation for Earthenware Horn Cups with a Horse Head Decoration(Treasure) (보물 도기 말머리장식 뿔잔의 제작 기법 연구와 보존처리)

  • KWON, Ohyoung;HAM, Chulhee;YU, Jia;KIM, Hanseul;PARK, Changyuel
    • Korean Journal of Heritage: History & Science
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    • v.55 no.1
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    • pp.51-61
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    • 2022
  • Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.

Investigation on Diesel Injection Characteristics of Natural Gas-Diesel Dual Fuel Engine for Stable Combustion and Efficiency Improvement Under 50% Load Condition (천연가스-디젤 혼소 엔진의 50% 부하 조건에서 제동효율 및 연소안정성 개선을 위한 디젤 분무 특성 평가)

  • Oh, Sechul;Oh, Junho;Jang, Hyungjun;Lee, Jeongwoo;Lee, Seokhwan;Lee, Sunyoup;Kim, Changgi
    • Journal of the Korean Institute of Gas
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    • v.26 no.3
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    • pp.45-53
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    • 2022
  • In order to improve the emission of diesel engines, natural gas-diesel dual fuel combustion compression ignition engines are in the spotlight. In particular, a reactivity controlled compression ignition (RCCI) combustion strategy is investigated comprehensively due to its possibility to improve both efficiency and emissions. With advanced diesel direct injection timing earlier than TDC, it achieves spontaneous reaction with overall lean mixture from a homogeneous mixture in the entire cylinder area, reducing nitrogen oxides (NOx) and particulate matter (PM) and improving braking heat efficiency at the same time. However, there is a disadvantage in that the amount of incomplete combustion increases in a low load region with a relatively small amount of fuel-air. To solve this, sensitive control according to the diesel injection timing and fuel ratio is required. In this study, experiments were conducted to improve efficiency and exhaust emissions of the natural gas-diesel dual fuel engine at low load, and evaluate combustion stability according to the diesel injection timing at the operation point for power generation. A 6 L-class commercial diesel engine was used for the experiment which was conducted under a 50% load range (~50 kW) at 1,800 rpm. Two injectors with different spray patterns were applied to the experiment, and the fraction of natural gas and diesel injection timing were selected as main parameters. Based on the experimental results, it was confirmed that the brake thermal efficiency increased by up to 1.3%p in the modified injector with the narrow-angle injection added. In addition, the spray pattern of the modified injector was suitable for premixed combustion, increasing operable range in consideration of combustion instability, torque reduction, and emissions level under Tier-V level (0.4 g/kWh for NOx).

Characteristics Associated with Citation Rates of the Journal of Korean Orthopaedic Association (An Analysis of Articles between 2001-2015) (대한정형외과학회지에 발표된 논문들의 피인용 횟수와 연관된 특성(2001년부터 2015년까지의 논문 분석))

  • Bae, Jung Yun;Kwak, Sang Ho;Kang, Sang Woo;Woo, Seung Hun;Ahn, Tae Young;Lee, Sang Hyun
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.6
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    • pp.487-494
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    • 2020
  • Purpose: No attempt has been made to identify the relationship between the study characteristics and citation rates of articles published in the Journal of the Korean Orthopaedic Association (JKOA). This study classified the study characteristics of articles in the JKOA and analyzed the relationship between the study characteristics and citation rates. Materials and Methods: A cohort study was conducted on all articles published from February 2001 to December 2015. Three independent reviewers classified the articles according to the article type, material, time of the study, design, clinical categories, number of authors, and number of cases. The citation numbers of each article by other journals were taken in January 2020. Univariate analyses were conducted to assess the effect of each characteristic, and multivariate linear regression analysis was performed to analyze the overall relationship between the characteristics and the citation rates. Results: A total of 1,640 articles were published from 2001 to 2015, and 724 articles were cited more than once. The articles published in 2009 had the highest average number of citations. Original articles had the highest citation rates, followed in descending order by surgical techniques and reviews, instructional course lectures, and case reports (p<0.001). Among the case reports, articles dealing with general trauma scored significantly higher average citations (mean=1.5, p=0.006). Among the original articles, articles on general orthopedics had the highest citation rates, followed in order by clinical articles and experimental articles. Among the clinical articles, epidemiologic studies (mean=5.0, p<0.001) and studies on the spine (mean=1.7, p<0.001) recorded significantly higher citation rates than the others. Conclusion: Of all the articles published in the JKOA from 2001 to 2015, articles dealing with general trauma had the highest citation rates among case reports. Among the original articles, epidemiologic studies and studies concerning the spine were cited significantly more than others.

An Overview of Surgical Treatment of Thymic Epithelial Tumors in Korea: A Retrospective Multicenter Analysis

  • Lee, Jun Oh;Lee, Geun Dong;Kim, Hyeong Ryul;Kim, Dong Kwan;Park, Seung-Il;Cho, Jong Ho;Kim, Hong Kwan;Choi, Yong Soo;Kim, Jhingook;Shim, Young Mog;Park, Samina;Park, In Kyu;Kang, Chang Hyun;Kim, Young Tae;Park, Seong Yong;Lee, Chang Young;Lee, Jin Gu;Kim, Dae Joon;Paik, Hyo Chae;the Korean Association for Research on the Thymus,
    • Journal of Chest Surgery
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    • v.55 no.2
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    • pp.126-142
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    • 2022
  • Background: Thymic epithelial tumors (TETs) are rare, and information regarding their surgical outcomes and prognostic factors has rapidly changed in the past few decades. We analyzed surgical treatment practices for TETs and outcomes in terms of overall survival (OS) and freedom from recurrence (FFR) during a 13-year period in Korea. Methods: In total, 1,298 patients with surgically resected TETs between 2000 and 2013 were enrolled retrospectively. OS and FFR were calculated using the Kaplan-Meier method and evaluated with the log-rank test. Prognostic factors for OS and FFR were analyzed with multivariable Cox regression. Results: A total of 1,098 patients were diagnosed with thymoma, and 200 patients were diagnosed with thymic carcinoma. Over the study period, the total number of patients with surgically treated TETs and the proportion of patients who underwent minimally invasive thymic surgery (MITS) increased annually. The 5-year and 10-year survival rates of surgically treated TETs were 91.0% and 82.1%, respectively. The 5-year and 10-year recurrence rates were 86.3% and 80.0%, respectively. The outcomes of surgically treated TETs improved over time. Multivariable Cox hazards analysis for OS, age, tumor size, and Masaoka-Koga stage were independent predictors of prognosis. The World Health Organization classification and tumor-node-metastasis (TNM) staging were also related to the prognosis of TETs. Conclusion: Surgical treatment of TETs achieved a good prognosis with a recent increase in MITS. The M-K stage was the most important prognostic factor for OS and FFR. The new TNM stage could also be an effective predictor of the outcomes of TETs.

Development of Consumer Education Teaching-Learning Process for SMART Learning-Based Middle School Home Economics Education (스마트러닝 기반 중학교 가정교과 소비생활 교수-학습안 개발)

  • Seo, Yu Ri;Chae, Jung Hyun
    • Journal of Korean Home Economics Education Association
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    • v.32 no.4
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    • pp.149-170
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    • 2020
  • The purpose of this study was to develop and evaluate a Smart learning-based middle school home economics education plan to improve the online home economics education classes. The educational plan in this study was completed through the process of analysis, design, development, and evaluation. The results of this study are as follows. First, as a result of analyzing consumer life units in the middle school textbooks based on 2015-revised curriculum, Smart learning activities were presented in only two out of the 12 textbooks analyxed. Second, a Smart learning-based middle school home economics education plan was developed in this study with the following characteristics: the topics and contents are structured so that to help learners actively engage in the teaching and learning activities; the education plan to reflects various media and current issues that learners may be interested in; the lesson plans were structured with the premise of online classes; softwares that enable real-time discussion and collaboration are used; and the evaluation method are composed of online activities. Third, the expert evaluation scores for the educational plan and activity materials developed were 4.52 (5-point Likert scale), when averaged across subject, goal, content, teaching/learning activity, and evaluation, and the overall content validity index(CVI) was 0.95. The adequacy of execution, benefit, attractiveness, usefulness, and feasibility were highly with an average of 4.62. Based on the experts' comments, the education plan and activity materials were revised and completed. This study is meaningful in that it developed teaching and learning activities based on online classes after the COVID-19 outbreak, overcoming the limitations of offline classes. It has implications for face-to-face home economics classes due to COVID-19, as it suggests ways to blend online and offline teaching/learning activities depending on the situation.

Improving the Current Status and Cultural Value of Donguibogam Wanyoung Woodblocks (<동의보감(東醫寶鑑)> 완영(完營)책판의 현황과 문화재적 가치 제고(提高))

  • KIM, Hwaseon
    • Korean Journal of Heritage: History & Science
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    • v.55 no.2
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    • pp.50-64
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    • 2022
  • This thesis is a study on the woodblock of Donguibogam by Jeolla Gamyeong(Wanyoung Woodblock). It was registered as a tangible cultural property in Jeollabuk-do in 2005. The purpose of this article is to determine the current status and value of the Donguibogam Wanyoung Woodblock. Jeonju Hyanggyo's Wanyoung Woodblock was used to print books in Gamyeong, Jeolla Province. Currently, ten kinds of woodblocks are preserved. In 1987, a wooden bookshelf was installed and preserved in "Jangpangak" of Jeonju Hyanggyo. It is now preserved and managed at Chonbuk National University Museum. Among the ten woodblocks, the Wanyoung woodblock of Donguibogam is presumed to be a woodblock of a book printed by Jeolla Gamyeong in 1814. The value of Donguibogam has long been recognized domestically and internationally. Donguibogam, compiled in 1610, was first published in 1613 in the wood type of Gaeju Gapinja. Following its publication, its value was recognized not only in Joseon but also in China and Japan. In 2009, the first edition of Donguibogam was registered as a UNESCO World Heritage. Accordingly, Donguibogam has been recognized for various aspects, but little research has been conducted on the woodblocks that printed Donguibogam. Therefore, this paper analyzes the current status of the Wanyoung woodblock of Donguibogam, aiming to enhance its meaning and value. King Seonjo presented the ideals of public health care and preventive medicine when compiling Donguibogam, which was distributed according to his instructions. For this reason, the first edition of Donguibogam was registered as a UNESCO World Heritage. It can be said that the production of Donguibogam woodblocks was an important tool in realizing Joseon's ideals through national dissemination. Furthermore, the woodblock of Donguibogam represents the spirit of thinking about the people, going beyond the purpose of printing, and it was meaningful in the spread of medical knowledge among the people. In this article, I will examine the overall contents of the Wanyoung woodblock of Donguibogam to enhance its meaning and value. The results show that the Wanyoung woodblock of Donguibogam is meaningful in that it is almost the only one produced and stored by Gamyeong. Moreover, Wanyoung woodblocks are meaningful in that perfect editions could be preserved and disseminated for a long time, unlike other wood-type prints.

Perception of Korean Residential Gardens and Gardening in the 1920~30s (1920~30년대 한국 주택정원 인식과 정원가꾸기 양상)

  • Gil, Jihye;Park, Hee-Soung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.2
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    • pp.138-148
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    • 2022
  • The 1920s and 1930s were when new trends became prominent in Korean housing architecture. This study began with a curiosity about the appearance of residential gardens during the transition period, when housing types were changing. Since gardens are constantly evolving and living spaces, it is not easy to give a clear picture of their evolution. However, through popular magazines and newspaper articles published in the 1920-30s, this study investigated how people perceived the gardens socially and how they engaged in gardening. First, the study of Gyeongseong's urbanization process revealed that people perceived gardens as a way to give natural beauty to the urban environment. Therefore, the creation of a residential garden was strongly encouraged. Second, the housing improvement movement, which the architects actively discussed during this period, emphasized that a garden is a factor that can help improve the quality of the residential environment in terms of hygiene and landscape aesthetics. Third, since the media provided information on gardening, it was confirmed that the number of people engaged in gardening as a hobby increased. As designers and gardeners who had received a modern education became more active, the concept of "designed gardens" was formed. Lastly, although the houses were divided into various types, the shapes of the gardens did not show a significant difference according to the architecture type. They tended to embrace the time's ideal garden design and style. Therefore, even in a traditional hanok, Western-style gardens were naturally harmonized into the overall architecture, and exotic plant species could be found. Although the gardens found in media images were limited to those belonging to the homes of the intelligentsia, it can be seen that representativeness was secured, considering the popularity and ripple effect of the media. Therefore, this study contributes to the literature as it confirmed the ideal gardens and gardening methods in the 1920s and 30s.

Trend Analysis of Documenting the Gardens of Old Houses with the Measurement Drawings of National Folklore Cultural Heritage (국가민속문화재의 실측도면을 통해 살펴본 고택 정원의 기록화 경향 분석)

  • LIM, Cheyeon;LEE, Jaeyong
    • Korean Journal of Heritage: History & Science
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    • v.55 no.3
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    • pp.46-58
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    • 2022
  • This study analyzed the documentation trend of garden components such as plants, infrastructure, unit facilities, and structures, based on 188 measurement drawings of 94 old houses in a report on the documentation of the national folklore cultural heritage. The findings are as follows. First, it was found that plants and structures continuously appeared as the subject of measurement drawings, while infrastructure was often omitted. It was confirmed that unit facilities, which are smaller than other components, were frequently excluded from the documentation subject as well due to frequent changes such as movement, loss, and expansion. Second, the level of expression in measurement drawings showed different aspects for each component. The unit facilities showed a large change over time with respect to the level of documentation, and the level of documentation was somewhat polarized, particularly toward the latter stage. This suggests that the level of documenting the drawings limited to specific facilities improved, but the overall level of drawings did not improve, such as a lack of diversification of expression techniques suitable for various unit facilities. On the other hand, it was confirmed that the level of documenting the drawings for plants, infrastructure and structures did not change to a significant degree, implying that no improvements were made to the expression of components. Third, as for the technique of detailed expression, in the case of plants, vegetation status was prepared without distinction of old or protected trees that have historical value. Above all, there was no record of the vegetation structure that could help grasp the vegetation landscape of the outer area. As for the infrastructure, there was no consistent expression technique to systematically convey topographic changes such as the height and slope of the land. In addition, since there was no subtype classification defined for unit facilities and structures, there was no subject or method of documentation. This study is meaningful in that it expanded the category of documentation, which has been concentrated on buildings in old houses, to gardens, and called attention to the need for documenting the gardens for the preservation and management of old houses as an integration of the building and outer area.

Dynamic Equilibrium Position Prediction Model for the Confluence Area of Nakdong River (낙동강 합류부 삼각주의 동적 평형 위치 예측 모델: 감천-낙동강 합류점 중심 분석 연구)

  • Minsik Kim;Haein Shin;Wook-Hyun Nahm;Wonsuck Kim
    • Economic and Environmental Geology
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    • v.56 no.4
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    • pp.435-445
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    • 2023
  • A delta is a depositional landform that is formed when sediment transported by a river is deposited in a relatively low-energy environment, such as a lake, sea, or a main channel. Among these, a delta formed at the confluence of rivers has a great importance in river management and research because it has a significant impact on the hydraulic and sedimentological characteristics of the river. Recently, the equilibrium state of the confluence area has been disrupted by large-scale dredging and construction of levees in the Nakdong River. However, due to the natural recovery of the river, the confluence area is returning to its pre-dredging natural state through ongoing sedimentation. The time-series data show that the confluence delta has been steadily growing since the dredging, but once it reaches a certain size, it repeats growth and retreat, and the overall size does not change significantly. In this study, we developed a model to explain the sedimentation-erosion processes in the confluence area based on the assumption that the confluence delta reaches a dynamic equilibrium. The model is based on two fundamental principles: sedimentation due to supply from the tributary and erosion due to the main channel. The erosion coefficient that represents the Nakdong River confluence areas, was obtained using data from the tributaries of the Nakdong River. Sensitivity analyses were conducted using the developed model to understand how the confluence delta responds to changes in the sediment and water discharges of the tributary and the main channel, respectively. We then used annual average discharge of the Nakdong River's tributaries to predict the dynamic equilibrium positions of the confluence deltas. Finally, we conducted a simulation experiment on the development of the Gamcheon-Nakdong River delta using recorded daily discharge. The results showed that even though it is a simple model, it accurately predicted the dynamic equilibrium positions of the confluence deltas in the Nakdong River, including the areas where the delta had not formed, and those where the delta had already formed and predicted the trend of the response of the Gamcheon-Nakdong River delta. However, the actual retreat in the Gamcheon-Nakdong River delta was not captured fully due to errors and limitations in the simplification process. The insights through this study provide basic information on the sediment supply of the Nakdong River through the confluence areas, which can be implemented as a basic model for river maintenance and management.