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A Study on Applicability of Soil Strength for Surface Treatment (표층처리를 위한 현장의 강도적용에 관한 연구)

  • Yang, Tae-Seon;Kim, Byeong-Ho
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.3
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    • pp.45-52
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    • 2005
  • Most marine structures are constructed on very soft soil, soil improvements are needed for the area of road, buildings. In this paper, some considerations of several case studies on soil placement method after geotextile placement, known as surface treatment, are done. Considerations of strength applicability on the advanced construction method of sand and soil placement are proposed in this paper. Typical tensile strength of geotextile used in the surface soil stabilization method is 15t/m, and thickness of sand and soil placement between 1.6m and 3.1m. Undrained shear strength of soft clay layer ranges $0.2{\sim}1.2t/m^2$. In order to minimize the difficulties which include soil disturbance, soft soil gush and overturn of vertical drain installation rig more studies are needed.

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Forensic Engineering Study on the Evaluation of the Structural Stability of the Mobile Crane Accident (차량크레인 전도 사고의 구조 안정성 평가에 관한 법공학적 연구)

  • Kim, Jong-Hyuk;Kim, Eui-Soo
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.11-17
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    • 2013
  • Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

Aerodynamic performance of a novel wind barrier for train-bridge system

  • He, Xuhui;Shi, Kang;Wu, Teng;Zou, Yunfeng;Wang, Hanfeng;Qin, Hongxi
    • Wind and Structures
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    • v.23 no.3
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    • pp.171-189
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    • 2016
  • An adjustable, louver-type wind barrier was introduced in this study for improving the running safety and ride comfort of train on the bridge under the undesirable wind environment. The aerodynamic characteristics of both train and bridge due to this novel wind barrier was systematically investigated based on the wind tunnel tests. It is suggested that rotation angles of the adjustable blade of the louver-type wind barrier should be controlled within $90^{\circ}$ to achieve an effective solution in terms of the overall aerodynamic performance of the train. Compared to the traditional grid-type wind barrier, the louver-type wind barrier generally presents better aerodynamic performance. Specifically, the larger decrease of the lift force and overturn moment of the train and the smaller increase of the drag force and torsional moment of the bridge resulting from the louver-type wind barrier were highlighted. Finally, the computational fluid dynamics (CFD) technique was applied to explore the underlying mechanism of aerodynamic control using the proposed wind barrier.

Dilemma of Multicultural Coexistence: Korean Schools in Japanese Society

  • Ha, Kyung Hee
    • Journal of Contemporary Eastern Asia
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    • v.19 no.2
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    • pp.20-39
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    • 2020
  • In order to overturn the exclusion of Korean schools from the newly implemented free tuition program (2010) as part of sanctions against North Korea, members of Korean schools and Japanese supporters have focused on "students' innocence" and "multicultural coexistence" as viable frameworks to explain why the students are sympathetic and legitimate subjects who deserve equal rights. Examining different political strategies employed by the Korean schools and their supporters through ethnography and media analysis, the article pays close attention to how they claim their eligibility for these rights while they negotiate state surveillance and intervention in the process. I argue that in their efforts to gain recognition as deserving and sympathetic subjects, Korean schools are trapped in what political theorist Patchen Markell calls a "permanent temptation" in pursuing "recognition." Anti-North Korea sentiments in Japan have made the desire for good recognition even more urgent among Korean school community members. The paper will demonstrate that the search for recognition unwittingly reinforces and perpetuates existing relations of subordination and state dominance over their education as it has forced the Korean schools to accept various "conditions" that would radically alter the core principle, mission, and pedagogy of Korean school education that is rooted in decolonizing theory and praxis. This paper will shed lights on dilemma of multicultural coexistence the Korean minority population faces in Japan today.

Analysis of Roller Load by Boom Length and Rotation Angle of a Crawler Crane (크롤러 크레인의 붐 길이 선회각도에 의한 롤러 하중 해석)

  • Lee, Deukki;Kang, Jungho;Kim, Taehyun;Oh, Chulkyu;Kim, Jongmin;Kim, Jongmyeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.3
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    • pp.83-91
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    • 2021
  • A crawler crane, which consists of a lattice boom, a driving system, and a movable vehicle, is widely used on construction sites. The crawler crane often traverses rough terrain at these sites; as a result, an overload limiter needs to be installed on the crane to prevent it from overturning and breaking. In this paper, we studied the distributed load change in relation to boom length and the angle of rotation of the roller that comes in direct contact with the grounded track shoe. First, we developed a 3D model of a crawler crane and meshed it for finite elements. Then, we performed finite element analysis to derive the load on the roller. Finally, we graphed and examined the roller distributed load data of the case according to boom length and rotation angle. By detecting the load on the roller of the crawler crane, we can predict the potential for the crane to overturn before it happens.

Revision of Safety Standards through Analysis of Fatal Accidents Related to Mobile Scaffold in Construction Sites (건설현장 이동식 비계의 사망사고 분석을 통한 안전기준 개선 방안)

  • Ju Dong Park
    • Journal of the Korean Society of Safety
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    • v.38 no.1
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    • pp.42-54
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    • 2023
  • Mobile scaffold is used as a work platform in construction sites. According to industrial accident data, 10 fatalities occur annually on average due to falling from mobile scaffold in construction sites. To prevent such fatal accidents, safety standards must be improved by analyzing the causes of fatal accidents related to mobile scaffold. Accordingly, we analyzed domestic and international safety standards for mobile scaffold and analyzed the fatalities (117 persons) caused by mobile scaffold accidents in domestic construction sites during 2011-2020 and found that fall, overturn, and collapse accounted for 88% (103 persons), 10.3% (12 persons), and 1.7% (2 persons) of fatalities, respectively. The main causes of fatal accidents were found to be non-installation or insufficient installation of safety rails and outriggers and incorrect sequence of work. Based on the analysis results, we proposed strategies for improving the safety standards, such as the use of advanced guard rails and wheel-attached outriggers, to enhance the safety and field applicability of the mobile scaffold. Technology development and improvements in the safety standards for the use of mobile scaffold will aid in the prevention of fatal accidents caused by mobile scaffold.

Behavioral Characteristics Investigation of Rack Structure Depending on Forklift Impact Scenarios and Storage Distributions (지게차 충돌 위치 및 보관물류 분포에 따른 선반구조물의 거동특성분석)

  • Ok, Seung-Yong;Kwon, Oh-Yong;Paik, Shin Won
    • Journal of the Korean Society of Safety
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    • v.28 no.6
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    • pp.49-56
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    • 2013
  • The statistics of recent accidents in warehouses show that a heavy toll of lives were produced by various accidents, e.g. collision, overturn, fall, slip, exposure to harmful substances or environments, etc. Of significant concern amongst them is the collision, especially the collision between forklift and storage rack structure. Accordingly, this study focuses on behavioral characteristics of rack structure subjected to dynamic impact loading of a forklift. For this purpose, time-domain response analysis has been performed on a standard 2-bay six-story rack structure consisting of columns, beams and bracing members with perforated open section. In order to investigate the most critical scenario, the impact loads are applied in both down-aisle and cross-aisle directions, and the impact locations are also varied along the shelves of the palettes. In order to deal with storage distributions, three types of rack structures are further taken into account: original empty rack structure with no storage, half-loaded rack structure and fully-loaded rack structure. The numerical simulation results demonstrate that the dynamic characteristics of the rack structure are significantly dependent on the distribution of the storage goods and its natural period varies from 0.24sec to 1.06sec, approximately 4.4 times. Further, the parametric studies show that the forklift impact is most critical to the safety of the rack structure when it collides either at the base or at the top of the rack structure.

Social Reflection of Director Choi Donghoon -based on the Theory of Carnival of Mikhail M. Bakhtin (최동훈 영화의 사회반영성 -바흐친의 카니발 이론을 중심으로-)

  • Lee, Minho;Yi, Hyoin
    • The Journal of the Korea Contents Association
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    • v.13 no.6
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    • pp.125-136
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    • 2013
  • Director Choi Donghoon is the most famous director in Korea as a box office successor, especially (2102) has gained No. 1 box office attraction in Korean film history. However some critics have criticised the works of Dr. Choi because of their plebeianness. This paper focused on the reason of interaction with audiences through the theory of carnival of Mikhail M. Bakhtin. Because the theory of carnival is not only the adapted method to account for the power of popular culture to M. Baktin but also the useful method to understand the keys of interaction of Dr. Choi's films. It's not difficult to find the esthetic elements of carnival theory example for 'dethronement & coronation', 'overturn & ridicule', 'image of feast', 'language of square' in the films of Choi which are The Big Swindle(2004), Tazza: The High Rollers(2006), Woochi(2009), The Thieves(2012). Therefore this paper has endeavored that the box office attraction and success of communication with audiences is due to the realistic attitude and social reflection of Choi's films.

Moving Path following and High Speed Precision Control of Autonomous Mobile Robot Using Fuzzy (퍼지를 이용한 자율 이동 로봇의 이동 경로 추종 및 고속 정밀 제어)

  • Lee, Won-Ho;Lee, Hyung-Woo;Kim, Sang-Heon;Jung, Jae-Young;Roh, Tae-Jung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.7
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    • pp.907-913
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    • 2004
  • The major interest of general mobile robot is making a route and following a maked route. But, In the case of robot that is in need of movement of partial high speed, the condition of dynamic limitation is exist, and in these conditions, it demands controlling against movements we want. In this paper, in respect of the following a route at the situation that don't have the environmental map, that is, unknown environments, to prevent the slide of moving robot or the overturn that can happen for it moves fast, we organize the dynamic condition of limitation using the fuzzy logic, and we obtain more safe and fast route tracing ability by changing the standard velocity. Especially, by modeling the line tracing mobile robot, we design the tracing controller against a realtime changing target, and using the fuzzy optimized velocity limitation controller, we confirm that our robot shows its stable tracing ability by limiting its velocity intelligently against the continuously changing line.

Considerations in Allowing Voluntary Non-Reimbursable Treatments from a Public Law Perspective - A Commentary on Supreme Court Judgment 2010 Doo 27639, 27646 (ruled on June 8, 2012 by the Grand Bench) - (임의비급여 진료행위의 허용여부에 관한 공법적 고찰 - 대법원 2012. 6. 18. 선고 2010두27639, 27646 전원합의체 판결에 대한 평석 -)

  • Ha, Myeong-Ho
    • The Korean Society of Law and Medicine
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    • v.14 no.2
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    • pp.173-214
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    • 2013
  • Traditionally, the Supreme Court has held that medical treatment agreements covered by national health insurance should be distinguished from other medical treatment agreements which are viewed as a consummation of the autonomous free will between doctor and patient. Namely, the Supreme Court views medical treatment agreements covered by national health insurance to be bound by the National Health Insurance Law with the intent to promote the applicability and comprehensiveness of the national health insurance scheme. Yet, issues of voluntary non-reimbursable treatments are triggered not only by the mistakes or moral hazard of medical care institutions but also by systemic limitations of national health insurance coverage criteria. Thus, there is a need for legislative measures that allow certain medical treatments to be included or reflected in the national health insurance coverage system so that patients may receive prompt and flexible medical treatments. To reflect such concerns, the Supreme Court made an exception for voluntary non-reimbursable treatments and developed a strict test to be applied in such cases in Supreme Court Judgment 2010 Doo 27639, 27646 (ruled on June 8, 2012 by the Grand Bench). Such judgment, however, is not a fundamental overturn of the Supreme Court's prior rulings that voluntary non-reimbursable treatments are not allowed under the law. It is only a slight revision of its previous stance for cases in which there is a lack of legislative measures to make coverage of a new yet valid medical treatment possible under the current national health insurance coverage system.

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