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Performance Factors for Delaying Slope Failure through Hydraulic Experiments of Dam Overtopping (댐 월류 수리실험을 통한 사면붕괴지연 성능인자 도출)

  • Sung Woo, Lee;Dong Hyun Kim;Seung Oh Lee
    • Journal of Korean Society of Disaster and Security
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    • v.17 no.2
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    • pp.1-11
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    • 2024
  • Most reservoirs in South Korea are earthen dams, mainly because they are cost-effective and easy to construct. However, earthen dams are highly vulnerable to seepage and overtopping, making them prone to sudden failure during excessive flooding. Such sudden failures can lead to a rapid increase in flood discharge, causing significant damage to downstream rivers and inhabited areas. This study investigates the effect of riprap placement on the slopes of earthen dams in delaying dam failure. Delaying the failure time is crucial as it allows more time for evacuation, significantly reducing potential casualties, which is essential from a disaster response perspective. Hydraulic experiments were conducted in a straight channel, using two different sizes of riprap for protection. Unlike previous studies, these experiments were performed under unsteady flow conditions to reflect the impact of rising water levels inside the dam. The target dam for the study was a cofferdam installed in a diversion tunnel. Experimental results indicated that the presence of riprap protection effectively prevented slope failure under the tested conditions. Without riprap protection, increasing the size of the riprap delayed the failure time. This delay can reduce peak discharge, mitigating damage downstream of the dam. Furthermore, these findings can serve as critical reference material for establishing emergency action plans (EAP) for reservoir failure.

A Study on the Livestock Resources regarding on the Discharging Characteristics from Farm Land (농지 주입 시 배출특성에 대한 축분자원화물 연구)

  • Lim, Jai-Myug;Lee, Young-Sin;Han, Gee-Bong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.17 no.4
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    • pp.91-102
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    • 2009
  • In this study, to estimate the transforming (runoff and leachate) rate of the organic fertilizer made of livestock resources to farm land, laboratory scale test was conducted and the results were obtained as follows: The runoff volume from farm land showed the tendency of increase according to the increase of rainfall intensity. The most rainfall leachated into the underground at the rainfall intensity of 20mm/hr, and rainfall of 5L or less leachated at the rainfall intensity of > 32.4 mm/hr. This shows that surface runoff largely depends on the rainfall intensity when soil characteristic and hardness are similar in each site. When liquid compost was fertilized, the surface runoff was similar with the results from the reactor fertilized by compost, and leachate flow was found to be lower than compost. The runoff ratio of contaminant parameters from farm land were BOD 0.00003,, $COD_{cr}$ 0.00006, TN 0.00056, TP 0.00011, TOC 0.00005, Especially, the runoff ratio of TN showed 10 folds higher than other parameters. On the other hand, the runoff ratio of SS showed higher value of 0.001, and colloid particles of soil caused this result rather than the leachate from compost fertilizer. At all ranges of rainfall intensity, fertilizer removal ratio by farm land was found to be 94.9~98.4% for compost and 85.8~98.1% for liquid compost in terms of BOD. For TN, it resulted in 96.6~98.4% for compost and 97.2~98.5% for liquid compost, and thus the most fertilizer from livestock resources were shown to be reduced through farm land application.

Basic Characteristics and Field Demonstration Test of Ground Granulated Blast Furnace Slag using CO2 Fixed Desulfurized Gypsum (CO2 고정 탈황석고를 사용한 고로슬래그 미분말의 특성 및 현장실증)

  • Chang-Woo Lee;Hoon-Guk Choi;Sung-Kwan Seo;Jong-Ho Park
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.12 no.3
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    • pp.281-289
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    • 2024
  • In this study, CO2-immobilized desulfurized gypsum(CFDG) was applied to ground granulated blast furnace slag to examine the basic properties of mortar and concrete, and to evaluate its responsiveness through field demonstration test. CFDG had a relatively circular composition compared to desulfurized gypsum(DG), and its main components were CaO 47.6 % and SO3 22.1 %. As a result of mortar and concrete tests, the flow tended to increase and the compressive strength was at the same level. In addition, the target properties of concrete for application to farm roads, which were a slump of 120±25 mm and a compressive strength of 24 MPa, were satisfied with a slump of 135 mm and a compressive strength of 42.1 MPa at 28 days. In February 2024, an on-site demonstration of a farm road was conducted in Seongmun-myeon, Dangjin-si, and as a result of reviewing the compressive strength according to curing conditions, the physical properties and durability of unhardened concrete, the target results were satisfied, expanding the use of CFDG by applying fine powder of blast furnace slag and carbon reduction can be expected.

A Review of Image Analysis Techniques for Investigating Solute Transport in Porous Media (비파괴적 기법을 활용한 다공성 매체에서의 용질 이동 메커니즘 분석에 대한 고찰)

  • Seonggan Jang;Taeseop Kim;Changmin Kim;Minjune Yang
    • The Journal of Engineering Geology
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    • v.34 no.3
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    • pp.473-496
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    • 2024
  • This study reviewed image analysis techniques used in non-destructive investigations of solute transport mechanisms in porous media during contaminant transport. Commonly employed image analysis methods include X-ray imaging, light-transmission visualization, and light-reflection visualization using ultraviolet or visible light. These techniques provide precise, high-resolution data on solute concentration distributions, fluid flow dynamics, and multiphase systems. Through continuous monitoring without alteration of the experimental setup, they provide accurate insights into solute transport mechanisms. We outline the principles, applications, advantages, and limitations of each method, and explore their contribution to the understanding and prediction of solute transport. We also examine case studies in which these methods have been effectively applied. This review provides a comprehensive understanding of how image analysis techniques can contribute to addressing environmental issues such as groundwater contamination.

Research Trends of CV23 Electroacupuncture: A Literature Review Focusing on PubMed and Domestic Studies (염천(CV23)의 전침치료 연구 동향 : Pubmed와 국내논문을 중심으로)

  • Chae-Rim Yoon;Su-Hyun Choi;Nahyun Jeong;Dahee Jeong;Yoohyun Sim;Hae-in Jeong;Na-Yeon Ha;Jinsung Kim
    • The Journal of Internal Korean Medicine
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    • v.45 no.4
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    • pp.663-680
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    • 2024
  • Objectives: The purpose of this study was to analyze the research trends of electroacupuncture (EA) at CV23. Methods: Studies published until July 2024 were searched on PubMed and domestic databases (OASIS, ScienceON, RISS, KISS, KCI, KMbase, and DBpia) using the keywords "CV23", "lianquan", "electroacupuncture", "염천", "전침", and "전기자극". Results: A total of 16 studies were selected. There were 6 randomized controlled trials, 1 case report, and 9 experimental studies. Of the 16 papers selected, 15 examined the effect of EA at CV23 on improving swallowing function. Clinical studies found that EA at CV23 was effective in improving dysphagia, aphasia, and drooling symptoms through mechanisms such as increased hyolaryngeal movement, normalization of pathologically elevated NO, ET, and improvement of excitement of the swallowing motor cortex. According to experimental studies, EA at CV23 activates the brain region associated with swallowing function, promotes the swallowing reflex by increasing neurotransmitters, improves electromyography of the swallowing muscles, and improves blood flow around CV23. Conclusion: Electroacupuncture at CV23 may be an effective and safe method for post-stroke dysphagia, post-stroke aphasia, and post-stroke drooling. In the future, research should be conducted in different diseases and high-quality studies should be conducted.

An Ontology Model for Public Service Export Platform (공공 서비스 수출 플랫폼을 위한 온톨로지 모형)

  • Lee, Gang-Won;Park, Sei-Kwon;Ryu, Seung-Wan;Shin, Dong-Cheon
    • Journal of Intelligence and Information Systems
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    • v.20 no.1
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    • pp.149-161
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    • 2014
  • The export of domestic public services to overseas markets contains many potential obstacles, stemming from different export procedures, the target services, and socio-economic environments. In order to alleviate these problems, the business incubation platform as an open business ecosystem can be a powerful instrument to support the decisions taken by participants and stakeholders. In this paper, we propose an ontology model and its implementation processes for the business incubation platform with an open and pervasive architecture to support public service exports. For the conceptual model of platform ontology, export case studies are used for requirements analysis. The conceptual model shows the basic structure, with vocabulary and its meaning, the relationship between ontologies, and key attributes. For the implementation and test of the ontology model, the logical structure is edited using Prot$\acute{e}$g$\acute{e}$ editor. The core engine of the business incubation platform is the simulator module, where the various contexts of export businesses should be captured, defined, and shared with other modules through ontologies. It is well-known that an ontology, with which concepts and their relationships are represented using a shared vocabulary, is an efficient and effective tool for organizing meta-information to develop structural frameworks in a particular domain. The proposed model consists of five ontologies derived from a requirements survey of major stakeholders and their operational scenarios: service, requirements, environment, enterprise, and county. The service ontology contains several components that can find and categorize public services through a case analysis of the public service export. Key attributes of the service ontology are composed of categories including objective, requirements, activity, and service. The objective category, which has sub-attributes including operational body (organization) and user, acts as a reference to search and classify public services. The requirements category relates to the functional needs at a particular phase of system (service) design or operation. Sub-attributes of requirements are user, application, platform, architecture, and social overhead. The activity category represents business processes during the operation and maintenance phase. The activity category also has sub-attributes including facility, software, and project unit. The service category, with sub-attributes such as target, time, and place, acts as a reference to sort and classify the public services. The requirements ontology is derived from the basic and common components of public services and target countries. The key attributes of the requirements ontology are business, technology, and constraints. Business requirements represent the needs of processes and activities for public service export; technology represents the technological requirements for the operation of public services; and constraints represent the business law, regulations, or cultural characteristics of the target country. The environment ontology is derived from case studies of target countries for public service operation. Key attributes of the environment ontology are user, requirements, and activity. A user includes stakeholders in public services, from citizens to operators and managers; the requirements attribute represents the managerial and physical needs during operation; the activity attribute represents business processes in detail. The enterprise ontology is introduced from a previous study, and its attributes are activity, organization, strategy, marketing, and time. The country ontology is derived from the demographic and geopolitical analysis of the target country, and its key attributes are economy, social infrastructure, law, regulation, customs, population, location, and development strategies. The priority list for target services for a certain country and/or the priority list for target countries for a certain public services are generated by a matching algorithm. These lists are used as input seeds to simulate the consortium partners, and government's policies and programs. In the simulation, the environmental differences between Korea and the target country can be customized through a gap analysis and work-flow optimization process. When the process gap between Korea and the target country is too large for a single corporation to cover, a consortium is considered an alternative choice, and various alternatives are derived from the capability index of enterprises. For financial packages, a mix of various foreign aid funds can be simulated during this stage. It is expected that the proposed ontology model and the business incubation platform can be used by various participants in the public service export market. It could be especially beneficial to small and medium businesses that have relatively fewer resources and experience with public service export. We also expect that the open and pervasive service architecture in a digital business ecosystem will help stakeholders find new opportunities through information sharing and collaboration on business processes.

Seismic wave propagation through surface basalts - implications for coal seismic surveys (지표 현무암을 통해 전파하는 탄성파의 거동 - 석탄 탄성파탐사에 적용)

  • Sun, Weijia;Zhou, Binzhong;Hatherly, Peter;Fu, Li-Yun
    • Geophysics and Geophysical Exploration
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    • v.13 no.1
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    • pp.1-8
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    • 2010
  • Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.

Stage Costume Design for Performance Hamlet (II) - The Study on Pattern and Manufactured Product - (햄릿 공연을 위한 무대의상 디자인 (II) - 패턴 및 실물제작 -)

  • Kim, Soon-Ku;Hwang, Seong-Won
    • Fashion & Textile Research Journal
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    • v.6 no.1
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    • pp.41-50
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    • 2004
  • This research proposes the on-stage costumes for the play Hamlet of Shakespeare performed by Yunheedan Guhri Pae - the Street Theater Troupe. Stage costumes have an important role in displaying the characteristics of each characters to the audience and has big visual effects. However, in order to design the costumes in the object viewpoints of the audience, the survey on the images of the characters who had actually watched the performance was taken place and proposed the costume design according to the results of the survey. Hamlet a: This result was applied to propose a sweater in black color, black leather pants and vest. Hamlet b: This result was applied to propose hooded coat in purple in middle level of brightness and color spectrum and yellow coat. For free image, loose pants in blue and vest in the same color tone were proposed. Gertrude a: This result was applied to use purple (violet) with reddish tone to propose the formation of a dress applying tailored suit. Gertrude b: This result was applied to propose purple gown and the one-piece dress with black laces. Ophelia a: This result was applied to propose feminine white dress and cape in purple color tone. Ophelia b: This result was applied to propose dyed and weaved clothes. Through the surveys as above, the images of each character was driven in adjectives, and using the results driven from the brightness, coloration, and color, color images were proposed. Only one costume cannot make up for the stage costumes and because it exists as an element of stage production, it is true that costumes are limited in some areas. However, that limit can become the motive of the costume. There is a limit, which the designer cannot produce the costumes as he or she had designed but I believe it is the center of the on-stage customers to display the characteristics of the characters according to the given concept. The limit of this research is the fact that because the costumes were designed so they fit the conditions already given, thus it was difficult to regard the process of designing and producing the costume as a project done according to the interaction. And in the future, if it is possible, I wish for the joint research with the people responsible for stage art to take place as a practical stage art. It was possible to produce practical costume since they were produced for actual performance and the production of costumes considering the dance steps, line of flow, and acting, was able to reduce the trial and error on stage. Through this research, I felt that the understanding and smooth interaction on diverse other areas not limited to the costume design should be taken place and believe that this was a research that proposes new research method since there had been only a few previous research regarding the on-stage costumes for actual performances. Therefore, this research had depended on the surveys given to the audiences to endow objectivity, however, I wish this research can contribute to defining effective process and methods for the on-stage costumes with more active researches with diverse methods and in diverse areas. I am sorry that the costume production for all the characters and all the scenes in Hamlet couldn't be done due to many limitations. As the following research assignment, I am planning on designing the costumes for all the scenes.

Rhizosphere Enhances Removal of Organic Matter and Nitrogen from River Water in Floodplain Filtration (홍수터 여과를 이용한 하천수의 질소와 유기물 제거에 미치는 근권의 효과)

  • Jeong, Byeong-Ryong;Chung, Jong-Bae;Kim, Seung-Hyun;Lee, Young-Deuk;Cho, Hyun-Jong;Baek, Nam-Joo
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.1
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    • pp.8-15
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    • 2003
  • If contaminated river water is sprayed over a floodplain, the microbial processes can simultaneously remove organic matter and nitrogen during the infiltration through the sediment profile. The effect of rhizosphere on the removal of organic matter and nitrogen from contaminated river water was investigated using floodplain lysimeters. River water was sprayed at a rate of $68.0L\;m^{-2}\;d^{-1}$ on the top of the lysimeters with or without weed vegetation on the surface, Concentrations of $NO_3$, $NH_4$ and dissolved oxygen (DO), and chemical oxygen demand (COD) and Eh in water were measured as functions of depth for 4 weeks after the system reached a steady state water flow and biological reactions. A significant reductive-condition for denitrification developed in the 30-cm surface profile of lysimeters with weeds. At a depth of 30 cm, COD and $NO_3$-N concentration decreased to 5.2 and $0.9mg\;L^{-1}$ from the respective influent concentrations of 18.2 and $9.8mg\;L^{-1}$. The removal of $NO_3$ in lysimeters with weeds was significantly higher than in those without weeds. Vegetation on the top was assumed to remove $NO_3$ directly by absorption and to create more favorable conditions for denitrification by supply of organic matter and rapid $O_2$ consumption, In the lysimeters without weeds, further removal of $NO_3$ was limited by the lack of an electron donor, i.e. organic matter. These results suggest that the filtration through native floodplains, which include rhizospheres of vegetation on the surface, can be effective for the treatment of contaminated river water.

A Study on the Black Box Design using Collective Intelligence Analysis (집단지성 분석법을 활용한 블랙박스 디자인 개발 연구)

  • Lee, Hee young;Hong, Jeong Pyo;Cho, Kwang Soo
    • Science of Emotion and Sensibility
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    • v.21 no.2
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    • pp.101-112
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    • 2018
  • This study was carried out to enhance the competitiveness of blackbox design for domestic and international companies, based on the explosive growth of the blackbox market due to development of blackbox design for vehicle accident prevention and post-treatment. In the past, the blackbox market has produced products indiscriminately to meet the ever-increasing demand of consumers. Therefore, we thought a new design method was necessary to effectively investigate the needs of rapidly changing consumers. In this study, we aimed to identify the best-selling blackbox to understand the design flow, and the optimum area for a blackbox, considering the uniqueness of associated vehicle. Based on discussion with blackbox design experts, we studied the direction of design and the problems with blackbox use, which were reflected in blackbox development. Through this research, two types of design - leading blackbox (A type) and mass production blackbox (B type) - were proposed for compatibility of the blackbox with the car. The leading type of blackbox was positioned so that it was wrapped with the room mirror hinge before the screw was fastened, in order to achieve an integrated design. Therefore, we designed an integrated form and resolved the placement problem of an adhesive blackbox. To blend, the mass production blackbox implemented material and surface processing in the same way with the car, and adopted the slide structure to automatically turn off the main body power when removing the SDcard, reflecting consumer needs. This study considers evolving consumer needs through a case study and collective intelligence and deals with implementation of the whole design process during mass production. In this study, we aimed to strengthen the competitiveness of the blackbox design based on design method and its realization.