• Title/Summary/Keyword: Structural Solutions

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Characterization and Feasibility Study of the Soil Washing Process Applying to the Soil Having High Uranium Concentration in Korea (우라늄 함량이 높은 국내 토양에 대한 토양학적 특성 규명 및 토양세척법의 적용성 평가)

  • Chang, See-Un;Lee, Min-Hee
    • Journal of Soil and Groundwater Environment
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    • v.13 no.5
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    • pp.8-19
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    • 2008
  • The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.

Growth of Fe3O4 Particles and Their Magnetic Properties (Fe3O4 분말제조와 자기적 특성)

  • Kwon, Woo-Hyun;Lee, Seung-Wha;Chae, Kwang-Pyo;Lee, Jae-Gwang;Sur, Jung-Chul
    • Journal of the Korean Magnetics Society
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    • v.19 no.5
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    • pp.180-185
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    • 2009
  • Fe$_3$O$_4$ particles, prepared by a sol-gel method, were examined for their structural characteristic, particle shapes and sizes, and their magnetic properties. Two different chemical compositions (using a mol rate Fe$^{2+}$/Fe$^{3+}$ = 1/2 and only Fe$^{2+}$) and 2-methoxyethanol were used for making proper solutions. And the solutions were refluxed and dry in a dry oven and the samples were fired at 200$\sim$600$^{\circ}C$ in the N$_2$ atmosphere. The formation of single-phased spinel ferrite powders was identified with the X-ray diffraction measurement as they were fired at above 250$^{\circ}C$. The result of scanning electron microscopy measurement showed the increase of annealing temperature yielded the particle size increased. The magnetic transition was observed using the Mossbaur spectroscopy measurement. As the ferrite, prepared with the chemical composition (Fe$^{2+}$/Fe$^{3+}$ = 1/2), was fired at 250$^{\circ}C$, 78% of the ferrite had a ferrimagnetic property and 22% of the ferrite was non-magnetic. In case of preparing the sample with only Fe$^{2+}$ and annealed at 200$^{\circ}C$, it had a single phased spinel structure but its particle size was too small to be ferrimagnetic. The annealing temperature above 250$^{\circ}C$ made powders a spinel structure regardless of the preparation method. They had a typical soft magnetic property and their saturation magnetization and coercivity became larger as the annealing temperature increased.

Problems of Each Category of Gyeongsanjain Dano Festival and Solutions (경산자인단오제 연행의 분야별 문제와 종합적 개선방안)

  • Lee, Byoung Ok
    • (The) Research of the performance art and culture
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    • no.19
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    • pp.88-123
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    • 2009
  • Gyeongsanjain Dano Festival is a local festival of Yeongnam that was initially designated as Intangible Cultural Heritage No. 44 "Hanjanggun Nori" in 1971 and finally became Gyeongsanjain Dano Festival in 2007. At first, few parts of it were designated for preservation and it was succeeded as a whole without connections between each part. Problems also rise from the fact that it has not been closely studied. Gyeongsanjain Dano Festival is mostly classified into five parts: Keungut, Yeowonmu, Hojanggut, Hanmyoje, and Jainpalgwangdae. This study has closely discussed each part as follows: 1. Keungut 1) Process and Contents of Keungut - Characteristics of Gut in Daegu and Gyeongsan 2) Presence of Performers that can Execute Traditional Gut of Local Area 3) Problems with the Name of Keungut - Ex: 'Hanjanggungut' or 'Keungut' 4) Problems of Dano Festival without Parts to Summon and Send off Spirits before and After Keungut and Restoration Measures 2. Yeowonmu 1) Essence of Yeowonmu and Yeowonhwa 2) Problems with the Mass Game of Hundreds of High School Girls 3) Origin and Succession of Yeowonmu 3. Hojanggut 1) Changes in Characters of Hojanggut 2) Composition and Characteristics of Hojanggut 3) Problems with the Name and Characteristics of Hojanggut 4. Jainpalgwangdae Nori 1) Similarity with Newly Created Shows 2) Problems with the Name of Palgwangdae 3) Difference with the Composition of Other Mask Dances 4) Dances and Movements Distinguished from Other Mask Dances in Yeongnam The following are the solutions suggested for Gyeongsan Jain Dano Festival. First, for the restoration of Gyeongsanjain Dano Festival, Dano festivals and Byeolsinje of nearby areas with clear traditions could be benchmarked. Second, the major content of Gyeongsanjain Dano Festival is 'Hanjanggungut,' and it has to be the leading content of the festival. Third, the structural principle of Korean festival must be adopted and the process and principle must correspond to those of other traditional shows. Fourth, as Gyeongsanjain Dano Festival is the comprehensive form of art, folk, and festival, each part must be closely related in a well-planned scenario. Fifth, Intangible talents and successful training must be widely acknowledged for successful transmission and responsible performances. Sixth, traditional festivals must be restored along with the discovery and development of various festival repertories and spectacles such as tour programs and experiential tours that contribute to local economy.

The Effect of Personal Creativity on Knowledge Sharing and Innovation Behavior: Focused on Retail Workers (개인 창의성이 지식공유와 혁신행동에 미치는 영향: 유통업 종사자를 중심으로)

  • LEE, Joon-Pyo;PARK, Kye-Hong
    • Journal of Distribution Science
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    • v.17 no.10
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    • pp.93-105
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    • 2019
  • Purpose - First, empirical research will reveal how personal creativity affects the knowledge sharing and innovation behaviors of organizational members. Second, self-management competency will be verified to explain the causal relationship between independent and dependent variables as a mediating variable and to reduce the time interval. Research design, data, and methodology - There are two major research models. First, personal creativity (professionalism, emotional intelligence, internal motivation) has a positive impact on knowledge sharing (creation of knowledge, organization of knowledge, use of knowledge) and innovation behavior (deriving ideas, implementing ideas, promoting ideas). Second, self-management competency (intellectual capacity, emotional capacity, personality capacity) plays a mediating role. In addition to descriptive statistics and correlation analysis, Cronbach's α was calculated for 259 workers in the retail industry. In addition, confirmatory factor analysis was performed using the AMOS 24.0 program, and the influence on the measurement model was analyzed to verify the structural equation model. Results - First, personal creativity had a positive effect on knowledge sharing and innovation behavior. In other words, it was confirmed that the decision-making process accompanied by individual creativity can create an atmosphere of knowledge sharing and continue to innovate. Second, personal creativity had a positive effect on self-management competency, and self-management competency had a positive effect on knowledge sharing and innovation behavior. Third, self-management competency was found to partially mediate the influence of personal creativity on knowledge sharing and innovation behavior. Conclusions - First, it is important for managers to recognize the value of creative talents who can be a fundamental source of organizational success and competitive advantage, and to attract talented people. Second, managers should be able to develop decision-making processes to develop potential creativity and encourage creative ideas, opinions, or solutions when organizing the work environment of their members. Third, managers should promote the sharing and integration of new knowledge that underlies the creative views and attitudes of teams and organizational members. Unlike previous studies, which emphasize the role of the work environment in which creative behaviors are promoted, this study shows that creativity of individual members, itself, is an important determinant of knowledge sharing and innovation behavior.

Recommendations of Environmental Reduction Factor of FRP Rebar for Durability Design of Concrete Structure (콘크리트 보강용 FRP 보강근의 내구성 설계를 위한 환경영향계수의 제안)

  • Park Chan-Gi;Won Jong-Pil;Kang Joo-Won
    • Journal of the Korea Concrete Institute
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    • v.16 no.4 s.82
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    • pp.529-539
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    • 2004
  • The corrosion of steel rebars has been the major cause of reinforced concrete deterioration. FRP(Fiber-reinforced polymer) rebar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Therefore, the USA, Japan, Canada, UK. etc are using environmental reduction factor. Although difference design guidelines were drawn in many, including USA, Japan, Canada, UK etc, recommendations and coefficients that could take into account the long-term behavior of FRP reinforcement were not well defined. This study focuses on recommendation of environmental reduction factor of FRP rebar. Environment reduction factor were decided using durability test result. FRP rebars were subjected to twelve type of exposure conditions including alkaline solution, acid solution, salt solution and deionized water etc. The water absorption behavior was observed by means of simple gravimetric measurements and durability properties were investigated by performing tensile, compressive and short beam tests. Based on the experimental result, environmental reduction factor of hybrid FRP rebar(A), and (C) and CFRP rebar was decided as 0.85. Also, hybrid FRP rebar(B) and GFRP rebar were decided as 0.7 for the environmental reduction factor

A Study on the Genesis of Fluorite Deposits of South Korea (남한(南韓)의 형석광상(螢石鑛床)의 성인(成因)에 관(關)한 연구(硏究))

  • Chi, Jeong Mahn
    • Economic and Environmental Geology
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    • v.8 no.1
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    • pp.25-56
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    • 1975
  • Most fluorite deposits of South Korea are distributed in three metallogenic zones namly as: Hwacheon, Hwangangni and Geumsan metallogenic zones. Fluorite deposits of each zone show The characteristic features owing to the geological setting, the structural patterns and their forming processes. deposits of the Hwacheon metallogenic zone are wholly fissure filling hydrothermal veins emThe bedded in shear fractures of the granite gneiss or schists of Precambrian age or in the cooling fractures of the granite and acidic hypabyssal rocks which are assumed to be a differentiated sister rock of the granite. Localization of most fluorite veins of the region is structurally controlled by NW and EW fracture systems and genetically related to the granite intrusion which ascertained as motivating rock of the fluorite mineralization. Fluorites are in most cases accompanied by quartz, chalcedony mainly and rarely agate, calcite, barite and sulphide base metals in some localities. The deposits of the Hwangangni metallogenic zone were formed at the last stage of hydrothermal polymineralization of W, Mo, Cu, Pb, Zn. The majority of the fluorite ore bodies were originated from replacement in limestone beds of Great Limestone Series or in calcareous interbeds of metasediments, whereas some cavity-filling ore bodies were embedded in phyllites and schists of the Ockcheon system and along the fissures in the replaced beds which were originated by volume decrease. The localization of fluorite deposits in this region is genetically related to the Moongyong granite which has been dated as middle Cretaceous, and controlled structurally by the $N20^{\circ}{\sim}50^{\circ}W$ extension fracture system or axial planes of folds, and by faults of NE direction that acted as paths of ore solution. The deposits of the Geumsan metallogenic zone are seemed to be formed through the similar process as that of Hwangangni metallogenic zone, but characteristic distinctions are in that they are more prevailing fracture filling veins and large number of the deposits are localized in roof-pendants or xenolithes of limestone in granites and porphyries. Igneous rocks that presumably motivated the mineraltzation are middle Cretaceous Geumsan granite and porphyries. Metallogenic epoch of the fluorite mineralization of South Korea are puesumably limited in early-middle Cretaceous. Studies of the fluid inclusions in fluorites of the region reveal that the homogenization temperature of the fluorite deposits are as follows: Hwacheon metallogenic zone : $95^{\circ}C{\sim}165^{\circ}C$; Hwangangni metallogenic zone : $97^{\circ}C{\sim}235^{\circ}C$; Geumsan metallogenic zone : $93^{\circ}C{\sim}236^{\circ}C$. Judging from the above results, the deposits of the Hwancheon region were formed at the epithermal stage, and those in the Hwangangni and Geumsan regions, were deposited at epithermal stage preceded by mesothermal mineralization of small scale in which some sulphide minerals were deposited. The analytical data of minor elements in the fluorites reveal that ore solutions of Hwangangni metallogenic zone seemed to be emanated in more acidic stage of magma differentiation than Hwacheon metallogenic zone did.

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Analysis on the Stress of Hydraulic Cylinder for Large Vessel by Boundary Element Method (대형선박용 유압실린더에서 경제요소법을 이용한 응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.423-434
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    • 1995
  • It was used boundary element method(BEM) and analysed axisymmetric problem to solve hydraulic cylinder for large vessel acting uniform internal pressure(25N/m super(2)) within elastic limit. This paper was utilized the carbon steel tubes for machine structural purposed model, inner radius was 150mm and outer radius was 250mm, axial length was semi-infinite and the isoparametric element was used. The important results obtained in this study were summarized as follows. Radial, tangential and shearing stress occured the maximum stresses(48, -20 and 34MPa) at the inner radius and the minimum stresses(32, -4 and 18MPa) at the outer radius of the hydraulic cylinder for large vessel. But negative signs have meaning compressive stress and stress diminution ratio was about 0.15MPa/mm. The use of isoparametric element raised accuracy and the increment of input data lessened the error in internal point but computer run-time was increased. The double node was improved the internal solutions to settle discontinuity at corner and the double exponential formula lessened error of stress value at boundary neighborhood. And then coincidence between the analytical and exact results is found to be fairly good, showing that the proposed analytical by BEM is reliable.

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Nonlinear Flexural Modeling of Prestressed Concrete Beams with Composite Materials (복합소재 프리스트레스트 콘크리트보의 비선형 휨 모델링)

  • ;;Naaman, Antoine
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.269-280
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    • 1998
  • Recently, application of composite materials such as fiber reinforced concretes(FRCs) and fiber reinforced plastics(FRPs) in conjunction with conventional structural components has become one of the main research areas. A proper use of advanced composite materials requires understanding their resistance mechanism and failure mode when they are applied to structures or their components. Particular considerations are given in this research to develop an analytical model which can predict the nonlinear flexural responses of bonded and unbonded prestressed concrete beams possibly having layers of different cementitious composite matrices in a section and/or FRP tendons. The block concept is used, which can be regarded as an intermediate modeling method between the couple method with one block and the layered method with multiply sliced layers in a section. In order to find a particular deflection point of a beam under load, solutions to the 2N-variables are found numerically by using approximate N-force equilibrium equations and N-moment equilibirum equations. The model is shown to successfully predict the flexual behavior of variously reinforced bonded and unbonded prestressed concrete beams. The model is also successful in simulating a gradually increasing load after sudden drop inload resistance due to fracture of one or more FRP tendons. This feature is useful in tracing the overall load-deflection response of a beam prestressed with brittle FRP tendons.

Effect of We-ness and Flow on the Spectator Promotion of K-League (우리의식과 플로우가 K-리그 관람촉진에 미치는 영향)

  • Yoon, Jong-Hyun;Han, Se-Hee;Kim, Dong-Tae
    • The Journal of the Korea Contents Association
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    • v.14 no.1
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    • pp.435-443
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    • 2014
  • The aim of this study was to look for the cause of shortage of K-League spectators from a consumer's perspective and to offer solutions. For this, we offered enhancement method of the K-League spectators through dual path model based on existing relative researches. The first path involved consumer reaction to external factors of the K-League game. This path explained relational view(=we-ness) of consumers on K-League game(Hypothesis 1, 2). The second path explained personal view on K-League game. This path means consumer reaction to K-League game itself(Hypothesis 3, 4). The empirical study was based on a field survey and structural equation model. The results showed that we-ness positively affected team loyalty(Hypothesis 1) and the team loyalty positively affected spectating intentions(Hypothesis 2). It also revealed that flow of K-League game positively affected consumer satisfaction(Hypothesis 3). Finally consumer satisfaction was found to affect spectating intentions(Hypothesis 4). The significance of present study is to extend scope of research which is related with cheerleading of sports game. And this study emphasize the importance of we-ness and flow in sports game.

A Study on Analysis of Real Response of Steel Railway Bridges (강철도교의 실응답해석에 관한 연구)

  • Chang, Dong Il;Choi, Kang Hee;Lee, Hee Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.2
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    • pp.43-54
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    • 1989
  • In this paper, measured and calculated responses are compared in order to give how the static and dynamic responses occurred in steel railway bridges due to train loads could be calculated appropriately. From this, it is investigated how the impact factors are varied by changing the train speed above 100km/h Field measurement is carried out by the steel strain gages and displacement transducers at the main design points, and then the static and dynamic response, fundamental frequencies, damping ratios and impact factors of the bridges are obtained. Static analysis is done using the computer program developed according to three dimensional matrix structural analysis in which the trains and bridges are modelled as 1,2 and 3 dimensions. Dynamic analysis is done according to 2 approaches, the moving force and mass problem. In moving force problem, the solutions are obtained by the modesuperposition-method and in moving mass problem by the direct integration method. From this study, it is known that in order to obtain the static response in the railway bridges, the bridge could be modelled by 1 or 2 dimension as in the highway bridge, however the response ratio(measured/calculaled) is high comparing to the highway bridges. By the way, the dynamic response should be obtained by the moving mass problem. And by comparing the measured and code specified impact factors, it is known that the factors specified in the present railway bridge code are very safe under the present service speed below 100km/h. However, because the factors become very high under the speed above 100km/h, especially in the simple plate girder bridge, it is thought that the code specification on impact factor should be discussed enough under the rapid transit system.

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