• 제목/요약/키워드: 메커니즘 분석

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Prediction of Failure Strength of Reinforced Concrete Deep Beams using Two-dimensional Grid Strut-Tie Model Method (2차원 격자 스트럿-타이 모델 방법에 의한 철근콘크리트 깊은 보의 파괴강도 예측)

  • Yun, Young Mook;Kwon, Sang Hyok;Chae, Hyun Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.4
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    • pp.605-615
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    • 2016
  • It is difficult to form a rational strut-tie model that represents a true load transfer mechanism of structural concrete with disturbed stressed region(s). To overcome the difficulty and handle numerous load cases with just one strut-tie model, a two-dimensional grid strut-tie model method was proposed previously. However, the validity of the method was not fully examined, although the incorporated basic concepts and new methods regarding the effective strength of concrete strut, load carrying capacity of struts and ties, and geometrical compatibility of grid strut-tie model were explained in detail. In this study, for accurate strength analysis and reliable design of reinforced concrete deep beams, the appropriateness of the two-dimensional grid strut-tie model method is verified. For this, the failure strength of 237 reinforced concrete deep beams, tested to shear failure, is predicted by the two-dimensional grid strut-tie model method, and the results are compared with those obtained by the sectional shear design methods and conventional strut-tie model methods of current design codes.

Comparison of Fuel-NOx Formation Characteristics in Conventional Air and Oxyfuel Combustion Conditions (일반 공기 및 순산소 연소 조건에서 Fuel-NOx 생성 특성의 비교)

  • Woo, Mino;Park, Kweon Ha;Choi, Byung Chul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.5
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    • pp.481-488
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    • 2013
  • Nitric oxide ($NO_x$) formation characteristics in non-premixed diffusion flames of methane fuels have been investigated experimentally and numerically by adding 10% ammonia to the fuel stream, according to the variation of the oxygen ratio in the oxidizer with oxygen/carbon dioxide and oxygen/nitrogen mixtures. In an experiment of coflow jet flames, in the case of an oxidizer with oxygen/carbon dioxide, the $NO_x$ emission increased slightly as the oxygen ratio increased. On the other hand, in case of an oxygen/nitrogen oxidizer, the $NO_x$ emission was the maximum at an oxygen ratio of 0.7, and it exhibited non-monotonic behavior according to the oxygen ratio. Consequently, the $NO_x$ emission in the condition of oxyfuel combustion was overestimated as compared to that in the condition of conventional air combustion. To elucidate the characteristics of $NO_x$ formation for various oxidizer compositions, 1D and 2D numerical simulations have been conducted by adopting one kinetic mechanism. The result of 2D simulation for an oxidizer with oxygen/nitrogen well predicted the trend of experimentally measured $NO_x$ emissions.

Evaluation of Ultrasonic Nonlinear Characteristics in Artificially Aged Al6061-T6 (인공시효된 Al6061-T6의 초음파 비선형 특성 평가)

  • Kim, Jongbeom;Lee, KyoungJun;Jhang, Kyung-Young;Kim, ChungSeok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.3
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    • pp.220-225
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    • 2014
  • Generally, the nonlinearity of ultrasonic waves is measured using a nonlinear parameter ${\beta}$, which is defined as the ratio of the second harmonic's magnitude to the power of the fundamental frequency component after the ultrasonic wave propagates through a material. Nonlinear parameter ${\beta}$ is recognized as an effective parameter for evaluating material degradation. In this paper, we evaluated the nonlinear parameter of Al6061-T6 which had been subjected to an artificial aging heat treatment. The measurement was using the transmitted signal obtained from contact-type transducers. After the ultrasonic test, a micro Vickers hardness test was conducted. From the result of the ultrasonic nonlinear parameter, the microstructural changes resulting from the heat treatment were estimated and the hardness test proved that these estimates were reasonable. Experimental results showed a correlation between the ultrasonic nonlinear parameter and microstructural changes produced by precipitation behavior in the material. These results suggest that the evaluation of mechanical properties using ultrasonic nonlinear parameter ${\beta}$ can be used to monitor variations in the mechanical hardness of aluminum alloys in response to an artificial aging heat-treatment.

BCL2L10 Protein Induces Apoptosis in KGN-Human Granulosa Cells (KGN(난소과립세포)에서 BCL2L10 단백질의 세포사멸 유도 기능 연구)

  • Kim, Jae-Hong;Lee, Kyung-Ah;Bae, Jee-Hyeon
    • Development and Reproduction
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    • v.15 no.2
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    • pp.113-120
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    • 2011
  • BCL-2 family essential proteins to play a pivotal role to perform in apoptosis signaling pathways and essential proteins for the regulation of cell death. BCL2L10 protein is a member of BCL-2 family and it regulates both anti-apoptotic and pro-apoptotic function of specific tissue or cell line. BCL2L10 of function and expression is not reported in ovary cell lines. In this study we reported that BCL2L10 were significant expression of KGN cell line. Ectopic expression of BCL2L10 induced cell death, and its cells killing effect was blocked by pan-caspase inhibitor of the Z-VAD-fmk. Ectopic expression of BCL2L10 protein led to the activation of caspase 9 and caspase 3, suggesting apoptotic cell death, and confocal microscopic analyses showed that BCL2L10 was partially localized in mitochondria. Thus, we provide a novel function of BCL2L10 in KGN cells, which was involved in the intrinsic cell death pathway.

Shear behavior at the interface between particle and non-crushing surface by using PFC (PFC를 이용한 입자와 비파쇄 평면과의 접촉면에서의 전단 거동)

  • Kim, Eun-Kyung;Lee, Jeong-Hark;Lee, Seok-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.4
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    • pp.293-308
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    • 2012
  • The shear behavior at the particle/surface interface such as rock joint can determine the mechanical behavior of whole structure. Therefore, a fundamental understanding of the mechanisms governing its behavior and accurately estimation of the interface strength is essential. In this paper, PFC, a numerical analysis program of discrete element method was used to investigate the effects of the surface roughness on interface strength. The surface roughness was characterized by smooth, intermediate, and rough surface, respectively. In order to investigate the effects of particle shape and crushing on particle/surface interface behavior, one ball, clump, and cluster models were created and their results were compared. The shape of particle was characterized by circle, triangle, square, and rectangle, respectively. The results showed that as the surface roughness increases, interface strength and friction angle increase and the void ratio increases. The one ball model with smooth surface shows lower interface strength and friction angle than the clump model with irregular surface. In addition, a cluster model has less interface strength and friction angle than the clump model. The failure envelope of the cluster model shows non-linear characteristic. From these findings, it is verified that the surface roughness and particle shape effect on the particle/surface interface shear behavior.

Effect of Immobilization Method in the Biosorption and Desorption of Lead by Algae, Chlorella pyrenoidosa (Chlorella pyrenoidosa에 의한 납 흡.탈착시 고정화 방법의 영향)

  • Shin, Taek-Soo;Lim, Byung-Seo;Lee, Sang-Woo;Rhu, Kwon-Gul;Jeong, Seon-Ki;Kim, Kwang-Yul
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.8
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    • pp.663-672
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    • 2009
  • In this studies, the adsorption test using Chlorella pyrenoidosa was conducted to examine the effect of Pb adsorption according to various immobilized methods such as Ca-alginate, K-carrageenan, and Polyacrylamide. From the results, the duration to need to reach adsorption equilibrium was delayed according to the immobilization. And, the higher adsorption capacity of immobilized Chlorella pyrenoidosa was represented in the higher concentration of Pb, the smaller amount of immobilizing agent, and the higher pH of solution. The maximum adsorption capacity of Pb was shown in the adsorption test using Chlorella pyrenoidosa immobilized with Ca-alginate even though it was sensitive pH. The adsorption results properly represented with Freundlich isotherm equations. And, pseudo second-order chemisorption kinetic rate equation was applicable to all the biosorption data over the entire time range. The FT-IR analysis showed that the mechanism involved in biosorption of Pb by Chlorella pyrenoidosa was mainly attributed to Pb binding of carbo-acid and amide group. Adsorbed Pb on immobilized Chlorella prenoidosa was easily desorbed in the higher concentration of desorbents(NTA, HCl, EDTA, $H_2SO_4,\;Na_2CO_3$). Among the several desorbents, NTA showed the maximum desoption capacities of Pb from Chlorella pyrenoidosa immobilized with Ca-alginate and K-carrageenan and EDTA was the most effective in Chlorella pyrenoidosa immobilized with polyacrylamide. The desoprtion efficiency in the optimum condition was 90.0, 83.0, and 80.0%, respectively.

A Study of The Effects of Internal Political Economy on Relational Performance: focused on Mediating Effects of the Dimensions of Trust and Commitment (내부정치경제요인이 관계성과에 미치는 영향에 관한 연구 - 신뢰 차원과 결속 차원의 매개효과를 중심으로 -)

  • Seong, Min;O, Se-Jo
    • Proceedings of the Korean DIstribution Association Conference
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    • 2006.02a
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    • pp.43-78
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    • 2006
  • While trust and commitment, essential ingredients of the relationship quality variables, are core mediating variables for the purpose of maintaining the long-term relationship, in the context of the internal political economy of company and the relational performance of its members, there have been limited studies which explore as to how each of the dimensions have affect differently. The basic purpose of this study is to examine the relationship between an automobile manufacturer and its agencies. The main purpose of this study is to examine how each different dimension of trust and commitment on the automobile manufacturer have different mediating effects in the context of internal political economy variables and relational performance perceived by its agents. Another purpose is to investigate the mechanism by which the relational performance of the agencies is improved. An empirical study surveying 115 sales office managers at a leading automobile manufacturer in Korea was conducted. An analysis of the collected data indicates that while internal political economy variables have a positive influence on the agencies' relational performance through the mediating role of trust and commitment, agencies' benevolence on its headquarter has a different influence on the dimensions of commitment. Currently, an automobile manufacturer is advised to implement the relational management philosophy in dealing with its agencies with an hope of innovative orientation for customers. In this sense, this study is a big stride in providing ample implications for the automobile manufacturer in establishing trust and commitment, which are the prerequisite conditions in developing and maintaining a successful long-term relationship with its agencies, and in improving the agency's relational performance.

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A Study on the Effects of Communication Style and Commitment between Retailers and Suppliers on Relationship Performance (소매-공급업체간 커뮤니케이션 유형과 결속이 관계성과에 미치는 영향에 관한 연구)

  • Jung, Yeon-Sung;Oh, Se-Jo
    • Journal of Distribution Research
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    • v.12 no.4
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    • pp.49-77
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    • 2007
  • The purpose of this study is to examine a relationship between the headquarters and the sales offices of a car manufacturing company by comparing their channel types. It examines how the level of communication and commitment of sales offices on their headquarters differently affects some mediating effects between participation and relationship performance. It also tries to find out what kind of mechanisms are needed in order to improve the relationship. Through the data analysis of a total of 200 sales offices which are directly managed stores and agency stores by a domestic car manufacturing company, the following conclusions were reached: Participation, one of the variables in bureaucratic structuring, influences all dimensions of communication. Also, it has found that communication dimensions influence commitment dimensions differently by the type of channels, and commitment dimensions influence relationship performance by the type of channels. Recently, import car makers are accelerating their moves in the domestic market, and the importance of a customer-oriented retail innovation and a relationship management in an auto manufacturing industry is increasing. This study will give an useful suggestion on how to improve a long term relationship of distributors through an enhancement of communication and commitment.

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Measuring the Maximum Social Welfare Effects of Outlook Information Service for Fruits Sector in Korea (과일류 관측의 최대 사회후생 효과 계측)

  • Kim, Bae-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.11
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    • pp.6646-6651
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    • 2014
  • This study was carried out to find the social welfare effects of agricultural outlook information service for fruit in Korea. The goals of an agricultural outlook information service are to improve the efficiency of the agricultural product market, and stabilize the farmer's income and consumer price. This paper introduces the results of econometric analysis for the effects of social welfare benefits. According to the results of econometric analysis for the citrus industry, the effects of the social welfare benefits were estimated to be 15,228 million KRW on apples (ratio of the total revenue, 1.5%), 3,154 million KRW on pears (ratio of the total revenue, 1.8%), 1,936 million KRW on peaches (ratio of the total revenue, 0.9%), 5,211 million KRW on grapes (ratio of the total revenue, 1.0%), 44,976 million KRW on citrus (ratio of the total revenue, 5.4%), and 2,590 million KRW on sweet persimmon (ratio of the total revenue, 0.8%) in 2012.

A Study on the Mechanism of the Immersion of the Spectators of the Fictional Narrative Animation (허구서사 애니메이션의 관객 몰입 메커니즘 연구 - 구성주의 인지서사학적 접근을 중심으로 -)

  • Kim, Ki-Hong
    • Cartoon and Animation Studies
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    • s.17
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    • pp.37-51
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    • 2009
  • Immersion is the key factor in determining success or failure for fictional narrative animations. It does matter to not only for the socio-economic achievements like box-office success but to the asthetical achievement, immersion is very important prerequisite character that are raised in terms of research needs. Fictional narrative animation shares the audience's immersive method with the narrative content and Virtual Reality, since animation has the character which narrates itself with the visual image format (including sound) and added the fact that 3D format which emphasizes realism compared with the recent 2D animation has been ubiquitous phenomenon. In other words, the artistic for called 'animation' is located between the view point that text has the immersive point intrinsic and oppositely, specific function of the certain media which stays extrinsic of the text enforce the participants into the immersion. In any case, the subject who experience immersion is the audience, so the most useful theory to research the phenomenon 'immersion' is Constructivism cognitive narrotologic approach which lies the peader-spectator as the centric notion and is more useful than text analysis or research on the visual effects. In this study, research and review about the studies on the audience's immersive experience would be preceded particularly aroud the constructivism theories, and examine the uniqueness and naures of the animation which makes the audience immersive.

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