• Title/Summary/Keyword: Force Behind

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Numerical Simulation of Flow Characteristics behind a Circular Patch of Vegetation using a Two-Dimensional Numerical Model (2차원 수치모형을 이용한 원형군락 하류의 흐름특성 수치모의)

  • Kim, Hyung Suk;Park, Moonhyeong
    • Journal of Korea Water Resources Association
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    • v.48 no.11
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    • pp.891-903
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    • 2015
  • This paper presents numerical simulations of flow around a circular patch of vegetation using a depth-averaged two-dimensional numerical model which is capable of simulating flow structure in vegetated open channel. In order to account for vegetation effect, drag force terms are included in governing equations. Numerical simulations are conducted with various solid volume fractions (SVF). Flow passes through a circular patch and low velocity region, which is called wake region, is formed downstream of the patch. When SVF is larger than 0.08, a recirculation is observed. The location of the recirculation is moved further downstream as SVF decreases. Von-$K{\acute{a}}rm{\acute{a}}n$ vortex street is developed beyond the wake region due to interaction between two shear layers induced by a circular patch of vegetation. The vortex is developed as SVF is larger than 0.08, and the location of the vortex is consistent with the maximum of turbulence kinetic energy. The location of the peak of turbulence kinetic energy is moved further downstream as SVF decreases.

Formation of the Minority Societies and Socio-Cultural Adaptation of the Chinese and Korean Immigrants in Vancouver, Canada (중국인과 한국인 이민자들의 소수민족사회 형성과 사회문화적 적응: 캐나다 밴쿠버의 사례연구)

  • Kim, Doo-Sub
    • Korea journal of population studies
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    • v.21 no.2
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    • pp.144-181
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    • 1998
  • The main purpose of this study is to understand the socio-cultural adaptation and life-styles of the Chinese and Korean immigrants in Vancouver, Canada. Of interest are the immigration policies of the Canadian government and formation of the Chinese and Korean minority societies in Vancouver. Attention is given to estimating the size of the Korean population in Vancouver, utilizing the listings of telephone directory and the proportion of surname Kims in the Korean population. This paper focuses on explaining the distinctive adaptation patterns and socio-cultural characteristics of the Chinese and Korean immigrants. A conceptual scheme of socio-cultual adaptation of the minority immigrants, which is hypothesized as a function of the participation to the host society and the cultural identity, is also developed in this paper. Findings of the analysis suggest that the Chinese and Korean population in Vancouver witnessed a rapid growth since the mid 1980s, when the Canadian government launched the immigration programs for investors and entrepreneurs. It appears that the Chinese and Korean immigrants hold strong ethnic identity and maintain cultural traditions and life-styles of their own. While Chinese immigrants are characterized by active participation to the host society, Korean immigrants tend to confine themselves to the Korean enclave, and thus keep a certain distance from the host society. This appears to be particularly true for the Koreans who immigrated with a status of investor or entrepreneur. As the key force behind the ethnic differences in their adaptation, the role of voluntary associations is stressed. Finally, the future prospects of the Chinese and Korean societies and their acculturation are discussed in this study.

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A Study on the Current Status and Policy Direction of Open Banking (오픈뱅킹(Open Banking)의 현황과 정책방향에 관한 연구)

  • Park, Jeongkuk;Kim, Injai
    • Journal of Service Research and Studies
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    • v.10 no.1
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    • pp.17-31
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    • 2020
  • Open banking, the global trend of the financial industry, is the driving force behind various innovations in the financial market in the future. The right policy direction and detailed tasks are important for triggering the differentiation and reunion of the financial industry. The purpose of this study is to investigate and analyze the background of open banking, domestic and international trends, and Korea's open banking policy. The policy directions and tasks for successful settlement and activation of open banking system are carefully suggested. Open banking is a policy to allow third party provider(TPP) access to bank accounts and open payment functions under the explicit consent of the customer. The opening of the open banking era is expected to begin competition and cooperation between banks and fintech companies in earnest, thus enhancing the competitiveness of the financial industry and contributing to the utility of financial consumers. To this end, policymakers should make every effort to advance open-ended financial settlement infrastructure, open banking legal grounds, and minimize side effects such as customer data leakage and poor financial system stability. Banks and fintech companies will need to focus on scattered customer financial information on a single platform and develop it into a convergence and discrimination of true financial services.

Simplified Analysis Formula for the Interaction of the Launching Nose and the Superstructure of ILM Bridge (압출추진코와 ILM 교량 상부구조 상호작용 해석식의 단순화)

  • Lee, Hwan-Woo;Jang, Jae-Youp
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.3
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    • pp.245-258
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    • 2012
  • ILM(incremental launching method) is a way of construction, installing a girder producing spot behind the abutment, making the bridge girder infilled with concrete continuously and launching with using by jack. The superstructure of the bridge constructed by this method is temporarily located on the center of the span and the supporting points under construction. Therefore, the sections are structurally undergone maximum positive moment, maximum negative moment, and maximum shear force arising from self weight. On the other hand, launching nose is attached to the front of the girder to decrease the cantilever effect. The magnitude of this temporary stress creating on the upper section is dependent upon the launching nose's characteristics. This study has proposed an analysis formula simplified on the assumption that the launching nose section is a quasi-equivalent section(rigid; equivalent section, weight; tapered section) in order to ensure the accuracy of the analysis formula and improve its usage with reference to the interaction between the launching nose and the upper section; and a prismatic analysis formula modified by displacing a diaphragm's weight by a concentrated load in order to improve the accuracy of the existing analysis formula that assumes the launching nose section as the equivalent section. To judge the accuracy and usage of two analysis formulas proposed, we have compared and analyzed computational structural analysis programs and existing analysis formulas based on actual ILM bridge data. As a result, all of two reveal the superior accuracy and also their usage has been improved by the simplification of analysis formulas.

An Experimental Study on Resistance of rapid Freezing and Thawing of Chloride-inhibiting Low-Heat Cement (차염성 저발열시멘트의 급속동결융해 저항성에 관한 실험적 연구)

  • Sim, Jong-Sung;Park, Cheol-Woo;Park, Sung-Jae;Kang, Tae-Sung;Ju, Min-Kwan;Kim, Tae-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.589-592
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    • 2008
  • This study was conducted to assess the durability of Chloride-inhibiting Low-Heat Cement while being subjected to freezing-thawing during winter seasons. Although durability varies slightly depending on the conditions of the jobsite, frost damage to concrete resulting from repeated freezing and thawing over the course of seasonal changes is the leading cause behind lowered concrete durability. in addition, concrete that has been subjected to freezing and thawing during the winter season develops a significant amount of expansive force at the core and begins to exhibit signs of damage, such as cracking, peeling, and detachment from the aggregate. Therefore, this study fabricated test specimens using a Chloride-inhibiting Low-Heat Cement(CLC) and the widely used blast furnace slag cement(BFS) and Ordinary Portland Cement(OPC) with water-to-cement ratios of 35%, 40% and 45%, respectively, to assess the durability index of the CLC as per resistance to freezing-thawing. The specimens were then tested using the KS F 2456 method (Testing method for resistance of concrete to rapid freezing and thawing) to measure the dynamic modulus of elasticity. The dynamic modulus of elasticity measurements were then used to derive the durability indices. By comparing the durability indices, it was confirmed that CLC, BFS, and OPC all had superior durability.

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Laser Acceleration of Electron Beams to the GeV-class Energies in Gas Jets

  • Hafz, Nasr A.M.;Jeong, Tae-Moon;Lee, Seong-Ku;Choi, Il-Woo;Pae, Ki-Hong;Kulagin, Victor V.;Sung, Jae-Hee;Yu, Tae-Jun;Cary, John R.;Ko, Do-Kyeong;Lee, Jong-Min
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.8-14
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    • 2009
  • In a laser-plasma wakefield accelerator, the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal wave or plasma bubble in a way similar to the excitation of a wake wave behind a boat as it propagates on the water surface. Electric fields inside the plasma bubble can be several orders of magnitude higher than those available in conventional RF-based particle accelerator facilities which are limited by material breakdown. Therefore, if an electron bunch is properly phase-locked with the bubble's acceleration field, it can gain relativistic energies within an extremely short distance. Here, in the bubble regime we show the generation of stable and reproducible sub GeV, and GeV-class electron beams. Supported by three-dimensional particle-in-cell simulations, our experimental results show the highest acceleration gradients produced so far. Simulations suggested that the plasma bubble elongation should be minimized in order to achieve higher electron beam energies.

Computational Fluid Analysis for the Otter Boards - 3 . Efficiency Analysis of the Single Cambered Otter Boards for the Various Slot Position - (전개판에 대한 수직해법 - 3 . 슬롯에 따른 단순만곡형전개판의 성능분석 -)

  • 고관서
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.4
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    • pp.278-285
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    • 1991
  • The authors propose to use the slot system in order to improve of the efficiency for the cambered otter boards. The experiment is divided into 2 parts, one is the efficiency model test, and the other is the visualization model test. The hydrodynamic characteristics of the model otter boards were tested by efficiency model test to measure the shearing, drag force of the models and visualization test using hydrogen bubble method to observe the streak-line and time-line of flow around the models, and milk spout method to observe the separation zone in the wake behind the models. This study tested for 5 models such ad without slot, slot position 0.2C, 0.4C, 0.6C and 0.8C. The results obtained are as follows: \circled1 The maximum C sub(L) of model otter board with slot position 0.6C in attack angle 27$^{\circ}$ was the highest of all models, it's value was 1.59. \circled2 In general, the L/D ratio of the one slot otter boards were 16~28% higher than otter board without slot. \circled3 The slot position 0.6C was better than any other slot position, and it's conformed by visiualization. \circled4 As to the model otter board with slot position 0.6C, flow speed of the back side was faster 1.3 to 1.7 times than in the front side. \circled5 The size of the separated zone in case of the model otter board with 0.6C was smaller than that of any other models.

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A Design of Authority Management Protocol for Secure Storage Access Control in Cloud Environment (클라우드 환경에서 안전한 스토리지 접근 제어를 위한 권한 관리 프로토콜 설계)

  • Min, So-Yeon;Lee, Kwang-Hyong;Jin, Byung-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.12-20
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    • 2016
  • With the enhancements in existing major industries, cloud computing-based converging services have been created, as well as value-added industries. A variety of converging services are now provided, from personalized services up to industrial services. In Korea, they have become the driving force behind existing industries throughout the whole economy, but mainly in finance, mobile systems, social computing, and home services, based on cloud services. However, not only denial of service (DOS) and distributed DOS (DDOS) attacks have occurred, but also attack techniques targeting core data in storage servers. Even security threats that are hardly detected, such as multiple attacks on a certain target, APT, and backdoor penetration have also occurred. To supplement defenses against these, in this article, a protocol for authority management is designed to provide users with safe storage services. This protocol was studied in cases of integration between a cloud environment and big data-based technology, security threats, and their requirements. Also studied were amalgamation examples and their requirements in technology-based cloud environments and big data. With the protocol suggested, based on this, security was analyzed for attack techniques that occur in the existing cloud environment, as well as big data-based techniques, in order to find improvements in session key development of approximately 55%.

A Study on the Cultural Industrialization and Content Change Direction of Pyeongsari, a Novel 'Toji (Land )' Background Space (소설 『토지』 배경지 평사리의 문화산업화와 콘텐츠 변화 방향 연구)

  • Choi, You-Hee
    • Journal of Popular Narrative
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    • v.26 no.2
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    • pp.221-247
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    • 2020
  • This paper examines the meaning of Pyeongsari, the main stage of the novel 'Toji (Land )' and the original experience space engraved in the lives of the characters and suggests the direction of Pyeongsari as a 'Toji (Land )' content platform. Pyeongsa-ri, an imaginary space in the novel, starts from the background of the original work and turns into a representative tourist space for Ha Dong-gun. However, it is necessary to provide cultural experience-type contents that visitors can experience in person. In the original work, Pyeongsari is an ideal community and a symbol of the Korean modern history of suffering and pioneering. Therefore, taking advantage of this meaning, it is necessary to prepare a cultural experience space that shows Confucian culture, women's labor culture, and shamanic culture to draw on visitors' experiences. In addition, the app should be developed in connection with transformed works that have been the driving force behind the reorganization of Pyeongsari, and education and experience spaces using augmented reality are provided on the web. This interaction between digital and reality makes the meaning of the original or transformed works contemporaneous, while contributing to the visitor's own experience. In addition, through this, Pyeongsari can evolve into a cultural experience content platform that reflects the meaning of Korean culture and life. This paper is significant in that it suggests the direction of Pyeongsari's space planning for the 'geography of meaningful places'. In addition, while showing how the imaginary space of the original literary work has reorganized the space of reality, there are implications for the media content of the literary work and the terrain of the culture and arts industry.

Embodiments of Traditional Cultures in South Korean Films : Taking The Princess and the Matchmaker as an Instance (영화 <궁합>에 나타난 한국의 전통문화에 대한 표현)

  • Chen, Yiyu
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.4
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    • pp.53-62
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    • 2019
  • In recent years, South Korean has made a globally acknowledged achievement in movie industry. In terms of Art, films produced in South Korea obtained lots of awards in international movie festivals; in the business field, Korean movies are swiftly occupying the Asian or even the world film market. Extraordinary films with good reputations and high box office records are frequently launched and induced to a trend, which then forms into a cultural phenomenon and attributes to an important, major force in the so-called "Hallyu" culture. This, in part, benefits from the massive support of Korean government's cultural policies, and is also a product of the high degree of cultural consciousness of Korean movie producers. The Korean cultures, customs, and the underlying cultural elements of the East, that are presented in these movies, satisfy the audience and appeal their fondness. The Princess and the Matchmaker is a South Korean period romantic comedy film directed by Hong Chang-pyo and starred Shim Eun-kyung and Lee Seung-gi. The movie was presented on Feb 28th, 2018. It tells a story of Seo Do-yoon, the most proficient saju (fortune-teller) expert of the Joseon Era who selected a husband for Princess Song-Hwa based on her "fortune eight letters" (specifically, the time, day, month and year of her and her husbands' birth, normally in eight letters), in a hope of alleviating the rage of people following years of drought, and thus to resolve a national crisis. This paper takes The Princess and the Matchmaker as an example, from the aspects of cultural state, system, behavior and mentality, to analyze the traditional customs such as "fortune eight letters", "marriage by match" and the cultural concepts behind these phenomena, in order to explore the ways and methods of traditional culture in the modern cultural and artistic form of film.