• Title/Summary/Keyword: Transition of Flows

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Groundwater and Stream Water Acidification and Mixing with Seawater, and Origin of Liquefaction-Expelled Water in a Tertiary Formation in the Pohang Area (포항지역 제3기층내 지하수와 지표수의 산성화 및 해수혼합, 그리고 액상화 유출수 기원에 관한 연구)

  • Jeong, Chan Ho;Ou, Song Min;Lee, Yu Jin;Lee, Yong Cheon;Kim, Young Seog;Kang, Tae Seob
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.559-569
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    • 2022
  • This study investigated the acidification and mixing with seawater of groundwater, stream water, and reservoir water in the Hunghae area of Pohang City, as well as the source of water expelled to the stream by liquefaction induced by the Pohang earthquake on 15 November 2017. Geologically, the area consists of Tertiary sedimentary rocks. We collected six samples of groundwater, five of reservoir water, four of stream water, two of liquefaction water, and one of seawater to analyze the chemical composition and stable isotopes (𝛿D and 𝛿18O). Gogkang Stream flows eastward through the central part of the study area into the East Sea. The groundwater and reservoir water in the lower part of the stream are acidic (pH < 4), have a Ca(Mg)-SO4 composition, and high concentrations of Al, Fe, and Mn, likely due to the oxidation of pyrite in Tertiary rocks. The groundwater in the upper part of the stream have a Ca(Na)-HCO3(Cl) composition, indicating the mixing of seawater with the stream water. The 𝛿D and 𝛿18O isotope data indicate the isotopic enrichment of reservoir water by evaporation. Based on the chemical and isotopic data, it is inferred that the two samples of liquefaction water originated from alluvium water in a transition zone with stream water, and from deep and shallow groundwaters that has been infiltrated by seawater, respectively.

Characteristics of Plasma Discharge according to the Gas-flow Rate in the Atmospheric Plasma Jets (대기압 플라즈마 제트의 기체 유량에 대한 방전 특성)

  • Lee, Won Young;Jin, Dong Jun;Kim, Yun Jung;Han, Gook Hee;Yu, Hong Keun;Kim, Hyun Chul;Jin, Se Whan;Koo, Je Huan;Kim, Do Young;Cho, Guangsup
    • Journal of the Korean Vacuum Society
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    • v.22 no.3
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    • pp.111-118
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    • 2013
  • The influence of gas flow on the plasma generation in the atmospheric plasma jet is described with the theory of hydrodynamics. The plasma discharge is affected by the gas-flow streams with Reynolds number (Re) as well as the gas pressure with Bernoulli's theorem according to the gas flow rate inserted into the glass tube. The length of plasma column is varied with the flow types such as the laminar flow of Re<2,000 and the turbulent flow of Re>4,000 as it has been known in a general fluid experiments. In the laminar flow, the plasma column length is increased as the increase of flow rate. Since the pressure in the glass tube becomes low as the increase of flow velocity by the Bernoulli's theorem, the breakdown voltage of plasma discharge is reduced by the Paschen's law. Therefore, the plasma length is increased as the increasing flow rate with the fixed operation voltage. In the transition of laminar and turbulent flows, the plasma length is decreased. When the flow becomes turbulent as the flow rate is increasing, the plasma length becomes short and the discharge is shut down ultimately. In the discharge of laminar flow, the diameter of plasma beam exposed on the substrate surface is kept less than the glass diameter, since the gas flow is kept to the distinct distance from the nozzle of glass tube.

A Study on the Feminism Represented in Anne Teresa De Keersmaeker's Works (페미니즘 관점으로 본 안느 테레사 드 키어스매커(Anne Teresa De Keersmaeker)의 <로사스 댄스 로사스 Rosas danst Rosas>, <에레나의 아리아 Elena's Aria> 작품 분석 연구)

  • JUNG, Soodong
    • Trans-
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    • v.5
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    • pp.83-111
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    • 2018
  • This study aims to analyze early works of contemporary Europe female choreographer Anne Teresa de Keersmaeker, which are Rosas danst Rosas, Elena's Aria in terms of feminism. Started from 18C, feminism movements have changed the perception and conception of women. Since then, women in the work of art have been portrayed to be more powerful and independent than weakened images. The influence of feminism in this era made transition to let female artists act more outstandingly nowadays. Therefore, the study began with the need to reflect the image and role of female dancers in the artistic work with the viewpoints of feminism in the flows of social and cultural background. Works of Rosas danst Rosas represents the aspects of radical feminism. Physical suppression of female dancer reflects liberation of free will. Post-modern feminism is displayed at Rosas danst Rosas which escaped from original portrait of women and exposed new active contemporary image of woman. The Elena's Aria, Radial feminism is represented physical suppression of female dancer reflects liberation of free will. Through analysis of Anne Teresa's works with feminine sight, her works were mainly influenced by feminism occurred after 1980's. Having found other possibilities to explore her choreographic philosophy, insufficiency of domestic data about Anne Teresa was once again reckoned. The researcher hopes that by studying Anne Teresa from the feminist point of view, the various images produced by dancers will not disappear right away, rather creating a sense of unity and development without losing the meaning.

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Preparation and Characteristics of Polymer Additives for Functional Instant Adhesives (기능성 순간접착제용 중합체 첨가제의 제조 및 특성)

  • Ihm, H.J.;Ahn, K.D.;Kim, S.B.;Kim, E.Y.;Han, D.K.
    • Journal of Adhesion and Interface
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    • v.2 no.3
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    • pp.25-32
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    • 2001
  • Ethyl cyanoacrylate (ECA) is used as an instant adhesive, and it can be readily polymerized by moisture in air without any initiator and applied for industrial products and ohome use. However, pure ECA monomer is low-viscosity liquid at room temperature that flows into substrate surface. To thicken the instant adhesive, poly(methyl methacylate)(PMMA) is often added in it commercially. Another disadvantage of instant adhesive polymer is its brittleness In this study, functional polymers including PMMA for an additive of ECA were prepared to increase viscosity of the monomer and flexibility of the adhesive atthe same time The additives, P(MMA-VAc-EVE), were synthesized by radical copolymerization of MMA with VAc and EVE having low glass transition temperature (Tg). The additives were added to ECA to get functional instant adhesives. The chemical structures of the additives and ECA polymers were confirmed by $^1H$ NMR and FTIR, and their physical and mechanical properites were also evaluated. The Tg of the obtained additives decreased with increasing the content of VAc or VAc-EVE, indicating more improved flexibility. In addition, functional instant adhesive containing the additives showed higher bonding strength than that of the existing one.

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A Critical Note on the Electric Field in Direct and Alternating Current and Its Consciousness

  • Oh, Hung-Kuk
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.11a
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    • pp.98-104
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    • 2000
  • The conventional model did not take momentum conservation into consideration when the electron absorbs and emits the photons. II-ray provides momentum conservations on any directions of the entering photons, and also the electrons have radial momentum conservations and fully elastic bouncing between two atoms, in the new atom model. Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. Because the radius of hydrogen atom's electron orbit is the order of 10$^{-11}$ m and the radia of the nucleons in the nucleus are the order of 10$^{-14}$ m and then the converging $\pi$-gamma rays to the nucleus have so great circular momentum, the electron can not have a circular motion. We can say without doubt that any elementary mass particle can have only linear motion, because of the $\pi$-rays'hindrances, nearthenucleus. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The h v is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. Conventional Concept of Electric Field must be extended in the case of the direct and alternating current. Conventional concept is based on coulomb's force while the electric potential in the direct and alternating current is from Gibb's free energy. And also conventional concept has not any consciousness with human being but the latters has a conscious sensibility. The cell emf is from the kinetic energy of the open $\pi$-rays flow through the conducting wire. The electric potential in alternating current is from that the trans-orbital moving of the induced change of magnetic field in the wire produces flows of open $\pi$-rays, which push the rotating electrons on the orbital and then make the current flow. Human consciousness can induce a resonance with the sensibility of the open $\pi$-rays in the electric measuring equipment. Specially treated acupunctures with Nasucon is for sending an acupunctural effect from one place to another via space by someone's will power.

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Separated Control Signaling Protocol for WDM Optical Networks (파장 분할 다중화 방식을 사용하는 광 전송망을 위한 분리 제어 신호 방식)

  • No, Seon-Sik;Kim, Su-Hyeon;So, Won-Ho;Kim, Yeong-Cheon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.6
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    • pp.1-11
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    • 2000
  • In this paper, we propose a novel control signaling protocol that efficiently controls connection setup and increases the utilization of network resources. The proposed protocol, Separated Control Signaling Protocol(SCSP), separates bearer control from call control lot WDM optical networks. The main function of call control is to check the availability of network resources such as wavelengths and receivers at destination node. Bearer control is to reserve and assign wavelengths. The signaling architecture of this protocol consists of call controller and hearer controller The call controller handles call setup and release, activates the beater controller, and manages the status of call and bearer. The bearer controller reserves wavelengths, sets up bearer, tears down bearer. and notifies the status of beater to call controller. The state transition diagrams of each controller are designed. Using control messages and related primitives, the information flows for call setup and bearer setup, hearer teardown and call release, and reaction for setup failures are described to evaluate the performance. The simulation results show that the separated control signaling protocol is superior to conventional one in terms of call blocking probability and resource utilization.

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A Case Study on Autobiography Writing Program for Older Adults (노인자서전 쓰기 교육 프로그램 사례 연구)

  • Ji, Haeng Jung;Han, Jungran;Park, Seong Hie
    • 한국노년학
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    • v.31 no.2
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    • pp.223-241
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    • 2011
  • The purpose of this research is to analyze the effect of an autobiography writing program as a method of education for older adults. The authors participated in the processes of all 10 sessions of the autobiography writing program as instructors or program assistants at a senior welfare center in Seoul, 2007. Data used for analysis were learners' narrations in class, written autobiographies by learners, and researchers' memo-notes. We analyzed their narrative flows using Haenninen(2000)'s theory of narrative flow and reconstructed their categories of activities as life histories. 'The innen narration' constructed by learners was a spiritual process in which they have imbued their life and living conditions with meaning. The learners reminisced their lives as 'unreflective narration' in the beginning of education. However, as the class went on, they gradually reminisced them as "reflective narration" and finally developed them as 'meta-reflective narration' through the intentional reflection. Likewise, we could interpret the transition of learners into meta-reflecter as the completion of ego-integration. As a conclusion, we found the effects of the autobiography writing education for older adults in educational, social, and psychological aspects.

An evaluation of wall functions for RANS computation of turbulent flows (난류 흐름의 RANS 수치모의를 위한 벽함수 성능 평가)

  • Yoo, Donggeun;Paik, Joongcheol
    • Journal of Korea Water Resources Association
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    • v.53 no.1
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    • pp.1-13
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    • 2020
  • The most common approach for computing engineering flow problems at high Reynolds number is still the Reynolds-averaged Navier-Stokes (RANS) computations based on turbulence models with wall functions. The recently developed generalized wall functions blending between the wall-limiting viscous and the outer logarithmic relations ensure a smooth transition of flow quantities across two regions. The performances and convergence properties of widely used turbulence models with wall functions that are applicable for turbulence kinetic energy (TKE), turbulent and specific dissipation rates, and eddy viscosity are presented through a series of near wall flow simulations. The present results show that RNG k-𝜖 model should be carefully applied with small tolerance to get the stable solution when the first grid lies in the buffer layer. The standard k-𝜖 and RNG k-𝜖 models are not sensitive to the selection of wall functions for both TKE and eddy viscosity, while the k-ω SST model should be applied together with kL-wall function for TKE and nutUB-wall functions for eddy viscosity to ensure accurate and stable boundary conditions. The applications to a backward-facing step flow at Re=155,000 reveal that the reattachment length is reasonably well predicted on appropriately refined mesh by all turbulence models, except the standard k-𝜖 model which about 13% underestimates the reattachment length regardless of the grid refinement.

Dynamic O-D Trip estimation Using Real-time Traffic Data in congestion (혼잡 교통류 특성을 반영한 동적 O-D 통행량 예측 모형 개발)

  • Kim Yong-Hoon;Lee Seung-Jae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.1 s.9
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    • pp.1-12
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    • 2006
  • In order to estimate a dynamic origin and destination demand between on and off-ramps in the freeways, a traffic flow theory can be used to calculate a link distribution proportion of traffics moving between them. We have developed a dynamic traffic estimation model based on the three-phase traffic theory (Kerner, 2004), which explains the complexity of traffic phenomena based on phase transitions among free-flow, synchronized flow and moving jam phases, and on their complex nonlinear spatiotemporal features. The developed model explains and estimates traffic congestion in terms of speed breakdown, phase transition and queue propagation. We have estimated the link, on and off-ramp volumes at every time interval by using traffic data collected from vehicle detection systems in Korea freeway sections. The analyzed results show that the developed model describes traffic flows adequately.

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International Monetary System Reform and the G20 (국제통화제도의 개혁과 G20)

  • Cho, Yoon Je
    • KDI Journal of Economic Policy
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    • v.32 no.4
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    • pp.153-195
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    • 2010
  • The recent global financial crisis has been the outcome of, among other things, the mismatch between institutions and the reality of the market in the current global financial system. The International financial institutions (IFIs) that were designed more than 60 years ago can no longer effectively meet the challenges posed by the current global economy. While the global financial market has become integrated like a single market, there is no international lender of last resort or global regulatory body. There also has been a rapid shift in the weight of economic power. The share of the Group of 7 (G7) countries in global gross domestic product (GDP) fell and the share of emerging market economies increased rapidly. Therefore, the tasks facing us today are: (i) to reform the IFIs -mandate, resources, management, and governance structure; (ii) to reform the system such as the international monetary system (IMS), and regulatory framework of the global financial system; and (iii) to reform global economic governance. The main focus of this paper will be the IMS reform and the role of the Group of Twenty (G20) summit meetings. The current IMS problems can be summarized as follows. First, the demand for foreign reserve accumulation has been increasing despite the movement from fixed exchange rate regimes to floating rate regimes some 40 years ago. Second, this increasing demand for foreign reserves has been concentrated in US dollar assets, especially public securities. Third, as the IMS relies too heavily on the supply of currency issued by a center country (the US), it gives an exorbitant privilege to this country, which can issue Treasury bills at the lowest possible interest rate in the international capital market. Fourth, as a related problem, the global financial system depends too heavily on the center country's ability to maintain the stability of the value of its currency and strength of its own financial system. Fifth, international capital flows have been distorted in the current IMS, from EMEs and developing countries where the productivity of capital investment is higher, to advanced economies, especially the US, where the return to capital investment is lower. Given these problems, there have been various proposals to reform the current IMS. They can be grouped into two: demand-side and supply-side reform. The key in the former is how to reduce the widespread strong demand for foreign reserve holdings among EMEs. There have been several proposals to reduce the self-insurance motivation. They include third-party insurance and the expansion of the opportunity to borrow from a global and regional reserve pool, or access to global lender of last resort (or something similar). However, the first option would be too costly. That leads us to the second option - building a stronger globalfinancial safety net. Discussions on supply-side reform of the IMS focus on how to diversify the supply of international reserve currency. The proposals include moving to a multiple currency system; increased allocation and wider use of special drawing rights (SDR); and creating a new global reserve currency. A key question is whether diversification should be encouraged among suitable existing currencies, or if it should be sought more with global reserve assets, acting as a complement or even substitute to existing ones. Each proposal has its pros and cons; they also face trade-offs between desirability and political feasibility. The transition would require close collaboration among the major players. This should include efforts at the least to strengthen policy coordination and collaboration among the major economies, and to reform the IMF to make it a more effective institution for bilateral and multilateral surveillance and as an international lender of last resort. The success on both fronts depends heavily on global economic governance reform and the role of the G20. The challenge is how to make the G20 effective. Without institutional innovations within the G20, there is a high risk that its summits will follow the path of previous summit meetings, such as G7/G8.

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