• 제목/요약/키워드: simultaneity

검색결과 78건 처리시간 0.024초

Simultaneous Analysis of Gasonline and Chlorinated Solvents by GC/FID-SPME

  • 안상우;이시진;장순웅
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.350-353
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    • 2004
  • This study was conducted for a rapid and simple method using GC/FID and SPME to dectermin gasonline and chlorinated solvents simultaneity. A sodium chloride concentration of 25%(vol/w) combined with such as magnetic stirried, an absorption time of 20min, an extraction temperature of 4$0^{\circ}C$, the volume of minimized 50mL of gaseous phase and a desorption time of 5min pleprovided the greatest sensitivity while maintaining analytical efficiency. Analytical parameter such as linearity was also evaluated. The linear range extend from 30 to 500ppb. The results of chlorinated solvents and gasoline mixed samples showed that solvents have been completely removed from the sample preparation step and more accurated than those obtained by the other methods.

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현대 실내공간에서의 비물질적 특성에 관한 연구 (A Study on the Immateriality in Contemporary Interior Space)

  • 신홍경;옥창수
    • 한국실내디자인학회논문집
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    • 제13권3호
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    • pp.76-83
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    • 2004
  • Nowadays, our societies use digital technology in new architectural shape and space design to transcend three dimension limit so the boundary of the imagination world and actuality world has been collapsed. Traditional spatial value has been collapsed. Also indetermination and temporary assumption in time, fluidness and dematerialized, simultaneity and reiteration in image are relative with this circumstances. In architectural shape, media characteristics which secede from traditional characteristics of place tectonic value have occurred. Therefore, indifference and interests in shape, inter-permeation in interior and exterior space, homogeneous equivalence spatial extension have occurred. The purpose in this study examines dematerialized in contemporary space design and light materials and also investigates general and architectural background. The results of this study are as follows. First, circumstances of human have changed from physically limited boundary to unfixed, nonphysical, lightness and vague things. Second, casting off volume in shape and also dissembling exclusive and constructive Third, interior and exterior space by transparency intimates media possibility of information screen. Fourth, seek information and organic response, ambivalent transformation, accumulation of image and new mutual understanding system.

The Influence of Precipitated Phase in Al-4%Cu Alloy under High Magnetic Field

  • Jun, Jiang;Lee, Hyun-Jun;Min, Qi;Park, Won-Jo
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.239-243
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    • 2008
  • Nonferrous metals have a very important position in industry. At present, parts of shipbuilding, automobile, and aircraft etc. are designed and manufactured accurately, simultaneity need light-weight and high-strength. Aluminum copper alloys are one kind of typical precipitation hardening alloy which has been widely used. It is interesting to investigate transformation behavior of precipitated phase in such kind of alloys under high magnetic field. Transformation of materials under high magnetic field is many different compared with conventional condition. The author prepared the Al-4%Cu alloy.

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Empirical Study of Dynamic Corporate Governance: New Evidence from Chinese-listed SMEs

  • Shao, Lin;Yu, Xiaohong
    • 산경연구논집
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    • 제6권4호
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    • pp.27-37
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    • 2015
  • Purpose - This study first explores the possible dynamic relationship between ownership structure and firm performance using a panel of 4,900 Chinese-listed small- and medium-sized enterprises (SMEs) from 1999 to 2012. Research design, data, and methodology - We address this issue through a dynamic panel model using a method of moments (GMM) technique and dynamic simultaneous equations to alleviate the potential endogenous problem: unobserved heterogeneity, simultaneity, and dynamic endogeneity. Results - Under the framework of dynamic endogeneity, firm performance has a significantly positive influence on ownership, but not vice versa. Ownership and performance can be explained by their owned lagged values, respectively. Moreover, intertemporal endogeneity exists among ownership, investment, and performance through the application of system dynamic equations, which implies that the relationship among ownership structure, investment, and firm performance is dynamic by nature. Conclusions - This study also significantly contributes to a better understanding of dynamic corporate governance by providing further empirical evidence from the largest capital market in the Asian region.

The effect of the vertical excitation on horizontal response of structures

  • Ghaffarzadeh, Hosein;Nazeri, Ali
    • Earthquakes and Structures
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    • 제9권3호
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    • pp.625-637
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    • 2015
  • It is usual in design and assessment of structures to isolate the effects of vertical and horizontal excitations by ignoring their coupling effects. In this situation, total structural response is obtained by employing the well-known combination rules whereby independent assumed response components of earthquakes are combined. In fact, the effects of the simultaneity of the ground motion components are ignored. In this paper, the effect of vertical excitation on horizontal response of structures, the coupling of vertical and horizontal responses, has been evaluated. A computer program is prepared to perform nonlinear dynamic analysis based on the derived governing equations of coupled motions. In the case of simultaneous excitation the results show significant increases in spectral displacement in some periods of vibration in comparison to only horizontally excited systems. Moreover, whenever ratio of the vertical peak ground acceleration to horizontal one become larger, the significant increase in horizontal spectral displacements are observed.

Multiple Product Supplier 환경에서 주문할당 정책 (Order allocation policy in Multiple Product Supplier environment)

  • 홍은수;강경식
    • 대한안전경영과학회지
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    • 제18권4호
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    • pp.185-193
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    • 2016
  • Now, many studies of industrial field are focusing on the whole optimization of SCM. But, the reason for making simultaneity of the whole system of SCM difficult is reduced scale of studies on ordering area in SCM reducing the complexity. It's an important issue how to allocate orders in the environment of many suppliers under special situation. Through this thesis, this research intends to expect systematic and arranged supply of distribution area which can make a decision while allocating product orders and quantity and maintaining service standard suggested by minimizing total purchase costs.

타이포그래피의 시각적 리듬감 유형 연구 (Research on Types of Visual Rhythmic Sense in Typography)

  • 정유경
    • 디자인학연구
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    • 제18권2호
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    • pp.143-154
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    • 2005
  • 시각 커뮤니케이션 디자인에서 타이포그래피는 공간(평면)속에서 감추어진 '잠재적 태(胎)'이다. 타이포그래피에서 리듬을 보여준다는 것은 조형성을 가진 그래픽에 '미감'을 형성하는 것으로 그 표현방법이 매우 중요하다. 이러한 리듬이 시각적 흐름을 통하여 인지되어질 때 리듬감이 형성된다. 본 연구는 타이포그래피 작품뜩 통해 실증적 분석으로 시각적 리듬감의 새로운 유형을 제시한 것이다. 우선, 시각적 리듬감 형성을 기한 실험성이 강한 타이포그래퍼 필리포 마리네티, 로베르 마쌩, 볼프강 바인가르트, 데이비드 카슨 등을 연구의 대상으로 선정하였다. 시각적 이미지 특성 분석으로 어의변별척도(S. D. Scale)법을 사용하였고, 배리맥스(VARIMAX)로써 인자분석을 하여 시각적 리듬감의 유형을 도출하였으며, 다음과 같이 분류할 수 있었다. (1) 공감각적 리듬감(R-synesthesia)은 '청각의 시각화'와 '촉각의 시각화'를 통한 감각의 전이를 의미한다. (2) 동시적 리듬감(R-simultaneity)은 한 평면 안에 시간과 공간이 동시에 존재하는 것을 뜻한다. (3) 관계적 리듬감(R-connection)은 이질적인 요소들이 (한 평면 안에) 함께 공존하여 상호 관계적 역할을 하면서 전체적인 인상이 통일되어 나타나는 현상을 말한다. (4) 작가 중심적 리듬감(R-artist)은 작가가 내용을 주관적으로 해석하여 표현함에 다라 임의적, 계획적으로 독자의 시선을 유도하는 것을 의미한다. (5) 수용자 중심적 리듬감(R-reader).은 기존의 기독성을 탈피하여 수용자의 적극적인 참여로 형성된다.

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Primary user localization using Bayesian compressive sensing and path-loss exponent estimation for cognitive radio networks

  • Anh, Hoang;Koo, Insoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권10호
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    • pp.2338-2356
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    • 2013
  • In cognitive radio networks, acquiring the position information of the primary user is critical to the communication of the secondary user. Localization of primary users can help improve the efficiency with which the spectrum is reused, because the information can be used to avoid harmful interference to the network while simultaneity is exploited to improve the spectrum utilization. Despite its inherent inaccuracy, received signal strength based on range has been used as the standard tool for distance measurements in the location detection process. Most previous works have employed the path-loss propagation model with a fixed value of the path loss exponent. However, in actual environments, the path loss exponent for each channel is different. Moreover, due to the complexity of the radio channel, when the number of channel increases, a larger number of RSS measurements are needed, and this results in additional energy consumption. In this paper, to overcome this problem, we propose using the Bayesian compressive sensing method with a calibrated path loss exponent to improve the performance of the PU localization method.

Estimation of the air temperature over the sea using the satellite data

  • Kwon B. H.;Hong G. M.;Kim Y. S.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.392-393
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    • 2005
  • Due to the temporal and spatial simultaneity and the high-frequency repetition, the data set retrieved from the satellite observation is considered to be the most desirable ones for the study of air-sea interaction. With rapidly developing sensor technology, satellite-retrieved data has experienced improvement in the accuracy and the number of parameters. Nevertheless, since it is still impossible to directly measure the heat fluxes between air and sea, the bulk method is an exclusive way for the evaluation of the heat fluxes at the sea surface. It was noted that the large deviation of air temperature in the winter season by the linear regression despite good correlation coefficients. We propose a new algorithm based on the Fourier series with which the SST and the air temperature. We found that the mean of air temperature is a function of the mean of SST with the monthly gradient of SST inferred from the latitudinal variation of SST and the spectral energy of air temperature is related linearly to that of SST. An algorithm to obtain the air temperature over the sea was completed with a proper analysis on the relation between of air temperature and of SST. This algorithm was examined by buoy data and therefore the air temperature over the sea can be retrieved based on just satellite data.

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Neutron Monitor as a New Instrument for KSWPC

  • Oh, Su-Yeon;Yi, Yu;Kim, Yong-Kyun;Bieber, John W;Cho, Kyung-Seok
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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    • pp.34.1-34.1
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    • 2008
  • Cosmic ray (CR)s are energetic particles that are found in space and filter through our atmosphere. They are classified with galactic cosmic ray (GCR)s and solar cosmic ray (SCR)s from their origins. The process of a CR particle colliding with particles in our atmosphere and disintegrating into smaller pions, muons, neutrons, and the like, is called a cosmic ray shower. These particles can be measured on the Earth's surface by neutron monitor (NM)s. Regarding with the space weather, there are common types of short term variation called a Forbush decrease (FD) and a Ground Level Enhancement (GLE). In this talk, we will briefly introduce our recent studies on CRs observed by NM: (1) simultaneity of FD depending on solar wind interaction, (2) an association between GLE and solar proton events, and (3) diurnal variation of the GCR depending on geomagnetic cutoff rigidity. NM will provide a crucial information for the Korea Space Weather Prediction Center (KSWPC).

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