• Title/Summary/Keyword: DAVIS

Search Result 417, Processing Time 0.027 seconds

Influence of turbulent transport and chemistry on the distribution of $H_2O$$_2$, $CH_3$OOH, and HCHO in the remote marine boundary layer (오염의 영향을 받지 않은 해양 boundary layer에서의 $H_2O$$_2$, $CH_3$OOH, 그리고 HCHO에 대한 난류수송과 대기화학의 영향)

  • Wonil Chang;Lee, Meehye
    • Proceedings of the Korea Air Pollution Research Association Conference
    • /
    • 2002.11a
    • /
    • pp.223-224
    • /
    • 2002
  • This study is motivated by the discrepancies found in previous studies that compared the observed photochemically reactive species in the marine boundary layer (MBL) with the model simulations. In particular, HCHO was underpredicted in PEM-Tropics (B) and overpredicted in TRACE-A, $H_2O$$_2$ overpredicted, $CH_3$OOH overpredicted, and $CH_3$OH significantly overpredicted (Thompson et al., 1993; Heikes et at., 1996; Davis et al., 1996; Jacob et al., 1996; Schultz et al., 1997; Suhre et al., 1998). (omitted)

  • PDF

Virtual Space에 관한 사용자 수용 연구

  • 김학희;김준우;이기동
    • Proceedings of the Korea Association of Information Systems Conference
    • /
    • 2004.11a
    • /
    • pp.312-326
    • /
    • 2004
  • 본 연구는 Virtual Space의 수용에 어떻게 영향을 미치는지를 파악하고자 하는 연구이다. 이 연구는 정보기술수용 모형의 확장모형인 TAM2(Venkatesh & Davis, 2000)를 적용하여 연구하였으며, 실제 Virtual Space를 사용한 경험이 있는 사용자를 대상으로 설문하여 SPSS와 AMOS를 이용하여 TAM2 모형을 검증하고자 하였다. 연구결과 정보기술 수용에 대한 대상이 조직 내부의 이용자로 연구했던 TAM2와 다르게 외부변수 중 직무관련성과 결과 품질에 대한 변수가 유의하지 않은 것으로 나타났다. 하지만 주관적 규범, 이미지, 결과 논증가능성 등은 유용성에 정의 영향을 주었으며, 특히 외부 변수 중 주관적 규범은 매우 큰 영향을 주고 있는 것으로 나타나 새로운 정보기술의 수용에 있어 중요한 요인으로 분석되었다. 본 연구 결과의 시사점과 한계점 및 향후 연구방향을 결론에서 제시하였다.

  • PDF

MURO - Mangpo high school Unmanned Robotic Observatory

  • Kim, Hyunjong;Pak, Soojong;Kim, Youngjong
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.1
    • /
    • pp.52.1-52.1
    • /
    • 2016
  • We introduce the characteristics and performance of the 0.25m telescope at Mangpo high school Unmanned Robotic Observatory (MURO) which was established in Yangpyeong-gun, Gyeongi-do, KOREA in 2015 January. MURO system included Astrohaven 2.1m non-rotation fiberglass clamshell dome, Paramount MEII mount, Takahashi CCA 0.25m wide field telescope, FLI PL 16803 4K CCD with 7-positions filter wheel system, all sky camera and point grey wide field camera, IR 4 chanel heat sensor camera for security, DAVIS realtime weather cast, and power controled by ARS system. All control softwares are from off-the-shelf products based on Windows 7 OS to be easily operated and maintained. We expect to perform variety of science programs ranging from supernovae follow-up observation to narrow band imaging survey as well as science class activities at Mangpo high school.

  • PDF

IRREDUCIBILITY OF GALOIS POLYNOMIALS

  • Shin, Gicheol;Bae, Jae Yun;Lee, Ki-Suk
    • Honam Mathematical Journal
    • /
    • v.40 no.2
    • /
    • pp.281-291
    • /
    • 2018
  • We associate a positive integer n and a subgroup H of the group $({\mathbb{Z}}/n{\mathbb{Z}})^{\times}$ with a polynomial $J_n,H(x)$, which is called the Galois polynomial. It turns out that $J_n,H(x)$ is a polynomial with integer coefficients for any n and H. In this paper, we provide an equivalent condition for a subgroup H to provide the Galois polynomial which is irreducible over ${\mathbb{Q}}$ in the case of $n=p^{e_1}_1{\cdots}p^{e_r}_r$ (prime decomposition) with all $e_i{\geq}2$.

A Numerical Study of Initial Unsteady Flow and Mixed Convection in an Enclosed Cavity Using the PISO Algorithm (PISO 알고리즘을 이용한 밀폐공간내에서의 유동 및 혼합대류에 관한 연구)

  • Choi, Y.G.;Chung, J.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.2 no.1
    • /
    • pp.63-73
    • /
    • 1990
  • A numerical analysis of initial unsteady state flow and heat transfer in an enclosed cavity has been performed by the Modified QUICK Scheme. The stable QUICK Scheme which modified the coefficient always to be positive is included in this numerical analysis. The implicit method is applied to solve the unsteady state flow; between iterations the PISO (Pressure - Implicit with Splitting of Operators) algorithm is employed to correct and update the velocity and pressure fields on a staggered grid. The accuracy of the Modified QUICK Scheme is proved by applying fewer grid systems than those which Ghia et al. and Davis applied. The initial unsteady mixed convection in an enclosed cavity is analyzed using the above numerical procedure. This study focuses on the development of the large main vortex and secondary vortex in forced convection, the effects of the Rayleigh Number in natural convection and the relative direction of the forced and natural convection.

  • PDF

A Speech Perception-Based Study of the Patterning of Sonorants in Consonant Clusters

  • Seo, Mi-Sun
    • Speech Sciences
    • /
    • v.11 no.4
    • /
    • pp.233-247
    • /
    • 2004
  • This study explores sound alternations in a consonant cluster in which at least one consonant is a sonorant (a son/C cluster, hereafter). In this study, I argue that phonological processes affecting son/C clusters result from low perceptual salience rather than from the Syllable Contact Law as discussed in Vennemann (1988), Clements (1990), Rice & Avery (1991), Baertsch & Davis (2000), among others. That is, as a main factor motivating the alternations in the cluster, I consider contrasts of weak perceptibility triggered by phonetic similarity between two members of a cluster (Kawasaki 1982, Ohala 1992, 1993). Based on the findings from a typological survey in 31 different languages, I show that a speech perception-based account makes a correct prediction regarding the patterning of sonorant/sonorant sequences and that of obstruent/sonorant sequences, while the syllable contact account does not.

  • PDF

A Study of Modern Art and Fashion Trend Image -Based on after 1995 Fashion Trend- (현대예술과 패션의 트랜드 이미지에 관한 연구 -95년 이후 Fashion Trend를 중심으로-)

  • 이은영
    • The Research Journal of the Costume Culture
    • /
    • v.6 no.3
    • /
    • pp.88-99
    • /
    • 1998
  • Image of Modern Art & Fashion are created on the whole in daily life. Image itself is not simple. There is no more distinction between content & form through mutual crossing for intellectual thinking. Specially, image of reproduction circumstance too many mixtual and compromise (collage) are continued to occur. They could pursuit to change their image through the more increase of impulse, exception and popular experience. In this thesis, I studied about image of Modern fashion & Art. In the modern art, visual image showed as anti-beauty and combination of cultural system. It has shown in the theory of Fred Davis and through fashion brand advertising image as follows; Youth vs maturity (ageless image), male s female and androgynous vs unisexuality (genderless image), colligation vs monopoly (street mode image). As a results, the modern trend image are showing the value of the ambivalence. It can be said that he anti-beauty which are occasionally showed in ambivalence has shown a tendency toward another tradition (feminity) through giving an impulse and paradox.

  • PDF

How Apparel Companies Use Social Media: The Case of Facebook

  • Seo, Min-Jeong;Burns, Leslie Davis
    • The Research Journal of the Costume Culture
    • /
    • v.20 no.3
    • /
    • pp.430-442
    • /
    • 2012
  • This study focused on how the U.S. apparel companies use social media as a new marking channel. On Facebook Wall the contents of messages in English initiated by companies and consumers were investigated and categorized by using content analysis. Chi-square analysis and t-test were utilized to compare the use of social media by companies with higher and lower business performance. The majority of messages initiated by apparel companies gave their consumers useful information about new products, promotions, and recruiting. On the other hand, messages initiated by consumers contained a variety of content related to companies, users, and products. Apparel companies with lower business performance were more actively engaged in posting messages and responding to consumers. The results will be helpful in employing social media to build new marketing strategies through direct communications with consumers.

An evaluation of the Mantel-Fleiss validity criterion for the Mantel-Haenszel statistic

  • Younghae Chung;Charles S. Davis
    • Communications for Statistical Applications and Methods
    • /
    • v.5 no.1
    • /
    • pp.265-275
    • /
    • 1998
  • In testing the partial association between two variables after controlling for the S levels of a third factor, the Mantel and Haenszel (1959) statistic is often used. Since the statistic is based on the asymptotic distribution of the sum X of S hypergeometric variates, a guideline for the minimum requirements for the application of the statistic is useful. Mantel and Fleiss (1980) developed a criterion based on the guideline for the Pearson's $X^2$ statistic. The criterion requires the distance from the expected value to the closer bound of X to be at least five. The Mantel-Fleiss (MF) criterion was studied through a simulation using the hypergeometric sampling scheme. The criterion is not satisfactory. The size of statistic exceeded nominal 0.05 level nearly 1/5 of the cases even when the criteion is met. However, the results show that the statistic is much more unstable and conservative when the criterion is not met.

  • PDF

An Empirical Study on the Critical Factors for Successful m-Learning Implementation (성공적인 m-Learning 구현을 위한 핵심 요인에 대한 연구)

  • Whang, Jae-Hoon;Kim, Dong-Hyun
    • Journal of Information Technology Applications and Management
    • /
    • v.12 no.3
    • /
    • pp.57-80
    • /
    • 2005
  • This study defined the notion of general idea on m-learning as based upon e-Learning and mobile internet related literature review and identified the m-Learning distinctive features. Also, this study has searched for factors that are expected to influence the use intended for m-Learning from self-regulated learning, which is acknowledged to be a useful method for learning accomplishment in education field, in order to measure the relationship between learners' motivation and use intention. Then it has empirically validated the conceptual model based on Davis' TAM (Technology Acceptance Model) As a result, self-efficacy, self-determination, interest, contents quality, time management, help seeking, and Peer study are factors affecting Perceived usefulness. Also self-efficacy, self-determination, interest, contents qualify, time management, and peer study are factors affecting perceived ease of use. Finally both perceived usefulness and perceived ease of use are significant factors affecting use intention.

  • PDF