• Title/Summary/Keyword: $Z_2$

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Structure-Reactivity Relationship of Benzyl Benzenesulfonates. Part 4. Application of Correlation Interaction Coefficients

  • 여수동;정덕영;박종환;김성홍;황규탁
    • Bulletin of the Korean Chemical Society
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    • v.19 no.4
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    • pp.434-436
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    • 1998
  • The mechanism of nucleophilic displacement was studied by using three variable systems of ${\rho}_X,\; {\rho}_Y,\; and {\rho}_Z$ obtained from the change of substituent X, Y, and Z for the reaction of (Z)-substituted benzyl (X)-benzensulfonates with (Y)-substituted thiobenzamides in acetone at 45 ℃. The results ${\rho}_Z$<0 and ${\rho}_YZ$>${\rho}_XZ$ indicate that this reaction series proceeded via a dissociative $S_N2$ mechanism. The prediction of the movement of TS by using the sign of ${\rho}_XZ{\cdot}{\rho}_{YZ}$ accorded with the Hammond postulate.

RESULTS ASSOCIATED WITH THE SCHWARZ LEMMA ON THE BOUNDARY

  • Bulent Nafi Ornek
    • Communications of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.389-400
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    • 2023
  • In this paper, some estimations will be given for the analytic functions belonging to the class 𝓡(α). In these estimations, an upper bound and a lower bound will be determined for the first coefficient of the expansion of the analytic function h(z) and the modulus of the angular derivative of the function ${\frac{zh^{\prime}(z)}{h(z)}}$, respectively. Also, the relationship between the coefficients of the analytical function h(z) and the derivative mentioned above will be shown.

3D Shape Reconstruction based on Superquadrics and Single Z-buffer CSG Rendering (Superquadric과 Z-버퍼 CSG 렌더링 기반의 3차원 형상 모델링)

  • Kim, Tae-Eun
    • Journal of Digital Contents Society
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    • v.9 no.2
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    • pp.363-369
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    • 2008
  • In this paper, we have proposed 3D shape reconstruction using superquadrics and single z-buffer Constructive Solid Geometry (CSG) rendering algorithm. Superquadrics can obtain various 3D model using 11 parameters and both superquadrics and deformed-superquadrics play a role of primitives which are consisted of CSG tree. In addition, we defined some effective equations using z-buffer algorithm and stencil buffer for synthesizing 3D model. Using this proposed algorithm, we need not to consider the coordinate of each 3D model because we simply compare the depth value of 3D model.

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Antioxidant Activity of (8E,13Z,20Z)-Strobilinin/(7E,13Z,20Z)-Felixinin from a Marine Sponge Psammocinia sp.

  • Jiang, Ya-Hong;Ryu, Seung-Hee;Ahn, Eun-Young;You, Song;Lee, Burm-Jong;Jung, Jee-H;Kim, Dong-Kyoo
    • Natural Product Sciences
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    • v.10 no.6
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    • pp.272-276
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    • 2004
  • During the course of our screening for bioactive metabolites from marine sponges, EZZ, the inseparable 1:1 mixture of (8E,13Z,20Z)-strobilinin and (7E,13Z,20Z)-felixinin has been found to deliver significant cytotoxicity against some cancer cell lines. In this study, the antioxidant activity of EZZ was first time evaluated by a series of antioxidant assays. It was found that EZZ was weak in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), but it was comparable to ascorbic acid in scavenging ABTS and superoxide radicals. In addition, EZZ could protect DNA from hydroxyl radical-induced strand cleavage. The findings of the present study suggest that EZZ possess certain antioxidant activity, which might help to prevent occurrence of cancer by alleviating the oxidative stress in cells.

A Study on Shifted Multi-Z-Buffers Anti-Aliasing for 3D Implicit Surface Rendering (3차원 임플리시트 곡면 렌더링을 위한 시프트(shifted) 멀티 Z-버퍼 앤티 앨리어싱 연구)

  • Park Hwa Jin;Kim Hak Ran
    • Journal of Korea Multimedia Society
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    • v.8 no.2
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    • pp.249-257
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    • 2005
  • This paper aims at reducing aliasing in pixel-based rendering for 3D implicit surfaces by shifted multi Z-buffers. The voxelized implicit surfaces with high resolution take so much time in generating high Quality image without aliasing. So in rendering a voxelized implicit surfaces, a new antialiasing method which can generate a high quality image at a lower resolution is required. Therefore, this paper suggests that a method which get various sampling values by shifting several z-buffers in each voxel and average them, The advantages are effective memory, simple calculation and easy convergence with various filters. But, the increase of number of z-buffer also increase the consuming time rapidly. Therefore, the research for representing the relation the degree of image quality with the consumption of time as a number is required.

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A Fuel Cell System with Z-Source Inverter and Ultracapacitors (Z-소스 인버터와 울트라커패시터를 이용한 연료전지 시스템)

  • Kim, Yoon-Ho;Lee, Uk-Young;Kim, Soo-Hong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.12 no.4
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    • pp.285-290
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    • 2007
  • When input parameters like gas volume or load of the fuel cell system is changed, the fuel cell system can generate transient voltage disturbances. In this paper, a fuel cell system with Z-source inverter and ultracapacitors for voltage disturbance compensation is proposed. The structure of Z-source inverter is simple. It has unique features that can boost/buck input voltage with a DC/DC converter using only a modified switching pattern. The characteristics of the proposed topologies for the fuel cell system with Z-source inverter and ultracapacitors are analyzed using simulation, and verified by experiments. The simulation and experimental results show that the proposed system is capable of operating with stable response to the system transient and voltage disturbances.

A Study on the Effects of Strengths Perspective Group Art Therapy on Stress, Depression, and Impulsivity of Middle School Male Smoking (강점 관점 집단미술치료가 흡연 남자 중학생의 스트레스, 우울 및 충동성에 미치는 영향)

  • Kim, Jeong-hui;Kim, Min-kyeong
    • Journal of the Korea Convergence Society
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    • v.11 no.1
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    • pp.337-347
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    • 2020
  • The purpose of this study was to investigate the effects of strengths perspective group art therapy on the strength-related perspectives on the stress, depression and impulsivity of male middle school students who smoke. Data were collected from 15 middle school smokers from two middle schools in A city. Among them, 8 experimental groups and 7 other control groups were willing to participate in art therapy. The collected data were analyzed by nonparametric test considering the number of groups was 15. The Mann-Whitney U test and Wilcoxon signed ranks test were performed. As a result, the strength-focused group art therapy program showed stress (z = -2.521, p <.05), depression (z = -2.527, p <.05), impulse (z = -2.371, p < .05). Therefore, it can be found that strengths perspective group art therapy has a positive effect on the psychological well-being of smoking middle school students, and furthermore, it is necessary to study the deep emotional state of smoking middle school students.

Seasonal Variation and Statistical Analysis of Particulate Pollutants in Urban Air (도시대기립자상물질중 오염성분의 계절적 변동 및 통계적 해석)

  • 이승일
    • Journal of environmental and Sanitary engineering
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    • v.9 no.2
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    • pp.8-23
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    • 1994
  • During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

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Development and Evaluation of an Evidence-based Nursing Protocol for Postoperative Nausea and Vomiting (근거기반의 수술 후 오심·구토 관리 프로토콜의 개발 및 임상적 평가)

  • Oh, In Ohg;Yoo, Jae Yong;Oh, Eui Geum
    • Journal of Korean Biological Nursing Science
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    • v.19 no.2
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    • pp.86-97
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    • 2017
  • Purpose: Postoperative nausea and vomiting (PONV) is very common among postoperative orthopedic surgical patients with patient-controlled analgesia (PCA), especially for narcotics. Therefore, the purpose of this study was to investigate the effects of an evidence-based PONV management protocol on nursing and patient outcomes. Methods: A methodological study was conducted to develop PONV protocol and a quasi-experimental study to evaluate the effectiveness of protocol. The preliminary PONV protocol was drawn by conducting a systematic review and by reviewing clinical guidelines and best practice recommendations. Validation of the content was done by expert clinicians, and the clinical applicability was evaluated by staff nurses and patients. The effect was evaluated in clinical outcomes associated with PONV and nursing outcomes. Results: In the experimental group, the occurrence of vomiting (z= 2.147) was significantly decreased, the maintenance PCA (${\chi}^2=4.212$) and the satisfaction of patients (z= 5.007) were significantly higher. In the outcomes of nurses, the PONV knowledge of nursing care (z = 3.791), awareness (z = 2.982) and self-efficacy (z= 2.745) were higher in the experimental group. The attitude towards evidence-based nursing practice (z= 2.446) was significantly positive. Conclusion: The results show that an evidence-based approach to the implementation of PONV care is effective in improving patient clinical outcomes and quality of care.

COHOMOLOGY GROUPS OF CIRCULAR UNITS

  • Kim, Jae-Moon;Oh, Seung-Ik
    • Journal of the Korean Mathematical Society
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    • v.38 no.3
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    • pp.623-631
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    • 2001
  • Let $\kappa$ be a real abelian field of conductor f and $\kappa$(sub)$\infty$ = ∪(sub)n$\geq$0$\kappa$(sub)n be its Z(sub)p-extension for an odd prime p such that płf$\phi$(f). he aim of this paper is ot compute the cohomology groups of circular units. For m>n$\geq$0, let G(sub)m,n be the Galois group Gal($\kappa$(sub)m/$\kappa$(sub)n) and C(sub)m be the group of circular units of $\kappa$(sub)m. Let l be the number of prime ideals of $\kappa$ above p. Then, for mm>n$\geq$0, we have (1) C(sub)m(sup)G(sub)m,n = C(sub)n, (2) H(sup)i(G(sub)m,n, C(sub)m) = (Z/p(sup)m-n Z)(sup)l-1 if i is even, (3) H(sup)i(G(sub)m,n, C(sub)m) = (Z/P(sup)m-n Z)(sup l) if i is odd (※Equations, See Full-text).

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