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Radio-loud AGN in the AKARI-NEP field

  • Karouzos, M.;Im, M.;Takagi, T.;Matsuhara, H.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.46.1-46.1
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    • 2012
  • A unique ensemble of datasets is available for the AKARI North Ecliptic Pole (NEP) field, having being observed virtually across the whole electromagnetic spectrum. We have undertaken a study of radio sources in the NEP field and in particular radio-loud AGN. We present preliminary results concerning the identification of these radio-loud AGN using a host of different selection criteria. We aim to study the host galaxies of these systems within the current framework of galaxy evolution and the role that AGN play in it.

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A FUNCTION-FIELD ANALOGUE OF THE GOLDBACH COUNTING FUNCTION AND THE ASSOCIATED DIRICHLET SERIES

  • Shigeki Egami;Kohji Matsumoto
    • Bulletin of the Korean Mathematical Society
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    • v.61 no.1
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    • pp.135-145
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    • 2024
  • We consider a function-field analogue of Dirichlet series associated with the Goldbach counting function, and prove that it can, or cannot, be continued meromorphically to the whole plane. When it cannot, we further prove the existence of the natural boundary of it.

Improved Breast Irradiation Techniques Using Multistatic Fields or Three Dimensional Universal Compensators (Multistatic Field또는 3차원 공용보상체를 사용한 유방의 방사선 조사법의 평가)

  • Han Youngyih;Cho Jae Ho;Park Hee Chul;Chu Sung Sil;Suh Chang-Ok
    • Radiation Oncology Journal
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    • v.20 no.1
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    • pp.24-33
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    • 2002
  • Purpose : In order to improve dose homogeneity and to reduce acute toxicity in tangential whole breast radiotherapy, we evaluated two treatment techniques using multiple static fields or universal compensators. Materials and Methods : 1) Multistatic field technique : Using a three dimensional radiation treatment planning system, Adac Pinnacle 4.0, we accomplished a conventional wedged tangential plan. Examining the isodose distributions, a third field which blocked overdose regions was designed and an opposing field was created by using an automatic function of RTPS. Weighting of the beams was tuned until an ideal dose distribution was obtained. Another pair of beams were added when the dose homogeneity was not satisfactory. 2) Universal compensator technique : The breast shapes and sizes were obtained from the CT images of 20 patients who received whole breast radiation therapy at our institution. The data obtained were averaged and a pair of universal physical compensators were designed for the averaged data. DII (Dose Inhomogeneity Index : percentage volume of PTV outside $95\~105\%$ of the prescribed dose) $D_{max}$ (the maximum point dose in the PTV) and isodose distributions for each technique were compared. Results : The multistatic field technique was found to be superior to the conventional technique, reducing the mean value of DII by $14.6\%$ (p value<0.000) and the $D_{max}$ by $4.7\%$ (p value<0.000). The universal compensator was not significantly superior to the conventional technique since it decreased $D_{max}$ by $0.3\%$ (p value=0.867) and reduced DII by $3.7\%$ (p value=0.260). However, it decreased the value of DII by maximum $18\%$ when patients' breast shapes fitted in with the compensator geometry. Conclusion : The multistatic field technique is effective for improving dose homogeneity for whole breast radiation therapy and is applicable to all patients, whereas the use of universal compensators is effective only in patients whose breast shapes fit inwith the universal compensator geometry, and thus has limited applicability.

On Problematizing IS Research: A Critical Reading of the KMIS SOLOMO Research Agenda

  • Juhn, Sung H.
    • Asia pacific journal of information systems
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    • v.22 no.4
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    • pp.31-49
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    • 2012
  • In this essay, we problematize the problematics of the KMIS SOLOMO research agenda. We propose that the SOLOMO agenda is a conditioned product of the various assumptions, biases, premises, and presuppositions that the field of IS collectively succumbs to and shares, and thus needs to be problematized to arrive at a new set of research questions for the field. The problematization begins with the ontology that underlies the agenda. We argue that the agenda is largely drawn from a dichotomic, deep ontology of Human vs. Technology. While such ontology is neither right nor wrong in its own right, we suggest it is what underlies and influences the field's whole mode of inquiry including its research agenda. We propose an alternative ontology, the Actor-Network Theory (ANT), which as a flat ontology provides a radically different set of research questions for the field. Next we take issue with the teleology of the SOLOMO agenda, and suggest that the telos of the agenda, and of the field of IS and the whole of Management discipline together, are anchored upon the capitalist episteme so that it creates a significant hole in its teleological scape. While not in any sense calling for an ideological demagogue, we propose that the field of IS should open itself to an alternative teleology including a leftist perspective. We draw upon the Critical Management Studies (CMS) to explore how further problematization can be made on the SOLOMO agenda, generating questions about its performativity, denaturalization, and reflexivity. As a result of the discussions, a list of new problematized research questions for the SOLOMO agenda is generated. In the end we state the motivation of the essay and call for a critical refurbishing of the field of IS.

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Optical Design of an Off-Axial-Field Two-Mirror System with a Displaced Stop and a Secondary Mirror (조리개와 제 2거울이 횡이동된 비축시야 2반사 광학계 설계)

  • Nam, Ji-Woo;Lee, Jong-Ung
    • Korean Journal of Optics and Photonics
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    • v.31 no.6
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    • pp.304-313
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    • 2020
  • By using an off-axial field with an inverse Cassegrain system where the aperture stop is at the secondary mirror, the two-mirror system can be used for a wide-field objective. However, aberration corrections in conventional two-mirror systems are limited because the design parameters are too small. In this study, we present a new improved design of the off-axial-field two-mirror system. The new design has an independently displaced aperture stop and a secondary mirror. The new design parameters yield more improvement in correction for 5th-order coma and astigmatism, and better aberration balancing for the whole off-axial field. The spot sizes of the new design system are reduced to half of those for a conventional reference design, and the improvement effects are shown for the whole field evenly.

Measurement of three dimensional shapes using phase-shifting shadow moire method (위상 이동 그림자 무아레 방법을 이용한 3차원 형상의 측정)

  • 강영준
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.4
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    • pp.39-45
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    • 1997
  • Shadow moire topography has been used as a noncontact method for measuring the 3-D shapes of objects. The moire fringes are results from the superposition of a master grating and its shadow projected on the surface of an object. But in case of the classical shadow moire method, in general, the resolution is a few tenths of millimeter. It is difficult to use a phase -shifting method in shadow moire because it is impossible to obtain uniform phase shifts on the whole field. But in this study , We introduce a phase-shifting method to improve the resolution of the classical shadow moire method. This method is based on the fact that if the depth of object is much less than the distance between the observer and the master grating, the phase shifts are almost uniform on the whole field area. Finally, we applied this new phase-shifting method to the measurement of the 3-D shape of a coin.

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High-temperature superconductors for NMR/MRI magnets:opportunities and challenges

  • Iwasa, Yukikazu;Bascunan, Juan;Hahn, Seungyong;Yao, Weijun
    • Superconductivity and Cryogenics
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    • v.11 no.2
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    • pp.23-29
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    • 2009
  • The unique features of HTS offer opportunities and challenges to a number of applications. In this paper we focus on NMR and MRI magnets, illustrating them with the NMR/MRI magnets that we are currently and will shortly be engaged: a 1.3 GHz NMR magnet, an "annulus" magnet, and an $MgB_2$whole-body MRI magnet. The opportunities with HTS include: 1) high fields (e.g., 1.3 GHz magnet); 2) compactness (annulus magnet); and 3) enhanced stability despite liquid-helium-free operation ($MgB_2$whole-body MRI magnet). The challenges include: 1) a large screening current field detrimental to spatial field homogeneity (e.g., 1.3 GHz magnet); 2) uniformity of critical current density (annulus magnet); and 3) superconducting joints ($MgB_2$magnet).

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Separation of Isochromatics and Isoclinics from Photoelastic Fringes in a Circular Disk by Phase Measuring Technique

  • Baek, Tae-Hyun;Kim, Myung-Soo;Yoshihau Morimoto;Motoharu Fujigaki
    • Journal of Mechanical Science and Technology
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    • v.16 no.2
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    • pp.175-181
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    • 2002
  • A new polariscope system involving two rotating optical elements and a digital camera for whole field fringe analysis allows automated data to be acquired quickly and efficiently. The developed phase measuring technique that uses eight images through a circular polariscope is presented for the digital measurement of isochromatics and isoclinics, respectively, from photoelastic fringes in a circular disk under diametric compression. Isochromatics can directly be obtained using wrapped isoclinic phases calculated by the arc tangent operator which is the four-quadrant operator from -$\pi$ to $\pi$. It is not required to unwrap isoclinic phases for the calculations of isochromatics. Unwrapped isoclinics are directly determined from isochromatic parameters. Distributions of digitally determined isoclinics are in close agreement to manual measurements. The errors which would appear in unwrapping process of isoclinics can be avoided in the determination of isochromatics.

Studies on the Production of Burley Tobacco in Paddy-field. I. Optimum Fertilization and Harvesting Method. (버어리종 논담배 재배에 관한 연구 I. 시비량 및 수확방법에 대하여)

  • 김상범;김용규;추홍구
    • Journal of the Korean Society of Tobacco Science
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    • v.5 no.1
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    • pp.25-33
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    • 1983
  • This study was carried out to investigate the transplanting time, optimum fertilization and harvesting method, chemical contents and physical properties of burley tobacco in paddy field. The results obtained as follows. 1. It is recommendable to transplant after March. 29 to escape the frost injury. By reducing compound fertilizer and whole plant stalk curing, advanced the. last priming date by 5-8 days. 2. Total alkaloid, total nitrogen and phosphorus contents of cured leaf was comparable to those of upland-produce(1 tobacco, but potassium and chloride contents some what high. 3. Filling power and combustibility was also comparable to upland, and filling power was increased by reducing fertilizer and whole plant stalk curing. 4. In the 20o reducing fertilizer-5 Primings volt. the yield was some what decreased, but visual quality and value per 10a were high. 5. The total raw income of tobacco and rice cropping was increased 124~170% than that of rice cropping.

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A Study on the Factors of Korean Companies’ Telecommunication Service Selection Strategy (우리나라 기업의 전략적 통신서비스 선택요인에 관한 연구)

  • Ahn, Jaek-Young;Lee, Deok-Joo
    • IE interfaces
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    • v.16 no.spc
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    • pp.70-75
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    • 2003
  • There have been dramatic technology changes in telecommunication sector during last two decades. New application services like the introduction of international mobile services, fiber optical home services and satellite personal services are expected to play a major role in the whole field of telecommunication services. In the users' viewpoint, the proper selection and the efficient application of the specific telecommunication service among the various alternatives at hand are recognized as principle means for ensuring the whole business competitiveness. Despite the definite need for the telecommunication service selection strategies, very few researches have been reported in this field. In this paper, attempts are made to identify the companies' decision factors considered in selecting the telecommunication services, to draw the strategic dimensions and categorize each company with respect to the identified dimensions, and to finally find the characteristics of each strategic group in selecting the telecommunication service.