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A NEW CHANNEL TO SEARCH FOR EXTRA-SOLAR SYSTEMS WITH MULTIPLE PLANETS VIA GRAVITATIONAL MICROLENSING

  • HAN CHEONGHO;PARK MYEONG-GU
    • Journal of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.35-40
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    • 2002
  • Gaudi, Naber & Sackett pointed out that if an event is caused by a lens system containing more than two planets, all planets will affect the central region of the magnification pattern, and thus the existence of the multiple planets can be inferred by detecting additionally deformed anomalies from intensive monitoring of high magnification microlensing events. Unfortunately, this method has important limitations in identifying the existence of multiple planets and determining their parameters (the mass ratio and the instantaneous projected separation) due to the degeneracy of the resulting light curve anomalies from those induced by a single planet and the complexity of multiple planet lensing models. In this paper, we propose a new channel to search for multiple planets via microlensing. The method is based on the fact that the lensing light curve anomalies induced by multiple planets are well approximated by the superposition of those of the single planet systems where the individual planet-primary pairs act as independent lens systems. Then, if the source trajectory passes both of the outer deviation regions induced by the individual planets, one can unambiguously identify the existence of the multiple planets. We illustrate that the probability of successively detecting light curve anomalies induced by two Jovian-mass planets located in the lensing zone through this channel will be substantial. Since the individual anomalies can be well described by much simpler single planet lensing models, the proposed method has an important advantage of allowing one to accurately determine the parameters of the individual planets.

Effects of Role-Play Method Related to the Global Warming and Ecosystem on High School Students' Knowledge Achievement as well as the Attitude towards Environment (역할극을 활용한 지구 온난화와 생태계 변화에 관한 수업이 고등학생들의 학업 성취도와 환경적 태도에 미치는 효과)

  • Kim, Dong-Ryeul;Son, Yeon-A;Moon, Doo-Ho
    • Hwankyungkyoyuk
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    • v.21 no.4
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    • pp.12-24
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    • 2008
  • In this research, we have carried out an experiment with grade 10 students. Students will be choosing their roles and creating their own script in relation to the environmental problems such as the seriousness of global wanning and the mutation of ecosystem. Throughout this process, they will come up with a solution to the problem In addition, we will assess students' knowledge achievement as well as the changes in attitudes toward environment, and analyze whether the role-play method of education is efficient or not. According to the research result, we have confirmed that the method of role-play as a education tool was more efficient than the traditional lecturing method. Students experienced higher rate of knowledge acquisition and more optimistic effects on their attitudes toward the mutation of ecosystem and also the seriousness of the global wanning. Students also pointed out in the interview that the role-play allowed them to share their thoughts with other classmates, which were not carried out frequently in the traditional education system In addition, each member of groups could participate cooperatively with teammates, which ultimately helped them to develop scientific and introspective ways of thinking.

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PHYTOPLANKTON BLOOMING AND OCEANIC CONDITIONS IN THE SEAS AROUND THE SPRATLY ISLANDS

  • Dien, Tran Van;Tang, DanLing;Kawamura, Hiroshi
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.529-532
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    • 2006
  • The oceanic currents in the South China Sea (SCS) are strongly influenced by monsoon winds. A review on the SCS currents has indicated that previous studies have pointed out an anticyclonic circulation in the area between the southern Vietnam coast and the Spratly Islands. However, its detail is not understood because of less information of in situ observations. The physical-biological interaction is quite new research area, which has been established and promoted by means of the ocean color remote sensing. Temporal/spatial variability of the phytoplankton activities are well captured by ocean color (OC) -derived Chlorophyll-a images. Combining the OC-Chl-a and the other high-resolution satellite data (e.g., SST images), the biological aspects of oceanographic variation is well described. The blooming phenomena in the area between the southern Vietnam coast and the Spratly islands are further investigated. Change in the wind-system related to the El Nino generates upwelling/SST-cooling in the sea south of the Spratly Islands through the air-sea-land interaction was studied. The seasonal upwelling is also associated with the harmful algal bloom (HAB) off two side of Indochina Peninsula have investigated. The seasonal variation of SCS phytoplankton blooming and related oceanic conditions in Vietnam coast was observed. Ocean color satellite data has effective contribute to study the oceanic condition and phytoplankton blooming in South China Sea.

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The Validity of Developing a Three Generation Family Apartment as a Cultural Housing Model in Korea : The Empirical Basis (실증적 관점에서 본 삼대가족 아파트 개발의 타당성에 관한 연구)

  • 이연숙
    • Journal of the Korean housing association
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    • v.3 no.1
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    • pp.21-33
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    • 1992
  • The purpose of this research was to find empirical evidence to support the varidity of developing a three generation family apartment as a cultural housing model In Korea. This was done through interviews, a questionnaire mailing survey and the delphi method.Major findings were as follows;There was a string preference for the elderly to live together with their married children, whereas their married children preferred to live independently, being separated from their old parents.Housewives of the younger generation recognized many advantages or good points of the three generation living together. They, however pointed out many disadvantages as well. Most of the good points were related to psychological comfortableness steming from living close each other, while most of the bad points to behavioral constraints steming from living together in one residential unit. This suggested that a new type of heusing, which provides privacy for each generation as well as the feeling of closeness between the two generations, needs to be developed to disseminate positive aspects of the three generation family cuture.There is a concensus among professionals that the three generation family apartment is a promising cultural housing model in korea, especially for the elderly in Korea.

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Discrimination of Insulation Defects in a Gas Insulated Switchgear (GIS) by use of a Neural Network Based on a Chaos Analysis of Partial Discharge (CAPD)

  • Jung, Seoung-Yong;Ryu, Cheol-Hwi;Lim, Yun-Sok;Lee, Ja-Ho;Koo, Ja-Yoon
    • Journal of Electrical Engineering and Technology
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    • v.2 no.1
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    • pp.118-122
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    • 2007
  • In this work, experimental investigation is carried out in order to design and fabricate the UHF sensor that is able to detect the partial discharges produced from 10 artificial defects introduced into the real scale 70kV GIS mock-up under high voltage within a well shielded room. As well, in order to verify the on-site applicability of our method, the newly proposed CAPD (chaos analysis of partial discharge) is combined with spectral analysis for identifying the nature of 10 artificial defects under investigation. The PD pattern recognition of each defect has been fulfilled by applying our ANN software. The result indicates that the recognition rate reaches up to 80% by the newly proposed method while the traditional PRPD analysis method allows us to obtain 41%. In consequence, it can be pointed out that the proposed method seems likely to be applicable to the real GIS at the site.

ANALYSIS OF THE NODALISATION INFLUENCE ON SIMULATING ATMOSPHERIC STRATIFICATIONS IN THE EXPERIMENT THAI TH13 WITH THE CONTAINMENT CODE SYSTEM COCOSYS

  • Burkhardt, Joerg;Schwarz, Siegfried;Koch, Marco K.
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1135-1142
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    • 2009
  • The activities related to this paper are to investigate the influence of nodalisation on simulating atmospheric stratification in the THAI experiment TH13 (ISP-47) with the German containment code COCOSYS. This article focuses on different nodalisations of the vessel dome, where an atmospheric stratification occurred due to a high helium content. The volume of the dome was divided into several levels that were varied horizontally into different geometries. These geometries differ in the number of zones as well as in the existence of zones that enable the direct rise of an ascending steam plume into the vessel dome. Additionally, the vertical subdivision of the vessel dome was increased to simulate density gradients in a more detailed way. It was pointed out that the proper simulation of atmospheric stratifications and their dissolution depends on both a suitable horizontal as well as vertical nodalisation scheme. Besides, the treatment of fog droplets has an influence if their settlement is not simulated correctly. This report gives an overview of the gained experience and provides nodalisation requirements to simulate atmospheric stratifications and their proper dissolution.

Two new records of free-living marine nematodes of the family Ironidae de Man, 1876 (Nematoda: Enoplida) from Korea

  • Hyo Jin Lee;Heegab Lee;Hyun Soo Rho
    • Journal of Species Research
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    • v.12 no.1
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    • pp.55-67
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    • 2023
  • Two new records of marine nematodes, belonging to the family Ironidae de Man, 1876, are reported based on the specimens collected from intertidal sediments from the west coast of Korea. Conilia sinensis is characterized by a relatively long body length, a well-developed buccal cavity with three claw-like teeth, the presence of a single spicule with transverse striations, the presence of rib-shaped telamons, and single precloacal supplement. Pheronous donghaiensis is distinguished from other species of the genus by a well-developed buccal cavity with four claw-like solid teeth and minute denticles, relatively short and thick spicules with the central septum, the presence of 8-9 curved tubular-shaped precloacal supplements, and a sharp pointed tail with three small tubular supplements arranged into two rows in males. In this report, we provide a taxonomic description and illustrations of two unrecorded species of the family Ironidae by differential interference contrast microscopy. This is the first taxonomic report on the species of the family Ironidae from Korea.

The Ribostamycin Biosynthetic Gene Cluster in Streptomyces ribosidificus: Comparison with Butirosin Biosynthesis

  • Subba, Bimala;Kharel, Madan Kumar;Lee, Hei Chan;Liou, Kwangkyoung;Kim, Byung-Gee;Sohng, Jae Kyung
    • Molecules and Cells
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    • v.20 no.1
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    • pp.90-96
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    • 2005
  • A cluster of genes for ribostamycin (Rbm) biosynthesis was isolated from Streptomyces ribosidificus ATCC 21294. Sequencing of 31.892 kb of the genomic DNA of S. ribosidificus revealed 26 open reading frames (ORFs) encoding putative Rbm biosynthetic genes as well as resistance and other genes. One of ten putative Rbm biosynthetic genes, rbmA, was expressed in S. lividans TK24, and shown to encode 2-deoxy-scyllo-inosose (DOI) synthase. Acetylation of various aminoglycoside-aminocyclitol (AmAcs) by RbmI confirmed it to be an aminoglycoside 3-N-acetyltransferase. Comparison of the genetic control of ribostamycin and butirosin biosynthesis pointed to a common biosynthetic route for these compounds, despite the considerable differences between them in genetic organization.

FIBREWISE INFINITE SYMMETRIC PRODUCTS AND M-CATEGORY

  • Hans, Scheerer;Manfred, Stelzer
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.4
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    • pp.671-682
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    • 1999
  • Using a base-point free version of the infinite symmetric product we define a fibrewise infinite symmetric product for any fibration $E\;\longrightarrow\;B$. The construction works for any commutative ring R with unit and is denoted by $R_f(E)\;l\ongrightarrow\;B$. For any pointed space B let $G_I(B)\;\longrightarrow\;B$ be the i-th Ganea fibration. Defining $M_R-cat(B):= inf{i\midR_f(G_i(B))\longrihghtarrow\;B$ admits a section} we obtain an approximation to the Lusternik-Schnirelmann category of B which satisfies .g.a product formula. In particular, if B is a 1-connected rational space of finite rational type, then $M_Q$-cat(B) coincides with the well-known (purely algebraically defined) M-category of B which in fact is equal to cat (B) by a result of K.Hess. All the constructions more generally apply to the Ganea category of maps.

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The estimation for Shear Deformation Analysis of Reinforced Concrete members using Reliability Theory. (신뢰성이론을 이용한 철근 콘크리트 부재의 전단변형 해석에 관한 평가)

  • 최광진;장일영;송재호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.559-564
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    • 1998
  • The object of this thesis is an analytical study on shear deformation of reinforced concrete members using monte carlo method. Using the established experimental data that has been presented in various documents the stress-strain relationships curves of reinforced concrete (300kgf/$\textrm{cm}^2$~400kgf/$\textrm{cm}^2$) models are proposed. Finally, the theoretical values calculated using the analytical method developed in this study have been investigated in comparison with the experimental ones which were carried out earlier in order to prove its validity. From the results it has been shown that theoretical values agree quite well with experimental ones, and it could be pointed out that the presented analytical method is widely acceptable for the practical analysis of shear displacement of reinforced concrete members.

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