• Journal of electromagnetic engineering and science
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• 제2권1호
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• pp.11-15
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• 2002

In this paper, we have proposed the new configuration of wideband antenna using CPW fred lines. The proposed antenna has CPW feed lines and U-slot to achieve wade bandwidth with good impedance matching. The use of CPW feed line can decrease the number of substrates. It is compared with the conventional antenna find by a microstrip fled line. The parameters of CPW fred lines were studied by using the quasi-static approximation which is based on the conformal mapping method. The analysis of CPW discontinuities such as the tapered-step structure and the open ended gap were studied by using the quasi-static approximation which is based on the boundary element method. Also, the equivalent circuit model of multi-layer antenna were proposed using the cavity model. Experiment results of the proposed antenna 7how wide-bandwidth characteristics and good radiation patterns in passband.

• 천문학회보
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• 제42권2호
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• pp.43.3-43.3
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• 2017

NGC 6822 is a dwarf irregular galaxy in the Local Group and it is located in 500 kpc, further than the Large Magellanic Cloud and the Small Magellanic Cloud. Therefore, we can study star-forming processes by local condition in NGC 6822 instead of tidal force of the Galactic gravitational field. Hubble V is the brightest of several H II complexes in this galaxy. We observed Hubble V by using IGRINS attached on the 2.7 m telescope at the McDonald Observatory in Texas, US in May 2016. We performed a spectral mapping of $15^{{\prime}{\prime}}{\times} 7^{{\prime}{\prime}}$area on H and K bands, and detected emission lines of bright $Br{\gamma}\;{\lambda}2.1661{\mu}m$ and weak He I ${\lambda}2.0587{\mu}m$. Molecular hydrogen lines of 1-0S(1) ${\lambda}2.1218{\mu}m$, 2-1 S(1) ${\lambda}2.2477{\mu}m$, and 1-0 S(0) ${\lambda}2.2227{\mu}m$ was also detected. These emission lines show the structure of an ionized core and excited surface of clouds by far-ultraviolet photons, photodissociation region (PDR). We present three-dimensional maps of emission line distributions through multi slit scanning data and compare these results with the previous study. This presentation shows the physical structure of the star-forming regions and we discuss a PDR model and an evolution of Hubble V complex.

• Journal of Electrical Engineering and information Science
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• 제1권2호
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• pp.96-100
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• 1996

This paper describes a concrete method for computing characteristic impedances and effective dielectric constants of the microstrip coupled lines without and with a dielectric overlay. The frequency-independent spectral domain method is used for the analysis of these lines. This method is a powerful, accurate, and numerically efficient approach for planar transmission line structure. For designing the optimal directional coupler, the velocities of even and odd mode must be equal but velocities of these two modes are different in the conventional coupled line which is inhomogeneous. The results show that these two velocities can be almost same according to variations of structural and material parameters in terms of the overlay(superstrate).

• Journal of electromagnetic engineering and science
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• 제15권1호
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• pp.31-36
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• 2015

The design of a new compact band-pass filter is proposed, which is based on the microstrip composite right- and left-handed transmission- line (CRLH-TL) structure. Particularly, the interdigital coupled (IDC) lines of the CRLH geometry are proposed to be parted by inserting open stubs to meet the specifications on the passband. In addition, there is another pair of stubs to complete the design in a limited space. These are considered in the TL-based analysis and the design parameters are calculated by genetic algorithm optimization. The measurement is shown to be acceptable and agreeable with the circuit and electromagnetic field simulations. In addition, the zerothorder resonance (ZOR) phenomenon is verified.

• 한국전자파학회논문지
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• 제15권6호
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• pp.554-559
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• 2004

본 논문에서 새로운 구조의 2단 대역통과 여파기 구조를 제시하였다. 제시된 구조는 마이크로스트립 헤어핀선로와 그 아래의 접지면에 슬롯선로를 구현한 형태이다. 각 공진기 선로가 유전체의 양면에 위치하여 여파기의 크기를 크게 줄일 수 있고 감쇄극을 통과대역 양쪽에 적절하게 위치시키어 저지대역 특성을 개선시킬 수 있다. 설계 및 제작된 여파기는 중심주파수(1.9 ㎓)에서 69 MHz치 대역폭을 나타내었다. 구현된 여파기는 일반적인 λ/4결합선로 여파기에 비해 33 %정도의 크기를 가지며, 통과대역밖의 양쪽에 감쇄극을 위치시키어 여파기의 차단특성을 개선하였다. 부가적으로 일반적인 결합선로 여파기의 경우 동일사양의 여파기 구현시 입출력 결합선로의 경우 0.1 mm의 간격이 필요하나, 제시된 구조는 0.3 mm로 세 배 더 넓은 간격으로 구현이 가능하여 소형, 협대역 여파기 구현에 적합한 구조이다.

• Archives of Pharmacal Research
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• 제20권4호
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• pp.368-371
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• 1997

In an effort to increase of the antitumor activity of 2(S)-$2^{I}$,$5^{I}$-trihydroxy-7, 8-dimethoxyflavanone isolated from Scutellaria indica, we synthesized its analogues, II, III and IV. They showed potent cytotoxicity in vitro against cancer cell lines, L1210, K562 and A549. On the basis of $ED_50$ values against the cancer cell lines, III exhibited about 2-7 times stronger activity than I against various cell lines. We tested the antitumor activity of the analogues against Sarcoma 180 cells in vivo and evaluated the structure-activity relationship. The antitumor activity appeared to be related to the hydrogen bond between carbonyl group at C-4 and hydroxyl group at C-5, in contrast to cytotoxic action.

• 전자공학회지
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• 제23권12호
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• pp.115-125
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• 1996

This paper presents a new algorithm for the self-localization of a mobile robot using one degree perspective Invariant(Cross Ratio). Most of conventional model-based self-localization methods have some problems that data structure building, map updating and matching processes are very complex. Use of a simple cross ratio can be effective to the above problems. The algorithm is based on two basic assumptions that the ground plane is flat and two locally parallel sloe-lines are available. Also it is assumed that an environmental map is available for matching between the scene and the model. To extract an accurate steering angle for a mobile robot, we take advantage of geometric features such as vanishing points. Feature points for cross ratio are extracted robustly using a vanishing point and intersection points between two locally parallel side-lines and vertical lines. Also the local position estimation problem has been treated when feature points exist less than 4points in the viewed scene. The robustness and feasibility of our algorithms have been demonstrated through real world experiments In Indoor environments using an indoor mobile robot, KASIRI-II(KAist Simple Roving Intelligence).

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.43-43
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• 2018

Mutation breeding by radiation is useful for improving various crop species. Up to now, a total of 170 soybean mutant varieties have been released in the world, which is the second most registered varieties after rice. Despite the economic importance of soybean, there have been no TRAP marker system studies on genetic relationships between/among mutant lines. To develop a strategy of Mutant Diversity Pool (MDP) conservation, a study on the genetic diversity of 210 soybean mutant lines (8 cultivars and 202 mutants) was performed through a TRAP analysis. Sixteen primer combinations amplified a total of 551 fragments. The highest (84.00%) and lowest (32.35%) polymorphism levels were obtained with primers MIR157B + Ga5 and B14G14B + Ga3, respectively. The mean PIC values 0.15 varied among the primer combination ranging from 0.07 in B14G14B + Sal2 to 0.23 in MIR157B + Sa4. Phylogenetic, principal component analysis (PCA) and structure analysis indicated that the 210 lines belong to four groups based on the 16 combination TRAP markers. AMOVA showed 21.0% and 79.0% variations among and within the population, respectively. Overall, the genetic similarity of each cultivar and its mutants were higher than within other mutant populations. Our results suggest that the TRAP marker system may be useful for assessing the genetic diversity among soybean mutants and help to improve our knowledge of soybean mutation breeding.

• 마이크로전자및패키징학회지
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• 제12권1호
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• pp.17-20
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• 2005

In this paper, we presented the quasi-static characteristics of novel microstrip lines with anisotropic grooved dielectric in finite metal. A quasi-static mode-matching method has been used to analyze this new structure and the simulation results are validated through comparison with other available results. The results in this paper show that it is possible to control the propagation characteristics of microstrip lines with the use of anisotropic grooved dielectric in finite metal. Also anisotropic grooved dielectric in microstrip line can be newly added to the design parameters of high performance three dimensional monolithic microwave circuits and other microwave applications.

• 대한전기학회논문지:전력기술부문A
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• 제50권10호
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• pp.464-471
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• 2001

Power utilities must satisfy both supplying high quality power economically and reducing EMF levels. In general, in order to reduce EMF levels from transmission line, it is effective to install shielding wires, configure wires with minimal space or modify structure of other conductors, etc., but these techniques require much cost and time. To some extent, the EMF levels associated with critical transmission lines can be reduced by redistributing the scheduled power generation, since it can change the power flows. There this technique can be readily applied without modifying other structures. This paper considers the OPF(Optimal Power Flow) with the EMF constraints in transmission lines to determine the power generation redistributions and demonstrates numerically the effectiveness of the approach.