• 한국통신학회논문지
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• 제12권4호
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• pp.347-356
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• 1987

本 論文에서는 高速 光 디지털 傳送시스템과 같은 高速 unipolar 信號 傳送시스템에 適合한 새로운 mBIZ 傳送路符號를 提案하였다. mBIZ符號는 情報信號系列 傳送速度를 $\frac{(m+1)}{m}$ 만큼 速度變換한 後 m 비트마다 補助 서어비스 비트 하나를 揷入한 信號系列과 出力傳送路符號系列의 한 비트를 遲延시킨 信號系列을 Exclusive NOR하여 符號化하기 때문에 redundancy를 줄일 수 있을 뿐만 아니라 復號回路 역시 간단하게 構成할 수 있다. mBIZ符號는 回符號連積數를 (m+1)비트 이내로 抑壓할 수 있으며 傳送路符號系列의 마크率이 1/2이기 때문에 電力 스펙트럼에 存在하는 高低周波 成分들을 抑壓할 수 있다.

• 한국광물학회지
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• 제11권2호
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• pp.117-125
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• 1998

Crystallization behavior of platinum minerals within Pt-Sb-Bi bearing ore magmas and mineralogical properties of the existing minerals were investigated at 1,00$0^{\circ}C$ by synthetic experiment. High purity reagents were used as starting materials and silica tubings as containers. Reaction products were analysed by reflecting microscopy, X-ray diffraction, electron probe microanalysis, and micro-hardness test. Stable minerals at 1,00$0^{\circ}C$ are platinum, electron probe microanalysis, and micro-hardness test. Stable minerals at $1,000^{\circ}C$ are platinum, stump-flite (PtSb) and geversite (PtSb2). They are in equilibrium with liquid (ore magma). Platinum contains considerable amount of Sb of 7.5 at.%, whereas Bi only up to 0.9 at.%. Pure stumpflite is hexagonal with space group P63/mmc, and unit cell parameters are a=4.1318(6), c=5.483(1)$\AA$. VHN50=417(2)$\AA$. Geversite has cubic structure with space group Pa3. Cell parameters are a=6.4373(2)$\AA$ and Vicker hardness values VHN50=663.5 (566~766). Both stumpflite and geversite show solid solution and their end-members are Pt48.8Sb40.7-Bi10.5, and Pt33.7-Sb59.8Bi6.5, respectively. Although stumpflite (m.p. $1,043^{\circ}C$) and unnamed PtBi (m.p. 7$65^{\circ}C$) do not form a complete solid solution at $1,000^{\circ}C$, they are known, at $600^{\circ}C$, to form a continuous solid solution. Geversit (m.p. $1,226^{\circ}C$) also forms complete solid solution with insizwaite (m.p. $660^{\circ}C$). Unit cell dimensions of the minerals above increases with the amount of Bi substituting for Sb.

• 충청수학회지
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• 제29권2호
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• pp.229-253
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• 2016

As a generalization of (i, j)-weakly m-continuous functions [43], we introduce the notion of weakly M(i, j)-continuous functions and obtain many characterizations and some properties of the functions. We show that the function is a unified form of some functions between m-spaces and certain kinds of weakly continuous functions in bitopological spaces.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.6-8
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• 2007

In this paper, We propose reasoning system for object recognition and space classification using not only visual features but also contextual information. It is necessary to perceive object and classify space in real environments for mobile robot. especially vision based. Several visual features such as texture, SIFT. color are used for object recognition. Because of sensor uncertainty and object occlusion. there are many difficulties in vision-based perception. To show the validities of our reasoning system. experimental results will be illustrated. where object and space are inferred by bi -directional rules even with partial and uncertain information. And the system is combined with top-down and bottom-up approach.

• 호남수학학술지
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• 제39권4호
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• pp.591-601
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• 2017

In this paper, by means of the $S{\breve{a}}l{\breve{a}}gean$ operator, we introduce a new subclass $\mathcal{B}^{m,n}_{\Sigma}({\gamma};{\varphi})$ of analytic and bi-univalent functions in the open unit disk $\mathbb{U}$. For functions belonging to this class, we consider Fekete-$Szeg{\ddot{o}}$ inequalities.

• 천문학회보
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• 제41권1호
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• pp.59.2-59.2
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• 2016

보현산천문대가 준공되면서, 1.8 m 망원경이 연구자들에게 공개된지 20년이 되었다. 당시 보현산 천문대의 연구자들은 1.8 m 망원경을 도약망원경이라 부르면서, 우리나라 천문학의 비약적인 발전의 토대가 되기를 희망하였다. 보현산천문대 10주년 기념 담양 워크샵에서 BOES의 성과를 발표한 이후 10년 동안, 천문연구원 광학천문기술 그룹에서는 BOES 편광분광기와 IGRINS를 개발 완료하였으며, GMTNIRS의 개념설계와 GCLEF의 기본설계가 진행되었다. 여기에서는 그동안 개발된 고분산 천체분광기 프로젝트의 성과를 정리하고, 앞으로의 계획을 논의한다.

• 한국자기학회지
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• 제16권5호
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• pp.245-248
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• 2006

Sol-gel법을 이용하여 단일상을 갖는 $Tb_{3-x}Bi_xFe_5O_{12}$ 분말 시료를 제조하였으며, 그 결정학적 및 자기적 특성을 x-선 회절법(XRD), 진동 시료 자화율 측정법(VSM), $M\"{o}ssbauer$ 분광법으로 연구하였다. XRD 분석 결과 결정구조는 Ia3d의 공간그룹을 갖는 cubic 구조임을 알 수 있었고, Bismuth의 치환량이 x=0.5, 0.75, 1.0 및 1.25로 증가할수록 격자상수가 각각 $a_0=12.466{\AA},\;12.487{\AA},\;12.499{\AA},\;12.518{\AA}$으로 선형적으로 증가함을 확인할 수 있었다. VSM을 이용한 온도에 따른 자기모멘트 측정 결과 Bismuth의 치환량이 증가하면 $N\'{e}el$ 온도는 증가하며 compensation 온도는 감소함을 확인할 수 있었다. 또한 field cooled 조건에서 비정상적인 음의 자화값이 관측되었다. $M\"{o}ssbauer$ 스펙트럼은 4.2 K에서부터 $N\'{e}el$ 온도까지 측정하였으며, 분석 결과 상온에서 모든 시료의 이성질체 이동치의 값은 평균적으로 0.27mm/s로 철의 이온상태가 +3가 임을 확인할 수 있었다.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.49-58
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• 2013

ARGO-M is a satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute with the consideration of mobility and daytime and nighttime satellite observation. The ARGO-M optical system consists of 40 cm receiving telescope, 10 cm transmitting telescope, and detecting optics. For the development of ARGO-M optical system, the structural analysis was performed with regard to the optics and optomechanics design and the optical components. To ensure the optical performance, the quality was tested at the level of parts using the laser interferometer and ultra-high-precision measuring instruments. The assembly and alignment of ARGO-M optical system were conducted at an auto-collimation facility. As the transmission and reception are separated in the ARGO-M optical system, the pointing alignment between the transmitting telescope and receiving telescope is critical for precise target pointing. Thus, the alignment using the ground target and the radiant point observation of transmitting laser beam was carried out, and the lines of sight for the two telescopes were aligned within the required pointing precision. This paper describes the design, structural analysis, manufacture and assembly of parts, and entire process related with the alignment for the ARGO-M optical system.

• Journal of Magnetics
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• 제13권3호
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• pp.110-113
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• 2008

In this study, heavy rare earth garnet $Tb_2Bi_1Ga_1Fe_4O_{12}$ powders were fabricated by a sol-gel and vacuum annealing process. The crystal structure was found to be single-phase garnet with a space group of Ia3d. The lattice constant $a_0$ was determined to be 12.465 ${\AA}$. From the analysis of the vibrating sample magnetometer (VSM) hysteresis loop at room temperature, the saturation magnetization and coercivity of the sample are 7.64 emu/g and 229 Oe, respectively. The N$\acute{e}$el temperature($T_N$) was determined to be 525 K. The M$\ddot{o}$ssbauer spectrum of $Tb_2Bi_1Ga_1Fe_4O_{12}$ at room temperature consists of 2 sets of 6 Lorentzians, which is the pattern of single-phase garnet. From the results of the M$\ddot{o}$ssbauer spectrum at room temperature, the absorption area ratios of Fe ions on 24d and 16a sites are 74.7% and 25.3%(approximately 3:1), respectively. These results show that all of the non-magnetic Ga atoms occupy the 16a site by a vacuum annealing process. Absorption area ratios of Fe ions are dependent not only on a sintering condition but also on the temperature of the sample. It can then be interpreted that the Ga ion distribution is dependent on the temperature of the sample. The M$\ddot{o}$ssbauer measurement was carried out in order to investigate the atomic migration in $Tb_2Bi_1Ga_1Fe_4O_{12}$.

• Journal of Astronomy and Space Sciences
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• 제28권2호
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• pp.155-162
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• 2011

Korea Astronomy and Space Science Institute has been developing one mobile and one stationary satellite laser ranging system for the space geodesy research and precise orbit determination since 2008, which are called as ARGO-M and ARGO-F, respectively. They will be capable of daytime laser ranging as well as nighttime and provide the accurate range measurements with millimeter level precision. Laser ranging accuracy is mostly dependent on the optics and optoelectronic system which consists of event timer, optoelectronic controller and photon detectors in the case of ARGO-M. In this study, the optoelectronic system of ARGO-M is addressed and its critical design is also presented. Additionally, the experiment of the integrated optoelectronic system was performed in the laboratory to validate the functional operation of each component and its results are analyzed to investigate ARGO-M performance in advance.