• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.770-779
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• 1992

Five (alkynylethoxymethylene)$Fe(CO)_4 complexes (1) are prepared through the reaction of Fe(CO)_5$ with alkynyllithium (R = n-Pr, cyclohexyl, t-Bu, trimethylsilyl, Ph) and subsequent O-ethylation of the resulting acyl anion complexes with ethyl fluorosulfonate. In the reactions of trimethylsilyl-substituted alkynylcarbene complex (1d) with 8 open-chain 1,3-dienes, ({\eta}^3-vinylcarbene)Fe(CO)3 complexes (2) are obtained as major products.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.27-29
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• 2010

유비쿼터스 환경에서 대표적인 장치들 가운데 하나로서 이동장치를 고려할 수 있다. 요즈음 전반적인 이동장치의 흐름은 스마트폰에 주목하고 있으며, 이를 이용한 증강현실 등 객체들에 대한 지리적인 위치 및 현실적용 사례가 증가하고 있으며, 이들에 대한 데이터 처리가 매우 중요해지고 있다. 이와 같이 사용자에게 제공하는 모바일 응용 서비스들은 이동 객체에 기반한 다양한 서비스에 대한 기술이 요구되어지며, 또한 이들 기술을 활용하여 데이터를 시각적으로 인덱싱하여 신속하게 데이터가 처리되는 것을 시각적으로 표현하는 기술도 요구되어지고 있다. 그러나 이와 같이 사용자의 작업 이해를 높이기 위한 시각화 작업이 부족한 것이 사실이다. 이러한 문제를 해결하기 위해 본 논문에서는 하위 트리를 갖는 R 트리 인덱스를 활용하여 객체 생성을 수행하며, 생성된 객체들을 기반으로 3차원 도형으로 표현한 구현 결과를 보인다. 또한, 생성되는 시점에서 객체에 붙여진 이름은 마우스를 이용한 위치점과 인접하였을 때 이름을 표시할 수 있도록 시각화한 결과에 대해 살펴본다.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.321-328
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• 2022

The current development tend of the gun propellants that they should have low sensitivity and high energy. We studied a nitrocellulose based propellant composition that replaced sensitive NG with RDX and DEGDN which high energy and low sensitivity. The important factors in the design of the gun propellant were impetus and flame temperature. NC-based propellant containing RDX showed similar impetus but low flame temperature compared to KM30A1, a triple-based propellant. The developed propellant composition didn't show any abnormal combustion reaction and the characteristics of ballistic resistance were also confirmed.

• Journal of Korea Spatial Information System Society
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• v.10 no.1
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• pp.15-28
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• 2008

In ubiquitous sensor networks(USN) environment, it is essential to process region query for user-demand services. Using R-tree is a preferred technique to process region query for in-network query environment. In USN environment, USN middleware must select sensors that transfers region query with accuracy because the lifetime of sensors is that of whole sensor networks. When R-tree is used, however, it blindly passes the region query including non-existent sensors where MBR(Minimum Boundary Rectangle) of R-tree is Intersected by region of query. To solve in this problem, we propose a reconstruction of region query method which is a trie-structured Quad tree in the base station that includes sensors in region of query select with accuracy. We observed that the proposed method delays response time than R-tree, but is useful for reducing communication cost and energy consumption.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.11-17
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• 2010

Mobile device, one of typical devices in ubiquitous environment, is received attention owing to portability. In these days, technical researches on a kind of the device are focusing on applications of smart phone. For example, the techniques using geographical position and applied instances such as augmented reality techniques are gradually increasing. That makes data processing important. Mobile application services for users also require various application techniques based on moving objects. In addition, they require the techniques that processed data are needed to be shown in visualization. However, this is reality that it lacks of showing visualization works to improve the understanding of thing what it is. To reduce or solve the problems, in this paper we show the results to implement the R tree based 3 dimension index architecture in visualization. Further, we implemented and present creating objects, showing in 3D for the objects, catching spatial position on a node map through mini map function and improving the understanding of R tree by visualizing.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.809-822
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• 2004

In this paper, we propose a concurrency control algorithm based on R-tree for spatial database management system. The previous proposed algorithms can't prevent problem that search operation is to be blocking during update operations. In case of multidimensional indexes like R-tree, locking of update operations may be locked to several nodes, and splitting of nodes have to lock a splitting node for a long time. Therefore search operations have to waiting a long time until update operations unlock. In this paper we propose new algorithms for lock-free search operation. First, we develop a new technique using a linked-list technique on the node. The linked-list enable lock-free search when search operations search a node. Next, we propose a new technique using a version technique. The version technique enable lock-free search on the node that update operations is to be splitting.

• YAKHAK HOEJI
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• v.40 no.3
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• pp.293-299
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• 1996

The $^1H$- and $^{13}C$-NMR signals of (20R)-panaxadiol and (20R)-panaxatriol were completely assigned by the extensive application of modern 2D-NMR techniques, $^1H-^1H$ COSY, HMQC and HMBC.

• Journal of the Mineralogical Society of Korea
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• v.13 no.3
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• pp.164-170
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• 2000

Neutron single crystal and powder diffraction techniques have been applied to the structure analysis of yttria-stabilized zirconium, Z $r_{0.73}$ $Y_{0.27}$ $O_{1.87}$., prepared by the skull-melting method. The crystal structure has been determined to be cubic symmetry, space group Fm/equation omitted/ with a=5.155(2)$\AA$, V=136.99(5)$\AA$, Z=4, and R(F)=5.65%, $\omega$R(I)=10.57% for 70 integrated intensities of Bragg Peaks observed from single crystal of Z $r_{0.73}$ $Y_{0.27}$ $O_{1.87}$. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of $\Delta$/a~0.033 and 0.11 along <110> and <100> directions from the ideal positions of the fluorite structure, respectively. There are no significant differences in crystallographic data between the single crystal and powder studies. Diffraction pattern after Rietveld refinement, using neutron powder data, has shown the evidence of a tetragonal impurity phase, or a slight tetragonal distortion.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.2
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• pp.54-68
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• 2002

In this paper, We propose a multi-dimensional index structure, called a VA (vector approximate) -tree that constructs a tree with vector approximates of multi-dimensional feature vectors. To save storage space for index structures, the VA-tree employs vector approximation concepts of VA-file that presents feature vectors with much smaller number of bits than original value. Since the VA-tree is a tree structure, it does not suffer from performance degradation owing to the increase of data. Also, even though the VA-tree is MBR Minimum Bounding Region) based tree structure like a R-tree, its split algorithm never allows overlap between MBRs. We show through various experiments that our proposed VA-tree is the efficient index structure for large amount of multi-dimensional data.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.27-36
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• 2019

Soybean (Glycine max), as one of the foods with high plant proteins, contains a large amount of bioactive compounds and known to be effective in cardiovascular disease and obesity as well as in improving skin condition. The purpose of this study was to investigate the anti-photoaging effects of soybean fermented with Lactobacillus Rhamnosus ($Bio-Peptone^{(R)}$) by assessment of cytotoxicity against UVB, collagen synthesis after UVB-irradiation, tyrosinase activity, and melanin synthesis. Results showed that $Bio-Peptone^{(R)}$ protected skin fibroblasts against UVB-induced cytotoxicity and increased type I collagen synthesis. Furthermore, $Bio-Peptone^{(R)}$ significantly inhibited tyrosinase activity and reduced melanin contents. This study suggests that $Bio-Peptone^{(R)}$ has protective effects against UVB-induced skin damage. Thus, it is concluded that $Bio-Peptone^{(R)}$ is able to prevent skin damage against UVB and thus acts as anti-photoaging materials by protecting skin forming wrinkles and skin pigments.