• International Journal of Contents
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• 제3권2호
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• pp.6-17
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• 2007

Emerging modem database applications require multi-dimensional index structures to provide high performance for data retrieval. In order for a multi-dimensional index structure to be integrated into a commercial database system, efficient techniques that provide transactional access to data through this index structure are necessary. The techniques must support all degrees of isolation offered by the database system. Especially degree 3 isolation, called "no phantom read," protects search ranges from concurrent insertions and the rollbacks of deletions. In this paper, we propose a new phantom protection method for multi-dimensional index structures that uses a multi-level grid technique. The proposed mechanism is independent of the type of the multi-dimensional index structure, i.e., it can be applied to all types of index structures such as tree-based, file-based, and hash-based index structures. In addition, it has a low development cost and achieves high concurrency with a low lock overhead. It is shown through various experiments that the proposed method outperforms existing phantom protection methods for multi-dimensional index structures.

• 대한수학회보
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• 제44권1호
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• pp.109-116
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• 2007

We study an (n+1)($(n{\geq}3)$-dimensional contact CR-submanifold of (n-1) contact CR-dimension in a (2m+1)-unit sphere $S^{2m+1}$, and to determine such sub manifolds under conditions concerning the second fundamental form and the induced almost contact structure.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.894-898
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• 2011

The first example of lead compound from $Pb(NO_3)_2$ and $H_3L$ N-heterocyclic ligand $(H_3L\;=\;(HO_2C)_2(C_3N_2)(C_3H_7)CH_2(C_6H_4)(C_6H_3)CO_2H)$, $[Pb_4(L')_4]{\cdot}5H_2O$ 1 (L' = OOC$(C_3H_7)(C_3N_2)CH_2(C_6H_4)(C_6H_3)COO)$, has been obtained under hydrothermal condition by decarboxylation, and characterized by elemental analysis, IR, TGDTA, and single-crystal X-ray diffraction. Compound 1 possesses a rare two-dimensional upper-lower offset terrace-like layer structure. In 1, crystallographic distinct Pb(II) ion adopts five-coordination geometry, and two lattice water molecules occupy the voids between 2-D layers. Results of solid state fluorescence measurement indicate that the emission band 458 nm may be assigned to $\pi^*-n$ and $\pi^*-\pi$ electronic transitions within the aromatic systems of the ligand L', however, the emission bands centred at 555 nm, 600 nm and 719 nm may be derived from phosphorescent emission ($\lambda_{excitation}$ = 390 nm).

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.537-542
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• 2014

The three-dimensional (3-D) NAND flash structure with fully charge storage using edge fringing field effect is presented, and its programming characteristic is evaluated. We successfully confirmed that this structure using fringing field effect provides good program characteristics showing sufficient threshold voltage ($V_T$) margin by technology computer-aided design (TCAD) simulation. From the simulation results, we expect that program speed characteristics of proposed structure have competitive compared to other 3D NAND flash structure. Moreover, it is estimated that this structural feature using edge fringing field effect gives better design scalability compared to the conventional 3D NAND flash structures by scaling of the hole size for the vertical channel. As a result, the proposed structure is one of the candidates of Terabit 3D vertical NAND flash cell with lower bit cost and design scalability.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.93-96
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• 1996

We developed three dimensional Monte carlo ion implantation simulator which simulate distributions of impurities under the ion implantation on the tilted multi-layered layer. Our simulation reveals three dimensional shadow effect and sidewall scattering effect due to the geometrical shapes. For the evaluation of the developed three dimensional Monte carlo ion implantation simulator, calculations with 100,000 ions have been performed for the island and hole structures with a thin oxide of 100$\AA$ and nitride of 2000$\AA$. The simulation results showed that the distribution of ion decreases near the conner of the hole structure covered with a nitride layer and increases near the conner for the island structure open to oxide. Moreover, three dimensional distributions of ions were obtained with varying incident energy, tilt and rotation angle, mask depth and three-dimensional structure geometry.

• Applied Microscopy
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• 제39권2호
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• pp.185-189
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• 2009

초파리 망막 세포의 미세구조연구는 1960년대부터 수행되어 왔으나, 이 연구들은 2차원 구조연구에 국한되어 있었다. 본 논문은 초고압 동결법, 연속절편법, 초고압 전자현미경, 그리고 3차원 구조 구현법을 이용하여 초파리 성체의 망막 세포에 존재하는 미토콘드리아, 미세소관, 그리고 핵의 3차원 분포를 연구한 결과이다. 이를 통하여 미토콘드리아는 주로 세포막 가까이에 위치하며, 그 수는 렌즈와 가까운 말단부분에 많은 것을 알 수 있었고, 미세소관은 렌즈와 가까운 망막 말단부분과 시신경과 연결되는 기부에 특히 많은 수가 존재하는 것을 알 수 있었다. 이들은 망막 변성의 원인이 되는 세포 소기관이므로, 이들의 세포 내 3차원 분포는 병의 원인을 연구하는 데 있어 중요한 자료가 될 것으로 사료된다.

• 한국기계연구소 소보
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• 통권20호
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• pp.13-20
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• 1990

An algorithm is presented for 3-dimensional contour lines with a hidden line removal ~technique developed by T.L. Janssen(l). Contour line algorithm on any 3-dimensional plane cutting solid body is also shown. NUFIG(2) algorithm is adopted for searching contour lines. Test problems show well-established contour lines on the surface and also on the cutting plane of the structure.

• 한국산학기술학회논문지
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• 제9권5호
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• pp.1107-1112
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• 2008

건축 구조물의 진동특성은 시험으로 알아내기가 어렵기 때문에 지진이나 다른 가진에 대한 영향을 미리 평가하기가 매우 어려웠다. 그러나 근래에 들어 해석 기술이 발전함에 따라 건축물에 대한 성능을 예측해 볼 수 있게 되었다. 건축 구조물의 진동특성 예측은 지금까지는 2차원 평면 해석이 주를 이루었고, 3차원 해석은 이루어지지 않고 있었다. 2차원 해석은 건축물이 비대칭일 때 해석의 신뢰성을 떨어뜨리는 문제를 안고 있다. 본 논문에서는 주거건축물을 3차원으로 모델링하였으며, 지하철 통과시 주거 건축물의 진동 해석을 수행하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.161-162
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• 1997

It is very useful to perform the surgery simulation before implanting TAH(Total Artificial Heart} in a patient. The space of chest and the shape of vessels are different from patient to patient. So, It is desirable to customize a TAH design to the anatomy structure of a patient. Several studies are performed to visualize and explain the 3D structure of heart. These studies are performed using 2-dimensional ref or mated images and simple measurement. Anatomy structure of a human heart is not so simple. It is 4dimensional structure ; 3-dimensional plus time, heart beating. 3-dimensional reconstruction schemes of medical images developed for about 10 years are usually categorized into two types of rendering technique ; surface rendering and volume rendering. Volume rendering is preferable in medical image processing field because this technique can be applied without considering the complexity of geometry and change of field of interest. The usable space in the chest of patient can be measured by 3D volume matching of patient trunk and TAH model. This space changes with time. In this research we have developed the 4-dimensional volume match program of patient and TAH model. 3-dimensional rendered set of volumes along time were used to simulate TAH fitting trial. The quantitative measurement from this simulation could be applied to customize TAH design.

• 한국해양환경ㆍ에너지학회지
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• 제7권4호
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• pp.199-206
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• 2004

연안 해역에서의 대규모 외해 구조물의 건설은 구조물 배후의 해안선으로부터 외빈에 이르는 광범위한 영역에서 심각한 해빈변형을 야기학 수 있다. 신 등[2000]과 신과 홍[2004]은 일련의 3차원 이동상 실험을 통하여 외해 구조물 배후의 표사이동 양상을 밝혔으며, 본 연구는 이들 실험 결과를 토대로 복합 3차원 해빈변형모델을 제안한 것이다. 제안된 모델은 3차원 이동상 실험 결과와의 비교를 통해 검정하였으며, 그 결과 외해 구조물 배후에 대한 해안선 측의 톰보로 재현은 물론 외빈대에서의 침식ㆍ퇴적역에 있어서도 좋은 일치를 나타내었다. 또한 대규모 인공섬 건설에 의한 해빈변형문제가 실제 야기되었던 현지 해안에 제안된 모델을 적용하여 그 타당성을 확인하였다.