http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
공간 데이터베이스 시스템을 위한 새로운 형식의 효과적인 공간 색인 구조
권용원(YongWon Kwon),김명선(MyeongSun Kim),정창성(ChangSung Jeong) 한국정보과학회 1999 한국정보과학회 학술발표논문집 Vol.26 No.1B
지리정보처리, CAD/CAM, VLSI 설계 등, 시공간 데이터의 처리를 목적으로 하는 응용 분야에서뿐만 아니라 여러 형태의 지식 기반 시스템에서 대량의 다차원 속성 데이터에 대한 빠른 검색 및 조작을 위하여 효과적인 색인 방법의 지원이 필수적이다. 본 논문에서는 PAM 방식의 새로운 다차원 색인 구조인 하나 트리(Hana Tree)를 제안한다. 하나 트리는 균형 트리 구조(height-balanced tree)로서, 분할 공간간에 제한된 형태의 중첩이 허용되며, 데이터의 입력 및 검색과정에서 단일한 접근 경로를 보장한다. 그리고, 분할 공간의 모양이 다차원 직각면체를 유지하지 않으며, 일반적으로 분할 공간의 합이 전체 데이터 영역과 일치하지도 않는다. 하나 트리의 데이터 공간은 다차원의 하나 코드값으로 표현되며, 하나 함수를 통해서 입력 데이터를 데이터 공간상의 하나 코드값으로의 변환 및 역변환을 한다. 구현을 통해서, 하나 트리는 전체적으로 효과적인 수행성능을 얻을 수 있었다. 이는 하나 코드의 사용을 통한 트리 노드의 Fan-Out 증가와 트리 노드의 엔트리간에 공간 중첩 허용을 통한 디스크 사용 효율의 향상 때문이며, 디스크 사용 효율뿐만 아니라 데이터 입력 및 검색 효율 등을 포함하는 전체적으로 수행 성능이 향상된 실험 결과를 얻을 수 있었다.
Kwon, Minchul,Youn, Yeobum,Seo, Yongwon,Lee, Jong-Won,Lee, Jaehyoung,Lee, Joo Yong,Kim, Se-Joon,Lee, Huen American Chemical Society 2013 Energy & fuels Vol.27 No.9
<P>Investigations on the intrinsic properties of gas hydrates with multiple guests are essential to scientific and technological fields. In particular, even though evaluating and designing a hydrate phase process require isothermal phase equilibria, it is difficult to obtain extensive data with various components and compositions in a short period of time due to the static-analytic method. The present study introduces a new experimental determination on hydrate phase equilibria using continuous dissociation induced by extremely slow vapor volume expansion at a constant temperature. When a syringe pump is automatically operated at the microliter level during the dissociation process, the endothermic dissociation can be traced from the temperature readings. The validity and stability of the proposed technique were evaluated using pure CH<SUB>4</SUB> hydrates, and repeated measurements of three-phase (L<SUB>W</SUB>–H–V) equilibrium conditions are used to optimize the volumetric expansion rates. Then, an experimental approach is applied to incipient CH<SUB>4</SUB> + C<SUB>2</SUB>H<SUB>6</SUB> hydrates and identifies the structural transition behavior. This method is thought to provide extensive data and further improvements in terms of hydrate phase equilibria with multiple gas components.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ef401072s'>ACS Electronic Supporting Info</A></P>
Park, Woo-Young,Kwon, Yongwon,Lee, Changhee,Whang, Ki-Woong Optical Society of America 2014 Optics express Vol.22 No.suppl7
<P>An effective method for enhancing the light outcoupling efficiency from top-emitting organic light-emitting diodes (TEOLEDs) with a nano-sized stochastic texture surface (NSTS) is suggested. The broadly distributed pitch and the randomly sized of islands in the NSTS enable the photons that are otherwise trapped to be emitted over the broad emission wavelength range. The NSTS-embedded TEOLEDs have wide angular-dependent emission characteristics and an enhanced external quantum efficiency (EQE). Theoretical and full-wave optical calculations were performed to understand the mechanisms of the efficiency enhancement. Optimized TEOLEDs achieved a 32% EQE enhancement compared with the reference devices without the NSTS.</P>
Lee, Jaegi,Lee, Yongwon,Lee, Jeongmin,Lee, Sang-Min,Choi, Jeong-Hee,Kim, Hyungsub,Kwon, Mi-Sook,Kang, Kisuk,Lee, Kyu Tae,Choi, Nam-Soon American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.4
<P>We present an ultraconcentrated electrolyte composed of 5 M sodium bis(fluorosulfonyl)imide in 1,2-dimethoxyethane for Na metal anodes coupled with high-voltage cathodes. Using this electrolyte, a very high Coulombic efficiency of 99.3% at the 120th cycle for Na plating/stripping is obtained in Na/stainless steel (SS) cells with highly reduced corrosivity toward Na metal and high oxidation durability (over 4.9 V versus Na/Na+) without corrosion of the aluminum cathode current collector. Importantly, the use of this ultraconcentrated electrolyte results in substantially improved rate capability in Na/SS cells and excellent cycling performance in Na/Na symmetric cells without the increase of polarization. Moreover, this ultraconcentrated electrolyte exhibits good compatibility with high-voltage Na4Fe3(PO4)(2)(P2O7) and Na-0.7(Fe0.5Mn0.5)O-2 cathodes charged to high voltages (>4.2 V versus Na/Na+), resulting in outstanding cycling stability (high reversible capacity of 109 mAh g(-1) over 300 cycles for the Na/Na4Fe3(PO4)(2)(P2O7) cell) compared with the conventional dilute electrolyte, 1 M NaPF6 in ethylene carbonate/propylene carbonate (5/5, v/v).</P>
Effects of fabric combinations on the quality of glass fiber reinforced polymer hull structures
오대균,장재원,Jee Jae-hoon,Kwon Yongwon,Im Sanghyuk,HANZHIQIANG 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1
Conventionally, Chopped Strand Mat (CSM) and Woven Roving Mat (WRM) fabrics are combined to manufacture Glass Fiber Reinforced Polymer (GFRP) laminate structures for small vessels, such as fishing boats and yachts, according to established practical experience and traditional methods rather than the application of elaborate design rules. Combinations of the aforementioned fabrics positively contribute to improve the strength of hull structures. In this study, effects of fabric combination types on the quality of GFRP structures such as hull plates are quantitatively verified through experiments and statistical analysis. The results confirm the following: (1) hull plates fabricated by combining CSM and WRM exhibit enhanced strength in the normal glass fiber weight fraction (Gc) regions with an E-glass fiber content of 30e50%, and (2) the effect of reducing the amount of decrease in the strength is observed in high-Gc regions with an E-glass fiber content of 50% or higher. Furthermore, a combination of these fabrics demonstrated a significant effect in improving the quality of the composite laminates owing to a reduction in void defects in the hull plates.