• 한국세라믹학회지
• /
• 제51권5호
• /
• pp.430-434
• /
• 2014

$SiC_f$/SiC composites were prepared using the hybrid process of chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP). Before the application of PIP, partially matrix-filled preform composites with different densities were fabricated by control of chemical vapor infiltration time and temperature. The changes of the final density of the $SiC_f$/SiC composites had a tendency similar to that of preform composites partially filled by CVI. Composites with lower density after the CVI process had a larger increment of density during the PIP process. Three types of microstructures were observed on the fractured surface of the composite: 1) well pulled-out fibers and lower density, 2) slightly pulled-out fibers and higher density, and 3) only bulk SiC. The different fractions and distributions of the microstructures could have an effect on the mechanical properties of the composites. In this study, $SiC_f$/SiC composites prepared using a hybrid process of CVI and PIP had density values in the range of $1.05{\sim}1.44g/cm^3$, tensile strength values in the range of 76.4 ~ 130.7 MPa, and fracture toughness values in the range of $11.2{\sim}13.5MPa{\cdot}m^{1/2}$.

• 정보처리학회논문지A
• /
• 제15A권6호
• /
• pp.335-344
• /
• 2008

본 논문에서는 SLC와 MLC를 모두 가진 하이브리드 플래시 메모리를 효율적으로 사용하기 위한 적응적 가비지 컬렉션 기법을 제안한다. 하이브리드 플래시 메모리는 속도가 빠른 SLC 영역과 용량대비가격이 저렴한 MLC 영역으로 이루어져 있기 때문에 SLC 영역을 로그 버퍼로, MLC 영역을 데이터 블록으로 사용하는 것이 효율적이다. 제안하는 가비지 컬렉션 기법은 MLC 영역의 쓰기 속도가 매우 느리다는 점을 고려하여 SLC 로그버퍼에 기록된 데이터 중에서 더 이상 갱신되지 않으며 MLC 영역으로의 이동 비용이 적은 데이터를 MLC 영역의 데이터 블록으로 이동시키고, 자주 갱신될 데이터는 SLC 내부에서 이동시킴으로써 SLC 영역의 빈 공간을 확보한다. 또한 적응적 기법을 사용하여 입출력의 패턴을 관찰하여 가비지 컬렉션의 기준 값을 변화시킨다. 실험 결과, 본 논문에서 제안한 기법은 기존에 소개된 플래시 메모리 관리 기법에 비하여 하이브리드 플래시 메모리의 특징을 효율적으로 사용하여 성능을 향상시켰으며 워크로드에 따라서 최적에 가까운 가비지 컬렉션 기준 값을 찾아내는 것을 확인할 수 있었다.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2009년도 춘계학술대회
• /
• pp.737-740
• /
• 2009

본 논문에서는 기존 RTLS(Real Time Location Service)시스템의 이동개체에 대한 위치추정오차를 개선하기 위하여, 이동개체속도가 증감되는 각각의 구간을 구분하여 속도가 증감된 만큼 전송신호의 주기를 적응적으로 증감시키는 방법을 제안하였다. 보다 정확한 위치추정 값을 얻기 위하여, AercoScout사의 RTLS 시스템을 이용한 Hybrid(TDOA and RSSI) 방식에 의해 각각 측정된 좌표 값과, 계산에 의해 추정된 좌표 값을 최소자승법(Least Square Method)에 대입하여 실제 이동개체의 위치좌표 값과 비교하는 방법을 취하였다. 실제 제안된 방법에 의해 실험을 해본 결과, 이동개체의 실제 위치의 위치추정오차가 개선됨을 알 수가 있었다.

• Advances in Energy Research
• /
• 제7권1호
• /
• pp.35-52
• /
• 2020

The paper proposes a hybrid approach of artificial bee colony (ABC) and grey wolf optimizer (GWO) algorithm for multi-objective and multidimensional engine optimization of a converted plug-in hybrid electric vehicle. The proposed strategy is used to optimize all emissions along with brake specific fuel consumption (FC) for converted parallel operated diesel plug-in hybrid electric vehicle (PHEV). All emissions particulate matter (PM), nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) are considered as optimization parameters with weighted factors. 70 hp engine data of NOx, PM, HC, CO and FC obtained from Oak Ridge National Laboratory is used for the study. The algorithm is initialized with feasible solutions followed by the employee bee phase of artificial bee colony algorithm to provide exploitation. Onlooker and scout bee phase is replaced by GWO algorithm to provide exploration. MATLAB program is used for simulation. Hybrid ABC-GWO algorithm developed is tested extensively for various values of speeds and torque. The optimization performance and its environmental impact are discussed in detail. The optimization results obtained are verified by real data engine maps. It is also compared with modified ABC and GWO algorithm for checking the effectiveness of proposed algorithm. Hybrid ABC-GWO offers combine benefits of ABC and GWO by reducing computational load and complexity with less computation time providing a balance of exploitation and exploration and passes repeatability towards use for real-time optimization.

• Macromolecular Research
• /
• 제14권2호
• /
• pp.146-154
• /
• 2006

Organic and inorganic hybrid nanocomposites based on poly(ethylene 2,6-naphthalate) (PEN) and silica nanoparticles were prepared by a melt blending process. In particular, polymer nanocomposites consisting mostly of cheap conventional polyesters with very small quantities of inorganic nanoparticles are of great interest from an industrial perspective. The crystallization behavior of PEN/silica hybrid nanocomposites depended significantly on silica content and crystallization temperature. The activation energy of crystallization for PEN/silica hybrid nanocomposites was decreased by incorporating a small quantity of silica nanoparticles. Double melting behavior was observed in PEN/silica hybrid nanocomposites, and the equilibrium melting temperature decreased with increasing silica content. The fold surface free energy of PEN/silica hybrid nanocomposites decreased with increasing silica content. The work of chain folding (q) for PEN was estimated as $7.28{\times}10^{-20}J$ per molecular chain fold, while the q values for the PEN/silica 0.9 hybrid nanocomposite was $3.71{\times}10^{-20}J$, implying that the incorporation of silica nanoparticles lowers the work required to fold the polymer chains.

• 복식
• /
• 제64권6호
• /
• pp.131-147
• /
• 2014

Purpose of this study is to analyze the meaning of the hybrid digital culture and to find out the features of digital fashion shows appearing in the period of the hybrid digital culture as there have been almost no studies on the hybrid cultural values in the fashion shows and on the diachronic socio-cultural viewpoint of fashion show. The characteristics of hybrid digital culture were identified through the analysis of cases, and they were organized into three for this study; 'non-economic creativity', 'interactive communication' and 'transcendence'. Based on these characteristics, the features of hybrid digital cultures in the modern digital fashion shows were classified into the digitalization of presentation form and the acceptance by audience of digitalization using case studies. The features of digital fashion shows which appear through the presentation form in the digital fashion shows are as follows; 'Expansion of presentation media of runway' and 'Destruction of component factors of runway'. The features of digital fashion show in the perspective of audience's acceptance of digitalization are as follows; 'Audience's field experience through the live video', 'Participation by audience in interactive manner' and, 'Immersion in the virtual reality by the audiences'.

• 복식문화연구
• /
• 제12권5호
• /
• pp.792-804
• /
• 2004

Sportism is continuously expressed in every season in a different theme and established as a Mega-Trend of the early 21 th century fashion. This study was conducted to research the social and cultural sources of the sportism expressed in the early 21th century fashion. This study focused on hybrid as one of the post-modem phenomena. By analysing social and cultural sources of the sportism, three aspects were found; first, many different fashion trends are coincides in post-modem society, which is possible and accelerated by hybrid each other. Second, the complicated and competitive society urge the people to review the past and the originality. Third, youth-oriented and individualistic lifestyle was brought by the development of the technology and economic surplus. Hybrid of the TPO was analysed which made the sportism mega-trend. 'Formal wear was mixed with casual wear, casual wear with active sportswear, hi-fashion with street fashion, and hi-fashion influenced formal and casual wear again'. The sportism prevalent in 21th century fashion can be explained by this system of hybrid. Results of the analysis in this study can be categorized into four aesthetic values based on hybrid of the styles, which are glamorous sportism, romantic sportism, minimal sportism, and heritage sportism.

• The Journal of Advanced Prosthodontics
• /
• 제15권3호
• /
• pp.114-125
• /
• 2023

PURPOSE. The aim of the study was to evaluate the optical properties of new generation (3Y-TZP) monolithic zirconia (MZ) with different abutment types and resin cement shades. MATERIALS AND METHODS. A1/LT MZ specimens were prepared (10 × 12 × 1 mm, N = 30) and divided into 3 groups according to cement shades as transparent (Tr), yellow (Y) and opaque (O). Abutment specimens were obtained from 4 different materials including zirconia (Group Z), hybrid (Group H), titanium (Group T) and anodized yellow titanium (Group AT). MZ and abutment specimens were then cemented. L^*, a^*, and b^* parameters were obtained from MZ, MZ + abutment, and MZ + abutment + cement. ∆E₀₀₁^* (between MZ and MZ + abutment), ∆E₀₀₂^* (between MZ and MZ + abutment + cement) and ∆E₀₀₃^* (between MZ + abutment and MZ + abutment + cement) values were calculated. Statistical analyses included 2-way ANOVA, Bonferroni, and Paired Sample t-Tests (P < .05). RESULTS. Abutment types and resin cements had significant effect on L^*, a^*, b^*, ∆E₀₀₁^*, ∆E₀₀₂^*, and ∆E₀₀₃^* values (P < .001). Without cementation, whereas zirconia abutment resulted in the least discoloration (∆E₀₀₁^* = 0.68), titanium abutment caused the most discoloration (∆E₀₀₁^* = 4.99). The least ∆E₀₀₂^* = 0.68 value was seen using zirconia abutment after cementation with yellow shaded cement. Opaque shaded cement caused the most color change (∆E₀₀₃^* = 5.24). Cement application increased the L^* values in all groups. CONCLUSION. The least color change with/without cement was observed in crown configurations created with zirconia abutments. Zirconia and hybrid abutments produced significantly lower ∆E₀₀₂^* and ∆E₀₀₃^* values in combination with yellow shaded cement. The usage of opaque shaded cement in titanium/anodized titanium groups may enable the clinically unacceptable ∆E₀₀^* value to reach the acceptable level.

• 전기학회논문지
• /
• 제59권5호
• /
• pp.990-995
• /
• 2010

Harris corner detector is commonly used to detect feature points for recognizing 2-D or 3-D objects. However, the feature points calculated from both of query and target objects need to be same positions to guarantee accurate recognitions. In order to check the positions of calculated feature points, we generate a Huffman tree which is based on adjacent feature values as inputs. However, the structures of two Huffman trees will be same as long as both of a query and targets have same feature values no matter how different their positions are. In this paper, we sort feature values and calculate the Euclidean distances of coordinates between two adjacent feature values. The Huffman Tree is generated with these Euclidean distances. As a result, the information of point locations can be included in the generated Huffman tree. This is the main strategy for accurate recognitions. We call this system as the HRM(Hybrid Retrieval Machine). This system works very well even when artificial random noises are added to original data. HRM can be used to recognize biological data such as proteins, and it will curtail the costs which are required to biological experiments.

• Journal of Information Science Theory and Practice
• /
• 제7권2호
• /
• pp.23-31
• /
• 2019

We report results of selection-bias-free approaches to the analysis of the impact of open access (OA) models on citation metrics. We studied reference groups of Gold and Green OA articles and the group of non-OA (Paywall) articles with the new functionality of the Web of Science Core Collection database, the InCites platform of Clarivate Analytics, and the Dimensions database of Digital Science. For each reference group we obtained the values of the percent of cited articles and citation impact and their dependence on the depth of the citation period. Different research fields were analyzed in two schemas of the InCites platform. We report the higher values and growth rates of the citation metrics: citation impact and %Cited, in the OA reference groups over the Paywall group. The Green OA articles demonstrate the highest values of citation metrics among all the OA models. Dependence of the value of citation impact on citation period follows linear law with R2 values close to 0.9-1.0. The overall annual growth rates of citation impact of the Green OA, Gold OA, and the Paywall articles, k equal, respectively, 3.6, 2.4, and 1.4 in Dimensions and 4.6, 3.6, and 2.3 in the Web of Science Core Collection. We suppose that earlier results reported for the articles in pure OA journals vs. articles in Paywall journals were affected by the high citation impact of the Green and Hybrid OA articles that could not be elucidated in the Paywall journals at that time.