• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.704-705
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• 2009

• 디지털콘텐츠학회 논문지
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• 제17권2호
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• pp.71-79
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• 2016

본 논문에서는 차량 내부 환경에서 음성인식 성능을 향상시켜 안정적인 차량 제어를 위한 방법으로 사용하는 음원 위치추정방법의 성능 비교와 개선 방법을 제안하였다. 일반적으로 음원 위치추정에는 TDOA알고리즘을 사용하는데 여기에는 시간영역에서 상호상관함수를 이용하는 방법과, 주파수 영역에서 계산하는 GCC-PHAT 방법이 있다. 이중 GCC-PHAT 방법은 상호상관함수보다 반향과 잡음에 강한 특성을 보인다고 알려져 있다. 본 연구에서는 반향과 잡음이 많은 차량 환경에서 위 두 방법의 성능을 비교하고 추가로 미디언 필터 사용을 제안하여 음원위치 추정 성능과 시스템의 안정성을 나타내는 지표로 사용하는 분산값이 모두 향상됨을 확인하였다. 실험결과에서 음성을 사용한 실험에서는 두 방법의 성능 차이가 거의 없지만, 노래신호를 사용한 음원위치 추정에서는 GCC-PHAT 방법이 상호상관함수에 비해 인식률이 10% 우수함을 확인하였다. 또한 미디언 필터를 추가한 경우에는 상호상관함수 방법의 인식률을 최고 11%까지 향상시킬 수 있었고 분산값에서도 두 방법 모두 안정적인 성능을 보여주었다.

• IEIE Transactions on Smart Processing and Computing
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• 제3권2호
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• pp.96-102
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• 2014

The embedded processor market has grown rapidly and consistently with the appearance of mobile devices. In an embedded system, the power consumption and execution time are important factors affecting the performance. The system performance is determined by both hardware and software. Although the hardware architecture is high-end, the software runs slowly due to the low quality of codes. This study compared the performance of two major compilers, LLVM and GCC on a32-bit EISC embedded processor. The dynamic instructions and static code sizes were evaluated from these compilers with the EEMBC benchmarks.LLVM generally performed better in the ALU intensive benchmarks, whereas GCC produced a better register allocation and jump optimization. The dynamic instruction count and static code of GCCwere on average 8% and 7% lower than those of LLVM, respectively.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.569-572
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• 2008

본 논문에서는 Qt 임베디드를 이용한 무선 주문 시스템을 구성함으로서 실용성 있는 제품 제작에 활용될 수 있는 기법을 제안하고, 실제 구현하여 다양한 응용에 활용할 수 있음을 알 수 있다. 본 논문에서는 무선 네트워크상에서 Qt에서 제공되는 QSocket 클래스의 TCP/IP 프로토콜을 이용하여 데이터 입력, 전달, 수집, 재전송 등을 구현하였다. 서버 환경은 PC 상에서 Linux 9.0, gcc-2.95.3을 사용하였으며, PXA255 프로세서를 사용하는 3 대의 타겟 보드를 모두 액세스 포인터를 기반으로 하는 무선 네트워크로 구현하였다. 타겟 보드의 소프트웨어 툴은 gcc, tmake, qt-X11, qt-embedded를 사용하여 구성하였으며, 그래픽 인터페이스를 이용한 터치스크린 방식으로 설계함으로서 사용의 편리성을 추구하였다.

• The Journal of Asian Finance, Economics and Business
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• 제8권2호
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• pp.89-97
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• 2021

This research aims to investigate the impact of falling oil prices at the beginning of 2020 on 82 industrial companies listed on the GCC stock markets. The research sample period is divided into two periods pre-COVID and during COVID covering the period starting 1st January 2020 to May 15, 2020. The research uses the Panel Least Square (PLS) method and Panel Generalized Method of Moments (GMM) with fixed and random effects in each country. The results of GMM models reveal a positive relationship between oil prices and the share prices of industrial companies in the Gulf countries, which confirms that the share prices of industrial companies in the Gulf Cooperation Council (GCC) countries have been negatively affected by the decline in oil prices with the beginning of 2020. The findings show that the highest impact of falling oil prices has been recorded in the industrial companies in the kingdom of Saudi Arabia. However, the falling of oil prices does not have a significant effect on industrial companies in the state of Qatar. The research results suggest that GCC economies have to move on the path of non-reliance on Oil and gas-driven economy.

• BMB Reports
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• 제43권8호
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• pp.567-572
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• 2010

In this study, we cloned the ERF-B3 subfamily transcription factor gene BnaERF-B3-hy15 from Brassica napus L. Huyou15. This 600 bp gene encodes a 199 amino acid classic ethylene responsive factor (ERF), which shown no binding or very weak binding GCC box-binding activity by the yeast one-hybrid assay. We used gene shuffling and the yeast one-hybrid system to obtain three mutated sequences that can bind to the GCC box. Sequence analysis indicated that two residues, Gly156 in the AP2 domain and Phe62 at the N-terminal domain were mutated to arginine and serine, respectively. Changes of Gly156 to arginine and Phe62 to serine increased the GCC-binding activity of BnaERF-B3-hy15 and the alter of Gly156 to arginine changed the AP2-domain structure of BnaERF-B3-hy15.

• 펄프종이기술
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• 제42권5호
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• pp.74-82
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• 2010

Curtain stability without curtain contraction is critical for a successful operation in curtain coating, and this can be influenced by the change in particle dynamics and rheological properties of coating colors. In this study, polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) were added to control the rheology of GCC based curtain coating colors. Surface tension was increased slightly with increasing content of cobinder. Shear-thinning of viscosity was more pronounced for the CMC containing GCC coating colors. Complex modulus decreased when small amount of PVA was used as a cobinder, but it increased in other coating colors. Extensional viscosity was increased with increasing of the cobinder content, but CMC was more effective. Results indicate that pigment interaction with PVA is different from that with CMC. Dispersibility of coating colors was improved due to steric stabilization when small amounts of PVA was used, but flocculation occurred by bridging when the amount of PVA was increased. Dispersibility of coating colors was improved when small amount of CMC was added, while flocculation was observed by depletion effect when the concentration of CMC was increased in coating colors. Addition of cobinders at proper levels gave positive effects both in rheological properties and curtain stability. On the other hand, excessive amount of cobinders caused particle flocculation and this resulted in rheological and curtain stablity problems.

• 펄프종이기술
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• 제46권2호
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• pp.16-21
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• 2014

Characteristics of coating color penetration into paper were elucidated using various types of pulps and pigments. A commercial paper, KP and TMP handsheets were used for base paper. Clay and GCC were used as coating pigment. Laboratory rod draw down coater was used for coating application. Coating color penetration was evaluated by measuring the roughness of surface and back side of a coating layer. The results of coating roughness showed that clay was much better than GCC as a coating pigment. In case of pulp type, KP base paper was more effective than TMP base paper to reduce coating penetration.

• 펄프종이기술
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• 제47권4호
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• pp.30-37
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• 2015

Needs for high ash loading in printing paper increase as green house gas (GHG) emission regulation becomes more stricter and pressure of lowering paper production cost increases. To meet the needs, a new type of filler was developed. The mixture of ground calcium carbonate (GCC) and calcium oxide was pre-floccuated with polyelectrolyte and further treated with carbon dioxide to form new calcium carbonate between GCCs. The final products were called as hybrid calcium carbonate (HCC), and its properties were compared to the GCC and the pre-flocculated GCC. Results showed increase in tensile, smoothness, opacity, and bulk for HCC.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.73-78
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• 2002

This study examines self-compacting of concrete using Ground Calcium Carbonate(GCC) gathering in limestone mine of Banyans district in order to make self-compacting concrete in the range of design strength 300kgf/cm$^2$ and the optimal mix proportion of self-compacting concrete that can use in field structure. The result shows that the optimal GCC replacement ratio is 45$\pm$5% in the normal strength of design strength 300kgf/cm$^2$ and that the volume ratio of the optimal fine aggregate used as the way satisfying both viscosity and compacting ability without separating materials is 46%. The optimal volume ratio of the coarse aggregate considering the economical aspect of concrete is 50%. It is desirable that the optimal mix proportion satisfying self-compacting for replacement of GCC is decided through mix design according to each replacement ratio.