• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2014년도 춘계학술발표대회
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• pp.301-304
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• 2014

비정형 게임 Big Data에서 고효율 정보를 추출하고, 신뢰 할 수 있는 클러스터 게임서버 환경을 위한 병렬 처리를 위해 MapReduce를 사용한다. 본 논문에서는 빈번하게 입력되는 신규 게임데이터 처리를 위해 함수 Demap을 사용하는 Incremental MapReduce를 적용하여 불필요한 중간 값 저장과 재계산 없이 점차적으로 MapReduce 함수를 실행한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.31-34
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• 2007

In this study, optimum processing condition of AZ31 Mg alloy was investigated utilizing processing map and constitutive equation considering microstructure evolution (dynamic recrystallization) during hot-working. A series of mechanical tests were conducted at various temperatures and strain rates to construct a processing map and to formulate the recrystallization kinetics and grain size relation. Dynamic recrystallization (DRX) was observed to occur revealing maximum intensity at a domain of $250^{\circ}C$ and 1/s. The effect of DRX kinetics on microstructure evolution was implemented in a commercial FEM code followed by remapping of the state variables. The volume fraction and grain size of deformed part were predicted using a modified FEM code and compared with those of actual hot forged one. A good agreement was observed between the experimental results and predicted ones.

• 문화기술의 융합
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• 제8권2호
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• pp.361-366
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• 2022

대용량 데이터를 처리 하는 방식은 여러 가지가 있다. 처리 방법에 따라서 대용량 데이터 리스트를 만드는데 처리속도가 많은 차이를 두고 있다. 대표적으로 대용량 데이터 리스트를 만들기 위해서 대용량 데이터를 정규화 된 쿼리로 만들고 만들어 낸 쿼리의 결과를 List Map 담아두고 출력 가능한 형태로 변환 한다. 이러한 과정은 단계별로 처리 속도가 저하되는 원인으로 발생된다. 만들어 낸 쿼리의 결과를 List Map으로 담는 과정에서 데이터의 형태별로 저장되는 형식 다르기 때문에 처리속도의 차이가 나타난다. GO언의 동시성 처리를 통해서 기존에 처리속도의 차이가 발생되던 문제를 해결하고자 한다. 즉 GO언의 동시성 처리 결과가 기존의 List Map에 담는 형식과 동시성을 사용하여 처리하는 방식의 대용량 데이터 리스트 처리 방식이 얼마나 차이가 나고 어떠한 방식으로 진행되는지를 제공하여 보다 빠른 처리를 할 수 있도록 비교 한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.199-202
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• 2004

In this present study, an attempt was made to determine the deformation mode of the Zr-Ti-Cu-Ni-Be bulk metallic glass by compression test over a wide range of temperatures and strain rates. From the results, empirical deformation map could be constructed including the boundaries of different deformation modes. Considering power dissipation map and instability map developed on the basis of the Dynamic Materials Model (DMM), the processing map for extrusion could also be constructed. In addition, the macroscopic formability of this BMG alloy has also been examined through the extrusion in laboratory scale within undercooled liquid state. From the results of macroscopic extrusion formability, both deformation map and processing map present good criteria to determine optimal forming conditions.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.87-91
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• 2022

Bokeh effect is a stylistic technique that can produce blurring the background of photos. This paper implements to produce a bokeh effect with a single image by post processing. Generating depth map is a key process of bokeh effect, and depth map is an image that contains information relating to the distance of the surfaces of scene objects from a viewpoint. First, this work presents algorithms to determine the depth map from a single input image. Then, we obtain a sparse defocus map with gradient ratio from input image and blurred image. Defocus map is obtained by propagating threshold values from edges using matting Laplacian. Finally, we obtain the blurred image on foreground and background segmentation with bokeh effect achieved. With the experimental results, an efficient image processing method with bokeh effect applied using a single image is presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.418-421
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• 2003

Specimens of Ti-10Ta-10Nb have been hot upset forged after heating to either the $\alpha$+$\beta$ and $\beta$-phase field. The variety temperatures (At 650, 700, 750, 800, 85$0^{\circ}C$) and strain rates (At 0.001, 0.01. 0.1, 1, 10 $s^{-1}$ ) were used. On the basis of flow stress data obtained as a function of temperature and strain rate in compression, a processing map for hot working has been developed. At strain rates lower than about 0.1 $s^{-1}$ and almost temperatures, processing efficiency exhibited high, but at 0.001 $s^{-l}$, and temperature 80$0^{\circ}C$, low because the Shear band has occurred. On the basis of the processing map, the optimum processing routes available for hot working of this material are outlined.d.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.573-579
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• 2011

To meet the scalability and performance requirements of data analyses, which often involve voluminous data, efficient parallel or concurrent algorithms and frameworks are essential. We present a high-performance Korean morphological analyzer which employs the MapReduce framework on the graphics processing unit (GPU). MapReduce is a programming framework introduced by Google to aid the development of web search applications on a large number of central processing units (CPUs). GPUs are designed as a special-purpose co-processor. Their programming interfaces are typically formulated for graphics applications. Compared to CPUs, GPUs have greater computation power and memory bandwidth; however, GPUs are more difficult to program because of the design of their architectures. The performance of the Korean morphological analyzer using the MapReduce framework on the GPU is evaluated in comparison with the CPU-based model. The proposed Korean Morphological analyzer shows promising scalable performance on distributed computing with the GPU.

• 소성∙가공
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• 제15권4호
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• pp.333-339
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• 2006

Hot deformation behavior of a carbon steel (A350 LF2) was characterized by compression tests in the temperature range of $800-1250^{\circ}C$ and the strain rate range of $0.001-10s^{-1}$, The microstructural evolution during hot compression was investigated and deformation mechanisms were analyzed by constructing a deformation processing map. Processing maps were generated using the combination of dynamic material model (DMM) and flow instability theories based on the flow stability criteria and Ziegler's instability criterion. In order to evaluate the reliability of the map, the mirostructural characteristics of the hot compressed specimens were correlated with test conditions in the stable and unstable regime. The combined microstructural and processing map of A350 LF2 was applied to predict an optimum condition and unstable regions for hot forming.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2003년도 추계학술발표논문집 (중)
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• pp.899-902
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• 2003

무선 환경에서의 실시간 서비스의 확대와 노드의 이동성 증가에 따라 handover 시 발생되는 패킷 손실과 지연으로 인한 실시간 서비스의 중단이 해결해야 할 중요한 문제점이 되고 있다. 본 논문에서는 IETF (Internet Engineering Task Force)의 중요한 마이크로 이동성 프로토콜인 HMIPv6의 기본 동작을 설명하고, 여전히 문제점으로 남아있는 Inter-MAP (Mobility Anchor Point) handover의 성능을 향상시키기 위한 Dynamic MAP Switching handover 알고리듬을 제안한다. 제안한 알고리듬은 인접한 MAP 도메인을 중첩되게 설정하고 Inter-MAP handover가 발생되기 전에 미리 MAP을 switching한다. 따라서 Inter-MAP handover가 발생하지 않도록 함으로써 handover 시 발생하는 데이터의 손실 및 지연을 감소시킬 수 있다. 제안된 알고리듬의 성능 향상은 산술적 분석을 통하여 검증한다.

• Metals and materials international
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• 제24권6호
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• pp.1249-1255
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• 2018

High temperature compression tests for newly developed Al-Zn-Mg alloy were carried out to investigate its hot deformation behavior and obtain deformation processing maps. In the compression tests, cylindrical specimens were deformed at high temperatures ($300-500^{\circ}C$) and strain rates of 0.001-1/s. Using the true stress-true strain curves obtained from the compression tests, processing maps were constructed by evaluating the power dissipation efficiency map and flow instability map. The processing map can be divided into three areas according to the microstructures of the deformed specimens: instability area with flow localization, instability area with mixed grains, and stable area with homogeneous grains resulting from continuous dynamic recrystallization (CDRX). The results suggest that the optimal processing conditions for the Al-Zn-Mg alloy are $450^{\circ}C$ and a strain rate of 0.001/s, having a stable area with homogeneous grains resulting from CDRX.