• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.35-40
• /
• 2001

동적 전압 조정(DVS)은 모바일 환경에서 프로세서에서의 전력 소모를 줄일 수 있는 가장 효율적인 방법으로 많은 연구가 진행중이다 또한 MPEG 디코딩은 모바일 기기에서 가장 중요하고 또한 전력 소모가 큰 어플리케이션 중 하나이다. 본 논문에서는 모바일 환경에 적합한 MPEG 디코더를 DVS를 이용하여 구현하였고 전력 소모를 측정하였다. 제안된 첫번째 DVS 알고리즘은 이전의 workload에 의해 다음 workload를 예측하여 전압을 조정하는 것이고, 두번째 알고리즘은 MPEG 프레임의 종류 및 크기를 이용하여 다음 프레임의 디코딩 시간을 예측 한 후 전압을 조절하는 것이다. 실험을 통하여 두번째 알고리즘에 의한 MPEG 디코더가 더 정확한 workload 예측을 통하여 QoS의 저하를 최소화하면서 전력 소모를 더 많이 줄일 수 있었다.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.31-34
• /
• 2003

본 논문에서는 3GPP2 에 명시된 전송파형 필터의 특성을 살펴보고, 기존 시스템에서 고려되지 않았던 전송파형 정합필터의 간섭특성에 의한 성능손실을 분석하고 실험을 통해 검증한다. 또한, FCC 의 요구사항을 만족하며 수신필터의 간섭을 크게 줄인 MMSE 수신필터를 제안하며, 실험과 분석을 통해 제안된 필터에 의해 SNR 손실이 크게 줄어드는 결과를 보인다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.106-108
• /
• 2004

본 논문은 기존 전력 소비 감소만을 고려한 DVS와 달리 배터리 특성에 기반하여 DVS를 수행하는 기법을 제시한다. 배터리는 잔량에 따라 다른 전력 소비형태를 갖고 있으므로 잔량에 따라서 적합한 DVS 정책을 수행해야 효율적이다. 본 논문에서는 실험을 통해서 배터리의 특성을 파악하고, 그 특성에 따라 배터리 구간을 설정한 후 그에 적합한 DVS 알고리즘을 적용하는 기법을 제시한다. 이를 통해 효율적인 DVS 정책을 수립 할 수 있음을 IPAQ 5550 PDA에서 리눅스 운영 체제에서의 실험을 통해 보여준다.

• Ceramist
• /
• v.3 no.4
• /
• pp.24-31
• /
• 2000

• TTA Journal
• /
• s.82
• /
• pp.80-90
• /
• 2002

• Radiation Oncology Journal
• /
• v.31 no.1
• /
• pp.34-40
• /
• 2013

Purpose: To evaluate the predictive factors of radiation pneumonitis (RP) and associated changes in pulmonary function after definitive concurrent chemoradiotherapy (CCRT) in patients with non-small cell lung cancer (NSCLC). Materials and Methods: Medical records of 60 patients with NSCLC who received definitive CCRT were retrospectively reviewed. Dose volumetric (DV) parameters, clinical factors, and pulmonary function test (PFT) data were analyzed. RP was graded according to the CTCAE ver. 4.0. Percentage of lung volume that received a dose of threshold (Vdose) and mean lung dose (MLD) were analyzed for potential DV predictors. PFT changes were calculated as the difference between pre-RT and post-RT values at 3, 6, and 12 months after RT. Results: Twenty-two patients (37%) developed grade ${\geq}2$ RP. Among clinical factors, tumor location in lower lobe was associated with RP. Among the DV parameters, only MLD >15 Gy was associated with grade ${\geq}2$ RP. There were statistically significant decreases in PFT at all points compared with pre-RT values in grade ${\geq}2$ RP group. MLD was associated with forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) changes at 6 and 12 months. V10 was associated with FVC changes at 12 months. V20 and V30 were associated with FEV1 changes at 6 months and FVC changes at 12 months. Conclusion: After definitive CCRT in patients with NSCLC, MLD >15 Gy and lower lobe tumor location were predictors of grade ${\geq}2$ RP. Pulmonary functions were decreased after CCRT and the magnitude of changes was associated with DV parameters.

• Geotechnical Engineering
• /
• v.13 no.4
• /
• pp.177-198
• /
• 1997

Since decomposed granite soil shows various characteristics of shear behavior dependent on initial conditions such as weathering degree and grain breakage, it is nacessary to invert ligate stress -strain relationship and changes of shear characteristics for different initial conditions. Associated with abovefnentioned view, direct shear tests, and triaxial compression tutsts(Ef, CD) were carried out in this study for undisturbed and disturbed compacted weathered granite samples obtained from 4 construction work sites with the various weathering degree and components of parent rocks. The deformation behavior of undisturbed samples under small confining stress shows hardening to softening, which is similar to that of over nsolidated clay whereas disturbed weathered granite soils do hardeningfonstant regardless of weathering degree, which is also similar to sedimentary clay. Conventional direct shear-tests for undisturbed samples show a tendency to overestimate cohesion. It is possidle to approximate stress ratio(q/p') and volumetric increment ratio(dv/ds) in the triaxital compression tests by an equation, ($dv/d\varepsilon,=\alpha(M-\eta))$ irrespective of moisture content, weathering degree and disturbance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.10
• /
• pp.2080-2089
• /
• 2015

In 3D video compression, a disparity vector (DV) pointing a corresponding block position in an adjacent view is a key coding tool to exploit statistical correlation in multi-view videos. In this paper, neighboring block-based disparity vector (NBDV) is shown with detail algorithm descriptions and coding performance analysis. The proposed method derives a DV from disparity motion vector information, obtained from spatially and temporally neighboring blocks, and provides a significant coding gain about 20% BD-rate saving in a texture-video-first-coding scheme. The proposed DV derivation method is adopted into the recent 3D video coding standards such as 3D-AVC and 3D-HEVC as the state-of-the-art DV derivation method.

• Korean Journal of Materials Research
• /
• v.17 no.5
• /
• pp.250-255
• /
• 2007

The alloying effects on the electronic structures of Zinc are investigated using the relativistic $DV-X{\alpha}molecular$ orbital method in order to obtain useful information for alloy design. A new parameter which is the d obital energy level(Md) and the bonder order(Bo) of alloying elements in Zinc was introduced and used for prediction of the mechanical properties. The Md correlated with the atomic radius and the electronegativity of elements. The Bo is a measure of the strength of the covalent bond between M and X atoms. First-principles calculations of electronic structures were performed with a series of models composed of a MZn18 cluster and the electronic states were calculated by the discrete variational- $X{\alpha}method$ by using the program code SCAT. The central Zinc atom(M) in the cluster was replaced by various alloying elements. In this study energy level structures of pure Zinc and alloyed Zinc were calculated. From calculated results of energy level structures in MZn18 cluster, We found Md and Bo values for various elements of Zn. In this work, Md and Bo values correlated to the tensile strength for the Zn. These results will give some guide to design of zinc based alloys for high temperature applications and it is possible the excellent alloys design.

• Proceedings of the Korea Contents Association Conference
• /
• 2008.05a
• /
• pp.147-151
• /
• 2008

Since the first HDV(High Definition Video) camcoder, HDR-FX1 with 1080i resolution, had been launched at 2004, the image capture and record with HD resolution have been possible by the various types of camcoder and recorder which can support the HDV format. At a present day, a non-linear editing system, which is composed of only one computer, can capture, edit and export the image with HDV format. The HDV format has the same class of resolution with HD and the same data transfer bit rate of DV(Digital Video). Additionally, the image with HDV format can be recorded in 6mm DV cassette tape. It is possible because the HDV format uses the concept of Long GOP(Gorup of pictures) method for its compression. In this paper, the characteristic feature of HDV format, the essential factors in editing with HDV format and the concept of Long GOP method for its compression have been studied for the way of effective HDV editing.