• Journal of KIISE:Computer Systems and Theory
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• v.32 no.9
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• pp.457-464
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• 2005

In this paper a 3D memory system that allows 17 access types at an arbitrary position is introduced. The proposed memory system is based on two main functions: memory module assignment function and address assignment function. Based on them, the memory system supports 17 access types: 13 Lines, 3 Rectangles, and 1 Hexahedron. That is, the memory system allows simultaneous access to multiple data in any access types at an arbitrary position with a constant interval. In order to allow 17 access types the memory system consists of memory module selection circuitry, data routing circuitry for READ/WRITE, and address calculation/routing circuitry In the point of view of a developer and a programmer, the memory system proposed in this paper supports easy hardware extension according to the applications and both of them to deal with it as a logical three-dimensional away In addition, multiple data in various across types can be simultaneously accessed with a constant interval. Therefore, the memory system is suitable for building systems related to ,3D applications (e.g. volume rendering and volume clipping) and a frame buffer for multi-resolution.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.31-42
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• 2013

This paper proposes a photogrammetric rectification method based on Bayesian approach as a method that eliminates vertical parallax between stereo images to minimize visual fatigue of 3D contents. The image rectification consists of two phases; geometry estimation and epipolar transformation. For geometry estimation, coplanarity-based relative orientation algorithm was used in this paper. To ensure robustness for mismatch and localization error occurred by automation of tie point extraction, Bayesian approach was applied by introducing several prior constraints. As epipolar transformation perspective transformation was used based on condition of collinearity to minimize distortion of result images and modification for input images. Other algorithms were compared to evaluate performance. For geometry estimation, traditional relative orientation algorithm, 8-points algorithm and stereo calibration algorithm were employed. For epipolar transformation, Hartley algorithm and Bouguet algorithm were employed. The evaluation results showed that the proposed algorithm produced results with high accuracy, robustness about error sources and minimum image modification.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1348-1353
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• 2006

본 논문은 3 차원 게임 제어를 위한 인간의 동작인식에 대하여 기술하고 있다. 사용자의 편의성을 위하여 게임에 직관적으로 적용할 수 있는 인간의 동작들을 마커프리 모션 캡쳐 장비를 이용하여 취득하고, 이를 실시간으로 인식하는 동작 인식 시스템을 개발하였다. 또한, 개발된 동작인식기를 이용한 3차원 게임으로의 응용시스템의 접근 방식에 대하여 기술하고 있다. 개발된 동작 인식기는 LDA 방식에 기반을 둔 확률적 접근 방식으로 실시간으로 빠르고 정확하게 응용 시스템에 필요한 인간의 동작을 구별할 수 있도록 설계되었다. 개발된 시스템에서는 인식된 결과를 실시간으로 실제 어플리케이션에 전달하여 그 결과를 직접 사용자가 판단하여 다음 동작을 수행 할 수 있도록 되어 있다. 본 논문은, 이러한 실제 시스템의 개발을 통하여, 3 차원 인간 동작의 간단하고 유용한 활용 방법에 대한 해법을 제시하고 있다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.5 s.347
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• pp.17-24
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• 2006

The optical feedforward is known as a complicated technique in spite of its superior linearization. Here we optimized the feedforward circuit parameters using a systematic approach for optimum efficiency. A systematic approach was verified by transmission experiments of 2.14 GHz two tones. The compared third order IMD was enhanced by 38 dB for two-tone case. The experimental results for transmission of W-CDMA signals were described. The ACPR was enhanced by 20 dB for 1 W-CDMA carrier and by 16 dB for 3 W-CDMA carriers. Also, noise level was reduced by 7 dB.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.301-310
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• 2013

The aim of the present study is to enhance query speed of large 3D point cloud indexed in octree by parallel query using multi-cores. Especially, it is focused on developing methods of accessing multiple leaf nodes in octree concurrently to query points residing within a radius from a given coordinates. To the end, two parallel query methods are suggested using different strategies to distribute query overheads to each core: one using automatic division of 'for routines' in codes controlled by OpenMP and the other considering spatial division. Approximately 18 million 3D points gathered by a terrestrial laser scanner are indexed in octree and tested in a system with a 8-core CPU to evaluate the performances of a non-parallel and the two parallel methods. In results, the performances of the two parallel methods exceeded non-parallel one by several times and the two parallel rivals showed competing aspects confronting various query radii. Parallel query is expected to be accelerated by anticipated improvements of distribution strategies of query overhead to each core.

• Archives of design research
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• v.17 no.1
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• pp.241-252
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• 2004

In this time, CAD is most important tool in Product Design Process. Traditional design methods were hardly used in Concurrent Engineering Process. But, CAD tools based on Reverse Engineering method have a lot of serious problem in using designer's works. Especially, in the early stage in design process, adopting CAD tool is impossible, cause of a property of design - intuition. A late studies about CAD system have approaching its quantitative factors in not only software but also hardware. In this paper, I researched about the problems of traditional 3d CAD tools and the new interface approach methods in recent CAD studies. Then, I proposed the guidelines and two alternatives about to developing 3D3T in ubiquitous engineering environment.

• Journal of the Microelectronics and Packaging Society
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• v.4 no.2
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• pp.25-32
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• 1997

대용량, 고속 정보처리가 요구되는 System의 모듈은 Data 처리의 고속성 및 회로의 고집적이 가능한 MCM의 형태로 구현되어 ATM, GPS 및 PCS 등의 분야에 광범위하게 응 용되고 있다. 위와 같은 High Speed 응용분야에서의 System 성능은 Interconnect Line의 전달지연, 임피던스 부정합에 의한 신호 반사 손실. 신호선 간의 Crosstalk, Ground Bounce 등의 현상에 대한 최적화 여부에 결정적인 영향을 받는다. 그러나 Interconnect의 특성상 정 형이 존재하지 않으므로 추상적인 Library를 구축하는 형식으로 접근할 수밖에 없으며 이를 위하여 여러기본 구조를 정의한후 각 Dimension을 변수로 두고 해석 결과를 합성하여 Database화하는 접근방식이다. 본 논문에서는 MCM-D 공정을 이용하여 Interconnect Line 특성을 분석하고 Database화 하기 위한 Test Pattern을 구현하고 Time Domain reflectometry(TDR)을 이용하여 그특성들을 측정 분석하였다. Test pattern 제작은 MCM-D 공정으로 최소선폭 27$\mu$m, Via Hole 75$\mu$m으로 형성하였고 2 Layer Signal과 GND로 총 3Layer를 구현하였다. 특성분석을 위해 TDR장비와 모데링 및 Simulation S/W인 IPA 510 을 사용하였다. 이를 통해 MCM-D를 이용한 공정에서 Interconcet Line의 고주파 특성을 측정하고 정량화하여 LIbrary를 제작할수 있었다.

• Journal of Korea Game Society
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• v.8 no.2
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• pp.57-68
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• 2008

Texture Mapping is a technique for adding realism to an image in 3D graphics Chip. Bilinear filtering mode of this technique needs accesses of 4 texels to process one pixel. In this paper we analyzed the access pattern of texture, and proposed the high performance texture cache which can access 4 texels simultaneously. We evaluated using simulation results of 3D game(Quake 3, Unreal Tournament 2004). Simulation results show that proposed texture cache has high performance on the case where physical size is less then or equal 8KBytes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.91-94
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• 2012

본 논문에서는 3D 콘텐츠 제작에 있어 입체피로를 최소화하기 위한 영상의 수직시차 제거과정에 있어 사진측량기반의 강인기법을 제안하고자 한다. 영상의 수직시차 제거 과정은 크게 기하추정 단계와 에피폴라 변환 단계로 구성된다. 본 논문에서는 기하추정을 위해 사진측량에서 널리 활용되고 있는 공면조건 기반 상대표정 알고리즘을 적용한다. 이 때 상대표정 알고리즘에는 자동 정합점 추출에 따른 오정합과 위치오차에 강인성을 확보하기 위해 제약조건을 도입한 베이지안 접근방식을 적용하고자 하며, 이를 바탕으로 수행되는 에피폴라 변환에는 영상의 왜곡과 원 영상 대비 변형을 최소화하기 위해 공선조건기반의 중심투영변환기법을 적용하고자 한다. 알고리즘의 성능검증을 위한 비교 알고리즘으로, 기하추정에는 8점 알고리즘과 스테레오 캘리브레이션 기법이 사용되었으며 에피폴라 변환에는 Hartley 방법과 Bouguet 방법이 사용되었다. 실험결과는 제안알고리즘의 높은 정확도와 강인성, 그리고 활용적 가치를 보여주었다.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.157-168
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• 2011

Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.