• 대한전자공학회논문지SP
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• 제47권5호
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• pp.117-126
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• 2010

산란선을 흡수하여 보다 선명한 x선 영상을 얻기 위하여 산란방지 그리드를 사용하여 투사영상을 얻는데, 이때 그리드로 인한 왜곡이 발생한다. 본 논문에서는 회전된 그리드를 사용하여 투사영상을 얻고 단순한 1차원 저역필터를 영상의 공간영역에서 각 축으로 별도로 적용하여 그리드 왜곡을 효율적으로 제거하는 방법을 제안하고 그 성능을 고찰해 보았다. 제안한 방법은 왜곡 주파수를 별도로 예측할 필요 없이, 회전된 그리드를 사용하여 획득한 영상에 단순한 1차원 필터를 주파수영역이 아닌 공간영역에서 적용하므로 매우 단순하여 쉽게 구현이 가능하며 빠른 계산 속도를 가지는 장점을 가지고 있으면서 그 성능은 주파수영역에서 2차원 필터를 적용한 경우와 유사하다.

• 인터넷정보학회논문지
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• 제11권5호
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• pp.27-35
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• 2010

본 논문에서는 평면 스크린을 사용할 수 없는 휴대형 프로젝터의 사용 환경에서 평면이 아닌 임의의 영사면(혹은 벽면)의 기하학적 형태에 의해 발생되는 영상의 기하학적 왜곡을 효과적으로 보정할 수 있는 방법을 제안한다. 제안한 방법에서는 먼저 격자패턴을 임의의 영사면에 영사한 후 영사면의 형태에 따라 왜곡된 격자패턴과 원본 격자패턴 간의 기하학적 관계를 나타내는 직선의 방정식을 도출한다. 다음으로 영사면의 기하학적 형태에 따라 적절하게 적용될 수 있는 원본 격자패턴의 크기를 결정하여 도출된 직선의 방정식으로부터 왜곡된 영상을 대칭적으로 보정할 수 있는 보정패턴을 생성한다. 최종적으로 프로젝터로부터 영사될 실제 영상을 격자패턴과 동일하게 분할하여 보정패턴에 맞게 미리 워핑(warping)함으로써 영사된 영상의 기하학적 왜곡을 보정한다. 제안한 방법의 성능 평가를 위하여 평면 스크린을 사용할 수 없는 영사 환경에서 자주 접할 수 있는 영사면 형태들인 기울어진 평면, 꺾인 평면 및 곡면을 대상으로 영사 영상 보정에 대한 실험을 진행하였다. 실험결과로부터 일반적으로 발생하는 몇 가지 영사면의 형태들에 인한 기하학적 왜곡들이 적절히 보정되어 제안한 방법이 영사 영상의 기하학적 왜곡을 매우 효과적으로 보정할 수 있음을 알 수 있었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_1호
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• pp.23-28
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• 2001

A new numerical weather prediction and dispersion model, the Operational Multi-scale Environment model with Grid Adaptivity(OMEGA) including an embedded Atmospheric Dispersion Model(ADM), is introduced as a next generation atmospheric simulation system for real-time hazard predictions, such as severe weather or the transport of hazardous release. OMEGA is based on an unstructured grid that can facilitate a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from 20 -30 meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning and time. In particular, the unstructured grid cells in the horizontal dimension can increase the local resolution to better capture the topography or important physical features of the atmospheric circulation and cloud dynamics. This means the OMEGA can readily adapt its grid to a stationary surface, terrain features, or dynamic features in an evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with observed data.

• 한국의류산업학회지
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• 제9권4호
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• pp.418-424
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• 2007

The purpose of this study is to propose a standard of converting 3D shape of men in twenties to 2D patterns. This can be a basis for scientific and automatic pattern making for high quality custom clothes. Firstly, representative 3D body shape of men was modeled. Then the 3D model was divided into 3 shells, front, side and back. Among them, the front shell was divided into 4 blocks by bust line and princess line. Secondly, curves are generated on each block according to matrix combination by grid method. Then triangles were developed into 2D pieces by reflecting the 3D curve length. The grid was arranged to maintain outer curve length. Next, the area of developed pieces and block were calculated and difference ratio between the block area and the developed pieces' area is calculated. Also, area difference ratio by the number of triangles is calculated. The difference ratio was represented as graphs and optimal section is selected by the shape of graphs. The optimal matrix was set considering connection with other blocks. Curves of torso upper front shell were regenerated by the optimal matrix and developed into pieces. We validated it's suitability by comparing difference ratio between the block area and the developed pieces' area of optimal section. The results showed that there was no significant difference between block area and the pieces' area developed by optimal matrix. The optimal matrix for 2D developing could be characterized as two types according to block's shape characteristics, one is affected by triangle number, the other is affected by number of raws more than columns. Through this study, both the 2D pattern developing from 3D body shape and 3D modeling from 2D pattern is possible, so it's standardization also possible.

• 한국농촌건축학회논문집
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• 제13권4호
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• pp.115-124
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• 2011

This study examines the process of urban formation in the city of Yanji. The analysis is done by the change of street pattern and major facility location in a timely manner by appling space syntax method. This research categorizes the pattern of the urban growth focused on two urban forms, street and major buildings, in the city and is offered of the meaning of the first value on interpretation of the urban growth in the city of Yanji. The result of the research are as follows. First, the period of the city transformation is divided into four stage; intuitive period, grid-iron formative period, consolidation period, and urban expansion period. Second, characteristics of each stage have been analyzed. At the first stage, the city started to frame along both buildings and streets which were placed without a plan. At the second stage, the city was planned and constructed into new grid-iron pattern ignoring existing context by Jananese colony. At the consolidation period, the road system expands from the city center toward suburban. At the last expansion period, the shape of the city has complicated its shape with complex road system. This study contributes to provide a basic analysis and data to investigate how the Yanji city has evolved over period of time. But further continuous research should be done for future urban development of the Yanji city.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.281-287
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• 2021

Bioinformatics is formed with a blend of biology and informatics technologies and it employs the statistical methods and approaches for attending the concerning issues in the domains of nutrition, medical research and towards reviewing the living environment. The ceaseless growth of DNA sequencing technologies has resulted in the production of voluminous genomic data especially the DNA sequences thus calling out for increased storage and bandwidth. As of now, the bioinformatics confronts the major hurdle of management, interpretation and accurately preserving of this hefty information. Compression tends to be a beacon of hope towards resolving the aforementioned issues. Keeping the storage efficiently, a methodology has been recommended which for attending the same. In addition, there is introduction of a competent algorithm that aids in exact matching of small pattern. The DNA representation sequence is then implemented subsequently for determining 2 bases to 6 bases matching with the remaining input sequence. This process involves transforming of DNA sequence into an ASCII symbols in the first level and compress by using LZ77 compression method in the second level and after that form the grid variables with size 3 to hold the 100 characters. In the third level of compression, the compressed output is in the grid variables. Hence, the proposed algorithm S_Pattern DNA gives an average better compression ratio of 93% when compared to the existing compression algorithms for the datasets from the UCI repository.

• 정보처리학회논문지D
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• 제14D권5호
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• pp.471-482
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• 2007

본 논문에서는 기존 그리드 기반의 질의 색인 기법을 변형하여 보다 적은 저장 공간을 사용하면서 보다 빠른 연산을 수행하는 연속 영역 질의 처리 기법을 제안한다. 제안하는 기법의 주요 특징은 두 가지 이다. 첫째, 각 질의에 비트 식별자를 부여하고 그리드의 각 셀은 이러한 비트 식별자의 조합으로 이루어진 비트 열을 이용하여 질의들의 겹침 정보를 반영한다. 이러한 비트 열을 통해 셀이 어떤 질의들에 포함되어져 있는지 빠르게 판단한 수 있으며, 두 셀 사이의 각 셀을 포함하는 질의 식별자들을 비교하지 않고 비트 열만을 비교하여 질의들의 포함관계를 알아내어 불필요한 연산을 줄일 수 있다. 둘째, 셀들을 그룹단위로 관리하여 불필요하게 비트 열의 길이가 증가하여 저장 공간을 낭비하고 비트 열의 비교 연산 시간이 증가하는 문제를 해결한다. 제안하는 기법이 기존 연속 영역 질의 처리 기법에 비해 우수함을 성능 평가를 통해 입증한다.

• 전력전자학회논문지
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• 제13권5호
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• pp.369-375
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• 2008

본 논문에서는 Z-소스 인버터를 사용하여 단상 계통 연계형 태양광 시스템을 제어하는 기법을 제시하였다. 인버터 스위칭소자의 전압 스트레스를 고려하여 광전지 출력전압에 대한 계통 연계형 Z-소스 인버터의 동작영역을 분석하였다. 스위칭 손실을 감소시키면서 shoot-through 시간을 효율적으로 제어하는 스위칭 패턴을 사용하였다. 시뮬레이션 및 32-비트 DSP를 사용한 실험을 통하여 계통연계형 Z-소스 인버터의 제어 시스템의 성능을 평가하였다.

• Journal of Multimedia Information System
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• 제4권4호
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• pp.263-270
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• 2017

Various security threats exist in the smart grid environment due to the fact that information and communication technology are grafted onto an existing power grid. In particular, smart metering data exposes a variety of information such as users' life patterns and devices in use, and thereby serious infringement on personal information may occur. Therefore, we are in a situation where a de-identification algorithm suitable for metering data is required. Hence, this paper proposes a new de-identification method for metering data. The proposed method processes time information and numerical information as de-identification data, respectively, so that pattern information cannot be analyzed by the data. In addition, such a method has an advantage that a query such as a direct range search and aggregation processing in a database can be performed even in a de-identified state for statistical processing and availability.

• 한국기계가공학회지
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• 제13권3호
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• pp.111-117
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• 2014

With the development of technology, the display industry has been focusing on the development of new types of displays, such as bendable and wearable displays. However, the PVA/TAC polarizing film used in the manufacturing of a normal display is associated with low luminance and low efficiency. If the existing polarization film is replaced with a wire grid polarizer, it is possible to reduce the thickness significantly. Moreover enhanced brightness can also be expected. This study confirms the optical properties of the WGP through a simulation.