• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.699-711
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• 2014

This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension. Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is $92.23m^3/day$. The result of scenario analysis by pipe replacement, risks for water suspension was reduced $7.02m^3/day$ when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

• Journal of Information Management
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• v.39 no.3
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• pp.205-220
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• 2008

This research focused on the major determinants for the strategic utilization of technology tree as a strategic technology information repository after the adoption of the technology tree in the R&D intensive organization. The study was performed based on both theoretical study and qualitative case study approaches. The result is as follows; for the strategic utilization of the technology tree for the information repository, it should be the market base and be closely related with the technology roadmap. In terms of the needs of times, this study regarding the strategic utilization of technology tree as a strategic technology information repository and as a s strategic supplement for technology roadmap is anticipated to be a good reference for the R&D-oriented organizations and technology-related studies in coming years.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.227-229
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• 2014

플래시 메모리는 빠른 처리 속도, 비휘발성, 저 전력, 강한 내구성 등으로 인해 최근 스마트폰, 태블릿, 노트북, 컴퓨터와 같은 여러 분야에서 많이 사용하고 있다. 최근 기존에 사용하던 NAND 플래시가 미세화 기술의 한계에 봉착함에 따라 기존 2차원 구조의 NAND플래시를 대처할 장치로 3차원 수직구조 NAND 플래시 메모리(3D Vertical NAND)가 주목받고 있다. 기존의 플래시 메모리는 데이터를 효율적으로 삽입/삭제/검색하기 위해 B-tree와 같은 색인기법을 필요로 한다. 플래시 메모리 상에서 B-tree 구현에 관한 기존 연구로서는 BFTL(B-Tree Flash Translation Layer)기법이 최초로 제안되었다. 현재 3차원 V-NAND 구조의 플래시 메모리가 시작품으로 제작되어 머지않아 양산 될 예정이다. 본 논문에서는 향후 출시될 3차원 구조의 플래시 메모리에 적합한 Octree 기반의 파일시스템을 제안한다.

• Journal of Sensor Science and Technology
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• v.23 no.6
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• pp.377-382
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• 2014

Detecting and segmenting diffuse targets in laser ranging data is a critical problem for tactical reconnaissance. In this study, we propose a new method that facilitates the characterization of diffuse irregularly shaped objects using "spin images," i.e., local 2D histograms of laser returns oriented in 3D space, and a clustering process. The proposed "cluster-based spin imaging" method resolves the problem of using standard spin images for diffuse targets and it eliminates much of the computational complexity that characterizes the production of conventional spin images. The direct processing of pre-segmented laser points, including internal points that penetrate through a diffuse object's topmost surfaces, avoids some of the requirements of the approach used at present for spin image generation, while it also greatly reduces the high computational time overheads incurred by searches to find correlated images. We employed 3D airborne range data over forested terrain to demonstrate the effectiveness of this method in discriminating the different geometric structures of individual tree clusters. Our experiments showed that cluster-based spin images have the potential to separate classes in terms of different ages and portions of tree crowns.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.7
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• pp.921-926
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• 2012

In order to protect the genetic resource of native horse breeds, the genetic diversity of mitochondrial DNA (mtDNA) D-loop of three native horse breeds in western China were investigated. Forty-three 600 bp mtDNA D-loop sequences were analyzed by PCR and sequencing techniques, 33 unique haplotypes with 70 polymorphic sites were detected in these horses, which account for 11.67% of 600 bp sequence analyzed, showing the abundant genetic diversity of the three native horse breeds in western China. The Neighbour-Joining (NJ) phylogenetic tree based on 247 bp of 43 D-loop sequences demonstrated the presence of seven major lineages (A to G), indicating that the three native horse breeds in western China originated from multiple maternal origins. Consistent with the front, the NJ phylogenetic tree based on 600 bp of mtDNA D-loop sequences of 43 Chinese western native horses and 81 sequences of six horse breeds from GenBank indicated that the three horse breeds had distributed into the seven major lineages (A to G). The structure of the phylogenic tree is often blurred because the variation in a short segment of the mitochondrial genome is often accompanied by high levels of recurrent mutations. Consequently, longer D-loop sequences are helpful in achieving a higher level of molecular resolution in horses.

• The KIPS Transactions:PartA
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• v.8A no.3
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• pp.209-216
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• 2001

The effective way to apply incremental attribute grammar to a complex language process is the use of optimized algorithm. In optimized algorithm for incremental attribute grammar, the new input attribute tree should be exactly compared with the previous input attribute tree, in order to determine which subtrees from the old should be used in constructing the new one. In this paper the new optimized algorithm was reconstructed by analyzing the algorithm suggested by Carle and Pollock, and a generation process of new attribute tree d’copy was added. Through the performance evaluation for the suggested matching algorithm, the run time is approximately improved by 19.5%, compared to the result of existing algorithm.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.2
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• pp.65-70
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• 2015

In this paper, we describe the world's first real-time ray-tracing chip architecture. Ray-tracing technology generates high-quality 3D graphics images better than current rasterization technology by providing four essential light effects: shadow, reflection, refraction and transmission. The real-time ray-tracing chip named RayChip includes a real-time ray-tracing graphics processing unit and an accelerating tree-building unit. An ARM Ltd. central processing unit (CPU) and other peripherals are also included to support all processes of 3D graphics applications. Using the accelerating tree-building unit named RayTree to minimize the CPU load, the chip uses a low-end CPU and decreases both silicon area and power consumption. The evaluation results with RayChip show appropriate performance to support real-time ray tracing in high-definition (HD) resolution, while the rendered images are scaled to full HD resolution. The chip also integrates the Linux operating system and the familiar OpenGL for Embedded Systems application programming interface for easy application development.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.543-554
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• 2002

GIS (Geographic Information Systems) need faster access and better visualization. For faster access and better visualization in GIS, map generalization and levels of detail are needed. Existing spatial indexing methods do not support map generalization. Also, a few existing spatial indexing methods supporting map generalization do not support ail map generalization operations. We propose a new index structure, i.e. the LR-tree, supporting ail map generalization operations. This paper presents algorithms for the searching and updating the LR-tree and the results of performance evaluation. Our index structure works better than other spatial indexing methods for map generalization.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.454-457
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• 2011

본 연구에서는 소방시설의 성능위주의설계를 수행하기 위하여 ETA(Event Tree Analysis) 기법을 적용하는 방안을 고찰하였다. ETA기법에서는 화재시나리오를 사건(Event)의 인과관계로 된 각 단계의 사건으로 구성한다. 본 연구에서는 ETA에서 구성된 시나리오에 따른 심각도를 화재시뮬레이션과 피난 시뮬레이션을 통한 수행으로 사망자수를 도출하는 방안을 적용하였고, 각 시나리오의 빈도(확률)은 FTA(Fault Tree Analysis) 기법을 적용하여 분기 확률을 도출하도록 하였다. ETA에서 도출한 사망자수와 빈도를 이용하여 F-N 커브를 작성하여 위험도를 평가하여 소방설계의 보완 및 대책을 수립하는 방안을 제시하였다.

• Journal of the Korea Furniture Society
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• v.21 no.1
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• pp.17-25
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• 2010

Three buildings -Jibokjae, Hyubgildang and Palujung- are connected each other and consist of a library and reception complex for royal kings at Kyungbok Palace in Seoul. Jibokjae and Hyubgildang were known to have been moved from Changdok Palace in A.D. 1891. No construction records have been known for Palujung. In 2004, during repair of three buildings, a dendrochronological analysis was conducted to examine their building histories. We took 67 wood samples for dendrochronological analysis; 20 from Jibokjae, 37 Hyubgildang and 10 Palujung, respectively. The results showed that the felling dates of Jibokjae and Hyubgildang woods were A.D. 1877-1879/1880, indicating original construction of two buildings at early 1880s. Felling dates of Palujung were 1886-1889/1890, those of roof filling timbers 1890 and the connection part between Hyubgildang and Jibokjae 1886, confirming 1891's movement of Hyubgildang and Jibokjae and adding a new building, Palujung.