• Title/Summary/Keyword: Big-O

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An Improvement in K-NN Graph Construction using re-grouping with Locality Sensitive Hashing on MapReduce (MapReduce 환경에서 재그룹핑을 이용한 Locality Sensitive Hashing 기반의 K-Nearest Neighbor 그래프 생성 알고리즘의 개선)

  • Lee, Inhoe;Oh, Hyesung;Kim, Hyoung-Joo
    • KIISE Transactions on Computing Practices
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    • v.21 no.11
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    • pp.681-688
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    • 2015
  • The k nearest neighbor (k-NN) graph construction is an important operation with many web-related applications, including collaborative filtering, similarity search, and many others in data mining and machine learning. Despite its many elegant properties, the brute force k-NN graph construction method has a computational complexity of $O(n^2)$, which is prohibitive for large scale data sets. Thus, (Key, Value)-based distributed framework, MapReduce, is gaining increasingly widespread use in Locality Sensitive Hashing which is efficient for high-dimension and sparse data. Based on the two-stage strategy, we engage the locality sensitive hashing technique to divide users into small subsets, and then calculate similarity between pairs in the small subsets using a brute force method on MapReduce. Specifically, generating a candidate group stage is important since brute-force calculation is performed in the following step. However, existing methods do not prevent large candidate groups. In this paper, we proposed an efficient algorithm for approximate k-NN graph construction by regrouping candidate groups. Experimental results show that our approach is more effective than existing methods in terms of graph accuracy and scan rate.

Microstructures and Hardness of Al-Si Coated 11%Cr Ferritic Stainless Steel, 409L GTA Welds (Al-Si 용융도금된 11%Cr 페라이트 스테인리스강, STS409L GTA 용접부의 미세조직과 경도)

  • Park, Tae-Jun;Kong, Jong-Pan;Na, Hye-Sung;Kang, Chung-Yun;Uhm, Sang-Ho;Kim, Jeong-Kil;Woo, In-Su;Lee, Jong-Sub
    • Journal of Welding and Joining
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    • v.28 no.3
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    • pp.92-98
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    • 2010
  • Ferritic stainless steels, which have relatively small thermal expansion coefficient and excellent corrosion resistance, are increasingly being used in vehicle manufacturing, in order to increase the lifetime of exhaust manifold parts. But, there are limits on use because of the problem related to cosmetic resistance, corrosions of condensation and high temperature salt etc. So, Aluminum-coated stainless steel instead of ferritic stainless steel are utilized in these parts due to the improved properties. In this investigation, Al-8wt% Si alloy coated 409L ferritic stainless steel was used as the base metal during Gas Tungsten Arc(GTA) welding. The effects of coated layer on the microstructure and hardness were investigated. Full penetration was obtained, when the welding current was higher than 90A and the welding speed was lower than 0.52m/min. Grain size was the largest in fusion zone and decreased from near HAZ to base metal. As welding speed increased, grain size of fusion zone decreased, and there was no big change in HAZ. Hardness had a peak value in the fusion zone and decreased from the bond line to the base metal. The highest hardness in the fusion zone resulted from the fine re-precipitation of the coarse TiN and Ti(C, N) existed in the base metal during melting and solidification process and the presence of fine $Al_2O_3$ and $SiO_2$ formed by the migration of the elements, Al and Si, from the melted coating layer into the fusion zone.

A Study on the Buddhist scripture published in the Goryeo Dynasty (고려시대(高麗時代) 간행(刊行)의 불경판화(佛經版畵) 연구(硏究))

  • Suk, Hae-Yung
    • Journal of Korean Library and Information Science Society
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    • v.49 no.4
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    • pp.373-404
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    • 2018
  • The purpose of this study is to investigate the overall situation related to the engravings included in Buddhist scriptures produced in the Goryeo Dynasty. at the wooden board in Hae-in Temple(海印寺)'s ${\ll}$Hwa-eomgyeong(華嚴經)${\gg}$ are Ju-bon(周本) 80sheets(5sheets duplicates), Jin-bon(晉本) 12sheets, and ${\ll}$Ye-sugyeong(豫修經)${\gg}$ 44sheets, and There is a print of ${\ll}$cheon-tae-eun-sa-han-san-seub-deug-si-jib(天台隱士寒山拾得詩集)${\gg}$ at Songgwang Temple(松廣寺). Also ${\ll}$Uhjebijangjeon(御製秘藏詮)${\gg}$ included in the Koryo period Chojo Tripitaka is the Emperor $T{\grave{a}}iz{\bar{o}}ng$ of $S{\grave{o}}ng$ Poetry collection owned by Japan's Nanzanji(南禪寺). In each book from volume 1-20(volume17 is not there), there were 5 sheets of engravings and most of them are located in the same locations (1,5,9,13,17). And than 50 engravings that are contained in volume 1-10 are used repetitively in volume 11-20. In Volume 21 that corresponds to appendix, 3 engravings. This has a big value in that this is a Booljeondo(佛傳圖) of the fastest period that was made in Korea. In Chapter 3, we looked at the publications of the Goryeo Dynasty by century. We have confirmed that among 19 types of the 12 kinds of printed materials.

A Research on the Parametric Design Method in Pre-Design Phase for BIM application (BIM 적용을 위한 기획설계 단계의 파라메트릭 디자인기법에 대한 연구)

  • Ha, Seung-Beom
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.92-98
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    • 2021
  • Modern society needs constantly the rationality and the efficiency, and this flow of the time has become the paradigm of the whole society. This paradigm has a large influence on the architectural design and industry. Modern technology represented by the development of digital instrument and Information Technology through internet has created and developed two big trend, Parametric Design and BIM(Building information Modeling) in the architectural design and industry. These technologies, though created for different reasons, have a lot of influence on the architectural design and industry for a common purpose such as efficiency and rationality across the boundaries. In this context, this research will be embodied through the example about how parametric design should be made in the beginning of pre-design phase for BIM application. This research aims to consider the design process of Walt Diseny Consert Hall, the work of Frank O. Ghery, a deconstructivism architect, and to embody the shape of National Nederlanden Building in Prague, the Czech Republic, using parametric design tool in pre-design phase. This research later aims to be used as the basic data that can be applied to the entire architectural industry from a planning and a detailed design to a construction for the ultimate BIM application beyond the range of parametric design in pre-design phase. Later, the plan using the parametric design algorithm and BIM application in construction document phase will be conducted.

A Performance Study on CPU-GPU Data Transfers of Unified Memory Device (통합메모리 장치에서 CPU-GPU 데이터 전송성능 연구)

  • Kwon, Oh-Kyoung;Gu, Gibeom
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.5
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    • pp.133-138
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    • 2022
  • Recently, as GPU performance has improved in HPC and artificial intelligence, its use is becoming more common, but GPU programming is still a big obstacle in terms of productivity. In particular, due to the difficulty of managing host memory and GPU memory separately, research is being actively conducted in terms of convenience and performance, and various CPU-GPU memory transfer programming methods are suggested. Meanwhile, recently many SoC (System on a Chip) products such as Apple M1 and NVIDIA Tegra that bundle CPU, GPU, and integrated memory into one large silicon package are emerging. In this study, data between CPU and GPU devices are used in such an integrated memory device and performance-related research is conducted during transmission. It shows different characteristics from the existing environment in which the host memory and GPU memory in the CPU are separated. Here, we want to compare performance by CPU-GPU data transmission method in NVIDIA SoC chips, which are integrated memory devices, and NVIDIA SMX-based V100 GPU devices. For the experimental workload for performance comparison, a two-dimensional matrix transposition example frequently used in HPC applications was used. We analyzed the following performance factors: the difference in GPU kernel performance according to the CPU-GPU memory transfer method for each GPU device, the transfer performance difference between page-locked memory and pageable memory, overall performance comparison, and performance comparison by workload size. Through this experiment, it was confirmed that the NVIDIA Xavier can maximize the benefits of integrated memory in the SoC chip by supporting I/O cache consistency.

Microbial Hygienic Status of Poultry Meats and Eggs Collected at the Public Markets in Seoul and Kyung-gi Regions in 1996 (1996년도 서울${\cdot}$경기지역에서의 시판계육과 계란에 대한 미생물학적 위생실태)

  • Woo Yong-Ku
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.38-46
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    • 2005
  • To determine the actual hygienic status of domestic chicken meats sold in public markets (conventional markets and department stores), microbial contamination levels (Total cells, Coliforms and Staphylococcal cells) and zoonotic pathogens (Salmonella species, Campylobacter species, Listeria species, and Staphylococcus aureus) isolation tests were conducted. Chicken meats and eggs tested were collected from the conventional markets (Si-Jang) and department-stores located in Seoul and Kyung-gi regions in 1996. In total cells and coliforms contamination tests, chicken meats sold in department stores were much lesser contamination status than those of Si-Jang, but staphylococcal cells level was much more higher than that of conventional markets. Salmonella isolation frequency was investigated as $68.8\%$, but Campylobacter jejuni and Listeria monocytogenes isolation frequency were appeared both $64.0\%\;and\;63.3\%$. In case of eggs sold in public markets, one of S. gallinarum strain $(0.7\%)$ was isolated only on the egg-shell part among the four-hundred and fourty-six. In comparison with foreign imported chicken meats, there were no big differences in microbial contamination status. On the other hand, both Salmonella and L. monocytogenes were isolated only in the chicken wings from Korea and China, but not from U.S.A. This data suggest that more hygienic control system in order to produce the safe and hygienic chicken meats and eggs is need in our country as soon as possible.

A Customized Cancer Radiation Treatment Planning Simulation (ccRTPs) System via Web and Network (웹과 네트워크 기술을 이용한 환자 맞춤식 암치료 계획 시뮬레이션 시스템)

  • Khm, O-Yeon
    • Progress in Medical Physics
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    • v.17 no.3
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    • pp.144-152
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    • 2006
  • The telemedicine using independent client-server system via networks can provide high quality normalized services to many hospitals, specifically to local/rural area hospitals. This will eventually lead to a decreased medical cost because the centralized institute can handle big computer hardware systems and complicated software systems efficiently and economically, Customized cancer radiation treatment planning for each patient Is very useful for both a patient and a doctor because it makes possible for the most effective treatment with the least possible dose to patient. Radiation planners know that too small a dose to the tumor can result in recurrence of the cancer, while too large a dose to healthy tissue can cause complications or even death. The best solution is to build an accurate planning simulation system to provide better treatment strategies based on each patient's computerized tomography (CT) image. We are developing a web-based and a network-based customized cancer radiation therapy simulation system consisting of four Important computer codes; a CT managing code for preparing the patients target data from their CT image files, a parallel Monte Carlo high-energy beam code (PMCEPT code) for calculating doses against the target generated from the patient CT image, a parallel linear programming code for optimizing the treatment plan, and scientific data visualization code for efficient pre/post evaluation of the results. The whole softwares will run on a high performance Beowulf PC cluster of about 100-200 CPUs. Efficient management of the hardware and software systems is not an easy task for a hospital. Therefore, we integrated our system into the client-sewer system via network or web and provide high quality normalized services to many hospitals. Seamless communication with doctors is maintained via messenger function of the server-client system.

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Habitat Environment of Eleutherococcus senticosus Max. at Mt. Deokyu (덕유산 가시오갈피 자생지의 생육환경)

  • 박문수;김영진;박호기;김선;김규성;장영선
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.6
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    • pp.710-717
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    • 1996
  • To obtain the basic informations on the farm cultivation of Eleutherococcus senticosus Max., field survey of the native habitat in Mt. Deokyu such as weather, soils, vegetation and growth was carried out. The habitat of E. senticosus is situated at 127$^{\circ}$ 45'E, 35$^{\circ}$ 52' N in Mt. Deokyu where the elev-tion ranges from 1,050 to 1,300 meters above the sea level. Mean annual temperature forecasted around the habitat was 5.8$^{\circ}C$, mean maximum temperature in August, 24.6$^{\circ}C$ ; mean minimum temperature in January, -13.5$^{\circ}C$ and relative humidity during the growth periods, over 95%. To divide the area according to climatic conditions was classified cool temperature and humid rain forest zone. In another view, it belonged to deciduous broad-leaf forest zone and soil texture was sandy loam with dark brown gravels. Acidity and P$_2$O$_{5}$ content of soil represented pH 5.2~5.6 and 10ppm, respectively. The growth of E. senticosus was poor under the low light intensity(relative 20% of full sun-light) at the growing place of the habitat and the propagation was conducted by root sucker. The natural vegetation was consisted of big trees, 3 species; shrubs, 8 species and herbs, 4 species.

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The study on the breast types and characteristics of Chinese female adults. (Ver. 2) - Focused on the female college students in Shanghai - (중국 성인여성용 유방유형 및 특성에 관한 연구(제 II보) - 상해지역 20대 전반 여성을 중심으로 -)

  • Cha, Su-Joung;Sohn, Hee-Soon
    • Journal of Fashion Business
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    • v.14 no.1
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    • pp.57-75
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    • 2010
  • This study is done in Shanghai area by sample survey of female college students in their lower 20s. Through direct contact survey, this study collected and analyzed information on figure to understand feature of breasts and measurements of body to provide base information to improve product of brassiere for adult female in China. Data was analyzed by using SPSSWIN 13.0 Program and SAS 9.0. 1. From a result of factor analysis on 40 items of measures to derive the components of the shape of the breast, 6 factors were derived such as the factors to show the obesity of the bust, to show the ratio of the upper and lower area of the lower bust, droop and volume, to show the internal shape and broadness of the bust, to show the location and vertical size of the bust, to show the protrusion of the bust and the eternal shape of the bust. 2. From a result of classification on the shape of the breast of the Chinese women in their early 20s, 4 types were selected. Type 1 is the protrusion type that a woman has a broad drooped breast due to the development in the upper and lower parts of the chest as well as the highest height, a high degree of obesity in the bust part, big volume and much protrusion. Type 2 is the hemisphere type that the degree of obesity in the breast is second to Type 1 and a breast is located at a region higher than Type 1 as the degree of obesity in the breast is secondly highest, the lower part of the bust is bigger than the Type 1 and the degree of being broad and drooped is second to Type 1. Type 3 is the cone type with a breast of being drooped and broad a little bit and a certain degree of a volume. Type 4 is the flat type with the smallest value in the item that shows the obesity of the bust area and with the smallest value in the R$\ddot{o}$hrer index to have the small and slender body type for the bust area, which is somewhat flat due to a low slope at the internal side of the bust.

Supply Chain-based Freight Distribution Channel Choice Model using Distribution Channel Analysis (유통경로분석을 통한 공급사슬기반의 화물유통경로선택모형 개발)

  • Go, Yeong-Seung;Park, Dong-Ju;Kim, Chan-Seong;Kim, Hyeon-Su;Park, Min-Cheol
    • Journal of Korean Society of Transportation
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    • v.28 no.6
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    • pp.133-146
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    • 2010
  • The objective of this study is to develop a supply chain-based freight distribution channel choice model considering shippers' logistics behaviors which will be used for freight demand estimation. For this purpose, this study utilized the distribution channel data of the petrochemical and automobile industries collected by KTDB center. The distribution channel choice models for these industries were developed by including transport mode, time, cost, and shipment size. It was found that the multinomial logit model with transport cost, time and shipment size is the best, and as shipment increases, bigger transport mode is preferred. Generally direct distribution channel with small truck was preferred over the one using distribution center and/or big truck.