• Title/Summary/Keyword: red-black tree

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A Swapping Red-black Tree for Wear-leveling of Non-volatile Memory (비휘발성 메모리의 마모도 평준화를 위한 레드블랙 트리)

  • Jeong, Minseong;Lee, Eunji
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.6
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    • pp.139-144
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    • 2019
  • For recent decades, Non-volatile Memory (NVM) technologies have been drawing a high attention both in industry and academia due to its high density and short latency comparable to that of DRAM. However, NVM devices has write endurance problem and thus the current data structures that have been built around DRAM-specific features including unlimited program cycles is inadequate for NVM, reducing the device lifetime significantly. In this paper, we revisit a red-black tree extensively adopted for data indexing across a wide range of applications, and make it to better fit for NVM. Specifically, we observe that the conventional red-black tree wears out the specific location of memory because of its rebalancing operation to ensure fast access time over a whole dataset. However, this rebalancing operation frequently updates the long-lived nodes, which leads to the skewed wear out across the NVM cells. To resolve this problem, we present a new swapping wear-leveling red-black tree that periodically moves data in the worn-out node into the young node. The performance study with real-world traces demonstrates the proposed red-black tree reduces the standard deviation of the write count across nodes by up to 12.5%.

A Hierarchical Binary-search Tree for the High-Capacity and Asymmetric Performance of NVM (비대칭적 성능의 고용량 비휘발성 메모리를 위한 계층적 구조의 이진 탐색 트리)

  • Jeong, Minseong;Lee, Mijeong;Lee, Eunji
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.2
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    • pp.79-86
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    • 2019
  • For decades, in-memory data structures have been designed for DRAM-based main memory that provides symmetric read/write performances and has no limited write endurance. However, such data structures provide sub-optimal performance for NVM as it has different characteristics to DRAM. With this motivation, we rethink a conventional red-black tree in terms of its efficacy under NVM settings. The original red-black tree constantly rebalances sub-trees so as to export fast access time over dataset, but it inevitably increases the write traffic, adversely affecting the performance for NVM with a long write latency and limited endurance. To resolve this problem, we present a variant of the red-black tree called a hierarchical balanced binary search tree. The proposed structure maintains multiple keys in a single node so as to amortize the rebalancing cost. The performance study reveals that the proposed hierarchical binary search tree effectively reduces the write traffic by effectively reaping the high capacity of NVM.

Developing Black Color by Natural Dyeing for Contemporary Fashion: Dyeing of Silk Fabrics (현대패션 활용을 위한 천연염색에 의한 검정색 구현(1): 견직물을 중심으로)

  • Yeo, Youngmi;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.29 no.4
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    • pp.276-283
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    • 2017
  • The aim of this study is to develop an effective dyeing process for black color on the silk fabrics, using natural Indigo, Madder, Amur cork tree, Alder, Logwood, and Gallnut. All natural dye materials were water-extracted, concentrated, and freeze-dried. Seven different processes were carried out and the color differences(${\Delta}E$) of black color with each process from the chemical black dyed fabric were compared. The light, washing, and rubbing fastness were evaluated. The black dyeing of the silk fabrics was well carried and excellent black color was obtained in every methods. The profound black color could be obtained by the subtractive mixture of the three primary colors of red, yellow, and blue in the order of indigo(blue) - amur cork tree(yellow) - madder or lac(red). Black color was efficiently obtained by iron mordant when logwood or alder fruit was used. The color difference(${\Delta}E$) from the black color with chemical dyestuff was the lowest in the indigo - amur cork tree - lac - iron method. Light fastness and washing fastness were excellent in all dyeing processes, showing grade 5. The fastness to rubbing was excellent as shown grade 5 in the dry samples of logwood - iron process and alder fruit - iron process.

Kinds and Types of Dyes Used in the Joseon Dynasty (조선시대 염료의 종류와 유형)

  • Kim, Soon-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.38 no.2
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    • pp.201-215
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    • 2014
  • This study explores the kinds and types of dyes used in the Joseon Dynasty. Some literature including "Sanga Yorok", "Gyuhap Chongseo", "Imwon Gyeonjeji" were reviewed for this purpose. The findings are as follows. The colors obtained from the dyes were divided into seven color series, such as red, yellow and orange, green, blue, purple, brown, gray and black. These are practical color categories differed from abstract five cardinal colors [五方色]. The diachronic dyes used during the Joseon Dynasty were safflower and Japanese alder bark for red, indigo leaves for blue, gromwell for purple, chestnut tree bark for brown. The representative dyes used in the late Joseon Dynasty were safflower and sappan wood for red, wild pear tree bark and Pentapetes phoenicea for yellow and orange, indigo leaves for blue, sappan wood and gromwell for purple, mulberry tree for brown, and Chinese ink for gray. Common dyes used both in Joseon and China were safflower and sappan wood for red, pagoda tree blossom for yellow, a combination of pagoda tree blossom (or Amur cork tree) and indigo leaves (or sediment) for green, indigo leavers or sediment for blue, sappan wood and hollyhock for purple, and a combination of indigo leaves and Galla Rhois for gray and black.

Fast Implementation of the Progressive Edge-Growth Algorithm

  • Chen, Lin;Feng, Da-Zheng
    • ETRI Journal
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    • v.31 no.2
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    • pp.240-242
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    • 2009
  • A computationally efficient implementation of the progressive edge-growth algorithm is presented. This implementation uses an array of red-black (RB) trees to manage the layered structure of check nodes and adopts a new strategy to expand the Tanner graph. The complexity analysis and the simulation results show that the proposed approach reduces the computational effort effectively. In constructing a low-density parity check code with a length of $10^4$, the RB-tree-array-based implementation takes no more 10% of the time required by the original method.

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On the Growth of Pine Tree in the Damaged Forest by the Needle Gall Midge (솔잎흑파리 피해림의 소나무 생장에 관하여)

  • Im, Hyong Bin;Lim, Ung Kyu;Hoang, Chong Ser
    • The Korean Journal of Ecology
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    • v.1 no.2
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    • pp.66-71
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    • 1977
  • The growth of red and black pines in Muan, Seochen, Gapyeong and Kochang areas was compared by means of the growth of annual ring width and stem analysis to study the process of damages caused by pine needle gall midge. Red pine forest of Seocheon area began to suffer by pine needle gall midge from 1961 and the damage was to becoming severe from 1967. The damage became so intense tha tmany forests are withering to death from spring of 1975. Black pine forest also began to suffer from 1973. Red pine forest of Muan area was supposed to be suffered from 1973. Red pine forest of Kochang area suffered by pine needle gall midge from 1967. It seems that the damage became severe from 1973 and that black pine forest was also badly damaged from that time. Red pine forest of the control plot, Gapyeong area, began to suffer from 1967 and it also became intense from 1973. Although the areas of Seocheon, Muan, Kochang, and Gapyeong are different from each other in terms of locality and the infitration period of pine needle gall equally from 1967 due to mass development of population or other factors and the damage became more intense from 1973. Black pine forest was also badly damaged from that time. Black pine seems to be stronger in insect resistant than red pine. This can be justified by the fact that it began to suffer belatedly in each area and the degree of damage is moderate. The damage of Seocheon area is the severest following Kochang. Muan area is relatively moderate but the forest becoming decrease in growth.

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Study on Red and Black Heartwood Properties of Cryptomeria Japonica in Southern Region of Korea

  • Won, Kyung-Rok;Jung, Su-Young;Yoo, Byung-Oh;Hong, Nam-Euy;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.6
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    • pp.753-761
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    • 2017
  • The heartwood (HW) of Japanese cedar (Cryptomeria japonica) has usually a reddish color. But some trees have black-colored heartwood (BHW). BHW of Japanese cedar has a low commercial value because of the appearance. Therefore, in this study, a comparative analysis was conducted to evaluate the differences in the physical, mechanical, and inorganic element properties, and decay resistance of red-colored heartwood tree (RHW) and BHW. The physical properties showed significant difference between sapwood (SW) and HW, but there was no significant difference between RHW and BHW. From the results of mechanical properties, no significant difference was recognized in SW of RHW, HW of RHW, SW of BHW, and HW of BHW. There were decay resistance differences between RHW and BHW in HW, and between HW and SW in both RHW and BHW, respectively. The magnesium (Mg), potassium (K), and calcium (Ca) contents had significant differences between SW and HW in both RHW and BHW. In this present study, the decay resistances and the contents of Mg and K were higher in HW than in SW both for RHW and BHW, while these measurements were lower in RHW than in BHW. Therefore, BHW was considered to be worthy as a high-quality material as RHW.

Seasonal Characteristics of Fecal Sites of the Siberian Flying Squirrel Pteromys volans

  • Han, Chang Wook;Lim, Sang Jin;Park, Hee Bok;Park, Yung Chul
    • Journal of Forest and Environmental Science
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    • v.34 no.2
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    • pp.184-187
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    • 2018
  • Characteristics of fecal sites of the Siberian flying squirrel Pteromys volans was analyzed based on 132 sites of total 19 places. The fecal sites were more frequently found in winter (43.9%), and then followed by autumn (27.3%), spring (23.5%), and summer (5.3%). With the exception of summer, the fecal sites were more frequently found at the root collar than on the forked tree (p<0.01). Among 132 fecal sites, 88 sites (66.7%) were found on the rood collars and the other 44 sites (33.3%) were posited in the forked trees. Brown or red clay pellets were found at 44 fecal sites (33.4%) and 43 fecal sites (32.6%), and then black and yellow pellets were at 22 fecal sites (16.7%) and 19 fecal sites (14.3%), respectively. Green pellets were rarely found only at 4 sites (3.0%). Feces tend to have bright colors (brown, red clay and yellow) in winter and black in summer. Fecal sites with yellow pellets were much less found in all of the three seasons with the exception of winter, but highly increased in 25.4% in winter. The fecal sites with brown (33.4%) and red clay pellets (32.6%) were most frequently found through the four seasons.

Comparisons on Relative Growth of Red Pine, Black Pine and Pitch Pine by Means of Multiple Regression (다중회귀분석법에 의한 소나무, 곰솔 및 리기다소나무의 상대성장 비교)

  • Park, Man-Choon;Lee, Yun-Keun;Choi, Kee-Ryong
    • Journal of Environmental Science International
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    • v.19 no.3
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    • pp.305-312
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    • 2010
  • The purpose of this study is to compare the relative growth of annual ring width of red pine(Pinus densiflora), black pine(Pinus thunbergii) and pitch pine(Pinus rigida) by means of multiple regression method according to Graybill hypothesis. The obtained results are as follows. 1. The changes of rainfall have affected to tree growth during the periods of 1975 through 1978. 2. Among these pine trees, red pine was mostly influenced by environmental factors. 3. The growth of annual ring width was sensitively responded to the changes of rainfall and air temperature. 4. Among the heavy metals analyzed, the concentrations(ppm) of Lead(Pb) and Copper(Cu) were negatively effected on the growth of annual ring width of pine trees. 5. The analytical technique of annual ring width may be useful for estimation of the pollution in forest areas near industrial complexes.

Elucidation of the translocation of phosphamidon used for the control of pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye) in the trunks of pine trees by means of a radiotracer. Part 1. Translocation as affected by pine tree species and the treated season (방사성 추적자에 의한 솔잎혹파리 방제용 살충제 phosphamidon의 소나무 수간이동 구명 : I. 소나무 품종 및 계절별 이행)

  • Lee, Jae-Koo;Lee, Hyung-Rae;Kyung, Kee-Sung;Byun, Byung-Ho
    • Applied Biological Chemistry
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    • v.36 no.6
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    • pp.463-468
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    • 1993
  • In order to elucidate the translocation of the systemic insecticide, phosphamidon (2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate), treated to pine trees against pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye), $[vinyl,\;carbonyl-^{14}C]$ phosphamidon was implanted into the trunks of 10-year-old Korean red pine (Pinus densiflora Sieb. et Zucc.) and Japanese black pine (Pinus thunbergii Parl.), respectively. The upward movement rates of the chemical within Korean red pine in July and Japanese black pine in December were ca. 10 cm/hr and 2 cm/hr, respectively. The original radioactivity level persisted up to 75 days after treatment throughout the whole tree in Korean red pine in July, whereas it did up to 150 days in Japanese black pine in December. The chemical was translocated up to the top at the insecticidal level within 3 days after treatment in July, whereas in December it was within 15 days. The translocation of the chemical was much dependent upon pine tree species and the treated season. Methanol was suitable for the extraction of phosphamidon and its metabolites from pine needles. Autoradiography of the methanol extracts of pine needles collected from the treated pine trees proved that phosphamidon broke down very quickly within pine trees (ca. 80% metabolized within 7 days).

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