• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.1-12
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• 2015

NAND flash memory has being used for storage systems widely, because it has good features which are low-price, low-power and fast access speed. However, NAND flash memory has an in-place update problem, and therefore it needs FTL(flash translation layer) to run for applications based on hard disk storage. The FTL includes complex functions, such as address mapping, garbage collection, wear leveling and so on. Futhermore, implementation of the FTL on low-power embedded systems is difficult due to its memory requirements and operation overhead. Accordingly, many index data structures for NAND flash memory have being studied for the embedded systems. Overall performances of the index data structures are enhanced by a decreasing of page write counts, whereas it has increased page read counts, as a side effect. Therefore, we propose an index management method using a page mapping log table in $B^+$-Tree based on NAND flash memory to decrease page write counts and not to increase page read counts. The page mapping log table registers page address information of changed index node and then it is exploited when retrieving records. In our experiment, the proposed method reduces the page read counts about 61% at maximum and the page write counts about 31% at maximum, compared to the related studies of index data structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.387-397
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• 2021

Most of Korea's agricultural water is supplied by reservoirs, so dependence on them is very high. Accordingly, it is important to reduce this dependence and provide a stable agricultural water supply by utilizing an applicable alternative water source. Therefore, in this work, scenarios for different land uses were constructed, and an optimal water supply plan using rainwater and reused sewage water - which are alternative water sources - was created. A study was also conducted to determine the optimal capacity of a rainwater facility. From the analysis, a stable water supply was achieved in the scenario of maximum utilization of rainwater by changing an existing paddy area to a greenhouse area, and about 0.82 ton of flow capacity was required for 1 mm of rainfall on farms utilizing rainwater. As a result of analyzing the optimal scenario to derive the ratio of the storage capacity per unit water collection area, the rainwater storage capacity determined through MODSIM and the storage capacity determined through actual monitoring showed similar results, about 31 and 32 %, respectively, and the optimal capacity of rainwater facilities was calculated to be about 5,796,000-6,182,400 ton.

• Journal of Bio-Environment Control
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• v.9 no.3
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• pp.166-170
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• 2000

Three methods for heat collection, which were the flat solar collector, two fan with radiator, and square pipe method, were studied to sue efficiently solar energy in the three different glasshouses for two years. The flat plate solar collector method was made use of the commercial solar collector with collection area of 24$m^2$, the method of two fans with radiators collected solar energy at the top of the glasshouse. An thermal storage tank was constructed underneath in teach glasshouses. When an area of 1,000$m^2$ was heated to the minimum temperature of 9$^{\circ}C$, the decrease rate of heating fuel for the flat plate solar collector, the fan attached radiator and the square pipe methods were 7%, 19% and 28% respectively. The flat plate solar collector method, which could be heated approximately 40-50$m^2$, was currently used by most of the farmer. Under the condition, the decrease rate of annual heating fuel was 14% which was not better for an economic annual heating fuel. If the fan with radiator method was operated, the use of installation and maintenance were required. So, it could not be good economic efficiency of solar heating. The heating efficiency of the square pipe method was relatively better thant those of the flat plate solar collector or the fan attached radiator. Since the cost of materials and its installation of the use of square pipe method was lower than any other method. However, corrosion of the pipe, greater shade in the greenhouse and strength against the square pipe were problems that should be overcome in the square pipe method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.384-389
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• 2009

Germination characteristics of Chinese milk vetch(CMV) seeds produced from Hanam Province, China and Milyang, Korea were investigated to give basic information on the stability of seedling establishment in the CMV cultivation. The germination percentage of the imported CMV seed from China varied according to importation year and seed collection site ranging from 79~95%. The germination of black colored seed coat was lower than the light green colored ones and germination by seed weight was not significantly different. Although the seed germination was lower under dark than in the presence of light, it was not significantly different. The germination of the imported CMV seed slightly declined to only less than 6% after one-year of storage under natural environment conditions but it significantly decreased after two years. However, when the seed was stored at the $5^{\circ}C$, the seed germination was the same as after two years of storage. On the other hand, fresh CMV seed produced in Milyang, Korea had only 8% germination due to seed coat dormancy but the germination increased to 73~85% after breaking seed dormancy after a year of storage. The high germination percentage of 72~82% was still maintained even after 27 months of seed storage unlike the CMV seed produced from China. These results indicate that CMV seeds do not require light for germination and the seed from China should be used within one-year after importation while the seeds produced from Korea can be used even after two years from harvest for stable CMV seedling establishment in the CMV-rice cropping system.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.23-32
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• 2020

Geological CO₂ sequestration is a global warming response technology to limit atmospheric emissions by injecting CO₂ captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO₂ storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO₂ storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO₂ column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO₂ injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO₂ injected during the demonstration-scale CO₂ storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO₂ storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.126-144
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• 2024

The chrysanthemum vine pattern box from the Goryeo Dynasty expresses in great detail the representative features of Goryeo Dynasty lacquerware with mother-of-pearl, such as engraving patterns on the surface of fine mother-of-pearl, expressing vine stems using metal wires, and twisting metal wires to form the boundaries of each patterns. While the lacquerware with mother-of-pearl that remains today from the Goryeo Dynasty has the form of a sutra box and a box with lid, the chrysanthemum vine pattern box that is the subject of this study is in the shape of a box with a separate lid and body, making it difficult to estimate the purpose of production or the stored contents. In this study, we attempted to confirm the formative characteristics of the chrysanthemum vine pattern box in order to confirm its original form, and to investigate its structure and production technique through X-ray transmission. In addition, we attempted to identify the use and production purpose of the box by classifying and comparing the previously known lacquerware with mother-ofpearl from the Goryeo Dynasty by type. As a result of the investigation, fabric was confirmed the bottom of body and inner box through X-ray images. Through this, it was confirmed that the 'Mogsimjeopichilgi'(wooden core grabbing fabric technique) of wrapping the object with fabric was used. And through wood grain, it was possible to confirm the wooden board composition of the part presumed to be the restored part and the part presumed to have had existing Jangseog. In addition, it was confirmed that the joints were connected in a Majdaeim(part to part). Based on the survey results, a total of 14 pieces, including 9 Sutra boxes, 3 boxes, and 2 small boxes, that remain from the Goryeo Dynasty were classified by type and examined for similarity. Among them, there is a "Chrysanthemum Vine Pattern Sutra Box" from a private collection in Japan, a "Black Lacquered Chrysanthemum Arabesque Bun Sutra Box" from the Tokugawa Art Museum, a "Sutra Holder" from the British Museum, and a "Small Box with a Mother-of-Pearl Chrysanthemum Vine Pattern" from a private collection in Korea. The pattern composition of five points was most similar to the subject of this study. As a result of comparing the damage pattern, formative characteristics, and structural features of each part, it is presumed that the sutra holder in the British Museum was transformed into its current form from the original the chrysanthemum vine patterned box. Lastly, in order to confirm the purpose of production, that is, the use of this box, we investigated examples of Tripitaka Koreana printed version produced at a time similar to the social atmosphere of Goryeo at the time. Following the Mongol(元) invasion after the Goryeo military regime at the time, sutras appeared to pray for the stability of the nation and the soul of an individual, and with the development of domestic printing and paper in the 13th century, it gradually coincided with the transition from a scroll to a folded form, and the form of a box changed from a box. It is believed that the storage method also changed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.194-201
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• 2017

This study was conducted to determine the valid time for accurate detection of complete blood cell count (CBC) in pig blood using an automatic blood corpuscle analyzer (Hemavet 950FS). Blood samples were collected from 34 pigs (Duroc) with a 60 kg (${\pm}3.5$) body weight. Ten specimens with CBC parameters in normal range and with no hemolysis were selected among 34 samples and used in this study. Regarding leukocytes parameters, white blood cell (WBC), neutrophil (NE), and lymphocyte (LY) counts showed a low daily variation (coefficient of variation, CV), whereas monocyte (MO), eosinophil (EO), and basophil (BA) CVs were significantly high (19.7, 56.9, and 53.3%, respectively). On the other hand, all parameters of erythrocytes and thrombocytes showed stable daily variation. All parameters of leukocytes and thrombocytes were significantly reduced as storage time passed (P<0.01 or 0.001), except for lymphocytes (P=0.535). However, no significant differences were observed in parameters of erythrocytes from blood up to 120 hours. From above results, we assert that Hemavet 950FS is useful in analyzing CBC, except for MO, EO, and BA. For accurate detection of leukocyte and thrombocyte parameters, analysis should be performed within 4 hours after blood collection when using Hemavet 950FS. On the other hand, parameters of erythrocytes could be stably detected for at least 120 hours after blood collection.

• The Korean Journal of Community Living Science
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• v.25 no.3
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• pp.401-415
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• 2014

To prepare for the changes in the future, this study considered people in their seventies and eighties in rural areas in the last decade. Based on a survey of rural life by the Rural Development Administration, all factors were analyzed using SAS ver. 9.3. The rate of rice farming decreased, and vegetable-cultivation increased from 8.4% in 2001 to and 26.6% in 2008 for people in their seventies and eighties. The number of family members decreased to 1.96 in 2010 from 2.04 in 2001, and annual income increased by KRW 20-29 million for those in their seventies and eighties, whereas it was more than KRW 30 million for those in their forties. Bathing with warm water increased to 88.9% from 69.8%, and household waste treated by self-incineration decreased from 86.4% to 40.0% in the last decade. Separate collection spread since 2008. Food waste disposal and the burial (46.0%) showed had for people in their seventies and eighties, and animal feed increased (50.7%) for those in their forties at 2001. The separate collection increased by 39.6% in 2010 for those in their seventies and eighties and by 53.5% for those in their forties(p<0.05). The manufacture of jang and kimchi showed were little annual changes for people in their seventies and eighties. Food storage processing was higher for those in their forties. For those in their seventies and eighties, food group intake over the 2004-2010 period increased from 3.3 times a week to 4.2 times a week for protein foods and from 4.9 times a week to 5.5 times a week for vegetables. There was no change in fruits, milk, and seaweeds for those in their seventies and eighties, but there was an increase for those in their forties. The results suggest the continued increase in the manufacture of jang and kimchi and protein and vegetable intake for those in their seventies and eighties. Some direction to welfare, mechanized rice planting and living with neighbors together would be continued with good nutrition for elderly residents.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.311-316
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• 2008

Calcium phosphate cement (CPC) has been used as bone substitute successfully due to good biocompatibility and osteoconductivity. One of the important mechanical characteristics of CPC is flowablility, which can be evaluated by measuring rheological parameters. However, there have been few studies that measured rheological properties of CPC. The purpose of this study was to evaluate the rheological properties of CPC paste mixed with 2 kinds of setting solutions, 2% hydroxyprophyl methylcellulose (HPMC) and 35% polyacrylic acid (PAA). The CPC used was dicalcium phosphate dihydrate (DCPD). Rheological properties of CPC paste were measured using rheometer. The statistical analysis was carried out with Mann-whitney test with Bonferronis collection. CPC with both setting solutions showed shear thinning behavior. CPC with 2% HPMC showed signigicantly higher complex viscosity than CPC with 35% PAA(p<0.05).

• Animal cells and systems
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• v.16 no.1
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• pp.11-19
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• 2012

A major concern regarding the collection and storage of biodiversity information is the inefficiency of conventional taxonomic approaches in dealing with a large number of species. This inefficiency has increased the demand for automated, rapid, and reliable molecular identification systems and large-scale biological databases. DNA-based taxonomic approaches are now arguably a necessity in biodiversity studies. In particular, DNA barcoding using short DNA sequences provides an effective molecular tool for species identification. We constructed a large-scale database system that holds a collection of 5531 barcode sequences from 2429 Korean species. The Korea Barcode of Life database (KBOL, http://koreabarcode.org) is a web-based database system that is used for compiling a high volume of DNA barcode data and identifying unknown biological specimens. With the KBOL system, users can not only link DNA barcodes and biological information but can also undertake conservation activities, including environmental management, monitoring, and detecting significant organisms.