• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.1-14
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• 2020

In this paper, we propose to solve the problem of increasing system memory usage due to an increase in the number of mapping information management when using a NAND flash memory-based storage device in an existing sector-based file system. The proposed technique is to store only mapping information in page units based on index blocks and manage them in block units. To this end, the proposed technique uses a sequential offset for storing and managing a plurality of mapping information in one page in a small block, and a reverse offset for a spare page corresponding to a change in mapping information in the block. Through this, the proposed technique has the advantage that the number of block-unit deletions is less than that of the existing technique, and the system memory usage required for mapping information management is low. Reduced by about 32%.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.706-716
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• 2016

Because of efficient space utilization and fast key search times, B-trees have been widely accepted for the use of indexes in HDD-based DBMSs. However, when the B-ree is stored in flash memory, its costly operations of node updates may impair the performance of a DBMS. This is because the random updates in B-tree's leaf nodes could tremendously enlarge I/O costs for the garbage collecting actions of flash storage. To solve the problem, we make all the parents of leaf nodes the virtual nodes, which are not stored physically. Rather than, those nodes are dynamically generated and buffered by referring to their child nodes, at their access times during key searching. By performing node updates and tree reconstruction within a single flash block, our proposed B-tree can reduce the I/O costs for garbage collection and update operations in flash. Moreover, our scheme provides the better performance of key searches, compared with earlier flash-based B-trees. Through a mathematical performance model, we verify the performance advantages of the proposed flash B-tree.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.486-489
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• 2002

Construction management has been a target of the result and the index which were decided by whether the resourecs(time, cost and progress...etc) were used. but this has been serious problems in time and cost because of the shortage of storage space, the incident, lowering of efficiency for works, working impossible of between work categories and the demage of finished products. Therefore I noticed that more correct and more objective establish of data collecting system was necessary. it was through the diversification of information for exchange and communication between the construction site and participants. DVR(Digital Video Recorder) and internet technology were suggested for a solution to this problem. the collected information by DVR was divided to 3 steps as how long it used and how much it processed for improving efficiency of using and storage of information. and then it was verified through applying to cases at construction site.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.191-196
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• 2014

The solar water heating system is one of the seven green campus items installed at the Gangneung campus of Gangneung-Wonju National University. The solar water heating system has two types of solar collectors, four storage tanks and monitoring equipment. Fixed and azimuth-tracking solar collectors were installed to collect heat from the sun. The amount of heat collected by the two different types of solar collectors was calculated from the temperature of the monitored storage tanks. Our results showed that the amount of solar heat collected by the azimuth-tracking solar collector was 19% greater on a sunny day and 23% greater on a rainy day than that collected by the fixed solar collector; therefore, the azimuth-tracking solar collectors are, on an average, 21% more efficient than the fixed solar collectors.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.133-139
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• 2005

Oxidative stress is one of the major causes of failure in in vitro storage of boar semen. Reactive oxygen species (ROS) are known to be important mediators of such stress. The present study examined the effects of pyruvate and taurine on sperm motility and expression of BAD, Cytochrome c, Caspase-3 and Cox-2 protein in in vitro storage of boar semen, and tested the effect of semen treated with antioxidant with or without hydrogen peroxide on the development of IVM/IVF porcine embryos. Semen samples were transported to the laboratory at $17^{\circ}C$ within 2 hr after collection and were treated with different concentration of pyruvate $(1\~10mM)$ and taurine $(25\~100mM)$ with or without 250uM $H_2O_2$ respectively. The supplementation of pyruvate and taurine increased sperm motility in boar semen during in vitro incubation at $37^{\circ}C$. Expression of apoptosis protein (BAD, cytochrome c, caspase-3 and cox-2) were reduced in the group of boar semen treated with pyruvate and taurine when compared to the other groups. The developmental rates of IVM/IVF porcine embryos fertilized by semen treated with pyruvate and taurine were significantly increased when compared to control (P<0.005). These results indicate that supplementation of pyruvate and taurine as antioxidants in boar semen extender can improve the semen quality and increase in vitro development of porcine IVM/IVF embryos when boar semen treated with antioxidants was used for in vitro fertilization.

• The Journal of Bigdata
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• v.4 no.2
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• pp.93-103
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• 2019

In this paper, we introduce a big data platform and a metadata management technique for fishery science R & D information. The big data platform collects and integrates various types of fisheries science R & D information and suggests how to build it in the form of a data lake. In addition to existing data collected and accumulated in the field of fisheries science, we also propose to build a big data platform that supports diverse analysis by collecting unstructured big data such as satellite image data, research reports, and research data. Next, by collecting and managing metadata during data extraction, preprocessing and storage, systematic management of fisheries science big data is possible. By establishing metadata in a standard form along with the construction of a big data platform, it is meaningful to suggest a systematic and continuous big data management method throughout the data lifecycle such as data collection, storage, utilization and distribution.

• Journal of the Korean association of regional geographers
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• v.3 no.2
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• pp.105-120
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• 1997

One of the most important issues of object-oriented geographical database system is to develop an indexing technique which enables more efficient I/O processing within aggregation hierarchy or inheritance hierarchy. Up to present, several indexing schemes have been developed for this purpose. However, they have separately focused on aggregation hierarchy or inheritance hierarchy of object-oriented data model. A recent research is proposing a nested-inherited index which combines these two hierarchies simultaneously. However, this new index has some weak points. It has high storage costs related to its use of auxiliary index. Also, it cannot clearly represent the inheritance relationship among classes within its index structure. To solve these problems, this thesis proposes a pointer-chain index. Using pointer chain directory, this index composes a hierarchy-typed chain to show the hierarchical relationship among classes within inheritance hierarchy. By doing these, it could fetch the OID list of objects to be retrieved more easily than before. In addition, the pointer chain directory structure could accurately recognize target cases and subclasses and deal with "select-all" typed query without collection of schema semantic information. Also, it could avoid the redundant data storing, which usually happens in the process of using auxiliary index. This study evaluates the performance of pointer chain indexing technique by way of simulation method to compare nested-inherited index. According to this simulation, the pointer chain index is proved to be more efficient with regard to storage cost than nested-inherited index. Especially in terms of retrieval operation, it shows efficient performance to that of nested-inherited index.

• Korean Journal of Veterinary Service
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• v.35 no.3
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• pp.183-189
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• 2012

Tsutsugamushi disease or scrub typhus cause by Orientia tsutsugamushi is an endemic disease in Korea. Chigger mites and field rodents play roles in transmission of the disease by the vector and host of the agent. The purpose of this study is to investigate the density of the chigger mites and field rodents due to environmental factors such as temperature, relative humidity, soil thickness and the various vegetations to the 9 field rodent collection sites. The total 62 field rodents was captured by the Sherman collapsible traps from April to October 2009 at the Jangseong of Jeonnam Province, Korea. The trapping rate of the field rodents by the different collecting sites was dominant at subside storage water (24%), bush near by dam (22%), bank around field (20%), followed by 18% of grassy field and surround cattle shed. The distribution of chigger mites by the different collecting sites was the highest at Bush near by dam (28.7%). And the sites of subside storage water, bank around field and surround cattle shed were 20.4%, 18.8%, 16.4%, respectively. On the other hand the collecting sites of stream bank and ridges between rice paddies were not collected. The temperature to the collecting sites was showed $24.1^{\circ}C$ in June and $24.2^{\circ}C$ in October which was higher than April ($10.6^{\circ}C$), whereas lower than May ($25.3^{\circ}C$) and September ($26.8^{\circ}C$). The highest number of mites was collected at $24.2^{\circ}C$ and 46.6% relative humidity in October. The chigger mites and field rodents were highly collected between 18 and 24% at the sites where are loosely in the superficial layers of the soil from 8.0 cm to 10.2 cm. Total 25 species of vegetation were distributed at the collecting sites. In the present study, strong evidence was found that bank around field and grassy field were provided for the prevalence sites of tsutsugamushi disease.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.28-38
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• 2013

During the past decades, the B+-tree has been most widely used as an index file structure for disk-resident databases. For the disk based B+-tree, a node update can be cheaply performed just by modifying its associated disk page in place. However, in case that the B+-tree is stored on flash memory, the traditional algorithms of the B+-tree come to be useless due to the prohibitive cost of in-place updates on flash memory. For this reason, the earlier schemes for flash memory B+-trees usually take an approach that saves B+-tree changes from real-time updates into extra temporary storage. Although that approach can easily prevent frequent in-place updates in the B+-tree, it can suffer from a waste of storage space and prolonged search times. Particularly, it is not allowable to process range searches on the leaf node level. To resolve such problems, we devise a new scheme in which the leaf nodes and their parent node are stored together in a single flash block, called the p-node block.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.232-239
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• 2017

Objectives: The evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time. Materials and Methods: The experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The ${\times}12.8$ magnification was used for the 9 mm slices and ${\times}19.2$ magnification for the 3 mm and 6 mm slices under light-emitting diode (LED) transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis. Results: Dentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015). Conclusions: LED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.