• Journal of Korean Society for Atmospheric Environment
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• v.16 no.E
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• pp.59-68
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• 2000

In this paper Various aerosol cyclones that are developed recently form Kwangju Institute of Science and Technology(KJIST) for increasing collection efficiency or for decreasing pressure drop are reviewed. For the first time, new sets of experimental data are reported on the particle collection efficiency of cyclones with modified surface bodies namely, spiral guide body, circumferential groove body, and vertical groove body. Multi-cylinder cyclones by adding one or two additional cylindrical walls into the conventional cyclone are also described. Ad an attempt to increase the collection efficiency of small particles, electrocyclone using an externally applied electric field was designed and operated. In addition, factors affecting the cyclone performance were studied including flowrate, body and outlet sizes, cyclone dust outlet, and gas property.

• 한국데이터정보과학회:학술대회논문집
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• 2004.04a
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• pp.211-224
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• 2004

Distributing information on the internet is common in our daily life. In the past, e-mail has been the primary choice of exchanging information, but instant messengers are gaining popularity abroad and domestically because of their immediate responses. Instant messaging has become the fastest growing communication technology in recent years. Instant messaging is effectively a chat room for two people. Users that have accounts with the same provider are able to send messages via computer in real time. Instant messaging has exploded into the business world as companies now utilize the technology for everything from interoffice communication to client/customer communication. In this paper, we propose a method of instant messenger system design for effective collaboration of statistical data collection.

• Design & Manufacturing
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• v.12 no.2
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• pp.57-62
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• 2018

In diabetics, daily blood glucose testing is generally required at home, and thus, performing blood collection several times a day using a blood line is essential. Blood collection in the home and in the hospital is a source of pain and is the second most common cause of infection. In blood collecting device generally consists of four major parts: inner-case, outer case, main shaft and triger, and the most import part among those for necessary functionality is the main shaft. Filling time and injection pressure, filling balance, strain-rate analysis of change based on availability of the product. The Moldflow of FEM simulation is used for the analysis of injection molding process. In this study, aims to create a technique for injection molding and manufacturing of a main shaft of a high-performance blood-collecting apparatus capable of automatically extracting a lancet to relieve pain through depth control of the lancet.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.232-238
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• 2004

The dynamic characteristics of the current collection process of the high-speed railway are investigated through signals acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to obtain the dynamic characteristics. The main natural frequency of the pantograph is found to be 8.5Hz. There also are components at low frequencies varying linearly with the train speed. The contact frequency components above 20Hz is attenuated as they pass through the secondary suspension. The main frequency component of the load cell signal is found to be related with the rolling motion of the panhead generated by the stagger in the catenary.

• Journal of the Korean Society for information Management
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• v.15 no.2
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• pp.7-28
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• 1998

The purpose of this study is to overview and analyze the commercial document delivery systems. to this end, the study first compared the current systems under three headings, that is, non-collection-based systems(Infotrieve, OCLC, UnCover, BIDS, Swets & Zeitlinger, Kyobobook), collection-based systems(EBSCO, ISI, UMI, BLDSC, CISTI, INIST, NCSI, JICST, KINITI), and specialized collection-based systems(Engineering Information Inc., IEEE/IEE, BIOSIS, CAS, NAL, RSC, TWI, ADONIS). Next, the study analyzeed the advantages and disadvantages of each system, based on the four performance criteria : scope of inventory/journal coverage, turnaround time, delivery ost and payment options, reliability and satisfaction rate.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.375-378
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• 2011

This study is intended to realize an intelligent controller using fuzzy control algorithms in order to recycle energy by recycling the waste water heat discharged by waste water heat collection boilers. Using waste water inflow temperature changes and waste water inflow amount changes as parameters, we present characteristic curves of the number of compressors being operated at fixed speeds and the temperature of hot water being discharged. We propose an intelligent controller that determines the optimum number of compressors being operated at fixed speeds in real time by measuring changes in the temperature and amount of waste water inflows in order to minimize the number of compressors being operated at fixed speeds relative to the waste water load flowing into the waste water heat collection boiler.

• Particle and aerosol research
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• v.19 no.3
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• pp.77-87
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• 2023

We present the development of a wetcyclone sampler designed for the sampling of airborne bacteria. The wetcyclone design involves a combination of two traditional cyclone shapes and computational fluid dynamics (CFD) analysis to validate its effectiveness in terms of pressure drop and collection efficiency. The wetcyclone exhibits a collection efficiency of over 90% for bacteria, specifically targeting Staphylococcus aureus. Additionally, the wetcyclone enables continuous bioaerosol sampling using a liquid medium (deionized water), demonstrating a concentration ratio exceeding >105 and a stable microbial recovery rate of 81.9%. The application of real-time quantitative polymerase chain reaction (qPCR) and the colony counting method ensures precise measurement of the concentration ratio and microbial recovery rate.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.1-11
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• 2015

Recently, NAND flash memories are used for storage devices because of fast access speed and low-power. However, applications of FTL on low power computing devices lead to heavy workloads which result in a memory requirement and an implementation overhead. Consequently, studies of B+-Tree on embedded devices without the FTL have been proposed. The studies of B+-Tree are optimized for performance of inserting and updating records, considering to disadvantages of the NAND flash memory that it can not support in-place update. However, if a general garbage collection method is applied to the previous studies of B+-Tree, a performance of the B+-Tree is reduced, because it generates a rearrangement of the B+-Tree by changing of page positions on the NAND flash memory. Therefor, we propose a novel garbage collection method which can apply to the B+-Tree based on the NAND flash memory without the FTL. The proposed garbage collection method does not generate a rearrangement of the B+-Tree by using a block information table and a proxy block. We implemented the B+-Tree and ${\mu}$-Tree with the proposed garbage collection on physical devices with the NAND flash memory. In experiment results, the proposed garbage collection scheme compared to greedy algorithm garbage collection scheme increased the number of inserted keys by up to about 73% on B+-Tree and decreased elapsed time of garbage collection by up to about 39% on ${\mu}$-Tree.

• Journal of Embryo Transfer
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• v.32 no.2
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• pp.59-64
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• 2017

Embryo transfer (ET) could be a relevant tool for genetic improvement programs in horses similar to those already underway in other species and produce multiple foals from the same mare in one breeding season. However, there have been no reports describing equine embryo transfer performed in Korea. In the present study, we performed an equine embryo collection and transfer procedure for the first time. We examined the embryo collection and pregnancy, size of embryo during the incubation period after collection, and progesterone (P4) and estradiol-$17{\beta}$ (E2) concentrations in mare's serum at embryo collection and transfer. A total of 16 donors responded to estrus synchronization; estrus was induced in 12 donors and 4 recipients, and artificial insemination was successful in 10 donors and six blastocysts were collected from donors. Of these blastocysts, we monitored the size of blastocysts for 3 day during incubation and transferred 2 blastocysts to a recipient, with 1 successful pregnancy and foal achieved. The dimensions of equine embryo at day 7 to day 9 were $409{\mu}m$, $814{\mu}m$ and $1,200{\mu}m$. The serum P4 and E2 concentrations were $7.91{\pm}0.37ng/{\mu}L$ and $45.45{\pm}12.65ng/{\mu}L$ in the donor mare, and 1$6.06{\pm}3.27ng/{\mu}L$ and $49.13{\pm}10.09ng/{\mu}L$ in the recipient mare.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.466.2-466.2
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• 2014

The Quantum dot (QD) solar cells have been under active research due to their high light harvesting efficiencies and low fabrication cost. In spite of these advantages, there have been some problems on the charge collection due to the limitation of the diffusion length. The modification of advanced nanostructure is capable of solving the charge collection problem by increasing diffusion length of electron. One dimensional nanomaterials such as nanorods, nanowires, and nanotubes may enhance charge collection efficiency in QD solar cells. In this study, we synthesized $TiO_2$ anatase nanorod arrays with length of 200 nm by two-step sol-gel method. The morphology and crystal structure for the nanorod were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The anatase nanorods are single-crystalline and possess preferred orientation along with (001) direction. The photovoltaic properties for the heterojunction structure QD solar cells based on the anatase nanorod were also characterized. Compared with conventional $TiO_2$ nanoparticle based QD solar cells, these nanostructure solar cells exhibited better charge collection properties due to long life time measured by transient open circuit studies. Our findings demonstrate that the single crystalline anatase nanorod arrays are promising charge transport semiconductors for heterojunction QD solar cells.