• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.548-554
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• 2016

In this study, semi-aqueous solutions containing carboxylic acids such as oxalic acid (OA), lactic acid (LA) and citric acid (CA) were formulated for the removal of copper etching residues produced at the interconnection process, and their characteristics were analyzed. Carboxylic acids in the solutions were apt to form various copper complexes according to the value of pH. Semi-aqueous solution containing 10 wt% CA showed the lowest etching rate of copper in the range from pH2 to pH7 and the highest selectivity in the range of pH 2 to pH 4. However, the cleaning solution containing 10 wt% LA revealed the superior selectivity at the range from pH 5 to pH 7. Appropriate selection of carboxylic acid should be required to improve the performance of cleaning solution. In the case of CA, the etching selectivity of copper oxide complex to copper was increased with the concentration of CA in the solution, when the solutions contain over 5 wt% CA, the copper interconnection layer has a metallic copper surface more than 88% in the area. The result shows that CA contained semi-aqueous solution has a relatively good cleaning ability.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.2
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• pp.44-55
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• 1998

This study was carried out to investigate the feasibility of OTEC(Ocean Thermal Energy Conversion) operation, in the East Sea of Korea. Accumulated cruise data of NFRDI (National Fisheries Research and Development Institute) over the period 1966~1995 were used to locate appropriate spot by season as well as by latitude which would show the difference at least $15^{\circ}C$ or more between the surface layer and each depth of 50, 100, 150, 200, 250, 300, 400 and 500m. Our results showed that the coastal areas of Pohang city met the requirement of more than $20^{\circ}C$ difference for OTEC plant from August to October. In contrast, in case that $15^{\circ}C$ would be possible thermal difference to operate OTEC plant, most coastal areas in the East Sea including Pohang from June to December are potential candidates for this future energy source. Therefore, we present in this paper the first option to locate the best place for OTEC plant operation using Geographical Information System (GIS), which is currently used for multi-dimensional space analysis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.3
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• pp.109-124
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• 2018

In order to find the optimum culture condition for marine free-living nematoda in the laboratory, various agar media were developed and experiments were carried on nematodes. Nematodes have collected from the bottom of the sandy sediments' surface layer (about 5cm sediment) of Taean Mallipo beach's intertidal zone. Especially, with regard to agar medium, Killian medium was transformed slightly, density of agar had made a difference and this agar medium(height 2.0 mm on diameter 60 mm Petri dish) was divided. It was mixed with 5 different species of microorganism as nematodes' live food and added each culture medium. Five individuals of Enoplolaimus sp. on each culture medium were grown in a culture medium which was set on $20^{\circ}C$ and light blocked. Moreover, as a result of the optimum culture condition, 1.0% density of agar showed the highest survival rates (the average time of survival is 246.8 hours). On the other hand, the 0.4% density of agar adding Killian medium, bacto peptone and beef extract showed the lowest survival rates, which indicates the average time of survival is 27.6 hours. About Bathylaimus sp., on Killian medium's 1.0% density of agar(no feeding amount) showed the highest survival rates, which connects that the hatching rate 94.7% after 99.5 hours and it laid 7 eggs averagely on the spawning amount and the hatching rate experiment.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.301-312
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• 1998

To efficiently separate a protein stimulating sperm swim-up migration and movement from follicular proteins, the effect of paper chromatography and liquid chromatography with reverse phase column and superose column on protein separation was examined. And the results obtained were as follows; 1. The band component that was separated with paper chromatography stimulated sperm migration and movement depending on its additional levels. Especially, band I component significantly increased sperm migration. But, all components of bands 1, 2 and 3 showed lower sperm migration and movement, compared to follicular fluid at the same additional level. 2. Among the components separated from follicular protein of 2~5mm follicles with reverse phase column ($\mu$RPC), components at retention time (RT) of 3.33, 7.00, 13.87, and 16.6A minutes stimulated sperm migration within a limited range. 3. All components separated from follicular protein of 10mm follicles with $\mu$RPC column didn't stimulate sperm migration and movement. 4. Among the components separated from follicular protein of 2~5m follicles with superose column, components at retention volume (RV) of 1.35 and 0.82 ml significantly stimulated sperm migration and movement. In conclusion, protein components stimulating sperm migration and movement were efficiently separated with superose column in Smart system. Especially, components of RV 1.35 and RV0.82 stimulated sperm swim-up separation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.84-91
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• 2005

For long time, the takeoff and landing control of airship was worked by human handling. With the development of the autonomous control system, the exact controls during the takeoff and landing were required and lots of methods and algorithms were suggested. This paper presents the result of airship take-off and landing by buoyancy control using air ballonet volume change and performance control of pitch angle for stable flight within the desired altitude. For the complexity of airship's dynamics, firstly, simple PID controller was applied. Due to the various atmospheric conditions, this controller didn't give satisfactory results. Therefore, new control method was designed to reduce rapidly the error between designed trajectory and actual trajectory by learning algorithm using an artificial neural network. Generally, ANN has various weaknesses such as large training time, selection of neuron and hidden layer numbers required to deal with complex problem. To overcome these drawbacks, in this paper, the RBFN (radial basis function network) controller developed. The weight value of RBFN is acquired by learning which to reduce the error between desired input output through and airship dynamics to impress the disturbance. As a result of simulation, the controller using the RBFN is superior to PID controller which maximum error is 15M.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.5-5
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• 1999

The Principal deficiency of the existing notion about the sintering-mixtures consists in the fact that almost no attention is focused on the Phenomenon of alloy formation during sintering, its connection with dimensional changes of powder bodies, and no correct ideas on the driving force for the sintering process in the stage of establishing chemical equilibrium in a system are available as well. Another disadvantage of the classical sintering theory is an erroneous conception on the dissolution mechanism of solid in liquid. The two-particle model widely used in the literature to describe the sintering phenomenon in solid state disregards the nature of the neighbouring surrounding particles, the presence of pores between them, and the rise of so called arch effect. In this presentation, new basic scientific principles of the driving forces for the sintering process of a two-component powder body, of a diffusion mechanism of the interaction between solid and liquid phases, of stresses and deformation arising in the diffusion zone have been developed. The major driving force for sintering the mixture from components capable of forming solid solutions and intermetallic compounds is attributed to the alloy formation rather than the reduction of the free surface area until the chemical equilibrium is achieved in a system. The lecture considers a multiparticle model of the mixed powder-body and the nature of its volume changes during solid-state and liquid-phase sintering. It explains the discovered S-and V-type concentration dependencies of the change in the compact volume during solid-state sintering. It is supposed in the literature that the dissolution of solid in liquid is realised due to the removal of atoms from the surface of the solid phase into the melt and then their diffusicn transfer from the solid-liquid interface into the bulk of liquid. It has been shown in our experimental studies that the mechanism of the interaction between two components, one of them being liquid, consist in diffusion of the solvent atoms from the liquid into the solid phase until the concentration of solid solutions or an intermetallic compound in the surface layer enables them to pass into the liquid by means of melting. The lecture discusses peculimities of liquid phase formation in systems with intermediate compounds and the role of the liquid phase in bringing about the exothermic effect. At the frist stage of liquid phase sintering the diffusion of atoms from the melt into the solid causes the powder body to grow. At the second stage the diminution of particles in size as a result of their dissolution in the liquid draws their centres closer to each other and makes the compact to shrink Analytical equations were derived to describe quantitatively the porosity and volume changes of compacts as a result of alloy formation during liquid phase sinteIing. Selection criteria for an additive, its concentration and the temperature regime of sintering to control the density the structure of sintered alloys are given.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.43-50
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• 2004

One of the major advantages of microsurgical reconstruction for defects of the hand is that these techniques allow for selection of the most ideal tissue to reconstruct a particular defect, thus optimizing the functional and aesthetic outcome. The dorsalis pedis free flap is an excellent reconstructive tool for various hand reconstructions. It has a reliable vasculature with vessels that are relative large on a long pedicle. It provides thin pliable tissue and be innervated by deep peroneal nerve. Coupled with its thinness and pliability, it is ideal for innervated cover of critically sensitive area, especially such as the hand. Thus it can be used as a cutaneotendinous flap, or an osteocutaneous flap. Otherwise, the major criticism with this flap is related to its uncertain vascularity and the donor defect. It is the purpose of this paper to outline our technique of flap elevation and donor site closure and to indicate our current use of this flap in hand reconstruction. We have treated 10 cases (6 burn scar contracture cases, 4 acute hand trauma cases) of hand reconstruction from Dec. 3, 1997 to Mar. 4, 2004 using dorsalis pedis free flap. The key points for sucess in terms of a viable flap and acceptable donor site are the preservation of the critical dorsalis pedis-first dorsal metatarsal vascular axis and the creation of a viable bed for grafting. In addition, we substituted preserved superficial fat skin graft for split thickness skin graft and wet environment was offered for good graft take. Preserved superficial fat skin is defined as composite graft containing epidermis, dermis and superficial fat layer. With sufficient care in flap elevation and donor site closure, a good graft take of preserved superficial fat skin under wet environment can be achieved with no functional disability and minimal cosmetic deformity in donor site. This flap has proved itself to be a best choice for hand reconstruction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.15-23
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• 2017

The person Re-identification is the most challenging part of computer vision due to the significant changes in human pose and background clutter with occlusions. The picture from non-overlapping cameras enhance the difficulty to distinguish some person from the other. To reach a better performance match, most methods use feature selection and distance metrics separately to get discriminative representations and proper distance to describe the similarity between person and kind of ignoring some significant features. This situation has encouraged us to consider a novel method to deal with this problem. In this paper, we proposed an enhanced recurrent neural network with three-tier hierarchical network for person re-identification. Specifically, the proposed recurrent neural network (RNN) model contain an iterative expectation maximum (EM) algorithm and three-tier Hierarchical network to jointly learn both the discriminative features and metrics distance. The iterative EM algorithm can fully use of the feature extraction ability of convolutional neural network (CNN) which is in series before the RNN. By unsupervised learning, the EM framework can change the labels of the patches and train larger datasets. Through the three-tier hierarchical network, the convolutional neural network, recurrent network and pooling layer can jointly be a feature extractor to better train the network. The experimental result shows that comparing with other researchers' approaches in this field, this method also can get a competitive accuracy. The influence of different component of this method will be analyzed and evaluated in the future research.

• KSBB Journal
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• v.21 no.1 s.96
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• pp.42-48
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• 2006

Bacillus subtilis KMU-13 was isolated from the Lillehammer forest soils at Norway and shown a strong antifungal activity on cucumber scab, Cladosporium cucumerinum KACC 40576. B. subtilis KMU-13 produced a maximum level of antifungal substance under incubation aerobically at $30^{\circ}C$, 180 rpm for 48 hours in LB broth containing 0.5% maltose and 0.5% bactopeptone and initial pH adjusted to 6.0. Butanol extract of cultured broth was confirmed inhibitory zone by plate assay and Rf 0.64 value substance by thin layer chromatography (TLC) represented high antifungal activity against C. cucumerinum KACC 40576 and also shown fungal growth inhibitory activity against Botytis cinerea KACC 40573, C. gloeosporioides KACC 40804, D. byoniae KACC 40669, F. oxysporum KACC 40037, F. oxysporum KACC 40052, F. oxysporum f. sp. radicis-lycopersici KACC 40537, F. oxysporum KACC 40902, M. cannonballus KACC 40940, P. cambivora KACC 40160, R. soiani AG-1 KACC 40101, R. solani AG-4 KACC 40142, and S. scleotiorum KACC by agar diffusion method.

• Research in Plant Disease
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• v.14 no.1
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• pp.43-50
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• 2008

Rhizoctonia blight (large patch) caused by Rhizoctonia solani AG2-2 is one of the major diseases on zoysiagrass in golf courses. In this study, anatgonistic bacteria to R. solani AG2-2 were selected in vitro tests using confrontation bioassay and triple layer agar diffusion method. The most active bacteria, Bacillus subtilis CJ-9 were tested for controlling large patch in pots. Relative Performance Indies (RPI) was used as a criterion for the selection of potential biocontrol agent. B. subtilis CJ-9 showed resistance to major synthetic agrochemicals used in golf course. In field tests at golf course, B. subtilis CJ-9 was more effective in suppression of large patch severity and population development of R. solani AG2-2 in soil than chemical fungicides. B. subtilis CJ-9 could be an alternative to chemical fungicides for eco-friendly management of large patch on zoysiagrass.