• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1214-1220
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• 2003

Antimicrobial activity of Rhus javanica (RJ) extract against animal husbandry disease-related bacteria was determined by a paper disc method. The RJ extracts showed a significant antimicrobial activity against Gram positive (+) bacteria and especially the activity was most potent against L. monocytogenes and S. epidermidis. Minimum inhibitory concentrations (MIC) of the MeOH and EtOH extracts of RJ were in the range of 0.8 ∼ 16 mg/mL and 0.8 ∼ 10 mg/mL, respectively. Furthermore, among five solvent fractions (n-hexane, CHC1$_3$, EtOAc, n-BuOH and $H_2O$ frs.) from MeOH extract of RJ, the EtOAc fr. exhibited the most significant antimicrobial activity The antimicrobial activities of RJ extracts against most microbial strains were unstable by either heat treatment or acid treatment. The inhibitory effect of RJ extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of RJ extracts into growth medium. The growth of gram positive (+) bacteria, S. aureus, S. epidermidis and L. monocytogenes was inhibited for 72 hours when at least 300 ppm of RJ extracts added, but the growth of gram negative (-) bacteria was only inhibited when at least 500 ppm of RJ extracts were added. Taken together, tile antimicrobial activities of RJ extracts were more effective against gram positive (+) bacteria compared to those against gram negative (-) bacteria.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.41-50
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• 1987

The various conditions of photographs, especially kinds of films, combinated filters and seasons are important factors for forestry purpose aerial photography. In this paper the variations of tones were compared between color and color infrared, panchromatic black and white and infrared black and white, and among false color photographic images created by using 3 kinds of filters when prints are made. Color infrared film was good for identifying tree species, for its spectral signatures had a greater range of tones and hues than color signatures. In that case taken in May were more effective than taken April. False color photographs were not so good as color photographs because they were mostly dark and indistinct. Infrared black and white film with medium red filter showed potential for separating broad-leaved forests from conifers. MSS composed photographs, when composed with proper bands and densities, were proved useful for distinguishing land use types but not applicable to more detailed practices such as forest type separation and tree species identification.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.45-45
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• 2018

We had already reported the successful germination for green pods of purple lady's slipper orchid (Cypripedium macranthos Sw.). The green pod methods is to take immature seeds in green capsules, sterilize the capsule, and take out the sterile seeds. This method, however, needs very critical time of harvest. The critical time of seed harvest changes depending upon the species, condition of the specimen, and climatic influence, and the right time lies between 5 and 12 weeks after fertilization. In this study, the mature seeds were collected after 120-130 days with hand-polination of lady's slipper orchids. Mature seeds are usually dormant and it has to be overcome, either with hormone or storing the seeds near freezing for two or three months to break dormancy. The seeds were first surface sterilized with 70% ethanol and then transferred 1% NaOCl for 10-15 minutes, followed by rinses 3 times with sterilized distilled water. The cypripedium seeds consists of an embryo within a seed coat known as a testa. The testa is water repellent and the seed has a large air space between the embryo and testa so the seed tends to float on water. We had resolved the problems with vacuum pump to soak water into the testa before sterilization. The seeds were placed on liquid or agar solidified germination media. Cultures were incubated at $24{\pm}1^{\circ}C$ in dark. The seeds were germinated in 6-8 weeks in liquid suspension culture (germination percentage over 18%); however, the seeds on agar solidified media took more than 5 months to germinate and the germination percentage less than 5%. The most effective media for liquid culture was 1/4 strength Murashige and Skoog (MS) medium with 50 ml/l coconut water ($4brix^{\circ}$) at pH 5.8.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.327-335
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• 2001

In order to establish a whitefly control system using conventional groups of insecticide(carbamate, organophosphorus and pyrethroid insecticides), three alternative application methods were designed on the medium growth stage of cucumber. To discriminate the effectiveness of these sequences observed were the residual activity of insecticides, frequency of insecticide applications, residue of insecticides in cucumber leaves, development of insecticide resistance in whitefly, and yield of fruits. Spraying furathiocarb, a carbamate insecticide, was very effective in reducing the frequency of application for the control of white flies. The effectiveness of furathiocarb was enhanced by the potentiation process to carbofuran, the long residual activity, and the lower development rate of insecticide resistance. Methion, an organophosphorus insecticide, did not show resistance development after successive use but resulted in short residual activity. However, other organophosphates, profenofos and phenthoate, lost their activity by the resistance development. Decreasing activity was common to pyrethroids, deltamethrin and zetacypermethrin due to resistance. From these results it could be drawn a conclusion that furathiocarb, a carbamate insecticide, was the most desirable among conventional insecticide groups for the management of greenhouse whitefly population on the cucumber. To prevent an outbreak of the insect pest by various cause, it was recommended to choose acetamiprid, a nicotinoid, which showed very good control efficacy to the resistance insects to conventional insecticides.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.356-364
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• 2020

An experimental study to investigate the effect of self-cleaning of mortar mixed with photocatalyst was performed out in this study. Test parameters included the photocatalyst content and surface roughness of the specimens. The experimental mortar specimens were manufactured by mixing a photocatalyst by cement weight of 2.5%, 5.0%, 7.5% and 10.0%. In addition, the surface roughness was categorized into three cases. They included flat surface condition, little surface roughness(medium roughness), and high surface roughness. After mortar specimens were cured for 28 days, they were illuminated by an ultraviolet lamp for 24 hours and immersed in a methylene blue conditioning solution for 12 hours. Thereafter, an ultraviolet(UV) lamp was illuminated on the specimens for 48 hours in an experimental chamber and then the color change of methylene blue solution was measured by using a spectrophotometer over illuminating time of UV lamp. The color change of methylene blue tended to increase as photocatalyst contents increased. Test results meant that photocatalyst was effective for self-cleaning in mortar. However, the color change of the methylene blue solution did not show a noticeable tendency at different surface roughness conditions. It might be due to the uneven photocatalyst distribution on the surface of mortar specimens.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1150-1158
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• 2011

More than 100 Mbps rate is needed in the UBcN for a subscriber to receive broadband traffics with multi-channel like UDTV or 3DTV. Although the optical fiber is recently deployed for the FTTH, the UTP is the most widely used medium and will be used in UBcN age. Network providers may consider the 1000BASE-T or the vectorized VDSL if they adopts the UTP in the place where does not have optical fibers. But UTP should be expanded because 1000BASE-T and vectorized UTP needs 4 and 3 pairs cable, respectively while residential region has not exceeding 2 pair UTP cable. To solve the problem, we propose a 500BASE-T technology using 2 pairs UTP in this paper. The technology introduces a rate adaptation sublayer and a SERDES sublayer above and under the PCS, respectively. The rate adaptation sublayer is compatible for the GMII. Also, if we modify the SERDES sublayer, the technology can easily obtain 250BASE-T with 2 pairs UTP. We implement such functions with FPGA and analog board and verify the function of rate adaptation and symbol vector synchronization, and effective transmission rate by experiments. In particular, we show that link efficiency is increased by enable control in the rate adaptation sublayer.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.793-802
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• 2008

The development methods which utilize OSSs have been tried as new alternative to solve limits of the previous software developments such as the quality of software, and time and cost of developments. Especially, small and medium companies are suffering from difficulty in applying large-scale development methodology whenever they develop softwares. Therefore, in the current situation that demand for small-scale development methodology is increasing, the methods of utilizing OSSs can become an efficient way to save costs and reduce a development period. Accordingly, analysis of open-source is no fixed procedure or method to utilize open-source for software developments in the field. In this thesis, to solve such problems, we propose the procedures and methods for identifying and selecting suitable open-source, and effective methods for improvement and integration through least modification on the basis of synthesis of existing researches and experiences in development projects. For selection of OSSs, we did identify correct requirements for the software to be developed, investigate the open-source just matching with such requirements, draw a candidate index, establish assessment criteria, and the consequently present a method to select OSSs. And, we deduced the validity and improvement of each detailed activity from practical application to an actual project and assessment.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.293-300
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• 2014

TDMA(Time Division Multiple Access) is a channel access scheme for shared medium networks. The shared frequency is divided into multiple time slots, some of which are assigned to a user for communication. Techniques for TDMA can be categorized into two classes: synchronous and asynchronous. Synchronization is not suitable for small scale networks because it is complicated and requires additional equipments. In contrast, in DESYNC, a biologically-inspired algorithm, the synchronization can be easily achieved without a global clock or other infrastructure overhead. However, DESYNC spends a great deal of time to complete synchronization and does not guarantee the maximum time to synch completion. In this paper, we propose a lightweight synchronization scheme, C-DESYNC, which counts the number of participating nodes with GP (Global Packet) signal including the information about the starting time of a period. The proposed algorithm is mush simpler than the existing synchronization TDMA techniques in terms of cost-effective method and guarantees the maximum time to synch completion. Our simulation results show that C-DESYNC guarantees the completion of the synchronization process within only 3 periods regardless of the number of nodes.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.1
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• pp.133-158
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• 2011

In 2030s, as we enter in to the era of BT (Bio-Technology) market opening up, technologies in all areas such as IT, data analysis, IC and biochemistry are necessitated. New development in technology will be based on "Convergence", especially between IT and BT. In order to have synergy effects from the convergence, those related industries and universities should be physically inter-related in an appropriate location. Until 2009, 819 industrial clusters where many Korean industries and firms are concentrated have been constructed in Korea. They have had supports from various institutions and facilities. However, few systems designed to assist "intellectual property (IP) service" for technology convergence are found in Korea. Thus, by analyzing current problems and challenges of the Korean industrial clusters, this paper suggests a possible answer to maximize the synergy from technology convergence through organic cooperation among companies in industrial clusters. This paper finds that the Korean industrial clusters need to establish IP service supporting center while suggesting its function and concept on organization structure, and work flow, which help firms to develop IP strategies. In addition, the paper provides a direction for current IP system and policies implemented by the Korean government to be more effective to small-and-medium-sized companies located in the industrial clusters.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.799-804
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• 2016

Broadband powerline communication (BPLC) uses distribution lines as a medium for achieving effective bidirectional data communication along with electric current flow. As the material characteristics of power lines are not good at the communication channel, the development of power line communication (PLC) systems for internet, voice, and data services requires measurement-based models of the transfer characteristics of the network suitable for performance analysis by simulation. In this paper, an analytic model describing a complex transfer function is presented to obtain the attenuation and path parameters for a multipath power line model. The calculated results demonstrated frequency-selective fading in multipath channels and signal attenuation with frequency, and were in good agreement with the experimental results. Inductive coupling units are used as couplers for coupling the signal to the power line to avoid physical connections to the distribution line. The inductance of the ferrite core, which depends on the frequency, determines the cut-off frequency of the inductive coupler. Coupling loss can be minimized by increasing the number of windings around the coupler. Coupling efficiency was improved by more than 6 dB with three windings compared to the results obtained with one winding.