• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.10
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• pp.2272-2281
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• 1997

This paepr proposes a shared medium access control protocol for hgih-speed multimedia services of distributed subscriber home and small-sized business ATM networks. This protocol offers not only global fairness for the whole network at the same time, but also local fairness for different prioritytraffics on each node. Considering that the future B-ISDN service si a mixture of real and non-real time traffic data, this protocol is designed to accommodate the real time service, by controlling the priority of the real and non-real time data. The simulation results show that the proposed protocol has better performance than the other protocols.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.380-386
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• 2014

In this paper, a higher-order mode coupler using coaxial-structure waveguide for Ku-band monopulse satellite tracking is proposed. The proposed higher-order mode coupler is built in a coaxial structure for compactness and weight reduction, making it suitable for mobile tracking systems. The inner circular waveguide of coaxial-structure is used to extract the fundamental mode signal and the high-order mode signal is extracted from the four slots of the outer circular waveguide and then transmitted via given stepped rectangular waveguide structure. The simulated results show that proposed higher-order mode coupler covers 250 MHz(12.75 GHz ~ 13.00 GHz) bandwidth with return loss and insertion loss characteristics. The antenna patterns of fundamental mode and higher-order mode applicable to monopulse tracking are generated successfully. Designed higher-order mode coupler using coaxial waveguide structure for Ku-band is expected to be used for high precision monopulse satellite tracking systems.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.86-94
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• 2010

This paper proposed an authentication interworking protocol (AIP) based on IEEE 802.21 MIH in the heterogeneous networks. The proposed AIP using the RSA signature reduces handover delay time and communication message overhead when the mobile node moves between the heterogeneous networks. It defines new AIP TLV in MIH frame format and uses the MIH Information Server (MIHIS) for proxy signature issue instead of the authentication server for the heterogeneous networks. For low handover delay, the proposed AIP performs pre-authentication processes with MIH protocol before layer 2 handover. Also, this paper analyzed the performance of the handover and compared with the non-secure MIH protocol.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.124-130
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• 2012

In this paper, we propose a feature point selection method for MPEG CDVS CE-7 which is processing on International Standard task. Among a large number of extracted feature points, more important feature points which is used in image matching should be selected for the compactness of image descriptor. The proposed method is that remove the feature point in the extraction phase which is filtered by nearest neighbor distance ratio matching in the matching phase. We can avoid the waste of the feature point and employ additional feature points by the proposed method. The experimental results show that our proposed method can obtain true positive rate improvement about 2.3% in pair-wise matching test compared with Test Model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.480-485
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• 2004

In this paper, a new predistortion linearizing method using frequency up-conversion operation of mixer is proposed. This linearizing method doesn't require any additional signal sources in spite of frequency up-conversion mixing operation. This method extracts the 2nd low frequency intermodulation distortion signal from input signals and uses the extracted 2nd low frequency intermodulation distortion signal as mixing signal source. To show validation of the proposed predistortion method, we made K-PCS power amplifier. On 2-tone signals amplification process, the (C/I) ratio of amplifier is improved 26 ㏈ (@Po=22 ㏈m/tone), where two tones are 1.8544 ㎓ and 1.8556 ㎓, respectively. And (C/I) ratio is improved more than to 20 ㏈ for 17 ㏈ output signal dynamic range. On IS-95A CDMA 1FA amplification process, the improvements of adjacent channel power ratio(ACPR) are 10.8 ㏈ and 6.4 ㏈ at ${\pm}$885 ㎑ and ${\pm}$1.25 ㎒ offset points, respectively.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.238-242
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• 1996

The second instar milkweed bugs, Oncopeltus fasciatus were exposed to the residue of 6-methoxy-7-ethoxy-2, 2- dimethylchromene(or 7-ethoxy precocene 11, 7-EP-11) with one, two, or four different kinds of synergist(s) deposited as a residue on 9 cm diameter petri dishes. The anti juvenile hormone analog, 7-EP-I1 yielded a 50% effectiveness concentration at 1.18 wg/cmZ. The concentration of 7-EP-I1 and R020-9747 combined gave 0.084 ~*g/cm', as much 14 times more potent than with 7-EP-I1 alone. Most of the other synergists, including geraniol, 4-chalcone oxide, isosafrole, and piperonyl butoxide however, showed comparatively low level synergism with 1.0-4.3 times, depending upon the combinations of the synergist(s). The obtained results were considered that R020-9747, an analog of benzopyran with similar structure to that of 7-EP-I1 inhibited selectively the insect monooxygenase oxidative defense mechanism, in the body except for corpora allata because general antioxidants of piperonyl butoxide, isosafrole, and 4-phenyl chalcone oxide showed relatively mild synergism.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.171-178
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• 1993

The effects of Korean Red Ginseng (KRG) in rats submitted to exhaustion exercise have been studied, by measuring different enzymatic and hematological parameters in plasma and muscle. KRG powder was daily administered to 15 male Wistar rats for a period of two weeks. Another group of 15 rats with the same characteristics were administered physiological saline. Both groups were divided as follows: 5 control. 5 exercised till exhaustion and 5 recovered for 48 h after exhaustion. The following results were obtained for the groups treated with KRG in rapport to those treated with saline: - Higher endurance to running, - Increase of the osmotic resistence of red blood cells and higher presence of reticulocytes. - Lower triglyceride levels in plasma. - Increase non statistically significant of urea levels in plasma, - Lower non statistically significant hypoglycemia after exhaustion exercise. - Decrease of liver glycogen after exercise and faster recovery of the resting - level. - Protective effect on tissular damage produced by exhaustion exercise - Lower LDH activity in all studied muscles. only statistically significant in the WG.

• Korean Journal of Medicinal Crop Science
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• v.18 no.2
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• pp.118-125
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• 2010

This study was carried out to determine changes in general chemical composition, free sugars, physicochemical properties of extract, and ginsenoside contents depending upon processing methods. Ginseng roots harvested from the same field were employed for the processing into white ginseng (WG), taegeuk ginseng (TG), red ginseng A (RGA, steamed one time), and red ginseng B (RGB, steamed three times). The fat content decreased by increasing duration of treatment and number of steaming treatment. On the other hand, there was no significant variation in contents of ash and carbohydrate depending on processing methods. Contents of sucrose and maltose was higher in Taegeuk and red ginseng than those of white ginseng. Steamed ginseng root (taegeuk and red ginseng root) showed higher amount of water extractable solid than the unsteamed white ginseng, but the variation of crude saponin content was not distinctive depending on processing methods. The contents of total ginsenosides increased by the order of white, taegeuk, red A, and red B root. In summary, chemical composition and total ginsenoside content were different according to part of root and processing methods, thus implies the importance of quality control as well as pharmacological activity of ginseng root.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.247-256
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• 2013

According to the complete standard document for PHY/MAC layer of visible light communication through the IEEE 802.15.7 WG on Sept. 2011, visible light communication lays a good foundation for developing a variety of application services. Thus, visible light communication moves to the advanced research period for developing application services, but most of applications are limited only to PtP service model. However, PtMP communication environment for VLC is required to accommodate more various applications. In this paper, we analyze an effect of key parameters on network performance in the star topology based visible personal area network system. We implement a simulator with considering attributes of PHY and MAC layer which are defined by IEEE 802.15.7 standard documents, and analyze the VLC performance.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.143-149
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• 2015

This experiment was conducted to evaluate the synergistic effects of vitamin C and E on methylmercury (MeHg) toxicity in juvenile olive flounder Paralichthys olivaceus. In a $3{\times}3$ factorial design, 9 experimental diets containing three different vitamin C (0, 200 or 400 mg/kg diet in the form of l-ascorbyl-2-monophosphate) and vitamin E (0, 100 or 200 mg/kg diet in the form of dl-${\alpha}$-tocopheryl acetate) levels with the Hg toxicity level (20 mg/kg diet in the form of MeHg) were formulated. Triplicate groups of fish averaging $2.3{\pm}0.05g(mean{\pm}SD)$ were fed one of the 9 diets in a flow through system for 8 weeks. Fish fed 400 mg vitamin C/kg diet with 100 or 200 mg vitamin E/kg diet showed significantly (P < 0.05) higher weight gain (WG) than did fish fed the other diets. Fish fed 400 mg vitamin C/kg diet at all vitamin E levels and those which fed vitamin C and E equally at a rate of 200 mg/kg diet showed significantly (P < 0.05) higher feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) than did fish fed the other diets. Fish fed 200 and 400 mg vitamin C/kg diet exhibited significantly (P < 0.05) lower Hg concentration in their muscle as well as kidney than did fish fed the other diets. Therefore, these results clearly indicated that the synergistic effects of these two vitamins on MeHg toxicity by supplementing dietary vitamin C (200 and 400 mg/kg diet) with vitamin E (100 and 200 mg/kg diet) in juvenile olive flounder.