• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.489-490
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• 2001

해초가 밀생하기에 알맞은 연안 환경을 지닌 우리나라의 경우, 해초생태계에 관한 연구가 얼마 전까지만 해도 부진하였으나, 최근 들어 제주도와 광양만 잘피밭을 중심으로 활발히 연구가 진행되고 있다. 그 결과 해초의 형태 및 생활사 등에 관한 연구(Kong, 1981, 1982), 해초지 어류 군집에 관한 연구(Huh, 1986; Go and Cho, 1997a; Huh md Kwak, 1997d), 해초지에 서식하는 어류의 먹이습성에 관한 연구(Go et al., 1997b; Huh and Kwak,1997a, b, c,1998a, b, c, d, e, f), 저서생물에 관한 연구(Yun et al., 1997), 새우류에 관한 연구(Huh and An, 1997), 게류에 관한 연구(Huh and An, 1998), 부착해조류에 관한 연구(Huh et al., 1998) 등 다양한 연구 결과가 발표되고 있다. (중략)

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.510-516
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• 2021

Whitening agents derived from natural sources which do not have side effects are sought after. Schizophragma hydrangeoides is an edible plant that grows wild on Jeju Island. We aimed to determine whether S. hydrangeoides extracts show anti-melanogenic activity. Here, we found that 70% ethanol extracts of S. hydrangeoides leaf suppressed α-melanocyte-stimulating hormone-induced melanogenesis in B16F10 mouse melanoma cells. This activity of anti-melanogenesis in B16F10 cells were investigated by determining melanin content and tyrosinase activity, and by performing western blotting. The 70% ethanol extract downregulated tyrosinase and tyrosinase-related protein 1. In addition, the n-hexane fraction of S. hydrangeoides leaf (HFSH) exhibited significant anti-melanogenic activity among the various solvent fractions tested without reducing the viability of B16F10 cells. Taken together, these results indicate that extracts from S. hydrangeoides leaf can influence cellular processes via modulation of tyrosinase activity. Hence, S. hydrangeoides can be used as a whitening agent in the cosmetic industry and as a therapeutic agent for treating hyperpigmentation disorders in the clinic.

• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.13-19
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• 2011

Purpose: In real life there are both straight-paths and curved-paths. To evaluate walking ability of both kinds, a figure-8 walking test (F8WT) was developed. The aim of this study was to validate the measure in hemiplegic patients with walking difficulties and to identify correlations of curved walking ability with straight walking ability, motor function, and walking performance ability. Methods: Twenty subjects participated in this study. Curved walking was measured by a F8WT. Straight walking ability was measured by a 10-meter walking test (10MWT). Dynamic balancea bility was measured by timed up and go (TUG) tests. Walking performance ability was measured using a modified motor assessment scale (MMAS). Motor function was measured by the Fugl-Meyer assessment (FMA) scale. Data were analyzed using Pearson correlation analysis. Linear regression analyses were performed to explore other functional tests in mobility ability by F8WT time, 10MWT (dependent variable). Results: There was a significant positive correlation of F8WT time with 10MWT and TUG. There was a significant negative correlation of F8WT time with MMAS and FMA-coordination. There was a significant positive correlation of 10MWT with TUG. There was a significant negative correlation of 10MWT with MMAS and FMA-coordination. The F8WT time for curved walking ability was attributed to 10MWT for straight walking ability as 94% level of contribution. Conclusion: The results suggest that the F8WT is a good instrument for measuring walking ability because there is a robust correlation of F8WT time with 10MWT, TUG, MMAS, and FMA-coordination in hemiplegic patients who, after stroke, have a mobility deficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1104-1109
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• 2005

In this paper, a Ka-band harmonic mixer is designed and fabricated on the base of the multiplier theory that there is a bias point to maximize the third harmonic order($3f_{LO}$) with respect to a fundamental LO frequency($f_{LO}$), which can make the high-order mixing element($f_{RF}{\pm}3f_{LO}$) to be greater than other mixing elements, Pumping a RF frequency($f_{RF}$) and LO frequency($f_{LO}$). The harmonic mixer by the proposed design method is fabricated by using a commercial GaAs MESFET device with a plastic package and overcome these disadvantages that a conventional mixer in Ka-band suffer from a high cost, inefficient productivity and circuit complexity. The harmonic mixer have a -10 dB conversion loss at the IF Sequency($3f_{LO}-f_{RF}$=1.0GHz) by selecting a gate bias voltage for the maximum third-order LO harmonic element($3f_{LO}$=34.5 GHz) as pumping LO frequency($f_{LO}$=11.5 GHz) With respect to RF Sequency ($f_{RF}$=33.5GHz)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.2
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• pp.89-93
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• 2008

Goldfish were exposed to radioactive isotope $^{18}F$, which is used for positron emission tomography (PET). $^{18}F$ is created when the oxygen in water combines with hydrogen on exposure to positrons accelerated by a cyclotron. The temporal change in intestine contractility was measured by physiograph after the exposure to $^{18}F$. The distance between the goldfish and 580 mCi of $^{18}F$ was approximately 4 cm and the exposure was for 4 hrs. The absorption level calculated from the distance, exposure time, and half-life of $^{18}F$ was approximately 2 Gy. The contractile activity of goldfish intestine was lowest on the first day and increased gradually to 100% of the control level by a period of between 5 and 36 days.

• 대한핵의학회:학술대회논문집
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• 1990.04a
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• pp.206.2-207
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• 1990

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.475-476
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• 2008

• 대한핵의학회:학술대회논문집
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• 1997.05a
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• pp.184-184
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• 1997

• Proceedings of the Plant Resources Society of Korea Conference
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• 2008.11a
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• pp.71-71
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• 2008

• 대한생식의학회:학술대회논문집
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• 2001.06a
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• pp.56-56
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• 2001