• 한국응용과학기술학회지
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• 제23권1호
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• pp.37-44
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• 2006

Solvent-free low foaming scouring agents (LFSC) were prepared by blending of 2-ethylhexylaminoethyl sulfate (2-EHAS), POE(10) octadecylbenzyl- ammonium chloride (POBAC) and Sedlan FF-200 (FF-200). As the results of several tests, 2-EHAS/POBAC/FF-200/water (8g/12g/20g/60g) mixture (LFSC-5) showed good cleaning power, penetrating ability and stability to alkali, and gave less problem in water pollution. The foaming power of LFSC-5 measured by Ross and Miles method was 8mm foam height immediately after foaming, and that measured by Ross and Clark method was less than 300mm foam height at $30^{\circ}C$, and 18mm at $80^{\circ}C$. As a result, LFSC-5 proved a good low foaming scouring agent for fiber.

• 한국조리학회지
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• 제23권8호
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• pp.137-144
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• 2017

This study examined the components and physicochemical properties of Lepidium meyenii as a natural health food source. To accomplish this objective, the general and antioxidative contents of Lepidium meyenii were measured. Total contents of carbohydrates, crude protein, crude lipid, and ash were 56.04%, 33.77%, 1.49%, and 3.7%, respectively(dry wright basis). Total phenol contents of the 70% ethanolic extracts of Lepidium meyenii were 189.9 mg/g, 152.5 mg/g. Total flavonoid contents of the 70% ethanolic extracts were 166.0 mg/g, 78.2 mg/g. The antioxidative activities of Lepidium meyenii were significantly increased in a dose dependent manner on DPPH(1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging, FRAP(ferric reducing antioxidant power) activity, reducing power. The general nutrients and other antioxidant bioactive materials in Lepidium meyenii were also potential materials for good health food.

• Preventive Nutrition and Food Science
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• 제16권1호
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• pp.89-94
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• 2011

The potential biological activities of water and ethanol extracts from two varieties of Rubus coreanus Miquel fruits produced in the Gochang-gun (GR) and Hoengseong-gun (HR) regions of Korea were examined. The hydroxyl radical ($\cdot$OH) scavenging activity, reducing power, lipid peroxidation inhibitory activity, and antiproliferative activity on cancer cells by these extracts were examined, and $\alpha$-amylase and $\alpha$-glucosidase inhibition assays were also performed. The EtOH extract from GR showed high hydroxyl radical scavenging activity ($EC_{50}=119.47{\pm}5.13\;{\mu}g/mL$), lipid peroxidation inhibitory activity ($EC_{50}=213.45{\pm}3.14\;{\mu}g/mL$) and a concentration dependence, with OD values ranging from 0.15 to 0.56 (50 to 200 ${\mu}g/mL$), for reducing power. The EtOH extract from GR has the highest antiproliferative activities on MDA-MB-231 and HepG2 cancer cells among four extracts. Meanwhile, all extracts showed certain $\alpha$-amylase and $\alpha$-glucosidase inhibition activities. These results indicate that extracts from two varieties of R. coreanus fruits have significant antioxidant, anti-diabetic and anti-tumorigenic activities, which suggest these extracts could be a potential source for pharmaceutical.

• 한국지역사회생활과학회지
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• 제27권3호
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• pp.343-350
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• 2016

The antioxidant activity was examined on ultra-fine powdered (UFP) Ulmus davidiana (U. davidiana) var. japonica. The average particle size of UFP or commercial powdered (CP) was $1-3{\mu}m$ or $100{\mu}m$. The extraction was performed using either ethanol (EtOH) or hot-water. Contents of phenolic compound of CP and UFP U. davidiana extracts in EtOH was 40.38 and 65.61 mg/g, respectively. In DPPH, EtOH extract of UFP U. davidiana showed a significantly greater activity than hot-water extract at 40 and $200{\mu}g/mL$. At $200{\mu}g/mL$, the activity was over 90% in all groups. The reducing power of UFP U. davidiana var. japonica in EtOH extraction was 74.3%, which was significantly greater than in other samples (p<0.05). In addition, reducing powder was significantly higher in UFP-EtOH than in other samples at all concentrations except for $0.32{\mu}g/mL$. The above results suggest that EtOH extraction of U. davidiana showed slightly higher DPPH radical scavenging activity, and ultra-fine powder of U. davidiana extracts may show higher antioxidative activities based on reducing power.

• 동력기계공학회지
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• 제5권1호
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• pp.89-96
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• 2001

Decorative property of chromium deposition from oxalic acid bath containing chromium oxide and ammonium sulfate, has been examined over a wide range of bath compositions and plating conditions. The followings were determined as optimum bath composition, $CrO_3\;200{\sim}250g/{\ell},\;H_2C_2O_4{\cdot}2H_2O\;500{\sim}700g/{\ell},\;(NH_4){_2}SO_4\;40{\sim}120g/{\ell}$, and operation conditions; pH $2.0{\sim}2.5$, current density of $15{\sim}250Adm^2 $ at the bath temperatures of $30{\sim}80^{\circ}C$. Bright chromium deposits were obtained over a wide range of ammonium sulfate concentration, bath temperature, and current density. The current efficiency decreased with increasing current density and bath pH, and increased with Increasing bath temperature. The highest current efficiency was obtained in the bath containing $80g/{\ell}$ of ammonium sulfate. Bright chromium deposits were not obtained at conditions of all the highest current efficiencies.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3131-3135
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• 2008

This paper presents an energy harvester using piezoelectric elements that is a kind of generator which converts the mechanical power to the electric one using windmill system with many PZT actuators. In this study, low frequency characteristics of the cantilever-type piezoelectric actuator are experimentally investigated. Advantages of the cantilever use are to take a very large displacement and to improve the endurance of the PZT element. The material of cantilever is an aluminum and three kinds of cantilever of which size is $150[mm]{\times}20[mm]{\times}1.5[mm]$, $170[mm]{\times}20[mm]{\times}1.5[mm]$ and $190[mm]{\times}20[mm]{\times}1.5[mm]$ were experimented, respectively. The cantilever was fixed on the vibrator. The characteristics of frequency and mass variation of cantilever end part such as 0[g], 5[g], 10[g] are investigated. Maximum voltage was outputted at the condition of $150[mm]{\times}20[mm]{\times}1.5[mm]$ and 10[g] of mass. It was confirmed that the lower natural frequency at the larger length of cantilever and at the bigger of mass is gotten.

• ETRI Journal
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• 제34권3호
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• pp.352-360
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• 2012

This paper proposes a low-cost, low-power, and high-capacity optical-electrical-optical-type reach extender that can provide 3R frame regeneration and remote management to increase the reach and split ratio with no change to a legacy time division multiple access passive optical network. To provide remote management, the extender gathers information regarding optical transceivers and link status per port and then transmits to a service provider using a simple network management protocol agent. The extender can also apply to an Ethernet passive optical network (E-PON) or a gigabit-capable PON (G-PON) by remote control. In a G-PON, in particular, it can provide burst mode signal retiming and burst-to-continuous mode conversion at the upstream path through a G-PON transmission convergence frame adaptor. Our proposed reach extender is based on the quad-port architecture for cost-effective design and can accommodate both the physical reach of 60 km and the 512 split ratios in a G-PON and the physical reach of 80 km and the 256 split ratios in an E-PON.

• Nutritional Sciences
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• 제9권4호
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• pp.330-334
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• 2006

Chemical composition of the Eucommia ulmoides bark, including extractives, proximate, mineral, fatty acid and monosaccharide compositions, was studied The most abundant mineral was calcium (533.17 mg/l00 g). $\alpha-linolenic$ acid (24.7%) and linoleic acid (24.3%), showed higher contents among the fatty acids. Major monosaccharides of E. ulmoides balk were arabinose (13.94 mg/g), xylose (18.91 mg/g) and glucose (119.7 mg/g). From the bark of E ulmoides, four compounds were isolated and their structures were elucidated as caffeic acid (I), kaempferol (II), quercetin (III) and isoquercitrin (IV) by spectroscopic analysis such as NMR and MS, including cellulose TLC and other chemical evidence such as hydrolyzation and acetylation. The antioxidant activities of four isolated compounds were evaluated by DPPH free radical scavenging, hydroxyl scavenging and reducing power assays. The results indicated that all the isolated compounds showed higher DPPH radical scavenging activity than $\alpha-tocopherol$ and BHT that were used as positive controls and these four compounds exhibited considerable reducing power and hydroxyl radical (OH) scavenging activity. Considering from the results above, it suggests that the E. ulmoides bark is a potential natural source of antioxidant material.

• Journal of Plant Biology
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• 제29권3호
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• pp.175-183
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• 1986

Marine algal flora and intertidal vegetation around Samchonpo power plant, south coast of Korea, were investigated at three sites, specially referred to the seasonal variation of the species from April to October, 1982. A total of 84 species were identified; 8 green, 19 brown and 57 red algae. Among three sampling sites investigated, 65 species were collected at the first site located in front of the power plant, 66 at the second site, Namildae beach, and 61 at the third, Sinsudo, respectively. The algal vegetation at the first site was dominated in cover by Sargassum thunbergii and Ulva pertusa in April, Corallina spp. Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October. At the second site, it was dominated in cover by Sargassum thunbergii, Gigartina tenella and Ulva pertusa in April, Sargassum thunbergii and Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October, whereas at the third site Sargassum thunbergii and Ulva pertusa in April, and Chondria crassicaulis in October, respectively. The biomass among three investigated sites showed 2,360 g-fresh wt/$m^2$ on an average; 283 g-dry wt/$m^2$ at the first, 277 g-dry wt/$m^2$ at the second, and 256 g-dry wt/$m^2$ at the third site, respectively.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.43-51
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• 2021

As the number of mobile devices has been increasing tremendously, system capacity should be enlarged in future next generation communication, such as the fifth-generation (5G) and beyond 5G (B5G) mobile networks. For such future networks, non-orthogonal multiple access (NOMA) has been considered as promising multiple access technology. In this paper, to reduce both latency and complexity in existing NOMA, we propose non-successive interference cancellation (SIC) NOMA with asymmetric binary pulse amplitude modulation (2PAM), nearly without bit-error rate (BER) loss. First, we derive the closed form of BER expressions for non-SIC NOMA with asymmetric 2PAM, especially under Rayleigh fading channels. Then, it is shown that the BER performance of the stronger channel user who is supposed to perform SIC in conventional NOMA can be nearly achieved by the proposed non-SIC NOMA with asymmetric 2PAM, especially without SIC. Furthermore, we also show that the BER performance of the weaker channel user in conventional NOMA can be more closely achieved by the proposed non-SIC NOMA with asymmetric 2PAM. These BERs are shown to be achieved over the part of the power allocation range, which is consistent with the NOMA principle of user fairness. As a result, the non-SIC NOMA scheme with asymmetric 2PAM could be considered as a promising NOMA scheme toward next generation communication.