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Noise Reduction of Electric Vehicle using Passive Damping Material (수동형 패치를 이용한 전기차 소음 저감)

  • Kim, Hyunsu;Kim, Byeongil;Han, Won-ok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.6
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    • pp.117-122
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    • 2017
  • Cabin noise due to the electric powertrain of electrical vehicle may consists of motor noise caused by electrical mismatch and gear noise coming from reduction gearbox. These sound may be considered rather small noise compared to those of internal combustion engine, but without masking effect, the noise can be more annoying for customer. Thus, this paper demonstrates the characteristics of electrical vehicle powertrain noise, and the effect of passive damping material for the noise reduction. The typical motor noise can be affected by the motor torque. Also, it is demonstrated that the reduction gearbox may be a weak point for the noise path compared to the motor housing. With vehicle test, it is shown that the damping patch is more effective for noise reduction with deceleration condition than with acceleration condition.

The effect of word frequency on the reduction of English CVCC syllables in spontaneous speech

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.7 no.3
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    • pp.45-53
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    • 2015
  • The current study investigated CVCC syllables in spontaneous American English speech to find out whether such syllables are produced as phonological units with a string of segments, showing a hierarchical structure. Transcribed data from the Buckeye Speech Corpus was used for the analysis in this study. The result of the current study showed that the constituents within a CVCC syllable as a phonological unit may have phonetic variations (namely, the final coda may undergo deletion). First, voiceless alveolar stops were the most frequently deleted when they occurred as the second final coda consonants of a CVCC syllable; this deletion may be an intermediate process on the way from the abstract form CVCC (with the rime VCC) to the actual pronunciation CVC (with the rime VC), a production strategy employed by some individual speakers. Second, in the internal structure of the rime, the proportion of deletion of the final coda consonant depended on the frequency of the word rather than on the position of postvocalic consonants on the sonority hierarchy. Finally, the segment following the consonant cluster proved to have an effect on the reduction of that cluster; more precisely, the following contrast was observed between obstruents and non-obstruents, reflecting the effect of sonority: when the segment following the consonant cluster was an obstruent, the proportion of deletion of the final coda consonant was increased. Among these results, the effect of word frequency played a critical role for promoting the deletion of the second coda consonant for clusters in CVCC syllables in spontaneous speech. The current study implies that the structure of syllables as phonological units can vary depending on individual speakers' lexical representation.

Antioxidant activity of solvent extracts from Vitis coignetiea skins (용매별 머루 과피 추출물의 항산화 효과)

  • Park, Hyun-Sil
    • Culinary science and hospitality research
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    • v.17 no.1
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    • pp.208-217
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    • 2011
  • This study explores the antioxidant activity of solvent extracts from Vitis coignetiea skins, and the result is as follows. Total phenolic compound and flavonoids contents were the highest in ethyl acetate extract, $53.4{\pm}1.2\;mg$/100 g and $644.7{\pm}3.7\;mg$/100 g, respectively. Electron donating abilities of solvent extracts from Vitis coignetiea skin were proportionally increased with concentration and ethyl acetate extract ($80.93{\pm}0.58%$) showed the higher activity than BHT($63.21{\pm}0.72%$) at concentration of $50\;{\mu}l$/mL. Reducing power of solvent extracts from Vitis coignetiea skin was the highest in ethyl acetate extract(1.769) at concentration of $1,000\;{\mu}l$/mL. TBARS of ethyl acetate extract was higher than ascorbic acid. Nitrite scavenging ability of solvent extracts from Vitis coignetiea skin(pH 1.2, $1,000\;{\mu}l$/mL) was the highest in ethyl acetate extract($92.5{\pm}2.4%$).

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Physical Properties and Durability of Polymer Modified Mortar Using Styrene and Butyl Acrylate Latexes (St/BA 폴리머 시멘트 모르타르의 물리적 특성 및 내구성)

  • Hyung, Won-Gil
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.342-346
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    • 2009
  • The effects of the monomer ratios on the typical properties of polymer modified mortars that contain styrene and butyl acrylate latexes was investigated. Basic data was also obtained that is necessary for the development of appropriate latexes for cement modifiers. Polymer modified mortars that contain styrene and butyl acrylate latexes polymerized with various monomer ratios were prepared for different polymer-cement ratios. They were then tested to obtain the particle size of the polymer latexes, air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride-ion penetration. From the test results, the polymer modified mortars that have styrene and butyl acrylate latexes (with the mix proportions of synthesis having monomer ratios of between 40:60 to 60:40 for the appropriate mix proportions) could be recommended for practical applications. The basic properties of the polymer modified mortars were more affected by the polymer-cement ratio than by the monomer ratio, and were improved over unmodified mortar.

DEVELOPMENT OF AN IMPROVED FARE TOOL WITH APPLICATION TO WOLSONG NUCLEAR POWER PLANT

  • Lee, Sun Ki;Hong, Sung Yull
    • Nuclear Engineering and Technology
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    • v.45 no.2
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    • pp.257-264
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    • 2013
  • In Canada Deuterium Uranium (CANDU)-type nuclear power plants, the reactor is composed of 380 fuel channels and refueling is performed on one or two channels per day. At the time of refueling, the fluid force of the cooling water inside the channel is exploited. New fuel added upstream of the fuel channel is moved downstream by the fluid force of the cooling water, and the used fuel is pushed out. Through this process, refueling is completed. Among the 380 fuel channels, outer rows 1 and 2 (called the FARE channel) make the process of using only the internal fluid force impossible because of the low flow rate of the channel cooling water. Therefore, a Flow Assist Ram Extension (FARE) tool, a refueling aid, is used to refuel these channels in order to compensate for the insufficient fluid force. The FARE tool causes flow resistance, thus allowing the fuel to be moved down with the flow of cooling water. Although the existing FARE tool can perform refueling in Korean plants, the coolant flow rate is reduced to below 80% of the normal flow for some time during refueling. A Flow rate below 80% of the normal flow cause low flow rate alarm signal in the plant operation. A flow rate below 80% of the normal flow may cause difficulties in the plant operation because of the increase in the coolant temperature of the channel. A new and improved FARE tool is needed to address the limitations of the existing FARE tool. In this study, we identified the cause of the low flow phenomena of the existing FARE tool. A new and improved FARE tool has been designed and manufactured. The improved FARE tool has been tested many times using laboratory test apparatus and was redesigned until satisfactory results were obtained. In order to confirm the performance of the improved FARE tool in a real plant, the final design FARE tool was tested at Wolsong Nuclear Power Plant Unit 2. The test was carried out successfully and the low flow rate alarm signal was eliminated during refueling. Several additional improved FARE tools have been manufactured. These improved FARE tools are currently being used for Korean CANDU plant refueling.

Development of Economic Evaluation Solution and Power Prediction of Renewable Energy System (신재생에너지 발전 출력 예측과 경제성 종합평가 기술개발)

  • Jeoune, Dae-Seong;Kim, Jin-Young;Kim, Hyun-Goo;Kim, Jonghyun;Youm, Carl;Shin, Ki-Yeol
    • Journal of the Korean Solar Energy Society
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    • v.39 no.6
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    • pp.93-112
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    • 2019
  • In this paper, a very new web-based software for renewable energy system (RES) design and economic evaluation was introduced. This solution would provide the precise RES estimation service including not only photovoltaic (PV), wind turbine (WT) and fuel cell (FC) individually but also energy storage system (ESS) as combined forms with PV or WT. The three reasons why we ought to develop it are: First, the standardized tool suitable to the domestic environment for estimating power generation from RES facilities and economic evaluation is required. Secondly, the standardized tool is needed to spread domestic RES supply policy and to promote the new industry in the micro-grid field. The last, the reliability of economic evaluation should be enhanced more for new facilities. To achieve those aims, the weather database of one hundred locations have established and the RES facility database has also constructed. For the energy management, mathematical models for PV, WT, ESS and FC were developed. As a final phase, the analytical process to evaluate economics has performed with field data verification.

Radiation Technology in the Preparation of Polyethylene Oxide Hydrophilic Gels and Immobilization of Proteases for Use in Medical Practice

  • E.I.Vereschagin;Han, Do-Hung;A.W.Troitsky;O.V.Grishin;S.E.Petrov;E.P.Gulyaeva;L.A.Bogdanova;M.V.Korobeinikov;V.L.Auslender
    • Archives of Pharmacal Research
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    • v.24 no.3
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    • pp.229-233
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    • 2001
  • This Paper deals with the development of a technology for making a hydrophilic gel of Polyethylene oxide reception in which radiating ability is employed to cause cross-linking of Polymers in a water solution. The gel of polyethylene oxide was shown to be nontoxic contain 5-50% of polymer and be useful in composite medicinal forms along with biologically active substances including Bac. subtilis proteases. Proteases immobilized in the gel possess high thermal stability and proteolytic activity and are readily applied in medicine. The effect of immobilized proteolytic and glucolytic enzymes of Bac. subtillis (Immozimase) on the warm ischemia-reperfusion (I/R) which can cause hepatic and jejunum injury was also studied. These enzymes were immobilized on water-soluble polymer polyethylene glycol by means of an electron beam. The number of degraanulated mast cells as well as serum ALT after I/R in the group with Immozimase was decreased to almost half as compared with the control group. Pretreatment with Immozimase resulted in significant reduction of hepatic and gut neutrophil accumulation as compared with control animals. It was concluded that Immozimase has a protective effect for hepatic and gut ischemia/reperfusion, and this effect seems to be associated with prevention of leukocyte accumulation .

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Physiological Characteristics of Tannins isolated from Astringent Persimmon Fruits (떫은감에서 분리한 탄닌성분의 기능적 특성)

  • Seo, Ji-Hyung;Jeong, Yong-Jin;Kim, Kwang-Soo
    • Korean Journal of Food Science and Technology
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    • v.32 no.1
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    • pp.212-217
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    • 2000
  • This study was determined protein reaction, antioxidative activity, nitrite scavening ability and antimicrobial activity of tannins isolated from astringent persimmon fruits. Tannins extracted from green persimmon fruits reacted highly with BSA(bovine serum albumin). Reactions between tannins and BSA were more active when contents of tannin were higher than that of BSA. Antioxidative abilities of green persimmon tannin were comparable to that of BHT(butylated hydroxytoluene). Green persimmon tannins exhibited remarkable nitrite-scavenging activity. Different antimicrobial activities of persimmon tannins were observed depending on the maturity. The growth of V. parahaemolyticus and E coil were highly inhibited by the addition of persimmon tannins. Tannins from soft persimmon did not have antimicrobial activities against B. subtilis and S. typhimurium.

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Post-purchase Evaluation on the Maternity Wear on the Current Korean Market by Survey and Wear test

  • Park, Soon-Jee;Lee, Hee-Jung;Suh, Chu-Yeon
    • Journal of Fashion Business
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    • v.11 no.3
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    • pp.15-34
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    • 2007
  • This study was designed to collect a precise information concerning to the preference and evaluations after usage of pregnant Korean woman for the maternity wear bysurvey and wear tests. Through the survey, 212 respondents were asked to answer what type of maternity wear they prefer and what requirements for maternity wear design are important. According to the results of survey, the mostly preferred maternity wear items were pants and one-piece dress. Korean customers for maternity wear usually pay more for the one-piece dress than other items and they also usually put on medium price pants and low-price blouse. Concerning to the purchase criteria, it may be said that design and movability, fit factors are the buying decision criteria of great weight for Korean pregnant women. Special function most desired was thermal insulation, followed by buffer action, electromagnetic shield and quickly water-absorbent and dry property. Preferred maternity wear design details were flat collar, slightly fitted waist and empire style, gather skirt, rubber band waist. Wear test was performed for two kinds of blouse (BL) and one-piece dress (OP), and threekinds of pants (PT), which have different design details respectively. According to the wear test for ready-to-wear maternity garments, the garment which considers well the characteristics of Korean pregnant women body shape earned much higher score no matter of brands or prices. Generally, high-priced national brands received an excellent evaluation in design aspect, but not satisfied with comfort to move.

Marine Ecosystem on Dokdo and Ullungdo Islands

  • Kim, Ki-Tai
    • The Korean Journal of Ecology
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    • v.24 no.4
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    • pp.245-251
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    • 2001
  • Dokdo is a volcanic island, and its formative geological age took place at the end of the Pliocene Epoch. Dokdo is located at 131。 52′33" East longitude, and 37$^{\circ}$ 14′18" North latitude, and is consituted of 87 islands. The total area of Dokdo is 0.186 $\textrm{km}^2$ and the length of its coastline is 4 km. Ookdo is a treasury of fish resources where many varieties of fish including squid and Alaska pollack live in abundance of greatest importance. Dokdo is a forward fishery base. Ullung island is located at 37$^{\circ}$ 27′~37$^{\circ}$ 33′North latitude and 130$^{\circ}$ 47′~130$^{\circ}$ 56′East longitude. The area of Ullung is 72.92 $\textrm{km}^2$ and the length of its seashore is 44.21 $\textrm{km}^2$. The total marine product of Ullungdo(1995) is 9,066 tons (M/T). The largest is squid, 8,900 tons. For the sea area of the depths near the Ullungdo, coast, that of 50m or less is 2,477 ha, and that of 50- 100m is 1,471ha. This fact tells us that there is no extensive area of a very shallow sea, and that it is directly connected to the deep sea. Ullungdo is a treasury of marine bioresources with rich and varied fishes including squid and Alaska Pollack and many others. Presently there is a sovereignty dispute over Dokdo between Korea and Japan. Since A.D.512, Dokdo has been a part of territory of Korea. Dokdo is a part of Kyungsang-Bukdo, Ullung-gun, Ullung-up, Do-dong in the Korean administrative district division system. Japan strenuously claims sovereignty for significant economic reasons, including fishery rights, and has adhered to a contradictory position that "Dokdo is Japanese land" since Japan incorporated Dokdo into Japanese territory in 1905.ritory in 1905.

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