• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.11a
• /
• pp.5-5
• /
• 2009

Thin-film-transistors (TFTs) that can be prepared at low temperatures have attracted much attention because of the great potential for transparent and flexible electronics. One of the mainstreams in this field is the use of organic semiconductors such as pentacene. But device performance of the organic TFTs is still limited due to low field-effect mobility and rapid degradation after exposing to air. Alternative approach is the use of amorphous oxide semiconductors as a channel. Amorphous oxide semiconductors (AOSs) based TFTs showed the fast technological development, because AOS films can be fabricated at room temperature and exhibit the possibility in application like flexible display, electronic paper, and larges solar cells. Among the various AOSs, a-IGZO has lots of advantages because it has high channel mobility, uniform surface roughness and good transparency. [1] The high mobility is attributed to the overlap of spherical s-orbital of the heavy post-transition metal cations. This study demonstrated the effect of the variation in channel thickness from 30nm to 200nm on the TFT device performance. When the thickness was increased, turn-on voltage and subthreshold swing was decreased. The a-IGZO channels and source/drain metals were deposited with shadow mask. The a-IGZO channel layer was deposited on $SiO_2$/p-Si substrates by RF magnetron sputtering, where RF power is 150W. And working pressure is 3m Torr, at $O_2/Ar$ (2/28 sccm) atmosphere. The electrodes were formed with electron-beam evaporated Ti (30 nm) and Au (70 nm) bilayer. Finally, Al (150nm) as a gate metal was thermal-evaporated. TFT devices were heat-treated in a furnace at 250 $^{\circ}C$ and nitrogen atmosphere for 1hour. The electrical properties of the TFTs were measured using a probe-station. The TFT with channel thickness of 150nm exhibits a good subthreshold swing (SS) of 0.72 V/decade and on-off ratio of $1{\times}10^8$. The field effect mobility and threshold voltage were evaluated as 7.2 and 8 V, respectively.

• Journal of architectural history
• /
• v.28 no.6
• /
• pp.77-85
• /
• 2019

The Fisher House, the first Korean Legation in the USA was located at 1513 O Street in Washington, D.C. This house was a three-story brick building with a height of 12.2m(8.84m up to the eaves) and a mansard roof. Facing the street, it is 7.32m (24 feet) wide and 23.6m(77.4 feet) depth. There is a long hallway after the entrance and a parlor with a grand fireplace next to it. This long hallway leads to a central hallway with another fireplace and a central staircase connecting the 2nd and 3rd floors. After the stairs a dining room is with a fireplace in the middle, which then leads to a pantry for dishes and the kitchen. It can also be argued that The Fisher House was the first Western-style residence for Koreans who were officially dispatched from the government. On the other hand, when living in The Fisher House, Park Jung-yang, who was sent on the three premises of the Yeonjak, directly experienced how the United States sought independence from the U.K. through the Declaration of Independence, Mount Vernon, the Washington monument, the Arlington National Cemetery, and battlefields. Even though he was summoned back to Korea by China in less than a year, Park Jung-yang actively supported the independence movement when he became acting prime minister in 1896. In this regard, The Fisher House arguably is the birthplace of Korea's independence movement.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.5
• /
• pp.532-539
• /
• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.8
• /
• pp.1157-1164
• /
• 2015

The present investigation evaluated the antioxidant activities of water extracts from dandelion (Taraxacum officinale) aerial parts, roots, and mixed extracts. Mixed extract of T. officinale was a mixture of aerial parts and roots at 9:1 and 8:2 weight ratios. Extracts from aerial parts (DAE), roots (DRE), and mixture of aerial parts and roots (DME) were measured for cell viability and catalase activity in HepG2 cells, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and lipid peroxidation inhibitory activity. Cell viabilities of HepG2 cells treated with DAE, DRE, DME 8:2, and DME 9:1 against $H_2O_2$-induced oxidative damage were 63.4%, 54.6%, 76.7% and 83.4% at a concentration of $400{\mu}g/mL$, respectively. Catalase activity was highest in DME 9:1 (12.2 mU/min/mg protein) compared with DAE (9.0 mU/min/mg protein) and DRE (9.7 mU/min/mg protein). DPPH radical scavenging activity of DME showed a significantly lower $EC_{50}$ value than DAE ($EC_{50}$ value of DME $9:1=163.3{\mu}g/mL$, DME $8:2=172.4{\mu}g/mL$, and $DAE=173.7{\mu}g/mL$). Lipid peroxidation inhibitory activity of DME showed a significantly lower $EC_{50}$ value than DAE [$EC_{50}$ values of DME $(9:1)=454.4{\mu}g/mL$, DME $(8:2)=426.6{\mu}g/mL$, and $DAE=654.7{\mu}g/mL$]. The results indicate that a small amount of T. officinale roots increased antioxidant activity of aerial parts. Especially, a 9:1 mixture was more valuable than 8:2 mixture for industry.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.9
• /
• pp.1399-1406
• /
• 2015

The purpose of this study was to investigate the antioxidant activity of Korean traditional soy sauce and its relationship with physicochemical properties. Seventeen samples of soy sauce prepared by using a Korean traditional method were obtained from six provinces of Korea. The most powerful antioxidant activity of soy sauce was ranging from 8.96 to 63.39% for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, from 0.12 to 2.41 AE mg/mL for ferric reducing antioxidant power (FRAP) value, and from 8.42 to 115.69 TE mg/mL for oxygen radical absorbance capacity (ORAC). Protease activity and total polyphenol contents were highly correlated with antioxidant activities such as DPPH radical scavenging activity and FRAP value (R=0.97). The contents of amino nitrogen were also correlated with DPPH radical scavenging activity (R=0.92), FRAP (R=0.93), and ORAC values (R=0.80). Based on these results, antioxidant activities were highly influenced by protease activity, contents of total polyphenols, and amino nitrogen.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.11a
• /
• pp.182-195
• /
• 2000

Indigenous bacteria from poplar roots (Populus mnadensis var. eugenei, 'Imperial Carolina') and Southern Californian shrub rhizospheres as well as two tree-colonizing Rhizobium strains (ATCC 10320 and 35645) were genetically engineered to express constitutively and stably toluene o-monooxygenase (TOM) from Burkholderia cepacia G4 by integrating the torn locus into the chromosome. The poplar and Rhizobium recombinants degraded trichloroethylene (TCE) at 0.8-2.1 nmol/min.mg protein (initial TCE concentration, 10u M) and competitive against the unengineered hosts in wheat and barley rhizospheres for one month (colonization at 1-23 $\times$ 10$^{5}$ CFU/cm root). In addition, six of these recombinants colonized poplar roots stably and competitively with populations as high as 79 $\pm$ 12% of all rhizosphere bacteria after 28 days (0.2-31 $\times$ 10$^{5}$ CFU/cm root). Furthermore, five of the most-competitive poplar recombinants (e.g., Pb3-1 and Pb5-1 which were identified as Pseudomonas PsK) retained the ability to express TOM for 29 days as 100 $\pm$ 0% of the recombinants detected in the poplar rhizosphere had constitutive expression of TOM.

• Speech Sciences
• /
• v.8 no.1
• /
• pp.135-142
• /
• 2001

The present study was performed to investigate adequate levels of utterances which can give essential as well as useful information about the patients' voice, by examining the degrees of correlation between the levels of utterances (vowels, words, and phrase paragraph reading) and the entire utterance including all of the levels. For this purpose, a total of 10 individual utterance samples (5 vowels, 3 words, 1 phrase, 1 paragraph reading) were collected from each of the 30 subjects with voice disorder patients, and four experienced voice therapists evaluated them using GRBAS. The results showed that four therapists highly agreed upon on 'G' parameter. The coefficient of the correlation between each level of utterance and entire utterance tended to be above 0.70. Judgements of the vowel /$\varepsilon$/ as well as /o/ highly correlated with the judgement of the entire utterance. Regardless of severity, the judgement of the entire utterance highly correlated with the judgements of the vowel /u/ and the paragraph reading. These results suggest that experienced voice therapists can precisely evaluate patients' voice quality with only one sustained vowel in the clinic field, as is done with the entire utterance evaluation.

• The Korean Nurse
• /
• v.33 no.1
• /
• pp.80-91
• /
• 1994

This study was done to gather the basic information needed to identify how the home nursing care needs and implementation of self care is being carried out for chronically ill patients. The subjects of the study were 294 from chronically ill patients in a general hospital, a university hospital and seven primary health care center and the data was collected by a nurses, public health nurse practioners using questionairs from July 30 to September 30, 1993. The data were analyzed using percentage, mean, and T-test, ANOVA. Our objectives were to understand basic nursing information general characteristics, implementation of self care, home nursing care needs, implementation of self care depend on general characteristics. The results of the study were as follows 1) General characteristics of subjects. The majority of subjects are female (54.8%) 66.7% of residence are fishing and agrarian villages. 20.1% of disease are neurologic system (backache, neuralgia, HIVD, C.V.A). 2) Evnironmental offord reveals high point in implementation of self care.($2.76{\pm}1.37$) 3) B.P check reveals high peroentage in home nursing care needs.(84.7%) 4) Implementation of self care depend on general characteristics reveals significantly different by $sex^{*}$, educational $level^{**}$, monthly $income^{**}$, number of $family^*$,{\;}$disease^*$, and reason of $untreatment^{**}(^*<0.05,{\;}^{**}<0.01)$. In conclusion the study requires efforts of nurse practitioners, and the support of useful resouress by government.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.533-537
• /
• 2017

우리나라는 2012년에 4대강 사업을 통하여 수자원확보를 통한 가뭄대응전략으로 16개의 대형보가 건설되었고 영산강에는 승촌보와 죽산보 2개의 보가 건설되었다. 보의 건설로 흐름은 급격히 감소하여 정체구역의 수역이 확장되면서 여름에서 초가을까지 녹조현상은 매년 지속적으로 발생하고 있으며, 최근 국민들은 안전한 농산물의 안정적인 생산에 요구가 점증함에 따라 농업용수질 오염문제가 범국가적 문제로 대두되고 있고, 그 중요도 및 심각성이 점차 커져가고 있다(한강유역환경청, 2007). 많은 량의 물을 농업용수로 사용하고 있는 영산강의 녹조현상 및 수질개선이 절실하다. 따라서 본 연구에서는 영산강의 승촌보와 죽산보의 건설과 수질오염총량관리제의 시행에 따른 부영양화특성의 변화를 파악하기 위하여 환경부, 국립환경과학원(2006)에서 개발한 한국형 부영양화지수(TSIko) 평가법을 이용하여 영산강유역의 12개 주요지점에 대하여 수집한 자료를 봄(3월~5월), 여름(6월~8월), 가을(9월~11월), 겨울(12월~2월)로 분리하고, 다시 4대강 사업의 영향을 검토하기 위하여 2013년을 전후하여 분리하였으며, 계절별 수질인자 COD, T-P, Chl-a 값을 이용하여 계절별 $TSI_{Ko}$를 산정하여 영양상태를 4개의 등급으로 구분하여 부영양화특성을 파악하였다.

• Korean Linguistics
• /
• v.72
• /
• pp.257-282
• /
• 2016

The aim of this paper is to research phonological and morphological features in Korean Voices from Berlin. The Korean Voices from Berlin was recorded in 1917 at Berlin by 5 Korean prisoners engaged in World War I, some of them came from North Hamgyeong Province, the others came from Pyeongan Province, therefore these data show a North Korean regional dialect. The data are composed of three materials, counting numbers, reciting scriptures and singing folksongs. The results of this research are as follows. 1) The consonant system of Korean voices is similar to standard Korean. The 19 consonants are classified according to 5 manners of articulations and 5 points of articulations. 2) The liquid /l/ has three allophones, [ɾ] appeared in an onset position, [l] in a word medial coda position or preceded by [l], [ɹ] in a word final coda position. 3) The vowel system of Korean voices is similar to early 20th Korean's. It has 8 monophthongs, /a, ʌ, o, u, ɯ, i, e, ${\varepsilon}$/. 4) The 1 to 10 numbers in Korean voices are similar to Middle-Korean numerals. 5) The genitive particle '/ɯi/의' is pronounced [i], [ɯ], [${\varepsilon}$], especially [ɯ] is appeared in Sino Korean. 6) The /l/-deletion of conjugations are similar to Middle-Korean, /l/ deletion always occurred, if [+cor] consonants are followed.