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Growth and electrical properties of $Sr_2$$({Ta_{1-x}},{Nb_x})_2$)$O_7$ thin films by RF sputtering (RF Sputtering을 이용한 $Sr_2$$({Ta_{1-x}},{Nb_x})_2$)$O_7$ 박막의 성장 및 전기적 특성)

  • In, Seung-Jin;Choi, Hoon-Sang;Lee, Kwan;Choi, In-Hoon
    • Korean Journal of Materials Research
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    • v.11 no.5
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    • pp.367-371
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    • 2001
  • In this paper, theS $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) films among ferroelectric materials having a low dielectric constant for metal-ferroelectric-semiconductor field effect transistor(MFS-FET) were discussed. The STNO thin films were deposited on p-type Si(100) at room temperature by co-sputtering with S $r_2$N $b_2$ $O_{7(SNO)}$ ceramic target and T $a_2$ $O_{5}$ ceramic target. The composition of STNO thin films was varied by adjusting the power ratios of SNO target and T $a_2$ $O_{5}$ target. The STNO films were annealed at 8$50^{\circ}C$, 90$0^{\circ}C$ and 9$50^{\circ}C$ temperature in oxygen ambient for 1 hour. The value of x has significantly influenced the structure and electrical properties of the STNO films. In the case of x= 0.4, the crystallinity of the STNO films annealed at 9$50^{\circ}C$ was observed well and the memory windows of the Pt/STNO/Si structure were 0.5-8.3 V at applied voltage of 3-9 V and leakage current density was 7.9$\times$10$_{08}$A/$\textrm{cm}^2$ at applied voltage of -5V.of -5V.V.V.

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A Study of the Chemical Composition of Korean Traditional Ceramics (III): Comparison of Punch'$\breve{o}$ng with Kory$\breve{o}$ Ware and Chos$\breve{o}$n Whiteware (한국 전통 도자기의 화학 조성에 대한 연구 (III): 분청에 대한 고려자기와 조선백자와의 비교)

  • KohChoo, Carolyn Kyong-Shin;Choo, Woong-Kil;Ahn, Sang-Doo;Lee, Young-Eun;Kim, Gyu-Ho;Lee, Yeon-Sook
    • Journal of Conservation Science
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    • v.27 no.1
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    • pp.75-90
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    • 2011
  • At the beginning of the Chos$\breve{o}$n dynasty, punch'$\breve{o}$ng began as a simplified form of inlaid celadon, and in the two following centuries it developed into a popular folk craft in various styles and expressive decorations; overtime, it was increasingly made to resemble whiteware, and its production stopped after the Japanese invasion of Korea. In the present study, the body and glaze compositions of punch'$\breve{o}$ng were examined and compared with those of celadon and whiteware, whose compositions have previously been compared with those of Chinese ceramics. Here, the analyzed shards were organized into 28 groups based on their production sites and archaeological characteristics. For each group, the body and glaze compositions of several shards(usually three to five) were obtained, averaged, and compared with those of the other groups. These comparisons showed that the majority of the punch'$\breve{o}$ng bodies were formed, like those of celadon and whiteware, with mica-quartz porcelain stone, which was commonly used in Yuezhou, Jingdezhen, and other southern Chinese kilns. The glazes consisted of clay materials and flux components made from various proportions of wood ash, burnt limestone (glaze ash) and crushed limestone. Overall, the punch'$\breve{o}$ng glazes resembled the Kory$\breve{o}$ celadon and Kory$\breve{o}$ whiteware glazes more closely than the Chos$\breve{o}$n white wareglazes. However, the $TiO_2$ levels found in the tested punch'$\breve{o}$ng were low, similar to those of Chos$\breve{o}$n whiteware; this indicated that glaze stone was used as the clay component of the punch'$\breve{o}$ng glazes, as was the case for Chos$\breve{o}$n whiteware. This study of the material characteristics of punch'$\breve{o}$ng may be used as a comparative framework for analyzing ceramic shards discovered at current and future excavations within Korea.

Qualitative Analysis of $GeO_2$ in Germanium-Fortified Yeast. (게르마늄강화효모 내의 $GeO_2$ 정성분석)

  • Kim, So-Yeun;Kim, Myoung-Hee;Woo, Hee-Gweon;Kim, Bo-Hye;Sohn, Tsang-Uk;Jung, Jin-Wook;Baek, Dae-Heoun
    • Microbiology and Biotechnology Letters
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    • v.35 no.2
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    • pp.163-172
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    • 2007
  • This study was designed to investigate that inorganic germanium $(GeO_2)$ did not exist in germanium-fortified yeast or obtained to non-detectable value by current analytical methods and equipments. For this purpose, we achieved $GeO_2$ qualitative analysis protocol which could be the scientific basis of the study. Since reddish brown precipitate was formed from the reaction of $GeO_2$ with 1 equiv $NaBH_4$, and dark brown precipitate was also formed from the reaction of $GeO_2$ with 2 equiv $NaBH_4$, $GeO_2$ was qualitatively analyzed by observing these particular colored-precipitates. Because no color change was showed from the reaction between $NaBH_4$ and $SiO_2$, the color change could be caused by charge transfer transition on Ge-O and B binding properties. The reaction between $NaBH_4$ and germanium-fortified yeast did not show any color change and precipitate formation which meant no $GeO_2$ existed in germanium-fortified yeast. The reaction between $NaBH_4$ and supernatant specimen collected from the outside of dialysis membrane (MWCO 1,200 dalton) did not show any color change and precipitate formation. Therefore, we considered that the both germaniums in and outside of the dialysis membrane were organic germaniums. Germanium-fortified yeast which was biosynthesized organic germanium can be applied not only as a new functional material for improving health, prevention and treatment of chronic degenerative diseases including cancers, and the regulation of immune system, but also as a new materials.

Modeling Paddlewheel-Driven Circulation in a Culture Pond (축제식 양식장에서 수차에 의한 순환 모델링)

  • KANG Yun Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.6
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    • pp.643-651
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    • 2001
  • Paddlewheel-driven circulation in a culture pond has been simulated based on the depth integrated 2 dimensional hydrodynamic model. Acceleration by paddlewheel is expressed as shaft force divided by water mass discharged by paddlewheel blades. The model has been calibrated and applied to culture ponds as following steps:- i) The model predicted velocities at every 10 m along longitudinal direction from the paddlewheel. The model was calibrated comparing the results with the measured values at mass correction factor $\alpha$ and dimensionless eddy viscosity constant $\gamma$, respectively, in a range $15\~20$ and 6. ii) Wind shear stress was simulated under conditions of direction $0^{\circ}C,\;90^{\circ}C\;and\;180^{\circ}C$ and speed 0.0, 2.5, 5.0 and 7.5 m/s. Change rate of current speed was <$1\%$ at wind in parallel or opposite direction to the paddlewheel-driven jet flow, while $4\%$ at orthogonal angle. iii) The model was then applied to 2 culture ponds located at the Western coast of Korea. The measured and predicted currents for the ponds were compared using the regression analysis. Analysis of flow direction and speed showed correlation coefficients 0.8928 and 0.6782 in pond A, 0.8539 and 0.7071 in pond B, respectively. Hence, the model is concluded to accurately predict circulation driven by paddlewheel such that it can be a useful tool to provide pond management strategy relating to paddlewheel operation and water quality.

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A Study on Nutrition Intake of Middle School Girls in Chonnam Area (일부(一部) 전남지역(全南地域) 여자중학생(女子中學生)들의 영양실태(營養寶態) 조사연구(調査硏究) - 전라남도(全羅南道) 장흥군(長輿郡)과 보성군(寶城郡)을 중심(中心)으로 -)

  • Yoo, Hye-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.1
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    • pp.71-85
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    • 1984
  • The purpose of this study was to get a data which can provide a basis for future direction in nutritional education and to build up right eating habit and to find the way how to improve food life and the nutritional supply by evaluating the current nutritional intake of average middle school girls through the survey study of their daily food intakes and physical status. The survey of nutritional intakes and physical status in two girls middle schools, namely Jang'hung girls middle school at Jang'hung Up and Bo'song girls middle school at Bo'song Up, were carried by teachers majoring in Home Economics and nurse-teachers from 5 July to 7 July 1983. From a total of 1080 subjects of two girls middle schools, 887 subjects were surveyed. The results obtained from survey are summarized as follow: 1) Physical Status Average height, weight and chest girth of subjects in both middle schools were much lower than the Korean average standard (p<0.005${\sim}$p<0.001) and t-score of differences between two middle school girls were not significant. Rohrer index, nutrition rate and physique rate were also lower than Korean averag standard through all the ages in both girls middle schools. Menarche appeared mainly between the age of 13 to 15 (91.55 %), with a mean age of 14 (35. 01 %) and which was experienced by the subjects of 51.52 percentage among total surveyed Iniddlf school girls. 2) Nutritional Intakes The average daily intakes of all nutrient except iron, vitamin A, thiamin, ascorbic acid and niacin was lower than Korean Recommanded Dietary Allowances (RDA) . Especially average intake of calorie and calcium were much lower than Korean RDA(p<0.001) while average intake of thiamine and ascorbic acid were much higher than Korean RDA (p<0.001). T-score of differences of iron, thiamin, riboflavin between two middle school girls were very significant (p<0.001). Generally iron and riboflavin were the highest rate of intakes through three meals and breakfast took charge of considerable amount of all nutrient intake without omitting anything (about 30 % of daily nutrient intake). The nutrients of which ratio of nutrient intake by snack was more than 16.7 % were vitamin A, thiamin, riboflavin, ascorbic acid etc. and snack foods which were intake frequently in both middle school girls commonly were fruits, milk and milk products, bread and biscuits in sequence. 3) Correlations and t-score between physical status, menarche and nutrient intakes. Average intake of calorie at Jang'hung area was positively correlated with height, weight, nutrition rate and physique rate and this correlation was very significant (p<0.005). Average intake of calorie was also correlated with chest girth and Rohrer index (P<0.05). At Bo'song area, averse intake of riboflavin was negatively correlated with all the items of physical status (p<0.05-p<0.005), vitamin A was negatively correlated with chest girth and Rohrer index (p<0.05 respectively) and thiamin was also negatively correlated with chest girth, Rohrer index and nutrition rate (p<0.05 respectively). Especially niacin showed a negative cor-relation with all the items of physical status very significantly (p<0.005).The time of menarche showed a positive correlation with iron in both middle school girls commonly P<0.05 at Jang'hung, p<0.10 at Bo'song).

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Sijo and Chinese Poems in Han Yong-Un (만해(萬海) 한용운(韓龍雲)의 시조(時調)와 한시(漢詩))

  • Lee, Jong-Goun
    • Sijohaknonchong
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    • v.23
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    • pp.133-159
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    • 2005
  • This thesis is about Sijo(traditional Korean poem) made-up of 35 volumes and 45 poems written by Han Yong-un. The aim of this study is reappraise the Sijo which is not known to Korean people. There are four thesis about Sijo so far. Ko Myeong-su divided Sijo into separate subjects and researched it very deeply. After I read the Chinese Poems of Han Yong-un, I researched the relationships between subject matter and its theme. The relationships are between the moon and religion, spring and aspiration, autumn and grief or lose, and the sword and patriotism. I chose to discuss a Sijo 'Mugunghwa Shimeukwajeo'(무궁화(無窮花)를 심으과저) shich deals with the moon and religion. The main subject matter of this S is the moon. There are three poems in this volume. They are all about the moon. There is a Mugunghwa (無窮花) on the moon. This poem asserts that the moon is good for love, and it is the subject matter of the poet's religion. The moon in the Chinese poem 'Okjungkamwhiy'(獄中感懷) believes there is hope in prison. The moon in 'Wolbang(月方中) is Buddhist thinking. I researched 'Geochon'(早春) tee poems about spring and aspiration. The first poem is about the independent movement against the Japanese. Autumn is about the feeling of lose in the life. Sijo 'Chuyamong' (秋夜夢) is lose the lover. The second poem is about conquering all difficulties of the poet's current circumstance. The third poem is about the feeling of vacuum in his life. The fourth poem is about deploring losing his mind. 'Nam-a'(男兒) and 'Urinim'(우리님) are books about patriotism. These poems have the subject matter of a sword for song patriotism. 'Kiharksaeng'(寄學生), 'Anhaeju'(安海州), and 'Hwangmaecheon'(黃梅泉) are patriotic poems. In this study, I found that the subject matter and the theme in the Chinese poems of Han Yong-un(韓龍雲) are related. Mainly he used the metaphor of the moon for religion, spring for aspiration, autumn for grief or lose, and sword for patriotism.

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Application Plan of Goods Information in the Public Procurement Service for Enhancing U-City Plans (U-City계획 고도화를 위한 조달청 물품정보 활용 방안 : CCTV 사례를 중심으로)

  • PARK, Jun-Ho;PARK, Jeong-Woo;NAM, Kwang-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.18 no.3
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    • pp.21-34
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    • 2015
  • In this study, a reference model is constructed that provides architects or designers with sufficient information on the intelligent service facility that is essential for U-City space configuration, and for the support of enhanced design, as well as for planning activities. At the core of the reference model is comprehensive information about the intelligent service facility that plans the content of services, and the latest related information that is regularly updated. A plan is presented to take advantage of the database of list information systems in the Public Procurement Service that handles intelligent service facilities. We suggest a number of improvements by analyzing the current status of, and issues with, the goods information in the Public Procurement Service, and by conducting a simulation for the proper placement of CCTV. As the design of U-City plan has evolved from IT technology-based to smart space-based, reviews of limitations such as the lack of standards, information about the installation, and the placement of the intelligent service facility that provides U-service have been carried out. Due to the absence of relevant legislation and guidelines, however, planning activities, such as the appropriate placement of the intelligent service facility are difficult when considering efficient service provision. In addition, with the lack of information about IT technology and intelligent service facilities that can be provided to U-City planners and designers, there are a number of difficulties when establishing an optimal plan with respect to service level and budget. To solve these problems, this study presents a plan in conjunction with the goods information from the Public Procurement Service. The Public Procurement Service has already built an industry-related database of around 260,000 cases, which has been continually updated. It can be a very useful source of information about the intelligent service facility, the ever-changing U-City industry's core, and the relevant technologies. However, since providing this information is insufficient in the application process and, due to the constraints in the information disclosure process, there have been some issues in its application. Therefore, this study, by presenting an improvement plan for the linkage and application of the goods information in the Public Procurement Service, has significance for the provision of the basic framework for future U-City enhancement plans, and multi-departments' common utilization of the goods information in the Public Procurement Service.

GIS based Development of Module and Algorithm for Automatic Catchment Delineation Using Korean Reach File (GIS 기반의 하천망분석도 집수구역 자동 분할을 위한 알고리듬 및 모듈 개발)

  • PARK, Yong-Gil;KIM, Kye-Hyun;YOO, Jae-Hyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.4
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    • pp.126-138
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    • 2017
  • Recently, the national interest in environment is increasing and for dealing with water environment-related issues swiftly and accurately, the demand to facilitate the analysis of water environment data using a GIS is growing. To meet such growing demands, a spatial network data-based stream network analysis map(Korean Reach File; KRF) supporting spatial analysis of water environment data was developed and is being provided. However, there is a difficulty in delineating catchment areas, which are the basis of supplying spatial data including relevant information frequently required by the users such as establishing remediation measures against water pollution accidents. Therefore, in this study, the development of a computer program was made. The development process included steps such as designing a delineation method, and developing an algorithm and modules. DEM(Digital Elevation Model) and FDR(Flow Direction) were used as the major data to automatically delineate catchment areas. The algorithm for the delineation of catchment areas was developed through three stages; catchment area grid extraction, boundary point extraction, and boundary line division. Also, an add-in catchment area delineation module, based on ArcGIS from ESRI, was developed in the consideration of productivity and utility of the program. Using the developed program, the catchment areas were delineated and they were compared to the catchment areas currently used by the government. The results showed that the catchment areas were delineated efficiently using the digital elevation data. Especially, in the regions with clear topographical slopes, they were delineated accurately and swiftly. Although in some regions with flat fields of paddles and downtowns or well-organized drainage facilities, the catchment areas were not segmented accurately, the program definitely reduce the processing time to delineate existing catchment areas. In the future, more efforts should be made to enhance current algorithm to facilitate the use of the higher precision of digital elevation data, and furthermore reducing the calculation time for processing large data volume.

A new diagnostic method for diabetic neuropathy using $TcpO_2$ ($TcpO_2$ 이용한 당뇨병성 신경병증 환자의 조기진단)

  • Hong, Hyun-Ki;Kim, Sung-Woo;Nam, Ki-Chang;Cha, Eun-Jong;Kim, Deok-Won
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.3
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    • pp.1-8
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    • 2007
  • PDiabetic neuropathy is one of the most common diabetes related complications including diabetic nephropathy and retinopahty. In clinical practices, nerve conduction velocity (NCV) has been used as a standard method for diagnosing diabetic neuropathy. However, it applies maximum current of 100mA to nerves causing stress and pain to patients. In this study, as a non-invasive method, $TcpO_2$ was utilized to investigate the difference and relationship between $TcpO_2$ and $SpO_2$ of normal and diabetic neuropathy subjects. In addition, a new method of diagnosing diabetic neuropathy using $TcpO_2$ is suggested. 50 normal subjects and 50 diabetic patients with neuropathy diagnosed by NCV participated in this study. Parameters used in this study were $TcpO_2$, $TcpCO_2$, and $SpO_2$. As a result of the $TcpO_2$ measurements, statistical significances were found from $TcpO_2$ of hands and feet from normal and patients group(p<0.01). $SpO_2$ measured from index finger of normal and patient groups showed no statistical significance(p>0.05). On the other hand, $SpO_2$ measured from great toes of normal and patient groups showed statistical significance(p<0.01). Correlation coefficient between $SpO_2$ of finger and $TcpO_2$ of hand was 0.400 (p<0.01) and $SpO_2$ of toe and $TcpO_2$ of foot was 0.471(p<0.01). Both correlation values were statistically significant. Sensitivities and specificities of the $TcpO_2$ method were found to be 66 % and 92 %, respectively. If the suggested $TcpO_2$ method is used periodically, prevention and early diagnosis of diabetic neuropathy would be possible.

The Generation of Westerly Waves by Sobaek Mountains (소백산맥에 의한 서풍 파동 발생)

  • Kim, Jin wook;Youn, Daeok
    • Journal of the Korean earth science society
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    • v.38 no.1
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    • pp.24-34
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    • 2017
  • The westerly waves generation is described in the advanced earth science textbook used at high school as follows: as westerly wind approaches and blows over large mountains, the air flow shows wave motions in downwind side, which can be explained by the conservation of potential vorticity. However, there has been no case study showing the phenomena of the mesoscale westerly waves with observational data in the area of small mountains in Korea. And thus the wind speed and time persistency of westerly winds along with the width and length of mountains have never been studied to explain the generation of the westerly waves. As a first step, we assured the westerly waves generated in the downwind side of Sobaek mountains based on surface station wind data nearby. Furthermore, the critical or minimum wind velocity of the westerly wind over Sobaek mountains to generate the downwind wave were derived and calcuated tobe about $0.6m\;s^{-1}$ for Sobaek mountains, which means that the westerly waves could be generated in most cases of westerly blowing over the mountains. Using surface station data and 4-dimensional assimilation data of RDAPS (Regional Data Assimilation and Prediction System) provided by Korea Meteorological Agency, we also analyzed cases of westerly waves occurrence and life cycle in the downwind side of Sobaek mountains for a year of 2014. The westerly waves occurred in meso-${\beta}$ or -${\gamma}$ scales. The westerly waves generated by the mountains disappeared gradually with wind speed decreasing. The occurrence frequency of the vorticity with meso-${\beta}$ scale got to be higher when the stronger westerly wind blew. When we extended the spatial range of the analysis, phenomena of westerly waves were also observed in the downwind side of Yensan mountains in Northeastern China. Our current work will be a study material to help students understand the atmospheric phenomena perturbed by mountains.