• Title/Summary/Keyword: Polytechnic College

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Diterpenes of Biota orientalis Leaves (측백엽의 Diterpenes 성분)

  • Sung, Sang-Hyun;Koo, Kyung-Ah;Lim, Hye-Kyung;Lee, Heum-Sook;Cho, Jung-Hee;Kim, Hye-Soo;Kim, Young-Choong
    • Korean Journal of Pharmacognosy
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    • v.29 no.4
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    • pp.347-352
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    • 1998
  • Six minor diterpenes were isolated from Biota orientalis (Cupressa-ceae) leaves. On the basis of comparison with reported spectral data, they were identified as 7,15-isopimaradien-18-oic acid (isopimaric acid), 8(14),15-isopimaradien-18-oic acid (sandaracopimaric acid), 7,15-isopimaradien-3-ol, 7,15-isopimaradien-3,19-diol, 8(17),13-labdadien-16,15-olid-19-oic acid (demethylpinusolide), and 15-hydroxy-8(17),13-labdadien-19-oic acid (isocupric acid). They were first reported in the genus of Biota.

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HERMITE-HADAMARD TYPE INEQUALITIES FOR GEOMETRIC-ARITHMETICALLY s-CONVEX FUNCTIONS

  • Hua, Ju;Xi, Bo-Yan;Qi, Feng
    • Communications of the Korean Mathematical Society
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    • v.29 no.1
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    • pp.51-63
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    • 2014
  • In the paper, several properties of geometric-arithmetically s-convex functions are provided, an integral identity in which the integrands are products of a function and a derivative is found, and then some inequalities of Hermite-Hadamard type for integrals whose integrands are products of a derivative and a function whose derivative is of the geometric-arithmetic s-convexity are established.

Development of a Water Droplet Erosion Model for Large Steam Turbine Blades

  • Lee, Byeong-Eun;Riu, Kap-Jong;Shin, Se-Hyun;Kwon, Soon-Bum
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.114-121
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    • 2003
  • Water droplet erosion is one of major concerns in the design of modern large fossil steam turbines because it causes serious operational problems such as performance degradation and reduction of service life. A new erosion model has been developed in the present study for the prediction of water droplet erosion of rotor blades operated in wet steam conditions. The major four erosion parameter : impact velocity, impacting droplet flow rate, droplet size and hardness of target are involved in the model so that it can also be used for engineering purpose at the design stage of rotor blades. Comparison of the predicted erosion rate with the measured data obtained from the practical steam turbine operated for more than 90,000 hours shows good agreement.

A Utility Interactive System Control Using PV Generation (태양광 발전을 이용한 계통연계 시스템 제어)

  • Cho, Moon-Taek;Lee, Chung-Sik;Lee, Se-Hun;Hwang, Lak-Hun;Kim, Young-Soo;Na, Seung-Kwon;Song, Ho-Bin
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1224-1226
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    • 2007
  • 전압형 인버터에 의해 제어되며 인버터의 스위칭 게이트 신호 발생은 전압변조가 필요하다. 전압변조는 삼각파 비교 PWM, 공간전압벡터(Space voltage Vector) PWM기법 등으로 실현되고 있으나, SVPWM은 타 방식에 비해 고조파의 왜형률을 감소시키고, 디지털 구현이 용이하며 선형제어 영역을 증가시킬 수 있는 장점이 있다. 따라서 본 논문에서는 먼저 SVPWM의 스위칭 이론 및 각 섹터에 따른 방향에 대해 설명하였고, 태양광발전 시스템을 3상 PWM전압형 인버터로 구성하였고 안정된 변조를 위해서 동기신호와 제어신호를 위해 모토로라사의 56F8323 마이크로프로세서에 의해서 처리하였다. 또한 시스템의 출력전압과 전류의 파형은 전원전압과 출력전류가 위상이 일치되어 단위 역률로 안정된 전력을 공급할 수 있도록 제어하였다.

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Component Analysis and Antioxidant Activity of Maca (마카(Lepidium meyenii)의 부위별 함유성분 및 항산화 활성 비교)

  • Park, Sung-Jin;Kim, Oak-Lan;Rha, Young-Ah
    • Culinary science and hospitality research
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    • v.23 no.8
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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.

Structural health monitoring of the Jiangyin Bridge: system upgrade and data analysis

  • Zhou, H.F.;Ni, Y.Q.;Ko, J.M.
    • Smart Structures and Systems
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    • v.11 no.6
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    • pp.637-662
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    • 2013
  • The Jiangyin Bridge is a suspension bridge with a main span of 1385 m over the Yangtze River in Jiangsu Province, China. Being the first bridge with a main span exceeding 1 km in Chinese mainland, it had been instrumented with a structural health monitoring (SHM) system when completed in 1999. After operation for several years, it was found with malfunction in sensors and data acquisition units, and insufficient sensors to provide necessary information for structural health evaluation. This study reports the SHM system upgrade project on the Jiangyin Bridge. Although implementations of SHM system have been reported worldwide, few studies are available on the upgrade of SHM system so far. Recognizing this, the upgrade of original SHM system for the bridge is first discussed in detail. Especially, lessons learned from the original SHM system are applied to the design of upgraded SHM system right away. Then, performance assessment of the bridge, including: (i) characterization of temperature profiles and effects; (ii) recognition of wind characteristics and effects; and (iii) identification of modal properties, is carried out by making use of the long-term monitoring data obtained from the upgraded SHM system. Emphasis is placed on the verification of design assumptions and prediction of bridge behavior or extreme responses. The results may provide the baseline for structural health evaluation.

Decomposition of Interference Hyperspectral Images Based on Split Bregman Iteration

  • Wen, Jia;Geng, Lei;Wang, Cailing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.7
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    • pp.3338-3355
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    • 2018
  • Images acquired by Large Aperture Static Imaging Spectrometer (LASIS) exhibit obvious interference stripes, which are vertical and stationary due to the special imaging principle of interference hyperspectral image (IHI) data. As the special characteristics above will seriously affect the intrinsic structure and sparsity of IHI, decomposition of IHI has drawn considerable attentions of many scientists and lots of efforts have been made. Although some decomposition methods for interference hyperspectral data have been proposed to solve the above problem of interference stripes, too many times of iteration are necessary to get an optimal solution, which will severely affect the efficiency of application. A novel algorithm for decomposition of interference hyperspectral images based on split Bregman iteration is proposed in this paper, compared with other decomposition methods, numerical experiments have proved that the proposed method will be much more efficient and can reduce the times of iteration significantly.

A Study on Recognition and Improvement for the Evaluation of University Education on the Perspective of Industry (산업계관점 대학평가에 대한 인식 및 개선방안 연구)

  • Ko, Hyuk-Jin;Lee, Seok-Won;Han, Jiyoung
    • Journal of Engineering Education Research
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    • v.20 no.5
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    • pp.74-86
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    • 2017
  • The purpose of this study is to analyze the perceptions of college officials about the evaluation of university education on the perspective of industry, to make policy proposals for improvement by analyzing the preparing process of the departments that have received the evaluation of the best universities, In order to achieve the purpose of the study, we conducted literature review, survey studies, and in-depth interviews. The survey was conducted by professors related to this system, and finally the results of 51 responses were used for analysis. The contents of the survey were composed of the recognition, appropriateness, the utilization of the results, the proliferation and improvement plan of the evaluation of university education on the perspective of industry. In-depth interviews conducted 1:1 interviews with 5 professors. The evaluation of university education on the perspective of industry is generally perceived to be a bridge between industry and university education, but there is room for improvement in evaluation criteria, operating methods, and promotion strategies to public.

A Study of the Preference of Korean Traditional Desserts by Aged Group (연령별 한국 전통후식류의 기호도 조사)

  • Park, Sung-Jin;Han, Kyung-Soon;Kim, Young-Eon;Yoo, Seon-Mi
    • The Korean Journal of Food And Nutrition
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    • v.25 no.3
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    • pp.554-563
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    • 2012
  • The object of this research is to analyze and classify the preference on Korean traditional desserts by age groups. More women than men were observed to have a healthy diet. In addition, with regards to age, children and young people were founf to have a healthier diet than the median age. Women showed a preference for dessert more so than men. Both men and women showed to eat dessert when reminded, and the young, as well as middle-aged were found to eat dessert often. Korea sign a survey on the traditional dessert, like rice cake, were the preference for women, whereas men were fixated in soft drinks, fruit punch and Schisandra chinensis fruit punch with Rhododendron. Young people liked rice cakes, while the median age liked chajongryu hangwaryu. In soft drinks, fruit punch and watermelon Sikhye was preferred by two of the young, while the middle-aged preferred baesuk and Schisandra chinensis fruit punch.

Component Analysis and Antioxidant Activity of Citrus Peel (귤홍의 함유성분 분석과 항산화 활성)

  • Park, Sung Jin;Shin, Eon Hwan;Rha, Young-Ah
    • Culinary science and hospitality research
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    • v.23 no.3
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    • pp.158-165
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    • 2017
  • This study examined the components and physicochemical properties of citrus peel as a natural health food source by measuring the general and antioxidative contents of citrus peel. Total contents of carbohydrates, crude protein, crude lipid, and ash were 72.1%, 6.6%, 1.3%, and 3.7% respectively. Caloric content of citrus peel was 334.5 kcal, while total dietary fiber was 32.1%. Regarding mineral contents, Ca was the most abundant mineral, followed by K, Mg, and P. Total phenol contents of the 70% ethanolic extracts of citrus peel was $66.4{\pm}8.74mg\;GAE/g$. Total flavonoid contents of the 70% ethanolic extracts were $14.4{\pm}3.28mg\;RE/g$. The antioxidative activities of citrus peel were significantly increasing 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 and reducing power. Therefore, the general nutrients and other antioxidant bioactive materials in citrus peel proved that citrus peel possesses a high potential materials as a nutritious food.