• Title/Summary/Keyword: Ahn Jae-Hong

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New Geldanamycin Analogs from Streptomyces hygroscopicus

  • Wu, Cheng-Zhu;Jang, Jae-Hyuk;Ahn, Jong Seog;Hong, Young-Soo
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1478-1481
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    • 2012
  • Geldanamycin (GM) and its analogs are important anticancer agents that inhibit heat shock protein (Hsp) 90, which is a major chaperone protein in cancer cells. Accordingly, based on interest in obtaining novel natural GM derivatives, the potential of Streptomyces hygroscopicus JCM4427, a GM producer, was explored for novel natural GM derivative(s), resulting in the discovery of new GM analogs as a biosynthetic shunt product and intermediates from its fermentation broth. In this study, the fermentation, isolation, structure determination, and biological activity of the compounds, two new tetracyclic thiazinogeldanamycin (1) and 19-hydroxy-4,5-dihydrogeldanamycin (3), together with the three known 4,5-dihydrothiazinogeldanamycin (2), reblastatin (4), and 17-demethoxy-reblastatin (5), are described.

Ant Algorithm for Dynamic Route Guidance in Traffic Networks with Traffic Constraints (회전 제약을 포함하고 있는 교통 네트워크의 경로 유도를 위한 개미 알고리즘)

  • Kim, Sung-Soo;Ahn, Seung-Bum;Hong, Jung-Ki;Moon, Jae-Ki
    • Journal of Korean Society of Transportation
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    • v.26 no.5
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    • pp.185-194
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    • 2008
  • The objective of this paper is to design the dynamic route guidance system(DRGS) and develop an ant algorithm based on routing mechanism for finding the multiple shortest paths within limited time in real traffic network. The proposed ant algorithm finds a collection of paths between source and destination considering turn-restrictions, U-turn, and P-turn until an acceptable solution is reached. This method can consider traffic constraints easily comparing to the conventional shortest paths algorithms.

Growth Enhancement of the Microalga Tetraselmis suecica by an Extract of the Green Alga Monostroma nitidum

  • Cho Ji Young;Choi Jae Suk;Kang Se Eun;Ahn Sang Jung;Kim Joong Kyun;Hong Yong Ki
    • Fisheries and Aquatic Sciences
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    • v.8 no.1
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    • pp.1-5
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    • 2005
  • Cell growth of the marine microalga Tetraselmis suecica was regulated by the addition of seaweed extracts in its culture medium. Of 26 species of seaweed tested, water-soluble extracts from Monostroma nitidum and Pachymeniopsis elliptica and methanol-soluble extract from Sargassum confilsum enhanced the growth of T suecica cells. The water extract of M. nitidum was the most effective, producing up to a 2-fold increase in cell density with the addition of 1 mg/mL of extract to the culture medium. Cell size, gross biochemical composition, fatty acids, and digestion efficiency all differed marginally between cultures of T suecica grown with and without the M. nitidum extract.

The Properties of High Flowing Concrete with Fly Ash for CFT Structure (플라이 애쉬를 사용한 CFT 구조용 고유동콘크리트의 강도특성)

  • Ahn, Nam-Shik;Lim, Hong-Chul;Choi, Jae-Gon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.93-96
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    • 2006
  • To investigate the properties of high flowing concrete with fly ash and crushed sand for CFT structure, many batches were performed by a trial-error method and the results were analyzed by SPSS software program. In the experiment W/B was set up as 0.25 and the variables were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens (3, 7, 28 days). The results of this study are summarized as the follows; 1) The increase of the substitution ratio of fly ash, the decrease of dosage of SP and the increase of dosage of AEA due to very fine sphere particle of fly ash. 2) The increase of the blend ratio of crushed sand, the increase of dosage of S/a and water content related with viscosity. 3) Made the high flowing concrete, the increase S/a and the increase the water content.

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Novel PVA pixel design for mobile application with excellent off-axis image quality

  • Kim, Jae-Hyun;Kim, Gee-Bum;Choi, Ji-Youn;Jang, Yong-Kyu;Ahn, Seon-Hong;Kim, Kyeong-Hyeon;Kim, Sang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.295-298
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    • 2008
  • We developed a novel PVA pixel design for mobile application with excellent off-axis image quality and optical performance by introducing Active Level Shift technology and optimizing pixel structure. Our new pixel design enables better off-axis image quality without sacrificing other optical properties compared with a conventional mPVA structure.

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Joule-heating induced crystallization (JIC) for AMOLED TFT-Backplanes

  • Hong, Won-Eui;Lee, Joo-Yeol;Park, Doo-Jung;Ro, Jae-Sang;Ahn, Ji-Su;Lee, Il-Jeong;Kim, Sung-Chul
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.109-112
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    • 2008
  • The grain size of JIC poly-Si can be varied from few tens of nanometers to the one having the larger grain size exceeding that of excimer laser crystallized (ELC) poly-Si according transmission electron microscopy. JIC poly-Si exhibits an excellent uniformity with regards to the grain size. We report here the blanket crystallization of the large area using the $2^{nd}$ generation glass substrate.

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A Study on Transfer Function Identification of Plate Activity Vibration System (평판 능동 진동 시스템의 전달함수 식별에 관한 연구)

  • Lee, Jea-Ho;Ahn, Jae-Hong;Kang, Ki-Won;Park, Ki-Heon
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2317-2319
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    • 2004
  • In many cases the systems are so complex that it is not possible to obtain reasonable models using physical laws. Also a model based on physical laws contains a number of unknown parameters even if the structure is derived from physical laws. These problems can be solved by system identification. In this paper, plate activity vibration is selected as an example for system identification. the transfer functions of this system is derived by using ARMAX based on input/output data through experiment.

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Development of a Neural network for Optimization and Its Application Traveling Salesman Problem

  • Sun, Hong-Dae;Jae, Ahn-Byoung;Jee, Chung-Won;Suck, Cho-Hyung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.169.5-169
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    • 2001
  • This study proposes a neural network for solving optimization problems such as the TSP (Travelling Salesman Problem), scheduling, and line balancing. The Hopfield network has been used for solving such problems, but it frequently gives abnormal solutions or non-optimal ones. Moreover, the Hopfield network takes much time especially in solving large size problems. To overcome such disadvantages, this study adopts nodes whose outputs changes with a fixed value at every evolution. The proposed network is applied to solving a TSP, finding the shortest path for visiting all the cities, each of which is visted only once. Here, the travelling path is reflected to the energy function of the network. The proposed network evolves to globally minimize the energy function, and a ...

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Optimum Design of Suspension in Loading Container on Trailer (컨테이너 상차 시 트레일러 현가장치의 최적설계)

  • Kim, Jae-Heon;Hong, Do-Kwan;Kim, Joong-Wan;Jeon, Un-Chan;Ahn, Chan-Woo
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.710-715
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    • 2001
  • This research is presented for optimizing the coefficients of spring and damper by impact load which is applied to a trailer when the containers are loaded up trailer. The procedure utilize the condition that two containers, initial velocity of container, initial height of container and maximum of suspension stroke. The coefficients of spring and damper are calculated numerically through Newmark method uses finite difference expansions. The procedure of calculation is applied by one DOFs of mass-spring-damper system. The coefficients of spring and damper have large value as increase of height or decrease of stroke. The result of calculation is investigated and is used AGV design.

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A Performance prediction of Gas Turbine using syngas fuel in IGCC (가스화복합발전에서 Syngas 연료를 사용하는 가스터빈의 성능예측)

  • Seo, Seok-Bin;Kim, Jong-Jin;Chung, Jae-Hwa;Ahn, Dal-Hong
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.878-884
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    • 2001
  • IGCC(Integrated Gasification Combined Cycle) power plant are becoming more attractive because of fuel flexibility and low emission. In this study, performances are evaluated when the low caloric value syngas fuels producted in gasification process is used a gas turbine originally designed naturel gas fuel. Using GateCycle computational thermal analysis model, performances of GE 7FA gas turbine are predicted for using four types of syngas. Also, off design performance is presented for firing syngas fuel in the gas turbine.

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