• 제목/요약/키워드: Continuous-Time Model

검색결과 1,046건 처리시간 0.034초

Mechanistic Analysis of Taxol-induced Multidrug Resistance in an Ovarian Cancer Cell Line

  • Wang, Ning-Ning;Zhao, Li-Jun;Wu, Li-Nan;He, Ming-Feng;Qu, Jun-Wei;Zhao, Yi-Bing;Zhao, Wan-Zhou;Li, Jie-Shou;Wang, Jin-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.4983-4988
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    • 2013
  • Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.

도시 배수유역의 유출-수질 특성인자의 민감도 분석 (Sensitivity Analysis of Runoff-Quality Parameters in the Urban Basin)

  • 이종태;강태호
    • 한국수자원학회논문집
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    • 제30권1호
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    • pp.83-93
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    • 1997
  • 본 연구는 강우로 인한 도시 배수구역에서의 유출 및 수질 산정을 위한 주요인자들이 모의해석 결과치에 주는 영향을 분석하였다. 적용대상유역으로서 남가좌, 산본 배수구역과 미국의 Gray Haven, Kings Creek 배수구역 등의 4개 지역을 선택하였다. 실측치를 토대로 각 영향인자들의 최적치를 주요 유역영향인자들을 포괄적으로 수용하고 있는 SWMM모형으로 산정하고, 이를 기준값으로 하여 이들이 계산 결과치에 주는 민감도를 분석하였다. 유출영향 인자로서 불투수면적은 첨두유출량 및 유출용적에 가장 큰 영향을 줌을 알 수 있었다. 한편 지표면 저류 깊이는 완만한 경사의 유역에서 첨두유량 및 유출용적에 상당한 영향을 주었다. 한편, 오염농도 및 오탁부하량에 영향을 주는 주요매개변수로서는 단위면적, 오염축적의 정도를 나타내는 오염축적계수와 오염축적을 지속적으로 가능하게 하는 연속 무강우 일수 등이 큰 민감도를 보여주었다. 이는 비점원 오염물의 절대 축적량이 하천수질에 직접적인 영향을 주고 있음을 의미한다. 한편 강우초기의 수질에 영향을 주는 변수로서는 강우강도와 오염물질의 이송능력을 나타내는 이송계수 및 지수들의 영향이 상당하였다. 따라서 도시유역에서의 유출 및 수질 모의를 위하여서는 충분한 유역자료의 수집과 분석이 선행되어야 하며, 특히 불투수지역의 정확한 불리와 유역별 비점원 오염물의 축적량의 합리적 산정 과정에 많은 노력을 기울여야 할 것이다.

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카마스터의 지각된 핵심역량 수준이 고객만족에 미치는 영향: 고객접점(MOT)품질의 매개효과를 중심으로 (The Influence of the Car Master's Recognized Core Capability level in Achieving Customer Satisfaction: Emphasis on Mediating Effect of Moment of Truth Quality)

  • 안성범;송인암;황희중
    • 유통과학연구
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    • 제11권4호
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    • pp.37-49
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    • 2013
  • Purpose - This research identifies the meaning of the core capability level of Car Master and the reason why its service at the Moment of Truth should be demonstrated through empirical cases. It can be seen that this study differs from existing research because it proposes that the recognized core capability level to achieve customer satisfaction should focus on the mediating effect of Moment of Truth quality. This paper examines the effect of Car Master's recognized core capability level on customer satisfaction by using the variables mentioned above. Moreover, this study uses regression analysis to verify that the mediating effect of Moment of Truth quality on Car Master's capability level achieves customer satisfaction. Research design, data, and methodology - First, we present evidence that could apply to Car Master's recognized core capability level by detailing the relationship between customer satisfaction and a structuring factor for Car Master's core capability level. Our proposed research model observes the relationship between the structuring factor of core capability and customer satisfaction. Second, we had an opportunity to define how the core capability and Moment of Truth quality affect customer satisfaction by performing empirical analysis on the partial mediating effect of Moment of Truth quality at a recognized core capability level and Moment of Truth quality affecting customer satisfaction. Results - First, the results indicate that Car Master's recognized core capability level (product professionalism, marketing skill, and reliability) positively affects customer satisfaction. Second, the results show that an ability to listen and a sense of dedication positively affect customer satisfaction, and are among the Moment of Truth quality factors; but performance capability, which is one of the Moment of Truth quality factors, does not positively affect customer satisfaction. These results clearly differ from prior studies focused on Moment of Truth quality and consumer satisfaction. Third, the results show that Moment of Truth quality has a partial mediating effect in terms of the impact of Car Master's recognized core capability level in achieving consumer satisfaction. Conclusions - This research indicates that the company will be able to expand if they investigate and show an interest in more training and education for Car Master. The study verified that outstanding Car Masters show differentiated performance on customer satisfaction at the Moment of Truth in various instances. Thus, we believe that this is the time for a discussion on systematic and empirically recognized core capability levels and the Moment of Truth quality. The study on Car Master's recognized core capability level offers suitable solutions for Car Masters to respond to customers at the Moment of Truth. Further, this study emphasizes the importance of service as a critical factor having a direct relationship with the company's success and failure and contributing to building trust with the customer. Thus, an investment in continuous education and training for Car Master will help the growth of the business.

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지리적으로 분산된 디자이너들을 위한 3D 디자인 협업 환경 - 공유 조작과 원격 실재감을 지원하는 증강현실 기반 인터랙션 기법을 중심으로 - (Collaborative 3D Design Workspace for Geographically Distributed Designers - With the Emphasis on Augmented Reality Based Interaction Techniques Supporting Shared Manipulation and Telepresence -)

  • 사공경;남태진
    • 디자인학연구
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    • 제19권4호
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    • pp.71-80
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    • 2006
  • 국제화, 전문화, 분업화 되고 있는 비즈니스 환경으로 인해 제품 디자인 프로세스에서 협업의 중요성은 날로 높아지고 있다. 본 연구에서는 서로 다른 공간에 존재하는 디자인 전문가들이 3D 모델을 함께 검토하고 논의할 수 있는 실시간 원격디자인 협업 환경을 제안한다. 특히 원격 협업 환경에서 원격 실재감, 공유조작, 상대 인식 등의 비언어적인 의사소통 방법을 제공하는 새로운 인터랙션 기법을 개발하고, 디자인 리뷰와 관련된 작업에 어떠한 영향을 끼치는지 평가하였다. 관련연구 조사와 디자인 협업 행태의 관찰 실험을 기반으로 작업대상 관련, 작업공간 관련, 상대인식 관련 요구사항을 도출하였다. 이를 충족시키기 위해 증강현실(Augmented Reality) 기반의 3차원 원격 협업 환경을 구축하였고 원격 사용자에 대한 존재감을 제공하는 회전원반(Turn-table)과 가상그림자(Virtual Shadow)라는 인터랙션 도구를 개발하였다. 회전원반은 가상모델의 조작에 직관성을 부여하고 상대의 조작에 물리적인 단서를 제공한다. 가상그림자는 상대의 위치, 제스처, 지시 등의 인식 정보를 지속적이고 자연스럽게 제공한다. 평가 실험을 통하여 새로운 인터랙션 도구들이 3D 모델의 검토에 있어서 대략적인 지시를 효과적으로 지원하며 수정사항에 대한 논의를 촉진시킴을 알 수 있었다. 연구 결과는 가상의 3차원 모델을 다루는 원격에 위치한 사용자들(디자이너-디자이너, 디자이너-엔지니어, 혹은 디자이너-모델러 등) 간의 자연스러운 의사소통을 촉진하고 협업의 효율을 증대시키는데 기여할 수 있다.

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SUC2 Gene을 갖는 재조합 Saccharomyces cerebisiae의 Invertase 발현특성 (Expression of Invertase in Recombinant Saccharomyces cerebisiae Containing SUC2 Gene)

  • 정상철;장재권;김인규;변유량
    • 한국미생물·생명공학회지
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    • 제17권3호
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    • pp.263-268
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    • 1989
  • 유전자의 재조합 균주의 생산성을 향상시키기 위한 발효시스템 개발을 목적으로 regulated promoter 인 SUC2 gene 갖는 유전자 재조합 S. cerebisiae를 모델로하여 유전자 산물인 Invertase 발현에 미치는 글루코오스 농도의 영향, 발효 중 플라스미드의 불안정성, 생육특성 및 continuous fed batch system을 연구하였다. 유전자 재조합 균주는 biphasic growth 현상을 보였으며 글루코오스 농도가 0.9g/$\ell$에서 2.2g/L로 증가함에 따라 비증식 속도는 0.224 h$^{-1}$에서 0.226 h$^{-1}$로 증가했으며 숙주효모보다 낮은 값을 나타내었다. 유전자 재조합 균주의 invertase 생산은 발효조내의 글루코오스 농도에 크게 영향을 받아 글루코오스 농도가 0.25~0.4g/L로 감소될 때 invertase 생산이 시작되었으며 회분발효중 플라스미드의 분리는 글루코오스 자화기간 동안에 빈번히 일어났으나 에탄을 자화기간에는 완만해지는 경향을 보였다. 또한 통기를 해주지 않고 배지의 용존산소만으로 배양시킨 결과 통기를 한 경우에 비하여 invertase의 비활성과 총활성이 각각 1.5 및 1.3 배 증가되었다. 균체의 증식단계와 유전자의 발현단계로 구분하여 발효시키기 위하여 영양분을 함유한 글루코오스 용액을 48m1/h(0.096g 글루코오스/48L의 유량으로 12시간 연속적으로 공급하여 fed batch 배양한 결과 invertase의 비활성과 총활성이 비통기적 회분배양 보다 각각 1.74, 2.74배 증가되었다.

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온도가 농약효과에 미치는 영향분석 및 농약사용량 예측 모의실험 (Analysis of the Effect of Temperature on the Pesticide Efficacy and Simulation of the Change in the Amount of Pesticide Use)

  • 모형호;강주완;조기종;배연재;이미경;박정준
    • 환경생물
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    • 제34권1호
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    • pp.56-62
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    • 2016
  • 기후변화에 따른 해충개체군 증감모형은 해충방제를 위한 초발생예찰과 연속적 해충변동 양상의 파악에 매우 중요하다. 이러한 예측은 농약사용의 효율성을 높이고, 환경에 적은 영향을 줄 수 있으므로, 현대 해충방제전략의 화두로 볼 수 있다. 본 연구는 온도변화에 따른 해충의 농약효과에 따른 사충률의 변화를 개체군 모형과 결합시켜 모의했다. 감수성 점박이응애를 강낭콩을 기주로 20, 25, 30, $35^{\circ}C$에서 Acrinathrin-Spiromesifen 혼합제와 Azocyclotin 유기주석계 농약에 노출시켰다. 생물검정 결과 점박이응애의 사충률은 온도와 농약의 종류에 따라 유의한 차이가 발생했다. 점박이응애의 개체군 밀도변동 모의는 DYMEX를 이용했으며, 모의결과 농약의 종류별로 기후변화에 따른 초기방제 시기와 방제횟수에 차이가 나타날 것으로 예측됐다. 본 연구결과는 미래의 기후변화에 대응한 해충방제 전략과 농약 선발에 있어 중요한 시사점을 제공할 것으로 사료된다.

주작환(朱雀丸)이 일시적 국소 뇌허혈 유발 백서(白鼠)에 대한 인지 및 운동기능 회복에 미치는 효과 (The Recovery Effects of Joojakwhan - A Traditional Korean Medical Poly-herbal Drug for the Cognitions and Motor Functions in Mild Stroke Rat Model by Using Transient Middle Cerebral Artery Occlusion)

  • 김보은;강석봉;정대규
    • 동의신경정신과학회지
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    • 제24권4호
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    • pp.419-434
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    • 2013
  • Objectives: The object of this study is to observe the cognition and motor function recovery effects of Joojakwhan (JJW), a traditional Korean poly-herbal formula for treating various neuropsychiatric diseases such as dementia, for the mildly stroke rats, with 60 minutes of reperfusion transient middle cerebral artery occlusion (tMCAO). Methods: In the present study, 125, 250 and 500 mg/kg of JJW were orally administered, once per day for 10 continuous days 2 hours after the tMCAO. The body weight changes, infarct sizes under 2% 2, 3, 5-triphenyl tetrazolium chloride (TTC) stain, sensorimotor functions and cognitive motor behavior tests were serially monitored with cerebral caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP)-immunoreactivities and histopathological changes. The effects of tMCAO on sensorimotor functions were evaluated by using of limb placing and body-swing tests, and the cognitive motor behaviors were also observed with water maze tests. Results: From the results of tMCAO, with marked decreases of body weights, disorders of sensorimotor functions increases the limb placing test scores, and decrease the numbers and percentages of body swings to the ipsilateral sides. The cognitive motor behaviors increases the distances and time to reach the escape platform which included the inhibitions of the decreases with repeated trials that were observed with focal cerebral cortex infarct volumes. In addition, the marked increases of the atrophy, numbers of degeneration, caspase-3- and PARP-immunoreactive cells around peri-infarct ipsilateral cerebral cortex were also observed in tMCAO controls when compared with the sham control rats, respectively. Conclusions: The results obtained from this study suggest that oral administrations of JJW indicate obvious cognitions and motor function recoveries of the rats with tMCAO, mild strokes, which are mediated by neuro-protective effects through known antioxidant effects of components.

흉부CT 검사 시 HRCT 영상 재구성의 유용성 (Usefulness Evaluation of HRCT using Reconstruction in Chest CT)

  • 박성민;김긍식;강성민;유병규;이기배
    • 대한디지털의료영상학회논문지
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    • 제17권1호
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    • pp.13-18
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    • 2015
  • Purpose : Skip the repetitive HRCT axial scan in order to reduce the exposure of patients during chest HRCT scan, Helical Scan Data into a reconstructed image, and exposure of the patient change and visually evaluate the usefulness of the HRCT images. Materials and method : Patients were enrolled in the survey are 50 people who underwent chest CT scans of patients who presented to the hospital from January 2015 to March 2015. 50 people surveyed 22 people men and 28 people women people showed an average distribution of 30 to 80 years age was 48 years. 50 patients to Somatom Sensation 64 ch (Siemens) model with 120 kVp tube voltage to a reference mAs tube current to mAs (Care dose, Siemens) as a whole, including the lungs and the chest CT scan was performed. Scan upon each patient CARE dose 4D (Automatic exposure control, Siemens Medical Solution Erlangen, Germany) was to maintain the proper radiation dose scan every cross-section through a device that automatically adjusts the tube current of. CT scan is the rotation time of the Tube slice collimation, slice width 0.6 mm, pitch factor was made under the terms of 1.4. CT scan obtained after the raw data (raw data) to the upper surface of the axial images and coronal images for each slice thickness 1 mm, 5 mm intervals in the high spatial frequency calculation method (hight spatial resolution algorithm, B60 sharp) was the use of the lung window center -500 HU, windows were reconstructed into images in the interval -1000 HU to see. Result : 1. Measure the total value of DLP 50 patients who proceed to chest CT group A (Helical Scan after scan performed with HRCT) and group B (Helical Scan after the HR image reconstruction to the original data) compared with the group divided, analysis As a result of the age, but show little difference for each age group it had a decreased average dose of about 9%. 2. A Radiation read the results of the two Radiologist and a doctor upper lobe and middle lobe of the lung takes effect the visual evaluation is not a big difference between the two images both, depending on the age of the patient, especially if the blood vessels of the lower lobe (A: 3.4, B: 4.6) and bronchi(A: 3.8, B4.7) image shake caused by breathing in anxiety (blurring lead) to the original data (raw data) showed that the reconstructed image is been more useful in diagnostic terms. Conclusion : Scan was confirmed a continuous, rapid motion video to get Helical scan is much lower lobe lung reduction in visual blurring, Helical scan data to not repeat the examination by obtaining HRCT images reorganization reduced the exposure of the patient.

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구름에 의한 지표 일사량의 증가 (The effects of clouds on enhancing surface solar irradiance)

  • 정연진;조희구;김준;김영준;김윤미
    • 대기
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    • 제21권2호
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    • pp.131-142
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    • 2011
  • Spectral solar irradiances were observed using a visible and UV Multi-Filter Rotating Shadowband Radiometer on the rooftop of the Science Building at Yonsei University, Seoul ($37.57^{\circ}N$, $126.98^{\circ}E$, 86 m) during one year period in 2006. 1-min measurements of global(total) and diffuse solar irradiances over the solar zenith angle (SZA) ranges from $20^{\circ}$ to $70^{\circ}$ were used to examine the effects of clouds and total optical depth (TOD) on enhancing four solar irradiance components (broadband 395-955 nm, UV channel 304.5 nm, visible channel 495.2 nm, and infrared channel 869.2 nm) together with the sky camera images for the assessment of cloud conditions at the time of each measurement. The obtained clear-sky irradiance measurements were used for empirical model of clear-sky irradiance with the cosine of the solar zenith angle (SZA) as an independent variable. These developed models produce continuous estimates of global and diffuse solar irradiances for clear sky. Then, the clear-sky irradiances are used to estimate the effects of clouds and TOD on the enhancement of surface solar irradiance as a difference between the measured and the estimated clear-sky values. It was found that the enhancements occur at TODs less than 1.0 (i.e. transmissivity greater than 37%) when solar disk was not obscured or obscured by optically thin clouds. Although the TOD is less than 1.0, the probability of the occurrence for the enhancements shows 50~65% depending on four different solar radiation components with the low UV irradiance. The cumulus types such as stratoculmus and altoculumus were found to produce localized enhancement of broadband global solar irradiance of up to 36.0% at TOD of 0.43 under overcast skies (cloud cover 90%) when direct solar beam was unobstructed through the broken clouds. However, those same type clouds were found to attenuate up to 80% of the incoming global solar irradiance at TOD of about 7.0. The maximum global UV enhancement was only 3.8% which is much lower than those of other three solar components because of the light scattering efficiency of cloud drops. It was shown that the most of the enhancements occurred under cloud cover from 40 to 90%. The broadband global enhancement greater than 20% occurred for SZAs ranging from 28 to $62^{\circ}$. The broadband diffuse irradiance has been increased up to 467.8% (TOD 0.34) by clouds. In the case of channel 869.0 nm, the maximum diffuse enhancement was 609.5%. Thus, it is required to measure irradiance for various cloud conditions in order to obtain climatological values, to trace the differences among cloud types, and to eventually estimate the influence on solar irradiance by cloud characteristics.

OVERVIEW OF KSTAR INTEGRATED CONTROL SYSTEM

  • Park, Mi-Kyung;Kim, Kuk-Hee;Lee, Tae-Gu;Kim, Myung-Kyu;Hong, Jae-Sic;Baek, Sul-Hee;Lee, Sang-Il;Park, Jin-Seop;Chu, Yong;Kim, Young-Ok;Hahn, Sang-Hee;Oh, Yeong-Kook;Bak, Joo-Shik
    • Nuclear Engineering and Technology
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    • 제40권6호
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    • pp.451-458
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    • 2008
  • After more than 10 years construction, KSTAR (Korea Superconducting Tokamak Advanced Research) had finally completed its assembly in June 2007, and then achieved the goal of first-plasma in July 2008 through the four month's commissioning. KSTAR was constructed with fully superconducting magnets with material of $Nb_3Sn$ and NbTi, and their operation temperatures are maintained below 4.5K by the help of Helium Refrigerator System. During the first-plasma operation, plasmas of maximum current of 133kA and maximum pulse width of 865ms were obtained. The KSTAR Integrated Control System (KICS) has successfully fulfilled its missions of surveillance, device operation, machine protection interlock, and data acquisition and management. These and more were all KSTAR commissioning requirements. For reliable and safe operation of KSTAR, 17 local control systems were developed. Those systems must be integrated into the logically single control system, and operate regardless of their platforms and location installed. In order to meet these requirements, KICS was developed as a network-based distributed system and adopted a new framework, named as EPICS (Experimental Physics and Industrial Control System). Also, KICS has some features in KSTAR operation. It performs not only 24 hour continuous plant operation, but the shot-based real-time feedback control by exchanging the initiatives of operation between a central controller and a plasma control system in accordance with the operation sequence. For the diagnosis and analysis of plasma, 11 types of diagnostic system were implemented in KSTAR, and the acquired data from them were archived using MDSpius (Model Driven System), which is widely used in data management of fusion control systems. This paper will cover the design and implementation of the KSTAR integrated control system and the data management and visualization systems. Commissioning results will be introduced in brief.