• 제목/요약/키워드: radiation response

검색결과 1,314건 처리시간 0.024초

마코프 모델을 이용한 원전 비상 통신 시스템 성능 분석 (Performance Analysis of Emergency Communication System of Nuclear Power Plant using Markov Model)

  • 손광섭
    • 전자공학회논문지
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    • 제51권3호
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    • pp.10-21
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    • 2014
  • 후쿠시마 원전사고는 자연재해에 의한 중대사고 발생 시 전원공급 중단 및 극한 환경으로 인해 발전소 내부 상황을 정확하게 파악하지 못하였고, 대부분의 계측제어시스템이 그 기능을 제대로 발휘하지 못해 비상냉각기능이 상실되어 수소폭발 및 다량의 방사능이 누출된 사고였다. 본 논문에서는 중대사고 발생 시에도 발전소 내부 상황을 감시하고, 적절히 제어할 수 있는 비상대응시스템에 대하여 소개하고, 비상대응시스템에 사용되는 무선통신망의 성능요구사항에 대해서 논의하고, 요구사항을 만족시킬 수 있는 비상통신망의 성능을 마코프 모델을 이용하여 분석하였다.

자기감응 액추에이터를 이용한 능동소음제어 (Active Noise Control Using Sensory Actuator)

  • 고병식
    • 대한기계학회논문집A
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    • 제20권5호
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    • pp.1573-1581
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    • 1996
  • This paper present as experimental demonstratio of DSP and a sensory actuator that is used to actively control sound transmission/radiation through a vibrating plate. A plane acoustic wave incident on a clamped, thin circular plate was used as a noise source, and a sensory actuator bounded to the plate was used to control and sense vibration of the plate. The sound transmission reduction problem was tranformed as a structural vibration control problem that actively control the structural vibration modes coupled to acoustic modes. The results show that the first structural vibration mode is controlled with a reduction of 78 percent in the displacement and velocity of the plate. This corresponds to a 13dB reduction in the acoustic response. These experimental results indicate that a sensory actuator bounded to the plate can be employed to attenuate the sound transmitted to radiated from the plate.

팬과 히트 싱크를 이용한 LED 전조등의 냉각성능 해석 (Cooling Performance of LED Head Lamp with Heat Sink and Cooling Fan)

  • 고만석;이주한;오상준;조현석;서태범
    • 대한기계학회논문집B
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    • 제33권12호
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    • pp.947-951
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    • 2009
  • LED has the merits of high reliability, semi-permanent life, rapid-response and its small size for use as light source of head lamp. But the dependence of its performance and life on temperature affect on its practical use. Which dependence makes problem when the LED is heated up to a higher temperature level by self-generation of heat, due to "highly integration" to get enough quantity of light. To solve this problem, effective cooling system is needed that consider conduction, convection and radiation. This study points out the limits of natural convection cooling system and propose of forced convection with heat sink. Also, it describes a correlation between heat sink area and fluid velocity using numerical analysis to optimize the cooling system.

Anti Inflammatory Effect of Low Level Laser Irradiation on the LPS-stimulated Murine Immunocytes

  • Jin, Dan;Lee, Jong-Young;Cho, Hyun-Chul;Kim, Soo-Ki
    • Molecular & Cellular Toxicology
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    • 제1권2호
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    • pp.124-129
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    • 2005
  • Pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin-12 (IL-12) and interleukin $(IL-1)-{\beta}$, play a key role in causing inflammatory diseases, which are rheumatoid arthritis, Crohn's disease and sepsis. Accumulating evidences suggest that low level laser irradiation (LLLI) may have an anti-inflammatory action. However, there are few data regarding down regulation of Th1 immune response by using the diod typed laser emitting device for human patients. As a fundamental step in order to address this issue, we investigated immunological impact of the low level laser irradiation (10 mw laser diode with a wavelength of 630 nm) on expression of pro-inflammatory cytokines in murine immunocytes (splenocytes and peritoneal macrophages) in vitro. The LLLI on lipopolysaccharide (LPS 100 ng/ml)-stimulated murine splenocytes and macrophages, clearly down regulated mRNA expression of $TNF-{\alpha}$ and IL-12 in dose-dependent manner. In addition, LLLI significantly inhibits the NO production in the LPS-stimulated murine macrophages. This data suggests that LLLI (wavelength of 630 nm) may exert an anti-inflammatory action via modulation of pro-inflammatory cytokine and NO production pathway.

자궁경부암에서 $^{18}F-FDG$ PET의 임상 이용 (Clinical Application of $^{18}F-FDG$ PET in Cervix Cancer)

  • 오소원;김석기
    • Nuclear Medicine and Molecular Imaging
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    • 제42권sup1호
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    • pp.101-109
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    • 2008
  • Cervix cancer is one of common gynecological cancers in the world, and staged with FIGO or TNM system. However, these clinical staging systems lack information about lymph node or distant metastases, thus imaging modalities are considered to make an appropriate therapeutic plan and enhance overall survival rate. In this context, FDG PET is recommended to pre-treatment stating and prognosis prediction, for it could noninvasively evaluate the status of lymph nodes, especially abdominal paraaortic nodes which are closely related with prognosis. Moreover, the degree of FDG uptake is correlated with prognosis. Although there is no consistent method for surveillance of cervix cancer, FDG PET seems a very important tool in detecting tumor recurrence because it is much more advantageous than conventional imaging modalities such as MRI for discerning recurrent tumor from fibrosis caused by radiation or surgery. Furthermore, FDG PET could be used to evaluate treatment response. On the other hand, recently introduced PET/CT is expected to play an ancillary role to FIGO staging by adding anatomical information, and enhance diagnostic performance of PET by decreasing false positive findings.

Survival Following Non Surgical Treatments for Oral Cancer: a Single Institutional Result

  • Larizadeh, Mohammad Hasan;Shabani, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.4133-4136
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    • 2012
  • Aim: To report the results of radiotherapy with or without chemotherapy in the patients with oral cancer. Methods: Over the 2003-2009 periods, a total number of 69 patients with squamous cell carcinoma of the oral cavity that refused surgery or had unresectable tumor were enrolled in this study. A total dose of 60 to 70 Gy (2 Gy per day) was given to the primary tumor and clinically positive nodes. In the patients with locoregionally advanced disease (57 patients with $T_3$, $T_4$ lesions and/ or $N^+$) induction chemotherapy following by concomitant chemoradiation was used. Induction chemotherapy consisted of 3 cycles of Cisplatin and 5-Flourouracil with or without Docetaxel. Weekly cisplatin was used in concomitant protocol. Kaplan-Meier method was used to calculate overall survival. Log-rank test and Cox regression model were used for comparison purposes. Results: Median follow-up was 32 months. The mean age of the patients was 59.2 years. The overall response rate after induction chemotherapy was 68.4%. Actuarial overall survival rates after 2 and 3 years were 38% and 26%, respectively. Clinical stage emerged as the only independent predictor of survival. Conclusion: Outcome of the patients with oral cancer is poor. Presenting with an advanced stage lesion contributed to this result. The role of chemotherapy in advanced cases remains to be defined.

저항 사다리 회로 기반의 다중레벨 가시광을 이용하는 의료 데이터 전송 시스템 (Bio-Medical Data Transmission System using Multi-level Visible Light based on Resistor Ladder Circuit)

  • 안진영;정완영
    • 센서학회지
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    • 제25권2호
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    • pp.131-137
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    • 2016
  • In this study, a multilevel visible light communication (VLC) system based on resistor ladder circuit is designed to transmit medical data. VLC technology is being considered as an alternative wireless communication due to various advantages such as ubiquity, license free operation, low energy consumption, and no radio frequency (RF) radiation characteristics. With VLC even in places where traditional RF communication (e.g., Wi-Fi) is forbidden, significant bio-medical signal including the electrocardiography (ECG) and photoplethysmography (PPG) data can be transmitted. More lives could be saved anywhere by this potential advantage of VLC with a fast emergency response time. A multilevel transmission scheme is adopted to improve the data capacity with keeping simplicity, where data transmission rate can increase by log2m times (m is the number of voltage levels) than that of conventional VLC transmission based on on/off keying. In order to generate multi-amplitudes, resistor ladder circuit, which is a basic principle of digital to analog convertor, is employed, and information is transferred through LED (Light-Emitting Diode) with different voltage level. In the receiver side, multilevel signal is detected by optical receiver including a photo diode. Then, the collected data are analyzed to serve the necessary medical care to the concerned patient.

자연재해 및 방사능 오염 모니터링용 USN 식물공장관리방법 및 시스템 개발 (A Study on the System Development and Management Method of USN Plants for Monitoring of Natural Disasters and Radioactive Contamination)

  • 주해종;조문택;이충식;백종무
    • 한국방사선학회논문지
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    • 제5권6호
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    • pp.351-355
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    • 2011
  • 본 논문은 재난재해와 방사선 오염으로부터 안전한 농작물 관리를 위한 플랫폼, 그리고 식물 생장 모니터링 시스템을 제안하였다. 또한, 식물생장을 모니터링하여 식물공장 내에서 생장하는 식물의 크기를 효율적으로 측정할 수 있는 시스템을 개발하였다. 본 연구에 따른 기대효과는 첫째, 자연재해와 방사능오염 감시를 통해 신속하고 정확한 대처 기능으로 농산물 품질과 생산성 향상을 가져올 수 있다. 둘째, 식물의 크기 측정 데이터를 유지 관리하는데 소요되는 시간을 절약하여 경비를 절감할 수 있다. 마지막으로 식물 공장 관리자의 작업 효율을 향상시킬 수 있다.

방사선 센서 적용을 위한 CdS 소자 제조 및 X선 반응 특성 (The fabrication of CdS films and characteristics of x-ray response of CdS films for radiation sensor applications)

  • 박지군;최장용;김경진;김소영;이형원;남상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.72-76
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    • 2004
  • 본 논문은 CdS의 소성 온도가 방사선 검출 특성에 미치는 영향을 조사하였다. CdS 센서는 스크린 프린터 방식을 이용해 $40{\mu}m$의 두께로 제조하였다. XRD 와 SEM을 이용하여 형성된 CdS 필름의 구조 및 형상을 분석하였다. 제조된 CdS 센서에 대해 X선 반응 특성을 조사하기 위해 I-V 측정을 수행하였다. 인가 전압에 따른 Dark current, x-ray sensitivity 및 선량에 따른 Linearity을 측정한 결과 CdS 센서가 $450^{\circ}C$이상 소성시 방사선에 대한 우수한 검출 특성을 보였다.

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Early Efficacy of Endostar Combined with Chemoradiotherapy for Advanced Cervical Cancers

  • Ke, Qing-Hua;Zhou, Shi-Qiong;Huang, Min;Lei, Yong;Du, Wei;Yang, Ji-Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.923-926
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    • 2012
  • The aim of this study was to investigate the early outcome of Endostar combined with chemoradiotherapy for advanced cervical cancer. Fifty-two cases (FIGO IIb to IVa) were divided randomly into two groups, receiving chemoradiotherapy alone (CRT group) and Endostar combined with chemoradiotherapy (CRT+E group). For the patients in the CRT+E group, Endostar was administered daily with the dosage of 7.5 $mg/m^2$, and cisplatin was administered weekly with the dosage of 20 $mg/m^2$ during the radiation. The regimens lasted for 4 weeks with no difference in chemoradiotherapy between the two groups. The early outcome complete remission rate was 73.1%, partial remission rate was 23.1% and the total response rate was 96.2% in CRT+E group, a significant improvement on the 34.6%, 42.3% and 76.9%, respectively, in the CRT group. One year survive rates were 100% and 84.6% in the CRT+E group and CRT groups, the difference being significant. Endostar combined with chemoradiotherapy can improve the early outcome of the advanced cervical cancer, and adverse effects were not encountered.