• Title/Summary/Keyword: 신호효과

Search Result 3,177, Processing Time 0.042 seconds

A Study on Scenario to establish Coastal Inundation Prediction Map due to Storm Surge (폭풍해일에 의한 해안침수예상도 작성 시나리오 연구)

  • Moon, Seung-Rok;Kang, Tae-Soon;Nam, Soo-Yong;Hwang, Joon
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.19 no.5
    • /
    • pp.492-501
    • /
    • 2007
  • Coastal disasters have become one of the most important issues in every coastal country. In Korea, coastal disasters such as storm surge, sea level rise and extreme weather have placed many coastal regions in danger of being exposed or damaged during subsequent storms and gradual shoreline retreat. A storm surge is an onshore gush of water associated with a tow pressure weather system, typically in typhoon season. However, it is very difficult to predict storm surge height and inundation due to the irregularity of the course and intensity of a typhoon. To provide a new scheme of typhoon damage prediction model, the scenario which changes the central pressure, the maximum wind radius, the track and the proceeding speed by corresponding previous typhoon database, was composed. The virtual typhoon scenario database was constructed with individual scenario simulation and evaluation, in which it extracted the result from the scenario database of information of the hereafter typhoon and information due to climate change. This virtual typhoon scenario database will apply damage prediction information about a typhoon. This study performed construction and analysis of the simulation system with the storm surge/coastal inundation model at Masan coastal areas, and applied method for predicting using the scenario of the storm surge.

Application of Dynamic Reaction Cell - Inductively Coupled Plasma Mass Spectrometry for the Determination of Calcium by Isotope Dilution Method (반응셀 유도결합플라스마 질량분석분석기를 이용한 칼슘 동위원소비율의 측정과 동위원소희석법의 적용)

  • Suh, Jungkee;Yim, Yonghyeon;Hwang, Euijin;Lee, Sanghak
    • Analytical Science and Technology
    • /
    • v.15 no.5
    • /
    • pp.417-426
    • /
    • 2002
  • Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

Clinical Experience of LINAC-based Stereotactic Radiosurgery for Angiographically Occult Vascular Malformations (혈관조영상 잠재혈관기형에 대한 선형가속기형 정위방사선수술의 임상경험)

  • Kim Dae Yong;Ahn Yong Chan;Lee Jung Il;Nam Do-Hyun;Lim Do Hoon;Lee Jeong Eun;Yeo Inhwan;Huh Seung Jae;Noh Young Joo;Shin Seong Soo;Hong Seung-Chyul;Kim Jong Hyun
    • Radiation Oncology Journal
    • /
    • v.19 no.1
    • /
    • pp.1-9
    • /
    • 2001
  • Purpose : To establish the role of stereotactic radiosurgery (SRS) for the treatment of patients with angiographically occult vascular malformation (AOVM). Materials and Methods : Eleven patients (12 lesions) with AOVM were treated with linear accelerator-based SRS between February 1995 and December 1999. A magnetic resonance imaging of each patients showed well-circumscribed vascular lesion with reticulated core of heterogeneous signal intensity and peripheral rim of low signal intensity. SRS were peformed with the median peripheral dose of 16 Gy (range 13~25). A single isocenter was used with median collimator size of 14 mm (range 8~20) diameter. Results : With a median follow-up period of 42 months (range 12~56), rebleeding occurred in 3 AOVMS at 5, 6 and 12 months after SRS but no further bleeding did. Two patients experienced radiation-induced necrosis associated with permanent neurologic deficit and one patient showed transient edema of increased 72 signal intensity. Conclusion : SRS may be effective for the prevention of rebleeding in AOVM located in surgically inaccessible region of the brain. Careful consideration should be needed in the decision of case selection and dose prescription because the incidence of radiation-induced complications is too high to be accepted.

  • PDF

Outcome of LINAC Radiosurgery for a Cavernous Angioma (해면상혈관종에 대한 선형가속기를 이용한 고선량 정위 방사선수술의 임상경험)

  • Hong Semie;Chie Eui Kyu;Park Suk Won;Kim Il Han;Ha Sung Hwan;Park Charn Il
    • Radiation Oncology Journal
    • /
    • v.21 no.2
    • /
    • pp.107-111
    • /
    • 2003
  • Purpose: To establish the role of stereoactic radiosurgery using a linear accelerator for the treatment of patients with cavernous angloma. Materials and Methods: Between February 1995 and May 1997, 11 patients with cavernous angioma were treated with stereotactic radiosurgery using a linear accelerator. Diagnoses were based on the magnetic resonance imaging in 8 patients, and the histological in 3. The vascular lesions were located on the brainstem (5 cases), cerebellum (2 cases) thalamus (1 case) and cerebrum (3 cases). The clinical presentation at onset included previous intracerebral hemorrhages (9 cases) and seizures (2 cases). All patients were treated with a a linac-based radiosurgery. The median dose of radiation delivered was 16 Gy ranging from 14 to 24 Gy, which was typically proscribed to the 80$\%$ isodose surface (range 50 $\~$ 80$\%$), corresponding to the periphery of the lesion with a single isocenter. Ten patients were followed-up. Results: The median follow-up was 49 months ranging from 8 to 73 months, during which time two patients developed an intracerebral hemorrhage, 1 at 8 months, with the other at 64 months post radiosurgery. One patient developed neurological deficit after radiosurgery, and two developed an edema on the T2 weighted images of the MRI surrounding the radiosurgical target. Conclusion: The use of stereotactic radiosurgery in the treatment of a cavernous angioma may be effective in the prevention of rebleedlng, and can be safely delivered. However, a longer follow-up period will be required.

Effect of the Dose Reduction Applied Low Dose for PET/CT According to CT Attenuation Correction Method (PET/CT 저선량 적용 시 CT 감쇠보정법에 따른 피폭선량 저감효과)

  • Jung, Seung Woo;Kim, Hong Kyun;Kwon, Jae Beom;Park, Sung Wook;Kim, Myeong Jun;Sin, Yeong Man;Kim, Yeong Heon
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.18 no.1
    • /
    • pp.127-133
    • /
    • 2014
  • Purpose: Low dose of PET/CT is important because of Patient's X-ray exposure. The aim of this study was to evaluate the effectiveness of low-dose PET/ CT image through the CTAC and QAC of patient study and phantom study. Materials and Methods: We used the discovery 710 PET/CT (GE). We used the NEMA IEC body phantom for evaluating the PET data corrected by ultra-low dose CT attenuation correction method and NU2-94 phantom for uniformity. After injection of 70.78 MBq and 22.2 MBq of 18 F-FDG were done to each of phantom, PET/CT scans were obtained. PET data were reconstructed by using of CTAC of which dose was for the diagnosis CT and Q. AC of which was only for attenuation correction. Quantitative analysis was performed by use of horizontal profile and vertical profile. Reference data which were corrected by CTAC were compared to PET data which was corrected by the ultra-low dose. The relative error was assessed. Patients with over weighted and normal weight also underwent a PET/CT scans according to low dose protocol and standard dose protocol. Relative error and signal to noise ratio of SUV were analyzed. Results: In the results of phantom test, phantom PET data were corrected by CTAC and Q.AC and they were compared each other. The relative error of Q.AC profile was been calculated, and it was shown in graph. In patient studies, PET data for overweight patient and normal weight patient were reconstructed by CTAC and Q.AC under routine dose and ultra-low dose. When routine dose was used, the relative error was small. When high dose was used, the result of overweight patient was effectively corrected by Q.AC. Conclusion: In phantom study, CTAC method with 80 kVp and 10 mA was resulted in bead hardening artifact. PET data corrected by ultra- low dose CTAC was not quantified, but those by the same dose were quantified properly. In patients' cases, PET data of over weighted patient could be quantified by Q.AC method. Its relative difference was not significant. Q.AC method was proper attenuation correction method when ultra-low dose was used. As a result, it is expected that Q.AC is a good method in order to reduce patient's exposure dose.

  • PDF

Developments of Functional Sausage using Plant Extracts from Pine Needle and Green Tea (솔잎 및 녹차 추출물을 이용한 기능성 소시지 개발)

  • 김수민;조영석;성삼경;이일구;이신호;김대곤
    • Food Science of Animal Resources
    • /
    • v.22 no.1
    • /
    • pp.20-29
    • /
    • 2002
  • The functional sausage added to effective extracts are prepared to carried out to investigate functional and storage characteristics. This products were stored at different temperature. The changes of pH were tended to be a little ranged from pH 6.07 to pH 6.35 in control. At the same time, the pH changes treated with plant extracts showed the same tendency as control. The treatments using natural extracts revealed a little low TBARS value during storage at 10$^{\circ}C$. The nitrite scavenging ability of extracts from pine needle were higher than those of green tea extracts, irrespective of storage temperature. The VBN content was tended to be increased as storage time goes by, irrespective of storage temperature. The treatments using plant extracts revealed a little low VBN content, compared to control during storage. The changes of total bacteria were more increased to 2.2${\times}$10$^1$∼3.2 ${\times}$ 10$\^$6/ CFU/g during storage at 30$^{\circ}C$ than 2.2${\times}$10$^1$∼3.3${\times}$10$^2$CFU/g in case of storage at 10$^{\circ}C$. The treatments using plant extracts revealed an antimicrobial activity until storage at 3 days, compared to control. The lightness of sausage color were a little more decreased gradually during storage at 30$^{\circ}C$ than those of storage at 10$^{\circ}C$. Overall, the lightness of sausage color treated with pine needle extracts were a more bright than those of control. However, the redness of sausage color treated with pine needle and green tea showed the most lowest red color, compared to control. Sensory test suggested that the changes of sausage color, flavor, texture and taste were tended to be decreased gradually. In conclusion, pine needle extract was the most effective natural resources on the basis of the functional and physico-chemical properties of sausage of sausage.

Real-Time 3D Ultrasound Imaging Method Using a Cross Array Based on Synthetic Aperture Focusing: I. Spherical Wave Transmission Approach (합성구경 기반의 교차어레이를 이용한 실시간 3차원 초음파 영상화 기법 : I. 구형파 송신 방법)

  • 김강식;송태경
    • Journal of Biomedical Engineering Research
    • /
    • v.25 no.5
    • /
    • pp.391-401
    • /
    • 2004
  • 3D imaging systems using 2D phased arrays have a large number of active channels, compelling to use a very expensive and bulky beamforming hardware, and suffer from low volume rate because, in principle, at least one ultrasound transmit-receive event is necessary to construct each scanline. A high speed 3D imaging method using a cross array proposed previously to solve the above limitations can implement fast scanning and dynamic focusing in the lateral direction but suffer from low resolution except at the fixed transmit focusing along the elevational direction. To overcome these limitations, we propose a new real-time volumetric imaging method using a cross array based on the synthetic aperture technique. In the proposed method, ultrasound wave is transmitted successively using each elements of an 1D transmit array transducer, one at a time, which is placed along the elevational direction and for each firing, the returning pulse echoes are received using all elements of an 1D receive array transducer placed along the lateral direction. On receive, by employing the conventional dynamic focusing and synthetic aperture method along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. In addition, in the proposed method, a volume of interest consisting of any required number of slice images, can be constructed with the same number of transmit-receive steps as the total number of transmit array elements. Computer simulation results show that the proposed method can provide the same and greatly improved resolutions in the lateral and elevational directions, respectively, compared with the 3D imaging method using a cross array based on the conventional fixed focusing. In the accompanying paper, we will also propose a new real-time 3D imaging method using a cross array for improving transmit power and elevational spatial resolution, which uses linear wave fronts on transmit.

Immunomodulatory Activity of Water Extract of Ulmus macrocarpa in Macrophages (유근피 추출물이 대식세포 면역조절에 미치는 영향)

  • Kwon, Da Hye;Kang, Hye-Joo;Choi, Yung Hyun;Chung, Kyung Tae;Lee, Jong Hwan;Kang, Kyung Hwa;Hyun, Sook Kyung;Kim, Byung Woo;Hwang, Hye Jin
    • Journal of Life Science
    • /
    • v.26 no.1
    • /
    • pp.50-58
    • /
    • 2016
  • The root bark of Ulmus macrocarpa has been used in traditional medicine for the treatment of various diseases such as edema, infection and inflammation. Nevertheless, the biological activities and underlying mechanisms of the immunomodulatory effects remain unclear. In this study, as part of our ongoing screening program to evaluate the immunomodulatory potential of new compounds from traditional medicinal resources, we investigated the effects of U. macrocarpa water extract (UME) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the productions of as nitric oxide (NO) and cytokines such tumor necrotic factor (TNF)-α, interleukin (IL)-1β and IL-10 were evaluated. Although the release of IL-1β remained unchanged in UME-treated RAW 264.7 macrophages, the productions of NO, TNF-α and IL-10 were significantly increased, along with the increased expression of inducible NO synthase, TNF-α and IL-10 expression at concentrations with no cytotoxicity. UME treatment also induced the nuclear translocation of nuclear factor κB (NF-κB), and phosphorylation of Akt and mitogen-activated protein kinases (MAPKs) indicating that UME activated macrophages through the activation of NF-κB, phosphoinositide-3-kinase (PI3K)/Akt and MAPKs signaling pathways in RAW 264.7 macrophages. Furthermore, pre-treatment with UME significantly attenuated the production of NO, but not TNF-α, IL-1β and IL-10, in lipopolysaccharide-stimulated RAW 264.7 cells suggesting that UME may be useful in preventing inflammatory diseases mediated by excessive production of NO. These findings suggest that the beneficial therapeutic effects of UME may be attributed partly to its ability to modulate immune functions in macrophages.

Design and Performance Evaluation of Selective DFT Spreading Method for PAPR Reduction in Uplink OFDMA System (OFDMA 상향 링크 시스템에서 PAPR 저감을 위한 선택적 DFT Spreading 기법의 설계와 성능 평가)

  • Kim, Sang-Woo;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.3 s.118
    • /
    • pp.248-256
    • /
    • 2007
  • In this paper, we propose a selective DFT spreading method to solve a high PAPR problem in uplink OFDMA system. A selective characteristic is added to the DFT spreading, so the DFT spreading method is mixed with SLM method. However, to minimize increment of computational complexity, differently with common SLM method, our proposed method uses only one DFT spreading block. After DFT, several copy branches are generated by multiplying with each different matrix. This matrix is obtained by linear transforming the each phase rotation in front of DFT block. And it has very lower computational complexity than one DFT process. For simulation, we suppose that the 512 point IFFT is used, the number of effective sub-carrier is 300, the number of allowed sub-carrier to each user's is 1/4 and 1/3 and QPSK modulation is used. From the simulation result, when the number of copy branch is 4, our proposed method has more than about 5.2 dB PAPR reduction effect. It is about 1.8 dB better than common DFT spreading method and 0.95 dB better than common SLM which uses 32 copy branches. And also, when the number of copy branch is 2, it is better than SLM using 32 copy branches. From the comparison, the proposed method has 91.79 % lower complexity than SLM using 32 copy branches in similar PAPR reduction performance. So, we can find a very good performance of our proposed method. Also, we can expect the similar performance when all number of sub-carrier is allocated to one user like the OFDM.

Quality characteristics and antioxidant activity of drink prepared with black garlic and Oenanthe javanica DC (흑마늘과 미나리를 이용하여 제조한 음료의 품질 및 항산화 특성)

  • Jeong, Tae-Seong;Kim, Jin-Hak;An, Sin-Ae;Won, Yong-Duk;Lee, Shin-Ho
    • Food Science and Preservation
    • /
    • v.21 no.2
    • /
    • pp.193-198
    • /
    • 2014
  • The quality and antioxidative characteristics of drinks prepared with different mixing ratios of black garlic and Oenanthe javanica DC., BD-1 (black garlic only), BD-2 (black garlic:Oenanthe javanica DC.=2:1), BD-3 (black garlic:Oenanthe javanica DC.=1:1), and BD-4 (black garlic:Oenanthe javanica DC.=1:2), were studied. The pH increased with the increasing concentration of Oenanthe javanica DC. extract in all the tested drinks, but the sugar contents decreased. The total polyphenol contents of the drinks were 28.48 ${\mu}g/mL$ (BD-1), 41.91 ${\mu}g/mL$ (BD-2), 42.36 ${\mu}g/mL$ (BD-3), and 46.96 ${\mu}g/mL$ (BD-4). The SOD-like activity was highest for BD-4 (18.60%), followed by BD-3 (15.53%), BD-2 (12.53%), and BD-1 (10.27%). The thiobarbituric acid reactive substances (TBARS) was highest for BD-4 (52.51%), followed by BD-3 (45.70%), BD-2 (39.44%), and BD-1 (28.72%). The ferrous ion chelating activity increased with the increasing concentration of Oenanthe javanica DC extract, and BD-4 showed the best activities among all the tested drinks. The water-soluble vitamin content (vitamins B1, B2, B6, and C) of BD-4 (1197.77 ${\mu}g/mL$) was higher than those of the other drinks (BD-1, 213.02 ${\mu}g/mL$; BD-2, 477.87 ${\mu}g/mL$; BD-3, 914.72 ${\mu}g/mL$), and the vitamin C (806.21 ${\mu}g/mL$) content of the water-soluble vitamins at BD-4 was higher than those of vitamins B1 (68.04 ${\mu}g/mL$), B2 (312.51 ${\mu}g/mL$), and B6 (11.01 ${\mu}g/mL$). BD-4 showed the best score in the sensory evaluations, such as in the evaluation of the color, flavor, taste, and overall acceptability.