• Title/Summary/Keyword: Gamma function

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A study on the Effectivness of Hand-made Paraffin Thyroid Phantom (Paraffin을 이용한 Thyroid Phantom제작에 따른 유용성에 관한 연구)

  • Park, Soung-Ock;Lee, In-Ja
    • Journal of radiological science and technology
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    • v.30 no.3
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    • pp.237-243
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    • 2007
  • Phantoms are very necessary for quality assurance of radio nuclides imaging systems to maintain standards and to ensure reproducibility of test. General quality assurance and instrument quality control are essential in every hospital. The human tissue equivalent materials are aluminum, areryl, water and epoxy..etc. It is very important to select optimum equivalant materials for a phantoms in QC. Especially, paraffin is very similar with human soft tissue in X or Gamma-ray physical characteristics and easy to buy with economically. We made a paraffin thyroid phantom and compare with thyroid areryl phantom, also used commercially in practice. Two small size cold spots(3 and 6 mm diameter) and a hot spot(3 mm diameter) embeded in paraffin phantom. And imaged with $^{99m}TcO_4$ by camera for analysis about spatial resolution and noise at the hot and cold spots. We got some results as below : 1. No difference in counting rate and noise between both arcryl and paraffin thyroid phantoms. 2. The best spatial resolution can be seen 6 cm distance between pinhole collimator and thyroid phantoms(arcryl and paraffin). 3. More optimal spatial resolution could acquired in paraffin thyroid phantom. Paraffin is very similar with human soft tissue in atomic number, density and relative absorbtion function, and can be shaped easily what we wanted. So we can recommendation paraffin as quality assurance phantom because its usefulness, economical benefit and purchasability.

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Asymptotic Variance of Flood Quantiles from the Generalized Logistic Distribution using the Method of Maximum Likelihood (Generalized Logistic 분포형의 최우도법을 이용한 확률홍수량의 근사적 분산)

  • Shin, Hong-Joon;Heo, Jun-Haeng;Kim, Young-Il
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1522-1526
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    • 2007
  • 최근 영국의 Institute of Hydrology에서는 Generalized logistic (GL) 분포형을 홍수빈도해석시 GEV 분포형을 대체하는 분포형으로 추천한 바 있으며, 그로 인해 GL 분포형의 사용이 증가하고 있는 추세이다. 하지만 아직 그 사용빈도에 반하여 분포형 자체의 특성, 그 중에서도 확률홍수량의 근사적 분산에 관한 연구는 거의 이루어지지 않았다. 따라서 본 연구에서는 최우도법을 이용하여 GL 분포형의 확률홍수량에 대한 근사적 분산에 관한 연구를 수행하였으며, 이를 표본 크기, 재현기간, 매개변수들의 함수로 나타내었다. 또한 확률홍수량의 근사적 분산의 적용성을 검토하기 위해 Monte Carlo 모의실험을 수행하였으며, 모의실험은 형상 매개변수$(\beta)$$\pm0.5$이면 gamma function으로 인하여 표본 크기에 관계없이 분산값이 무한대에 가까워지므로 형상매개변수의 범위는 $-0.5{\leq}{\beta}{\leq}+0.5$로 제한하였다. 모의결과 최우도법에 의해 계산된 분산식은 형상매개변수 $-0.25{\leq}{\beta}{\leq}+0.5$의 범위에서 비교적 잘 맞는 것을 확인할 수 있었으며, 기존에 알려진 대로 표본크기가 크면 클수록 정확해지는 것을 알 수 있다. 또한 표본크기가 작은 경우 형상매개변수 전 범위에서 정확도가 떨어지는 것을 확인할 수 있으며, 최우도법의 경우 표본크기가 작은 경우를 제외하고 $-0.25{\leq}{\beta}{\leq}+0.5$ 범위에서 quantile 산정시 quantile이 약간 과다추정되는 경향이 있는 것을 알 수 있으며, 이는 분산이 과다 추정되는 결과를 초래하며 이로 인해 해석해보다 약간씩 큰 값을 나타내는 것으로 판단되었다..이 극단적인 선정적인 폭력성에 탐닉하게 되는 경향이 있다. 현실은 결코 아름답지 못하고, 행복하게 살 수 없다는 것에 대한 깨달음에서 기인한다. 욕구불만의 강도가 심해질수록 폭력성은 더욱 강하게 나타나는데 개인에게서 뿐만 아니라 가족, 동료, 사회 단체나 종교, 국가간에도 집단적으로도 발생하게 된다. 사회적으로 볼 때 폭력은 용인되는 것이 아니므로 도덕적으로 절제를 하거나 상대방과 적절한 타협과 조정을 필요로 한다. 그러나 절제의 한계를 넘어선다고 생각되거나, 조정의 노력이 불가능하거나, 실패했을 때 폭력적인 행동으로 나타나게 된다. 리차즈(I.A Richards)는 분노와 공포는 일단 겉잡을 수 없는 경향이 있다고 하면서 오늘날 폭력에 대한 요구가 일상의 정서 생활에 있어, 억압을 통한, 빈곤함을 반영하고 있지 않은지 생각해봐야 할 것이라고 충고한다. 조성 가이드라인(안)을 제시하였다.EX>$\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째, 경기도 광주에서 백자관요가 운영되었으므로 지방인 상주지역에도 더 이상 백자를 조달받을 필요가 없이, 일반 지방관아와 서민들의

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Protective Effect of DWP-04 Against Hepatotoxicity Induced by D-galactosamine (흰쥐에서 DWP-04가 D-galactosamine에 의해 유도된 간독성의 보호효과)

  • Lee Jung-Hee;Chi Sang Cheol;Kim Seok-Hwan;Shin Young-Ho;Choi Jongwon
    • Journal of Life Science
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    • v.15 no.3 s.70
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    • pp.461-467
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    • 2005
  • This study was conducted to investigate the biological activity and hepatoprotective effect of DWP-04 [DDB : selenium yeast: glutathione (31.1 : 6.8 : 62.1(w/w/w)] in D-galactosamine (GaIN) intoxicated rats. The DWP-04 (50, 100 or 200 mg/kg) or its vehicle was orally administered everyday before the start of GaIN injection (400 mg/kg, ip) for two weeks and animal decapitated for 24 hrs after GaIN­injected. The activities of serum enzymes, markers of liver function, were increased in the GaIN group compared to normal group and significantly lowered in the DWP-04 pretreated group than in the GaIN group. Hepatic lipid peroxide level and activities of phase 1 enzymes were significantly higher than those of GaIN group compared to normal group and lower in the DWP-04 pretreated group than in the GaIN group, and phase II enzyme activities in liver were lower in the GaIN group than in the normal group and were increased in the DWP-04 pretreated group than in the GaIN group. Total hepatic glutathione content and glutathione biosynthesis enzymes were lower in the GaIN group than in the normal group and were increased in the DWP-04 pretreated group than in the GaIN group. Therefore, the current results indicated that DWP-04 administration alleviated the GaIN-induced adverse effect through enhancing the antioxidant enzyme activities.

In vitro Anti-diabetic Effects of Crude Extracts of Platycodi Radix (In vitro에서 길경 추출 분획물의 항당뇨 효과 조사)

  • Ko, Byoung-Seob;Kwon, Dae-Young;Hong, Sang-Mee;Park, Sun-Min
    • Korean Journal of Food Science and Technology
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    • v.39 no.6
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    • pp.701-707
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    • 2007
  • Anti-diabetic effect of Platycodi radix (PR) extract fractions was determined if vitro by investigating insulin-like action, insulin sensitizing action, glucose-stimulated insulin secretion, gene expression related to ${\beta}-cell$ function and mass, and ${\alpha}$-glucoamylase suppressing action. Insulin-like activity was not promoted by the treatment of PR methanol factions in 373-L1 fibroblast. However, treatment with 0, 20 and 100% PR methanol fractions along with 1 ng/mL insulin increased insulin-stimulated glucose uptake in 373-L1 adipocytes. In addition, the treatment of 0% and 100% methanol fractions along with differentiation inducers significantly increased the differentiation of 373-L1 fibroblasts to adipocytes. These fractions may contain insulin sensitizer. The 20%, 80% and 100% methanol fractions enhanced glucose-stimulated insulin secretion in Min6 cells, insulin secreting cell line. This was related to the mechanism to promote glucose sensing and ${\beta}-cell$ proliferation, which was regulated by the induction of IRS-2, glucokinase and PDX-1 genes. As expected, 20, 80 and 100% methanol fractions increased mRNA levels of IRS-2, glucokinase and PDX-1 genes. However, PR fractions did not affect the ${\alpha}-glucoamylase$ activity in vitro. These data suggested that PR extract fractions have anti-diabetic actions through improving insulin sensitization, glucose-stimulated insulin secretion, and ${\beta}-cell$ proliferation. Therefore, PR extracts can be beneficial for anti-diabetic treatment in lean diabetic patients.

Immuno-stimulating Activities of Skipjack Tuna Katsuwonus pelamis Cooking Juice Concentrates on Mouse Macrophages and Spleen Cells (참치(Katsuwonus pelamis) 자숙액 농축물의 마우스 대식세포 및 비장세포에 대한 면역증강활성)

  • Kang, Bo-Kyeong;Kim, Koth-Bong-Woo-Ri;Ahn, Na-Kyung;Choi, Yeon-Uk;Kim, Min-Ji;Bark, Si-Woo;Pak, Won-Min;Kim, Bo-Ram;Park, Ji-Hye;Bae, Nan-Young;Ahn, Dong-Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.776-784
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    • 2014
  • Tuna cooking juice concentrate (TCJC) is by-produced during the canning processing of skipjack tuna Katsuwonus pelamis and it is well known that TCJC contains various nutritional components. Therefore, the immuno-stimulating activity of TCJC was investigated using macrophage RAW 264.7 cell line and the spleen cell isolated from BALB/c mice. The TCJC increased the production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ in a dose-dependent manner compared to the control in RAW 264.7 cells without any toxicity. In particular, the production of TNF-${\alpha}$ was increased over 300-fold. The production of both Th1 cytokine (such as IFN-${\gamma}$, TNF-${\alpha}$, IL-2, and IL-12) and Th2 cytokine (IL-4, IL-6, IL-10) was also increased by TCJC treatment in splenocytes. Moreover, the TCJC increased the splenocyte proliferation in a concentration-dependent manner compared to control. These results indicate that TCJC may enhance immune function by promoting various cytokine production.

Screening of genes differentially expressed in cultured human periodontal ligament cells and human gingival fibroblasts (배양된 치주인대세포와 치은섬유아세포에서 상이하게 발현된 유전자들의 검토 양상)

  • Yoon, Hye-Jeong;Choi, Mi-Hye;Yeo, Shin-II;Park, Jin-Woo;Choi, Byung-Ju;Kim, Moon-Kyu;Kim, Jung-Chul;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.36 no.3
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    • pp.613-625
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    • 2006
  • Periodontal ligament(PDL) cells and human gingival fibroblasts(HGFs) play important roles in development, regeneration, normal function, and pathologic alteration. PDL cells and HGFs have the similarity related with general characteristics of fibroblast such as spindle shaped morphology, the presence of vimentin intermediate filament and the synthesis of interstitial collagens and fibronectin. There were many studies about the differences between PDL cells and HGFs, but they were not about whole gene level. In this study, we tried to explain the differences of gene expression profiles between PDL cells and HGFs, and the differences among three individuals by screening gene expression patterns of PDL cells and HGFs, using cDNA microarray. Although there were some variants among three experiments, a set of genes were consistentely and differentially expressed in one cell type. Among 3,063 genes, 49 genes were more highly expressed in PDL cells and 12 genes were more highly expressed in HGFs. The genes related with cell structure and motility were expressed more highly in PDL cells. These are cofilin 1, proteoglycan 1 secretory granule, collagen type I(${\alpha}$ 1), adducin gamma subunit, collagen type III(${\alpha}$ 1), fibronectin, lumican(keratan sulfate proteoglycan), and ${\alpha}$ -smooth muscle actin. Tissue inhibitor of metalloproteinase known as the enzyme controlling extracellular matrix with matrix metalloproteinase is more highly expressed in PDL cells, osteoprotegerin known as osteoclastogenesis inhibitory factor is more highly expressed in HGFs. We performed northern blot to verify cDNA microarray results on selected genes such as tissue inhibitor of metalloproteinase, fibronectin, osteoprogeterin. The result of northern blot analysis showed that each cell expressed the genes in similar pattern with cDNA microarray result. This result indicates that cDNA microarray is a reliable method in screening of gene expression profiles.

Development of mixed Th1/Th2-type immune response in mice following immunization with GP63 from Leishmania donovani (내장리슈만편모충 유래 GP63 항원을 마우스에 접종한 후 관찰되는 Th1/Th2-type 복합 면역반응)

  • Shin, Sung-shik
    • Korean Journal of Veterinary Research
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    • v.41 no.2
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    • pp.211-218
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    • 2001
  • The $M_r$ 63,000 glycoprotein (GP63) and lipophosphoglycan (LPG) of Leishmania donovani were evaluated as vaccine candidates against visceral leishmaniasis. Mice were immunized with liposomeencapsulated GP63 and/or LPG that were purified from the soluble extract of L. donovani promastigotes, and were challenged with virulent amastigotes. Mice immunized with GP63/LPG in liposomes plus BCG resulted in a 27.4% reduction of amastigotes in the liver compared to the control group (liposomes plus BCG), and mice immunized with liposome-GP63 plus BCG failed to induce a protective immune response against the challenge infection. Immunization of mice with GP63 fused to the Schistosoma japonicum glutathione S-transferase (GP63-GST) plus BCG also failed to elicit protective immunity. To analyze the cause of failure to induce protection, cytokine release from the spleen cells of immunized mice and Leishmania-specific serum antibodies were analyzed. Spleen cells from mice immunized with GP63-GST plus BCG that were exposed to soluble extract of L. donovani in vitro produced 10-fold greater quantities of IFN-gamma and 3-fold greater quantities of IL-5 than cells from mice receiving BCG only or saline. Western blot analysis revealed that sera from these mice had Leishmania-specific antibodies recognizing 1 to 3 antigens of L. donovani with M. W. of 60-65 kDa. Although immunization of mice with GP63-GST induced a strong Th1 response, this study indicated that GP63-GST simultaneously elicited the Th2 response of the CD4+ T-cell, which was known to abrogate the protective immune response conferred by the Th1 effector function.

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Status of Development of Pyroprocessing Safeguards at KAERI (한국원자력연구원 파이로 안전조치 기술개발 현황)

  • Park, Se-Hwan;Ahn, Seong-Kyu;Chang, Hong Lae;Han, Bo Young;Kim, Bong Young;Kim, Dongseon;Kim, Ho-Dong;Lee, Chaehun;Oh, Jong-Myeong;Seo, Hee;Shin, Hee-Sung;Won, Byung-Hee;Ku, Jeong-Hoe
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.3
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    • pp.191-197
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    • 2017
  • The Korea Atomic Energy Research Institute (KAERI) has developed a safeguards technology for pyroprocessing based on the Safeguards-By-Design (SBD) concept. KAERI took part in a Member-State Support Program (MSSP) to establish a pyroprocessing safeguards approach. A Reference Engineering-scale Pyroprocessing Facility (REPF) concept was designed on which KAERI developed its safeguards system. Recently the REPF is being upgraded to the REPF+, a scaled-up facility. For assessment of the nuclear-material accountancy (NMA) system, KAERI has developed a simulation program named Pyroprocessing Material Flow and MUF Uncertainty Simulation (PYMUS). The PYMUS is currently being upgraded to include a Near-Real-Time Accountancy (NRTA) statistical analysis function. The Advanced Spent Fuel Conditioning Process Safeguards Neutron Counter (ASNC) has been updated as Non-Destructive Assay (NDA) equipment for input-material accountancy, and a Hybrid Induced-fission-based Pu-Accounting Instrument (HIPAI) has been developed for the NMA of uranium/transuranic (U/TRU) ingots. Currently, performance testing of Compton-suppressed Gamma-ray measurement, Laser-Induced Breakdown Spectroscopy (LIBS), and homogenization sampling are underway. These efforts will provide an essential basis for the realization of an advanced nuclear-fuel cycle in the ROK.

Effects of Fructans on Blood Glucose, Activities of Disaccharidases and Immune Function in Streptozotocin-Induced Diabetic Mice (당뇨 유발 생쥐에서 Fructan이 혈당과 이당류분해효소 활성 및 면역능에 미치는 영향)

  • Jeong, Hyun-Jin;Sung, Hye-Young;Choi, Young-Sun;Cho, Sung-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1188-1194
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    • 2005
  • This study was conducted to investigate effects of fructans (chicory inulin, fructooligosaccharide and chicory inulin oligosaccharide) on blood glucose, activities of disaccharidases in small bowel and kidneys, and splenocyte proliferation in streptozotocin-induced diabetic mice. Sixty ICR male mice were divided into one normal group and four diabetic groups. Diabetes was induced by injecting streptozotocin after 2 weeks of experimental diets feeding. Experimental diets based on AIN93G diet were control diet, 6$ \%$ fructooligosaccharide (FOS) diet, 6$\%$ chicory inulin oligosaccharide (CIOS) diet, 6$\%$ chicory inulin (Cl) diet, and given for 25 days after streptozotocin injection. Plasma glucose was lower in Diabetic-Cl group as compared to Diabetic-control group. Plasma insulin level was not different among diabetic groups. Specific activities of jejunal maltase and sucrase in diabetic groups were about double as that of Normal group. Jejunal maltase activity and plasma glucose were positively correlated (r=0.643). However, specific activity of renal maltase in diabetic groups was not significantly different as compared to Normal group. Stimulation index of splenocyte proliferation by lipopolysaccharide (LPS) was significantly increased in Diabetic-CIOS as compared to Diabetic-control. Stimulation index of splenocyte proliferation by Concanavalin A (ConA) tended to be higher in Diabetic-CIOS group. Concentrations of interleukin-2 and interferon- $\gamma$ secreted from splenocytes induced by ConA were not significantly different among all groups. In conclusion, fructans may be effective for lowering plasma glucose, possibly by lowering disaccharidase activity and for increasing immune responses in diabetic con-ditions, where their effects can be different depending on degree of polymerization.

Color Image Rendering using A Modified Image Formation Model (변형된 영상 생성 모델을 이용한 칼라 영상 보정)

  • Choi, Ho-Hyoung;Yun, Byoung-Ju
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.71-79
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    • 2011
  • The objective of the imaging pipeline is to transform the original scene into a display image that appear similar, Generally, gamma adjustment or histogram-based method is modified to improve the contrast and detail. However, this is insufficient as the intensity and the chromaticity of illumination vary with geometric position. Thus, MSR (Multi-Scale Retinex) has been proposed. the MSR is based on a channel-independent logarithm, and it is dependent on the scale of the Gaussian filter, which varies according to input image. Therefore, after correcting the color, image quality degradations, such as halo, graying-out, and dominated color, may occur. Accordingly, this paper presents a novel color correction method using a modified image formation model in which the image is divided into three components such as global illumination, local illumination, and reflectance. The global illumination is obtained through Gaussian filtering of the original image, and the local illumination is estimated by using JND-based adaptive filter. Thereafter, the reflectance is estimated by dividing the original image by the estimated global and the local illumination to remove the influence of the illumination effects. The output image is obtained based on sRGB color representation. The experiment results show that the proposed method yields better performance of color correction over the conventional methods.