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An Optimal Weight Method for CT Image Denoising

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Journal of Electronic Science and Technology 2012年第2期10卷 124-129页

作者： Dinh Hoan Trinh Marie Luong Jean-Marie Rocchisani Canh duong pham Huy Dien pham Francoise Dibos the LAGA Laboratory Université Paris 13 Sorbonne Paris CitéF-93430 Villetaneuse France the L2TI Laboratory Université Paris 13 Sorbonne Paris CitéF-93430 Villetaneuse France the Hopital Avicenne-Medicine Nucleaire the CIID Laboratory Vietnam Academy of Science and Technology

This paper proposes a novel exemplar- based method for reducing noise in computed tomography （CT） images. In the proposed method, denoising is performed on each block with the help of a given database of standard image blocks. For each noisy block, its denoised version is the best sparse positive linear combination of the blocks in the database. We formulate the problem as a constrained optimization problem such that the solution is the denoised block. Experimental results demonstrate the good performance of the proposed method over current state-of-the-art denoising methods, in terms of both objective and subjective evaluations.

关键词： Constrained quadratic programming computed tomography image exemplar-based denoising.

Soil Gas Radon Measurement for Identifying Active Faults in Thua Thien Hue (Vietnam)

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Journal of Geoscience and Environment Protection 2020年第7期8卷 44-64页

作者： pham Tich Xuan Nguyen Anh duong Vu Van Chinh pham Thanh Dang Nguyen Xuan Qua Nguyen Van Pho Institute of Geological Sciences Vietnam Academy of Science and Technology Hanoi Vietnam Institute of Geophysics Vietnam Academy of Science and Technology Hanoi Vietnam

The solid-state nuclear track detectors have long been applied to assess the activity of tectonic faults. We measured the Radon (Rn) concentration in soil gas on 09 profiles with a total of 245 measurement points in Thua Thien Hue area (Vietnam). Measurement results show that the Rn concentration in soil gas ranges from ~10 Bq/m3 to 144,570 Bq/m3. There is a clear difference in the Rn concentration on the granite rock of Dai Loc complex compared to the remaining rocks. The calculated background value and anomaly threshold of Rn concentration on the granite rock of Dai Loc complex and on the remaining rocks are 33,488 Bq/m3, 82,839 Bq/m3 and 5313 Bq/m3, 24,850 Bq/m3 respectively. Spatial distribution of Rn concentration in soil gas reflects the existence of faults since Rn concentration increases at the points above or near fault lines. The level of expression of fault activity is assessed by radon activity index (KRn), which is calculated by the ratio of anomaly value to background value of Rn concentration. According to KRn, in Thua Thien Hue area, only the Dakrong-Hue fault shows a strong expression of activity with high and very high KRn (the maximum KRn = 27.21). The Truong Son, Huu Trach River, Ta Trach River and Bo River fault zones do not show clear activity with low and medium KRn. There is no Rn anomaly value recorded on the Rao Trang fault, demonstrating that it is likely to be inactive at present. The study results indicate that the Rn concentration in soil gas is a strong evidence of the existence of faults or tectonic fracture zones as the Rn concentration always increases at the points above or near the fault line.

关键词： Radon Active Fault Radon Activity Index Thua Thien Hue Vietnam

Trace of the Wishart Matrix and Applications

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Open Journal of Statistics 2015年第3期5卷 173-190页

作者： T. pham-Gia Dinh N. Thanh duong T. Phong Université de Moncton Moncton Canada University of Science Hochiminh City Vietnam Ton Duc Thang University Hochiminh City Vietnam

The trace of a Wishart matrix, either central or non-central, has important roles in various multi-variate statistical questions. We review several expressions of its distribution given in the literature, establish some new results and provide a discussion on computing methods on the distribution of the ratio: the largest eigenvalue to trace.

关键词： Trace Wishart Matrix Sphericity Latent Roots A-Hypergeometric Functions Humbert Function

Anti-inflammatory effects of alkaloid enriched extract from roots of Eurycoma longifolia Jack

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Asian Pacific Journal of Tropical Biomedicine 2019年第1期9卷 18-23页

作者： Dao Thi Thanh Hien Tran Phi Long Tran Phuong Thao Jeong-Hyung Lee duong Thu Trang Nguyen Thi Thu Minh pham Van Cuong Do Thi Ngoc Lan Nguyen Hai Dang Nguyen Tien Dat Deparment of Traditional Pharmacy Hanoi University of Pharmacy Department of Biochemistry College of Natural Sciences Kangwon National University Advanced Center for Bio-organic Chemistry Institute of Marine Biochemistry Vietnam Academy of Science and Technology National Institute of Drug Quality Control Center for Research and Technology Transfers

Objective: To examine the in vitro and in vivo anti-inflammatory effects of the alkaloid enriched extract(ELA) from the roots of Eurycoma longifolia. Methods: The in vitro antiinflammatory effects of ELA were evaluated by examining its inhibitory activities against nitric oxide(NO) production and inducible nitric oxide synthase(iN OS) and cyclooxygenase2(COX-2) expressions in lipopolysaccharide(LPS)-stimulated RAW264.7 cells. The level of NO produced in the culture media was determined by Griess method. The i NOS and COX-2 protein expressions were analyzed by Western blot. The in vivo effect of ELA was evaluated on LPS-induced septic shock in mice model. Mice mortality was monitored for5 days after injection of LPS. The chemical contents of the ELA were determined by using various chromatographic and spectroscopic techniques. Results: The ELA was found to exhibit a significant anti-inflammatory effect in both in vitro and in vivo models. The results demonstrated that ELA dose-dependently inhibited LPS-induced NO production as well as the protein iN OS and COX-2 expressions. In the septic shock model, ELA dose-dependently protected mice from LPS-induced mortality. Further study on the isolated components of ELA indicated that 9,10-dimethoxycanthin-6-one may contribute significantly to the antiinflammatory effects of the extract. Conclusions: These results suggest that ELA exhibits the anti-inflammatory activity via suppression of pro-inflammatory mediators such as NO, iN OS,and COX-2 and protects mice from LPS-induced mortality in septic shock model.

关键词： Eurycoma longifolia Anti-inflammation Alkaloid 9,10-dimethoxycanthin-6-one

Coastal Sea Water Quality of Nha Trang Bay, Khanh Hoa, Viet Nam

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Journal of Shipping and Ocean Engineering 2015年第3期5卷 123-130页

作者： Vo Tran Tuan Linh duong Trong Kiem pham Hong Ngoc Le Hung Phu pham Huu Tam Le Thi Vinh Department of Hydro-Geo Chemistry Institute of Oceanography Viet Nam Academy of Science and Technology (VAST) Viet Nam

Nha Trang Bay is famous not only because of its beauty, but also of the biodiversity values, especially coral reefs. Thus, the sea water quality monitoring systems are necessary for effective and available managements to protect the ecosystems and for sustainable development. There have been several monitoring systems here but they have been done separately and unconnectedly. This research was done to take an overview and access the status and changes of water quality from 2007-2014. The data obtained rainy seasons over the years showed a quite good environment here. The environment changes were also monitored and there were some changes between seasons and over years, decreasing, increasing, or unobvious trends. However, the difference was not so much; and there was not the sign of environmental degradation in the bay from 2007 to 2014. Besides, the stoichiometric nutrients limitations were initially assessed. Since Si ratios here were always higher compared to N and P, there was not increased potential for non-diatom algal blooms. Together with the recorded nutrients concentration data, it can be said that there was no evidence of eutrophication in the bay. Although there was partial contamination of some parameters at few moments, the sea water quality of Nha Trang bay was still in a good condition （according to Vietnamese and ASEAN criteria）.

关键词： Nha Trang bay sea water quality environmental trend nutrients limitations

Enhancing sensitivity in atomic force microscopy for planar tip-on-chip probes

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Microsystems & Nanoengineering 2022年第3期8卷 39-49页

作者： H.tung Ciftci Michael Verhage Tamar Cromwijk Laurent pham Van Bert Koopmans Kees Flipse Oleg Kurmosikov Department of Applied Physics Eindhoven University of TechnologyPO Box 5135600 MB Eindhoventhe Netherlands DRF/RAMIS/SPEC-LEPO Centre CEA de Saclay91191 Gif-sr-VvetteFrance Institut Jean Lamour Lorraine University54000 NancyFrance

We present a new approach to tuning-fork-based atomic force microscopy for utilizing advanced"tip-on-chip"probes with high sensitivity and broad ***,such chip-like probes with a size reaching 2×2 mm^(2)drastically perturb the oscillation of the tuning fork,resulting in poor performance in its intrinsic force ***,restoring initial oscillatory characteristics is necessary for regaining high *** this end,we developed a new approach consisting of three basic steps:tuning-fork rebalancing,revamping holder-sensor fixation,and electrode *** rebalancing allows the tuning fork to recover the frequency and regain high Q-factor values up to 10^(4)in air and up to 4×10^(4)in ultra-high vacuum *** floating-like holder-fxation using soft wires significantly reduces energy dissipation from the mounting *** with the soft wires,reconfigured electrodes provide electrical access to the chip-like probe without intervening in the force-sensing ***,our easy-to-implement approach allows converting the atomic force microscopy tip from a passive tool to a dedicated microdevice with extended functionality.

关键词： tuning atomic utilizing

变压器绕组热点温度与油色谱在线监测应用研究

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变压器绕组热点温度与油色谱在线监测应用研究

作者：杨英松（duong ANH tung）昆明理工大学

学位级别：硕士

电力变压器是变电站内最重要的一次设备,其运行状况直接关系到发电、供电系统的安全性和可靠性。变压器故障的形式和发展是比较复杂,往往与多种因素有关,所以实现变压器的智能化状态监测和判断是非常重要的工作。变压器有很多种监测方法... 详细信息

电力变压器是变电站内最重要的一次设备,其运行状况直接关系到发电、供电系统的安全性和可靠性。变压器故障的形式和发展是比较复杂,往往与多种因素有关,所以实现变压器的智能化状态监测和判断是非常重要的工作。变压器有很多种监测方法,比如：油色谱气体成分、绕组温度、红外测温、局部放电、冷却系统、震动测量等监测技术。本论文针对油浸式电力变压器,通过研究绕组热点温度和油色谱监测,提出变压器在线监测系统-TOMS(Transformer Online Monitoring System)。TOMS采用间接法实现绕组热点温度测量和采用Doernenburg比值法实现油色谱气体成分测量。TOMS系统进行综合故障判断与评估,即可发现变压器运行过程中的潜伏性故障,同时提高变压器过负载运行能力;因此能对变电站智能自动化系统给予很大的补助功能。

关键词：关键词变压器在线监测绕组热点温度油色谱气体成分间接法 Doernenburg比值法 TOMS

Prolonged post-thaw culture of embryos does not improve outcomes of frozen human embryo transfer cycles: A prospective randomized study

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Asian pacific Journal of Reproduction 2019年第6期8卷 260-266页

作者： Minh Tam Le Van Trung Nguyen Thanh tung Nguyen MBlake EVans Thai Thanh Thi Nguyen Tam AnThi Nguyen Dinh duong Le Vu Quoc Huy Nguyen Ngoc Thanh Cao Micah J.Hill Department of Obstetrics and Gynecology Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Center for Reproductive Endocrinology and Infertility Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Department of Histology and Embryology Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Walter Reed National Military Medical Center 8901 Rockville PikeBethesdaMD20889USA Department of Public Health Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam

Objective:To evaluate the impact of prolonged post-thaw embryos culture on pregnancy outcome during frozen embryo transfer ***:This prospective cohort study evaluated 324 thaw transfer cycles with 819 embryos from 269 patients at the Center for Reproductive Endocrinology and Infertility of Hue University Hospital in *** frozen embryo transfer cycles were divided into two groups at the time of thawing:the short culture group(2-hour post-thaw culture)and the overnight culture group(overnight culture for 18 h)before the embryo was transferred into the *** rates of embryo intact,grade A embryo at frozen and transfer time and continuing cleavage were *** clinical outcomes including serum beta-human chorionic gonadotropin,clinical pregnancy and implantation rate were evaluated after 14 days,4 weeks,6 weeks,respectively,after embryo ***:Human chorionic gonadotropin positive occurred in 39.5%of patients in the short culture group compared to 25.9%in the overnight culture group with risk difference(RD)=13.6%,relative risk(RR)=1.343,95%confidence interval(CI)1.085-1.663,P<*** pregnancy rate of the short culture group and overnight culture group was 33.3%and 24.1%,respectively(RD=9.2%,RR=1.242,95%CI 0.996-1.549,P=0.06)and the implantation rate in the short culture group and overnight culture group was 16.5%and 11.0%,respectively(RD=5.5%,RR=1.244,95%CI 1.046-1.479,P=0.01).In women of advanced age(≥35 years)and women who received 3 embryos,pregnancy outcomes were found to be significantly(P<0.05)higher in the short culture than in the overnight culture ***:The prolonged post-thaw culture period does not increase pregnancy outcome in comparison with the short culture.

关键词： Embryo vitrification Post-thaw culture Frozen embryo transfer Biochemical pregnancy rate Clinical pregnancy rate Implantation rate

Assessment of Growth and Productivity on Four Black Pepper Varieties (<i>Piper nigrum</i>L.) in Three Target Provinces of Vietnam

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Engineering（科研） 2021年第12期13卷 647-655页

作者： duong Thi Oanh Nguyen Van Long Nguyen Quang Ngoc Tran Thi Dieu Hien pham Thi Hoai Nguyen Ba Huy Pepper Research and Development Centre Pleiku City Viet Nam

Black pepper varieties, namely “Vinh Linh”, “Lada”, “An Do” and “Loc Ninh” were planted in three different ecological regions: Dak Lak, Gia Lai and Dong Nai in order to compare the growth ability, productivity, and quality of peppercorn. The experiments were designed in the Randomized Complete Block Design (RCBD) with four replications. The results of study have been indicated that “Vinh Linh” and “Lada” both varieties performed better crucial parameters of growth, productivity and yield, after 36 months planted. Although having greater growth parameter in the location of Dong Nai province, four varieties showed lower yield than other regions. By contrast, the four pepper types achieved the highest yield in Gia Lai, followed by Dak Lak. With respect to peppercorn quality, “Vinh Linh”, “Loc Ninh” and “Lada” achieved requirements of Vietnamese Standard (TCVN 7036:2008) including bulk density: 535.69 - 612.72 g/l;piperine: 4.06 - 4.31 g/100g and volatile oil at 2.72 - 3.16 ml/100g. In contrast, “An Do” variety presented the poorest level of piperine (3.78 g/100g), and unachieved requirements.

关键词： Pepper Varieties Growth Yield Ecology Vietnam