• Title/Summary/Keyword: TcB

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How do diverse precipitation datasets perform in daily precipitation estimations over Africa?

  • Brian Odhiambo Ayugi;Eun-Sung Chung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.158-158
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    • 2023
  • Characterizing the performance of precipitation (hereafter PRE) products in estimating the uncertainties in daily PRE in the era of global warming is of great value to the ecosystem's sustainability and human survival. This study intercompares the performance of different PRE products (gauge-based, satellite and reanalysis) sourced from the Frequent Rainfall Observations on GridS (FROGS) database over diverse climate zones in Africa and identifies regions where they depict minimal uncertainties in order to build optimal maps as a guide for different climate users. This is achieved by utilizing various techniques, including the triple collection (TC) approach, to assess the capabilities and limitations of different PRE products over nine climatic zones over the continent. For daily scale analysis, the uncertainties in light PRE (0.1 5mm/day) are prevalent over most regions in Africa during the study duration (2001-2016). Estimating the occurrence of extreme PRE events based on daily PRE 90th percentile suggests that extreme PRE is mainly detected over central Africa (CAF) region and some coastal regions of west Africa (WAF) where the majority of uncorrected satellite products show good agreement. The detection of PRE days and non-PRE days based on categorical statistics suggests that a perfect POD/FAR score is unattainable irrespective of the product type. Daily PRE uncertainties determined based on quantitative metrics show that consistent, satisfactory performance is demonstrated by the IMERG products (uncorrected), ARCv2, CHIRPSv2, 3B42v7.0 and PERSIANN_CDRv1r1 (corrected), and GPCC, CPC_v1.0, and REGEN_ALL (gauge) during the study period. The optimal maps that show the classification of products in regions where they depict reliable performance can be recommended for various usage for different stakeholders.

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A Study on the single crystal growth of the optic-grade $LiTaO_3$ as a electro-optic materials

  • Kim, B.k.;J.K. Yoon
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.526-526
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    • 1996
  • The single crystal of LiTaO3 is well known eletro-optic material as well as the piezoelectric one applied to SAW filter. LiTaO3 has large electro-optic effects, so applied to optical switch, acosto-optic deflector, and optical memory device using photorefractive effects. The crystal growth of SAW-grade LiTaO3 has been studied many aspects, but there is no detail research about optic-grade crystal growth. The conditions of optic-grade LiTaO3 single crystal are as below. The optical transmittance must be over 75%, and axial and radial concentratiom uniformity below 1%. The variation of Curie temperature depending on Li/Ta ratio must be also below 2$^{\circ}C$ and no internal no internal cracks and defects. Because of the limitation of crystal quality, the growing of optic-grade LiTaO3 single crystal is very difficult compared with the growing of SAW-grade. In this research, upper conditions of optic-grade single crystal was investigated after growing of 1 inch diameter and 1.5 inch length LiTaO3 single crystal having no internal cracks and defects using Czochralski method. Curie temperature was determined with DSC and measuring capacitance and lattice parameter was calculated about the grown crystal and ceramic powder samples of various Li/Ta ratio. The result of Tc variation was below 1.2$^{\circ}C$ all over the grown crystal, so it is confirmed that LiTaO3 was grown under congruent melting composition having optical homogeniety. Also, the optical transmittance was about 78%, which was sufficient for optical device.

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Trigonella Goenum-Graecum Seed Extract Alleviates Menopausal Symptoms and Osteoporosis in Ovariectomized Rats (호로파(葫蘆巴) 종자 추출물이 난소 절제술을 받은 쥐에서 갱년기 증상 및 골다공증에 미치는 영향)

  • Min Ju Kim;Mi-Rae Shin;Hak Joo Choi;Seong-Soo Roh
    • The Korea Journal of Herbology
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    • v.39 no.3
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    • pp.85-95
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    • 2024
  • Objectives : We proposed the hypothesis that administering Trigonella foenum-graecum seed extract (TSE) could alleviate menopausal symptoms and osteoporosis resulting from estrogen deficiency. Methods : Ovariectomized (OVX) rats were administered TSE at doses of 300 or 600 mg/kg body weight for 8 weeks, followed by measurement of serum lipid profile and serum bone markers using ELISA kits. Additionally, analysis of related genes in the femur and uterus was performed using Western blot and real-time PCR. Additionally, micro-CT analysis was performed to investigate the protective effect of TSE against bone loss due to oophorectomy. Results : The administration of TSE led to significant reductions in triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and glucose levels in the serum of OVX rats. Furthermore, TSE increased estradiol levels in the serum and notably improved the levels of biochemical markers associated with bone metabolism. Additionally, TSE exerted significant regulatory effects on the mRNA levels of alkaline phosphatase (ALP) and receptor activator of nuclear factor kappa-B ligand (RANKL)-genes closely associated with bone metabolism in the femur. TSE also demonstrated pronounced effects on uterine tissue, with improvements observed in gene expression related to estrogen receptors. Conclusion : Our findings confirm the efficacy of TSE in ameliorating menopause symptoms by modulating elements associated with both bone and lipid metabolism in the serum, uterine tissue, and femur of OVX rats. The present findings suggest that TSE may offer potential therapeutic effects for symptoms related to menopause and osteoporosis in females.

The Comparison of Glomerular Filteration Rate by Kidney Depth in Dynamic kidney Scan (동적신장검사에서 신장깊이에 따른 사구체여과율 비교)

  • Hwang, Ju-Won;Lim, Young-Hyen;Yun, Jong-Jun;Lee, Hwa-Jin;Lee, Mu-Seok;Jung, Ji-Uk;Park, Se-Yun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.2
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    • pp.73-77
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    • 2014
  • Purpose Find out about the significance of the GFR values calculated by the kidney depth is measured by comparing the values obtained for kidney depth was measured GFR in the CT image kidney depth and is calculated by Tonnesen law in $^{99m}Tc$-DTPA dynamic kidney scan with each applies. Materials and Methods Among patients with normal value (75~120 mL/min) computed GFR conducted of dynamic renal scan to visit from February 2013 to February 2014 and donor GFR values in patients with normal value. The mean age was 46.9 years with 14 men 13 females. We used abdomen CT image which checked before conducting dynamic Kidney scan for measuring the depth of kidney. We only used CT image that contains renal hilum and measured outermost front of the kidney from the skin surface (a) and the final surface (b) caculated the average depth of [(a + b) / 2] respectively. Using the same ROI in order to limit the change in GFR values by the other additional element was set before and after the depth value was excluded from the GFR falls kidney disease. Results Using Tonnesen law the average value was caculated 5.94 cm from the right kidney 5.90 cm from the left kidney. It was 6.83 cm, 8.71 cm in the left kidney and the right kidney average value of the depth measured on the basis of the CT image. The respective increase in left kidney 0.93 cm and right kidney 2.77 cm calculated on the basis of CT image actually measured values. GFR was calculated as the average depth of the subject calculated by the method Tonnesen $83.3{\pm}9.79mL/min$. $98.6{\pm}14.07mL/min$ GFR was applied to calculate the average depth of the subjects using the CT image, is the difference appears 15.26 mL/min was increased after seting up depth value, P value was less than 0.01 which is significant. Conclusion The difference between GFR before-after setting up depth value cause that the different of depth value. Is a measured depth of the extension value of the calculated estimates Whereas Tonnesen kidney depth method is to use in calculating the value of GFR in a typical dynamic elongation test depth derived using the CT image depth. Is thought to be able to calculate more accurately the GFR value by the distance to the center of kidney more accurately measured in the skin thereby.

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Changes of Lipid and Lipoprotein Compositions in Kawasaki Disease and its Impact on Cardiac Complications (가와사끼병에서 혈중 지질과 지단백의 변화와 심장 합병증에 미치는 영향에 관한 연구)

  • Yun, Sin Weon;Lee, Ho Seok;Kim, Dong Woon;Rhee, Kang Won;Jung, Young Soo
    • Clinical and Experimental Pediatrics
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    • v.48 no.12
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    • pp.1370-1377
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    • 2005
  • Purpose : Delineation of serum lipid and lipoprotein values in children after Kawasaki disease(KD) is important because of the predilection of this disease for the coronary arteries. Methods : The KD group was composed of 51 patients who were hospitalized from Jan. 2002 to Dec. 2003. Control was 25 patients with non-KD febrile illness. The levels of total lipid, phospholipid, triglyceride, HDL-cholesterol(HDL-C), LDL-cholesterol, total cholesterol, apolipoprotein A1(apo A1), apolipoprotein B, and Lipoprotein(a) were measured and compared with Echocardiographic findings. Measurements were obtained in four time periods: acute febrile, subacute, convalescent phase and 1 year after KD. Results : HDL-C($33.64{\pm}7.49mg/dL$ vs $50.43{\pm}14.41mg/dL$, P<0.01) and apo A1($99.75{\pm}6.39mg/dL$ vs $113.34{\pm}11.35mg/dL$, P<0.05) were decreased more in the acute febrile period of KD than in the control, but these changes were not correlated with cardiac complications. All lipid profiles were markedly elevated in the subacute stage and normalized in the convalescent stage; there were no changes until 1-year follow up. There were no significant differences in the changes of lipid profiles, including Lp(a) and coronary dilatation, in any time periods. Conclusion : KD is associated with important abnormalities in lipid metabolism, but these changes were transient and appear to be due to the disease itself. These data lead us to infer that KD dose not cause such permanent changes in lipid abnormalities as to be considered a risk factor for atherosclerosis, beyond that caused by the disease itself.

Effects of Puffed and Fermented Red Ginseng on Blood Glucose-related Biomarkers in Streptozotocin-Induced Diabetic Rats (팽화발효홍삼이 Streptozotocin 유발 당뇨쥐의 혈당관련 지표에 미치는 영향)

  • Park, Ju-Hun;Sung, Ki-Seung;Kim, Sung-Soo;Shim, Gun-Sub;Han, Chan-Kyu
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.5
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    • pp.630-637
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    • 2012
  • This study was performed to investigate the effects of puffed and fermented red ginseng on blood glucose-related biomarkers in streptozotocin-induced diabetic rats. Male Sprague-Dawley diabetic rats were orally injected with 0.85% NaCL as a diabetic control (DC), 300 mg/kg general red ginseng (RG), 300 mg/kg puffing red ginseng fermented by mixed strain culture of $Bifidobacterium$ $breve$ and $Lactobacillus$ $delbrueckii$ (BL), and 300 mg/kg puffing red ginseng fermented by $Enterococcus$ $faecalis$ (EF) for 5 weeks. The blood glucose level of group BL was significantly lower maintained than in groups DC and RG for the experimental period (p<0.05). It was also significantly lower than in groups DC, RG, and EF at the 5th week (p<0.05). In the oral glucose tolerance test, the blood glucose of group BL was maintained the lowest level (p<0.05), and the area under the blood glucose curve (AUC) was also significantly lower in group BL than in group DC (p<0.05). The fasting blood glucose and insulin levels after the experiment were significantly low in group BL (p<0.05), and the HOMA-IR was more significantly low in groups BL and EF than in group DC (p<0.05). Also, the HbA1c content of group BL was significantly low than in groups DC and RG (p<0.05). The serum TC level was significantly decreased in groups RG, BL, and EF than in group DC (p<0.05), and the LDL-C content was significantly low in group BL than in group DC (p<0.05). From the findings, it was shown that the puffed and fermented red ginseng made using a mixed strain culture of $B.$ $breve$ and $L.$ $delbrueckii$ could improve blood glucose-related biomarkers.

Comparison of Color Stability and Surface Roughness of 3D Printing Resin by Polishing Methods (연마 방법에 따른 3D 프린팅 레진의 색조 안정성과 표면 조도의 비교)

  • Heeju Kim;Yujin Kim;Jongsoo Kim;Joonhaeng Lee;Mi Ran Han;Jisun Shin;Jongbin Kim
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.2
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    • pp.205-216
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    • 2023
  • This study aimed to compare the color stability and surface roughness of three-dimensional (3D) printing resin according to polishing methods. 3D-printed resin specimens were fabricated at TC-80DP (Graphy, Seoul, Korea) with a stereolithography 3D printer, and the specimens were divided into three groups, each of which was not polished, was polished using Enhance®, and was polished using a Sof-LexTM disc. The CIE L*a*b* value and the surface roughness of each group were measured and immersed in artificial saliva and orange juice after 0, 1, 7, 30, and 60 days, and the color difference (ΔE*) was calculated. As a result of the study, no noticeable color change was observed in artificial saliva, but a noticeable color change was demonstrated in orange juice after 60 days of immersion, and the difference was significant. In the Sof-LexTM group, surface roughness according to the solution was found to be significantly higher in the orange juice than that in artificial saliva. No significant difference in color change was found according to the polishing method, but surface roughness was significantly lower in the Sof-LexTM group than both that of the unpolished group and that of the Enhance® group. Nevertheless, all groups exhibited clinically acceptable properties regardless of their higher surface roughness than the threshold for plaque accumulation. Overall, this study recommends utilizing Sof-LexTM for polishing 3D printing resin when used in primary anterior tooth coverage.

Joint Precoding Technique for Interference Cancellation in Multiuser MIMO Relay Networks for LTE-Advanced System (LTE-Advanced 시스템의 다중 사용자 MIMO Relay 네트워크에서 간섭 제거를 위한 Joint Precoding 기술)

  • Malik, Saransh;Moon, Sang-Mi;Kim, Bo-Ra;Kim, Cheol-Sung;Hwang, In-Tae
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.6
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    • pp.15-26
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    • 2012
  • In this paper, we perform interference cancellation in multiuser MIMO (Multiple Input Multiple Output) relay network with improved Amplify-and-Forward (AF) and Decode-and-Forward (DF) relay protocols. The work of interference cancellation is followed by evolved NodeB (eNB), Relay Node (RN) and User Equipment (UE) to improve the error performance of whole transmission system with the explicit use of relay node. In order to perform interference cancellation, we use Dirty Paper Coding (DPC) and Thomilson Harashima Precoding (THP) allied with detection techniques Zero Forcing (ZF), Minimum Mean Square Error (MMSE), Successive Interference Cancellation (SIC) and Ordered Successive Interference Cancellation (OSIC). These basic techniques are studied and improved in the proposal by using the functions of relay node. The performance is improved by Decode-and-Forward which enhance the cancellation of interference in two layers at the cooperative relay node. The interference cancellation using weighted vectors is performed between eNB and RN. In the final results of the research, we conclude that in contrast with the conventional algorithms, the proposed algorithm shows better performance in lower SNR regime. The simulation results show the considerable improvement in the bit error performance by the proposed scheme in the LTE-Advanced system.

Ameliorating Effect of Water Extract from Dendropanax morbifera Lev. on Memory Dysfunction in Streptozotocin-induced Diabetic Rats (스트렙토조토신(Streptozotocin) 유발 당뇨 동물모델에서 황칠나무 잎 추출물의 학습 및 기억력 개선 효과)

  • Kim, Ji Hye;Bae, Dong hyuck;Lee, Uk;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.48 no.3
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    • pp.275-283
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    • 2016
  • An anti-amnesic effect of water extract from Dendropanax morbifera Lev. leaves (DMW) on memory dysfunction in streptozotocin-induced diabetic rats was investigated to assess its potential industrial value. Daily administration of DMW (11 weeks) significantly reduced serum glucose, insulin, and blood urea nitrogen (BUN) levels increased by an intraperitoneal injection of streptozotocin (STZ, 55 mg/kg). In addition, the administration of DMW decreased escape latency and increased the time spent in the platform quadrant in the Morris water maze test. Step-through latency in a passive avoidance test was also improved. Finally, DMW produced ameliorating effects on STZ-induced cholinergic deficit through an inhibitory effect on acetylcholinesterase and the increment of acetylcholine level in the hippocampus. These results suggest that DMW might be used as a natural substance for improving diabetic induced cognitive impairment.

Improvement of the Adaptive Modulation System with Optimal Turbo Coded V-BLAST Technique using STD Scheme (선택적 전송 다이버시티 기법을 적용한 최적의 터보 부호화된 V-BLAST 적응변조 시스템의 성능 개선)

  • Ryoo, Sang-Jin;Choi, Kwang-Wook;Lee, Kyung-Hwan;You, Cheol- Woo;Hong, Dae-Ki;Hwang, In-Tae;Kim, Cheol-Sung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.2
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    • pp.6-14
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    • 2007
  • In this paper, we propose and observe the Adaptive Modulation system with optimal Turbo Coded V-BLAST (Vertical-Bell-lab Layered Space-Time) technique that is applied the extrinsic information from MAP (Maximum A Posteriori) Decoder in decoding Algorithm of V-BLAST: ordering and slicing. The extrinsic information is used by a priori probability and the system decoding process is composed of the Main Iteration and the Sub Iteration. And comparing the proposed system with the Adaptive Modulation system using conventional Turbo Coded V-BLAST technique that is simply combined V-BLAST with Turbo Coding scheme, we observe how much throughput performance has been improved. In addition, we observe the proposed system using STD (Selection Transmit Diversity) scheme. As a result of simulation, Comparing with the conventional Turbo Coded V-BLAST technique with the Adaptive Modulation systems, the optimal Turbo Coded V-BLAST technique with the Adaptive Modulation systems has better throughput gain that is about 350 Kbps in 11 dB SNR range. Especially, comparing with the conventional Turbo Coded V-BLAST technique using 2 transmit and 2 receive antennas, the proposed system with STD (Selection Transmit Diversity) scheme show that the improvement of maximum throughput is about 1.77 Mbps in the same SNR range.