다이캐스팅한 SiC 입자강화 알루미늄 복합재료의 피로균열 전파특성

김송희,윤여범,이기호,오준도,주희위,이지환 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.8

This study is to investigate the effect of load ratio on fatigue crack of die-cast SiC particulate aluminum composites. Fundamental fatigue crack propagation tests were performed with sub-sized C-T specimens at a load ratio of 0.1, 0.3 and 0.5 respectively. Crack closure measurements were conducted for explaning the effect of load ratio on fatigue crack growth. The experimental results showed that the fatigue crack growth rate increases with the load ratio, especially at near threshold. The composite reinforced with 20 vol.% SiC particles was better in fatigue crack growth resistance than that with 10 vol.% SiC particles. Through the measurement of Kop and ΔK at various R ratios the concept of effective stress intensity factor range ratio. U was reviewed to evaluate the stress ratio effect on fatigue crack growth. Relationships between U and variables such as ΔK and R were obtained empirically so that we could predict ΔK_(eff) that is of critical importance for the prediction of fatigue crack propagation rate.

A new constructive neural network method for noise processing and its application on stock market prediction

Xi, L.,Muzhou, H.,Lee, M.H.,Li, J.,Wei, D.,Hai, H.,Wu, Y. Elsevier Science, B.V 2014 Applied soft computing Vol.15 No.-

In this paper, in order to optimize neural network architecture and generalization, after analyzing the reasons of overfitting and poor generalization of the neural networks, we presented a class of constructive decay RBF neural networks to repair the singular value of a continuous function with finite number of jumping discontinuity points. We proved that a function with m jumping discontinuity points can be approximated by a simplest neural network and a decay RBF neural network in L<SUP>2</SUP>(@?) by each @? error, and a function with m jumping discontinuity point y=f(x),x@?E@?@?<SUP>d</SUP> can be constructively approximated by a decay RBF neural network in L<SUP>2</SUP>(@?<SUP>d</SUP>) by each ε>0 error. Then the whole networks will have less hidden neurons and well generalization in the same of the first part. A real world problem about stock closing price with jumping discontinuity have been presented and verified the correctness of the theory.

True Digestibility of Phosphorus in Different Resources of Feed Ingredients in Growing Pigs

Wu, X.,Ruan, Z.,Zhang, Y.G.,Hou, Y.Q.,Yin, Y.L.,Li, T.J.,Huang, R.L.,Chu, W.Y.,Kong, X.F.,Gao, B.,Chen, L.X. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.1

To determine the true digestible phosphorus (TDP) requirement of growing pigs, two experiments were designed with the experimental diets containing five true digestible P levels (0.16%, 0.20%, 0.23%, 0.26% and 0.39%) and the ratio of total calcium to true digestible P (TDP) kept at 2:1. In Experiment 1, five barrows (Duroc${\times}$Landrace${\times}$Yorkshire) with an average initial body weight of 27.9 kg were used in a $5{\times}5$ Latin-square design to evaluate the effect of different dietary P levels on the digestibility and output of P and nitrogen. In Experiment 2, sixty healthy growing pigs (Duroc${\times}$Landrace${\times}$Yorkshire) with an average body weight (BW) of 21.4 kg were assigned randomly to one of the five dietary treatments (12 pigs/diet), and were used to determine the true digestible phosphorus (TDP) requirement of growing pigs on the basis of growth performance and serum biochemical indices. The results indicated that the true digestibility of P increased (p<0.05) linearly with increasing dietary TDP level below 0.26%. The true P digestibility was highest (56.6%) when dietary TDP was 0.34%. Expressed as g/kg dry matter intake (DMI), fecal P output increased (p<0.05) linearly with increasing P input. On the basis of g/kg fecal dry matter (DM), fecal P output was lowest for Diet 4 and highest (p<0.05) for Diet 5. The apparent digestibility of crude protein (CP) did not differ (p>0.05) among the five diets, with the average nitrogen output of 12.14 g/d and nitrogen retention of 66% to 74% (p>0.05), which suggested that there was no interaction between dietary P and CP protein levels. During the 28-d experimental period of Experiment 2, the average daily gain (ADG) of pigs was affected by dietary TDP levels as described by Eq. (1): $y=-809,532x^4+788,079x^3-276,250x^2+42,114x-1,759$; ($R^2=0.99$; p<0.01; y = ADG, g/d; x = dietary TDP, %), F/G for pigs by Eq. (2): $y=3,651.1x^4-3,480.4x^3+1,183.8x^2-172.5x+10.9$ ($R^2=0.99$; p<0.01; y = F/G; x = dietary TDP, %), and Total P concentrations in serum by Eq. (3): $y=-3,311.7x^4+3,342.7x^3-1,224.6x^2+195.6x-8.7$ (R2 = 0.99; p<0.01; y = total serum P concentration and x = dietary TDP, %). The highest ADG (782 g/d), the lowest F/G (1.07) and the highest total serum P concentration (3.1 mmol/L) were obtained when dietary TDP level was 0.34%. Collectively, these results indicate that the optimal TDP requirement of growing pigs is 0.34% of the diet at a total Ca to TDP ratio of 2:1.

Bone Drilling System for Quantifying Hand Feeling in Orthopedic Surgery

( C. -y. Wu ),( J. -y. Su ),( C. -s. Hsu ),( Y. -h. Chen ),( K. -f. Chang ),( C. -c. Huang ),( H. -m. Wu ),( Y. -c. Tsai ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In this work, a bone drilling system was designed to quantify “hand feeling”, which can benefit surgeons to be more acquainted with bone hardness. A bi-axial force/torque sensor is mounted on the bone drilling system in order to measure the thrust force and the torque caused by drilling in bones. The system is assembled with a motorized stage, which is directly integrated with a surgical handpiece by an adjustable holder, to drill into various bones (porcine mandible, porcine femur, porcine rib) at different feed speeds and spindle speeds. The results reveal that the feed speed is positively corresponded with force and torque. However, the effect of spindle speed on force and torque is negligible. In addition, drilling bones without spraying water can cause the drilling temperature to increase to 73.3°C. According to the data from the experiments, the exact force and torque during bone drilling can be predicted with the given parameters. Thus, surgeons are capable of preventing the use of excessive force during bone drilling.

Dietary Requirement of True Digestible Phosphorus and Total Calcium for Growing Pigs

Ruan, Z.,Zhang, Y.-G.,Yin, Y.-L.,Li, T.-J.,Huang, R.-L.,Kim, S.W.,Wu, G.Y.,Deng, Z.Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.8

Sixty healthy growing pigs ($Duroc{\times}Landrace{\times}Yorkshire$ with an average BW of 21.4 kg) were used to determine the true digestible phosphorus (TDP) requirement of growing pigs on the basis of growth performance and serum biochemical indices. Pigs were assigned randomly to one of five dietary treatments (12 pigs/diet), representing five levels of TDP (0.16%, 0.20%, 0.23%, 0.26% and 0.39%). There were three replications per treatment, with four pigs (2 barrows and 2 gilts) in each replication (2 pigs/pen) A randomized-block design was used, with pen as the experimental unit. Experimental diets were formulated to provide the 5 TDP levels with a total calcium (Ca) to TDP ratio of 2:1, and offered to pigs at 5% BW for 28 d. The total Ca contents of the five diets were 0.33, 0.38, 0.45, 0.51 and 0.79%, respectively. During the 28-d experimental period, the ADG of pigs was affected by dietary TDP levels as described by Equation 1: y = $-809,532x^4+788,079x^3-276,250x^2+42,114x-1$,759; ($R^2$ = 0.99; p<0.01; y = ADG, g/d; x = dietary TDP, %). The feed:gain ratio for pigs was affected by dietary TDP levels as described by Equation 2: y = $3,651.1x^4-3,480.4x^3+1,183.8x^2-172.5x+10.9$ ($R^2$ = 0.99; p<0.01; y = feed:gain ratio; x = dietary TDP, %). Total P concentrations in serum were affected by dietary TDP levels as described by Equation 3: y = $-3,311.7x^4+3,342.7x^3-1,224.6x^2+195.6x-8.7$ ($R^2$ = 0.99; p<0.01; y = total serum P concentration and x = dietary TDP, %). The highest ADG (782 g/d), the lowest feed:gain ratio (1.07), and the highest total serum P concentration (3.1 mmol/L) were obtained when dietary TDP level was 0.34%. Collectively, these results indicate that the optimal TDP requirement of growing pigs is 0.34% of the diet (e.g., 5.1 g/day for a 30-kg pig that consumed 1.5 kg feed daily) at a total Ca to TDP ratio of 2:1.

Association between information provision and decisional conflict in cancer patients

Sim, J. A.,Shin, J. S.,Park, S. M.,Chang, Y. J.,Shin, A.,Noh, D. Y.,Han, W.,Yang, H. K.,Lee, H. J.,Kim, Y. W.,Kim, Y. T.,Jeong, S. Y.,Yoon, J. H.,Kim, Y. J.,Heo, D. S.,Kim, T. Y.,Oh, D. Y.,Wu, H. G.,K Oxford University Press 2015 Annals of Oncology Vol.26 No.9

<P>This article describes the clinical and demographic variables associated with patients' perception of inadequate information. Lower SES, female, unmarried status, type of cancer with good prognosis, and early stage of treatment process were associated with patients' inadequate information provision. In addition, perceived inadequate information provision correlates with high decisional conflict.</P><P><B>Background</B></P><P>In this study, we aimed to identify demographic and clinical variables that correlate with perceived information provision among cancer patients and determine the association of information provision with decisional conflict (DC).</P><P><B>Patients and methods</B></P><P>We enrolled a total of 625 patients with cancer from two Korean hospitals in 2012. We used the European Organization for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire (QLQ-INFO26) to assess patients' perception of the information received from their doctors and the Decisional Conflict Scale (DCS) to assess DC. To identify predictive sociodemographic and clinical variables for adequate information provision, backward selective logistic regression analyses were conducted. In addition, adjusted multivariate logistic regression analyses were carried out to identify clinically meaningful differences of perceived level of information subscales associated with high DC.</P><P><B>Results</B></P><P>More than half of patients with cancer showed insufficient satisfaction with medical information about disease (56%), treatment (73%), other services (83%), and global score (80%). In multiple logistic regression analyses, lower income and education, female, unmarried status, type of cancer with good prognosis, and early stage of treatment process were associated with patients' perception of inadequate information provision. In addition, Information about the medical tests with high DCS values clarity [adjusted odds ratio (aOR), 0.54; 95% confidence interval (CI) 0.30–0.97] and support (aOR, 0.53; 95% CI 0.33–0.85) showed negative significance. For inadequate information perception about treatments and other services, all 5 DCS scales (uncertainty, informed, values clarity, support, and effective decision) were negatively related. Global score of inadequate information provision also showed negative association with high DCS effective decision (aOR, 0.43; 95% CI 0.26–0.71) and DCS uncertainty (aOR, 0.46; 95% CI 0.27–0.77).</P><P><B>Conclusion</B></P><P>This study found that inadequate levels of perceived information correlated with several demographic and clinical characteristics. In addition, sufficient perceived information levels may be related to low levels of DC.</P>

Effects of Kisspeptin-10 on Lipid Metabolism in Cultured Chicken Hepatocytes

Wu, J.,Fu, W.,Huang, Y.,Ni, Y. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.9

Our previous studies showed that kisspeptin-10 (Kp-10) injected in vivo can markedly increase lipid anabolism in liver of quails. In order to investigate the direct effect of Kp-10 on lipid metabolism of hepatocytes in birds, cells were separated from embryos livers and cultured in vitro with 0, 100 and 1,000 nM Kp-10, respectively. The results showed that after 24 h treatment, cells viability was not affected by 100 nM Kp-10, but showed a mild decrease with 1,000 nM Kp-10 compared to the control cells. Based on the results of the cell viability, 100 nM dosage of Kp-10 was selected for the further study and analysis. Compared with control cells, total cholesterol (Tch) contents in 100 nM treated cells were increased by 51.23%, but did not reach statistical significance, while the level of triglyceride (TG), high density of lipoprotein-cholesterol (HDL-C) and low density of lipoprotein-cholesterol (LDL-C) were significantly increased. Real-time PCR results showed that ApoVLDL-II mRNA expression had a tendency to increase, genes including sterol regulatory element-binding protein-1 (SREBP-1), acetyl coenzyme A carboxylase ${\alpha}$ ($ACC{\alpha}$), carnitine palmitoyltransferase 1 (CPT1), 3-hydroxyl-3-methylglutaryl-coenzyme A reductases (HMGCR) and stearyl coenzyme A dehydrogenase-1 (SCD1) mRNA in hepatocytes were significantly down-regulated by 100 nM Kp-10. However, contrary to its gene expression, SREBP-1 protein expression was significantly up-regulated by 100 nM Kp-10. Some of the significant correlations in mRNA expression were found between genes encoding hepatic factors or enzymes involved in lipid metabolism in liver of birds. These results indicate that Kp-10 stimulates lipid synthesis directly in primary cultured hepatocytes of chickens.

Element-specific study of the anomalous magnetic interlayer coupling across NiO spacer layer in Co/NiO/Fe/Ag(001) using XMCD and XMLD

Wu, J.,Choi, J.,Scholl, A.,Doran, A.,Arenholz, E.,Wu, Y. Z.,Won, C.,Hwang, Chanyong,Qiu, Z. Q. American Physical Society 2009 Physical review. B, Condensed matter and materials Vol.80 No.1

ORBITAL-PHASE-DEPENDENT γ-RAY EMISSIONS FROM THE BLACK WIDOW PULSAR

Wu, E. M. H.,Takata, J.,Cheng, K. S.,Huang, R. H. H.,Hui, C. Y.,Kong, A. K. H.,Tam, P. H. T.,Wu, J. H. K. IOP Publishing 2012 The Astrophysical journal Vol.761 No.2

<P>We report on evidence for orbital phase dependence of the gamma-ray emission from the PSR B1957+20 black widow system using data from the Fermi Large Area Telescope. We divide an orbital cycle into two regions: one containing the inferior conjunction and the other containing the rest of the orbital cycle. We show that the observed spectra for the different orbital regions are fitted by different functional forms. The spectrum of the orbital region containing the inferior conjunction can be described by a power law with an exponential cutoff (PLE) model, which also gives the best-fit model for the orbital phase without the inferior conjunction, plus an extra component above similar to 2.7 GeV. The emission above 3 GeV in this region is detected with a similar to 7 sigma confidence level. The gamma-ray data above similar to 2.7 GeV are observed to be modulated at the orbital period at the similar to 2.3 sigma level. We anticipate that the PLE component dominant below similar to 2.7 GeV originates from the pulsar magnetosphere. We also show that inverse Compton scattering of the thermal radiation of the companion star off a 'cold' ultrarelativistic pulsar wind can explain the extra component above similar to 2.7 GeV. The black widow pulsar PSR B1957+20 may be a member of a new class of object, in the sense that the system is showing gamma-ray emission with both magnetospheric and pulsar wind origins.</P>

Acanthoic acid, a diterpene in Acanthopanax koreanum, protects acetaminophen-induced hepatic toxicity in mice

Wu, Y.-L.,Jiang, Y.-Z.,Jin, X.-J.,Lian, L.-H.,Piao, J.-Y.,Wan, Y.,Jin, H.-R.,Joon Lee, J.,Nan, J.-X. G. Fischer 2010 Phytomedicine Vol.17 No.6

The protective effect of a diterpenoid acanthoic acid (AA) isolated from Acanthopanax koreanum Nakai was investigated in acetaminophen (APAP)-induced hepatic toxicity. Drug-induced hepatotoxicity induced by an intraperitoneal (i.p.) injection of 300mg/kg (sub-lethal dose) of APAP. Pretreatment with AA (50 and 100mg/kg) orally 2h before the APAP administration attenuated the APAP-induced acute increase in serum aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activites, replenished the depleted hepatic glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities, decreased malondialdehyde (MDA) level and considerably reduced the histopathological alterations in a manner similar to silymarin (Sily). Immunohistochemical analyses also demonstrated that AA could reduce the appearance of necrosis regions as well as caspase-3 and hypoxia inducible factor-1α (HIF-1α) expression in liver tissue. Our results indicated that AA protected liver tissue from the oxidative stress elicites by APAP-induced liver damage and suggestes that the hepatic protection mechanism of AA would relate to antioxidation and hypoxia factor on APAP-induced hepatotoxicity.