Medical image diagnosis of lung cancer by multi-layered GMDH-type neural network self-selecting functions

In this study, a revised Group Method of Data Handling (GMDH)-type neural network self-selecting functions is applied to the computer aided image diagnosis (CAD) of lung cancer. The GMDH-type neural network algorithm has an ability of self-selecting optimum neural network architecture from three neural network architectures, such as sigmoid function neural network, radial basis function neural network and polynomial neural network. The GMDH-type neural network also has abilities of self-selecting the number of layers, the number of neurons in hidden layers and useful input variables. This algorithm is applied to CAD of lung cancers, and it is shown that this algorithm is useful for the CAD, and is very easy to apply to practical complex problems because optimum neural network architecture is automatically organized.     

Effect of hydrogen bond formation on dynamic mechanical properties of amorphous cellulose

The temperature dependence of the dynamic modulus (E′) and the mechanical loss tangent (tanδ) of amorphous cellulose prepared from cellulose triacetate by saponification was measured and compared with that of cellophane, recrystallized cellulose obtained by immersing amorphous cellulose in water, and cellulose triacetate. The E′ of amorphous cellulose decreased initially with increasing temperature and then began to increase at about 70°C with a maximum at 80°C, decreasing again at about 100°C. Another decrease in E′ was observed at 220°C accompanied by a discontinuity at 155°C. In the tan δ-versus-temperature curve, a medium peak at 60°C a shoulder peak at 146°C, and a broad peak at 200°C were observed. It was found that the transition at about 60°C was related to hydrogen bond formation by free OH groups. The transition at about 150°C was attributed to a recrystallization process by heating, and the relaxation at 200°C, to the glass transition of the polymer. The decrement in E′ observed at about 100°C was attributed to the cooperative motion of an individual pyranose ring in amorphous cellulose, juding from the E′ and tan δ assignment of other cellulose materials. The change in E′ was also measured isothermally as a function of time in the temperature range between 40°C and 80°C, where a maximum in tan δ and an increment in E′ were observed as the temperature dependence of the dynamic viscoelasticity. The change in E′ with elapsed time was analyzed kinetically, and an activation energy of 2.6 kcal/mole was calculated. This value is the expected activation energy of hydrogen bond formation.     

Validity of a self-administered food frequency questionnaire (FFQ) and its generalizability to the estimation of dietary folate intake in Japan

Background  

In an epidemiological study, it is essential to test the validity of the food frequency questionnaire (FFQ) for its ability to estimate dietary intake. The objectives of our study were to 1) validate a FFQ for estimating folate intake, and to identify the foods that contribute to inter-individual variation of folate intake in the Japanese population.     

Effect of chitin and chitosan on gelling properties of surimi from barred garfish (Hemiramphus far)

The addition of chitin/chitosan significantly increased the breaking force and deformation of gels prepared from barred garfish surimi (P < 0.05). Addition of 7B chitosan with 65.6% degree of deacetylation (% DD) at the level of 15 mg g⁻¹ resulted in the maximum increases in both breaking force and deformation of suwari and kamaboko gels compared to the control and gels containing chitin or chitosan with other % DD (P < 0.05). A chitosan concentration of 10 mg g⁻¹ was found to render the highest breaking force of kamaboko gel compared to other concentrations tested (P < 0.05). Kamaboko gel containing chitosan had an increased breaking force as the calcium chloride concentration increased (P < 0.05), indicating the role of endogenous transglutaminase in cross‐linking of protein–protein and protein–chitosan conjugates. Therefore the incorporation of chitosan and calcium chloride greatly improved the gelling properties of surimi from barred garfish without changes in colour. © 2000 Society of Chemical Industry     

Solidification characteristics of a droplet on a horizontal cooled wall

An experimental and numerical study of solidification characteristics of a droplet on a horizontal cooled wall is reported. Pure water and molten salt were utilized as the testing liquids. The droplet was cooled under a variety of conditions such as wall temperature and initial liquid temperature in a static atmosphere. Extensive observations of both solidification characteristics and morphologies of the droplet were made. Numerical calculations based on the Landau method considering the effects of both surface tension at the droplet surface and the density inversion at 4 °C within the droplet were carried out. It was found that the numerical results are qualitatively in good agreement with the experimental results except for the terminating period of solidification. © 1998 Scripta Technica, Heat Trans Jpn Res, 26(7): 469–483, 1997     

Melting heat transfer characteristics of a horizontal ice cylinder immersed in an immiscible liquid

The melting characteristics of a horizontal ice cylinder immersed in an immiscible liquid were investigated both experimentally and analytically. A clear cylindrical ice layer formed around a horizontal cooling tube with a coaxial outer heated tube was melted in oil as the test immiscible liquid in the annulus between the ice and outer tube. Both the melting behavior of ice and the flow patterns of the immiscible liquid were observed under a variety of outer wall temperature conditions. In the analysis, two boundary layers were introduced for both the melt water film and ambient liquid, respectively. It was found from the experiments that the tendency of the mean Nusselt number changes clearly at Ra = 10⁶, which corresponds to the temperature condition T0 = 12.0 °C. This analysis might be used to estimate the melting characteristics of such a system during the initial stage of low temperature conditions. © 1998 Scripta Technica, Heat Trans Jpn Res, 27(5): 336–352, 1998     

Comparative effects of α- and γ-linolenic acids on rat liver fatty acid oxidation

It has been reported that both n−3 and n−6 octadecatrienoic acids can increase hepatic fatty acid oxidation activity. It remains unclear, however, whether different enzymes in fatty acid oxidation show a similar response to n−3 and n−6 octadecatrienoic acids. The activity of hepatic fatty acid oxidation enzymes in rats fed an oil mixture rich in α-linolenic acid (18:3n−3) and borage oil rich in γ-linolenic acid (18:3n−6) was therefore compared to that in rats fed an oil mixture rich in linoleic acid (18:2n−6) and a saturated fat (palm oil) in this study. Linseed oil served as the source of 18:3n−3 for the oil mixture rich in this octadecatrienoic acid and contained 30.6% 18:3n−3 but not 18:3n−6. Borage oil contained 25.7% 18:3n−6 and 4.5% 18:3n−3. Groups of seven rats each were fed diets containing 15% various fats for 15 d. The oxidation rate of palmitoyl-CoA in the peroxisomes was higher in rats fed a fat mixture rich in 18:3n−3 (3.03 nmol/min/mg protein) and borage oil (2.89 nmol/min/mg protein) than in rats fed palm oil (2.08 nmol/min/mg protein) and a fat mixture rich in 18:2n−6 (2.15 nmol/min/mg protein). The mitochondrial palmitoyl-CoA oxidation rate was highest in rats fed a fat mixture rich in 18:3n−3 (1.93 nmol/min/mg protein), but no significant differences in this parameter were seen among the other groups (1.25–1.46 nmol/min/mg protein). Compared to palm oil and fat mixtures rich in 18:2n−6, a fat mixture rich in 18:3n−3 and borage oil significantly increased the hepatic activity of carnitine palmitoyl-transferase and acyl-CoA oxidase. Compared to palm oil and a fat mixture rich in 18:2n−6, a fat mixture rich in 18:3n−3, but not fats rich in 18:3n−6, significantly decreased 3-hydroxyacyl-CoA dehydrogenase activity. Compared to palm oil and a fat mixture rich in 18:2n−6, borage oil profoundly decreased mitochondrial acyl-CoA dehydrogenase activity, but a fat mixture rich in 18:3n−3 increased it. 2,4-Dienoyl-CoA reductase activity was significantly lower in rats fed palm oil than in other groups. Compared to other fats, borage oil significantly increased Δ³, Δ²-enoyl-CoA isomerase activity. Activity was also significantly higher in rats fed 18:2n−6 oil than in those fed palm oil. It was confirmed that both dietary 18:3n−6 and 18:3n−3 increased fatty acid oxidation activity in the liver. These two dietary octadecatrienoic acids differ considerably, however, in how they affect individual fatty acid oxidation enzymes.     

Derivation of ideal power distribution to minimize the maximum Kernel migration rate for nuclear design of pin-in-block type HTGR

ABSTRACT

Suppressing the kernel migration rates under normal operation condition is quite important from the viewpoint of the fuel integrity for High-Temperature Gas-cooled Reactors. It depends on both the fuel temperature and the fuel temperature gradient. The presence of the ideal axial power distribution to minimize the maximum kernel migration rate allows us to improve the efficiency of design work. Therefore, we propose a new method based on Lagrange multiplier method in consideration of thermohydraulic design in order to obtain the ideal axial power distribution to minimize the maximum kernel migration rate. For one of the existing conceptual designs performed by JAEA, the maximum kernel migration rate for the power distribution to minimize the maximum kernel migration rate proposed in this study is lower by approximately 10% than that for the power distribution as a conventional design target to minimize the maximum fuel temperature.     

Stabilization of a bicycle with two-wheel steering and two-wheel driving by driving forces at low speed

Recently, the personal mobility vehicle (PMV), a vehicle suitable for personal use, has been developed. It moves at low speed and is sufficiently small that it can be ridden in pedestrian space. This vehicle is expected to be a new method of transportation that is practical and environmentally friendly. As one form of PMV, the authors propose a twowheel vehicle with two modes: a two-wheel steering and two-wheel driving bicycle mode and a parallel two-wheel mode. This vehicle has four electric motors, two for driving and two for steering, and one generator connected to the pedals. In the bicycle mode, the rider rotates the pedals to generate electric power, and the motors in the wheels produce torque using the generated energy. The front and rear wheels are steered by the electric motor according to the angle of the handle. Therefore, this bicycle is controlled by a steer-by-wire and a drive-by-wire system. In the parallel two-wheel mode, the vehicle is stabilized according to the theory of the inverted pendulum. In this paper, we focus on the bicycle mode and analyze its stability. Stabilizing the bicycle is not easy since the proposed vehicle has tires with small diameters and the traveling speed is assumed to be low. It is known that the stability of bicycles is tuned by adjusting the bicycle parameters and changing the rear steer angle. However, since we aim to use the vehicle in a narrow walking space at low speed, such conventional methods are not always suitable. The authors propose the stabilization of the bicycle using driving forces and design a controller using linear-quadratic control theory. The results of the numerical simulations show the proposed method is effective in stabilizing the bicycle. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Chihiro Nakagawa received her M.S. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 2007. She is currently a doctoral student at the department at University of Tokyo and serves as a JSPS Research Fellow. Yoshihiro Suda received his Dr. Eng. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 1987. He is currently a Professor at the Institute of Industrial Science and the Director of Chiba Experiment Station, University of Tokyo. Kimihiko Nakano received his Dr. Eng. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 2000. He is currently an Associate Professor at the Institute of Industrial Science, University of Tokyo. Shoichiro Takehara received his Dr. Eng. degree in Department of Engineering Synthesis from Sophia University, Japan, in 2004. He is currently an Assistant Professor at the Department of Mechanical Engineering at Tokyo Metropoli-tan University.     

Detection accuracy of network anomalies using sampled flow statistics

We investigated the detection accuracy of network anomalies when using flow statistics obtained through packet sampling. Through a case study based on measurement data, we showed that network anomalies generating a large number of small flows, such as network scans or SYN flooding, become difficult to detect during packet sampling. We then developed an analytical model that enables us to quantitatively evaluate the effect of packet sampling and traffic conditions, such as anomalous traffic volume, on detection accuracy. We also investigated how the detection accuracy worsens when the packet sampling rate decreases. In addition, we show that, even with a low sampling rate, spatially partitioning monitored traffic into groups makes it possible to increase detection accuracy. We also developed a method of determining an appropriate number of partitioned groups, and we show its effectiveness. Copyright © 2011 John Wiley & Sons, Ltd.