• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.630-635
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• 2018

In this paper, we consider the stability condition for the linear discrete systems with time-varying delay and unstructured uncertainty. The considered system has time invariant system matrices for non-delayed and delayed state variables, but its delay time is time-varying within certain interval and it is subjected to nonlinear unstructured uncertainty which only gives information on uncertainty magnitude. In the many previous literatures, the time-varying delay and unstructured uncertainty can not be dealt in simultaneously but separately. In the paper, new stability conditions are derived for the case to which two factors are subjected together and compared with the existing results considering only one factor. The new stability conditions improving many previous results are proposed as very effective inequality equations without complex numerical algorithms such as LMI(Linear Matrix Inequality) or Lyapunov equation. By numerical examples, it is shown that the proposed conditions are able to include the many existing results and have better performances in the aspects of expandability and effectiveness.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.81-90
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• 2003

Existing web-based system management software solutions show some limitations in time and space. Moreover, they possess such as shortcomings unreliable error message announcements and difficulties with real-time assistance suppers and emergency measures. In order to solve these deficiencies, Wireless Remote Control System was designed and implemented. Wireless Remote Control System is able to manage and monitor remote systems by using mobile communication devices for instantaneous control. The implementation of Wireless Remote Control System leads to these security Problems as well as solutions to aforementioned issues with existing web-based system management software solutions. Therefore, this paper has focused on the security matters related to Wireless Remote Control System. The designed security functions include mobile device user authentication and target system access control. For security verification of these security functions introduced CPN(Coloured Petri Nets) which is capable of expressing every possible state for each stage. And then in this paper was verified its security through PI(Place Invariant) based on CPN(Coloured Petri Nets). The CPN expression and analysis method of the proposed security function can also be a useful method for analyzing other services in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.619-628
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• 2010

Shape Memory Alloy (SMA) has recently received attention in developing implantable surgical equipments and it is expected to lead the future medical device market by adequately imitating surgeons' flexible and delicate hand movement. However, SMA actuators have not been used widely because of their nonlinear behavior called hysteresis, which makes their control difficult. Hence, we propose a parameter, $t_1$, which is necessary for temperature control, by analyzing the open-loop step response between current and temperature and by comparing it with the values of linear differential equations. $t_1$ is a pole of the transfer function in the invariant linear model in which the input and output are current and temperature, respectively; hence, $t_1$ is found to be related to the state variable used for temperature control. When considering the parameter under heat treatment conditions, $T_{max}$ was found to assume the lowest value, and $t_1$ was irrelevant to the heat treatment.

• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.69-76
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• 2007

The accumulation curves of phenol in the flesh of apples were measured at $5^{\circ}C$, $25^{\circ}C$ and $40^{\circ}C$ when they were exposed to phenol vapor, The effective diffusivities of phenol at the rind and flesh were determined by comparing its experimentally obtained accumulation curves with simulated ones. The simulation was carried out by the non-steady state diffusion rate equation. The diffusion model assumed the consecutive diffusion of phenol at the rind and flesh of apples. The detection time of phenol in the flesh of apples was shortened with increasing temperature, and it accumulated amount also increased rapidly. The estimated effective diffusivity of phenol at the rind of apples increased with temperature as like $1.1{\times}10^{-13}\;m^2/s$ at $5^{\circ}C$, $1.4{\times}10^{-13}\;m^2/s$ at $25^{\circ}C$ and $2.2{\times}10^{-13}\;m^2/s$ at $40^{\circ}C$, but those at the flesh of apples were invariant as $1.5{\times}10^{-10}\;m^2/s$ at this temperature range. The effect of temperature on the diffusivity of phenol was small, but the increase of the vapor pressure of phenol with temperature accelerated the penetration of phenol at the rind, resulting in the rapid accumulation at the flesh of apple.

• Applied Biological Chemistry
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• v.23 no.1
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• pp.23-30
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• 1980

Labelling of chromatin proteins with 32P was observed after incubating isolated liver nuclei with $[{\gamma}-32P]$ ATP for 5 minutes at $37^{\circ}C$. The pattern of labelling with 32P was examined on SDS polyacrylamide gel electrophoresis with nuclei from rats maintained in a starvation state for 48 hours, following refeeding for 12 hours; and from fed streptozotocin-diabetic rats with insulin injection 6 hours before sacrifice. With 48h starved rat liver nuclei the level of phosphorylation for 0.14M NaCl soluble proteins was decreased in the molecular weights between 41,000 and 200,000 daltons relative to normal controls. Refeeding the starved rats reversed the change of phosphorylation pattern over 12 hour The level of phosphorylation for five phenol soluble non-histone proteins with molecular weights above 59,000 daltons was somewhat decreased with 48h starved rat liver nuclei as compared with that of normal controls. Starvation also decreased the phosphorylation level of major histones in relation to normal controls. The experiment with insulin injection into fed streptozotocin-diabetic rats showed the tendency to increase phosphorylation of 0.14M NaCl soluble proteins (130,000 dalton protein) and phenol soluble non-histone proteins (155,000 dalton protein). The phosphorylation level of histones appeared to be invariant under the experimental conditoins employed here. These results suggest the possibility that the phosphorylation and dephosphorylation of 0.14M NaCl soluble proteins and $H_1$ histone precede those of other chromatin associated nuclear proteins, It is of interest to find that insulin signal was correlated to phosphorylation of nuclear proteins while glucagon signet dephosphorylated nuclear proteins.