• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.433-436
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• 1990

An optimal Stabilization technique for a bilinear in duction model is introduced. This technique includes to o parts; the one is an stabilization control using Lyap unov Function which has the form of a sum of linear and quadratic function of the state variables, and the other is an optimal control using the performance index which depends on the choice of the elements of the Ly apunov matrices concerning both the state variables and the input variables. Therefore, induction motor is drived with the shorter transient time of the state variables and with the smaller overshoot of the ones, simulation results are obtained from a digital computer. Experimental ones are obtained from implementation of the optimizing controller using 8086 microprocessor kits and analog circuits are compared.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1032-1038
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• 2002

The Active Constrained Layer Damping(ACLO) combines the simplicity and reliability of passive damping with the low weight and high efficiency of active control to attain high damping characteristics. The proposed ACLD treatment consists of a viscoelastic damping which is sandwiched between an active piezoelectric layer and a host structure. In this manner, the smart ACLD consists of a Passive Constrained Layer Damping(PCLD) which is augmented with an active control in response to the structural vibrations. The Arc type shell model is introduced to describe the interactions between the vibrating host structure, piezoelectric actuator and visco damping, The system is modeled by applying ARMAX model and changing a state-space form through the system identification method. An optimum control law for piezo actuator is obtain by LQR(Linear Quadratic Regulator) Method. The performance of ACLD system is determined and compared with PCLD in order to demonstrate the effectiveness of the ACLD treatment, Also, the actuation capability of a piezo actuator is examined experimentally by using various thickness of Viscoelastic Materials(VEM).

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.45-58
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• 2013

In structural reliability analysis, the response surface method is a powerful method to evaluate the probability of failure. However, the location of experimental points used to form a response surface function must be selected in a judicious way. It is necessary for the highly nonlinear limit state functions to consider the design point and the nonlinear trend of the limit state, because both of them influence the probability of failure. In this paper, in order to approximate the actual limit state more accurately, experimental points are selected close to the design point and the actual limit state, and consider the nonlinear trend of the limit state. Linear, quadratic and cubic polynomials without mixed terms are utilized to approximate the actual limit state. The direct Monte Carlo simulation on the approximated limit state is carried out to determine the probability of failure. Four examples are given to demonstrate the efficiency and the accuracy of the proposed method for both numerical and implicit limit states.

• Coupled systems mechanics
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• v.11 no.2
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• pp.151-166
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• 2022

Peltier cells have low efficiency, but they are becoming attractive alternatives for affordable and environmentally clean cooling. In this line, the current article develops closed-form and semianalytical solutions to improve the temperature distribution of Bi₂Te₃ thermoelements. From the distribution, the main objective of the current work-the optimal electric intensity to maximize cooling-is inferred. The general one-dimensional differential coupled equation is integrated for linear and quadratic geometry of thermoelements, under temperature constant properties. For a general shape, a piece-wise solution based on heat flux continuity among virtual layers gives accurate analytical solutions. For variable properties, another piece-wise solution is developed but solved iteratively. Taking advantage of the formulae, the optimal intensity is directly derived with a minimal computational cost; its value will be of utility for more advanced designs. Finally, a parametric study including straight, two linear, barrel, hourglass and vase geometries is presented, drawing conclusions on how the shape of the thermoelement affects the coupled phenomena. A specially developed coupled and non-linear finite element research code is run taking into account all the materials of the cell and using symmetries and repetitions. These accurate results are used to validate the analytical ones.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3584-3602
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• 2022

NFV realizes flexible and rapid software deployment and management of network functions in the cloud network, and provides network services in the form of chained virtual network functions (VNFs). However, using VNFs to provide quality guaranteed services is still a challenge because of the inherent difficulty in intelligently scaling VNFs to handle traffic fluctuations. Most existing works scale VNFs with fixed-capacity instances, that is they take instances of the same size and determine a suitable deployment location without considering the cloud network resource distribution. This paper proposes a traffic forecasted assisted proactive VNF scaling approach, and it adopts the instance capacity adaptive to the node resource. We first model the VNF scaling as integer quadratic programming and then propose a proactive adaptive VNF scaling (PAVS) approach. The approach employs an efficient traffic forecasting method based on LSTM to predict the upcoming traffic demands. With the obtained traffic demands, we design a resource-aware new VNF instance deployment algorithm to scale out under-provisioning VNFs and a redundant VNF instance management mechanism to scale in over-provisioning VNFs. Trace-driven simulation demonstrates that our proposed approach can respond to traffic fluctuation in advance and reduce the total cost significantly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.641-648
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• 2006

In an attempt to get basic data for the utilization of saltwort powder (Salicornia herbaceae L.) as a ingredient in the Sulgidduk. D-optimal design of mixture design showed 14 experimental points including 4 replicates for three independent variables. The three independent variables selected for the experiment were water ($13{\sim}18%$), saltwort powder ($2{\sim}6%$), and sugar ($8{\sim}13%$). The optimum responses variables such as color value. texture, and sensory characteristics were evaluated. The compositional and functional properties of test were measured, and these values were applied to the mathematical models. According to the result of measuring probability of the color value, texture and sensory characteristics were respectively and significance was acknowledged (p<0.05). According to the result of F-test, color values (L, a, b), textural properties (gumminess, chewiness) and sensory characteristics (taste, softness) decided linear model, textural property (hardness) and sensory characteristics (color, smell, moistness, overall acceptance) decided quadratic model. A canonical form and trace plot showed that the influence of each ingredient on the mixture final product. An optimum formulation by numerical and graphical methods were similar. Water, saltwort powder, and sugar were 15.2%, 3.0%, and 9.8% respectively by numerical method, and 15.2%, 3.1%, and 9.7% respectively by graphical method.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.831-837
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• 2013

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size $35{\times}35{\times}40$ cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.539-543
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• 2006

Lodging is classified as root lodging caused by the loss of supporting force in the root, bending caused by the deformation of the stem and breaking where the stem breaks down as loads exceeding critical elasticity were applied. This research excluded breaking which is not in a state of equilibrium and tried to partition the level of lodging using an algebraic model in root lodging and stem lodging, or bending. When a vertical load was applied, the deformation of the stem of rice plant showed the form of a quadratic equation. The trace of the panicle neck in the process of lodging was an ellipse-shape. When loading was pure root lodging, the trace of the panicle neck became a circle of which culm length is the radius. When it was a pure stem lodging, the trace of the panicle neck is an ellipse of which major axis is culm length and minor axis is 0.64* culm length. When both stem lodging and root lodging occurred in a natural setting, the partitioning of lodging can be calculated by a formula using eccentricity of an ellipse, S=e*100/0.768(S is the ratio of stem lodging in the whole lodging, e is eccentricity of the ellipse). This method is expected to be useful in simple lodging partitioning. We could also calculate the partitioning of stem lodging and root lodging as units of angles as an accuracy method, by using a straight line calculated by differentiating a quadratic equation of stem deformation at the origin of the coordinates. These two methods for dividing root and stem lodging showed different values. However, each of them showed almost same values with different lodging degree in one plant.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.425-435
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• 2006

The objectives of this research were to investigate the drought resistance as well as the growth of Wisteria floribunda seedlings with the soil water conditions. The seedlings for the research were grown in pots with strict water content control on a frame located outdoors. During the experiments, the soil water contents were adjusted to 5, 10, 20, 30, 40, 50, 60, and 70%. In addition, the effects of Rhizobium inoculation on the growth of seedlings were investigated. The experimental results are summarized as follows: 1. The seedlings in the pots with 5% soil water content withered to death due to the water stress. Withering or any distinct growth was not observed from the seedlings in the 10% soil water content. It can be inferred from these results that about 5% of soil water content is the wilting point of W. floribunda seedlings and about 10% is the critical soil water content of its growth in this experiment soils. Therefore, it seems that W. floribunda possesses a good drought resistance. 2. From the analyses of the main growth parameters such as stem elongation, diameter growth, leaf area growth and total dry weight, it was found that the seedling growth can be improved with increasing soil water contents. The relation between each growth parameter(Y) and the soil water contents(W) was well described by a quadratic equation, $Y=a+bW+cW^2$. 3. In soil water contents higher than 20%, the seedling growth(Y) was remarkable along with-its extended growing period, and related to the growing period(D) by a quadratic equation, $Y=a+bD+cD^2$. 4. The artificial inoculation of Rhizobiun promoted the growth of Wisteria floribunda seedlings. 5. Rhizobium was found to be more readily inoculated and to form more root nodules compared to seedlings grown in higher soil water contents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.497-504
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• 2008

This study was conducted for the optimization of ingredients in salad dressing using Bokbunja (Rubus coreanum Miquel) juice. The experiment was designed according to the D-optimal design of mixture design, which included 14 experimental points with 4 replicates for three independent variables (Bokbunja juice $15.70\sim47.10%$, oil $23.50\sim39.20%$, vinegar $3.90\sim19.60%$). The compositional and functional properties of the prepared products were measured, and these values were applied to the mathematical models. A canonical form and trace plot showed the influence of each variable on the quality attribute of final mixture product. By the use of F-test, viscosity, color values (L, a, and b), emulsion stability and sensory characteristics (color) were expressed by a linear model, while the color values (L) and sensory characteristics (smell, taste, and overall acceptance) were by a quadratic model. The optimum formulations by numerical and graphical method were analogous: Bokbunja juice, oil and vinegar of 36.02%, 26.48%, and 12.00% by numerical method, respectively; those of 36.00%, 26.44%, and 12.06% by graphical method, respectively.