• Structural Engineering and Mechanics
• /
• v.44 no.2
• /
• pp.127-138
• /
• 2012

The composite materials may be exposed to environmental (thermal or hygral or both) condition during their service life. The effect of environmental condition is usually adverse from the point of view of design of composite structures. In the present research study the effect of hygrothermal condition on the design of laminated composite structures is investigated. The active fiber composite (AFC) which may be utilized as actuator or sensor is considered in the present analysis. The sensor layer is used to sense the level of response of the composite structures. The sensed voltage is fed back to the actuator through the controller. In this study both displacement and velocity feedback controllers are employed to reduce the response of the composite laminate within acceptable limit. The Newmark direct time integration scheme is employed along with modal superposition method to improve the computational efficiency. It is observed from the numerical study that the laminated composite structures become weak in the presence of hygrothermal load. The response of the structure can be brought to the acceptable level once the AFC layer is activated through the feedback loop.

• Structural Engineering and Mechanics
• /
• v.61 no.2
• /
• pp.221-230
• /
• 2017

In this paper, we investigated the propagation of thermoelastic surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order of nth order including time rate of strain under the influence of rotation. The general surface wave speed is derived to study the effectsof rotation andthermal onsurface waves. Particular cases for Stoneley, Love and Rayleighwaves are discussed.The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Our results for viscoelastic of order zero are well agreed to fibre-reinforced materials. Comparison was made with the results obtained in the presence and absence of rotation and parameters for fibre-reinforced of the material medium. It is also observed that, surface waves cannot propagate in a fast rotating medium.Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect of rotation on fibre-reinforced anisotropic general viscoelastic media are very pronounced.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.110-112
• /
• 2000

A new robust digital fuzzy controller design methodology is proposed for load frequency of nonlinear power system with valve position limits of governor in the presence of parametric uncertainties. The Takagi-Sugeno (TS) fuzzy model is adopted for fuzzy modeling of the nonlinear power system. A sufficient condition of robust stability for robust fuzzy control with parametric uncertainties is presented in the sense of Lyapunov. The controller that designed by preposed robust fuzzy controller design method is based compounding condition between continues system and discrete system. The effectiveness of controller that designed by the proposed robust fuzzy controller design method is demonstrated through simulation example.

• Archives of design research
• /
• v.15 no.4
• /
• pp.169-176
• /
• 2002

All kinds of artwork, including multimedia and digital image that has been subliminated into an af mediating two numbers 0 and 1 in recent age, are self-sufficient and autonomous in themselves. Nevertheless, each of those artworks can be realized as a real entity only if its appreciator is capable enough to explore some potential meaning out of it through his or her own perceptual work. According to Mikel Dufrenne, an artwork is composed of three existential tiers: "le sensible" or the sensible material; "fe representation" or the subject(le sujet), and "1′expression." Dufrenne contends that our esthetic perception can be realized by way of three steps that are comparable to those three tiers: perception of the presence of the body("le sensible"), contemplative perception by way of imagination("le representation"), and reflective perception ("1′expression") as a result of dialectics of sense and sensibility. This paper argues on the aesthetic perception with regard to digital image expressed by two numbers 0 and 1, putting focus on the epistemological role of sensibility(감) that explores "1′expression" a la Dufrenne.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.665-667
• /
• 1999

An adaptive algorithm is presented for diagnosis of actuator faults. The concept of unknown input decoupling is combined with an adaptive observer, leading to an adaptive diagnostic observer, which has the robustness property in the presence of an unmeasurable term such as uncertainties. The observation error equation for the adaptive diagnostic observer does not depend on the effect of uncertainties and used to construct an adaptive diagnostic algorithm that provides the estimates of the gains of actuators, which can be obtained directly via the use of the augmented error technique. The simulation results indicate that the proposed algorithm is more realistic in the sense that better robustness properties can be assured without knowledge about uncertainties and is potentially useful in the development of a fault tolerant control system.

• Sleep Medicine and Psychophysiology
• /
• v.10 no.1
• /
• pp.26-31
• /
• 2003

Restless leg syndrome (RLS) and periodic limb movement of sleep (PLMS), often concurrent, come under diagnosed disorders of sleep and treatable condition. RLS symptoms are evoked in the limbs at rest and increase in the evening and during the night. PLMS is characterized by periodic episodes of repetitive limb movements caused by muscle contractions during sleep. RLS is often associated with a sleep complaint and PLMS. Both RLS and PLMS represent one of the most commonly encountered sleep disorders in a primary care setting. The circadian rhythm and the presence of PLMS cause sleep disturbances in RLS. The emphasis on pathophysiology includes consideration of central nervous system localization, neurotransmitter, and the role of iron metabolism. Dopaminergic agents are considered the treatment of choice for RLS and PLMS. With proper diagnosis and effective treatment patients' ability to fall asleep and maintain sleep improves, and their sense of well being increases.

• ETRI Journal
• /
• v.36 no.4
• /
• pp.545-553
• /
• 2014

This paper proposes an algorithm to sense orthogonal frequency-division multiplexing (OFDM) signals in cognitive radio (CR) systems. The basic idea behind this study is when a primary user is occupying a wireless channel, the covariance matrix is non-diagonal because of the time domain cross-correlation of the cyclic prefix (CP). In light of this property, a new decision metric that measures the power of the data found on two minor diagonals in the covariance matrix related to the CP is introduced. The impact of synchronization errors on the signal detection is analyzed. Besides this, a likelihood-ratio test is proposed according to the Neyman-Pearson criterion after deriving probability distribution functions of the decision metric under hypotheses of signal presence and absence. A threshold, subject to the requirement of probability of false alarm, is derived; also the probabilities of detection and false alarm are computed accordingly. Finally, numerical simulations are conducted to demonstrate the effectiveness of the proposed algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.4
• /
• pp.666-671
• /
• 2017

A disturbance-observer-based adaptive neural tracker design problem is investigated for a class of perturbed uncertain non-affine nonlinear systems with unknown control direction. A nonlinear disturbance observer (NDO) design methodology using neural networks is presented to construct a tracking control scheme with the attenuation effect of an external disturbance. Compared with previous control results using NDO for nonlinear systems in non-affine form, the major contribution of this paper is to design a NDO-based adaptive tracker without the sign information of the control coefficient. The stability of the closed-loop system is analyzed in the sense of Lyapunov stability.

• Journal of dental hygiene science
• /
• v.10 no.4
• /
• pp.233-239
• /
• 2010

The study of the elderly and poor oral status interpersonal relationships and smooth social life limited to give is the social alienation and isolation, promoting to having problems with a sense of the elderly subjective oral health status and social efficacy affects whether analyzed. 1. Subjective oral health status authoring feel healthy food disorders, toothache, periodontal problems, tmj pain, dry mouth, bad breath symptoms such as 'sometimes' 'often' than a 'no' if you appear to be a highly subjective and social efficacy Efficacy of oral health status and social influence were more (p<0.01). 2. Subjective oral health status of the seven kinds of sub-variable that oral health status, food authoring disorders, toothache, gum disease, jaw joint or more, dry mouth, bad breath instantly and look at the relationship between social efficacy oral health status, ability of mastication, pain in oral, gum disease, tmj pain, dry mouth, presence of halitosis than positive (+) was correlated.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.17 no.2
• /
• pp.140-145
• /
• 2004

Systemic lupus erythematosus is a disease of unknown etiology that affects many organ system and is characterized by the presence of multiple autoantibodies that participated in immunology mediated tissue injury. A 36 years-old female patient was admitted to ward due to high fever and erythematous rash on face and hole body. She exhibited itching sense, joint pain, nausea, fatigue, sensitivity to light. The homatologic finding revealed anemia, decrease of lymphocyte, low platelet count, but LE cell, Anti nuclear antibody(ANA) were negative. In the point of Differentiation of Syndrome(辨證), SLE can be thought to be a category of Seasonal febril disease(溫病). This subject diagnosed as Domination of intense evil heat(熱毒熾盛), and was administrated with Chungonpadocyem-gamibang(淸瘟敗毒飮加味方). The clinical and laboratory findings of our patient were improved by herb medication, acupuncture therapy and general supportive measure.