• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.337-341
• /
• 2003

This paper provides a design method for a dynamic output feedback controller which stabilizes a class of linear time invariant systems. We suppose all the states of the given system is not measurable and only the outputs are used to stabilize the system. The systems considered cannot be stabilized by a static output feedback only. In the scheme we first assume that the given system can be stabilized by a state feedback composed of its output, velocity of the output and its higher order derivative terms. Instead of using the derivatives of the output, however, a dynamic system is constructed systematically which replaces the role of the derivative terms. Then, a high-gain output feedback stabilizes the composite system together with the newly constructed system. The performance of the proposed control law is illustrated in the comparative simulation studies of a numerical example with an observer-based control law.

• Archives of Pharmacal Research
• /
• v.26 no.5
• /
• pp.351-357
• /
• 2003

Five kinds of allylthiopyridazine derivatives were synthesized and their chemoprotective activities examined in rats exposed to aflatoxin $B_1$-toxicant. Rats were pretreated with five allylthiopyridazine derivatives at daily oral doses of 50 mg/kg for 10 consecutive days, and during this period with one or three repeated doses of the potent hepatotoxin, aflatoxin $B_1$. The hepatoprotective effects of the allylthiopyridazine derivatives against aflatoxin $B_1$ (1 mg/kg, three times at intervals of 3 days, i.p., or at 3 mg/kg, once at final days, i.p.) administration were showed the significantly normal as compared with control in body and liver weights. Aspartate aminotransferase and alanine aminotransferase levels were markedly elevated after aflatoxin $B_1$ administration, and pretreatment with allylthiopyridazine derivatives, before aflatoxin $B_1$ administration, resulted in decreased levels of these enzymes. In addition, the allylthiopyridazine derivatives, K6 (3-methoxy-), K8 (3-chloro-), K16 (3-ethoxy-) and K17 (3-n-propoxy), induced elevated hepatic GSH levels. Four kinds of allylthiopyridazine derivatives investigated were effective against aflatoxin $B_1$ -induced hepatotoxicity.

• Korean Journal of Pharmacognosy
• /
• v.48 no.1
• /
• pp.10-17
• /
• 2017

Ursi Fel's component ursodeoxycholic acid (UDCA), a traditional medicine, is used for the treatment of hepatic diseases. UDCA derivatives prepared by conjugation with antioxidant moiety such as maltol, sesamol, eugenol, mesitol and 3,4-(methylenedeoxy)aniline were expected to have various biological activity caused by synergistic effect of UDCA. Therefore, in this study, it was conducted the study of the manufacture of the UDCA derivatives and their biological activity. As a result, UDCA derivatives showed weak antioxidant activity in TBA method in vitro compared to original agents. SJ-505, SJ-502 and SJ-504 showed the effect of reducing ALT, AST, sorbitol dehydrogenase and ${\gamma}-glutamyltransferase$ in $CCl_4-induced$ liver injury experiment in vivo, even if the effects are weaker than UDCA and silymarin of the control group.

• Archives of Pharmacal Research
• /
• v.11 no.3
• /
• pp.175-180
• /
• 1988

1-Aryl-4-arylidene-2-oxazoline-5-ones (I) and the corresponding unsaturated amidoesters (II) and arylidene hypuric acid hydrazide (III) were obtained. The hydrazides and 1-aryl-1,3-dithiophenol-2-amidopropan-3-ones derivatives (IV) were also obtained. The derivatives were tested for their antibacterial activities.

• Archives of Pharmacal Research
• /
• v.24 no.5
• /
• pp.377-384
• /
• 2001

The reaction of either Digitoxin or Digoxin with cyanoacetic acid hydrazide gave the hydrazone derivatives 3a and 3b respectively. The reactivity of the latter products towards chemical reagents was studied to give heterocyclic derivatives with potential biological activities.

• Archives of Pharmacal Research
• /
• v.12 no.2
• /
• pp.138-142
• /
• 1989

The nucleophilic substitution reaction of 6-chloro purines (I) with malononitrile and ethyl cyanoacetate is carried out in DMSO and in the presence of an alkali. The possible tautomeric-ylidene form for the products is considered and discussed in view of IR, UV, NMR and mass spectral determinations. The derivatives were tested for their antitumor activities.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1655-1658
• /
• 1997

To obtain aircraft dynamic parameters, various estimation methods such as Maximum Likelihood, Linear Regression are applied. In this paper we adopt the extended Kalman filter(EKF) to estimate the stability and control derivatives in aircraft dynamic models from flight test data. The extended Kalman filter is applied to nonlinear augmented system assuming that unknown parameters are additional states. In this work, the results of the extended Kalman filter are compared with the results of the wind tunnel test using Chang Gong-91 aircraft flight test data.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.153-158
• /
• 1992

The purpose of this paper is to calculate the dynamic derivatives of single rotor Helicopter in forward flight. From trim condition, the equation of motion is derived, and we can calculate the dynamic dervatives. The results were compared with flight test data. The phase angle and stick displacement are obtained and compared at the trim condition.

• BMB Reports
• /
• v.41 no.1
• /
• pp.23-28
• /
• 2008

The altered amino acid (AA) levels as neurotransmitter closely correlate to neurodegenerative conditions including Alzheimer's disease (AD). Target profiling analysis of nineteen AAs in brain cortex samples from three Tg2576 mice as AD model and three littermate mice as control model was achieved as their N(O,S)-ethoxycarbonyl/tert-butyldimethylsilyl derivatives by gas chromatography. Subsequently, star pattern recognition analysis was performed on the brain AA levels of AD mice after normalization to the corresponding control median values. As compared to control mice, $\gamma$-aminobutyric acid among ten AAs found in brain samples was significantly reduced (P < 0.01) while leucine was significantly elevated (P < 0.02) in AD mice. The normalized AA levels of the three AD mice were transformed into distorted star patterns which was different from the decagonal shape of control median. The present method allowed visual discrimination of the three AD mice from the controls based on the ten normalized AA levels.

• Journal of Mechanical Science and Technology
• /
• v.19 no.2
• /
• pp.618-624
• /
• 2005

We present a new state-space approach to construct a dynamic output feedback controller which stabilizes a class of linear time invariant systems. All the states of the given system are not measurable and only the output is used to design the stabilizing control law. In the design scheme, however, we first assume that the given system can be stabilized by a feedback law composed of the output and its derivatives of a certain order. Beginning with this assumption, we systematically construct a dynamic system which removes the need of the derivatives. The main advantage of the proposed controller is regarding the controller order, which may be smaller than that of conventional output feedback controller. Using a simple numerical example, it is shown that the order of the proposed controller is indeed smaller than that of reduced-order observer based output feedback controller.