• Journal of Periodontal and Implant Science
• /
• v.43 no.4
• /
• pp.177-182
• /
• 2013

Purpose: Diabetes and periodontal disease are two common diseases with high prevalence rates. Recent evidence has shown a bidirectional relationship between diabetes and periodontitis. The aim of this study was to investigate the effects of nonsurgical periodontal therapy on glycemic control in type 2 diabetes mellitus patients. Methods: Sixty subjects aged 35-45 years with blood sugar controlled by oral hypoglycaemic agents were randomly divided equally among 3 groups: group A (scaling, mouthwash, and brushing), group B (mouthwash and brushing), and group C (brushing only). Glycated haemoglobin (HbA1c), fasting blood sugar (FBS), probing pocket depth (PPD), gingival index (GI), plaque index (PI), and the relevant drug history were recorded at baseline and after 3 months of intervention. Comparison of the mean difference among the variables was performed by parametric and nonparametric tests, which were further evaluated using multiple regression analysis. Results: The mean differences between the PPD, FBS, HbA1c, GI, and PI in groups A and B were found to be statistically significant (P<0.001). Multiple regression analysis in group A showed that out of all the independent variables, GI and frequency of drug administration independently (b=0.3761 and b=0.598) showed a significantly greater impact on HbA1c ($R^2$=0.832, P<0.05). Conclusions: Nonsurgical periodontal therapy can effectively decrease HbA1c levels in type 2 diabetes mellitus patients on medication.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.3
• /
• pp.595-598
• /
• 2010

Ab initio and DFT molecular orbital calculations predict that acetyl radical reacts with acetylene through interactions primarily involving the SOMO of the radical and the in-plane ${\pi}$-bond of acetylene. An energy barrier (${\Delta}E_1$) of 39.6 kJ $mol^{-1}$ is predicted for the preferred anti arrangement of reactants at the CCSD(T)/cc-pVDZ//BHandHLYP/cc-pVDZ level of theory. NBO analysis reveals additional interactions between the radical SOMO and the nearby C-H ${\sigma}$-bond in acetylene worth about 10% of the total transition state interaction energy. This type of orbital interaction has not previously been observed in radical addition reactions involving C-C ${\pi}$-bonds.

• Journal of the Korean Chemical Society
• /
• v.20 no.1
• /
• pp.15-18
• /
• 1976

The preferred conformation of benzenesulfenyl chloride was determined by EHMO calculation. It was found that the stability was dictated by the n-${\pi}$ conjugation of S atom with the benzene ring. The ethanolysis reaction of benzenesulfenyl chlorides has been studied. The rate constants obtained have been discussed in terms of substituent effects and d-orbital participation of sulfur atom. From a non-linear Hammett plot, bipyramid type of intermediate has been suggested.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.2
• /
• pp.108-115
• /
• 1999

This paper proposes the robot inverse calibration method using a neural networks. A highorder networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from $\pm$3 to $\pm$0.1.

• Kyungpook Mathematical Journal
• /
• v.50 no.4
• /
• pp.455-463
• /
• 2010

The differentiable manifold with f - structure were studied by many authors, for example: K. Yano [7], Ishihara [8], Das [4] among others but thus far we do not know the geometry of manifolds which are endowed with special polynomial $F_{a(j){\times}(j)$-structure satisfying $$\prod\limits_{j=1}^{k}\;[F^2+a(j)F+\lambda^2(j)I]\;=\;0$$ However, special quadratic structure manifold have been defined and studied by Sinha and Sharma [8]. The purpose of this paper is to study the geometry of differentiable manifolds equipped with such structures and define special polynomial structures for all values of j = 1, 2,$\ldots$,$K\;\in\;N$, and obtain integrability conditions of the distributions $\pi_m^j$ and ${\pi\limits^{\sim}}_m^j$.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.1
• /
• pp.133-138
• /
• 2011

This paper proposes a simple but robust self-tuning fuzzy logic controller for the speed regulation of a dual star induction machine based on indirect field oriented control. For feed the two star of this machine, two voltage source inverters based on sinus-triangular pulse-width modulation techniques are introduced. The simulation results show the robustness and good performance of the proposed controller.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.5 no.2
• /
• pp.63-72
• /
• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes a feedrate override Adaptive Control Constraint (ACC) system was developed. The feedrate override function was accomplished through a development of programmable machine controller (PMC) interface technique on the NC controller, Nonlinear model of the cutting process was linearized as an adaptive model with a time varying process parameter. An integral type estimator was introduced for on-line estimation of the cutting process parameter, Zero order hold digital control methodology which uses pole-assignment concept for tuning of PI controllers was applied for the ACC system. Performance of the ACC system wsa confirmed on the vertical machining center equipped with fanuc OMC through a large amount of experiment.

• Bulletin of the Korean Mathematical Society
• /
• v.26 no.2
• /
• pp.109-114
• /
• 1989

This paper deals with the classifying spaces of finite groups. To any finite group G we associate a space BG with the property that .pi.$_{1}$(BG)=G, .pi.$_{i}$ (BG)=0 for i>1. BG is called the classifying space of G. Consider the problem of finding a stable splitting BG= $X_{1}$$^{V}$ $X_{1}$$^{V}$..$^{V}$ $X_{n}$ localized at pp. Ideally the $X_{i}$ 's are indecomposable, thus displaying the homotopy type of BG in the simplest terms. Such a decomposition naturally splits $H^{*}$(BG). The main purpose of this paper is to give the classification theorem in stable homotopy theory for groups with periodic cohomology i.e. cyclic Sylow p-subgroups for p an odd prime and to calculate some universal stable element. In this paper, all cohomology groups are with Z/p-coefficients and p is an odd prime.prime.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.17 no.3
• /
• pp.259-265
• /
• 2012

This paper introduces a method for design and implementation of a current controller for boost converter operating in continuous conduction mode (CCM) using a digital signal processor (DSP). A Proportional-Integral (PI) type current controller outputs an average voltage command for inductor, used in the input side of the boost converter, and the duty-ratio of PWM (pulse width modulation) signal for switching device is directly calculated from the average voltage command. The gains of the PI current controller are selected such that the current response characteristics are the same as those of a first-order low-pass filter. The proposed current control scheme is implemented using a DSP based on fixed-point math operations and an experimental study has been performed to validate the proposed method.

• Proceedings of the KIEE Conference
• /
• 1987.07b
• /
• pp.1317-1321
• /
• 1987

A new type of motor-driven Total Artificial Heart(TAH) system with rolling cylinder mechanism has been developed. Brushless DC motor was chosen as energy converter and controlled by PI controller according to the given velocity profile under the highly time-varying load. Computer simulation was also performed to calculate the optimal gains of PI controller which minimize the input power, one of the most important parameter in artificial heart system.