• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.4
• /
• pp.517-524
• /
• 1998

This paper discusses the development of a reactive power controller using digital signal processing. Digital Signal Processing is the technique of using digital devices to Process continuous signals or data, often in real-time. And DSP algorithms are associated with a discrete time interval between input samples. When one designs a digital filter, one can use a Laplace transform to determine the continuous time frequency response. The corresponding discrete time transform is called Z transform and depends upon discrete samples of the input spaced equally in time. The objectives of this paper are to minimize real power losses and improve the power factor of a given system. Also, the implementation of a direct-form non recursive filter on the TMS320C31 has been described. The application of this microprocessor-based controller using DSP on test system reveals its numerous advantages. Performance and features of the controller for the reactive power control are analyzed.

• Proceedings of the KSME Conference
• /
• 2000.04a
• /
• pp.420-425
• /
• 2000

When spatially dense velocity distribution is measured by a scanning laser Doppler vibrometer, the Fourier transform method provides the real and imaginary parts of the mode shapes in the form of a polynomial. However the Fourier transform method is often impractical because the independent decomposition property of cosine and sine components into real and imaginary parts, respectively, does not hold due to the leakage problem which commonly occurs in the Fourier transform of harmonic signals. To deal with this problem, a Hilbert transform method is newly proposed in this article. The proposed method is free from the leakage problem and relatively robust to tire scanning error. A simulation example is provided to verify the effectiveness of this method.

• Journal of the Korean Mathematical Society
• /
• v.31 no.3
• /
• pp.339-352
• /
• 1994

A sumbanifold M of a quaternionic Kaehlerian manifold $\tilde{M}^m$ of real dimension 4m is called a generic submanifold if the normal space N(M) of M is always mapped into the tangent space T(M) under the action of the quaternionic Kaehlerian structure tensors of the ambient manifold at the same time.The purpose of the present paper is to study generic submanifold of quaternionic Kaehlerian manifold of constant Q-sectional curvature with nonvanishing parallel mean curvature vector. In section 1, we state general formulas on generic submanifolds of a quaternionic Kaehlerian manifold of constant Q-sectional curvature. Section 2 is devoted to the study generic submanifolds with nonvanishing parallel mean curvature vector and compute the restricted Laplacian for the second fundamental form in the direction of the mean curvature vector. As applications of those results, in section 3, we prove our main theorems. In this paper, the dimension of a manifold will always indicate its real dimension.

• Journal of the Korean Mathematical Society
• /
• v.50 no.3
• /
• pp.479-491
• /
• 2013

Let M be a smooth real hypersurface in complex space of dimension $n$, $n{\geq}3$, and assume that the Levi-form at $z_0$ on M has at least $(q+1)$-positive eigenvalues, $1{\leq}q{\leq}n-2$. We estimate solutions of the local $\bar{\partial}$-closed extension problem near $z_0$ for $(p,q)$-forms in Sobolev spaces. Using this result, we estimate the local solution of tangential Cauchy-Riemann equation near $z_0$ in Sobolev spaces.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.5A
• /
• pp.574-582
• /
• 2004

This paper shows the performance comparisons of several different rate scheduling schemes for non-real time data service over the uplink of burst switching-based direct sequencecode division multiple access (DS/CDMA) system to support the integrated voice/data service. The closed-form solution of optimal scheduling formulation, which minimizes average transmission delay when all of the active data users are transmitting simultaneously, is presented and mathematical analyses with other rate scheduling schemes, which provide efficiency criterion of transmission delay for rate scheduling schemes, are performed. Numerical results show the analyses explicitly.

• Journal of Korean Society for Quality Management
• /
• v.18 no.1
• /
• pp.21-28
• /
• 1990

In this paper, the capacity of system which provides the real time response call service to the customer is studied. The quality of call service depends on the response time of the service in the system. Therefore, the focus of this paper is to investigate the capacity of system under the restriction of response time. In this paper, the system is modeled by queueing network. The analytical method is applied to solve this queueing network. The solution of the model has product form solution. To get the reasonable capacities, nonlinear programming problem is formulated and is solved by GINO.

• Korean Security Journal
• /
• no.2
• /
• pp.161-191
• /
• 1999

Protection martial arts are neither the ability to protect oneself nor the exercise to increase the personal record. Their aim is to protect clients for the sake of their safety, Therefore, it needs special training course distinguished form general martial arts. Those who perform the duty of protection should make efforts to master every skill capable of meeting any situations in which unforeseen accidents may occur. So the coaches of protection martial arts should teach their disciples basic techniques by stages according to each martial art. They also should teach them systematically how to deal with each accidental affair on the ground of protection method. With teaching the way to cope with a crisis coaches might make the disciples feel real by presenting the real situation of different events to which protection arts can be applicable. And a mock exercise with a careful plan and enough practices as well as a mental training to all evaluate the anxiety which might be shown on duty could be helpful for educating elite personnel who will perform the duty of protection completely.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.16 no.2
• /
• pp.137-149
• /
• 2012

We propose an efficient method to measure the insurance risk of causality insurance companies by using the CreditRisk+ methodology. This method is superior to previous methods in several aspects. Its computation speed is very fast and the input data form is simple. It is able to aggregate both credit risk and insurance risk, so the insurance company can manage the risk in combined manner. In this paper, we propose a mathematical method to obtain the aggregate loss distribution of portfolios having correlation among products or business lines as a general case, and then suggest its implementation algorithm. Finally we apply this method to the real data from Korea Insurance Development Institute (KIDI) and discuss its availability to real applications.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1431-1436
• /
• 2004

In this paper, measuring programs for EMC type tests in the railway environments were designed and developed the train harmonic current in ATP frequency band and psophometric current using PXI components and LabVIEW software form National Instruments. As real time applications for EMC tests, harmonic current and psophometric current results of the train were also presented. This new measuring programs for EMC tests in the train are expected to increase test reliability and real-time performance.

• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.741-746
• /
• 2001

This paper presents an investigation of a vehicle-to-vehicle distance control using a Hardware-in-the-Loop Simulation(HiLS) system. Since vehicle tests are costly and time consuming, how to establish a efficient and low cost development tool is an important issue. The HiLS system consists of a stepper motor, an electronic vacuum booster, a controller unit and two computers which are used to form real time simulation and to save vehicle parameters and signals of actuator through a CAN(Controller Area Network). Adoption of a CAN for communication is a trend in the automotive industry. Since this environment is the same as that of a real vehicle, a distance control logic verified in laboratory can be easily transfered to a test vehicle.