• Fire Science and Engineering
• /
• v.16 no.4
• /
• pp.72-76
• /
• 2002

Nowaday, with the growth of software for electro-thermal analysis, it has been studied the precise analysis and investigation of cause for the electrical fire using computer simulation on the basis of theory for electro-thermal analysis. But it is very lacking for the precise analysis and investigation of cause for the electrical fire. In this paper, we have simulated the thermal analysis for electrical wire according to the value of current and deteriorating time in a overload and a short with the electrical wire of the L's company product(600 V VVF : Three core) using the elec-tro-thermal finite element method(Flux2D).

• Communications of the Korean Mathematical Society
• /
• v.14 no.3
• /
• pp.611-625
• /
• 1999

We consider ΜΑΡ/G/ 1 finite capacity queue with mul-tiple thresholds on buffer. The arrival of customers follows a Markov-ian arrival process(MAP). The service time of a customer depends on the queue length at service initiation of the customer. By using the embeded Markov chain method and the supplementary variable method, we obtain the queue length distribution ar departure epochs and at arbitrary epochs. This gives the loss probability and the mean waiting time by Little's law. We also give a simple numerical examples to apply the overload control in packetized networks.

• 전기의세계
• /
• v.27 no.1
• /
• pp.56-63
• /
• 1978

A new method is suggested for the bus active power vs. line power flow sensibility bector, applying the Optimally-Ordered Triangular Factorization Technique, and new algorithms are derived for the optimum measures against overloaded lines and transformers resulting from contingency analysis. According to the algorithms an online-purpose FORTRAN computer program package is developed and tested or the actual 48-bus, 91-line power system with good results.

• Journal of applied mathematics & informatics
• /
• v.5 no.3
• /
• pp.643-658
• /
• 1998

In this paper we analyze the performance of a statistical ATM multiplexer with bursty input traffic and two thresholds in the buffer by using queueing model. Two priority levels are considered for source traffic which is modeled by Markov Modulated Poisson Process to represent the bursty characteristics. Service time distributions of two priority sources are assumed to be same and deterministic for ATM environment. The partial buffer sharing scheme with one threshold may experience a sensitive state change around the threshold. But the proposed multiplexer with two thresholds avoids this hysterical phenominon to improve the system operation.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.4
• /
• pp.1132-1140
• /
• 2000

The purpose of this paper was to present the method of progress efficiency of morphosyntaxical analyzer for French information processing in the view of multilingual information processing. This study indicated that he method prohibit the additional useless word type by decomposing word type by decomposing works which were created by morphological amalgamation. Findings also suggested the need of preprocessing in order to decrease the overload of morphosyntaxical analysis algorithm. In addition, general rules were proposed to divide word form and to decompose complex sentence.

• IE interfaces
• /
• v.13 no.4
• /
• pp.738-744
• /
• 2000

This Paper presents a method for unfinished work transition probability distribution of modulated $n^*D/D/l$ queue with overload period. The Modulated $n^*D/D/l$ queue is well known as a performance analysis model of ATM multiplexer with superposition of homogeneous periodic on-off traffic sources. Theory of probability by conditioning and results of $N^*D/D/l$ queue are used for analytic methodology. The results from this paper are expected to be applied to general modulated $n^*D/D/l$ queue.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.593-596
• /
• 2001

It is necessary for calculation of repulsion forces acting on the closed electric contacts flowing over-current, e.g. inrush current and overload currents, to do optimum design of switching devices. In this paper, the farces and flux densities generated by currents at the contact point when circuit breakers are in closed state are obtained by using 3D finite element methode. To be convinced of the results, we measure electrogmanetic repulsion forces on contacts by measuring voltage between opened contacts in MCCB.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.6
• /
• pp.901-907
• /
• 2013

The development of high-rise firefighting vehicles warrants thorough structural analysis for ensuring vehicle stability. A few structural analyses were carried out using CAD data, material properties, load conditions, and boundary conditions for evaluating the structural stability of an overloaded multi-aerial platform for firefighting and rescue. Structural analysis was performed with an analytical model consisting of a turntable, six booms, two jib booms, and a basket structure. This model was operated in eight modes. All simulation was performed using NASTRAN, a commercial code. As a result, we confirm that the position of local stress exceeds that of the yield strength. Therefore, stress concentration relaxation is possible by introducing reinforcing boom structures, changing the shape, or imparting a larger moment of inertia to the booms' cross sections.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.8
• /
• pp.140-149
• /
• 2011

This paper deals with the impact analysis of the impedance change of 345/154[kV] power transformers on the KEPCO system's overall performance. Through the steady-state and dynamic analysis of power system, the maximum available impedance of power transformers were determined. Checking violation of short-circuit current ratings and transformer overload, parallel operation of power transformers, calculation of voltage variation ratio according to the impedance changes of power transformers are included in the steady-state analysis. In addition, transient and voltage stability analysis are also performed in the study. Available magnitudes to be able to change the impedance of the transformers in KEPCO system are finally determined in the paper.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.495-503
• /
• 2019

The purpose of this study was to investigate the general characteristics, work overload, work life balance, job engagement of working adolescents and the factors affecting job engagement. We examined 1,772 working adolescents under the age of 24 years in response to the fifth Korean Working Conditions Survey. Technical statistics, t-test, ANOVA, and regression analysis were used. The study results showed that men had high-level job engagement when they were professional, self-employed, 41-52 hours per week, and never experienced employment discrimination. For women, job engagement was high if they were under 19 years of age, college graduates, professions, temporary work, 41-52 hours a week, and had never experienced gender discrimination, and employment discrimination. In addition, the job engagement of both men and women was higher when work overload was less and work life balance was good. This study is meaningful in that it examined the job engagement of working youth by using the Korean Working Conditions Survey representative of Korean workers. However, it has limitations in that it does not take into account specific circumstances such as academic status or military service. Based on the study results, it can be used as basic data for developing educational programs to manage job engagement and understanding of working adolescents.