• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.628-635
• /
• 2004

The characteristic of thin film resistor with low TCR( temperature coefficient of resistance ) and high precision are studied. The thin film resistor for 1/4W was fabricated and characteristic of these resistors was investigated. The fabricated device had the thickness of $2.48{\leqq}$ and the resistivity of $0.27{\omega}mm$. The electrical characteristic was evaluated by HP 4339B and 4284A instruments with HP l6339A. The profile of trimmed structure was also measured by non contact interferometer. The change of resistance and TCR increased with increasing roughness and resistance. To reduce the effect of stress annealing treatment was performed in the range of 563 to 623 K after trimming. The characteristic was improved after annealing. It is expected the fabricated device can be useful for high precision and low TCR. Fabricated thin film resistor has average deviation of resistance less than $0.35{\%}$ and TCR within 60.60ppm/K.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.11 no.9
• /
• pp.391-397
• /
• 2001

The characteristic values of damping materials are variant on frequency and temperature. We measure the characteristic values(loss factor, young\\\\`s modulus) of damping materials in vibration test. We can not measure characteristic values of damping materials by themselves. So, we proposed a method, sticking damping material to thin steel beam and measuring of characteristic values of damping material on frequency and temperature. We didn\\\\`t use constraining layer but we measured characteristic values on conditioning temperature.

• Journal of Educational Research in Mathematics
• /
• v.12 no.2
• /
• pp.213-228
• /
• 2002

We know that curriculum is, first of all, related to teaching materials, namely, contents. Therefore, when we think of mathematics curriculum, we must take account of characteristic of mathematics. Vygotsky has studied the development of scientific concepts and everyday concepts. According to Vygotsky, scientific concepts grow down through spontaneous concepts; spontaneous concepts grow upward through scientific concepts. And mathematics is a representative of subjects dealing with scientific or theoretical concept. Therefore, his study provides scientific basis for mathematics curriculum design. In this context, Davydov notes that everyday concepts are developed through empirical abstraction, while scientific concepts require a theoretical abstraction. And Davydov constructed the curriculum materials for the teaching of number concept. Davydov's curriculum is an example of reflecting Vygotsky' theoretical view and his view about the types of abstraction. In particular, it represents mathematical characteristic of a 'science' by introducing number concept through quantitative relationship and use of signs. In conclusion, stance mathematical concepts have scientific characteristic, mathematics curriculum reflects this characteristic.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.763-764
• /
• 2006

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• Asia pacific journal of information systems
• /
• v.10 no.2
• /
• pp.177-196
• /
• 2000

Information Systems Planning(ISP) has gained considerable interest among researchers and practioners in recent years because of the impact of information systems on organization performance. This study aims at analyzing organizational characteristic factors, information system characteristic factors influencing ISP's performance. The organizational characteristic variables are considered organizational strategy, organizational culture, and managerial leadership. And the IS characteristic variables are considered IS resource and IS strategic role. The ISP's performance variables are measured BP-ISP integration effectiveness and ISP efficiency. For data on the 493 sampled company, a mail survey using a questionnaire was conducted in this study. The following results were obtained. First, there was significant relationship between organizational characteristics and ISP's performance. Specially, organizational strategy and organizational culture affect the both of BP-ISP integration effectiveness and ISP efficiency. Second, there was significant relationship between Information Systems characteristics and ISP's performance. Specially, IS resource and IS strategic role affect ISP efficiency.

• Nuclear Engineering and Technology
• /
• v.42 no.4
• /
• pp.426-433
• /
• 2010

The characteristic X-rays emitted from materials after gamma ray exposure was simulated and measured. A CdTe semiconductor detector and a $^{57}Co$ radiation source were used for energy spectroscopy. The types of materials could be identified by comparing the measured energy spectrum with the theoretical X-ray transition energy of the material. The sample composition was represented by the $K_{\alpha1}$-line (Siegbahn notations), which has the highest intensity among the characteristic X-rays of each atom. The difference between the theoretic prediction and the experimental result of K-line measurement was < 0.61% even if the characteristic X-rays from several materials were measured simultaneously. 2D images of the mixed materials were acquired with very high selectivity.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.2
• /
• pp.123-130
• /
• 2008

The effects of characteristic condition number on the convergence of preconditioned Navier-Stokes equations were investigated. The two-dimensional preconditioned Navier-Stokes adopting Choi and Merkle's preconditioning and the temperature preconditioning are considered. Preconditioned Roe's FDS scheme was adopted for spatial discretization and preconditioned LU-SGS scheme was used for time integration. It is shown that the convergence characteristics of the Navier-Stokes equations are strongly affected by the characteristic condition number. Also it is shown that the optimal characteristic condition numbers for viscous flows are larger than that in inviscid flows.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.2
• /
• pp.188-193
• /
• 2010

In this paper, SI(Signal Integrity) characteristic of the 4-layer PCB(Printed Circuit Boards) with a through-hole via was analyzed by impedance mismatching between the through-hole via and the transmission line, and deterioration of clock pulse response characteristic due to the P/G plane resonances which are generated between the power and the ground plane. The minimized impedance mismatching between the through-hole via and the transmission line for the improving of SI characteristic is confirmed by the TDR(Time Domain Reflector) simulation and lumped element modeling of the through-hole via. And the cancellation method of P/G plane resonances for improvement of the SI characteristic is represented by simulation result.

• Earthquakes and Structures
• /
• v.15 no.2
• /
• pp.123-132
• /
• 2018

In this paper the strain energy density (SED) model is used to analyze the seismic behavior of suspen-domes and a new criterion is established for judging the seismic failure based on a characteristic point in the SED model. Firstly, a nonlinear time-history response analysis was carried out using the finite-element package ANSYS for typical suspen-domes subjected to different ground motions. The seismic responses including nodal displacements, ratios of yielding members, strain energy density and structural maximum deformation energy were extracted corresponding to the increasing peak ground acceleration (A). Secondly, the SED sum ($I_d$) was calculated which revealed that the $I_d-A$ curve exhibited a relatively large change (called a characteristic point) at a certain value of A with a very small load increment after the structures entered the elastic-plastic state. Thirdly, a SED criterion is proposed to judge the seismic failure load based on the characteristic point. Subsequently, the case study verifies the characteristic point and the proposed SED criterion. Finally, this paper describes the unity and application of the SED criterion. The SED method may open a new way for structural appraisal and the SED criterion might give a unified criterion for predicting the failure loads of various structures subjected to dynamic loads.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.6
• /
• pp.657-662
• /
• 2017

This paper presents the reversible electrolysis characteristics of a solid oxide fuel cell (SOFC) using a $10{\times}10cm^2$ anode supported planar cell with an active area of $81cm^2$. In this work, current-voltage characteristic test and reversible electrolysis cycle test were carried out sequentially for 2,114 hours at a furnace temperature of $700^{\circ}C$. The current-voltage characteristics for reversible electrolysis mode was measured at a current of ${\pm}26.7A$ under various $H_2O$ utilization conditions. The reversible electrolysis cycle was performed 50 times at a current of ${\pm}32.4A$. As a result, The performance degradation of SOEC mode was larger than that of SOFC mode.