• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1051-1052
• /
• 2010

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.12
• /
• pp.2078-2083
• /
• 2007

We have analyzed operating characteristics of transformer-type superconducting fault current limiter (SFCL) according to the serial or parallel connections of secondary coils with $YBa_2Cu_3O_7$ (YBCO) thin films. The turn ratio between the primary and secondary coils was 63:21. Transformer-type SFCL using a transformer with secondary winding of serial or parallel coils could reduce the unbalanced quench caused by differences of the critical current density between YBCO thin films. We found that transformer-type SFCL having serial or parallel connections induced simultaneous quench between the superconducting units. The limiting current in the transformer-type SFCL with a parallel connection was lowered to 30 % compared to the SFCL with a serial connection. In the meantime, when the currents generated in the superconducting units were similar, the voltage value in the parallel connection was 60 % as low as that in the serial connection. However, the voltage generated in the primary winding was some higher. In conclusion, we found that transformer-type SFCL with parallel connection of secondary coils was more effective in fault current limiting characteristics and in the reduction of the consumption power for superconducting units compared to those of the transformer-type SFCL with serial connection of secondary coils.

• Journal of Power System Engineering
• /
• v.17 no.3
• /
• pp.50-56
• /
• 2013

The analysis of performance characteristics was carried out in the plate type evaporator with counter and parallel flow. To investigate performance of evaporator with water inlet temperature and refrigerant mass flow rate were changed. As a result, when the inlet temperature of water is $8^{\circ}C$, capacity of parallel flow evaporator higher than counter flow is 0.35%. But as the inlet temperature of water rises from $8^{\circ}C$ to $16^{\circ}C$, capacity of counter flow type evaporator higher than parallel flow type is 0.12%, 0.27%, 1.1%, 1.6%, respectively. The findings showed that counter flow type evaporator has a larger capacity than those that were parallel flow type evaporator. As the refrigerant mass flow rate rises, capacity and pressure drop increases in the counter and parallel flow type evaporator.

• Communications for Statistical Applications and Methods
• /
• v.15 no.4
• /
• pp.587-595
• /
• 2008

Parallel coordinate plot of Inselberg (1985) is useful for visualizing dozens of variables, but so far the plot's applicability is limited to the variables of numerical type. The aim of this study is to extend the parallel coordinate plot so that it can accommodate both numerical and categorical variables. We combine Hayashi's (1950, 1952) quantification method of categorical variables and Hurley's (2004) endlink algorithm of ordering variables for the parallel coordinate plot. In line with our former study (Kwak and Huh, 2008), we develop Andrews' type modification of conventional straight-lines parallel coordinate plot to visualize the mixed-type data.

• Journal of the Korean Institute of Educational Facilities
• /
• v.8 no.1
• /
• pp.5-14
• /
• 2001

The purpose of this study is to clarify the block type of school buildings based on present conditions, by picking up elementary school buildings of Chungbuk Province in Korea. The summary of the block types can be given below. 1) Elementary school buildings(495) in Chungbuk Province are almost built in an average block of 1.7school(290). 2) The block types of school buildings are classified with "-", "ㄱ", "ㄷ", and parallel type. There are many "-" types over and parallel types in the second place of them. 3) The "-" block types are uniformly distributed with 166 elementary schools, below 6 classroom, 7through 24classrooms, beyond 25 classrooms. The "ㄱ" block types are 8 schools, and built as the wing of "-" block type in a limited space. The parallel types are classified with 2 3 lines according to the numbers of paralleled school buildings. The 2 parallel types are firstly represented with more than 95 classrooms, and 5 schools of "ㄷ" types, built as the wing of 2 parallel types, are only represented over 25 classrooms. The 3 parallel types are only 16 schools of all. They are uniformly seen in old and new school buildings.

• Proceedings of the KIEE Conference
• /
• 2006.10b
• /
• pp.208-211
• /
• 2006

We have analyzed operating characteristics of hybrid-type superconducting fault current limiter (SFCL) according to the parallel connection of secondary windings with $YBa_{2}Cu_{3}O_{7}$ (YBCO) films. The turn ratio between the primary and secondary windings of each reactor was 63:21. Hybrid-type SFCL using a transformer with parallel reactors could reduce the unbalanced quench caused by differences of the critical current density between YBCO films. We found that hybrid-type SFCL having parallel connection induced simultaneous quench between the superconducting elements. The quench-starting point at this time was almost same. When the applied voltage was 200V, the limiting current in the hybrid-type SFCL with a serial connection was lowered to 34 percent than that in the SFCL with a parallel connection. In the meantime, when the voltage generated in the superconducting elements was the same, the current value in the parallel connection was 60 percent less than in the serial connection. The voltage generated in the primary winding also showed the similar behavior. In conclusion, we found that the fault current was limited more effectively in the SFCL with the serial connection but the power burden of the superconducting elements was reduced in the parallel connection.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.57 no.3
• /
• pp.323-327
• /
• 2008

We investigated the quench characteristics of a flux-lock type superconducting fault current limiter (SFCL) depending on the methods of the serial and parallel connections between the superconducting elements. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting elements in series and parallel. In this paper, the analyses of voltage, current, and resistance of the superconducting elements connected in serial and parallel were performed to increase the power capacity of the flux-lock type SFCL. A part of the superconducting elements was not quenched in $2{\times}2$ serial connection between the elements and then the power burden of the quenched elements was increased. However the elements with $2{\times}2$ parallel connection was all quenched. This means that the power burden of each superconducting element can be reduced under the same conditions. We found that $2{\times}2$ parallel connection was more profitable for the current limiting effects and the increase of the power capacity.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.1 s.178
• /
• pp.129-135
• /
• 2006

In this study, a two-axis ultra-precision stage driven by piezoelectric elements is presented. The stage has a flexure-type parallel linear guide mechanism consisting of quad-symmetric simple parallel linear springs and quad-symmetric double compound linear springs. While the simple parallel linear springs guide the linear motion of a moving plate in the stage, the double compound linear springs follow the motion of the simple parallel linear spring as well as compensate the parasitic motions caused by the simple parallel linear springs. The linear springs are designed by rectangular beam type flexures that are deformed by bending deflection rather than axial extension, because the axial extension is smaller than the bending deflection at the same force. The designed guide mechanism is analyzed by finite element method(FEM). Then two-axis parallel linear stage is implemented by the linear guide mechanism combined with piezoelectric elements and capacitance type displacement sensors. It is shown that the manufactured ultra-precision stage achieves 3 nm of resolution in x- and y-axis within 30 ${\mu}m$ of operating range.

• Communications of the Korean Mathematical Society
• /
• v.23 no.3
• /
• pp.371-376
• /
• 2008

In this paper, it is shown that if f satisfies the following functional inequality (0.1) $${\parallel}\sum\limits_{i,j=1}^3\;f{(xi,yj)}{\parallel}{\leq}{\parallel}f(x_1+x_2+x_3,\;y_1+y_2+y_3){\parallel}$$ then f is a bi-additive mapping. We moreover prove that if f satisfies the following functional inequality (0.2) $${\parallel}2\sum\limits_{j=1}^3\;f{(x_j,\;z)}+2\sum\limits_{j=1}^3\;f{(x_j,\;w)-f(\sum\limits_{j=1}^3\;xj,\;z-w)}{\parallel}{\leq}f(\sum\limits_{j=1}^3\;xj,\;z+w){\parallel}$$ then f is an additive-quadratic mapping.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.3
• /
• pp.63-68
• /
• 2022

In this study, we produced defect detection models using parallel convolution neural networks. If convolution neural networks are constructed parallel type, the model's detection accuracy will increase and detection time will decrease. We produced parallel-type defect detection models using 4 types of convolutional algorithms. The performance of models was evaluated using evaluation indicators. The model's performance is detection accuracy and detection time. We compared the performance of each parallel model. The detection accuracy of the model using AlexNet is 97 % and the detection time is 0.3 seconds. We confirmed that when AlexNet algorithm is constructed parallel type, the model has the highest performance.