• Journal of ILASS-Korea
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• v.24 no.3
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• pp.114-121
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• 2019

The effect of injector driving current pattern on fuel injection rate of solenoid diesel common rail injector was studied by computer simulation. The time resolved fuel injection rate and injected quantity per stroke of a common rail injector driven with the five current patterns were computer simulated. The fuel injection rate and injected quantity per stroke according to the rail pressure and fuel injection period were also computer simulated. When the common rail injector was driven with the five driving current patterns of peak & hold, there was no difference in the fuel injection rate in the peak section regardless of all the current patterns of the five cases. On the other hand, the magnitude of the hold current value influenced the injection rate and injected quantity per stroke. That is, in the current pattern of three cases where the hold current value is equal to or more than a constant value of the peak current value, the fuel injection rates for the given common rail rail pressure and injection period are same one another. On the other hand, the current pattern of the two cases, in which the hold current value is smaller than a certain value, there is a large fluctuation in the fuel injection rate.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.231-232
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• 2008

The effect of n-electrode patterns on the current distribution in active region is investigated in GaN-based blue vertical light emitting diodes (VLEDs). A 3-dimension circuit model is adopted to analyze the current flow patterns in VLEDs. We had fabricated VLEDs having different n-electrode patterns, measured their current-voltage characteristics, and compared to the numerical simulation. It turns out that the current spreading in VLEDs is strongly dependent on the n-electrode pattern. Some design guidelines for n-electrode patterns to produce uniform current injection are presented.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.2
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• pp.159-177
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• 2009

Objectives : The purpose of this study is to examine sleeping patterns and diet patterns of the children in day-care centers in Seongdong-district and to find out the relationships between those two patterns and children growth. Methods : 686 day-care center kids participated in the examination. We measured their heights and weights. We also conducted a questionnaire survey (of them) on their sleeping patterns and diet patterns. Based on the findings, we have analyzed correlations of the factors. Results : 1. We have interviewed 686 children in day-care centers in Seongdong-district. Substantial survey was conducted to 672(14 kids didn't go through regular medical checkups). Their age ranged from 4 months to 120 months and weights covered from 6.20 kg to 50.80 kg with the average of 16.97kg. Their height ranges were from 70.4cm to 140.6cm and the average was 100.76cm. 2. The survey results showed that birth-height affects children's current height. The results from the group of age over 25months and the group covering 2 to 6 years indicated that birth-height affected the current height as well. However, the result from the age group over 37 months showed that birth-height didn't relate to the current height. 3. Results from questionnaires on sleeping patterns indicate that children sleeping longer are taller than the other. Results of other questionnaires showed no substantial relations to height. 4. Results from questionnaires on diet patterns, cold food eating habit affects growth. Conclusions : According to the results above, sleeping patterns substantially affects the growth. In order to find out, however, the specific relations between them, further research would be necessary.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.475-478
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• 2006

In electrical impedance tomography (EIT) an array of electrodes is attached on the boundary of an object and small alternating currents are injected through these electrodes, and then the resulting voltages are measured. An estimation for the cross-sectional resistivity distribution in the object is obtained by using these current and voltage data in a nondestructive manner. In this paper, the electrical impedance imaging of two-phase flows undergoing rapid transient is considered with a special emphasis on the effect of the current pattern on the image reconstruction. The trigonometric current pattern, which is commonly used in the conventional static electrical impedance imaging, shows poor performance in case of the dynamic imaging considered in this work. Extensive numerical experiments are conducted with various kinds of current patterns and their effects on the image reconstruction performance are examined.

• Journal of Korean Vacuum Science & Technology
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• v.7 no.2
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• pp.39-44
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• 2003

Recent ULSI and multilevel structure trends in microelectronic devices minimize the line width down to a quarter micron and below, which results in the high current densities in thin film interconnections. Under high current densities, an EM(electromigration) induced failure becomes one of the critical problems in a microelectronic device. This study is to improve thin film interconnection materials by investigating the EM characteristics in PSG(phosphosilicate glass)/SiO$_2$ passivated Al-l%Si thin film interconnections. Straight line patterns, wide and narrow link type patterns, and meander type patterns, etc. were fabricated by a standard photholithography process. The main results are as follows. The current crowding effects result in the decrease of the lifetime in thin film interconnections. The electric field effects accelerate the decrease of lifetime in the double-layered thin film interconnections. The lifetime of interconnections also depends upon the current conditions of P.D.C.(pulsed direct current) frequencies applied at the same duty factor.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.505-510
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• 2000

Vehicle performances such as fuel consumption and catalyst-out emissions are affected by a driving pattern, which is defined as a driving cycle with the grade in this study. We developed an algorithm to recognize a current driving pattern by using a neural network. And this algorithm can be used in adapting the driving control strategy to the recognized driving pattern. First, we classified the general driving patterns into 6 representative driving patterns, which are composed of 3 urban driving patterns, 2 suburban driving patterns and 1 expressway driving pattern. A total of 24 parameters such as average cycle velocity, positive acceleration kinetic energy, relative duration spent at stop, average acceleration and average grade are chosen to characterize the driving patterns. Second, we used a neural network (especially the Hamming network) to decide which representative driving pattern is closest to the current driving pattern by comparing the inner products between them. And before calculating inner product, each element of the current and representative driving patterns is transformed into 1 and -1 array as to 4 levels. In the end, we simulated the driving pattern recognition algorithm in a temporary pattern composed of 6 representative driving patterns and, verified the reliable recognition performance.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.49-65
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• 1992

The writer did a survey of current textile patterns for the purpose of identifying a motif trend. After identifying a current motif trend the writer used an IBM PC 386 Computer and Lumena Software to design actual patterns. The results are as follows: 1. The most common currently used prints are floral patterns. 2. Knowing that floral patterns are most popular, the writer established a motif using the Rose of Sharon, the national flower of Korea. 3. Using computer graphics to move, enlarge and scale-down motif, the writer has been able to design various textile patterns. 4. Creating patterns with computer graphics was not only more efficient, but it also produced more accurate designs and a greater variety of designs. 5. Using the many computer graphic functions avaliable, a greater variety of patterns changes and compositions can be displayed than would be possible if produce by hand. 6. Computer simulations of textiles and clothing made it possible to evaluate the printed fabric or finished product. Faults in the printed fabric or clothing could be corrented before production. Through simulation then it is possible to create higher quality garments and readuce costly mistakes. Thereby greater profits will be realized from the finished garments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.9
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• pp.445-452
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• 2001

Two switching signal patterns are proposed to prevent short circuit of PWM ac choppers. The voltage detection method and the current detection method are proposed to execute two switching signal patterns. In the voltage detection method, the dead-time has to be inserted to the switching signals after polarity of input voltage is checked by voltage transducer at input side. In the current detection method, the direction of load current is checked by current transducer at output side, and the dead-time delay is not considered. Controlling circuit built by current detection method is simple because the dead-time delay is considered. The experimental results are presented to prevent short circuit of ac chopper safely.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.9
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• pp.1049-1059
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• 2011

This study investigates the current state of companies that manufacture and sell outdoor wear. A survey was conducted to identify what problems they had and what aspects they needed to supplement through a comparison and analysis of their block patterns. Companies that manufactured outdoor wear and those that sold them were separately surveyed to understand their current state. The manufactures included 4 companies and 14 sellers. The survey used interviews to cover the areas of target consumers, development patterns, production lines, body size, nominal size, production size, and functional materials for each item, and aspects that need improvement. The survey period was from September $3^{rd}$ to $10^{th}$ 2008. There were three block patterns for jackets, T-shirts, and pants. The investigator collected the patterns used by three outdoor clothing manu-facturers for comparison and assessment. As a result, the mean age of the target consumers set by the outdoor clothing manufacturers and sellers was 25.3-50.7 and 29.2-42.5, respectively, which shows that the outdoor clothing had a wider distribution of target consumers than the sellers. It is imperative for them to segment and differentiate the target consumers and concepts. The basic body measurements the companies used to draw the upper and lower garment patterns were the bust circumference for the upper garment patterns and the waist circumference for the lower garment patterns. The basic nominal size was 95 for the upper garment and 70 for the lower garment. Also analyzed were the block patterns according to the items to understand the pattern characteristics of each of the companies. There were a total of 35, 36, and 30 items for the jackets, T-shirts, and pants, respectively, to measure size. The items were then compared with one another in mean and standard deviation. The analysis indicate that the block patterns were not fit for women in their twenties or thirties to wear and required revisions in the length of the upper garment, the height of sleeve cap, bust circumference, hip length, and pant length.

• International Journal of Control, Automation, and Systems
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• v.6 no.4
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• pp.613-619
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• 2008

A method to produce a desired current pattern in a multiple-source EIT system using voltage sources is presented. Application of current patterns to a body is known to be superior to the application of voltage patterns in terms of high spatial frequency noise suppression, resulting in high accuracy in conductivity and permittivity images. Since current sources are difficult and expensive to build, the use of voltage sources to apply the current pattern is desirable. An iterative algorithm presented in this paper generates the necessary voltage pattern that will produce the desired current pattern. The convergence of the algorithm is shown under the condition that the estimation error of the linear mapping matrix from voltage to current is small. Simulation results are presented to illustrate the convergence of the output current.