• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.6
• /
• pp.840-845
• /
• 2010

In this paper, short-wavelength transmission line employing periodically arrayed capacitive devices (PACD) structures were developed for application to a development of miniaturized on-chip passive components on GaAs monolithic microwave integrated circuit (MMIC). The transmission line employing PACD structure showed a wavelength much shorter than conventional microstrip line. Concretely, the wavelength of the transmission line employing PACD structure was 8 % of the conventional microstrip line on GaAs substrate at 5GHz. And It was 38% of the microstrip line employing PPGM at 5GHz. It was recognized that the basic characteristics of the transmission line employing PACD structure were investigated for application to the miniaturized passive on-chip components.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.162-165
• /
• 2007

TFT-LCD process has two advantages as compared with the semiconductor-process. It is that cycle time is short and number of the final products are small. But it needs complicated inspection / assembly line to be treated manually and much higher labor costs in the TFT-LCD process. Also, It is necessary to build PICS(Production Information and Control System) which is automated and intelligent. In this paper, an automated process of LCD module assembly line that can increase productivity and reduce the cost of production to strengthen the competitiveness corresponding with global market is planned in comparison with its manual/semi-auto. It is noted that The automated line for COG$\sim$FOG process replacing with the existing facilities had the following effects; the productivity is increased to about 1.5 times and labor cost reduced 85%. In addition, whole assembly line can be short and simple.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1426-1430
• /
• 2009

AC AT feeding method consists return circuits of electric train inserting in parallel between trolly line and feeding line and connecting neutral line to rail and FPW. Due to increasing electric load at feeding system, collecting voltage of train and end voltage are going down. So to increase voltage between trolly line and rail, the usefulness of new autotransformer are considered which variation of short impedance and change of line voltage is simulated with modified winding ratio of autotransformer from 1:1 to variable tab.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.371-373
• /
• 2005

An enhancement for a transmission and substation equipment in power system make the system impedance to be lower. In principle, if the system impedance become low, system stability will be better, but the fault current become very higher. It is a very big problem for CB operating. As a fact of CB operating performance, high amplitude of the fault current may cause CB operation failure because of exceeding standard value in TRV. So we simulated TRV by using the EMTP. Generally there are two types of TRV in actual power system. One is short line fault, the other is bus terminal fault. In this paper, we simulated the TRv at short line fault as installed current limit reactors to reduce fault current in 345kV ultra-high voltage system. Short line fault is caused from single line fault in transmission line.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.2
• /
• pp.115-123
• /
• 2009

In this paper, we extract the parasitic elements of the transmission line with the defected ground structure(DGS) and the short-circuited comb line section using the Short-Open Calibration(SOC). The scattering matrixes of short, open and the distributed elements in microstrip line are measured by full electro-magnetic(EM) simulator and Vector Network Analyser(VNA). The electro-magnetic effects of the proposed structures are considered by the II and T equivalent circuits with frequency independent elements, and the relations between the measured scattering parameters and the elements in the circuits are shown by performing 2 port network analysis. Moreover, to design the 2.4 GHz bandpass filter with second order butterworth prototype, the proposed methods are applied. As results, the measured $S_{11}$ and $S_{21}$ indicate -20 dB and -1.3 dB at center frequency, and these are shown within 5 % error compare to the predicted results at $0.5{\sim}5\;GHz$.

• Journal of electromagnetic engineering and science
• /
• v.9 no.3
• /
• pp.164-173
• /
• 2009

In this paper, two new circuit structures for European and U.S. ultra-wide band(UWB) bandpass filters(BPFs) with sharp roll-off characteristics are introduced. We show first that the ultra-wide bandpass property is obtained from a $\lambda$/4 open T resonator with a capacitively coupled $\lambda$/4 short-circuited line, which provides two attenuation poles at lower and upper cutoff frequencies. Then, two identical capacitively coupled input/output lines, which can be $\lambda$/4-length open ends or $\lambda$/2-length short ends, with the T-resonator, are adopted to suppress lower and higher frequency components outside of the pass band. There is coupling between the input and output lines providing two additional transmission zeros in the lower and upper transition bands of the filter. Since the coupling between the T-resonator with the $\lambda$/4 short-circuited line and the input/output lines limits the bandwidth of the filter to the European UWB band, both the $\lambda$/4 short-circuited line and the input/output lines are inserted between the two stacked T-resonators for the U.S. UWB band. The filter structures are simulated with ADS and HFSS and realized with low-temperature co-fired ceramic(LTCC) green tape which has the dielectric constant of 7.8. Measurement results agree well with HFSS simulation results.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.3 no.3
• /
• pp.35-39
• /
• 1980

Although the product line produces a large volume of goods in a relatively short time, once the product line is established there are numerous problems that arise in connection with this product line. One of these problems is the problem of balancing operations or stations in terms of equal times and in terms of the times required to meet the desered rate of production. The objective of line balancing is minimizing the idle time on the line for all combinations of work stations subject to certain restrictions. In general, there are two types of line-balancing situations : (1) assembly line balancing and (2) fabrication line balancing. Two approaches to the assembly line balancing problem have been used. The first assumes a filed cycle time and find the optimum number of work stations. The second approach to the assembly line balancing problem assumes the number of work stations to be fixed and systematically coverages on a solution which minimizes the total delay time by minimizing the cycle time. Here the cycle time is determined by the longest station time. In this paper, by using the second approach method, a general mathematical model, problem solutions, and computer program for the assembly line balancing problem is presented. Data used is obtained from the company which has been confronted with many problems arising in connection with their assembly line.

• The Journal of Korea Robotics Society
• /
• v.9 no.3
• /
• pp.140-146
• /
• 2014

This paper introduces a dual-arm robot painter system which is capable of sketching a camera-captured image with short line segments. To express various curved edges in the image by combining line segments, we first apply edge detection algorithm to the entire image, split the edged image into small boxed pieces, and then apply Hough Transformation to each piece so that the edges inside the piece can be approximated with short line segments. To draw the picture within a reasonable time, we designed a simple dual-arm robot system and controlled both arms concurrently according to linear interpolation algorithm. From the experiments, we could verify that simple linear motions can describe various images effectively with a unique brush style.

• ETRI Journal
• /
• v.31 no.3
• /
• pp.254-262
• /
• 2009

This paper presents a novel simple filter design method based on a parallel short-ended coupled-line structure with capacitive loading for size reduction and ultra-broad rejection of spurious passbands. In addition, the introduction of a cross-coupling capacitor into the miniaturized coupled-line can create a transmission zero at the second harmonic frequency for better frequency selectivity and attenuation level. The aperture compensation technique is also applied to achieve a strong coupling in the coupled-line section. The influence of using the connecting transmission line to cascade two identical one-stage filters is studied for the first time. Specifically, such a two-stage bandpass filter operating at 2.3 GHz with a fractional bandwidth of 10% was designed and realized with low-temperature co-fired ceramic technology for application in base stations that need high power handling capability. It achieved attenuation in excess of -40 dB up to $4f_0$ and low insertion loss of -1.2 dB with the size of 10 mm ${\times}$ 7 mm ${\times}$ 2.2 mm. The measured and simulated results showed good agreement.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.6
• /
• pp.1070-1074
• /
• 2010

In this study we deal with a simple computer simulation algorithm to decide the PRT station capacity. PRT system is different from the conventional rail traffic system in such point that the station is off-line so as to guarantee a very short headway. This characteristic has correlation with the accurate prediction of the line capacity and with the scale of the off-line station. In this paper physical factors and vehicles per hour that are necessary to decide the off-line station scale and the off-line station capacity, respectively, are shown through a simple compter simulations.