• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.117-122
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• 2005

An assembly system (AS), a valuable tool for mass production, is generally composed of a number of workstations and a transport system. While the workstations perform some preplanned operations, the transport system moves the assemblies by special designed pallets from one station to another. One common problem associated with automatic assembly systems is that some assembly operations may have relatively long cycle times. As a consequence, the productivity, as determined by the operations with the longest cycle time, can be reduced significantly. Therefore, special forms of parallel workstations were developed to improve the performance of an assembly system. In this paper, three most commonly used parallel stations: on-line, off-line and tunnel-gated stations in a free transfer assembly system are studied via discrete event simulation. Our findings revealed that the off-line parallel system has the best performance because the two independent parallel stations can lower the buffer requirement; reduce the sensitivity to variability of processing time and balance of a line. On-line parallel systems were found to have a relatively poor performance, because the operations of two parallel stations block each other, and higher buffer capacity is required to achieve similar capacity. The tunnel-gated system was more efficient than the on-line system since the first parallel station can operate independently. More importantly, we have quantified the productivity of the three different strategies mentioned. Engineers can choose the optimal strategies for installing parallel stations under their working environment.

• Tribology and Lubricants
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• v.15 no.1
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• pp.24-28
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• 1999

This paper describes a new pivoting technique to improve bearing performance in pivoted pad thrust bearings. This new technique adjusts the pivot line in a line pivoted pad thrust bearing to be parallel to the trailing edge of a sector shaped pad. Bearing performance factors such as load carrying capacity, frictional torque and flow rate are numerically investigated for conventional point-pivoted and line-pivoted pads and for the new parallel-line pivoting technique. It is shown that the load carving capacity can be maximized with the new technique.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.65-70
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• 2005

Pressure ripples, which are inevitably generated by a fluctuation of flow rate caused by a pump mechanism, include noises and vibrations in hydraulic pipeline. These noises and vibration deteriorate the stability and accuracy of hydraulic systems. The accumulator and hydraulic attenuator are normally used to reduce the pressure ripples. In this study, a parallel line is introduced to the hydraulic pipeline for the hydraulic system with a bent-axis piston pump as a method to reduce the pressure ripples. The dynamic characteristics of the hydraulic pipeline with a parallel line are analyzed by a transfer matrix in the frequency domain. The usefulness of the hydraulic pipeline with a parallel line was ascertained by experiment and simulation. The results from the experiment and simulation show that the hydraulic pipeline with a parallel line were effective in reducing the pressure ripples.

• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1229-1235
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• 2020

A line parallel to the ground is frequently shown in our daily life, which enables us to guess its direction. Especially, such a guess tends to become clear when a vanishing line of the ground is shown together. In this paper, a vision based pallet measurement method is suggested, which uses a technique for estimating three-dimensional direction of a line parallel to the ground. The technique computes actually a vector heading to intersection of a given imaged line parallel to the ground and the ground vanishing line determined previously on calibrating a measurement camera. Through an experiment of measuring a real commercial pallet with various orientation and distance, we found that the technique could measure the orientation of the pallet correctly and accurately. The technique worked well even though an edge line available on the front plane of a pallet was almost parallel to the ground vanishing line.

• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.273-286
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• 2005

We teach students to explore geometric figures by its properties and establish relationships between some basic figures. The concept of parallel line play very im-portant roles in such geometry learning process. In this study, 1 investigate the con-cept of parallel line we teaching in elementary school. Students have wrong concept images for parallel line, which is the result of the elementary school mathematics text books, where only typical cases for parallel line Is presented and there is no method to find if two lines is parallel or not. Therefore, we should teach explicitly students to find if two lines is parallel or not. The depth study on it is needed to develope students' geometric thought level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1072-1077
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• 2006

In this paper a novel 3-phase line interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) is proposed. And the strategy of voltage control in proposed UPS system is explained. The objective of voltage control in parallel(shunt) and series PWM VSC of proposed UPS system is to guarantee satisfactory characteristics in steady state and transient state.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.201-203
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• 2005

A new 3-phase line-interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) was introduced recently, In this paper, the strategy of voltage control in suggested UPS system is explained. The objective of proposed voltage controllers in parallel(shunt) and series PWM VSC is to guarantee satisfactory characteristics in steady state and transient state.

• The Korean Journal of Applied Statistics
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• v.25 no.4
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• pp.633-640
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• 2012

Biological methods are described for the assay of certain substances and preparations whose potency cannot be adequately assured by chemical or physical analysis. The principle applied through these assays is of a comparison with a standard preparation to determine how much of the examined substance produces the same biological effects as a given quantity (the Unit) of the standard preparation. In these dilution assays, to estimate the relative potencies of the unknown preparations to the standard preparations, it is necessary to compare dose-response relationships of standard and unknown preparations. The dose-response relationship in the dilution assay is non-linear and sigmoid when a wide range of doses is applied. The parallel line model (applied to the dose region with the steepest slope) is used to estimate the relative potency. In this paper, the statistical theory in the parallel line model is explained with an application to a dilution assay data. The parallel line method is implemented in a SAS program and is available at the author's homepage(http://cafe.daum.net/go.analysis).

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.202-207
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• 2013

In this paper, a high dividing ratio unequal power divider using parallel connection transmission line is presented. Because a very low impedance transmission line can't implement a microstrip technology, this can fabricate a parallel connection transmission line with high impedance. When we design a high dividing ratio divider, we need the very low impedance line. The parallel connection transmission line could be implemented to obtain a low impedance line characteristic. To validity this approach, we are implemented a 10:1 unequal divider at center frequency 1 GHz. The performances of power divider agree with simulation results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.888-895
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• 2004

This paper proposes new miniaturization method of parallel coupled line filter by using capacitors and grounding. Proposed method can reduce resonator size by using only a small number of capacitor and grounding of parallel coupled line filter which is conventional in field of RF filters because of its design and fabrication simplicity. This paper applies the miniaturization method of transmission line and parallel coupled line to parallel coupled line filter, and presents that grounding can reduce the number of shut capacitors. Presented miniaturized method has merits of miniaturization of parallel coupled line, harmonic suppression, and improvement of high frequency skirt with harmonic suppression. For verification of proposed method, this paper presents a hairpin filter, which has 900 MHz center frequency and 10 % FBW, miniaturized to λ/4 by proposed method.