• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.58-65
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• 2008

The study on dual arm robot manipulator which consists of two 6-DOF srms and one 2-DOF torso is introduced. This dual arm robot manipulator is designed for automation of assembly process in automotive manufacturing line. Each industrial 6-DOF arm can be used as a stand-alone type of industrial robot manipulator with 6-DOF and as a manipulator part of dual arm robot at the same lime. These structures help the robot maker willing to succeed in emerging market of dual arm robots have the high competitive power for the current industrial robot market and the emerging market of dual arm robot at the same time. The research results of the design concept, workspace analysis and the PC-based controller will be introduced.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.673-678
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• 2015

Terahertz dual-band frequency selective surface filters made by perforating two different rectangular holes in molybdenum have been designed, fabricated and measured. Physical mechanisms of the dual-band resonant responses are clarified by three differently configured filters and the electric field distribution diagrams. The design process is straightforward and simple according to the physical concept and some formulas. Due to the weak coupling between the two neighboring rectangle holes with different sizes in the unit cell, good dual-band frequency selectivity performance can be easily achieved both in the lower and higher bands by tuning dimensions of the two rectangular holes. Three samples are fabricated, and their dual-band characteristics have been demonstrated by a THz time-domain spectroscopy system. Different from most commonly used metal-dielectric structure or metal-dielectric-metal sandwiched filters, the designed dual-band filters have advantages of easy fabrication and low cost, the encouraging results afforded by these filters could find their applications in dual-band sensors, THz communication systems and other emerging THz technologies.

• Journal of the Korean institute of surface engineering
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• v.47 no.6
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• pp.362-367
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• 2014

We report the design, fabrication of a $Si_3N_4$ probe and calculation of its mechanical properties for DPN(dip pen nanolithography), which consists of dual tips. Concept of dual tip probe is to employ individual tips on probe as either an AFM tip for imaging or a writing tip for nano patterning. For this, the dual tip probe is fabricated using low residual stress $Si_3N_4$ material with LPCVD deposition and MEMS fabrication process. On the basis of FEM analysis we show that the functionality of dual tip probe for imaging is dependent on the dimensions of dual tip probe, and high ratio of widths of beam areas is preferred to minimize curvature variation on probe.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.10
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• pp.552-557
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• 2015

The nanostereolithography process using a femtosecond laser has been shown to have strong merits for the direct fabrication of 2D/3D micro structures. In addition, a femtosecond laser provides efficient tools for precise micromachining owing to the advantages of a small and feeble heat effect zone. In this paper, we report an effective fabrication process of 3D micro optical and fluidic devices using nanostereolithography process composed of a dual stage system. Process conditions for additive and subtractive fabrication are examined. The Piezo stage scanning system is used for 3D micro-fabrication in unit area of sub-mm scale, and the motor stage is employed in fabrication on the scale of several mm. The misalignment between the pizeo- and motor- stages is revised through rotational transformation of CAD data in the unit domain. Here, the effectiveness of the proposed process is demonstrated through examples using 3D optical and microfluidic structures.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.179.3-179
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• 2001

This paper describes the dual system technology of PC based control system at steel plant. Because PC is developed to be used in wide area such as Office Automation, Personal, It is cheaper and more portable than the present process control system, but is less stable and less reliable. In this research, We gathered the fault example of a general process control system and steel process control system, analyzed the cause of fault and decided the target fault that took over in our proposed system. The proposed PC based system is the dual system that has a shared RAID system connected by SCSI bus between two systems. In order to assist system reliability, we proposed watchdog manager to monitor ...

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.12
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• pp.1240-1245
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• 2009

The throughput characteristics of the cluster tool with dual blade robot are analyzed. Using equipment's cycle time chart of the equipment, simple analytic form of the throughput is derived. Then, several important throughput characteristics are analyzed by the throughput formula. First, utilization of the process chamber and the robot are maximized by assigning the equipment to the process whose processing time is near the critical process time. Second, rule for selecting optimal number of process chambers is suggested. It is desirable to select a single process chamber plus a single robot structure for relatively short time process and multi process chambers plus a single robot, namely cluster tool for relatively long time process. Third, throughput variation between equipments due to the wafer transfer time variation is analyzed, especially for the process whose processing time is less than critical process time. And the throughput and the wafer transfer time of the equipments in our fabrication line are measured and compared to the analysis.

• International Journal of Automotive Technology
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• v.7 no.1
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• pp.1-7
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• 2006

The ignition delay of a dual fuel system has been numerically investigated by adopting a constant volume chamber as a model problem simulating diesel engine relevant conditions. A detailed chemical kinetic mechanism, consisting of 28 species and 135 elementary reactions, of dimethyl ether (DME) with methane ($CH_{4}$) sub-mechanism has been used in conjunction with the multi-dimensional reactive flow KIVA-3V code to simulate the autoignition process. The start of ignition was defined as the moment when the maximum temperature in the combustion vessel reached to 1900 K with which a best agreement with existing experiment was achieved. Ignition delays of liquid DME injected into air at various high pressures and temperatures compared well with the existing experimental results in a combustion bomb. When a small quantity of liquid DME was injected into premixtures of $CH_{4}$/air, the ignition delay times of the dual fuel system are longer than that observed with DME only, especially at higher initial temperatures. The variation in the ignition delay between DME only and dual fuel case tend to be constant for lower initial temperatures. It was also found that the predicted values of the ignition delay in dual fuel operation are dependent on the concentration of the gaseous $CH_{4}$ in the chamber charge and less dependent on the injected mass of DME. Temperature and equivalence ratio contours of the combustion process showed that the ignition commonly starts in the boundary at which near stoichiometric mixtures could exists. Parametric studies are also conducted to show the effect of additive such as hydrogen peroxide in the ignition delay. Apart from accurate predictions of ignition delay, the coupling between multi-dimensional flow and multi-step chemistry is essential to reveal detailed features of the ignition process.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.27-33
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• 2008

This paper designs Shared Memory on the Dual Core system so that it operates a general System V IPC on the Linux O.S. Shared Memory is the technique that many processes can access to identical memory area. We treat Shared Memory which is SVR in a kernel step. We design a share memory facility of Linux operating system on the Dual Core System. In this paper the suggesting of share memory facility design plan in Dual Core system is enhance the performance in existing an unity processor system as a dual core practical use. We attemp a performance enhance in each CPU for each process which uses a share memory.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.460-467
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• 2006

Adsorption experiments for $H_2$, $CO_2$, CO, and their binary mixtures on zeolite 5A were performed by static volumetric method. Experimental data were obtained at temperatures of 293.15, 303.15 and 313.15 K and at pressures to 25 atm. The parameters obtained from single component adsorption isotherm. Multicomponent adsorption equilibria could be predicted and compared with experimental data. Langmuir isotherm, Langmuir-Freundlich isotherm and Dual-Site Langmuir isotherm be used to predict the experimental results for binary adsorption equilibria of $CO_2/CO$ and $H_2/CO_2$ on zeolite 5A. Dual-Site Langmuir isotherm showed the best agreement with the experimental results.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.2
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• pp.203-214
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• 2007

This study aimed at researching the process selection for two-stage and dual media filtration system, as a technology substituting the existing sand filter without expanding the site when retrofitting an old filter bed or designing a new one. In order to select the process for optimum complex filtration system, three running conditions have been tested. Test results demonstrated that Run 3 in which the 1st stage was filled with anthracite and coarse sand, and the 2nd stage was filled up with activated carbon and fine sand reduced the head loss and the load of turbidity substances. Also, Run 3 showed better performance in removing TOC, particle counts, THMFP and HAAFP, compared to other two conditions. 99 % of Cryptosporidium was removed. Bisphenol-A was rarely removed from the 1st stage of coarse sand and 2nd stage of fine sand, but 99 % of it was removed from the 2nd stage of activated carbon. In conclusion, when it is required to retrofit an old rapid filter bed or design a new one for the purpose of improving filtration performance, the following two-stage and dual media filtration system is suggested: the 1st stage of filter bed needs to be filled up with coarse sand to remove turbidity as the pretreatment for extending duration of filtering, the top part of 2nd stage needs to be filled up with granular activated caron to remove dissolved organic matters and others as the main process, and finally the bottom part of 2nd stage needs to be filled up with fine sand as the finishing process.