• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.361-361
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• 2012

PZT (Pb(Zr,Ti)O3) thin films have been used widely in the MEMS application, due to their inherent ferroelectric and piezoelectric properties. Such ferroelectricity induces much higher dielectric constants compared to those of the nonperovskite materials. In this work, the PZT thin films were deposited onto Indium-Tin-oxide (ITO) substrates through the spin-coating of PZT sols. The deposited PZT thin films were characterized in terms of the electrical and optical properties with special emphases on conductivity and optical constants. The detailed analysis techniques incorporate the dc-based current-voltage characteristics for the electrical properties, spectroscopic ellipsometry for optical characterization, atomic force microscopy for surface morphology, X-ray Photoelectron Spectroscopy for chemical bonding, Energy-dispersive X-ray Spectrometry for chemical analyses and X-ray diffraction for crystallinity. The ferroelectric phenomena were confirmed using capacitance-voltage measurements. The integrated physical/chemical features are attempted towards energy-oriented applications applicable to next-generation high-efficiency power generation systems.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.273-277
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• 2003

A general process of electronic assembly is composed of a series of geometric alignments and bonding/screwing processes. After assembly, the function is tested in a following process of inspection. However, assembly of micro-optic devices requires both processes to be performed in equipment. Coarse geometric alignment is made by using vision and optical function is improved by the following fine motion based on feedback of tunable laser interferometer. The general system is composed of a precision robot system for 3D assembly, a 3D vision guided system for geometric alignment and an optical feedback system with a tunable laser. In this study, we propose a new fast alignment algorithm of micro-optic devices for both of visual and optical alignments. The main goal is to find a fastest alignment process and algorithms with state-of-the-art technology. We propose a new approach with an optimal sequence of processes, a visual alignment algorithm and a search algorithm for an optimal optical alignment. A system is designed to show the effectiveness and efficiency of the proposed method.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.17-23
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• 2001

Lasting machines for shoe manufacturing are continuously developed with the aid of automation and CAM(Computer Aided Manufacturing). Although automation and CAM techniques have tremendously reduced the labor in shoe manufacturing, there still remain some parts manufactured by experts. In order to enhance the capability and efficiency of machines for labor-free shoe manufacturing, CAD data of a shoe last is essential. While CAD datarization takes the fundamental role in the shoe design and manufacturing, there has been little research for the CAD datarization of a shoe last. In this paper, a new procedure for CAD datarization of a shoe last using finite element patches and a tension sl)line method is proposed for application to shoe manufacturing machines. The outer line of a shoe-last sole is interpolated by a tension spline method and bonding lines are extracted from the shoe CAD data. Data set for a control algorithm of the tasting machine can be produced from the CAD data.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.122-127
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• 2001

Lasting machines for shoe manufacturing are continuously developed with the aid of automation and Computer Aided Manufacturing (CAM). Although automation and CAM techniques have tremendously reduced the labor in shoe manufacturing field, there still remain some parts manufactured by experts. In order to enhance the capability and efficiency of machines for labor-free shoe manufacturing, CAD data of a shoe last is indispensable. While CAD datarization takes the fundamental role in the shoe design as well as the shoe manufacturing, there has been little research for the CAD datarization of a shoe last. In this paper, a new procedure for CAD datarization of a shoe last using finite element patches is proposed and some data for the control part of the shoe lasting machine are extracted and interpolated from the CAD data. The outer line of a shoe-last sole is interpolated by a tension spline method and bonding lines are extracted from the shoe CAD data. Finally, initial setting data for the lasting machine are extracted from the last CAD data and initial setup parts of the lasting machine.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.37-43
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• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.6-13
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• 2011

In this study, we used activated carbon (AC) and charcoal (CH) as carbon sources with $TiO_2$ powder to prepare spherical carbons containing titania (SCCT) by using phenolic resin (PR) as a bonding agent. The physicochemical characteristics of the SCCT samples were examined by BET, XRD, SEM, EDX, iodine adsorption and compressive strength. The photocatalytic activity was evaluated by measuring the removal efficiency of three kinds of organic dyes: methylene blue (MB), methyl orange (MO) and rhodamine B (Rh.B) under a UV/SCCT system. In addition, evaluation of chemical oxygen demand (COD) of piggery waste was done at regular intervals and gave a good idea about the mineralization of wastewater.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.3
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• pp.166-173
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• 2009

The reliability of hafnium oxide gate dielectrics incorporating lanthanum (La) is investigated. nMOSFETs with metal/La-doped high-k dielectric stack show lower $V_{th}$ and $I_{gate}$, which is attributed to the dipole formation at the high-k/$SiO_2$ interface. The reliability results well correlate with the dipole model. Due to lower trapping efficiency, the La-doping of the high-k gate stacks can provide better PBTI immunity, as well as lower charge trapping compared to the control HfSiO stacks. While the devices with La show better immunity to positive bias temperature instability (PBTI) under normal operating conditions, the threshold voltage shift (${\Delta}V_{th}$) at high field PBTI is significant. The results of a transconductance shift (${\Delta}G_m$) that traps are easily generated during high field stress because the La weakens atomic bonding in the interface layer.

• Journal of Welding and Joining
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• v.32 no.5
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• pp.65-71
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• 2014

Atmospheric plasma spraying (APS) is world-widely used process in the automotive industry as a method to provide wear resistance coatings for engine cylinder bore, using various materials. The weight of engine blocks can be considerably decreased by removing cast iron liners, which can finally result in the improvement of fuel efficiency. In this study, five kinds of powder materials, 1.2C steel powder and 1.2C steel powder mixed with 5, 10, 15, 20 wt.%. molybdenum powder, were deposited by atmospheric plasma spraying in order to investigate the effect of molybdenum on the wear resistance of coatings. Microstructural analysis showed that molybdenum splats were well distributed in 1.2C steel matrix with intimate bonding. The molybdenum added coatings showed better tribological properties than 1.2C steel coating. However, above the 15 wt.%. blending fraction, wear resistance was somewhat degraded with poor roughness of worn surface due to the brittle fracture occurred in molybdenum splats. Consequently, compared to conventional liner material, gray cast iron, 10 wt. pct. molybdenum blended 1.2C steel coating showed much better tribological properties and therefore it looks very feasible to replace gray cast iron liner.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.38-43
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• 2005

Natural Com Starch(NCS) spray system has been widely used In multiply board mill for the better bonding strength between board layers. However the unsuitable NCS spray system could lead to a drop in plybond efficiency of multiply board. It could also result in the accumulation of unretained-starch in the white water system, which could not only rise in BOD and COD level but also reduce the effects of rosin-alum sizing system and other additives. In this study, the simple and rapid method by UV-spectroscopy for measuring the starch contents in the white water was proposed, and the quantitative analysis for dissolved starch content in white water was carried out in two kinds of board production process. It could be confirmed that about 150 ppm of oxidized starch was retained in white water dewatered from undertop ply of multiply board process, and about 470 ppm of natural starch was dissolved in white water originated from unsuitable spraying system in the multiply board production lines for cup base paper.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.307-312
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• 2000

This study was carried out to develop an automatic grafting system suitable for fruit-vegetable seedlings. The study consisted of two research sections: 1) development of a medium-sized, low-cost automatic grafting system for cooperative farms and commercial seedlings production company, and 2) commercializing research for prototype development based on the above concepts. The grafting robot developed in this research can be described as follows, a. Developed grafting robot can cover the whole operations for grafting scion and rootstock, only if operator provides scion and rootstock tray. b. Five seedlings can be grafted at one time, and about 1,200 seedlings can be grafted in one hour. c. The success ratio of mechanical grafting scion and rootstock with ceramic pin bonding provided by the holder is more than 95% when the conditions of seedlings are satisfied. d. The grafting efficiency has improved over 10 times compared with manual work, and the grafting cost generated 44% savings.