• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1171-1177
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• 2013

In this study, the torque transmitting capability of a flexible disk coupling was investigated. Flexible disc coupling is used to transmit power between two axes, and there exist mis-alignments such as angle of deviation and end play between two shafts. A disk is an important part in the flexible disk coupling because the disk has to transmit power between two mis-aligned shafts. To investigate the effect of mis-alignment on load carrying capacity, finite element analyses were carried out. Analyses were carried out for two types of disk; i.e., circular and square disks. The rotational and bending stiffness of disk plates was predicted to investigate the effect of mis-alignment on stress. As a result, it was shown that the mis-alignment can cause severe decrease in load-carrying capacity. And, the square disk showed better performance than the circular disk.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.4
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• pp.468-473
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• 2014

This paper describes the in-flight alignment of SDINS (Strapdown Inertial Navigation Systems) using an EKF (Extended Kalman Filter) and a UKF (Unscented Kalam Filter), which allow large initial attitude error uncertainty. Regardless of the inertial sensors, there are nonlinear error dynamics of SDINS in cases of large initial attitude errors. A UKF that is one of the nonlinear filtering approaches for IFA (In-Flight Alignment) are used to estimate the attitude errors. Even though the EKF linearized model makes velocity errors when predicting incorrectly in case of large attitude errors, a UKF can represent correctly the velocity errors variations of attitude errors with nonlinear attitude error components. Simulation results and analyses show that a UKF works well to handle large initial attitude errors of SDINS and the alignment error attitude estimation performance are quite improved.

• Journal of IKEEE
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• v.22 no.3
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• pp.874-877
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• 2018

Many SMDs (surface mount device) are mounted and mutually connected on a PCB (printed circuit board). System performance degrades when their transmission characteristics are bad. Pads connecting a PCB and SMDs affects PCB transmission characteristics significantly, so pad should be properly aligned to optimize impedance matching. In this paper, effects on PCB transmission characteristics are simulated by pad alignment. When frequency is relatively low, pad alignment seldom affect PCB transmission characteristics, but it affects more and more when frequency or pad size becomes larger. Therefore, pad alignment should be carefully chosen based on target frequency and pad size. Especially, the proposed edge-aligned pad is generally more advantageous over the conventional centered-aligned pad in 12~16 GHz Ku-band frequency.

• Journal of Families and Better Life
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• v.9 no.2
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• pp.345-366
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• 1991

The concrete purpose of this study is to examine the possibility of applying S.Minuchin's structural family therapy theory to each clinical families so that it can solve efficiently the clinical problems Korean family. The test results are as follows: 1)The Results of Question I : Types of Korean family problems can be divide into six. Then the most frequent type of problem was marital problem. 2) The Results of Question II: Korean normal family showed rater difussed boundary and higher rate of wife dominant type than that of husband dominant type in aspect of boundary and power, and had low tendency toward alignment and neutral adjustment. 3)The Results of Quesion III; Amidst the clinical families, family structural traits of the families which have marital problems showed a clear boundary, the tendency toward alignment, and higher tate of husband dominant type than that of wife dominant type. And family structural traits of children problem family had the tendency of alignment and showed little wife-dominanted families in power. Finally, mother-in -law and daughter-in-law problemed family had several characters such as diffused boundary, the tendency of alignment and high adjustment. 4)The Results of Question IV : As a result of camparing problemed families with normal families in family structure, there was high adaptability of S.Minuchin's structural theory to the two family groups; the groups of marital problems and those of children problem.

• The Journal of Information Systems
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• v.17 no.4
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• pp.129-156
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• 2008

This study empirically tested a research model and hypothesis extracted and based on IT governance and knowledge sharing theories. In this study we targeted CIO and IS managers to find the effects of the degree of knowledge sharing between CEO and CIO regarding five areas of IT governance decision-making: IT principles, IT architecture, IT infrastructure, business application needs, and IT investment and prioritization, on IT and business alignment. Additionally we studied the effects of business alignment on the effectiveness of information systems. Results showed that the degree of knowledge sharing in CEO and CIO on IT principles, IT infrastructure, IT investment and prioritization had a positive influence on IT and business alignment, ultimately showing a positive influence on the effectiveness of information systems. This research has shown that fording the preferable relationship between IT and business affected by performing high quality decision making based on knowledge sharing and consequently it also is a basis to provide a positive influence to the effectiveness of the information system.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.181-188
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• 2011

A simulation technique, which simulate dynamic motion and communication environments of ship in the lab, is needed in order to reduce the testing cost when we evaluate the transfer alignment performance of shipboard INS. Hardware-In-the-Loop Simulation(HILS) can be used as an effective test method for those system because it can provide flexible and realistic simulation environments, various test scenario, and repeated test environment in the lab without additional cost and person. This paper presents the methods for implementing the real time HILS environment for testing transfer alignment performance of shipboard INS. It includes real time executive for controlling realtime simulation and calculating the ship motion, communication method for interfacing between the systems, and coordinate transformation method for converting real ship coordinate attitude data to lab coordinate attitude data.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.337-344
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• 2017

In this paper, the optical axis alignment(OAA) of an infrared sensor(IRS) using a microwave sensor(MWS) was presented as a method of an axis alignment to minimize the problems that could be caused by the misalignment of the two sensors in the missile including the dual-mode sensor. The azimuth(AZ) and elevation(EL) angles of the two targets used for each sensor test were calculated by using the transformation equation and the test results of the MWS and IRS, and then the proposed OAA was verified by comparing the angles. Furthermore, the validity of the proposed OAA was demonstrated by confirming the abnormality of the OAA through the test results of the electro optical head(EOH) of the IRS which was equipped with a tilt on the missile fuselage.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.44.1-44.1
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• 2010

poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a bacterially derived copolymer produced by fermentation. PHBV has been attractive because of its potential environmental, pharmaceutical and biomedical applications. Recently, the electrospinning technique has been used to fabricate fibrous mat for biomedical applications such as artificial blood vessel, drug release and scaffolds, because this method is simple and easy to get ultrafine polymer fibers. Depending on speed of rotation drum collector, fiber structure was different. In this work, PHBV fiber was aligned by electrospinnning machine. Furthermore, alignment of PHBV fiber mats was given angle such as $45^{\circ}$, $60^{\circ}$ and $90^{\circ}$. The morphology of each aligned PHBV fiber mat was observed by SEM technique. The mechanical property was evaluated depending on alignment angle. Especially, cell attachment ability depending on alignment of PHBV fiber mats was carried out using MG- 63 osteoblast like cells.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.510-514
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• 2003

We have studied the alignment of liquid crystals (LCs) on homeotropic polymeric surface that is scanned using an atomic force microscope (AFM) tip by optical polarizing microscopy and computer simulation. The scanned areas on one substrate are 5 $\mu\textrm{m}$ ${\times}$ 5 $\mu\textrm{m}$, 10 $\mu\textrm{m}$ ${\times}$ 10 $\mu\textrm{m}$, and 20 $\mu\textrm{m}$ ${\times}$ 20 $\mu\textrm{m}$ and this substrate is assembled to another substrate coated. with homeotropic polymer. The fabricated micro-LC cell using two substrates does not show any hysteresis and disclination lines inside the nano-rubbing areas, while changing voltage up and down. This indicates that the pretilt angle exists in the areas, thereby forming a hybrid LC configuration. From the experimental and computer simulation results, we can understand that the AFM rubbing clearly changes surface status of homeotropic alignment layer and causes the pretilt angle to an initial scanning direction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.311-312
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• 2005

By using 45$^{\circ}$ obliqued evaporation method with electron beam system, uniformly vertical liquid crystal (LC) alignment was achieved. And a high pretilt angles of about 2.5$^{\circ}$ were measured. Also, it was verified that there are no variations of pretilt angle as a function of $SiO_x$ thin film thickness 20nm and 50nm. A good LC alignment states were observed at annealing temperature of 250$^{\circ}C$. The high pretilt angle and the good thermal stability of LC alignment by 45$^{\circ}$ obliqued electron beam evaporation method on the $SiO_x$ thin film can be achieved.