• Korean Journal of Materials Research
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• v.4 no.8
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• pp.927-933
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• 1994

The effect of particle shape and size on the settling characteristics in monodisperse suspensions of non-spherical particles was investigated. The slope index n values which was obtained from the plot of logarithm of settling rate vs. voidage were increased with the decrease of particle size because different amount of liquid could be adsorbed on irregular particle shape and/or size at same volume concentration. From the experimental results, an equation, $n_{i}=n(a+b/d_{v})$ where n is value of spherical particles, dv is minimum particle diameter and a, b are constants for characteristic of particles.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.555-561
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• 2008

This paper describes an e-Engineering framework to support collaborative design of automotive suspension systems developed at KIMM(Korea Institute of Machinery and Materials). The e-Engineering framework is proposed and developed on the base of the multi-layered software agents including engineering task agent which is generated from the domain knowledge of experts. The developed framework is aim to widely spread application to the small and medium enterprises by adopting open source technologies such as JADE (Java Agent Development Framework) and by using the independent characteristics related with applicant H/W and 81W system. This framework can provide an integrated design environment to support distributed personnel, design activities and engineering resources during product development process. For the validation of the system's applicability and efficiency, the several practical design processes for automotive suspension systems of RR/FR lower arms and RR cross member are applied and discussed.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.40-46
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• 2015

Microcapsules containing the suspension of conducting materials such as carbon nanotube (CNT) or polyaniline (PANI) were prepared by in-situ polymerization of melamine and formaldehyde. Stable microcapsules were prepared and the mean diameter of the observed microcapsules was in the range of $10-20{\mu}m$. The surface morphology and chemical structure of microcapsules were investigated using optical microscope (OM), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR). The thermal properties of samples were investigated by thermogravimetric analysis (TGA). The conductivity of ruptured microcapsule containing the suspension of CNTs or PANIs in tetrachloroethylene and Isopar-G was measured. As the amount of CNTs and PANIs in the core of microcapsules increased, the measured current increased. Conductivity measurement results suggest that poly (melamine-formaldehyde) based core-shell microcapsules could be applied to self-healing electronic materials systems, where CNTs or PANIs bridge a broken circuit upon release.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.73-78
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• 2013

In this paper, the vibration for a pickup actuator is described by mathematically analyzing its suspension configuration and motion, confined to lateral and torsional directions of suspensions. In order to prove the accuracy of this result, it is compared to a finite element analysis. Also it is shown that modal frequencies can be modified by changing design parameters in mathematical motion expressions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.381-382
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.351-351
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• 2004

For greeting the era of ubiquitous network, data storage devices have been essentially attached to mobile data devices. As a result, the minimization of the storage device has arisen as major interests in the next generation data storage technology. So, there are many researches for the small form factor ODD. In this paper, we propose a pick up that consists of a linear VCM and 2-wire focusing actuator for a small form factor ODD. For the sake of checking performance of the coarse actuator, PID controller is designed. Experiment with controller and DSP board shows its propriety as a fine tracking actuator. And, 2-wire suspension actuator is designed in order to be contained in a coarse actuator and to satisfy the thickness of a PCMCIA type. Through the experiment of designed actuator, It verifies performance as a focusing actuator.

• Analytical Science and Technology
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• v.13 no.5
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• pp.608-615
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• 2000

A determination method of trace nickel and cobalt in water samples was studied and developed by adsorbing their complexes on ion exchange resin suspension. The analytical ions were formed as complexes with a ligand of APDC (ammonium pyrrolidinedithiocarbamate) and adsorbed on anion exchange resin of Dowex 2-X8. After the suspension was filtered out with membrane filter, the complexes were dissolved in HCl solution by an ultrasonic vibrator for ET-AAS determination. Several conditions were optimized as followings. pH of sample solution: 5.0, amount of ligand APDC: more than 430 times in mole ratio, the type and concentration of acid: 0.1 M HCl, and vibration time: 7 minutes. The addition of palladium in the HCl solution could improve the reproducibility and sensitivity by a matrix modification in the absorbance measurement. This procedure was applied for the analysis of three kinds of real water samples. The detection limits equivalent to 3 times standard deviation of blank were Co 0.36 ng/mL and Ni 0.27 ng/mL and recoveries in spiked samples were 99-102% for cobalt and 100-105% for nickel.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.435-441
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• 2017

Studies on self-healing have currently been diversified and the methods to evaluate the studies have become more diversified as well. Among them, the back-scattered electron (BSE) image acquired through the scanning electron microscope (SEM) is attempted as the means to evaluate the self-healing effect on cracks. In order evaluate by the BSE image, sophisticated pre-processing of specimen is critical and this injected inside the particle, pore and artificial crack of the hardener to stabilize the structure of the newly generated self-healing product and it enables to endure the stress on polishing without deformation. The impregnated specimen smoothen the surface to obtain the BSE image of high resolution that polishing is made for diamond suspension for wet polishing after dry polishing. As a result of evaluating the self-healing product on the impregnated and polished self-healing specimen, the generated product is formed from the surface of the artificial crack and the self-healing substances are confirmed as $Ca(OH)_2$ and C-S-H.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.539-549
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• 2024

This study employed text mining techniques like frequency analysis, word clouds, and LDA topic modeling to assess consumer satisfaction and dissatisfaction with Hyundai Motor Company in the Chinese market, compared to brands such as Toyota, Volkswagen, Buick, and Geely. Focusing on compact vehicles from these brands between 2021 and 2023, this study analyzed customer reviews. The results indicated Hyundai Avante's positive factors, including a long wheelbase. However, it also highlighted dissatisfaction aspects like Manipulate, engine performance, trunk space, chassis and suspension, safety features, quantity and brand of audio speakers, music membership service, separation band, screen reflection, CarLife, and map services. Addressing these issues could significantly enhance Hyundai's competitiveness in the Chinese market. Previous studies mainly focused on literature research and surveys, which only revealed consumer perceptions limited to the variables set by the researchers. This study, through text mining and comparing various car brands, aims to gain a deeper understanding of market trends and consumer preferences, providing useful information for marketing strategies of Hyundai and other brands in the Chinese market.

• Investigative Magnetic Resonance Imaging
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• v.10 no.1
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• pp.20-25
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• 2006

Purpose : To evaluate the NMR relaxation properties of newly developed high performance paramagnetic complexes. Materials and methods : 4-aminomethylcyclohexane carboxylic acid (0.63g, 4 mmol) was mixed with the suspension solution of DMF (15mL) and DTPA-bis-anhydride (0.71g, 2 mmol) to synthesize the ligand. The ligand was then mixed with Gd2O3 (0.18g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1mM and then the relaxation times were measured at 1.5T(64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG(Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. Using MATLAB(Version 7.1) program, T1 magnetic relaxation map, R1 map, T2 magnetic relaxation map and R2 map were developed to represent magnetic relaxation time and magnetic relaxivity as image. Results : Compared to $R1=4.9mM^{-1}sec^{-1}$ and $R2=4.8mM^{-1}sec^{-1}$ of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, R1 of SUK090(Gd-C32H74N5O24) was $12.46mM^{-1}sec^{-1}$ and R1 of SUK091(Gd-C34H78N5O24) was $12.77mM^{-1}sec^{-1}$. However, R1 of SUK092(Gd-C30H56N5O17) was decreased to $2.09mM^{-1}sec^{-1}$. In case of R2, SUK090(Gd-C32H74N5O24) was $8.76mM^{-1}sec^{-1}$ and SUK091(Gd-C34H78N5O24) was $7.60mM^{-}1sec^{-1}$ whereas SUK092(Gd-C30H56N5O17) was decreased to $1.82mM^{-1}sec^{-1}$. Conclusion : Among three new paramagnetic complexes, SUK090(Gd-C32H74N5O24) and SUK091(Gd-C34H78N5O24) showed higher T1, T2 magnetic relaxation rates than that of commercially available paramagnetic MR agent and thus expected to have more contrast enhancement effect.