• Journal of the Korea Society for Simulation
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• v.24 no.1
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• pp.1-8
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• 2015

This research focuses on the method of inventory management to find out the best way in various SCM. There are several comparable methods of inventory management like Min-Max, regular interval, fixed target inventory that have different lead-time and demand for each product. Also, the inventory performances between the case of three-stages and two-stages in SCM are analyzed. 8 scenarios for the simulation are suggested considering order ways and stages. Input data for the simulation is from the result of the previous studies and actual data in the market. The performance measurements are selected as sales revenue, total number of sales, total delivery cost, total inventory shortages, the number of inventory shortage occurrence, the loss for inventory shortages, average inventory, handling cost, net profit. According to the results of the simulation, fixed target inventory management is better than existing inventory management method by net profit and inventory and so on. Also, it was confirmed that the increase in profit is obtained when SCM stages is reduced from three-stages to two-stages in existing SCM. The result of the research provides significant meaning that newly introduced target inventory management system shows good performance and SCM performance can be improved by reducing the stages.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.5
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• pp.544-555
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• 2002

The aim of this study is to develop the $^1H$-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

• Polymer(Korea)
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• v.38 no.3
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• pp.351-357
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• 2014

In membrane covered stent, occlusion and fracture from membrane degradation by gastric acid sometimes occurred. Therefore, we investigated the physical properties of membrane covered stent according to its ingredient and concentration in gastric acid environment. Membrane covered stents consisted of silicone and polyurethane with 15%, 18%, 20% concentrations were used. After incubating stents in a condition of pH 1.2, we checked any changes at every 3 weeks for 18 weeks. The changes of membrane surface, radial expansion and recovery force of stent were investigated. Coating thickness increased proportionally to an increase in ingredient concentration. Surface was evenly coated with silicone compared to the case with polyurethane and its homogeneity was excellent in a high concentration. Degradation was much severe in the case of polyurethane. The radial force of silicone was higher than polyurethane, and the decrease of radial and recovery force was higher in the case of polyurethane. In conclusion, high concentration of silicone membrane was more stable than polyurethane in acid environment of in vitro study.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.333-338
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• 2015

In this study, we investigated carbonation-regeneration and agglomeration characteristics of dry sorbents. Experiment has been proceeded in the batch-type reactor, which is made of quartz: 0.05 m of I.D and 0.8 m in height. The sorbents that is collected at the cyclone of the carbonation reactor of continuous process were used in this study. The reactivity was studied at the various concentrations of water vapor, $N_2$ and $CO_2$ in the fluidizing gas at regeneration reaction. As a result, the reactivity increased as the regeneration temperature increased, the reactivity decreased as the concentration of water vapor increased. The absorption capacity showed the highest value in case of using $N_2$ 100% as regeneration gas. And decreased in order of $H_2O+N_2$, $CO_2$ 100% and $H_2O+CO_2$. The agglomeration characteristics were investigated according to the particle sizes and concentrations of water vapor at carbonation reaction. As a result, the particle with smaller size and higher concentration of water vapor showed the higher agglomeration characteristic.

• Journal of the Korean Magnetics Society
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• v.19 no.3
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• pp.113-119
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• 2009

$^{57}Fe_xCu_{1-x}O$(x = 0.0, 0.02) powders were prepared by sol-gel method and their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction and $M{\ddot{o}}ssbauer$ spectroscopy (MS). The crystal structure of the samples is found to be monoclinic without any secondary phases and their lattice parameters increase with increasing annealing temperature ($T_A$), which is attributed to an increase in oxygen-vacancy content. MS measurements at room temperature indicate that $Fe^{3+}$ ions substitute $Cu^{2+}$ sites and ferromagnetic phase grow with increasing $T_A$. Magnetic hyperfine and quadrupole interactions of $^{57}Fe_{0.02}Cu_{0.98}O$ ($T_A=500^{\circ}C$) in the antiferromagnetic state at 17 K have been studied, yielding the following results: $H_{hf}=426.94\;kOe$, ${\Delta}E_Q=-3.67\;mm/s$, I.S.=0.32 mm/s, ${\theta}=65^{\circ}$, ${\phi}=0^{\circ}$, and ${\eta}=0.6$.

• Journal of the Korean Magnetics Society
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• v.18 no.1
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• pp.19-23
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• 2008

The mixed ferrite $V_xFe_{3-x}O_4$(x=0.0, 0.15, 0.5, 1.0) thin films were prepared by sol-gel method. Their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and conversion electron $M\"{o}ssbauer$ spectroscopy(CEMS). The crystal structure is found to be cubic spinel throughout the series($x{\leq}1.0$), and the lattice parameter $a_0$ increases linearly with increasing V content. XRD, XSP and CEMS indicate that $V^{3+}$ substitution for $Fe^{3+}$ in B-site is superior to $V^{2+}$ substitution for $Fe^{2+}$ in B-site. It is noticeable that both quadrupole shift and hyperfine field decreases with increasing V composition, suggesting the change of local symmetry and accompanying line-broadening. The line-broadening on CEMS spectra can be explained by the distribution of magnetic hyperfine fields.

• Journal of the Korean Magnetics Society
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• v.24 no.3
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• pp.81-85
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• 2014

Nano-sized Ba-ferrite, Ni-Zn ferrite and $BaFe_{12}O_{19}/Ni_{0.5}Zn_{0.5}Fe_2O_4$ nanocomposite ferrite were prepared by sol-gel combustion method. Nanocomposite was calcined at temperature range of $600{\sim}900^{\circ}C$ for 1 h. According to the diffraction patterns, hard/soft nanocomposite was indicated to the coexistence of the magnetoplumbite structural $BaFe_{12}O_{19}$ and spinel $Ni_{0.5}Zn_{0.5}Fe_2O_4$ and agree with the standard data (JCPDS 10-0325). The particle size of nanocomposite turn out to be less than 90 nm. The nanocomposite ferrite shows a single-phase magnetization behavior, implying that the hard magnetic phase and soft magnetic phase were well exchange-coupled. The specific saturation magnetization ($M_s$) of the nanocomposite is located between hard ($BaFe_{12}O_{19}$) and soft ferrite ($Ni_{0.5}Zn_{0.5}Fe_2O_4$). The remanence (Mr) of nanocomposite ferrite is much higher than that for the individual $BaFe_{12}O_{19}$ and $Ni_{0.5}Zn_{0.5}Fe_2O_4$ ferrite. $(BH)_{max}$ is increased, generally.

• Journal of Service Research and Studies
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• v.10 no.2
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• pp.17-29
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• 2020

This study was performed to derive a modern service management model reflecting the philosophy of the new business administration. Service management as the modern business administration should be faithful to the spirit of modernity. In addition, service management must be faithful to the essence of service in service economy era. And since modern management is to manage organizations those are the central organizations of human society, it must be managed according to the common principles of the world. Management that satisfies these three management philosophy conditions is defined as modern service management. In this study, we analyzed that the existing service management framework does not meet these standards of modern management and derived an improved modern service management model. The modern service management model must be a management model that reflects the essence of intangible goods called service, it must be a management framework that reflects the modern spirit, and it must be a management model that reflects the common principles of the world required by the central organization of the modern economic society. Therefore, this study analyzed the modern spirit in addition to the service essence and the common principle of the world analyzed in the previous study, and presented a modern service management model with these three requirements. Also, examples of modern service management were presented. This study is a conceptual model, and analytical research is needed to demonstrate that this management model can consistently produce excellent management performance by strengthening empirical studies in the future.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.33-42
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• 2005

In this paper, we propose an efficient segmentation algerian using morphological grayscale reconstruction for region-based coding. Each segmentation stage consists of simplification, marker extraction and decision. The simplification removes unnecessary components to make an easier segmentation. The marker extraction finds the flat zones which are the seed points from the simplified image. The decision is to locate the contours of regions detected by the marker extraction. For the simplification, we use a new connected operator based on the size and contrast. In the marker extraction stage, the regions reconstructed to original values we excluded from the candidate marker. For the other regions, the regions which are larger than structuring elements or have higher contrast than a threshold value are selected as markers. For the initial segmentation, the conventional hierarchical watershed algorithm and the extracted markers are used. Finally in the region merging stage, we propose an efficient region merging algorithm which preserves a high quality in terms of the number of regions. At the same time, the pairs which have higher contrast than a threshold are excluded from the region merging stage. Experimental results show that the proposed marker extraction method produces a small number of markers, while maintaining high quality and that the proposed region merging algorithm achieves a good performance in terms of the image quality and the number of regions.

• Journal of Adhesion and Interface
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• v.2 no.3
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• pp.9-15
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• 2001

To estimate the effect of the surface state of the EVA foam on an adhesion, the surface was treated with solvents having different values of a solubility parameter and a surface tension. The morphology and the contact angle were measured by SEM and contact angle tester, respectively. The value of the critical surface tension(${\gamma}_{c,0}$) of the EVA foam calculated by Zismann plot was 27.08 dyne/cm. The surface state and the ${\gamma}_c$ of the EVA foam were changed by solvent treatment. The swelling ratio of EVA foam was influenced by solubility parameter of a solvent, on the other hand the degree of change in the surface state was dependent on a surface tension of a solvent. When a surface tension of solvent. When a surface tension of solvent is lower than ${\gamma}_{c,0}$ of the EVA foam, the wettability of a solvent was good and the surface state was greatly changed. The adhesion strength of EVA foam was greatly improved to above 600% as compared to that of the untreated one. As the ${\gamma}_c$ of EVA was closed to the surface tension of the primer, the good adhesion strength was obtained.