• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.91-103
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• 2006

Given a bill of materials (BOM) tree T labeled by the breadth first search (BFS) order from node 0 to node n and a general network ${\Im}=(V,A)$, where V={1,2,...,m} is the set of production facilities and A is the set of arcs representing transportation links between any of two facilities, we assume that each node of T stands for not only a component. but also a production stage which is a possible stocking point and operates under a periodic review base-stock policy, We also assume that the random demand which can be achieved by a suitable service level only occurs at the root node 0 of T and has a normal distribution $N({\mu},{\sigma}^2)$. Then our integrated model of facility location problems and safety stock optimization problem (FLP&SSOP) is to identify both the facility locations at which partitioned subtrees of T are produced and the optimal assignment of safety stocks so that the sum of production cost, inventory holding cost, and transportation cost is minimized while meeting the pre-specified service level for the final product. In this paper, we first formulate (FLP&SSOP) as a nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables. We then show that the linear programming relaxation of the reformulated model has an integrality property which guarantees that it can be optimally solved by a column generation method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.175-179
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• 2007

In this study, we investigated the anti-obesity activity of extracts collected from wild plants in Jeju island. The inhibitory effect of plant extracts on the differentiation of preadipocyte 3T3-L1 was examined by oil red-O staining. We found that extracts collected from 6 plants among 31 plants, namely, Aralia elata(Miq.) Seem, Polygonum multiflorum Thunberg, Artemisia asiatica, platycodon grandiflorum(Jacq.) A. Dc., Polygonum cuspidatum S. et Z., Magnolia obovata Thunb, significantly inhibited preadipocyte differentiation. Additionally, 4 plant extracts were also found to have antioxidant activities in DPPH radical scavenging assay. Taken together, these results show that 6 plant extracts suppress the differentiation of preadipocytes, suggesting the potential use of 6 plant extracts as anti-obesity agents.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.279-284
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• 2005

We investigated the impedance matching characteristics of UHF-band RFID tag antenna and tag chip for increased reading range. A voltage multiplier designed using 0.4 $\mu$m zero-$V_T$ MOSFET showed that DC output voltage of about 2 V can be obtained using standard CMOS process. The input impedance of the voltage multiplier was examined to achieve impedance matching to the RFID tag antenna using analytical and numerical approaches. The input impedance of the voltage multiplier could be varied in a wide range by selecting the size of MOSFET and the number of multiplying stages, and thus can be impedance matched to a tag antenna in presence of other tag circuit blocks. A meander line inductively-coupled RFID tag antenna operating at UHF band also shows the feasibility of impedance matching to tile RFID tag chip.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.43.1-43.1
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• 2010

A novel method to characterize the topology of the early-universe intergalactic medium during the epoch of cosmic reionization is presented. The 21-cm radiation background from high redshift is analyzed through calculation of the 2-dimensional (2D) genus. The radiative transfer of hydrogen-ionizing photons and ionization-rate equations are calculated in a suite of numerical simulations under various input parameters. The 2D genus is calculated from the mock 21-cm images of high-redshift universe. We construct the 2D genus curve by varying the threshold differential brightness temperature, and compare this to the 2D genus curve of the underlying density field. We find that (1) the 2D genus curve reflects the evolutionary track of cosmic reionization and (2) the 2D genus curve can discriminate between certain reionization scenarios and thus indirectly probe the properties of radiation-sources. Choosing the right beam shape of a radio antenna is found crucial for this analysis. Square Kilometer Array (SKA) is found to be a suitable apparatus for this analysis in terms of sensitivity, even though some deterioration of the data for this purpose is unavoidable under the planned size of the antenna core.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.9 no.1
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• pp.77-87
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• 2014

Objectives: The Purpose of this study is to report the effects of Korean medical treatment on patient of peroneal neuropathy caused by sitting cross-legged. Methods: The patient diagnosed as peroneal neuropathy was treated by Acupuncture, Bee Venom therapy, Herbal medicine. To evaluate the effects of Korean treatment, we used Range of Motion(ROM) of Ankle, Visual Analog Scale(VAS), Numeric Rating Scale(NRS), Ankle-Hind-foot Scale(AHS), Digital Infrared Thermal Imaging(DITI). Results: After treatment, ROM of Ankle, VAS, NRS, AHS were improved. Temperature Difference(${\Delta}T$) was decreased on DITI. Conclusions: This study suggests that Korean medical treatment might be effective on sitting cross-legged patient diagnosed as Peroneal Neuropathy.

• The Research Journal of the Costume Culture
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• v.20 no.1
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• pp.62-71
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• 2012

The purpose of this research is to analyze the characteristics of the color combination in Eco fashion design. 532 pictures related to eco was collected through Eco brand web sites from 2008 through 2011. The characteristics for analysis include color combination and tone. The method of research is content and statistical analysis. The result of the research is summed up below. First, achromatic color was most frequently presented in Eco fashion. Also monotone color or single color combination were displayed often. Secondly, many dresses were of single color combination and T-shirt items displayed contrast color combination created by luminosity difference. Third, the outcome of comparing seasons was that both seasons presented single color and contrast color combination. The difference between countries proved slight as single color coloration dominated. This considered the process which was non-chemical manufacture for eco-friendly. For the combination of colors, the same coloration with single colors or contrast coloration due to the differences of brightness were presented quite often, generally, the modern image fashion without fancy factors have shown a lot. These results that minimalism trend was included in eco-friendly image.

• Fashion & Textile Research Journal
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• v.21 no.1
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• pp.27-35
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• 2019

Fashion Influencer of Instagram get a lot of attention from the public, and they play a major role in shaping peoples' taste. This study attempts to analyze the fashion design of fashion influencer in Instagram. The data was collected from Apr. 15th to April 30th, 2017, and the pictures were collected from May, 2016 to April, 2017. Total of 460 pictures were collected based on the number of "likes". The method of study was content analysis and the cross tabulation analysis and frequency using SPSS Statics 24 Based on the above results, influencers were mostly models that have many "likes" on their photos. Many of influencers were wearing black, white, or blue dresses that do not have any patterns. Many others were wearing indigo, black, or white jeans with T-shirts. In summary of the above contents, influencer also found out that the materials of their clothes were both hard and soft, and that the casual style was the most popular among influencer, and that influencer also liked elegant, modern, mannish, or sexy looks. Therefore, through this study, it was found that the fashion design of influencer had a unique fashion image. Gigi Hadid, Kendall Jenner, and Blake Lively are the representative influencers of fashion instagram. Gigi Hadid was a casual and manish image, Kendall Jenner was a casual and sexy image, and Blake Lively was an elegant image.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1084-1090
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• 2009

This paper presents a balun consisting of a T-junction, a Right/Left Handed Transmission line(RLH-TL), and a conventional Right Handed(RH) line. It is assumed that the RLH-TL consists of N unit-cells. We provide closed-form solutions and design a very compact wideband(80 %) balun using CPW lines based on the obtained solutions. Then, we propose a capacitively loaded loop antenna designed for a uniform current distribution. The antenna resistance of the proposed antenna at resonance is about 204 ohms. The length of the unit cell is about $\lambda/12$(total length: $1\;\lambda$). The magnetic field generated from the proposed antenna is stronger than that of the conventional one by as much as 20 dB. We used a coplanar strip line(CPS) to combine the loop antenna and balun. The proposed antenna may be used as a near field UHF RFID reader antenna.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.100-107
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• 2021

As a significant technology in the smartization era promoted by the Fourth Industrial Revolution, the secondary battery industry has recently attracted significant attention. The demand for lithium-ion batteries (LIBs), which exhibit excellent performance, is considerably increasing in different industrial fields. During the manufacturing process of LIBs, it is necessary to join the cathode and anode sheets with thicknesses of several tens of micrometers to lead taps of the cathode and anode with thicknesses of several hundreds of micrometers. Ultrasonic welding exhibits excellent bonding when bonded with very thin plates, such as negative and positive electrodes of LIBs, and dissimilar and highly conductive materials. In addition, ultrasonic welding has a small heat-affected zone. In LIBs, Cu is mainly used as the negative electrode sheet, whereas Cu or Ni is used as the negative electrode tab. In this study, one or two electrode sheets (t0.025 mm Cu) were welded to one lead tab (t0.1 mm Cu). The welding energy and pressure were used as welding parameters to determine the welding strength of the interface between two or three welded materials. Finally, the effects of these welding parameters on the welding strength were investigated.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.191-194
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• 1993

Apparent washout of T1-201 may occur between redistribution and reinjection images. To examine the frequency of it, we prospectively compared 4-hour redistribution and reinjection images in 63 consequent patients. All patients underwent pharmacological stress test using 0.56 mg/kg dipyridamole. Immediately after the 4-hour redistribution images, 1 mCi T1-201 was injected at rest, and images were reacquired 10 minutes after reinjection. The stress, redistribution, and reinjection images were then analyzed semiquantitatively (0=no uptake, 1=faint uptake, 2=mildly diminished uptake, 3=normal uptake). Of the 100 abnormal myocardial regions on the stress images, 54 showed either complete or partial reversibility on 4-hour redistribution images. After reinjection 11(21.2%) of these regions demonstrated apparent T1-201 washout due to low differential uptake of the tracer. Such lesions would appear irreversible if redistribution imaging is not performed before reinjection. Thus 4-hour redistribution imaging should be performed for assessment of myocardial ischemia and viability.