• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.651-673
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• 2007

In the studies on residential move, there has been tendency of dichotomy where short distance moves are largely caused by housing to adjust to changes in households while long distance moves are induced by shift in labor market. However, some empirical studies have proven that residential move is so complex process that the simple dichotomy should be elaborated. In this sense, the present study seeks to identify compounded course of residential move in Korea. In determining migration history, families with younger householders, renters, householders with higher educational attainment and smaller households show a higher probability to move. In case of mobility, women were more prone to move compared to man. Women compared to man, older age augmented the probability to own a house after migration. Families with householders following an occupation of sales and technical service showed lowest tendency to own houses while it marked the highest in the group of professionals. Higher land price of a region was negatively related to owning houses after migration. The present study revealed that factors in macro level as well as micro level significantly affect the move of individuals with varying effects in accordance with migration history.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.162-171
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• 2002

The purpose of this study was to examined whether high voltage pulsed current stimulation(HVPCS) enhances the migration and proliferation of fibroblasts from tendon biopsies to provides evidence that the cellular activities of fibroblast are enhanced by HVPCS. Flexor digitorum profundus tendon of chickens were excised, biopsied and cultured in M199 medium for a day. The biopsies through which a cathodal HVPC with 100 pps, 50 V for 30 minutes was passed in medium. A day after treatment, the biopsies embedded in fibrin clot were covered by the addition of 1ml of M199 medium to the well, and placed in the $CO_2$ incubator for the duration of the experiment. The migration distance of cells from tendon biopsies were measured at 6 days after treatment, and proliferation of cells from tendon biopsies were measured at 7 days after treatment. The migration distance of cells from tendon biopsies in the HVPCS group demonstrated significantly greater than the shame treated control group (t=-2.675, p<0.05). Also HVPCS had significantly increased optical density of fibroblasts from tendon biopsies (t=-2.136, p<0.05). These results indicate that the HVPCS with 100pps, 50V for 30minutes enhanced either the migration and proliferation of fibroblast from tendon biopsies. These results supposed that the HVPCS activates cellular responses in fibroblasts from tendon biopsies. This suggests that enhanced the migration and proliferation of fibroblast by HVPCS may be one of the mechanism involved in tendon healing.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.165-166
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• 2008

Bistatic spotlight synthetic aperture radar(BSSAR) with single track configuration uses the transmitter and the receiver which travel along the single track such as the leader-follower. For the BSSAR imaging, we modify the range migration algorithm. In time domain, we make the monostatic SAR using shifting of path, Then, in frequency domain, we compensate the separated distance between the scene center and the flight path using the principle of the stationary phase (PSP).

• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.79-88
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• 2012

Migration tests were performed with conservative tracers in a fractured zone that had a single fracture of about 2.5 m distance at the KURT. To interpret the migration of the tracers in the fractured rock, a solute transport model was developed. A two dimensional variable aperture channel model was adopted to describe the fractured path and hydrology, and a particle tracking method was used for solute transport. The simulation tried not only to develop a migration model of solutes for open flow environments but also to produce ideas for a better understanding of solute behaviours in indefinable fracture zones by comparing them to experimental results. The results of our simulations and experiments are described as elution and breakthrough curves, and are quantified by momentum analysis. The main retardation mechanism of nonsorbing tracers, including matrixdiffusion, was investigated.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.136-138
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• 2006

Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. Ion migration phenomena has been observed in the field of exposing the specific environment and using for a long time. Also as the RoHS restriction was started in July 1st, 2006, Pb-free solder was utilized in electronics assemblies. In this case, it is very important to compatible between components and printed circuit board(PCB), thus surface treatment materials of PCB was changed to Sn, Sn-3.0Ag-0.5Cu, Cu. Therefore these new application become to need to reevaluate the sensitivity about electrochemical ion migration. This study was evaluated the occurrence time of electrochemical ion migration using by water drop test. We utilized PCB(printed circuit board) having a comb pattern as follows 0.1, 0.318, 0.5, 1.0 mm pattern distance. Sn-3.0Ag-0.5Cu and Sn-37Pb were electroplated on the comb pattern. 6.5V and 15.0V were applied in the comb pattern and then we measured the electrical short time causing by occurring the ion migration. In these results, we evaluate the sensitivity and derived the prediction models of ion migration occurrence time depending on the pattern materials, applied voltage and pattern spacing of PCB conductor.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.411-421
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• 2011

This study aims to analyze the trend of migration and to find the factors which influence to migration in Chuncheon, Wonju and Gangneung. The results are as follows. First, the employment chance and education chance give positive effect to migration. And it agrees with the results of the preceeding researches. Second, Though the statistical significance is low, the result that urbanized degree gives positive effect to migration indicates the possibility of positive effect of urban convenience to migratioin. Third, the pavement rate of the roads which is substituted for public goods service gives the negative effect to migratioin, though the statistical significance is low. This result shows the possibility that the road building has influenced the extending of traffic distance and the spreading of residence area. In conclusion, this study identifies the positive effect of employment chance and education chance to migration, and the results of this study are supposed to be considered in the regional plan in Gangwon-do.

• Journal of the Korean association of regional geographers
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• v.7 no.3
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• pp.107-120
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• 2001

This study is concerned with providing a reliable procedure of calibrating a set of places specific distance parameters and with applying it to U.S. inter-State migration flows between 1985 and 1900. It attempts to conform to recent advances in quantitative geography that are characterized by an integration of ESDA(exploratory spatial data analysis) and local statistics. ESDA aims to detect the spatial clustering and heterogeneity by visualizing and exploring spatial patterns. A local statistic is defined as a statistically processed value given to each location as opposed to a global statistic that only captures an average trend across a whole study region. Whereas a global distance parameter estimates an averaged level of the friction of distance, place-specific distance parameters calibrate spatially varying effects of distance. It is presented that a poisson regression with an adequately specified design matrix yields a set of either origin-or destination-specific distance parameters. A case study demonstrates that the proposed model is a reliable device of measuring a spatial dimension of migration, and that place-specific distance parameters are spatially heterogeneous as well as spatially clustered.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.18-25
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• 2007

In sensor networks, sensor nodes have limited computational capacity, power and memory. Thus energy efficiency is one of the most important requirements. How to extend the lifetime of wireless sensor networks has been widely discussed in recent years. However, one of the most effective approaches to cope with power conservation, network scalability, and load balancing is clustering technique. The function of a cluster head is to collect and route messages of all the nodes within its cluster. Cluster heads must be changed periodically for low energy consumption and load distribution. In this paper, we propose an energy-aware cluster head selection algorithm and Distance Estimation-based distributed Clustering Algorithm (DECA) in wireless sensor networks, which exchanges cluster heads for less energy consumption by distance estimation. Our simulation result shows that DECA can improve the system lifetime of sensor networks up to three times compared to the conventional scheme.

• Journal of Veterinary Clinics
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• v.35 no.5
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• pp.195-199
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• 2018

Zinc is necessary for normal functions in the immune system. The objective of the study is to examine the effect of zinc on the chemotactic activity of porcine peripheral blood polymorphonuclear cells (PMNs). A modified Boyden chamber was used to determine the directional migration distance of PMNs. Various concentrations of zinc showed no chemotactic activity to PMNs. However, culture supernatant from peripheral blood mononuclear cells (PBMCs) treated with zinc remarkably increased the chemotactic activity of PMNs when compared with culture supernatant from PBMCs treated without zinc. Culture supernatant from PBMCs treated without zinc also increased the migration distance of PMNs relative to vehicle control (medium alone). Increasing effect in chemotactic activity of PMNs by culture supernatant from PBMCs treated with zinc was inhibited by treatment of porcine anti-interleukin (IL)-8 polyclonal antibody (pAb). This effect was not affected by heat treatment ($4-85^{\circ}C$). This corresponded with heat stable physical characteristics of IL-8. These results suggest that zinc can upregulate the chemotaxis of PMNs, which is primary mediated by IL-8 chemotactic factor released from PBMCs treated with zinc.

• Archives of Plastic Surgery
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• v.45 no.5
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• pp.425-431
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• 2018

Background The umbilicus makes an important contribution to the natural appearance of the abdomen. To date, studies on its position in Korean women are lacking, and no standards have been established. The purpose of this study was to investigate the position of umbilicus in Korean women and to review changes in its position after ipsilateral pedicled rectus abdominis musculocutaneous (IP-RAM) flap. Methods This research consisted of two studies. In first study, 100 females who visited the emergency department with gastroenteritis between 2007 and 2011 were included. In second study, 40 women who underwent IP-RAM flap in the same period were included. Using abdominal computed tomography, we measured the distance between xiphoid process and umbilicus, represented by value a, and the distance between umbilicus and symphysis pubis, represented by value b. Thus, the location of the umbilicus was represented by the ratio a/b. The data were analyzed using Pearson correlation test and paired t-test. Results In study 1, the mean value of a/b was 1.07. Pearson correlation test revealed a significant correlation between age and a/b. In study 2, the mean value of a/b was 1.16 in preoperative measurements and 1.01 in postoperative measurements. The paired t-test showed a significant difference between preoperative and postoperative measurements, indicating cephalic migration of the umbilicus after surgery. Conclusions The natural position of the umbilicus showed caudal migration with aging. Additionally, in a comparison of preoperative and postoperative measurements in patients who underwent IP-RAM flap, cephalic migration of the umbilicus was observed after surgery.