• Journal of Chest Surgery
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• v.48 no.4
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• pp.246-251
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• 2015

Background: Upper limb ischemia is less common than lower limb ischemia, and relatively few cases have been reported. This paper reviews the epidemiology, etiology, and clinical characteristics of upper limb ischemia and analyzes the factors affecting functional sequelae after treatment. Methods: The records of 35 patients with acute and chronic upper limb ischemia who underwent treatment from January 2007 to December 2012 were retrospectively reviewed. Results: The median age was 55.03 years, and the number of male patients was 24 (68.6%). The most common etiology was embolism of cardiac origin, followed by thrombosis with secondary trauma, and the brachial artery was the most common location for a lesion causing obstruction. Computed tomography angiography was the first-line diagnostic tool in our center. Twenty-eight operations were performed, and conservative therapy was implemented in seven cases. Five deaths (14.3%) occurred during follow-up. Twenty patients (57.1%) complained of functional sequelae after treatment. Functional sequelae were found to be more likely in patients with a longer duration of symptoms (odds ratio, 1.251; p=0.046) and higher lactate dehydrogenase (LDH) levels (odds ratio, 1.001; p=0.031). Conclusion: An increased duration of symptoms and higher initial serum LDH levels were associated with the more frequent occurrence of functional sequelae. The prognosis of upper limb ischemia is associated with prompt and proper treatment and can also be predicted by initial serum LDH levels.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.52.1-52.1
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• 2017

Galaxy clusters are the most massive gravitationally bound systems and thus probably the most recent objects to form. One of promising routes to understand the assembly history of galaxy clusters is to measure observable quantities of components in clusters that are sensitive to the evolutionary state of the cluster. Recent deep observations on the nearby clusters show distinct diffuse intracluster light (ICL), that the light from stars are not bound any individual cluster galaxy, however until now this component has not been well studied due to its faint nature, with typical brightness of ~100 times fainter than the sky background. As shown in galaxy cluster simulation studies, the ICL abundance increases during various dynamical exchanges of galaxies such as the disruption of dwarf galaxies, major mergers between galaxies and the tidal stripping of galaxies. Thus, the ICL is an effective tool to measure the evolutionary stage of galaxy clusters. Moreover, the investigation of the ICL evolution mechanism will allow us understand the galaxy evolution process therein. In this pilot study, we target the Coma cluster, where the existing ICL studies are limited only in the central region. With large and uniform deep optical images from the Subaru telescope, available only recently (Okabe et al. 2014), we are developing a robust ICL measurement technique, extracting the ICL surface brightness and color profiles, which will allow us to study the origin of the ICL and its connection to the evolutionary history of the Coma cluster. For the next phase, we plan to utilize the plenty of spectroscopy data from the MMT telescope to compare ICL properties with the star formation history of the brightest cluster galaxies (BCG), and discuss the ICL formation mechanism of the Coma cluster by comparing the distribution of cluster galaxies with the distribution of diffuse light inside the Coma cluster.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.233-244
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• 2004

ZnO epilayer were synthesized by the pulesd laser deposition(PLD) process on $Al_2O_3$ substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193nm) excimer laser. The epilayers of ZnO were achieved on sapphire ($Al_2O_3$)substrate at a temperature of $400^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are $8.27{\times}10^{16}\;cm^{-3}$ and $299\;{\textrm}cm^2/V.s$ at 293K. respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;3.3973\;eV\;-\;(2.69{\times}10^{-4}\;eV/K)T^2/(T+463K)$. After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10K. The native defects of $V_{zn},\;Vo,\;Zn_{int},\;and\;O_{int}$ obtained by PL measurements were classified as a donors or acceptors type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in $ZnO/Al_2O_3$ did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.

• Journal of KSNVE
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• v.7 no.2
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• pp.319-329
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• 1997

Wigner-Ville distribution has been recognized as a useful tool and applied to various types of mechanical noise and vibration signals, but its limitation which mainly comes from the cross-talk has not been well addressed. The cross-talk takes place for a signal with multiple components, simply because the Wigner-Ville distribution is a bilinear transform. The cross-talk often causes a negative value in the distribution. This cannot be accepted for the Wigner- Ville distribution, because it is an expression of power. Smoothing the Wigner-Ville distribution by convoluting it wih a window, is most commonly used to reduce the cross-talk. There can be infinite number of distributions depending on the windows. In this paper, we attempted to develop a distribution which is the best or the optimal in reducing the cross-talk. This could be possible by employing the ambiguity function. For a general signal, however it is difficult to express the ambiguity function as a mathematically closed form. This requires an appropriate modeling to make such expression possible. We approximated the Wigner-Ville distribution as a sum of linear segments. In the ambiguity function domain, the legitimate components are reflected as linear lines passing through the origin. Every lines has its own length and slope. But, the cross-talk is widely distributed in the ambiguity function plane. Based on this realization, we proposed a two-dimensional window which is in fact 'rotating window', that can eliminate cross-talk component. The rotating window is examined numerically and is found to have a better performance in reducing the cross-talk than conventional windows, the Gaussian window.

• Journal of the Korean association of regional geographers
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• v.12 no.2
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• pp.229-244
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• 2006

Geographical indications are signs which identify a good as originating in the territory of a specific country, region, or locality, where the quality, reputation or other characteristics of the product is essentially attributable to its geographical origin. Korea has implemented geographical indication system through its Agricultural Product Quality Control Act since 1999. This research analyzes the impacts and implications of geographical indications on a particular cultural industry in a region using a case study of Boseong green tea which is the first product that was officially registered as a geographical indication in Korea. The results show that the geographical indication has contributed to the promotion of green tea industry in Boseong not only through increase of production but also through development of tourism. The implication is that a geographical indication can be used as an effective method to cope with trade liberalization in terms of agricultural policy. Another implication is that a geographical indication provides an efficient tool for place marketing.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.21-26
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• 2012

Suspension culture is a useful tool for culturing embryonic stem (ES) cells in large-scale, but the stability of pluripotency and karyotype has to be maintained $in$ $vitro$ for clinical application. Therefore, we investigated whether the chromosomal abnormality of ES cells was induced in suspension culture or not. The ES cells were cultured in suspension as a form of aggregate with or without mouse embryonic fibroblasts (MEFs), and 0 or 1,000 U/ml leukemia inhibitory factor (LIF) was treated to suspended ES cells. After culturing ES cells in suspension, their karyotype, DNA content, and properties of pluripotency and differentiation were evaluated. As a result, the formation of tetraploid ES cell population was significantly increased in suspension culture in which ES cells were co-cultured with both MEFs and LIF. Tetraploid ES cell population was also generated when ES cells were cultured alone in suspension regardless of the existence of LIF. On the other hand, the formation of tetraploid ES cell population was not detected in LIF-free condition, in which MEFs were included. The origin of tetraploid ES cell population was turned out to be E14 ES cells and not MEFs by microsatellite analysis and the basic properties of them were still maintained despite ploidy-conversion to tetraploidy. Furthermore, we identified the ploidy shift from tetraploidy to near-triploidy as tetraploid ES cells were differentiated spontaneously. From these results, we demonstrated that suspension culture system could induce ploidy-conversion generating tetraploid ES cell population. Moreover, optimization of suspension culture system may make possible mass-production of ES cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.394-394
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• 2013

The spin-orbit interaction has received great attention in the field of spintronics, because of its property and applicability. For instance, the spin-orbit interaction induces spin precession which is the key element of spin transistor proposed by Datta and Das, since frequency of precession can be controlled by electric field. The spin-orbit interaction is classified according to its origin, Dresselhaus and Rashba spin-orbit interaction. In particular, the Rashba spin-orbit interaction is induced by inversion asymmetry of quantum well structure and the slope of conduction band represents the strength of Rashba spin-orbit interaction. The strength of spin-orbit interaction is experimentally obtained from the Shubnikov de Hass (SdH) oscillation. The SdH oscillation is resistance change of channel for perpendicular magnetic field as a result of Zeeman spin splitting of Landau level, quantization of cyclotron motion by applied magnetic field. The frequency of oscillation is different for spin up and down due to the Rashba spin-orbit interaction. Consequently, the SdH oscillation shows the beat patterns. In many research studies, the spin-orbit interaction was treated as a tool for electrical manipulation of spin. On the other hands, it can be considered that the Rashba field, effective magnetic field induced by Rashba effect, may interact with external magnetic field. In order to investigate this issue, we utilized InAs quantum well layer, sandwiched by InGaAs/InAlAs as cladding layer. Then, the SdH oscillation was observed with tilted magnetic field in y-z plane. The y-component (longitudinal term) of applied magnetic field will interact with the Rashba field and the z-component (perpendicular term) will induce the Zeeman effect. As a result, the strength of spin-orbit interaction was increased (decreased), when applied magnetic field is parallel (anti-parallel) to the Rashba field. We found a possibility to control the spin precession with magnetic field.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.265-271
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• 2011

Lymphoma is the most common hematopoietic malignancy in dogs. Diagnosis of lymphoma is classically performed by morphological assessment and immunohistochemistry. But some cases in the early stage are difficult to distinguish and need more objective and accurate methods. So, Polymerase chain reaction (PCR) for antigen receptor rearrangements (PARR) and flow cytometric immunophenotype of lymphoma have been developed continuously. In this study, we performed these two methods to classify lymphoma type in 3 cases. According to PARR analysis, B cell origin lymphoma was diagnosed in two of three cases by testing PBMC and lymph node. All fine needle aspiration (FNA) samples of lymph nodes had high expression of CD21 on >88% of total cell population and PBMC samples also showed high expression of CD21 on >30% of total lymphocytes in those two cases, while the expression of CD3, CD4 and CD8 was absent. These results suggest that concurrent use of PARR and flow cytometric immunophenotype is more effective and valuable tool for the diagnosis and monitoring of canine lymphoma patients.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.613-620
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• 2020

This study aimed to investigate the current state and trends of health literacy research conducted on female marriage immigrant in South Korea over the past 10 years. A total of 107 related studies were searched through the web database, and 10 of them that met the inclusion criteria were finally analyzed. Most of the studies conducted in the healthcare fields such as nursing. Of the 9 studies were descriptive study, and there were no intervention studies. Most of studies involving women from main country of origin such as Vietnam, China, and the Philippines, and many studies conducted convenience sampling of less than 200 subjects from some regions for reasons such as accessibility. As a tool for measuring health literacy, KHLAT was most frequently used. For future research, collaborative research with healthcare fields and other fields through interdisciplinary interaction is necessary, and a circumstance in which field workers actively participate in research should be prepared. In addition, further studies including larger sample and community-based intervention improve health literacy are needed. Finally, efforts to improve the methodological consistency in the application of health literacy tools and to develop standardized instruments are required.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.495-502
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• 2016

Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. The objective of this study was to evaluate the use of unmanned aerial vehicle (UAV) for the monitoring IRG growth. Unmanned aerial vehicle imagery obtained from middle March to late May in Nonsan, Chungcheongnam-do. Unmanned aerial vehicle imagery corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). We analyzed the relationships between $NDVI_{UAV}$ of IRG and biophysical measurements such as plant height, fresh weight, and dry weight over an entire IRG growth period. The similar trend between $NDVI_{UAV}$ and growth parameters was shown. Correlation analysis between $NDVI_{UAV}$ and IRG growth parameters revealed that $NDVI_{UAV}$ was highly correlated with fresh weight (r=0.988), plant height (r=0.925), and dry weight (r=0.853). According to the relationship among growth parameters and $NDVI_{UAV}$, the temporal variation of $NDVI_{UAV}$ was significant to interpret IRG growth. Four different regression models, such as (1) Linear regression function, (2) Linear regression through the origin, (3) Power function, and (4) Logistic function were developed to evaluate the relationship between temporal $NDVI_{UAV}$ and measured IRG growth parameters. The power function provided higher accurate results to predict growth parameters than linear or logistic functions using coefficient of determination. The spatial distribution map of IRG growth was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to power function. From these results, $NDVI_{UAV}$ can be used as a new tool for monitoring IRG growth.