• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.57-62
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• 2011

The shortage of transplantable kidneys has many efforts to regenerate bioartificial kidneys using transgenic animals and diverse kinds of scaffolds which are important tools for cell seeding. However, there are many limitations for clinical applications so far. Recently, decellularized bioscaffolds using animal organs come into spotlight because of its many superior advantages. In current study, we produced decellularized kidney bioscaffolds of pig which is an attractive animal as a clinical model for human. We decellularized pig kidneys with 1% SDS detergent solution using peristaltic pump systems for 12h. After decellularization process, the kidney bioscaffolds preserved intact 3D morphology including glomerular structure and almost DNA from pig was entirely removed. In addition, this process could preserve micro vascular network which is necessary for cell survival. Although, additional studies for recellularization and transplantation should be required, the decellular vascularized kidney bioscaffolds might have many potentials for kidney regeneration.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.63-72
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• 2008

Signalized intersections are operated without a signal preemption control strategy in Korea, thus there is no priority treatment for an emergency vehicle passing through the intersections. In this paper, a signal preemption control strategy is introduced to improve the safety and operational efficiency of an emergency vehicle. Using the micro simulation tool, the effects on delay and travel speed of the signal preemption control strategy are analyzed for various traffic conditions to identify the general performance trends. Then, another simulation analysis is performed to verify the feasibility of the control strategy using real network data collected from field study. Results show that the preemption control strategy provides the positive impact on emergency vehicles' operation, but the positive impact is reduced as the v/c ratios increase. As expected, the average delays of the normal vehicles are slightly increased, but the magnitude is not significant. Therefore, it is expected that the introduction of the preemption control strategy in Korea would produce the positive social benefits.

• Korean Journal of Childcare and Education
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• v.10 no.5
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• pp.47-62
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• 2014

The purpose of this study targeted 93 full 5-year-old preschoolers was to examine young children's recognition of the relationships with their mothers, teachers, and peers and to analyze the effect of children's recognition on their self-concept. Children's recognition of the relationships with the people around and their self-concepts were measured by use of picture diagrams to help children's understanding and their replies. Data analysis showed that young children recognize their relationships with the people around positively, and that children's conflict recognition with their teachers influence negatively on their self-concept. This study is meaningful in that it directly researched preschooler's cognition of the relationships with the people around themselves from situation in the lack of preceding research that it comprehensively studied about relationships with the preschooler and others, and it executed one-to-one interview with preschooler using the picture tool for preschooler developed by the investigator in order to measure the preschooler's cognition.

• Tuberculosis and Respiratory Diseases
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• v.59 no.1
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• pp.47-52
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• 2005

Background : Chlamydia pneumoniae is a clinically important pathogen, the diagnosis of such infection being based mainly on serology. Microimmunofluorescence (MIF) is the current standard diagnostic method, but is subjective and time-consuming, so the authors tested the serology of chronic cough patients using an EILSA method for the Chlamydial antibody, which is a more objective method, and compared the results with those of the standard method. Method : Thirty-five patients, who visited Kangwon National University Hospital between August 2003 and July 2004, were evaluated. A MIF and ELISA tests were used to determine C. pneumoniae antibody titers. Nasopharyngeal aspirates were examined by polymerase chain reaction (PCR). The Spearman rank correlation test was used for data analysis. Results : Sensitivities of ELISA for IgG, IgA and IgM, as judged by MIF, were 84.0, 84.0 and 40.0% and the specificities were 60.0, 60.0 and 96.7%, respectively. Three patients were Chlamydia PCR positive. Conclusion : ELISA can be a useful tool for studying the seroprevalence of Chlamydia pneumoniae. However, further studies will be required prior to its clinical use.

• East Asian Economic Review
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• v.17 no.2
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• pp.161-206
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• 2013

Since the global financial crisis in 2008, the world economy has been suffering from the Great Recession characterized by high and persistent unemployment as well as drastic fall in asset prices. Real business cycle theory or new-Keynesian economics which has been the dominant paradigm in macroeconomics for the last four decades is unable to explain the high and persistent unemployment during the Great Recession. This implies that the economics of Keynes should be taken seriously again as a tool to explain the Great Recession. Farmer (2012) proposes a new way of interpreting the economics of Keynes by providing it with a solid micro-foundation based on labor markets with search. According to Farmer (2012), aggregate economic activity independently depends on the long-term self-fulfilling expectations about the stock prices. As a consequence, the government or the central bank should implement a policy that influences the public's confidence about the stock market. For an open economy like the Korean economy, it is not only stock price but also the price of asset such as house that matters more for the aggregate economic activity. Households in the Korean economy hold more than 70 percent of their wealth in the form of real estate asset, especially housing asset. This makes the public's confidence about the future prices of houses even more important in explaining the business cycles of the Korean economy. Policymakers should implement policies to improve the confidence of households about the housing market to recover from the recession caused by a fall in house prices. Little theoretical work has been done in explaining fluctuations in the aggregate economic activity from the point of house prices. This paper develops a small open economy model with traded and non-traded capital based on Farmer (2012) and shows that the aggregate economic activity also independently depends on the households' self-fulfilling expectations about the future prices of non-traded asset such as houses.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.67-74
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• 2009

Exposures to environmental chemicals that mimic endogenous hormones are proposed for a number of adverse health effects, including infertility, abnormal prenatal and childhood development and above all cancers. In addition, recently miRNA (micro RNA) has been recognized to play an important role in various diseases and in cellular and molecular responses to toxicants. In this study, endocrine disrupting environmental toxicant, nonylphenol (NP) was treated to MCF-7 (Human breast cancer cell) and HepG2 (Human hepatocellular liver carcinoma) cell line at 3 hrs and 48 hrs time point and miRNA analysis using $mirVana^{TM}$ miRNA bioarray was performed and compared with total mRNA microarray data for the same cell line and treatment. Robust data quality was achieved through the use of dye-swap. Analysis of microarray data identifies a total of 20 and 11 miRNA expressions at 3 hrs and 48 hrs exposure to NP in MCF-7 cell line and a total of 14 and 47 miRNA expression at 3 hrs and 48 hrs exposure respectively to NP in HepG2 cell line. Expression profiling of the selected miRNA (let-7c, miR-16, miR-195, miR-200b, miR200c, miR-205, and miR-589) reveals changes in the expression of target genes related to metabolism, immune response, apoptosis, and cell differentiation. The present study can be informative and helpful to understand the role of miRNA in molecular mechanism of chemical toxicity and their influence on hormone dependent disease. Also this study may prove to be a valuable tool for screening potential estrogen mimicking pollutants in the environment.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.761-769
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• 1999

In this paper the effect of aging heat treatment to the Corrosion behavior for the Nimonic 80A superalloy was studied by AC Impedance methods. Tested solution was 3.5% with tempera-ture $25^{\circ}C$ Electro-chemical corrosion test were carried out for the Nimonic 80A super-alloy which solution heat treated at $1080^{\circ}C$ for 8 hours followed by aging heat treated at $650^{\circ}C,\;700^{\circ}C,\;750^{\circ}C\;800^{\circ}C$ and $850^{\circ}C$ with 16hours under vacuum environment. The obtained results were as follows; 1. Base metal and solution-treated materials were exhibited similar corrosion tendency as Ran-dle equivalent cell. The value of passive film resistance was 579 ohms for the base metal and 124,770 ohms for the solutionized metal such a difference was arose by the ${{\gamma}_^'}$ precipitate on the metal surface during heat treatment. 2. The measure value of $R_p$ for heat-treated at $650^{\circ}C,\;700^{\circ}C,\;800^{\circ}C$and $850^{\circ}C$ were 97,943, 93, 111, 26,961, 15,798 and 11,780ohm respectively. Which indicated that the passive film resistance Rp was reduced as aging temperature increased due to the growth of grain size and sensitization at the grain boundary. 3. The similar tendency was exhibited for corrosion behavior of the electro-chemical corrosion polarization method and AC impedance method and confirmed that AC impedance method was useful tool for corrosion research.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.80-88
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• 2013

In currently developed engine condition monitoring systems, most field engine maintenance engineers have difficulties to use them in fields due to complexity, unpractical use, lack of understanding, etc. Therefore a practical usable engine condition monitoring system must be needed. This work proposes a practical performance condition monitoring of a small turbojet engine through comparing between the on-line performance monitoring data and the initial clean performance data calculated by the base engine performance model. Moreover the proposed monitoring system checks the gas path components' on-line health condition through comparing the component performance characteristics between the running engine represented as a deteriorated engine or a degraded engine and the base engine performance model represented as a clean engine. The proposed condition monitoring system is coded in a friendly GUI type program for easy practical application by a commercial tool, MATLAB/SIMULINK and LabVIEW.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.31-36
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• 2017

In this paper, designed infrared (IR) emitter device for infrared scene projector (IRSP) which is used for evaluating the performance of IR sensor systems was simulated by using finite element analysis (FEA) tool and fabricated by using MEMS (Micro Electro-Mechanical System) technology. The performance of the fabricated IR emitter unit device was characterized in the vacuum chamber by using IR image microscope for MWIR($3{\sim}5{\mu}m$), which showed 423K apparent temperature (Tapp) and 22msec time constant (${\tau}$).

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.143-146
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• 2004

Background and Object: The role of fine needle aspiration cytology (FNAC) and frozen section (FS) in management of thyroid neoplasms continues to generate considerable controversy. We reviewed our current experience to determine the clinical utility of FNAC and FS in our surgical management and investigated reliability of FNAC and FS in planning the extent of thyroid resection. Material and Method: 212 patients who had operations for thyroid disease from May 1996 to November 2003 were included our retrospective study. FNAC was undertaken in 175 patients and FS was done in 148 patients. Result: The sensitivity and specificity of FNAC were 72.1% and 100%, respectively, and those of FS were 67.2% and 100%. The results of FNAC were benign (n=72) , malignancy (n=31), indeterminate (n=9), and nondiagnostic (n=63). The results of FS were benign (n=95), and malignancy (n=53). The 9 indeterminate cases on FNAC were benign (n=6) and malignancy (n=3) on final pathology, and benign (n=7) and malignancy (n=2) on FS. The false negative of FNAC were micro papillary carcinoma (n=6) and follicular carcinoma (n=6). The false negative of FS were micropapillary carcinoma (n=10) and follicular carcinoma (n=2). Conclusion: When results of FNAC are interpreted as indeterminate, FS is a valuable tool. FS is helpful in determining the extent of thyroidectomy when results of FNAC were follicular neoplasm. However we always concerned about micropapillary carcinoma and follicular carcinoma although FNAC and FS were benign.