• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.47-48
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• 2006

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1812-1820
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• 2017

This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.

• Child Health Nursing Research
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• v.17 no.2
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• pp.91-99
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• 2011

Purpose: This study was done to develop a cell phone addiction prevention program for middle school students, and to examine the effects of the program on self-esteem, self-efficacy, impulsiveness, and cell phone use. Methods: The study was designed using a nonequivalent control group pre-test-post-test design. The participants were 63 middle school students (31 in the experimental group and 32 in the control group). Students in the experimental group were given the cell phone addiction prevention program. The data were analyzed using the SPSS/WIN 14.0 program. Results: Students in the experimental group reported a significant increase in self-esteem compared to students in the control group. Students in the experimental group also reported a significant decrease in cell phone use compared to students in the control group. Conclusion: The results of the study indicate that the cell phone addiction prevention program was effective in increasing self-esteem and decreasing cell phone use in middle school students.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.343-362
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• 1995

The purpose of this study was to investigate chronic radiation effects on the basal cell of the rat tongue epithelium according to different irradiation timing. Forty-two female rats were devided into 5 experimental groups according to different irradiation timing and were irradiated single dose of 396cGy by MK cell irradiator using Cs-137. Experimental rats were sacrificed at the 2nd week, 4th week and 6th week after birth. The specimens were examined with light microscope and transmission electron microscope. The following results were obtained. 1. The first changes after irraditation were vacuoles. The vacuoles were chiefly observed in the cytoplasm, perinuclei area, and nuclei. 2. The most severe degenerative changes in the basal cell layer were observed in all experimental groups. ; cellular disarrangement, vacuole formation, widening of intercellular space, enlarged mitochondria & rER, and chromatin clumping were seen. 3. The cellular degenerative changes were most severe at the 4th week after birth in all experimental group, and the basal cell hyperplasia was seen at the 6th week in the most of experimental groups 4. The experimental groups 3 and 4 show more severe and more prolonged cellular degeneration than experimental groups 1 and 2, which were irradiated in pregnancy, and experimental group 5, which was irradiated after tongue maturation.

• Child Health Nursing Research
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• v.18 no.3
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• pp.109-118
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• 2012

Purpose: This study was done to develop an education program on cell phone use for elementary school students, and examine its effects on their knowledge, attitude, self-efficacy, and self-control in cell phone use. Methods: The study was designed using a nonequivalent control group pretest-posttest design. The participants were 64 elementary school students (31 in the experimental group and 33 in the control group). Students in the experimental group were given the education program on cell phone use. The data were analyzed using the SPSS/WIN 19.0 program. Results: Students in the experimental group reported increased knowledge and attitude regarding cell phone use which were significantly higher than students in the control group (p<.001, p<.001). But, self-efficacy and self-control for students in the experimental group were not different from those in the control group. Conclusion: The study results indicate that the education program for cell phone use is effective in increasing knowledge and attitude regarding cell phone use in elementary school students.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.7
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• pp.881-890
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• 2011

Analyses of performance and behavior of the individual PEM fuel cells (PEMFC) under different operating conditions are of importance optimally to design and efficiently to operate the stack. The paper focuses on experimental analyses of a two-cell stack under different operating conditions, which performance and behavior are measured by the voltage of a cell as well as the stack. Experimental parameters include stoichiometric ratio, temperature of the air supplied under different working stack temperatures and loads. Results showed that the cell voltages are dominantly influenced by the temperature of the air supplied among others. In addition, an inherent difference between the first and the second cell voltage exists because of the tolerances of the cell components and the resulting different over-potentials at different equilibrium states. Furthermore, it is shown that the proton conductivity in the membranes conditioned by the humidity in the cathode channel highly affects the voltage differences of the two cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.559-574
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• 1996

The purpose of this study was to determine whether there was any correlation between temporomandibular joint dysfunction and structure of the mandibular condyle. Weanling rats had their masseter muscles resected and immunohistochemical findings were observed with a light microscope. The results obtained were as follows : 1. The condylar cartilage region was divided into articular, proliferating, cartilage cell and hypertrophic cell layers according to cell morphology. 2. In light microscopic views, the proliferating and cartilage cell layers of the experimental group decreased gradually and at the 8th week significantly. 3. In immunohistochemical staining for type I and II collagen, a reaction was detected in the lower part of proliferating cell and cartilage cell layers. In the cartilage cell layers, a stronger cellular reaction was present. Immunohistochemical staining for type II collagen reacted more strongly than that of type I collagen. 4. In immunohistochemical staining for proteoglycan, the staining of the experimental group resembled the control group and gradually showed a weak reaction. The proliferating and cartilage cell layers reacted more strongly than the hypertrophic cell layer. 5. In immunohistochemical staining for proliferating cell nuclear antigen(PCNA), the strong reaction was detected in the nucleus of the proliferating cell layer both in control and experimental groups. But the thickness of the proliferating layer decreased in experimental group, consequently the reaction of the experimental group was reduced more than that of the control group.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.255-259
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• 1993

The efficacy of the autotransfusion system is a reducing the need of intraoperative and postoperative transfusion in cardiovascular surgery. Between January 1990 and December 1991, we experienced 23 cases of autotransfusion using Haemonetic Cell Saver in cardiovascular surgery [Experimental group]. Another 13 cases which were taken similiar operations without Cell Saver during same period [Control group]. The amounts of blood transfused are 4.23 1.84 units in Control group, 2.82 1.84 units in Experimental group. Postoperatively, both groups showed decreased platelet counts, mild prolongation of prothrombin and partial thromboplastin time compred to preoperative value [P<0.001], but there were no significant differences between two group [P=NS]. Plasma hemoglobin was markedly increased in Experimental group compared with Control group [p<0.05]. In Experimental group, amount of average processed blood by Cell Saver was 700ml of which composition was hemoglobin 17mg/dl, hematocrit 50.0%, RBC 5,590,000/ml, WBC 7500/ml, and platelet 40,000/ml. The culture of the processed blood revealed no growth of the organisms. Conclusively, Cell Saver autotransfusion system is a simple, safe, and cost effective method especially in the cases associated with massive bleeding. However, it requires familiarity with system, gentle manipulation of suction tip, and careful selection of candidates to obtain maximal benefits .

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2385-2389
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• 2008

This is the experimental research that tries to explain a variety of RH is how to affect the cell performance and the flooding phenomenon of proton exchange membrane fuel cell (PEMFC). A value of PH changes to 0%, 50% and 90% as its variation, either stoichiometric flow rate changes to 1.5, 2 and 4. Into the comparison between theoretical and experimental value, this study analyzes that a variety of PH is how 10 affect flooding in the cathode of the proton exchange membrane fuel cell. The effect of air stoichiometry, air humidity and different flow fields are also discussed in this paper This study has accomplished the measurement of performance as the variety of RH in the cathode of proton exchange membrane fuel cell, moreover it has recorded the visualization of flooding in the cathode with a high-speed micro camera.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.136-145
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• 2010

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.