• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.47-49
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• 1993

The squirrel cage three-phase induction motor has been used in all types of industry for a number of years. A series of noise components were identied analytically from the expressions for the node numbers and frequencies of the magnetic force waves, taking into account the stator and rotor sldtting, eccentricity, asymmetric and iron saturation. A method is presented for calculating the magnetic energy distribution of eccentrical and asymmetric the squirrel cage induction motor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2391-2395
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• 2009

Active control schemes which modify the excitation to correct for any of the nonideal characteristics of the SPMSM is described. Especially, because of design limitations(size and cost) in automobile, the back-EMF of SPMSM can't be perfectly designed with sinusoidal wave and iron core of stator is saturated so that torque ripple is unavoidable. An active cancellation method of the pulsating torque components which would otherwise be generated using the classic sinusoidal current excitation is illustrated.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1143-1146
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• 1993

The magnetic properties of aluminium anodized film in which Co-Fe alloy electrodeposited are investigated with regard to the alloy composition of magnetic films. The electrodeposited Co-Fe particles are confirmed to be single phase Co-Fe alloys by X-ray diffractions. The coercive force as well as the magnetic anisotropy energy can be controlled by changing the composition of the alloy. Magneticfilms having high saturation magnetization and high coercive force were obtained.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.343-350
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• 1995

An overview will be given on recent Mossbauer and magnetization investigation of the applied field dependence of the magnetic properties of typical systems without strong magnetic anisotropy and showing the absence of magnetic saturation in high fields (including iron-rich spin glass (amorphous $Fe_{93}Zr_{7}$, soft ferromagnets (amorphous $Fe_{88}Zr_{12}$, $Fe_{70}Ni_{20}Zr_{10}$ and $Fe_{88}B_{12}$) and pure Fe). The results emphasize that shape anisotropy due to surface irregularities causes misalignment between the magnetization and the applied field in the otherwise collinear magnetic structure.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.14-15
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• 2002

Iron nitride alloy films prepared in the form of laminated ${(Fe_{97}Al_3)}_{85}N_{15}/Al_2O_3$ multilayers (Ml's) due to excellent soft magnetic properties and high saturation magnetization [1, 2] are very promising materials for poles and shields in ultra high density thin film heads. The present work concerns the ferromagnetic (FM) coupling effect as a function of the thickness of $Al_2O_3$ spacers by analysis of the magnetic domain structure.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.362-369
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• 2002

Background : Anemia is still the most common nutrient deficiency worldwide, especially in adolescence because of an insufficient supply of iron, an increased iron requirement due to accelerated physical growth and blood loss due to menstruation in girls. This study was designed to assess the anemia and serum iron status of middle school girls. Methods : Hematologic examinations, physical examinations and questionnaires were performed for middle school girls in 1990, 1997, 1999 and 2000. Anemia was defined as a serum hemoglobin level of less than 11.5 g/dL. Iron deficiency was defined as a serum ferritin level of less than 10 ng/mL. Iron deficiency anemia was defined as anemia plus one of the following; MCV less than 78 fL, Ferritin level less than 10 ng/mL or Transferrin saturation rate less than 10%. Results : There was no significant difference in mean Hb between urban and rural areas and decreases in mean Hb as with age. The prevalence of anemia decreased by year; 13.5% in 1990, 6.9 % in 1997, 6.0% in 1999, and 5.7% in 2000. It was high in high school girls(10.1% in 1997 and 12.6% in 2000). The prevalence of iron deficiency decreased by year; 36.1% in 1990, 13.9% in 1997, 13.3% in 1999, and 23.2% in 2000. It was 21.3% in 1997 high school girls and 37.8% in 2000. The prevalence of iron deficiency anemia(IDA) decreased by year; 10.0% in 1990, 4.6% in 1997, 8.3% in 1999, and 6.1% in 2000. It was 11.6% in 1997 high school girls and 18.6% in 2000. Conclusion : Although the prevalence of iron deficiency decreased during this period, the prevalence of anemia in the elder adolescence girls was high. Two things are recommended; first, it is necessary to screen for anemia in middle school girls and high risk groups, second, it is important to evaluate the knowledge of nutrition and to enforce effective nutritional education, leading to subjects receiving adequate nutrition.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.273-281
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• 2018

Background: Ferritin is used to detect iron overload in patients with chronic red blood cell transfusions. Although ferritin reflects the amount of iron storage in the body, it may increase nonspecifically in inflammation and infection. This study analyzed the cause of increased ferritin and the association with a red blood cell (RBC) transfusion. Methods: The medical records of patients who visited the authors' hospital from January to December 2017 and underwent a ferritin test were reviewed retrospectively. Hyperferritinemia was defined as a ferritin level more than 1,000 ng/mL. The causes of hyperferritinemia were investigated by examining the laboratory findings and medical records. Results: The results revealed 417 cases of hyperferritinemia in 238 patients during the period. The most common diseases were hematologic malignancies from 125 cases (30.0%) in 31 patients and infectious diseases were the second most common. Iron overload was suspected in 119 cases in 33 patients, and 12 patients (76 cases) were transfused with more than 8 units of RBC for 1 year before the test. Conclusion: In hyperferritinemia, the rate of iron overload is high considering the underlying diseases and chronic RBC transfusion. To determine iron storage status accurately, it will be helpful to measure the C-reactive protein (CRP) and iron saturation in the ferritin test. Careful attention should be paid to habitual iron formulations and frequent transfusions due to the possibility of iron overload.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.29-34
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• 2007

The fault current limiting characteristics of a flux-lock type superconducting fault current limiter(SFCL) according to fault angles were investigated. From the electrical equivalent circuit with the magnetization branch, the inner magnetic flux of this SFCL due to fault angles was induced and its effect on the limited fault current was analyzed. From the fault current limiting experiments, the exciting current, which described the saturation of the iron core, was calculated and its dependence on the fault angle was analyzed. Before the fault happened, the exciting current did not happen, that it kept zero value. However, after the fault happened, the exciting current flowed and, the exciting current in case of the additive polarity winding showed higher value than for the case of the subtractive polarity winding. The analysis results were compared with the experimental ones, and experimental results agreed with the analysis ones.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.203-206
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• 2001

The effects of SrTiO$_3$ addition and sintering temperature on the microstructure and magnetic properties of yttrium iron garnet (YIG) were investigated. The lattice Parameter increasing of sintered YlG with small amount of SrTiO$_3$ addition was supposed to be substituted $Y^{+3}$, Fe$^{+3}$ ions to Sr$^{+2}$,Ti$^{+4}$ ions which are relatively large in ionic ranius. A YIG specimen sintered at 142$0^{\circ}C$ with 0.2mol% SrTiO$_3$ showed above 98% densification of theoretical density. Saturation magnetization (M$_s$) at room temperature decreased a little bit with increasing SrTiO$_3$, addition but no great chance. In addition, the coercivity (H$_c$) was almost not changed by sintering temperature.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.3
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• pp.302-314
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• 1999

This study was conducted to evaluate nutrient intake, indices of anemia, serum lipids, and their correlations in 40 Korean female college students aged 21 to 25 years. Fasting blood samples were collected in October. 1997 Nutrient intake was investigated by 24-hour recall method for three days. Anthropometric measurements, blood pressure, iron status and serum lipids of the subjects were determined. The mean values for age. height, weight, BMI and blood pressure of the subjects were 22.1 years, 160.6cm, 54.4kg and 109.1/66.9mmHg, respectively. According to the body composition analysis, total body water, % body fat, lean body mass and WHR were 26.7L. 29.5%, 36.5kg and 0.8, respectively. Average daily intake of energy was 1,858.4kcal. Protein, phosphorus, vitamin B$_1$, vitamin B$_2$, niacin and vitamin C intakes were higher than the Korean recommended dietary allowence(RDA), whereas calcium, iron, vitamin A intakes were tower than that. Hemoglobin(Hb), hematocrit(Hct), serum iron(SI) and total iron binding capacity(TIBC) were measured and transferrin saturation (TS%) was calculated from serum. The mean values for Hb, Hct, SI, TIBC and TS were 13.6$\mu\textrm{g}$/㎗, 41.6%,97.8$\mu\textrm{g}$/㎗, 319.6$\mu\textrm{g}$/㎗ and 31.9%, respectively. The Prevalence rates of iron deficiency assessed by Hb and Hct were found to be 10% and 2.5%, respectively. However, when assessed with TIBC, the prevalence rate of iron deficiency was increased to 32.5%. The mean values for serum triglyceride(TG), total cholesterol(TC), HDL-Chol, LDL-Chol concentrations and atherogenic index(AI) were 154.7mg/㎗, 80.0mg/㎗, 47.4mg/㎗, 91.3mg/㎗ and 2.6, respectively. Correlations among indices of anemia. there were positive correlations between Hb and Hct, between SI and TS : negative correlations between TIBC and TS or SI. Correlations among serum lipids, there were positive correlations between TC and TG or LDL-cholesterol. Energy intakes were correlated positively with TIBC(p＜0.05), and vitamin C intakes negatively correlated with Hb(P＜0.05). And vitamin A intakes were negatively correlated with TG(p＜0.01). TC(p＜0.05) and LDL-Chol(p＜0.01). Hb negatively correlated with TG(P＜0.05). Body weights(p＜0.05), lean body mass(p＜0.05) and total body water(p＜0.01) werenegatively correlated with Hb. BMI and WHR correlated with TG and TC(p＜0.01). These results indicated that subjects with higher energy intake and overweight had a tendency to have iron deficiency. Increases in BMI and WHR were related to increases in serum lipids levels and decreases in TIBC. The results also showed that serum lipids were decreased when vitamin A and iron intakes were sufficient.