• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.115-117
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• 2001

A percentage current differential relaying algorithm is widely used for bus protection. However, it may maloperate external faults with CT saturation. This paper proposes a percentage current differential relaying algorithm for bus protection using CT saturation detecting algorithm. The CT saturation detecting algorithm uses difference of secondary current of CT and detects CT saturation. The proposed method distinguishes percentage differential relay operation caused by faults from percentage differential relay operation caused by CT saturations.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.9
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• pp.446-450
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• 2000

A conventional variable percentage current differential relaying algorithm for bus protection may misoperate for external faults with severe CT saturation and internal faults with high impedance. This paper proposes a percentage differential current relaying algorithm for bus protection combined with a compensating algorithm of secondary currents of CTs. Even though CTs are saturated and their secondary currents are severely distorted, the proposed relaying algorithm does not only misoperate for external faults with CT saturation but also detects the internal faults with high fault impedance. Thus, the method improves the sensitivity of the relays and does not require any counterplan for CT saturation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.1
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• pp.44-49
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• 2003

This paper describes a percentage current differential relaying algorithm for bus protection blocked by a CT saturation detection algorithm. The detection algorithm blocks the output of a current differential relay only if a differential current is caused by CT saturation in the case of an external fault. Moreover, if a current differential relay operates faster than the detection algorithm, the blocking signal is not ignited. On the other hand. if the detection algorithm operates faster than a current differential relay, the output of the relay is blocked. The results of the simulation show that the proposed algorithm can discriminate internal faults from external faults ever when a CT is saturated in both cases. This paper concludes by implementing the algorithm into the TMS320C6701 digital signal processor. The results of hardware implementation are also satisfactory The algorithm can not only increase the sensitivity of the current differential relay but Improve the stability of the relay for an external faults.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.9-11
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• 2002

This paper proposes a percentage current differential relaying algorithm for bus protection using an advanced compensation algorithm of the secondary current of CTs. A percentage current differential relaying algorithm may maloperate in case of external faults with CT saturation. Thus, it needs an additional method to cope with CT saturation. The advanced compensation algorithm is unaffected by a remanent flux. The proposed relaying algorithm does not need any additional methods for CT saturation and is unaffected by the remanent flux and has the wide operating zone of current differential relays.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1139-1141
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• 1999

A variable percentage current differential relaying algorithm is widely used for bus protection. However, it may maloperate in case of high-impedance internal faults and external faults with CT saturation and thus additional method to cope with CT saturation is necessary. This paper proposes a percentage current differential relaying algorithm for bus protection using a compensating algorithm of secondary current of CTs. As the proposed method compensates the distorted secondary currents of CTs it can improves the sensitivity of relays in a large current region and does not need any additional method for CT saturation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.4
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• pp.127-133
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• 1988

This study was performed to obtain the basic data analyzing salt movement and desalinization effects, and two different desalinization experiments through leaching and rinsing were carried out, using samples of silt loam soil and silty clay loam soil collected in reclaimed tidelands. The relationships between the electrical conductivity of saturation extract and the electrical conductivity at various dilutions, and the correlations between electrical conductivity, total salt concentration, exchangeable sodium percentage and pH during the desalinization of reclaimed tidelands, were analyzed by the statistical method. The results obtained from this study were summarized as follows: 1.The sample soils used in this study were saline-sodic soils in accordance with the USDA classi- fication system of salt affected soils. 2.The electrical conductivity of saturation extract could be estimated conveniently, using the electrical conductivity of extract from various different soil-water suspensions. 3.The total salt concentration could be expressed in the electrical conductivity, but there was a little difference by soil textures. 4.The regression analysis showed that the relationship between the electrical conductivity of saturation extract and the exchangeable sodium percentage during the desalinization of reclaimed lands could be described by a linear regression equation. 5.The value of pH showed a tendency to increase according as the exchangeable sodium percentage decreased during the desalinization of reclaimed tidelands.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.3
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• pp.158-164
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• 2003

This paper proposes a percentage current differential relaying algorithm for bus protection using an advanced compensating algorithm of the secondary current of current transformers (CTs). The compensating algorithm estimates the core flux at the start of the first saturation based on the value of the second-difference of the secondary current. Then, it calculates the core flux and compensates distorted currents using the magnetization curve. The algorithm Is unaffected by a remanent flux. The simulation results indicate that the proposed algorithm can discriminate internal faults from external faults when the CT saturates. This paper concludes by implementing the algorithm into a TMS320C6701 digital signal processor. The results of hardware implementation are also satisfactory. The proposed algorithm can improve not only stability of the relay in the case of an external fault but sensitivity of the relay in the case of an internal fault.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.93-97
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• 2012

This study was conducted to evaluate the efficiency of various inorganic and organic materials to improve physical properties of soil. Saline sodic soil (saturation percentage = 40.36%, $EC_e=5.15dS\;m^{-1}$, $pH_s=8.70$, $SAR=18.84(m\;mol\;L^{-1})^{1/2}$, bulk density =$1.49Mg\;m^{-3}$) was collected, brought to wire house and filled in pots after laboratory analysis for various parameters. Different sources of organic nutrients like farm manure (FM), press mud, compost, poultry manure and sesbania green manure were analyzed for their chemical composition. The experiment comprised of 12 treatments replicated thrice; $T_1$: control (recommended NPK), $T_2:{\frac{1}{2}}$ recommended NPK, $T_3$: FM at 1.5% by soil weight, $T_4$: pressmud at 1.5% by soil weight, $T_5$: compost at 1.5% by soil weight, $T_6$: poultry manure at 1.5% by soil weight, $T_7$: sesbania green manure at 1.5% by soil weight, $T_8:T_2$ + FM at 0.75% by soil weight, $T_9:T_2$ + pressmud at 0.75% by soil weight, $T_{10}:T_2$ + compost at 0.75% by soil weight, $T_{11}:T_2$ + poultry manure at 0.75% by soil weight, $T_{12}:T_2$ + sesbania green manure at 0.75% by soil weight. These treatments were applied using completely randomized (CR) design and appropriate time was given to decompose these organic nutritional sources. Seeds of wheat cultivar Sahar-2006 were sown. After harvesting the wheat, soil samples were collected from each pot and analyzed for various physical properties like bulk density, porosity and saturation percentage. An improvement in physical properties (bulk density, porosity and saturation percentage) of soil was noticed with the application of various organic nutritional sources but role of compost alone ($T_5$) remained prominent.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.8-13
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• 2011

A percentage current differential relay is widely used for transformer protection. Because many percentage current differential relays recently use modified methods instead of conventional methods for deciding the operating characteristics of the large current region, in this paper, the operating region of a percentage current differential relay is analyzed in input-output current domain instead of operating-restraint current domain. An effective method to set the operating region when a CT is saturated is proposed with a series of investigations comparing a conventional method with the proposed modified method. The performance of the proposed method is evaluated for internal and external faults of a power transformer having the voltage rating of 345/154kV. EMTP-RV is used for the relaying data collection.

• Journal of Nutrition and Health
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• v.7 no.3
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• pp.1-13
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• 1974

The relative state of human iron storage may be ascertained more reliably through determination of the serum iron, iron binding capacity, transferrin saturation and absorption of radioactive iron in conjunction with studies of red cell morphology than from the study of red cell morphology alone. Recent investigations have shown that there is an increase in red cell protoporphyrin concentration in iron deficiency anemia. The significance of the red cell protoporphyrin has been discussed greatly during the years since its discovery. Two of the main factors which appear to influence the amaunt of protoporphyrin are increased erythropoiesis and factors interfering with the utilization of iron in the synthesis of hemoglobin, and iron deficiency. Recently Heller et al. have described a simplified method for blood protoporphyrin assay and this technique could be used assess nutritional iron status, wherein even minor insufficiencies are detectable as increased protoporphyrin concentrations. Based on the evaluation of the relationship between nutritional iron status and red cell protoporphyrin as an index suitable for the detection of the iron deficiency is described in this paper. RESULTS 1. Hemoglobin Concentrations and Anthropometric Measurements. The mean and standard deviations of the various anthropometric measurements of different age and sex groups are shown in table 1. There measurements have been compared with the Korean Standard. In the absence of local standards for arm circumference and skin-fold thickness over triceps, they have been compared with the standard from Jelliffe. Table 2,3, and 4 give anthropometric measurements and frequency (%) of anemia in children surveyed. The mean height of the children studid was 10 to 20 percent; below the Korean Standard. The distribution of height below 80 percent of the Standard was 21.2 percent, however, among anemic group this percentage was 27.7 percent. In general, the mean weight of the children was 10 to 15 percent below the Korean Standard. The percentage of children with weight less than 80 percent of the Standard was about 35 percent. But in the anemic group of the children, this percentage was 44 percent. The mean arm circumference was about 15 percent lower than the Jelliffe's standard. 61.2 percent of the children had values of arm circumference below 80 percent of the standard. Children with low hemoglobin levels, this percentage was 80 percent. The mean skinfold thickness over the triceps of the children studied was about 25 Percent lower than the Jelliffe's standard and 61.2 percent of the children had the value less than 80 percent of the standard. Among anemic children, this percentage was 70.8%. As may be seen from table 5, the mean hemoglobin concentration of the total group was 11.3g/100ml. Hemoglobin concentration was less than 11.0g/100ml. in 65(36.5%) of the 178 children. The degree of anemia in most of these children was mild with a hemoglobin level of less than 8.0g/100ml. found in only one child. In general, the prevalence of anemia was high in female children than male and decreased its frequency with increasing age. Relatively close relationship was observed between hemoglobin level and anthrophometric measurements especially high between arm circumference and skinfold thickness and hemoglobin but very low in height and low in weight and hemoglobin level, estimated by chi-square value. II. Serum iron, Transferrin saturation (1) Serum iron, and transferrin saturation Serum iron, transferrin saturation and red cell protoporphyrin concentrations were estimated in sub-sample of 84 children from 1 to 6 years and 24 older children between 7 and 13 years of age. The findings are presented in table 6. The mean serum iron concentration of the total group was 59ug/100ml. However, the level incrased with age from 36.6ug/100ml. (1-3years) to 80.8ug/100ml. (7-13 years). 60 percent of these children had a serum iron level less than 50ug/10ml. in the 1-3 years age group and 31.4 percent for 4-6 years group. These contrast with the finding of 12.5 percent anemic children in the 7-13 years age group. The mean transferrin saturation for the total group was 18.1 percent and frequency of anemia by transferrin saturation was observed same pattern as serum iron concentration. (2) Red cell protoporphyrin concentrations. (a) Red cell protoporphrin levels of children: Red cell protoporphyrin and other biochemical data are shown in table 4. The mean concentration in red cell of all children was fround 46.3ug/100ml. RBC. and differences with age groups were observed; in the age group 1-3 years, the mean concentration was $59.5{\pm}32.14$ ug/100ml. RBC; 4-6 years $44.1{\pm}22.57$ ug/100ml. RBC. and 7-13 years, $39.0{\pm}13.56$ ug/100ml. RBC. (b) Normal protoporphyrin values in adults: It was observed that in 10 normal adult males studied here the level of protoporphyrin in red cell ranged from 18 to 54 ug/100ml. RBC. and the mean concentration was $47.5{\sim}14.47$ ug/100ml. RBC. Other biochemical determination made on the same subjects are presented in table 8. (c) Red tell protoporphyrin concentration of occupational blood donors: The results of analyses for red cell protoporphyrin as well as serum iron, transferrin saturation and hemoglobin in the 76 blood donors are presented in table 7 and 8. In this experiment, donors were selected at random, however, most of them bled repeatedly because of poor economic situation, I doubt. Table 9 shows the distribution of red cell protoporphyrin concentration and hemoglobin concentration of occupational donors. The mean hemoglobin value for the total was 11.9 g/100 ml. When iron deficiency anemia is defined as a transferrin saturation below 15%, prevalence of anemia was 47.4 percent and the mean serum iron was 27.1ug/100ml. and red cell protoporphyrin, 168.3ug/100ml. RBC. However, mean serum iron and protoporphyrin concentration of above 15% transferrin saturation were 11.6 ug/100 ml. and 58.8 ug/100 ml. RBC. respectively. The mean Protoporphyrin concentration of non-anemic (above 15% transferrin saturation) donors was slightly higher than the results of normal adult males.