• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.49 no.9
• /
• pp.526-537
• /
• 2000

This paper deals with a sliding mode controller with integral compensation in a magnetic suspension system The control scheme comprises an integral controller which is designed for achieving zero steady-steate error under step disturbance input and a sliding mode controller which is designed for enhancing robustness under plant parametric variations. A procedure is developed for determining the coefficients of the switching plane and integral control gain such that the overall closed-loop system has stable eigenvalues. A proper continuous design signal is introduced to overcome the chattering problem. The performance of a magnetically suspended balance beam using the proposed integral sliding mode controller is illustrated. Simulation and experimental results also show that the proposed method is effective under the external step disturbance and input channel parametric variations.

• Journal of Nutrition and Health
• /
• v.24 no.2
• /
• pp.124-131
• /
• 1991

This study was to examine the effects of dietary protein levels and the sources of protein(animal and plant) on calcium and phosphorus metabo lism in 10 healthy Korean female adults. The 26­d day study consisted of a 6-day adaptation period and lO-day moderate protein(109 N, 550mg Ca) a and IO-day high protein( 14g N, 570mg Ca) pe­r riod. During the experimental period, the subjects w were divided into two groups, either consuming a animal protein diet(75 % animal protein) or plant protein diet(75 % plant protein). Calcium(300 mg) was supplemented to two subjects of each d dict group for the last 4 days. Feces, urine and diet were analyzed nitrogen. calcium and phos­p phorus. The apparent absorption of calcium was significantly increased as the protein intake was inc­r reased from 60g to 90g in animal protein diet. A Average calcium absorption rate was 30% and 46 % from high and moderate levels of animal p protein diet Urinary calcium excretion was not affected by t the amount of the protein intake in both animal and plant protein diet. There was significantly higher urinary calcium excretion(I34mg) in high I level of animal protein diet than that( 83mg) in h high level of plant protein diet. Calcium balance was improved as the protein intake increased and c calcium was supplemented. Phosphorus absorp­t tion was more efficient in the high animal diet(77.81 %) than in the high plant diet(55-65%). The overall results indicate that an increase of protein and calcium supplement in moderate pro­ttein intake can improve calcium balance due to the increase of calcium absorption.

• Molecules and Cells
• /
• v.21 no.1
• /
• pp.147-152
• /
• 2006

Most plant organs develop from meristems. Rice FON1, which is an ortholog of Clv1, regulates stem cell proliferation and organ initiation. The point mutations, fon1-1 and fon1-2, disrupt meristem balance, resulting in alteration of floral organ numbers and the architecture of primary rachis branches. In this study, we identified two knockout alleles, fon1-3 and fon1-4, generated by T-DNA and Tos17 insertion, respectively. Unlike the previously isolated point mutants, the null mutants have alterations not only of the reproductive organs but also of vegetative tissues, producing fewer tillers and secondary rachis branches. The mutant plants are semi-dwarfs due to delayed leaf emergence, and leaf senescence is delayed. SEM analysis showed that the shoot apical meristems of fon1-3 mutants are enlarged. These results indicate that FON1 controls vegetative as well as reproductive development by regulating meristem size.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.4
• /
• pp.77-86
• /
• 2021

In this study, to use as basic data for the organic waste resource energy incentive system, the energy efficiency is evaluated through the mass balance and energy balance calculation results of the anaerobic digester where food waste, food waste leachate and various organic wastes are treated. As a result of the mass balance analysis for 11 biogasification facilities, it was confirmed that 21.1% of process water and 25.7% of tap water were input in large amounts, excluding organic waste. Accordingly, it accounted for 87.6% of the total effluent of linked treated water. In addition, considering that 15.7% of the total input volume is converted to biogas and the average total solids (TS) is 22%, an average material conversion rate of 75% was confirmed. As a result of the energy balance analysis, the energy conversion rate was confirmed to be 78.5% on average by analyzing the biogas calorific value compared to the potential energy of the influent. The average biogas production efficiency including external energy sources for biogas production was 69.4%, and the biogas plant efficiency to which unused effluent energy was applied was 58.9% on average.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.7
• /
• pp.57-69
• /
• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.9
• /
• pp.1228-1232
• /
• 2001

Forty five Soviet Chinchilla rabbits weaned at 35 d of age were fed 5 experimental diets prepared by using oat plant meal ($T_2,\;T_4$) and tall fescue hay ($T_3,\;T_5$) at 25% and 50% level along with control ($T_1$). The gain in body weight at 84 d of age decreased with test material substitution, however, the differences were non significant when compared with oat plant meal and were significant (p<0.05) with tall fescue hay at both the levels. Feed conversion ratio also deteriorated with test material and its increasing proportion and the differences were significant (p<0.05). The performance-index calculated were 42.1, 36.7, 29.4, 33.3 and 18.8 in $T_1,\;T_2,\;T_3,\;T_4$ and $T_5$, respectively. Digestibility of all the organic nutrients decreased significantly (p<0.05) with test material incorporation, as a result nutritive value of the test diets decreased linearly. Nitrogen balance as per cent of intake was higher in oat plant meal substituted diet compared to tall fescue substituted diet. Cost per kg live weight gain was lowest with 50% oat plant meal followed by 25% oat plant meal incorporation. It was highest with tall fescue hay substitution. Nutritive value of oat plant meal as calculated was DCP 5.1%, TDN 35.8% and that of tall fescue hay was DCP 6.5%, TDN 30.8%. Thus, oat plant meal can be substituted safely up to 25% in the feeding regime of weaner rabbits whereas, for tall fescue hay the safe limit is below 25% level and needs to be ascertained.

• Journal of Korea Water Resources Association
• /
• v.37 no.9
• /
• pp.737-744
• /
• 2004

In this study, to evaluate the effect of forest vegetation on the long-term water balance in a watershed, semi-distributed and physically based parameter model, SWAT was applied to the Bocheong watershed, and the variation of hydrological components such as evapotranspiration, surface flow, lateral flow, base flow, and total runoff was investigated with coniferous and deciduous forests, respectively. First, SWAT model was modified to simulate the actual plant growth pattern of coniferous trees which have the uniform value of leaf area index all the seasons of the year. The modified model was applied to the watershed that is assumed to have only one land cover in the whole watershed, and the variation of the water balance components was investigated for each land cover. It was found that coniferous forest affected the increase in evapotranspiration and decrease in runoff more than deciduous forest. However, the age and the density of stand, the location, and soil characteristics and meteorological conditions including the tree species should be also considered to examine the effect more quantitatively and to reduce the uncertainties in simulated output from the hydrological model.

• Journal of Climate Change Research
• /
• v.4 no.3
• /
• pp.235-244
• /
• 2013

Carbon dioxide emission estimation methods consist of four tiers according to the IPCC guideline. In this study, estimated results by tier 3 and tier 4 were compared with the theoretically calculated $CO_2$ emissions based on the mass balance approach for a gas fired power plant between March and May 2011. It was found that the relative differences were upto 17% between the measured emissions by tier 4 and theoretically estimated emissions, while the results of tier 3 were similar to those from theoretically estimated ones. The comparisons suggested the possibility of misestimation due to replacing missing, abnormal, or invalid data in continuous emissions monitoring system. When using only the data without those missing, abnormal, or invalid data, the relative differences decreased somewhat but still showed consistent differences depending on the stack. It is suggested that this differences might be due to the accuracy of the measurement instruments for the tier 4, especially, for the flow rate measurement instrument.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05a
• /
• pp.641-646
• /
• 1998

In order to enhance the dynamic and interactive simulation capability of a system thermal hydraulic code for nuclear power plant, applicability of flow network models in SINDA/FLUIN $T^{™}$ has been tested by modeling feedwater system and coupling to DSNP which is one of a system thermal hydraulic simulation code for a pressurized heavy water reactor. The feedwater system is selected since it is one of the most important balance of plant systems with a potential to greatly affect the behavior of nuclear steam supply system. The flow network model of this feedwater system consists of condenser, condensate pumps, low and high pressure heaters, deaerator, feedwater pumps, and control valves. This complicated flow network is modeled and coupled to DSNP and it is tested for several normal and abnormal transient conditions such turbine load maneuvering, turbine trip, and loss of class IV power. The results show reasonable behavior of the coupled code and also gives a good dynamic and interactive simulation capabilities for the several mild transient conditions. It has been found that coupling system thermal hydraulic code with a flow network code is a proper way of upgrading simulation capability of DSNP to mature nuclear plant analyzer (NPA).

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.3
• /
• pp.223-229
• /
• 1986

These studies were investigated ionic balance of leaves from different stalk positions of tobacco plant (cv. NC82) grown on pots supplied with nitrate salts solution in the phytotrone. The results of studies are summerized as follows: 1. In comparision with the leaves along the stalk positions, lower position contained higher proportion of total cation and total anion including organic acid, but their concentration lessened gradually at the upper stalk. The ratio in amounts of inorganic cations and anions in leaf laminae depended on their stalk positon, being more than three times in the fifth, but becoming about 1.3 in the tenth. 2. Inorganic cations in the laminae were mostly $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$, comprising about 80% of total with the first two regardless of their stalk positions. Among these two ions $Ca^{{+}{+}}$ tended to become higher at lower stalks, while $K^+$ was higher in younger and became lower when leaves got older and/or more number of leaves were emerged. 3. Total cations were balanced with inorganic and organic acid anions. Composition of inorganic and organic anions were different along stalk positions, ionic balance was governed by organic acid anions dominantly in older leaves, but by inorganic anions in the younger leaves. 4. The discrepancy in the balance between total cations and anions was more pronounced in the older leaves containing higher amount of cations and organic acids. It was suggested that discrepancy was due to precipitation of oxalate as Ca-salt which was not dissolved in the methylation solution of measurement employed.