• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.424-428
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• 2007

In the current most tool using heat and mass balance in a coal gasifier is dependent on commercial code such as STANJAN, CHEMKIN. However, in order to keep the self-reliance technology, it is necessary to develop the original design tool available for comprehension and analysis on the spot. So in this study, its own heat and mass balance program is developed on the assumption that the process in a coal gasifier is adiabatic and quasi-equilibrium. The mass balance is calculated by using the chemical equilibrium principle. Also the heat and mass balance according to main operating factors such as temperature, pressure and O2/Coal ratio, was carried in this tool. This heat and mass balance was verified on the basis of the results simulated in STANJAN, commercial codes using similar logic.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.181-188
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• 2019

In this study, the Heat & Mass balance design optimization tool has developed by linking the design input/output variables with the Heat & Mass balance calculation solver and optimization algorithm and also automating the iterative calculation process. As a result of testing this optimization tool for 10 kinds of power plant, it was expected to improve the NPV and IRR compared with general design methods.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.12a
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• pp.63-72
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• 2007

Current estimates of the ice-mass balance over the Greenland and the Antarctica using retrievals of time-varying gravity from GRACE are presented. Two different GRACE gravity data, UTCSR RL01 and UTCSR RL04, are used for the estimates to examine the impact of the relative accuracy of background models in the GRACE data processing for inter-annual variations of GRACE gravity data. In addition, the ice-mass balance is appraised from the conventional GRACE data, which represents global gravity, and the filtered GRACE data, which isolates the terrestrial gravity effect from GRACE gravity data. The former estimate shows that there exists similar negative trends of ice-mass balance over the Greenland from UTCSR RL01 and UTCSR RL04 while the time series from the both GRACE data over the Antarctica differ significantly from each other, and no apparent trends are observed. The result for the Greenland from the latter calculation is similar to the former estimate. However, the latter calculation presents positive trends of ice-mass balance for the Antarctica from both GRACE data. These results imply that residual oceanic geophysical signals, particularly for ocean tides, significantly corrupt the ice-mass estimate over the Antarctica as leakage error. In addition, the spatial alias of GRACE is likely to affect the ice-mass balance because the spatial spectrum of ocean tides is not conserved via GRACE sampling, and thus ocean tides contaminate terrestrial gravity signal. To minimize the alias effect, I suggest to use the combined gravity models from GRACE, SLR and polar motion.

• Journal of Sport and Applied Science
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• v.5 no.4
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• pp.1-8
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• 2021

Purpose: Sarcopenia is defined as a decrease in muscle mass, strength, and function with age that affects overall body function. We aimed to investigate the effect of combined training on body composition, balance, and muscle function in sarcopenia elderly. Research design, data, and methodology: Twenty-eight sarcopenia elderly (age 74.9±4.5 years) were randomly assigned to an exercise, EG (n=14), or a control, CG (n=14), group. The EG performed an intervention consisting of combined exercise training (60-75 min) for a total of 12 weeks, three times a week. The CG maintained their usual daily lifestyle during the intervention period. We measured body weight, body mass index (BMI), % body fat, free fat mass, balance ability, peak torque in shoulder, knee, and lumbar joints normalized for bodyweight in one second. Results: The EG showed improved body composition (i.e., BMI, fat-free body mass, fat mass; all p < 0.031, η² > 0.179), balance (i.e., right and left of static and dynamic balance and fast 10 m walk; all p < 0.049, η² > 0.152), and muscular function (i.e., 90°/sec and 180°/sec peak power per kg bodyweight, 90°/sec average power per kg bodyweight, 180°/sec total work, and 180°/sec endurance ratio; all p < 0.045, η² > 0.158). Conclusions: Combined exercise training improves muscle mass and strength, body composition, balance, and muscle function in sarcopenia elderly.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.124-129
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• 1991

A mass balance method which measures directly both the sorbed pesticide and equilibrium solution concentration was compared with the batch method in a hypothetical experiment to determine the precision of sorption measurement. The mass balance method was shown to improve precision of sorption measurement. The two methods were also tested experimentally on the Wahiawa soil, 0-20, 40-60 and 100-120 cm, and Salinas soil, 0-15 and 115-130 cm. The mass balance method greatly improved precision of sorption measurement on the deep Wahiawa subsoil having the lowest sorption. The coefficient of variation (CV) for $K_d$ measurement was 20.3% for the batch method and 8.4% for the mass balance method. For other soil samples tested, precision of the batch method was relatively high but was still improved by the mass balance method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.314-319
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• 2006

Main focus on balance shaft module is to reduce the vibration triggered from engine block and compensate it from unbalance mass in balance shaft. Since the performance of balance shaft module is controlled by rotor shape including unbalance mass, a design strategy on rotor is key issue on determine the quality of balance shaft system. Even the design result on balance shaft mostly affect the lay-out of housing and other related components, its issue on balance shaft should be considered in advance throughout the total design procedure. In this paper, optimal design strategy focused on balance shaft is presented to make a design process efficiently with ensuring its high performance. And its method is verified with field design process of balance shaft in commonly adapted vehicle with 3-cylinder and 4-cylinder engine.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.427-436
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• 2015

Developing two process models to simulate wastewater treatment process is needed to draw a comparison between measured BOD data and estimated process model data: a mathematical model based on the process mass-balance and an ANN (artificial neural network) model. Those two types of simulator can fit well in terms of effluent BOD data, which models are formulated based on the distinctive five parameters: influent flow rate, effluent flow rate, influent BOD concentration, biomass concentration, and returned sludge percentage. The structuralized mass-balance model and ANN modeI with seasonal periods can estimate data set more precisely, and changing optimization algorithm for the penalty could be a useful option to tune up the process behavior estimations. An complex model such as ANN model coupled with mass-balance equation will be required to simulate process dynamics more accurately.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.3
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• pp.277-283
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• 2008

Balance shaft module contributes to reduce the engine-born vibration by compensating it from a unbalance mass with opposite phase but practically, this device has some problems during the operation in a high speed owing to the considerable amount of unbalance mass that leads to the large quantity of bending deformation as well as torque fluctuation at the balance shaft. To tackle two main problems, the design strategy on balance shaft is suggested by addressing the optimal location of unbalance mass and supporting hearing based on the formulation of objective function that minimizes critical issues, both bending deformation as well as torque fluctuation. The boundary condition of balance shaft assumes to be free such that any external force or contact component is not taken into consideration in this study.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.425-433
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• 2013

A mass balance of process was calculated by using the analysis of basic unit and environmental assessment of all the processes of Busan fashion color industry cooperative that operates a combined heat and power plant and a bio treatment plant. The mass balance for the combined heat and power plant was done, based on boiler and water treatment processes while each unit reactor was used for the bio treatment plant. From the results above, a resource recycle network, a treatment flowchart for food waste water/wastewater treatment and a carbon reduction program were established.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.801-806
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• 2008

Large quantity of bending deformation as well as rotating torque fluctuation at the balance shaft are main struggles during the operation in a high speed rotation and thereby, two issues should be cleared at the design process of balance shaft module. Since two issues are highly related with balance shaft itself and particularly much sensitive to the location of both supporting bearing and unbalance mass, the design strategy on balance shaft should be investigated at the aspect of controlling two critical issues at the early stage of balance shaft design. To tackle two main problems, the formulation of objective function that minimizes critical issues, both bending deformation as well as torque fluctuation, is suggested to derive the optimal information on balance shaft. Then, optimal informations are reviewed at the practical logics and the guideline at the selection of locations, both supporting bearing and unbalance mass, is addressed at the final chapter.