• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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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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• 제5권3호
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• pp.181-188
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• 2019

본 연구에서는 발전시스템의 설계 입출력변수들을 Heat & Mass balance 계산 solver 및 최적화 알고리즘과 연계하고 반복계산 과정을 자동화함으로써 기술 및 경제적 측면을 고려한 최적의 발전시스템 Heat & Mass balance 설계를 도출하는 최적설계 자동화 기법을 개발하였다. 그리고 이에 대한 효과를 분석하기 위하여 발전소 형식별 10종에 대하여 최적설계 기법을 적용한 결과, NPV 및 IRR에 대한 개선 효과를 기대할 수 있었다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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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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• 제5권4호
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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.

• 한국토양비료학회지
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• 제24권2호
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• pp.124-129
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• 1991

Batch 측정법(測定法)은 농약(農藥)의 토양중(土壤中) 흡착량(吸着量) 측정(測定)에 사용되는 가장 일반적인 방법(方法)이다. 이 Batch 측정법(測定法)은 토양용액중(土壤溶液中)의 농약농도변화(農藥濃度變化)로부터 간접적으로 흡착량(吸着量)을 측정(測定)하기 때문에 흡착력(吸着力)이 낮은 토양(土壤)에서는 용액중(溶液中)의 농도변화(濃度變化)가 작아 흡착측정(吸着測定)이 어렵거나 불가능(不可能)하다. 본(本) 시험(試驗)에서는 용액중(溶液中)의 농약(農藥)의 농도(濃度)를 측정(測定)함과 동시(同時)에 토양(土壤)에 흡착(吸着)된 농약(農藥)을 직접 추출하여 흡착량(吸着量)을 측정(測定)하는 방법(方法)을 설정(設定)하고 Mass balance 방법(方法)이라고 이름하였다. 용액중(溶液中) 농도(濃度) 및 토양에 흡착(吸着)된 농약(農藥)을 직접 추출하여 흡착량(吸着量)을 측정(測定)하는데 일정한 임의의 측정오차(測定誤差)를 설정(設定)하고 Batch 방법(方法)과 Mass balance 방법(方法)을 비교(比較)한 가설시험결과(假設試驗結果) Mass balance 방법(方法)이 측정오차(測定誤差)를 크게 줄일수 있을 것으로 판단(判斷)되었다. 이 가설시험(假設試驗)을 Wahiawa 토양(土壤) 0-20cm, 40-60cm, 100-120cm와 Salinas 토양(土壤) 0-15cm, 115-130cm 깊이에서 얻는 5개(個) 토양시료(土壤試料)에서 실증(實證)한 결과(結果) Mass balance방법(方法)은 모든 토양(土壤)에서 측정요차(測定誤差)를 경감(輕減) 시킬수 있었으며, 특(特)히 흡착력(吸着力)이 낮은 Wahiawa 토양(土壤) 100-120cm의 토양(土壤)에서 측정오차(測定誤差)를 크게 줄일 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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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.

• 상하수도학회지
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• 제29권3호
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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.

• 한국소음진동공학회논문집
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• 제18권3호
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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.

• 한국환경과학회지
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• 제22권4호
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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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.