• Title/Summary/Keyword: Balance coefficients

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Analysis for water cycle change using SWAT model and water balance analysis depending on water reuse in urban area (SWAT모델과 물수지분석을 이용한 물재이용에 의한 도시물순환 변화 분석)

  • Kim, Young-Ran;Hwang, Seong-Hwan;Lee, Sung-Ok
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.4
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    • pp.447-457
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    • 2015
  • Water cycle within the human civilization has become important with urbanization. To date, water cycle in the eco-system has been the focus in identifying the degree of water cycle in cities, but in practicality, water cycle within the human civilization system is taking on an increasing importance. While in recent years plans to reuse water have been implemented to restore water cycle in cities, the effect that such reuse has on the entire water cycle system has not been analyzed. The analysis on the effect that water reuse has on urban areas needs to be go beyond measuring the cost-savings and look at the changes brought about in the entire city's water cycle system. This study uses a SWAT model and water balance analysis to review the effects that water reuse has on changes occurring in the urban water cycle system by linking the water cycle within the eco-system with that within the human civilization system. The SWAT model to calculate the components of water cycle in the human civilization system showed that similar to measured data, the daily changes and accumulative data can be simulated. When the amount of water reuse increases in urban areas, the surface outflow, amount of sewer discharge and the discharged amount from sewage treatment plants decrease, leading to a change in water cycle within our human civilization system. The determinant coefficients for reduced surface outflow amount and reduced sewer discharge were 0.9164 and 0.9892, respectively, while the determinant coefficient for reduced discharge of sewage treatment plants was 0.9988. This indicates that with an increase in water reuse, surface flow, sewage and discharge from sewage treatment plants all saw a linear reduction.

Nutrient Requirements of Exercising Swamp Buffalo, Bubalus bubalis, from Materials Balance and In Vivo Body Composition by the Body Density Method. I. Aspects of Energy and Protein Metabolism in Working Cows

  • Mahardika, IG.;Sastradipradja, D.;Sutardi, T.;Sumadi, IK.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.605-612
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    • 2000
  • Four young swamp buffalo cows of similar age ranging in weight between 280 to 380 kg and trained to do physical work were used in a study to determine energy and protein requirements for draught using a $4{\times}4$ Latin square designed experiment. The experiment consisted of field trials employing 4 levels of work load, e.g. no work as control, and loads amounting 450 to 500 Newton (N) pulled continuously for 1, 2 and 3 h daily for 14 consecutive days. Cows were fed king grass (Penisetum purpuroides) ad libitum and were subjected to materials balance trials. Body composition was estimated in vivo by the body density method and daily energy expenditure (EE) was calculated from ME minus retained energy (RE). The results show that EE while not working ($EE_{resting}$) was $0.42kgW^{0.75}MJ/d$ and maintenance ME ($ME_m$) was $0.37kgW^{0.75}MJ/d$. ME requirement increased to 1.65 times maintenance for the work of 3 hours. The energy expended for doing exercise ($E_{exercise}$) was 9.56, 20.0 and 25.86 MJ/cow for treatments 1, 2 and 3 II, respectively. Fat retention was absent in all groups of working cows, but protein retention was only negative for cows undertaking 3 h work. The relationship between $E_{exercise}$ (MJ), work load (F, kN), work duration (t, h) and body mass (W, kg) was found to be: $E_{exercise}=(0.003F^{1.43}t^{0.93})/W^{0.09}MJ$. The maintenance requirement for digestible protein was $2.51kgW^{0.75}g/d$, whereas digestible protein for growth ($DP_{growth}$) and for work ($DP_{work}$) followed the equations: $DP_{growth}=[(258+1.25W^{0.75}){\Delta}Wkg/d]g$ and $DP_{work}=[12.59e^{0.95t}]g$, respectively The coefficients a, b and c for the calculation of $E_{exercise}$ components according to the Lawrence equation were found to be 2.56 J/kgW.m, 5.2 J/kg load carried.m and 0.29, respectively, thus efficiencies to convert ME into work were 0, 16.09, 27.3 and 32.44% for control, 1, 2 and 3 h/d work, respectively. ME and DP requirements for a 250 to 400 kg working buffalo cow allowing to growth up to 0.5 kg/d are presented.

Thermodynamic Analysis of a Double-Effect Absorption Heating System Using Water-LiCl-$CaCl_2-Zn(NO_3)_2$ Solution at Solar Evaporator Heating (LiCl-$CaCl_2-Zn(NO_3)_2$ 수용액을 사용하는 흡수 2중효용 시스템에서 태양열을 증발기 열원으로 사용하는 난방기의 열역학적 해석)

  • Won, Seung-Ho
    • Journal of the Korean Solar Energy Society
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    • v.27 no.3
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    • pp.87-94
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    • 2007
  • In this paper, with water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture which utilizes solar energy at the evaporator heat source, a thermodynamic analysis was performed to provide design data for a double-effect absorption heating system. A comparative study of the water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture against the water-LiBr pair was conducted by a computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the heating COP is higher for the water-LiCl-$CaCl_2-Zn(NO_3)_2$ mixture than for the water-LiBr pair, and FR is lower for the former.

Thermodynamic Analysis of a Double-Effect Absorption Heating System Using Water-LiBr- LiSCN Solution As $20{\sim}40^{\circ}C$ Range Solar Evaporator Heating (태양열을 증발기 열원으로 사용($20{\sim}40^{\circ}C$범위)하며 LiSCN+LiBr 수용액을 사용하는 흡수식 2중효용 난방시스템의 열역학적 해석)

  • Won, Seung-Ho
    • Journal of the Korean Solar Energy Society
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    • v.26 no.4
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    • pp.73-81
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    • 2006
  • In this paper, with water-LiBr-LiSCN mixture which utilizes solar energy as mid temperature range evaporator heat source, a thermodynamic analysis was performed to provide design data for a double-effect absorption heating system. A comparative study of the water-LiBr-LiSCN mixture against the water-LiBr pair was conducted by a computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the heating COP is higher for the water-LiBr-LiSCN mixture than for the water-LiBr pair, and FR is lower for the former.

A Study on the Influence Affect of Thermal Sensation in Korean and Japanes to Sit Directly on a Heated Floor (바닥난방시 바닥 접촉면에 의한 한국인과 일본인의 온열감 반응에 대한 비교 연구)

  • Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.1
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    • pp.81-89
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    • 2002
  • The objective of this paper is to clarify the combined effect of heat conduction, air temperature and thermal radiation on the person seated on the floor under operation of floor heating system. Experiments were conducted for summer seasons under 8 kinds of condition: combinations of air temperature $20^{\circ}C$, $22.5^{\circ}C$ and floor temperature $20^{\circ}C$, $22.5^{\circ}C$, $30^{\circ}C$, $35^{\circ}C$ and $40^{\circ}C$ under still air. Japanese and Koreans were adopted as subjects. To evaluate the effect of conduction operative temperature modified by heat conduction was derived from the human heat balance equation. New weighting coefficients were estimated from the modified operative temperature and modified mean skin temperature. As for thermal sensation the modified operative temperature more significantly correlated to that sensation each heat transfer processes. As the floor temperature is higher, the human conduction heat gain from floor increase and the dry heat from the human body decrease.

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Rule-Based Fuzzy-Neural Networks Using the Identification Algorithm of the GA Hybrid Scheme

  • Park, Ho-Sung;Oh, Sung-Kwun
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.101-110
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    • 2003
  • This paper introduces an identification method for nonlinear models in the form of rule-based Fuzzy-Neural Networks (FNN). In this study, the development of the rule-based fuzzy neural networks focuses on the technologies of Computational Intelligence (CI), namely fuzzy sets, neural networks, and genetic algorithms. The FNN modeling and identification environment realizes parameter identification through synergistic usage of clustering techniques, genetic optimization and a complex search method. We use a HCM (Hard C-Means) clustering algorithm to determine initial apexes of the membership functions of the information granules used in this fuzzy model. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are then adjusted using the identification algorithm of a GA hybrid scheme. The proposed GA hybrid scheme effectively combines the GA with the improved com-plex method to guarantee both global optimization and local convergence. An aggregate objective function (performance index) with a weighting factor is introduced to achieve a sound balance between approximation and generalization of the model. According to the selection and adjustment of the weighting factor of this objective function, we reveal how to design a model having sound approximation and generalization abilities. The proposed model is experimented with using several time series data (gas furnace, sewage treatment process, and NOx emission process data from gas turbine power plants).

A Study on the Limitation and Improvement of Simple Window Model applied to EnergyPlus (EnergyPlus에 적용된 Simple Window Model의 한계와 개선에 관한 연구)

  • Kim, Tae Ho;Ko, Sung Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.10
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    • pp.515-529
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    • 2017
  • EnergyPlus, which is widely used in various fields, provides Simple Window Model, a window model that can be used practically. However, the results of building load using the model are different from those of the standard model. The main cause of the deviation by Simple Window Model was analyzed to be due to the assumption that all windows were considered as single layer. The purpose of this study is to propose a window model that improves the cause of deviation by Simple Window Model and can be easily calculated from the algebraic relations. The proposed window model solved the heat balance equation algebraically by using seven window characteristic coefficients. The coefficient relationships consisted of the heat transmission coefficient and solar heat gain coefficient as input parameters make practical use and calculation possible. As a result of comparing the deviation between each window model by implementing the dynamic analysis method, the proposed window model showed that the deviation of the total heating/cooling energy consumption was reduced to 1/3 compared to Simple Window Model for one year. Although the maximum energy consumption did not show any significant improvement, the indoor temperature evaluation showed significantly reduced deviation.

Relations among Health Behaviors, Health Symptoms and Physical Fitness of People in the Same Community (일지역주민의 체력에 영향을 미치는 요인 - 신체증상과 건강행위를 중심으로 -)

  • Bae, Sun-Hyoung
    • Research in Community and Public Health Nursing
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    • v.18 no.2
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    • pp.211-222
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    • 2007
  • Purpose: This study was conducted to identify relations among health behaviors, health symptoms and physical fitness of people in the same community. Method: The study was designed as a descriptive survey and the participants were 1,621 healthy people. Data were collected from March to December, 2003 using a structured questionnaire on health behaviors, health symptoms and physical fitness. Data were analyzed by descriptive statistics, $\chi^2$-test, t-test, two-way ANOVA, Pearson correlation coefficients and multiple regression using SPSS/PC. Results: The result of multiple regression showed that sex, age, and BMI were related to physical fitness. In health-related physical fitness, regular exercise was related to cardiorespiratory endurance and flexibility, and daily caffeine intake was related to muscular endurance. In performance-related physical fitness, having breakfast regularly was related to power, daily caffeine intake was related to agility, and regular lifestyle and health symptoms were related to balance. Conclusion: In conclusion, this study suggests that for better physical fitness, nursing strategies and intervention programs should include physical fitness-related factors, and education programs should be developed based on the above parameters to promote positive perception of physical fitness.

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Numerical Study on Pulverized Coal Combustion Applying Two-Phase WSGGM (이상 회체가스 가중합산모델을 적용한 미분탄 연소의 수치적 연구)

  • Yu, Myoung-Jong;Kang, Shin-Jae;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.10
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    • pp.1368-1379
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    • 2000
  • A numerical study on swirling pulverized coal combustion in an axisymmetric enclosure is carried out by applying the 2-phase weighted sum of gray gases model (WSGGM) approach with the discrete ordinate method (DOM) to model the radiative heat transfer equation. In the radiative transfer equation, the same polynomial equation and coefficients for weighting factors as those for gas are adopted for the coal/char particles as a function of partial pressure and particle temperature. The Eulerian balance equations for mass, momentum, energy, and species mass fractions are adopted with the standard and RNG k-${\varepsilon}$ turbulence model, whereas the Lagrangian approach is used for the particulate phase. The eddy-dissipation model is employed for the reaction rate for gaseous mixture, and the single-step and two-step first-order reaction model for the devolatilization process for coal. Special attention is given to establish the thermal boundary conditions on radiative transfer equation By comparing the numerical results with experimental ones, the radiation model used here is confirmed and found to provide an alternative for simulating the radiative transfer.

An Exploratory Study of Hope Structures of the Newly Diagnosed Cancer Patients (진단 초기 암환자의 희망구조 파악을 위한 탐색적 연구)

  • Park, Moon-Kyoung;Kim, Dal-Sook
    • Asian Oncology Nursing
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    • v.9 no.2
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    • pp.114-121
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    • 2009
  • Purpose: This study was to explore the hope structures of the newly diagnosed cancer patients by examining the relationships between hope and the three concepts of 'Personal Spirit', 'Risk' and 'Authentic Caring' which composed the multidimensions of the Nekolaichuk and Bruera's hope model. Methods: Data was collected via survey from 32 newly diagnosed cancer patients. The perceived meaning of life (PML) for 'personal spirit', perceived confidence in cure (PCC) for 'risk', and perceived family support (PFS) and perceived support from medical team (PSM) for 'authentic caring' were adapted from the definitions of the concepts in the model. Hope, PML, and PCC were measured with VAS. PFS and PSM were measured with Korean version of 'Cobb's family support scale', which was modified by Kang. Pearson correlation coefficients were used to identify the relationships among the concepts. Results: The significant relationships were revealed between hope and PCC (p<.001), hope and PML (p<.001), PML and PCC (p<.001), PFS and PML (p=.030), and PSM and PML (p=.047). Conclusion: The newly diagnosed cancer patients experience hope in different ways. The cancer patients' hope immediate after diagnosis, however, is most likely to be experienced as seeking balance between uncertainty about cancer treatment and the meaning of life.

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