• Title/Summary/Keyword: Environmental variable

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A Study on Environmental and Economic Cost Analysis of Coal Thermal Power Plant Comparing to LNG Combined Power Plant (석탄화력발전대비 LNG복합화력발전 환경성 및 경제성 비용분석에 관한 연구)

  • Kim, Jong-Won
    • Asia-Pacific Journal of Business
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    • v.9 no.4
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    • pp.67-84
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    • 2018
  • This study is about comparing coal thermal plant to LNG combined power plant in respect of environmental and economic cost analysis. In addition sensitive analysis of power cost and discount rate is conducted to compare the result of change in endogenous and exogenous variable. For environmental assessment, when they generate 10,669GWh yearly, coal thermal power plant emits sulfur oxides 959ton, nitrogen oxide 690ton, particulate matter 168ton and LNG combined power plant emits only nitrogen oxide 886ton respectively every year. Regarding economic cost analysis on both power plants during persisting period 30 years, coal thermal power plant is more cost effective 4,751 billion won than LNG combined taking in account the initial, operational, energy and environmental cost at 10,669GWh yearly in spite of only LNG combined power plant's energy cost higher than coal thermal. In case of sensitive analysis of power cost and discount rate, as 1% rise or drop in power cost, the total cost of coal thermal power plant increases or decreases 81 billion won and LNG combined 157 billion won up or down respectively. When discount rate 1% higher, the cost of coal thermal and LNG combined power plant decrease 498 billion won and 539 billion won for each. When discount rate 1% lower, the cost of both power plant increase 539 billion won and 837 billion won. With comparing each result of change in power cost and discount rate, as discount rate is weigher than power cost, which means most influential variable of power plan is discount rate one of exogenous variables not endogenous.

Characterizing nonlinear oscillation behavior of an MRF variable rotational stiffness device

  • Yu, Yang;Li, Yancheng;Li, Jianchun;Gu, Xiaoyu
    • Smart Structures and Systems
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    • v.24 no.3
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    • pp.303-317
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    • 2019
  • Magneto-rheological fluid (MRF) rotatory dampers are normally used for controlling the constant rotation of machines and engines. In this research, such a device is proposed to act as variable stiffness device to alleviate the rotational oscillation existing in the many engineering applications, such as motor. Under such thought, the main purpose of this work is to characterize the nonlinear torque-angular displacement/angular velocity responses of an MRF based variable stiffness device in oscillatory motion. A rotational hysteresis model, consisting of a rotatory spring, a rotatory viscous damping element and an error function-based hysteresis element, is proposed, which is capable of describing the unique dynamical characteristics of this smart device. To estimate the optimal model parameters, a modified whale optimization algorithm (MWOA) is employed on the captured experimental data of torque, angular displacement and angular velocity under various excitation conditions. In MWOA, a nonlinear algorithm parameter updating mechanism is adopted to replace the traditional linear one, enhancing the global search ability initially and the local search ability at the later stage of the algorithm evolution. Additionally, the immune operation is introduced in the whale individual selection, improving the identification accuracy of solution. Finally, the dynamic testing results are used to validate the performance of the proposed model and the effectiveness of the proposed optimization algorithm.

Development of Prediction Model for Renewable Energy Environmental Variables Based on Kriging Techniques (크리깅 기법 기반 재생에너지 환경변수 예측 모형 개발)

  • Choy, Youngdo;Baek, Jahyun;Jeon, Dong-Hoon;Park, Sang-Ho;Choi, Soonho;Kim, Yeojin;Hur, Jin
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.3
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    • pp.223-228
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    • 2019
  • In order to integrate large amounts of variable generation resources such as wind and solar reliably into power grids, accurate renewable energy forecasting is necessary. Since renewable energy generation output is heavily influenced by environmental variables, accurate forecasting of power generation requires meteorological data at the point where the plant is located. Therefore, a spatial approach is required to predict the meteorological variables at the interesting points. In this paper, we propose the meteorological variable prediction model for enhancing renewable generation output forecasting model. The proposed model is implemented by three geostatistical techniques: Ordinary kriging, Universal kriging and Co-kriging.

Consolidation Analysis of Geotextile Tubes Filled with Highly Compressible Sludge Using Variable Coefficients of Consolidation

  • Kim, Hyeongjoo;Kim, Hyeongsoo
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.12
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    • pp.25-32
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    • 2021
  • Geotextile tube technology has been perceived as an economical solution for liquid sludge treatment, and analyzing its consolidation behavior is necessary to be able to evaluate the dewatering capabilities of large geotextile tubes filled with contaminated soil, tailings, sewage sludge, and so on. The objectives of this study are to present a method that can adequately convey the consolidation behavior of geotextile tubes filled with sewage sludge, and to investigate the effects of various geotextile tube consolidation parameters. In this study, variable coefficients of consolidation are utilized to analyze the consolidation process of geotextile tubes filled with sewage sludge. The consolidation solution was verified by comparing the measured and predicted data from a hanging bag test conducted in the literature. After verifying the proposed solution, the consolidation parameters of a geotextile tube composed of a woven polypropylene outer layer and a non-woven polypropylene layer filled sewage sludge were obtained. Using the obtained parameters, the consolidation behavior of a large-scale composite geotextiles tube was predicted.

Study on Hospital Environmental Causes Affected the Mother′s Comfort After Her Child Birth (산욕부 안위에 영향을 미치는 병원환경 요인에 관한 연구)

  • 변수자
    • Journal of Korean Academy of Nursing
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    • v.8 no.1
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    • pp.1-15
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    • 1978
  • The Purpose of this study is to examine closely the causes influenced upon the comfort and recovery of the woman delivered of a child in the hospital at the same time to understand environmental status of hospitals in order to promote mother's health recovery, and to improve hospital environment by emphasizing the meaning of environment and health before the medical staff and hospital administrative authority. In the method of servery of the research, 165 post paestum patients have been randomly selected who were accommodated and delivered their babies at OB(obstetric ) & GY (Gynecologic) unit the 7 general hospitals for the period of 6 December 1976 through 17 December 1976. As for the survey, it has been used of Questionnaire where we have 65 items in the respect of personal environment in the hospital such as trusting nurse, ability, reliability, kindness and etiquette of nurse and tile character of nurse the relationship with patients the other respect of physical environment included 9f temperature, moisture. air-ventilation lightening noise, cleanness. facilities, and the third realm being of mother's hearth ground to have the following conclusion 1. The feature of the collected personnel they are from OB or GY sects of from OB unit of the other 5 hospitals except the two general hospitals of the college or school Otherwise the rate of the patients to nurses would be 9 : 1. As for the nurses'ground it would be appeared of 20-25 years of age as the 76%. either 3 year course or 4 year course in the education would be each 50% and less than 2 year experience case would record as of 60 %. In the respect of hospital physical environmental status, there we have two hospitals without any thermometers, on the other han4 nowhere there's hygrometer, otherwise, the lightening is normal or over than normal As for the structure of noise protection the corridors're, generally speaking worse than rooms, nerver hueless, there's no ventilating system in the hospitals. The rooms'repainted in white and yellow, light green white, or green color. The patient's clothing were in green pink blue, light green or in white co for. There're not anything special in both decoration and equipments. Most of them used tall beds except in one hospital 2. To the extent of perception of patient's hatch 9round and hospital environment it is presented that they perceived nurse's ability in highest in total human variable, though perceived kindness or etiquette in the lowest otherwise, comparatively high in total average. 3. In the respect of physical environment it is highest perceived of lightening terms, otherwise, lowest perceived of air ventilation and total average became lowest than the one of the original record 4. To ages, in the respect of hatch ground rather old aged mother than the younger one has perceived that nurse would be trusting, in good service character, able, at the same time, liable, Otherwise, in physical environment regardless of age, they perceived lightening in high and remarkably lower in ventilation As a result of the examination of the difference in hospital environment to each age it is appeared of statistical difference at 5% level of ability in the personal environment otherwise little difference as for physical environment 5. In the respect of perceiving level to educational standard it is highly perceived of personal environment for higher ranking group rather than lower group in the educational standard. In case of physical environment it is highly perceived for lower level group rather than higher level group in educational background. The variables which have statistical significance at 5% level are from trusting kindness, etiquette and total kindness, etiquette and total all significance at 5% level are from trusting, kindness, etiquette and total human environment variable in personal environment, otherwise, there's little difference in the physical environment. 6. The perceiving level due to times of admission and accommodation at the hospital would be cleared out as gradual higher perception both physical and personal environment in the hospital. At 5% significant level of the ventilation condition in physical environmental variable it is presented of meaningful difference otherwise, there we have little difference both in Personal variable and other one. 7. In accordance with living standard, the perception degree of personal environment in tee hospital would be inclined to increase to higher living standard on the other hand, in case of the physical environment, the perception level world increase to lower living standard At 5 % level, the trustuariable and total scores in the personal eicuironmectal variable there appeared a meaningful/ significant difference otherwise, there presented little difference both in physical environmental and other variable to the living standard 8. Pertaining to family unit, the mother of an independent family unit perceived highly in all respect of the personal and the physical environment in the hospital rather than the woman of succeeding family unit. At 5 % level there appeared a difference in the respect of kindness and etiquette both in personal environment variable, on the other hand, there hardly marked a difference between other variable and physical environmental one. 9. The degree of perception to comforting level has little connection with a statistical difference the age, educational level hospital admitting times, living standard or family unit. 10. The most effective variable to mother's comforting level will be nurse's ability, reliability, trusting manner, and total physical environment variable in order.

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Stability of Environmental Disposition Validated Through a Shout Term Education -The Effect of 'Interior Design History' Course on Students' Environmental Disposition- (단기교육 영향에 대한 실내환경적 성향의 안정성 규명연구 -'실내디자인 양식사' 수강경험이 실내환경적 성향에 미치는 영향-)

  • 이연숙;이선미;이경은;민지희
    • Korean Institute of Interior Design Journal
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    • no.20
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    • pp.3-9
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    • 1999
  • The purpose of this study was to verify the stability of environmental disposition through analyzing the short term effect of the 'Interior Design History' course on students environmental dispositions, especially their interior image preferences toward traditional/modern, female/masculine, and simple/complex characteristics. The pre-test post-test control group experimental design was used. The independent variable was the experience of the Interior Design History course, and the dependent variable was environmental disposition measured by IIPS(Interior Image Preference Scale). The measurements were done at both beginning and end of fall semester, 1997. Subjects were using 71 undergraduate students of Drafting course (control group) and 35 undergraduate students of Interior Design History course (experimental group) at Y University. Data were analyzed using frequency, percentage, mean, and F-test through ANOCOVA. This research revealed no effect of the Interior Design History course on students interior environmental dispositions. The stability of those environmental dispositions and also the validity of the IIPS were proved.

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A Model of Environmental Naturalness for Roadscape - Focused on the National Road in Suburb Areas - (도로경관의 자연환경성 모형 -교외지역 국도를 중심으로-)

  • Hong, Yeong Rok;Gwon, Sang Jun;Jo, Tae Dong
    • Journal of Environmental Science International
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    • v.13 no.6
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    • pp.505-512
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    • 2004
  • This study was attempted to review the information data for minimizing the destruction of environmental naturalness and the visual damage of landscape from road construction by establishing a model of environmental naturalness for national roads in the suburb areas to suggest an answer to a research question, ' hat does decide the environmental naturalness of roadscape?'. We found that 1) The road-side slope showed no statistical significance in the description of environmental naturalness of roadscape, but the fact that the road-side slope from road construction is the destruction of natural topography cannot be overlooked. 2) In terms of the direction of value variations for independent variables, signboard and telegraph post, soundproofing and protection wall, structure, and building acted toward negative (-) direction, while mountains, sky, road trees, fields, and surrounding green including the road-side slope acted toward positive(+) direction. 3) The variable with highest relative contribution to dependent variables among independent variables is building, which has importance as many as 148 times of road-side slope, while the variable road-side slope has the least importance. Building has the importance of 7.22 times, mountains 5.51 times, road trees 2.59 times, surrounding green 2.54 times, structure 2.41 times, signboard and telegraph post 2.37 times, soundproofing and protection wall 2.20 times, and sky 1.32 times of the fields as a standard criterion values 1.

Factors Influencing Decision Making of People Migrated to Rural Area for Farming - Case of Gyeongsangbuk-do - (귀농·귀촌의 의사결정요인에 관한 연구 - 경상북도 6개 시·군을 대상으로 -)

  • Woo, Seong-Ho;Lee, Seong-Keun
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.2
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    • pp.101-116
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    • 2015
  • This study aims to identify the decision-making factors of people who have returned to rural areas for farming and residence according to personal characteristics and regions. The survey was conducted on 420 return farmers of six cities and counties in Gyeongsangbuk-Do from September 1st to October 11th 2013. For data analysis, researchers used 280 answered sheets and utilized two-way ANOVA and multinomial logistic regression analysis. Research results indicate three factors of returning to farm which are pull to rural area, push from city, and policy factor. The highest scores of factor is pull to rural area (2.93), the second one is push from city (2.31), and the lowest score is politic factor (2.18). In addition, these three factors of returning to farm are elucidated by environmental variable, economic variable, and information and opportunity provided by government. In other words, the factor of pull to rural area is related environmental variable and the factor of push from city is affected by economic variable. Lastly, politic factor pertains to information and opportunity provided by government.