• Title/Summary/Keyword: Change rate of index

Search Result 525, Processing Time 0.039 seconds

The Influence of a Vortex on a Freely Propagating Laminar Methane-Air Flame

  • Lee, Ki-Yong
    • Journal of Mechanical Science and Technology
    • /
    • v.18 no.5
    • /
    • pp.857-864
    • /
    • 2004
  • The change in the NO emission indices (EINO) in a two-dimensional plane has been investigated, which is due to the interaction between a vortex and methane-air flames established at different equivalence ratios, by solving the field equation. After solving the field equation, the spatial distribution of G-values is obtained. The NO emission index is calculated after applying the appropriate relation between the G-values and the NO production rate or the mass fraction of methane obtained from the library of freely propagating flames created from detailed simulations. When a vortex exists in a reacting flow field, in general EINO slightly increases, whereas ElNO is lowered in the vicinity of the vortex regardless of flow direction. A change in vortex size has negligible impact on EINO$\_$T/ but increasing the vortex strength slightly increases EINO$\_$T/ in the domain of this study.

A Dimensionless Index for Quantitative Evaluation of Apple Freshness

  • Cho, Y.J.
    • Agricultural and Biosystems Engineering
    • /
    • v.1 no.1
    • /
    • pp.38-42
    • /
    • 2000
  • Though the freshness for agricultural products is an important factor related to their quality management, this terminology is being used restrictedly because it is very subjective. In this study, a dimensionless index which had the span of the maximum of 1 through the minimum of 0 was proposed to describe freshness of the product with time-variant quality and was applied to Tsugaru and Fuji apples. First, the compressive properties having the linearity in their change regarding time elapsed after harvest were selected. For Tsugaru apple, bio-yield and rupture forces had high correlation with time while for Fuji, bio-yield and rupture deformations had high correlations. When the slope, or ratio of force to deformation, was considered, the effect of cultivar could be neglected. When the linearly time-variant compressive properties for Tsugaru and Fuji apples were involved in the freshness indices, they described well freshness of apples. Also, the freshness decay constant depicted a characteristic which related to freshness decay rate. Therefore, the freshness index can be utilized to manage the quality during storage and distribution of apples.

  • PDF

Evaluating Adaptability of Bimodal Tram in Seoul Metropolitan (수도권 주요축별 바이모달 트램 적용성 평가)

  • Lee, Jun;Jang, Jun-Seok;Eom, Jin-Gi
    • Proceedings of the KSR Conference
    • /
    • 2010.06a
    • /
    • pp.2283-2291
    • /
    • 2010
  • This paper evaluated the effectiveness for the case of it introduced the bimodal tram for the capital area adaptability of the bimodal tram in the limelight as the new transportation means of the next generation for capital area major transportation corridor. The KTDB with 1,142 zones was utilized for the analysis and the major transportation axis around the main road in which the traffic is high. The analysis index selected around the transportation index in which it can show up by the bimodal tram application and the decrease rate of the road traffic density, the travel time change, the carbon emission quantity change, and etc. was chosen as a result. It was analyzed as the axis in which the bimodal tram adaptability effect that it is high with the section this relative including the major analyzed result west AnSan IC~ Songsan Bridge, the SuWon terminal ~ SaDang station, the UiJungBu terminal ~ DoBongSan station, and etc. can be appeared and it was predicted that the travel demand reduction on the road of about 4~6% showed up.

  • PDF

A study on the selection of priority management watershed for the restoration of water cycle (물순환 회복을 위한 우선관리유역 선정 방안에 대한 연구)

  • Kim, Jaemoon;Baek, Jongseok;Park, Jaerock;Park, Byungwoo;Shin, Hyunsuk
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.10
    • /
    • pp.749-759
    • /
    • 2022
  • The paradigm of water cycle management in the watershed is changing due to the increase in abnormal climate phenomena caused by climate change and the increase in impervious area due to urbanization. Research is continuously underway based on Low Impact Development technology that can suppress water cycle distortion. In this study, factors that can reflect water cycle distortion were selected before applying LID, and the PSR index for each 148 watershed was calculated for the the Nakdonggang River basin. As of 1975, the PSR index is calculated by calculating the pressure index P, which represents the rate of change in impervious surface area to 2019, the phenomenon index S, which represents the rate of change in water cycle for each subwatershed, and the Low Impact Development area countermeasure index R. The lower PSR index value, the higher the priority management watershed, and the water cycle recovery priority management watershed was calculated in the order of 1, 2, 87, 90, 91, and 147. It is expected that the efficient application of low-impact development factors in accordance with the order of priority management of water cycle by subwatershed in the large area will contribute to the recovery of water cycle distortion.

Health Vulnerability Assessment for PM10 in Busan (부산지역 미세먼지에 대한 건강 취약성 평가)

  • Lee, Won-Jung;Hwang, Mi-Kyoung;Kim, Yoo-Keun
    • Journal of Environmental Health Sciences
    • /
    • v.40 no.5
    • /
    • pp.355-366
    • /
    • 2014
  • Objectives: This study seeks to evaluate the vulnerability assessment of the human health sector for $PM_{10}$, which is reflected in the regional characteristics and related disease mortality rates for $PM_{10}$ in Busan over the period of 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), vulnerability to $PM_{10}$ is comprised of the categories of exposure, sensitivity, and adaptive capacity. The indexes of the exposure and sensitivity categories indicate positive effects, while the adaptive capacity index indicates a negative effect on vulnerability to $PM_{10}$. Variables of each category were standardized by the rescaling method, and each regional relative vulnerability was computed through the vulnerability index calculation formula. Results: The regions with a high exposure index are Jung-Gu (transportation region) and Saha-Gu (industrial region). Major factors determining the exposure index are the $PM_{10}$ concentration, days of $PM_{10}{\geq}50$, ${\mu}g/m^3$, and $PM_{10}$ emissions. The regions that show a high sensitivity index are urban and rural regions; these commonly have a high mortality rate for related disease and vulnerable populations. The regions that have a high adaptive capacity index are Jung-Gu, Gangseo-Gu, and Busanjin-Gu, all of which have a high level of economic/welfare/health care factors. The high-vulnerability synthesis of the exposure, sensitivity, and adaptive capacity indexes show that Dong-Gu and Seo-Gu have a risk for $PM_{10}$ potential effects and a low adaptive capacity. Conclusions: This study presents the vulnerability index to $PM_{10}$ through a relative comparison using quantitative evaluation to draw regional priorities. Therefore, it provides basic data to reflect environmental health influences in favor of an adaptive policy limiting damage to human health caused by vulnerability to $PM_{10}$.

A Policy Suggestion for the Adaptation of Climate Change in Korea (우리나라의 기후변화 대응방안에 관한 정책 제언)

  • Shin, Im Chul;Kim, Yeongsin
    • Atmosphere
    • /
    • v.19 no.1
    • /
    • pp.53-66
    • /
    • 2009
  • The purpose of this study is to describe the roles of carbon dioxide in the climate change, and carbon dioxide reduction policies in some countries. In addition, ways to cope with climate change in Korea are also discussed. Currently, global temperatures are rising due to the carbon dioxide produced by human beings. Global temperatures will rise approximately $6^{\circ}C$ until 2100 if we emit carbon dioxide at a present rate. Temperature rise will affect the terrestrial and oceanic resources, and ultimately influence the socio-economic structures including political stability. Most of the carbon dioxide comes from fossil fuels. Therefore, it is urgent to reduce the use of energy, which comes from fossil fuels. Solving the climate change due to the increases in carbon dioxide is a global problem. Korea should participate in the international community and cooperate with each other in order to reduce the carbon dioxide concentration. No policy was announced for the reduction of carbon dioxide so far. Korea should make a policy for the reduction of carbon dioxide in a specific year compared to that of certain standard year such as 1990 or 2005. Making policy should be based on the scientific result of the amount of carbon dioxide emitted and absorbed. Germanwatch announced the Climate Change Performance Index (CCPI) in order to evaluate an effort to reduce the carbon dioxide for 56 countries which emits 90 % of global carbon dioxide. Ranking for Korea is 51 among 56 countries. This clearly indicates that the appropriate carbon dioxide reduction has not been exercised yet in Korea. Researchers have a moral responsibility to provide updated new ideas and knowledges regarding climate change. Politicians should have a sharp insight to judge the ideas provided by researchers. People need an ethics to reduce the carbon dioxide in every day's life. Scientific research should not be influenced by stress caused by external budget and negative impact of capitalism. Science should be based on the pure curiosity.

The Effect of Aerobic Exercise and Weight Training Combined with Oriental Medicine on Body Composition in Obese Patients (운동요법과 한방치료의 병행치료가 비만환자의 신체구성에 미치는 영향)

  • Shin, Ho-Jeung;Kim, Sun-Min;Kim, Kil-Soo;Kim, Chun-Jong
    • Journal of Korean Medicine for Obesity Research
    • /
    • v.2 no.1
    • /
    • pp.73-82
    • /
    • 2002
  • Objectives: The purpose of this study is to investigate the effect of the aerobic exercise and weight training combined with VLCD(very low calorie diet) and chegameuyiin-tang(體減薏苡仁湯) on the change of the body composition during 15 days of hospitalization treatment. Methods: Twenty four female obese patients were observed. Exercise regimen was composed with aerobic exercise and weight training program, and the intensity of aerobic exercise were 50% HRmax(maximal heart rate) twice time a day and weight training were 50% 1RM(one repetition maximum) a day. All subjects diet regimen was VLCD of 600kcal/day. Results & Conclusions. 1. There was no significant difference between the aerobic exercise and the weight training groups in the change of body weight, fat mass, and percent body fat, waist-hip ratio, body mass index and resting metabolic rate. 2. In the comparison of the change rate of FFM(fat free mass), weight training group preserved FFM better than aerobic-exercise-only-group with no statistical significance.

  • PDF

Change of Heart Rate Variability on Menstruation in Women at College (여대생 월경(月經)의 심박변이도 변화에 대한 연구)

  • Kim, Gyeong Cheol;Kim, Yi Soon
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.26 no.5
    • /
    • pp.745-752
    • /
    • 2012
  • This study aims to show the change of Heart Rate Variability(HRV) and Pulse wave velocity(PWV) on menstruation in women at college. Heart Rate Variability(HRV) and Pulse wave velocity(PWV) of 122 women at college were measured at their menstruation and ordinary period. SDNN, RMSSD, SDSD, HRV Index(%), stress resistance and cardiac activity were significantly higher at their menstruation than ordinary period, but Total Power and pNN50(%) were opposite. The automatic nervous system balance and physical stress were decreased in groups without dysmenorrhea than with one. PWV(E-R) and PWV(E-L) were much higher at menstruation than ordinary period. PTT(F-R) and PTT(F-L) were decreased in groups without dysmenorrhea than with severe one. We demonstrated that menstruation can effect on Heart Rate Variability and Pulse wave velocity and dysmenorrhea can cause the imbalance of autonomic nervous system.

Effects of Heart Rate Variability after Visiting the Gotjawal Forest in Jeju (제주 곶자왈숲 삼림욕 후에 심박동변이에 미친 영향)

  • Sin, Bangsik;Lee, Hyung H.;Lee, Keun Kwang
    • Journal of Naturopathy
    • /
    • v.7 no.1
    • /
    • pp.1-9
    • /
    • 2018
  • The purpose of this study is to statistically investigate the changes in mean differences of the vascular age types and index, heart beating, vessel elasticity, diastolic reserves contents measured by the fingertip plethysmogram before and after the subjects (49 people) visit the Gotjawal forest for two hours. While there is no significant change in the mean differences of vascular age types and index, heart beating, diastolic reserves contents in the control group before and after the visit, the differences in the test groups gets higher than the control group and shows a significant difference. Moreover, the variance analyses of the mean values of the contents shows a significant change after the visit. There is no significant change in the values of vessel elasticity changes between the groups after the visit, but the change of values is significant in the within group, and it is not significant between group by variance analysis. The differences of the heart beating was insignificant in the within group, but significant between group after the visit. In conclusion this study proves the effects of forest bathing, because the HRV index significantly improved after the bathing. Therefore the b-c-d-e/a ratio may be useful for evaluation of HRV.

  • PDF

Measurement of Semi-Volatile Organic Compounds from Flooring Material and Evaluation on Airflow Characteristics in a Test Chamber (바닥재에서 발생하는 준휘발성유기화합물 측정 및 챔버 내 기류 특성 평가)

  • Seo, Jang-Hoo;Kato, Shinsuke;Lim, Mann-Taek
    • Proceedings of the SAREK Conference
    • /
    • 2009.06a
    • /
    • pp.762-767
    • /
    • 2009
  • Some types of semi-Volatile organic compounds (SVOC) that are emitted from plastics used in building materials and household appliances have associated health risks, even at low concentrations. In this study, micro chamber method for measuring SVOC is introduced and SVOC such as di (2-ethylhexyl) phthalate and butylated hydroxyltoluene emitted a flooring material were measured using a micro chamber method. Airflow characteristics in a micro test chamber deeply depended on air exchange rate. From the evaluation using an index of air change efficiency, such as the air age and the coefficient of air change performance, a fixed air exchange rate of $1.5\;h^{-1}$ in the micro chamber is desirable.

  • PDF