• Title/Summary/Keyword: density index

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Evaluation on Pollution Load Characteristics and Influence of Tributaries in the Hwangguji Stream (황구지천 유역의 오염부하 특성 및 지류 영향 평가)

  • Lim, Su-Jin;Lim, Byung-Ran;Lee, Han-Saem;Kang, Joo-Hyoung;Ahn, Tae-Ung;Shin, Hyun-Sang
    • Journal of Korean Society on Water Environment
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    • v.37 no.4
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    • pp.249-262
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    • 2021
  • This study investigated the pollution characteristics of the main pollution zone in the Hwangguji watershed and the influence of the tributary on the main stream. The characteristics of the main pollution zone, including, the water quality index (WQI), stream rating, load duration curve (LDC), delivery load density (DLD), and contribution of the tributary to the mainstream, were evaluated by time-series visual heatmap. The WQI of the mainstream of Hwangguji was lowered to the poor (IV) level from the inflow point of Suwon stream (SW) and the LDC excess rate in the T-P was higher than that of BOD5, especially for the wet season, suggesting that management of non-point source with T-P is preferred. The contribution (%) of the tributaries in the upstream section of Hwangguji watershed were BOD5 14.54%, TOC 15.67%, T-N 5.43%, and T-P 6.97%. In particular, the Suwon sewage treatment plant located in the mainstream showed a high contribution of BOD5 (64.40%) and T-P (53.54%), respectively, due to the high discharge rate (6.019 m3/sec). Meanwhile, Sammi and Gal stream have a large impact on the mainstream with high DLD and poor WQI. Thus, both streams were considered as pollution hot spots. These results provide useful basic data for preparing more effective water quality improvement and management plans in the watershed.

Investigating the future changes of extreme precipitation indices in Asian regions dominated by south Asian summer monsoon

  • Deegala Durage Danushka Prasadi Deegala;Eun-Sung Chung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.174-174
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    • 2023
  • The impact of global warming on the south Asian summer monsoon is of critical importance for the large population of this region. This study aims to investigate the future changes of the precipitation extremes during pre-monsoon and monsoon, across this region in a more organized regional structure. The study area is divided into six major divisions based on the Köppen-Geiger's climate structure and 10 sub-divisions considering the geographical locations. The future changes of extreme precipitation indices are analyzed for each zone separately using five indices from ETCCDI (Expert Team on Climate Change Detection and Indices); R10mm, Rx1day, Rx5day, R95pTOT and PRCPTOT. 10 global climate model (GCM) outputs from the latest CMIP6 under four combinations of SSP-RCP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are used. The GCMs are bias corrected using nonparametric quantile transformation based on the smoothing spline method. The future period is divided into near future (2031-2065) and far future (2066-2100) and then the changes are compared based on the historical period (1980-2014). The analysis is carried out separately for pre-monsoon (March, April, May) and monsoon (June, July, August, September). The methodology used to compare the changes is probability distribution functions (PDF). Kernel density estimation is used to plot the PDFs. For this study we did not use a multi-model ensemble output and the changes in each extreme precipitation index are analyzed GCM wise. From the results it can be observed that the performance of the GCMs vary depending on the sub-zone as well as on the precipitation index. Final conclusions are made by removing the poor performing GCMs and by analyzing the overall changes in the PDFs of the remaining GCMs.

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Grouping Method Based Query Range Density for Efficient Operation Sharing of Spatial Range Query (공간영역질의의 효율적인 연산 공유를 위한 질의영역 밀집도 기반의 그룹화 기법)

  • Lim, Jung-Hyeun;Shin, Soong-Sun;Baek, Sung-Ha;Lee, Dong-Wook;Kim, Kyung-Bae;Bae, Hae-Young
    • Annual Conference of KIPS
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    • 2009.04a
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    • pp.348-351
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    • 2009
  • 유비쿼터스 사회를 실현하는 핵심기술인 u-GIS 공간정보 기술은 데이터 스트림 처리 시스템(Data Stream Management System)과 지리정보 시스템(Geography Information System)이 결합된 플랫폼인 u-GIS DSMS를 요구한다. u-GIS DSMS는 GeoSeonsor에서 수집되는 센서 테이터와 GIS의 공간정보 데이터를 결합하여 처리하는 공간영역질의가 다수 요구된다. 이런 공간영역질의들은 특정 지역에 밀집하게 등록되는 경향이 있으며, 유사한 프리디킷을 가질 가능성이 높다. 이러한 특징은 공간영역질의가 특정 지역에 밀집되면 다수의 비슷한 연산들이 반복적으로 처리하기 때문에 시스템 성능이 저하 될 것이다. 이를 해결하기 위해 영역질의 색인기법 연구가 활발히 진행되고 있다. 그러나 기존의 VCR-Index와 CQI-Index 기법은 질의영역을 셀 구조나 가상구조로 분할하여 처리하기 때문에 자원 및 연산을 공유 할 수 없어 질의 처리 속도가 현저히 저하되기 때문에 대량의 공간영역질의 처리에는 부적합하다. 그래서 본 논문에서는 공간영역질의의 효율적인 연산 공유를 위한 질의영역 밀집도 기반의 그룹화 기법을 제안한다. 이 기법은 질의영역의 밀집도를 이용하여 공간영역질의들을 그룹화 후 색인을 구성한다. 색인된 영역들의 데이터는 단일 큐로 구성 후 질의들의 프리디킷을 분석하여 자원 및 연산 공유기법을 통해 기존의 기법보다 처리 속도 향상 및 메모리 사용을 감소시켰다.

Usefulness of DECT Application for Compensation of Image Contrast Difference According to CT Contrast Agent Density (CT 조영제 농도에 따른 영상 대조도 차 보상을 위한 DECT 적용의 유용성)

  • Hyeon-Ju Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.417-422
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    • 2023
  • In this study, normal saline was diluted with the contrast medium at a certain ratio for the purpose of reducing the image quality poor and side effects caused by the contrast medium during CT examination. At this time, by finding the energy level of DECT that can compensate for the decrease in contrast of the image according to the degree of dilution, the usefulness of applying DECT for compensating the difference in image contrast was investigated through comparative analysis by applying SNR, CNR, and SSIM. As a result, when a dilution ratio of 4 (contrast medium): 6 (normal saline) and the energy level of DECT of 65 keV were applied, the contrast difference was the most similar to that when using the undiluted contrast medium. At this time, SNR was 813.71 ± 37.6, CNR was the highest at 921.87 ± 17.1, and SSIM index was measured at 0.851, which is the most similar to 1. The results of this study are meaningful in providing basic information for finding the appropriate dilution rate and energy level for each examination site through future clinical studies. It is believed that it can be reduced.

Determination of homogeneity index of cementitious composites produced with eps beads by image processing techniques

  • Comak, Bekir;Aykanat, Batuhan;Bideci, Ozlem Salli;Bideci, Alper
    • Computers and Concrete
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    • v.29 no.2
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    • pp.107-115
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    • 2022
  • With the improvements in computer technologies, utilization of image processing techniques has increased in many areas (such as medicine, defence industry, other industries etc.) Many different image processing techniques are used for surface analysis, detection of manufacturing defects, and determination of physical and mechanical characteristics of composite materials. In this study, cementitious composites were obtained by addition of Grounded Granulated Blast-Furnace Slag (GGBFS), Styrene Butadiene polymer (SBR), and Grounded Granulated Blast-Furnace Slag and Styrene Butadiene polymer together (GGBFS+SBR). Expanded Polystyrene (EPS) beads were added to these cementitious composites in different ratios (20%, 40% and 60%). The mechanical and physical characteristics of the composites were determined, and homogeneity indexes of the composites were determined by image processing techniques to determine EPS distribution forms in them. Physical and mechanical characteristics of the produced samples were obtained by applying consistency, density, water absorption, compressive strength (7 and 28 days), flexural strength (7 and 28 days) and tensile splitting strength (7 and 28 days) tests on them. Also, visual examination by using digital microscope, and image analysis by using image processing techniques with open source coded ImageJ program were performed. As a result of the study, it is determined that GGBFS and SBR addition strengthens the adhesion sites formed as it increases the adhesion power of the mixture and helps to get rid of the segregation problem caused by EPS. As a result of the image processing analysis it is demonstrated that GGBFS and SBR addition has positive contribution on homogeneity index.

Effects of a Health Partnership Program Using Mobile Health Application for Male Workers with Cardiovascular Risk Factors in Small and Medium Enterprises: A Randomized Controlled Trial (심혈관질환 위험인자를 가진 중소규모 사업장 남성 근로자의 모바일헬스 앱 활용 건강파트너십 프로그램의 효과: 무작위 실험연구)

  • Kim, Eun Jin;Hwang, Seon Young
    • Journal of Korean Academy of Nursing
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    • v.54 no.1
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    • pp.44-58
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    • 2024
  • Purpose: This study aimed to apply a health partnership program using commercially available mobile health apps to improve cardiovascular risk factors in male employees and verify its effectiveness. Methods: Using a randomized control group pretest-posttest design, male employees with cardiovascular risk factors from five small and medium-sized workplaces were randomly assigned to an experimental group (n = 32) and a control group (n = 31). The experimental group was encouraged to use three mobile health apps for 12 weeks to acquire the necessary cardiovascular disease-related information and practice strengthening training, walking, and diet management appropriate to their level. They also received feedback on their weekly activities and motivational text messages from health partners. Hypotheses were tested using the SPSS WIN 22.0. Results: The experimental group showed a significant difference compared to the control group in terms of their perception of mobile health app (p < .05), self-efficacy for exercise and diet, self-management partnership, and cardiovascular disease prevention health behavior (p < .001). In particular, there were significant decreases in the body mass index, ratio, serum fasting blood sugar, total cholesterol, and triglyceride in the experimental group (p < .001); however, there was no significant difference in high-density lipoprotein-cholesterol. Conclusion: Intervention using mobile apps based on partnership with health managers is effective in improving the objective cardiovascular risk index in male employees; therefore, such intervention should be continuously used as a useful lifestyle modification strategy in the workplace.

Analysis of the Factors Influencing the Efficiency of Natural Recreation Forest Management (자연휴양림 경영효율성에 대한 영향 요인 분석)

  • Seung Yeon Byun;Do-il Yoo;Ja-Choon Koo
    • Journal of Korean Society of Forest Science
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    • v.113 no.2
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    • pp.153-163
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    • 2024
  • Since the onset of the COVID-19 pandemic, there has been a significant shift in the lifestyle patterns of the populace across various domains. Concerns surrounding COVID-19 have emerged as pivotal catalysts of change in recreational habits with people giving a particular preference for environments with low population density and increased openness. This trend has resulted in an uptick in excursions to natural reserves, coastlines, and parks. However, during the peak of infectious outbreaks, widespread adherence to social distancing measures has precipitated a steep decline in tourist footfall across natural recreation forests, exacerbating financial deficits to a considerable extent. Thus, this research sought to compare and analyze the operational efficacy and productivity of national, public, and private natural recreation forests pre- and post-COVID-19 pandemic by utilizing non-parametric methodologies, such as data envelopment analysis and the Malmquist productivity index analysis. The objective was to identify the factors contributing to the decreases in efficiency and productivity and ultimately offer nuanced recommendations tailored to respective administrative bodies. This study's distinctive focus on the analysis of management efficiency and productivity in natural recreation forests nationwide offers significant academic and practical relevance.

A Study on the Heat Transfer Analysis of High-Temperature Single Bubble in Water (수중 고온 단일 기포의 열전달 해석 연구)

  • SeokTae Yoon
    • Journal of Korea Society of Industrial Information Systems
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    • v.29 no.1
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    • pp.117-123
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    • 2024
  • Bubbles generated in water receive an upward buoyant force due to the density and pressure difference of the surrounding fluid. Additionally, the behavior, shape, and heat exchange process of bubbles vary depending on the viscosity, surface tension, rising speed, and size difference with the surrounding fluid. In this study, we modeled speed, and heat transfer of a high-temperature single bubble rising in a cylindrical water tank. For this purpose, velocity, and temperature of the bubbles were calculated using theoretical equations, to be compared with numerical simulation results. The numerical analysis was performed using a commercial software, and the stability of the numerical analysis with mesh size was confirmed through calculation of the grid convergence index. The numerical analysis of the rising speed and temperature of a single bubble showed the values to converge when the minimum cell size was 1/160 of the bubble diameter, and the temperature decrease was confirmed to be the same as that of the surrounding fluid within 0.05 seconds.

A Study on Calorie and Proximate Components of Traditional Korea Gruel (한국 전통죽의 영양소에 관한 연구 - 열량 및 일반성분을 중심으로 -)

  • Yoon, Sook-Ja;Hawer, Woo-Derck
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.7
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    • pp.879-885
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    • 2008
  • This study was conducted to analyze 15 traditional Korean gruels for nutrient density using the Index of Nutrient Quality (INQ). The calorie of the gruels ranged from 148.8 (Daechujuk) to 294.1 kcal (Jatjuk) per serving size. The calorie in 'Jatjuk' was the highest, covering 33.3% of Dietary Reference Intakes for Koreans (KDRI) per meal. The carbohydrate content was between 23.0 g (Dakjuk) and 52.1 g (Patjuk) per serving size. The average content of carbohydrate in gruels was $34.7{\pm}9.1\;g per serving size which covers 24.4% of KDRI per meal. Among the 15 gruels, Patjuk contained the highest carbohydrate content (52.1 g per serving size, 36.7% of KDRI per meal). The highest nutrient density (INQ) of carbohydrate in gruels was Dachujuk (INQ 1.4). The protein content of the gruels was between 2.3 (Huinjuk) and 22.3 g (Dakjuk) per serving size. The average content of protein in gruels was 25.6% of KDRI per meal. Dakjuk contained the highest protein content ($8.2{\pm}4.9\;g$ per serving size) and followed by Dakjuk (INQ 2.5), Guljuk (INQ 1.5) and Kongjuk (INQ 1.3) in nutrient density (INQ) of protein. The fat content of the gruels were between 0.3 (Daechujuk) and 17.8 g (Jatjuk) per serving size. The average content of fat in gruels was $17.8{\pm}0.12\;g$ per serving size which showed 21.1% of KDRI per meal. Among the gruels, Jatjuk contained the highest fat ($17.8{\pm}0.12\;g$ per serving size, 77.4% of KDRI per meal). In order of the high nutrient density (INQ) of protein, Jatjuk (INQ 2.4) was followed by Heugimjajuk (INQ 1.5) and Kongjuk (INQ 1.5).

Some Factors Affecting Bone Mineral Status of Postmenopausal Women (폐경 후 여성의 골격상태에 영향을 미치는 요인분석)

  • 오세인;이행신;이미숙;김초일;권인순;박상철
    • Korean Journal of Community Nutrition
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    • v.7 no.1
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    • pp.121-129
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    • 2002
  • Osteoporosis, the typical metabolic bone disease of the elderly, is characterized by a reduction in bone mineral density (BMD) and increased fracture risk. Genetic and environmental factors are known to play a key role in bone metabolism, and diet is also considered to be one of the important factors. The purpose of the present study was to investigate the relationship among the factors affecting BMD, including stature, body weight, age, time period since onset of menopause, and biochemical markers of bone turnover in postmenopausal women. Seventy-eight postmenopausal women who visited health promotion center for health examinations volunteered to participate in this study and they were divided into two groups according to the time period since onset of menopause : women with a time period since onset of menopause of less than 5 years (Group 1) and women with a time period since onset of menopause of 5 years or more (Group 2). The demographic characteristics and dietary intake were surveyed using a questionnaire. BMDs of the lumbar spine and femoral neck of subjects were measured by dual energy X-ray absorptiometry. Serum levels of 25-hydroxy-vitamin D and parathyroid hormone (PTH), known to be indicators of bone related hormone status, were anlyzed. Serum samples were measured for calcium, phosphorus, alkaline phosphatase, and osteocalcin as bone formation indicators, and urine was analysed for deoxypyridinoline, creatinine, calcium, and sodium as bone resorption indicators. The results are as follow : The mean BMDs of the lumbar spin and femoral neck were $1.02 \pm 0.02 g/cm^2 and 0.81 \pm 0.02 g/cm^2 respectively, and the BMD level of Group 2 was significantly lower than tat of Group 1 (p<0.01, p<0.05, respectively). The mean daily intake of energy was 1838 $\pm$ 55 kcal. When nutrient intake was compared with the recommended dietary allowances (RDA) of the subjects, only calcium, vitamin A and riboflavin intake showed means lower than the RDA. The nutrient intake did not show any significant differences between Group 1 and 2 Serum and urine levels of biochemical markers of bone turnover did not show any significant differences between Group 1 and 2, and all were within the normal range. However, the PTH and deoxypyridinoline levels showed a tendency to be higher, and the osteocalcin level to be lower in Group 2 than in Group 1. Although age and years after menopause (YAM) showed negative correlations with lumbar spine bone mineral density (LBMD) (r= -0.38, p<0.001, and r= -0.26, p< 0.05, respectively), no correlation was found with femoral neck bone mineral density (NBMD). While height, body weight and body mass index (BMI) showed a positive correlation with LBMD (r= 0.32, p<0.001, r= 0.38, p<0.001, r= 0.22, p= 0.05, respectively), only body weight and BMI showed a positive correlation with NBMD (r= 0.30, p<0.01, and r= 0.27, p<0.05, respectivley). There was no significant corealtion between BMDs and the nutrient intake of subjects, except in the case of carbohydrates (r= 0.22, p<0.05). Also, serum and urine levels of bone turnover markers showed no significant correlation with nutrient intake. On the other hand, serum osteocalcin had a positive correlation with vitamin C intake (r= 0.22, p= 0.05), and urine deoxypyridinolin showed a negative correlation with niacin intake (r= -0.22, p= 0.05). Urinary na was negatively correlated with protein intake(r= -0.23, p= 0.05). The results suggested that it is difficult to prevent the decrease in bone mass among postmenopausal women eating the usual Korean diet. However, the BMDs of the lumbar spine and femoral neck were positively related to body weight ad BMI in postmenopausal women. Therefore, this study confirmed that one of the most effective ways to minimize bone loss in postmenopausal women would be to maintain an adequate body weight with balanced nutrient intake and activity in the pre-and postmenopausal periods.