• Title/Summary/Keyword: cities

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A study of improvement of river water quality(T-P) in pilot-scale operation (파일롯 규모의 운영에 따른 하천수질(T-P) 개선에 관한 연구)

  • Choi, Kyoungsoo;Lee, Chaeyoung
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.5
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    • pp.323-334
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    • 2021
  • Pilot-scale coagulation and sedimentation processes were operated to investigate the T-P (Total phosphorus) removal efficiency. A multiple regression model was also derived to predict the water quality improvement effect with river water characteristics. The inflow rates for the pilot-scale facility were 157-576 m3/day, and the coagulant doses were in the range of 13.7-58.5 mg/L (average 38.9 mg/L) for PAC (Poly alum chloride) and 16.5-62.1 mg/L (average 36.0 mg/L) for alum. The results found that the influent BOD (Biochemical oxygen demand) and T-P concentrations were 4.9 mg/L and 0.115 mg/L, and the removal efficiencies were 52.7% and 59.4%, respectively. T-P removal efficiencies on wet weather days were higher by 10% than dry weather days because influent solids influenced T-P's coagulation process. The pH of river water was 6.9-7.8, and the average pH was 7.3. Although the pH variation was not significant, the trend showed that the treatment efficiency of T-P and PO4-P removal increased. Thus, the pH range considered in this study seems to be appropriate for the coagulation process, which is essential for phosphorous removal. The T-P removal efficiencies were 19.6-93.3% (average 59.2%) for PAC and 16.4-98.5%(average 55.9%) for alum; thus, both coagulants showed similar results. Furthermore, the average coagulant doses were similar at 42.4 mg/L for PAC and 41.3 mg/L for alum. When the T-P concentration of the effluent was compared by the [Al]/[P] ratio, the phosphorus concentration of the treated water decreased with an increasing [Al]/[P] ratio, and the lowest T-P concentration range appeared at the [Al]/[P] ratio of 10-30. A seasonal multiple regression analysis equations were derived from the relationships between 10 independent and dependent variables (T-P concentration of effluent). This study could help lake water quality maintenance, reduce eutrophication, and improve direction settings for urban planning, especially plans related to developing waterfront cities.

Study on the Evaluation Method of Autonomous Vehicle Driving Ability Based on Virtual Reality (가상환경 기반 자율주행 운전능력 평가방안 연구)

  • Kim, Joong Hyo;Kim, Do Hoon;Joo, Sung Kab;Oh, Seok Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.5
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    • pp.202-217
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    • 2021
  • Following the fatal accident of pedestrians caused by Autonomous Vehicle by Uber, the world's largest ride-hailing company, two people were killed in a self-driving car accident by Tesla in April. There is a need to ensure the safety of road users. Accordingly, in order to secure the safety of Autonomous Vehicle driving, it is necessary to evaluate Autonomous Vehicle driving technologies in various situations based on the road and traffic environment in which the Autonomous vehicle will actually drive. Therefore, this study used UC-win/Road ver.14.0 based on general driver's license test questions to present a virtual reality-based Autonomous Vehicles driving ability evaluation tool among various driving ability test method. Based on this, it was intended to test driving ability for unexpected situations in complex and diverse driving environments, and to confirm its practical applicability as an optimal tool for Autonomous vehicle ability test and evaluation.

Research on Digital twin-based Smart City model: Survey (디지털 트윈 기반 스마트 시티 모델 연구 동향 분석)

  • Han, Kun-Hee;Hong, Sunghyuck
    • Journal of Convergence for Information Technology
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    • v.11 no.11
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    • pp.172-177
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    • 2021
  • As part of the digital era, a digital twin that simulates the weak part of a product by performing a stress test that reduces the lifespan of some expensive equipment that cannot be done in reality by accurately moving the real world to virtual reality is being actively used in the manufacturing industry. Due to the development of IoT, the digital twin, which accurately collects data collected from the real world and makes it the same in the virtual space, is mutually beneficial through accurate prediction of urban life problems such as traffic, disaster, housing, quarantine, energy, environment, and aging. Based on its action, it is positioned as a necessary tool for smart city construction. Although digital twin is widely applied to the manufacturing field, this study proposes a smart city model suitable for the 4th industrial revolution era by using it to smart cities and increasing citizens' safety, welfare, and convenience through the proposed model. In addition, when a digital twin is applied to a smart city, it is expected that more accurate prediction and analysis will be possible by real-time synchronization between the real and virtual by maintaining realism and immediacy through real-time interaction.

Apache NiFi-based ETL Process for Building Data Lakes (데이터 레이크 구축을 위한 Apache NiFi기반 ETL 프로세스)

  • Lee, Kyoung Min;Lee, Kyung-Hee;Cho, Wan-Sup
    • The Journal of Bigdata
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    • v.6 no.1
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    • pp.145-151
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    • 2021
  • In recent years, digital data has been generated in all areas of human activity, and there are many attempts to safely store and process the data to develop useful services. A data lake refers to a data repository that is independent of the source of the data and the analytical framework that leverages the data. In this paper, we designed a tool to safely store various big data generated by smart cities in a data lake and ETL it so that it can be used in services, and a web-based tool necessary to use it effectively. Implement. A series of processes (ETLs) that quality-check and refine source data, store it safely in a data lake, and manage it according to data life cycle policies are often significant for costly infrastructure and development and maintenance. It is a labor-intensive technology. The mounting technology makes it possible to set and execute ETL work monitoring and data life cycle management visually and efficiently without specialized knowledge in the IT field. Separately, a data quality checklist guide is needed to store and use reliable data in the data lake. In addition, it is necessary to set and reserve data migration and deletion cycles using the data life cycle management tool to reduce data management costs.

On Study of Runoff Analysis Using Satellite Information (위성자료를 이용한 유출해석에 관한 연구)

  • Kang, Dong Ho;Jeung, Se Jin;Kim, Byung Sik
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.2
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    • pp.13-23
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    • 2021
  • This study intended to assess the reliability of topographic data using satellite imaging data. The topographical data using actual instrumentation data and satellite image data were established and applied to the rainfall-leak model, S-RAT, and the topographical data and outflow data were compared and analyzed. The actual measurement data were collected from the Water Resources Management Information System (WAMIS), and satellite image data were collected from MODIS observation sensors mounted on Terra satellites. The areas subject to analysis were selected for two rivers with more than 80% mountainous areas in the Han River basin and one river basin with more than 7% urban areas. According to the analysis, the difference between instrumentation data and satellite image data was up to 50% for peak floods and up to 17% for flood totals in rivers with high mountains, but up to 13% for peak floods and up to 4% for flood totals. The biggest difference in the video data is Landuse, which shows that MODIS satellite images tend to be recognized as cities up to 60% or more in urban streams compared to WAMIS instrumentation data, but MODIS satellite images are found to be less than 5% error in forest areas.

Evaluation of pure oxygen with MBR(Membrane Bio Reactor) process for anaerobic digester effluent treatment from food waste (순산소의 MBR(Membrane Bio Reactor) 공정 적용을 통한 음식물류 폐기물 혐기성소화 유출수 처리 평가)

  • Park, Seyong;Kim, Moonil;Park, Seonghyuk
    • Journal of the Korea Organic Resources Recycling Association
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    • v.29 no.3
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    • pp.5-16
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    • 2021
  • In this study, the applicability of the MBR(Membrane Bio Reactor) process of oxygen dissolve was evaluated through comparison and evaluation of the efficiency of oxygen dissolve device and conventional aeration device in the explosive tank within the MBR process. The organic matter and ammonia oxidation by oxygen dissolve device were evaluated, and the efficiency of persaturation was evaluated by applying real waste water (anaerobic digester effluent treatement from food waste). SCOD and ammonia removal rates for oxygen dissolve device and conventional aeration device methods were similar. However, it was determined that the excess sludge treatment cost could be reduced as the yield of microorganisms by oxygen dissolve device is about 0.03 g MLSS-produced/g SCOD-removed lower than that of microorganisms by conventional aeration device. The removal rates of high concentrations of organic matter (4,000 mg/L) and ammonia (1,400 mg/L) in anaerobic digester effluent treatment from food waste were compared to the conventional aeration device and the oxygen dissolve device organic matter removal rate was approximately 13% higher than that of the conventional aeration device. In addition, for MLSS, the conventional aeration device was 0.3 times higher than for oxygen dissolve device. This is believed to be due to the high progress of sludge autooxidation because the dissolved oxygen is sufficiently maintained and supplied in the explosive tank for oxygen dissolve device. Therefore, it was determined that the use of oxygen dissolve device will be more economical than conventional aeration device as a way to treat wastewater containing high concentrations of organic matter.

Analysis of Intercepted Flow according to Change of Flow Width in Gutter (도로 흐름폭 변화에 따른 차집유량 분석)

  • Joo, Dong Won;Kim, Jung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.4
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    • pp.377-386
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    • 2021
  • In dense cities, which are covered by many impermeable areas, rainwater flows quickly along the roads and collects in certain areas. The surface runoff that fails to get intercepted by the roadside rain gutters results in a wider flow of water along the sides, which in turn increases the amount of water on the road and causes traffic congestion as well as accidents due to slippage. Based on these issues, this study was carried out in order to propose an intercepted flow calculation formula. To this end, the maximum longitudinal slopes of arterial roads and expressways were reflected to depict a road condition of 2~10 %, while a general traverse slope of 2 % was selected for the traverse slope on the side. As for the road lane condition, two, three, and four lanes were chosen for the area from the centerline to the sidewalk. As for the experimental flow rate, the rainwater runoffs at the actual design frequency of 5, 10, 20, and 30 years for road conditions were converted into experimental flow rates, and as a result, flow rates ranging from 1.36 l/s to 3.96 l/s were divided into ten flow rates for a hydraulic experiment. Also, an equation taking into consideration the inflow velocity and flow width along the roadsides was proposed. The results of the experiment showed an increase in flow width and a decrease in interception rate. Also, the inflow velocity at a traverse slope of 2 % was measured, while increasing the longitudinal slope. Accordingly, an equation for calculating the flow intercepted by rain gutters at a flow width reflecting the longitudinal slope of the road and rainwater runoff, according to the design frequency, was derived by performing a regression analysis using IBM SPSS Statistics 24. It is deemed that the equation derived in this study will be useful in designing rain gutters for roads.

Effect of Dementia Attitudes according to Dementia Education in University Students on the Recognition of Dementia Policy - Mediating effect of dementia knowledge - (대학생의 치매교육에 따른 치매태도가 치매정책인식에 미치는 영향 - 치매지식 매개효과 중심으로 -)

  • Choi, HeeJung;Kim, JiSuk;Kim, JungEun
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.2
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    • pp.325-331
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    • 2021
  • The purpose of this study was to identify the effect of dementia attitudes according to dementia education in university students on the recognition of dementia policy, focusing on the mediating effect of dementia knowledge. The participants were 306, 1~2 grad of students of U and K university in 2 G cities. The data were collected from September 1 to 31, 2017, and analyzed using the SPSS/WIN 21.0 program with t-test, Pearson correlation coefficients and multiple stepwise regression. There were significant differences in the education group compared to the non-education group in recognition of dementia policy, dementia knowledge, and dementia attitude according to the subject's dementia education. The level of dementia attitudes, recognition of dementia policy, dementia knowledge and attitudes were more than moderate. The positive correlations among recognition of dementia policy, dementia knowledge and attitudes were significant. Dementia knowledge was a predictor of recognition of dementia policy (t=2.35, p=019) and showed a significant partial mediating effect, and the explanatory power was 17.8%. It is necessary to continuously systematically provide the development and application of dementia education programs for the whole people to raise correct dementia knowledge, positive attitudes toward dementia, and awareness of dementia policies.

Regional Quality of Life Satisfaction and Life SOC Service Gap Analysis: A Case of Chungcheongnam-do (지역의 삶의 질 만족도와 생활SOC 서비스 격차분석: 충청남도를 사례로)

  • Hong, Sung-Hyo;Im, Jun-Hong;Lee, Gyounju
    • Land and Housing Review
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    • v.12 no.4
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    • pp.61-79
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    • 2021
  • Despite the rapid economic growth, people's quality of life has not been improved and the regional and hierarchical disparities of it have deepened. We analysed regional differences in quality of life and it was found that non-capital regions, provinces and rural areas compared to Seoul and capital region, metropolitan cities, and urban areas respectively, show a relatively lower level of satisfaction in the quality of life. An in-depth analysis of Chungcheongnam-do province shows that the trend was similar to that of the national analysis. The quality of life satisfaction of the elderly was lower than that of the young and middle-aged, and this trend was similar regardless of region. Young people living in the Dong area showed high satisfaction with the quality of life than the middle-aged and elderly living in the Myeon area. It was observed the level of Life SOC services in urban areas have been better than the one in rural areas. However, there is no clear relationship between quality of life satisfaction and the expansion of Life SOC, therefore, it is difficult to argue that the government intervention to expand Life SOC will improve the citizen's quality of life satisfaction. The implication of the study is that the future supply policy of the Life SOC should be based on the detailed analysis of the impact on the environment, and linking with the development of various programs in progress rather than supplying a Life SOC that provides a single service. Furthermore, in rural areas it is essential to enhance user demand by combining several services in supply and to improve the efficiency of managing the services.

A Study on the Change of the Chinese Performing Art Market during the period of the 10th 5year Development Plan. (중국 공연예술 시장 고찰 - 제10차 5개년 계획 기간(2001~2005)을 중심으로 -)

  • Oh, Soo Kyung
    • (The) Research of the performance art and culture
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    • no.18
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    • pp.449-480
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    • 2009
  • In this paper, I tried to study the change of the Chinese performing arts market during the 10th 5year development plan, from year 2001 to year 2005 by both of the quantitative and qualitative analysis, because it's really the time when we need to understand the growing market of chinese culture along with the development of the Chinese cultural industry. During that period, the Chinese government developed the policy to establish a healthy cultural market and strengthen it's cultural power; the parts who product the piece of performing arts including the performing troupes, the theatres and the production companies were consolidated and became familiar to market through the reformation of the organization; and the audience who consume the performing arts and entertainments still shows very Chinese characteristics in the cities and villages. In the village, the audiences invite the troupe to play their local theatre in many occasions of their life according to their traditional beliefs, also somehow to show their wealth. The fact that the local governments and the companies are very important consumer groups in China is also very 'Chinese' characteristics. It means that Chinese performing arts are still more or less under the influence of the political ideas. Nonetheless it is worthy of notice that Chinese performing arts not only develope the new contents in very creative way and also try to learn the knowhow of the excellent items of foreign countries by inviting them to the festivals or organize a co-productions on the basis of the upgraded cultural power through the 10th 5 year development plan.