• Title/Summary/Keyword: operating current

Search Result 3,349, Processing Time 0.029 seconds

Case Studies for the Establishment of Korean National Urban Park (사례로 본 한국 국가도시공원 조성 연구)

  • Choi, Hyeyoung;Seo, Young-Ai
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.50 no.2
    • /
    • pp.116-126
    • /
    • 2022
  • Although the 'Act on Urban Parks and Green Spaces' was revised in 2016 to provide a legal foundation for national urban parks, there was no further discussion or follow-up research for the implementation of national urban parks. This study investigates Korea's park and green space regulations and national urban park cases from across the world. It aims to analyze worldwide cases and set a course for a viable national urban park system in Korea. The importance and characteristics of national urban parks were evident after reviewing the cases of Japan, Sweden, Finland, and Canada, which have national urban park systems, and the United States and Germany, which aid city parks with national budgets. Each country determined the plans and procedures by assessing the scope of government intervention and the government's role. The importance of communication between the state and municipal governments and private sector participation and governance was recognized. A system was also formed in which local governments actively participate in the nomination, establishment, administration, and management of national urban parks. The results of this study are as follows. First, the concept of equitable national development should be implemented to activate the national urban park system. Second, the national urban park should be a land management tool that may be used to balance development and preservation. Third, a specific method of securing, constructing, administering, and operating national urban parks should be supplemented by the current legislative framework amendment. Furthermore, the establishment of a sustainable research institute is needed to comprehensively analyze parks and green space systems and make appropriate decisions.

A Study on the Food Security for Low-income Older Adults: A Case Study on Meals on Wheels Project in Seoul (저소득 재가노인의 식생활 보장에 관한 연구: 서울시 저소득 어르신 식사배달사업을 중심으로)

  • Kim, Junghyun;Chon, Yongho;Chang, Hyeja
    • 한국노년학
    • /
    • v.40 no.4
    • /
    • pp.617-638
    • /
    • 2020
  • It is important to maintain a healthy dietary habit to enjoy better health and quality of life in later life. However, taking care of one's dietary lifestyle at an older age may be a challenge. Especially, community dwelling low-income older adults are one of the most vulnerable population in regards to holding a well balanced healthy diet. The purpose of this research is to identify the current status of food delivery services for low-income older adults and explore related issues. In order to achieve the aim, this study conduced two sets of focus group interviews with 8 nutritionists and 7 social workers in Seoul. According to the research results, there are issues related to meals on wheels such as vague eligibility, poor operation conditions, work overload, and difficulty in realizing customized meal delivery. Food security for low-income older adults is a prerequisite for aging in place. It is necessary to discuss the ways to create favorable operating conditions to deliver customized meals and manage nutrition and hygiene from the perspective of social work.

Experimental Study on Reduction of Nitrogen-Containing Compounds Contained in Crude Methylnaphthalene Oil by Solvent Extraction (II) (용매 추출에 의한 조제 메틸나프탈렌유에 함유된 함질소화합물의 저감에 관한 실험적 연구(II))

  • Kang, Ho-Cheol;Kim, Su Jin
    • Applied Chemistry for Engineering
    • /
    • v.33 no.5
    • /
    • pp.477-481
    • /
    • 2022
  • As a part of improving the quality of crude methylnaphthalene (CMNO), this study was experimentally examined the reduction of nitrogen-containing compounds (NC) present in the CMNO by solvent extraction. The CMNO was composed of three kinds of NC [quinolone (QU), iso-quinoline (IQU), indole (IN)], three kinds of bicyclic aromatic compound [BAC; naphthalene (NA), 1-methylnaphthalene (1MNA), 2-methylnaphthalene (2MNA)] and biphenyl (BP) etc., in addition to an aqueous formamide solution, which were used as raw materials and a solvent, respectively. The increase in the volume fraction of water to the solvent in the initial state (yw,0) caused a sharp decrease in the distribution coefficient and the yield of NC, but conversely raised the increased selectivity of NC based on 2MNA. The compositions of QU, IQU and IN in the raffinate oil recovered through the equilibrium extraction of batch co-current 5-stage under constant conditions [yw,0 = 0.1, volume fraction of solvent to feed (CMNO) at the initial state = 1, operating temperature = 303 K, liquid-liquid contacting time = 72 h] were reduced by about 51.5%, 55.2%, and 71.8%, respectively, when compared to those of CMNO. From the excellent reduction rate of NC, the formamide extraction method suggested in this study can be expected to be a useful reduction method for NC contained in the CMNO.

Web-based Disaster Operating Picture to Support Decision-making (의사결정 지원을 위한 웹 기반 재난정보 표출 방안)

  • Kwon, Youngmok;Choi, Yoonjo;Jung, Hyuk;Song, Juil;Sohn, Hong-Gyoo
    • Korean Journal of Remote Sensing
    • /
    • v.38 no.5_2
    • /
    • pp.725-735
    • /
    • 2022
  • Currently, disasters occurring in Korea are characterized by unpredictability and complexity. Due to these features, property damage and human casualties are increasing. Since the initial response process of these disasters is directly related to the scale and the spread of damage, optimal decision-making is essential, and information of the site must be obtained through timely applicable sensors. However, it is difficult to make appropriate decisions because indiscriminate information is collected rather than necessary information in the currently operated Disaster and Safety Situation Office. In order to improve the current situation, this study proposed a framework that quickly collects various disaster image information, extracts information required to support decision-making, and utilizes it. To this end, a web-based display system and a smartphone application were proposed. Data were collected close to real time, and various analysis results were shared. Moreover, the capability of supporting decision-making was reviewed based on images of actual disaster sites acquired through CCTV, smartphones, and UAVs. In addition to the reviewed capability, it is expected that effective disaster management can be contributed if institutional mitigation of the acquisition and sharing of disaster-related data can be achieved together.

Low temperature growth of Ga2O3 thin films on Si substrates by MOCVD and their electrical characteristics (MOCVD에 의한 Si 기판 위의 Ga2O3 박막 저온 결정 성장과 전기적 특성)

  • Lee, Jung Bok;Ahn, Nam Jun;Ahn, Hyung Soo;Kim, Kyung Hwa;Yang, Min
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.32 no.2
    • /
    • pp.45-50
    • /
    • 2022
  • Ga2O3 thin films were grown on n-type Si substrates at various growth temperatures of 500, 550, 600, 650 and 700℃. The Ga2O3 thin films grown at 500℃ and 550℃ were characterized as featureless flat surface. Grown at higher temperatures (600, 650, and 700℃) showed very rough surface morphology. To figure out the annealing effect on the thin films grown at relatively low temperatures (500, 550, 600, 650 and 700℃), the Ga2O3 films were thermally treated at 900℃ for 10 minutes. Crystal structure of the Ga2O3 films grown at 500 and 550℃ were changed from amorphous to polycrystalline structure with flat surface. Ga2O3 film grown at 550℃ was chosen for the fabrication of a Schottky barrier diode (SBD). Electrical properties of the SBDs depend on the thermal treatment were evaluated. A MSM type photodetector was made on the low temperature grown Ga2O3 thin film. The photocurrent for the illumination of 266 nm wavelength showed 5.32 times higher than dark current at the operating voltage of 10 V.

Analysis of Spatial Characteristics Affecting the Use of Public Bicycles: Case of 'Tashu' in Daejeon (공공자전거 이용에 영향을 미치는 공간 특성 분석 - 대전광역시 '타슈'를 대상으로 -)

  • Ahn, Minsu;Yi, Changhyo
    • Journal of the Korean Regional Science Association
    • /
    • v.38 no.4
    • /
    • pp.75-91
    • /
    • 2022
  • With the recent increase in interest in climate change issues, the use of bicycles is complementing public transportation and attracting attention as one of the eco-friendly means of transportation. Daejeon Metropolitan City has been operating Tashu, a public bicycle, since 2008. This study empirically analyzed the spatial characteristics that affect the use of public bicycles by grasping the current status and characteristics of public bicycles and applying spatial econometrics analysis, an analysis model that considers the spatial dependence of spatial data. In addition, a comparative analysis was performed by deriving the results of analyzing six models in terms of rental, return, peak time, non-peak time, weekday, and weekend based on the spatial error model identified as the optimal spatial econometrics model. The analysis model results showed that significant spatial characteristics differed according to the type of public bicycle use. In general, the use of public bicycles was high in areas with a high proportion of young people, a high number of public transportation users, good access to universities and rivers, and relatively low land use mix, and high proportion of apartments. These results indicated that public bicycles are used for commuting purposes on weekdays and leisure purposes on weekends, and if the convenience of using bicycles is improved, the use of public bicycles can be further increased.

Heat transfer analysis in sub-channels of rod bundle geometry with supercritical water

  • Shitsi, Edward;Debrah, Seth Kofi;Chabi, Silas;Arthur, Emmanuel Maurice;Baidoo, Isaac Kwasi
    • Nuclear Engineering and Technology
    • /
    • v.54 no.3
    • /
    • pp.842-848
    • /
    • 2022
  • Parametric studies of heat transfer and fluid flow are very important research of interest because the design and operation of fluid flow and heat transfer systems are guided by these parametric studies. The safety of the system operation and system optimization can be determined by decreasing or increasing particular fluid flow and heat transfer parameter while keeping other parameters constant. The parameters that can be varied in order to determine safe and optimized system include system pressure, mass flow rate, heat flux and coolant inlet temperature among other parameters. The fluid flow and heat transfer systems can also be enhanced by the presence of or without the presence of particular effects including gravity effect among others. The advanced Generation IV reactors to be deployed for large electricity production, have proven to be more thermally efficient (approximately 45% thermal efficiency) than the current light water reactors with a thermal efficiency of approximately 33 ℃. SCWR is one of the Generation IV reactors intended for electricity generation. High Performance Light Water Reactor (HPLWR) is a SCWR type which is under consideration in this study. One-eighth of a proposed fuel assembly design for HPLWR consisting of 7 fuel/rod bundles with 9 coolant sub-channels was the geometry considered in this study to examine the effects of system pressure and mass flow rate on wall and fluid temperatures. Gravity effect on wall and fluid temperatures were also examined on this one-eighth fuel assembly geometry. Computational Fluid Dynamics (CFD) code, STAR-CCM+, was used to obtain the results of the numerical simulations. Based on the parametric analysis carried out, sub-channel 4 performed better in terms of heat transfer because temperatures predicted in sub-channel 9 (corner subchannel) were higher than the ones obtained in sub-channel 4 (central sub-channel). The influence of system mass flow rate, pressure and gravity seem similar in both sub-channels 4 and 9 with temperature distributions higher in sub-channel 9 than in sub-channel 4. In most of the cases considered, temperature distributions (for both fluid and wall) obtained at 25 MPa are higher than those obtained at 23 MPa, temperature distributions obtained at 601.2 kg/h are higher than those obtained at 561.2 kg/h, and temperature distributions obtained without gravity effect are higher than those obtained with gravity effect. The results show that effects of system pressure, mass flowrate and gravity on fluid flow and heat transfer are significant and therefore parametric studies need to be performed to determine safe and optimum operating conditions of fluid flow and heat transfer systems.

Measures to improve the legal system for commercialization of sand dams (샌드댐 상용화를 위한 법제도 개선 방안)

  • Shim, Young-Gyoo;Chung, Il-Moon;Kim, Min-Gyu
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.8
    • /
    • pp.635-643
    • /
    • 2022
  • Attempts are being made to use the sand dam as an alternative water resource securement facility by installing and operating sand dams in valleys, where water intake capacity is extremely limited, in areas with limited water supply in the upstream watershed of Korea. In the case of some countries in Africa, where sand dams are known to be most actively installed and used, it is difficult to find examples of establishing and applying a separate legal system for sand dams. A sand dam is a kind of groundwater dam, and in view of its concept, structural and technical form and characteristics, purpose, use, and function, it will be said that it has the legal character and status as a facility for securing groundwater resources specified in the current 「Ground Water Act」. Interpretation and application of regulations on facilities for securing groundwater resources also supports this. Therefore, it is legal and realistic to promote and implement the sand dam project as one of the installation and management projects for securing underground water resources based on the 「Ground Water Act」.

Improvement Mechanism for Automatic Web Vulnerability Diagnosis (웹취약점 자동진단 개선방안)

  • Kim, Tae-Seop;Jo, In-June
    • The Journal of the Korea Contents Association
    • /
    • v.22 no.2
    • /
    • pp.125-134
    • /
    • 2022
  • Due to the development of smartphone technology, as of 2020, 91.9% of people use the Internet[1] to frequently acquire information through websites and mobile apps. As the number of homepages in charge of providing information is increasing every year, the number of applications for web vulnerability diagnosis, which diagnoses the safety of homepages, is also increasing. In the existing web vulnerability check, the number of diagnostic personnel should increase in proportion to the number of homepages that need diagnosis because the diagnosticians manually test the homepages for vulnerabilities. In reality, however, there is a limit to securing a web vulnerability diagnosis manpower, and if the number of diagnosis manpower is increased, a lot of costs are incurred. To solve these problems, an automatic diagnosis tool is used to replace a part of the manual diagnosis. This paper explores a new method to expand the current automatic diagnosis range. In other words, automatic diagnosis possible items were derived by analyzing the impact of web vulnerability diagnosis items. Furthermore, automatic diagnosis identified possible items through comparative analysis of diagnosis results by performing manual and automatic diagnosis on the website in operation. In addition, it is possible to replace manual diagnosis for possible items, but not all vulnerability items, through the improvement of automatic diagnosis tools. This paper will explore some suggestions that can help improve plans to support and implement automatic diagnosis. Through this, it will be possible to contribute to the creation of a safe website operating environment by focusing on the parts that require precise diagnosis.

A study on the selection of evapotranspiration observatory representative location in Chuncheon Dam basin (증발산량 관측 대표위치 선정에 관한 연구: 춘천댐 유역을 중심으로)

  • Park, Jaegon;Kim, Kiyoung;Lee, Yongjun;Hwag-Bo, Jong Gu
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.11
    • /
    • pp.979-989
    • /
    • 2022
  • In hydrological surveys, observation through representative location is essential due to temporal and spatial limitations and constraints. Regarding the use of hydrological data and the accuracy of the data, there are still insufficient observatories to be used in a specific watershed. In addition, since there is virtually no standard for the location of the current evapotranspiration, this study proposes a method for determining the location of the evapotranspiration. To determining the location of evapotranspiration, a grid is selected in consideration of the operating range of the Flux Tower using the eddy covariance measurement method, which is mainly used to measure evapotranspiration. The grid of representative location was calculated using the factors affecting evapotranspiration and satellite data of evapotranspiration. The grid of representative location was classified as good, fair, and poor. As a result, the number of good grids calculated was 54. It is judged that the classification of the grid has been achieved regarding topography and land use as a characteristic that appeared in the classification of the grid. In particular, in the case of elevation or city area, there was a large deviation, and the calculated good grid was judged to be a group between the two distributions.