• Title/Summary/Keyword: The Pre-feasibility study

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Analysis of Factors Affecting Economic Feasibility of Long-term Public Rental Housing Reconstruction Project

  • Joe, Won Goog;Cho, Jae Ho;Son, Bo Sik;Chae, Myung Jin;Lim, Nam Gi;Chun, Jae Youl
    • Architectural research
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    • v.24 no.3
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    • pp.85-91
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    • 2022
  • The public rental housing policy aims to provide the housing to the vulnerable class who do not have enough credit to own houses. The Korean government introduced new policies for housing supply to improve the availability of new houses. However, it is difficult to expand the supply because of the accumulated deficit of public rental housing. In this study, the economic feasibility of long-term public rental housing reconstruction projects was examined to ensure the economic and sustainable growth of public rental housing. The research found that the compensation for the accumulated deficit is needed. Also the research analyzed and identified the factors affecting the economic feasibility of reconstruction projects. The significant factors identified in this research are: the supply price of pre-sale/rental housing in the reconstruction project, total cost of the reconstruction project, and total floor area of the reconstruction project. According to the analysis results, it is necessary to increase the rent of existing long-term public rental housing, expand the government subsidy, increase the supply price of pre-sale/rental housing, and reduce the total project cost. However, there are limitations. For example, the fluctuations of construction market, residents' burden of housing costs, and the limit of the budget of the public housing authority. The increasing total Floor Area Ratio(FAR) limitation of the reconstruction project would be the realistic solution to the problem because it gives incentives to the reconstruction project.

An analytical model of the additional confining stress in a prestress-reinforced embankment

  • Fang Xu;Wuming Leng;Xi Ai;Hossein Moayedi;Qishu Zhang;Xinyu Ye
    • Smart Structures and Systems
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    • v.31 no.5
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    • pp.517-529
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    • 2023
  • Using a device composed of two lateral pressure plates (LPPs) and a steel reinforcement bar to apply horizontal pressure on slope surfaces, a newly developed prestress-reinforced embankment (PRE) is proposed, to which can be adopted in strengthening railway subgrades. In this study, an analytical model, which is available of calculating additional confining stress (σH) at any point in a PRE, was established based on the theory of elasticity. In addition, to verify the proposed analytical model, three dimensional (3D) finite element analyses were conducted and the feasibility in application was also identified and discussed. In order to study the performance of the PRE, the propagation of σH in a PRE was analyzed and discussed based on the analytical model. For the aim of convenience in application, calculation charts were developed in terms of three dimensionless parameters, and they can be used to accurately and efficiently predict the σH in a PRE regardless of the embankment slope ratio and LPP side length ratio. Finally, the potential applications of the proposed analytical model were discussed.

Effects of ultrasound coupled with potassium permanganate pre-treatment of sludge on aerobic digestion

  • Demir, Ozlem
    • Advances in environmental research
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    • v.5 no.4
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    • pp.251-262
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    • 2016
  • The biodegradability and decomposition efficiencies increase with the pre-treatment of sludge in a digestion process. In this study, the feasibility of ultrasound coupled with potassium permanganate oxidation as a disintegration method and digestibility of aerobic reactor fed with disintegrated sludge with ultrasound coupled potassium permanganate were investigated. The first stage of the study focused on determining the optimum condition for ultrasonic pre-treatment for achieving better destruction efficiency of sludge. The second part of the study, the aerobic digestibility of sludge disintegrated with ultrasound and potassium permanganate oxidation alone and combined were examined comparatively. The results showed that when 20 min of ultrasonic pre-treatment applied, the specific energy output was 49384 kJ/kgTS with disintegration degree of 58.84%. During the operation of aerobic digester, VS/TS ratios of digesters fed with disintegrated sludge decreased indicating that disintegration methods could obviously enhance aerobic digestion performance. The highest reduction in volatile solids was 75% in the digester fed with ultrasound+potassium permanganate disintegrated sludge at the end of the operation compared to digester fed with raw sludge. Total Nitrogen (TN) and Total Phosphorus (TP) levels in sludge supernatant increased with this combined method significantly. Besides, it promoted the production of ${\bullet}OH$, thus enhancing the release of Carbon (C), Nitrogen (N) and Phosphorus (P) from the sludge. Disintegration with all methods used in this study could not improve Capillary Suction Time (CST) reduction in disintegrated digesters during the operation. The results demonstrated that the combined ultrasound treatment and potassium permanganate oxidation method improves the biodegradability compared to control reactor or their single application.

The effect and feasibility of knee extension assist orthosis on balance and gait in subacute stroke patients : case study (아급성 뇌졸중 환자에게 무릎 신전 보조기기가 균형과 보행에 미치는 효과 및 유용성 : 사례 연구)

  • Shim, Jung Woo;Yang, Seong Jae;Yoon, Hyun Sik
    • Journal of Korean Physical Therapy Science
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    • v.27 no.3
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    • pp.35-44
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    • 2020
  • Background: This study was to confirm the effect and feasibility of knee extension assist orthosis (KEAO) on balance and gait in subacute stroke patients. Design: Case study. Methods: The subjects of the study were 4 subacute stroke patients, who had an onset period of less than 6 months. The limit of stability (LOS) and berg balance scale (BBS), timed up and go test (TUG) were used to verify the dynamic balance ability, static balance ability, and gait ability pre and post and after wearing the knee extension assist orthosis (KEAO). In addition, the satisfaction survey was to confirm the feasibility of the knee extension assist orthosis (KEAO) through the to Korean quebec user evaluation of satisfaction assistive technology 2.0 (K-QUEST 2.0). Results: After the wearing on KEAO, the distance for the limit of stability decreased by mean 541.25±240.46 mm2, and the score on the berg balance scale improved by mean 5±2.71 point, and the time for the timed up and go test deceased by mean 3.75±1.71 second. The stability and durability were found to be full score, and the control, ease, effectiveness were some high score, and the size, weight, comfort were some low score in the satisfaction and feasibility. Conclusion: The knee extension assist orthosis (KEAO) produce in this study was improved the static balance ability, dynamic balance ability and gait ability of subacute stroke patients, and the satisfaction and feasibility were high in the stability, durability and effectiveness of the user.

Development of the Analysis Methodology for Interrelationship between Transportation Facilities (교통시설 상호연관성 분석방법론 개발)

  • Namkung, Baekkyu;Chung, Sungbong;Chang, Yu-Jin
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.169-176
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    • 2013
  • PURPOSES : Lots of criticism such as over/duplication investment, inconsistency of the policies among local governments and national plans etc. has been aroused due to the policy of supply-driven construction for transportation facilities. Recently, according to the environmental-friendly transportation policy, the investment of railroad has been expanded gradually, however the duplication with existing road facility makes it difficult to construct railroad. Thus it is necessary to evaluate the interrelationship between new project and existing facilities in the planning stage. However the method and the criteria for analyzing the duplication and over-investment of projects are not established in the manual, thus the feasibility of these projects are carried out from the economic point of view. METHODS: First, It reviewed about interrelationship criteria(domestic, overseas) and proposed implications and this study directions. Next, It developed the methods of evaluating independency, competitiveness and complementarity. RESULTS : In this study, the methods of evaluating independency, competitiveness and complementarity etc. are suggested to analyze the interrelationship between transportation facilities. The case study was carried out to examine the applicability of the methods. CONCLUSIONS: The methods raise rationality of decision-making compared to existing one. In the future, these methods are introduced into the manual of pre-feasibility study and feasibility study, more efficient decision-making and investment are expected.

Feasibility Study on the Vitrification of Concentrated Boric Acid Waste (붕산농축폐액 유리화 타당성 연구)

  • Cho, Hyun-Je;Kim, Deuk-Man;Park, Jong-Kil
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.2
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    • pp.143-150
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    • 2010
  • Vitrification technology has been gradually recognized as one of effective solidification methods for concentrated boric acid wastes generated in PWR. Vitrification for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. A feasibility study for the vitrification of concentrated boric acid wastes has been performed with developing the pre-treatment methods of powdered wastes, glass compositions using glass formulation and demonstration test. The pre-treatment method is pelletizing the powder type for stable feeding within cold crucible melter. The glass compositions should be developed considering molten glass are related with wastes reduction. High contents of sodium and boron within borate wastes give influence to waste loading. A variety of factors obtained from the demonstration test are reviewed, which is wastes feeding rate, off-gas characteristics on stack and glass characteristics of final products such as durability for implementing the wastes disposal requirement. The aim of this paper is to present the feasibility of vitrification and review the solidification method for concentrated boric acid wastes and obtain the physicochemical characteristics of solidified glass.

Investigation of Teachers' Awareness of Flipped Classroom to Explore its Educational Feasibility (거꾸로 교실(Flipped Classroom)의 교육적 활용가능성 탐색을 위한 교사 인식 조사)

  • Park, TaeJung;Cha, HyunJin
    • The Journal of Korean Association of Computer Education
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    • v.18 no.1
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    • pp.81-97
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    • 2015
  • Although Flipped Classroom(FC) which has recently attracted attention of educational field, showed its various educational effects such as learning academic achievement, attitude, collaborative learning and self-regulated learning. other studies also showed a number of significant problems and challenges in practically implementing. Thus, this study aims to investigate in-service and pre-service teachers awareness of FC in order to explore its educational feasibility for successfully adopting it to classrooms through the alternative solutions to its limitations. To achieve this goal, we firstly conducted literature review on teaching and learning models and guidelines to draw educational prerequisites and then analyzed needs of 156 pre-service teachers and 42 in-service teachers. According to survey results, 80% of teachers are willing to apply FC to their classes and hope to be offered with pre-learning activity materials and guidelines. They consider junior high school students and college students as appropriate learners, social science, science, Korean, and English as suitable subjects, and video content as optimal materials for pre-learning activities.

Effectiveness Analysis of Preliminary Evaluation of Public Library Establishment Feasibility Based on the Revised Library Act (도서관법 개정에 따른 공공도서관 설립 타당성 사전평가의 실효성 분석)

  • Kim, Hyo-Yoon
    • Journal of Korean Library and Information Science Society
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    • v.53 no.3
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    • pp.119-135
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    • 2022
  • The purpose of this study is to determine whether the pre-evaluation of the feasibility of establishing a public library, which is mandatory according to the revision of the Library Act, can improve the quality of the library. Therefore, the effectiveness of the preliminary evaluation was analyzed through the case analysis of the preliminary evaluation of the public library construction support project, which was implemented for the same purpose before the revision of the Library Act. In the case of libraries built after preliminary evaluation, most of the minimum standards for legal librarians required by the Enforcement Decree of the Library Act were secured, which helped secure basic library personnel. However, there were few libraries that secured and operated as much manpower as originally planned, and in some cases, the application applied to operate the library directly, but it was changed to consignment operation at the time of opening, so the pre-review details were not faithfully reflected. This study proposed re-establishing realistic librarian placement standards according to the revision of the law and introducing a post-evaluation using the library registration system so that it would not be a formal pre-process through case analysis.

Feasibility Study for an Optical Sensing System for Hardy Kiwi (Actinidia arguta) Sugar Content Estimation

  • Lee, Sangyoon;Sarkar, Shagor;Park, Youngki;Yang, Jaekyeong;Kweon, Giyoung
    • Journal of agriculture & life science
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    • v.53 no.3
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    • pp.147-157
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    • 2019
  • In this study, we tried to find out the most appropriate pre-processing method and to verify the feasibility of developing a low-price sensing system for predicting the hardy kiwis sugar content based on VNIRS and subsequent spectral analysis. A total of 495 hardy kiwi samples were collected from three farms in Muju, Jeollabukdo, South Korea. The samples were scanned with a spectrophotometer in the range of 730-2300 nm with 1 nm spectral sampling interval. The measured data were arbitrarily separated into calibration and validation data for sugar content prediction. Partial least squares (PLS) regression was performed using various combinations of pre-processing methods. When the latent variable (LV) was 8 with the pre-processing combination of standard normal variate (SNV) and orthogonal signal correction (OSC), the highest R2 values of calibration and validation were 0.78 and 0.84, respectively. The possibility of predicting the sugar content of hardy kiwi was also examined at spectral sampling intervals of 6 and 10 nm in the narrower spectral range from 730 nm to 1200 nm for a low-price optical sensing system. The prediction performance had promising results with R2 values of 0.84 and 0.80 for 6 and 10 nm, respectively. Future studies will aim to develop a low-price optical sensing system with a combination of optical components such as photodiodes, light-emitting diodes (LEDs) and/or lamps, and to locate a more reliable prediction model by including meteorological data, soil data, and different varieties of hardy kiwi plants.

Evaluation on Enhanced Biodegradability in Landfill Leachate by Fenton Oxidation (Fenton 산화법에 의한 매립장 침출수의 생물 분해성 증진에 관한 평가)

  • Lee, Byung-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.3
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    • pp.250-256
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    • 2005
  • This study was aimed to investigate treatment feasibility of leachate from D landfill that is located in gyr대ungbuk. From the analytical results of leachate, organic and nonbiodegradable matters were contained in high concentration. Thus chemical treatment was introduced to degrade nonbiodegradable matters in pre or post biological process. Two types of Fenton oxidation were adapted in this study. The first one is pre treatment process before biological treatment. The second one is post treatment process after biological treatment. The optimal conditions of both treatment methods were investigated as follows. In case of pre treatment process, the optimal conditions appeared in $Fe^{+2}/H_2O_2$(mmol/mmol): 0.1, $H_2O_2/CODcr$(mg/mg): 27.0, pH: 3 and reaction time: 2hrs. On the other hand, in case of post treatment process, the optimal conditions appeared in $Fe^{2+}$(mmol/mmol): 0.14, $H_2O_2/COD_{cr}$(mg/mg): 57.4, pH: 3 and reaction time: 1.25hrs. In the above optimal conditions, high COD removal was obtained in pre and post treatment process. Also it can expect that Fenton oxidation converted nonbiodegradable matters into biodegradable matters.