• Title/Summary/Keyword: Systematic reduction study

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Wind-induced vibration characteristics and parametric analysis of large hyperbolic cooling towers with different feature sizes

  • Ke, Shitang;Ge, Yaojun;Zhao, Lin;Tamura, Yukio
    • Structural Engineering and Mechanics
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    • v.54 no.5
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    • pp.891-908
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    • 2015
  • For a systematic study on wind-induced vibration characteristics of large hyperbolic cooling towers with different feature sizes, the pressure measurement tests are finished on the rigid body models of three representative cooling towers with the height of 155 m, 177 m and 215 m respectively. Combining the refined frequency-domain algorithm of wind-induced responses, the wind-induced average response, resonant response, background response, coupling response and wind vibration coefficients of large cooling towers with different feature sizes are obtained. Based on the calculating results, the parametric analysis on wind-induced vibration of cooling towers is carried out, e.g. the feature sizes, damping ratio and the interference effect of surrounding buildings. The discussion shows that the increase of feature sizes makes wind-induced average response and fluctuating response larger correspondingly, and the proportion of resonant response also gradually increased, but it has little effect on the wind vibration coefficient. The increase of damping ratio makes resonant response and the wind vibration coefficient decreases obviously, which brings about no effect on average response and background response. The interference effect of surrounding buildings makes the fluctuating response and wind vibration coefficient increased significantly, furthermore, the increase ranges of resonant response is greater than background response.

Optimization of three small-scale solar membrane distillation desalination systems

  • Chang, Hsuan;Hung, Chen-Yu;Chang, Cheng-Liang;Cheng, Tung-Wen;Ho, Chii-Dong
    • Membrane and Water Treatment
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    • v.6 no.6
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    • pp.451-476
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    • 2015
  • Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving the energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum-cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo steady state approach for equipment sizing and the dynamic optimization using overall system mathematical models. The s-SMDDS employing three MD configurations, including the air gap (AGMD), direct contact (DCMD) and vacuum (VMD) types, are optimized. The membrane area of each system is $11.5m^2$. The AGMD system operated for 500 kg/day water production rate gives the lowest unit cost of $5.92/m^3$. The performance ratio and recovery ratio are 0.85 and 4.07%, respectively. For the commercial membrane employed in this study, the increase of membrane mass transfer coefficient up to two times is beneficial for cost reduction and the reduction of membrane heat transfer coefficient only affects the cost of the DCMD system.

Denoising Traditional Architectural Drawings with Image Generation and Supervised Learning (이미지 생성 및 지도학습을 통한 전통 건축 도면 노이즈 제거)

  • Choi, Nakkwan;Lee, Yongsik;Lee, Seungjae;Yang, Seungjoon
    • Journal of architectural history
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    • v.31 no.1
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    • pp.41-50
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    • 2022
  • Traditional wooden buildings deform over time and are vulnerable to fire or earthquakes. Therefore, traditional wooden buildings require continuous management and repair, and securing architectural drawings is essential for repair and restoration. Unlike modernized CAD drawings, traditional wooden building drawings scan and store hand-drawn drawings, and in this process, many noise is included due to damage to the drawing itself. These drawings are digitized, but their utilization is poor due to noise. Difficulties in systematic management of traditional wooden buildings are increasing. Noise removal by existing algorithms has limited drawings that can be applied according to noise characteristics and the performance is not uniform. This study presents deep artificial neural network based noised reduction for architectural drawings. Front/side elevation drawings, floor plans, detail drawings of Korean wooden treasure buildings were considered. First, the noise properties of the architectural drawings were learned with both a cycle generative model and heuristic image fusion methods. Consequently, a noise reduction network was trained through supervised learning using training sets prepared using the noise models. The proposed method provided effective removal of noise without deteriorating fine lines in the architectural drawings and it showed good performance for various noise types.

Study on Tax Exemption and Reduction for Religious Bodies in Korea - Proposals for improvement in the systems of tax exemption and reduction for religious bodies under the Local Tax Law - (지방세법상 종교단체 비과세·감면의 연구)

  • Park, Sang-Bong
    • Management & Information Systems Review
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    • v.31 no.4
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    • pp.363-376
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    • 2012
  • In Korea, religious bodies are being given tax benefits like tax exemption and reduction in accordance with the Local Tax Law. By the way, there's no difference between tax benefits given to religious bodies and other kinds of non-profit corporations. In other words, tax exemption and reduction for religious bodies are being made without considering the very nature of the bodies. This is causing lots of problems. Currently, tax supports to religious bodies are mostly focusing on tax items related to their property, considerably diverting from the ultimate purpose and objectives of tax exemption and reduction for religious organizations. This is not also weakening local finance, but also diverting from the basic intent of so-called the induction system that if necessary, tax supports are given, but they have to be minimized. To solve these problems, comprehensive actions need to be taken, for example, reducing tax benefits given to religious bodies' property and motivating the bodies to make a variety of donations like in developed countries. Now, religious bodies should change their consciousness of tax liability that is imposed by the Local Tax Law. And the government should be more systematic in the collection and management of data that are necessary to levy taxes on religious bodies. If required, the government show the data to religious bodies, convincing them to positively fulfil their tax liability without complaint. This study discusses the current state and problems of existing local tax systems in relation to religious bodies and then propose how to improve the systems. If the systems of tax exemption and reduction for religious bodies under the Local Tax Law can be improved, it would contribute to improve the finance of local autonomous bodies.

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A Study on the Characteristics of System Furniture (시스템 가구의 특성에 관한 연구)

  • 신홍경
    • Korean Institute of Interior Design Journal
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    • no.6
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    • pp.45-52
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    • 1995
  • The presentation of the method by which the furniture and the architecture can be unified in one category, and the study and the verification on the mutual relation in the shape and the function are having been consistently made till the late twenties. The change of the social structure such as increasing the unit dwelling space with the small scale comes to need the efficiency in using space and the open dwelling space by the systematic spa-cial formation. Therefore, the understanding of the mean-ing and the characteristics of system furnitures as the design method which can meet such needs will be made here in this study. The application of the systematic consideration as the method of interior design means the formation of the firm image on the spacial environment through the mix-ture and link of the heterogeneous factors, the organic connection of each surface, the establishment of the natu-ral relation by linking the heterogeneous materials mutu-ally. and the easiness of the entire plan in the end. This study aims at analyzing and studying the typical charac-teristics by understanding the historical background and methodical principle which enabled the appearance of this kind of thought, and the adapted cases of the wood and metal material system furniture. There may be difference between the structural sub-stance and formative consideration. Transformative furni-ture which consists of the factors is the concept for the encrease of the multi purpose value by mixing the unit cabinets. One system can be separated horizontally, verti-cally, and to the drawers, and it gives us the disengage-ment from the artificial environment, since all the heights and width can be transformed as per each situa-tion of the space. The factors which can not be found in the other existing furniture are as follows. 1. disengagement from the artificial environment. 2. establishing the new productiosn trend as freed from the customers' fashion trend. 3. presenting the producing condition which leads the exact technology. 4. flexibility of the furniture which enables the reduction and enlargement in each situation.

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Establishing the Importance Institution for Prevention of Human Error (인적오류 예방을 위한 제도의 상대적 중요도 분석)

  • Moon, Woo-Choon;Kim, Woong-Yi
    • Journal of Advanced Navigation Technology
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    • v.17 no.4
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    • pp.377-385
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    • 2013
  • Since the late 1950s, concerted efforts to reduce the accident rate in aviation have yielded unprecedented levels of safety. Although, the overall accident rate has declined considerably over the years, unfortunately reductions in human error-related accidents in aviation have failed to keep pace with the reduction of accidents due to environmental and mechanical factors. Today, a very large percentage of all aviation are attributable, directly or indirectly, to some form of human error. As a result of many study, a range of prevention of human error have been developed. but each of kind is lack of a precision, effectiveness and seem to be considered for aspect of deficiency as an systematic accessibility. So, we're going to analysis the most effective and systematic prevention of human error and study on consolidating method for human error and aviation safety. In this study, several alternatives for the prevention of human errors a priority to understand and solve problems by identifying the implications for human error to be presented.

An Analysis of SEASAT Altimeter Measurements over the East China Sea (동지나해(東支那海)의 SEASAT 위성(衛星) 고도계(高度計) 자료분석(資料分析))

  • Choi, Byung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.85-93
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    • 1985
  • An initial attempt was made to investigate sea surface topography in the East China Sea using the SEASAT-A altimeter data. Over the study area for the two major typhoon surges generated during the SEASAT mission, space and time variability of the shallow water tides, meteorological effects and earth tides were removed from the altimetric measurements using the systematic procedures which include the two-dimensional sea model of the East China Sea. The analysis of ten flights over the ground track for the typhoon periods were presented and discussions were made for further studies. This initial study has been undertaken in association with the programme of establishment of systematic altimeter data reduction system for the study of shelf dynamics in the East China Sea.

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Damage assessment of beams from changes in natural frequencies using ant colony optimization

  • Majumdar, Aditi;De, Ambar;Maity, Damodar;Maiti, Dipak Kumar
    • Structural Engineering and Mechanics
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    • v.45 no.3
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    • pp.391-410
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    • 2013
  • A numerical method is presented here to detect and assess structural damages from changes in natural frequencies using Ant Colony Optimization (ACO) algorithm. It is possible to formulate the inverse problem in terms of optimization and then to utilize a solution technique employing ACO to assess the damage/damages of structures using natural frequencies. The laboratory tested data has been used to verify the proposed algorithm. The study indicates the potentiality of the developed code to solve a wide range of inverse identification problems in a systematic manner. The developed code is used to assess damages of beam like structures using a first few natural frequencies. The outcomes of the simulated results show that the developed method can detect and estimate the amount of damages with satisfactory precision.

Low Fertility & Infertility (저출산/불임)

  • Kim, Young-Shim;Hwang, Hae-Shin;Hwang, Hye-Jung
    • Korean Journal of Child Studies
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    • v.30 no.6
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    • pp.75-84
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    • 2009
  • Recently, low birthrate has been recognized as a social problem, which is expressed as catastrophy of population. There are several reasons why low birth rate has occurred directly and indirectly, generating total economic and social burden for our society. That is, low birthrate should not be simply regarded as reduction of population. The present study identified the reasons of low birthrate and the current status of infertility, and examined practical and theoretical issues in terms of low birthrate. It is our contention that low birthrate and infertility is one of the most important governmental issue to enhance quality of life of the public. Thus, integrated and systematic policy must be developed and implemented to effectively meet the issues.

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A Study on the Improvement of Energy Efficiency in Warehouses (물류센터의 에너지 효율 개선 방안에 관한 연구)

  • Sun, Jong-Keun;Ryoo, Ho-Sang
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.6
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    • pp.66-72
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    • 2012
  • The main sources of energy consumption in warehouses are MHE(Material Handling Equipment), HVAC(Heating, Ventilating and Air Conditioning) and Lighting. Warehouses in advanced countries raise energy efficiencies with energy consumption diagnosis, technology development and systematic management and improvements for MHE, HVAC and Illuminating, etc. They have managed illuminating system, air conditioning, motor driven system, air circulation method, dock facility, layout, AS/RS, conveyor system and battery management, etc. Ansong Pyeongtaek area investigation resulted that 43.9[%] of enterprises are managing partly energy consumption source. But the data resulted with not substantial management of energy consumption but passive management for only electric bill curtailment. Therefore through survey research & visiting interviews of some companies in Ansong Pyeongtaek area, we understood the status of energy consumption source management and proposed energy efficiency methods on the basis of that results.