• Title/Summary/Keyword: passive construction

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Principle of restoration ecology reflected in the process creating the National Institute of Ecology

  • Kim, A. Reum;Lim, Bong Soon;Seol, Jaewon;Lee, Chang Seok
    • Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.105-116
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    • 2021
  • Background: The creation of the National Institute of Ecology began as a national alternative project to preserve mudflats instead of constructing the industrial complexes by reclamation, and achieve regional development. On the other hand, at the national level, the research institute for ecology was needed to cope with the worsening conditions for maintaining biodiversity due to accelerated climate change such as global warming and increased demand for development. In order to meet these needs, the National Institute of Ecology has the following objectives: (1) carries out studies for ecosystem change due to climate change and biodiversity conservation, (2) performs ecological education to the public through exhibition of various ecosystem models, and (3) promotes regional development through the ecological industry. Furthermore, to achieve these objectives, the National Institute of Ecology thoroughly followed the basic principles of ecology, especially restoration ecology, in the process of its construction. We introduce the principles and cases of ecological restoration applied in the process. Results: We minimized the impact on the ecosystem in order to harmonize with the surrounding environment in all the processes of construction. We pursued passive restoration following the principle of ecological restoration as a process of assisting the recovery of an ecosystem degraded for all the space except in land where artificial facilities were introduced. Reference information was applied thoroughly in the process of active restoration to create biome around the world, Korean peninsula forests, and wetland ecosystems. In order to realize true restoration, we pursued the ecological restoration in a landscape level as the follows. We moved the local road 6 and high-voltage power lines to underground to ensure ecological connectivity within the National Institute of Ecology campus. To enhance ecological diversity, we introduced perch poles and islands as well as floating leaved, emerged, wetland, and riparian plants in wetlands and mantle communities around the forests of the Korean Peninsula in the terrestrial ecosystem. Furthermore, in order to make the public aware of the importance of the intact nature, the low-lying landscape elements, which have disappeared due to excessive land use in most areas of Korea, was created by imitating demilitarized zone (DMZ) landscape that has these landscape elements. Conclusions: The National Institute of Ecology was created in an eco-friendly way by thoroughly reflecting the principles of ecology to suit its status and thus the impact on the existing ecosystem was minimized. This concept was also designed to be reflected in the process of operation. The results have become real, and a result of analysis on carbon budget analysis is approaching the carbon neutrality.

Pullout Resistance Characteristics of Strip-type Reinforcement based on Extensibility (신장성에 따른 띠형 보강재의 인발저항 특성)

  • Lee, Kwang-Wu;Cho, Sam-Deok;Han, Jung-Geun;Hong, Kikwon
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.37-44
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    • 2012
  • This paper describes large scale pullout test results, in order to evaluate extensibility effect of strip-type reinforcement. The same test for ribbed steel strip reinforcement also is conducted to compare the friction resistance reinforcements' evaluation results. The pullout resistance of the ribbed steel strip reinforcement, which has a small cross sectional areas, was better than the friction resistance reinforcements' due to the bearing (passive) resistance. In case of friction resistance reinforcements, the pullout resistance of extensible reinforcement was better than inextensible reinforcement' even though they have a similar cross sectional areas.

The New Challenges for the Republic of Korea Navy and the Development of Maritime Task Flotilla's Force Development (한국해군의 새로운 도전과 기동전단의 발전 방향)

  • Kim, Duk-ki
    • Strategy21
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    • s.39
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    • pp.163-197
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    • 2016
  • The completion of Jeju Naval Base on February 2016 made the Republic of Korea Navy(ROKN) review the size and role of the Maritime Task Flotilla(MTF). The new strategic environment for the 12st century and the new challenges require the Navy to counter North Korea's provocations and prevent potential enemy's threat. The Navy is also required to take part in the variety of international roles and missions commensurated with Korea's global status to maximize the national interest. Despite these changes, Korea's military construction concept is still unable to break away from the old paradigm of the North Korean threat largely centered. In order to develop the current MTF into the Task Group with the construction of Jeju Naval Base, the Navy must newly not only establish new force development plan and fleet management concepts but also go to persuade and convince policy decision makers. To this end, the following efforts should be promoted. First, the ROK Navy steps up efforts in order to share with the Task Group's vision and strategy. The Navy should also provide the size and structure as well as the missions and roles of the Task Group to react to new maritime security environment. Second, the Navy analyse the MTF's ability and what is required and necessary to perform its duty. After that, it must set out the direction of the Task Group's force development. Third, the current missions and roles of the MTF should be re-established to respond various threats. Finally, accommodating of new technology to the MTF should intensify its strengths. The ROK Navy has a mixed force structure consisting of three fixed- base fleets and a MTF. The fixed base fleet has a passive force to defend and protect its own sea areas, but the MTF should actively not only counter North Korea's threats, including ballistic missiles, but also fight potential threats and takes international missions as a primary task force. However, the MTF has a limited capability to accomplish given missions and long-range operations, and thus, the ROK Navy is strongly required to construct the Task Group.

FDDI Throughput and Application Analysis of MAP Network Construction in Manufactruing Environment (제조 환경에서 MAP 네트워크 체제의 FDDI 효율과 적용 해석)

  • Kim, Jeong-Ho;Lee, Min-Nam;Lee, Sang-Beom
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.1
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    • pp.95-105
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    • 1995
  • An appendix to the MAP 3.0 specification notes that there are primary advantages to use of fiber optics : noise immunity, ability to run in difficult electrical environments, safety and high data rates. All of these may be quite useful in various manufacturing environments. In this paper, we study on construction schmes for a fiber-based 802.4 MAP system including the use of both bus and star topologies. We suggest passive star network and FDDI network for manufacturing environment. And then, we propose the FDDI protocol including the use a dual ring topology running at 100 Mbps to physical and datalink layer of MAT specification and analysis it's protocol and topology for abilities in manufacturing environments, We evaluate about applications service, time-critical processing and topology of two models in manufacturing environment.

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Experimental study on a Cantilever Type Metallic Damper for Seismic Retrofit of Building Structures (건물의 내진보강을 위한 캔틸레버타입 강재댐퍼의 실험)

  • Ahn, Tae-Sang;Kim, Young-Ju;Park, Jin-Hwa;Kim, Hyung-Geun;Jang, Dong-Woon;Oh, Sang-Hoon
    • Journal of Korean Society of Steel Construction
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    • v.24 no.2
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    • pp.149-161
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    • 2012
  • The use of seismic energy-dissipative devices for passive control is increasing exponentially in the recent years for both new and existing buildings. Use of these devices started in and has been somewhat limited to developed countries. One of the current challenges is to promote the use of seismic dampers in earthquake-prone developing countries by lowering the cost of the devices. This paper proposed a new type of seismic damper based on yielding of a cantilever type metallic element for seismic retrofit of existing and new building structures. The hysteretic behavior and energy dissipation capacity of the proposed damper was investigated using component tests under cyclic loads. The experimental results indicated that the damping device had stable restoring force characteristics and a high energy dissipation capacity. Based on these results, a simple hysteretic model for predicting the load-displacement curve of the seismic damper was proposed.

Deriving of Major Risk Factors for Planning Phase of u-City Project (U-City사업 계획단계에서의 핵심 리스크 요인 도출)

  • Kim, Ho-Ki;Kwon, Soon-Wook
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.4
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    • pp.139-148
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    • 2011
  • u-City projects are different with the existing urban development projects progress via convergence with IT technology. Therefore, it inheres many risk factors more than the existing development projects as including more complexity and variety. The risk management system to systematically manage those risks which get identified and quantified is required. Especially, the planning phase that is appeared the various forms has a large effect on the success of the business. However, the management of risk factors remains in the passive form. So the problems on u-City project in the planning phase and risk factors of existing development business were analyzed for the continuous growth and the successful performance of u-City project, and those risk factors was identified and quantified by using statistical technique. In the results of it, the core risk factors were obtained through which way and the basis for the effective risk management in u-City business is provided.

Emergy-Simulation Based Building Retrofit

  • Hwang, Yi
    • KIEAE Journal
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    • v.14 no.3
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    • pp.5-13
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    • 2014
  • This paper introduces emergy(spelled with "m") that is a new environmental indicator in architecture, aiming to clarify conflicting claims of building design components in the process of energy-retrofit. Much of design practitioners' attention on low energy use in operational phases, may simply shift the lowered environmental impact within the building boundary to large consumption of energy in another area. Specifically, building energy reduction strategies without a holistic view starting from natural formation, may lead to the depletion of non-renewable geobiological sources (e.g. minerals, fossil fuels, etc.), which leaves a building with an isolated energy-efficient object. Therefore, to overcome the narrow outlook, this research discusses the total ecological impact of a building which embraces all process energy as well as environmental cost represented by emergy. A case study has been conducted to explore emergy-driven design work. In comparison with operational energy-driven scenarios, the results elucidate how energy and emergy-oriented decision-making bring about different design results, and quantify building components' emergy contribution in the end. An average-size ($101.9m^2$) single family house located in South Korea was sampled as a benchmark case, and the analysis of energy and material use was conducted for establishment of the baseline. Adoption of the small building is effective for the goal of study since this research intends to measure environmental impact according to variation of passive design elements (windows size, building orientation, wall materials) with new metric (emergy) regardless of mechanical systems. Performance simulations of operational energy were developed and analyzed separately from the calculation of emergy magnitudes in building construction, and then the total emergy demand of each proposed design was evaluated. Emergy synthesis results verify that the least operational energy scenario requires greater investment in indirect energy in construction, which clearly reveals that efficiency gains are likely to be overwhelmed by increment of material flows. This result places importance on consideration of indirect energy use underscoring necessity of emergy evaluation towards the environment-friendly building in broader sense.

Real-time hybrid simulation of smart base-isolated raised floor systems for high-tech industry

  • Chen, Pei-Ching;Hsu, Shiau-Ching;Zhong, You-Jin;Wang, Shiang-Jung
    • Smart Structures and Systems
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    • v.23 no.1
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    • pp.91-106
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    • 2019
  • Adopting sloped rolling-type isolation devices underneath a raised floor system has been proved as one of the most effective approaches to mitigate seismic responses of the protected equipment installed above. However, pounding against surrounding walls or other obstructions may occur if such a base-isolated raised floor system is subjected to long-period excitation, leading to adverse effects or even more severe damage. In this study, real-time hybrid simulation (RTHS) is adopted to assess the control performance of a smart base-isolated raised floor system as it is an efficient and cost-effective experimental method. It is composed of multiple sloped rolling-type isolation devices, a rigid steel platen, four magnetorheological (MR) dampers, and protected high-tech equipment. One of the MR dampers is physically tested in the laboratory while the remainders are numerically simulated. In order to consider the effect of input excitation characteristics on the isolation performance, the smart base-isolated raised floor system is assumed to be located at the roof of a building and the ground level. Four control algorithms are designed for the MR dampers including passive-on, switching, modified switching, and fuzzy logic control. Six artificial spectrum-compatible input excitations and three slope angles of the isolation devices are considered in the RTHS. Experimental results demonstrate that the incorporation of semi-active control into a base-isolated raised floor system is effective and feasible in practice for high-tech industry.

A Study on the Performance Measuring Methods and Standard for the Technical Package in Zero Energy Building (제로에너지빌딩의 기술 패키지 구성을 위한 성능 기준 및 성능 측정 방법에 관한 연구)

  • Sung, Uk-Joo;Rim, Min-Yeop;Kim, Seok-Hyun;Cho, Soo
    • Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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    • v.12 no.6
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    • pp.543-556
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    • 2018
  • Zero energy building was attended for energy consumption minimization by the energy saving technology about building heating and cooling energy consumption and the renewable energy production facility. So the government has supported the zero energy building supply for decreasing green gas emissions. The study about inventory of zero energy building has many proceeding. That inventory need the information of material and equipment. So information of material and equipment about zero energy building must be included for the zero energy building realization. Actually the database of zero energy building inventory construction through the inventory established studies has difficult because the database need many information. In this study, author proposed the test methods and performance reference for upload at inventory. It was constructed to material - module - package. Also the author analyzed the construction of the technical package for zero energy building. The author separated performance category to the energy performance for energy analysis and other performance for confirmed the durability, stability and etc. This performance category proposed the table. The test methods of material and equipment in the passive package and active package proposed to the international standard and korea standard basically korea standard. Also the performance reference was proposed to korea legal standard and various standard by this study results. And the authors proposed the table of performance value, test methods, performance reference. By result of this study, the test methods and performance reference will be used the basic data for inventory of zero energy building.

Improving the seismic behavior of diagonal braces by developing a new combined slit damper and shape memory alloys

  • Vafadar, Farzad;Broujerdian, Vahid;Ghamari, Ali
    • Structural Engineering and Mechanics
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    • v.82 no.1
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    • pp.107-120
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    • 2022
  • The bracing members capable of active control against seismic loads to reduce earthquake damage have been widely utilized in construction projects. Effectively reducing the structural damage caused by earthquake events, bracing systems equipped with retrofitting damper devices, which take advantage of the energy dissipation and impact absorption, have been widely used in practical construction sites. Shape Memory Alloys (SMAs) are a new generation of smart materials with the capability of recovering their predefined shape after experiencing a large strain. This is mainly due to the shape memory effects and the superelasticity of SMA. These properties make SMA an excellent alternative to be used in passive, semi-active, and active control systems in civil engineering applications. In this research, a new system in diagonal braces with slit damper combined with SMA is investigated. The diagonal element under the effect of tensile and compressive force turns to shear force in the slit damper and creates tension in the SMA. Therefore, by creating shear forces in the damper, it leads to yield and increases the energy absorption capacity of the system. The purpose of using SMA, in addition to increasing the stiffness and strength of the system, is to create reversibility for the system. According to the results, the highest capacity is related to the case where the ratio of the width of the middle section to the width of the end section (b1/b) is 1.0 and the ratio of the height of the middle part to the total height of the damper (h1/h) is 0.1. This is mainly because in this case, the damper section has the highest cross-section. In contrast, the lowest capacity is related to the case where b1/b=0.1 and the ratio h1/h=0.8.