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Pb Isotopic Composition of the Ore Deposits Distributed in Jeonbuk Province (전북 광상의 납 동위원소 조성에 대한 고찰)

  • Chung Jae-Il;Park Kye-Hun
    • The Journal of the Petrological Society of Korea
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    • v.15 no.2 s.44
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    • pp.81-89
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    • 2006
  • Pb isotopic compositions were determined from the ore deposits of Beonam, Dongjin, Jeoksang and Bukchang mines distributed within Jeolabuk-do. As a result, individual mine shows significantly different values of Pb isotopic compositions from each other. Pb isotopic values of the Beonam, Bukchang and Dongjin mines altogether from linear variation, but it is too steep to represent their formation age. Instead, such trend suggests that these ore leads were originated from binary mixing. Precambrian basement rocks and Mesozoic granitoids are suggested for such two end-members. The relative contribution of lead from each source seems to be quite different for each ore deposit, implying that the circulation of the ore-forming fluid was very localized when they were formed. In the case of Dongjin mine it seems significant portion of the ore leads were originated from the basement rocks, which suggests that related igneous rock seems to have acted as heat source to generate circulation of the fluid rather than the source of the ore-forming elements.

Study on Practical Evaluation for Sustainability in Textile and Fashion Companies (섬유·패션기업의 지속가능성 실천 평가 연구)

  • Syn, Hye-Young;Geum, Key-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.38 no.2
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    • pp.137-146
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    • 2014
  • The practice of sustainability is an important subject to integrate into the management, product planning, manufacturing by textile and fashion companies as well as consumption by end-users. This study shows an evaluation scale designed to assess the practical cases in order to suggest efficient and systematic methods to fulfill the practice of sustainability in textile and fashion companies. First, companies should practice environmental sustainability to use eco-friendly material and cleaner production, protect the environment, and save natural resources. Second, social sustainability is required to fulfill social responsibility and ethical needs. Third, companies should perform various innovative activities, transparency in management, fair competition and economic contribution in the local community in order to maintain economic sustainability to survive in industry. Finally, cultural sustainability should be fulfilled by textile and fashion companies as part of the intellectual-cultural industry in a way that increases the importance of ethnic and cultural diversity. Textile and fashion companies should fulfill four environmental, social, and economic cultural sustainable subjects in a balanced method to accomplish sustainability. The concerns and practices of environmental sustainability are comparatively highly rated due to the analysis of the evaluation scale. However, cultural sustainability (a need of the times) is poorly rated and needs more attention. Therefore, the evaluation scale can be used as a standard tool to fulfill the sustainability of companies and brands from the viewpoint of improving poor and insufficiently sustainable items as well as balancing sustainability management.

Service Architecture Models For Fog Computing: A Remedy for Latency Issues in Data Access from Clouds

  • Khalid, Adnan;Shahbaz, Muhammad
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.5
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    • pp.2310-2345
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    • 2017
  • With the emergence of the Internet of Things (IoT) the world is projecting towards a scenario where every object in the world (including humans) acts as a sender and receiver of data and if we were to see that concept mature we would soon be talking of billions more users of the cloud networks. The cloud technology is a very apt alternative to permanent storage when it comes to bulk storage and reporting. It has however shown weaknesses concerning real-time data accessibility and processing. The bandwidth availability of the cloud networks is limited and combined with the highly centralized storage structure and geographical vastness of the network in terms of distance from the end user the cloud just does not seem like a friendly environment for real-time IOT data. This paper aims at highlighting the importance of Flavio Bonomi's idea of Fog Computing which has been glamorized and marketed by Cisco but has not yet been given a proper service architecture that would explain how it would be used in terms of various service models i-e IaaS, PaaS and SaaS, of the Cloud. The main contribution of the paper would be models for IaaS, PaaS and SaaS for Fog environments. The paper would conclude by highlighting the importance of the presented models and giving a consolidated overview of how they would work. It would also calculate the respective latencies for fog and cloud to prove that our models would work. We have used CloudSim and iFogSim to show the effectiveness of the paradigm shift from traditional cloud architecture to our Fog architecture.

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.

Investigation of stiffening scheme effectiveness towards buckling stability enhancement in tubular steel wind turbine towers

  • Stavridou, Nafsika;Efthymiou, Evangelos;Gerasimidis, Simos;Baniotopoulos, Charalampos C.
    • Steel and Composite Structures
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    • v.19 no.5
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    • pp.1115-1144
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    • 2015
  • Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

A Study on the Ultimate Strength Analysis of Damaged Tubular Members (손상원통부재(損傷圓筒部材)의 최종강도(最終强度) 해석(解析)에 관한 연구(硏究))

  • Jeom-K.,Paik;Byung-C.,Shin
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.1
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    • pp.24-34
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    • 1990
  • In this paper, the formulation of a new simplified finite element is made to analyze the ultimate strength of damaged tubular members subjected to combined axial force and end moment. A damaged tubular member that has the bending deformation and the local dent is modeled by beam elements. Tangent elastic stiffness matrix of a beam element which contains the effect of the geometric nonlinearity is derived by using the updated Lagrangian approach. Here the contribution of the stiffness in the dented area is neglected since its resistance against the external loads is considered to be small. A fully plastic interaction curve of the element under combined loads taking account of the local dent effect is selected as a yielding criterion at each nodal point. Also tangent elasto-plastic stiffness matrix of the element is formulated by plastic node method. Comparison with the present solution and the existing experimental results is made showing that the present method gives quite an accurate solution.

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Research Outcomes and Limitations of Records and Archives Organization in Korea (국내 기록조직 연구의 성과와 과제)

  • Lee, Eun-Ju;Rho, Jee-Hyun
    • Journal of Korean Society of Archives and Records Management
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    • v.20 no.4
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    • pp.129-146
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    • 2020
  • This study aims to investigate the outcomes and limitations of research studies on records and archives organization published in Korea. In particular, it will serve as an in-depth examination of the contribution of this area of research to the improvements and changes in the country's records management field. To this end, 150 journal articles related to the records and archives organization were gathered. After extracting refined keywords from the titles and author-assigned keywords, terminology analysis and contents analysis were conducted. On the one hand, terminology analysis (frequency and network analysis) identified frequently discussed topics and the relationships between them. On the other hand, through content analysis, the study revealed the detailed contents regarding the two main topics and their meanings.

Estimation of Shear Strength of Beam-Column Joints (철근콘크리트 보-기둥 접합부 전단강도 평가)

  • Choi, Ha-Young;Kim, Byoung-Il;Lee, Jung-Yoon
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.185-193
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    • 2012
  • In this study, an estimation equation was proposed to predict the shear strength of RC interior beam-column connections. The proposed equation considered the effect of both truss and arch mechanisms, while the existing equations in the ACI and AIJ design codes consider only arch mechanism. In addition, the proposed equation estimates the shear strength of RC joints by considering the contribution of the vertical and horizontal steel bars on the effective compressive strength of concrete. The shear strength of RC joints calculated by the proposed equation was compared with the test results of 54 RC joints, which failed in shear before plastic hinges developed at the end of the adjacent beams. The comparison study showed that the proposed equation estimated the strength of the 54 specimens with a mean value of 1.14 and the coefficient of variation of 20%. The proposed equation provides improved prediction compared to those obtained from the equations in the ACI and AIJ design codes.

Effects of Robot-Mediated Gait Training Combined with Virtual Reality System on Muscle Activity: A Case Series Research

  • Heo, Seoyoon;Kim, Mooki;Choi, Wansuk
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.2
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    • pp.2021-2027
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    • 2020
  • Background: Previous robot-mediated gait training has been proven several limitations such as pointless repeated motion training, decreased presence, etc. In this research, adult stroke patients were participated in robot-mediated gait training accompanied with or without virtual reality program. Objectives: Exploring whether the results indicated virtual reality system has contribution to muscle strength and balance ability. Design: A case series research, cross-over trial. Methods: Eleven participants (male 4, female 7) with adults diagnosed as stroke from medical doctor ware engaged. The participants received 2 treatment sessions of identical duration, robot-assisted gait training with virtual reality and robot-assisted gait training with screen-off randomly crossed over include 1-day for each person of wash-out period. The parameter was muscle activity, the researchers assessed sEMG (surface electromyography). Results: The result showed less muscle activities during training in robot-assisted gait training with virtual reality circumstances, and these indicated muscles were gluteus medius muscle, vastus medialis muscle, vastus intermedius and vastus lateralis muscle, semimembranosus muscle, gastrocnemius-lateral head, and soleus muscle (P<.05). Conclusion: In this study, we analyzed the outcome of muscle activity for clinical inference of robot-assisted gait training with virtual reality (VR). Less muscle activity was measured in the treatment accompanied by VR, therefore, a more systematic, in-depth and well-founded level of follow-up research is needed.

Analysis of Variation for Drainage Structure with Flow Direction Methods on the Basis of DEM (DEM을 기반으로 한 흐름방향 모의기법에 따른 배수구조의 변동성 해석)

  • Park, Hye-Sook;Kim, Joo-Cheol
    • Journal of Korean Society on Water Environment
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    • v.34 no.4
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    • pp.391-398
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    • 2018
  • The main purpose of this study is to suggest and recommend the more reliable flow direction methods within the framework of DEM and power law distribution, by investigating the existing methodologies. To this end SFD (single flow direction method), MFD (multiple flow direction method) and IFD (Infinite flow direction method) are applied to analyze the determination of a flow direction for the water particles as seen in the Jeonjeokbigyo basin, and then assessed with respect to the variation of flow accumulation in that region. As the main results revealed, the study showed the different patterns of flow accumulation are found out from each applications of flow direction methods utilized in this study. This brings us to understand that as the flow dispersion on DEM increases, in this case the contributing areas to the outlet grow in sequence of SFD, IFD, MFD, but it is noted that the contribution of individual pixels into outlet decreases at that time. In what follows, especially with the MFD and IFD, the result tends to make additional hydrologic abstraction from rainfall excess, as noted due to the flow dispersion within flow paths on DEM. Based on the parameter estimation for a power law distribution, which is frequently used for identify the aggregation structure of complex system, by maximum likelihood flow accumulation can be thought of as a scale invariance factor. In this regard, the combination of flow direction methods could give rise to the more realistic water flow on DEM, as revealed through the separate flow direction methods as utilized for dispersion and aggregation effects of water flow within the available different topographies.