• Environmental Engineering Research
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• 제24권4호
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• pp.699-710
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• 2019

Electric vehicles (EVs) are spreading rapidly and many counties are promoting hybrid and fully EVs through legislation. Therefore, an increasing amount of lithium ion batteries will reach the end of their usable life and will require effective and sustainable end-of-life management plan which include landfill disposal or incineration. The current research focuses on more sustainable methods such as remanufacturing, reuse and recycling in order to prepare for future battery compositions and provide insights to the need recycling methods to be developed to handle large amounts of batteries sustainably in the near future. The two most prominent material recovery techniques are hydrometallurgy and pyrometallurgy which are explored and assessed on their relative effectiveness, sustainability, and feasibility. Hydrometallurgy is a superior recycling method due to high material recovery and purity, very low emissions, high prevalence of chemical reuse and implementation of environmentally sustainable compounds. Expanding recycling technologies globally should take the research and technologies pioneered by Umicore to establish a sustainable recycling program for end-of-life EVs batteries. Emerging battery technology of Telsa show the most effective designs for high performance batteries includes the use of silicon which is expected to increase capacity of batteries in the future.

• Steel and Composite Structures
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• 제34권1호
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• pp.123-139
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• 2020

The tube outward local buckling of Concrete-Filled Steel Tube (CFST) beam under high compression stress is still considered a critical problem, especially for steel tubes with a slender section compared to semi-compact and compact sections. In this study, the flexural performance of stiffened slender cold-formed square tube beams filled with normal concrete was investigated. Fourteen (14) simply supported CFST specimens were tested under static bending loads, stiffened with different shapes and numbers of steel stiffeners that were provided at the inner sides of the tubes. Additional finite element (FE) CFST models were developed to further investigate the influence of using internal stiffeners with varied thickness. The results of tests and FE analyses indicated that the onset of local buckling, that occurs at the top half of the stiffened CFST beam's cross-section at mid-span was substantially restricted to a smaller region. Generally, it was also observed that, due to increased steel area provided by the stiffeners, the bending capacity, flexural stiffness and energy absorption index of the stiffened beams were significantly improved. The average bending capacity and the initial flexural stiffness of the stiffened specimens for the various shapes, single stiffener situations have increased of about 25% and 39%, respectively. These improvements went up to 45% and 60%, for the double stiffeners situations. Moreover, the bending capacity and the flexural stiffness values obtained from the experimental tests and FE analyses validated well with the values computed from equations of the existing standards.

• 한국환경교육학회지:환경교육
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• 제18권2호
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• pp.23-30
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• 2005

The purpose of this study is to develop School Agenda 21 to activate environmental education at schools. In detail, this study is intended to develop operating procedures, major issue areas or domains, and instructions on the preparation for School Agenda 21. School Agenda 21 means the action plan which students, teachers, parents, and other concerned parties (including office of education, local municipal bodies, and NGOs) write under agreement with respect to their respective roles in order to activate environmental educations oriented toward sustainable development. The results of this study are as follow. First, the operating procedures for School Agenda 21 consist of seven steps; organization, diagnosis of problems, setup of targets or objectives, development of codes of behavior, system establishment, practices and reviews, and evaluation and feedbacks. Second, major issue areas for School Agenda 21 are classified into six; school management, class operation, independent subject activity, separate subject activity, non-subject activity, and external relations of school. Third, instructions of the preparation of School Agenda 21 address these 10 concepts; balance, unification, continuity, daily routine, linkage, environmental justice, participation, peculiarity of schools and classes, regional peculiarity, and concreteness, which consider 7 principles for environmental education, levels of learners, regional features, and concreteness. School Agenda 21 developed from this study converts existing environmental education toward sustainable development environmental education, and developed for the purpose to activate school environmental education, but ultimate purpose of this study are realizing sustainable society, sustainable future to realize education for sustainable development. So School Agenda 21 is expected to important performance way making possible Local Agenda 21, National Agenda 21, Agenda 21 as if education, public recognition and discipline contents of the 36 chapter of Agenda 21.

• Geomechanics and Engineering
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• 제21권5호
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• pp.413-422
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• 2020

The choice of eco-friendly materials for ground improvement is a necessary way forward for sustainable development. Adapting naturally available biopolymers will render the process of soil stabilization carbon neutral. An attempt has been made to use β-glucan, a natural biopolymer for the stabilization of lean clay as a sustainable alternative with specific emphasis on comprehending the effect of confining stresses on lean clay through triaxial compression tests. A sequence of laboratory experiments was performed to examine the various physical and mechanical characteristics of β-glucan treated soil (BGTS). Micro-analysis through micrographs were used to understand the strengthening mechanism. Results of the study show that the deviatoric stress of 2% BGTS is 12 times higher than untreated soil (UTS). The micrographs from Scanning Electron Microscopy (SEM) and the results of the Nitrogen-based Brunauer Emmett Teller (N₂-BET) analysis confirm the formation of new cementitious fibres and hydrogels within the soil matrix that tends to weld soil particles and reduce the pore spaces leading to an increase in strength. Hydraulic conductivity (HC) and compressibility reduced significantly with the biopolymer content and curing period. Results emphases that β-glucan is an efficient and sustainable alternative to the traditional stabilizers like cement, lime or bitumen.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1049-1054
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• 2009

Sustainable housing design can contribute to dramatically reduced energy usage and can be applied to all new building projects. This paper explores the potential in Korea of applying available energy efficient building technologies. The objective was to determine the degree of energy reduction that can easily be achieved in new building design. The pilot project is providing some prototypes with display units which incorporate principles of sustainable design and performance utilizing the eco-design objectives. This building challenges ingrained preconceptions about system designs for four energy saving levels(40%, 60%, 80% and zero energy) and exposes barriers to low energy buildings posed by new standards and guidelines.

• Journal of Construction Engineering and Project Management
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• 제3권1호
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• pp.28-34
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• 2013

Use of recycled aggregates in portland cement concrete (PCC) construction can offer benefits associated with both economy and sustainability. Testing performed to date indicates that recycled brick masonry aggregate (RBMA) can be used as a 100% replacement for conventional coarse aggregate in concrete that exhibits acceptable mechanical properties for use in structural and pavement elements, including satisfactory performance in some durability tests. Recycled brick masonry aggregate concrete (RBMAC) is currently not used in any type of construction in the United States. However, use of RBMAC could become a viable construction strategy as sustainable building practices become the norm. This paper explores the feasibility of use of RBMAC in several types of sustainable construction initiatives, based upon the findings of previous work with RBMAC that incorporates RBMA produced from construction and demolition waste from a case study site. A summary of material properties of RBMAC that will be useful to construction professionals are presented, along with a discussion of advantages and impediments to use. Several quality assurance and quality control techniques that could be incorporated into specifications are identified.

• 아태비즈니스연구
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• 제9권3호
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• pp.71-82
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• 2018

This study verifies whether the sustainable tax strategy provides unique information on earnings persistence and brings about the difference of value relevance of accounting information. Sustainability is measured by the 5-year coefficient of variation in cash ETR, such as in McGuire et al.(2013), which measures variability in long-term performance of tax avoidance. The value relevance of accounting information in this study is modified by the Ohlson model(1995), which explains the value of the firm by using accounting information such as net assets and net income and other non-accounting information. The samples of this study are the firms listed on the securities market from 2004 to 2015 and the final samples are 3,133 firm-year. The results of this empirical analysis show that the value relevance of accounting information increases as firms have long-term and sustainable tax strategies. Most of the prior studies on tax strategies have examined the tax minimization strategy that minimizes the tax cost. However, this study is different in that the sustainability of the tax strategy affects the value relevance of accounting information. The results of this study will be useful for the users to make decision using the value relevance of accounting information.

• Communications for Statistical Applications and Methods
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• 제18권1호
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• pp.119-130
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• 2011

본 연구의 목적은 한국 보험회사의 지속가능성과를 측정하고 분석하여 지속가능경영을 위한 전략적 시사점을 제공하는데 있다. 분석방법으로는 상관분석, 회귀분석, 분산분석, T-검정을사용한다. 분석결과 첫째, 생명보험에서는 사회지표가, 손해보험에서는 환경지표가 상대적으로 중요한 변수로 분석되었다. 둘째, 지속가능점수를 종속변수로 하고 기업의 규모와 재무건전성을 독립변수로 한 회귀분석 결과규모가 통계학적으로 유의하게 정(+)의 영향을 미치는 변수로 분석되었다. 이는 지속가능성장을 위한 필요조건으로 일정 수준 이상의 규모가 요구됨을 시사한다. 셋째, 분산분석 및 T-검정 결과 생명보험산업에서는 중소형사가 대형사에 비해 사회지표 및 명성지수에서 통계학적으로 유의하게 낮은 성과를 보여주는 것으로 나타났다. 손해보험산업에서는 중소형사가 대형사에 비해 사회지표를 제외한 모든 지표에서 통계학적으로 유의하게 낮은 성과를 보여주는 것으로 나타났다. 따라서 중소형사의 지속가능한 발전을 위해서는 생명보험의 경우 사회지표 및 명성지표 측면에서, 손해보험의 경우는 경제, 환경, 명성 등의 측면에서 노력이 요구되어진다고 볼 수 있다.

• 지식경영연구
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• 제7권2호
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• pp.35-52
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• 2006

Increasing competitive pressure, the constantly accelerating transformation of the economy, and a stronger focus on value creation have initiated the search for sustainable sources of competitive advantage in organizations. In this context, the concept of treating organizational knowledge as a valuable strategic resource has become quite popular recently. Knowledge has become the most critical component in the struggle for sustained competitive advantage and knowledge management (KM) has also been described for its possible role in creating sustainable competitive advantage. In order to examine the contingency between KM resources, KM strategies, and KM performance of organizations, a contingency model of KM, which is based on resource-based theory as well as knowledge-based theory, is developed from the information systems and strategic management literature in order to assess the following questions: (i) What KM resources affect the organization's KM strategies? (ii) Is there a relationship between KM strategies and organizational performance enhanced by KM? A detailed exploratory analysis of survey responses from 79 Korean companies provides the following significant findings: (i) This study found support for the proposed contingency model of KM; (ii) The organization's KM strategies are determined by social resources and its capabilities; (iii) An organization with a culture-based KM strategy is more likely to enhance organizational KM performance than an organization with a technology-based KM strategy.

• 교육녹색환경연구
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• 제15권1호
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• pp.11-18
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• 2016

본 연구는 학교현장의 안전교육 과정에서 학교시설 비구조재 중 위험도가 상대적으로 높은 천장재의 내진성능을 평가하고 대책방안을 제시하는 것이다. 평가도구의 개발을 위하여 본 연구는 다음과 같은 4단계로 진행되었다. 첫 단계에서는 국내 외의 내진성능평가 가이드라인들을 분석하여 주요 천장재의 구성품목과 각 품목별 평가방법들을 조사하고, 두 번째 단계에서는 문헌조사의 결과를 기반으로 주요 품목들의 내진성능 실태를 면밀하게 조사하였다. 세 번째 단계에서는 조사된 천장재 구조를 정량적으로 평가하여 지반 및 지진의 유형에 따른 적정성을 평가하였다. 마지막으로 국내 학교시설 천장재에서 우선적으로 고려되어야 할 내진성능보강 대책방안을 제시하였다.