• 한국지반환경공학회 논문집
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• 제11권3호
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• pp.53-62
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• 2010

1990년대 초 쏘일네일링 공법이 국내에 처음 도입된 이후 쏘일네일링 공법은 사면안정 및 지반굴착의 보강공법으로 널리 쓰이고 있으며, 쏘일네일링 공법의 적용이 확대됨에 따라 초기의 쏘일네일링 공법에 대한 여러 가지 개선된 쏘일네일링 공법도 발달하였다. 최근에 많이 쓰이는 쏘일네일 공법들은 크게 그라우트에 대한 개선 공법과 쏘일네일 자체에 대한 개선 공법으로 분류된다. 그라우트에 대한 개선공법으로는 대표적으로 가압그라우팅 공법을 들 수 있으며, 쏘일네일 자체에 대한 개선공법으로는 자천공 쏘일네일 공법, 제거식 쏘일네일 공법 등과 더불어 본 연구의 대상이 되는 확장그라우팅 공법이 있다. 본 연구에서는 확장그라우팅 공법의 인발거동 특성을 평가하기 위하여 3차원 유한차분 해석을 수행하였다. 수치해석 결과를 통하여 확장그라우팅 공법이 적용된 쏘일네일링의 인발거동특성에 대하여 기술하였다.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.539-545
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• 2013

Although individual-level factors (e.g., attitudes, personality) have long been associated with day-to-day attendance decisions, increasingly researchers have recognized "the social nature of attendance dynamics and their susceptibility to social control (Johns, 2008)." Implications of this social approach for research would be to focus attention on the causes and effects of absence culture (i.e., absence-related perceptions, beliefs, values), and the effects of absence culture on individual and group attendance within social units. Construction projects typically require workers to work in teams or crews on highly interdependent projects, and, thus, are particularly relevant contexts to study absence culture. In this paper we apply a system dynamics (SD) model to study absence culture by utilizing the advantages of SD in capturing a feedback process and state changes. We were particularly interested in: (a) the awareness of social norms within construction crews that pertained to attendance, (b) the interplay between formal attendance rules (policy) and these social norms, and (c) how these sources of influence affected the decision-making process of construction crew members. We expect that the results of this work will help construction organizations evaluate (or re-consider) the effects of their attendance control policies (e.g., timing, strength, and frequency) within a social context. Moreover, our findings suggest that the key to reducing excessive absences might be to invest time in influencing absence culture directly rather than imposing frequent and strict regulations - which, in turn, may inadvertently fortify a culture that works against the organization's interests.

• 한국환경교육학회지:환경교육
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• 제19권2호
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• pp.81-95
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• 2006

School is an excellent place for children to loam environment-conscious behavior and for teachers to bring up environmental education. School has a plenty of teaching materials such as school building, pond, school forest, waste and school supplies. Especially, the environmental education for and with school supplies can be very effective, as it is mostly the first products for children to learn the buying and consumption in their daily life. In this study we conducted a survey on the environmental attitude of two groups of 5th graders towards environmentally friendly school supplies. The experimental group received environmental education on school supplies and the control group did not. The survey results showed that almost 50% of the children did not consider the environmental impact, but rather the price, design and function when buying the school supplies. However, more than 70% of children were willing to use the recycled school products, implying that they are aware of environmental Issues and want to contribute to the preservation and improvement of the environment. The children recognized paper/notebooks and paints/crayons as the major environmental problems. Writing appliances such as pens, pencils, highlighters and markers were also considered as environmental concerns, since most of them are made of plastics and they are not easily biodegradable nor refillable. We also exemplify a lesson-plan for environmental education program on school supplies and make suggestions to encourage the use of those eco-friendly school materials.

• Journal of Radiation Protection and Research
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• 제40권4호
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• pp.267-276
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• 2015

원전 기체 및 액체 방사성폐기물 중 가장 배출 기여도가 높은 삼중수소를 대상으로 국내 원전 가압경수로 및 가압중수로에 대해서 배출량 비교 분석과 풍향 빈도 분석, 또한 환경매체 중 삼중수소 거동 추이를 비교 분석하였다. 분석결과 먼저 기체 및 액체 삼중수소 배출량은 가압경수로보다 가압중수로에서 기체는 2013년 기준 약 10배 이상, 액체는 2배 내지 3배 정도 더 배출을 하고 있는 것을 알 수 있었다. 배출량 분석시 특이사항은 일부 원전에서 2개 호기가 배출량이 동일하게 분석된 것을 알 수 있었는데 이는 정확한 배출관리 및 분석을 위해서는 호기별 독립적인 배출관리 및 분석이 이루어져야 할 것으로 판단된다. 풍향빈도 분석은 16 방위 기준 평균 범위가 1.7~11.5%의 넓은 범위를 보였으며 풍향에 따라 환경매체 분석용 시료채취 지점을 분석해본 결과 대체적으로 풍향에 따라 잘 선정되어 있으나 일부 지점 검토가 필요한 것을 알 수 있었다. 환경매체 중 삼중수소 농도 추이 분석은 원전으로부터 거리가 가까울수록 삼중수소 농도가 높은 것을 확인할 수 있었고 가압경수로 원전의 경우는 원거리 환경매체는 극히 미미한 수준을 나타낸 반면 가압중수로 원전은 비록 원거리 환경매체라 하더라도 가압경수로 원전의 근거리 농도 수준 이상으로 월등히 많이 검출이 되고 있음을 알 수 있었다. 이렇게 가압중수로 원전에서 삼중수소 배출량이 높고 환경매체 중 삼중수소가 기준치 미만이긴 하나 검출이 되고 있으므로 계통에서의 관리 강화와 환경에서의 모니터링이 지속적으로 이루어져야 할 것으로 판단된다.

• 농촌의학ㆍ지역보건
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• 제33권3호
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• pp.279-291
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• 2008

= ABSTRACT =Objectives : We evaluated the effect of the aircraft noise on the behavior and affect status of the local elementary school students. Methods : The daytime noise levels of the exposed and control areas were compared and the self answered questionnaires from 272 students and their parents of the exposed area and 91 of the control area were collected. The questionnaires are regarding the noise sensitivity and the psychosocial status of the students, noise sensitivity of the parents and the parents' behavioral evaluation for their children. Results : The mean noise level of the exposed area (67.6 dB(A)) showed higher level than the control area (57.1 dB(A), 58.2 dB(A), 60.2 dB(A)) and it was statistically significant. The mean score for noise sensitivity and the mean score for brief mental exam. in the exposed students were lower than the mean scores in the control group but they were not statistically significant (p=0.056 & 0.165). The mean score for behavioral evaluation of students by their parents in the exposed area(15.5) was higher than the mean score in the control group(13.2) and it was statistically significant(p=0.043). The mean score for noise sensitivity in the exposed parent(27.5) was higher than the mean score in the control group(24.1) and it was statistically significant(p=0.045). Conclusions : This study revealed that the noise sensitivity of the parents affected the behavioral evaluation of the students than noise-exposure itself. The further study is needed to evaluate relationship between aircraft noise and it's effect on children's health.

• Geomechanics and Engineering
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• 제15권3호
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• pp.823-831
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• 2018

The most important issue during shield TBM tunneling in soft ground formations is to appropriately control ground surface settlement. Among various operational conditions in shield TBM tunneling, the face pressure and backfill pressure should be the most important and immediate measure to restrain surface settlement during excavation. In this paper, a 3-D hydro-mechanical coupled FE model is developed to numerically simulate the entire process of shield TBM tunneling, which is verified by comparing with real field measurements of ground surface settlement. The effect of permeability and stiffness of ground formations on tunneling-induced surface settlement was discussed in the parametric study. An increase in the face pressure and backfill pressure does not always lead to a decrease in surface settlement, but there are the critical face pressure and backfill pressure. In addition, considering the relatively low permeability of ground formations, the surface settlement consists of two parts, i.e., immediate settlement and consolidation settlement, which shows a distinct settlement behavior to each other.

• 한국물환경학회지
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• 제21권6호
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• pp.602-608
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• 2005

A laboratory-scale experiment was conducted to investigate control of soluble microbial products (SMP) by the internal recycle rate in the submerged membrane separation activated sludge process. The internal recycle rate of the reactor RUN 1 and RUN 2 were 100 % and 200 %, respectively. SMP concentration was rapidly accumulated in the reactor (RUN 1). The variation of accumulated SMP concentration was related to the denitrification rate at the beginning experiment however SMP concentration decreased without correlatively to the denitrification rate during long operation time. The microbial kinetic model was rapidly presented in the both microbial growth and extinction in the reactor (RUN 1). In the SMP kinetic model, Internal recycle rate is the lower, value of UAP and BAP which SMP matter were presented low. The study about development of kinetic model is relatively well adjusted to the experiment exception SMP. In the future, SMP formation equation must be thought that continually research is necessary.

• Computers and Concrete
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• 제19권4호
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• pp.339-346
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• 2017

The main objective of this paper was to illuminate the effect of marine environmental condition on durability of reinforced concrete (RC)-corroded columns strengthened with carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) layers. Small-scale columns were prepared and corroded by an accelerated corrosion process. After strengthening, compressive strength tests were carried out on control and weathered specimens. In this research, a marine simulator was designed and constructed similar to the tidal zone of marine environment in south of Iran which was selected as a case study in this research. Mechanical properties of wrapped specimens were studied after placing them inside the simulator for 3000 hours. Marine environment decreased ultimate strength by 4.5% and 26.3% in CFRP and GFRP-wrapped columns, respectively. In some corroded-columns, strengthening was carried out after replacing damaged cover by self-compacted mortar. In this method, by confining with one layer of CFRP and GFRP, 4.2% and 22.4% reduction in ultimate strength was observed, respectively, after exposure. Furthermore, the elastic-brittle behavior has been verified in this retrofit method. Also results of tension tests revealed, the ultimate tensile strength was degraded by 2% and 28.8% in CFRP and GFRP sheets, respectively, after applying marine exposure.

• 한국물환경학회지
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• 제20권6호
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• pp.692-697
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• 2004

Biological phosphorus removal is characterized by complex interactions between different intracellular components of energy as PHA. Therefore, fundamental understanding of the behavior of the intracellular components and their influence on the removal of phosphorus is essential before control strategies to stabilize the proper process. The purpose of this study is to investigate relationship between release of phosphorus and synthesis of intracellular storage polymer. Mass of stored intracellular storage polymer was 21.2 mg PHA/L, 28.8 mg PHA/g MLSS. And phosphorus release/intracellular storage polymer synthesis rate was 1.8545 mg stored polymer/mg Phosphate. In the aerobic phase, mass of PAOs synthesis is 49.37 mg PAOs/L. And PAOs fraction was 6.7-6.9%. Thus intracellular storage polymer synthesis by PAOs is calculated as 493mg PHA/g PAOs.

• Smart Structures and Systems
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• 제12권3_4호
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• pp.309-325
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• 2013

Environmental and operational variables are inevitable concerns by researchers and engineers when implementing the damage detection algorithm in practical projects, because the change of structural behavior could be masked by the conditions in a large extent. Thus, reliable damage detection methods should have a virtue of immunity from environmental and operational variables. In this paper, the pair cointegration method was presented as a novel way to remove the effect of environmental variables. At the beginning, the concept and procedure of this approach were introduced, and then the theoretical formulation and numerical simulations were put forward to illustrate the feasibility. The jump exceeding the control limit in the residual indicates the occurrence of damage, while the direction and magnitude imply the most potential damage location. In addition, the simulation results show that the proposed method has strong ability to resist the noise.