• Geomechanics and Engineering
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• 제37권3호
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• pp.213-222
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• 2024

Determination of jointed rock mass properties plays a significant role in the design and construction of underground structures such as tunneling and mining. Rock mass classification systems such as Rock Mass Rating (RMR), Rock Mass Index (RMi), Rock Mass Quality (Q), and deformation modulus (Em) are determined from the jointed rock masses. However, parameters of jointed rock masses can be affected by the tunnel depth below the surface due to the effect of the in situ stresses. In addition, the geomechanical properties of rocks change due to the effect of metamorphism. Therefore, the main objective of this study is to apply correlation analysis to investigate the relationships between rock mass properties and some parameters related to the depth of the tunnel studied. For this purpose, the field work consisted of determining rock mass parameters in a tunnel alignment (~7.1 km) at varying depths from 21 m to 431 m below ground surface. At the same excavation depths, thirty-seven rock types were also sampled and tested in the laboratory. Correlations were made between vertical stress and depth, horizontal/vertical stress ratio (k) and depth, k and Em, k and RMi, k and point load index (PLI), k and Brazilian tensile strength (BTS), Em and uniaxial compressive strength (UCS), UCS and PLI, UCS and BTS. Relationships were significant (significance level=0.000) at the confidence interval of 95% (r = 0.77-0.88) between the data pairs for the rocks taken from depths greater than 166 m where the ratio of horizontal to vertical stress is between 0.6 and 1.2. The in-situ stress parameters affected rock mass properties as well as metamorphism which affected the geomechanical properties of rock materials by affecting the behavior of minerals and textures within rocks. This study revealed that in-situ stress parameters and metamorphism should be reviewed when tunnel studies are carried out.

• 대한공업교육학회지
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• 제36권2호
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• pp.111-130
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• 2011

이 연구는 기술교사의 변화몰입과 기술교육혁신 요구, 커뮤니케이션 및 자기효능감의 구조적 관계를 구명하기 위한 것으로, 문헌연구와 조사연구에 의하여 수행되었다. 변인 간의 가설적 모형의 적합성을 검증하기 위해 카이자승, 근사치 오차평균제곱근(RMSEA), 적합지수(GFI), 조정적합지수(AGFI), 표준적합지수(NFI), 비교적합지수(CFI) 등을 활용하였다. 연구의 결과에 의하면, 첫째, 기술교육 혁신요구는 기술교사들 간 커뮤니케이션과 변화몰입에 직접적인 영향을 주는 것으로 나타났다. 둘째, 기술교사들 간 커뮤니케이션은 변화몰입에 직접적인 영향을 미치는 것으로 나타났다. 셋째, 자기효능감은 기술교사들의 변화몰입에 직접적으로 영향을 미치는 것으로 나타났다. 따라서, 기술교사들이 변화에 몰입하여 기술교육이 더욱 발전하고 활성화되기 위해서는 기술교사들 간에 활발한 커뮤니케이션이 이루어져야 하며, 무엇보다도 기술교사들이 기술교육의 현황을 분명하게 인식함으로써 기술교육 혁신의 필요성에 공감하도록 할 필요가 있다. 또한, 기술교사들의 자기효능감을 제고하기 위한 정책적인 노력이 있어야 할 것으로 판단된다. 기술교사들의 기술교육혁신 요구, 변화몰입, 커뮤니케이션, 자기효능감 등의 관계를 분석하기 위한 이 연구는 기술교육 분야에서는 처음으로 시도된 것으로 추후에 관련 연구가 이어져야 할 것이다. 특히, 기술교사들의 변화몰입에 영향을 미치는 체계적인 변인 도출, 기술교육 혁신을 성공적으로 이루어내기 위한 방안 등의 연구가 요구된다.

• 펄프종이기술
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• 제42권5호
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• pp.37-46
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• 2010

This study was carried out to develop new application field and obtain the basic data of mixed paper with wood pulp and chitosan fiber for producing functional paper. Two types of wood pulp, such as SwBKP and HwBKP, were mixed with chitosan fiber. Physical and optical properties, water vapor absorption, air permeability, antibacterial activity and ash were measured. And the surface morphology of manufactured paper was observed using SEM. The results are as follows. It was revealed that density, breaking length, burst index, tear index, folding endurance and brightness were reduced but water vapor absorption and air permeability were on the rise in the structural view of SwBKP according to increasing the chitosan fiber ratio. Those HwBKP added chitosan fiber were great not only in the strength but also water vapor absorption and air permeability except for brightness. The water vapor absorption was lower and the air permeability was higher in the HwBKP added various chitosan fiber ratios than those with no chitosan fiber. It is estimated that these properties were related with various mixed rate of chitosan fiber. Particularly, air permeability was strongly dependent on the mixed rate of chitosan fiber. The chitosan fiber has superior antibacterial property, comparing with wood fiber. Adding chitosan fiber to the wood pulp was found to have an excellent antibacterial activity, more than 90%. The ashes were determined within 0.5%. Special bonds between chitosan fiber and wood pulp was observed by SEM and it means that the chitosan fiber were combined equally in the interior of wood pulp. In conclusion, mixing wood pulp with chitosan fiber can not only improves the quality of paper but also extend the usage of paper as a functional paper by using inherent property of chitosan. After all, production of functional paper added chitosan fiber is expected for new valuable industry of paper.

• 공업화학
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• 제25권1호
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• pp.90-95
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• 2014

이축압출기(twin screw extruder)를 이용하여 나일론66 압출시료를 압출횟수에 따라 제조하였다. 압출횟수에 따른 화학구조, 열적 특성, 용융지수, 결정구조, 인장특성, 충격특성 및 유변학적 특성을 FT-IR, $^1H$-NMR 용융지수 측정기, DSC, TGA, XRD, 만능시험기, Izod 시험기, 그리고 유변물성측정기를 이용하여 분석하였다. FT-IR과 $^1H$-NMR을 이용하여 확인한 결과 압출시편에서의 화학구조 변화는 확인되지 않았다. 압출횟수에 따라 분자량이 감소하는 것을 용융지수를 이용하여 확인하였으며, 열 이력이 용융온도와 분해온도에는 큰 영향을 주지 않는 것을 DSC와 TGA를 이용하여 확인하였다. 압출시편의 기계적 특성 평가결과 인장강도, 충격강도 및 탄성률은 유사한 값을 보이나, 신율의 경우 큰 폭으로 감소하였다. 유변학적 특성 측정결과 낮은 주파수에서의 복합점도 값이 압출 횟수에 따라 감소하였다. 압출시편의 G'-G" 곡선의 기울기나 형태가 변하지 않는 것으로부터 압출시편에 가교와 같은 구조변화가 크게 나타나지 않음을 알 수 있었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.107-114
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• 1999

The large-scale distribution of crops Is usually determined by climate. We present the results of a climate-crop prediction based on spatial bio-physical process model approach, implemented in a GIS (Geographic Information System) environment using several regional and global agriculture-environmental databases. The model utilizes daily climate data like temperature, rainfall, solar radiation being generated stocastically by in-built model weather generator to determine the daily biomass and finally the crop yield. Crops are characterized by their specific growing period requirements, photosynthesis, respiration properties and harvesting index properties. Temperature and radiation during the growing period controls the development of each crop. The model simulates geographic/spatial distribution of climate by which a crop-growing belt can also be determined. The model takes both irrigated and non-irrigated area crop productivity into account and the potential increase in productivity by the technical means like mechanization is not considered. All the management input given at the base year 1995 was kept same for the next twenty-year changes until 2015. The simulated distributions of crops under current climatic conditions coincide largely with the current agricultural or specific crop growing regions. Simulation with assumed weather generated derived climate change scenario illustrate changes in the agricultural potential. There are large regional differences in the response across the country. The north-south and east-west regions responded differently with projected climate changes with increased and decreased productivity depending upon the crops and scenarios separately. When water was limiting or facilitating as non-irrigated and irrigated area crop-production effects of temperature rise and higher $CO_2$ levels were different depending on the crops and accordingly their production. Rise in temperature led to yield reduction in case of maize and rice whereas a gain was observed for wheat crop, doubled $CO_2$ concentration enhanced yield for all crops and their several combinations behaved differently with increase or decrease in yields. Finally, with this spatial modeling approach we succeeded in quantifying the crop productivity which may bring regional disparities under the different climatic scenarios where one region may become better off and the other may go worse off.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.244-244
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• 2015

Managed Aquifer Recharge (MAR) in the form of Aquifer Storage and Recovery (ASR) systems are being applied for numerous water augmentation projects both in developed and developing countries. Given the onset of Climate Change and its influence on weather patterns and land use, it has been acknowledged the utilization of this technology will be ever increasing. This technique like all others does have its drawbacks or disadvantages, whereby to overcome these drawbacks or disadvantages it is recommended that logical planning process be followed. In this study, we developed a decision framework known as "Decision framework for the planning, designing, construction/testing and implementation of subsurface water storage system" to further standardize the planning and design process of subsurface water storage system to increase the probability of having a successful ASR/ASTR project. The formulation of this framework was based on earlier frameworks, guidelines, published papers and technical reports which were compiled into a data collection database. The database of which consider both qualitative and quantitative aspect for example recharge objectives, site location, water chemistry of the native, source and recovered water, aquifer characteristics(hydraulic conductivity, transmissivity, porosity), injection/pumping rate, ecological constraints, societal restrictions, regulatory restrictions etc. The assimilation of these factors into a singular framework will benefit the broad spectrum of stakeholder as it maps the chronological order under which ASR project should be undertaken highlighting at each stage the feasibility of the project. The final stage of which should result in fully operational ASR system. The framework was applied to two case studies and through the application of a modified ASR site selection suitability index (Brown et al., 2005) a score was derived to identify the performance of each site. A high score of which meant a maximize chance of success given the reduce presence of project constraints.

• 한국습지학회지
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• 제22권4호
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• pp.245-256
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• 2020

본 연구의 목적은 우리나라 환경산업 해외시장 진출 전략 수립을 위하여 선진국과의 환경산업 기술경쟁력을 평가하고자 하였다. 환경산업 기술경쟁력을 평가하기 위하여 국내·외 환경산업기술 분류체계를 바탕으로 환경산업 분야별 중점 기술을 분류하고, 기술경쟁력 평가지표를 구축하였다. 평가지표 자료 구축을 수행한 후 델파이 분석 및 논문·특허 분석, 수출·입 분석을 수행하였으며, 지표값에 대한 표준화 분석을 수행하였다. 또한, AHP(Analytic Hierarchy Process) 기법을 통해 평가지표별 가중치를 산정하여 한국, 미국, 영국, 독일, 프랑스의 환경산업기술 경쟁력 평가 결과를 도출하였다. 평가 결과, 모든 환경산업 분야에서 미국이 상대적으로 기술경쟁력이 가장 높은 것으로 평가되었으며, 한국은 선진국에 비해 상대적으로 가장 낮은 경쟁력을 가지고 있는 것으로 평가되었다. 특히, 한국은 다매체 환경관리 및 지속가능 사회시스템 구축분야가 선진국에 비해 기술경쟁력 수준이 가장 낮은 것으로 나타났다. 따라서 국내 환경산업기술이 글로벌 선진시장에 진출하기 위해서는 국내 강점인 사물인터넷, 클라우드, 빅데이터, 모바일, 인공지능 기반의 4차 환경산업 개발을 통해 경쟁력을 강화해야 할 것으로 판단된다.

• 대한원격탐사학회지
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• 제30권3호
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• pp.341-350
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• 2014

Landsat images can monitor the snow-covered Earth surface variations with the ground resolution of 30m and the multi-spectral bands in the visible, NIR, SWIR and TIR spectral regions for the last 30 years. The Southern Volcanic Zone (SVZ) of Chile consists of many volcanoes, and all of the volcanoes are covered with snow at the top of mountain. Snow cover area in southern province of the SVZ of Chile (37 to $46^{\circ}S$) have been influenced by significant frontal retreats as well as eruptive activities. In this study, we have investigated the changes of the snow-cover area and snow-line elevation at Mt. Villarrica and Mt. Llaima, Chile from three Landsat images acquired on Feb. 1990, 2005 and 2011. The snow-cover areas are 13.42, 26.75 and $21.60km^2$ at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 3.82, 25.12 and $8.89km^2$ at Mt. Llaima in 1990, 2005 and 2011, respectively. The snow-line elevations are 1871, 1738 and 1826m at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 2007, 1822 and 1818m at Mt. Llaima in 1990, 2005 and 2011, respectively. The results indicate that both of the snow-cover and snow-line changes are strongly related with the volcanic activity change. The results demonstrate that the snow-cover area and snow-line elevation changes can be used as an indicator of the volcanic activity at Mt. Villarrica and Mt. Llaima, Chile.

• 해양환경안전학회지
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• 제24권1호
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• pp.10-17
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• 2018

종합 안전관리체계인 e-navigation을 준비하기 위해 선박의 의도된 경로를 선박 대 선박, 그리고 선박 대 육상 간에 공유하는 경로교환에 대한 연구가 활발히 진행 중이다. 하지만 경로교환을 위한 기술적인 측면에서의 연구 개발은 진행되고 있으나, 그 효과나 문제점 등 도입 필요성에 대한 연구는 부족한 실정이다. 본 연구는 선박조종 시뮬레이션을 통해 경로교환이 항해 안전에 미치는 영향을 정량적으로 분석하고, 시뮬레이션 수행자들의 주관적인 평가를 종합하여 경로교환의 효과를 검증하였다. 선박 간 경로교환을 할 경우 최초 충돌회피 시점은 평균 3.43분 더 빨라졌으며, 충돌회피 방향은 60 %가 변경되었다. 또한 타선 A와의 최근접점은 31 % 더 가까워지고, 평균 타 사용지수는 57 % 줄어들었다. 그리고 설문 응답자의 95 %는 경로교환이 충돌회피 의사결정에 영향, 85 %는 안전운항에 긍정적인 영향, 90 %는 사고예방 효과, 70 %는 항해사의 심리적 부담 경감, 70 %는 경로교환을 실무에 도입해야한다고 답하였다.

• 한국조경학회지
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• 제31권5호
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• pp.73-85
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• 2003

With more and more people paying attention to substantial democracy, participatory democracy is presented as a practical strategy and an index of Korean democracy. In this social and political atmosphere, participation in environmental planning and design is essential. Nonetheless, the true meaning of “participation” is not used properly because many people do not understand it correctly, The concept of social and political participation is “the action or attempt of ordinary members of society for affecting on the result of decision making.” Based on this concept, participation is accomplished through conventional means and as a form of mobilization in environmental planning and desist Most of the theories on public participation in landscape architecture are technical theories. Therefore, this paper proposes that planning and design of landscape architecture be understood as a communicative action that aims to enable stakeholders to reach a consensus through communication. This study offers the framework of theory to understand and practice planning and design of landscape architecture as a communicative action, after reviewing communicative action theory and communicative planning theory. Results suggest that communicative action theory should be accepted in landscape architecture to overcome the shortcomings of instrumental rationality -- the same way planning theory accepted this theory --and to join the culture of experts focusing on the artistic truth and the culture of life of the world. In addition, accepting communicative action theory enables the acquisition of the instrumental effect and social learning effect and the making of social capital. This study also suggested prerequisite for using the method. There should be change in the social institution and in individual action. In addition the method is composed of three steps: creating the atmosphere for communication; communicating, and; reaching a consensus among stakeholders. Finally, raising the possibility of applying the theory presented in this study requires the accumulation of know-how through trial and error.