• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.525-525
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• 2023

영산강·섬진강수계는 광역상수원의 수질개선을 위해 제도적인 노력과 예산을 투입하고 있다. 제도 도입 시행 후 20여년이 경과하면서 수변구역 내 오염원 제거가 이루어졌음에도 불구하고 주암호와 동복호의 수질은 크게 개선되지 않고 있다. 따라서, 효율적인 수질개선을 위해서는 섬진강수계 토지매수 대상 지류지천의 과학적 방법을 통한 오염 인자 조사 및 분석, 실측 자료에 기반한 우선순위 산정이 필요하다. 본 연구에서는 수질 전문가 50명을 대상으로 설문조사를 실시하고AHP 기법을 통해 주암호 19개, 동복호 9개, 상사호 9개, 수어호 3개, 탐진호 16개 하천의 우선순위를 분석하였으며, 각 지류지천별 오염원 인자(생활계, 축산계, 산업계, 토지계)와 실측 인자(T-P 농도, T-P 단위면적당 오염부하량)를 이용해 하천별 배점을 산정하였다. 그 결과, 1위부터 10위 우선순위 하천의 경우 배점 합계 점수가 최소 65.9점부터 최대 82.0점까지의 점수 범위를 보였으며, 주로 배점 가중치가 가장 높은 T-P 농도와 T-P 단위면적당 오염부하량이 높은 값을 보였다. 총 배점 대비 인자별 구성 비율을 계산해본 결과, 실측 인자 중 관측 T-P 농도는 평균 33.9%, T-P 단위면적당 오염부하량은 평균 32.7%로 총합 66.6%의 값을 보였다. 또한, 높은 배점값을 보인 지류지천은 오염원 인자에서도 높은 값을 보여 토지매수로 인한 수질개선 효과가 높아질 것으로 판단된다.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.483-494
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• 2007

The properties of fracture system on road-cut slopes along the Busan-Ulsan express way under construction are investigated and analyzed. Fracture spacing distributions show log-normal form with extension fractures and negative exponential form with shear fractures. Straight line segments in log-log plots of cumulative fracture length indicate a power-law scaling with exponents of -1.13 in site 1, -1.01 in site 2 and -1.52 in site 3. It is likely that the stability and strength of rock mass are the lowest in site 1 as judged from the analyses of spacing, density and inter-section of fractures in three sites. In contrast, the highest efficiency of the fracture network for conducting fluid flow is seen in site 3 where the largest cluster occupies 73% through the window map. Based on the field survey data, this study modified weighting values of the RMR system using a multiple regression analysis method. The analysis result suggests a modified weighting values of the RMR parameters as follows; 18 for the intact strength of rock; 61 for RQD; 2 for spacing of discontinuities; 2 for the condition of discontinuities; and 17 for ground water.

• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.85-96
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• 2006

This study was conducted to suggest a method to determine weighting values of each parameter of the RMR system considered with geologic characteristics of a study area. This study reviewed the weighting values of the RMR system for the Cretaceous sedimentary rocks distributed in Ulsan area. Based on the data of field survey at the study area, a multiple regression analysis was used to set up an optimal weighting values of the RMR parameters. For the multiple regression analysis, each parameter of the RMR and the slope gradient were regarded as the independent variable and the dependent variable, respectively. The analysis result suggested a modified weighting values of the RMR parameters as follows; 30 for the intact strength of rock; 18 for RQD; 8 for spacing of discontinuities; 32 for the condition of discontinuities; and 12 for ground water.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.251-258
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• 2006

In this paper, the applicability to the Korean rock condition of using the deformation moduli based on Rock Mass Rating (RMR) and Pressuremeter Test (PMT) is evaluated. The correlations among deformation moduli and various rock properties were also analyzed. It appears that the existing correlations using RMR overestimate the deformation moduli and wide variation was found between predicted moduli using these correlations and measured values. As for the correlations among the deformation moduli and various rock properties, Rock Quality Designation (RQD) and unconfined compressive strength (UCS) were found to correlate to deformation moduli reasonably well, but joint spacing and joint conditions appear to correlate poorly to RQD and UCS. Additionally, groundwater can not be correlated with the modulus values. While the depth has very little contribution to deformation modulus, it should be factored in the simple regression analyses with various rock mass properties, especially with the correlations made with UCS, RQD etc. With the deficiencies of these correlations, more in depth analysis techniques such as multivariate correlations may be to reliably estimate deformation modulus of rock mass.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.10
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• pp.291-298
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• 2023

In this paper, we study whether the programming questions of the Informatics·Computer recruitment tests were suitable for selecting teachers with required programming skills. The average points of the programming questions constituted 38%(20.8 points) of the total scores for the entire curriculum based on the results from analyzing the previous questions in the past 5 years. Moreover, the distribution of points for each evaluation criteria within programming and data structure, two exam subjects which have a high proportion of programming questions, demonstrated a large deviation ranging from 0% to 47% and 0% to 53% respectively. In this study, a questionnaire survey was conducted on 31 teachers to examine if the previous programming questions were suitable for measuring teachers' competency in programming abilities required in the actual teaching experience. Computational thinking ability was ranked the highest at 58% in response to the area that needs to be evaluated in the recruitment test. In response to the relevance of previous questions, problem solving ability was ranked the highest at 2.84 on a 5-point scale, but the overall appropriateness was deemed low. C language and Python were regarded as the computer languages suitable to be tested for programming questions with each ranked 55% and 45%. The finding confirms that teachers preferred Python and the incumbent C language to others. Based on the results of the questionnaire, we recommend changes in the programming questions to improve the selection criteria.

• Explosives and Blasting
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• v.28 no.2
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• pp.133-147
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• 2010

A Suggestion of In-situ Rock Mass Evaluation and Correlation between Rock Mass Classfication MethodsThe purpose of this study is to find out rock mass classification method which is practically applicable to a field and to consider a correlation between the new method and the old method. Rock mass is an aggregate of separated blocks. To express the aggregate, the properties of both intact rock and rock mass should be considered. In this study, therefore, parameters for rock mass description are classified into rock strength and rock structure. Indices for parameters evaluation are obtained from old method and the strength and structure property of rock is described by using those indices. Value of 25 is allocated to each parameter obtained. $RMR_{basic}$ =0.86(X=Method)+14.47 is derived between $RMR_{basic}$ and this study and $RMR^*$ = 0.87(X-Method)+9.20 is derived between revised RMR and this study. Coefficient of determination is $R^2$=0.841 and $R^2$=0.846 each.

• The Journal of Korean Association of Computer Education
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• v.12 no.5
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• pp.15-22
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• 2009

In this thesis, we performed research focusing on the following details: First, questions made in the information computer subject of the employment examination for the 2009 academic year were classified into each major field and the weight and distribution of marks for each field were analyzed; Second, using questionnaire, (1) the distribution of items for major fields and opinions of the verification of teacher's ability, (2) the opinions of difficulty of the examination, the allocation of time and the proportion of subject contents and subject pedagogy; and (3) the recognitions of instructor group and examinee group were examined and the results were compared and analyzed. According to the results of this study, questions were made evenly in the fields of each subject as the intention of making the questions. Also, for each result of the questions about first examination and second examination, there were not significant difference between professor group and examinee group.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.23-35
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• 2012

Due to the convenience, RMR has been widely applied in civil engineering works such as tunnel, slope, and so on. Many researchers have studied to suggest more simple and trustable RMR by modifying its parameters. However, those researches have just focused on looking for easy modified-RMRs by reducing number of parameters using various statistical analyses. Therefore, this research studied questions of modified-RMRs and gaps between RMR and its parameters. Approximately 2,000 parameters of 400 RMRs from various tunnel sites were normalized respectively and compared with one another to study their relations and divergences. The comparison results showed that there were common patterns among RMR and parameters. Data of uniaxial compressive strength and RQD, qualitative parameters, were located in upper side of RMR line. Discontinuity condition and ground water, quantitative oriented parameters, were opposite to them. It means if both qualitative and quantitative parameters can be properly combined then it can be easy to make simple and easy modified-RMRs without using difficult statistics. This results also show that the majority of field engineers used to estimate RMR conservatively when they did quantitative oriented parameters.