• Journal of the Korean Society for information Management
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• v.18 no.1
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• pp.65-84
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• 2001

The purpose of this study was to design and evaluate a metadata system for internet-based syllabi in computer science. The study constructed two prototype systems for the experiment. One was constructed using only Dubline Core (DC) elements and the other was a DC-expanded system with additional eight elements that are not the part of DC elements. The thlrty subjects were chosen from those who majored in Computer Science. Two retrieval tasks were assigned to them. One was to find syllabi in which they are' interested and the other was to find relevant course syllabi for a given course title. After the search, they were asked to evaluate the systems in terms of efficiency, accuracy, and their satisfaction of the system. The result of the first experiment indicates that DC-based system performed significantly better in terms of search time and DC-expanded system in terms of satisfaction measure. An additional experiment was conducted to test efficiency of the browsing categories. The interview with subjects was carried out to find any difficulties associated with the current browsing scheme. The subjects expressed much1 satisfaction about assigning a course to multiple browsing categories.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.465-474
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• 2009

The emergence of the digital age has changed the paradigm of education. Recently, the new paradigm needs new digital books that contain more interactive contents. Our goal is to design the digital textbook with convenient interfaces and cutting effects for interactive and effective education. To achieve these goals, we propose interfaces and contents which are designed after a lot of discussion with educational experts. In the implementation step, cutting algorithm is proposed to generate the cut planes of the 3D objects, based on the free strokes specified by the users. In order to test the performance of the contents, the testbed was implemented so that students try our digital book and present their evaluation results on the convenience and the effectiveness.

• Smart Structures and Systems
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• v.4 no.1
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• pp.1-17
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• 2008

This study proposes a conceptual framework of in-situ vibration tests and analyses for quality appraisal of non-slender, cast-in-place piles with irregular cross-section configuration. It evaluates a frequency index from vibration recordings to a series of impulse loadings that is related to total soil-resistance forces around a pile, so as to assess if the pile achieves the design requirement in terms of bearing capacity. In particular, in-situ pile-vibration tests in sequential are carried out, in which dropping a weight from different heights generates series impulse loadings with low-to-high amplitudes. The high-amplitude impulse is designed in way that the load will generate equivalent static load that is equal to or larger than the designed bearing capacity of the pile. This study then uses empirical mode decomposition and Hilbert spectral analysis for processing the nonstationary, short-period recordings, so as to single out with accuracy the frequency index. Comparison of the frequency indices identified from the recordings to the series loadings with the design-based one would tell if the total soil resistance force remains linear or nonlinear and subsequently for the quality appraisal of the pile. As an example, this study investigates six data sets collected from the in-situ tests of two piles in Taipu water pump project, Jiangshu Province of China. It concludes that the two piles have the actual axial load capacity higher than the designed bearing capacity. The true bearing capacity of the piles under investigation can be estimated with accuracy if the amplitude of impact loadings is further increased and the analyses are calibrated with the static testing results.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.217-236
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• 2006

In this study, the LCM was applied as the preliminary study for the cutterhead design of TBM and the drilling performance evaluation. The optimum cutting condition is obtained from the LCM tests and the effects of the design factors of IBM cutterhead, such as penetration depth and cutter spacing, on drilling performance are estimated. In this study, hence, to predict the accurate performance of TBM, instead of one-dimensional penetration depth applied in existing studies, three-dimensional cutting volume was quantified and measured. For this, the digital photogrammetry technique was applied to the LCM tests. Also, AUTODYN 2D was applied to investigate the applicability of the numerical analysis technique to simulate the cutting process of rock by the TBM disc cutter.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.473-483
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• 2014

According to the Korean Building Code (KBC), the validity of the application of 800MPa grade steel(HSA800) to composite column should be verified by experimental or analytical method. Thus, stub column tests for encased and filled composite members with HSA800 steel were conducted, and axial strength and the validity of design compressive strength equations in KBC were evaluated. The test results show that the equation of the compressive strength of encased composite column member in KBC should be modified in order to use HSA800 steel without any reduction of specified minimum yield strength. For this purpose, it is suggested that the interval of hoop should be narrowed and the effective concrete area should be used. The equation of the compressive strength of filled composite column member in KBC is applicable to filled composite column with HSA800 steel without any modification.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.47-55
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• 2002

The slope reinforcing method utilized in this paper reinforces the ground overall by means of filling borehole as well as permeating grout material into ground by injecting it through the grouting pipe. In order to reflect these characteristics to design, not only the ground reinforcing effect by the structural material itself but also the ground strength improvement effect by the grouting injection must be quantitively evaluated. But precedent research of it has been insufficient. Therefore, the slope reinforcing method was applied to the weathered rockmass slope situated in the highway in order to analyze reinforcing effect and the instrumentation of slope was performed. Through analysis of this field test, the slope reinforcing method was proved to be effective and back analysis method based on instrumentation values of slope was proposed to apply to reinforcing design. In this paper, the effectiveness of reinforcing method was certified through proposed back analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.3
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• pp.3-19
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• 1987

The purpose of this study was to investigate desirable width / height ratio of enclosed space and to offer basic information for the design of enclosed spaces. The data of this study were gathered from the experiment through simulation. Photographic sampling of 7 campus sites located in Kwanak campus of Seoul National University and slides of perspective drawings of enclosed spaces with various D/H ratio (12, 1, 2, 4, 6, 9, 12)were used for simulation. A response format was made using the method of paired comparison and students from various departments were randomly selected for evaluation. In the method of analysis of data Thurstone's equation of Comparative Judgement was used for calculating preference score. A1so non-linear regression analysis was used for finding out relations between preference and D/H ratio. The other method of data analysis were correlation, Chi - test. And the results were summarized as follows. 1. In sketch simulation the ratio of D/H 4 got the highest preference store. This result suggests that desirable D/H ratio of enclosed space is D/H 4. And at the lower range of D/H ratio, as ratio increases, the preference score increases. At the higher range of D/H ratio, however, as ratio increases, the preference score starts to decrease from the cardinal point of D/H 4. 2. In campus photograph simulation preference is influenced by slope, elevation change of floor, trees, lawn area, familiarity, space arrangement, and exterior shape of building besides D/H ratio. 3. The preference virtue was not significantly affected by order effect. This result suggests that order effect can be ignored in the study of visual preference. 4. There are so many factors related to preference that it is difficult to explore those factors without scientific information based on scientific method. We must carry out study for scientific approach of planning and design based on precise, complete simulation technique.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.1
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• pp.55-61
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• 2017

Recently several researches have been conducted to develop sliding track system in which friction between concrete track and bridge slab has been reduced. This paper investigated shear load carrying capacity of lateral supporting concrete block which should be implemented to resist lateral load due to train in sliding track system. In order to evaluate shear load carrying capacity of lateral supporting concrete block, analytical model has been developed considering concrete friction and rebar dowel action along construction joint. The proposed model predicted test results on the shear load carrying capacity from literature conservatively by 13~23% because effect of aggregate interlock along crack surface was neglected. Since construction joint status is ambiguous on construction site, it can be concluded that the proposed model can be used for reasonable design of lateral supporting concrete block. Based on the proposed model, design proposal for lateral supporting concrete block has been established.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.448-455
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• 2007

In 1992, the first design standard of quake proof bridge was established. However, most bridge structures which were constructed without considering earthquake in former times need performance of quakeproof property. Quakeproof analysis in current bridges, is based on analysis of load base which just has strength over the load of simple structures but is not checked through simple comparison of strength performance of structures so that we would like to check that ADRS method is reasonable or not using ADRS method(Accleration-Displacement Response Spectrum Method), a analysis method based on displacement of object of performance test. As the result of that, the capacity spectrum method can avoid complex dynamic analysis in analysis based on loads and it efficiently applies to design verification with normal checking for quakeproof performance and aimed performance of new structures. However we can not consider effects of high modes and it has problem that does not consider falling of performance in structures by repeated load.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.67-76
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• 2012

This study examined the optimal ingredient mixing ratio for the preparation of steamed cake containing mugwort (Artemisia princeps var. orientalis) powder. After preliminary studies, the following ingredient ranges were determined; 110~129% sugar, 3~8% mugwort powder, 10~25% oil. Among the different mixture designs, the D-optimal design was chosen for analysis. The results of F-test, specific gravity, viscosity, volume and color values (L, a, b), hardness decided a linear model, while the sensory characteristics (color, taste, texture and overall acceptance) decided a quadratic model. The fitness analysis results showed that in all characteristic, the probabilities were significant within 0.05%; thus, the models were accepted as appropriate. The response surface and trace plot results showed that increasing amounts of mugwort powder decreased the brightness, and increased redness and yellowness. As the level of added oil increased, the softness of the cake increased. Cake samples received low sensory evaluation scores when sugar, mugwort powder, and oil were added above their optimal levels. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method presented as: sugar, mugwort powder, and oil at 120.7%, 5.1%, and 16.2%, respectively(flour weight basis). The above results demonstrate the feasibility of adding mugwort powder to sponge cake, and therefore, the commercialization of mugwort powder cake marketed as a functional food is deemed possible.