• Tunnel and Underground Space
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• v.28 no.5
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• pp.400-425
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• 2018

This study presents the research results and current status of the DECOVALEX-2019 project Task B. Task B named 'Fault slip modelling' is aiming at developing a numerical method to simulate the coupled hydro-mechanical behavior of fault, including slip or reactivation, induced by water injection. The first research step of Task B is a benchmark simulation which is designed for the modelling teams to familiarize themselves with the problem and to set up their own codes to reproduce the hydro-mechanical coupling between the fault hydraulic transmissivity and the mechanically-induced displacement. We reproduced the coupled hydro-mechanical process of fault slip using TOUGH-FLAC simulator. The fluid flow along a fault was modelled with solid elements and governed by Darcy's law with the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by creating interface elements between two separating rock blocks in FLAC3D. A methodology to formulate the hydro-mechanical coupling relations of two different hydraulic aperture models and link the solid element of TOUGH2 and the interface element of FLAC3D was suggested. In addition, we developed a coupling module to update the changes in geometric features (mesh) and hydrological properties of fault caused by water injection at every calculation step for TOUGH-FLAC simulator. Then, the transient responses of the fault, including elastic deformation, reactivation, progressive evolutions of pathway, pressure distribution and water injection rate, to stepwise pressurization were examined during the simulations. The results of the simulations suggest that the developed model can provide a reasonable prediction of the hydro-mechanical behavior related to fault reactivation. The numerical model will be enhanced by continuing collaboration and interaction with other research teams of DECOLVAEX-2019 Task B and validated using the field data from fault activation experiments in a further study.

• Architectural research
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• v.15 no.1
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• pp.9-15
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• 2013

Effects of physical attributes of workstation enclosures on the performance of office workers with different difficult levels of office tasks and moods are presented. Performance scores in complex tasks were expected to increase with greater workstation enclosures while those in simple tasks would be the same. Mood ratings were expected to be higher in lower workstation enclosures. Performance of 102 college students on ambient office sounds (45 dBA) with office tasks were measured for 100 minutes under three different workplace enclosures: (1) four foot partitions on two sides; (2) six foot partitions on three sides; and (3) a fully enclosed workstation with eight foot partitions. The tasks were to memorize a paragraph with 130 words (complex task) and to search phone numbers (simple task). The complex task performance in the fully enclosed workstation was increased compared to that in the workstation with four foot partitions (p < 0.001) and to that in the workstation with six foot partitions (p < 0.05). However, occupants in the fully enclosed workstation with office sounds without speech generally gave higher mood ratings. It indicates that closed individual offices may offer important contributions to collaborative work as well as individual productivity. These findings would help design community revise open plan design to increase collaboration among office workers.

• KIEAE Journal
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• v.4 no.1
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• pp.11-20
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• 2004

Innovative daylighting systems in buildings in various climatic zones around the world have been developed under the IEA SHC Task21. The performance assessment were obtained by monitoring the most systems using full-scale test model rooms or actual buildings under real sky conditions. This study aims to analyze the configuration and monitoring system of the nine Mock-up models of the IEA SHC Task21 comparatively. For the purpose, the geometry of the test rooms (length, width, height, window area, glazed area and occupied), reflectance of walls, floor and ceiling, transmittance of glazing (transmittance for hemispherical irradiation, normal irradiation and U-value) were compared. And equipment for measurement (manufacturer, range, calibration, maximum calibration error, cosine response error, fatigue error), and data acquisition system (manufacturer, type, number of differential analogue input channels, A/D converter resolution in bits, data acquisition software) were also analyzed comparatively. Some findings of these experimental methodology of standard monitoring have been proven to be a valuable one for future assessment of advanced daylighting systems in our country.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.58-61
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• 2002

In this paper, we present a new generalized k-Tree-based (CU/PE) allocation model to perform dynamic resource (CU/PE) allocation/deallocation decision for the reconfigurable MSIMD/MIMD multi-dimensional (k-D) mesh-connected architectures. Those reconfigurable multi-SIMD/MIMD systems allow dynamic modes of executing tasks, which are SIMD and MIMD. The MIMD task requires only the free sub-system; however the SIMD task needs not only the free sub-system but also the corresponding free CU. In our new k-Tree-based (CU/PE) allocation model, we introduce two best-fit heuristics for the CU allocation decision: 1) the CU depth first search (CU-DFS) in O(kN$_{f}$ ) time and 2) the CU adjacent search (CU-AS) in O(k2$^{k}$ ) time. By the simulation study, the system performance of these two CU allocation strategies was also investigated. Our simulation results showed that the CU-AS and CU-DFS strategies performed the same system performance when applied for the reconfigurable MSIMD/MIMD 2-D and 3-D mesh-connected architectures.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.41-48
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• 2012

Objective: Companies want to expand their business by providing their services at other devices and new services based upon existing services. Therefore, they look for building brand identity by providing same experience throughout devices and services. Background: Many services are available to use at multiple devices including mobile phones, tablet, personal computers, and televisions, thanks to proliferation of n-screen and cloud technology. Method: It was discussed that consistency, which emphasizes the regularity and has been one of essential aspects of user interface design, seems not effective to be applied to n-screen services, owing to different screen size, input and output peripherals, usage environment and users' attitude. Results: A new definition of same experience among different devices and services, called coherence, was introduced and abstraction levels of user interfaces were proposed as the denominator of defining coherence. Then types of users' task knowledge at each abstraction level were discussed with examples. Conclusion: This paper concluded by discussing design requirements for designing coherent user interfaces among devices and services.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.8
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• pp.594-601
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• 2004

We analyze checkpoint strategy for multiple real-time periodic tasks with hard deadlines. Real-time tasks usually have deadlines associated with them. For multiple real-time tasks, checkpoint strategy considering deadlines of all tasks is very difficult to derive. We analyze the problem of checkpoint placement for such multiple periodic tasks. In our strategy, the interval between checkpoints is determined for each task considering its deadline. An approximated failure probability over a specified interval is derived. Then the number of checkpoints for each task is selected to minimize the approximated failure probability. To show the usefulness of our strategy, error bound between the exact and the approximated failure probability is estimated, which is revealed to be quite small.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.435-447
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• 1996

In this paper, we propose the method that extracts the speech feature using the hearing model through signal processing techniques. The proposed method includes the following procedure ; normalization of the short-time speech block by its maximum value, multi-resolution analysis using the discrete wavelet transformation and re-synthesize using the discrete inverse wavelet transformation, differentiation after analysis and synthesis, full wave rectification and integration. In order to verify the performance of the proposed speech feature in the speech recognition task, korean digit recognition experiments were carried out using both the DTW and the VQ-HMM. The results showed that, in the case of using DTW, the recognition rates were 99.79% and 90.33% for speaker-dependent and speaker-independent task respectively and, in the case of using VQ-HMM, the rate were 96.5% and 81.5% respectively. And it indicates that the proposed speech feature has the potential for use as a simple and efficient feature for recognition task

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.87-102
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• 2017

With increasing interest in 3D printing, the interest in the 3D modelling training that should precede the 3D printing is increasing. However, the existing 3D modelling software is developed mostly by foreign brands. Thus, the interfaces are all in English. 3D modelling software training for Korean novices who are not familiar with these terms has constraints. This study aims to explore what to consider when developing a Korean model for 3D modelling educational software for 3D printing in the face of such reality. For this goal, after having novices with no experience in 3D modeling to perform a house building task using either 12D Design or Tinker CAD, we conducted a survey. It was found in the result that more users favored Tinker CAD over 123D Design, and the errors involved while working with the Tinker CAD were less than those with the 123D Design, and the ratio of people who completed the task with the Tinker CAD was higher than that with the 123D Design. In general discussion, an introductory level educational 3D modeling software development is proposed which utilize characteristics of Tinker CAD (easy modelling is possible by three-dimensional figures) and web-based method. Also, a beginner/intermediate level educational 3D modeling software development is proposed which utilize characteristics of 123D Design (with finer measurement manipulations and figure alignment) and Windows-based method.

• Journal of Biomedical Engineering Research
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• v.37 no.1
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• pp.15-20
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• 2016

Essential tremor is a neurological disorder with a tremor of the arms and hands. It is well known that essential tremor is characterized by the postural tremor and the action tremor. There has been no report on the quantitative difference in the characteristics of two tremor types. The purpose of this study was to investigate the possible difference in tremor characteristics of postural and action tremors. Seventeen patients with essential tremor ($68.9{\pm}7.9years$, 7 men, 10 women) participated in this study. Patients performed the tasks of postural maintenance (arms outstretched) and daily actions (spiral drawing). Three-axes (pitch, roll and yaw) gyro sensors were attached on index finger, back of hand and forearm, from which the segment and the joint angular velocities were calculated. Outcome measure was the tremor amplitude defined as the root-mean-square mean of the vector-sum angular velocity at segments and joints. Two-way ANOVA showed that task and joint had main factor on the tremor amplitude (p < 0.05). Post-hoc analysis revealed that tremor amplitude at the metacarpo-phalangeal joint was not affected by task (p > 0.05). However, tremor amplitude at the wrist joint differed among the tasks (p < 0.05), and it was greater in the action tasks than in postural task. Tremor was greater at finger segments than at hand and forearm and it increased in action tasks. The results of this study would be helpful for the understanding and task-specific treatments of the essential tremor.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1174-1180
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• 2006

The present study was sought to clarify whether the combination of mental activity with subway noise affects hematological variables. Fifty-six healthy volunteers participated in this experiment and underwent a stress task consisting of combination_of mental activity (mental arithmetic) with subway noise for 50 min and 60min of recovery after the end of the stress task. Venous blood samples were collected for measuring CBC, prothrombin time (PT), activated partial thromboplastin time (aPTT), erythrocyte sedimentation rate (ESR), fibrinogen concentration, D-dimer and high sensitive C-reactive protein (H-CRP) levels before (baseline), 50min of stress task (S-50m), and 60 min of recovery (R-60m). Total leukocyte, neutrophil and lymphocyte counts significantly increased at R-60m compared with baselines. RBC count at S-50m was higher, while monocyte counts at S-50m and R-60m were lower than those of baselines. aPTTs shortened at S-50m and R-60m, but PT reduced at R-60m as compared with baselines. D-dimer and H-CRP levels at S-50m and R-60m were significantly higher than those of baselines. These findings imply that a combination of mental activity with subway noise nay cause leukocytosis, homo-concentration, shortened PT and aPTT, decreased ESR, and raised D-dimer and H-CRP levels, suggesting possible development of inflammation and prothrombogenic reaction attributable to a subway environment.