• Journal of Information Management
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• 제38권2호
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• pp.153-173
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• 2007

[ $OntoFrame^{(R)}$ ] system provides information dissemination service and inference service, based on Semantic Web framework to fully support R&D activities. Although it is one of state-of-the-art systems in the viewpoint of functionality, we are not able to declare whether it has satisfiable usability because of the omission of usability test in development process. Thus, this research tries to reveal the usability level of the $OntoFrame^{(R)}$, and further to find ways to achieve a user-center system. Both 'theory-based assessment' by a software ergonomics expert and 'user test' by four users are used for evaluating the usability of the $OntoFrame^{(R)}$. We look forward this research to being a basic reference for practical systems aiming at satisfiable usability.

• KIPS Transactions on Software and Data Engineering
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• 제9권5호
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• pp.169-176
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• 2020

Recently, deep neural networks (DNNs) have brought revolutions to many mobile and embedded devices by providing human-level machine intelligence for various applications. However, high inference accuracy of such DNNs comes at high computational costs, and, hence, there have been significant efforts to reduce computational overheads of DNNs either by compressing off-the-shelf models or by designing a new small footprint DNN architecture tailored to resource constrained devices. One notable recent paradigm in designing small footprint DNN models is sharing parameters in several layers. However, in previous approaches, the parameter-sharing techniques have been applied to large deep networks, such as ResNet, that are known to have high redundancy. In this paper, we propose a parameter-sharing method for already parameter-efficient small networks such as ShuffleNetV2. In our approach, small templates are combined with small layer-specific parameters to generate weights. Our experiment results on ImageNet and CIFAR100 datasets show that our approach can reduce the size of parameters by 15%-35% of ShuffleNetV2 while achieving smaller drops in accuracies compared to previous parameter-sharing and pruning approaches. We further show that the proposed approach is efficient in terms of latency and energy consumption on modern embedded devices.

• Journal of rehabilitation welfare engineering & assistive technology
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• 제11권3호
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• pp.253-259
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• 2017

Conventional upper extremity rehabilitation paradigm after brain injury has several shortcomings that is monotonous, simple, and repetitive in exercises over a long period of time, thereby causing training efficiency to decline as a consequence of low interest and participation. To resolve this issue, this paper proposes a new rehabilitative program integrating a wearable device integrated with EMG and motion sensor and a mobile game for the upper limbs' rehabilitative training. The developed wearable device is manufactured in the form of band, making it easy to wear. The mobile game is designed to enable rehabilitative training through games reflective of flexion, extension, abduction, and adduction identified by motion sensors along with grasp motion recognized by EMG signals measured from the wearable device. It also provides a tailored rehabilitative environment suitable for individual patients based on difficulty adjustments. As a consequence of applying the developed program to 14 brain injury in need of the upper limb rehabilitation and taking surveys on the utility of the developed rehabilitative program, the responses indicated that the developed rehabilitative program is far much more interesting and fun than the conventional rehabilitative program, further to the desire of those surveyed to reuse the developed program in the future.

• Journal of the Institute of Electronics Engineers of Korea SC
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• 제42권1호
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• pp.1-11
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• 2005

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of agile prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. However, there is an important problem with the conventional 2D lamination method. That is the inaccuracy of 3D model surface, which is caused by the stair-type surface generated in virtue of vertical 2D cutting. In this paper, We design the new control algorithm that guarantees the constant speed, precise positioning and tangential cutting on the 5DOF SFFS. We develop the tangential cutting algorithm to be controlled with constant speed and successfully implemented in the 5DOF CAFL/sup VM/ system developed in this paper. Finally, this paper confirms its high-performance through the experimental results from the application into CAFL/sup VM/ system.

• Journal of the Earthquake Engineering Society of Korea
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• 제6권2호
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• pp.9-19
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• 2002

Steel piers and concrete-filled steel(CFS) piers, in spite of reasonable strength, high ductility, small section, and fast construction, have not been considered as one of alternatives to RC piers even in the highly populated urban area where aseismic safety, limited space and fast construction are indispensably required. This paper, the first of two companion papers for the seismic performance of steel and CFS piers, tests steel and CFS piers under quasi-static cyclic loading to estimate their ductility and strength. Additional details such as rebars and base ribs are added to increase the ductility of a concrete-filled steel pier with minimum additional cost. Also, simplified numerical analyses using nonlinear spring and shell elements are examined for the estimation of the ductility and strength of concrete-filled steel piers and a steel pier. The result shows that concrete-filled steel peirs have higher energy absorption, i.e., ductility and strength than those of steel pier and increasing bonding between in-filled concrete and lower diaphragm, and the improved details of stress concentrated region would be important for the ductility and strength of a pier. Numerical results show that simplified modeling with nonlinear springs and shells has potential to be effective modeling technique to estimate the seismic performance of a concrete-filled steel pier.

• Journal of the Earthquake Engineering Society of Korea
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• 제6권2호
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• pp.63-71
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• 2002

This paper examines the ASCE first generation benchmark problem for a seismically excited cable-stayed bridge, and proposes a new semi-active control strategy focusing on inclusion of effects of control-structure interaction. This benchmark problem focuses on a cable-stayed bridge in Cope Girardeau, Missouri, USA, for which construction is expected to be completed in 2003. Seismic considerations were strongly considered in the design of this bridge due to the location of the bridge in the New Madrid seismic zone and its critical role as a principal crossing of the Mississippi River. In this paper, magnetorheological(MR) fluid dampers are proposed as the supplemental damping devices, and a clipped-optimal control algorithm is employed. Several types of dynamic models for MR fluid dampers, such as a Bingham model, a Bouc-Wen model, and a modified Bouc-Wen model, are considered, which are obtained from data based on experimental results for full-scale dampers. Because the MR fluid damper is a controllable energy-dissipation device that cannot add mechanical energy to the structural system, the proposed control strategy is fail-safe in that bounded-input, bounded-output stability of the controlled structure is guaranteed. Numerical simulation results show that the performance of the proposed semi-active control strategy using MR fluid dampers is quite effective.

• Journal of the Earthquake Engineering Society of Korea
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• 제9권2호통권42호
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• pp.37-46
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• 2005

To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

• Journal of the Earthquake Engineering Society of Korea
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• 제16권2호
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• pp.47-60
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• 2012

Based on the Korean Building Standard Law, a building less than 3-stories and $1000m^2$ in area is defined as a small-level building and, as a result, this type of building has been excluded from the requirement to comply with seismic design. In order to prevent the loss of life and property under earthquake loadings, the small-scale building should satisfy the seismic performance specified in the current code through a seismic retrofit. In this study, a seismic retrofit scheme of a Buckling-Restrained Knee Brace (BRKB) was developed for non-seismic 2-story steel buildings, including small-scale buildings, using a fragility contour method. In order to develop an effective retrofit scheme of the BRKB for the building, a total of 75 BRKB analytical models were used to achieve the desired performance levels and analyzed using the fragility contour method. The seismic performance of the retrofitted building was evaluated in terms of the weight of the developed BRKB systems. This study shows that the fragility contour method can be used for rapid evaluation and is an effective tool for structural engineers.

• Journal of the Earthquake Engineering Society of Korea
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• 제16권5호
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• pp.41-53
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• 2012

The objective of this study is to evaluate the seismic capacity of RC piers with small aspect ratios. Test specimens were selected from the prototype piers among existing national roadway bridges which are expected to fail in shear and/or complex shear-flexural mode. Two groups of full scale RC pier models were constructed with aspect ratios of 2.25 and 2.67. Quasi-static tests have been implemented to investigate the failure behavior of the RC piers in terms of the lap-spliced longitudinal reinforcing steel and the aspect ratio. It is confirmed that regarding its shear-flexural behavior, the pier is very sensitive to the aspect ratio or details. In the case of a test pier with highly lap-spliced longitudinal bars, the bond failure of lap-splice steels was the dominant cause of failure before the occurrence of flexure or shear-flexural failure, despite a slight change in the aspect ratio. Finally, based on the test results and analysis, this paper proposes formulas for the yielding and ultimate displacements of circular reinforced concrete bridge piers without seismic details. These formulas will be useful for the investigation and upgrade of the seismic capacity of bridge piers without seismic details.

• Journal of the Earthquake Engineering Society of Korea
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• 제13권3호
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• pp.11-19
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• 2009

Recently, concerns relating to the maintenance of large structures have been increased. In addition, the number of large structures that need to be evaluated for their structural safety due to natural disasters and structural deterioration has been rapidly increasing. It is common for the structural characteristics of an older large structure to differ from the characteristics in the initial design stage, and changes in dynamic characteristics may result from a reduction in stiffness due to cracks on the materials. The process of deterioration of such structures enables the detection of damaged locations, as well as a quantitative evaluation. One of the typical measuring instruments used for the monitoring of bridges and buildings is the dynamic measurement system. Conventional dynamic measurement systems require considerable cabling to facilitate a direct connection between sensor and DAQ logger. For this reason, a method of measuring structural responses from a remote distance without the mounted sensors is needed. In terms of non-contact methods that are applicable to dynamic response measurement, the methods using the doppler effect of a laser or a GPS are commonly used. However, such methods could not be generally applied to bridge structures because of their costs and inaccuracies. Alternatively, a method using a visual image can be economical as well as feasible for measuring vibration signals of inaccessible bridge structures and extracting their dynamic characteristics. Many studies have been conducted using camera visual signals instead of conventional mounted sensors. However, these studies have been focused on measuring displacement response by an image processing technique after recording a position of the target mounted on the structure, in which the number of measurement targets may be limited. Therefore, in this study, a model experiment was carried out to verify the measurement algorithm for measuring multi-point displacement responses by using a DIC (Digital Image Correlation) technique.