• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.415-424
• /
• 2019

In this paper, a minimum rotation radius was designed and fabricated to overcome the threshold so that elderly or disabled people who have difficulty moving can move and transfer safely and conveniently in a narrow room. In the indoor environment, where the sedentary culture develops, this study aimed to provide convenience for passengers with fracture diseases, geriatric diseases, and other knee and waist diseases. First, links, seats, armrests, covers, motors, batteries, chargers, controllers, etc. were attached to the frame so that they could be moved and lifted indoors. The product design and structure were designed considering the user's environment and physical characteristics, and IoT functions were added. A driving experiment was performed to confirm the operating performance of the manufactured indoor moving and lifting wheelchair. The performance tests, such as continuous running time, turning radius, maximum actuator load, maximum lift height, sound pressure level, minimum sensing distance of the driving aid sensor, interworking of server and app programs, device compatibility, and duty cycle error rate, were performed. As a result of the test, the built-in wheelchair could achieve the performance test target of each item and operate successfully.

• Design Convergence Study
• /
• v.15 no.2
• /
• pp.1-15
• /
• 2016

The purpose of this study is to identify the characteristics of aging-friendly technology that can be integrated into future smart homes in an aging society. The literature survey and content analysis method were used to collect and analyze data. Papers of the international journal ICOST (International Conference on Smart Homes and Health Telematics) that professionally deal with converged technologies were analysis units. Sixty-five papers among 215 papers published from 2007 through 2014 were selected on the basis of end-users orientation. Totally, out of 65 papers 76 technology items were extracted. Characteristics of those technologies were analyzed focusing on purpose and application methods. As results, in terms of purpose, the technologies were oriented to provide both of psychological and physiological support to the users, focusing on the safety, convenience, health and entertainment to extend independent life of the elderly. Among the application method such as building structure, furniture, product, wearable device and free movable robot, product were dominant. Through those results, the aging-friendly technology is expected to alleviate a wide range of issues in aging society.

• Journal of Distribution Science
• /
• v.11 no.2
• /
• pp.45-55
• /
• 2013

Purpose - The development and implementation of OSS (Open Source Software) led to a dramatic change in corporate IT infrastructure, from system server to smart phone, because the performance, reliability, and security functions of OSS are comparable to those of commercial software. Today, OSS has become an indispensable tool to cope with the competitive business environment and the constantly-evolving IT environment. However, the use of OSS is insufficient in small and medium-sized companies and software houses. This study examines the need for OSS Intermediaries in the Software Distribution Channel. It is expected that the role of the OSS Intermediary will be reduced with the improvement of the distribution process. The purpose of this research is to prove that OSS Intermediaries increase the efficiency of the software distribution market. Research design, Data, and Methodology - This study presents the analysis of data gathered online to determine the extent of the impact of the intermediaries on the OSS market. Data was collected using an online survey, conducted by building a personal search robot (web crawler). The survey period lasted 9 days during which a total of 233,021 data points were gathered from sourceforge.net and Apple's App store, the two most popular software intermediaries in the world. The data collected was analyzed using Google's Motion Chart. Results - The study found that, beginning 2006, the production of OSS in the Sourceforge.net increased rapidly across the board, but in the second half of 2009, it dropped sharply. There are many events that can explain this causality; however, we found an appropriate event to explain the effect. It was seen that during the same period of time, the monthly production of OSS in the App store was increasing quickly. The App store showed a contrasting trend to software production. Our follow-up analysis suggests that appropriate intermediaries like App store can enlarge the OSS market. The increase was caused by the appearance of B2C software intermediaries like App store. The results imply that OSS intermediaries can accelerate OSS software distribution, while development of a better online market is critical for corporate users. Conclusion - In this study, we analyzed 233,021 data points on the online software marketplace at Sourceforge.net. It indicates that OSS Intermediaries are needed in the software distribution market for its vitality. It is also critical that OSS intermediaries should satisfy certain qualifications to play a key role as market makers. This study has several interesting implications. One implication of this research is that the OSS intermediary should make an effort to create a complementary relationship between OSS and Proprietary Software. The second implication is that the OSS intermediary must possess a business model that shares the benefits with all the participants (developer, intermediary, and users).The third implication is that the intermediary provides an OSS of high quality like proprietary software with a high level of complexity. Thus, it is worthwhile to examine this study, which proves that the open source software intermediaries are essential in the software distribution channel.

• The Journal of the Acoustical Society of Korea
• /
• v.39 no.2
• /
• pp.120-130
• /
• 2020

This paper solves the problem in underdetermined convolutive mixture by improving the disadvantages of the multichannel nonnegative matrix factorization technique widely used in blind source separation. In conventional researches based on Spatial Covariance Matrix (SCM), each element composed of values such as power gain of single channel and correlation tends to degrade the quality of the separated sources due to high variance. In this paper, level and frequency normalization is performed to effectively cluster the estimated sources. Therefore, we propose a novel SCM and an effective distance function for cluster pairs. In this paper, the proposed SCM is used for the initialization of the spatial model and used for hierarchical agglomerative clustering in the bottom-up approach. The proposed algorithm was experimented using the 'Signal Separation Evaluation Campaign 2008 development dataset'. As a result, the improvement in most of the performance indicators was confirmed by utilizing the 'Blind Source Separation Eval toolbox', an objective source separation quality verification tool, and especially the performance superiority of the typical SDR of 1 dB to 3.5 dB was verified.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.4
• /
• pp.1665-1673
• /
• 2013

Recently, the interest and demand on free formed structure providing aesthetic value as well as functionality has been increasing. Formwork has numerous advantages such as high strength, convenience, accuracy and good quality of surface roughness. Nevertheless, it increases construction cost and period to build complex shapes. For these purpose, deposition construction systems such as Contour Crafting and Concrete Printing have been developed with active collaboration between university and industry by applying the rapid prototyping technology to the construction industry in USA and England. Since there has been no related research in Korea, the possibility of spin-off technology and its fusion cannot be expected. In this paper, design elements including mechanical system and control system related to automatic deposition construction system prototype for constructing a free curved structure without mold are described. As for an appropriate material for the system, fiber reinforced mortar was selected by experiments on compressive strength, fluidity, viscosity and setting time. By performing transfer and extrusion experiments, the possibility of the development of deposition construction system was demonstrated. Based on this research results, it is required to keep the automatic deposition construction system improve and extend it into the new application area in construction industry.

• Journal of IKEEE
• /
• v.24 no.2
• /
• pp.654-660
• /
• 2020

Through the output of brain waves during muscle operation, this paper checks whether it is possible to find characteristic vectors of brain waves that are capable of dividing left and right movements by extracting brain waves in specific areas of muscle signal output that include the motion of the left and right muscles or the will of the user within EEG signals, where uncertainties exist considerably. A typical surface EMG and noninvasive brain wave extraction method does not exist to distinguish whether the signal is a motion through the degree of ionization by internal neurotransmitter and the magnitude of electrical conductivity. In the case of joint and motor control through normal robot control systems or electrical signals, signals that can be controlled by the transmission and feedback control of specific signals can be identified. However, the human body lacks evidence to find the exact protocols between the brain and the muscles. Therefore, in this paper, efficiency is verified by utilizing the results of application of CSP (Common Spatial Pattern) filter to verify that the left-hand and right-hand signals can be extracted through brainwave analysis when the subject's behavior is performed. In addition, we propose ways to obtain data through experimental design for verification, to verify the change in results with or without filter application, and to increase the accuracy of the classification.

• The KIPS Transactions:PartD
• /
• v.13D no.7 s.110
• /
• pp.889-900
• /
• 2006

Even though sensor networks are different in user requests and data characteristics depending on each application area, the existing researches on stream data transmission problem focus on the performance improvement of their methods rather than considering the original characteristic of stream data. In this paper, we introduce a hierarchical or distributed sensor network architecture and data model, and then evaluate the multivariate data reduction methods suitable for user requirements and data features so as to apply reduction methods alternatively. To assess the relative performance of the proposed multivariate data reduction methods, we used the conventional techniques, such as Wavelet, HCL(Hierarchical Clustering), Sampling and SVD (Singular Value Decomposition) as well as the experimental data sets, such as multivariate time series, synthetic data and robot execution failure data. The experimental results shows that SVD and Sampling method are superior to Wavelet and HCL ia respect to the relative error ratio and execution time. Especially, since relative error ratio of each data reduction method is different according to data characteristic, it shows a good performance using the selective data reduction method for the experimental data set. The findings reported in this paper can serve as a useful guideline for sensor network application design and construction including multivariate stream data.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.42 no.1
• /
• pp.1-11
• /
• 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.

• Resources Recycling
• /
• v.31 no.4
• /
• pp.3-11
• /
• 2022

Owing to the increasing demand for electric vehicles (EVs), appropriate management of their waste batteries is required urgently for scrapped vehicles or for addressing battery aging. With respect to technological developments, data-driven diagnosis of waste EV batteries and management technologies have drawn increasing attention. Moreover, robot-based automatic dismantling technologies, which are seemingly interesting, require industrial verifications and linkages with future battery-related database systems. Among these, it is critical to develop and disseminate various advanced battery diagnosis and assessment techniques to improve the efficiency and safety/environment of the recirculation of waste batteries. Incorporation of lithium-related chemical substances in the public pollutant release and transfer register (PRTR) database as well as in-depth risk assessment of gas emissions in waste EV battery combustion and their relevant fire safety are some of the necessary steps. Further research and development thus are needed for optimizing the lifecycle management of waste batteries from various aspects related to data-based diagnosis/classification/disassembly processes as well as reuse/recycling and final disposal. The idea here is that the data should contribute to clean design and manufacturing to reduce the environmental burden and facilitate reuse/recycling in future production of EV batteries. Such optimization should also consider the future technological and market trends.

• Composites Research
• /
• v.35 no.6
• /
• pp.378-393
• /
• 2022

As an emerging power generation technology, triboelectric nanogenerators (TENGs) have received increasing attention due to their boundless promise in energy harvesting and self-powered sensing applications. The recent rise of soft robotics has sparked widespread enthusiasm for developing flexible and soft sensors and actuators. TENGs have been regarded as promising power sources for driving actuators and self-powered sensors, providing a unique approach for the development of soft robots with soft sensors and actuators. In this review, TENG-based soft robots with different morphologies and different functions are introduced. Among them, the design of biomimetic soft robots that imitate the structure, surface morphology, material properties, and sensing/generating mechanisms of nature has greatly benefited in improving the performance of TENGs. In addition, various bionic soft robots have been well improved compared to previous driving methods due to the simple structure, self-powering characteristics, and tunable output of TENGs. Furthermore, we provide a comprehensive review of various studies within specific areas of TENG-enabled soft robotics applications. We first explore various recently developed TENG-based soft robots and a comparative analysis of various device structures, surface morphologies, and nature-inspired materials, and the resulting improvements in TENG performance. Various ubiquitous sensing principles and generation mechanisms used in nature and their analogous artificial TENG designs are demonstrated. Finally, biomimetic applications of TENG enabled in tactile displays as well as in wearable devices, artificial electronic skin and other devices are discussed. System designs, challenges and prospects of TENGs-based sensing and actuation devices in the practical application of soft robotics are analyzed.