• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.97-104
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• 2000

Pneumatic cylinder is widely used for mechanical handling systems. Often, the impact occurs at the both ends points of pneumatic cylinder and generates destructive shock with in the structural operating members of the machine or equipment. To reduce the damage of system, therefore, shock absorbing devices are required. Cushioning of pneumatic cylinders at one or both ends of piston stroke is used to reduce the shock and vibration. The cylinder body have to withstand under high velocity and load. In this research, the pneumatic cushioning cylinder moving tests have been conducted for different load mass and supply pressure. The velocity of pneumatic cylinder actuation system with multiple orifice cushion sleeve which is set vertically controled with meter-in/out system. This study examines the dynamic characteristics of pneumatic cylinder with cushion devices. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion region characteristics was also revealed in the meter-in system.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.459-465
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• 2008

Locations of nodes as well as gathered data from nodes are very important because generally multiple nodes are deployed randomly and data are gathered in wireless sensor network. Since the nodes composing wireless sensor network are low cost and low performance devices, it is very difficult to add specially designed devices for positioning into the nodes. Therefore in wireless sensor network, technology positioning nodes precisely using low cost is very important and valuable. This research proposes Cooperative Positioning System, which raises accuracy of location positioning and also can find positions on multiple sensors within limited times.

• The Journal of Korea Robotics Society
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• v.2 no.1
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• pp.21-28
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• 2007

The Intelligent Space(ISpace) provides challenging research fields for surveillance, human-computer interfacing, networked camera conferencing, industrial monitoring or service and training applications. ISpace is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment, it is very important that the system knows the location information to offer the useful services. In order to achieve these goals, we present a method for representing, tracking and human following by fusing distributed multiple vision systems in ISpace, with application to pedestrian tracking in a crowd. And the article presents the integration of color distributions into particle filtering. Particle filters provide a robust tracking framework under ambiguity conditions. We propose to track the moving objects by generating hypotheses not in the image plan but on the top-view reconstruction of the scene. Comparative results on real video sequences show the advantage of our method for multi-object tracking. Also, the method is applied to the intelligent environment and its performance is verified by the experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.31-36
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• 2005

Intelligent Space (iSpace) is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment comes to have intelligence. In iSpace, the locations of multiple humans and other objects are obtained and tracked by using multiple camera and color-based method. In addition, we describe a context-aware information system which is based on Spatial-Knowledge-Tags (SKT). SKT system enables humans to access information and data by using spatial location of human and stored information in storage. The proposed tracking method is applied to the intelligent environment and its performance is verified by the experiments.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.570-576
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• 2015

Existing flash storage devices such as universal flash storage and solid state disk support command queuing to improve storage I/O bandwidth. Command queuing allows multiple read/write requests to be pending in a device queue. Because multi-channel and multi-way architecture of flash storage devices can handle multiple requests simultaneously, command queuing is an indispensable technique for utilizing parallel architecture. However, command queuing can be harmful to the latency of fsync system call, which is critical to application responsiveness. We propose a dynamic queue depth adaptation technique, which reduces the queue depth if user application is expected to send fsync calls. Experiments show that the proposed technique reduces the fsync latency by 79% on average compared to the original scheme.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.119-125
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• 1995

Strained multiple quantum well(SMQW) PBH-DFB-LDs emitting at 1.55$\mu$m wavelength has been fabricated using OMVPE and LPE crystal growth tecnique. Using the SMQW active layer, a linewidty enhancement factor of 2.65 was obtained at lasing wavelength and consequnently, packaged 42 modules showed a very low average chirp of 0.44nm at 2.5Gbps NRZ direct modulation. The 77 devices showed average threshold current of 8.72mA and average slope efficiency of 0.181 mW/mA, and single longitudinal mode operation with SMSR larger than 30dB up to 5mW. Among the 77 devices, standard deviation of lasing wavelength of 3.57nm was obtained owing to a good crystal growth uniformity.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.1-4
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• 2014

Although physical modeling synthesis is becoming more and more efficient in rich and natural high-quality sound synthesis, its high computational complexity limits its use in portable devices. This constraint motivated research of single-instruction multiple-data many-core architectures that support the tremendous amount of computations by exploiting massive parallelism inherent in physical modeling synthesis. Since no general consensus has been reached which grain sizes of many-core processors and memories provide the most efficient operation for sound synthesis, design space exploration is conducted for seven processing element (PE) configurations. To find an optimal PE configuration, each PE configuration is evaluated in terms of execution time, area and energy efficiencies. Experimental results show that all PE configurations are satisfied with the system requirements to be implemented in portable devices.

• Journal of the Korea Society of Computer and Information
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• v.22 no.6
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• pp.79-86
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• 2017

In this paper, we implement a common module that can integrate multiple biometric information for integrated patient monitoring system. Conventional biomedical instruments have many devices attached to each patient, making it difficult to monitor abnormality signs of many patients in real time. In this paper, we propose a module for an integrated monitoring system that can perform centralized monitoring using a common module that integrates multiple measurement devices. A protocol for sending and receiving packets between the measuring device and the common module is designed, and the packets transmitted through the network are stored and managed through the integrated monitoring system and provide information to various users such as medical staff. The results of this study are expected to contribute to the management of patients and efficient medical services in hospitals.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.221-228
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• 2021

Recent improvements on the quality, fidelity and availability of biometric data have led to effective human physical activity detection (HPAD) in real time which adds significant value to applications such as human behavior identification, healthcare monitoring, and user authentication. Current approaches usually use machine-learning techniques for human physical activity recognition based on the data collected from wearable accelerometer sensor from a single wearable smart device on the user. However, collecting data from a single wearable smart device may not provide the complete user activity data as it is usually attached to only single part of the user's body. In addition, in case of the absence of the single sensor, then no data can be collected. Hence, in this paper, a continuous HPAD will be presented to effectively perform user activity detection with mobile service infrastructure using multiple wearable smart devices, namely smartphone and smartwatch placed in various locations on user's body for more accurate HPAD. A case study on a comprehensive dataset of classified human physical activities with our HAPD approach shows substantial improvement in HPAD accuracy.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.331-334
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• 2003

In this paper a new OSD (On-Screen Display) development system for digital devices is presented. The proposed system is an example of the ubiquitous systems because it can be used to co-develop an OSD tn any time at any place if the web can be accessed. In UI, OSD is an important pan of digital devices. Especially, OSD implementations for multiple languages are essential to export digital devices and make them user-friendly. The proposed system consists of four components: font editor, menu editor. R/C simulator, and screen editor. It provides all the functions to develop an OSD and the result can be downloaded to a digital device. The proposed system was used to develop an OSD for 31 countries and the lead time of development was reduced from 52.7 days to 20 days.