• Journal of Biomedical Engineering Research
• /
• v.31 no.3
• /
• pp.217-226
• /
• 2010

The lower limb orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs was developed in this study. Compared to other knee extension assistive devices being developed by other researchers, our device is designed especially for the elderly people and intended only for slight assistance so that the subjects can keep their muscular strength. For the effectiveness of system, muscular activities of major muscles in lower limbs during sit-to-stand (STS) and squat motion were measured and analyzed. Subjects were performed the STS and squat motion with and without lower limb orthosis. We made comparison muscular activities between with and without lower limb orthosis. Lower limb orthosis was controlled using muscular stiffness force feedback that is controlled by muscular activities of the measured muscle from force sensor. For analysis of muscular activities, electromyography of the subjects was measured during STS and squat motion, and these were measured using MP 150(BIOPAC Systems, Inc.). Muscles of interest were rectus femoris(RF), vastus lateralis(VL), vastus medialis(VM) and vastus intermedius(VI) muscles in lower limbs of the right side. A biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors of wearing and not wearing orthosis on right side. The test were performed using the concentric isokinetic mode of test with the velocity set at 60°/s for muscles around the knee joints. The experimental result showed that muscular activities in lower limbs wearing orthosis using muscular stiffness force of a vastus medialis muscle was reduced and knee extension torque of an knee joint wearing lower limb orthosis was increased. With this, we confirmed the effectiveness of the developed lower limb orthosis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.269-274
• /
• 2004

The marine electronic system for safe navigation such as ECDIS has been contributing to increase the safety of navigation, decreasing the mariner's load of navigation. The ECDIS should be developed and approved by international standard of IMO for performance standard and IEC for type-approval method and required results. However, these standards have some ambiguities for us not to directly adopt them for real approval system, so we should analyze them for more clear meaning and prepare our own detail standard for type-approval system. The first thing to do for the goal of this research was to analyze the standard in detail and make ambiguity be cleared in our own standards, considering each test item in view of test methodology. For the result of analysis we could develop more evident and detail type-approval standard for each test item with test technology needed. Especially, we developed the colour differentiation test process of ECDIS monitor, which include the colour differentiation formula derived from CIE colour scheme. Several test items require sensor informations of navigation equipment compatible with IEC 61162. We also developed the signal simulator for general messages of IEC 61162 that must be provided. Additionally, the type-approval processes and standards for Back-up arrangement and RCDS mode were developed.

• Journal of Aerospace System Engineering
• /
• v.12 no.4
• /
• pp.75-80
• /
• 2018

The working principle of a satellite camera involves a focusing mechanism for controlling the focus of the optical system, which is essential for proper functioning. However, research on focusing mechanisms of satellite optical systems in Korea is in the beginning stage and developed technology is limited to a thermal control type. Therefore, in this paper, we propose a motor-driven focusing mechanism applicable to small satellite optical systems. The proposed mechanism is designed to generate z-axis displacement in the secondary mirror by a motor. In addition, three flexure hinges have been installed on the supporter for application of preload on the mechanism resulting in minimization of the alignment error arising due to manufacturing tolerance and assembly tolerance within the mechanism. After fabrication of the mechanism, the alignment errors (de-space, de-center, and tilt) were measured with LVDT sensors and laser displacement meters. Conclusively, the proposed focusing mechanism could achieve proper alignment degree, which can be applicable to small satellite optical system.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.13-21
• /
• 2004

The dissemination of commercial satellite images. which have the high spatial resolution such as aerial photos, are the active trend in remote sensing community because of the recent development in satellite and sensor technology. Such high resolution satellite images provide a unique tool for the monitoring of ongoing urban land use change. Especially KOMPSAT-1, which was launched at December 1999 and successfully operated up to now, provides repeatedly panchromatic images over Korean peninsula, which has the spatial resolution of 6.6m. Based upon this KOMPSAT-1 EOC image data we can try to analyze and assess the temporal urban land use change, which could not be done because lack of such data. The aim of this paper is to analyze and assess the spatial land use characteristics of Daejeon Metropolitan City based on KOMPSAT-1 EOC data. The land use map of year 2001 is generated through the modification of the year 2000 land use map, which is published by National Geographic Information Institute, using visual interpretation of KOMPSAT-1 EOC image which is acquired in year 2001. This study can be the start point of the time series analysis of the long term land use change monitoring mit KOMPSAT-1 EOC data.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.1
• /
• pp.47-58
• /
• 2018

The heterogeneous cellular network (HCN) is most significant as a key technology for future fifth generation (5G) wireless networks. The heterogeneous network considered consists of randomly macrocell base stations (MBSs) overlaid with femtocell base stations (BSs). The stochastic geometry has been shown to be a very powerful tool to model, analyze, and design networks with random topologies such as wireless ad hoc, sensor networks, and multi- tier cellular networks. The HCNs can be energy-efficiently designed by deploying various BSs belonging to different networks, which has drawn significant attention to one of the technologies for future 5G wireless networks. In this paper, we propose switching off/on systems enabling the BSs in the cellular networks to efficiently consume the power by introducing active/sleep modes, which is able to reduce the interference and power consumption in the MBSs and FBSs on an individual basis as well as improve the energy efficiency of the cellular networks. We formulate the minimization of the power onsumption for the MBSs and FBSs as well as an optimization problem to maximize the energy efficiency subject to throughput outage constraints, which can be solved the Karush Kuhn Tucker (KKT) conditions according to the femto tier BS density. We also formulate and compare the coverage probability and the energy efficiency in HCNs scenarios with and without coordinated multi-point (CoMP) to avoid coverage holes.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.4
• /
• pp.196-205
• /
• 2017

In recent years, the service design in the medical sector evolves through practical service research and development that can visualize both intangible and intangible service elements in an integrative way and derive innovative solutions to help customers feel the service more important value. With the improvement of personal income, interest in medical welfare and well-being is increasing day by day, and the focus of the medical sector shifts from the concept of treatment of diseases and illness to preventive medicine. In response to this trend, research and development of home health care system, which greatly reduces the time and space constraint of health checkup and health care by combining ubiquitous concept with medical welfare, are being actively conducted, and the needs for improving products and medical environment based on user-centered medical service and user needs in accordance with the Health Care 3.0 Era, it becomes necessary to develop on-site medical diagnostic products that reflect user-centered needs and needs. This study is intended to research and develop a product that sufficiently reflects the needs of users by applying suitable materials and shape for on-site diagnostic product in researching and developing Wireless X-ray Detector.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.6
• /
• pp.122-130
• /
• 2010

Seventy percent of Korea's national territory is covered with mountains, and the land is frequently exposed to typhoons and localized torrential downpours, particularly in July through September. For this reason, slope failure is one of the most frequent types of natural disasters in Korea. To prevent the damage caused by slope failure, the Korean government, academia and industry have strived together to develop and install a wired system for monitoring slope failures. However, conventional wired monitoring systems have been reported to have limitations, such as possible system errors caused by lightning, and the difficulties of restoration and management of the systems. To solve these problems, this research suggests a USN-based monitoring system for slope failures. First, the trend of slope measurement and USN technology was analyzed, and then the current status of damage caused by slope failures in Korea was reviewed. Next, a USN-based monitoring scenario for slope failures, incorporating both USN and slope monitoring technique, was developed. Finally, sensors were decided based on the developed scenario. It is expected that the results of this study will be utilized as fundamental data for the development of monitoring prototype systems for slope failures in the future. The development of the USN-based monitoring system for slope failures and its application in the field will also ultimately contribute to the prevention of slope failures and the minimization of related damage.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.48 no.6
• /
• pp.104-113
• /
• 2011

While converging USN Services, a single physical infrastructure can be used in several services and in several physical infrastructures can make up a single service. Therefore the physical infrastructure and service have to manage separately for effective convergence of USN Services. However, established Identification Scheme is not suitable to distinguish various services that USN provides. This paper suggests USN Service Identification Scheme that can be separated and managed. Through USN Service Identification Scheme suggested, firstly, it is possible to obtain Service Identification Scheme utilizing various technology such as RFID TAG, QR Code, radio broadcasting, etc. because it is possible to process USN Service Identification Scheme. Secondly, it is easy to mange the service, develope the user application program and interlock with established USN Standard technique as view from service provider. Thirdly, it is possible to manage systematically USN Service. Fourthly, users can search USN Service easily, so it can contribute actively for invigoration of USN service. This thesis, firstly, has analyzed about standard related USN Service and USN Identification Scheme. Secondly, this has suggested brand-new USN Service Identification Scheme based on established USN Identification Scheme.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.6
• /
• pp.63-70
• /
• 2011

A bicycle is different from vehicles in the structure that a rider is fully exposed to the surrounding environment. Therefore, it needs to make use of prior information about local weather, air quality, trail road condition. Moreover, since it depends on human power for moving, it should acquire route property such as hill slope, winding, and road surface to improve its efficiency in everyday use. Recent mobile applications which are to be used during bicycle riding let us aware of the necessity of development of intelligent bicycles. This study aims to develop a riding state (up-hill, down-hill, accelerating, braking) recognition algorithm using a low-power wrist watch type embedded system which has 3-axis accelerometer and wireless communication capability. The developed algorithm was applied to 19 experimental riding data and showed more than 95% of correct recognition over 83.3% of the total dataset. The altitude and temperature sensor also in the embedded system mounted on the bicycle is being used to improve the accuracy of the algorithm. The developed riding state recognition algorithm is expected to be a platform technology for intelligent bicycle interface system.

• Journal of Animal Environmental Science
• /
• v.8 no.3
• /
• pp.199-208
• /
• 2002

This paper introduces the method to make management network about milking cow farm tasks. The object of this research was to design of biological measuring system and managing network system in a livestock farm. This auto-management system provides informations about individual cows' temperature, conductivity of milk and weight for efficient management of feeding, and milking works by a micro-processor and RS -485 type serial COM. ports. And measured bio-data which are basic informations for remote raising management are saved to user PC by serial communication between the PLC and user PC. Milking cow farm is divided into three working place to each measurement work and feed. The first working place is milking station which has two thermometers, a conduct meter and a scale set. The second working place is feeding station, and the third place is cattle cage. These are combined by network system and the PLC which is used to drive network and sub-modules. Sub-modules have a micro-process to control the sensor and to interface with network. The PLC which drive network and control sequence has two serial communication port to be linked with user PC for sending the measured data and for receiving data. Above all, in this study tells the sequence operating method by the driving scenario of breeding milk cow for livestock auto-management using the PLC and network system.