• IEIE Transactions on Smart Processing and Computing
• /
• v.6 no.1
• /
• pp.1-9
• /
• 2017

This paper proposes to improve the performance of a strap down inertial navigation system using a foot-mounted low-cost inertial measurement unit/magnetometer by configuring an attitude and heading reference system. To track position accurately and for attitude estimations, considering different dynamic constraints, magnetic measurement and a zero velocity update technique is used. A conventional strap down method based on integrating angular rate to determine attitude will inevitably induce long-term drift, while magnetometers are subject to short-term orientation errors. To eliminate this accumulative error, and thus, use the navigation system for a long-duration mission, a hybrid configuration by integrating a miniature micro electromechanical system (MEMS)-based attitude and heading detector with the conventional navigation system is proposed in this paper. The attitude and heading detector is composed of three-axis MEMS accelerometers and three-axis MEMS magnetometers. With an absolute algorithm based on gravity and Earth's magnetic field, rather than an integral algorithm, the attitude detector can obtain an absolute attitude and heading estimation without drift errors, so it can be used to adjust the attitude and orientation of the strap down system. Finally, we verify (by both formula analysis and from test results) that the accumulative errors are effectively eliminated via this hybrid scheme.

• KIEAE Journal
• /
• v.12 no.2
• /
• pp.25-32
• /
• 2012

This paper focused on the daylighting performance of residential high-rise buildings in South-Korea. the purpose of this study is to estimate the visual environment of sunlight coming into opening according to sky conditions, orientation of windows and each space of Apartment buildings. Season of the year, weather, and time of day combine with predictable movement patterns of the sun to create highly variable and dynamic daylighting conditions. Daylighting design is usually based on the dominant sky condition and the micro-climate for the building site. There are three common sky conditions: clear sky, overcast sky, and partly cloudy sky. The clear sky includes sunshine and is intense and brighter at the horizon than at the zenith, except in the area around the sun. Daylight received within a building is directly dependent upon the sun's position and the atmospheric conditions. Easily used charts, diagrams, and software programs allow study of solar geometry for any geographic location and time of day. on the other hand, the overcast sky is characterized by diffuse and variable levels of light and has dense cloud cover over 90% of the sky. This paper was calculated by a Desktop Radiance program. The space dimensions were based on a unit module of real constructed apartment having divided into five sections such as living room, room1, room2, room3 and kitchen.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.12
• /
• pp.723-731
• /
• 2005

The $4{\times}4$ homogeneous transformation matrix is a compact representation of orientation and position of an object in robotics and computer graphics. A coordinate transformation is accomplished through the successive multiplications of homogeneous matrices, each of which represents the orientation and position of each corresponding link. Thus, for real time control applications in robotics or animation in computer graphics, the fast multiplication of homogeneous matrices is quite demanding. In this paper, a parallel-architecture vector processor is designed for this purpose. The processor has several key features. For the accuracy of computation for real application, the operands of the processors are floating point numbers based on the IEEE Standard 754. For the parallelism and reduction of hardware redundancy, the processor takes column vectors of homogeneous matrices as multiplication unit. To further improve the throughput, the processor structure and its control is based on a pipe-lined structure. Since the designed processor can be used as a special purpose coprocessor in robotics and computer graphics, additionally to special matrix/matrix or matrix/vector multiplication, several other useful instructions for various transformation algorithms are included for wide application of the new design. The suggested instruction set will serve as standard in future processor design for Robotics and Computer Graphics. The design is verified using FPGA implementation. Also a comparative performance improvement of the proposed design is studied compared to a uni-processor approach for possibilities of its real time application.

• Hwankyungkyoyuk
• /
• v.20 no.2
• /
• pp.16-24
• /
• 2007

The purpose of this study is to understand how the unit objectives and contents associated with environment are reflected on the 6 kinds of chemistry- I textbooks in the 7th curriculum and to present how to deal with the environmental education in chemistry- I. The results of this study are as follows. First, units associated with environment account for an average of 43.7% on chemistry- I in 7th curriculum. Second, contents of units related to environmental education on chemistry- I in 7th curriculum are environmental pollution(17.8%), environmental preservation and environmental pollution prevention(15.9%), environmental hygiene(12.2%), and any other things, Environmental pollution takes up a considerable part of environmental education. Third, the results for analyzing the objectives of chemistry- I in 7th curriculum show that Information Knowledge Awareness(34.0%) and Skill (29.9%) take up most parts. Fourth, Orientation (I) as analysis standard for objective of the units related to environmental education accounts for 10.2% of the total. It is clear that environmental education is carried out from STS point of view. In conclusion, environmental education in Chemistry- I focuses on fostering students' ability to apply the fundamental notion of chemistry to real life associated with environments. Therefore, it is necessary that environmental education in Chemistry- I should include value, attitude and participation and that improve students' ability to approach the environmental problem comprehensively.

• Steel and Composite Structures
• /
• v.35 no.6
• /
• pp.789-798
• /
• 2020

The effect of Chitosan (CS), Carbon Nanotube (CNT) and hybrid (CS-CNT) fillers on the natural frequency of drilled composite plate is investigated by experimentally in this study. The numerical validation is also made with a program based on Finite Element Method (SolidWorks). Nine types filled and one neat composite plates are used in the study. The fillers ratios are 1% CS, 2% CS, 3% CS, 0.1% CNT, 0.2% CNT, 0.3% CNT, 1% CS+0.3% CNT, 2% CS+0.3% CNT, 3% CS+0.3% CNT. The specimens cut to certain sizes by water jet from the plates 400 mm × 400 mm in dimensions. Some of them are drilled in certain dimensions with drill. The natural frequency of each specimen is measured by the vibration test set up to determine the vibration characteristic. The vibration test set up includes an accelerometer, a current source power unit, a data acquisition card and a computer. A code is written in Matlab^® program for the signal processing. The study are investigated and discussed in four main points to understand the effect of the fillers on the natural frequency of the composite plate. These are the effect of fillers contents and amounts, orientation angles of fibers, holes numbers and holes sizes. As results, the natural frequency of the plate with 1% CS and 0.1% CNT hybrid filler is lower than those of the plates with other fillers ratios for 45° orientation angle. Besides, in the composite plate with 0° orientation angle, the natural frequency increases with increasing the filler ratio. Moreover, the natural frequency increases until a certain hole number and then it decreases. Furthermore, the natural frequency is not affected until a certain hole diameter but then it decreases.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.10 s.241
• /
• pp.1329-1335
• /
• 2005

An aluminum or CFRP (Carbon Fiber ReinfDrced Plastics)is representative one of light-weight materials but its axial collapse mechanism is different from each other. The aluminum member absorbs energy by stable plastic deformation, while the CFRP member absorbs energy by unstable brittle failure with higher specific strength and stiffness than those in the aluminum member. In an attempt to achieve a synergy effect by combining the two members, aluminum CFRP compound square members were manufactured, which are composed of aluminum members wrapped with CFRP outside aluminum square members with different fiber orientation angle and thickness of CFRP, and axial collapse tests were performed fur the members. The axial collapse characteristics of the compound members were analyzed and compared with those of the respective aluminum members and CFRP members. Test results showed that the collapse of the aluminum CFRP compound member complemented unstable brittle failure of the CFRP member due to ductile characteristics of the inner aluminum member. The collapse modes were categorized into four modes under the iuluence of the fiber orientation angle and thickness of CFRP. The absorbed energy Per unit mass, which is in the light-weight aspect was higher in the aluminum CFRP compound member than that in the aluminum member and the CFRP member alone.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.5
• /
• pp.169-179
• /
• 2019

During the initial design stage of apartment complex, the photovoltaic(PV) system has been considered as an alternative of renewable energy system and planned to install at the rooftop floor level in general. The electric power generation characteristics can be influenced by the block layout, building orientation and roof top structure because of azimuth angle, tilt angle, and partial shading. This study aims to investigate power generation characteristics of photovoltaic system in apartment buildings by considering the partial shading conditions due to the block layout, building orientation and roof-top structures. For the photovoltaic module arrangement planning in rooftop floor level, shading areas were firstly analyzed due to the adjacent building structure. And the annual and seasonal power generation of PV system were analyzed through the PVsyst simulation results. The results show that shading period at the roof top surface can be increased due to the parapet and water tank. Initial design power capacity can be decreased by considering the daily insolation period and distance between PV modules through the shading simulation. As the number of PV modules decreases, the annual power generation can be decreased. However annual power generation per unit area of PV modules can be increased and performance ratio can be increased above 80%. Also the power generation of PV system can be critically affected by building orientation and the performance ratio can be drastically decreased in east-oriented buildings due to the shading problems caused by adjacent structures at roof top level such as parapet and water tank.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.5 no.9
• /
• pp.107-116
• /
• 1999

The purpose of this study is to present reference materials for the planning and research of related environments by introducing the theoretical background and samples of the environments for older people with cognitive impairments. Major contents of the study include cognitive impairments and residential facility of older people, model environments for special care unit, therapeutic dimensions of environments, outdoor garden, activity calendar, and site-visits of the sample facilities. Some results of the study could be summarized as follows ; 1) Special care unit for the people with cognitive impairments has been required and developed. 2) Weiss Institute, Corrine Dolan Alzheimer Center, and Wood Place in Oakmont were analyzed as model environments. 3) Therapeutic dimensions such as safety & security, awareness & orientation, opportunities for socialization, regulated sensory stimulation, provisions for privacy, ties to the healthy & familiar, and autonomy & control were proposed. 4) The advantages of outdoor garden for the people with cognitive impairments were explained. 5) Activity calendar for a facility was introduced and recognized as a essential guide for environment planning. 6) Sample facilities showed small size households and various ideas of environments for the older people with cognitive impairments.

• Journal of the Korean Institute of Rural Architecture
• /
• v.13 no.4
• /
• pp.99-106
• /
• 2011

Since 1982, schools have been closed down by urbanization in rural areas. 3,386 schools had been closed down by March 2010. The average 300 schools was closed down every year. 55.7% closed schools were sold, 14.5% closed schools were rented. 6.3% closed schools have been utilized as education facilities. First, the closed school should be utilized as education facilities. And it should be utilized as public facilities as well as welfare facilities for local residents. This paper presents a case of the welfare facility remodeled using Don-Yi middle school in Okcheon-Gun, Chungcheongbuk-Do and propose the unit care composition. The main contents is composed of posts, beams floors, stairs. Masonry infill walls and windows ware improved. Corridors were placed. A classroom were divided into 2 rooms with the Korean traditional heating system(on-dol) for four. Other conveniences were designed for a cafeteria, recreation, a restroom as space required. It is effective to utilize the closed school that has magnificent views and orientation, space construction. The Unit-care system is proposed by 4 types developments.

• Journal of Mechanical Science and Technology
• /
• v.18 no.4
• /
• pp.640-648
• /
• 2004

This paper describes a new magnetization method for non-destructive testing with magneto-optical sensor (denoted as MO sensor) which have the following characteristic : high observation sensitivity, independence of the crack orientation, and precise imaging of a complex crack geometry such as multiple cracks. When a magnetic field is applied normally to the surface of a specimen which is significantly larger than its defects, approximately the same magnetic charge per unit area occurs on the surface of the specimen. If there is a crack in the specimen, magnetic charge per unit area has the same value at the bottom of the crack. The distribution of the vertical component of the magnetic flux density, B$\_$Z/, is almost uniform over the no-crack area (denoted as B$\_$Z,BASE/), while the magnetic flux density is smaller in the surroundings of the crack(denoted as B$\_$Z,CRACK/) If B$\_$Z, BASE/ is a bit larger than the saturated magnetic flux density of the MO sensor (B$\_$s/) , then small magnetic domains occur over the crack area and a large domain over the non-crack area because B$\_$Z,CRACK/ is smaller than B$\_$s/.