• KIEAE Journal
• /
• v.7 no.6
• /
• pp.65-72
• /
• 2007

The economic growth of the modern society brought economic expansion of the national income. It is to increase the demand that faced with community or convenience facilities helping living of the residents, but the community facilities in the apartment helping living of residents do not adapt resident living conditions or demands. This study analyzes as follows the use present situation of the community facilities supplied with an apartment plan and building plans. The objective of the study is to understand a problem of an installation standard of community facililities throughout research. The study way was based on literature review, a field study and an interview with manager in the apartments. We are as follows telling the conclusion of this research. The builder must plan the facilities which the resident requests from the plan stage to the conclusion. We must consider the operation method according to the facilities. The facilities must be planed to make the contentment of the resident with the usage.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.55 no.4
• /
• pp.139-143
• /
• 2006

Recently, standard of living improved and Information-Communication industry developed rapidly. Thereby, interest about electric power quality is rising worldwide. So, research and Development to enhance electric power quality in various viewpoint until most suitable supply system from each kind device to improve electric power quality. And specially, interest about voltage quality is rising by diffusion increase of information communication appliance and minuteness control appliance etc. Also Power consumption is increasing, but expansion of large size generator by environmental and site security problem is difficult. So, introduction of distribution generation is investigated actively by electric-power industry reorganization. Voltage management of power system had been controlled by ULTC (Under Load Tap Changer) in substation and pole transformer on the high voltage distribution line. But, voltage control device on substation and distribution line is applied each other separatively. Therefore, efficiency of line voltage control equipment is dropping. Also, research about introduction upper limit of distribution generation is consisting continuously. This paper presents cooperation use way between voltage control device and introduction upper limit of distribution generation for most suitable voltage control in distribution power system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.24 no.7
• /
• pp.722-729
• /
• 2013

This paper presents the influence on the transmission characteristics of dimensional tolerances of rectangular waveguides usually used as a low-loss transmission line in the millimeter-wave band. We derived the Green's functions of the waveguide with eigenfunction expansion method. The reflection coefficient of the waveguide with a post is calculated by using internal impedance in order to investigate the influence of dimensional tolerances of the waveguide. In order to check the validity of the theoretical analysis, the calculated reflection coefficients are compared with the measured results.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.05a
• /
• pp.109-114
• /
• 2003

Wireless communication systems are inevitable for efficient underwater activities. Because of the poor propagation characteristics of light and electromagnetic waves, acoustic waves are generally used for the underwater wireless communication. Although there are many kinds of information type, visual images take an essential role especially for search and identification activities. For this reason, we developed an acoustic-based underwater image transmission system under a dual use technology project supported by MOCIE (Ministry of Commerce, Industry and Energy). For the application to complicated and time-varying underwater environments all-digital transmitter and receiver systems are investigated. Array acoustic transducers are used at the receiver, which have the center frequency of 32kHz and the bandwidth of 4kHz. To improve transmission speed and quality, various algorithms and systems are used. The system design techniques will be discussed in detail including image compression/ decompression system, adaptive beam- forming, fast RLS adaptive equalizer, ${\partial}/4$ QPSK (Quadrilateral Phase Shift Keying) modulator/demodulator, and convolution coding/ Viterbi. Decoding.

• Journal of the Korean Ceramic Society
• /
• v.20 no.1
• /
• pp.25-30
• /
• 1983

This experiment was studied in the system of (1-x) CaO MgO $2SiO-Al_2O_3$ to investigate forming of solid solution. The technique empolyed was the well known water-quenching method. Differential thermal analysis of the each glass water quenched indicated that under 30 mole% $Al_2O_3$ was lowered with increasing of the amount of $Al_2O_3$ It was supposed by X-ray diffraction patterns of each specimen sintered at various temperature that only solid solution was formed under the 30mole % $Al_2O_3$ compositions solid solution and anorthite were formed at the 20mole% $Al_2O_3$ composition anorthite solid solution and spinel$(MgAl_2O_4)$ were formed over the 40mole% $Al_2O_3$ compositions. The maximum density and thermal expanison coefficient was 2.89g/cm 7.74x106./C$^{\circ}$ respectively in the composi-tion of 10 mole% $Al_2O_3$ . All the specimens showed linear thermal expansion behavior. Microhardness was as high as 850kg/nm2 in the composition of 5, 10, 20 mole % $Al_2O_3$ and dielectric constant was 7.3-6.9.

• Journal of the Korean Data and Information Science Society
• /
• v.9 no.1
• /
• pp.19-27
• /
• 1998

We considered the bandwidth selection method which has asymptotic optimal convergence rate $n^{-1/2}$ in kernel regression function estimation. For the proposed bandwidth selection, we considered Mean Averaged Squared Error as a performance criterion and its Taylor expansion to the fourth order. Then we estimate the bandwidth which minimizes the estimated approximate value of MASE. Finally we show the relative convergence rate between optimal bandwidth and proposed bandwidth.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.7 no.2
• /
• pp.27-36
• /
• 2001

This study aims to provide space organization of the Postpartum Care Center and basic data for architectural planning in the reasonable size. Nurturing method of infants at independent Postpartum Care Center combines rooming-in and non rooming-in and space organization is planned accordingly. Types of the existing floor plans are classified as a type centered on maternity protection room, a type of the separate space for multipurpose, a near type to the infants' room. New types of plane are presented as follows a core type concentrate upon nurse room, the infants' room and the same environmental and balanced corridors between the both. When an average capacity of 20 at Postpartum Care Center is planned, proper suitable floor space of Postpartum Care Center is above $753.9m^2$ and $37.69m^2$ per postpartum woman is required. It is indicated that an average floor space per postpartum woman of the reviewed facilities is smaller than one of the Postpartum Care Center in a plan and plane distributed by function too lack in nursing space. Expansion of space for the Postpartum Care Center is generally required, also the enlargement of nursing space is necessary to be harmonized with the management of a medical facilities and those mutual cooperation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.12
• /
• pp.2731-2736
• /
• 2009

In this paper, a new implementation method of OFDM (orthogonal frequency division multiplexing) system with an orthogonal basis matrix is developed mathematically. The basis matrix is based on the Haar basis but has an appropriate form for modulation of multiple subchannel signals of OFDM. It is verified that the new basis matrix can be expanded with a simple recursive algorithm. The order of synthesis matrix in the transmitter is increased by the factor of two with every expansion. Demodulation in the receiver is carried out by its inverse matrix, which can be generated recursively with the orthogonal basis matrix. It is shown that perfect reconstruction of original signals is possibly achieved in the proposed OFDMsystem.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.33 no.3
• /
• pp.201-207
• /
• 2020

With the expansion in the use of DC power systems and increased need for system maintenance, the development of measurement devices for maintenance requires high stability. Of the different kinds of DC current measurement devices, the single-shot measurement device causes the input signal of the current measuring unit to initially generate a high inrush current. The high inrush current flows into the signal processor of the meter, shortening the life of the internal fuses and causing failure. Therefore, in this study, the I²t value for increasing the durability of the fuse is designed using the available wire diameter. Operating characteristics for 210~400% over-current of the rated current, which is relatively low over-current, are realized by the plating of low melting tin metal. As a result, a method of designing a fuse element for a DC power supply, which improves the safety of the DC current measurement device by blocking the failure caused by the inrush current, is presented.

• Journal of the Society of Disaster Information
• /
• v.11 no.3
• /
• pp.337-345
• /
• 2015

As the modern society becoms industry acceleration and urbanization, disaster and safetry education becoms important to educate and exercise the people for the disaster response and safety. This study suggests safety management method by simulation training and an attitude survey. The researchers of the study suggest as followers: First must be about strengthening eduation that accords to responsibility and part. The second need about manual build and simulation training for expansion disaster and crisis management. The last must be consideration to reconstitute of organization which of be not up to the disaster and crisis management.