• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.374-381
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• 2023

This study focuses on the implementation of C-band radio navigation in the 5.03 ~ 5.15 GHz terrestrial band to cooperate with GNSS navigation mainly used in existing UAMs. This is one of the navigation technologies that can fully satisfy the requirements of Title 14 of CFR-135.165. According to the FAA, the use of two or more independent navigation sources for aircraft is proposed for aircraft. This study proceeded with the link budget derivation through radio wave propagation path loss analysis, and antenna shape design for miniaturized Doppler VOR, and DME design with enhanced positional distance resolution compared to conventional aircraft. The ground navigation system which is the result of this study, consists of a VOR/DME ground station and a terminal that can be mounted on UAM. Significant performance was confirmed through the production and testing of each prototype.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2273-2280
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• 2013

This article introduces the next-generation air surveillance system and investigates how to design of front-end low noise amplifier of the ground station receiver. In consideration of the international standard documentation and the performance of existing products, the study conducts the link budget on the entire system so that it can be competitive in terms of receive sensitivity or reliability. To obtain a proper low noise amplifier, standards of design are decided so that such factors as gain, gain flatness, and reflective loss can be optimal. In its design, the bias circuit appropriate for the characteristics of low power, low noise, or high gain was built, and according to the results of the simulation conducted after the optimal design, its gain was 16.24dB, noise factor was 0.36dB, input-output reflective loss was -18dB and -28dB each, and frequency stability was 1.11. According to the results measured after the design, its gain was 17dB, noise factor was 0.51dB, gain flatness was 0.23dB, and input-output reflective loss was -18.28dB and -24.50dB each, so the results gained were suitable for building the overall system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.36-42
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• 2011

The current healthcare information systems field to meet the growing demand for healthcare for a variety of building systems and operation, and subsequent information on the budget continues to increase, but the current system, although the association link between the various systems made does not, with organizations with information about each of the standardization and real-time network status data do not consist of various materials, such as insufficient to provide real-time issues have been raised. This paper proposes a Integrated information system on Healthcare based on JXTA to solve problems mentioned above. Until now, in a network environment for data storage and management is the most widely used server-intensive structure, while an increase in users and traffic difficulties in data management and communications services to handle the growing number of servers increase faster than information associated with the cost savings, P2P model in terms of efficient data management has emerged as a new solution. Therefore this paper designs a platform for Integrated information system on Healthcare based on JXTA as a method to integrate health information data and services, and then proves that the new information system on healthcare based on JXTA is the suitable model.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.71-79
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• 2014

In this paper, the microstrip array antenna is studied to replace the parabolic antenna in the direct satellite reception. A microstrip array antenna has been used in extremely limited area, but if it is applied to practical life like a direct satellite reception antenna, we expect that it will be used in various way. First of all, if we use a microstrip array antenna for a direct satellite reception antenna, it should be guaranteed characteristics of broadband frequency. Therefore, the goal of this paper is designing technique an antenna which guarantees broadband frequency band for a direct satellite reception. In this paper, the proposed microstrip antenna is fed by orthogonal two feed lines to a rectangular patch and a sequentially rotated feeding technique is designed proposed for a good axial ratio in broadband frequency band. The rectangular patch is designed to satellite reception band, and the width and length are W=L=8.9 mm ($0.352{\lambda}o$) respectively. The antenna's ground plane has dimensions of $250{\times}250mm$. The experimental results verify that the proposed antenna had the axial ratio of above 1dB broader than that of the conventional feeding antenna. In order to verify the performance, a $8{\times}8$ array having two pairs was fabricated and tested. The maximum gain is 20.8 dB, the sidelobe level confirm less than -10 dB. It is verified by link budget calculation that C/N=6.7 dB can be obtained for domestic use if this proposed antenna is used in Koreasat reception system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.519-528
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• 2006

This thesis is regarding of fabricating wibro PAM. First of all, we need to set specification based on link budget for wibro communication circumstance in order to develop PAM, then we decided specification concerning of wibro PAM by considering TTAS_Ko_06_0082R1 which is standarded in Korea, and IEEE Std. 802. 16d/e which is international standard. We selected the Doherty structure to increase efficiency, and pre-distorter structure to increase linearity. The fabricated PAM has not only a result of $26.5dB{\pm}1.0dB$ gain characteristics and maximum of -14 dB return loss characteristics in full frequency bands and full output ranges, but also a result of 37 dBc at 4 tone IMD characteristics which is improved result of 843 and a result of 31 dBc spurious characteristics which is improved result of 5 dB at 4.77 MHz offset point in status of having 27 % efficiency in the 26 dBm high power amplifier output signal. We confirmed the suggested structure is better than others by comparing with normal structure, balanced structure and Doherty structure without predistorter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.291-299
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• 2018

The purpose of this study was to review the government's policy on the enhancement of sports facilities for community residents regarding the lack of knowledge surrounding the infrastructure of sports facilities. The government has invested approximately 2.4 trillion won to establish 220 community sports centers, 385 billion won for 194 multi-purpose indoor centers, and 1.3 trillion won for rebuilding 1,870 school outdoor fields. On the other hand, there are problems with the link between the crumb rubber infill on sports fields and cancer, a lack of availability of indoor sports centers, and an increased federal budget deficit. It is the responsibility of government to plan and construct outdoor fields that are large enough to accommodate all people and allow them to play activities. In addition, the guidelines should ensure that the indoor space required for physical activities at each teaching station is large enough to accommodate all students in the class and handle two classes. The government should suggest the federal government guidelines based on a good understanding of the concept of infrastructure in sports facilities. The government also should make efforts to reduce the regulatory powers and provide the community with an autonomous right to plan and construct sports facilities.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.200-208
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• 2020

The purpose of this study was to investigate and compare health, medical and welfare service providers' and local residents' perception on community care. The participants were 68 service providers and 95 local residents. The data were analyzed using independent t-test and chi-square test. The results showed that the degree of agreement of service providers on the need for policy, and visiting services were higher. Service providers' ability to link local residents with a need for care to community resources was higher, but in the activation of self-help group in community, local residents agreed more. In add budget of policy to health insurance, local residents agreed less. In perception on priority for community care policy, high priorities were preparation of financial resources and care culture. To effectively operate community care policy, it is necessary to establish a care culture through active exchanges for reducing differences in policy and opinions of recipients.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.405-410
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• 2018

Distribution of a series of procedure for establishment and revision for various instructions on information security for public institutions and diversified process of performance system following the compliance with the instruction are applied to the integrated procedure that any revision or change has led to the studies that are applied on the basis of all environment requirements and the facilitation of such studies in the integrated procedure for the entire information security. However, as the difference of possessing the work territory for each institution, maintaining and securing the security with the heterogeneous type for subject, the information still displays the issues to link to a series of process to the procedure to secure the foregoing as stability, In addition, the notice should be made by the public institutions for the result structured and notified on the basis of budget and the additional time and expenses for re-distributing to the private institutions would be another issue for the part to accomplish the purpose of such study. Therefore, under this study, the subject of information security of similar institutions should be sorted out and statistically classified, and it proposes the integration procedure through a series of diversity and multi-change process and summarize the same in the proposed procedure to engage in studies to secure the optimal stability.

• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.84-89
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• 2014

Worldwide Interoperability for Microwave Access (WiMAX) is an efficient technology for 20th century communication system. The technology provides broadband speed without the need for cables and is based on the IEEE 802.16 standard(also called Wireless MAN). Mobile WiMAX is defined as IEEE802.16e which is advanced and efficient technology for mobile telecommunication rather than GSM, CDMA technology. In this work link budget calculation for WiMAX have been done. Cell range have been calculated over digital modulations and they are BPSK, QPSK and QAM. Here different types of models like Cost 231 model have been used for different types of areas like open, rural and urban areas and Erceg-Greenstein model for sub-urban areas. Effect of various parameters like frequency, base station antenna height, transmission power and SNR over cell range have been studied. Analysis have done for both uplink and downlink.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.85-101
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• 2013

The primary goal of this research is to link two currently disconnected literature; the history of urban redevelopment and the one of urban parks and open spaces in the United States (US). Through this exercise, this study attempts to reveal examples of urban parks and open spaces that have yielded economic effects, and emphasize their possibility as a measure of urban redevelopment. Five phases are presented, starting with two Pre-World War II urbanization periods, and three subsequent periods of Post-World War II urban redevelopment (1940s~1960s, late 1960s~1970s, 1980s~present). While urban parks in the 19th century urbanization period held a preeminent place in urban design, policy and economy, ensuing depression and World War II diminished their role as a channel to ease unemployment. In the first phase of urban redevelopment, the economic motive to build open space was to boost the appeal of specific locales in order to draw people and businesses back to a neglected city. In the second phase, public effort to create and maintain urban parks and open spaces declined due to the budget austerity, instead, community open spaces flourished through the voluntary actions and helped neighborhoods to regain desirability. In the third phase, the aspirations and functions of such projects resemble their forerunners of the first phase, but their targets extended to global businesses and elites.