• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.470-473
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• 2018

Using High-order Modulation in wideband system is sensitive to change of wireless channel environment as well as changes in ripple characteristics that can occur when baseband signals pass through RF equipment. Therefore, it is necessary to design and RF tuning that minimizes ripple characteristics change, which is difficult to implement systematically and takes a long time. In this paper, we analyze the fixed ripple characteristics of the baseband signal distored through the RF transmitting and receiving equipment. And the function of compensating the compensation filter by the modem receiver is implemented in 256 TCM. Also, it is confirmed that SNR and received sensitivity are improved by applying a digital compensation filter in a channel with poor RF equipment ripple characteristics.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.127-134
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• 2002

GPS is one of today's most widely used surveying techniques. But, users can't acquire an enough accuracy in applications of the navigation or geodesy by the GPS positioning technique because of the effects of the ionosphere and troposphere and US DoD's systematic errors. The solution of these restrictions is the DGPS technique that is to eliminate the common errors and can achieve a high accuracy. Although of sufficient density for good DGPS, accuracy of positioning is just not dense enough to provide complete coverage for real-time positioning, because distances between base and rover is short. In this paper, we designed and implemened a RTK-GPS error correction signal transmission system for long-distance using the TCP/IP, which consist of TCP, UDP and IP, which allows a user to increase the distance at which the rover receiver is located from the base, due to radio modem.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.861-869
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• 2014

This paper shows the research of a platform architecture relates to the LTE-based macro basestation; the proposed platform architecture is designed with the interface between the baseband signal and IF (Intermediate Frequency) per codeword. Using this method, we can smoothly transmit/receive a large amounts of data regardless of the number of antenna in a macro base station which is used technology such as massive MIMO. In this paper, We analyzed the evolution of LTE technology and the trend in the development of the LTE-based system. For validation of the proposed architecture, we compare the general architecture of a conventional with the proposed architecture. From the calculation results of transmission quantity data, we see that the proposed architecture can give better performance than the existing architecture. By presenting this architecture, we hope to provide a new foundation for Design and Implementation of a LTE base station platform which is used technology such as massive MIMO, carrier aggregation (CA), coordinated multi point (CoMP).

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1672-1677
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• 2004

Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modem air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras($1280pixel{\times}1024pixel$) were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.201-210
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• 1996

There is increasing attention about radiology teaching files on the Internet in the field of diagnostic radiology. The purpose of this study was to aid in the creation of new radiology teaching file by analysing the present radiology teaching file sites on the Internet with many aspects and evaluating images on those sites, using Macintosh IIci computer, 28.8kbps TelePort Fax/Modem, Netscape Navigator 2.0 software The results were as follow : 1. Analysis of radiology teaching file sites (l) Country distribution was the highest in USA(57.5％). (2) Average number of cases was 186 cases and radiology teaching file sites with search engine were 9 sites (22.5％). (3) At the method of case arrangement, anatomic area type and diagnosis type were found at the 10 sites(25％) each, question & answer type was found at the 9 sites(22.5％). (4) Radiology teaching file sites with oro-maxillofacial disorder were 9 sites(22.5％). (5) At the image format, GIF format was found at the 14 sites(35％). and ]pEG format found at the 14 sites(35％). (6) Created year was the highest in 1995(43.7％). (7) Continuing case upload was found at the 35 sites(87.5％). 2. Evaluation of images on the radiology teaching files (l) Average file size of GIF format (71 Kbyte) was greater than that of JPEG format(24 Kbyte). (p<0.001) (2) Image quality of GIF format was better than that of JPEG format. (p<0.001).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.5
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• pp.40-45
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• 2011

In this paper, to develop a broadband power line communication modem and network technologies, we analysis the characteristics of underground power line communication channel through actual tests. To measure the amount of attenuation by length and structure of broadband power line communication channel, we configure a measurement system of the channel with signal generator, spectrum analyzer and non-contacted coupler. For actual tests, we choose two of the longest lines among medium-voltage lines as a single line in the test lines and measure the characteristics of noise and signal attenuation level of the channel. The experimental results show that the channel has a impulse noise which can remarkably reduce communication capability. In the case of long lines, high-frequency attenuation appeared by length of the lines.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.103-110
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• 2008

In this paper, an efficient butterfly structure for 8K/2K-Point Radix-4 FFT algorithm using CORDIC(coordinate rotation digital computer) is proposed. It is shown that CORDIC can be efficiently used in twiddle factor calculation of the Radix-4 FFT algorithm. The Verilog-HDL coding results for the proposed CORDIC butterfly structure show 36.9% cell area reduction comparison with those of the conventional multiplier butterfly structure. Furthermore, the 8K/2K-point Radix-4 pipeline structure using the proposed butterfly and delay commutators is compared with other conventional structures. Implementation coding results show 11.6% cell area reduction. Due to its efficient processing scheme, the proposed FFT structure can be widely used in large size of FFT like OFDM Modem.

• Journal of National Security and Military Science
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• s.4
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• pp.45-82
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• 2006

This paper seeks to search for wisdoms that may be applied to modern leadership through Tasan Jeong Yakyong's ideology, ShilHak, from the Chosun Dynasty. The present period is referred as the period of transformation and innovation or the period of knowledge information The leadership appropriate for the current period is thus called revolutionary leadership. This leadership accomplishes its goals by influencing the constituent's values, ethics, behavioral norms, and visions based on the leader's moral values, knowledge, and information. Thus, the essence of this paper is in acquiring wisdoms of leadership by company revolutionary leadership with Tasan's life. Tasan pursued change and innovation in a time where Chosun was in a state of decay by following the flow of world powers towards the concept of studying truth based upon facts such as changing the system of thought, reforming legislation, and developing technology. Moreover, he gave courage and hope to the people by demonstrating such leadership in practice. In addition, despite false accusations and spending 18 years in exile, he showed revolutionary life as an active intellectual by leaving 542 volumes of writing through his 'value innovation' that he "pursue things only for the people and the state." Consequently, the paper first deals with what kind of leadership is required for a leader in the position of a general and examines the kind of leadership capacity demanded. Subsequently, Tasan 's revolutionary life and hints of leadership messages in MokMinSimSuh are examined. Thus, this paper is centered upon the leadership of generals regarding how MokMinShimSuh may be applicable to modern leadership.

• Lingua Humanitatis
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• v.1 no.2
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• pp.141-158
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• 2001

Criticism of today finds itself in an awkward situation, for it is now being transformed in the same way that literature and the arts were transformed by the avant-garde movements at the end of the 19th century and the beginning of the 20th century. It is characterized predominantly by a break with harmony and with the values of realism. As such, it is driven by a post-modem ethos, an artistic, social, and cultural phenomenon that veers toward open, fragmentary, and indeterminate forms. In this paper, I examine today's most urgent social and cultural issues with reference to artistic production and criticism, in order to illuminate the true nature of criticism. The outstanding questions in the world of art criticism are given in five categories: the lack of critical reality in argumentative criticism; the problem of artistic and literary production in global capitalism; the artistic mind and its consciousness of socio-historical ideology; anxiety of the rise of cyberjournalistic criticism; and the question of subordination to western systems in the field of interpretation and criticism. For my analysis, I have tried to formulate a three-dimensional critique structure that will help us organize the relationships between the points of argument: 1) criticism as a creative force behind the artist; 2) criticism as critique of artistic production; and 3) criticism as critique of other critics. This multi-layered structure will be appropriate to our task of interpretation and evaluation, as the proposed complex structure of criticism will be able to embrace the diverse aspects of our problematic argument. In the final analysis, my argument resolves itself into a question of art, more specifically into a question of criticism as a protective device of art in an age threatened by globalization and cultural monopolization.

• Journal of Agricultural Extension & Community Development
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• v.3 no.2
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• pp.285-297
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• 1996

One of the characteristics of the last four decades after 'World War II', was the 'discovery of famine' in the underdeveloped country, like Korea. A flurry of activities followed this sad discovery. Countless organizations and programs were set up to fight poverty and to combat famine in rural sector. In these days, the dominant development theory was 'modernization theory' which have gratuitously assumed that third world countries are like western countries are, and respond to the same stimuli as western countries do, although third world countries have completely different cultures, traditions, and mentality from western countries. Among the many problems caused by 'modernization theory', this research focused on the noel environmental problems. In the West the discovery of nature and its progressive control by means of science and technology are phenomena. Modem progress born in the West and carried to the rest of the world is not integrally positive and therefore can't be identified with the internal development of man and nature. As a result, the so-called modernization of Korea and other countries is contributing to the degradation of the nature and environment. It is important to give up the illusion that the fight against famine is a simple matter that could be solved through the imitation of western countries. It is also necessary to abandon the belief that the earth as a reservoir of unlimited resources, there to be exploited ad hoc for mankind's survival. Man-environment relationship must, essentially, be one of mutualism and not a case of survival of the fittest: In other words, man's survival is directly related to the survival of the earth and its resources.