• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.145-150
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• 2016

In this paper, we proposes a DTV indoor receiving antenna with a gap sleeve monopole structure. The proposed antenna uses a basic structure of a sleeve monopole and gap sleeve. To optimize antenna, we have adjusted the gap between monopole and sleeve, the gap between sleeve and ground. In order to confirm the property of antenna parameters, it was used a commercial software, HFSS. For the antenna fabrication, a FR4 dielectric substrate which has a dielectric constant of 4.7 was used. The size of the antenna was $213mm{\times}40mm{\times}1.6mm$. Frequency band of the fabricated antenna was 432MHz ~ 827MHz, and the bandwidth was 395MHz. The maximum gain of the antenna was 2.19dBi. Consequently, it was confirmed the possibility of practical application of the DTV indoor receiving antenna with a gap sleeve monopole structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.135-141
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• 2020

This paper summarizes the data of a monopole antenna with a sleeve structure that can be applied in various ways. Sleeve monopole antennas have broadband characteristics and are used for multi-frequency applications. The sleeve monopole antenna is composed of a vertical conductor, which is a radiator, and a sleeve having the same structure as a coaxial cable. The sleeve acts as a radiator and an open stub. The length of the sleeve should be 1/3~2/3 of the total length of the antenna. A monopole antenna having a sleeve structure is applicable to a vehicle wiper antenna. In addition, the case of applying this antenna to a broadband sleeve antenna using a loading coil, a broadband printed sleeve monopole antenna for an ISM band, a gap sleeve and a double sleeve, and a UWB planar monopole antenna using half cutting was summarized and analyzed in terms of structure and broadband.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.481-491
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• 2003

We present a near-optimal blind decision feedback equalizer (DFE) for Advanced Television Systems Committee digital television (DTV) receivers. By adopting a modified trellis decoder (MTD) with trace back depth of 1 for the decision device In the DFE, we obtain a hardware-efficient near-optimal blind DFE approaching to the optimal DFE which has no error propagation. The MTD uses absolute distance instead of Euclidean distance for computation of a path metric, resulting. In reduced computational complexity. Comparing to the conventional slicer, the MTD shows outstanding performance improvement of decision error probability and is comparable to the original trellis decoder using Euclidean distance. Reducing error propagation in the DFE leads to the improvement of convergence performance in terms of convergence speed and residual error. Simulation results show that the proposed blind DFE performs much better than the blind DFE with the slicer.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.219-224
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• 2019

The number of solar power installation companies including domestic small scale (50kW or less) is increasing rapidly, but the efficient operation system and management are insufficient. Therefore, a new type of operating system is needed as a maintenance management aspect to maximize the generation amount in the current state rather than the additional function which causes the increase of the generation cost. In this paper, we utilize Big Data and sensor network to maximize the operating efficiency of solar power plant and analyze the expert system to develop power generation prediction technology, module unit fault detection technology, life prediction of inverter components and report technology, maintenance optimization And to develop a smart monitoring system that enables optimal operation of photovoltaic power plants such as development of algorithms and economic analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.171-178
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• 2019

Korea's shipbuilding industry is in a critical condition due to changes in the domestic and international environment. To overcome this crisis, preemptive development of products and technologies through prediction of new demand for ships is necessary. The goal of this research is to develop an artificial intelligence algorithm based on ship big data in order to predict new demand for ships. We intend to develop a big data analytics platform specialized in predicting ship demand and to utilize the forecast results of new ship demand through data analysis for planning/development of new products. By doing so, the development of sustainable new business models for equipment and equipment manufacturers will create new growth engines for shipyard and shipbuilders. Furthermore, it is expected that shipbuilders will be able to create business cases based on measurable performance, plan market-oriented products and services, and continuously achieve innovation that has high market destructive power.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.263-269
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• 2014

In this paper, I disprove Hadwiger conjecture of the vertex coloring problem, which asserts that "All $K_k$-minor free graphs can be colored with k-1 number of colors, i.e., ${\chi}(G)=k$ given $K_k$-minor." Pursuant to Hadwiger conjecture, one shall obtain an NP-complete k-minor to determine ${\chi}(G)=k$, and solve another NP-complete vertex coloring problem as a means to color vertices. In order to disprove Hadwiger conjecture in this paper, I propose an algorithm of linear time complexity O(V) that yields the exact solution to the vertex coloring problem. The proposed algorithm assigns vertex with the minimum degree to the Maximum Independent Set (MIS) and repeats this process on a simplified graph derived by deleting adjacent edges to the MIS vertex so as to finally obtain an MIS with a single color. Next, it repeats the process on a simplified graph derived by deleting edges of the MIS vertex to obtain an MIS whose number of vertex color corresponds to ${\chi}(G)=k$. Also presented in this paper using the proposed algorithm is an additional algorithm that searches solution of ${\chi}^{{\prime}{\prime}}(G)$, the total chromatic number, which also remains NP-complete. When applied to a $K_4$-minor graph, the proposed algorithm has obtained ${\chi}(G)=3$ instead of ${\chi}(G)=4$, proving that the Hadwiger conjecture is not universally applicable to all the graphs. The proposed algorithm, however, is a simple algorithm that directly obtains an independent set minor of ${\chi}(G)=k$ to assign an equal color to the vertices of each independent set without having to determine minors in the first place.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.496-501
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• 2021

The representation of shamanism or shaman in Korean cinema has changed according to eras. Since the 2000s, shamanism and shaman appear more frequently than before as the main subjects and characters in movies. The full-scale exploration of shamans usually takes places in documentary works, such as <'Mudang'>(2002), (2006) and (2011). Shamans are summoned in more various appearences in feature films. In this article, we will compare and analyze the representations of shamanism and shaman in recent Korean occult genre films. (2015), (2016), and (2017) are works that utilize new subjects and visual effect styles that were difficult to see in Korean horror films before. In these three films, the meaning of shaman and gut shows distinct differences from each others. Through the analysis of these films, we would like to explore the characteristics and possibilities of Korean occult films.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.223-230
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• 2015

As the Transportation Simplex Method of the general transportation problem are inapplicable to the large-scale unbalanced transportation problem, a commercialized linear programming package remains as the only viable means. There is, however, no method made available to verify the optimality of solutions attained by the package. This paper therefore proposes a simple heuristic algorithm to the large-scale unbalanced transportation problem. From a given problem of $31{\times}15$supply and demand areas, the proposed algorithm determines the number of demands areas for each supply area and executes on the latter in the ascending order of each of their corresponding demand areas. Next, given a single corresponding demand area, it supplies the full demand volume and else, it supplies first to an area of minimum associated costs and subsequently to the rest so as to meet the demand to the fullest extent. This initial optimal value is then optimized through an adjustment process whereby costs are minimized as much as possible. When tested on the $31{\times}15$cost matrix, the proposed algorithm has obtained an optimal result improved from the commercial linear programming package by 8.9%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.105-117
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• 2015

In this paper, we consider 19 cells with the two tiers for polar-rectangular coordinates (PRCs) and provide the cell edge performance of cellular networks based on distance from cell center i.e., BS (base station). When FFR is applied(or adopted) to cell edge, it is expected that BS cooperation, or a coordinated multipoint (CoMP) multiple access strategy will further improve the system performance. We proposed a new method to evaluate the sum rate capacity of the MIMO DC of multicell system. We improve the performance of cell edge users for intercell interference cancelation in cooperative downlink multicell systems. Simulation results show that the proposed scheme outperforms the reference schemes, in terms of cell edge SINR (signal-to-interference-noise ratio) with a minimal impact on the network path loss exponent. We show 13 dB improvements in cell-edge SINR by using reuse of three relative to reuse of one. BS cooperation has been proposed to mitigate the cell edge effect.

• Journal of Broadcast Engineering
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• v.4 no.1
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• pp.12-21
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• 1999

Without a question. the most significant new medium for transmitting information is the Internet. Unfortunately. the multimedia elements that enrich our titles are extremely bulky. While the Internet hype is available in unlimited supply. Internet bandwidth and functionality of web browser are not making the net quite hospitable to multimedia data formats. In this thesis. for smoother and better communications over the net. a study is done on still image compression techniques. based on wavelet transform which is selected on MPEG-4 as a still image compression standard and a strong candidate for the JPEG-2000 standard. For Internet service. the study of plug-in programming and ActiveX control is implemented to enrich the functionality of web browser. As a result. the proposed still image service gives better image quality than current standard JPEG and does not yield to the common blocking artifacts.