• Journal of the Korean Statistical Society
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• v.31 no.2
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• pp.143-152
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• 2002

In an effort to make a right choice among ratio estimation strategies and PPS sampling strategies, we conduct an empirical investigation of the relative performances of three ratio estimation strategies and four PPS estimation strategies using a set of 12 natural populations. The quality of a strategy is measured in the traditional way, namely with the consideration of efficiency, achieved coverage rate of the nominal 99% confidence interval and approach to normality (asymmetry).

• Journal of Information Technology Applications and Management
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• v.22 no.2
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• pp.43-70
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• 2015

Concerns have been growing about whether domestic internet protocol television (IPTV) can establish a solid foothold in the pay TV market, largely because of the lack of IPTV-only content and service differentiation. It has been difficult for IPTV providers to attract valuable PPs (program providers) to strengthen their positions, and IPTV providers have invested much money into procuring content. To survive this difficult situation, IPTV providers need to reappraise their profit sharing methods and content distribution structure to facilitate the expansion of their subscriber base. This can be done by attracting valuable PPs to IPTV providers and securing extra revenue by distributing more content for their PP partners. The IPTV industry has a different structure and value chain from the digital cable industry. Moreover, profit sharing schemes among participants in the IPTV industry are complicated. Thus it is essential to analyze the criteria for profit sharing, the selection of attributes in profit sharing, and their cause-effect relationship in developing fair pricing for broadcast content in the IPTV industry. This study introduces the attributes that need to be considered for the pricing of content and profit sharing among IPTV providers and PPs. In addition, this study uses system dynamics to analyze the relationship among those attributes along with additional associated factors for the pricing of content.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.1-13
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• 2021

This study postulates that Government as a Platform(GaaP) could be a next generation government model, drawing activation strategy from success factors of webtoon platform by NAVER. It suggests success factors of Naver webtoon case based on three main components of platform strategy. First, in the aspect of platform infrastructure, Naver webtoon was established based on powerful portal site by parent company Naver and improved platform accessibility through using webtoon without login. Second, in the aspect of stakeholder engagement, Naver webtoon has offed webtoon at no cost and it has taken an intermediary role for supporting the stakeholders with PPS. Third, in the aspect of outputs production, Naver webtoon offered real time feedback from webtoon users that could affect webtoon production and established incubating system that allow users to create their webtoon. And due to PPS, it makes possible to various create second outputs based on webtoon, which can contribute to activating webtoon ecosystem.

• Journal of Power Electronics
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• v.18 no.1
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• pp.34-44
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• 2018

This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC-DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.287-295
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• 2021

This study examines the performance of program providers(PP) considering various factors. This study employs the panel regression models with the dataset from 2014 to 2019. This study analyzes how various market structural factors and behavioral factors have impact on the performance. The results show that the high proportion of retransmission fees to broadcasting revenue is negatively associated with total media revenue and operating income while advertising revenue is positively associated with these factors. The results imply PPs that have heavily depended on the fees have not showed a superior performance. Current PP markets are evaluated to have low average revenue per users and thus the size of retransmission fees cannot be enlarged. Under such market conditions, PPs focusing on raising advertising revenue show better performance. This study also suggests that PPs that own diverse channel assets have improved their performances.

• Cartoon and Animation Studies
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• s.45
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• pp.127-146
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• 2016

The most presentative case would be functional evolution of webtoon as a contents business model, which has taken a initiating role in both innovated strategic experiments and outcomes. Most of all, There are the launch of PPS(Page Profit Sharing) sevice in NAVER webtoon, the paid service model implementation in KAKAOpage and potential business as an exclusive application in Lezhin entertainment This study to analyze these phenomina and results can figure out how the business model in the webtoon platform is developed in various fields diversely and what makes this model evolved and extended. Especially, the diversification of the webtoon platform has been received attention since it pursued the grouped spin off through horizontal convergence and transformational expansion among similar platforms, and also this shows that which factors enhance these phenomina to be controled and expanded. On the basis of the result of this study, we try to find the way to connect business vision of the domestic webtoon platform with affiliated business. Furthermore, it proposes the interrelationship between this and the business strategy for overseas in the globalized platform.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.547-566
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• 2014

This study investigates the decisive factors affecting the survival or collapse of cable networks in the Korean paid broadcasting market from 1993 to 2010. The effects of performance variables discussed in previous studies were verified through survival analyses. According to the results, the most influential factors in the survival of cable networks were horizontal integration (MPP), channel genre, the scheduling of HDTV content, and the proportion of access program scheduling. These findings imply that the differentiation strategy of content suppliers is the most decisive factor among all business performance-related factors. Specifically, the content supply power and strategy of the program provider (PP) have the greatest influence on cable network viability. The present study is meaningful as the first attempt to establish the performance of PPs in Korean pay broadcasting markets through the viewpoint of organizational mortality. Accordingly, the present study can supplement the results of cross-sectional studies conducted with smaller samples.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.9-19
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• 2021

The data mining design incorporated with big data based cloud computing system is investigated for the nuclear terrorism prevention where the conventional physical protection system (PPS) is modified. The networking of terror related bodies is modeled by simulation study for nuclear forensic incidents. It is needed for the government to detect the terrorism and any attempts to attack to innocent people without illegal tapping. Although the mathematical algorithm of the study can't give the exact result of the terror incident, the potential possibility could be obtained by the simulations. The result shows the shape oscillation by time. In addition, the integration of the frequency of each value can show the degree of the transitions of the results. The value increases to -2.61741 in 63.125th hour. So, the terror possibility is highest in later time.

• Communications for Statistical Applications and Methods
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• v.13 no.1
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• pp.61-72
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• 2006

When using the well-known variance estimator of Sen (1953) and Yates and Grundy (1953) in inclusion probability proportional to size sampling, we often encounter the problems due to the calculation of the joint probabilities. Sarndal (1996) and Knottnerus (2003) proposed alternative strategies for variance estimation to avoid those problems in the traditional method. We discuss some of practical issues that arise when they are used. Also, we describe the traditional strategy using a sampling procedure available in a statistical software. It would be one of the attractive choices for design-based variance estimation.

• Polymer(Korea)
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• v.38 no.4
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• pp.550-556
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• 2014

Recently, the peptide(or protein)-polymer hybrid materials (PPs) were sought in many research areas as potential building blocks for assembling nanostructures in selective solvents. In PPs, the facile routes of preparing well-defined peptide-polymer bio-conjugates and their specific activities in various applications are important issues. Our strategy to prepare the peptide-polymer hybrid materials was to combine atom transfer radical polymerization (ATRP) method with solid phase peptide synthesis. The standard solid phase peptide synthesis method was employed to prepare the PYGK (proline-tyrosine-glycine-lysine) peptide. PYGK is an analogue peptide, PFGK (proline-phenylalanine-glycine-lysine), which interacted with plasminogen in fibrinolysis. The peptide and the peptide-initiator were characterized with MALDI-TOF mass spectrometry and $^1H$ NMR spectrometer. The peptide-polymer, pSt-PYGK was characterized by GPC, IR, $^1H$ NMR spectrometer and TLC. Spherical micellar aggregates were determined by TEM and SEM. Current synthesis methodology suggested opportunities to create the well-defined peptide-polymer hybrid materials with specific binding activity.