• Journal of Positioning, Navigation, and Timing
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• 제9권4호
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• pp.305-317
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• 2020

The navigation message is composed of the information contained in the message and the structure for transmitting this information. In order to design a navigation message, considerations in terms of message content and message structure must be elicited. For designing a Korea Positioning System (KPS) navigation message, this paper explains performance indicators in terms of message structure and message content. Most of the performance analysis of GNSS navigation messages already in operation was performed only for Time-to-first-fix-Data (TTFFD). However, in the navigation message, the message content is composed of Clock-Ephemeris Data (CED) and additional information. So, this paper proposes a new performance indicator R_(Non-CED) that can be analyzed from the viewpoint of receiving additional information along with an explanation of TTFFD focusing on the CED reception time. This paper analyze the performance in terms of message structure using these two performance indicators. The message structures used for analysis are the packetized message protocol like GPS CNAV and the packetized and fixed pattern message protocol like GPS CNAV-2. From the results, it is possible to proffer how KPS navigation messages can have better performance than GPS navigation messages. And, these two performance indicators, TTFFD and R_Non-CED, can help to design the minimum TTFF required performance of KPS navigation messages.

• Journal of Information Technology Applications and Management
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• 제22권2호
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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.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (하)
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• pp.1915-1918
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• 2002

Managing semistructured data needs fine granularity such as markup elements. XML has major effect in managing web content, it enables content reusability, enriches information with metadata, ensures valid document links, etc. We introduce our content model as an integrated work which handles content objects as controllable units. The paper concerns on modeling news site and how the content is classified due to the site structure, aggregated content and reusability. The model stores instance XML document into relation database using fragmentation strategy.

• Macromolecular Research
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• 제17권5호
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• pp.339-345
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• 2009

The core/shell type structure of the highly crosslinked poly(glycidylmetharylate-co-divinylbenzene) microspheres prepared in the precipitation polymerization in acetonitrile was thoroughly verified by means of swelling, $^1H$ NMR, XPS, TEM and TGA measurements. In the XPS measurement, the higher the GMA content, the higher the oxygen content was observed, implying that the higher content of GMA is observed in the particle surface. The further verification of the core/shell structure of the poly(GMA-co-DVB) particles was carried out using $^1H$ NMR and TEM techniques, resulting in the poly(GMA-co-DVB) particles with the GMA rich-phase and DVB rich-phase. In overall, the poly(GMA-co-DVB) microspheres consist of a highly crosslinked DVB rich-phase in the core and slightly or non-crosslinked GMA rich-phase in the shell part due to the different reaction ratios between two monomers and self-crosslinking density of DVB.

• 펄프종이기술
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• 제38권3호
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• pp.7-12
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• 2006

The pore structure of paper was modified by the application of the blending of pulp, refining, and filler particle size and ash content. It was conformed that the reflectivity of paper can be modified by the combination of the above parameters. It was also found that the change of reflectivity of paper was greatly dependent on the pore structure, such as average pore size, pore size distribution and porosity. The average pore size was decreased with addition of HwBKP, but the smallest average pore size was obtained from the addition of 80% HwBKP Refining of pulp decreased both average pore size and the reflectivity of paper. The pore size distribution of filled paper can be varied by the combination of filler particle size and ash content

• 한국경영과학회지
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• 제30권1호
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• pp.187-198
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• 2005

The structure of a Web site can prevent the search robots or crawling agents from confusion in the midst of huge forest of the Web pages. We formalize the view on the World Wide Web and generalize it as a hierarchy of Web objects such as the Web as a set of Web sites, and a Web site as a directed graph with Web nodes and Web edges. Our approach results in the optimal hierarchical structure that can maximize the weight, tf-idf (term frequency and inverse document frequency), that is one of the most widely accepted content centric measures in the information retrieval community, so that the measure can be used to embody the semantics of search query. The experimental results represent that the optimization model is an effective alternative in the dynamically changing Web environment by replacing conventional heuristic approaches.

• 한국지반환경공학회 논문집
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• 제14권1호
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• pp.33-42
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• 2013

In this paper, a series of monotonic undrained shear tests were carried out on four kinds of sand-fine mixtures with various fines content. Two kinds of sands (Silica sand V3, V6) and fines (Iwakuni natural clay, Tottori silt) were mixed together in various proportions, while paying attention to the void ratio expressed in terms of sand structure $(F_c{\leq}F_{cth})$. The undrained shear strength of mixtures below the threshold fines content was observed so that as the plastic fines content increases, maximum deviator stress ratio decrease for dense samples while an increase is noted for loose samples. For non-plastic fines, the increase in the amount of fines leads to an increase in density of the soil, which results in an increase in strength. Then, the monotonic shear strength of the mixtures was estimated using the concept of granular void ratio. It was found that the shear strength of mixtures is greatly dependent on the skeleton structure of sand particles.

• 한국수산과학회지
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• 제42권3호
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• pp.276-283
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• 2009

Enrichment in nutrients coming from urban sewage outfalls can lead to eutrophication in coastal areas, which can also change the species composition and community structure of macro algal communities. We investigated the structure of the macro algal community within three rocky shores in order to assess any possible differences in their characteristics. Site 1 was located near Tongyeong city's sewage outfall, Site 2 was located near a public beach area, and Site 3 faced open channel of the Ocean. All three sites were located within the same stretch of the coast, where Site 2 was located between sites 1 and 3. We measured the nutrient concentration in water and the tissue nitrogen content in macro algae samples. Nutrients in the water column surrounding site 1 were high in ammonium ($30.2\pm1.8{\mu}M$), nitrate ($26.2{\pm}0.1{\mu}M$), and phosphate ($2.7{\pm}0.1{\mu}M$) content, and were characterized by low numbers of macroalgal species and species and a low species diversity index. In contrast, site 3 exhibited relatively low nutrient concentration levels and a high number of macroalgal species and a high species diversity index. Comparative analysis showed that the tissue nitrogen content of macroalgae were significantly (P<0.05) affected by the nutrient concentration in the water column. The tissue nitrogen content of green algae within site 1 was higher than the others sites. However, the tissue nitrogen content of brown algae was similar at all three sites. Thus, the tissue nitrogen content of macro algae and the macro algal community structure of intertidal rocky shores were dependent on location and the performance of macroalgal communities was dependent on water quality.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2008년도 제7회 추계학술대회 및 정기총회
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• pp.525-530
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• 2008

• 한국게임학회 논문지
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• 제6권2호
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• pp.33-44
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• 2006

본 논문은 디지털 기술의 발전에 따른 문화콘텐츠 유통의 발전, 특히 게임산업의 유통체계를 살펴보고 있다. 컨버젼스 기술의 발전에 따라, 문화콘텐츠 유통에 있어서 핵심적인 가치의 중심은 플랫폼에서 콘텐츠로 옮겨가고 있는데, 이와 관련하여 특히 게임산업의 유통구조에서는 3가지 유형(오프라인, 온라인, 모바일 게임)이 나타난다고 알려지고 있다. 본 논문에서는 심층인터뷰 등을 통한 사례조사를 통해 앞으로 통합적인 모델로 발전할 것으로 검증하고 있다. 결론적으로 본 논문은 이러한 변화에 맞추어 앞으로 문화콘텐츠산업의 장기적인 발전을 위해 유통구조의 개선, 기업과 퍼블리셔 등 관계자들의 갈등해소, 국제화 등을 위한 다각적 정책지원이 더욱 필요함을 제안하고 있다.