• Title/Summary/Keyword: Tries Structure

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Enhancing Retrieval Performance for Hierarchical Compact Binary Tree (계층형 집약 이진 트리의 검색 성능 개선)

  • Kim, Sung Wan
    • Journal of Creative Information Culture
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    • v.5 no.3
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    • pp.345-353
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    • 2019
  • Several studies have been proposed to improve storage space efficiency by expressing binary trie data structure as a linear binary bit string. Compact binary tree approach generated using one binary trie increases the key search time significantly as the binary bit string becomes very long as the size of the input key set increases. In order to reduce the key search range, a hierarchical compact binary tree technique that hierarchically expresses several small binary compact trees has been proposed. The search time increases proportionally with the number and length of binary bit streams. In this paper, we generate several binary compact trees represented by full binary tries hierarchically. The search performance is improved by allowing a path for the binary bit string corresponding to the search range to be determined through simple numeric conversion. Through the performance evaluation using the worst time and space complexity calculation, the proposed method showed the highest performance for retrieval and key insertion or deletion. In terms of space usage, the proposed method requires about 67% ~ 68% of space compared to the existing methods, showing the best space efficiency.

Elucidating Electrochemical Energy Storage Performance of Unary, Binary, and Ternary Transition Metal Phosphates and their Composites with Carbonaceous Materials for Supercapacitor Applications

  • Muhammad Ramzan Abdul Karim;Waseem Shehzad;Khurram Imran Khan;Ehsan Ul Haq;Yousaf Haroon
    • Journal of Electrochemical Science and Technology
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    • v.15 no.3
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    • pp.321-344
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    • 2024
  • Transition metal compounds (TMCs) are being researched as promising electrode materials for electrochemical energy storage devices (supercapacitors). Among TMCs, transition metal phosphates (TMPs) have good, layered structures owing to open framework and protonic exchange capability among different layers, good surface area due to engrossed porosity, rich active redox reaction sites owing to octahedral structure and variable valance metallic ions. Hence TMPs become more ideal for supercapacitor electrode materials compared to other TMCs. However, TMPs have got some issues like low conductivity, rate performance, stability, energy, and power densities. But these problems can be addressed by making their composites with carbonaceous materials, e.g., carbon nanotubes (CNTs), graphene oxide (GO), graphitic carbon (GC), etc. A few factors like high surface area, excellent electrical conductivity of carbon materials and variable valence metal ions in TMPs caused great enhancement in their electrochemical performance. This article tries to discuss and compare the published data, majorly in last decade, regarding the electrochemical energy storage potential of pristine unary, binary, and ternary TMPs and their hybrid composites with carbonaceous materials (CNTs, GOs/rGOs, GC, etc.). The electrochemical performance of the hybrids has been reported to be higher than the pristine counterparts. It is hoped that the current review will open a new gateway to study and explore the high performance TMPs based supercapacitor materials.

The Construction and Application of Planning Support System for the Sustainable Urban Development (지속가능한 도시개발을 위한 계획지원시스템의 구축과 활용에 관한 연구)

  • Lee, Hee-Yeon
    • Journal of the Korean Geographical Society
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    • v.42 no.1 s.118
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    • pp.133-155
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    • 2007
  • The sustainable urban development has emerged as a new paradigm of urban studies in recent years. A review of the literature of land use and transport policies in relation to sustainable development reveals a consensus that the main objectives of sustainable strategy should decrease the numbers and length of journeys, and change the land use pattern towards mixed use and high density. However, there is a lack of empirical research as to what types of policies might influence effectively the reduction in the energy consumption and emission of $CO_2$. in order to sustain urban development. This paper tries to construct the conceptual structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to construct the structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to the alternative scenarios. The PSS is composed of three components (input-modeling-output). The core of PSS is integrating land use-transport-environment modeling. The advantages of integrating land use-transport-environment modeling are well known, but there are very few such integrated modeling packages in practice. So this paper tries to apply TRANUS software, which is an integrated land use and transport model. The TRANUS system was calibrated to city of Yongin for the base year. The purpose of the application of TRANUS to Yongin is to examine the operability of TRANUS system in Korea. From the outputs and results of operating the system, TRANUS may be effectively used to evaluate the effects of alternative sustainable urban development policies, since sustainablilty indicators can be extracted from several aspects such as land use consumption, total trips, distance and cost, energy consumption, ratio of transport split.

Dilemma and Its Institutional Solutions in the Port ODA of Korea (항만분야 공적개발원조(ODA)의 딜레마 해소를 위한 제도 개선방안)

  • Kim, Bo Young;Kang, Yunho
    • Journal of Navigation and Port Research
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    • v.38 no.4
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    • pp.409-419
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    • 2014
  • In accordance with the global age, countries in the world try to dedicate to collaboration among them through ODA (Official Development Assistance), in order to solve the-rich-get-richer and the poor-get-poorer problems among countries, to develop the developing countries' economies, and to improve their level of social welfare. Also, Korea is so active in ODA as a member of OECD, even if it is in the initial process. Nowadays, in Korea, the importance of ODA in the field of port has been brought into relief. Accordingly, the paper intends to analyze the dilemma structure of port ODA from the perspectives both of new institutionalism and Samaritan's dilemma game, and it tries to seek the improvements of ODA institutions to create effective outcomes based on the analysis. Through the analysis, dilemma structure was identified regarding the institutions of port ODA. And the results of the analysis suggested the improvements of port ODA institutions including strengthening of on-the-spot aid system, establishment of payoffs system for inducing recipient countries' efforts, and institutionalization of reliable threat. It would contribute to develop the theoretical model of ODA analysis and create effective outcomes of ODA in the field of ports.

A Study on the Competitiveness Improvement of Coastal Shipping for Northeast Asia Logistics-Hub (동북아(東北亞) 물류거점화(物流據點化)를 위한 연안해운(沿岸海運) 경쟁력(競爭力) 제고방안(提高方案)에 관(關)한 연구(硏究))

  • Lee, Yon-Jae;Ahn, Ki-Myung;Kim, Kwang-Hee;Kim, Hyun-Duk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.441-449
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    • 2005
  • The purpose of this research is to present the improvement measure of lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge. For this purpose, this research tries to find out major northeast asia environment factors and accordingly the effects of its. The effects of coastal shipping system's development strategy is analysed by structural equation model and multiple regression model. Research results show that three types of coastal shipping developing strategy(connected transportation system, structure of coastal shipping system, governmental support policy) will contribute much to be logistic hub-nation. The contribution effects is increasing cargo from strengthened feeder transport system and maximizing logistic service &minimizing logistic costs. From the result, some implications are derived as follow. First, familiar environmental balanced ocean-coastal transport system is required. Second the one-stop logistic service system is necessary to build excusive feeder port, and to establish Ro-Ro ship & high-speed ship, etc.. Third, governmental support policy and subsidy(tax exempted oil & various tax benefits) are required to bring up lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge.

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Institutional Complementaries of Production and Welfare: Some Evidences from the Advanced Welfare Capitalist Countries (생산과 복지의 제도적 상보성에 관한 비교연구: 선진자본주의 국가를 중심으로)

  • Ahn, Sang-Hoon
    • Korean Journal of Social Welfare
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    • v.57 no.2
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    • pp.205-230
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    • 2005
  • This study empirically examines if there is a certain linkage between the production regimes and welfare systems; and if linked, how they are linked. It also investigates what the different regimes performed in terms of economic growth and redistribution. As a matter of fact, we have a series of studies that explores structural diversity of production and welfare. However, the existing studies are limited in that they consider only specific facets of the structure, although the structure of welfare capitalism should be studied as a comprehensive whole. This is the gap which this study tries to overcome. The study is composed of two major parts. The first one is the cluster analysis that examines if Esping-Andersen's notion about three different welfare regime and the thesis of diversity of capitalism can be dealt within a single research framework. The second is the ANOVA analysis investigating if variables of production and welfare are to be statistically different in the trichotomy framework. According to the result of the analyses, we can find at least two important evidences about institutional complementaries of production and welfare. First, Esping-Andersen's framework is useful to comprehensively deal with production as well as welfare. Secondly, there are statistically different regimes of production and welfare in the context of political economic and social policy variables. What is the most striking conclusion of the study is that there is no difference among the regimes in terms of the level of economic efficiency; while we can find a huge differences in terms of the level of welfare effectiveness. In conclusion, there is no substantive evidence to argue that welfare is innately antithesis of economic growth.

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System Design for a Urban Energy Monitoring and Visualization Environment Using Ubiquitous Sensor Network and Social Sensor Networking (Ubiquitous Sensor Network 및 Social Sensor Networking을 이용한 도시 에너지 모니터링 가시화 시스템 설계)

  • Choe, Yoon;Jang, Myeong-Ho;Kim, Sung-Ah
    • Journal of the HCI Society of Korea
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    • v.5 no.2
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    • pp.7-14
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    • 2010
  • Urban Data collected through Sensor Network is becoming crucial to understand and analyse a city. Thus, the Ubiquitous Sensor Network builds the foundation of the u-City development. This research aims to develop an energy monitoring application with an intuitive visualization environment which integrates energy usage information on top of urban geospatial information. Such a system will be able to facilitate effective energy supply plan at the early stages of urban planning, and eventually to encourage citizens to conserve energy by giving them real time monitoring information in an easy to understand visual environment. The system provides multiple layers of energy-related information coupled with the geospatial information layer in order to accommodate multiple viewpoints. On the other hand, the system provides logical Level of Detail control based on urban spatial information hierarchy. We defined the system concept and functions, and designed the data structure and the methods of information visualization. This paper presents the visualization methods, data structure, interactions scenarios which combines spacial information, E-GIS data and the energy related sensor data. Furthermore this research tries to introduce the concept of Social Sensor Networking to enhance the monitoring quality.

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Character Design Research for Local Brand Marketing -Focused on the package design for fastfood Bibimbob, 'Mix-bob' (지역브랜드 마케팅을 위한 캐릭터패키지 디자인 연구 -전주비빔밥 응용 패스트푸드 '믹스밥' 패키지 개발을 중심으로)

  • Joh, Yun-Sook
    • Cartoon and Animation Studies
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    • s.45
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    • pp.283-298
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    • 2016
  • Design is a fatal factor to differentiate and survive one product from the other in fierce competition of the market, when other conditions such as price or quality makes no much difference. Among many marketing tools, package design is known as a direct communication that visualizes and forms the very initial brand image of a product. Package design is not only for packing, transporting, storing and loading but for engraving the brand image in a consumers' mind and lead them to purchasing. One of recent package design trands is various ways of using character, not just as a printed image on the surface but as a part of three dimensional structure of package. If it succeed, the package design could give out the secondary fun and impact to the consumers. The package design with an effective character is itself a great marketing tool and valuable design asset, which can bring a further profit to the company. Especially, character-package can be a powerful and effective marketing method for various local products, in needs of further publication and sales with limited cost. It should motivate the sales of the products by grabbing their attention and taken as a souvenir. This research takes a character package as a useful marketing method for a local brand in Jeonju, South Korea, and tries to design a three dimensional package using its own character. Through the process, the research aims to propose an important design strategy for repositioning or enhancing an existing brand.

Agglomeration Economies and Intra-metropolitan Location of Firms: A Spatial Analysis on Chicago and Seoul (집적경제와 도시내 기업입지에 대한 공간분선: 서울과 시카고를 대상으로)

  • Jungyul Sohn
    • Journal of the Korean Geographical Society
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    • v.36 no.5
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    • pp.561-577
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    • 2001
  • Urban spatial structure is closely related to the spatial distribution of urban economic activities. The spatial distribution pattern is no more than an aggregated expression of the location and/or relocation behavior of individual firms and establishments. In this respect, it is important to identify and examine the factors that affect the spatial behavior of individual firms for a more comprehensive understanding of urban space. Agglomeration economies are one of the most prominent urban economic phenomena in the modern metropolitan area. Most firms in an urban space seek external economies through the spatial clustering of their activities. Agglomeration economies feature prominently in the analysis of urban economic structure across urban areas. While the agglomeration economies between cities focus at the macro-scale of analysis, such economies within any given city focus more on the micro geographical scale. There have been a number of researches on agglomeration economies, among which there are relatively few approaches based on an intra-urban context. This proper explores the agglomeration economies at the micro scale and tries to reseal the spatial realization of the agglomeration economies within and between sectors. Three sectors are considered in the analysis; manufacturing, retail and service. The model is based on simultaneous equation systems combined with spatially weighted variables and estimated by the KRP estimators.

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A Study on the Impact Factors of Contents Diffusion in Youtube using Integrated Content Network Analysis (일반영향요인과 댓글기반 콘텐츠 네트워크 분석을 통합한 유튜브(Youtube)상의 콘텐츠 확산 영향요인 연구)

  • Park, Byung Eun;Lim, Gyoo Gun
    • Journal of Intelligence and Information Systems
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    • v.21 no.3
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    • pp.19-36
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    • 2015
  • Social media is an emerging issue in content services and in current business environment. YouTube is the most representative social media service in the world. YouTube is different from other conventional content services in its open user participation and contents creation methods. To promote a content in YouTube, it is important to understand the diffusion phenomena of contents and the network structural characteristics. Most previous studies analyzed impact factors of contents diffusion from the view point of general behavioral factors. Currently some researchers use network structure factors. However, these two approaches have been used separately. However this study tries to analyze the general impact factors on the view count and content based network structures all together. In addition, when building a content based network, this study forms the network structure by analyzing user comments on 22,370 contents of YouTube not based on the individual user based network. From this study, we re-proved statistically the causal relations between view count and not only general factors but also network factors. Moreover by analyzing this integrated research model, we found that these factors affect the view count of YouTube according to the following order; Uploader Followers, Video Age, Betweenness Centrality, Comments, Closeness Centrality, Clustering Coefficient and Rating. However Degree Centrality and Eigenvector Centrality affect the view count negatively. From this research some strategic points for the utilizing of contents diffusion are as followings. First, it is needed to manage general factors such as the number of uploader followers or subscribers, the video age, the number of comments, average rating points, and etc. The impact of average rating points is not so much important as we thought before. However, it is needed to increase the number of uploader followers strategically and sustain the contents in the service as long as possible. Second, we need to pay attention to the impacts of betweenness centrality and closeness centrality among other network factors. Users seems to search the related subject or similar contents after watching a content. It is needed to shorten the distance between other popular contents in the service. Namely, this study showed that it is beneficial for increasing view counts by decreasing the number of search attempts and increasing similarity with many other contents. This is consistent with the result of the clustering coefficient impact analysis. Third, it is important to notice the negative impact of degree centrality and eigenvector centrality on the view count. If the number of connections with other contents is too much increased it means there are many similar contents and eventually it might distribute the view counts. Moreover, too high eigenvector centrality means that there are connections with popular contents around the content, and it might lose the view count because of the impact of the popular contents. It would be better to avoid connections with too powerful popular contents. From this study we analyzed the phenomenon and verified diffusion factors of Youtube contents by using an integrated model consisting of general factors and network structure factors. From the viewpoints of social contribution, this study might provide useful information to music or movie industry or other contents vendors for their effective contents services. This research provides basic schemes that can be applied strategically in online contents marketing. One of the limitations of this study is that this study formed a contents based network for the network structure analysis. It might be an indirect method to see the content network structure. We can use more various methods to establish direct content network. Further researches include more detailed researches like an analysis according to the types of contents or domains or characteristics of the contents or users, and etc.