• Title/Summary/Keyword: depth-first search

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Low-delay Node-disjoint Multi-path Routing using Complementary Trees for Industrial Wireless Sensor Networks

  • Liu, Luming;Ling, Zhihao;Zuo, Yun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.11
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    • pp.2052-2067
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    • 2011
  • Complementary trees are two spanning trees rooted at the sink node satisfying that any source node's two paths to the sink node on the two trees are node-disjoint. Complementary trees routing strategy is a special node-disjoint multi-path routing approach. Several complementary trees routing algorithms have been proposed, in which path discovery methods based on depth first search (DFS) or Dijkstra's algorithm are used to find a path for augmentation in each round of path augmentation step. In this paper, a novel path discovery method based on multi-tree-growing (MTG) is presented for the first time to our knowledge. Based on this path discovery method, a complementary trees routing algorithm is developed with objectives of low average path length on both spanning trees and low complexity. Measures are employed in our complementary trees routing algorithm to add a path with nodes near to the sink node in each round of path augmentation step. The simulation results demonstrate that our complementary trees routing algorithm can achieve low average path length on both spanning trees with low running time, suitable for wireless sensor networks in industrial scenarios.

Combining Local and Global Features to Reduce 2-Hop Label Size of Directed Acyclic Graphs

  • Ahn, Jinhyun;Im, Dong-Hyuk
    • Journal of Information Processing Systems
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    • v.16 no.1
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    • pp.201-209
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    • 2020
  • The graph data structure is popular because it can intuitively represent real-world knowledge. Graph databases have attracted attention in academia and industry because they can be used to maintain graph data and allow users to mine knowledge. Mining reachability relationships between two nodes in a graph, termed reachability query processing, is an important functionality of graph databases. Online traversals, such as the breadth-first and depth-first search, are inefficient in processing reachability queries when dealing with large-scale graphs. Labeling schemes have been proposed to overcome these disadvantages. The state-of-the-art is the 2-hop labeling scheme: each node has in and out labels containing reachable node IDs as integers. Unfortunately, existing 2-hop labeling schemes generate huge 2-hop label sizes because they only consider local features, such as degrees. In this paper, we propose a more efficient 2-hop label size reduction approach. We consider the topological sort index, which is a global feature. A linear combination is suggested for utilizing both local and global features. We conduct experiments over real-world and synthetic directed acyclic graph datasets and show that the proposed approach generates smaller labels than existing approaches.

Development of Expert System For Designing Power Transmission Gears(I) -Diagnosis of the Causes and Remedies of Gear Failures- (동력전달용 치차설계 전문가 시스템 개발연구(I) -치차파손의 원인과 대책의 진단-)

  • 정태형;변준형;이규호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.6
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    • pp.2026-2036
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    • 1991
  • An expert system is developed which can diagnose the causes and remedies of the failures of power transmission gears. The basic components of the expert system are knowledge base, inference engine, and working memory. The knowledges in knowledge base are classified into the knowledges for determining the failure types and for diagnosis of causes and remedies of the failures. The former is represented hierarchically into the main category of eleven groups by rules and the sub category of twenty four groups by facts, while the later is represented by facts according to the each group of knowledges. In the inference engine some considerations are implemented, i.e., the backward chaining method and depth first search to determine the category of the failures, the meta-knowledges to shorten the search space, the certainty factor to evaluate the reliability of result, and the unification strategy to diagnose the causes and remedies of the failures. The working memory is established to hold the results during inference temporarily. In addition, knowledge acquisition facility, explanation facility, and user interface are included for the usefulness of user. This expert system is written with the PROLOG programming language on IBM-PC compatible computer operated by MS-DOS and be executed alone.

Qualitative Study on Emotion Aspect Experiencing When Consumers are Purchasing Clothing Through T.V Home-Shopping (T.V홈쇼핑 의류제품(衣類製品) 구매(購買)시 경험(經驗)하는 감정적(感情的) 측면(側面)에 관(關)한 질적연구(質的硏究))

  • Cha, In-Suk;Lee, Kyoung-Hee
    • Journal of Fashion Business
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    • v.8 no.1
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    • pp.34-48
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    • 2004
  • The purpose of this study is to explore emotion aspects of consumers purchasing clothing through cable television home shopping. Qualitative research method is used to widely understand how emotion aspects of consumers have effected on their purchasing behavior. The results of depth interviews may be classified into 13 feelings factors satisfaction, pleasure/delight, respect, attraction, fresh, convenience, unburdened, emptiness, displeasure/temper, anxiety, tedious, distrust, regret. The content of information acquiring from the process of clothing purchase decision making is analysed. In the problem recognition stage, purchase motivation were physical space (around people) and imaginary space(by how clothing goods are introduced to consumers thorough TV monitor). In the information search stage, purchasing action patterns to search information were situational pattern and habitual pattern. In alternative evaluation stage, the considering best important factors to choice clothes were quality, price, design, and color. In purchase stage, consumers said they felt anxiety, because of characteristics of purchase way that they should pay first and then received the ordered goods a fews days later. In post-purchase behavior stage, if consumers satisfied goods purchased through TV home shopping, they recommended it to around others, but unsatisfied with ordered goods, they tried to refund, exchange with anther one, or write it on homepage of the home shopping company.

A Study on the Consumers' Perceptions and Behavioral Characteristics toward Fashion Products in Omni-channel Retailing (옴니채널 리테일링에서 패션 제품 소비자의 인식 및 행동 특성 탐구)

  • Kim, Yunjeong;Lee, Yuri
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.1
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    • pp.170-183
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    • 2017
  • The rapid growth of digital consumption has significantly changed the shopping behavior of consumers. The consumption paradigm is changing; subsequently, an omni-channel has been introduced that empowers consumers to interact with firms through a myriad of touch points in multiple channels. This study is to understand the perceptions and behavioral characteristics of consumers in the purchase process (e.g., information search and purchase phase). A qualitative method was adopted for this study and data were collected through semi-structured in-depth interviews with 15 omni-channel consumers. The results of this study were as follows. At the information search stage, consistency was the most important consideration for consumers who also wanted to retain channel-specific benefits. Consumers also searched for differentiated information among distribution channels. At the purchase stage, participants choose a shopping channel according to shopping values. They utilized newly introduced services (e.g., "online purchase, offline pick-up", FinTech) that combine retail channels. Our findings provide significance in managing omni-channel services. First, it is recommended that fashion retailers provide seamlessly integrated experience to consumer and adopt a consumer-centered channel choice strategy. Second, fashion retailers must maintain a constant attitude toward shopping experience to fashion, such as shopping enjoyment and exclusiveness.

Video Index Generation and Search using Trie Structure (Trie 구조를 이용한 비디오 인덱스 생성 및 검색)

  • 현기호;김정엽;박상현
    • Journal of KIISE:Software and Applications
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    • v.30 no.7_8
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    • pp.610-617
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    • 2003
  • Similarity matching in video database is of growing importance in many new applications such as video clustering and digital video libraries. In order to provide efficient access to relevant data in large databases, there have been many research efforts in video indexing with diverse spatial and temporal features. however, most of the previous works relied on sequential matching methods or memory-based inverted file techniques, thus making them unsuitable for a large volume of video databases. In order to resolve this problem, this paper proposes an effective and scalable indexing technique using a trie, originally proposed for string matching, as an index structure. For building an index, we convert each frame into a symbol sequence using a window order heuristic and build a disk-resident trie from a set of symbol sequences. For query processing, we perform a depth-first search on the trie and execute a temporal segmentation. To verify the superiority of our approach, we perform several experiments with real and synthetic data sets. The results reveal that our approach consistently outperforms the sequential scan method, and the performance gain is maintained even with a large volume of video databases.

A Study on Stowage Automation Algorithm for Cargo Stowage Optimization of Vehicle Carriers (차량 운반선의 화물 적재 최적화를 위한 적재 자동화 알고리즘 연구)

  • JI Yeon Kim;Young-Jin Kang;Jeong, Seok Chan;Hoon Lee
    • The Journal of Bigdata
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    • v.7 no.2
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    • pp.129-137
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    • 2022
  • With the development of the 4th industry, the logistics industry is evolving into a smart logistics system. However, ship work that transports vehicles is progressing slowly due to various problems. In this paper, we propose an stowage automation algorithm that can be used for cargo loading of vehicle carriers that shortens loading and unloading work time. The stowage automation algorithm returns the shortest distance by searching for a loading space and a movable path in the ship in consideration of the structure of the ship. The algorithm identifies walls, ramps and vehicles that have already been shipped, and can work even with randomly placed. In particular, it is expected to contribute to developing a smart logistics system for vehicle carriers by referring to the ship's master plan to search for vehicle loading and unloading space in each port and predict the shortest movable path.

A Qualitative Research on Purchase Decision-Making Process by Limited Edition Fashion Consumers (리미티드 에디션 패션제품 구매자의 구매의사결정과정에 관한 연구)

  • Hwang, Kyeong-Yi;Koh, Ae-Ran
    • Human Ecology Research
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    • v.54 no.6
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    • pp.599-610
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    • 2016
  • The purposes of this study are to identify the characteristics of limited edition fashion consumers, to analyze their purchase decision-making processes, and to examine negative factors of consumers' recognition toward limited edition fashion products. A qualitative investigation was conducted by doing in-depth interviews with 11 selected consumers in their twenties and thirties who have actively purchased and consumed limited edition fashion products. The results of this study can be summarized as follows. First, there are four sub-categories of appearance management activity, acceptance of fashion trend, information-seeking behavior, and hedonic shopping orientation for the limited edition fashion consumers' characteristics. Second, the purchase decision-making process of limited edition fashion consumers are identified as seven steps: need recognition, information search, evaluation of alternatives, planning and courtship, purchase, post-purchase evaluation, and post-purchase behavior. Courtship/attachment formation and post-purchase behavior are unique steps when compared to general purchase decision-making process. Third, this study identified negative factors of consumers' recognition toward limited edition this study in order to suggest several improvement plans for enterprises using limited marketing. Four sub-categories are examined: outrageous price, tricks of company, fatigue due to purchasing competition, and re-sellers. In conclusion, this study indicates that the purchase decision-making process of limited edition consumers, which involves two distinctive steps including courtship/attachment formation and post-purchase behavior, can be differentiated from general consumers. The results of this study provides preliminary data for further research for in-depth analysis of limited edition consumers.

Intelligent Brand Positioning Visualization System Based on Web Search Traffic Information : Focusing on Tablet PC (웹검색 트래픽 정보를 활용한 지능형 브랜드 포지셔닝 시스템 : 태블릿 PC 사례를 중심으로)

  • Jun, Seung-Pyo;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.19 no.3
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    • pp.93-111
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    • 2013
  • As Internet and information technology (IT) continues to develop and evolve, the issue of big data has emerged at the foreground of scholarly and industrial attention. Big data is generally defined as data that exceed the range that can be collected, stored, managed and analyzed by existing conventional information systems and it also refers to the new technologies designed to effectively extract values from such data. With the widespread dissemination of IT systems, continual efforts have been made in various fields of industry such as R&D, manufacturing, and finance to collect and analyze immense quantities of data in order to extract meaningful information and to use this information to solve various problems. Since IT has converged with various industries in many aspects, digital data are now being generated at a remarkably accelerating rate while developments in state-of-the-art technology have led to continual enhancements in system performance. The types of big data that are currently receiving the most attention include information available within companies, such as information on consumer characteristics, information on purchase records, logistics information and log information indicating the usage of products and services by consumers, as well as information accumulated outside companies, such as information on the web search traffic of online users, social network information, and patent information. Among these various types of big data, web searches performed by online users constitute one of the most effective and important sources of information for marketing purposes because consumers search for information on the internet in order to make efficient and rational choices. Recently, Google has provided public access to its information on the web search traffic of online users through a service named Google Trends. Research that uses this web search traffic information to analyze the information search behavior of online users is now receiving much attention in academia and in fields of industry. Studies using web search traffic information can be broadly classified into two fields. The first field consists of empirical demonstrations that show how web search information can be used to forecast social phenomena, the purchasing power of consumers, the outcomes of political elections, etc. The other field focuses on using web search traffic information to observe consumer behavior, identifying the attributes of a product that consumers regard as important or tracking changes on consumers' expectations, for example, but relatively less research has been completed in this field. In particular, to the extent of our knowledge, hardly any studies related to brands have yet attempted to use web search traffic information to analyze the factors that influence consumers' purchasing activities. This study aims to demonstrate that consumers' web search traffic information can be used to derive the relations among brands and the relations between an individual brand and product attributes. When consumers input their search words on the web, they may use a single keyword for the search, but they also often input multiple keywords to seek related information (this is referred to as simultaneous searching). A consumer performs a simultaneous search either to simultaneously compare two product brands to obtain information on their similarities and differences, or to acquire more in-depth information about a specific attribute in a specific brand. Web search traffic information shows that the quantity of simultaneous searches using certain keywords increases when the relation is closer in the consumer's mind and it will be possible to derive the relations between each of the keywords by collecting this relational data and subjecting it to network analysis. Accordingly, this study proposes a method of analyzing how brands are positioned by consumers and what relationships exist between product attributes and an individual brand, using simultaneous search traffic information. It also presents case studies demonstrating the actual application of this method, with a focus on tablets, belonging to innovative product groups.

Mining Frequent Closed Sequences using a Bitmap Representation (비트맵을 사용한 닫힌 빈발 시퀀스 마이닝)

  • Kim Hyung-Geun;Whang Whan-Kyu
    • The KIPS Transactions:PartD
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    • v.12D no.6 s.102
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    • pp.807-816
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    • 2005
  • Sequential pattern mining finds all of the frequent sequences satisfying a minimum support threshold in a large database. However, when mining long frequent sequences, or when using very low support thresholds, the performance of currently reported algorithms often degrades dramatically. In this paper, we propose a novel sequential pattern algorithm using only closed frequent sequences which are small subset of very large frequent sequences. Our algorithm generates the candidate sequences by depth-first search strategy in order to effectively prune. using bitmap representation of underlying databases, we can effectively calculate supports in terms of bit operations and prune sequences in much less time. Performance study shows that our algorithm outperforms the previous algorithms.