• Title/Summary/Keyword: 순차탐색

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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.

A Slope Information Based Fast Mask Generation Technique for ROI Coding (관심영역 코딩을 위한 기울기 정보 기반의 빠른 마스크 생성 기법)

  • Park, Sun-Hwa;Seo, Yeong-Geon;Lee, Bu-Kweon;Kang, Ki-Jun;Kim, Ho-Yong
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.1
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    • pp.81-89
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    • 2009
  • To support dynamic Region-of-Interest(ROI) in JPEG2000, a fast ROI mask generation is needed. In the existing methods of ROI coding, after scanning all the pixels in order and discriminating ROI, an ROI mask has been generated. Our method scans 4 pixels of the corners in one code block, and then based on those informations, scans the edges from the corners to get the boundaries of ROI and background. These informations are consisted of a distributed information of ROI and two coordinates of the pixels, which are the points the edges and the boundaries meet. These informations are transmitted to encoder and supported for fast ROI mask generation. There were no great differences between the proposed method and the existing methods in quality, but the proposed method showed superiority in speed.

Factors Influencing Buyers' Choice of Online vs. Offline Channel at Information Search and Purchase Stages (정보탐색과 구매 단계에서 온라인과 오프라인 채널선택의 영향요인)

  • Kim, Sang-Hoon;Park, Gye-Young;Park, Hyun-Jung
    • Journal of Distribution Research
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    • v.12 no.3
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    • pp.69-90
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    • 2007
  • This study is set out to investigate the factors that influence customers' behavior of choice and switching between online and offline channels, separating the purchase decision into two stages, i.e., information search and purchase. Factors influencing channel choice are found to differ from stage to stage. The main results of this study are as follows. At the information search stage, customers' channel knowledge had impacts on the choice of the channel. Customers are more likely to visit offline bookstores when they have hedonic shopping orientation and higher involvement level with books. On the contrary, customers are more apt to search online when they have a lot of online shopping experiences. At the purchase stage, the results varied according to the search channel. When customers search for information online, the following variables lead to online purchases: online shopping experiences with books, price-focused shopping orientation, and time availability for shopping. Perceived risk made customers purchase offline even though they searched online. In case of offline searching, customers with more convenience-focused, hedonic-focused shopping orientation and less tim availability purchased offline.

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Information-Seeking Pathways by Mothers in the Context of Their Children's Health (어린이 건강과 관련한 어머니들의 정보탐색 경로)

  • Lee, Hanseul
    • Journal of Korean Library and Information Science Society
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    • v.52 no.3
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    • pp.21-48
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    • 2021
  • Today, with countless health information being accessible through online and offline, the public has been able to explore health-related information in various ways. The current study focuses on the information-seeking behavior of the mothers who actively explore information related to the health of their healthy infants (aged between 0 and 3 years). The researcher had conducted in-depth interviews of 24 American, Korean, and Korean immigrant mothers living in the United States, and then analyzed the sequential order of the information sources that they have used to search for the health-related information about their children. The current research highlights that the mothers' information-seeking pathways and searched topics tended to differ in accordance with their child(ren)'s health conditions (e.g., ill vs. healthy). For instance, regarding the information sources used, more diverse health information sources (e.g., public libraries, government health agencies, daycare teachers) were used when their child(ren) was not ill. In addition, when a child was ill, mothers were likely to focus on information about specific diseases or symptoms first, whereas when the child was healthy, they used to explore information on various health topics such as growth and development, nutrition and diets, parenting, and so on. Based on the results, implications for the information professionals are discussed when designing and providing health-related information services to mothers of healthy infants and toddlers.

An Adaptive Priority-based Sequenced Route Query Processing Method in Road Networks (도로 네트워크 환경에서 적응적 우선순위 기반의 순차적 경로 처리 기법)

  • Ryu, Hyeongcheol;Jung, Sungwon
    • KIISE Transactions on Computing Practices
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    • v.20 no.12
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    • pp.652-657
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    • 2014
  • Given a starting point, destination point and various Points Of Interest (POIs), which contain a full or partial order, for a user to visit we wish to create, a sequenced route from the starting point to the destination point that includes one member of each POI type in a particular order. This paper proposes a method for finding the approximate shortest route between the start point, destination point and one member of each POI type. There are currently two algorithms that perform this task but they both have weaknesses. One of the algorithms only considers the distance between the visited POI (or starting point) and POI to visit next. The other algorithm chooses candidate points near the straight-line distance between the start point and destination but does not consider the order of visits on the corresponding network path. This paper outlines an algorithm that chooses the candidate points that are nearer to the network path between the start point and destination using network search. The algorithm looks for routes using the candidate points and finds the approximate shortest route by assigning an adaptive priority to the route that visits more POIs in a short amount of time.

Handwritten Hangul Word Recognition from Small Vocabulary using Grapheme Combination Type (자모 결합 유형을 이용한 적은 어휘에서의 필기 한글 단어 인식)

  • Jin, Yu-Ho;Kim, Ho-Yeon;Kim, In-Jung;Kim, Jin-Hyeong
    • Journal of KIISE:Software and Applications
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    • v.28 no.1
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    • pp.52-63
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    • 2001
  • 필기 단어 인식 방법에는 낱자별 분할 및 낱자 단위 인식을 통해 인식하는 방법과 단어 사전을 이용하여 단어와 영상을 직접 비교하는 방법이 있다. 이 중 후자는 인식 대상이 되는 단어들이 작은 수의 어휘로 제한되었을 대 매우 효과적이다. 본 논문에서는 입력 영상이 주어졌을 때 자모를 순차적으로 탐색하고 그 결과의 최적 조합을 찾아 인식하는 사전을 이용한 필기 한글 단어 인식 방법을 제안한다. 입력 영상은 사전의 각 단어와의 매칭을 통해 인식된다. 단어는 필기 순서로 정렬된 자모열로 표현하고 입력 영상은 획들의 집합으로 표현한다. 단어의 자모들은 입력 영상으로부터 추출된 획들의 집합으로부터 단계적으로 탐색된다. 각 단계에서는 전 단계까지의 매칭 상태와 탐색하려는 자모의 형태로부터 자모가 존재할 것이라고 기대되는 정합 기대 영역을 설정한 후 그 안에서 자모 탐색기를 이용해 자모를 찾는다. 자모 탐색기는 획들의 집합으로 이루어진 복수의 자모 후보와 그 점수를 출력한다. 각 단계마다 생성된 자모 후보들은 최적의 단어 매칭을 찾기 위한 탐색 공간을 이룬다. 본 연구에서는 단어 사전을 trie로 구성하고, 탐색 과정에서 dynamic programming을 이용하여 효과적으로 탐색을 수행하였다. 또한 인식 속도를 향상시키기 위해 산전 축소, 탐색 공간 축소 등 다양한 지식을 이용하였다. 제안하는 방법은 무제약으로 쓰여진 필기 단어도 인식 할 수 있을 뿐 아니라, 동적 사전을 이용하기 때문에 사전의 내용이 변하는 환경에서도 적용할 수 있다. 인식 실험에서는 39개의 단어로 이루어진 사전에 대하여 613개의 단어 영상에 대해 실험한 결과 98.54%의 높은 인식률을 보임으로써 제안하는 방법이 매우 효과적임을 확인하였다. 아니라 곰팡이 균주도 실제 praxis에 적합하게 개발시킬수 있다. 따라서 앞으로 발효육제품제조에 있어 starter culture가 갖는 의미는 매우 중요하며 특히 짧은 숙성기간을 거치는 발효소시지의 제조에 있어서는 필수불가결한 공정의 한 분야로 자리잡게 될 것이다.큰 차이 없었으나 이중포장과 진공포장은 상당히 효과적임을 알 수 있었다.로는 18%에 비하여 22%가 더 적합한 것으로 생각되었다.$0.15{\sim}0.35%$이었다.irc}C$에서 $13.49{\times}10^{-3}$이었다. 이 값들을 Arrhenius식에 대입하여 구한 활성화 에너지는 24.795 kJ/Kmol이었다. 이 값으로부터 결정한 살균 포장약주 명가의 상용 저장 수명은 $10^{\circ}C$에서 2년, $20^{\circ}C$에서 1년 4개월, $25^{\circ}C$에서 1년 2개월 이었다. 서울의 매월 평균 온도를 기준으로 계산할 때 본제품의 상용저장기간은 1년 8개월이었다.로 반죽이 호화되고 가열시간이 그 이상으로 증가할 때도 반죽의 호화가 약간은 진행되지만 $90^{\circ}C$ 이상의 가열온도에서는 가열시간 0.5분 이내에 반죽의 호화가 급속히 일어나고 가열 시간을 증가시켜도 더이상의 호화는 일어나지 않았다. 같은 조건에서는 waxy corn starch 반죽의 호화 속도가 corn starch보다 더 빠른 것으로 나타났다. 대표적으로 52% 수분함량에서 반응속도상수(k)와 가열온도(T)사이의 관계식은 corn starch의 경우 $logk=11.1140-4.1226{\times}10^3(1/T)

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Subgraph Searching Scheme Based on Path Queries in Distributed Environments (분산 환경에서 경로 질의 기반 서브 그래프 탐색 기법)

  • Kim, Minyoung;Choi, Dojin;Park, Jaeyeol;Kim, Yeondong;Lim, Jongtae;Bok, Kyoungsoo;Choi, Han Suk;Yoo, Jaesoo
    • The Journal of the Korea Contents Association
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    • v.19 no.1
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    • pp.141-151
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    • 2019
  • A network of graph data structure is used in many applications to represent interactions between entities. Recently, as the size of the network to be processed due to the development of the big data technology is getting larger, it becomes more difficult to handle it in one server, and thus the necessity of distributed processing is also increasing. In this paper, we propose a distributed processing system for efficiently performing subgraph and stores. To reduce unnecessary searches, we use statistical information of the data to determine the search order through probabilistic scoring. Since the relationship between the vertex and the degree of the graph network may show different characteristics depending on the type of data, the search order is determined by calculating a score to reduce unnecessary search through a different scoring method for a graph having various distribution characteristics. The graph is sequentially searched in the distributed servers according to the determined order. In order to demonstrate the superiority of the proposed method, performance comparison with the existing method was performed. As a result, the search time is improved by about 3 ~ 10% compared with the existing method.

Displacement mapping using an image pyramid based multi-layer height map (이미지 피라미드 기반 다층 높이 맵을 사용한 변위 매핑 기법)

  • Chun, Young-Jae;Oh, Kyoung-Su
    • Journal of the Korea Computer Graphics Society
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    • v.14 no.3
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    • pp.11-17
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    • 2008
  • Many methods which represent complex surfaces using height map without a number of vertex have been researched. However, a single layer height map cannot present more complex objects because it has only one height value on each position. In this paper, we introduce the new approach to render more complex objects, which are not generated by single layer height map, using multi layer height map. We store height values of the scene to each texture channel by the ascending order. A pair of ordered height values composes a geometry block and we use this property. For accurate ray search, we store the highest value in odd channels and the lowest value in even channels to generate quad tree height map. Our ray search algorithm shows accurate intersections between viewing ray and height values using quad tree height map. We solve aliasing problems on grazing angles occurred in previous methods and render the result scene on real-time.

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Path Search Method using Genetic Algorithm (유전자 알고리즘을 이용한 경로 탐색)

  • Kim, Kwang-Baek;Song, Doo-Heon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.6
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    • pp.1251-1255
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    • 2011
  • In this paper, we propose an optimal path search algorithm that contains all nodes using genetic algorithm. An object in this approach is formed as an equation related with the Euclidean distance between an intermediate node and the starting node and between an intermediate node and the goal node. Like other genetic algorithm structures, our algorithm defines a fitness function and selects a crossover spot node and a bitwise crossover point. A new node out of such operation survives only if it satisfies the fitness criteria and that node then becomes the starting node for the next generation. Repetition continues until no changes are made in the population. The efficiency of this proposed approach is verified in the experiment that it is better than two other contestants - sequential approach and the random approach.

Finding the K Least Fare Routes In the Distance-Based Fare Policy (거리비례제 요금정책에 따른 K요금경로탐색)

  • Lee, Mi-Yeong;Baek, Nam-Cheol;Mun, Byeong-Seop;Gang, Won-Ui
    • Journal of Korean Society of Transportation
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    • v.23 no.1
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    • pp.103-114
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    • 2005
  • The transit fare resulted from the renovation of public transit system in Seoul is basically determined based on the distance-based fare policy (DFP). In DFP, the total fare a passenger has to pay for is calculated by the basic-transfer-premium fare decision rule. The fixed amount of the basic fare is first imposed when a passenger get on a mode and it lasts within the basic travel distance. The transfer fare is additionally imposed when a passenger switches from one mode to another and the fare of the latter mode is higher than the former. The premium fare is also another and the fare of the latter begins to exceed the basic travel distance and increases at the proportion of the premium fare distance. The purpose of this study is to propose an algorithm for finding K number of paths, paths that are sequentially sorted based on total amount of transit fare, under DFP of the idstance-based fare policy. For this purpose, the link mode expansion technique is proposed in order to save notations associated with the travel modes. Thus the existing K shortest path algorithms adaptable for uni-modal network analysis are applicable to the analysis for inter-modal transportation networks. An optimality condition for finding the K shortest fare routes is derived and a corresponding algorithms is developed. The case studies demonstrate that the proposed algorithm may play an important role to provide diverse public transit information considering fare, travel distance, travel time, and number of transfer.