• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.696-704
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• 2005

Flooding is usually utilized to find a multi hop route toward the destination which is not within transmission range in Ad Hoc networks. However, existing flooding schemes deteriorate the network performance because of periodic message exchanges, frequent occurrence of collisions, and redundant packet transmission. To resolve this, a flooding scheme using on demand cluster formation is proposed in this paper. The scheme employs ongoing Packets for constructing a cluster architecture as the existing on demand clustering scheme. Unlike to the existing on demand clustering scheme, the scheme makes use of unicast packet transmission to reduce the number of collisions and to find the flooding candidates easily. As a result, the proposed scheme yields fewer flooding nodes than other schemes. Simulation results proved that the proposed scheme reduces the number of transmissions and collisions than those of two other schemes.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.211-221
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• 2006

Manufacturing Execution System(MES) immediately enables users to share the information of systems industrywide, efficiently manages synthetic information with data collection through treating the data in a fast way, and helps their decision-making. MES for real-time information processing requires certain conditions such as data modeling of RFID, which has recently attracted attentions, and monitoring of each product unit from manufacture to sales. However, in the middle of processing the unit with a RFID tag, transponders(readers) can't often read the tag due to reader's malfunctions, intentional damages, loss and the circumstantial effects; for that reason, users are unable to confirm the location of the product unit. In this case, users cannot avoid tracing the path of units with uncertain clues. In this paper we suggest that the unique MES based on RFID and Bayesian Network can immediately track the product unit, and show how to evaluate it.

• Journal of Digital Contents Society
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• v.18 no.8
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• pp.1475-1480
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• 2017

The flourishing China mobile e-book App market has caused a series of problems, for which enhancing the user experience become an urgent matter. As a whole, user experience is related to the five planes such as the device, platform, medium, form and content. However, to understand the user needs is the logical starting point of the whole process. Contextual interview has been conducted in this study, while four types of tasks such as discovering and accessing a target e-book, setting and experiencing the reading interface, listening to the e-book and reviewing and sharing were asked to perform during the process, which has resulted in relevant problems and unpleasant factors in user experience. Based on the aforementioned contents, guidelines for enhancing the user experience of China mobile e-book App has been summarized as a result.

• Journal of Navigation and Port Research
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• v.40 no.3
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• pp.97-103
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• 2016

The precise prediction of ships propulsion performance is very important to find out the ships optimum route. This paper describes the development of computer program to generate the database of propulsion performance for the ships optimum routing system. The propulsion performance of ship in the sea is caused by not only ships conditions such as drift and hull roughness, but also various sea conditions such as wave and wind. These prediction methods of added resistance are based on the ships speed trial analysis methods of the ISO 15016:2002 standard, and a few prediction methods of the wind and hull roughness are supplemented. These prediction methods have been applied to the comprehensive computer program. And the database calculation for the research ice breaker the Araon has been carried out, which shall be used for the calculation of optimum route. Furthermore, this program shall be used for the route optimization in global shipping routes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.334-340
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• 2017

Reliability is considered a particularly important design factor for systems that have critical results once a failure occurs in a system, such as trains, airplanes, and passenger ships. The reliability of the system can be improved in several ways, but in a system that requires considerable reliability, the redundancy of parts is efficient in improving the system reliability. In the case of duplicating parts to improve reliability, the kind of parts and the number of duplicating parts should be determined under the system reliability, part costs, and resources. This study examined the redundancy allocation of multi-level systems with serial structures. This paper describes the definition of a multi-system and how to optimize the kind of parts and number of duplications to maximize the system reliability. To optimize the redundancy, the cuckoo search algorithm was applied. The search procedure, the solution representation and the development of the neighborhood solution were proposed to optimize the redundancy allocation of a multi-level system. The results of numerical experiments were compared with the genetic algorithm and cuckoo search algorithm.

• The Journal of the Acoustical Society of Korea
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• v.37 no.6
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• pp.437-442
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• 2018

In this paper, we propose a method for estimating the position of a source in a closed form when a single source has coherently distributed property against a circular array. When a sound source reaches a sensor through multipath environments, it is seen as a distributed source and can be represented by four variables: the nominal azimuth, nominal elevation, azimuth angular spread, elevation angular spread. Therefore, it requires a lot of computation by a search method such as DSPE (Distributed Source Parameter Estimator). In this paper, we propose a method of estimating the nominal azimuth and elevation angle in a closed form using correlation function and least squares method for fast position estimation. In particular, if the source is assumed as Gaussian distribution model, the standard deviation is also estimated in a closed form. In the simulation, the validity of the proposed method is confirmed by comparing with the DSPE.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1239-1251
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• 1999

In this paper a scalable QoS-based hierarchical inter-domain routing scheme for distributed multimedia applications in a high speed wide area network. The problem of QoS-based routing is formulated as a multicriteria shortest path problem, known as NP-complete[21,30]. Our routing scheme consists of two phases. In Phase 1, two graph construction algorithms are performed to model the network under consideration as a graph. The graph contains a part of the network topology which is completely neglected or partially considered by existing routing schemes, thus maintaining more accurate topology information. In Phase 2, a heuristic call-by-call algorithm is performed for selecting a feasible path efficiently in depth first search-like manner on the graph and tailoring to each application's QoS requirements, beginning at a vertex that represents the source node. In this paper, a simple rule is also produced, by which the visiting order of outgoing edges at each vertex on the graph is determined. The rule is based on each edge's the minimum normalized slackness to the QoS requested. The proposed routing scheme extends the PNNI-type hierarchical routing framework. Note that our routing scheme is one of a few QoS-based hierarchical routing schemes that address explicitly the issue of selecting a path with multiple metrics.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.235-246
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• 2013

Age estimations by forensic odontology play a great role in personal identification. The purpose of this study was to analyze the characteristics of age estimation cases in Korea. Surveying clients who requested age estimation at the Department of Oral Medicine, Kyungpook National University Dental Hospital from March 2012 to March 2013. The results were as follows: 1. On gender distribution, females(57.14%) were more than males(42.86%). The elderly with 50's and over 60's were majorities(89.28%) of clients, and no clients were below 40's. Most of clients were equal to and lower than elementary school graduate(69.64%). 2. The most frequent reason for age discrepancy between registered age and alleged age was mistakes by family or relatives(80.36%). The purposes of age estimation were welfare(62.50%), social relationship problem(12.50%), to find right age(10.71%), and occupation(8.93%). 3. In order of route to visit at Department of Oral Medicine, they were via government office(48.21%), acquaintances(21.43%), mass media(14.29%), and clinic(10.71%). Clients had high degree of comprehension on age estimation with forensic odontology (scored 7.03 out of 10). The 2/3 of clients were satisfied with present fee for age estimation. 4. The percentage on the proximity of estimated age to alleged age was 69.81%. 4(11.43%) clients were approved on age correction by court.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.188-199
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• 2018

Genomic epidemiology exploits various basic microbial research areas. High-throughput sequencing technologies dramatically have been expanding the number of microbial genome sequences available. Abundant genomic data provide an opportunity to perform strain typing more effectively, helping identify microbial species and strains at a higher resolution than ever before. Genomic epidemiology needs to find antimicrobial resistance genes in addition to standard genome annotations. Strain typing and antimicrobial resistance gene finding are static aspects of genomic epidemiology. Finding which hosts infected which other hosts requires the inference of transient transmission routes among infected hosts. The strain typing, antimicrobial resistance gene finding, and transmission tree inference would allow for better surveillance of microbial infectious diseases, which is one of the ultimate goals of genomic epidemiology. Among several high-throughput sequencing technologies, genomic epidemiology will benefit from the more portability and shorter sequencing time of the Oxford Nanopore Technologies's MinION, the third-generation sequencing technology. Here, this study reviewed computational methods for quantifying antimicrobial resistance genes and inferring disease transmission trees. In addition, the MinION's applications to genomic epidemiology were discussed.

• Food Science and Preservation
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• v.17 no.5
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• pp.571-580
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• 2010

We sought to define the main motivational factors promoting consumption of Prunus mume products. We surveyed both specialized high-volume consumers and public consumers, and focused on consumption of and preferences for Prunus mume and Prunus mume products. We investigated how products were preferentially consumed, purchase experience, purchase location, purchase price, consumption experience, factors important in a purchase decision, preference factors, dissatisfaction factors, consumption outlook, comments on new processed foods, and activation of consumption. A total of 534 responses were received and data were analyzed using the SAS program (Version 9.1) of the Frequency test; Chi-square test was used to detect significant factors. A greater percentage of high-volume(compared with low-volume) consumers processed personal products at home. The public consumer tended to buy commercial products. However, public consumers who were older, who had higher incomes, and who were heads of households, tended to both buy commercial products and to prepare foods at home. The common purchase methods used by high-volume consumers were internet and direct marketing, but the public consumer frequented department stores and hypermarkets. High-volume consumers observed that commercial products were expensive, and such consumers seemed to be particularly cost-sensitive. The decisive factor triggering purchase decisions in high-volume consumers was the geographical origin of the fruit, whereas the public consumer was more concerned with taste. In public, positive factors were that the product was good for health and had a pleasant taste. Some of those surveyed complained of a lack of variety in Prunus mume products and that the amount of Prunus mume in certain products was low. To promote and increase consumption, convenient-to-eat products with healthy images are needed.