• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2007년도 추계학술대회 및 제23회 정기총회
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• pp.245-246
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• 2007

본 논문은 동북아시아 항만에 기항하는 선사들의 서비스 노선의 변화를 통해 기항패턴을 분석하고, 각 항만의 처리량 및 기항패턴의 변화에 따른 동북아지역 항만간의 점유율의 변화를 분석하고자 한다. 이를 위해 기존 연구들과 정량화된 자료를 검토하고 동북아시지역 항만들의 기간항로 점유율(타지역 규모 이용)을 분석한다. 여기서 타지역 규모라 함은 타지역에서 연결되는 항만들의 규모를 의미하며, 이를 토대로 동아시아 지역 항만들의 거점화 정도를 알아본다.

• 복식
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• 제65권6호
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• pp.25-35
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• 2015

The purpose of this study is to investigate the characteristics of members and communities that have significant influence in the online fashion community through their word-of-mouth activities. In order to identify the influence and the diffusion of word-of-mouth in fashion community, the study selected one online fashion community. Then, the study sorted the online posts and comments made on fashion information and put them into the matrix form to perform social network analysis. The result of the analysis is as follows: First, the fashion community network used in the study has many active members that relay information very quickly. Average time for information diffusion is very short, taking only one or two days in most cases. Second, the influence of word-of-mouth is led by key information produced from only a few members. The number of influential members account for less than 20% of the total number of community members, which indicate high level of degree centrality. The diffusion of word-of-mouth is led by even fewer members, which represent high level of betweenness centrality, compared to the case of degree centrality. Third, component characteristic shares similar information with about 70% of all members being linked to maximize information influence and diffusion. Fourth, a node with high degree centrality and betweenness centrality shares similar interests, presenting strain effect to particular information. Specially, members with high betweenness centrality show similar interests with members of high degree centrality. The members with high betweenness centrality also help expansion of related information by actively commenting on posts. The result of this research emphasizes the necessity of creation and management of network to efficiently convey fashion information by identifying key members with high level of information influence and diffusion to enhance the outcome of online word-of-mouth.

• 대한기계학회논문집A
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• 제31권6호
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• pp.651-658
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• 2007

A new tree-structured neural network classifier is proposed for the automatic real-time inspection of cold-rolled steel strip surface defects. The defects are classified into 3 groups such as area type, disk type, area & line type in the first stage of the tree-structured neural network. The defects are classified in more detail into 11 major defect types which are considered as serious defects in the second stage of neural network. The tree-structured neural network classifier consists of 4 different neural networks and optimum features are selected for each neural network classifier by using SFFS algorithm and correlation test. The developed classifier demonstrates very plausible result which is compatible with commercial products having high world-wide market shares.

• Journal of Computing Science and Engineering
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• 제7권3호
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• pp.198-203
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• 2013

In this paper, we focus on a novel Internet architecture, based on the urbanization of virtual machines. In this approach, virtual networks are built linking specific virtual elements (router, switch, firewall, box, access point, etc.). A virtual network represents a network with an independent protocol stack that shares resources from the underlying network infrastructure. Virtualization divides a real computational environment into virtual computational environments that are isolated from each other, and interact with the upper computational layer, as would be expected from a real, non-virtualized environment. Metamorphic networks enhance several concepts related to future networks, and mainly the urbanization of virtual machines. We present this new paradigm, and the methodology, based on the worldwide metamorphic network platform "M-Net". The metamorphic approach could solve many complex problems, especially related to Cloud computing services.

• 산업기술연구
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• 제27권B호
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• pp.37-42
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• 2007

A mobile ad hoc network (MANET) is a kind of wireless ad hoc network. It is a self-configuring network of mobile nodes connected by wireless links. Infostation is a lower cost and low power system that provides very high bit rate with limited coverage. In this study, we propose search and rescue system that combines MANET of climbers with Infostations. A climber shares location information of climbers with other climbers while climbing, and delivers the information to Infostations. This system is an intermittent network due to the mobility of nodes. From the system, we can track the locations of missing climbers. Ultimately, proposed system achieves low cost and reduces memory requirement using Infestations. We also analyze the performance of the proposed system by simulation. From the performance analysis results, we expect that the proposed system will be very useful to early detect climbers' locations in emergency situations in Korea mountain areas.

• Journal of Information Processing Systems
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• 제19권1호
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• pp.130-138
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• 2023

The traffic flow in an urban area is affected by the date, weather, and regional traffic flow. The existing methods are weak to model the dynamic road network features, which results in inadequate long-term prediction performance. To solve the problems regarding insufficient capacity for dynamic modeling of road network structures and insufficient mining of dynamic spatio-temporal features. In this study, we propose a novel traffic flow prediction framework called shared spatio-temporal attention convolution optimization network (SSTACON). The shared spatio-temporal attention convolution layer shares a spatio-temporal attention structure, that is designed to extract dynamic spatio-temporal features from historical traffic conditions. Subsequently, the graph optimization module is used to model the dynamic road network structure. The experimental evaluation conducted on two datasets shows that the proposed method outperforms state-of-the-art methods at all time intervals.

• 전자통신동향분석
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• 제37권3호
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• pp.74-84
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• 2022

The Korean mobile service market has persistently grown with the number of subscribers and volume of mobile traffic. It shows the slow diffusion of 5G subscribers, and rapid growth of both the MVNO(Mobile Virtual Network Operator) market and unlocked mobile phones. Therefore, this study derives the direction of telcos' strategies and policy implications by empirically analyzing the usage and attitude of LTE and 5G subscribers. Our major findings are as follows: First, our current mobile service subscription market constitutes most long-term customers for their incumbent carriers only by device change from lock-in with bundle services. Mobile tariffs, data speed, and benefits of bundle services are important factors affecting choices and customers' satisfaction with a provider and intentions of churning to another. Second, demand and satisfaction for using 5G are less because speeds and service tariffs act as pain points for 5G services. Third, the users' high preferences for MVNOs and unlocked mobile phones are linked to their subscription to MVNOs' low-cost plans with unlocked mobile phones on online channels. These streams lead to a big change in the market competition that MNO(Mobile Network Operator)s' market shares are expected to decrease and MVNOs' shares will be increased by two times, in the near future. Therefore, MNOs need to change their distribution strategies from offline to online channels and try to resolve the stereotype, "mobile tariffs are expensive," by enhancing their service values. Finally, as consumers prefer one-stop service in the same channel regardless of the distribution channel, policies should focus on the consumers' needs for convenience rather than on the channel separation for perfectly unlocked mobile phones.

• 경영과정보연구
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• 제11권
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• pp.45-69
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• 2002

One of important technology that must improve compulsorily on information-oriented society stores, search and transmit cultural contents data of great quantity in heterogeneous environment. SAN appeared by solution to resolve the problem such as integration management of heterogeneous system data, effective practical use of storage, data transmission limit is happened from here. SAN is system that manage and shares data of large quantity efficiently attaching directly to high speed network such as Fiber Channel that storage system has been attached to server individually SAN became more complicated than existent storage environment although offer much advantage such as decrease of storage expense and flexibility of system configuration. This study argues management way could consider in such environment that understand complexity and component of networked storage system.

• Industrial Engineering and Management Systems
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• 제15권4호
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• pp.324-334
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• 2016

Manufacturers and retailers are interested in how prices, promotions, discounts and other marketing variables can influence the sales and shares of the products that they produce or sell. Therefore, many models have been developed to predict the brand share. Since the customer choice models are usually used to predict the market share, here we use hybrid model of Probabilistic Neural Network and Artificial Bee colony Algorithm (PNN-ABC) that we have introduced to model consumer choice to predict brand share. The evaluation process is carried out using the same data set that we have used for modeling individual consumer choices in a retail coffee market. Then, to show good performance of this model we compare it with Artificial Neural Network with one hidden layer, Artificial Neural Network with two hidden layer, Artificial Neural Network trained with genetic algorithms (ANN-GA), and Probabilistic Neural Network. The evaluated results show that the offered model is outperforms better than other previous models, so it can be use as an effective tool for modeling consumer choice and predicting market share.

• 한국항만경제학회지
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• 제33권2호
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• pp.1-18
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• 2017

본 연구는 세계 최대 선사인 머스크의 글로벌 해상운송에 대하여 전 세계 102개 국가에 위치한 281개 항만을 통해 총 6,318개 경로에 대한 네트워크를 구성하고, 사회네트워크분석을 이용해 항만 및 국가별 특성을 분석했다. 중국 정부는 적극적인 항만 개발과 동시에 세계 거점항만과의 협력 확대를 추진하고 있으며, 일대일로 사업을 통해 해상운송에서 중국이 차지하는 비중과 영향력을 확대하고 있다. 중국의 항만 개발은 수출입 및 원자재 수급에 대한 안정적이고 독립적 물류 네트워크 구축의 의미를 포함하고 있으며, 해상 경로개발은 개별항만의 경쟁력 뿐 아니라 세계 해운시장에서 가장 큰 비중 및 영향력을 갖고 있는 미국 등 강대국과 이를 둘러싸고 있는 주요 국가의 관계구조와도 매우 밀접한 연관성을 갖고 있다. 이러한 관점에서 해상운송에 관한 연구는 개별항만과 함께 국가별 특성에 대한 분석이 병행되어야할 필요가 있다. 본 연구는 항만들 간의 관계적 측면에서 특징을 파악했고, 이를 국가 단위로 적용했으며, 중국과 미국, 한국의 개별 네트워크를 비교하여 중국 해상경로의 특징과 연구에 대한 시사점을 모색했다. 분석의 주요 결과로 머스크 해상네트워크에서 중국, 미국과 파나마, 말레이시아, 스페인 등의 비중이 높았으나, 중국 개별 네트워크에서는 중국, 한국과 대만, 베트남 등의 비중이 높게 나타났다. 또한, 부산항과 광양항 등 한국항만이 중국 네트워크에서 큰 경쟁력을 확보하고 있는 것을 확인할 수 있었다.