• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.12
• /
• pp.3815-3835
• /
• 2022

Density-based outlier detection is one of the hot issues in data mining. A point is determined as outlier on basis of the density of points near them. The existing density-based detection algorithms have high time complexity, in order to reduce the time complexity, a new outlier detection algorithm DODMD (Density-based Outlier Detection in Multidimensional Datasets) is proposed. Firstly, on the basis of ZH-tree, the concept of micro-cluster is introduced. Each leaf node is regarded as a micro-cluster, and the micro-cluster is calculated to achieve the purpose of batch filtering. In order to obtain n sets of approximate outliers quickly, a greedy method is used to calculate the boundary of LOF and mark the minimum value as LOF_min. Secondly, the outliers can filtered out by LOF_min, the real outliers are calculated, and then the result set is updated to make the boundary closer. Finally, the accuracy and efficiency of DODMD algorithm are verified on real dataset and synthetic dataset respectively.

• The Journal of shipping and logistics
• /
• v.34 no.4
• /
• pp.695-710
• /
• 2018

Following the collapse of Hanjin Shipping, building a strong maritime cluster is one of the policy measures for the re-construction of the Korean shipping and shipbuilding industries. Thus, the purpose of this study is to develop a policy alternative for building a maritime cluster. Using Porter's diamond models, we analyzed the Imabari maritime cluster of Japan, which is characterized by cooperation between key industries, such as shipping, shipbuilding, shipbuilding equipment, and finance. The Imabari Maritime Cluster is equipped with complete domestic demand conditions and related supporting industry conditions. Although the strengths of the production conditions include excellent family-based management and strong support from regional administration and banks which develops independency among cluster members, the weak points include the absense of robust port services and difficulty in recruiting young talent in small and medium-sized cities. We can confirm that the company's strategy is focused on stable management, rather than a short-term view.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2005.10a
• /
• pp.327-332
• /
• 2005

This paper aims to analysis for evaluation factor and success prediction of port innovative cluster. This paper is divided three factors such ac policy, source and operation. In addition, three factors are divided into the twelve detail factors. the weight of each factor is calculated by Kohonen Network. At the result, this paper places the priority on the source factor.

• Journal of Advanced Marine Engineering and Technology
• /
• v.41 no.2
• /
• pp.146-149
• /
• 2017

Si clusters generated during the plasma chemical vapor deposition (CVD) process have a great influence on the quality of the fabricated films. In particular, in hydrogenated amorphous silicon thin films (a-Si:H) used for thin film solar cells, Si clusters are mainly responsible for light-induced degradation. In this study, we investigated the amount of clusters incorporated into thin films using a quartz crystal microbalance (QCM) and specially designed cluster eliminating filters, and investigated the effect of the DC grid mesh in preventing cluster incorporation. Experimental results showed that as the applied voltage of the grid mesh, which is placed between the electrode and the QCM, decreased, the number of clusters incorporated into the film decreased. This is due to the electrostatic force from the grid mesh bias, and this method is expected to contribute to the fabrication of high-quality thin films by preventing Si cluster incorporation.

• Journal of Navigation and Port Research
• /
• v.43 no.2
• /
• pp.122-133
• /
• 2019

The maritime industry has emerged as a new growth engine. The municipalities that own the port are trying to add value through the maritime industry. Overseas port cities are also creating maritime industrial clusters to generate profits and strengthen competitiveness. Therefore, it is very important to understand the comparative status of the domestic maritime industry by region. Based on this analysis, it is possible to establish maritime industrial clusters and strategies for integration. This study analyzed the structure of the maritime industry located in Jeollanamdo province, the southwestern part of Korea. Through the analysis of existing literature, the maritime industry was reclassified into 5 major categories, 21 subcategories, and 84 subcategories. Based on the reclassified maritime industry, the analysis of the Jeollanamdo province maritime industry was based on applying the location quotient and the shift-share analysis. As a result of analyzing the geographical location of Jeollanamdo province, other industries showed the highest value of 2.790, followed by fisheries (2.227), shipbuilding industry (1.164) and marine tourism industry (0.554). The growth effect of the maritime industry in Jeollanamdo province was 35,323 people, and net growth effect excluding national growth effect was 11,945 people. In particular, the net growth effect of the shipbuilding industry was the highest at 11,320, followed by shipping logistics (6,371) and marine tourism (1,529). On the other hand, there was no net growth effect in fisheries. The results of this study can be used as basic data for the construction of the maritime industrial cluster for Jellanamdo province in the future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2010.04a
• /
• pp.191-192
• /
• 2010

This study classify the every meshes in Busan metropolitan city, based on the building need. The number of the effective meshes is 3289, all of those meshes are databased with simplified 7 building needs. The area for residential, commercial, educational needs occupy 92.4 % among all the areas. To simplify the multiple variables, principal component analysis is performed before the cluster analysis. Ans as the result 5 classification are obtained.

• Journal of Navigation and Port Research
• /
• v.40 no.2
• /
• pp.67-72
• /
• 2016

Vietnam's sea-port industry has experienced a significant development in recent years. Especially in Northern Vietnam, both the demand and supply of handling services for containerized cargoes have increased at a considerable rates. Accompany with such movement, the competition among container terminals in the area becomes fiercer. In this paper, Hierarchical Cluster Analysis is employed to classify all 11 container terminals in Northern Vietnam by collecting data concerning terminal competitiveness. After the classification, each group will be discussed in order to reveal more details about their competitive characteristics. The paper consists of five sections. Section 1 is the general introduction. Section 2 provides a general literature review about competitiveness and factors to evaluate competitiveness. Section 3 explains variables and methodology applied to do the analysis. Section 4 presents the results with linkage to the current condition. Section 5 summarizes the analysis results. It is shown that container terminals in Northern Vietnam should not only pay attention to their service qualities but also have to find out an appropriate mechanism to avoid unhealthy competition. The paper is expected to contribute a background for further researches in container terminals' competition in the region as well as hints for operators in planning and making decisions.

• Journal of Navigation and Port Research
• /
• v.31 no.10
• /
• pp.885-890
• /
• 2007

The purpose of this study is for providing a strategic plan of waterfront belt development at the coastal area of Busan city that might enhance the possibility on healthy use of spare time of the residents and demand of tourism, together with raising the potential and the value added effect of coastal space. This study is one of a series of studies for developing waterfront belt at Busan coastal area. In this study we suggest the new concepts of waterfront belt, waterfront cluster and waterfront greenway. And then we present a model of making waterfront belt through waterfront cluster, which is an aggregate of individual waterfront spaces, using waterfront greenway. After that we apply this model to Haeundae coastal area and test the applicability of the model.

• Journal of Navigation and Port Research
• /
• v.27 no.3
• /
• pp.315-320
• /
• 2003

Since the beginning of open-door policy, China has been making rapid annual growth with an average 10% economic development. And due to this rapid growth, cargo volumes via ports have been also rapidly increased, and accordingly, current China government has intensively invested in port development. Further, this development project is significantly big scale, compared with those project which Korea and Japan have. Thus, China is beginning to threaten Korean ports, especially Busan port which try to be a hub port in Northeast Asia. For this reason, it has been very important issue for Korea and Busan port to investigate or analyze Chinese ports based on empirical data. Especially, although various studies related to Shanghai and Hong Kong have been conducted, the competitiveness of overall Chinese major ports has been little studied. In this paper, we analyzed competitiveness level of eight Chinese ports with capabilities as container terminal, based on reliable sources. From data analysis, eight Chinese ports were classified into four groups according to competitiveness level. Rankings among four clusters based on competitiveness level are cluster(Hone Kong), cluster C(Shanghai), cluster A(Qingdao, Tianjin, and Yantian) and cluster D(Dalian, Shekou, and Xiamen).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.645-648
• /
• 2016

Cluster based wireless sensor networks have a characteristic that the cluster heads collect and aggregate data from sensor nodes and send data to sink node. In addition, between the adjacent sensor nodes deployed in the same area is characterized to the similar sensing data. In this paper, we propose a transmission algorithm for improving the energy efficiency using these two features in the cluster-based wireless sensor networks. Adjacent neighboring nodes form a pair and the two nodes sense data on shifts for one round. Additionally, two cluster heads are selected in a cluster and one of them alternately collects data from nodes and transmits data to the sink. This paper describes a transmission rounding method and a transmission frame for increasing energy efficiency and compared with conventional methods. We perform computer simulations to evaluate the performance of the proposed algorithm, and show better performance in terms of energy efficiency as compared with the LEACH algorithm.