• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.80-85
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• 2015

In this paper, we present, an indstrial RFID layered microstrip patch antenna is designed using an inset feed method in order to improve recognition rates in a long distance as tags are attached to metal object by improving a problem of feeding power in fabricating metal tags and reducing effects of metallic object. The inset feed shows a distinctive characteristic that has no separation between emitters and feed lines differing from a structure with the conventional inductive coupling feed. This structure makes possible to produce a type that presents a low antenna height and enables impedance coupling for tag chips. Although it shows a difficulty in the impedance coupling due to increases in the parasite capacitance between a ground plane and an emitter in an antenna according to decreases in the height of a tag antenna, it may become a merit in designing the tag antenna because the antenna impedance can be determined as an inductive manner if a shorted structure is used for feeding power. Therefore, in this paper the microstrip patch antenna is designed as a modified type and applies the inset feed in order to reduce effects of metallic objects where the antenna is be attached. Also, the antenna uses a multi-layer structure that includes a metal plate between radiator and ground instead of using a single layer.

• The Journal of Bigdata
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• v.4 no.2
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• pp.159-173
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• 2019

Last-Mile delivery optimization plays a key role in the urban supply chain operation, which is the most expensive and time-consuming and most complicated part of the whole delivery process. The urban consolidation center (UCC) is regarded as a significant asset for supporting customer demand in the last-mile delivery service. It is the key benefit of UCC to improve the load balance of vehicles and to reduce the total traveling distance by finding the better route with the well-organized multi-leg vehicle journey in the urban area. This paper presents the model using multiple scenario analysis integrated with mathematical optimization techniques using Geographic Information System (GIS). The model aims to find the best solution for the distribution network consisted of DC and UCC, which is applied to the case of Ulaanbaatar Mongolia. The proposed methodology integrates two sub-models, location-allocation model and vehicle routing problem. The multiple scenarios devised by selecting locations of UCC are compared considering the general performance and delivery patterns together. It has been adopted to make better decisions the quantitative metrics such as the economic value of capital cost, operating cost, and balance of using available resources. The result of this research may help the manager or public authorities who should design the distribution network for the last mile delivery service optimization using UCC within the urban area.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.220-226
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• 2013

Recently, with the rapid development of factory automation and logistics system, a few workers were able to manage the broad workplace such as large vessels and warehouse. To estimate the exact location of these workers in the conventional wireless indoor localization systems, three or more fixed nodes are generally used to recognize the location of a mobile node consisting of a single node. However, these methods are inefficient in terms of node deployment because the broad workplace requires a lot of fixed nodes compared to workers(mobile nodes). Therefore, to efficiently deploy fixed nodes in these environments that need a few workers, this paper presents a novel estimation algorithm which can reduce the number of fixed nodes by efficiently recognizing the relative coordinates of two fixed nodes through a mobile node composed of three nodes. Also, to minimize the distance errors between mobile node and fixed node, rounding estimation(RE) technique is proposed. Experimental results show that the error rate of localization is improved, by using proposed RE technique, 90.9% compared to conventional trilateration in the free space. In addition, despite the number of fixed nodes can be reduced by up to 50% in the indoor free space, the proposed estimation algorithm recognizes precise location which has average error of 0.15m.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.338-343
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• 2022

As the revitalization of the global maritime industry continues, the number of foreign ships navigating the maritime territories of maritime neighboring countries has rapidly increased. However, large-scale marine accidents have occurred, caused by the insufficient establishment of a system for management and operation relative to vessels' safety-condition. To address that, the IMO has granted the right to exercise port state control, especially for foreign vessels, to countries with jurisdiction over maritime territories with strengthening regulations and guidelines. In particular, the Republic of Korea, as a member of the TOKYO MOU, is conducting PSC, but as of 2020, the proportion of foreign ships was three times higher than that of national ships that called in domestic ports. However, the inspection rate was low at 9% which has not met the recommended level by the TOKYO MOU. Thus, this study conducted an IPA analysis as well as content analysis, by collecting the practical opinions and views of PSCO through objective questionnaires and written expert interviews, for improving the efficiency and effectiveness of domestic PSC. As a result, it was derived that the importance and performance related to human factors such as life on board, working environment, and response to safety accidents should be improved in to raise the quality of PSC inspection. Additionally, the work environment and performance of PSC in domestic ports for foreign vessels could be improved, if multifaceted support bases are established, for administrative unification of related tests for PSC, recruitment of PSCO, activation of the defection-reporting system, reorganization of the PSC execution group, etc.

• Journal of Internet of Things and Convergence
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• v.10 no.1
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• pp.39-45
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• 2024

Container volume is a very important factor in accurate evaluation of port performance, and accurate prediction of effective port development and operation strategies is essential. However, it is difficult to improve the accuracy of container volume prediction due to rapid changes in the marine industry. To solve this problem, it is necessary to analyze the impact on port performance using the Internet of Things (IoT) and apply it to improve the competitiveness and efficiency of Busan Port. Therefore, this study aims to develop a prediction model for predicting the future container volume of Busan Port, and through this, focuses on improving port productivity and making improved decision-making by port management agencies. In order to predict port container volume, this study introduced the Extreme Gradient Boosting (XGBoost) technique of a machine learning model. XGBoost stands out of its higher accuracy, faster learning and prediction than other algorithms, preventing overfitting, along with providing Feature Importance. Especially, XGBoost can be used directly for regression predictive modelling, which helps improve the accuracy of the volume prediction model presented in previous studies. Through this, this study can accurately and reliably predict container volume by the proposed method with a 4.3% MAPE (Mean absolute percentage error) value, highlighting its high forecasting accuracy. It is believed that the accuracy of Busan container volume can be increased through the methodology presented in this study.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.710-715
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• 2023

Urbanization brings many challenges such as traffic, housing, and environment. To solve these problems, researchers are working on new transportation systems like urban air mobility (UAM). UAM aircraft should fly safely without burdening the existing air traffic system in the early stage of low-density operation. The airspace should also be managed and operated efficiently. Therefore it is important to make urban air traffic predictable by using corridors and collecting data on low-density operations in the early stage. For this purpose various simulations are needed before operation to create scenarios that estimate potential collisions between UAM aircraft and to evaluate the risks of aircraft spacing, loss of separation (LoS), and near mid air collision (NMAC). This paper focuses on identifying the requirements and considerations for setting separation standards for urban air traffic based on the results of studies.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.509-515
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• 2006

As international trade has been increased, the competition of major ports is getting hard. The objective of this competition is that to get more cargoes, so port managements and operators are struggling to obtain cargoes. In addition the competition structure has classified several forms bemuse of specialization, integration and subdivision of port players. In this paper, therefore, we analyze the change of competition structure by port players' development characteristics. In the result of this study, competition structure is divided into five groups as among nations, among ports, among container terminal operation companies, among global container terminal operation companies and among container terminal operation companies operated by shipping companies. And they have showed not only competition but also co-operation partly in order to get strategic position.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.32-32
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• 2016

정부는 1999년 제정된 연안관리법에 따라 2000년부터 시행 중인 '연안정비계획' 등을 통하여 연안 침식 대응사업을 지원하고 있다. 그러나 연안의 개발은 지속적으로 일어나고 있으며 그 중 동해항 3단계 북방파제 축조공사가 내년 3월 중으로 착공할 것으로 예상된다. 동해항 3단계 개발사업은 동해항을 환동해권 물류 중심 거점 항만으로 육성하기 위해, 오는 2020년까지 대규모 항만개발과 방파제 등이 축조될 예정이다. 이에 따라 본 연구에서는 동해항 3단계 개발사업의 추진에 따른 인근해변의 해안침식 저감대책 방안으로 해안선 및 수심 변화를 예측하고자 한다. 동해항 인근의 추암 해수욕장부터 삼척 해수욕장까지 대상지역 N-line 모델 적용 및 Case분석을 실시한다. 해안선 변화는 Polar coordinate에서 개발된 One-line 모델에 회절 효과를 반영하고 해빈 경사와 쇄파고에 따라 횡단 방향으로 발생하는 표사로 인한 추가적인 해안선 변화 효과를 반영하여 입사파고 변동에 따른 단기적인 해안선 변화의 변동 폭을 제공한다. 연평균 입사 파고에 따라 형성되는 연안방향 표사로부터 해안선이 변동하며 이 해안선을 기준으로 연평균 파고에 따른 전진 폭과 최고 파고에 따른 침식 폭을 제시한다. 동해항 개발 전 변화 예측 모델링과 동해항 개발 후 변화 예측 모델링을 통해 개발에 따른 장래 해안선의 변화 예측 모델링 결과 분석 및 검토를 실시, 동해항 인근 지역에 적합한 해안선 유지관리 방법 결정 및 제안을 하는데 도움을 줄 것이라 기대된다.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.219-223
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• 2014

In line with the advanced wireless communication technology, M2M (Machine-to-Machine) communication has drawn attention in industry. M2M communication features are installed and operated in the fields where human accessibility is highly limited such as disaster, safety, construction, health and welfare, climate, environment, logistics, culture, defense, medical care, agriculture and stockbreeding. In M2M communication, machine replaces people for automatic communication and countermeasures as part of unmanned information management and machine operation. Wireless M2M inter-device communication is likely to be exposed to intruders' attacks, causing security issues, which warrants proper security measures including cross-authentication of whether devices are legitimate. Therefore, research on multiple security protocols has been conducted. The present study applied SessionKey, HashFunction and Nonce to address security issues in M2M communication and proposed a safe protocol with reinforced security properties. Notably, unlike most previous studies arguing for the security of certain protocols based on mathematical theorem proving, the present study used the formal verification with Casper/FDR to prove the safety of the proposed protocol. In short, the proposed protocol was found to be safe and secure.

• Convergence Security Journal
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• v.14 no.4
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• pp.95-100
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• 2014

The trend of business work that is related to supply chain changed into e-business using the electronic document However, the small and medium enterprise organizations still use huge volume of paper document, especially in private sector. Recently, the need for eco-friendly and low cost logistics becomes increasing. For this, it has expanded to exchange or to use e-document rather than the paper or manual processing in supply chain business. Therefore, this paper proposed the electronic access system for supply chain by business process modeling. If it is using the proposed system, it can be saving the exchanged or the scanned document to system, and user can utilize that document on just accessing system whenever they need the document. We believe it might reduce the burden of each organization because they don't need to save large volume data to their system or place. Furthermore, the benefits will effect across the national as well as global.