• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.33.2-42
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• 2000

This study probes the necessity of establishing a logistic free zone in Port of Busan. It considers the economic effects of establishing the logistic free zone of Busan Port, and suggests policy prescriptions for introducing the free zone system and improving the logistics functions of Busan Port. Using input-output table data, the regression analysis was able to provide a quantitative prediction on effects of making the Busan Port a tariff-free zone. Influence for the regional economy due to the enforcement of the free zone system this research found that a strong positive effects should be expected on the Busan regional economy once the logistic free zone would be set up at the Port of Busan. The positive economic effects on Busan regional industries might be further strengthened if the value-added logistics function of Busan Port could be supplemented by linking to the hinterland of Busan Port.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.83-90
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• 1999

Centralized safety stock in a periodic replenishment system which consists of one central warehouse and m regional warehouse can reduce backorders allocation the centralized safety stocks to regional warehouse in a certain instant of each replenishment cycle. If the central warehouse can not monitoring inventories in the regional warehouse, then we have to predetermine the instant of allocation according to demand distribution and this instant must be same for all different replenishment cycle. However, transition of inventory level in each cycle need not to be same, and therefore different instant of the allocation may results reduced shortage compare to the predetermined instant of allocation. In this research, we construct a dynamic model based on the assumption of monitoring inventories inventories in the regional warehouse everyday, and develop an algorithm minimize shortage in each replenishment cycle using dynamic programming approach.

• 한국항공운항학회지
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• 제11권2호
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• pp.7-21
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• 2003

The objective of this study is to evaluate a feasibility of navigation systems appropriate for the Asia-Pacific region. As an independent navigation system, four, five, and six geosynchronous satellite constellations are simulated to provide a navigation system for the region and dilutions of precision of the proposed systems are analyzed and compared.

• 한국위성정보통신학회논문지
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• 제7권3호
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• pp.121-129
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• 2012

현재까지 한국의 자국 우주기반 지역위성항법시스템은 개발되거나 구체적으로 계획되어 있지 않다. 그러나 국내 지역위성항법시스템의 개발요구는 여러 가지 수요 외적인 요인으로도 결정될 수 있으며, 커져가는 국내의 위성항법시스템에 대한 의존도는 결국 자국 위성항법시스템의 개발 및 보유를 궁극적으로 요구할 것으로 사료된다. 한반도 주변을 활용서비스 대상으로 설정하는 지역위성보강항법 시스템 또는 지역위성항법 시스템 둘 다 설계 궤도나 시스템 설계개념은 그리 선택의 여지가 많지 않다. 또한 우주감시 분야는 국내에서 막 태동하는 연구개발 분야이며 미래 한국형항법위성시스템을 보유했을 때 항법시스템의 유지와 항법메세지의 생성을 위해서 반드시 필요한 기술 분야이기도 하다. 이 연구에서는 한국보다 먼저 구축이 기대되는 일본의 준천정위성시스템의 한국 지역 활용도를 분석하고, 유사한 시스템을 한국에 적용했을 때의 활용도 분석, 독자적인 위성항법시스템을 도입했을 때 사용가능한 궤도 얼개 분석, 그리고 이차적인 추적시스템으로서 지상기반 광학추적시스템의 가관측성 등을 분석하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.361-365
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• 2006

High ionospheric spatial gradient during ionospheric storm is most concern for the landing approach with GNSS (Global Navigation Satellite System) augmentation systems. In case of the GBAS (Ground-Based Augmentation System), the ionospheric storm causes sudden increase of the ionospheric delay difference between a ground facility and a user (aircraft), and the aircraft position error increases significantly. Since the ionosphere behavior and the storm effect depend on geographic location, understanding the ionospheric storm behavior at specific regional area is crucial for the GNSS augmentation system development and implementation. Korea Aerospace Research Institute and collaborating universities have been developing an integrity monitoring test bed for GBAS research and for future regional augmentation system development. By using the dense GPS (Global Positioning System) networks in Korea, a regional ionosphere map is constructed for finding detailed aspect of the ionosphere variation. Preliminary analysis on the ionospheric gradient variation during a recent storm period is performed and the results are discussed.

• 한국항행학회논문지
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• 제28권1호
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• pp.1-14
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• 2024

위치, 항법 및 시각정보 서비스를 제공하는 위성항법시스템은 위성시스템, 지상시스템, 사용자시스템으로 구성된다. 지상시스템의 구성요소인 감시국은 위성항법시스템의 서비스 제공 및 고장 검출을 위해, 위성항법 신호를 연속적으로 수집하고 위성의 SIS (signal-in-space) 고장과 수신기 및 다중반사파를 포함한 Local 고장과 같은 신호 이상을 검출하여 수신한 데이터와 검출 결과를 중앙처리국으로 전송하는 역할을 한다. 본 논문에서는 기존 위성항법시스템 감시국의 수신한 위성 신호에 대한 품질 판단 및 고장 검출을 위한 주요 모니터와 측정치 전처리 과정을 소개하고, 이를 활용하여 차세대 지역 위성항법시스템 (RNSS; regional navigation satellite system) 감시국의 구성요소와 아키텍처 및 알고리즘 개발 방안을 제시하였다.

• 한국항만학회지
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• 제14권4호
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• pp.387-394
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• 2000

If a system such a port and regional economy has a large boundary and complexity, the system's substance is considered as a black box, forecast accuracy will be very low. Futhermore various components in a port and regional economy exert significant influence on each other. To copy with these problem the from of structure models were introduced by using SD model. This study has the issue of simplifying the regional economic effects of the port as contributing to raising the regional income. The regional economic effects of port have various indirect ones except for this. So, SD(System Dynamics) was presented, and applied to simulate port and regional economy.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 춘계학술대회
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• pp.473-480
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• 2010

항로표지 당국의 핵심 목표는 교통량과 위험도에 적합한 항로표지를 종합적으로 융합하여 제공함으로써 해상교통 안전 및 해양환경보호에 필요한 요건을 충족시키는데 있다. e-Navigation은 해상 항법 및 통신 신뢰도 개선에 필요한 현대화되고 검증된 장비를 통해 안전하게 항해하고자 하는 항해자의 필요에 의해 개발되었다, 위치결정에는 GNSS가 폭넓게 이용되고 있지만, 안전하고 완전하며 환경적으로 깨끗한 항해를 위해서는 기존 항로표지 계속해서 이용할 수 있도록 유지 및 진화시킬 필요가 있다. 본 논문에서는 기존 항로표지의 최신 현황을 비롯하여 기존 항로표지에 대한 기술적 관점과 항해자의 관점으로 e-Navigation 환경에서 전통적 항로표지의 역할을 검토하고, 진화 및 미래상을 제시하고자 한다.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.333-339
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• 2022

The satellite navigation system was developed for the purpose of calculating the location of local users, starting with the Global Positioning System (GPS) in the 1980s. Advanced countries in the space industry are operating Global Navigation Satellite System (GNSS) that covers the entire earth, such as GPS, GLONASS, Galileo, and BeiDou, by establishing satellite navigation systems for each country. Regional Navigation Satellite Systems (RNSS) such as QZSS and NavIC are also in operation. In the early 2010s, only GPS and GLONASS could calculate location using a single system for location determination. After 2016, the EU and China also completed the establishment of GNSS such as Galileo and BeiDou. As a result, satellite navigation users can benefit from improved availability of GNSS. In addition, before Galileo and BeiDou's Full Operational Capability (FOC) declaration, they used combined navigation algorithms to calculate the user's location by adding another satellite navigation system to the GPS satellites. Recently, it may be possible to calculate a user's location for each navigation system using the resources of a single system. In this paper, we evaluated the performance of single system navigation and combined navigation solutions of GPS, GLONASS, Galileo, BeiDou and QZSS individual navigation systems using high-performance GNSS receivers.

• 한국항해항만학회지
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• 제36권7호
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• pp.553-559
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• 2012

It is extremely important to predict the logistics requirements in a scientific and rational way. However, in recent years, the improvement effect on the prediction method is not very significant and the traditional statistical prediction method has the defects of low precision and poor interpretation of the prediction model, which cannot only guarantee the generalization ability of the prediction model theoretically, but also cannot explain the models effectively. Therefore, in combination with the theories of the spatial economics, industrial economics, and neo-classical economics, taking city of Erdos as the research object, the study identifies the leading industry that can produce a large number of cargoes, and further predicts the static logistics generation of the Erdos and hinterlands. By integrating various factors that can affect the regional logistics requirements, this study established a logistics requirements potential model from the aspect of spatial economic principles, and expanded the way of logistics requirements prediction from the single statistical principles to an new area of special and regional economics.