• Title/Summary/Keyword: 항만대기

Search Result 202, Processing Time 0.025 seconds

How sun spot activity affects on positioning accuracy?: Case study of solar storm (태양 흑점활동이 측위오차에 미치는 영향: 태양폭풍 사례연구)

  • Yoo, Yun-Ja;Cho, Deuk-Jae;Park, Sang-Hyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2011.06a
    • /
    • pp.27-28
    • /
    • 2011
  • A solar flares have the 11-year cycle and release a large energy which may produce coronal mass ejections (CME). The NOAA (National Oceanic and Atmospheric Administration) predicted that the sun spot activity will be maximized in 2013-2014. A strong solar flare can cause the disturbance of global positioning system including various communication of TV, radio broadcasting. The actual solar storm in 1989 caused power outages in Canada during 9 hours and about 600 million people had experienced a blackout. Such a solar storm can shorten the GPS satellite's life span about 5 to 10 years which can be resulted in economic loss considering the amount of multi-billion won. This paper analyzed the recent solar storm of X-class occurred on 15th of February about 10:45 this year that was reached Korea (Bohyun observatory) on 18th of February about 10:30 (local time), and compared with the data of before and after a week. The proton data of 18th of February considered that the solar strom reached on earth showed a fluctuation compared to the data of before and after a week. The positioning results at Daejeon also showed higher positioning error compared to the data of before and after a week results.

  • PDF

How sun spot activity affects on positioning accuracy?: Case study of solar storm (태양 흑점활동이 측위오차에 미치는 영향: 태양폭풍 사례연구)

  • Yoo, Yun-Ja;Cho, Deuk-Jae;Park, Sang-Hyun
    • Journal of Navigation and Port Research
    • /
    • v.35 no.6
    • /
    • pp.477-482
    • /
    • 2011
  • Solar flares have the 11-year cycle and release a large energy which may produce coronal mass ejections (CME). The NOAA (National Oceanic and Atmospheric Administration) predicted that the sun spot activity will be maximized in 2013-2014. A strong solar flare can cause the disturbance of global positioning system including various communication of TV, radio broadcasting. The actual solar storm in 1989 caused power outages in Canada during 9 hours and about 600 million people had experienced a blackout. Such a solar storm can shorten the GPS satellite's life span about 5 to 10 years which can resulted in economic loss considering the amount of multi-billion won. This paper analyzed the influence of recent X-class solar storm occurred on 15th of February about 10:45 this year that was reached Korea (Bohyun observatory) on 18th of February about 10:30 (01:30 - UTC), and compared with the data before and after a week. The proton data of 18th of February considered that the solar storm reached on earth showed a fluctuation compared to the data before and after a week. The positioning results at Daejeon and Seoul of Korea also showed higher positioning error compared to the data before and after a week results.

Efficiency Analysis for Certified Integrated Logistics Warehousing firms Using DEA (DEA를 이용한 종합물류인증기업의 효율성 분석 : 물류창고업종을 중심으로)

  • Kang, Da-Yeon;Lee, Ki-Se
    • Journal of Navigation and Port Research
    • /
    • v.43 no.4
    • /
    • pp.256-263
    • /
    • 2019
  • The trade volume of Northeast Asian countries is increasing and with the advent of the 4th revolutionary era, minimizing the logistics costs of firm is becoming an important competitive factor. With respect to this, in 2006, the government introduced a certified Integrated logistics firm system to improve the competitiveness of local logistics firms and reduce the logistics costs of firms. They argued that the certified Integrated logistics firm system increased the reliability of logistics firms and increased the efficiency of the logistics industry. On the other side, they argue that the system puts a burden on firms and becomes a big business-oriented market consolidation. This study analyzed the efficiency of Warehousing firms using DEA model. The CCR, BBC efficiency and RTS (return to scale) of 15 Warehousing firms were evaluated. This study also suggested the Warehousing firms which can be benchmarked based on analyzed information.

A Study on Backup PNT Service for Korean Maritime Using NDGNSS (NDGNSS 인프라를 활용한 국내 해상 백업 PNT 서비스 연구)

  • Han, Young-Hoon;Lee, Sang-Heon;Park, Sul-Gee;Fang, Tae-Hyun;Park, Sang-Hyun
    • Journal of Navigation and Port Research
    • /
    • v.43 no.1
    • /
    • pp.42-48
    • /
    • 2019
  • The significance of PNT information in the fourth industrial revolution is viewed differently in relation to the past. Autonomous vehicles, autonomous vessels, smart grids, and national infrastructure require sustainable and reliable services in addition to their high precision service. Satellite navigation system, which is the most representative system for providing PNT information, receive signals from satellites outside the earth so signal reception power is low and signal structures for civilian use are open to the public. Therefore, it is vulnerable to intentional and unintentional interference or hacking. Satellite navigation systems, which can easily acquire high performance of PNT information at low cost, require alternatives due to its vulnerability to the hacking. This paper proposed R-Mode (Ranging Mode) technology that utilizes currently operated navigation and communication infrastructure in terms of Signals of OPportunity (SoOP). For this, the Nationwide Differential Global Navigation Satellite System (NDGNSS), which currently gives a service of Medium Frequency (MF) navigation signal broadcasting, was used to validate the feasibility of a backup infrastructure in domestic maritime areas through simulation analysis.

Importance Analysis of ESG Management Diagnosis Items for Small and Medium-sized Logistics Companies (중소·중견 물류기업 ESG 경영 이행 진단항목 중요도 분석)

  • Wonbae Park;Maowei Chen;Jayeon Lee;Kyongjun Yun
    • Journal of Korea Port Economic Association
    • /
    • v.40 no.2
    • /
    • pp.53-64
    • /
    • 2024
  • ESG management has garnered significant recognition as a crucial concern across all global industries. Within the logistics sector, there is a growing awareness of the importance of ESG management. However, active engagement in ESG practices remains predominantly confined to large corporations, leaving small and medium-sized logistics companies lagging in their comprehension and implementation of ESG principles. Previous studies have consistently underscored the necessity of establishing ESG management guidelines. Furthermore, there has been a call to determine the relative weights assigned to various ESG implementation evaluation criteria, taking into account the distinctive attributes of each category of logistics company. This study endeavors to ascertain the weightings of ESG implementation evaluation items for different types of logistics companies by employing the Analytic Hierarchy Process (AHP) methodology. The framework of evaluation is based on the evaluation items outlined in prior research, particularly focusing on ESG management guidelines tailored for small and medium-sized logistics companies. The findings of the analysis reveal distinct prioritizations across different sectors within the logistics industry. For maritime logistics companies, the environment emerges as the foremost concern, followed by society, information disclosure, and governance. Conversely, land transportation companies prioritize society, followed by governance, environment, and information disclosure. In the warehousing sector, environment takes precedence, followed by society, information disclosure, and governance. Comprehensive logistics firms, on the other hand, prioritize the environment, followed by information disclosure, society, and governance. Such guidelines are pertinent for regulatory bodies and industry stakeholders seeking to assess ESG practices within these enterprises. Moreover, this research contributes to the body of knowledge available to domestic small and medium-sized logistics companies, aiding them in effectively navigating and implementing ESG management principles.

Basic Research for the Development of Collision Risk Model of Passing Vessels at an Anchorage (Safety Domain) (정박지 통항선박의 충돌위험 모델 개발을 위한 기초연구 - 정박지 통항선박의 안전 -)

  • Lee, Jin-Suk;Kwon, Yumin;Choi, Jung-Suk
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.1
    • /
    • pp.67-73
    • /
    • 2021
  • The purpose of this study is to obtain a safe area for a passing vessel between anchored vessels by developing a model to predict the collision risk, frequent collisions occur between the anchored vessel and the passing vessel through the anchorage. For this, this study selected the southern anchorage of Busan port, which is the largest harbor in Korea, as the target area and extracted and analyzed VTS (Vessel Traffic Service) data during the period in which anchored vessels were the most waited. The ratio of D/L for each bearing was obtained to determine the safe distance (D) passes based on the length (L) of the passing vessel between anchored vessels. Based on the average domain of the D/L ratio distribution, the percentage of anchored vessels within the scope of the pre-studied ship's domain was analyzed to obtain a domain reflecting the degree of risk of VTSOs. Further research will evaluate and analyze the collision risk of a passing vessel using Domain-watch, the minimum safe distance between anchored vessels, and the safe domain of a passing vessel through anchorage, to develop a model for VTS to manage anchorages more efficiently and safely.

Estimation of Atmospheric Pollutant Emissions from Vessels in Major Harbor Cities in Korea and related Social Cost (국내 주요 항구도시의 선박 배기가스 배출량 산정 및 사회적 비용 추정)

  • Choi, Jung-kil;Kim, Myung-won;Lee, Hyo-jin;Kang, Tea-soon;Lee, Kang-wung
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.7
    • /
    • pp.905-917
    • /
    • 2021
  • Atmospheric pollutant emissions, mainly exhaust gas emissions from vessels, and the resultant social costs of pollution in the Korean harbor cities of Incheon, Mokpo, Gwangyang, Busan and Ulsan, are examined in this study, and the need for an emissions reduction plan is highlighted. Busan had several vessels entering its port, while Mokpo had few vessels, yet the vessels emission contribution was high in both the cities. Ulsan had world-class heavy-chemical industries, Gwangyang had steel mills and Incheon had a manufacturing industry and more vessels entering its port than Mokpo, yet the emission contribution was low in these cities. By calculating exhaust gas emissions from the vessels, it was found that CO2 was the highest, followed by NOx and SOx. By vessel type, Busan, Ulsan, and Incheon had more oil tank vessels, Gwangyang had more cargo vessels, and Mokpo had more ferries. As a result of social cost, Busan paid the highest, while the highest emission was PM. The use of low-sulfur oil can directly reduce PM and, SOx emissions and indirectly reduce NOx emissions. However, in order to reduce high CO2 emissions, only low-sulfur oil will not help. Therefore, the study suggested the need for reduction plan that use of fossil fuels, by using alternative maritime power (AMP).

Characteristics of Vacuum Consolidation by Comparing with Surcharge Loading Consolidation (성토재하공법과 비교한 진공압밀공법의 압밀특성 분석)

  • Sim, Dong-Hyun;Lee, Jae-Hwan;Jeong, Sang-Seom
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.5C
    • /
    • pp.201-208
    • /
    • 2010
  • In this study, the ground settlement was investigated by using monitoring data of the test sites where vacuum consolidation method and surcharge method were applied for improving deep soft soil. The monitoring data are chosen in ${\bigcirc}{\bigcirc}$ area port construction site reclaimed with very soft dredged clay. These data are analyzed to compare the consolidation characteristics between the different loading methods for soil improvement. Through analysis of the loading time, it is shown that the ground settlement reaches its allowable value under vacuum consolidation loading by about 45% faster than that of the surcharge loading consolidation. This could be explained that vacuum consolidation method makes the isotropic consolidation condition so that the time for reaching a certain final preloading without soil failure can be shortened.

Air Quality Monitoring in Residential Areas near Ports and Industrial Complexes in Busan (부산시 항만 및 산단 인근 주거지역 대기질 모니터링과 분기별 특성확인)

  • Hyunji Ju;Seungho Lee;Minjung Kim;Gabeen Lee;Young-Seoub Hong
    • Journal of Environmental Health Sciences
    • /
    • v.50 no.3
    • /
    • pp.181-190
    • /
    • 2024
  • Background: Air pollutants have been reported to have harmful effects on human health. Busan is a vulnerable area in terms of air quality due to the installation of various industrial complexes, particularly the port industry. However there is limited research data on the ambient air quality of residential areas near ports and industrial complexes. Objectives: This study aimed to determine the quarterly levels of air pollutants near industrial complexes and ports and to identify trends and characteristics of air pollutant exceedances. Methods: Air measurements were conducted quarterly. The measured air pollutants included O3, SO2, CO, NO2, PM10, and PM2.5. PM10 and PM2.5 were measured using BAM-1020 equipment, while O3, SO2, CO, and NO2 were measured using AP-370 Series equipment. The quarterly concentration levels of air pollutants were determined, and the influence of precipitation and commuting hours on fine particulate matter was examined. Analysis of variance (ANOVA) was conducted to determine if there was significance between the concentrations of fine particulate matter during commuting hours and non-commuting hours. Results: The concentrations of air pollutants were generally higher in the first and second quarters. Furthermore, the concentrations of PM10 and PM2.5 tended to decrease continuously following consecutive rainfall, with concentrations at the end of rainfall periods lower than those observed at the beginning. The frequency of exceeding average concentrations of PM10 and PM2.5 was higher on weekdays. Moreover, the average concentrations of PM10 and PM2.5 during weekday commuting hours were higher compared to non-commuting hours. Conclusions: The concentrations of air pollutants in the survey area were found to be higher than the overall average in Busan. Based on this study, continuous air quality monitoring is necessary for residential areas near industrial complexes and ports. For further research, health biomonitoring of residents in these areas should be conducted to assess their exposure levels.

A study on Perception and Response Strategy of Korean Ship Owners on Global Sulphur Cap 2020 (황산화물(SOx) 배출 저감 규제에 대한 국적선사의 인식과 대응 전략에 관한 연구)

  • Lee, Choong-Ho;Kim, Hyun-Jung;Park, keun-Sik
    • Journal of Korea Port Economic Association
    • /
    • v.34 no.4
    • /
    • pp.141-160
    • /
    • 2018
  • In this paper, to analyze the perception and response strategy of Korean ship owners on Global Sulphur Cap 2020, examined the IMO environmental regulation status focusing on MARPOL Annex VI regulation about air pollution prevention, technological measures to reduce SOx emission, shipping industry and management status of Korean ship owners. First of all, the questionnaire was conducted for Korean ship owners after selecting the evaluation factors. The purpose of this study was to investigate the difference of the perception and response strategy of Korean ship owners by corporation size and main vessel type using frequency and cross analysis. It is confirmed that various researches on SOx emission reduction have been carried out from various points of view at home and abroad. In this study, existing studies related to technical factors for regulatory response and economics analysis were examined and evaluation factors were selected. As a result of analysis, it is found that large-sized shipping companies are more prepared for regulatory response than small and medium-sized bulk carrier owners. There were similar perception and the direction of response strategy about the impacts by corporation size and main vessel type. In about two years to be implemented in 2020, It is necessary to find an appropriate response strategy based on the support policy of the government and related organizations and the systematic analysis of the ship owners. Through this study, although the difference between the perception and response strategy of the ship owners by corporation size and main vessel type was understood, it was found that there were limitations on specific response strategy and corporate data collection. In future research, we should overcome the limitations of this study and conduct an in-depth study.