• 제목/요약/키워드: Fleet

검색결과 353건 처리시간 0.031초

Optimization of Earthwork Operation for Energy-saving using Discrete Event Simulation

  • Yi, Chang-Yong;Lee, Dong-Eun
    • 국제학술발표논문집
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    • The 6th International Conference on Construction Engineering and Project Management
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    • pp.537-539
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    • 2015
  • considerate operation is a major issue in the equipment-intensive operation. Identifying an optimal equipment combination is important to achieve low-energy operations. An Earthwork operation planning system, which measures the energy consumption of construction operations by taking into account construction equipments' engineering attributes (e.g., weight, capacity, energy consumption rate, etc.) and operation conditions (e.g., road condition, attributes of materials to be moved, geometric information, etc.), is essential to achieve the low-energy consumption. This study develops an automated computerized system which identifies an optimal earthmoving equipment fleet minimizing the energy consumption. The system imports a standard template of earthmoving operation model and compares numerous scenarios using alternative equipment allocation plans. It finds the fleet that minimizes the energy consumption by enumerating all cases using sensitivity analysis. A case study is presented to verify the validity of the system.

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INVESTIGATION OF EMISSION RATES OF AMMONIA, NITROUS OXIDE AND OTHER EXHAUST COMPOUNDS FROM ALTERNATIVE- FUEL VEHICLES USING A CHASSIS DYNAMOMETER

  • Huai, T.;Durbin, T.-D.;Rhee, S.-H.;Norbeck, J.-M.
    • International Journal of Automotive Technology
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    • 제4권1호
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    • pp.9-19
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    • 2003
  • Exhaust emissions were characterized for a fleet of 10 alternative-fuel vehicles (AFVx) including 5 compressed natural gas (CNG) vehicles. 3 liquefied petroleum gas (LPG) vehicles and 2 85% methanol/15% California Phase 2 gasoline (M85) vehicles. In addition to the standard regulated emissions and detailed speciation of organic gas compounds, Fourier Transform Infrared Spectroscopy (FTIR) was used to measure ammonia (NH$_3$) and nitrous oxide ($N_2$O) emissions. NH$_3$, emissions averaged 0.124 g/mi for the vehicle fleet with a range from <0.004 to 0.540 g/mi. $N_2$O emissions averaged 0.022 g/mi over the vehicle fleet with range from <0.002 to 0.077 g/mi. Modal emissions showed that both NH$_3$, and $N_2$O emissions began during catalyst light-off and continued as the catalyst reached its operating temperature. $N_2$O emissions primarily were formed during the initial stages of catalyst light-off. Detailed speciation measurements showed that the principal component of the fuel was also the primary organic gas species found in the exhaust. In particular, methane, propane and methanol composed on average 93%, 79%, and 75% of the organic gas emissions, respectively, for the CNG, LPG. and M85 vehicles.

Web-based Agricultural Machinery Rental Business Management System

  • Shin, Seung-Yeoub;Kang, Chang-Ho;Yu, Seok-Cheol;Kim, Byounggap;Kim, Yu-Yong;Kim, Jin-Oh;Lee, Kyou-Seung
    • Journal of Biosystems Engineering
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    • 제39권4호
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    • pp.267-273
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    • 2014
  • Purpose: This study was conducted to develop a web-based business management system to ensure the efficient operation and transparent management of government-subsidized agricultural machinery rental businesses. Methods: An MS_SQL2000 database management system (DBMS) solution was utilized in the system for high system compatibility and integrated management. This system was targeted to be compatible with Internet Explorer 6.0 or later and to ensure security and seamless web operations. The system administrator is able to manage a fleet of agricultural machinery, including various inventory codes, release and return, fleet registry, and business performance. Users (farmers) may search the database of rental machinery and reserve them. Results: With respect to rental reservations, the system administrator can manage the fleet by setting the rental status to Approved, Released, or Returned. Through the web, the administrator can also create a database that includes machinery specifications, features, and rental rates. In addition, business performance data can be analyzed using a diverse array of tools to streamline the rental business. Without having to go to the rental office, users can save time and money by searching for and renting agricultural machinery through the information available on the website, including availability, specifications, and rental fees. After deploying the system, the time required to analyze monthly performance and create reports was dramatically reduced from 20 days per person to one day per person. Conclusions: Since 2014, AMRB has been installed and is operating in agricultural machinery rental businesses in 31 cities and counties in South Korea. This study recommends continued expansion and dissemination of AMRB for the systematic and efficient management of agricultural machinery rental businesses.

변혁적 리더십이 조직몰입에 미치는 영향 - 해양경찰 함정승조원을 중심으로 - (The Effect of Transformational Leadership on Organizational Commitment - Focused on Fleet Crew of Korean Coast Guard -)

  • 신호식;윤대근
    • 해양환경안전학회지
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    • 제19권6호
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    • pp.621-628
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    • 2013
  • 본 연구는 근무여건의 열악함에도 불구하고 많은 역할을 담당하고 있는 해양경찰 함정의 조직유효성 향상을 위해 함장의 변혁적 리더십이 일반 함정승조원의 조직몰입에 어떠한 영향을 미치는지를 파악하기 위함이다. 연구를 위하여 변혁적 리더십이 조직 몰입에 미치는 다양한 선행연구를 조사하였고, 가설을 설정하여 변혁적 리더십이 조직몰입에 미치는 영향에 대하여 검증을 시도하였다. 변혁적 리더십이 조직몰입에 미치는 영향에 대해 검증하기 위하여 변혁적 리더십을 독립변수로, 조직몰입을 종속변수로, 그리고 다섯 가지 인구통계학적 특성을 사용하여 연구의 모형을 설정하였다. 연구의 결과 변혁적 리더십의 지적자극이 조직몰입의 조직목적(t=6.664, p=0.000)과 근속몰입(t=4.057, p=0.000)에서 해양경찰 함정 일반 승조원에게 가장 크게 영향을 미치는 것으로 보이며, 우리가 일반적으로 영향력이 클 것으로 생각하는 개별배려는 거의 영향을 주지 못하는 것으로 나타났다.

한국의 해양안보전략개념과 해군·해경 간 협력의 발전방향 (ROK's maritime security strategic concept and cooperation direction for the ROK Navy and Coast Guard)

  • 정삼만
    • Strategy21
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    • 통권42호
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    • pp.258-292
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    • 2017
  • This paper is designed to make a national strategic concept for the ROK's maritime security and to explore cooperation directions for the ROK Navy and Coast Guard in order to implement the newly-made maritime security strategic concept. As strategy is composed of three main categories(goals, ways, means), the goal of the ROK's maritime security strategy is 'Safe and Affluent Sea' and the way to realize the goal is the principle of cooperative leverage, and the means as tasks to implement the strategic concept are maritime safety, maritime security, and maritime stewardship. The concept of national fleet as used in the US is applied to promoting the cooperation between the ROK Navy and Coast Guard. Thus, under the newly-established maritime security strategic concept along with the national fleet model, followings are suggested as policy proposals for facilitating mutual cooperation between the ROK Navy and Coast Guard in dealing with not only traditional threats but also non-traditional treats at sea and from the sea as well. First, the ROK Navy and Coast Guard has been making efforts to enhance interoperability between the two sea services. However, the mutual cooperations have been focused mainly on areas on operational level rather than policy level. Therefore, the two sea services are recommended to enlarge exchanges and cooperation in policy areas. Second, there are still demands for further cooperation areas between the two sea services in command and communications. The interoperability in C2 between the two needs to be upgraded even to the areas of anti-terrorist activities ar sea, ASUW, ASW, maritime interdiction, etc. Third, mutual comparability between the two needs to be reflected in the maritime forces development to ensure the comparability in UNREP and other logistics areas. Fourth, the standardization of logistical materials and equipments is needed as a way of sustaining operational capability and logistical capacity for the ROK Navy and Coast Guard as well. Fifth, the ROK Navy and Coast Guard are recommended to participate more actively in international maritime cooperation activities such as PASSEX. Sixth, Complementary laws and regulations need further to be revised and to be newly made for collectively managing swiftly maritime accidents and natural disasters at sea.

해양경찰 함장의 변혁적 리더십이 승조원의 직무만족에 미치는 영향 (The Effect of Captain's Transformational Leadership on Job Satisfaction of KCG)

  • 신호식;윤대근
    • 해양환경안전학회지
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    • 제19권1호
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    • pp.23-30
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    • 2013
  • 우리나라 해양경찰 함정 승조원은 근무여건의 열악함에도 불구하고 많은 역할을 담당하고 있다. 본 연구는 해양경찰 함정의 조직유효성 향상을 위해 함장의 변혁적 리더십이 열악한 함정에서 근무하는 일반 승조원의 직무만족에 어떠한 영향을 미치는지를 파악하기 위함이다. 연구를 위하여 변혁적 리더십이 직무만족에 미치는 다양한 선행연구를 알아보았고, 가설을 설정하여 변혁적 리더십이 직무만족에 미치는 영향에 대하여 검증을 시도하였다. 검증을 위하여 변혁적 리더십을 독립변수로, 직무만족을 종속변수, 그리고 여섯 가지 요소의 인구통계학적 특성으로 연구의 모형을 설정하였다. 연구의 결과 변혁적 리더십의 지적자극이 해양경찰 함정 일반 승조원의 직무만족에 가장 크게 영향을 미치는 것으로 나타났으며, 개별배려는 영향을 주지 못하는 것으로 나타났다.

Design Conditions for Dolphin Berth by Tanker Fleet Analysis

  • Kang, Seok-Jin;Lee, Joong-Woo;Lee, Dong-Hyun;Kim, Hee-Jae
    • 한국항해항만학회지
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    • 제37권6호
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    • pp.647-653
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    • 2013
  • Energy acquisition due to the increase of oil price is one of the most important issues and policy for most countries. Various tankers have been built in the world and sent to the trade market. It is necessary to build the port infrastructure and facilities to give them proper services such as mooring, packing, storing, and transshipment, etc. However, the domestic guidelines or standards for design and construction for the dolphin berth among these facilities are out of date and do not meet the recent trend of tanker types. Therefore, it requires amendment on the guidelines or standards. In this study, a detailed analysis of the tanker fleet, covering 8,000 ships under operation and order to build, is made to estimate the proper PBL(Parallel Body Length) of each tanker class. After discussion and comparison on the dolphin berth design and construction codes of various countries, those are the leading countries of tanker operation and management, suggestion was made to amend on the design code. The referred codes are of Korea, Japan, UK, USA, and Canada. The analysis of tanker fleet shows the PBL as 0.45L under the normal ballast condition. In order to verify the deduced amendment on the domestic design code for dolphin berth, it was selected one of the domestic dolphin berth, located at the Yeosu oil terminal, which is almost completed to construct. The design criteria and expected tankers to moor in that terminal were analyzed and the appropriateness and countermeasure for deficiency were summarized.

해상운임에 영향을 미치는 주요 요인에 관한 연구 (Analysis of the Factors Influencing the Ocean Freight Rate)

  • 김명희
    • 한국항해항만학회지
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    • 제46권4호
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    • pp.385-391
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    • 2022
  • 본 연구에서는 수요 및 공급요인 외 해상운임에 영향을 주는 다양한 변수들을 발굴하고자 다변량 시계열분석을 수행해 보았다. 우선 종속변수에는 해상운임을 대용할 변수로 Shipping Intelligence에서 제공하고 있는 종합운임지수(ClarkSea Index), 벌크선운임(Clarksons Average Bulker Earnings), 탱커선운임(Clarksons Average Tanker Earnings) 등을 활용하였다. 선행연구를 통해 해상운임에 영향을 미칠 것으로 예상되는 세계 해상물동량(World Seaborne Trade), 세계 선복량(World Fleet), 유가(Brent Crude Oil Price), 세계 GDP성장률(GDP World), OECD 산업생산성장률(Industrial Production OECD), 금리(US$ LIBOR 6 Months), OECD 인플레이션(CPI OECD) 등을 독립변수로 설정하여 회귀분석을 수행해 보았다. 데이터는 시계열자료로 1992년부터 2020년까지의 연데이터로 구성하였다. 분석결과 종합운임지수에는 해상물동량과 유가가, 벌크선운임에는 해상물동량만이, 탱커선운임에는 해상물동량, 유가, 산업생산성장률, 인플레이션 등이 통계적으로 유의미한 영향을 미치는 것으로 나타났다.

Integrated Ship Cybersecurity Management as a Part of Maritime Safety and Security System

  • Melnyk, Oleksiy;Onyshchenko, Svitlana;Pavlova, Nataliia;Kravchenko, Oleksandra;Borovyk, Svitlana
    • International Journal of Computer Science & Network Security
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    • 제22권3호
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    • pp.135-140
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    • 2022
  • Scientific and technological progress is also fundamental to the evolving merchant shipping industry, both in terms of the size and speed of modern ships and in the level of their technical capabilities. While the freight performance of ships is growing, the number of crew on board is steadily decreasing, as more work processes are being automated through the implementation of information technologies, including ship management systems. Although there have been repeated appeals from international maritime organizations to focus on building effective maritime security defenses against cyber attacks, the problems have remained unresolved. Owners of shipping companies do not disclose information about cyberattack attempts or incidents against them due to fear of commercial losses or consequences, such as loss of image, customer and insurance claims, and investigations by independent international organizations and government agencies. Issues of cybersecurity of control systems in the world today have gained importance, due to the fact that existing threats concern not only the security of technical means and devices, but also issues of environmental safety and safety of life at sea. The article examines the implementation of cyber risk management in the shipping industry, providing recommendations for the safe ship operation and its systems in order to improve vulnerability to external threats related to cyberattacks, and to ensure the safety and security of such a technical object as a seagoing ship.