• Title/Summary/Keyword: Efficiency of operations

Search Result 1,344, Processing Time 0.024 seconds

Study on the Freight Forwarding System of Advanced Shipping Country - A Case of United States of America System - (선진 해운국의 Freight Forwarding System에 관한 연구 - 미국제도를 중심으로 -)

  • Kim, Se-Won
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.20 no.3
    • /
    • pp.416-428
    • /
    • 2008
  • In the end of 2007, Korea Government promulgated the Rule of 'Basic Act of Logistics Policy' for improving international logistics forwarding business. The goals of these rules are to achieve the development of our nation's economics for providing the security and efficiency of logistics system and enforced competition of logistics enterprises. This is established the basic principles of the legal basis for expanding into the Logistics Hub Center of North-east Asia. However In May 1999 new licensing requirements for ocean freight forwarders and NVOCCs operating in the USA were established by the US Federal Maritime Commission(FMC). Due to these regulations, each ocean transportation service provider in the USA acting as ocean freight forwarder, NVOCCs, or NVOCC agent must obtain a license to operate as Ocean Transportation Intermediary(OTI) before it begins operations. Only licensed OTIs may act as US transportation agents or receiving agents of other NVOCCs, on both US exports and imports. In this context, I think this study will be contributes for the development of korean freight forwarding system by analysis and comparing with between the Rule of the Basic Act of Logistics Policy of Korea and OTI freight forwarder & NVOCCs of USA.

Need for internal control of public sector

  • Mohammadi, Shaban
    • The Journal of Economics, Marketing and Management
    • /
    • v.3 no.1
    • /
    • pp.33-39
    • /
    • 2015
  • Managers are always trying to be the best internal controls in their organizations copper approximate because they know that be effective internal control over previous systems, to fulfill the mission of the organization and minimize unexpected events will be extremely difficult. On the other hand, the existence of internal controls to increase efficiency, reduce head loss, assets and achieving a reasonable assurance of the reliability of financial statements and compliance with laws and regulations will be. Internal control, not an event, but a series of operations and activities on the basis of output. Internal controls help to achieve the goal of minimizing the problems of implementing appropriate internal controls. Internal control is an integral component of corporate governance that will provide reasonable assurance of achieving the organization's objectives. preventing, detecting errors and fraud goes to work. Responsibility for the prevention and detection of fraud and error in the public sector is the responsibility of managers. Managers of internal control and consistently applying appropriate accounting systems, this responsibility will play (Lin et al., 2011). Since the public sector organizations differ from each other, thus establishing internal controls cant be the same for all organizations and agencies of the public sector. Establish specific controls on each system to factors such as size, type of operation and organizational goals that the system is designed, it depends. On the other hand, rapid advances in information technology, the need to update internal control guidelines in relation to Create a new computer system so as to ensure that the activities of managers and effective control Should be updated if necessary.

Characteristics of Synchronous and Asynchronous modes of fluctuations in Francis turbine draft tube during load variation

  • Goyal, Rahul;Cervantes, Michel J.;Gandhi, Bhupendra K.
    • International Journal of Fluid Machinery and Systems
    • /
    • v.10 no.2
    • /
    • pp.164-175
    • /
    • 2017
  • Francis turbines are often operated over a wide load range due to high flexibility in electricity demand and penetration of other renewable energies. This has raised significant concerns about the existing designing criteria. Hydraulic turbines are not designed to withstand large dynamic pressure loadings on the stationary and rotating parts during such conditions. Previous investigations on transient operating conditions of turbine were mainly focused on the pressure fluctuations due to the rotor-stator interaction. This study characterizes the synchronous and asynchronous pressure and velocity fluctuations due to rotor-stator interaction and rotating vortex rope during load variation, i.e. best efficiency point to part load and vice versa. The measurements were performed on the Francis-99 test case. The repeatability of the measurements was estimated by providing similar movement to guide vanes twenty times for both load rejection and load acceptance operations. Synchronized two dimensional particle image velocimetry and pressure measurements were performed to investigate the dominant frequencies of fluctuations, vortex rope formation, and modes (rotating and plunging) of the rotating vortex rope. The time of appearance and disappearance of rotating and plunging modes of vortex rope was investigated simultaneously in the pressure and velocity data. The asynchronous mode was observed to dominate over the synchronous mode in both velocity and pressure measurements.

Testing for Speed-Independent Asynchronous Circuits Using the Self-Checking Property (자가검사특성을 이용한 속도독립 비동기회로의 테스팅)

  • 오은정;이정근;이동익;최호용
    • Proceedings of the IEEK Conference
    • /
    • 1999.11a
    • /
    • pp.384-387
    • /
    • 1999
  • In this paper, we have proposed a testing methodology for Speed-Independent asynchronous control circuits using the self-checking property where the circuit detects certain classes of faults during normal operation. To exploit self-checking properties of Speed-Independent circuits, the Proposed methodology generates tests from the specification of the target circuit which describes the behavior of the circuit. The generated tests are applied to a fault-free and a faulty circuit, and target faults can be detected by the comparison of the outputs of the both circuits. For the purpose of efficient comparison, reachability information of the both circuits in the form of BDD's is used and operations are conducted by BDD manipulations. The identification for undetectable faults in testing is also used to increase efficiency of the proposed methodology. The proposed identification uses only topological information of the target circuit and reachability information of the good circuit which was generated in the course of preprocess. Experimental results show that high fault coverage is obtained for synthesized Speed-Independent circuits and the use of the identification process decreases the number of tests and execution time.

  • PDF

Real-time geometry identification of moving ships by computer vision techniques in bridge area

  • Li, Shunlong;Guo, Yapeng;Xu, Yang;Li, Zhonglong
    • Smart Structures and Systems
    • /
    • v.23 no.4
    • /
    • pp.359-371
    • /
    • 2019
  • As part of a structural health monitoring system, the relative geometric relationship between a ship and bridge has been recognized as important for bridge authorities and ship owners to avoid ship-bridge collision. This study proposes a novel computer vision method for the real-time geometric parameter identification of moving ships based on a single shot multibox detector (SSD) by using transfer learning techniques and monocular vision. The identification framework consists of ship detection (coarse scale) and geometric parameter calculation (fine scale) modules. For the ship detection, the SSD, which is a deep learning algorithm, was employed and fine-tuned by ship image samples downloaded from the Internet to obtain the rectangle regions of interest in the coarse scale. Subsequently, for the geometric parameter calculation, an accurate ship contour is created using morphological operations within the saturation channel in hue, saturation, and value color space. Furthermore, a local coordinate system was constructed using projective geometry transformation to calculate the geometric parameters of ships, such as width, length, height, localization, and velocity. The application of the proposed method to in situ video images, obtained from cameras set on the girder of the Wuhan Yangtze River Bridge above the shipping channel, confirmed the efficiency, accuracy, and effectiveness of the proposed method.

Entropy and exergy analysis and optimization of the VVER nuclear power plant with a capacity of 1000 MW using the firefly optimization algorithm

  • Talebi, Saeed;Norouzi, Nima
    • Nuclear Engineering and Technology
    • /
    • v.52 no.12
    • /
    • pp.2928-2938
    • /
    • 2020
  • A light water nuclear Reactor has been exergy analyzed, and the rate of irreversible exergy loss and exergy destruction is calculated for each of its components. The ratio of these losses compared to the total input exergy loss is calculated, which shows that most irreversible losses occur in the reactors, turbines, steam generators, respectively, as well as in the downstream operations. The main aim of this paper is to optimize the power plant using an innovative firefly algorithm and then to propose a novel strategy to improve the overall performance of the plant. As shown in the results, the exergy destruction rate of the plant decreased by 1.18% using the firefly method, and the exergy efficiency of the plant reached 29.3% comparing to the operational amount of 28.99%. Also, the results of the firefly optimization process compared to the Genetic algorithm and gravitational search algorithm to study the accuracy of the model for exergy analysis fitness problems in the power plants and the results of this comparison has shown that the results are nearly similar in the mentioned methods. However, the firefly is faster and more accurate in limited iterations.

Performance Evaluation and Parametric Study of MGA in the Solution of Mathematical Optimization Problems (수학적 최적화 문제를 이용한 MGA의 성능평가 및 매개변수 연구)

  • Cho, Hyun-Man;Lee, Hyun-Jin;Ryu, Yeon-Sun;Kim, Jeong-Tae;Na, Won-Bae;Lim, Dong-Joo
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2008.04a
    • /
    • pp.416-421
    • /
    • 2008
  • A Metropolis genetic algorithm (MGA) is a newly-developed hybrid algorithm combining simple genetic algorithm (SGA) and simulated annealing (SA). In the algorithm, favorable features of Metropolis criterion of SA are incorporated in the reproduction operations of SGA. This way, MGA alleviates the disadvantages of finding imprecise solution in SGA and time-consuming computation in SA. It has been successfully applied and the efficiency has been verified for the practical structural design optimization. However, applicability of MGA for the wider range of problems should be rigorously proved through the solution of mathematical optimization problems. Thus, performances of MGA for the typical mathematical problems are investigated and compared with those of conventional algorithms such as SGA, micro genetic algorithm (${\mu}GA$), and SA. And, for better application of MGA, the effects of acceptance level are also presented. From numerical Study, it is again verified that MGA is more efficient and robust than SA, SGA and ${\mu}GA$ in the solution of mathematical optimization problems having various features.

  • PDF

A Pilot Study for Remediation of Groundwater by Surfactant -Enhanced Soil Flushing

  • Park, Jong Oh;Lee, Dal-Heui
    • Journal of Soil and Groundwater Environment
    • /
    • v.21 no.5
    • /
    • pp.1-7
    • /
    • 2016
  • The removal of non-aqueous phase liquids (NAPLs) from groundwater using pure water, via pump and treat, is quite ineffective due to their low solubility and hydrophobicity. Therefore, the objectives of pilot tests were to select potentially suitable surfactants that solubilize tetrachloroethylene (PCE) and trichloroethylene (TCE) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in surfactant-enhanced soil flushing (SESF). Used experimental method for surfactant selection was batch experiments. The surfactant solution parameters for SESF pilot tests were surfactant solution concentration, surfactant solution pH, and the flow rate of surfactant solution in the SESF pilot system. Based on the batch experiments for surfactant selection, DOSL (an anionic surfactant) was selected as a suitable surfactant that solubilizes PCE and TCE present as contaminants. The highest recovery (95%) of the contaminants was obtained using a DOSL surfactant in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a surfactant solution concentration of 4% (v/v), a surfactant solution pH of 7.5, and a flow rate of 30 L/min of surfactant solution (Lee and Woo, 2015). The maximum removal of contaminants (89%) was obtained when optimum conditions were simultaneously met in pilot-scale SESF operations. These results confirm the viability of SESF for treating PCE and TCE-contaminated groundwater.

A Study on the Mitigation Polices for the Negative Effect of Nanotehcnology-applied Products Using Conjoint Analysis (컨조인트 분석을 이용한 나노기술 적용제품의 부정적 영향 완화 정책 효과 분석)

  • Bae, Seoung Hun;Shin, Kwang Min;Lim, Jung Sun;Yoon, Jin Seon;Kang, Sang Kyu;Kim, Jun Hyun;Cho, Su Ji;Lee, Ki-Kwang
    • Korean Management Science Review
    • /
    • v.32 no.3
    • /
    • pp.1-12
    • /
    • 2015
  • This study aims to analyze the efficiency of the government policy of Nanotechnology which is expected to minimize nanotechnology's potential risk, using the methodology of conjoint analysis and market share analysis. The attributes of conjoint analysis were divided into potential risk factor and the policy factor. It was found that the policy factor could alleviate the potential risk, subsequently increasing consumers' utility. Additionally, the government certification was more powerful than the mandatory labelling. The market share also increased in result of the nanotechnology-applied product with the certification or labeling either. The result of this study can be used as a reference to related policy makers in the fields of Nanotechnology.

NORAD TLE TYPE ORBIT DETERMINATION OF LEO SATELLITES USING GPS NAVIGATION SOLUTIONS

  • Cho, Chang-Hwa;Lee, Byoung-Sun;Lee, Jeong-Sook;Kim, Jae-Hoon;Choi, Kyu-Hong
    • Journal of Astronomy and Space Sciences
    • /
    • v.19 no.3
    • /
    • pp.197-206
    • /
    • 2002
  • NORAD Two Line Elements (TLE) are widely used for the increasing number of small satellite mission operations and analysis. However, due to the irregular periodicity of generation of the NORAD TLE, a new TLE that is independent of NORAD is required. A TLE type Orbit Determination (TLEOD) has been developed for the generation of a new TLE. Thus, the TLEOD system can provide an Antenna Control Unit (ACU) with the orbit determination result in the type of a TLE, which provides a simple interface for the commercialized ACU system. For the TLEOD system, NORAD SGP4 was used to make a new orbit determination system. In addition, a least squares method was implemented for the TLEOD system with the GPS navigation solutions of the KOMPSAT-1. Considering both the Orbit Propagation (OP) difference and the tendency of $B^{*}$ value, the preferable span of the day in the observation data was selected to be 3 days. Through the OD with 3 days observation data, the OP difference was derived and compared with that of Mission Analysis and Planning (MAPS) for the KOMPSAT-1. It has the extent from 2 km after sit days to 4 km after seven days. This is qualified enough for the efficiency of an ACU in image reception and processing center of the KOMPSAT-2.