• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.645-660
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• 1997

An application of the genetic algorithm(GA) to the loading sequencing problem in port container terminals is presented in this paper. The efficiency of loading operations in port container terminals is highly dependent on the loading sequence of export containers. In order to sequence the loading operation, we hove to determine the route of each container handling equipment (transfer crane or straddle carried in the yard during the loading operation. The route of a container handling equipment is determined in a way of minimizing the total container handling time. An encoding method is developed which keeps intermediate solutions feasible and speeds up the evolution process. We determine the sequence of each individual container which the container handling equipment picks up at each yard-bay as well as the visiting sequence of yard-bays of the equipment during the loading operation. A numerical experiment is carried out to evaluate the performance of the algorithm developed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.17-27
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• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1167-1180
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• 2023

Due to the tightened regulatory environment since the Fukushima accident, the capacity factor of Korean nuclear power plants has been declining since 2011. To overcome this circumstance, a shift from 18-month to 24-month cycle operation is being considered in Korea. Therefore, in this study, loading patterns(LPs) for 24-month cycle operation of the Korean standard nuclear power plant(OPR-1000) are suggested and economic evaluations are performed. A single-zone LP with 89 fresh fuels was evaluated to be optimal for 24-month operation of OPR-1000 in terms of economic gain. The 24-month operation of OPR-1000 with this LP gives a profit of 7.073 million dollars per year compared to 18-month operation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4A
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• pp.315-321
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• 2010

In Ad-hoc networks, centralized power control is not suitable due to the absence of base stations, which perform the power control operation in the network to optimize the system performance. Therefore, each node should perform power control algorithm distributedly instead of the centralized one. The conventional distributed power control algorithm does not consider the adaptive bit loading operation to change the MCS (modulation and coding scheme) according to the received SINR (signal to interference and noise ratio), which limits the system throughput. In this paper, we propose a novel distributed bit loading and power control algorithm, which considers the adaptive bit loading operation to increase total system throughput and decrease outage probability. Simulation results show that the proposed algorithm performs much better than the conventional algorithm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.4
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• pp.330-336
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• 2004

To meet the increasing demand from various fishing fields for training of fishing equipment operators, a fishing winch simulator was designed to train maritime students in the correct and safe operation of hydraulic winches under various load conditions related to fishing operations. The aim of this study is to describe the basic dynamic characteristics of the newly developed hydraulic fishing winch simulator and particularly to analyze the mechanical responses produced on the winch operation controls. The winch simulator consists of two winch units, a computer control and data acquisition system, a control consol and other associated mechanisms. When one winch is in hauling mode, the other one will always be in loading mode. The revolution speed of the hauling winch was controlled by a proportional directional control valve, and the braking torque of the loading winch was controlled by a proportional pressure control valve. The simulation experiments indicated that the dynamic characteristics of the hauling winch followed the braking response characteristics of the loading winch. The tests also showed that the warp speed and tension linearly depend on the pressure differential across the motor of the loading winch controlled by operating the proportional pressure control valve during the hauling operation. The experience gained from various training courses showed that the fishing winch simulator was very realistic and it was valuable for training novice winch operators. The results of the winch simulation exercise were recorded and used to evaluate the training on the operation and handling of the winch system. From these test results, we concluded that the tension acting on the warp during hauling operations can successfully be simulated by controlling the pressure differential across the motor with step changes of the control input signal to the proportional pressure control valve of the loading winch.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.783-791
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• 2002

A laboratory-scale dual-column biofilter system was used to study the biofiltration of dimethyl disulfide(DMDS). The biofiltration of DMDS was found to depend on the pollutant loadings rather than the inlet concentrations. It was estimated that the pollutant was only inhibitory to the operation of the biofilters at DMDS concentrations greater than 5500 ppmv A residence time of 30 seconds(120 m$^3$/m$^2$/h volumetric loading) was determined as appropriate for efficient operation(>90%). The maximum elimination capacity for both compost mixtures under the current experimental conditions was found to range from 7.5 to 10 g-DMDS/m$^3$/h. A lower DMDS maximum elimination capacity was exhibited under acidified conditions.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.201-208
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• 2005

Recently, the container terminal requires the study of method to increase efficiency through change of its operation method. Loading plan is a very important part to increase the efficiency of container terminal. Loading Plan is largely divided into two cases, deciding loading location and loading scheduling and this Paper proposes a more efficient method of container loading scheduling. Container loading scheduling is a problem of combination optimization to consider several items of loading location and operation equipments. etc. An existing method of cluster composition that decides the order of container loading scheduling has a restriction to increase the efficiency of work owing to rehandling problem. Therefore, we Propose a more efficient method of container loading scheduling which composes containers with identical attribution, based on ship loading list and yard map, into stack units of cluster, applying to hierarchical clustering method, and defines the restriction of working order. In this process, we can see a possible working path among clusters by defining the restriction of working order and search efficiency will be increased because of restricted search for working path.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.426-432
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• 2000

The hydraulic loading system real-time simulator using a PC and I/O interface board is developed to simulate the dynamic characteristics of hydraulic loading system in real time. The simulator receives the digital on-off control signals generated by the operator through the D/I channels, updates the state and output variables of the hydraulic loading system responding to the input signals and draw the moving pictuters of the lift cylinder, lift arm and loading box on the PC monitor in real time. Also, the operator can observe the displacement and pressure of cylinder, the rotatinal angle, reaction force, and safety factors of lift arm representing the operation of hydraulic loading system through the PC monitor in real time. The real-time simulator can be a very useful tool to design industrial dynamic systems and feel the goodness of the system operation since the operator can observe the moving pictures of the operating system in real time as he operates the real time simulator.

• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.197-208
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• 2019

This paper assessed the impacts of the specification of the yard, handling equipment, and operation approaches on the expected number of re-handles during the loading operation for empty containers. When the various types of empty containers from multiple shipping liners are placed in separate spaces from each other, then the storage space cannot be fully utilized. So as to increase the utilization of the storage space, empty containers from multiple vessel liners are stored together incurring additional re-handles during the loading operation. Several formulas are derived for the estimation of the expected number of handles, including re-handles, for empty container retrieval from a bay. Transfer cranes and top handlers are utilized as handling equipment and various retrieval strategies are examined. Numerical analysis was conducted to assess the effects of various designs and operational parameters of the container stacking yard on the expected number of handles.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.167-174
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• 1998

Recently several researches of high speed container ship and loading system are mainly accomplished in U.S.A. and Japan. Its shipping service is not realized but it is realized in near future. To effective use of the feature and efficiency of them, quay, loading/unloading. yard operation system, port management system and connection transport system must be well integrated and operated. Specially, loading /unloading speed of container crane is important for making effective use of them. To speed up loading/unloading system, RO-RO and LO-LO methods that are mostly exclusive system are studied on the container crane with special structure and mechanism to handle individual container or bundle of containers. In this paper these methods are shown. When new high speed loading system of container is desighed, the realistic constrains must be considered.