• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.495-498
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• 2003

In order to analyze water supply capacity in estuary barrage dam, a system was developed in which base model was consisted of daily water balance model and daily inflow model. Agricultural water demand to paddy fields and domestic and industrial water demand were considered in this daily water balance model. Also outflow volume through sluice gate and inside water level at time to start outflow was conditioned initially to simulate reservoir storage. The DAWAST model was selected to simulate daily reservoir inflow in which return flows from agricultural, domestic and industrial water were included to simulate runoff. Using this developed system, water supply capacity in the Keum river estuary reservoir was analyzed.

• Journal of Information Processing Systems
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• v.15 no.3
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• pp.538-549
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• 2019

Cloud computing is the concept of providing information technology services on the Internet, such as software, hardware, networking, and storage. These services can be accessed anywhere at any time on a pay-per-use basis. However, storing data on servers is a challenging aspect of cloud computing. This paper utilizes cryptography and access control to ensure the confidentiality, integrity, and proper control of access to sensitive data. We propose a model that can protect data in cloud computing. Our model is designed by using an enhanced RSA encryption algorithm and a combination of role-based access control model with extensible access control markup language (XACML) to facilitate security and allow data access. This paper proposes a model that uses cryptography concepts to store data in cloud computing and allows data access through the access control model with minimum time and cost for encryption and decryption.

• Tunnel and Underground Space
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• v.23 no.3
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• pp.241-259
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• 2013

A packed bed thermal energy storage (TES) consisting of solid storage medium of rock or concrete through which the heat transfer fluid is circulated is considered as an attractive alternative for high temperature sensible heat storage, because of the economical viability and chemical stability of storage medium and the simplicity of operation. This study introduces the technologies of packed bed thermal energy storage, and presents a numerical model to analyze the thermal energy balance and the performance efficiency of the storage system. In this model, one dimensional transient heat transfer problem in the storage tank is solved using finite difference method, and temperature distribution in a storage tank and thermal energy loss from the tank wall can be calculated during the repeated thermal charging and discharging modes. In this study, a high temperature thermal energy storage connected with AA-CAES (advanced adiabatic compressed air energy storage) was modeled and analyzed for the temperature and the energy balance in the storage tank. Rock cavern type TES and above-ground type TES were both simulated and their results were compared in terms of the discharging efficiency and heat loss ratio.

• Fire Science and Engineering
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• v.33 no.5
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• pp.61-65
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• 2019

In the present study, the hydrodynamic force affected by a lapping wave induced by supplied falling water acting on the vertical wall of a portable water storage tank was analyzed using a nonlinear Peregrine model. The lapping wave's maximum run-up amplitudes and the hydrodynamic forces in the wall of the tank measured by linear and nonlinear Peregrine's models were compared numerically. As a result, it was concluded that the linear model may underestimate the effects on the vertical wall; therefore, it is more appropriate to use a nonlinear Peregrine model. Furthermore, this result can contribute to the stable structural designs of portable water storage tanks.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.58-63
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• 2013

LNG(Liquefied Natural Gas) has been considered as the green energy. Thus, the demand of natural gas is keep increasing around the world, and various studies are actively under progress about the LNG storage tank. To calculate the seismic forces of actual LNG storage tank, FEM model has to include inner tank, outer tank, pile and soil to implement the interaction between structure and ground. So, this paper is represent the study about inner tank model of three cases using Malhotra method in EN 1998-4(European Standard). The results of calculation were compared, and the most suitable to inner tank model was suggested.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.2
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• pp.1-8
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• 2014

The automobile manufacture is a typical integrated assembly production that the numerous parts are committed sequentially to the assembly line. In this type of automobile manufacture, WBS (white body storage) and PBS (paint body storage) are operated to adjust the production sequence and to buffer. Starvation (impossibility of production owing to the insufficient supply) or blocking (impossibility of production owing to the over capacity) could occur in some chance, hence, both storages (WBS, PBS) are integrated as a prevention. This system is called integrated storage. In this paper, we suggest the simulation model of 'WBS-PBS integrated storage' and methodology of operation considering both 'Color grouping' and 'Option leveling.'

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.179-184
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• 1997

A solution procedure to minimize total carousel related costs has been developed under the carousel throughput rate and total storage capacity requirements. The carousel related costs include carousel facility costs which are proportional to the number of carousels and carousel operating costs which are directly related to the moving distances of carousels. The number of carousels is dependent upon the size of a carousel and the moving distances are determined by the size of a carousel, storage item assignment to each carousel, and the item positions in a carousel. When the storage/retrieval requirements for each storage item is equal, an optimal algorithm has been developed. When the storage/retrieval requirements is unequal, a heuristic solution procedure has been developed because of the complexity of the problem.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.9
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• pp.727-735
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• 2003

The determination of completion time constitutes an important step in developing algorithms for short-term production scheduling. Existing completion time algorithms of multi-product batch processes often assume that intermediate storage tanks are always available when it is needed. In this paper, we consider a serial multi-product batch plants with ZW and NIS policy intermediate storge tank. We limit storage residence time and allocated products in the intermediate storage tank to minimize the quality change of the stored material as well as to reduce the clearing time during product change. A set of recurrence relations is suggested to calculate the completion times for the given batch sequence of products on all processing units. Also analytic solution for the suggested model is solved by a graphical method. The effectiveness of these results is proved by a few illustrative examples.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.184-192
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• 2016

Purpose: To solve the decay phenomenon of Hanfu apples that occurs during storage and obtain the best environmental parameters for preserving Hanfu apples using Fluent. Methods: Preservation storage was designed by analyzing the characteristics of Hanfu-apple storage and the natural environment in northeast China. The boundary conditions and simulation of a preservation model were established. Results: Compared with the initial values, the hardness decreased by $1.95kg/cm^2$, the sugar-acid ratio decreased by 20.43, and weight-loss rate was 3.98%. Conclusion: The results for the temperature field and velocity field of the empty storage were analyzed using Fluent. Hanfu apples can maintain good quality during the period of storage, according to our analysis of the Hanfu-apple hardness, weight loss, and change in the sugar-acid ratio during the 90-day preservation period.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.193-196
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• 2014

Experimantal evaluation of an energy storage device with high rotational speed to store regenerative energy which might be generated during the braking period of the trains is presented. The proposed ESS is small scale model and has 5kW output power, high rotational speed. In general railway trains generate regenerative energy for 10-20 sec when the train brakes and also high traction energy is needed for very short moment (10 sec) when the train increases the traction force. Considering such characteristics of the railway system energy storage device for the railway should have very fast response property. Among the various energy storage devices flywheel energy storage system has the fastest response property, which means that flywheel ESS is the most suitable for the railway system.