• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2431-2449
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• 2024

As problems such as water pollution and fish species depletion have become serious, a land-based fish farming is receiving a great attention for ensuring stable productivity. In the fish farming, it is important to determine the timing of shipments, as one of key factors to increase net profit on the aquaculture. In this paper, we propose a system for predicting net profit to support decision of timing of shipment using fish farming-related statistical data. The prediction system consists of growth and farm-gate price prediction models, a cost statistics table, and a net profit estimation algorithm. The Gaussian process regression (GPR) model is exploited for weight prediction based on the analysis that represents the characteristics of the weight data of cultured fish under the assumption of Gaussian probability processes. Moreover, the long short-term memory (LSTM) model is applied considering the simple time series characteristics of the farm-gate price data. In the case of GPR model, it allows to cope with data missing problem of the weight data collected from the fish farm in the time and temperature domains. To solve the problem that the data acquired from the fish farm is aperiodic and small in amount, we generate the corresponding data by adopting a data augmentation method based on the Gaussian model. Finally, the estimation method for net profit is proposed by concatenating weight, price, and cost predictions. The performance of the proposed system is analyzed by applying the system to the Korean flounder data.

• Journal of Navigation and Port Research
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• v.28 no.4
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• pp.285-291
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• 2004

The productivity of container terminal is determined by its various operation methods. This paper aims at finding out the factors to enhance the productivity of container handling of quay crane, using simulation technique. Three levels of decision making in terminal operation, strategy, and tactics and operation are selected for defining parameters of simulation The result of the simulation and test shows that the significant factors to improve the productivity are the stack height of container, block dispersion and the distance in yard planning for shipment. Decision making in the operation level, however, is of significance in the mixed condition of strategic and tactical level. The result shows meaningful guidelines in decision making under strategic, tactical and operation level.

• IE interfaces
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• v.25 no.2
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• pp.178-186
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• 2012

The DRAM module is an important part of servers, workstations and personal computer. Its malfunction causes a lot of damage on customer system. Therefore, customers demand the highest quality products. The company applies DRAM module Outgoing Quality Assurance Inspection(OQA) to secures the highest quality. It is the key process to decides shipment of products through sample inspection method with customer oriented tests. High fraction of defectives entering to OQA causes inevitable high quality cost. This article proposes the application of ensemble learning to classify the lot status to minimize the ratio of wrong decision in OQA, observing a potential in reducing the wrong decision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.139-148
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• 2011

This paper presents the minimum-cost network selection scheme which determines the transmission instance in the multi-band maritime communication system, so that the shipment-related real-time information can be transmitted within the maximum allowed period. The transmission instances and the corresponding network selection process are modeled by a Markov Decision Process (MDP), for the channel model in the 2-state Markov chain, which can be solved by stochastic dynamic programming. It derives the minimum-cost network selection rule, which can reduce the network cost significantly as compared with the straight-forward scheme with a periodic transmission.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.43-54
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• 2010

In recent years there have been studies on tour based approaches for freight travel demand modelling. The purpose of this paper is to analyze tour type choice behavior of commercial vehicles which are divided into round trips and chained tours. The methods of the study are based on the decision tree and the logit model. The results indicates that the explanation variables for classifying tour types of commercial vehicles are loading factor, average goods quantity, and total goods quantity. The results of the decision tree method are similar to those of logit model. In addition, the explanation variables for tour type classification of small trucks are not different from those for medium trucks', implying that the most important factor on the vehicle tour planning is how to load goods such as shipment size and total quantity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.7-14
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• 2016

Unlike most researches that focus on single manufacturer or single buyer, this research studies the cooperation policy for two participants of supply chain such as single vendor and single buyer. Especially, this paper deals with single vendor-single buyer integrated-production inventory problem. If the buyer orders products, then the vendor will start to make products and then the products will be shipped from the vendor to the buyer many times. The buyer is supposed to order again when the buyer's inventory level hits reorder point during the last shipment and this cycle keeps repeated. The buyer uses continuous review inventory policy and customer's demand is assumed to be probabilistic. The contribution of this paper is to present a mixed approach and derive its cost function. The existing policy assumes that the size of shipping batch from single vendor to single buyer is increasing, called Type 1, or constant, called Type 2. In mixed approach, the size of shipping batch is increasing at the beginning part of the cycle, and then its size is constant at the ending part of the cycle. The number of shipping for Type 1 and Type 2 in a cycle in mixed approach is determined to minimize total cost. The relationship between parameters, for example, the holding cost per product, the set up cost per order, and the shortage cost per item and decision variables such as order quantity, safety factor, the number of shipments, and shipment increasing factor is figured out via sensitivity analysis. Finally, it is statistically proved that the mixed approach is superior to the existing approaches.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.60
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• pp.27-46
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• 2013

The Incoterms and United Nations Convention on Contract for the international Sales of Goods(CISG) allocate a risk in their articles. These rules make a decision that the parties who make a transaction are bound to bear the risk or damages of goods. Though a goods have a damages or loss during a transportation, buyer is liable for the payment of purchase price. In this case, this paper defines the meaning whether who can bear the risk under Incoterms and CISG. In the majority cases which deal between parties, after shipment or at the end of carriage, the loss or damages are found in buyer's hand. If a damages or loss is made during transit, customarily these risk are covered by insurance. Otherwise, these rules provide a tools for solving this problems. Then, between parties should be accomplished their target equitably.

• Journal of the Korea Safety Management & Science
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• v.8 no.2
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• pp.115-128
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• 2006

The study analyzes those relations of customer service level of each sales branch, level of cooperations among branches, and overall system-wide service level for an item. Under the continuous review method, each sales branch places an order to the outside supplier, and the each branch receives the order quantity after elapsing a certain lead time. Under these circumstances, those branches with stockout condition may be supplied by other branches with keeping stocks to cover the shortages. This policy generally increases the system-wide customer service level for an item throughout cooperations for the safety plan among branches. Therefore, in the context of inventory policy, the decision rules to determine the proper branch levels of service and cooperation levels of service are important goals in terms of attaining desired system-wide service level. This research has suggested the method and procedure to reach above goals.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.305-306
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• 2022

In accordance with the Act on Punishment of Serious Disasters, terminal operators are required to establish and operate a safety and health management system such as manpower and budget necessary for disaster prevention, and establish and implement measures to prevent recurrence in the event of a disaster. This is a study on how to use the port facility safety management system linkage to prevent safety accidents in port facilities due to the introduction of autonomous driving port equipment and to support decision-making promptly in case of safety accidents.

• Journal of the Korean Institute of Navigation
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• v.22 no.4
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• pp.1-14
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• 1998

There are three basic modes of operation of ships: liner, tramp and industrial operations. Industrial operations, where the owner of the cargo, i.e. the industrial carrier controls the ships, abound in the shipment of bulk commodities, such as oil, chemicals and ores. Industrial carriers strive to minimize the shipping cost of their cargoes. This paper is concerned with the operational optimization problem of a fleet owned by major international oil company. The major oil company is a holding corporation for a group of oil producing, transporting, refining, and marketing companies located in various countries throughout the world. The operational optimization problem of the fleet is divided into two-phases. The front end corresponds to the optimization of transporting crude oil, product mix, and the distribution of product oil to meet market demand. The back end tackles the operational optimization problem of the fleet to meet the transportation demand derived from the front end. A case study is carried out with the H major oil company problem composed by reflecting the practices of an international major oil company. The results are summarized and examined in the point of optimization for the total operation of the H major oil company and the operational optimization problem of the fleet. The paper concludes with the remark that the results of the study might be useful and applicable in practices of these related decision problems.