• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3751-3770
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• 2015

Many sorts of image processing software facilitate image editing and also generate a great number of doctored images. Forensic technology emerges to detect the unintentional or malicious image operations. Most of forensic methods focus on the detection of single operations. However, a series of operations may be used to sequentially manipulate an image, which makes the operation detection problem complex. Forensic investigators always want to know as much exhaustive information about a suspicious image's entire processing history as possible. The detection of the operation chain, consisting of a series of operations, is a significant and challenging problem in the research field of forensics. In this paper, based on the histogram distribution uniformity of a manipulated image, we propose an operation chain detection scheme to identify histogram equalization (HE) followed by the dither-like operation (DLO). Two histogram features and a local spatial feature are utilized to further determine which DLO may have been applied. Both theoretical analysis and experimental results verify the effectiveness of our proposed scheme for both global and local scenarios.

• IE interfaces
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• v.17 no.2
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• pp.233-241
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• 2004

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types of effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and AGV)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.44-51
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• 2009

A bonded warehouse is the warehouse located in bonded area. It functions not only as a general warehouse but also as a place for managing the work related to import and export bonded goods. As a general warehouse, it uses the rack system to store the goods and the folk lift truck to move the unitized goods. The operation of the storing system closely related to the efficiency of space uses in a warehouse and vehicle working. Thus, vehicle performance measured in distance units in the ware-house could be used as one of the key performance measure in warehouse system. This paper focuses on the operation efficiency of the bonded warehouse which uses rack system for the storing and the folk lift truck for moving goods. The method of load allocation for balancing the rack uses and vehicle operation for maximizing efficiency are the specific concerns in this paper. The simulation study is conducted to find a policy for efficient vehicle operation based on balanced rack utilization, and the favorable result for the system operation would lead the usable proposal in vehicle operation.

• School Mathematics
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• v.8 no.1
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• pp.1-25
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• 2006

To be good at numeration is an important matter in learning mathematics. Unlike the 6-th curriculum, integers are introduced in middle school curriculum for the first time in the 7-th curriculum. Therefore, to help the students team integers systematically and thoroughly, it is necessary that we allow more space for process of introduction, process of operations and practice of operations in the 7-th curriculum text book than that of 6-th curriculum text book. As specific and systemic visualized teaching of operation is especially important in building the concept of operation, by using visualized teaching methods, students can understand the process of operation more fully and systematically. Moreover, students become proficient in operation of positive number and negative numbers by expending this learning process of operations to the operations used absolute value. In 7-th grade mathematics, the expression of positive numbers and negative numbers visually are useful for understanding of operations for numbers. But it is not easy to do so. In this paper we use arrows(directed segments) to express positive numbers and negative numbers visually and apply them to perform the operations for numbers. Using arrows, we can extend the method used in elementary school mathematics to the methods for operations of positive numbers and negative number in 7-th grade mathematics. By experiments, we can know that such processes of introduction for operations are effective and this way helps teachers teach and students learn.

• Korea Journal of Hospital Management
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• v.21 no.1
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• pp.43-50
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• 2016

The public medical centers are required to make efficient and profitable operation. The efficiency is usually measured by DEA(data envelopment analysis), and profitability is measured by medical income rate. But DEA is measured by relative, not absolute value. So, profitability rate is used alternatively for DEA. This study want to analyze the interchangeability between DEA ranking and medical income rate ranking among public medical centers. The return on total assets is same ranking with DEA on bed number, employee number and total asset, but 60-70% relationship with DEA on bed number and employee number, as input resources. The operating margin is similar ranking with DEA on bed number and employee number, but 50-60% relationship with DEA on bed number, employee number and total asset, as input resources.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.101-107
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• 2010

Purpose: The free flap has been widely used as one stage reconstructive procedure the skin and soft tissue defect. The secondary adjuvant operations are often needed for better results as functional and aesthetic compartment. Therefore, we focus on the secondary adjuvant surgeries for better outcome after free flaps. Methods: One hundred ninety six consecutive patients underwent free flaps between January, 2002 and February 2009. The cases constituted ninety two male patients and one hundred four female patients. For the patients who got free flap operation, we investigated secondary adjuvant operations what type of procedures was applied according to the reconstructed sites. All clinical data were based on the patient's medical records. Results: Of one hundred ninety six patients in whom free flap was performed, a total of eighty two patients(41.8%) received the secondary adjuvant operation. Because of many patients got multiple secondary adjuvant operations, the number of the secondary adjuvant operation become one hundred fifty five cases. The most common used procedure is a liposuction, and the second one is a lipoinjection. Conclusion: As the secondary adjuvant operation like a liposuction, lipoinjection, etc., satisfaction for operative result was increased in the aspects of function and aesthetics. So the secondary adjuvant operation in free flap surgeries contributed in raising the patient's quality of life.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.817-824
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• 2009

To prevent turbidity breakthrough in a depth filter caused by hydraulic shock loads, influence of turbidity and particle number in filtrate by variation of operating filter number depending on inflow change was investigated. Inflow quantity at the S water treatment plant (WTP) was varied and ratio of maximum/minimum inflow quantity was 2.2, therefore filtration velocity was also subsequently changed. The S WTP changed operating filter number depending on inflow variation to minimize change of filtration velocity. Particle breakthrough was not severe when operation system was changed, out-of-operation and re-start of filter was repeated depending on inflow quantity. Slight particle breakthrough was noticed when re-start of filter was implemented at the filter that had a cumulative filtration run time of less than 10 h or more than 50 h. This can be attributed to the inadequate ripening and over accumulation of particles on media. Therefore, it is more efficient to choose a re-starting filter basin which has cumulative filtration run time more than 10 h or less than 50 h to reduce particle breakthrough. Filter number variation depending on inflow change was proven to be a method for improvement of unit filter run volume (UFRV).

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.417-425
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• 2006

The purpose of this study were to a) investigate operation of human resource in contract foodservice management company (CFMC), b) identify the staffing indices for the establishment an labor productivity for CFMC, and c) develop standardized model of staffing demand as foodservice's scale in CFMC. The data was collected using FS intra-net system from 138 contract-managed foodservice operations in A CFMC and statistical analysis was completed using the SAS/win package (ver. 8.0) for description analysis, ANOVA, Duncan multiple comparison, pearson correlation analysis, and regression analysis. The types of operation were included factory (45%), small scale operation (26%), office (11%), department store (10%), training institute (4%), and hospital (3%). The distribution of foodservice scale was classified by meal served was as follows; 'less than 500 meals (47%)', 'from 500 to 1500 meals (25%)', 'from 1500 to 2500 meals (17%)', and 'more than 2500 meals (12%)'. There was two types of contract method, fee-contract (53%) and profit-and-loss contract (46%) Some variables were significantly high operation indices such as selling price, food cost, monthly sales, net profit and others were significantly low operation indices such as labor, meal time a day in the small foodservice on meal scale (p<.001). The more foodservice was large, the more human resource was disposed on dietitian, cook, cooking employee altogether (p<.001). Foodservice in A CFMC was divided into 2 groups by 500 meals a day, according to comparative analysis of labor productivity as meal scale per working hour, meal scale a day and operation indices as meal per foodservice employee, meal per cooking employee (p<.001). The regression equation model was developed as 'the number of employees=1.82+0.014 ${\times}$ meal served' in the operation of less than 500 meals, 'the number of employees=9.42+0.013 ${\times}$ meal scale a day -0.94 ${\times}$ meal scale per working hour' in the operation over 500 meal scale using labor productivity indices and operation indices. Therefore, CFMC could be enhanced efficiency of human resource arrangement using the standardized model of staffing demand and would be increased effectiveness of profit.

• The Mathematical Education
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• v.47 no.1
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• pp.61-74
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• 2008

The objective of this research is to verify the effect after development and application of a program for advance of number sense. This program presents an opportunity to explore suitable ways for the characteristics of problems by clarifying the meaning of number and operation through various thought processes, not focused on algorithm. To fulfill the objectives I developed the program for advance of number sense, and verify the effect on the improvement of number sense after applying to the developed program. As a result, it was confirm that this program was helpful to the improvement of the students' mathematical aptitude which resulted in a positive change in their attitude.

• Journal for History of Mathematics
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• v.20 no.3
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• pp.59-72
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• 2007

In this paper we find the germ of geometric interpretation of complex number in the Euclid Element and try to show the evolution of geometric interpretation of complex number by through Descarte, Wallis, Vessel. As a result, relations and differences between them are found. They related line with complex number and interpreted complex number geometrically by generalizing the multiplication operation.