• Journal of KIISE:Information Networking
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• v.31 no.4
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• pp.393-404
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• 2004

Recently, mSCTP (Mobile SCTP) has been proposed as a transport layer approach for supporting mobility. mSCTP is based on the ‘multi-homing’ feature of Stream Control Transmission Protocol(SCTP), and utilize the functions to dynamically add or delete IP addresses of end points to or from the existing connectionin order to support mobility. In this paper, we propose a mechanism to determine when to add or delete an W address, utilizing the link layer radio signal strength information in order to enhance the performance of mSCTP We also propose a mechanism for a mobile node to initiate the change of data delivery path based on link layer radio signal strength information. In addition, if it takes long time to acquire new data path, we propose an approach for reducing handover latency. The simulation results show that the performance of proposed transport layer mobility support mechanism is competitive compared to the traditional network layer mobility supporting approach. Especially, when the moving speed of mobile node is fast, it shows better performance than the traditional network layer approaches.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.305-313
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• 2018

With the explosive growth of smart phones and efficiency, the Android of an open mobile operating system is gradually increasing in the use and the availability. Android systems has proven its availability and stability in the mobile devices, the home appliances's operating systems, the IoT products, and the mechatronics. However, as the usability increases, the malicious code based on Android also increases exponentially. Unlike ordinary PCs, if malicious codes are infiltrated into mobile products, mobile devices can not be used as a lock and can be leaked a large number of personal contacts, and can be lead to unnecessary billing, and can be cause a huge loss of financial services. Therefore, we proposed a method to detect and delete malicious files in real time in order to solve this problem. In this paper, we also designed a method to detect and delete malicious codes in a more effective manner through the process of installing Android-based applications and signature-based malicious code detection method. The method we proposed and designed can effectively detect malicious code in a limited resource environment, such as mobile environments.

• Journal of Information Technology Services
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• v.19 no.3
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• pp.57-73
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• 2020

The proportion of digital evidence in criminal cases has increased, while at the same time, the spread of the Internet has made it easy to delete information that is stored in another place and thus, the Internet is being used to delete online criminal evidence. To respond quickly and effectively to cybercrime, 29 countries signed the Convention on Cybercrime in 2001 through the Council of Europe. Article 16 of the Convention relates to the expedited preservation of stored computer data and requires signatories to adopt legislative measures to enable its competent authorities to order expeditious preservation of specified computer data where there are grounds to believe that the data is particularly vulnerable to loss or modification. More than 60 countries have joined the Convention since 2001 and have made efforts to improve their legal system in line with it. The United States legislated 18 U.S.C. § 2703(f) to preserve electronic evidence pending the issuance of a court order. The German Code of Criminal Procedure §§ 94~95 allows prosecution authorities to seize evidence or issue production orders without court control in urgent circumstances. A custodian shall be obliged to surrender evidence upon a request that evidence be preserved, and non-compliance results in punishment. Japan legislated the Criminal Procedure Act § 197(3) and (4) to establish a legal base for requesting that electronic records that are stored by an ISP not be deleted. The Korean Criminal Procedure Act § 184 outlines procedures for the preservation of evidence but does not adequately address the expeditious preservation of digital evidence that may be vulnerable to deletion. This paper analyzes nine considerations, including request subjects, requirements, and cost reimbursement to establish directions to improve the legal system for the expedited preservation of digital evidence. A new method to preserve online digital evidence in urgent cases is necessary.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.758-762
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• 2008

Embedded systems usually utilize Flash Memories with very nice characteristics of non-volatility, low access time, low power and so on. For the multimedia database systems, R-tree is an indexing tree with nice characteristics for multimedia access. MR-tree, which is an upgraded version of R-tree, has shown better performance in searching, inserting and deleting operations than R-tree. Flash memory has sectors and blocks as a unit of read, write and delete operations. Especially, the delete is done on a unit of 512 byte blocks with very large operation time and it is also known that read and write operations on a unit of block matches caching nature of MT-tree. Our research optimizes MR-tree operations in a unit of Flash memory blocks. Such an adjusting leads in better indexing performance in database accesses. With MR-tree on a 512B block units we achieved fast search time of database indexing with low height of MR-tree as well as faster update time of database indexing with the best fit of flash memory blocks. Thus MR-tree with optimized operations shows good characteristics to be a database index schemes on any systems with flash memory.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.265-275
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• 2014

This paper introduces a new algorithms for reconstructing the suffix tree of character string, when a substring id deleted from the string or a string is inserted into the string as a substring. The algorithem has two main functions, delete-structure and insert-structure. The main objective of this algorithm is to save the time for constructing the suffix tree of an edited string, when the suffix tree of the original string is available. We tested the performance of this algorithm with some DNA sequences. This test shows that delete-reconstructing can save time when the length of the subsequence deleted is less than 30% of the original sequence, and the insert-reconstructing takes less time with regard to the length of inserted sequence.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.711-720
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• 2010

This study is aimed to compare choices on interaction problems, and to consider the reason of the choices. It was expected that the interaction problems are influenced from national culture, age, gender and so on. The first interaction problem in this study is default answer button when user operates to delete all messages on SMS in-box. Second one is action when pop-p window warning dangerousness of install showed on web browsing. The third one is type(analog/digital) and information expression of control panel on soup maker. 639 Korean data and 784 data from China, Japan and the Netherlands are analyzed through cross-tabulation and chi-square test. In the results, many Japanese choose 'No' answer at SMS delete problem, while many Dutch choose 'Yes'. The result suggests that uncertainty avoidance effect on interaction problems. On warning pop-up, Younger generation and men choose actively 'install' than older one and women. On type of control panel, Dutch subjects preferred analog type than other countries' subjects. On expression of control panel, older generation and individualistic subjects relatively preferred text style than other style.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.51-59
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• 2014

This paper suggests a method of lessening number of a graph's edges population in order to rapidly obtain the minimum spanning tree. The present minimum spanning tree algorithm works on all the edges of the graph. However, the suggested algorithm reduces the edges population size by means of applying a method of deleting maximum weight edges in advance from vertices with more than 2 valencies. Next, it applies a stopping criterion which ideally terminates Borůvka, Prim, Kruskal and Reverse-Delete algorithms for reduced edges population. On applying the suggested algorithm to 9 graphs, it was able to minimize averagely 83% of the edges that do not become MST. In addition, comparing to the original graph, edges are turned out to be lessened 38% by Borůvka, 37% by Prim, 39% by Kruskal and 73% by Reverse-Delete algorithm, and thereby the minimum spanning tree is obtained promptly.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.251-255
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• 2008

In most file systems, if a file is deleted, only the metadata of the file is deleted or modified and the file's data is still stored on the physical media. Some users require that deleted files no longer be accessible. This requirement is more important in embedded systems that employ flash memory as a storage medium. In this paper, we propose a secure deletion method for NAND flash file system and apply the method to YAFFS. Our method uses encryption to delete files and forces all keys of a specific file to be stored in the same block. Therefore, only one erase operation is required to securely delete a file. Our simulation results show that the amortized number of block erases is smaller than the simple encryption method. Even though we apply our method only to the YAFFS, our method can be easily applied to other NAND flash file systems.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.103-106
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• 2000

Primary mediastinal liposarcoma is very rare, and only a few cases have ever been reported. A 25 year-old man who had coughing and mild fever for a month is reported. The simple delete X-ray and computed tomography of the chest revealed a huge mass in the right thoracic cavity that originated in the anterior mediastinum. Cytologic examination of the needle aspiration biopsy confirmed the diagnosis of a primary mediastinal liposarcoma. Through an exploratory right thoracotomy and a median sternotomy, the huge mass, lobulated and weighing about 2,500 gm delete, was extirpated. Mass was attached to a portion of the pericardium and diaphragm, but there was no invasion or metastasis to the pleura and lung. The patient was discharged 12 days after the operation. He is continuously receiving radiotherapy.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.543-549
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• 2018

The importance of prediction is becoming more emphasized, due to the uncertain business environment. In order to implement the predictive model, a number of data engineers and scientists are involved in the project and various prediction ideas are suggested to enhance the model. it takes a long time to validate the model's accuracy. Also It's hard to redesign and develop the code. In this study, development method such as Lego is suggested to find the most efficient idea to integrate various prediction methodologies into one model. This development methodology is possible by setting the same data layout for the development code for each idea. Therefore, it can be validated by each idea and it is easy to add and delete ideas as it is developed in Lego form, which can shorten the entire development process time. Finally, result of test is shown to confirm whether the proposed method is easy to add and delete ideas.