• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.239-244
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• 2014

As the usefulness of mobile device is kept growing the privacy of the cloud computing is receiving more attentions. Even though many researches and solutions for privacy matters are suggested we are still worrying about the security problems. In addition most of cloud computing systems uses file-level synchronization which make it difficult to modify a part of a file. If we use data-centric app that stores data on embedded DBMS such as SQLite, a simple synchronization may incur some loss of information. In this paper we propose a solution to build a personal cloud that supports record-level synchronization. And we show a prototype system which uses RESTful web services and the same schema on mobie devices and the cloud storage. Synchronization is achieved by using a kind of optimistic concurrency control.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.31-38
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• 2004

In mobile agent environments, migration of an agent occurs continuously due to the mobility of agents. So cascaded delegation can occur among places for delegating the privilege to execute the agent. Because the existing delegation scheme considers only the delegation between two places that participate in migration of an agent, it does not support secure cascaded delegation. In this paper, we propose a cascaded delegation scheme that provides agents with secure cascaded delegation in mobile agent environments. Depending on the trust-relationship among places, the proposed scheme achieves the goal by nesting each delegation token or by nesting only initial token signed by creator of the agent within the signed part of the next immediate delegation token. And we prove that the proposed scheme is secure against the attack of replaying a message and the attack of substituting a delegation token.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.153-160
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• 2003

Recently, deployments of firewalls and NATs ire increasing to provide network security features or to solve the problem of public IP shortage. But, in these environments, peers in different firewall or NAT environments may get limited services because they cannot open direct communicate channels. This can be a significant problem in pure P2P environments where the peers should get or provide services by opening direct channels among themselves. In this paper, we propose a scheme for dynamically selecting a peer that fan be used as a proxy server. The proxy server supports the communication between the peers in different firewall or NAT environments. The proposed scheme is operating system independent and supports bidirectional communication among the peers in P2P environments. Additionally, the proposed scheme can distribute network traffic by dynamically allocating proxy servers to the peers that is not located in the firewall or NAT environments.

• The Journal of Internal Korean Medicine
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• v.28 no.2
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• pp.346-353
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• 2007

Background : Over a thousand years of clinical preparation of Ephedrain traditional Korean medicine has confirmed effectiveness and security. Recently. Ephedra-containing herbal preparations to treat obesity are common. The aim of this study is to identify effects of Ephedra on psychological anxiety. Objectives : To determine effects of Ephedraon psychoactivity and autonomic nervous system. Methods : The study design was a double-blind randomized controlled trial. The subjects of this study were healthy adults. They were allocated to either the Ephedragroup (N =66) or the placebo group (N =32), Ephedra(8 g) or a placebo in similar opaque capsules was given twice a day for 2 weeks. Anxiety score was estimated with State-Trait Anxiety Inventory before first and after last medication. 36 of the Ephedragroup and 24 of the placebo group finished the trial and were analyzed. Paired samples T-test and independent samples T-test were applied to statistical analysis. Results : The following result was obtained: After taking Ephedra. state anxiety increased significantly. In the placebo group. both state and trait anxiety increased although significance was not reached. Conclusions : It is concluded that the intake of Ephedraplays a significant role in the increase of anxiety in healthy adults. It is suggested that anxiety level change should be considered when using Ephedra in clinics.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.37-48
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• 2008

VoIP service is a transmission of voice data using SIP protocol on IP based network, The SIP protocol has many advantages such as providing IP based voice communication and multimedia service with cheap communication cost and so on. Therefore the SIP protocol spread out very quickly. But, SIP protocol exposes new forms of vulnerabilities on malicious attacks such as Message Flooding attack and protocol parsing attack. And it also suffers threats from many existing vulnerabilities like on IP based protocol. In this paper, we propose a new Virtual Proxy Server system in front of the existed Proxy Server for anomaly detection of SIP attack and stateful management of SIP session with enhanced security. Based on stateful virtual proxy server, out solution shows promising SIP Message Flooding attack verification and detection performance with minimized latency on SIP packet transmission.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.271-279
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• 2018

Various technologies have been developed to more efficiently share content such as P2P and CDN. These technologies take a common approach that request packets are responded by distributed network nodes, not by a single distributor. Such approaches not only resolve network congestion around content distributors, but also make it possible to distribute content regardless of the system and network status of content distributors. However, when receiving content from distributed nodes/hosts, not from authenticated distributors, users cannot practically identify which node/host sent content to them. Due to this characteristic, various hacking caused by the malicious modification of content is possible. Therefore, to make such approaches more secure, a content authentication technique is required. In this paper, we propose a improved operation of MHT used in CCN for authenticating distributed content. Then we evaluate the proposed method by comparing its performance with the existing technology.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.89-96
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• 2006

Magnetic Resonance Imaging (MRI) scanner is the device to draw an image of conditions and the spread of various tissue in the body. It is used by making the patient into rounded superconductor and using high frequency which cause resonances. It uses superconduction magnet and high frequency that is non-ionizing radiation so can acquire biochemical, physical, and functional information of tissue. It is also very useful because it can scan tomography from many different angles to diagnose disease of a nervous system, the heart, and a skeletal structure. It also has advantages of that there is no risk of radiation exposure and the ability of observation on organizations such as brains, livers and the spinal cord of people. Since these features, the rate of use has been increased accordingly more considerations of the security are required when it plans. The weight of devices and the cover problem of the strong magnetic field which is occurred by magnetic resonance at the time of diagnosis can cause very important structure problems and architectural condition. That also the recent tendency which needs stronger equipment means that planning of the MRI unit should generally aim at purposing of the proximity for the device maintenance and up-grade and of further expansion. However there are not enough studies and data on the magnet resonance imaging in domestic hospitals. According to these reasons, this study has an object of indicating basic data on MRI unit plan standard and alternative proposals.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.3
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• pp.159-168
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• 2017

Smartphone malware has increased because Smartphone users has increased and smartphones are widely used in everyday life. Since 2012, Android has been the most mobile operating system. Owing to the open nature of Android, countless malware are in Android markets that seriously threaten Android security. Most of Android malware detection program does not detect malware to which bypass techniques apply and also does not detect unknown malware. In this paper, we propose lightweight method for detection of Android malware using static analysis and deep learning techniques. For experiments we crawl 7,000 apps from the Google Play Store and collect 6,120 malwares. The result show that proposed method can achieve 98.05% detection accuracy. Also, proposed method can detect about unknown malware families with good performance. On smartphones, the method requires 10 seconds for an analysis on average.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.13-20
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• 2011

The face recognition has been used in a variety fields, such as identification and security. The procedure of the face recognition is as follows; extracting face features of face images, learning the extracted face features, and selecting some features among all extracted face features. The selected features have discrimination and are used for face recognition. However, there are numerous face features extracted from face images. If a face recognition system uses all extracted features, a high computing time is required for learning face features and the efficiency of computing resources decreases. To solve this problem, many researchers have proposed various Boosting methods, which improve the performance of learning algorithms. Mutual-Boost is the typical Boosting method and efficiently selects face features by using mutual information between two features. In this paper, we propose a GroupMutual-Boost method for improving Mutual-Boost. Our proposed method can shorten the time required for learning and recognizing face features and use computing resources more effectively since the method does not learn individual features but a feature group.

• Research in Community and Public Health Nursing
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• v.12 no.1
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• pp.32-38
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• 2001

This study focused on the understanding the life of the elderly in the institution by phenomenological method. The participants were seven. who were 4 men and 3 women living in the elderly institution in Taegu. The data were collected through the indepth interviews and participant observation from June 20. 1999 to January 10. 2000 and analyzed by phenomenological analytic method by Giorgi. The structure of the meaning were as follows: Unhappy life: irresponsibility. self-centered thought. hardness. Irresistible life: misfortune. unhealthiness. Reading their son's intention. Bitter life: unfair treatment from their sons and daughters, betrayed feeling for their being thrown away. Outside oriented life: a fear of others' attention, wrong information about institutionalized life, maladjustment. Self-consolation life: comfortableness, convenience, economic merit of low cost. Dissatisfied life: discomfort from communal living. unkindness of the institution staffs, depreciated tendency to the elder people, irrational social security system. economic distress, physical pain, restrained feeling. Tenacity to their sons and daughters longingness for their sons and daughters, regretableness, waiting, Regretable life: remorse for their past life. agony, guilty, loneliness, grief, self-abandonment, self-depreciation, other residents' death in common. Inharmonious life with other residents complaint, conflict, ignorance, selfishness. Yearning life for opposite sex: sexual interest. Preparing for their life: control over their body and mind, consideration for others. A life with hope: blessing death, forever healthfulness, affiliation to their family. From the results of this study an education and consultation should be done as soon as possible to remove the negative recognition of the institutional life to the facility residents. the family and the future consumers of elderly institution. To minimize the maladjustment to facility life of residents, a new program and interventions for the new comer's are needed. The thesis with above results will widen the understandings of institutional residents and an important guidance for a better nursing care in elderly institutions of korea.