• Journal of KIISE
• /
• 제43권3호
• /
• pp.275-288
• /
• 2016

In this paper, we investigate the security issues of the Android platform which dominates the global market of smart mobile devices. The current permission model for Android security is not powerful and has two problems. One is the coarse-grained relationship between permissions and methods which require them. The other is that mobile users do not have rights to control the permissions of the application. To solve these problems, we propose MacDroid which can control the platform's resources for accessing installed applications. Users can control the application's behavior via MacDroid's policy. We have divided the permission set into method units. The results of the performance test using a pure Android platform show that our proposed scheme can improve security within a short time.

• The Journal of the Korea Contents Association
• /
• 제10권7호
• /
• pp.88-97
• /
• 2010

Recently the more convenient services are provided to people in the city in line with the change of city paradigm and the recent development of ubiquitous. For example, Information on bus arrivals an effective advertisement the combination of high technology and departures through smart-phones. However, in respect of the mobile advertisement, because of difficulties such as the means of transferring the mass storage data or the burden of communication charges. there need means to improve such difficulties. This study has been conducted aiming to overcome such difficulties. This study suggests the strategic differentiation plan through the analysis of the media characteristics such as real time service information when in traveling, U-Bus business model in the category of mobile advertisement, etc. and also the concrete system establishment plan from the operation center via network to the delivery of the advertisement through vehicle terminals. In respect that this study suggests the implications as a practical business model through the fusion of high technology and diverse media. It has great significance.

• KIISE Transactions on Computing Practices
• /
• 제20권12호
• /
• pp.688-693
• /
• 2014

With the advent of ubiquitous environments, the smart phone has come into wide use and the demand for various content increases. Thus, in order to efficiently utilize limited resources cognitive radio technology is regarded as a possible solution. Besides spectrum sensing or access schemes, the provision of VoIP traffic service for secondary users with limited spectrum resources is a very important issue. In this paper, a resource allocation and control system for VoIP QoS provision in cognitive radio networks is proposed. Firstly, as the system model, the time structure of the network is addressed and, according to the structure, a bandwidth broker is proposed. In addition, based on available bandwidth estimated by the bandwidth broker, a connection admission control for secondary users is developed. It is demonstrated that the provision of VoIP QoS is greatly affected by channel utilization, the number of channels, and the length of timeslot.

• The Journal of the Korea Contents Association
• /
• 제17권2호
• /
• pp.404-414
• /
• 2017

With the development of smartphones and online social networks, users produce a lot of contents and share them with each other. Therefore, users spend time by viewing or receiving the contents they do not want. In order to solve such problems, schemes for recommending useful contents have been actively studied. In this paper, we propose a contents recommendation scheme using collaborative filtering for users on online social networks. The proposed scheme consider a user trust in order to remove user data that lower the accuracy of recommendation. The user trust is derived by analyzing the user activity of online social network. For evaluating the user trust from various points of view, we collect user activities that have not been used in conventional techniques. It is shown through performance evaluation that the proposed scheme outperforms the existing scheme.

• The Journal of the Korea Contents Association
• /
• 제17권11호
• /
• pp.60-69
• /
• 2017

Recently, with the rapid development of internet and smart phones, social network services that can create and share various information through relationships among users have been actively used. Especially as the amount of information becomes enormous and unreliable information increases, expert recommendation that can offer necessary information to users have been studied. In this paper, we propose an expert recommendation scheme considering users' interests, human relations, and response quality. The users' interests are evaluated by analyzing their past activities in social network. The human relations are evaluated by extracting the users who have the same interesting fields. The response quality is evaluated by considering the user's response speed and response contents. The proposed scheme determines the user's expert score by combining the users' interests, the human relations, and the response quality. Finally, we recommend proper experts by matching queries and expert groups. It is shown through various performance evaluations that the proposed scheme outperforms the existing schemes.

• Knowledge Management Research
• /
• 제19권2호
• /
• pp.163-185
• /
• 2018

In order to solve problems in an uncertain and complicated management environment of the modern world, a creative solution that combines diverse perspectives, knowledge, and effort based on diversity within an organization is required. Smart work environment provides an opportunity to express the potential diversity of an individual, extending the source of ideas to the organization, enhancing communication, and linking and sharing information and knowledge. So, this results in increased creative behavior. The purpose of this study is to investigate the effect of the process of connecting and sharing information and knowledge of organizational members on creative behavior and the effect of smart work environment in the process. The purpose of this study is to identify roles of job autonomy, self-efficacy, knowledge sharing and smart work environment in creative process. For the study, 353 surveys with work use group(156 people) and unused group(197 people). Statistical analysis included validity and reliability analysis, structural model analysis. The results showed that self-efficacy and job autonomy had positive effects on creative behavior and knowledge sharing, and job autonomy had a positive effect on self-efficacy. Knowledge sharing has a positive effect on creative behavior, and mediates the relationship between self-efficacy, job autonomy and creative behavior. Particularly, knowledge sharing has a more positive effect on smart work use group. In case of smart work use group, self-efficacy and job autonomy have a relatively high influence on knowledge sharing rather than direct influence on creative behavior appear. This result implies that the achievements of smart work are revealed in terms of knowledge sharing and creative behavior.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제13권12호
• /
• pp.6105-6110
• /
• 2012

Smart devices have made our daily life more intelligent and provided convenient life styles in which advanced interface and high speed LTE enable us to have proliferation of empirical Apps. This research has analyzed and evaluated Unstructured data from the users who experienced 'Hair Style Magic Mirror App' by focusing on emotional information. Further this study suggests some directions that the application development industry should take in the near future. The findings through Chi-Square analysis indicate that the application has not affected the overall satisfaction of the consumers; consumers received higher satisfaction in paid version of applications than free versions. Emotional Information analysis shows that users value the practicality of each application the most. Thus, the application developers should focus on practicality and sensitivity side corresponding to the demand of consumers.

• Journal of KIISE
• /
• 제41권9호
• /
• pp.686-698
• /
• 2014

Recently, large-scale streaming sensor data have emerged due to explosive supply of smart phones, diffusion of IoT and Cloud computing technology, and generalization of IoT devices. Also, researches on combination of semantic web technology are being actively pushed forward by increasing of requirements for creating new value of data through data sharing and mash-up in large-scale environments. However, we are faced with big issues due to large-scale and streaming data in the inference field for creating a new knowledge. For this reason, we propose the RDFS rule based parallel reasoning scheme to service by processing large-scale streaming sensor data with the semantic web technology. In the proposed scheme, we run in parallel each job of Rete network algorithm, the existing rule inference algorithm and sharing data using the HBase, a hadoop database, as a public storage. To achieve this, we implement our system and evaluate performance through the AWS data of the weather center as large-scale streaming sensor data.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제13권6호
• /
• pp.2707-2712
• /
• 2012

Desktop-based computing environment is changed into mobile computing using smart phone and cloud computing providing common behavior and big data by network. Because of this transformation software development and operating environment is changed into heterogeneous distributed environment. As a result, dynamic service composition or changement is required. However, there is few research of techniques supporting service composition or changement dynamically in this situation. This paper suggests a technique for customizing services dynamically of mobile applications based on android platform. Especially we propose a customization technique of service by applying ontology technique to improve sharing and reuse of service. We applied proposed technique into meeting notification system, and obtain that it can be customized into various services such as email, sms, twitter service, and so on.

• Journal of KIISE
• /
• 제42권12호
• /
• pp.1623-1628
• /
• 2015

As the performance of mobile devices has increased, high-end multicore CPUs have become the norm in smartphones. However, such high performance devices are exposed to the problem of battery depletion due to the energy consumption caused by software performance, and despite increases in battery capacity. The required resources are dynamic and varied, and further user interaction is highly random; thus, Linux-based power management such as DVFS is needed to fulfill requirements. In order to reduce power consumption, we propose a method to restrict the CPU frequency of data download while maintaining user reactivity. This can supplement the weakness of existing Linux-based power management techniques like DVFS in relation to webpage loading. Through the implementation of our method at the application level, we confirm that energy consumption from webpage loading is reduced.