• Journal of KIISE
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• v.43 no.7
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• pp.763-772
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• 2016

With the spread of smartphones containing multiple on-board sensors, the market for context aware applications have grown. However, due to the limited power capacity of a smartphone, users feel discontented QoS. Additionally, context aware applications require the utilization of many forms of context and sensing information. If context transition has occurred, types of needed sensors must be changed and each sensor modules need to turn on/off. In addition, excessive sensing has been found when the context decision is ambiguous. In this paper, we focus on power consumption associated with the context transition that occurs during indoor/outdoor detection, modeling the activities of the sensor associated with these contexts. And we suggest a freezing algorithm that reduces power consumption in context transition. We experiment with a commercial application that service is indoor/outdoor location tracking, measure power consumption in context transition with and without the utilization of the proposed method. We find that proposed method reduces power consumption about 20% during context transition.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.11
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• pp.411-418
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• 2016

Context-aware application has a lot of power consumption because it creates context by using a number of smartphone's sensors. Furthermore, only few kinds of researches have been conducted that provide information for the evaluation result of power consumption in the aspect of applications. In addition, evaluation of power consumption do not consider user's usage pattern or provide only total amount of power consumption, and inform developers power consumption of sensors undistinguishable. It makes developers hard to develop a power consumption-considered application. If developers could get information for power consumption of context-aware application in detail, a development of power-considered context-aware applications would be possible. Consequently, this paper proposes a BMT(Bench Mark Test) model which is able to inform developers useful evaluation criteria and result about power consumption of smartphone's components and sensors with usage pattern considered.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.44-47
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• 2011

In this paper, we propose context-aware based on Low Power Sensing Algorithm. The proposed sensing algorithm reduces power consumptions using low-power sensing algorithms and low-power sensing protocols. Experimental results show that the average power consumption of the proposed method is up to half consumption that of the conventional method.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.2
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• pp.202-207
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• 2007

Ontology has many merits such as high expression power and extensibility etc. and there are some suggestion on development of ubiquitous environment using ontology. For collecting and analysing the context information in ubiquitous environment, we need a context-awareness system. For these reason, some context-awareness systems have been developed using ontology, but they have insufficient representation power of context information and are independent to domain. In this paper, we define the context type to improve the extensibility of context framework, and develop the context ontology adopting the defined contort type to represent or inference various context information. We define the ontology to be easily adopted the and domain. Also, we use SWRL to represent numerical formulas and Horn-Logic expression.

• Journal of Integrative Natural Science
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• v.11 no.1
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• pp.44-50
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• 2018

In this paper, we propose a context-aware power management (CPM) scheme using beacons to reduce the power consumption of personal computers (PCs). In the proposed CPM scheme, the PC, smartphone, control server, and Internet of Things (IoT) device are necessary. PC users first log in the control server using their smartphones and select PCs to turn on. Then, the selected PCs automatically go into three different modes, i.e., sleep, shutdown, and standby power off modes, in order when the PC users leave the PCs without turning off them. Further, we develop a testbed with the proposed CPM scheme using the Arduino with Bluetooth low energy (BLE) and relay modules. Finally, it is shown that the proposed CPM scheme outperforms the conventional scheme in terms of the power consumption.

• Journal of Korea Multimedia Society
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• v.19 no.7
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• pp.1166-1178
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• 2016

In Internet of Things (IoT) environments, billions of interconnected devices and multimedia sensors generate a huge amount of multimedia traffic. Since the environment are in general deployed as a server-centric architecture wireless sensor networks could be bottlenecks between IoT gateways and IoT devices. The bottleneck causes high power consumption of the device and triggers very heavy network overload by transmission of sensing data. The deterioration could decrease the quality of multimedia streaming service due to delay, loss, and waste of device power. Thus, in this paper, we propose a context-based adaptive multimedia streaming scheme to support enhanced QoS and low power consumption in IoT environments. The goal of the scheme is to increase quality score per voltage of the streaming service, given an adaptation algorithm with context that are classified network and hardware such as throughput, RTT, and CPU usage. From the both context, the quality score per voltage is used in the comparison of a only network context-based adaptive multimedia streaming scheme, a fixed multimedia streaming and our scheme. As a result, we achieves a high improvement that means the quality score per voltage is increased up to about 4, especially in case of resolution change.

• Korea Information Processing Society Review
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• v.11 no.6
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• pp.56-75
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• 2004

In this article we address some system characteristics and challenging issues in developing Context-aware Middleware for Ubiquitous Computing. The functionalities of a Context-aware Middleware includes gathering context data from hardware/software sensors, reasoning and inferring high-level context data, and disseminating/delivering appropriate context data to interested applications/services. The Middleware should facilitate the query, aggregation, and discovery for the contexts, as well as facilities to specify their privacy policy. Following a formal context model using ontology would enable syntactic and semantic interoperability, and knowledge sharing between different domains. Moddleware should also provide different kinds of context classification mechanical as pluggable modules, including rules written in different types of logic (first order logic, description logic, temporal/spatial logic, fuzzy logic, etc.) as well as machine-learning mechanical (supervised and unsupervised classifiers). Different mechanisms have different power, expressiveness and decidability properties, and system developers can choose the appropriate mechanism that best meets the reasoning requirements of each context. And finally, to promote the context-trigger actions in application level, it is important to provide a uniform and platform-independent interface for applications to express their need for different context data without knowing how that data is acquired. The action could involve adapting to the new environment, notifying the user, communicating with another device to exchange information, or performing any other task.

• The Journal of Industrial Distribution & Business
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• v.5 no.1
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• pp.11-15
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• 2014

Purpose - The core objective of this study is to comprehend the diverse nature of implementation of sources of power in the Indian context. Research design, data, and methodology - After a meticulous review of the relevant literature on various types of power with a particular kind of managers'involvement, the article reviews the Indian managers' behavioral perception and attitudinal disposition while exercising power in their organization, along with a judicious blend of different kinds of power to drive the organization to the expected level. Results - As an input to a full-fledged research study, researchers had taken up this precise discussion and observation on how the managers' community in India exercises its power. Generally, Indian managers usually implement legitimate power besides reward and coercive power as per the situation, by extending copious benefits to different stakeholders. Based on the psychological and behavioral disposition, Indian managers exercised power in their respective organizations in a fruitful manner. Conclusions -This article has carefully covered the entire corporate sector regardless of magnitude, type, or ownership. It is quite beneficial to all the proactive researchers and academia along with the corporate world.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.119-132
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• 2021

This study focused on examining the impact of the social context that causes gender differences in entrepreneurship, not the phenomenon itself. Specifically, this study verified the moderating effect of the social context on the relationship between gender and entrepreneurship using data from 20 countries in the Global Entrepreneurship Trend Report (GETR). In order to test hypotheses involving social context implications, Hofstede's cultural dimension factors such as power distance, individualism, masculinity, and uncertainty avoidance variables, and institutional factors such as gender equality and social security are used as specific variables reflecting the social context. Empirical analysis through GLM found that gender did not independently influence entrepreneurship, and gender had a significant effect by interacting with power distance, individualism, uncertainty avoidance, gender equality, and social security variables, respectively. Such empirical results show that the gender difference in entrepreneurship is not due to the unique characteristics inherent in each gender but on the level of the country's social context to which the individual belongs.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.225-232
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• 2009

Context-aware technologies for ubiquitous computing are necessary to study the representation of gathered context-information appropriately, the understanding of user's intention using context-information, and the offer of pertinent services for users. In this paper, we propose the WS-CAM(Web Services based Context-Aware Middleware) framework for context-aware computing. WS-CAM provides ample power of expression and inference mechanisms to various context-information using an ontology-based context model. We also consider that WS-CAM is the middleware-independent structure to adopt web services with characteristic of loosely coupling as a matter of communication of context-information. In this paper, we describe a scenario for lecture services based on the ubiquitous computing e e e e e e to verify the utilization of WS-CAM We also show an example of middleware-independent system expansion to display the merits of web-based services. WS-CAM for lecture services represented context-information itodomaits as OWL-based ontology model effectively, and we confirmed the information is inferred to high level context-information by user-defined rules. We also confirmed the context-information is transferred to application services middleware-independently using various web methods provided by web services.