• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.139-148
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• 2008

Many types of sensor data exhibit strong correlation in both space and time. Suppression, both temporal and spatial, provides opportunities for reducing the energy cost of sensor data collection. Unfortunately, existing clustering algorithms are difficult to utilize the spatial or temporal opportunities, because they just organize clusters based on the distribution of sensor nodes or the network topology but not correlation of sensor data. In this paper, we propose a novel clustering algorithm with suppression techniques. To guarantee independent communication among clusters, we allocate multiple channels based on sensor data. Also, we propose a spatio-temporal suppression technique to reduce the network traffic. In order to show the superiority of our clustering algorithm, we compare it with the existing suppression algorithms in terms of the lifetime of the sensor network and the site of data which have been collected in the base-station. As a result, our experimental results show that the size of data was reduced by $4{\sim}40%$, and whole network lifetime was prolonged by $20{\sim}30%$.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.7
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• pp.263-270
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• 2014

This paper suggests a method for predicting a box-office success of the film. Lately, as the growth of the film industry, a variety of studies for the prediction of market demand is being performed. The product life cycle of film is relatively short cultural goods. Therefore, in order to produce stable profits, marketing costs before opening as well as the number of screen after opening need a plan. To fulfill this plan, the demand for the product and the calculation of economic profit scale should be preceded. The cases of existing researches, as a variable for predicting, primarily use the factors of competition of the market or the properties of the film. However, the proportion of the potential audiences who purchase the goods is relatively insufficient. Therefore, in this paper, in order to consider people's perception of a movie, Twitter was utilized as one of the survey samples. The existing variables and the information extracted from Twitter are defined as off-line and on-line element, and applied those two elements in machine learning by combining. Through the experiment, the proposed predictive techniques are validated, and the results of the experiment predicted the chance of successful film with about 95% of accuracy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.737-740
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• 2013

The widespread use of smart home appliances with smart home networking is leading to a next generation of a new technology that exploit user contextual information to provide a richer experience. However, in the most part of home networking systems the intelligent personalization services between user and home appliances have not been adequately supplied in respect of the long lifespan of the legacy home appliances. In addition, without installing smart home appliances when constructing new building the users can not use this service. To use this service, the legacy home appliance need to attach enabler equipped with the various sensors just as it is smart home appliances. The goal is to create a service that enables appliances to exchange information and control their actions through the IoT gateway to achieve nonintrusive behavior and customized services without human intervention. In this paper, we propose a ontology model to represent the user context to be able to induce right service automatically and use it to discover, utilize and enhance different services in real time that the user may be interested in.

• Convergence Security Journal
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• v.20 no.4
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• pp.113-123
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• 2020

The fourth industrial revolution can be called the hyper-connected-based intelligent revolution triggered by advanced information technology and intelligent technology, and the basis for implementing these technologies is 'data'. This study proposes a way to strategically use data in order to lead this intelligent revolution in the defense area. First of all, implications through analysis of domestic and international trends and prior research and current status of defense data management were analyzed, and four directions for development were presented. If the government composes conditions for building, releasing, sharing, distribution, and convergence of defense data considering the environment of national defense in the future, it is expected that it will serve as a foundation and a shortcut to be a digitalized strong military through smart defense innovation in the era of the fourth industrial revolution.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.71-81
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• 2021

This paper examines the ongoing research on ways to improve cybersecurity during the entire life cycle of weapons systems applied in advanced countries such as the United States, analyzes restrictions on obtaining domestic weapons systems, and presents effective security evaluation measures. By consistently performing mission-based risk assessment in the cybersecurity test and evaluation plan suitable for domestic circumstances at all stages of acquisition, important information is provided to major decision-making organizations in a timely manner to support decision-making, and to respond to identified vulnerabilities in cybersecurity. It is proposed to set the rules of engagement so that the protection measures can be verified, and a simulated invasion is proposed. In addition, the proposed cybersecurity test and evaluation system was compared with the domestic weapon system test and evaluation. Through this, the mission-based risk assessment element was grafted into the cybersecurity test and evaluation system research conducted so far to identify risks in a timely manner between acquisition projects, thereby supplementing the capability to support major decision-making.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.1-10
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• 2023

The nuclear power plant(NPP)'s Instrumentation and Control(I&C) system periodically conducts integrity checks for the maintenance of self-diagnostic function during normal operation. Additionally, it performs functionality and performance checks during planned preventive maintenance periods. However, there is a need for technological development to diagnose failures and prevent accidents in advance. In this paper, we studied methods for estimating the reliability function by utilizing environmental data and self-diagnostic data of the I&C equipment. To obtain failure data, we assumed probability distributions for component features of the I&C equipment and generated virtual failure data. Using this failure data, we estimated the reliability function using representative artificial intelligence(AI) models used in survival analysis(DeepSurve, DeepHit). And we also estimated the reliability function through the Cox regression model of the traditional semi-parametric method. We confirmed the feasibility through the residual lifetime calculations based on environmental and diagnostic data.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.4
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• pp.77-82
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• 2020

Wireless sensor networks (WSNs) suffer from not only a short lifetime due to limited energy but also an energy imbalance between nodes close to the sink and others. In order to fundamentally solve the short lifetime, recent studies utilize the environmental energy such as solar power. Additionally, WSNs using mobile sinks are being studied to address the energy imbalance problem. This paper proposes an improved CTP (Collection Tree Protocol) scheme which uses these two approaches simultaneously. Basically, it is based on a CTP scheme which is a very popular data collection strategy designed for the typical battery-based WSNs with a fixed sink. Therefore, we tailored it for solar-powered WSNs with a mobile sink. Performance verification confirms that our scheme reduces the number of blackout nodes significantly compared to the typical CTP, thus increases the amount of data collected by the sink.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.997-1005
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• 2009

In this paper, we suggest an energy-efficient clustering scheme based on cross-layer design in wireless sensor networks. The proposed scheme works adequately for the characteristic environment of the networks. In the proposed clustering scheme, we separate clusters composed of sensor nodes in the event area from clusters of the other area when an event occurs by using an application layer information. We can save energy from multiple paths through multiple clusters to deliver the same event. We also suggest TDMA scheduling for non-evented clusters. In the scheduling, we allocate one time slot for each node to save energy. The suggested clustering scheme can increase the lifetime of the entire network. We show that our scheme is energy efficient through simulation in terms of the frequency of event occurrences, the event continual time and the scope.

• The Journal of Information Technology
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• v.1 no.2
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• pp.195-208
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• 1998

Domestic corporation in High-tech industry invest huge amounts of economic resources into the Research & Development(R&D) department, especially into new product development. It might be an adequate explanation for this phenomena that as the product life cycle gets shorter, and environmental uncertainty necessitates core competency from every corporation, new product planning becomes a vital going concern for the company to keep and increase its market share This could originate from an inappropriate combination between new products and other marketing mix elements. But it could be that the main cause of these failures com from unsatisfactory customers. In the other words, R&D department failed to sufficiently recognize market needs. This could be solved through integration between marketing department R&D department This study supposes that integration between these two departments-marketing department and R&D department influences the success of new product. In other to prove this, this study examined the determinant factors which influence the integration and the relationships

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.1-9
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• 2015

Recently, cognitive radio technology has been spotlighted for the efficient use of limited frequency technology. The most important part of CR is to protect the incumbent user's communications. Therefore, CR user should be sensing the currently using channel and another hopping channel for sudden appearance of the Incumbent User. In this paper, we propose the cooperative channel sensing to protect the IU considering each CR user's remained power and sensing-zone, sense the spectrum bands in a fairly distributed manner and share the results among the users within respective sensing zone. Sensing scheme including inband sensing and outband sensing is utilized. The inband sensing is in charge of current using channel scanning while the outband sensing mainly cares about other channels. The performance results by computer simulations show that our sensing scheduling scheme reduces the number of sensing nodes and saves energy need to channel sensing.