• International journal of advanced smart convergence
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• v.8 no.4
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• pp.179-187
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• 2019

Vehicular density is usually low in a highway environment. Consequently, connectivity of the vehicular ad hoc networks (VANETs) might be poor. We are investigating the problem of deploying the approximation optimal roadside units (RSUs) on the highway covered by VANETs, which employs VANETs to provide excellent connectivity. The goal is to estimate the minimal number of deployed RSUs to guarantee the connectivity probability of the VANET within a given threshold considering that RSUs are to be allocated equidistantly. We apply an approximation algorithm to distribute RSUs locations in the VANETs. Thereafter, performance of the proposed scheme is evaluated by calculating the connectivity probability of the VANET. The simulation results show that there is the threshold value M of implemented RSUs corresponding to each vehicular network with N vehicles. The connectivity probability increases slowly with the number of RSUs getting larger.

• Journal of Information Technology Services
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• v.10 no.3
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• pp.213-236
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• 2011

Mobile devices are widely accepted as a convenient machine which provides computing capability as well we cell phone capability. Because of limited resources on mobile devices, complex applications could not be deployed on the devices. Service-based mobile applications (SMAs) can provide a solution to overcome the limitation by subscribing cloud services. Since SMAs have complex structures than standalone applications, it is challenging to develop high quality SMAs, to manage both services and mobile applications, and to implement automated billing for subscribed services. Therefore, there is a great demand for a platform for super mobile computing, which supports all key activities in managing life cycle of SMAs. In this paper, we present technical aspects of a platform which is under development; Super Mobile Autonomous Reliable plaTform (SMART). We believe that it provides a number of practical features which are essential in supporting life-cycle of SMAs; development, deployment, management, and operation.

• Journal of Korean Society for Quality Management
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• v.31 no.2
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• pp.131-142
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• 2003

QFD(Quality Function Deployment) is design method which is focused to guarantee of quality and function to satisfy for customer’s need. QFD are used entire manufacturing, specially new production development and design. HOQ(House of Quality) are important tool of QFD, which is implement that complex function and communications of customer. Actually implementation of HOQ are difficult by HOQ's size. It is well known that complexity of HOQ are exponentially increasing by increasing of HOQ’s size. In this Paper, we study of HOQ Complexity reduction by Quantification Method of Type Ⅲ. That method is efficiency and minimize of loss information by reduction HOQ. We give example and prove our suggestion method is better than other methods.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.354-358
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• 2001

Cosim (Hardware and Software Co-Simulator) is a JavaBeans-based simulation tool fur validating systems architecture and estimating performance of web applications. Cosim has four components: Modeler, Translator, Engine and Scenario. Users start from Modeler to describe systems architecture in UML(Unified Modeling Language) deployment diagram, and then specify hardware & software performance parameters such as execution delay, network topology, and frame size. All information specified on Modeler are sent to Translator, and then automatically converted to Java programs. Scenario is responsible to run the Java program and produce results in text reports and graphs. Developers can reduce development time and cost by validating systems architecture of web applications before the actual deployment.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.5
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• pp.209-217
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• 2012

In the present, Wireless Sensor Network(WSN) has been used for the purpose of the military operation with surveillance systems and for collecting useful information from the natural environment. Basically, low-power, easy deployment and low cost are the most important factors to be deployed for WSNs. Lots of researches have been studied to meet those requirements, especially on the node capacity and battery lifetime improvements. Recently, the study of wireless mesh networks applied into the surveillance systems has been proceeded as a solution of easy deployment. In this paper, we proposed large-scale intelligent multi-layer surveillance systems based on QoS assuring Wireless Mesh Networks and implemented them in the real testbed environment. The proposed system explains functions and operations for each subsystem as well as S/W and H/W architectures. Experimental results are shown for the implemented subsystems and the performance is satisfactory for the surveillance system. We can identify the possibility of the implemented multi-layer surveillance system to be used in practice.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.307-309
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• 2003

In the initial deployment stage of optical access networks, optical network systems and optical fiber cables have been provided mainly for commercial buildings or users in KT. According to the demand of residential users who expect to subscribe broadband multimedia services as high bit rate services, the optical access networks get closer to the residential users as FTTCab or FTTH So, it is very important to install optical access networks economically and effectively because that the total cost and usability of optical fiber cables depends on that. Especially, one of characteristics in access networks is the possibility of variation on services demands and technology evolution. Also access networks must be prepared for the final deployment, FTTH. Therefore, the designing and planning of optical access networks are coming to be very important activity for most of telecommunications service providers.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.71-80
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• 1998

This study proposed a method to apply certain fuzzy-related Quality control concepts to design customer-oriented products considering user requirements and information starting with the product development stage. This approach showed how to define the importance level of design elements and how to Quantify complex subjective perception of products using the fuzzy linguistic rating method and quality function deployment concepts. Using this approach, various customer requirements could be interpreted and reflected on the early design phase of a new product. To validate the proposed method, an experiment was conducted for designing the shape of the beeper using 14 subjects and 10 commercial beeper products. Front area, width/length ratio, thickness, curve variance, weight, and display area were selected as design elements of the beeper. The results showed that among design elements, front area and weight are significantly related with the subjective perception of the products. Consequently, this study indicates that customer decision on product selection could be made by quantification of user perception for beeper products.

• Journal of Information Technology Services
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• v.13 no.3
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• pp.201-219
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• 2014

This paper considers service deployment and priority optimization for multiple service-oriented applications sharing reusable services, which are deployed as multiple instances in the cloud. In order to handle variations in the workloads of the multiple applications, service instances of the individual reusable services are dynamically provisioned in the cloud. Also service priorities for each application in a particular reusable service are dynamically adjusted. In this paper, we propose an analytic performance model, based on a queueing network model, to predict the expected sojourn times of multiple service-oriented applications, given the number of service instances and priority disciplines in individual reusable services. We also propose a simple heuristic algorithm to search an optimal number of service instances in the cloud and service priority disciplines for each application in individual reusable services. A numerical example is also presented to demonstrate the applicability of the proposed performance model and algorithm to the proposed optimal decision problem.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.99-100
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• 2006

One of the fundamental problems in sensor networks is the deployment of sensor nodes. The Fuzzy C-Means(FCM) clustering algorithm is proposed to determine the optimum location and minimum number of sensor nodes for the specific application space. We performed a simulation using two dimensional L shape model. The actual length of the L shape model is about 100m each. We found the minimum number of 15 nodes are sufficient for the complete coverage of modeled area. We also found the optimum location of each nodes. The real deploy experiment using 15 sensor nodes shows the 95.7%. error free communication rate.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.435-441
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• 2013

This paper review about kerberos security authentication scheme and policy for big data service. It analyzed problem for security technology based on Hadoop framework in big data service environment. Also when it consider applying problem of kerberos security authentication system, it analyzed deployment policy in center of main contents, which is occurred in commercial business. About the related applied Kerberos policy in US, it is researched about application such as cross platform interoperability support, automated Kerberos set up, integration issue, OPT authentication, SSO, ID, and so on.