• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.769-779
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• 2017

Nutrient (i.e., nitrogen and phosphorus) budgets are required under a 'Livestock Excreta Survey'. A nutrient budget is one of the agri-environmental indicators that calculates the difference between the inputs and outputs of the amount of nutrients within a certain boundary and for a certain time period (e.g., 1 year). In this study, a nutrients budget model was developed to effectively determine the surplus of nutrients within a region in Korea. The C# program language was used in order to facilitate the deployment of a graphical user interface (GUI) and to enhance compatibility. Also, the model was developed on Windows OS, which is the commonly used operating system in Korea. The model was based on the OECD/Eurostat nutrient budget method, and it was modified to consider manure composting procedures as well. There are key features of the nutrient budget model, including directly use of the original data sets from various input and output sources, and a collectively exchange of the address in different formats. The model can quickly show the results of various spatial and temporal resolutions with the same data, as well as perform a sensitivity analysis with coefficients and easily compareresults using tables and graphs. Further, it would be necessary to study the extension of the scope of utilization, such as the application of various nutrient budget methods. It would also be helpful to investigate both pre and postprocessing information such as linking input data through online systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8B
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• pp.569-580
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• 2005

In case of one of the next generation mobile telecommunication; WCDMA service, the relevant market growth is delayed by market uncertainty, lack of effective demands, rapid evolution of technology, non-existence of business strategy, lack of distinction with competitive services and killer applications. In this study we intended to analyze the influence factors of market diffusion and marketing strategy of WCDMA. For doing so, we obtained both promotion and hindrance factors for diffusing the market of WCDMA through expert survey. Also we acquired such categories as factor for adoption, willingness to pay, killer application, preferred terminal and pronising customer, which becomes the reason ifluencing on the decision of WCDMA service marketing strategy. On the basis of such results, this paper suggests the direction of deployment for marketing focusing on the strategies as customer, price, sewice, terminal provision, and positioning of WCDMA.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.87-105
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• 2020

Purpose: This paper aims to propose a practical strategy for smart factories and a step-by-step quality strategy according to the maturity of smart factory construction. Methods: The characteristics, compositional requirements, and diagnosis system are examined for smart factories through theoretical considerations. Several cases of implementing smart factory are studied considering the company maturity level from the aspect of the smartness concept. And specific quality techniques and innovation activities are carefully reviewed. Results: The maturity level of smart factory was classified into five phases: 1) ICT non-application, 2) basic, 3) intermediate 1, 4) intermediate 2, 5) advanced level. A five-step quality strategy was established on the basis of case studies; identify, measure, analyze, optimize, and customize. Some quality techniques are introduced for step-by-step implementation of quality strategies. Conclusion: To build a successful smart factory, it is necessary to establish a quality strategy that suits the culture and size of the company. The quality management strategy proposed in this paper is expected to contribute to the establishment of appropriate strategies for the size and purpose of the company.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.155-162
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• 2010

To ensure accurate measurements of wireless network performance, it should be collected real-time data which are transmitted between a large number of nodes in the actual network environment. Therefore, it is necessary to develop simulation tool for finding optimal network system design method such as media access control, routing technique, ad-hoc algorithm of node deployment while overcoming spatial and temporal constraints. Our research attempts to provide an improved architecture and design method of simulation tool for wireless network is an application of multi-threading technique in these issues. We finally show that usability of the proposed simulator by comparing results derived from same test environment in the wireless LAN model of our simulator and widely used network simulation package, NS-2.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.127-135
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• 2020

In this paper, we propose an IoT-enabled solution for tour photography services with small-size investment and resources in the travel and tourism industries, being able to impact on economic, social, and cultural values. An IoT-enabled camera is developed based on an open hardware and software platform complying with oneM2M, which can make traditional embedded systems oneM2M-compliant devices due to a middleware solution called TAS (thing adaptation software). IoT cameras deployed around photo zones in a tour site could be remotely controlled via an IoT gateway with a Web-based application on a smartphone. Users would perform a pan and tilt camera control if they want and then take and download a perfect photo picture (even though they are away from the tour site). We expect that the proposed solution will promote the deployment IoT-enabled technologies in tour and travel industries which are important parts of the tertiary sector.

• Smart Structures and Systems
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• v.6 no.8
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• pp.939-951
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• 2010

A low-cost wireless sensor network (WSN) solution with highly expandable super and simple nodes was developed. The super node was designed as a sensing unit as well as a receiving terminal with low energy consumption. The simple node was designed to serve as a cheaper alternative for large-scale deployment. A 12-bit ADC inputs and DAC outputs were reserved for sensor boards to ease the sensing integration. Vibration and thermal field tests of the Chi-Lu Bridge were conducted to evaluate the WSN's performance. Integral acceleration, temperature and tilt sensing modules were constructed to simplify the task of long-term environmental monitoring on this bridge, while a star topology was used to avoid collisions and reduce power consumption. We showed that, given sufficient power and additional power amplifier, the WSN can successfully be active for more than 7 days and satisfy the half bridge 120-meter transmission requirement. The time and frequency responses of cables shocked by external force and temperature variations around cables in one day were recorded and analyzed. Finally, guidelines on power characterization of the WSN platform and selection of acceleration sensors for structural health monitoring applications were given.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.486-490
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• 2014

In this study, the Hazard-based model to decide regional oil recovery capacity by using AHP is suggested and regional oil recovery capacity is calculated by applying the model. The simulation for oil recovery capacity by mobilization of regional oil recovery equipments is carried out to verify the availability of the model. The worst oil spill accident in Daesan Taean Pyeongtaek region, which is located in geographically disadvantageous position among the regions that the worst oil spill accident may occur, is supposed for the simulation. As a result of simulation, the quantity of oil that can be recovered for three days on the scene of oil spill accident is worked out as $15,841k{\ell}$, which can satisfy the goal of national oil recovery capacity for the worst oil spill accident, therefore the model is verified as practicable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.6
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• pp.672-677
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• 2016

Development of Internet has been successfully inspired with extensive deployment of the network technology and application. However, increases in Internet usage had caused a lot of traffic overload in these days. Thus, we need a continuous research and development on the network virtualization for effective resource allocation. In this paper, we propose a minimal cost virtual network mapping algorithm using Piecewise Linear Cost Function. We exploited an algorithm with Linear Programming and D-VINE for node mapping, and Shortest Path Algorithm based on linear programming solution is used for link mapping. In this way, we compared and analyzed the average cost for arrival rate of VN request with linear and tree structure. Simulation results show that the average cost of our algorithm shows better efficiency than ViNEyard.

• Journal of Communications and Networks
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• v.9 no.3
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• pp.296-311
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• 2007

Mobile multi-robot teams are useful in many critical applications such as search and rescue. Explicit communication among robots in such mobile multi-robot teams is useful for the coordination of such teams as well as exchanging data. Since many applications for mobile robots involve scenarios in which communication infrastructure may be damaged or unavailable, mobile robot teams frequently need to communicate with each other via ad hoc networking. In such scenarios, low-overhead and energy-efficient routing protocols for delivering messages among robots are a key requirement. Two important primitives for communication are essential for enabling a wide variety of mobile robot applications. First, unicast communication (between two robots) needs to be provided to enable coordination and data exchange. Second, in many applications, group communication is required for flexible control, organization, and management of the mobile robots. Multicast provides a bandwidth-efficient communication method between a source and a group of robots. In this paper, we first propose and evaluate two unicast routing protocols tailored for use in ad hoc networks formed by mobile multi-robot teams: Mobile robot distance vector (MRDV) and mobile robot source routing (MRSR). Both protocols exploit the unique mobility characteristics of mobile robot networks to perform efficient routing. Our simulation study show that both MRDV and MRSR incur lower overhead while operating in mobile robot networks when compared to traditional mobile ad hoc network routing protocols such as DSR and AODV. We then propose and evaluate an efficient multicast protocol mobile robot mesh multicast (MRMM) for deployment in mobile robot networks. MRMM exploits the fact that mobile robots know what velocity they are instructed to move at and for what distance in building a long lifetime sparse mesh for group communication that is more efficient. Our results show that MRMM provides an efficient group communication mechanism that can potentially be used in many mobile robot application scenarios.

• Structural Monitoring and Maintenance
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• v.2 no.3
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• pp.283-300
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• 2015

Visual condition inspections remain paramount to assessing the current deterioration status of a bridge and assigning remediation or maintenance tasks so as to ensure the ongoing serviceability of the structure. However, in recent years, there has been an increasing backlog of maintenance activities. Existing research reveals that this is attributable to the labour-intensive, subjective and disruptive nature of the current bridge inspection method. Current processes ultimately require lane closures, traffic guidance schemes and inspection equipment. This not only increases the whole-of-life costs of the bridge, but also increases the risk to the travelling public as issues affecting the structural integrity may go unaddressed. As a tool for bridge condition inspections, Unmanned Aerial Vehicles (UAVs) or, drones, offer considerable potential, allowing a bridge to be visually assessed without the need for inspectors to walk across the deck or utilise under-bridge inspection units. With current inspection processes placing additional strain on the existing bridge maintenance resources, the technology has the potential to significantly reduce the overall inspection costs and disruption caused to the travelling public. In addition to this, the use of automated aerial image capture enables engineers to better understand a situation through the 3D spatial context offered by UAV systems. However, the use of UAV for bridge inspection involves a number of critical issues to be resolved, including stability and accuracy of control, and safety to people. SLAM (Simultaneous Localisation and Mapping) is a technique that could be used by a UAV to build a map of the bridge underneath, while simultaneously determining its location on the constructed map. While there are considerable economic and risk-related benefits created through introducing entirely new ways of inspecting bridges and visualising information, there also remain hindrances to the wider deployment of UAVs. This study is to provide a context for use of UAVs for conducting visual bridge inspections, in addition to addressing the obstacles that are required to be overcome in order for the technology to be integrated into current practice.