• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.9
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• pp.67-75
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• 1999

In this paper, a shape decomposition method using morphological operations is studied for decomposing the complex shape in 2-D image into its simple primitive elements. The serious drawback of conventional shape representation algorithm is that primitive elements are extracted too much to represent and to describe the shape. To solve these problems, a new shape decomposition algorithm using primitive elements tat are similar to the geometrical characteristics of shape and 4 scan modes is proposed in this study. The multiple primitive elements as circle, square, and rhombus are extracted by using multiscan modes in a new algorithm. This algorithm have chatacteristics that description error and number of primitive elements is reduced. Then, description efficiency is improved. The procedures is also simple and the processing time is reduced.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.1064-1070
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• 2010

Korea Department of Defense has been developing Link-K, Korean Joint Tactical Datalink, to support their independent joint operations and trying to enlarge the scope of Link-K tactical message delivery to nodes in IP based tactical networks for sharing situation awareness more broadly. A Link-K tactical message size is too small to fit into an IP packet, inefficiently wasting most of the IP packet space of the low bandwidth IP-based tactical networks. This paper proposes a new Link-K tactical message aggregation and delivery method when tactical messages need to be sent to some nodes located at IP-based tactical networks. With numerical analysis and OPNET simulation studies, we prove the effectiveness and efficiency of the proposed method.

• Journal of KIBIM
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• v.8 no.3
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• pp.12-19
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• 2018

The research aims to find implications of machine learning and urban big data as a way to construct the flexible transportation network system of smart city by responding the urban context changes. This research deals with a problem that existing a bus headway model is difficult to respond urban situations in real-time. Therefore, utilizing the urban big data and machine learning prototyping tool in weathers, traffics, and bus statues, this research presents a flexible headway model to predict bus delay and analyze the result. The prototyping model is composed by real-time data of buses. The data is gathered through public data portals and real time Application Program Interface (API) by the government. These data are fundamental resources to organize interval pattern models of bus operations as traffic environment factors (road speeds, station conditions, weathers, and bus information of operating in real-time). The prototyping model is implemented by the machine learning tool (RapidMiner Studio) and conducted several tests for bus delays prediction according to specific circumstances. As a result, possibilities of transportation system are discussed for promoting the urban efficiency and the citizens' convenience by responding to urban conditions.

• Journal of the Korean Solar Energy Society
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• v.29 no.1
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• pp.50-57
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• 2009

Heliostat in the tower type solar thermal power plant is a mirror system tracking the sun's movement to collect the solar energy and it is the most important subsystem determining the efficiency of solar thermal power plant. Thus a good performance of it, which is mostly the accurate sun tracking performance under the various hazardous operating condition, is required. Heliostat control system is a system to manage the heliostat sun tracking movement and other operations. It also communicates with the master controller through the heliostat filed control system to receive and send the informations required to operate the heliostat as a part of the solar thermal power plant. This study presents a heliostat control system designed and developed for the 1MW solar thermal power plant. We first define the functionality of heliostat control system. Then sun tracking controller as well as the sun tracking algorithm satisfying the required functionality have been developed. We tested the developed heliostat control system and it showed a good performance in regulation of heliostat motion and communication.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.286-295
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• 2006

This paper presents a design of a real-time software GPS receiver which runs on a PC. The software GPS receiver has advantages over conventional hardware based receivers in terms of flexibility and efficiency in application oriented system design and modification. In odor to reduce the processing time of the software operations in the receiver, a shared memory structure is used with a dynamic data control, and the byte-type IF data is processed through an Open Multi-Processing technique in the mixer and integrator which requires the most computational load. A high speed data acquisition device is used to capture the incoming high-rate IF signals. The FFT-IFFT correlation technique is used for initial acquisition and FLL assisted PLL is used for carrier tracking. All software modules are operated in sequence and are synchronized with pre-defined time scheduling. The performance of the designed software GPS receiver is evaluated by running it in real-time using the real GPS signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.5153-5170
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• 2016

The benefit of the scalability and flexibility inherent in cloud computing motivates clients to upload data and computation to public cloud servers. Because data is placed on public clouds, which are very likely to reside outside of the trusted domain of clients, this strategy introduces concerns regarding the security of sensitive client data. Thus, to provide sufficient security for the data stored in the cloud, it is essential to encrypt sensitive data before the data are uploaded onto cloud servers. Although data encryption is considered the most effective solution for protecting sensitive data from unauthorized users, it imposes a significant amount of overhead during the query processing phase, due to the limitations of directly executing operations against encrypted data. Recently, substantial research work that addresses the execution of SQL queries against encrypted data has been conducted. However, there has been little research on top-k join query processing over encrypted data within the cloud computing environments. In this paper, we develop an efficient algorithm that processes a top-k join query against encrypted cloud data. The proposed top-k join processing algorithm is, at an early phase, able to prune unpromising data sets which are guaranteed not to produce top-k highest scores. The experiment results show that the proposed approach provides significant performance gains over the naive solution.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.621-631
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• 2017

Many developing countries considering the introduction of nuclear power find that large-scale reactor plants in the range of 1,000 MWe to 1,600 MWe are not grid appropriate for their current circumstance. By contrast, small modular reactors are generally too small to make significant contributions toward rapidly growing electricity demand and to date have not been demonstrated. This paper proposes a radically simplified re-design for the nuclear steam cycle for a medium-sized reactor plant in the range of 600 MWe. Historically, balance of plant designs for units of this size have emphasized reliability and efficiency. It will be demonstrated here that advances over the past 50 years in component design, materials, and fabrication techniques allow both of these goals to be met with a less complex design. A disciplined approach to reduce component count will result in substantial benefits in the life cycle cost of the units. Specifically, fabrication, transportation, construction, operations, and maintenance costs and expenses can all see significant reductions. In addition, the design described here can also be expected to significantly reduce both construction duration and operational requirements for maintenance and inspections.

• Journal of National Security and Military Science
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• s.15
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• pp.31-55
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• 2018

It has been fifteen years since military science was introduced into private and public universities since 2004. The department focuses on the improvements of the South Korean Army quality based on the Korean Army's traits including: an increase of power in the armed force and operations through research, development, and the expansion of a cooperation between the public (civilians) and military. Approximately, four hundred students from various universities in the military science department graduate in order to become an officer. The fourth industrial revolution causes structural transformation to our lives. Through the use of Artificial Intelligence (AI,) war and the military as a whole will be altered significantly particularly with regard to efficiency. Nevertheless, it is important for us to train officers in creative ways so that they can deal with situations where machines will be unable to handle situations. Considering this change in our lives, it is necessary for the military science departments to change the way to teach and train their students. In order to accomplish this goal, we need to introduce a method called "Flipped Learning" and during the process all the members need to participate and communicate in an interactive way. By doing this, the military science departments will play an important role by improving human resource in terms of military and national security.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.161-168
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• 2011

In 2009, Jeon et al proposed the lightweight strong authentication and strong privacy protocol, where the tag requrires only simple bitwise operations and random number generator. JK-RFID authentication protocol provides strong security: eavesdropping, replay, spoofing, Location tracking, DoS attack and forward security. Nevertheless, this paper points out the vulnerability of the forward security and improve the process of key updating. As a result, proposes an enhanced JK-RFID authentication protocol providing forward security and verify its satisfaction. In addition, a security and an efficiency of the proposed scheme analyze. Since partial adjustments of the key updating operation in JK-RFID authentication protocol, our protocol improve the forward security.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.129-136
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• 2023

In this paper, we describe a rule-based risk classification algorithm to perform Risk-based Inspection (RBI) on imported goods at customs. The RBI system is a method to automatically select which cargos have to be inspected and manage potential risks in boarder. In this study, we designed a rule-based risk classification algorithm for RBI solutions and implemented them using the Svelte web application framework. The risk classification algorithm proposed in this paper uses different indicative risk factors such as HS code, country of origin, importer's reliability, trade relationships, and logistics routes to classify cargos into Green, Yellow, and Red channels. To achieve this, we assigned risk categories to each risk factor and randomly generated risk scores within a specific range for each risk category. This system is expected to contribute to the increased efficiency of customs operations and protect public safety by minimizing the risk of imported hazardous materials.