• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.245-250
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• 2020

Currently, unmanned military vehicles under development in Korea have more devices to carry out various missions, and interface cables between them are also increasing. In addition, due to a small space problem inside the unmanned vehicle, devices are required to be miniaturized and integrated. For two reasons, connectors also need to be selected, which makes them vulnerable to noise due to the closer distance between the pins. In this paper, we analyzed how much the magnetic field produced by noise at the connector pin where cable twist is released affects the surrounding pin and presented the guide for optimal pin placement. First, the effect of magnetic field is greater than the crosstalk between pin and pin. Second, the magnetic field on both sides between + and - is strong when approaching one step with noise source. Third, the magnetic field strength is improved when setting the ground pin as the ground pin between the noise and the original signal when approaching the A noise source and the two steps. Fourth, in the case of a differential mode communication, the optimal placement area of the sensitive signal was presented according to positions Tx± and Rx±.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.581-591
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• 2005

Collaborative filtering systems have problems involving sparsity and the provision of recommendations by making correlations between only two users' preferences. These systems recommend items based only on the preferences without taking in to account the contents of the items. As a result, the accuracy of recommendations depends on the data from user-rated items. When users rate items, it can be expected that not all users ran do so earnestly. This brings down the accuracy of recommendations. This paper proposes a collaborative recommendation method for extracting typical group preferences using user-item matrix optimization and user profiles in collaborative tittering systems. The method excludes unproven users by using entropy based on data from user-rated items and groups users into clusters after generating user profiles, and then extracts typical group preferences. The proposed method generates collaborative user profiles by using association word mining to reflect contents as well as preferences of items and groups users into clusters based on the profiles by using the vector space model and the K-means algorithm. To compensate for the shortcoming of providing recommendations using correlations between only two user preferences, the proposed method extracts typical preferences of groups using the entropy theory The typical preferences are extracted by combining user entropies with item preferences. The recommender system using typical group preferences solves the problem caused by recommendations based on preferences rated incorrectly by users and reduces time for retrieving the most similar users in groups.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.722-728
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• 2012

Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

• Journal of Korean Classical Literature and Education
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• no.35
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• pp.5-46
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• 2017

This study aims to investigate the context of materials in literature textbooks and the awareness about the educational value of classical literature, as part of an interest in literature education phenomena. This study accepts the premise that textbooks affect the practice of classical literature education and, in particular, materials in textbooks are chosen according to the intentions, demands, and perspectives of education in specific social conditions. I divided the educational value of classical literature into two categories, classical and literary value, and investigated the actual conditions and context of materials of literature textbooks based on the 2009 revised curriculum and the 2011 revised curriculum. Classical literature is generally alienated and excluded; contemporary literature materials are mostly included and organized in the domains of 'the role of literature', 'reception and production of literature' and 'literature and life.' In addition, the tendency to heighten classical value and diminish literary value is deepening. In order to solve the problem that classical literature is only included as the product of the past, changes must be made not just to the curriculum, which are external changes, but to the awareness of the essence of classical literature, which are internal changes. Above all, generality as 'literature' and the sense of distance about space and time as 'classic' should be connected to various relationships which respond to problematic situations and the demands of learners. Based on the relationships, we can expect a rich diversity of contexts and aspects of included classical literature. In addition, an extension of the width and scope of included classical literature is anticipated. The reduction of workload, the advent of the concept of capability and the dissolution of traditional literature concepts are the changes of external environment, which is continuously requiring renewed investigation into classical literature beyond simple appropriateness.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.79-89
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• 2019

While most research focuses on the k-nearest neighbors (kNN) queries in the database community, an important type of proximity queries called k-farthest neighbors (kFN) queries has not received much attention. This paper addresses the problem of finding the k-farthest neighbors in road networks. Given a positive integer k, a query object q, and a set of data points P, a kFN query returns k data objects farthest from the query object q. Little attention has been paid to processing kFN queries in road networks. The challenge of processing kFN queries in road networks is reducing the number of network distance computations, which is the most prominent difference between a road network and a Euclidean space. In this study, we propose an efficient algorithm called FANS for k-FArthest Neighbor Search in road networks. We present a shared computation strategy to avoid redundant computation of the distances between a query object and data objects. We also present effective pruning techniques based on the maximum distance from a query object to data segments. Finally, we demonstrate the efficiency and scalability of our proposed solution with extensive experiments using real-world roadmaps.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.61-73
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• 2018

In the defense modeling and simulation, for the detailed analysis of the communication system, many studies have carried out the analysis under the C3 SoS(system of systems) which consists of C2(command and control) and C(communication). However, it requires time and space constraints of the C2 system. To solve this problem, this paper proposes a communication analysis method in the standalone system environment which is combined with the C system after abstracting the C2 system. In the abstraction process, we hypothesize the traffic model and mobility model for C system analysis and learn the parameters in the model based on machine learning. Through the proposed method, it is possible to construct traffic and mobility model with different output according to the battlefield. This case study shows how the process can be applied to the C3 SoS and the enhanced accuracy than the existing method. We expect that it is possible to carry out the efficient communication analysis against many experimental scenarios with various communication parameters.

• Economic and Environmental Geology
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• v.54 no.5
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• pp.505-513
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• 2021

Recently, housing prices in metropolitan areas is also increasing in the UK and Australia. Their governments are trying to solve this problem by the housing development in the quarry sites near cities. The cases reviewed in this study, Erith Hill Quarry (The Quarry), Plymstock Quarry, Lilydale Quarry (Kinley), and Bombo Quarry are the mixed-used development cases in the closed quarry sites through the urban planning system. In the UK, the local government uses the urban planning scheme such as the planning permit system, section 106. The local government permits the quarry site development on the condition that it provides necessary public facilities, such as schools and affordable housing for the local community. In Australia, local governments use up-zoning permission rights to convert land uses in quarries from industrial to mixed-use. Development plans have to include urban infrastructure and open space in addition to affordable housings. In the case of Australia, establishing a development plan in advance and filling the quarry pit with overburden through a phased development is expected to have the effect of reducing the project cost. Both countries think that developing brownfields, such as quarry sites, is a more sustainable and eco-friendly development from the perspective of future generations than developing new green fields. Such a perspective of the UK and Australia will be able to give policy implications for our slightly rigid urban development system.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.177-188
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• 2021

In South Korea, with the advancement of the 'Port' project, the regeneration industry adapted to the modern economic development has been promoted, leading to construction around the port was also redefined. Therefore, through regeneration, the problem of image construction of buildings around the port has been re-examined, in which color is an important content of image construction. In this study, the exterior walls of abandoned factory buildings in the port area of Bongnaedong, Pusan were selected as the color research object and evaluated according to the characteristics of the regenerated factory buildings combined with the building color function. Technically, KSCP color analysis system is used for color analysis. In this way, the color plan for the exterior walls of the factory buildings is proposed to visually enhance the image of abandoned factory buildings and attract more attention, thus driving the regional economic development. The results of this study show that in order to adapt to the regional, industrial and commercial characteristics of the regenerated port space, the color hue, lightness, chroma and use area of the building can be changed to enhance the aesthetic value and enhance the inductivity and security.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.433-443
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• 2021

Value Engineering(VE) is an organized effort to create the most value through a functional analysis and creation of alternatives. Depending on the VE job plan, a VE Workshop must be performed in a certain place within a certain period of time. A VE Workshop, which is an organized activity that aims to create the best value through functional analysis and creation of alternatives, should be held in a certain place and at a scheduled time according to the VE job plan. In the Pre-Study, VE Study and Post-Study phases of VE, functional assessments, performance evaluations and idea evaluations are driven by variable management techniques and analysis methods, respectively. Generally, VE is executed for about 3 to 5 days in a particular place to create value. However, there are many problems associated with limiting all VE processes to a specific place and schedule. Moreover, in Korea, VE teams are required to finish all VE processes in a limited time because of the short duration of VE workshops, the necessity of which has been overlooked. Therefore, an efficient VE support system is required to resolve the problem of time and space limitations. In this study, a VE support system based on the Mobile environment was developed to support the VE Workshop process. This VE support system enables participants to review design documents, drawing sheets and all VE-related documents using mobile devices. After the Workshop, participants can conveniently rearrange the result(evaluation of function and ideas) at the workshop. Not only can the members of VE team can review the design documents, drawing sheet and all VE-related documents in the step before the workshop, but also the result(evaluation of function and ideas) of the workshop can be easily rearranged in the phase after the workshop under the developed supporting system using mobile devices.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.359-365
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• 2021

GEO-KOMPSAT-2A (GK2A) AMI (Advanced Meteorological Imager) Best Detector Select (BDS) map is pre-determined and uploaded before the satellite launch. After the launch, there is some possibility of a detector performance change driven by an abrupt temperature variation and thus the status of BDS map needs to be evaluated and updated if necessary. To investigate performance of entire elements of the detectors, AMI BDS analyses were conducted based on a technical note provided from the AMI vendor (L3HARRIS). The concept of the BDS analysis is to investigate the stability of signals from detectors while they are staring at targets (deep space and internal calibration target). For this purpose, Long Time Series (LTS) and Output Voltage vs. Bias Voltage (V-V) methods are used. The LTS for 30 secs and the V-V for two secs are spanned respectively for looking at the targets to compute noise components of detectors. To get the necessary data sets, these activities were conducted during the In-Orbit Test (IOT) period since a normal operation of AMI is stopped and special mission plans are commanded. With collected data sets during the GK2A IOT, AMI BDS map was intensively examined. It was found that about 1% of entire detector elements, which were evaluated at the ground test, showed characteristic changes and those degraded elements are replaced by alternative best ones. The stripping effects on AMI raw images due to the BDS problem were clearly removed when the new BDS map was applied.