• Particle and aerosol research
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• v.9 no.1
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• pp.1-6
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• 2013

New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.97-104
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• 2015

In this paper, we propose a data envelopment analysis (DEA) and analytic hierarchy process (AHP) integrated model to improve the selection process in the acquisition of a weapon system which is the key component to the success of the project. In particular, we applied DEA in the first stage to choose a frontier group among the candidates in the selection process of the next-generation fighter system (the 3rd FX) in Korea. Then, by using the Delphi technique, we surveyed military experts and applied AHP to determine the best choice among the candidates. The results of the study match the actual decision made by the Korean government in the weapon system acquisition. The results of the proposed DEA-AHP integrated method in the selection of the next-generation fighter systems in Korea demonstrate the usefulness of the method. In this paper, we also discuss the future implications of the proposed model.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.149-155
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• 2023

In urban areas it can be difficult to utilize global navigation satellite systems (GNSS) due to signal reflections and blockages. It is thus crucial to detect reflected or blocked signals because they lead to significant degradation of GNSS positioning accuracy. In a previous study, a classifier for global positioning system (GPS) signal reception conditions was developed using three features and the support vector machine (SVM) algorithm. However, this classifier had limitations in its classification performance. Therefore, in this study, we developed an improved machine learning based method of classifying GPS signal reception conditions by including an additional feature with the existing features. Furthermore, we applied various machine learning classification algorithms. As a result, when tested with datasets collected in different environments than the training environment, the classification accuracy improved by nine percentage points compared to the existing method, reaching up to 58%.

• ETRI Journal
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• v.46 no.1
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• pp.118-126
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• 2024

In human conversations, listeners often utilize brief backchannels such as "uh-huh" or "yeah." Timely backchannels are crucial to understanding and increasing trust among conversational partners. In human-machine conversation systems, users can engage in natural conversations when a conversational agent generates backchannels like a human listener. We propose a method that simultaneously predicts backchannels and recognizes speech in real time. We use a streaming transformer and adopt multitask learning for concurrent backchannel prediction and speech recognition. The experimental results demonstrate the superior performance of our method compared with previous works while maintaining a similar single-task speech recognition performance. Owing to the extremely imbalanced training data distribution, the single-task backchannel prediction model fails to predict any of the backchannel categories, and the proposed multitask approach substantially enhances the backchannel prediction performance. Notably, in the streaming prediction scenario, the performance of backchannel prediction improves by up to 18.7% compared with existing methods.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.3
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• pp.235-256
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• 2020

The purpose of this study is to define a method of building an integrated service to provide various science and technology knowledge infrastructures that are helpful in R&D activities, and to show the cases that are adapted the methodologies. Knowledge infrastructures scattered throughout the entire R&D cycle, such as generating/development of ideas, finding the R&D project, performing the project, and spreading results, are segmented in terms of services, functions, information, and data, and links and converges to provide the knowledge infrastructure that desired by users in one place. We define the integrated service classification, integration level model, integrated architecture, and integrated user authentication system in consideration of logical linkage and integration rather than physical integration of individual knowledge infrastructures. Also, we considered the extensibility as the reference model for building of similar integrated service.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.193-198
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• 2013

In general, a product consists of one or more parts. Different parts of a product can perform the same function. According to "the design hypothesis of an integrated part", parts having the same function may be integrated into one part. A part can also perform more than one function. The form or material characteristic of a part may perform its function. In this study, we develop a method for defining the functions of components and for integrating parts having the same functions. We have successfully integrated some parts of a three-hole punch using the proposed method. The results satisfy axiomatic design.

• Journal of Platform Technology
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• v.6 no.3
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• pp.31-37
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• 2018

Recently, the platforms for open science are being developed for helping researchers and scientists who are interested in convergence studies. This paper is focused on deriving a design method for an integrated architecture for knowledge infrastructure in science and technology and to set up the integration level of details and association between data and services in the integrated architecture. To facilitate the open science in research lifecycle, reconstructing individual services into modular and independent function blocks needs to be reusable and interoperable. The proposed design methodology is used for manipulating a service integration for the convergence service of S&T(Science and Technology) knowledge infrastructure. It can support to seamlessly access computing resources and the research results including artifacts digitally enabled scholars, researchers, and engineers participating in multidisciplinary collaborations.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.107-113
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• 2006

It is essential to guarantee a handoff dropping probability below a predetermined threshold for wireless mobile networks. Previous studies have proposed admission control policies for integrated voice/data traffic in wireless mobile networks. However, since QoS has been considered only in terms of CDP (Call Dropping Probability), the result has been a serious CBP (Call Blocking Probability) unfairness problem between voice and data traffic. In this paper, we suggest a new admission control policy that treats integrated voice and data traffic fairly while maintaining the CDP constraint. For underprivileged data traffic, which requires more bandwidth units than voice traffic, the packet is placed in a queue when there are no available resources in the base station, instead of being immediately rejected. Furthermore, we have adapted the biased coin method concept to adjust unfairness in terms of CBP. We analyzed the system model of a cell using both a two-dimensional continuous-time Markov chain and the Gauss-Seidel method. Numerical results demonstrate that our CAC (Call Admission Control) scheme successfully achieves CBP fairness for voice and data traffic.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1463-1471
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.509-516
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• 2003

Smaller enterprises begin on practical use to form integrated informational system on the inside of company according to development of internet and information techniques. The past days, it was managed mainly information system for the inside of enterprise, but in the present time, e-business between enterprise and enterprise, enterprise and customer, country and enterprise, ERP system, etc are activated. To construct the integrated informationalized system, smaller enterprices use the informational process strategy methods to analyze and evaluate the level of enterprise, construct the information infra and informationalized system. In this paper, 1 introduce the informationalized process strategy method about implimentation of the integrated informationalized system for smaller enterprice, do the modelling for one smaller enterprice by proposed method.