• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.249-255
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• 2022

Potholes are an important clue to the structural defects of asphalt pavement and cause many casualties and property damage. Therefore, accurate pothole detection is an important task in road surface maintenance. Many machine learning technologies are being introduced for pothole detection, and data preprocessing is required to increase the efficiency of deep learning models. In this paper, we propose a preprocessing method that emphasizes important textures and shapes in pothole datasets. The proposed preprocessing method uses intensity transformation to reduce unnecessary elements of the road and emphasize the texture and shape of the pothole. In addition, the feature of the porthole is detected using Superpixel and Sobel edge detection. Through performance comparison between the proposed preprocessing method and the existing preprocessing method, it is shown that the proposed preprocessing method is a more effective method than the existing method in detecting potholes.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.180-190
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• 2007

Recently investigation institutions have found the clue leading to solution of the problem by digital evidence. Digital medium is used extensively in real life. Accordingly, offender is leaving from traces of crime to digital form. But, Korea's digital evidence investigation is low level yet. Definite legislation about digital evidence is not readied in present our country. And professional investigation manpower about digital evidence is insufficient. These problem may have to be supplemented urgently. Systematic, technological supporting is required. Specialize and discussed digital evidence investigation's controversial point and capacity reinforcement way for efficient confrontation in cyber crime who is diversified gradually in text.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.184-191
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• 2015

As the power electronics system increases the frequency, the power loss and thermal management are paid more attention. This research presents a real time model of dissipation power with junction temperature response for 120kw IGBT inverter which is applied to the thermal management of high power IGBT inverter. Since the computational time is critical for real time simulation, look-up tables of IGBT module characteristic curve are implemented. The power loss from IGBT provides a clue to calculate the temperature of each module of IGBT. In this study, temperature of each layer in IGBT is predicted by lumped capacitance analysis of layers with convective heat transfer. The power loss and temperature of layers in IGBT is then communicated due to mutual dependence. In the dynamic model, PWM pulses are employed to calculation real time IGBT and diode power loss. Under Matlab/Simulink$^{(R)}$ environment, the dynamic model is validated with experiment. Results showed that the dynamic response of power loss is closely coupled with effective thermal management. The convective heat transfer is enough to achieve proper thermal management under guideline temperature.

• Journal of KIISE:Software and Applications
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• v.35 no.9
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• pp.554-561
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• 2008

Prediction technique of user's intention can be used as a post-processing method for reducing the search space of an automatic speech recognizer. Prediction technique of system's intention can be used as a pre-processing method for generating a flexible sentence. To satisfy these practical needs, we propose a statistical model to predict speakers' intentions that are generalized into pairs of a speech act and a concept sequence. Contrary to the previous model using simple n-gram statistic of speech acts, the proposed model represents a dialogue history of a current utterance to a feature set with various linguistic levels (i.e. n-grams of speech act and a concept sequence pairs, clue words, and state information of a domain frame). Then, the proposed model predicts the intention of the next utterance by using the feature set as inputs of CRFs (Conditional Random Fields). In the experiment in a schedule management domain, The proposed model showed the precision of 76.25% on prediction of user's speech act and the precision of 64.21% on prediction of user's concept sequence. The proposed model also showed the precision of 88.11% on prediction of system's speech act and the Precision of 87.19% on prediction of system's concept sequence. In addition, the proposed model showed 29.32% higher average precision than the previous model.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.175-184
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• 2012

The aim of this study is to inquire into the influential relationship between perceived characteristics and psychological attitude toward smart phone in relation with the smart phone. This study conducted a questionnaire survey targeting domestic college students who are using the smart phone in an effort for an empirical test of the research model. The theoretical implications of this study laid foundation for doing research on the behavior of perceived characteristics and psychological attitude toward technology, and supplied a clue to diverse, in-depth research works on the further smart phone. The study-suggested practical implications are as follows: First, it is required that the usefulness and easy of use of the smart phone should be reinforced in order to form a positive attitude toward the smart phone. Second, the sense of dependence on the smart phone has an influence on user satisfaction.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1319-1324
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• 2013

The mean shift algorithm has achieved considerable success in object tracking due to its simplicity and robustness. It finds local minima of a similarity measure between the color histograms or kernel density estimates of the target and candidate image. However, it is sensitive to the noises due to objects or background having similar color distributions. In addition, occlusion by another object often causes a face region to change in size and position although a face region is a critical clue to perform face recognition or compute face orientation. We assume that depth and color are effective to separate a face from a background and a face from objects, respectively. From the assumption we devised a bilateral filter using color and depth and incorporate it into the mean-shift algorithm. We demonstrated the proposed method by some experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.3808-3814
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• 2011

The prediction of heat transfer and pressure drops in the exchanger passages is a clue to the problem of heat exchanger design. In order to make such predictions for non-Newtonian fluids, it is necessary to know the relation between the viscous properties of the fluid and the wall shear rate in the duct. This study deals with the limits of validity of the power law equation. The useful methodology of the present research involves a consideration of a more general equation which has power law and Newtonian behavior as asymptotes. It isconcluded that use of the power law equation outside of its applicability range can lead to serious errors inpredicting the heat transfer and pressure drops. The present computational results of the friction factors times Reynolds number for shear-thinning fluid flows in a triangular duct are compared with previous published results, showing agreement with 0.13 % in Newtonian region and 2.85 % in power law region. These shear-thinning fluid results also showed the 12% increase of convective heat transfer enhancement compared with Newtonian heat transfer.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.5
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• pp.61-72
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• 2019

The purpose of this study is to propose the clue of planning guideline for the elderly welfare center supporting the healthy life of the elderly through deriving the planning element of the elderly welfare center based on the Salutogenic Model(SM). The research method was proceeded with literature review. The meaning of Sense of Coherence(SOC) and Generalised Resistance Resources(GRR) which constitute Salutogenic Model is established. The correlation between SOC and GRR is analyzed. The conclusions of this study are as follows. First, EBD, BD, HD, UD, and BFD were studied as planning theories that could enhance the SOC of space. Second, based on the five planning theories, 43 planning elements needed for the elderly welfare center plan were derived. Third, as a result of classifying the plan elements based on the SOC, 'Manageability' is divided into 22 elements, 'Meaningfulness' is 11 and 'Comprehensibility' is 10 elements. Fourth, the details of the SOC items for each theory are as follows: BFD focuses on 'Manageability' with 'Manageability'(74%) and 'Comprehensibility'(26%), but 'Meaningfulness' does not exist. And UD regards 'Comprehensibility'(66%) as important, and 'Manageability' and 'Meaningfulness' as 17%. BD, on the other hand, has a high percentage of 'Meaningfulness'(70%), 'Comprehensibility'(21%) and 'Manageability'(9%). Next, the 'Manageability' of HD and EBD is 46%. And HD was 'Meaningfulness'(34%), 'Comprehensibility'(20%), and EBD was 'Meaningfulness'(30%) and 'Comprehensibility'(24%). The three items of SOC showed different distribution according to the spatial planning theory. As a result of the analysis, the spatial planning theory with the 'Comprehensibility' was related to Universal Design(UD), and the spatial planning theory with the 'Manageability' was related to Barrier-Free Design(BFD). In addition, the spatial planning theory of 'Meaningfulness' was related to Bio-philic Design(BD). Therefore, the plan of the elderly welfare center needs to approach the multidimensional design methodology to enhance the SOC(Sense of Coherence).

• Journal of Internet Computing and Services
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• v.23 no.6
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• pp.1-13
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• 2022

As the information and communication environment develops, the environment of military facilities is also development remarkably. In proportion to this, cyber threats are also increasing, and in particular, APT attacks, which are difficult to prevent with existing signature-based cyber defense systems, are frequently targeting military and national infrastructure. It is important to identify attack groups for appropriate response, but it is very difficult to identify them due to the nature of cyber attacks conducted in secret using methods such as anti-forensics. In the past, after an attack was detected, a security expert had to perform high-level analysis for a long time based on the large amount of evidence collected to get a clue about the attack group. To solve this problem, in this paper, we proposed an automation technique that can classify an attack group within a short time after detection. In case of APT attacks, compared to general cyber attacks, the number of attacks is small, there is not much known data, and it is designed to bypass signature-based cyber defense techniques. As an attack model, we used MITRE ATT&CK® which modeled many parts of cyber attacks. We design an impact score considering the versatility of the attack techniques and proposed a group similarity score based on this. Experimental results show that the proposed method classified the attack group with a 72.62% probability based on Top-5 accuracy.

• Journal of Educational Research in Mathematics
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• v.18 no.4
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• pp.483-497
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• 2008

This study investigated what kind of informal knowledge is emergent and what role informal knowledge play in process of solving 2-digit by 2-digit multiplication task. The data come from 4 times interviews with a 3th grade student who had not yet received regular school education regarding 2-digit by 2-digit multiplication. And the data involves the student's activity paper, the characteristics of action and the clue of thinking process. Findings from these interviews clarify the child's informal knowledge to modeling strategy, doubling strategy, distributive property, associative property. The child formed informal knowledge to justify and modify her conjecture of the algorithm.