• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.190-200
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• 2001

This paper is addressed to welding defect feature vector selection and implementation method of welding defect classifier using fuzzy techniques. We compare IAV, zero-crossing number as time domain analysis, power spectrum coefficient as frequency domain, histogram as both domain for welding defect feature selection. We choose histogram as feature vector by graph analysis and find out that maximum frequent occurrence number and section of corresponding signal scale in relative histogram show obvious difference between normal welding and voiding with penetration depth defect. We implement a fuzzy welding defect classifier using these feature vector, test it to verify its effectiveness for 695 welding data frame which consist of 4000 sampled data. As result of test, correct classification rate is 92.96%. Lab experimental results show a effectiveness of fuzzy welding defect classifier using relative histogram for practical Laser welding monitoring system in industry.

• Journal of Korean Elementary Science Education
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• v.29 no.4
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• pp.441-450
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• 2010

The purpose of this study was to evaluate the level of elementary gifted students' argumentation and examine the special features of argumentation founded in scientific inquiry. 28 students were selected in the special education center for the gifted in K National University. They were organized 8 groups of 3~4 students and engaged in scientific inquiry activity. The researcher wasn't involved in students' inquiry activity and argumentation except for the guiding and introducing their activity. In the first session, each group carried out the experiment 'Putting a heated can in the water' and then, the students discussed to probe their experimental results and build their explanation. In the second session, each group presented their experiment results and evidence from their experiment justifying their claims, and had questions from other groups. The protocol data during 8 groups' argumentations were analyzed using 'Rubric for Scientific Argumentation Assessment' (Yang et al., 2009) in three domains- the form, content and attitude. As a result, in form domain, almost groups were rated 2 points due to their argument without rebuttal on the subcategory of 'composition', but they got a good grade above 3 points in subcategory such as 'claim', 'ground', and 'conclusion'. In content domain, almost groups got points above 3 points. In attitude domain, there were some striking contrast between each groups. Six groups got good score more than 4 points on the subcategory of openness, but two groups, they alleged and got score below 3 point. While the 6 groups of all got 4 points in the aspect of participation, 3 groups got 3 points lower than because they only just asserted and not interact with other groups. Throughout the argumentation, two features were found that; as time goes by, arguments were refined; Students tended to use their prior to knowledge rather than evidence such as experimental data in making claims and conclusions.

• Journal of Broadcast Engineering
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• v.1 no.1
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• pp.67-73
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• 1996

In general, the high quality audio coding(HQAC) has the structure of the convertional data compression techniques combined with moodels of human perception. The primary auditory characteristic applied to HQAC is the masking effect in the spectral domain. Therefore spectral techniques such as the subband coding or the transform coding are widely used[1][2]. However no effort has yet been made to apply the temporal masking effect and temporal redundancy removing method in HQAC. The audio data compression method proposed in this paper eliminates statistical and perceptual redundancies in both temporal and spectral domain. Transformed audio signal is divided into packets, which consist of 6 frames. A packet contains 1536 samples($256{\times}6$) :nd redundancies in packet reside in both temporal and spectral domain. Both redundancies are elminated at the same time in each packet. The psychoacoustic model has been improved to give more delicate results by taking into account temporal masking as well as fine spectral masking. For quantization, each packet is divided into subblocks designed to have an analogy with the nonlinear critical bands and to reflect the temporal auditory characteristics. Consequently, high quality of reconstructed audio is conserved at low bit-rates.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1401-1411
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• 2023

In the face of escalating utilization of the marine spatial domain, conflicts have emerged among stakeholders, necessitating effective management strategies beyond conventional government permits and regulations. Particularly within the domain of aquaculture, operational oversight relies on a localized licensing system, posing challenges in accurately assessing the prevailing circumstances. This research employs synthetic aperture radar (SAR) imagery as a tool to monitor coastal aquaculture fish farms, aimed at enhancing insights into management protocols. Leveraging Sentinel-1A imagery and time series SAR data integration, a superimposition technique is utilized, facilitating noise reduction while retaining crucial information regarding smaller-scale facilities, such as fish farms. Through analysis of VH polarization data, a detection overall accuracy of approximately 88% for coastal fish farms was achieved. The findings of this study offer potential applications in the continuous monitoring of aquaculture farms in correspondence with seasonal variations in aquaculture yields, thereby proposing frameworks for the establishment of effective management cycles for marine space utilization.

• Journal of Intelligence and Information Systems
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• v.9 no.2
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• pp.19-38
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• 2003

In this research, we propose the mechanism to develop self-evolving expert systems (SEES) based on data mining (DM), fuzzy neural networks (FNN), and relational database (RDB)-driven forward/backward inference engine. Most researchers had tried to develop a text-oriented knowledge base (KB) and inference engine (IE). However, this approach had some limitations such as 1) automatic rule extraction, 2) manipulation of ambiguousness in knowledge, 3) expandability of knowledge base, and 4) speed of inference. To overcome these limitations, knowledge engineers had tried to develop an automatic knowledge extraction mechanism. As a result, the adaptability of the expert systems was improved. Nonetheless, they didn't suggest a hybrid and generalized solution to develop self-evolving expert systems. To this purpose, we propose an automatic knowledge acquisition and composite inference mechanism based on DM, FNN, and RDB-driven inference engine. Our proposed mechanism has five advantages. First, it can extract and reduce the specific domain knowledge from incomplete database by using data mining technology. Second, our proposed mechanism can manipulate the ambiguousness in knowledge by using fuzzy membership functions. Third, it can construct the relational knowledge base and expand the knowledge base unlimitedly with RDBMS (relational database management systems) module. Fourth, our proposed hybrid data mining mechanism can reflect both association rule-based logical inference and complicate fuzzy relationships. Fifth, RDB-driven forward and backward inference time is shorter than the traditional text-oriented inference time.

• Journal of Convergence for Information Technology
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• v.7 no.3
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• pp.159-164
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• 2017

The purpose of this study is to develop and secure the human resources of SMEs by examining the causal relationship between job characteart-time job experience and career development of youth. In order to achieve the purpose of the study, 10,119 youths in the middle and high schools in Korea who participated in the panel data collection by the Korea Youth Policy Institute were surveyed from May 20 to July 12 in 2013, Panel data were used. The results of the study are as follows. First, it was found that the part-time job experience had a statistically significant effect on the planning, which is a sub-area of career development. Second, the part-time job experience has a statistically significant effect on attitude, a sub-domain of career development. Third, it was found that the part-time job experience had a statistically significant effect on the self knowledge, which is a sub-domain of career development. Fourth, it was shown that the part-time job experience had a statistically significant effect on career behavior, one of the sub-areas of career development. Fifth, it was found that the part-time experience characteristics had a statistically significant effect on the independence of sub-domains of career development. Therefore, since the part-time work of youth has a positive effect on career development, it is expected that the human resources of the future of SMEs will be secured if they create a place for career experience and job experience in connection with middle, high school and SMEs.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10871-10874
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• 2015

Background: Gestational trophoblastic neoplasia (GTN) is a malignant disease which occurs in women of reproductive age. Treatment of GTN has an excellent outcome and further pregnancies can be expected. However, data concerning quality of life in these cancer survivor patients are limited. This study aimed to assess quality of life in women who were diagnosed with GTN and remission after treatment, and to determine factors that may affect quality of life status. Materials and Methods: This cross sectional study was conducted from July 2013 to May 2014 in the Gestational Trophoblastic Disease Clinic, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Patients who were diagnosed GTN and complete remission were recruited. Data collection was accomplished by interview with two sets of questionnaires, one general covering demographic data and the other focusing on quality of life, the fourth version of Functional Assessment of Cancer Therapy (FACT-G). Descriptive statistics were used to determine general data and quality of life scores. Students t-test and one way ANOVA were used to compare between categorical and continuous data. Results: Forty four patients were enrolled in this study. The overall mean quality of life score (FACT-G) was 98.2. The overall FACT-G score was not significantly correlated with age, education level, stage of disease, treatment modalities, and time interval from remission to enrollment. However, patients who needed further fertility showed significant lower FACT-G scores in the emotional well-being domain (p=0.02). Conclusions: Overall quality of life scores in post-treatment gestational trophoblastic neoplasia patients are in the mild impairment range. Patients who desire fertility suffer lower quality of life in the emotional well-being domain.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.335-343
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• 2024

Real-time target signal processing techniques for FMCW LiDAR are described in this paper. FMCW LiDAR is gaining attention as the next-generation LiDAR for self-driving cars because of its detection robustness even in adverse environmental conditions such as rain, snow and fog etc. in addition to its long range measurement capability. The hardware architecture which is required for high-speed data acquisition, data transfer, and parallel signal processing for frequency-domain signal processing is described in this article. Fourier transformation of the acquired time-domain signal is implemented on FPGA in real time. The paper also details the C-FAR algorithm for ensuring robust target detection from the transformed target spectrum. This paper elaborates on enhancing frequency measurement resolution from the target spectrum and converting them into range and velocity data. The 3D image was generated and displayed using the 2D scanner position and target distance data. Real-time target signal processing and high-resolution image acquisition capability of FMCW LiDAR by using the proposed parallel signal processing algorithms based on FPGA architecture are verified in this paper.

• Journal of Photoscience
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• v.11 no.1
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• pp.35-40
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• 2004

[Ru(2,2'-bipyridine)$_2$(4,4'-dicarboxy-2,2'-bipyridine)]$^{2+}$(RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To evaluate the usefulness of this luminophore (RuBDc) for studying macromolecular dynamics, its intensity and anisotropy decays when conjugated to RNA bacteriophage MS2 were examined using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and the mean intensity decay time was 442.2 ns. The anisotropy decay data showed a single rotational correlation time (2334.9 ns), which is typical for a spherical molecule. The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc can be useful for studying rotational diffusion of biological macromolecules.s.

• ETRI Journal
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• v.36 no.1
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• pp.99-105
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• 2014

This paper presents a new locomotion mode recognition method based on a transformed correlation feature analysis using an electromyography (EMG) pattern. Each movement is recognized using six weighted subcorrelation filters, which are applied to the correlation feature analysis through the use of six time-domain features. The proposed method has a high recognition rate because it reflects the importance of the different features according to the movements and thereby enables one to recognize real-time EMG patterns, owing to the rapid execution of the correlation feature analysis. The experiment results show that the discriminating power of the proposed method is 85.89% (${\pm}2.5$) when walking on a level surface, 96.47% (${\pm}0.9$) when going up stairs, and 96.37% (${\pm}1.3$) when going down stairs for given normal movement data. This makes its accuracy and stability better than that found for the principal component analysis and linear discriminant analysis methods.