• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.681-684
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• 2021

In this paper, we study image clustering without labeling using machine learning techniques. We proposed an unsupervised machine learning technique to design an image clustering model that automatically categorizes images into groups. Our experiment focused on inception convolutional neural networks (inception V3) with k-mean methods to cluster images. For this, we collect the public datasets containing Food-K5, Flowers, Handwritten Digit, Cats-dogs, and our dataset Rice Germination, and the owner dataset Palm print. Our experiment can expand into three-part; First, format all the images to un-label and move to whole datasets. Second, load dataset into the inception V3 extraction image features and transferred to the k-mean cluster group hold on six classes. Lastly, evaluate modeling accuracy using the confusion matrix base on precision, recall, F1 to analyze. In this our methods, we can get the results as 1) Handwritten Digit (precision = 1.000, recall = 1.000, F1 = 1.00), 2) Food-K5 (precision = 0.975, recall = 0.945, F1 = 0.96), 3) Palm print (precision = 1.000, recall = 0.999, F1 = 1.00), 4) Cats-dogs (precision = 0.997, recall = 0.475, F1 = 0.64), 5) Flowers (precision = 0.610, recall = 0.982, F1 = 0.75), and our dataset 6) Rice Germination (precision = 0.997, recall = 0.943, F1 = 0.97). Our experiment showed that modeling could get an accuracy rate of 0.8908; the outcomes state that the proposed model is strongest enough to differentiate the different images and classify them into clusters.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.55-67
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• 2023

Lightweight face recognition models, as one of the most popular and long-standing topics in the field of computer vision, has achieved vigorous development and has been widely used in many real-world applications due to fewer number of parameters, lower floating-point operations, and smaller model size. However, few surveys reviewed lightweight models and reimplemented these lightweight models by using the same calculating resource and training dataset. In this survey article, we present a comprehensive review about the recent research advances on the end-to-end efficient lightweight face recognition models and reimplement several of the most popular models. To start with, we introduce the overview of face recognition with lightweight models. Then, based on the construction of models, we categorize the lightweight models into: (1) artificially designing lightweight FR models, (2) pruned models to face recognition, (3) efficient automatic neural network architecture design based on neural architecture searching, (4) Knowledge distillation and (5) low-rank decomposition. As an example, we also introduce the SqueezeFaceNet and EfficientFaceNet by pruning SqueezeNet and EfficientNet. Additionally, we reimplement and present a detailed performance comparison of different lightweight models on the nine different test benchmarks. At last, the challenges and future works are provided. There are three main contributions in our survey: firstly, the categorized lightweight models can be conveniently identified so that we can explore new lightweight models for face recognition; secondly, the comprehensive performance comparisons are carried out so that ones can choose models when a state-of-the-art end-to-end face recognition system is deployed on mobile devices; thirdly, the challenges and future trends are stated to inspire our future works.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.41-42
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• 2014

본 논문에서는 종전의 3상 PWM 정류기의 문제점을 극복하기 위하여 3상 Z-Source PWM 정류기를 제안하였다. 제안된 정류기는 시스템의 간소화, 안정화, 비용상승을 고려하여 상태관측기가 적용된 센서리스 제어 기법을 적용하였다. 3상 Z-Source PWM 정류기는 교류측 전압센서 없이 DC-link단 전압센서와 입력단 전류 센서만을 이용하여 교류측 전압을 추종한다. 제안된 3상 Z-Source PWM 정류기는 PSIM 시뮬레이션을 통하여 검증 하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.4
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• pp.221-228
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• 2021

With the advent of the IoT (internet of things) era, there has been discussion on how to efficiently use various information from daily life. In academic and industrial society, various smart devices such as smart watches, smart phones, and smart glasses have been developed and commercialized for narrowing the physical/psychological distance with user information. According to recent developments of smart devices, the contemporary people have desired to check their body information and treat disease by themselves. According to the needs of the time, biological researches by phototherapy/monitoring have been actively conducted. Among various light sources, microLEDs have been spotlighted due to their superior optoelectric properties and stability. In this paper, we would like to review the state-of-the research results on the next-generation biological therapy devices via microLEDs.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.165-170
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• 2020

Histone Deacetylases (HDACs) are enzymes that have control gene expression regulation and cell state. In additions, inhibitions of HDACs are associated with growth arrest, differentiation, or apoptosis of tumor cell. Thus HDAC inhibition is one of the interesting biological targets. A variety of HDAC inhibitors has been developed by many scientists, and some of chemical structures related with HDAC inhibitors were modified to give radiolabeled HDAC inhibitors for positron emission tomography (PET) study. In this highlight review, the development of radiolabeled HDAC inhibitors for PET study are described.

• Journal of Drive and Control
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• v.21 no.1
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• pp.53-58
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• 2024

With the recent development of intelligence and automation technologies for construction machinery, the demand for safety and efficiency of road-cutting operations has continued to increase. In response to this, a double-blade road cutter has been developed that can automatically cut roads. However, a double-blade road cutter has a load difference between the two blades due to the ground and wear conditions of the cutting blades. The difference in load between the two blades distorts the direction of travel of the cutter. In this study, a vision sensor-based driving guide technology was developed to correct the driving path of road cutters. In addition, we developed a load-sensing technology that detects blade loads in real-time and controls driving speed in the event of overload.

• Resources Recycling
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• v.33 no.1
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• pp.22-30
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• 2024

To synthesize the Ti₃AlC₂ MAX phase, a crucial precursor for generating the two-dimensional material MXene, the use of Ti scrap as an initial material is an economically feasible approach. This study aims to optimize the synthesis conditions for the phase fraction of the Ti₃AlC₂ MAX phase utilizing Ti scrap as the Ti source. The deoxidation of Ti powders, prepared through the hydrogenation-dehydrogenation process from Ti scrap, was effectively accomplished using the deoxidation in solid-state (DOSS) process. The optimal synthesis conditions were established by blending DOSS-Ti, Al, and graphite powders with particle sizes ranging from 25 ~ 32 ㎛ in a molar ratio of 3:1.1:2. The resulting phase fractions were as follows: Ti₃AlC₂ at 97.25 wt.%, TiC at 0.93 wt.%, and Al₃Ti at 1.82 wt.%. Furthermore, the oxygen content of the Ti₃AlC₂ MAX powder, spanning from 25 ~ 45 ㎛, was measured at 4,210 ppm.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.369-377
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• 2013

The purpose of this study was to examine the state of smoking among college students and the relationship between their state of smoking and smoking beliefs in an effort to provide information on the development and utilization of smoking-prevention and antismoking programs geared toward stepping up the health promotion of college students. The subjects in this study were 1,696 people at 10 different universities located in North Jeolla Province. A survey was conducted from May 1 to June 1, 2012, and the collected data were analyzed. The findings of the study were as follows: 1. Smoking status was as follows: smoking was 23.7% for students with experience, the first one when smoking was the highest 42.1% in high school and a four-year duration of smoking was highest in at least 46.1%. 2. As for smoking beliefs by general characteristics, the respondents whose monthly allowance was between 300 and 390 thousand Korean won and 400 thousand Korean won or more got 1.91 (p<0.001), Concerning the relationship between smoking and oral health, the biggest group that replied there was no relationship between the two got 2.00, which was the highest score (p<0.001). 3. Regarding the links between the state of smoking and smoking belief, the respondents who answered elementary school days in the time to begin smoking got 2.66, which was the highest score, and the one who answered four out of their five close friends were smoking got 2.60, which was the highest score (p<0.05). 4. As to the relationship of smoking dependence and intention of quitting smoking, the respondents who answered they were quite dependent on smoking got 2.75 (p<0.001), which was the highest score. And the respondents who answered they had no intention to give up smoking got 2.68, which was the highest score (p<0.01).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.454-460
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• 2021

In this work, we synthesized alloy-core InZnP quantum dots, which are more efficient than single-core InP quantum dots, using a solution process method. The effect of synthesis conditions of alloy core on optical properties was investigated. We also investigated the conditions that make up the gradient shell to minimize defects caused by lattice mismatch between the InZnP core and ZnS is 7.7%. The stable synthesis temperature of the InZnP alloy core was 200℃. Quantum dots consisting of three layered ZnSe gradient shell and single layered ZnS exhibited the best optical property. The properties of quantum dots synthesized in 100 ml and in 2,000 ml flasks were almost equal.

• Journal of Engineering Education Research
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• v.23 no.6
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• pp.33-39
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• 2020

This paper analyzes the current state of operation and the effect of introduction of the single accreditation system, which was fully introduced in 2016 by the Accreditation Board of Engineering Education Korea(ABEEK). Because Engineering Education Accreditation are program-based certification, and department operates accreditation programs and non-accreditation programs, if a student under the accreditation program fails to graduate from the accreditation program, he or she must complete the transfer to a non-accreditation program at least one year before graduation. Since 2016, when the single accreditation system was introduced, freshmen of department have allowed non-accreditation graduation only for reasons prescribed separately by the program's regulations or guidelines. In order to identify and reflect the operational status and effectiveness of the single accreditation system in the 2020 accreditation review, ABEEK conducted a complete survey on the current status of graduates in February 2020 among 157 programs at 26 universities receiving the 2020 accreditation review. The results of this study are expected to be used as basic data for the improvement of the single accreditation system in the future by examining the effects of the single accreditation system implemented after 2016 and considering the problems at the site due to the introduction of the single accreditation system of programs that ABEEK had not previously expected.