• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.30-34
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• 2005

This paper describes the design and manufacturing of a focused-ion-beam machining system which can make small features of nano size. We use a SIMION simulator in order to obtain the design data of an ion column. The simulation result shows that the focal length of ion beam decreases as the applied voltage of object lens increases. Finally, we obtained the good images of a mesh of 50 micrometers by using the adjustment of applied voltage, acceleration power, and dimension of each elements.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.408-410
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• 2022

최근 데이터 획득 위치에 가장 근접하고, 저 수준의 계산력을 제공하는 엣지 기기를 중심으로 직접 딥러닝 추론을 수행하고자 하는 요구가 증가하고 있다. 본 논문에서는 드론에서 촬영한 교통 영상 데이터를 기반으로, 다수의 차량 종류 및 보행자를 식별하는 모델을 Jetson Nano 에 탑재하여 기본 성능을 측정한다. 더불어, 자원제약형 기기 환경에서 TensorRT 와 Deepstream 을 활용하여 객체 식별 모델의 연산 경량화 및 추론 가속화 성능을 극대화하기 위한 구현 및 실험을 수행하여 Anchor-based 및 Anchor-free 객체 식별 모델의 정확도와 실시간 대응력을 평가하고 논의한다.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.295-302
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• 2022

In this paper, a wedge prism application method was studied to design a full-high-definition (FHD)-class high-resolution flexible endoscope. In the case of the conventional flexible endoscope optical system, the F number is made large or a liquid lens is applied to obtain the same imaging performance in a wide depth of field. However, there is a problem in that the diameter of the optical system increases because an additional light guide and equipment are required. To solve this problem, two wedge prisms were applied to the flexible endoscope optical system to adjust the image distance for each object distance. First, two wedge prisms were symmetrically placed on the designed endoscopic optical system. An image distance satisfying the target imaging performance according to each objective distance was derived. Next, the wedge prism decenter value for controlling the image distance was derived. By combining these two data, a wedge prism decenter value that satisfied the target imaging performance at each object distance was applied in multi configurations. As a result of the optimal design applied with the wedge prism, a target imaging performance of more than 20% of the modulation transfer function for a resolution of 178 cycles/mm was satisfied in the entire depth of field of 100 mm-7 mm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.51-56
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• 2015

The object of this study is to obtain the optimum mix proportion of halogen free compound with flame resistance and, for the purpose, thermal/electrical characteristics test are conducted using compatibilizing agents, flame resistance agents, hydroxide aluminum, sunscreen, antioxidant and silicon oil on the base resin of linear low density polyethylene (LLDPE), Ethylene vinyl acetate copolymer (EVA). Existing compound method accompanies many requirements to be satisfied including a lot of addition of flame resistance agents, prohibition of impact on mixing capability with base and property and etc. In this study, different from the existing method, the optimum mix proportion is determined and experimented by adding nano clay. Oxygen index test shows no difference between specimens while T-6, T-9 shows oxygen index of 29[%] and 26[%], respectively. This is concluded that hydroxide aluminum, which is a flame resistance agent, leads low oxygen index. From UL94-V vertical flame resistance test, the combustion behavior is determined as V-0, Fail based on UL94-V decision criteria. Viscometry shows low measurements in specimens with separate addition of compatibilizing agents or nano clay. Volume resistivity test shows low measurement mainly in specimens without compatibilizing agents. Therefore, with the flame resistance compound shows better performance for thermal/electrical property and the optimum mix proportion are achieved among many existing materials.

• Journal of the Korea Society of Computer and Information
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• v.29 no.8
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• pp.43-51
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• 2024

This paper proposes a method for acquiring and analyzing ocular data using a special-purpose diver mask targeted at divers who primarily engage in underwater activities. This involves tracking the user's gaze with the help of a custom-built ocular dataset and a YOLOv8-nano model developed for this purpose. The model achieved an average processing time of 45.52ms per frame and successfully recognized states of eyes being open or closed with 99% accuracy. Based on the analysis of the ocular data, a gaze tracking algorithm was developed that can map to real-world coordinates. The validation of this algorithm showed an average error rate of about 1% on the x-axis and about 6% on the y-axis.

• Journal of Broadcast Engineering
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• v.27 no.2
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• pp.185-197
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• 2022

Recently, deep learning networks with high performance for object recognition are emerging. In the case of object recognition using deep learning, it is important to build a training data set to improve performance. To build a data set, we need to collect and label the images. This process requires a lot of time and manpower. For this reason, open data sets are used. However, there are objects that do not have large open data sets. One of them is data required for license plate detection and recognition. Therefore, in this paper, we propose an artificial license plate generator system that can create large data sets by minimizing images. In addition, the detection rate according to the artificial license plate arrangement structure was analyzed. As a result of the analysis, the best layout structure was FVC_III and B, and the most suitable network was D2Det. Although the artificial data set performance was 2-3% lower than that of the actual data set, the time to build the artificial data was about 11 times faster than the time to build the actual data set, proving that it is a time-efficient data set building system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.151-159
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• 2018

Recently, stereoscopic technology has become a potential for blue ocean as a new growth power industry, and interest in it has been steadily increasing with the development of virtual and augmented reality technologies. Various methods such as binocular parallax and polarized glasses have been developed and used for stereoscopic image expression, but they have limitations such as eye damage, headache, crosstalk and resolution degradation. In this paper, we present a new method of stereoscopic image representation that can overcome the limitations and verify its applicability through basic experiments for object extraction and real - time image representation.

• Toxicological Research
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• v.28 no.2
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• pp.73-79
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• 2012

While the ability to develop nanomaterials and incorporate them into products is advancing rapidly worldwide, understanding of the potential health safety effects of nanomaterials has proceeded at a much slower pace. Since 2008, Korea Food and Drug Administration (KFDA) started an investigation to prepare "Strategic Action Plan" to evaluate safety and nano risk management associated with foods, drugs, medical devices and cosmetics using nano-scale materials. Although there are some studies related to potential risk of nanomaterials, physical-chemical characterization of nanomaterials is not clear yet and these do not offer enough information due to their limitations. Their uncertainties make it impossible to determine whether nanomaterials are actually hazardous to human. According to the above mention, we have some problems to conduct the human exposure risk assessment currently. On the other hand, uncertainty about safety may lead to polarized public debate and to businesses unwillingness for further nanotechnology investigation. Therefore, the criteria and methods to assess possible adverse effects of nanomaterials have been vigorously taken into consideration by many international organizations: the World Health Organization, the Organization for Economic and Commercial Development and the European Commission. The object of this study was to develop risk assessment principles for safety management of future nanoproducts and also to identify areas of research to strengthen risk assessment for nanomaterials. The research roadmaps which were proposed in this study will be helpful to fill up the current gaps in knowledge relevant nano risk assessment.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.215-220
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• 2012

Miniature ultrasonic and tactile sensors on Si substrate have been proposed, fabricated and characterized to detect objects for a dexterous robot. The ultrasonic sensor consists of piezoelectric PZT thin film on a Pt/Ti/$SiO_2$ and/or Si diaphragm fabricated using a micromachining technique; the ultrasonic sensor detects the piezoelectric voltage as an ultrasonic wave. The sensitivity has been enhanced by improving the device structure, and the resonant frequency in the array sensor has been equalized. Position detection has been carried out by using a sensor array with high sensitivity and uniform resonant frequency. The tactile sensor consists of four or three warped cantilevers which have NiCr or $Si:B^+$ piezoresistive layer for stress detection. Normal and shear stresses can be estimated by calculation using resistance changes of the piezoresitive layers on the cantilevers. Gripping state has been identified by using the tactile sensor which is installed on finger of a robot hand, and friction of objects has been measured by slipping the sensor.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2435-2440
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• 2003

Manipulation of the nano/micro scale object has been a key technology in biology as the sizes of DNA, chromosome, nucleus, cell and embryo are within such order. For instance, for embryo cell manipulation, the cell injection is performed manually. The operator often spends over a year to carry out a cell manipulation project. Since the typical success rate of such operation is extremely low, automation of such biological cell manipulation has been asked. As the operator spends most of his time in finding the position of cell in the Petri dish and in injecting bio-material to the cell from the best orientation. In this paper, we propose a new strategy and a vision system, by which one can find, recognize and track nucleus, polar body, and zona pellucida of the embryo cell for automatic biomanipulation. The deformable template matching algorithm has been used in recognizing the nucleus and polar body of each cell. Result suggests that it outperforms the conventional methods.