• BioChip Journal
• /
• 제12권4호
• /
• pp.332-339
• /
• 2018

The future neuro-prosthetic devices would be required spikes data monitoring through sub-nanoscale transistors that enables to neuroscientists and clinicals for scalable, wireless and implantable applications. This research investigates the spikes monitoring through integrated CNT front-end amplifier for neuro-prosthetic diagnosis. The proposed carbon nanotube-based architecture consists of front-end amplifier (FEA), integrate fire neuron and pseudo resistor technique that observed high electrical performance through neural activity. A pseudo resistor technique ensures large input impedance for integrated FEA by compensating the input leakage current. While carbon nanotube based FEA provides low-voltage operation with directly impacts on the power consumption and also give detector size that demonstrates fidelity of the neural signals. The observed neural activity shows amplitude of spiking in terms of action potential up to $80{\mu}V$ while local field potentials up to 40 mV by using proposed architecture. This fully integrated architecture is implemented in Analog cadence virtuoso using design kit of CNT process. The fabricated chip consumes less power consumption of $2{\mu}W$ under the supply voltage of 0.7 V. The experimental and simulated results of the integrated FEA achieves $60G{\Omega}$ of input impedance and input referred noise of $8.5nv/{\sqrt{Hz}}$ over the wide bandwidth. Moreover, measured gain of the amplifier achieves 75 dB midband from range of 1 KHz to 35 KHz. The proposed research provides refreshing neural recording data through nanotube integrated circuit and which could be beneficial for the next generation neuroscientists.

• Nuclear Engineering and Technology
• /
• 제54권9호
• /
• pp.3272-3282
• /
• 2022

To improve the safety and life extension qualities of nuclear fuel rods which is currently made of zirconium (Zr) alloy, research on the application of chromium (Cr) coating was conducted. Cr coating has advantages such as increased corrosion resistance and reduced oxidation rate, but non-destructive thickness evaluation studies are needed to ensure the reliability of the steps taken to provide uniform coating thickness. Eddy current testing (ECT) is a representative non-destructive technique for such as thickness evaluation and surface defect inspection. To inspect changes in thickness at micron scale, the Swept Frequency Eddy Current Testing (SFECT) method was applied to select a frequency range sensitive to changes in thickness. The coating thickness was evaluated using changes in signals, such as that for impedance. In this study, basic research was performed to evaluate the thickness of the Cr coating on a rod using an encircling sensor and the SFECT technique. The sensor design parameters were determined through simulation, after which the new sensor was manufactured. A sensor capable of measuring the thickness of a non-uniformly Cr-coating rod was selected through an experiment evaluating the performance of the manufactured sensor. This was done using the impedance-difference of a Cr-coating rod and a Zr alloy rod. The possibility of evaluation of the Cr coating thickness was confirmed by comparing the experimental results with the selected sensor and the signals of the measured Cr-coating rod. All simulation results were verified experimentally.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제11권11호
• /
• pp.473-478
• /
• 2022

온라인 저지 시스템 지원하기 위한 표절 검사, 소스코드 분석 및 자동화된 튜터링 기법이 연구되고 있다. 최근 딥러닝 기술 기반의 소스코드 유사도 분석을 통한 표절 감지 기술들이 제안되었으나, 자동화된 튜터링을 지원하기 위한 딥러닝 기반의 연구는 미흡한 실정이다. 따라서 본 논문에서는 자바 바이트코드와 문제정보를 결합하여 학습하고, 학습자가 온라인 저지 시스템에 코드를 제출하기 전에 pass/fail 여부를 예측할 수 있는 GRU 기반의 Input / Output side FiLM 모델을 제안한다. 또한 온라인 저지에 수집되는 데이터의 특성상 비대칭이 발생하기 때문에 밸런스 샘플링 기법을 적용하여 데이터를 균등하게 분포시켜 두 상황을 제안한 모델로 학습하였다. 실험 결과 Input side FiLM 모델이 가장 높은 73.63%의 성능을 보였다. 이를 기반으로 학습자들이 온라인 저지의 평가를 받기 전에 pass/faill 여부를 확인하여 소스코드 개선에 대한 피드백 기능에 적용 가능할 것으로 예상된다.

• 한국음향학회지
• /
• 제42권5호
• /
• pp.395-401
• /
• 2023

음향 이벤트 검출(Sound Event Detection, SED)은 음향 신호에서 관심 있는 음향의 종류와 발생 구간을 검출하는 기술로, 음향 감시 시스템 및 모니터링 시스템 등 다양한 분야에서 활용되고 있다. 최근 음향 신호 분석에 관한 국제 경연 대회(Detection and Classification of Acoustic Scenes and Events, DCASE) Task 4를 통해 다양한 방법이 소개되고 있다. 본 연구는 다양한 영역에서 성능 향상을 이끌고 있는 Dense Convolutional Networks(DenseNet)을 음향 이벤트 검출에 적용하기 위해 설계 변수에 따른 성능 변화를 비교 및 분석한다. 실험에서는 DenseNet with Bottleneck and Compression(DenseNet-BC)와 순환신경망(Recurrent Neural Network, RNN)의 한 종류인 양방향 게이트 순환 유닛(Bidirectional Gated Recurrent Unit, Bi-GRU)을 결합한 DenseRNN 모델을 설계하고, 평균 교사 모델(Mean Teacher Model)을 통해 모델을 학습한다. DCASE task4의 성능 평가 기준에 따라 이벤트 기반 f-score를 바탕으로 설계 변수에 따른 DenseRNN의 성능 변화를 분석한다. 실험 결과에서 DenseRNN의 복잡도가 높을수록 성능이 향상되지만 일정 수준에 도달하면 유사한 성능을 보임을 확인할 수 있다. 또한, 학습과정에서 중도탈락을 적용하지 않는 경우, 모델이 효과적으로 학습됨을 확인할 수 있다.

• Journal of Positioning, Navigation, and Timing
• /
• 제12권3호
• /
• pp.271-280
• /
• 2023

Pedestrian Dead Reckoning (PDR) methods using initial sensors are being studied to provide the location information of smart device users in indoor environments where satellite signals are not available. PDR can continuously estimate the location of a pedestrian regardless of the walking environment, but has the disadvantage of accumulating errors over time. Unlike this, WiFi signal-based wireless positioning technology does not accumulate errors over time, but can provide positioning information only where infrastructure is installed. It also shows different positioning performance depending on the environment. In this paper, an integrated positioning technology integrating two positioning techniques with different error characteristics is proposed. A technique for correcting the error of PDR was designed by using the location information obtained through WiFi Measurement-based fingerprinting as the measurement of Extended Kalman Filte (EKF). Here, a technique is used to variably calculate the error covariance of the filter measurements using the WiFi Fingerprinting DB and apply it to the filter. The performance of the proposed positioning technology is verified through an experiment. The error characteristics of the PDR and WiFi Fingerprinting techniques are analyzed through the experimental results. In addition, it is confirmed that the PDR error is effectively compensated by adaptively utilizing the WiFi signal to the environment through the EKF to which the adaptive error covariance proposed in this paper is applied.

• 시큐리티연구
• /
• 제56호
• /
• pp.9-30
• /
• 2018

범죄 문제가 심각한 우리 사회의 현실에서, 최근에는 범죄와 범죄두려움 문제를 실질적으로 줄이기 위하여 CPTED 등 각종 범죄의 사전 예방 전략을 도입하고 있으며, 소위 타겟하드닝(Target Hardening) 또한 범죄예방, 특히 침입범죄의 방지 전략의 하나로서 활용되고 있다. 침입범죄와 같이 가장 빈번하게 발생하면서 국민 특히 취약계층 서민들의 생활안전을 꾸준하고 집요하게 위협하는 위험도 높은 범죄 유형에 대응하기 위해 그간 우리 사회가 자원을 투자해 온 셉테드 전략은 CCTV나 조명, 경보장치 등 간접적이고 심리적인 억제를 중심으로 하고 있어서 직접적으로 방어하기에는 사실상 실효성에 많은 한계가 있다. 바로 이런 한계를 극복하기 위한 타겟하드닝은 침입범죄와 같은 범죄를 보다 직접적이고 실효적으로 차단하고 방지하는 전략으로 잘 알려져 있다. 우리나라에서도 2016년에 전국 최초로 안산시에서 실험이 이루어졌고 이 연구는 실험지역을 선정하여 침입방어성능이 인증된 방범시설을 주요 침입구인 창문 등에 설치하는 타겟하드닝 전략을 수행한 후 침입범죄 감소효과를 경찰 공식 범죄통계를 활용하여 분석한 것이다. 소위 범죄전이효과도 살펴보기 위해 방범인증시설 설치지역과 주변 완충지역, 그리고 통제지역과의 범죄발생을 비교하는 WDQ(Weighted Displacement Quotient) 분석을 수행하였다. 분석 결과 타겟하드닝 CPTED기법의 침입 범죄 경감의 효과는 상당한 것으로 나타났다. 통제지역에서도 침입범죄가 다소 감소한 것은 사실이지만, 방범인증시설이 설치된 실험지역의 주택들은 침입 범죄가 설치 후에 크게 감소하였다. 완충지대로 범죄전이 효과는 보이지 않았으며 오히려 주변지역의 범죄 또한 감소하였다.

• 대한간호학회지
• /
• 제25권1호
• /
• pp.45-60
• /
• 1995

This study investigated the effects of education program conducted through individual home visit by CHPs, which was developed ,by the operational re-search technique for families of dementia patients. (Yeo Shin Hong et at,1994) The study was conducted in the form of a primary experimental design with 43 people as subjects, including dementia patients and family member in several Myon areas of Chungcheong Namdo between June 10 and August 20, 1994. The data was collected by questionnaires through the home visit by the CHPs. The results of study are as follows. 1. There is no difference in the quality of life between before and after the education program. 2. Role stress 'before the education program' was significantly different than 'after the education program'. 3. There was no difference in the feeling of burden between before and after the education program. 4. There was a significant difference in the abnormal behaviors of patients between before and after the education program. 5. The knowledge of dementia by the patient's family increased significantly after the education program, compared to that of 'before the education program'. 6. There was a significant difference in the attitude of family members toward the education program on dementia between before and after the education program. 7. The results of analysis on the coefficient relationship of various variables showed that the age of patients and family members have a significant correlation with role stress(p=.01). 8. In the subjective evaluation of family members on changes in actual nursing actions and the improvement of knowledge and technique in terms of daily living, (including abnormal behavior of patients, adjustment of environment for patients, activity programs for patients, communication technique with patients, ensuring the safety of patients, clothing, meals and elimination, 60-65% of family members responded that their knowledge had increased. As for improvement in techniques for each item, the technique for communication with patients showed the greatest improvement while the action program method for patients showed the least change. As for the nursing service provided to patients, most respondents showed a positive change. The specific items for which more than 80% respondents answered positively were as follows : recognizing the demand of patients, getting patients to do simple house works, talking softly and gently, removing dangerous things, preparing comfortable clothes that are easy to put on and take off, and limiting water consumption at night. As a result of study, the following suggestions can be made. The purpose of the study was to examine the effect of an education program developed and applied for dementia patients and family members in the community. This needs to be compared with a similar study conducted in the urban setting. In addition, a community service program (ex : nursing hem and shelter) including the application of the education program should be developed and the study done to investigate its effect.

• 조형예술학연구
• /
• 제11권
• /
• pp.79-108
• /
• 2007

"Printing is an Art of reproduction & a Technique of However printing has extended its limitation from a genre of reproduction itself and now it stands on the turning point as an art such as painting or sculpture which expresses artist's originality. Early Printing has had relations in depth with press printing in terms of information recording, preservation, and transmission. It was acknowledged value in a way of information satisfaction different from how it is valued as a pure art today. But, later printing has transferred its function from a mean of reproduction to pure art due to the development of printing skills and photography invention. It can be said that the concept of modern printing is taking over its genealogy as a creative work not as just printing. Also its expression capability is widen to dimensional printing and high-tech multimedia from original tradition techniques. As we discussed above, modern painting is very open to various changes. This modern painting aspect can be seen as an extended interpretation of 'board' concept. This dissertation raises a question why monotype and monoprint couldn't secure its position in printing history in spite of numerous artists' tryouts in its way. Monotype and monoprint fundamentally based on intaglio technique in its history. Yet, its systematic study hasn't been worked out. This is because of the lack of recognition of monotype and monoprint's originality as printing. Especially in monoprint, it has known as an early stage in copperplate printing process which is an attempt to solve the technique limitation or trial work for edition. Likewise the reason why monotype and monoprint remains at the edge of printing border ambiguously is because of conceptual, technical characteristics which are against traditional printing. In traditional printing, the concept of board is important as a method of reproduction. Different from the fact, monotype and monoprint accept the form of medium 'board' conceptually out of limited condition as mentioned. Thus monotype and monoprint hasn't stand out for several reasons until late 20th century when it started come out to public as people starts to have interests that works from famous artists are actually based on monotype and monoprint. This dissertation likes to step into the monotype and monoprint theoretically which is not well known in domestic and try to study the meaning of monotype and monoprint as a printing medium which is also hasn't been considered sincerely. For this study the process follow as below. First, look into how monotype and monoprint has a concept and history. Next, check differences through comparison with traditional printing and how printing can be understood in what aspects at the same time. After, verify how monotype and monoprint have influence on the acceptance of extended concept of 'board'. This study will show the expressional possibility of monotype and monoprint which has already known as 'tableau printing' in today's situation where adventurous experiments of printing medium are going on with the development of technology.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 춘계학술대회 논문집
• /
• pp.191-194
• /
• 2007

In hot embossing lithography which has shown to be a good method to fabricate polymeric patterns for IT and bio components, it is very important to determine the proper process conditions of pressure, temperature, and time. It is also a key factor for predicting the optical properties of final product to calculate residual stress distribution after the embossing process. Therefore, to design the optimum process with right conditions, the ability to predict viscoelastic behavior of polymer during and after the hot embossing process is required. The objective of the present investigation is to establish simulation technique based on constitutive modeling of polymer with experiments. To analyze deformation behavior of viscoelastic polymer, the large strain material properties were obtained from quasi-static compression tests at different strain rates and temperatures and also stress relaxation tests were executed. With this viscoelastic material model, finite element simulation of hot embossing was executed and stress distribution is obtained. Proper process pressure is very important to predict the defect and incomplete filling.