• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1364-1367
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• 2008

Oxidative stress damages all cellular constituents, and therefore, cell has to possess various defense mechanisms to cope. Saccharomyces cerevisiae, widely used as a model organism for studying cellular responses to oxidative stress, contains three glutathione peroxidase (Gpx) proteins. Among them, Gpx3 plays a major defense role against oxidative stress in S. cerevisiae. In this study, in order to identity the new interaction proteins of Gpx3, we carried out two-dimensional gel electrophoresis after immunoprecipitation (IP-2DE), and MALDI-TOF mass spectrometry. The results showed that several proteins including protein disulfide isomerase, glutaredoxin 2, and SSY protein 3 specifically interact with Gpx3. These findings led us to suggest the possibility that Gpx3, known as a redox sensor and ROS scavenger, has another functional role by interacting with several proteins with various cellular functions.

• Journal of Information Technology Services
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• v.19 no.3
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• pp.139-149
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• 2020

There are now many different commercial weather sensors suitable for smart farms, and various smart farm devices are being developed and distributed by companies participating in the government-led smart farm expansion project. However, most do not comply with standard specifications and are therefore limited to use in smart farms. This paper proposed the connecting structure of operating non-standard node devices in smart farms following standard specifications supporting smart greenhouse. This connecting structure was proposed as both a virtual node module method and a virtual node wrapper method. In addition, the SoftFarm2.0 system was experimentally operated to analyze the performance of the implementation of the two methods. SoftFarm2.0 system complies with the standard specifications and supports non-standard smart farm devices. According to the analysis results, both methods do not significantly affect performance in the operation of the smart farm. Therefore, it would be good to select and implement the method suitable for each non-standard smart farm device considering environmental constraints such as power, space, distance of communication between the gateway and the node of the smart farm, and software openness. This will greatly contribute to the spread of smart farms by maximizing deployment cost savings.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.103-110
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• 2011

In this paper, we propose a gaze recognition interface for smart wheelchair. The gaze recognition interface is a user interface which recognize the commands using the gaze recognition and avoid the detected obstacles by sensing the distance through range sensors on the way to driving. Smart wheelchair is composed of gaze recognition and tracking module, user interface module, obstacle detector, motor control module, and range sensor module. The interface in this paper uses a camera with built-in infra red filter and 2 LED light sources to see what direction the pupils turn to and can send command codes to control the system, thus it doesn't need any correction process per each person. The results of the experiment showed that the proposed interface can control the system exactly by recognizing user's gaze direction.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.834-837
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• 2005

In this paper, we describe the method of non-invasive blood pressure measurement using pulse wave transit time(PWTT). PWTT is a new parameter involved with a vascular that can indicate the change of BP. PWTT is measured by continuous monitoring of ECG and pulse wave. No additional sensors or modules are required. In many cases, the change of PWTT correlates with the change of BP. We measure pulse wave using the photo plethysmograph(PPG) sensor in an earlobe and we measure ECG using the ECG monitoring device our made in the chest. The measurement device for detecting pulse wave consists of infrared LED for transmitted light illumination, pin photodiode as light detector, amplifier and filter. We composed 0.5Hz high pass, 60Hz notch and 10Hz low pass filter. ECG measurement device consists of multiplexer, amplifier, filter, micro-controller and RF module. After amplification and filtering, ECG signal and pulse wave is fed through micro-controller. We performed the initial work towards the development of ambulatory BP monitoring system using PWTT. An earlobe is suitable place to measure PPG signal without the restraint in daily work. From the results, we can know that the dependence of PWTT on BP is almost linear and it is possible to monitoring an individual BP continuously after the individual calibration.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.45-50
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• 2011

Recently, machine olfactory systems that have been proposed as an artificial substitute of the human olfactory system are being studied by many researchers because they can scent dangerous gases and identify the type of gases in contamination areas instead of the human. In this paper, we present an effective design method for the gas identification system. The design method adopted the sequential combination between genetic algorithms and TSK fuzzy logic system. First, the proposed method allowed the designed gas identification system effectively performing the pattern analysis because it was able to avoid the curse of dimensionality caused by use of a large number of sensors. Secondly, the method led the gas identification system to good performance because it was able to deal with drift characteristics of the sensor data by using description ability of the fuzzy system for nonlinear data. In simulation, we demonstrated the effectiveness of the designed gas identification system by using the simulation results of five types of gases.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.131-137
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• 2016

In this study, a multilevel visible light communication (VLC) system based on resistor ladder circuit is designed to transmit medical data. VLC technology is being considered as an alternative wireless communication due to various advantages such as ubiquity, license free operation, low energy consumption, and no radio frequency (RF) radiation characteristics. With VLC even in places where traditional RF communication (e.g., Wi-Fi) is forbidden, significant bio-medical signal including the electrocardiography (ECG) and photoplethysmography (PPG) data can be transmitted. More lives could be saved anywhere by this potential advantage of VLC with a fast emergency response time. A multilevel transmission scheme is adopted to improve the data capacity with keeping simplicity, where data transmission rate can increase by log2m times (m is the number of voltage levels) than that of conventional VLC transmission based on on/off keying. In order to generate multi-amplitudes, resistor ladder circuit, which is a basic principle of digital to analog convertor, is employed, and information is transferred through LED (Light-Emitting Diode) with different voltage level. In the receiver side, multilevel signal is detected by optical receiver including a photo diode. Then, the collected data are analyzed to serve the necessary medical care to the concerned patient.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.225-232
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• 2004

Recently, there has been a rapid development in computer technology, which has in turn led to develop the automated welding system using Artificial Intelligence (AI). However, the automated welding system has not been achieved duo to difficulties of the control and sensor technologies. In this paper, the classification of the optimized bead geometry such as bead width, height penetration and bead area in the Gas Metal Arc (GMA) welding with fuzzy logic is presented. The fuzzy C-Means algorithm (FCM), which is best known an unsupervised fuzzy clustering algorithm is employed here to analysis the specimen of the bead geometry. Then the quality of the GMA welding can be classified by this fuzzy clustering technique and the choice for obtaining the optimal bead geometry can also be determined.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.283-291
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• 2007

In the age of ubiquitous computing, computer systems will be seamlessly integrated into our everyday life, providing services and information to us in an anywhere, anytime fashion. This ubiquitous computing can be used for developing a ubiquitous learning (U-learning). In this paper, we present a framework for U-school in which ubiquitous computing technologies are applied to advance the existing ERSS (Korea's Educational Resources Sharing System). Our framework applies mobile, sensor, and context-aware technologies to the existing ERSS. This framework presents a user-centric learning environment, using user-centric scenario. The U-school with context-aware services therefore can lead to the just-in-time learning or learner-led learning based on dynamic contexts acquired from learners, teachers and computing entities.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.131-131
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• 2014

양자점은 전통적인 유기 염료에 비해 흡광영역이 넓고 발광 피크의 폭이 좁으며, 흡광과 발광 사이의 에너지 차가 커서 검출이 용이하고, 광안정성이 우수할 뿐만 아니라, 단순히 크기를 조절함으로써 발광 피크의 에너지를 제어할 수 있는 특장 때문에 많은 연구가 진행되었다. 그러나 많은 나노입자들과 마찬가지로 실질적인 응용을 위해서는 양자점 나노입자들도 대부분 표면개질을 거쳐야 하는데, 이 과정이 까다롭고 또 표면개질 중에 나노입자들의 응집이 일어나거나 광특성이 나빠지는 등의 문제가 흔히 발생한다. 한편, 서브미크론 크기의 입자들은 나노입자에 비해 응집현상이 미미해서 상대적으로 취급이 용이하다. 그 중에서도 실리카 입자들은 합성방법도 쉽게 확립되어 있고 생체친화성이 우수하며 그 표면화학 반응이 이미 잘 알려져 있어서 활용하기가 매우 용이하다. 따라서 양자점 층을 실리카 표면 가까이에 자기조립을 통해 배열한 하이브리드 구조는 양자점의 장점을 편리하게 이용할 뿐만 아니라 실리카의 표면개질 특성도 그대로 이용할 수 있다는 이중의 장점이 있다. 본 논문에서는 코어/쉘 구조로 안정화된 II-VI 반도체 양자점 층을 아래 그림 1과 같이 실리카 콜로이드 내에 배열한 하이브리드 구조를 소개하고, 이 하이브리드 구조를 표면개질 하여 LED 칩 위에 패키징 함으로써 백색광을 제조한 연구 및 더 나아가 중심에 초상자성 클러스터 핵을 배치하고 이를 둘러싼 실리카 콜로이드 표면 가까이에 양자점 층을 배열한 초상자성 하이브리드 구조를 합성하여 이를 on-site sensor에 적용한 연구 결과를 소개한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.683-686
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• 2002

It is fundamental to count and pack the pills in the medicine manufacture field but those tasks are time and labor consuming. Thus, the need fur automation of those tasks is necessarily getting increased in order to get effective mass production. It Is significant to perceive pills quickly and precisely. There were many trials for this processing but the performance of the existing counting machines varies about size, shape and dispersion tendency of pills. In this paper, the authors try to improve the counting performance of a pill counting machine that has optical sensors with the neural network. The passing signal of pill is acquired with optical sensor and the passage signal of the pill is extracted as input patterns. The gradient and integration of signal during passing time and the time keeping the pill interrupt the light from the LED are used as characteristic feature. The back propagation and perception algorithm are used for training. Experimental results with several pills show that the designed algorithm is a little bit effective to reduce the noise effect which is generated from interference among the machine components and unreliable environment.