• Electrical & Electronic Materials
• /
• v.10 no.3
• /
• pp.233-238
• /
• 1997

We have investigated gas-detection characteristics of CuTBP (Copper-tetra-tert-butylphthalocyanine) chemiresistor devices exposed to air/200ppm N $O_{2}$ gases. The CuTBP films were made by Langmuir-Blodgett (LB) techniques. Sensitivity, response time, recovery time, and reproducibility of the devices were measured by current voltage characteristics. Interdigital electrode was used to improve the sensitivity. It was observed that a conductance G increases monotonically as the number of interdigital electrode finger pairs increases. As the number of interdigital electrode finger pairs increases, the sensitivity S( $G_{gas}$/ $G_{air}$) increases more than 50 times and stable. But the response time was delayed. The average recovery time of the CuTBP chemiresistor devices turned out to be about 100 second. We have also investigated applicability of the CuTBP chemiresistor device for a gas sensor.sor.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.2
• /
• pp.157-164
• /
• 2014

In this paper, we design a gripping force control system using tactile sensor to prevent slip when gripper tries to grasp and lift an object. We use a flexible tactile sensor for measuring uniplanar pressure on gripper's finger and develop an algorithm to detect the onset of slip using the sensor output. We also use a flexible pressure sensor to measure the normal force. In addition, various signal processing techniques are used to reduce noise included in the sensor output. A 3-finger gripper is used to grasp and lift up a cylindrical object. The tactile sensor is attached on one of fingers, and sends output signals to detect slip. Whenever the sensor signal is similar to the slip pattern, gripper force is increased. In conclusion, this research shows that slip can be detected using the tactile sensor and we can control gripping force to eliminate slip between gripper and object.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.2 no.4
• /
• pp.280-287
• /
• 2002

We present technical issues involved in the development of actuators and sensors for applications to high-precision Micro Electro Mechanical System (MEMS). The technical issues include fabrication uncertainty and noise disturbance, causing major difficulties for MEMS to achieve high-precision actuation and detection functions. For nano-precision actuators, we solve the fabrication instability and electrical noise problems using digital actuators coupled with nonlinear mechanical modulators. For the high-precision capacitive sensors, we present a branched finger electrodes using high-amplitude anti-phase sensing signals. We also demonstrate the potential applications of the nanoactuators and nanodetectors to high-precision positioning MEMS.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.12
• /
• pp.1097-1102
• /
• 2003

In this paper, we used only PR as etching mask, while it used usually Cr/AU as etching mask, and in order to fabricate a photosensor has the increased sensitivity, we investigated on the sensitivity of general type and p-i-n type diode. we designed microchannel size width max 10um, min 5um depth max 10um, reservoir size max 100um, min 2mm. Fabrication of microfluidic devices in glass substrate by glass wet etching methods and glass to glass fusion bonding. The p-i-n diode has higher sensitivity than photodiode, Considering these results, we fabricated p-i-n diodes on the high resistive(4㏀$.$cm) wafer into rectangle and finger pattern and compared internal resistance of each pattern. The internal resistance of pin diode can be decreased by the application of finger pattern has parallel resistance structure from 571Ω to 393Ω.

• Journal of the Korean Society of Industry Convergence
• /
• v.18 no.3
• /
• pp.167-172
• /
• 2015

In this paper, we propose a new approach to design and control a smart gripper of robot system. A control method for flexible grasping a object in partially unknown environment was proposed, where a proximate sensor detecting the distance between the fingertip and object was used. Based on the proximate sensor signal the finger motion controller could plan the grasping process divided in three phases. The first step is scanning process which two first joints were moved to mid-position of the detected range by a state-variable feedback position controller, after the scanning was finished. The contact force of fingertip was then controlled using the detection sensor of the servo controller for finger joint control. The proposed grasping planning was tested on rectangular bar.

• Proceedings of the KSME Conference
• /
• 2001.06c
• /
• pp.53-58
• /
• 2001

This paper presents a high resolution capacitive microaccelerometer for applications to personal information systems. We reduce the mechanical noise level of the microaccelerometer by increasing the proof-mass based on deep RIE process. We reduce the electrical noise level by increasing the amplitude of an AC sense voltage. The high sense voltage is obtained by DC-to-DC voltage multiplier. In order to solve the nonlinearity problem caused by the high sense voltage, we modify the conventional comb electrode of straight finger type into that of branched finger type, resulting in self force-balancing effects for enhanced detection linearity. The proposed branched finger capacitive microaccelerometer was fabricated by the deep RIE process of an SOI wafer. The fabricated microaccelerometer reduces the electrical noise at the level of $2.4{\mu}g/\sqrt{Hz}$ for the sense voltage of l6.5V, which is 10.1 times smaller than the electrical noise level of $24.3{\mu}g/\sqrt{Hz}$ at 0.9V. For the sense voltage higher than 2V, the electrical noise level of the microaccelerometer became smaller than the constant mechanical noise level of $11{\mu}g/\sqrt{Hz}$. Total noise level, including the electrical noise and the mechanical noise, has been measured as $9{\mu}g/\sqrt{Hz}$ for the sense voltage of 16.5V, which is 3.2 times smaller than the total noise of $28.6{\mu}g/\sqrt{Hz}$ for the sense voltage of 0.9V. The self force-balancing effect results in the increased stiffness of 1.98 N/m at the sense voltage of 17.8V, compared to the stiffness of 1.35 N/m at 0V, thereby generating the additional stiffness at the rate of $0.002N/m/V^{2}$.

• Journal of Trauma and Injury
• /
• v.27 no.4
• /
• pp.139-144
• /
• 2014

Purpose: Detection and determination of tendon injury in the finger or hand is not easy. Therefore, we aimed to study and evaluate the accuracy and the effectiveness of ultrasonography for the diagnosis of finger tendon injury. Methods: In this study, we enrolled patients, regardless of age and sex, with lacerations on their fingers. Patients with invisible wounds were excluded. We evaluated the accuracy and the effectiveness of ultrasonography and compared the results obtained from ultrasonography and with those obtained by visual observation of the injuries. Results: The sensitivity, the specificity and the accuracy of ultrasonography were found to be 66.7%, 100% and 91.3%, respectively (p<0.001) while those of physical examination were 71.4%, 98.3% and 91.3%, respectively. Small differences were observed between the sensitivities and specificities of the two examinations; however, the accuracies were the same (p<0.001). The area under the receiver operating characteristic (ROC) curve, which was used for diagnosis of tendon rupture using ultrasonography, was found to be 0.985 (95% confidence interval CI: 0.929-0.999),while that of physical examination was 0.938 (95% CI: 0.861-0.980). Conclusion: Ultrasonography can be used an effective diagnostic tool for patients with finger tendon injury.

• Journal of Digital Convergence
• /
• v.11 no.7
• /
• pp.157-163
• /
• 2013

In this paper, we propose a vision and depth information based real-time hand gesture interface method using finger joint estimation. For this, the areas of left and right hands are segmented after mapping of the visual image and depth information image, and labeling and boundary noise removal is performed. Then, the centroid point and rotation angle of each hand area are calculated. Afterwards, a circle is expanded at following pattern from a centroid point of the hand to detect joint points and end points of the finger by obtaining the midway points of the hand boundary crossing and the hand model is recognized. Experimental results that our method enabled fingertip distinction and recognized various hand gestures fast and accurately. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 90% and the performance indicated over 25 fps. The proposed method can be used as a without contacts input interface in HCI control, education, and game applications.

• Journal of Korea Multimedia Society
• /
• v.18 no.10
• /
• pp.1149-1156
• /
• 2015

This paper proposes the hand contour detector which is robust to noises. Existing methods reduce noises by applying morphology to extracted edges, detect finger tips by using the center of hands, or exploit the intersection of curves from hand area candidates based on J-value segmentation(JSEG). However, these approaches are so vulnerable to noises that are prone to detect non-hand parts. We propose the noise tolerant hand contour detection method in which non-skin area noises are removed by applying skin area detection, contour detection, and a threshold value. By using the implemented system, we observed that the system was successfully able to detect hand contours.

• The Magazine of the IEIE
• /
• v.29 no.4
• /
• pp.62-76
• /
• 2002

스마트 안테나는 한정된 채널을 최대한 효율적으로 이용하여 용량(capacity)을 최대화시킬 수 있는 기술이다. 본 논문은 스마트 안테나의 원리와 기술을 설명하고 한양대학교 통신신호처리 연구실에서 연구·개발 중인 동기식 CDMA 스마트 안테나 시스템을 사용하여 이동통신 시스템의 주된 관심사인 용량을 최대화하는 방법을 제시한다. 스마트 안테나 시스템의 전체적인 성능 증가를 위해서는 핑거(finger)뿐 아니라 탐색기(searcher), 추적기(tracker) 각각의 성능도 우수해야 하므로, 본 논문에서는 현재까지 활발히 연구가 이루어지지 않은 탐색기, 추적기의 성능을 분석하고 BER(Bit Error Rate), FER(Frame Error Rate) 및 검출 확률 (detection probability)등의 모의 실험 결과를 바탕으로 스마트 안테나의 우수성을 분석한다.