• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.148-155
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• 2008

This study presents a process control of the wafer edge exposure (WEE) used in 300[mm] wafer environment. WEE, as a key module of the overall track system (coater and developer) for making patterns on wafer, is a system to expose the UV-ray on the wafer to remove a photo resist around edge of the wafer. It can measure, memorize and control the distance and angles from wafer center to edge. Recently in the 300[mm] semiconductor fabrication, the track system strongly requires that WEE station has a controller with high throughput and accuracy to increase process efficiency. We have designed and developed the controller, and present here a WEE control algorithm and experimental results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.111-116
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• 2020

Flexible tactile sensors, which are primarily used as grippers in robots, are mainly used to handle highly elastic or highly flexible objects. That is, flexible grippers are used when an object cannot be sufficiently controlled by applying a specific output force or taking a specific grabbing action. This is because a flexible tactile sensor needs to measure the pressure applied directly to held objects while deforming according to the shape of the object to be handled. CNT-based sensors used to be made from a highly flexible polymer to give flexibility and it is known that the sensors are greatly affected by the contact resistance of the terminal that connects the sensor to an electrical circuit; therefore, this paper clarifies the contact resistance of MWCNTs-based flexible tactile sensors and terminals. The effects of main and plating materials for terminals are investigated and the combinations of main and plating materials that exhibit contact resistance are measured in a typical industrial environment.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.60-64
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• 2023

In this study, the electrical contact resistance characteristics between graphene and metals, which is one of important factors for the performance of graphene-based devices, were compared. High-quality graphene was synthesized by chemical vapor deposition (CVD) method, and Al, Cu, Ni, and Ti as electrode materials were deposited on the graphene surface with equal thickness of 50 nm. The contact resistances of graphene transferred to SiO₂/Si substrates and metals were measured by the transfer length method (TLM), and the average contact resistances of Al, Cu, Ni, and Ti were found to be 345 Ω, 553 Ω, 110 Ω, and 174 Ω, respectively. It was found that Ni and Ti, which form chemical bonds with graphene, have relatively lower contact resistances compared to Al and Cu, which have physical adsorption properties. The results of this study on the electrical properties between graphene and metals are expected to contribute to the realization of high-performance graphene-based devices including electronics, optoelectronic devices, and sensors by forming low contact resistance with electrodes.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.149-160
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• 2023

This study develops a time-varying system-based noncontact fabric sensor that can measure cerebral blood-flow signals to explore the possibility of brain blood-signal detection and emotional evaluation. The textile sensor was implemented as a coil-type sensor by combining 30 silver threads of 40 deniers and then embroidering it with the computer machine. For the cerebral blood-flow measurement experiment, subjects were asked to attach a coil-type sensor to the carotid artery area, wear an electrocardiogram (ECG) electrode and a respiration (RSP) measurement belt. In addition, Doppler ultrasonography was performed using an ultrasonic diagnostic device to measure the speed of blood flow. The subject was asked to wear Meta Quest 2, measure the blood-flow change signal when viewing the manipulated image visual stimulus, and fill out an emotional-evaluation questionnaire. The measurement results show that the textile-sensor-measured signal also changes with a change in the blood-flow rate signal measured using the Doppler ultrasonography. These findings verify that the cerebral blood-flow signal can be measured using a coil-type textile sensor. In addition, the HRV extracted from ECG and PLL signals (textile sensor signals) are calculated and compared for emotional evaluation. The comparison results show that for the change in the ratio because of the activation of the sympathetic and parasympathetic nervous systems due to visual stimulation, the values calculated using the textile sensor and ECG signals tend to be similar. In conclusion, a the proposed time-varying system-based coil-type textile sensor can be used to study changes in the cerebral blood flow and monitor emotions.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.380-388
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• 2000

The finite element analysis of a micro turbine was made to investigate safety margin of its operating condition for the high aspect ratio nickel micro turbine blades fabricated by conventional LIGA-like method. From our study, we found that the fabricated turbine could not exceed its yield strength even if the pressure difference between inlet and outlet of turbine blade was about 44kPa, and the correlation of friction coefficient and the maximum stress, caused by contact friction between outer diameter of shaft and inner diameter of turbine blade, was somewhat reciprocal. The maximum stress was decreased with the increasing contact friction, when turbine blade was in its state of rotation. By the results of our study, we conclude that it is possible to fabricate metal micro turbine more easily han surface micromachining technology and to operate with no risk of metal structure's damage, which is caused by yield strength, if the operating condition with the design of micro turbine itself are optimized. It is useful to adopt other applications which have the contact problems between a moving part and the fixed one in micro structures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.324-326
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• 2011

Measuring a biosignal during sleep is an important part of diagnosis and treatment of sleep disorder and also used to determine the general quality of sleep. As in current polysomnography, Contact method, which requires the attachment of electrodes to the skin, is the typical method to measure a biosignal during sleep. The procedure of this test is often considered to be inconvenient and tiresome because it requires attaching the device to the skin for each observation, and also limits free movement throughout the test. For this reason, the research on the acquiring the biosignal information without any attachment of a fixture on the skin is being conducted actively these days. In this study, it is suggested to check the heart rate per minute and the presence of breathing by placing a Piezo, which is a film type of pressure sensor, on the bed.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1405-1410
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• 2018

The Ringer's Solution used in medical institutions is one of the injections helpful for recovering the body condition from fever or dehydration by supplying the water to the body. The medical staffs frequently check the amount of Ringer's Solution prescribed for the relevant patient to check the time for replacing the Ringer's Solution. However, currently, many nurses experience the excessive workload because of the insufficient workforce and lots of workload assigned to each of the nurses; so the they cannot provide the high-quality medical services to patients and guardians. In order to solve this problem, this thesis designed and realized the Ringer's Solution replacement time control system through the non-contacting sensor, IoT device using WiFi, and OCS interlock. Thus, this study is expected to be able to efficiently operate the Ringer's Solution replacement work and also to provide the high-quality medical service to patients and guardians by automatically notifying the timing of Ringer's Solution replacement to medical staffs, and omitting the inefficient intermediate step in the past.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.379-385
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• 2017

In general, distribution board, panel board and motor control center can be installed over a wide area such as residence of group, building, schools, factories, ports, airports, water service and sewerage, substation and heavy industries that are used to supply converts the voltages extra high voltage into optimal voltage. There are electrical accidents due to rise of contact temperature, loose contact between busbar, deterioration of the contact resistance, over temperature of the busbars. In this paper, we designed and implemented the busbar joint and temperature measurement system, which can measure the joint resistance of busbar and loose connection between busbar using potentiometer and non-contact infrared sensor. The experimental results show that tightening the bolt and nut is fully engaged, resistance was decreased and maximum error range was 0.1mm. Also, the experimental result showed that the temperature at the contact area is increased from $27.3^{\circ}C$ to $69.3^{\circ}C$by the contact resistance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2168_2169
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• 2009

산업이 발달함에 따라 전기는 우리 일상생활에 있어 없어서는 안 될 중요한 요소이나, 전기는 시각적인 흐름을 볼 수가 없어 전기설비나 전기용품 사용중에 발생할 수 전기사고에 대해서 사전에 사고를 감지하고 예측하기 어려워 사고 위험성에 대하여 무방비 상태가 되나, 전력 사용량, 전기 위험도 분석 등에 대한 기술은 그에 미치지 못하고 있다. 이에 전기 사용 상태에 대한 분석이 가능하기 위해서는 분전반내부에 분석 회로장착이 필요하며, 전류 분석을 위해서는 전류센서(CT)가 구성되어 져야 하고, 이 전류신호는 data cable을 통하여 분석보드로 전송 되어져야 한다. 이는 수배전반 내부에 전력 케이블과의 접촉 문제, 결선 의 어려움 등이 있어 이를 해결 하고자 통신기능을 갖는 센서 내장형 차단기를 개발하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.10-19
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• 1996

This paper presents a finger-shaped multisensor system which can measure the tyep and position of a target surface by contactl. The multi-sensor system consists of a sphere-shpaed optical tactile sensor located at the finger tip and a force/torque sensor located at the joint of a finger. The optial tactile sensor determines the type and position of the target surface using the shape and position of the CCD image of the touching area generated by a contact between the sensor and the taget surface. The force/torque sensor also determines the position and surface normal vector by applying the distributionof forces and torques t the contact point to the equations of finger shape. The measurements on the position and surface normal vector at a contact point obtined by two individual sensors are fused using a statistical method. The integrated sensor system has 0.8mm error in position measurement and 1.31$^{\circ}$ error in normal vector measurement. The developed sensor system has many applications, such as autonomous compliance control, automatic grasping and recognition, etc.