• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.417-428
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• 2018

In this study, we fabricated hierarchically self-assembled thin films composed of graphene oxide (GO) sheets and gold nanoparticles (Au NPs) using the Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) techniques and investigated their gas-sensing performance. First, a thermally oxidized silicon wafer ($Si/SiO_2$) was hydrophobized by depositing the LB films of cadmium arachidate. Thin films of ligand-capped Au NPs and GO sheets of the appropriate size were then sequentially transferred onto the hydrophobic silicon wafer using the LB and the LS techniques, respectively. Several different films were prepared by varying the ligand type, film composition, and surface pressure of the spread monolayer at the air/water interface. Their structures were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their gas-sensing performance for $NH_3$ and $CO_2$ was assessed. The thin films of dodecanethiol-capped Au NPs and medium-sized GO sheets had a better hierarchical structure with higher uniformity and exhibited better gas-sensing performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1087-1091
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• 2007

Exact impedance modeling of the electrode/electrolyte interface is important in bio-signal sensing electrode development. Therefore, the investigation of the equivalent circuit models for the interface has been pursued for a long time by several researchers. Previous circuit models fit the experimental results in limited conditions such as frequency range, type of electrode, or electrolyte. This paper describes a new electrical circuit model and its capability of fitting the experimental results. The proposed model consists of three resistors and two constant phase elements. Electrochemical impedance spectroscopy was used to characterize the interface for Au, Pt, and stainless steel electrode in 0.9% NaCl solution. Both the proposed model and the previous model were applied to fit the measured impedance results for comparison. The proposed model fits the experimental data more accurately than other models especially at the low frequency range, and it enables us to predict the impedance at very low frequency range, including DC, using the proposed model.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.544-547
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• 2007

Because data processing systems in recent years are more complicated, main function of the data processing is divided as several sub-functions which are implemented and verified in each subsystem of the data processing system. For the verification of data processing system, many interface tests among subsystems are required and also a lot of simulation systems are demanded. This paper proposes CTHS (Common Test Harness System) for satellite ground segment development which has all of functions for interface test of the data processing system in one PC. Main functions of the CTHS software are data interface, system log generation, and system information display. For the interface test of the data processing system, all of actions of the CTHS are executed by a pre-defined operation scenario which is written by purpose of the data processing system test.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.31-40
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• 2018

We designed and implemented the attachable smart adapter for the general management of each company's agricultural machine regardless of whether it is equipped with a CAN (Controller Area Network) module. The smart adapter consists of a main board (Raspberry Pi3B), which operates agricultural machine's management software in Linux environment, and a self-developed interface board for power adjustment and status sensing. For the status monitoring, a sensing interface using a serial input was defined between the smart adapter and the sensors of the agricultural machine, and the state diagram of the agricultural machine was defined for diagnosis. We made a panel to simulate the sensors of the agricultural machine using the switch's on/off contact point, and confirmed the status monitoring and diagnostic functions by inputting each state of the farm machinery from the simulator panel.

• 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.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.117-120
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• 2002

This paper is to develop the sensing system for opening-force measurement such as O-Ring muscular meridian. We designed to overcome the functional limit that the conventional force-sensor can measure just the closing-force. Therefore, the new sensor can meet a variety of application as well as O-Ring test. The structure of the new sensor is an actuator-type system using an electromagnet. That is made up of mechanical system, electromagnet, current transformer and computer interface circuit. Driving software and user interface program of the new sensor system also is explained in this paper.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.183-186
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• 2007

The aim of this analysis is to verify the electrical compatibility of the interfaces which exist between COMS(Communication, Ocean and Meteorological Satellite) AOCS(Attitude Orbit Control Subsystem) equipments and external equipments. For each interface, this study checked the compatibility between equipments for the power links, commands, digital telemetry, analog telemetry and failure condition. In addition with this interface compatibility verification, this study outputs the electrical and manufacturing constraints to be applied at harness level.

• Journal of Adhesion and Interface
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• v.9 no.1
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• pp.3-8
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• 2008

Self-sensing was evaluated for carbon nanofiber (CNF)/epoxy composites with two different aspect ratios via electro-micromechanical technique and wettability test. Volumetric electrical resistance was measured to evaluate the comparative dispersion degree indirectly and it decreased due to the increase of electric contacts with increasing CNF concentration. The dispersion degree was evaluated indirectly by calculating coefficient of variation (COV) of volumetric electrical resistance. The CNF type A with a high aspect ratio showed better self-sensing than the case of CNF type B with a short aspect ratio. The CNF type B/epoxy composite showed little self-sensing at a concentration higher than 2 vol% probably due to poor dispersion. The apparent modulus of CNF type B was higher than that of CNF type A due to the orientation effect and the high surface area. The thermodynamic work of adhesion was consistent with the result of apparent modulus.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.71-75
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• 1999

In this paper, we present the 3DOF force-reflecting interface which allows to acquire force of object within a virtual environment. This system is composed of device, virtual environment model, and force-reflecting rendering algorithm. We design a 3 DOF force-reflecting device using the parallel linkage, torque shared by wire, and the controller of system applied by impedance control algorithm. The force-reflecting behaviour implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. Especially how force should be supplied to user, we know using a God-Object algorithm. As we experiment a system implemented by the interface of 3D virtual object and 3DOF force-reflecting interface, we can feel a contact, non-contact of 3D virtual object surface and sensing of push button model.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.195-198
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• 1995

In this paper We propose one computer interface device for handicapped people. Input signals of the interface device are movements of eyeballs and head of handicapped. The movements of the eyeballs and head are detected by an image processing system. One feature of our system is that the operator is not obliged to wear any burdensome device like glasses and a helmet. The sensing performance of the image processing of the eyeballs and head is evaluated through experiments. Experimental results reveal the applicability of our system.