• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.187-194
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• 2008

This paper proposes an effective countermeasure to an intrinsic hardware vulnerability of the keyboard controller that causes sniffing problem on the password authentication system based on the keyboard input string. Through the vulnerability, some possible attacker is able to snoop whole the password string input from the keyboard even when any of the existing keyboard protection software is running. However, it will be impossible for attackers to gather the exact password strings if the proposed policy is applied to the authentication system though they can sniff the keyboard hardware protocol. It is expected that people can use secure Internet commerce after implementing and applying the proposed policy to the real environment.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.646-653
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• 2021

The medical bed developed in this study consists of N keys and each is driven vertically by an actuator. Since M sensors are mounted on each keyboard to measure body pressure, the resolution of the body pressure map is determined by the MN. A sensor controller is mounted on each keyboard, and the body pressure values measured from M sensors are transmitted to the main controller through a serial communication network such as CAN (Car Area Network). Each keyboard is equipped with a servo driver that drives a motor, and it is connected to the main controller via CAN to control the height of the keyboard according to the displacement value indicated by the main controller. In addition, the maximum body pressure value and body pressure ratio applied to each part of the keyboard are calculated and used as the basic data for controlling bed comfort by artificial intelligence. As a result, the proposed system can be a foundation that can be used for the control of body comfort and pressure sore prevention by artificial intelligence to be developed in the future.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.619-625
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• 2023

In this paper, the remote care of medical beds with multiple body pressure sensors is described. Falling is one of the factors that seriously threaten the safety of patients and harm their health. In this study, a new bed was developed to overcome this. The bed system consists of a keyboard that can operate, a keyboard controller that manages the movement of the keyboard, a sensor that measures body pressure, a sensor controller that transmits and receives sensor values, a main controller that checks it and operates automatically or manually according to the algorithm, and a server that oversees all these information. The bed system checks the patient's location through a sensor and wirelessly alerts the server through the main controller when the patient determines that there is a risk of falling, so that the nurse or nurse can recognize the patient's dangerous condition. The server may receive state data transmitted from the wired/wireless terminal to monitor whether the bed system is operating normally. The controller of the keyboard operates a keyboard-type mechanism and automatically controls the prevention of bedsores connected by body pressure sensors to physically separate the area to which the patient's pressure is applied to prevent bedsores. The main controller checks the presence of the patient's bed and transmits it to the server. In conclusion, the proposed system can smart monitor the user's state and perform remote care.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.151-158
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• 2021

The main cause of ulcer is pressure, which starts to develop when the critical body pressure (32mmHg) is exceeded, and when the critical time elapses, ulcer occurs. In this study, the keyboard mechanism of the medical bed with 4 bar links was adopted, and each key can be controlled vertically. A key has one servo drive and one sensor controller which hasseveral body pressure sensors. The sensor controllers and the servo drives are connected to the main controller by two CAN (Car Are Network) in series, respectively. By reading the maximum body pressure value of each keyboard sensor, and by calculating the error value based on the critical body pressure, the fuzzy controller moves each key so that the total error becomes zero. If the fuzzy controller fails, then it prevents ulcer by lifting and lowering the keys of the bed alternatively within a short time. Thus, the controller operates in two-stage. The validity and effectiveness of the proposed approach have been verified through experiments.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.213-218
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• 2023

In order to use the VR HMD, operation through separate controllers in both hands is required. Methods for text input in VR include a method of selecting virtual keyboard keys on the screen one by one using a controller, a method of inputting through a keyboard that is a resource of a computer by connecting a computer and VR, or a method of inputting through a keyboard that is a resource of a computer by purchasing a wireless keyboard in VR and wireless keyboard connection method. As such, the text input method in current VR equipment causes inconvenience and additional costs to users. For these reasons, most of the VR-related contents are limited to simple functions such as games or viewers, and there is a risk that VR equipment will be recognized as a simple game machine. Therefore, in this study, a multi-input interface using hand tracking provided by the Oculus Quest2 device is designed and partially implemented. Through this, it is expected that various tasks such as document work and business processing as well as games can be conveniently used using VR equipment.

• Journal of the Korean Society for Precision Engineering
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• v.4 no.4
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• pp.25-35
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• 1987

This paper deals with the design of the digital controller for DC servo motor, and it is implemented for the cartesian coordinate 4 axes manipulator. A design method of the controller is adopted an algorithm using the digital position locked loop(DPLL) method and the linear PID control for the smooth motion. To simplify the hardware configuration of control system, 8279 keyboard/display controller, Z-80 CTC counter and 8255 PPI are used. Therefore the design method to control each motor as real-time is presented. To show effectiveness of the design, the PWM circuit and frequency/voltage converter are applied for the velocity control of robot system. When the proposed controller is applied to the 4-axes manipulator, it reveals that the error probabilities of X, Y and Z axis as 0.033%, 0.023% and 0.028% respectively.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.839-842
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• 1998

The wide spread of multimedia system demands a large viewin gdesply device which can inform a message to many peoples in open area. This paper is about the design, simulating and testing of a large viewing LED pannel control ASIC(application specific integrated circuit). This LED pannel control ASIC runs on 16 bit microprocessor MC68EC000 and has following functions:16 line interlaced LED pannel controller, memory controller, 16 channel priority inerrupt controller, 2 channel direct memory access controller, 2 channel 12 bit clock and timer, 2 channel infrared remocon receiver, 2 channel RS-232C with 16byte FIFO, IBM PC/AT compatible keyboard interface, battery backuped real time clock, ISA bus controller, battery backuped 256 byte SRAM and watech dog timer. The 0.6micron CMOS sea of gate is used to design the ASIC in amount of about 39,000 gates.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.56-63
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• 2016

This paper presents a novel method for detecting a ghost key at the membrane type keyboard, which has additional resistive coating to the membrane film. Also, the optimal ratio of resistances for detecting a ghost key was designed based on the characteristics of the membrane film. The optimal ratio of resistances was considered to be able to detect the worst case (i.e., difference voltage between normal key and ghost key is minimum). The ability of the proposed methods are evaluated by simulation studies in this paper. In order to verify the proposed method, the experiment was carried out with a designed circuit and A/D (analog to digital) in MCU (micro controller unit). The proposed method is implemented into the membrane type keyboard and is verified by experimental results.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.94-102
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• 2009

As an advance in medical technology development is being made, and people are increasingly aware of the importance of health, related investments and people's average life expectancy rise, which in turn leads to an increase in elderly people. Also, with a growing number of elderly people enjoying their leisure activities, the utilization of multimedia contents using computers is on the increase, leading to an activated research into the establishment of digital culture for the elderly people. This paper proposes a Korean text input system to enable the elderly to utilize digital contents. Text input interface has conventionally depended on keyboards. However, the keyboard wherein many keys are dispersed creates problems for the elderly, such as a protracted recognition of keys and a lowered concentration when they use the keyboard. To address these problems, in this paper, the grip type controller interface for console games was used and a corresponding alphabet location algorithm was developed. To verify these efforts, a simulator was developed to test 20 elderly people; as a result, their satisfaction over and convenience of using the grip type interface increased.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.449-454
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• 2003

In this paper, GU environmental controller is implemented with USB(Universal serial bus) IF(interface). Especially, the performance examination of ultrasound diagnostic device which connects external USB port with front panel is automatically inspected by VC++ examination program. The test program minimizes the operation of inspector with making the examined result audible or visible, and maximizes the productivity of custom device. The GUI environmental controller controls a standard keyboard, a track ball with dedicated buttons to emulate a standard two-button mouse, switches, rotary encoders, an analog potentiometer group, two alpha-numeric displays. and a touch screen; all of which generate events for the host.