• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.159-166
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• 2019

Objectives: The purpose of this study was to evaluate the personal exposure to $PM_{10}$ by body parts for the development of dust monitoring wearable device for swine farmers. Methods: Tasks were classified by using motion pictures taken by action cameras attached to swine farmers. Concentrations of $PM_{10}$ were measured by attaching direct-reading instruments at the head, neck and waist of worker. Differences of $PM_{10}$ exposure between body parts were analyzed with linear regression. Results: We identified three tasks(vaccination, moving pigs, and manure treatment). $PM_{10}$ concentration during vaccination was the highest among the tasks, and the body part showing the highest concentration of $PM_{10}$ was the waist regardless of task. In all tasks, the closer distance between the body parts, the higher were the R-squared values(vaccination 0.4221, moving pigs 0.6990, and manure treatment 0.2164). Conclusions: We presumed that $PM_{10}$ concentrations were affected by the parts of the body in which they were measured. In order to develop swine farmer's wearable device for monitoring dust concentration in air, the determination of the positions of monitoring sensor to ensure accurate measurement is essential. Considering the results of this study, wearable sensor should be positioned at the waist.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.21-31
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• 2008

Ubiquitous environment is constructed by development of an IT technology, offer environment of many service changed to mobile environment. Also, existed service offered at fixed position like home or company, but according to development of mobile device. user require service as moving. Wibro can offer as user moving using mobile device. As requirement should be included authentication, in case of authentication between UICC and AAA authentication server is offered in Wibro, service is available. However, when UICC requires initial authentication to AAA authentication server, identification information of UICC expose as plaintext, so privacy infringement of mobile device occurs. Therefore, identification information of terminal generate randomly using OTP(One-Time Password) that generated in mobile terminal, and we proposed mechanism of privacy protection. Also, we proposed mechanism that offer secure service to user as offer authentication from OTP framework, and offer OTP combination authentication detailedly.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.135-140
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• 2005

Vegetable transplanting operation has been wholly depended on human labor that needs 18.4 hrs per 10 acres in Korea. Since periods of vegetable transplanting operations are limited, their mechanization has been strongly demanded. This study was conducted to develop a transplanting device that was the core technology for vegetable transplanter. In order to find out transplanting track and velocity of transplanting device, a kinematic analysis software was employed. Evaluation of prototype was carried out in the circular soil bin with high speed camera. Rotary type transplanting device produced an elliptic loci when two links of different lengths were moving to the opposite direction. The length of two links was 75mm and 44mm, respectively. Maximum displacement of rotary type transplanting device was 238mm. It seemed that the transplanting elliptic loci of transplanting device were identical between the simulation output generated by kinematic analysis software and the circular soil bin test result with a high speed camera. The rotary type transplanting device can be suitable fur transplanting short height vegetable, less than 20 cm length vegetables such as Chinese cabbage and cabbage, etc.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1330-1338
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• 2011

Social activities of the elderly have been increasing as our society progresses toward an aging society. As their activities increase, so does the occurrence of falls that could lead to fractures. Falls are serious health hazards to the elderly. Therefore, development of a device that can detect fall accidents and prevent fracture is essential. In this study, we developed a portable fall detection system for the fracture prevention system of the elderly. The device is intended to detect a fall and activate a second device such as an air bag deployment system that can prevent fracture. The fall detection device contains a 3-axis acceleration sensor and two 2-axis tilt sensors. We measured acceleration and tilt angle of body during fall and activities of daily(ADL) living using the fall detection device that is attached on the subjects'. Moving mattress which is actuated by a pneumatic system was used in fall experiments and it could provide forced falls. Sensor data during fall and ADL were sent to computer and filtered with low-pass filter. The developed fall detection device was successful in detecting a fall about 0.1 second before a severe impact to occur and detecting the direction of the fall to provide enough time and information for the fracture preventive device to be activated. The fall detection device was also able to differentiate fall from ADL such as walking, sitting down, standing up, lying down, and running.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1435-1440
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• 2017

Recently, VR and AR are emerging as an area of interest in ICT. In virtual reality to feel like a real, many people are looking for them because of its charm. However, the motion of the VR image and the moving object are not synchronized exactly, and a problem of feeling nausea is also occurring. The problem should be solved by the application of Attraction in the VR system. In this paper, we propose a module that minimizes delay time by synchronizing movement of VR image and moving object. The proposed module calculates the moving distance using the direction and the acceleration sensor that the user views through the VR device. The module proposed in this paper will pay attention to the fact that the movement of the attraction moves along a fixed path, so that the accurate travel distance can be calculated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2380-2388
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• 2015

A hardware implementation of MOD(moving object detection) algorithm using EGML(effective Gaussian mixture learning)- based background subtraction to detect moving objects in video is described. Some approximations of EGML calculations are applied to reduce hardware complexity, and pipelining technique is adopted to improve operating speed. The MOD processor designed in Verilog-HDL has been verified by FPGA-in-the-loop verification using MATLAB/Simulink. The MOD processor has 2,218 slices on the Virtex5-XC5VSX95T FPGA device and its throughput is 102 MSamples/s at 102 MHz clock frequency. Evaluation results of the MOD processor for 12 images in the IEEE CDW-2012 dataset show that the average recall value is 0.7631, the average precision value is 0.7778 and the average F-measure value is 0.7535.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.5
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• pp.786-792
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• 2022

In the cloud computing environment, there has been a lot of research into the Fog/Edge Computing (FEC) paradigm for securing user proximity of application services and computation offloading to alleviate service delay difficulties. The method of predicting dynamic location change patterns of edge devices (moving objects) requesting application services is critical in this FEC environment for efficient computing resource distribution and deployment. This paper proposes an optimal moving pattern extraction algorithm in which variable weights (distance, time, congestion) are applied to selected paths in addition to a support factor threshold for frequency patterns (moving objects) of edge devices. The proposed algorithm is compared to the OPE_freq [8] algorithm, which just applies frequency, as well as the A^* and Dijkstra algorithms, and it can be shown that the execution time and number of nodes accessed are reduced, and a more accurate path is extracted through experiments.

• Journal of Applied Reliability
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• v.14 no.3
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• pp.147-151
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• 2014

An actuator latch device of a hard disk drive is installed for locking an actuator to hold a magnetic head parked in a parking zone. Applying an external force to the drive, the head can move away from the parking zone and destroy data on the disk. A magnet latching mechanism is used to prevent the actuator from moving when the computer is not in use. A permanent magnet holds the actuator when the head is in the parking zone. When the computer is turned on, the actuator has to overcome the latch magnet in order to move. A stronger latch magnet will hold the actuator adequately, but the actuator will not be released when unlocking is required. A breakthrough solution is needed to improve the reliability of the drive without any deterioration of its performance. In order to obtain the idea for resolving this technical contradiction, we analyse patents for actuator latch device of a hard disk drive. A practical way for solving contradictions in product development using TRIZ is proposed in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.89-98
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• 2014

A diagnostic fluoroscopy X-ray system uses a 32kW or greater X-ray generator for obtaining real-time moving images and high-resolution images. Fluoroscopy X-ray systems have to use a high-capacity AC power source to perform long-time low-power fluoroscopy and short-time high-power spot exposure. In this paper, we propose a hybrid type X-ray generator for fluoroscopy X-ray system which can perform fluoroscopy and spot exposure with a low-capacity AC power source and an energy storage device. The characteristics of energy storage devices are compared and each energy storage device is modelled to equivalent circuit. And the characteristics of available energy are analyzed as a function of output voltage and power. A 32kW class hybrid X-ray generator with EDLC as an energy storage device for fluoroscopy X-ray system was constructed, and its validity was verified by means of simulations and experiments.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.21-26
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• 2017

According to the data of Korea Occupational Safety and Health Agency, electric shock accidents during recent 11 years exceeded more than 60% in architecture/other and construction work, the countermeasures for safety are required in the harsh environment of a construction site where moving electric machines and equipments are widely used. The establishment of countermeasure for insulation degradation and defect is required, in consideration of increasing trend for accidents caused by defective insulation among low voltage electrical installation each year. The aim of this study is to propose the policy about portable electrical tool standards and/or worker's safety standards for preventing electric shock accidents on safety workings, and is to develop the technology and the safety device to prevent electric shock for accident prevention reduction through experiments. It obtained the followings through this study; statistical data analysis of late about 10 years of electric shock-related industrial accidents analysis and portable electric tools; safety device development of 'device for testing continuous grounding and power shut-down' to prevent electric shock from portable electric tools. Furthermore, developed results and proposal in this study will help to prevent the electric shock accidents from portable electric tools and will be expected the utilization of policy formulation, educational data and field supplement of the safety device, and etc.