• Journal of Biosystems Engineering
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• v.40 no.1
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• pp.19-27
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• 2015

Purpose: A system to measure the visibility of agricultural tractor operators was designed and evaluated according to ISO standards, and a blind area diagram around the tested tractor was created based on the manual method recommended by the National Institute for Occupational Safety and Health (NIOSH). Methods: A visibility measurement system was designed and evaluated based on the ISO 5006 and ISO 5721-1 standards. Two bulbs used to simulate the operator's eyes were mounted on a bar with a supporting frame. A wooden frame was used to determine the seat index point position. The 12-m visibility test circle was divided into six sectors of vision, and the test tractor was placed at the center of the circle. Artificial light was supplied in the darkened environment, and shadow or masking effects were measured manually around the 12-m circle. Results: When the bulbs were placed at the operator's eye level, front visibility was good; no masking was found in the "A" vision sector, but larger masking widths were found in the "B" and "C" vision sectors. Since the masking width exceeded 700 mm, additional tests, such as movement of the light sources to both sides of the operator's eye level, were performed. Less than six masking effects were found in the semi-circle of vision to the front, and more than one masking was found in the "B" and "C" visual fields. The minimum distance between the centers of two masking effects exceeded 2500 mm when measured as a chord on the semi-circle of vision. A blind area diagram was created to define the exact nature of the blind spots and mirror visibility. Conclusions: Visibility evaluation is an effective way to enable proper and safe operation for agricultural tractor operators. Inclusion of this visibility evaluation test in the general testing process might aid tractor manufacturers.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.249-255
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• 2010

The visibility evaluation is significant for the development of construction equipment. The visibility evaluation follows the standards of ISO 5006, ISO 14401-1, and ISO 14401-2. The evaluation contains the operator's visibility and the visibility of rear-view mirrors. The operator's visibility includes the visibility test which requires the recognition of the rectangular line surrounding the machine by one meter and the circle with a 12 meter radius. This study describes the two evaluation processes for the development of the wheel loader. The first process is the light bulb shadow test by using a prototype wheel loader. The second process is based on computer simulation in virtual space. The advantages and disadvantages of computer simulation process are investigated.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.42-49
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• 2018

Pilot Aptitude Research Equipment (PARE) is a simulator developed to measure or research pilot aptitude and train for student pilots. Design of an ergonomic PARE operation console is required to operate the equipment effectively. This study carried out five steps : (S1) operator questionnaire survey, (S2) anthropometric design formula development, (S3) usability evaluation, (S4) improvement design, and (S5) validation considering both Physical User Interface (PUI) and Graphic User Interface (GUI) of PARE operation console. The operator questionnaire surveyed needs for each PUI and GUI part of the console from two PARE actual operators. In terms of PUI, the anthropometric design formula was developed by using design variables, body dimensions, target population characteristics, and reference posture related to the PARE console. In terms of GUI, the usability evaluation was conducted by three usability testing experts with a 7-point scale (1 : very low, 4 : neutral, 7 : very high) on GUI of the PARE operation console by seven usability criteria. The improved PARE operation console was designed to reflect the optimal values of design variables calculated from design formula, the results from usability testing, and the operator's needs. The improvement effect was observed by 20 people who had experience with the PARE operation console. As a result of the validation, monitor visibility and cockpit visibility for the improved PUI design and visibility and efficiency for the improved GUI design were significantly increased by more than 90% respectively. The improved design of the PARE operation console in this study can contribute to enhance operation performance of the PARE.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.401-406
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• 2010

Vessel Operator has been navigating with subjective sate distance in accordance with night & daytime, fore & aft, port & stbd abeam and visibility situation. This sate distances may different depending on inside & outside harbor limit, current, wind and visibility situation. By now, the concept of proper sate distance between navigating vessels has been adopted in Korea, using the early 1980's foreign data. And the safe distance is being used with the same value without any consideration of inside & outside harbor and the kind of vessel. So it is necessary to evaluate or search proper distance concept based on different sate consciousness of Korean manners. This paper aims to develop the basic model for marine traffic evaluation and the new model of marine traffic congestion. Also this paper proposes the basic control guideline of vessel traffic service center. The result of this study showed that minimum sate distance should be 4.4L forward, 3.1L aft and 26L abeam in case of good visibility in daytime, considering various parameters such as visibility, day and night. Some differences Here found between the existing minimum sate distance and the new minimum sate distance derived from the result of this study.

• Journal of the Korea Safety Management & Science
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• v.22 no.1
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• pp.15-21
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• 2020

Industrial Motors diagnostic equipment is highly dependent on the automation system, so if there are defects in the automation equipment, it can only rely on the operator's intuitive judgment.To help with intuitive judgment, Park's Vactor Approach(PVA) represents the current signal as a pattern of circles, so it can tell if a fault occurs when the circle is distorted. However, the failure to judge the degree of distortion of the circle pattern is the basis of the fault, so it will face difficulties. In this paper, in order to compare the faults of PVA, the period of d-axis current of PVA pulsation was mastered, so that two phase differences occurred in the same signal source. Through experiments, it is confirmed that this is a 90 degree cross formation of PVA, which is convenient for judging from the vision that there is no fault, thus helping the operator to make intuitive judgment.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.120-126
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• 2009

The purpose of this study was to develop a visibility evaluation system for cabin type combine. Human's field of view was classified into five levels (perceptive, effective, stable gaze, induced, and auxiliary) depending on rotation of human's head and eye. Divider, reaper lever, gearshift, dashboard, and conveying part were considered as major viewpoints of combine. Visibilities of combine was evaluated quantitatively using the viewpoints and the human's field of view levels. The visibility evaluation system for cabin type combine was consisted of a laser pointer, stepping motors to control the direction of view, gyro sensors to measure horizontal and vertical angle, and I/O interface to acquire the signals. Tests were conducted with different postures ('sitting straight', 'sitting with $15^{\circ}$ tilt', 'standing straight', and 'standing with $15^{\circ}$ tilt'). The LSD (least significant difference) multiple comparison tests showed that the visibilities of viewpoints were different significantly as the operator's postures were changed. The results showed that the posture at standing with $15^{\circ}$ tilt provided the best visibility for operators. The divider of the combine was invisible due to blocking with the cabin frame at many postures. The reaper lever showed good visibilities at the postures of sitting or standing with $15^{\circ}$ tilt. The gearshift, the dashboard, and the conveying part had reasonable visibilities at the posture of sitting with $15^{\circ}$ tilt. However, most viewpoints of the combine were out of the stable gaze field of view level. Modifications of the combine design will be required to enhance the visibility during harvesting operation for farmers' safety and convenience.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.182-186
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• 2021

Tone mapping operator is designed to reproduce visibility of real-world scenes such as HDR images on limited dynamic range display devices. This paper presents and implements compare and to estimate some tone mapping algorithms commonly used. The evaluation is performed by applying tone mapping operators on 7 HDR images, and by presenting the results with subjective estimation. Reinhard tone mapping algorithm is the best in the visual experimental results. The goal of this work is to discuss what is visible of high dynamic range on a normal display device and to determine to which better algorithm is. This work motivates us to make more progress through the new proposal of tone mapping operator on future work.

• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1557-1564
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• 2010

This study present to operator system about performance method by diagrammatic and analysis based on Petri Nets when accordion is performed. Especially, this study present to the basis an automatic performance education by visibility according to divide place and transition of correlation of musical objects. In this, our purpose is flexible performance of deadlock-freeness by visibility of operating process and detail of marking. This study is effective and useful of understand to performance process by Petri Nets modeling inclusive of many musical instrument. The first time, this study suggest performance model of accordion based on Petri Nets and verify of efficiency, an example.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.452-457
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• 2011

The internal temperature of an operating room had to keep within $20^{\circ}C$. However, the doctor who is wearing operating gown and mask caused to rise temperature because of the thermal occurrence of dental LED light source. At first, the surgery environment is getting worse. And then last, it would increase bleeding rate by the expansion of patient's exposured blood vessel. A surgical operator can distribute the patient's tissue through such surgery environment, exactly. It can do accurate surgery. So, it gave to effect that surgical operator's eye condition is getting better and it could keep a mutual assistance system. For this research, we develop the LED dental light source module of high color rendition. It performed simulation for replacing established the method of Halogen lamp and Plazma lamp of light source. We analyzed intensity of illumination and the change of viability by changing the height of light source module.

• Journal of KIISE
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• v.43 no.8
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• pp.848-856
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• 2016

Seeking and recognizing maritime targets are very important tasks for maritime safety. While searching for maritime targets using radar is possible, recognition is conducted without automatic identification system, radio communicator or visibility. If this recognition is not feasible, radar operator must tediously recognize maritime targets using movement features on radar base on know-how and experience. In this paper, to support the radar operator's mission of continuous observation, we propose an algorithm for automatic recognition of an unknown ship using movement features on radar and a method of detecting potential ship related accidents. We extract features from contact range, course and speed of four types of vessels and evaluate the recognition accuracy using SVM and suggest a method of detecting potential ship related accidents through the algorithm. Experimentally, the resulting recognition accuracy is found to be more than 90% and presents the possibility of detecting potential ship related accidents through the algorithm using information of MV Sewol. This method is an effective way to support operator's know-how and experience in various circumstances and assist in detecting potential ship related accidents.