• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.367-374
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• 2023

As the Fourth Industrial Revolution accelerating, countries worldwide are developing technologies to digitize and automate various industrial sectors. Building smart factories not only reduces costs through improved process productivity but also allows for preemptive identification and removal of risk factors through the practice of Health, Safety, and Environment (HSE) management, thereby reducing industrial accident risks. In this study, we visualized pressure, temperature, power, and wind speed data measured in real-time via a monitoring GUI, enabling field managers and workers to easily access related information. Through the work environment monitoring system developed in this study, it is possible to conduct economic analysis on per-unit basis, based on the digitization of production management elements and the tracking of required resources. By implementing HSE in shipyards, potential risk factors can be improved, and gas and electrical leaks can be identified, which are expected to reduce production costs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.125-131
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• 2006

The existing X-ray generators are either ones which are settled at fixed places or ones which are movable to sick rum. Movable generators can be very useful according to the circumstances of patients, but there remains a restraint that AC220[V] in the hospitals must be provided. When examining a first-aid patient who stays distant from the hospital or when grouping patients caused by disaster, the services of doctors at emergency centers should be very restrictive. Hence, this study developed a portable digital X-ray power supply unit that are utilizable at the accident spot or in a moving ambulance. By using the nit, the information of patients can be transmitted to the emergency center on the spot and thereby doctors can make a correct diagnosis. The properties of the unit are as follows: First, portable batteries(DCl2[V]) are utilized as electric source for the wit. Second PIC16F84A is utilized as control circuit in order to guarantee considerable reliance and to provide various functions. This portable digital X-ray power supply unit is expected to contribute to the emergency medical service system to be more advanced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.593-602
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• 2020

Power cables installed in domestic factories or underground can cause accidents depending on the manufacturing process, installation, and environmental conditions during use. When an accident occurs in a power cable, it can cause enormous economic loss and social confusion. Hence, the importance of preventive management of the cable through diagnosis is increasing to prevent it. Therefore, in this paper, a diagnostic sample cable was produced by simulating a part that could be a problem due to the installation, manufacturing defects, or deterioration of cables that can occur in the field. Dielectric loss Tangent (tan 𝛿; TD), and Partial Discharge(PD) tests were performed. Partial discharge and AC (60Hz) withstand voltage equipment using High-Frequency Current Transformer (HFCT) were applied After applying a VLF (Very Low Frequency) power supply with a frequency of 0.1Hz was applied. As a result, B and C phase defect samples at a 2.0U₀ voltage through the VLF could measure the internal partial discharge in the A-phase normal sample cable from the noise at a 0.5U₀ to 2.0U₀ voltage. In addition, the 1.5U₀ voltage was measured through the AC (60Hz) withstand voltage equipment of the commercial frequency to verify its effectiveness. Partial discharge in the run-off state was measured at a voltage of 1.0U₀, and there was a risk when installing the equipment. AC power equipment showed a difficulty of movement by volume or weight. The diagnostic method, through the VLF of the quadrant state, revealed its safety and effectiveness.

• Journal of the Korean Magnetics Society
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• v.21 no.1
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• pp.23-31
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• 2011

From among the NDT (nondestructive testing) methods, the MFL (magnetic flux leakage) method is specially suitable for testing pipelines because pipeline has high magnetic permeability. The system applied to MFL method is called the MFL PIG. The previous MFL PIG showed high performance in detecting the metal loss and corrosions. However, MFL PIG is highly unlikely to detect the cracks which occur by exterior-interior pressure difference in pipelines and the shape of crack is long and very narrow. In MFL PIG, the magnetic field is performed axially and there is no changes of cross-sectional area at cracks that the magnetic field passes through. Cracks occur frequently in the pipelines and the risk of the accident from the cracks is higher than that from the metal loss and corrosions. Therefore, the new PIG is needed to be researched and developed for detecting the cracks. The circumferential MFL (CMFL) PIG performs magnetic fields circumferentially and can maximize the magnetic flux leakage at the cracks. In this paper, CMFL PIG is designed and the distribution of the magnetic fields is analyzed by using 3 dimensional nonlinear finite element method (FEM). In CMFL PIG, cracks, standards of NACE, are detectable. To estimate the shape of crack, the leakage of magnetic fields for many kinds of cracks is analyzed and the method is developed by signal processing.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.49-54
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• 2006

The X-ray unit developed by this study is to diagnose emergency cases which is too far from a hospital and to classify the patients. We have to use the X-ray in a ambulance or the scene of an accident where we cannot use the AC220 outlet because of the distance from a hospital as well. The X-ray unit developed has a characteristics as follows. First of all, as the unit has a condenser in itself where there is no electric supply, we can use the X-ray inspector in a mountain area or a island. Second, we can detect by digital detector the information taken by X-ray from DC 12[V] electricity and store as a form of file. A control circuit can secure the reliability of the X-ray unit by using the Pic16F84A X-ray and provide various functions. The X-ray unit which suits remote emergency system can be efficiently used for the emergent cases who is too far from a doctor and a hospital or in the situation where it is difficult to diagnose, transcribe and treat simultaneously.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.296-301
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• 2020

Three types of traffic signal systems are two-color signal systems that flash red and green and are mainly used on crosswalks, next, three-color equalization systems mainly used at T-shaped intersections with red and yellow lights and a green arrow, and third, four-color intersections that generally have red, yellow and green colored lights and a green arrow. In what is known as the "dilemma zone" area, a driver collects information that influences his/her decision whether to stop, speed, tail, interrupt, or violate a traffic light, depending on the intersection width, vehicle speed, cognitive response time and reference yellow signal time. This study examined the impact of changes in the length of the dilemma zone areas based on changes in yellow signal times, the speed of the intersection passages, and signal lamps. Downward adjustments of 50km/h and 60km/h affected yellow signal time. The yellow signal time increased by 0.1 to 2.3[s] due to this effect and the dilemma zone area increased by 1.22 to 26[m]. The driver of the dilemma zone could quickly decide to reduce the time remaining of the straight (3color, 4color) green signal to reduce the potential of a traffic accident at the intersection traffic. Safe entry of red (LED palm) and left-turn signals for entering flashed at the intersection and operated at midnight.

• Journal of Korean Foot and Ankle Society
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• v.1 no.1
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• pp.59-64
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• 1997

The aims of free tissue transplantation to the injured foot are to cover the exposed blood vessels, nerves, muscles, tendons and bones, to clear up infection, to lessen the morbidity, to shorten the hospitalization, and to prepare for further surgical procedures when no local or transpositioning flaps are available. Authors have carried out free flap transplantation in 13 cases of crushing injury, osteomyelitis and electrical burn in the foot at Chonbuk National University Hospital from June 1992 through May 1996. The results were as follows : 1. 9 cases of 13 (69%) were sustained from the traffic accident. 2. The dorsalis pedis free flap transplantation has been performed most frequently in 5 cases (38.5%), followed gracilis muscle flap in 4 cases(30.7%), rectus abdominis muscle flap in 2 cases(15.4%), latissimus dorsi muscle flap and upper arm flap in 1 each. 3. 6 muscle flaps were covered with split thickness skin graft 20 days after microsurgical anastomosis. 4. All of 13 cases were survived after microsurgical procedure and showed excellent coverage in the foot.

• Journal of IKEEE
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• v.23 no.4
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• pp.1457-1460
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• 2019

In this paper, we proposed the development of a mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarm that can be location-tracked and irradiated. To measure radiation exposure dose, we use the PIN-Diode radiation measurement sensor module, a semi-conductive radiation measurement sensor that can minimize size and weight. The design for removing leakage current is carried out to enhance the characteristics of the radiation measurement sensor using PIN-Diode. The IMU sensor module is used to estimate the location of the current fireman at the same time as the accident estimate by adding together the data and the values for acceleration on the three axis. Experiments were conductied by an authorized testing agency to determine the efficiency of the proposed mixed sensor parts for integrated radiation exposure protection fireman's life-saving alarms. The cumulative dose measurement range was measured in the range of 10 μSv to 10 mSv, the highest level in the world. The accuracy was measured from ±6.3% to ±9.0% (137 Cs) and normal operation was found at the international standard of ±15%. In addition, positional accuracy was measured within ±10%, resulting in a high level of results, demonstrating its effectiveness. Therefore, it is expected that more firemen will be able to provide with superior performance integrated radiation exposure protection fireman life-saving alarm.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.93-96
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• 2004

In this paper, we analyzed the current limiting characteristics according to increase of source voltage in the flux-lock type high-Tc superconducting fault current limiter (SFCL). The flux-lock type SFCL consisted of two coils, which were wound in parallel each other through an iron core, and high-Tc superconducting (HTSC) element connected with coil 2 in series. The flux-lock type SFCL has the characteristics better in comparison with the resistive type SFCL because the fault current in the flux-lock type SFCL can be divided into two coils by the inductance ratio of coil 1 and coil 2. The fault current limiting operation of the flux-lock type SFCL can be different due to winding direction of the two coils. The winding method where the decrease of linkage flux between two coils in the accident happens is called the subtractive polarity winding and the winding method in case of the increase of linkage flux is called the additive polarity winding. The fault current limiting experiments according to the source voltage were performed for these two winding methods. Through the comparison and the analysis of the experimental data, we confirmed that the quench time was shorter, irrespective of the winding direction as the source voltage increased and that the fault current and the HTSC's resistance increased as the amplitude of the source voltage increased. The additive polarity winding made the fast quench time and the lower resistance of HTSC element in comparison with the subtractive polarity winding. The fault current of the subtractive polarity winding was larger than that of the additive polarity winding. In conclusion, we found that the additive polarity winding reduced the burden of SFCL because the quench time was shorter and the fault current was smaller than those of the subtractive polarity winding.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.43-49
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• 1968

Epidemiological and statistical observations were made of fire hazards that occurred during the past 18 years, 1948 to 1965. Injury and mortality rates for all ages were computed chronologically. For the years of 1955, 1961 and 1965, all fire accidents were epidemiologically analysed to draw characteristic patterns in relation to the seasonal and 24 hour distribution, causes and sites of accidents etc.. Fire hazards observed herein are the categorys E 916 of the International Classification of Causes of Death, 1955, and includes all accidents caused by fire and explosion of combustible materials. The following conclusion was made: 1. The average number of annual deaths due to fire was 183 and the number of the in jured due to the same cause was 335. The mortality rate per 100,000 population was 0.8 and the ratio of injuries per death was 1.83. 2. The casually rate including both the dead and injured was 5.0 per 100,000 in Seoul, the highest among the provinces and followed by 3.4 in Cheju -Do, 2.1 in Kangwon-Do, 1.7 in Kyunggi-Do accordingly. The other provinces had a range of 0.6 to 1.2. 3. The monthly distribution of fro accidents showed that the winter months, December through February, had more frequent accidents, while the summer season, June through August had less. The 24 hour distribution of accidents showed more cases from 12:00 to 18:00 and less from 4:00 to 10:00 hours. 4. The per cent distribution of causes of accidents showed; 90.0% for careless, 10.0% for arson. The cause of carelessness was further breakdown into; 15.0% for kitchen fire places, 13.8% for fire playing, 9,4% for electrical heating and wires, 8.3% for fuels, 6.3% for matches, 5.2% for ash dumps and the remaining for others. 5. The accidents as classified by place revealed that 56.8% of the total occurred at the common dwelling houses, 11.3 at various industrial workshops, 9.3% at the street shops and the remaining at the miscellaneous places.