• Fire Science and Engineering
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• v.23 no.5
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• pp.125-132
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• 2009

In this study we could contribute to the development of a precise checking tool with which the reliability of the automatic fire detection systems was enhanced and the safety of the people was ensured. In the same way as the domestic technical standard, the portable smoke sensitivity tester, which was developed in this work, could be used to check the capability of the smoke detectors installed in the field. Its heater inside was warmed up to $400^{\circ}C$ in 40 seconds and the paper as a smoke source was burned to produce smoke for the test. With the Photoelectric smoke detector it was possible to measure and control the smoke concentration in a range from 0%/m to 25%/m. With the adjustment of rpm of the fan, it was possible to keep a constant wind velocity in a range from 20cm/sec to 40cm/sec.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.35-45
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• 2006

RIn this paper. we describe real-time parallel processing simulator developed for the use of performance analysis of rolling missiles. The real-time parallel processing simulator developed here consists of seeker emulator generating infrared image signal on aircraft, real-time computer, host computer, system unit, and actual equipments such as auto-pilot processor and seeker processor. Software is developed according to the design requirements of mathematic model, 6 degree-of-freedom module, aerodynamic module which are resided in real-time computer. and graphic user interface program resided in host computer. The real-time computer consists of six TI C-40 processors connected in parallel. The seeker emulator is designed by using analog circuits coupled with mechanical equipments. The system unit provides interface function to match impedance between the components and processes very small electrical signals. Also real launch unit of missiles is interfaced to simulator through system unit. In order to use the real-time parallel processing simulator developed here as a performance analysis equipment for rolling missiles, we perform verification test through experimental results in the field.

• Journal of Biomedical Engineering Research
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• v.42 no.3
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• pp.100-106
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• 2021

Measuring Intima-media thickness (IMT) with ultrasound images can help early detection of coronary artery disease. As a result, numerous machine learning studies have been conducted to measure IMT. However, most of these studies require several steps of pre-treatment to extract the boundary, and some require manual intervention, so they are not suitable for on-site treatment in urgent situations. in this paper, we propose to use deep learning networks U-Net, Attention U-Net, and Pretrained U-Net to automatically segment the intima-media complex. This study also applied the HE, HS, and CLAHE preprocessing technique to wireless portable ultrasound diagnostic device images. As a result, The average dice coefficient of HE applied Models is 71% and CLAHE applied Models is 70%, while the HS applied Models have improved as 72% dice coefficient. Among them, Pretrained U-Net showed the highest performance with an average of 74%. When comparing this with the mean value of IMT measured by Conventional wired ultrasound equipment, the highest correlation coefficient value was shown in the HS applied pretrained U-Net.

• Journal of Drive and Control
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• v.20 no.3
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• pp.15-24
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• 2023

The aim of this study was to measure and evaluate the exhaust emission factors of agricultural tractors. Engine characteristics and three exhaust emissions (CO, NO_x, PM) were collected under actual agricultural operating conditions. Experiments were performed on idling, driving, plow tillage, and rotary tillage. The load factor (LF) was calculated using the collected engine data, and the emission factor was analyzed using the LF and exhaust emissions. The engine characteristics and exhaust emissions were significantly different for each working condition, and in particular, the LF was significantly different from the currently applied 0.48 LF. The data distribution of exhaust emissions was different depending on the engine speed. In some conditions, the emission factor was higher than the exhaust emission standards. However, since most emission limit standards are values calculated using an engine dynamometer, even if the emission factor measured under actual working conditions is higher, it cannot be regarded as wrong. It is expected that the results of this study can be used for the inventory construction of a calculation for domestic agricultural machinery emissions in the future.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.371-380
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• 2013

The purpose of this study was to develop the equation of $\dot{V}O_{2max}$ by $sub_{max}imal$ PACER method for obese middle school boys. For this, $_{max}$imal test using Bruce protocol in lab was performed and then PACER $_{max}imal$ test with portable $\dot{V}O_{2max}$ equipment. To decide the level of submaximal test, during PACER with portable equipment, we found the section in which target hreat rate(over 75%$HR_{max}$) and then per section(75%,80%,85%,90%,95%) metabolic responses were recorded, with which we analyzed multiple regression by stepwise method. Model 1(at 90%$HR_{max}$): $\dot{V}O_{2max}$(ml/kg/min) = 142.721-0.275(repetition)-0.48(HR)+0.177(weight)-1.536(age)[%error 3.90ml/kg/min; performance until 2 stage(13 repetition)]. Model 2(at 95%$HR_{max}$): $\dot{V}O_{2max}$(ml/kg/min) = 182.851-0.103(repetition)-0.744(HR)+0.186(weight)-0.324(age)[%error 4.51ml/kg/min; performance until 3 stage(25 repetitions)]. estimated $\dot{V}O_{2max}$ from Model 1 was different about $3.25{\pm}6.32ml/kg/min$(%error=6.84%), otherwise model 2 was $3.16{\pm}4.54ml/kg/min$(%error=5.75%). considering %HRmax, as the submaximal test model 1 might be fit more than model 2 for obese middle school boys.

• Journal of Biosystems Engineering
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• v.13 no.3
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• pp.44-51
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• 1988

The objective of this study is to develop a grain handling system for loading, unloading and transporting of rough rice stored at the in-bin drying and storage (IBDS) developed by the Korea Advanced Institute of Science and Technology(KAIST). A mechanized Fain handling system consisted of a portable auger and a gate was developed and tested. The test results can be summarized as the following: 1) The loading capacity of the handling system developed is $16.2m^3/h$ (8.3 ton/h) for the Indica type rice and $13.0m^3/h$(7.3 ton/h) for the Japonica type. It is greater than that of manual handling as much as 2.5 - 2.7 times. 2) The unloading capacity of the handling system developed is $16.0m^3/h$(8.2 ton/h) for the Indica type rice and $12.6m^3/h$(7.0 ton/h) for the Japonica type. It is greater than that of the manual as much as 4.7 - 5.5 times. 3) For 3-ton capacity of the storage, the loading and unloading can be performed for 20 and 30 minutes by one man operation of equipment. while 60 and 120 minute for the manual of 2 men, respectively. 4) The volumetric efficiency of the system developed is 0.42 - 0.54 and the power efficiency is 4.0 - 4.4. 5) The break-even quantity of the handling system developed is about 38.6 ton($68.7m^3$) of rough rice and the initial investment for the system would be returned within five years for the most owners of the KAIST IBDS system.

• Fire Science and Engineering
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• v.26 no.2
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• pp.17-31
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• 2012

Regarding the landslide that took place around 00:08 on July 27, 2011, in a village in the city of Chuncheon (Sanjidanggol, Majeoksan, Cheonjeon-ri, Sinbuk-eup, Chuncheon-city, Gangwon-province), this paper surveyed fire-fighting officers who were injected into the site to rescue the disaster, thereby determining the problems surrounding the initial fire-fighting response and improvement measures. As a result, specialist education of volunteer fire-fighters and utilization, improvement measures included the early response ability enhancement of and cooperation between relevant agencies, the strengthening of specialist education about landslide response, the strengthening of situation management and field command system, the installation and operation of speedy field emergency infirmary, the operation of an appropriate volunteer waiting facility, the operation of an appropriate control lines, appropriate control of media, a sufficient securing of individuals' rescue equipment and fuel for heavy equipment, the provision of sufficient portable radios and chargers, the securing of fire-fighting budget thereof.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.453-459
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• 2020

It is important to increase the probability that all developed weapon systems can be operated in a steady state at any time. In the case of Integrated Logistics Support, this probability is referred to as operational availability, and the numerical value is quantified during the development process. There are several ways to improve operational availability for successful development of weapon systems. One of the methods is to reduce total corrective maintenance time through Automatic Test Equipment(ATE). Recently, customers in the defense market have become aware of this and demand ways to improve operational availability of weapon systems. Therefore, this paper proposes ways to improve operational availability of weapon systems by changing the method of operating the ATE. The detailed method is to allow field maintenance personnel to carry out field maintenance support onsite. This is an effective way to reduce the total corrective maintenance time of weapon systems by reducing the travel time of field maintenance personnel. The proposed ATE is proved to be able to achieve superior maintenance and operational availability.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.211-215
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• 2021

It is estimated that there are 40 million people with AIDS worldwide, with most cases occurring mainly in developing countries. HIV, the virus that causes AIDS, is infected with CD4+ T cells in the blood and gradually destroys CD4+ T cells for several months to 10 years, thereby lowering the patient's immune function. AIDS patients who have weakened immunity in this way will die from various diseases. The current method for counting the number of CD4+ T cells is usually performed by flow cytometry. The flow cytometry method has the advantage of high accuracy, but it is difficult to use in developing countries because it requires skilled professionals and equipment is expensive. As a result of this study, a device for AIDS screening was developed by capturing leukocytes from a small amount of 5 ㎕ blood through a microfilter and analyzing CD4+ T cells and CD8+ T cells from the captured cells. cheaper and easier to carry and use than current test equipment.

• Progress in Medical Physics
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• v.32 no.4
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• pp.145-152
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• 2021

Purpose: During the treatments of cancer patients with a linear accelerator (LINAC) using photon beams with energies ≥8 MV, the components inside the LINAC head get activated through the interaction of photonuclear reaction (γ, n) and neutron capture (n, γ). We used spectroscopy and measured the dose rate for the LINAC in operation after the treatment ended. Methods: We performed spectroscopy and dose rate measurements for three units of LINACs with a portable high-purity Germanium (HPGe) detector and a survey meter. The spectra were obtained after the beams were turned off. Spectroscopy was conducted for 3,600 seconds, and the dose rate was measured three times. We identified the radionuclides for each LINAC. Results: According to gamma spectroscopy results, most of the nuclides were short-lived radionuclides with half-lives of 100 days, except for ⁶⁰Co, ⁶⁵Zn, and ¹⁸¹W nuclides. The dose rate for three LINACs obtained immediately in front of the crosshair was in the range of 0.113 to 0.129 µSv/h. The maximum and minimum dose rates measured on weekends were 0.097 µSv/h and 0.092 µSv/h, respectively. Compared with the differences in weekday data, there was no significant difference between the data measured on Saturday and Sunday. Conclusions: Most of the detected radionuclides had half-lives <100 days, and the dose rate decreased rapidly. For equipment that primarily used energies ≤10 MV, when the equipment was transferred after at least 10 minutes after shutting it down, it is expected that there will be little effect on the workers' exposure.