• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.427-433
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• 2017

In the case of high-strength or low thermal conductivity material milling, tool breakage occurs easily because of the high friction temperature. Therefore, the effectiveness of the coolant supply is very important for proper tool cooling. As the manually adjustable joint mechanism nozzle is generally used for coolant supply, the cooling efficiency is very low. It also has a bad influence on the workspace environment because of coolant scattering. In this study, the milling characteristics of STS316L were investigated according to the coolant spray position based on the automatic adjustable system. Tool wear and surface roughness were measured according to the coolant spray position. Through these experiments, the effectiveness of the fabricated system was explained.

• Analytical Science and Technology
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• v.7 no.4
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• pp.427-434
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• 1994

For the analysis of the relatively volatile lead in blood by GFAAS(graphite furnace atomic absorption spectrophotometer), one can not raise the ashing temperature beyond certain degree due to the elevation of the baseline. Previous investigations showed that background is stabilized when the ashing temperature is raised to $700^{\circ}C$ using a matrix modifier. In this study, same result was obtained at the ashing temperature of around $550^{\circ}C$ even when the matrix modifier is not used and only Triton X-100 is used as a diluent, on an instrument which is equipped with both temperature and current controller(Shimadzu, AA-6501S) and thus the temperature control is fast and accurate. Background correction methods of $D_2$ arc and SR(self reversal) were reviewed. The results show that the absorbance is higher for the $D_2$ arc method, but the background correction is higher for the SR method.

• Progress in Medical Physics
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• v.17 no.1
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• pp.40-46
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• 2006

Hepatoma is one of 3 most common malignancies in Korea, the survival rate is not improved since last decades because of delayed diagnosis and limited treatment conditions. Radiation was one of treatment options but the impact on the survival is not remarkable. High dose exposure to target area was suggested for improved effect but low tolerance dose of normal liver tissue is the main limited factor. IMRT is the advanced form of 3DCRT, for focusing high dose on target with minimal dose to surrounding normal tissues. Motion of the tumor by respiration, cardiac pulsation and peristalsis is the main treatment harrier of IMRT for treatment of hepatoma patients. Development of QA technique for acceptable geometrical uncertainties and dose error on target volume is essential for IMRT in clinical treatment but proper QA technique is not yet developed. This study compared the verification film dosimetry with measured dose in phantom and calculated dose in planning computer on exactly same conditions of patient treatments. Within 3% dose differences between 3 groups were confirmed. We suggest that our verification QA technique is easy, economic, iterative and acceptable in clinical application for advanced hepatoma patients.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.285-292
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• 1999

An analytical method applicable to quality control and its optimum conditions were studied for rapid and efficient analysis of sorbic and benzoic acids used as preservatives in the commercial soybean paste. In gas chromatographic analysis of sorbic and benzoic acids, the application of HP-FFAP (acid modified polyethylene) wide bore column improved the separation ability significantly. By setting the oven temperature of GC to $200^{\circ}C$, the total elapsed time for quantitative analysis was also reduced to the level required in using packed column. By extracting sorbic and benzoic acids from soybean paste with an automatic steam distillation device, the elapsed time for analysis was reduced by 80% more compared to using conventional steam distillation method. The recoveries of sorbic and benzoic acids by the automatic steam distillation were 98.1% and 99.9%, respectively. The sorbic acid was found in 3 samples of 14 commercial soybean pastes, of which contents were $466{\sim}530ppm$, while $0.3{\sim}4.4ppm$ of benzoic acid was found in all the samples.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.86-89
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• 2015

Quantitative Evaluation of Image Quality using Automatic Exposure Control This it leads, the relationship of control and image between of photographing condition, DR proper use method proposing. Chest phantom acquires Chest PA images which it follows in conditional change, Image evaluation factor (SNR (Signal to Noise Ratio), CNR (Contrast to Noise Ratio), PSNR (Peak Signal to Ratio), RMS (Root Mean Square)). It excepted RMS price, SNR, CNR, PSNR the case which uses AEC it came out being high The fact that the quality of image is better there was a case which does not use AEC. but Price it was slight. Image qualitative it was deficient in AEC use presence. Through this, the overall situation and most efficient use of radiation workers is better suited. But Passive AEC use would be appropriate for use rather than proactive AEC.

• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.142-147
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• 1989

In this report, we set up a simple device which enabled us to obtain data useful to estimate the relative capacity of thermal energy retention of greenhouse built with various plastic coverings. A box($20cm{\times}20cm{\times}30cm$) framed with flexiglass at the edges and covered with thin plastic films was made, in which were placed a thermostat-controlled nichrom wire heater and a thermal probe made of thermister to monitor temperature changes. A wheaston-bridge type transducer and a chart recorder were used to record the changes of temperature inside the box The data obtained by using the device showed that the relative rate of heat toss through plastic films with identical thickness decreased in the order of PE film>EVA film>PVC film and that IR additives such as fine silica gel improved the insulating power of plastic films. This observations are in well accord with general information, demostrating the feasibility of the device in usefulness for the purpose of screening of various commercial plastic coverings.

• Journal of Mushroom
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• v.13 no.3
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• pp.233-236
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• 2015

This report is the result of devising a method for utilizing the device of the load cell to maintain a constant water content of the medium every day to prepare a cultural substrates with the mixer for growing mushrooms bottle cultivation. A load cell was device under the medium mixer. It is developed when the device reaches the weight calculated as amount of substrate bottled and number of the bottle, it is automatically terminated by water injection. In addition, measuring the water content of each medium and the total weight of the medium reaches the target moisture content were calculated by using the program Cheong et al. (2015). Enter the total weight of the medium on the display unit of the load cell, when starting the water supply to reach the weight-based mixing media, the water supply is stopped. This method can improve the convenience by reducing the user's trouble in repeated work medium prepared by automating water supply. The suitable moisture content of the mixed medium for some kind of mushroom can be improved by the composition accuracy. And mycelial culture period, primordial period, mushroom growing period is maintained even of the medium can be produced stably. Therefore, it is possible to achieve a stable management of the mushroom farm according to mushroom quality and quantity stable throughout the year.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.73-85
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• 2009

An investigation was conducted to get the basic data for establishing structural safety and environmental management of tomato greenhouses in Chungnam region. The contents of the investigation consisted of actual state of greenhouse structures and environmental control facilities. Most of greenhouses were arch type single-span plastic houses and they had too low height for growing tomatoes. Frameworks of multi-span greenhouses were suitable, but those of single-span were mostly insufficient. Every greenhouse had thermal curtain movable or covering fixed inside the greenhouse for energy saving, and heating facilities were mostly warm air heater. Irrigation facilities were mostly drip tube and controlled by manual operation or timer. Almost all of the greenhouses didn't install high level of environmental control facilities such as ventilator, air circulation fan, $CO_2$ fertilizer, insect screen, supplemental light, and cooling device.

• Korean journal of applied entomology
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• v.49 no.1
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• pp.37-42
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• 2010

As an environment-friendly phytosanitary measure, CATTS (controlled atmosphere temperature treatment system) has been developed to kill several quarantine insect pests infesting subtropical agricultural commodities. This study tested any possibility to apply CATTS to apples to effectively eliminate the peach fruit moth, Carposina sasakii, which has been regarded as a quarantine insect from the imported countries. When the larvae of C. sasakii were directly exposed to $46^{\circ}C$ (an installed lethal temperature of CATTS), they showed a median lethal time at 14.66 min. Addition of high carbon dioxide to the temperature treatment enhanced the thermal limit susceptibility of C. sasakii to $46^{\circ}C$. CATTS device was constructed to automatically control $CO_2$ concentration and temperature with real-time monitoring both in the chamber and in the fruit. The larvae internally infesting apples were tested using the CATTS device and showed 100% lethality after 60 min exposure to a treatment of $46^{\circ}C$ under 15% $CO_2$ in the chamber. Relatively long exposure may be due to the deviation between the ramping temperature ($0.35^{\circ}C$/min) of the chamber and the ramping temperature (0.12-$0.23^{\circ}C$/min) inside apple fruit, where the tested larvae were located. This study suggests a possibility that CATTS can be applied as a quarantine measure to kill the larvae of C. sasakii locating inside the apples.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.147-155
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• 2024

Gallium-68-prostate-specific membrane antigen-11 (⁶⁸Ga-PSMA-11) is a positron emission tomography radiopharmaceutical that labels a Glu-urea-Lys-based ligand with ⁶⁸Ga, binding specifically to the PSMA. It is used widely for imaging recurrent prostate cancer and metastases. On the other hand, the preparation and quality control testing of ⁶⁸Ga-PSMA-11 in medical institutions takes over 60 minutes, limiting the daily capacity of ⁶⁸Ge/⁶⁸Ga generators. While the generator provides 1,110 MBq (30 mCi) nominally, its activity decreases over time, and the labeling yield declines irregularly. Consequently, additional preparations are needed, increasing radiation exposure for medical technicians, prolonging patient wait times, and necessitating production schedule adjustments. This study aimed to reduce the ⁶⁸Ga-PSMA-11 preparation time and optimize the automated synthesis system. By shortening the reaction time between ⁶⁸Ga and the PSMA-11 precursor and adjusting the number of purification steps, a faster and more cost-effective method was tested while maintaining quality. The final synthesis time was reduced from 30 to 20 minutes, meeting the standards for the HEPES content, residual solvent EtOH content, and radiochemical purity. This optimized procedure minimizes radiation exposure for medical technicians, reduces patient wait times, and maintains consistent production schedules, making it suitable for clinical application.