• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.403-406
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• 2006

A new medical X-ray PIV technique was developed using a conventional medical X-ray tube. To acquire images of micro-scale particles, the X-ray PIV system consists of an x-ray CCD camera with high spatial resolution, and a X-ray tube with small a focal spot. A new X-ray exposure control device was developed using a rotating disc shutter to make double pulses which are essential for PIV application. Synchronization methodology was also developed to apply the PIV technique to a conventional medical X-ray tube. In order to check the performance and usefulness of the developed X-ray PIV technique, it was applied to a glycerin flow in an opaque silicon tube. Tungsten particles which have high X-ray absorption coefficient were used as tracer particles. Through this preliminary test, the spatial resolution was found to be higher than ultrafast MRI techniques, and the temporal resolution was higher than conventional X-ray PIV techniques. By improving its performance further and developing more suitable tracers, this medical X-ray PIV technique will have strong potential in the fields of medical imaging or nondestructive inspection as well as diagnosis of practical thermo-fluid flows.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.205-214
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• 2016

Objectives: The purpose of the study is to investigate the current status and radiographic safety management in Korea. Methods: A self-reported questionnaire was completed by 200 dental hygienists in Jeonbuk province from September 1, 2014 and October 31, 2014. The questionnaire consisted of general characteristics of the subjects, radiation knowledge, radiation safety management, and radiation exposure anxiety. Data were analyzed using SPSS 18.0 program. Results: Duration of clinical experience(r=0.142) and number of daily radiation shot(r=0.145) showed a positive correlation to radiation safety management, and a nrgative correlation to use of intraoral films and digital devices(r=-0.587). A logistic regression analysis was performed in order to evaluate the influence on radiography knowledge. The results showed that the factors had significant influences on the age group over 41 years old(OR 7.25; 95% CI 1.30-40.43) and those who took a position above team leader(OR 0.23; 95% CI 0.59-0.90). Conclusions: It is very important to have the safety management toward dental intraoral imaging and radiograpgic shot in the dental hygienists. Continuous efforts should be emphasized on radiographic safety management and behavior.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.182-186
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• 2014

Recently, the use of panoramic radiography has shown a constant increase, and significant research is underway. However, radiation exposure attracts less attention in dental radiography than in other types of radiography. We used an OSLD for measurement of the entrance skin dose in eyeballs and the thyroid region, both of which are not covered by examinations but are included in radiographical regions and are sensitive to radiation, as well as orally in Incheon and reported the results. The entrance skin dose was 0.0282 mSv on average for the oral region, and 0.0259 mSv on average for the eyeball, and 0.0261mSv on average, for thyroid gland. While there is no proper shielding method for the eyeball, a thyroid protector is not used by most hospitals and most hospitals are equipped with an apron and a thyroid protector separately; thus, it is necessary to use an integration of an apron and a thyroid protector and medical device manufacturers need to develop a method for controlling the length of the slit in the slit-type area of radiation occurrence in order to reduce unnecessary exposure.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.2
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• pp.81-93
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• 2013

This review was described to investigate the feasibility of using ultrasound as an image tool for interventions of lumbar spine. This article will first provide an overview of lumbosacral spine surface anatomy and sonoanatomy. A detailed understanding of anatomy is critical for interpretation of ultrasound and procedural performance at spine. Fluoroscopy is most commonly used in interventional spine procedures, but radiation exposure is the major concern when obtaining fluoroscopic images. Ultrasound is radiation-free, is easy to use, and can provide real-time images with high accuracy. Also this device can be used in virtually any clinical setting. Ultrasound guidance offers a reliable alternative to fluoroscopy or computed tomography for lumbar interventions and can be safely performed without radiation exposure.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.362-370
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• 2022

The assessment of specific impacts on the environment is a preventive measure for environmental protection which is based on the definition and proposal of measures that can prevent harmful effects, reduce or eliminate them. In the physical sense, vibration is the oscillating motion of an object with the effect of internal or external forces applied to it. People who touch a vibrating surface or object will feel these vibrations. In general, there are two types of vibration exposure. The first are the vibrations of the hands and arms transmitted by the held parts of tools or machinery. The second are whole-body vibrations transmitted from a seat or surface to a motorized car. The risk of injury to workers exposed to vibration varies depending on the size, frequency, type, duration of exposure, and organ affected. The purpose of this paper is to review the measurements of vibrations in the Kosovo Energy Corporation in the mine Sibovc Southwest, where coal with a rotary excavator is exploited and the evaluation of vibrations for working conditions for workers working in that environment and improving working conditions for the measurement of vibrations we have used the device Minimate DS 078, the purpose of such environmental impact assessment is to collect data and predict the harmful impacts on the environment, namely the impact on water, air, soil, life and health of as well as identify and propose measures that could prevent, reduce or eliminate altogether.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.7-10
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• 2022

A functional polyethylene terephthalate substrate to increase light extraction efficiency of organic light-emitting diodes is studied. We formed nano-structured PET surfaces by controlling the power, gas, and exposure time of the linear ion-beam. The haze of the polyethylene terephthalate can be controlled from 0.2% to 76.0% by changing the peak-to-valley roughness of nano structure by adjusting the exposure cycle. The treated polyethylene terephthalate shows average haze of 76.0%, average total transmittance of 86.6%. The functional PET increases the current efficiency of organic light-emitting diodes by 47% compared to that of organic light-emitting diode on bare polyethylene terephthalate. In addition to polyethylene terephthalate with light extraction performance, by conducting additional research on the development of functional PET with anti-reflection and barrier performance, it will be possible to develop flexible substrates suitable for organic light-emitting diodes lighting and transparent flexible displays.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.228-234
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• 2023

In this study, the performance of a gold biosensor combined with light microscope imaging system (GB-LMIS) was comparatively evaluated against enzyme-linked immunosorbent assay (ELISA) for detecting Salmonella under simulated chilling condition. The optimum concentration of antiSalmonella polyclonal antibodies (pAbs) was determined to be 12.5 and 100 ㎍/ml for ELISA and GBLMIS, respectively. GB-LMIS exhibited a sufficient and competitive specificity toward three tested Salmonella among only. To mimic a real-world situation, chicken was inoculated with Salmonella cocktail and stored under chilling condition for 48 h. The overall growth of Salmonella under chilling condition was significantly lower than that under non-exposure to the chilling condition (p < 0.05). No significant differences in bacterial growth were observed between brain heart infusion and brilliant green broth during the enrichment period (p > 0.05). Finally, both GB-LMIS and ELISA were employed to detect Salmonella at every 2-h interval. GB-LMIS detected Salmonella with a competitive specificity by the direct observation of bacteria on the sensor using a charge-coupled device camera within a detection time of ~2.5 h. GB-LMIS is a feasible, novel, and rapid method for detecting Salmonella in poultry facilities.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.363-369
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• 2023

In this study, to check the function of managing the severity of ultraviolet rays with a smart watch, a popular health care IT device, It was tested whether measuring heart rate using a PPG(Photoplethysmography) sensor representatively used in a smart watch could tell skin changes caused by ultraviolet rays. Through this experiment, we examined the possibility that the skin color tanned by ultraviolet rays can be determined only by the heart rate measurement function of the PPG sensor. In addition, the possibility of expanding the heart rate measurement function of the PPG sensor to the use of skin condition management was considered. we used an Arduino-based reflective PPG sensor to measure changes in heart rate by selecting body sites with high and low UV rays exposure. A significant value was derived through tests considering factors such as gender, UV exposure, and age. As a result, the study identified the possibility of adding ultraviolet rays and skincare items to future smart watch healthcare items and the possibility of expanding skin measurement methods. It is also possible to suggest the direction of future research.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3517-3523
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• 2010

Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.189-196
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• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.