• Journal of Sensor Science and Technology
• /
• v.6 no.3
• /
• pp.228-236
• /
• 1997

Radioactive materials need to control, measure and protect precisely the overflow because they are dangerous. In this paper, GM-counter type radiation detector system, that can precisely measure the quantity of radioactivity using improved counting program is designed and program that can store and transfer the counted data is studied. The manufactured system, counting system of GM-counter type radiation detector, and counter program can be utilized to measure them at various methods in an atomic power plant and research centers.

• Journal of Science and Technology Studies
• /
• v.11 no.2
• /
• pp.31-66
• /
• 2011

The main issue in Korean debates over genetically modified (GM) foods have been government's responsibility to guarantee consumers' right-to-know and make informed choice. Counter-experts' critique over the current regulatory processes based upon substantial equivalence have not been widely publicized. Through interviews and textual analysis, this paper explored three groups' performances in Korean GM food controversies-regulatory scientists, civil society organizations, and counter-experts. Analytic focus was made upon how each of the groups interact with current GM food regulations. While making conflicts with regulatory scientists and their 'discourse of compliance with global standards,' counter-experts were excluded from regulatory processes. This article suggests that the processes and contexts in which counter-experts failed to form strong alliance with other groups need to be examined in order to further understand the specific contours of Korean GM food controversies.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2003.10a
• /
• pp.415.1-415.1
• /
• 2003

• Nuclear Engineering and Technology
• /
• v.10 no.3
• /
• pp.137-144
• /
• 1978

A method is presented here in order to determine a nonlinearity correction of observed counter rates in a GM counter. An expression, which is developed under the assumption of dead time dependence on counting rates, gives good agreement with the results obtained from the experimental work. The variation of pulse voltages from a GM counter with counting rates was measured with the aid of pulse height analyzer. This method gives accurate values for the dead time over a wide range of counting. The technique as outlined allows tile exact correction of the nonlinearity caused by dead time loss. It was observed that the dead time decreases as the counting rate increases.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.10a
• /
• pp.375.2-375
• /
• 2002

• Journal of the Korean Society of Radiology
• /
• v.2 no.1
• /
• pp.5-10
• /
• 2008

This study developed a PDA based wireless communication radiation measuring instrument using Bluetooth. The proposed system is composed of Student Radiation Monitor of Vernier using GM (Geiger Mueller) counter tube as a radiation measuring sensor, LabPro of Vernier as a module for data collection, Promi SD 101 of Initium, which can make Bluetooth communication up to 30 m, for wireless data transmission, and HP 5550 embedded with Pocket PC 2003 as OS for data storage and display. Because GM counter tube is used as a radiation measuring sensor, the system cannot measure radiation energy but measures count volume and count rate. When the result of natural radiation measuring by the PDA based system was compared with that by a PC based system, it was found that the proposed system transmits and receives data without distortion.

• Journal of radiological science and technology
• /
• v.39 no.4
• /
• pp.565-570
• /
• 2016

Radioactive iodine($^{131}I$) treatment reduces recurrence and increases survival in patients with differentiated thyroid cancer. However, it is important in terms of radiation safety management to measure the radiation dose rate generated from the patient because the radiation emitted from the patient may cause the exposure. Research methods, it measured radiation dose-rate according to the elapsed time from 1 m from the upper abdomen of the patient by intake of radioactive iodine. Directly comparing the changes over time, high dose rate sensitivity and efficiency is statistically significant, and higher chamber than GM counter(p<0.05). Low dose rate sensitivity and efficiency in the chamber had lower levels than gm counter, but not statistically significant(p>0.05). In this study confirmed the characteristics of calibrated ionization chamber and GM counter according to the radiation intensity during high-dose radioactive iodine therapy by measuring the accurate and rapid radiation dose rate to the patient explains, discharged patients will be reduced to worry about radiation hazard of family and others person.

• Nuclear Engineering and Technology
• /
• v.51 no.4
• /
• pp.1081-1090
• /
• 2019

Detailed pulse shape analysis of a Geiger-$M{\ddot{u}}ller$ counter is performed to understand the pulse shape dependence on operating voltage. New data is presented to demonstrate that not all pulses generated in a GM counter are identical. In fact, there is a strong correlation between the operating voltage and the pulse shape. Similar to detector deadtime, pulse shapes fall in three distinct regions. For low voltage region, where deadtime was reported to reduce with increasing voltage, pulse generated in this region was observed to have a fixed pulse width with a variable tail. The pulse width and fall time of the tail was observed to be a function of applied voltage; exponentially reducing with increasing voltage with an exponent of negative 6E-04 and 2E-03 respectively. The second region showed a pulse without any significant tail. During this time the detector deadtime was earlier reported to be at its minimum. The highest voltage region demonstrated a different deadtime mechanism where the second pulse was reduced in width. During this time the deadtime seemed to be increasing with increasing voltage. This data allows us to gain some unique insight into the phenomenon of GM detector deadtime not reported thus far.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.1
• /
• pp.21-25
• /
• 2005

Purpose: $^{14}C$-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid $^{14}C$-UBT (Heliprobe method), which was equipped with $Geiger-M\ddot{u}ller$ counter and compared the results with those obtained by using the conventional method. Materials and Methods: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and $^{14}C$-UBT. A 37 KBq $^{14}C$-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Hellprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. Results: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). Conclusion: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.

• Journal of Radiation Protection and Research
• /
• v.28 no.3
• /
• pp.183-187
• /
• 2003

Collimator for $M{\ddot{o}}ssbauer$ source was manufactured for compton scattering experiment. Exposure dose rate was calculated and measured using GM counter for radiation evaluation. These results were well agreed to each other and used for collimator design. SUS303 was used for collimator material because exposure dose rate at 10 cm is about 2 mR/h. The radiation emited from the 35 mm, 65 mm hole was measured using gamma camera which have 4' diameter. 2-D radiation image was acquired and analyzed. The radiation size at Gamma Camera was 8.0 mm and 5.8 mm respectively.