• The korean journal of orthodontics
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• v.26 no.3
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• pp.255-265
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• 1996

The purpose of this study was to investigate if there were a significant difference between cephalometric measurements of mandibular position derived from a centric occlusion tracing compared to those of a converted centric relation tracing in the Class III malocclusion. The sample consisted of 25 Class III malocclusion and 25 normal occlusion persons who had no orthodontic treatment. The records included an lateral cephalometrics in centric occlusion, centric relation and centric occlusion bite registration and diagnostic casts mounted on the SAM II articulator in CR. The amount of CR-CO discrepancy of condyle was recorded using a MPI(Mandibular Position Indicator, MPI $200^{(R)}$, Great Lakes Orthodontics, USA). The conversion of the CO cephalogram to CR using the MPI readings was performed on the Conversion work sheet. Measures of mandibular position were chosen for the purpose of this study. The comparison of the difference between CO and CR cephalometric measurements in the normal occlusion and Class III malocclusion group were studied. The results were as follows: 1. In the features of CR-CO discrepancy of the condyle, the condyle was displaced posterior and inferior when the teeth were in centric occlusion. The horizontal component(${\Delta}X$) in Class HI malocclusion group was greater than the vertical component(${\Delta}Z$) and also greater than the horizontal component(${\Delta}X$) in normal occlusion group. There was no statistically significant correlation between MPI measurements and the groups of normal occlusion and Class III malocclusion group. 2. In the comparison of the cephalometric measurements in each group, Normal occlusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity and ODI. Class HI malocclusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity, ODI, SNB, APDI, L1-FP and it had more significance than the normal occlusion group. 3. The Value of cephalometric measurements was significantly different between CO and CR but there were no differences between the groups of normal occlusion and Class III malocclusion. The results of this study suggest that if the discrepancies are greater than the amount of normal displacement from clinically captured centric relation, centric relation should be considered as the starting point for proper diagnosis and treatment planning.

• Journal of radiological science and technology
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• v.34 no.2
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• pp.91-96
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• 2011

The purpose of this study was to analyze the change of morphologic pelvis according to age and gender. Pelvis AP(anterior-posterior) projection were taken from 382 individuals (men: 194, women: 188) at the age of twenty and older. We measured four values of pelvis using CR (computed radiological system) including maximum pelvic breadth (MPB), sacral breadth (SB), transverse diameter of pelvic inlet (TD), and distance between femoral heads (DFH). Average (t-test, ANOVA) and Pearson correlation were calculated for comparison. While there was no significant difference of gender in case of MPB, significant differences were observed in SB (men 97.76 mm, women 102.00 mm), TD (men 138.0 mm, women 149.79 mm), and DFH (men 141.94 mm, women 150.39 mm). The DFH values were negatively correlated with the age (men r=-0.280, women r=-0.207). The morphological changes of pelvis were measured high in the men of 50's and in the women of 60's and 70's. The SB, TD and DFH were greater in the women than in the man. As the ages get higher, the deviation of pelvis were gradually increased, which indicates that the morphological changes of pelvis with respect to the age reflects an aging process.

• Journal of radiological science and technology
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• v.28 no.1
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• pp.9-12
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• 2005

In this study, film type radiation sensor tips are fabricated for remote sensing of X or g-ray with inorganic scintillators and plastic optical fiber. The visible range of light from the inorganic scintillator that is generated by X and g-ray is guided by the plastic optical fiber and is measured by optical detector and power-meter. It is expected that the fiber-optic radiation sensor which is possible to be developed based on this study is used for remote, fast and exact sensing of X or g-ray because of its characteristics such as very small size, light weight and no interference to electromagnetic fields.

• Journal of the Korean Institute of Telematics and Electronics
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• v.3 no.3
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• pp.14-21
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• 1966

In this article, a recording system for nuclear radiation detection by means of circular radial deflection as an instrument and its applications are described. In the electronic circuit of the instrument, the linearity of a deflected pulse on a circular sweep is especially contribed by employing a multiplying circuit, not to mention the one of a circular time base itself. A sequence of random pulses was recorded on a circular sweep of the CRT screen by means of one cycle unblanking due to a logic circuit. It seems that the intrument is suitable for measuring a decay curve of a short-lived nuclide and its pulse spectrum

• Journal of Yeungnam Medical Science
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• v.6 no.1
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• pp.141-149
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• 1989

The purpose of this study was to aid the case analysis and diagnosis of the maxillofacial deformities for orthognathic surgery. The applied method for analysis was a Cephalometries for Orthognathic Surgery(COGS) by Burstone. Lateral cephalograms were obtained from 59 subjects over 21 years old, that consisted of 30 males and 29 females with normal occlusion, acceptable profile. The results were as follows : 1. The author made the tables of means, standard deviations in each item, sex. 2. The author performed whether there was significance (P<0.05) between the registered male and female's measurement in each item.

• Journal of Radiation Protection and Research
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• v.12 no.1
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• pp.12-25
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• 1987

A basic multichannel analyser (MCA) system have been designed and constructed with the successive approximation type ADC (Analog to Digital Converter). Linear Gate, window, and palse stretcher consist of mainly linear and logic IC's, and are properly combined together to achieve short dead time and good linearity of the system. ADC 1211 (analysing time: $120{\mu}sec$) and S-RAM (static random acess memory) 6264 are used in ADC module. Two 6264 memories are connected in parallel in order to-provide enough counting capacity ($2^{16}-1$). Interfaced microcomputer Apple II controls this system and analizes the counted data. The system is tested by input pulses between 0V to 10V from oscillator.

• The korean journal of orthodontics
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• v.41 no.2
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• pp.98-111
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• 2011

Objective: Superimposition of frontal cephalograms cannot be performed when the cephalograms are taken with different vertical head rotations. The purpose of the present study was to evaluate the validity of correcting the positional change of frontal cephalometric landmarks caused by vertical head rotation. Methods: In 30 adult individuals, frontal and lateral cephalograms were taken at a $90^{\circ}$ angle. Geometric principles of radiography were used to calculate the possible vertical and horizontal landmark changes if the head should be rotated down $5^{\circ}$ about an ear rod axis. The calculated changes were then compared with cephalometric changes measured on frontal cephalogram actually taken with the head rotated down $5^{\circ}$. Results: When the frontal cephalograms were taken with the head rotated down $5^{\circ}$ about an ear rod axis, significant changes in the vertical position of the landmarks occurred, particularly in the landmarks located farther anteriorly from the ear rod axis. The comparison of calculated changes and real cephalometric changes showed that the differences were less than 0.4 mm in the vertical direction and less than 0.2 mm in the horizontal direction. The differences between calculated and real changes were smaller in the landmarks less affected by vertical head rotation. Conclusions: Even when frontal cephalograms are taken at different vertical head rotations, the concomitant changes in the position of the landmarks can be corrected through calculation using the geometric principle of radiography as long as frontal and lateral cephalograms are taken perpendicular to each other.

• Journal of the Korean Society of Radiology
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• v.1 no.3
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• pp.11-16
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• 2007

In this study, the potential of a newly developed simulation toolkit, GATE for the simulation of electronic portal imaging devices (EPID) in radiation therapy was evaluated by characterizing the performance of the metal plate/phosphor screen detector for EPID. We compared the performances of the GATE simulator against MCNP4B code and experimental data obtained with the EPID system in order to validate its use for radiation therapy.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.117-122
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• 2005

According to the Para. 5 of Art 2 of the Korean Nuclear Safety Regulations, which was revised in 1999, internal dose assessment as well as external one should be performed by law for employees at a nuclear power plant from 2003, and their estimate errors should also be within 50%. Thus, more accurate internal dosimetry becomes important. Corresponding to such regulation revision, we are developing a more accurate thyroid-uptake internal dosimetric system and have developed a Monte Carlo simulation code, the so-called CALEFF, to calculate the detection efficiency of the dosimetric system. In this paper, we calculated detection efficiencies with various test conditions by using the CALEFF code and discussed their characteristics. We may use the detection efficiency calculated by the code in calibrating the thyroid internal dose from measured data.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.95-100
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• 1996

현재 방사선 비상훈련에 사용하는 TID-14844 의 방사선원항은 너무 보수적이고, 각 사고경로별로 방사선원항의 특성을 나타낼 수 없으므로, 원전의 비상사고 발생시 주민의 피폭선량을 최소화하기 위한 발전소 요원의 신속, 정확한 대처능력을 배양하기 위하여 현실적인 방사선원항 평가자료의 필요성이 대두되어 왔다. 본 연구에서는 보수성을 배제한 최적 분석기법을 이용하여 선정된 사고경로에 대해 MAAP 전산코드로 사고진행 및 방사선원항을 분석하였고, 격납건물내 방사선계측기의 예측치를 평가할 수 있는 방법론을 개발하였으며, 이를 통해 사고경로별 안전변수 및 방사선 계측기 등에서의 사고 진행에 따른 예측치 등을 계산함으로써 효과적인 비상대책 수립을 위한 실질적인 방사선원항 데이타 베이스를 구축하였다.