• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.811-822
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• 2001

최근 임플란트를 원하고, 필요로 하는 환자가 증가하면서 술전의 정확한 진단이 보다 중요해졌고 다양한 진단방법이 소개되고 이용되어져 왔다. 그 중 보편적으로 가장 널리 사용되어지는 방법이 방사선 촬영법이고 그 중에서도 파노라마방사선사진이다. 하지만 파노라마방사선사진의 용이함과 간편성에도 불구하고 그 방법 자체가 가지고 있는 한계점 때문에 CT/MPR(Computer Tomography/Multiplanar Reformatting)이 일부 환자에서는 반드시 필요하다는 주장이 대다수이다. 본 연구의 목적은 하악 구치부에 임플란트 시술을 받은 환자를 대상으로 파노라마방사선사진의 확대율을 알아보고 파노라마방사선사진과 CT/MPR에서 치조정-하악관간 거리가 실제 어느 정도 차이를 보이는지, 그리고 CT/MPR에 대한 파노라마방사선사진의 확대율에 환자의 하악골의 경사도와 하악관의 해부학적 위치가 어떤 영향을 미치는지를 알아보는 것이다. 본 연구는 서울대학 치과병원 치주과를 내원하여 하악구치부에 Dental Implant 시술을 받은 15명의 환자, 32개 부위를 대상으로, 임플란트 시술을 위한 술전 파노라마방사선사진과 CT/MPR, 술후의 파노라마방사선사진, CT/MPR상을 자료로, 임플란트가 식립될 위치에서 치조정에서 하악관의 길이, 하악골의 협설폭경, 하악골의 설측면에서 하악관의 수평길이, 임플란트 매식체의 설측에서 하악관까지의 수평거리를 계측하였고 이 해부학적 계측치들이 CT/MPR에 대한 파노라마방사선사진의 확대율과 어떤 상관관계에 있는지 Pearson's correlation coefficient test를 이용해 살펴보았다. 1. CT/MPR에 대한 파노라마방사선사진의 확대율은 CT/MPR상에서 하악골 단면의 협설폭경(Pearson test에서의 상관관계 분석시, 상관계수 r=-0.604), 임플란트 매식체의 설측에서 하악관까지의 수평거리(r=-0.515), 하악골의 설측면에서 하악관까지의 수평거리(r=-0.640)와 뚜렷한 음적 선형관계가 있었다. 2. CT/MPR에 대한 파노라마방사선사진의 확대율은 CT/MPR상에서 하악골의 장축의 각도와는 뚜렷한 양적 선형관계(Pearson test에서의 상관관계 분석시, 상관계수 r=-0.446)가 있었다. 3. 여러 요소중 CT/MPR에 대한 파노라마방사선사진의 확대율과 가장 유의성있는 연관성을 보이는 것은 CT/MPR상에서 하악골의 설측면에서 하악관까지의 수평거리였다(r=-0.640) 4. CT/MPR에 대한 파노라마방사선사진의 확대율은 일반적으로 생각되어지는 파노라마방사선사진의 확대율 125%보다 큰, 약 135%로 나왔다. 이상의 결과로 볼 때, 하악골의 설측면에서 하악관까지의 수평거리가 CT/MPR에 대한 파노라마방사선사진의 확대율에 가장 영향을 미치는 요소로 추정되며 확대율은 125%보다 높은 것으로 나타났다.

• The Korean Journal of Nuclear Medicine
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• v.4 no.1
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• pp.51-60
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• 1970

In 1969 this laboratory had prepared 131 mc. of radiopharmaceuticals in total (Hippuran and other four kinds) and distributed to the major medical establishments. The quality and stability of these products were reviewed by means of radio paper partition chromatography and thin layer chromatography and results were compared to those of foreign products. Generally, the quality and stability of the product of this laboratory were better than those of the foreign product, even though the properties of the radiopharmaceutical were varied by the procedure of the preparation adopted. Various precautions for handling radiopharmaceuticals for clinical use were also described with a view of quality control and stability test there of.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.5
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• pp.1-6
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• 2001

In this paper, we propose the initial optimized structure of the Radial Basis Function Network(RBFN) which is more simple in the part of the structure and converges more faster than Neural Network. For this, we use the analysis method using time frequency localization and we can decide the initial structure of the RBFN suitable for the given problem. When we compose the hidden nodes with the radial basis functions whose localization are similar with the target function in the plane of the time and frequency, we can make a good decision of the initial structure having an ability of approximation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.26-35
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• 1996

In this paper, characteristics of the electromagnetically coupled broadband microstrip antennas are analyzed by the Finite Difference Time Domain (FDTD) method, and antenna para- meters are optimized to get maximum bnadwidth. By using short radial tuning stub in microstrip feedline, electromagnetically coupled microstrip antenna shows broadband ($\simeq$13%) characteristics, and the characteristics are varied as a function of radius, radial angle, and position of the radial tuning stub. Operating frequency, return loss, VSWR and input impedance are calculated by Fourier transforming the time domain results. After optimization of the parameters, maximum bandwidth of the radial stub tuning microstrip antenna is about 15% and the ripple char- acteristic of the VSWR is better than the rectangular tuning stub microstrip antenna.

• The Journal of the Acoustical Society of Korea
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• v.29 no.7
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• pp.431-438
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• 2010

The radiation pattern of conformal transducers installed on a curved surface is likely to be complicated depending on the array pattern on the curved surface. In this research, the acoustic sources constituting a conformal transducer are arrayed in equi-angle, equi-interval, and geodesic dome forms, and the radiation pattern function of each of the array geometries has been derived, and therewith the radiation pattern has been analyzed for each array geometry. Based on the analysis result, we have determined the equi-interval array geometry that provides the widest beam width with the lowest side lobe level among the three array geometries. Results of the present work are expected to be utilized to the design of conformal transducer structures.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.117-123
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• 2001

Anchovy scoop nets, a kind of lift net have been used in the coastal area of Cheju and South sea of Korea. An incandescent lamp(AC 100V, 1kW) is being used as a fishing lamp for gathering anchovy. Fishing lamp was installed at 1m ahead of the prow and 1.5m higher than the water surface. The fishing lamp let fish school rise to the water surface and attract to bag net. Accordingly, a successful anchovy catching depends on controling of fishing lamp. On the study, the distribution of spectral irradiance illumination of incandescent lamp(1kw) and the irradiance efficiency of reflection plate were analyzed and discussed to investigate the ability of fishing lamp which can attract anchovy school effectively. The results obtained are summarized as follows : 1. Around 180% of irradiance efficiency of incandescent lamp was increased by using the reflection plate. The light of lamp was radiated into water with circular shape. 2. The irradiance illumination of incandescent lamp in air was a maximum in wave length of 994nm but it was 690nm at 0.5m and 1.0m of water depth. 3. The relationship between water depth(x) and water illumination(y) of vertical light is represented as follows : y=146.03e supper(-0.37x) 4. The light of incandescent lamp(1kW) pass through much better into vertical direction than horizontal but it was estimated that the light was not able to reach depth of 20m.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.12
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• pp.489-498
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• 2022

Recently, the textile industry, which is labor-intensive, is attempting to reduce process costs and optimize quality through artificial intelligence. However, the fiber spinning process has a high cost for data collection and lacks a systematic data collection and processing system, so the amount of accumulated data is small. In addition, data imbalance occurs by preferentially collecting only data with changes in specific variables according to the purpose of fiber spinning, and there is an error even between samples collected under the same fiber spinning conditions due to difference in the measurement environment of physical properties. If these data characteristics are not taken into account and used for AI models, problems such as overfitting and performance degradation may occur. Therefore, in this paper, we propose an outlier handling technique and data augmentation technique considering the characteristics of the spinning process data. And, by comparing it with the existing outlier handling technique and data augmentation technique, it is shown that the proposed technique is more suitable for spinning process data. In addition, by comparing the original data and the data processed with the proposed method to various models, it is shown that the performance of the tensile tenacity and elongation prediction model is improved in the models using the proposed methods compared to the models not using the proposed methods.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.103-107
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• 2012

This paper analyzes changes in the external radiation dose rate of PET-CT test patients as a part of providing basic materials for reduction of radiation exposure to PET-CT test patients. In theory the measurement of external radiation dose rate of PET-CT test patients shows that the further the distance from the patient injected with radioactive pharmaceutical and a longer time elapsement from the injection leads to a smaller amount of radiation. Particularly, the amount of radiation marked the highest in the chest was at 4.17 minutes immediately after the intravenous injection and in the head after 77.47 minutes after urination in advance to the PET-CT test. As in the generalized information, it is desired to keep distance between the patient and caretakers or professionals to reduce the amount of radiation exposure from PET-CT test patients and to resume contact the patient after the time when the radiation has reduced. If contact is unavoidable, it is desired to keep at least 200cm from the patient. In addition, the amount of radiation reached the highest in the chest at first and then in the head from 77 minutes after injection. Accordingly, it would be helpful in achieving the optimization if contact is made based on the patient's physical characteristics. This study is significant as it measures changes in radiation the dose rate by; distance from the PET-CT test patient, time elapsed, and specific parts of body. Further studies based on the findings in this paper are required to analyze changes in radiation dose rate in accordance with individual characteristics unique to PET-CT patients and to utilize the results to reduce the amount of radiation patient, caretakers and professions are exposed.

• Journal of the Korean Society of Radiology
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• v.18 no.1
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• pp.53-63
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• 2024

The purpose of this study was to analyze radiological technologists' (RT) task perceptions of intravenous injection behavior of contrast medium and use it as basic data for future workforce response plans. We surveyed a total of 172 RT using questionnaire terms consisting of demographic characteristics, job priorities, and RT' task perceptions of intravenous injection behavior. Statistical analysis was performed using descriptive statistics, frequency analysis, independent samples T-test, and ANOVA analysis. As a result, first, current clinical RT were highly aware of the need for intravenous injection behavior as a response to the future workforce of them, and the workload burden resulting from this was evaluated as low. Second, the fear of intravenous injection behavior was found to be significant, so it is judged to be useful to perform them as selective job actions rather than all RT' task. Third, the need for training courses and certification for RT' intravenous injection behavior is being raised, and additional specific research on this is required. Last, RT' positive perception of intravenous injection behavior could be expected as a foundation for improving national medical services, strengthening RT expertise, and expanding tasks.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.181-186
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• 2015

Measurement of xenon radioisotopes from nuclear fission is a key element for monitoring underground nuclear weapon tests. $^{131m}Xe$, $^{133}Xe$, $^{133}mXe$ and $^{135}Xe$ in the air can be detected via low background systems such as a beta-gamma coincidence counting system. Radioxenon monitoring is performed through air sampling, xenon extraction, measurement and spectrum analysis. The minimum detectable concentration of $^{135}Xe$ can be significantly variable depending on the sampling time, extraction time and data acquisition time due to its short half-life. In order to optimize the acquisition time with respect to certain experimental parameters such as sampling and xenon extraction, theoretical approach and experiment using SAUNA system were performed to determine the time to minimize the minimum detectable concentration, which the results were discussed.