• Journal of radiological science and technology
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• v.40 no.2
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• pp.187-195
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• 2017

Early diagnosis for upper facial trauma is difficult by using the standard Water's view (S-Water's) in general radiograph due to overlapping of anatomical structures, the uncertainty of patient positioning, and specific patients with obese, pediatric, old, or high-risk. The purpose of this study was to analyze appropriate exposure angles through a comparison of two different protocols (S-Water's vs. reverse Water's view (R-Water's)) by using a head phantom. A head phantom and general radiograph with 75 kVp, 400 mA, 45 ms 18 mAs, and SID 100 cm. Images of R-Water's were obtained by different angles in the range of $0^{\circ}$ to $50^{\circ}$, which adjusted an angle at 1 degree interval in supine position. Survey elements were developed and three observers were evaluated with four elements including the maxillary sinus, zygomatic arch, petrous ridge, and image distortion. Statistical significant analysis were used the Krippendorff's alpha and Fleiss' kappa. The intra-class correlation (ICC) coefficient for three observers were high with maxillary, 0.957 (0.903, 0.995); zygomatic arch, 0.939 (0.866, 0.987); petrous ridge, 0.972 (0.897, 1.000); and image distortion, 0.949 (0.830, 1.000). The high-quality image (HI) and perfect agreement (PA) for acquired exposure angles were high in range of the maxillary sinus ($36^{\circ}-44^{\circ}C$), zygomatic arch ($33^{\circ}-40^{\circ}$), petrous ridge ($32^{\circ}-50^{\circ}$), and image distortion ($44^{\circ}-50^{\circ}$). Consequently, an appropriate exposure angles for the R-Water's view in the supine position for patients with facial trauma are in the from $36^{\circ}$ to $40^{\circ}$ in this phantom study. The results of this study will be helpful for the rapid diagnosis of facial fractures by simple radiography.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.560-564
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• 2007

Korea Basic Science Institute(KBSI) has three general electron microscopes including High Voltage Electron Microscope(HVEM) which is the only one in Korea. Observed images through an electron microscope are what they are tilted by each step and saved, offering the more better circumstances for observers, a reconstruction to 3D could be a essential process. In this process, a warping method decreases distortions maximumly of avoided parts of a camera's focus. All these image treatment processes and 3D reconstruction processes are based on an accompaniment of a highly efficient computer, a number of Grid Node Personal computers share this process in a short time and dispose of it. Grid Node Personal computers' purpose is to make an owner can share different each other and various computing resources efficiently and also Grid Node Personal computers is applying to solve problems like a role scheduling needed for a constructing system, a resource management, a security, a capacity measurement, a condition monitoring and so on. Grid Node Personal computers accomplish roles of a highly efficient computer that general individuals felt hard to use, moreover, a image treatment using the warping method becomes a foundation for reconstructing to more closer shape with an real object of observation. Construction of the electron microscope volume 랜더링 system based on Grid Node Personal computer through the warping process can offer more convenient and speedy experiment circumstances to observers, and makes them meet with experiment outcome that is similar to real shapes and is easy to understand.

• Korea journal of population studies
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• v.27 no.1
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• pp.171-201
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• 2004

Modern sciences in the West are deeply rooted in the Greek and Roman cultural heritage. Consequently, the academic achievements accomplished by the scholars of the Arabs including Persian world, the profound thoughts developed in the Indian subcontinent, and the excellent works made by the East Asian scholars have mostly been neglected in the past. This paper attempts to compare the thoughts and theories on population developed by the Western scholars with those of East Asian scolars, in chronological order, ancient, mediaeval, and modern period before Malthus. The thesis that excessive population growth may reduce output per worker, depress levels of living for the masses and engender strife is of great antiquity. In fact, overpopulation in East Asia, especially in China, goes back to very ancient times, most Confucian scholars maintained the notion of a numerical balance between population and environment. They also looked for means to check the increase in numbers. The foundations of a theory of optimum population level, fully developed in the twentieth century, can be found in their writings. Although early population thoughts in China had not advanced far in the analysis of the significance of population size and growth, it had taken only a few steps forward. At some times and to some observers, populousness appeared desirable; at other times and to other observers, it seemed all too evident that the number of people could become too great. These viewpoints foreshowed some of the later developments. The early population literatures reviewed here seem to consist of a number of quite isolated contributions. In fact, however, there may have been a greater continuity of thought than now appears, for many of the contributions may have been lost and there are many gaps in the record. An intensive review on comparing two works, those of Malthus' and Hong, Liang-chi's, are presented in this paper. Only five years before Malthus published his famous work, An Essay on the Principle of Population, Hong published his theories on population. Some of them, Hong insisted, are very similar to the Malthusian concepts of geometrical increase, natural and artificial checks of population. Despite the excellent works in the ancient period, this paper concludes with an investigation of the reasons why modem achievements in scientific areas in the East Asia have been far behind that of the West.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.388-402
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• 1996

Background : To compare the diagnostic accuracies of High-resolution CT(HRCI) and chest radiography in the diagnosis of diffuse infiltrative lung disease(DILD). Methods : This study included ninety-nine patients with a diagnosis of acute or chronic DILD, representing 20 different diseases. Twelve normal subjects were included as control. The disease state was confirmed either pathologically or clinically. Radiographs and CT scans were evaluated separately by three independent observers without knowledge of clinical and pathologic results. The observers listed three most likely diagnoses and recorded degree of confidence. Results : The sensitivity of HRCT in the detection of DILD was 98.9% compared to 97.9% of chest radiography. Overall, a correct first-choice diagnosis was made in 48% using chest radiographs and in 60% using HRCT images. The correct diagnosis was among the top-three choices in 64% when chest radiographs were used, and in 75% when HRCT images were reviewed. Overally a confident diagnosis was reached more often with HRCT(55%) than with chest radiography(26%). The correct first-choice diagnosis increased remarkably when the HRCT was used in usual interstitial pneumonia, miliary tuberculosis, diffuse panbronchiolitis and lymphangitic carcinomatosis. Conclusion : HRCT is confirmed to be superior to conventional radiography in the detection and accurate diagnosis of DILD. HRCT is especially valuable in the diagnosis of usual interstitial pneumonia, miliary tuberculosis, diffuse panbronchiolitis, and lymphangitic carcinomatosis.

• Journal of radiological science and technology
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• v.28 no.3
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• pp.203-209
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• 2005

Objective True lateral scapular image was very important to diagnosis the scapular fracture and dislocation induced by traumatic injury. The aim of this study was to know the patient rotation angle to be showing the scapular true lateral in Korean. Subjects and Materials Thirty patients(22men, 8 women, mean ages 53.4)with scapular pain, had supine anteroposterior projection taken with $32^{\circ}$, $37^{\circ}$, $42^{\circ}$ trunk rotation angle changing the manual angulation material. Radiographs were evaluated independently by 5 experienced observers(1 orthopedics surgery specialist, 1 diagnostic radiology specialist, 3 radiological technologist) They assessed overlab of vertebral border and axillary border of scapular as follows; Totally overlapping of vertebral border and axillary border is 4, partially overlapping is 3, not overlapping is 2 and oblique location with two borders is 1. All observers scored using by PACS monitor. Results $32^{\circ}$ trunk rotation was scored $1.53{\pm}0.39$, $37^{\circ}$ trunk rotation was scored $3.83{\pm}0.15$ and $42^{\circ}$trunk rotation was scored $2.17{\pm}0.43$. There was no difference(p<0.05) between group of more than 100cm of the girth of the chest and group of less than 100cm. Similarly, men and women group showed no difference(p<0.05) with trunk rotation statistically. Conclusions There was no result of trunk rotation angle to radiograph the true scapular lateral image up to date. This studies were summarized as follows; Adaptation of $37^{\circ}$ trunk rotation was the best to show the true scapular lateral image in Korean. Our results were very useful to get the true scapular lateral images in clinic.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.393-402
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• 2000

Purpose: Tc-99m-MIBI (MIBI) and Tc-99m-Tetrofosmin (TF) are commonly used for scintimammog (SMM). We compared the diagnostic ability of SMM using Tc-99m-MIBI and Tc-99m-TF for the diagnosis of breast mass. Materials and Methods: The study subjects were comprised of 123 breast lesior 86 normal breasts of 114 patients who underwent SMM. Bilateral prone images and anterior supine images obtained at 5 minutes and 1 or 3 hours after intravenous injection of 740 MBq of either MIBI or TF. of tumors were not significantly different between the MIBI and TF groups. First, two observers read the SMM without clinical information (1st interpretation), then read again with information about location (2nd interpretation). Sensitivity and specificity of each radiopharmaceutical for the diagnosis of cancer were evaluated in terms of image acquisition time, tumor size, and location. Results: The SMM a good agreement between two observers for 1st and 2nd interpretation, except for TF SMM at 3 hr. first interpretation, the sensitivities at 5 min, 1 hr, and 3 hr were not significantly different between MIBI TF SMM (81.6%, 80.0%, 60.9% in MIBI vs. 88.9%, 80.6%, 42.9% in TF), although the sensitivities of images were significantly lower than 5 min images in both MIBI and TF SMM. The specificity of TF at was superior to that of MIBI (81.5%, 90.0%, 82.9% in MIBI vs. 96.7%, 100%, 90.0% in TF, p<0.01 MIBI TF at 5 min). For the second interpretation with information of mass location, the sensitivities at 3 hr were significantly lower than 5 min images (86.8%, 86.7%, 78.3% in MIBI vs. 88.9%, 93.5%, 57.1% between MIBI and TF SMM. However, there was no significant difference in the specificity (60.0%, 75.0% for MIBI vs. 86.7%, 100%, 100% for TF). MIBI and TF SMM showed lower sensitivities for the with less than 1 cm than tumors with more than 1 cm. However, the location of tumors did not sensitivity and specificity between MIBI and TF SMM. Conclusion: The ability for the differential of breast tumor is similar between MIBI and TF SMM, and delayed image is not necessary. TF may be than MIBI considering the specificity of SMM without clinical information and labeling convenience.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.93-98
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• 2020

Purpose: Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols. Materials and Methods: A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Micro-computed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test. Results: Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT. Conclusion: Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.349-362
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• 1996

To determine the factors to affect on stone surface porosities produced from hydrogen gas of additional silicone, both putty and syringe type of 7 commercially different additional silicone impression materials(Blend-A-Scon, Correct VPS, Exaflex, Express, Extrude, Provil, Reprosil) were chosen and NewFujirock(GC) was poured into the impressions of detail-reproducing test block at 1, 15, 30, 45, 60 minutes after the impression materials had set and 4 specimens were made for each pouring time, each type of impression material, and each consisency and So, 280 specimens were made in total. The number of surface porosities of same area($2826 mm^2$) which were typically caused by hydrogen gas using the stereoscope(X 7.5) by two observers. Comparison of putty-syringe type and among the impression materials are tested by Kruscal-Wallis method and Mann-Whitney method(p<0.05). The results are as follows. 1. The number of porosities decreased as the pouring time of stone was delayed on both putty and syringe type of additional silicone materials. 2. The putty type significantly produced more porosities than syringe type except for the group of Reprosil.(p<0.05). 3. In case of putty type, the number of porosities increased as following order. Reprosil / Blend-A-Scon and Provil / Correct VPS and Extrude / Express and Exaflex. 4. In case of syringe type, Blend-A-Scon and Extrude produced no porosity and Exaflex and Provil at 30 minites, but Express produced porosities even at 60 minutes and the most. Additional silicone impression material releases hydrogen gas, and that fact can make the resulting die stone model useless. So, to minimize these adverse effects, it is desirable not to expose putty type of additional silicone on critical impression surface because putty type has a tendency to produce more porosities than syringe type. And it is important to have sufficient time before pouring the stone on impression because porosities produce less as time passes after setting of impression material. Also, there are differences among 7 additional silicone impression materials, so it is desirable to choose adequate brand of additional silicone for good laboratory work.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.187-192
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• 1991

This study was carried out to estimate the stand volume for Japanese larch(Larix leptolepis) by Strand sampling method. The data collected for this study were based on the 380 sample plots from the field survey, which were distributed in the major part of Korea(Kyeongi, Kangweon, Chungbuk, Chungnam, Chunbuk and Kyeongbuki), and the plotless sampling instrument such as dendrometer, spiegel relascope and tele-relascope were used. The procedure for this study is summarized briefly as follows : 1. There were not only significant differences between volume estimation by Strand sampling method and that by plot survey method, and the relationship was y=bx, where b approached nearly 1. Therefore, the stand volume of Japanese larch could by estimated by Strand sampling method. 2. The value measured by three different plotless sampling instruments did not showed any significant differences between instruments and observers, density and instruments, and ground slope and instruments. 3. With the stand volume, basal area height showed the highest correlation and stand form height, average height, basal area per ha correlated with the volume in thier orders. 4. The best fitted equation of stand volume estimation with basal area height by relascope was as follow. log V=-0.0375+0.8910 log GH-1.5946 1/GH Stand volume table also was obtained using the above estimeated equation. 5. The relationship between estimated value and actual value was Y=bx, where b was nearly 1. The correlation coefficient was very high and the percentage of estimated error was 4.5%.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.287-298
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• 1992

The main purpose of this study is to obtain information on the factors influencing forest scenic beauty in order to make and manage scenic forest of recreation areas. 62 slides were taken for the study. Each photograph was independently judged by college students in 10 different major fields, with a total 264 observers after reliability test in the study. The ratings were scaled using a computer program developed by Brown & Daniel(1990). The results of rating scale analysis indicate that respondents' major field difference affects visual preference for forest scenic beauty. Similarly, with different sexual, forest visit frequency, and community type in childhood, people tend to rate their preference differently. The respondents' rating scale of relative scenic beauty of near-view forest scenes can largely be explained in terms of forest physical characteristics of forest landscape. Bare ground area and stash area are represented negative esthetic effects, while DBH, number of trees per hectare, sky area showed positive esthetic effects. These 6 variables in the model can be accounted for 74% of total variance in perceived forest scenic beauty. With this study result, it can be concluded that forest physical characteristics are significantly related to visual preference for near-view forest scenes.