• Progress in Medical Physics
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• v.20 no.2
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• pp.72-79
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• 2009

Scatter correction for I-131 plays a very important role to improve image quality and quantitation. I-131 has multiple and higher energy gamma-ray emissions. Image quality and quantitative accuracy in I-131 imaging are degraded by object scatter as well as scatter and septal penetration in the collimator. The purpose of this study was to estimate scatter and septal penetration and investigate two scatter correction methods using Monte Carlo simulation. The gamma camera system simulated in this study was a FORTE system (Phillips, Nederland) with high energy, general-purpose, parallel hole collimator. We simulated for two types of high energy collimators. One is composed of lead, and the other is composed of artificially high Z number and high density. We simulated energy spectrum using a point source in air. We estimated both full width at half maximum (FWHM) and full width at tenth maximum (FWTM) using line spread function (LSF) in cylindrical water phantom. We applied two scatter correction methods, triple energy window scatter correction (TEW) and extended triple energy window scatter correction (ETEW). The TEW method is a pixel-by pixel based correction which is easy to implement clinically. The ETEW is a modification of the TEW which corrects for scatter by using abutted scatter rejection window, which can overestimate or the underestimate scatter. The both FWHM and FWTM were estimated as 41.2 mm and 206.5 mm for lead collimator, respectively. The FWHM and FWTM were estimated as 27.3 mm and 45.6 mm for artificially high Z and high density collimator, respectively. ETEW showed that the estimation of scatter components was close to the true scatter components. In conclusion, correction for septal penetration and scatter is important to improve image quality and quantitative accuracy in I-131 imaging. The ETEW method in scatter correction appeared to be useful in I-131 imaging.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.253-259
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• 2004

in this study, we developed a Monte Carlo imaging simulation code written by the visual C$\^$++/ programing language for design optimization of a digital X-ray imaging system. As a digital X-ray imaging system, we considered a Gd$_2$O$_2$S(Tb) scintillator and a photosensor array, and included a 2D parallel grid to simulate general test renditions. The interactions between X-ray beams and the system structure, the behavior of lights generated in the scintillator, and their collection in the photosensor array were simulated by using the Monte Carlo method. The scintillator thickness and the photosensor array pitch were assumed to 66$\mu\textrm{m}$ and 48$\mu\textrm{m}$, respertively, and the pixel format was set to 256 x 256. Using the code, we obtained X-ray images under various simulation conditions, and evaluated their image qualities through the calculations of SNR (signal-to-noise ratio), MTF (modulation transfer function), NPS (noise power spectrum), DQE (detective quantum efficiency). The image simulation code developed in this study can be applied effectively for a variety of digital X-ray imaging systems for their design optimization on various design parameters.

• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.54-67
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• 1992

The author studied the mental status of 497 patients admitted in non-psychiatric wards and 42 patients diagnosed as mental disorders by DSM-III-R criteria and admitted in three general hospitals located in Pusan city, using NADS and PSCS. The assessment were obtained from October, 1991 to March, 1992 and the results as follows: The mean ${\pm}$ SD of Anxiety-Depression scores were $34.4{\pm}10.4$ in non-psychiatric patients and $50.0{\pm}18.3$ in psychiatric patients. The psychiatric group had significantly higher scores than non-psychiatric group. The mean ${\pm}$ SD of Psychosis scores were $3.9{\pm}4.4$ in non-psychiatric patients and $20.3{\pm}9.8$ in psychiatric patients. The psychiatric group had significantly higher scores than non-psychiatric group. In the psychosocial factors, dissatisfaction in family atmosphere and acquaintanceship with parellts(P<0.001, relatively), pessimistic in future, present and past self-images(P<0.001, relatively), and yes in previous psychiatric treatment of admission(P<0.01, relatively) had common significant relationships to Anxiety-Depression and Psychosis scores. There were correlationships between NADS scores and PSCS scores(${\gamma}$ = 0.74), past and present self-images(${\gamma}$ = 0.45), present and future self images(${\gamma}$ = 0.45), past and future self-images(${\gamma}$ = 0.34) and family atmosphere and acquaintanceship with parents(${\gamma}$ = 0.49). The regression analysis revealed that present self-image, acquaintanceship with parents, future self-image, past self-image, and family atmosphere, in order of significance were to be descriptive or predicable variances for Anxiety-Depression status. The discriminant analysis according to Anxiety-Depression scores showed that the cases of incorrect classification were 22 for non-psychiatric patient group and 2 for psychiatric patient group.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.165-171
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• 2002

Purpose : In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. Materials and Method : A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetrie image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was peformed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. Results : CSI in the supine position was successfully peformed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The differences between the DRRs and the portal films were less than 3 mm in the vertebral contour. Conclusion : CSI in the supine position is feasible in patients who cannot lie on prone position, such as pediatric patienta under the age of 4 years, patients with a poor general condition, or patients with a tracheostomy.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.313-323
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• 2009

Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in $T_2^*$-DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

• Sleep Medicine and Psychophysiology
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• v.6 no.2
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• pp.110-115
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• 1999

Objectives: To investigate the effect of mandibular repasitioning device on airway sige and airway collapsibility in patients with obstructive sleep apnea syndrome(OSAS). Methods: Cine CT with polysomnographic monitoring was performed during sleep in nine(OSAS) patients before and after manibular repositioning device(MRD) application. Axial CT images were obtained in five upper airway levels(retropalatal-high, retroalatal-low, retroglossal, epiglottis, and hypopharynx levels). In each airway level, one axial CT image was obtained during sleep apnea period and 10 serial axial CT images were scanned every 1 second during normal sleep breathing. After wearing MRD, all CT images were obtained by the same method. The cross-sectional areas of airway were measured by automatic tracing method. The changes of minimum airway size and maximum airway size after MRD were evaluated. The airway collapsibility was calculaed before and after MRD. Results: During sleep apnea, the airway of retropalatal-low level was the most frequently narrowest site. During normal sleep breahing the minimum airway size was increased significantly after MRD at retropalatal-low level(p=0.011). The mean airway collapsibility was the highest at retropalatal-low level. MRD decreased the airway collapsibility significantly at retropalatal-low level(p=0.021) and epiglottis level(p=0.038). Conclusions: The enlargement of the minimum airway size and decreased airway collapsibility may be the therapeutic mechanism of MRD in obstructive sleep apnea.

• Cartoon and Animation Studies
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• s.36
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• pp.281-302
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• 2014

Human beings have advanced to release instinctive desire. Among the human desires, sexual desire is classed as a basic desire with appetite and has been expressed in many ways from prehistoric times to present. Despite the social and ethical restriction, expression of sexual image has been evolved with change of time and medium's development. Thanks to inventing the photograph technique, Change of pornographic image has showed a dramatic aspect since early 20th century. The video which delivers message more directly than the picture boosted this change, and the animation has experimented the expression methods and techniques numerously exceeding the limit of realistic image which reappeared by the device. In this thesis, I want to discuss how human beings express sexual desire in animation based on society's sex culture, and analyzed Japanese pornographic animation as its obvious cases. Japanese pornographic animation should be interpreted as the result of culture and society system's history. Through Heian, Edo and early Meiji period, Japanese sex culture has been kept very openly and preposterously. Transformation, metamorphosis, pedophilia, tentacle sex and exposure of specific body parts that are frequently appear in Japanese animation can be interpreted by ancient Japanese open sex culture like Wakashu, polygamy, sleeping in mixed sex group and pederasty. These Japanese odd sex culture is hard to find elsewhere and settled as intrinsic sexual expression in Japanese animation. This situation was institutionally severed by European Modernization's force at the end of World War II in 20th century. However, it seems they have been keeping their influence in a proper form until now. In this study, I discussed that pornographic animation should be interpreted in a frame of cultural phenomenon by researching the series of procedure that ancient Japanese open sex culture has been changed by the system. Sexuality which is found in general Japanese animation was started from their history, and the dichotomous expression about women can be understood that it is bent by institutionally regulated sexual opinion. Japanese history and culture can be understood that it is transformed to the dichotomy that are simultaneously according freedom of eroticism to the pornographic animation, and the fear and irresistible temptation about the woman's body as the other.

• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.203-212
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• 2017

A scientific model refers to a conceptual system that can describe, explain, and predict a particular physical phenomenon. The co-construction of the scientific model is attracting attention as a new teaching and learning strategy in the field of science education and various studies. The evaluation and modification of models compared with the predicted models of data from the real world is the core of modeling strategy. However, there were only a limited data provided by the teacher in many studies of modeling comparing the students' predictions of their own models. Most of the students were not given the opportunity to evaluate the suitability of the model with the data in the real world. The purpose of this study was to develop a scientific model co-construction program that can evaluate the model by directly comparing the predicted models with the observed data from the real world. Through a collaborative discussion between teachers and researchers for 6 months, a 5-session scientific model co-construction program on the subject 'image formation by convex lenses' for second grade middle school students was developed. Eighty (80) students in 3 classes and a science teacher with 20 years of service from general public co-educational middle school in Gyeonggi-do participated in this 2-week program. After the class, students were asked about the helpfulness and difficulty of the class, and whether they would like to recommend this class to a friend. After the class, 95.8% of the students constructed the scientific model more than the model using the construction rule. Students had difficulties to identify principles or understand their friends, but the result showed that they could understand through model evaluation experiment. 92.5% of the students said that they would be more than willing to recommend this program to their friends. It is expected that the developed program will be applied to the school and contribute to the improvement of students' modeling ability and co-construction ability.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.52-62
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• 2011

By studying the classic poetry and prose with a theme of Plantain, I would like to study why Plantain has been planted in our traditional garden for a long time. Also, through this study, I want to find when Plantain was introduced to in our country. We use description study method for studying the classic poetry and prose with a theme of Plantain. As a result, we found a few things like below. First, the introduction of Plantain to our country traces back to unified Silla in the poetry of Choe Chi Won. Also, Plantain was planted and loved generally as a general garden plant in the middle of Goryeo through poetry and paintings. Second, the meaning of Plantain is like this. 1) It means development and enjoyment of arts of summer because the leaves of Plantain were used for drinking alcohol and writing and poetry instead of papers. 2) In Buddhism, Plantain was thought to awaken 'gong(空)', 'mua(無我)', and 'brevity' of lesson of Buddha by the special shape and the image of falling rain to the leaves. Also, it was used widely in Buddhist temples because of the story of 'Hye ga dan bi(慧可斷臂)'. 3) In Confucianism, it is the emblem of lesson 'a wise man tries to be strong and tries not to stop following to God'(自强不息). 4) The large leaf of Plantain is called 'bongmi(鳳尾)' thanks to the image of likeness with tails of Bongwhang(鳳凰). Third, design use of Plantain is like this. 1) The large leaf of Plantain was used for giving an image of freshness and brightness in the garden in summer. 2) Our ancestor thought 'the sound of falling rain to Plantain'(芭蕉雨聲) as a picturesque sound in summer. Also, Plantain was highly utilized because our ancestor thought Plantain is the best plant for implementing 'soundscape'. Thus, the most characteristic use of several design uses is 'acoustic use'. 3) Plantain was also planted in a indoor pot for viewing. 4) Plantain was used for making food and medicine in the palace and private house as a practical use. The limit of this study is that I mainly use the text translated into Korean of database of overall Korean classics. We hope the new things related to this study would be added up to this study by translating original texts into Korean more.

• Asia Marketing Journal
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• v.8 no.3
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• pp.41-74
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• 2006

It is frequently observed that consumers' behavior and performance in their weight control are greatly affected by the degree of self-control by the consumers themselves. In other words, effective weight control behavior is only possible when the consumers invest a substantial amount of endeavors and self-control. The present study empirically investigated the effect of the self-image congruence and subjective norm formed by self- concept reflected in weight control behavior on weight control attitude formation, actual behavior, and performance. For more in-depth research, rather than simply showing differences in performance based on self-control, the present study divided the subjects into high and low self-control groups for a comparative purpose. Based on empirical research employing general consumers and those who were engaged in an actual weight loss program at professional weight control centers as subjects, the study found the following results: First, for both high and low self-control groups, self-image congruence significantly affected attitude toward weight control, but not the actual weight control behavior. The results indicate that in weight control, the actual behavior must be preceded by the attitude. Second, subjective norm directly affected both attitude toward weight control, and behavior for the low self-control group while it affected the behavior only for the high self-control group. The results show that the lower self-control is, the more powerful the effect of referents is. Third, weight control attitude positively affected weight control behavior only for the high self-control group. Fourth, weight control behavior significantly affected the performance for both high and low self-control groups. Compared to the low group, the high self-control group showed more powerful effect of behavior, suggesting the crucial role of self-control in successful weight control. The results also imply that the role of referents is relatively more important for the low self-control group.