• Radiation Oncology Journal
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• v.25 no.2
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• pp.134-144
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• 2007

[ $\underline{Purpose}$ ]: Immobilization devices that improve the setup reproducibility of pelvic cancer patients and that provide comfort to patients during radiotherapy were designed and the feasibility of the devices was evaluated. $\underline{Materials\;and\;Methods}$: A customized device was designed to immobilize a knee, thigh, and foot of a patient. Sixty-one patients with prostate cancer were selected and were divided into two groups-with or without devices. The setup errors were measured with respect to bony landmarks. The difference between digitally reconstructed radiographs (DRR) and simulation films, and the differences between DRR and portal films were measured. $\underline{Results}$: The left-right (LR), anterior-posterior (AP) and craniocaudal (CC) errors between the DRR and simulation films were $1.5{\pm}0.9\;mm$, $3.0{\pm}3.6\;mm$, and $1.6{\pm}0.9\;mm$, respectively without devices. The errors were reduced to $1.3{\pm}1.9\;mm$, $1.8{\pm}1.5\;mm$ and $1.1{\pm}1.1\;mm$, respectively with the devices. The errors between DRR and portal films were $1.6{\pm}1.2\;mm$, $4.0{\pm}4.1\;mm$, and $4.2{\pm}5.5\;mm$, respectively without the devices and were reduced to $1.0{\pm}1.8\;mm$, $1.2{\pm}0.9\;mm$, and $1.2{\pm}0.8\;mm$, respectively, with the devices. The standard deviations among the portal films were 1.1 mm, 2.1 mm, and 1.0 mm at each axis without the devices and 0.9 mm, 1.6 mm and 0.8 mm with the devices. The percentage of setup errors larger than 3 mm and 5 mm were significantly reduced by use of the immobilization devices. $\underline{Conclusion}$: The designed devices improved the setup reproducibility for all three directions and significantly reduced critical setup errors.

• The Korean Journal of Nuclear Medicine
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• v.32 no.2
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• pp.151-160
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• 1998

Purpose: Piccolo et al. advocated the usefulness of $^{99m}Tc$-MDP breast scan in differential diagnosis of breast mass with high accuracy. But there are little or no follow-up studies about it as we know. We studied $^{99m}Tc$-MDP uptake pattern and lesion/background ratio in patients complaining palpable breast lesions to evaluate the clinical usefulness of $^{99m}Tc$-MDP scan. Materials and Methods: Total 34 patients were studied with physical examination, mammo-gram and $^{99m}Tc$-MDP scan prospectively. Anteroposterior and both lateral view of breast were obtained 5 minutes after iv injection of 740 MBq $^{99m}Tc$-MDP. Breast uptake pattern of $^{99m}Tc$-MDP was analyzed by a grade system: 0=no uptake, grade 1=bilateral diffuse uptake, grade 2=asymmetric faint uptake, grade 3=focal hot uptake. 20 cases were pathologically confirmed by excision biopsy or aspiration biopsy. 14 cases were normal in physical examination and mammogram. Results: Pathologic results showed 7 carcinomas, 6 benign solid tumors, and 7 fibrocystic changes. Grade 3 pattern of $^{99m}Tc$-MDP uptake was noted in 4/7 carcinomas, 3/6 benign solid tumors, and 1/7 fibrocystic changes. Grade 2 pattern was 217, 0/7, 3/7 respectively. The average L/B ratio was 1.66 in carcinomas, 1.68 in benign solid masses, 1.20 in fibrocystic diseases, 1.05 in normal patients. L/B ratio was higher in carcinoma and benign mass groups than in fibrocystic change and normal control groups(p=0.005). But there was no statistical difference between L/B ratio of malignant mass group and benign mass group. Conclusion: $^{99m}Tc$-MDP scan is not suitable to routine clinical use for breast mass diagnosis. It might be used in limited conditions when whole body bone scan is planned.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.127-133
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• 2014

Purpose: Low dose of PET/CT is important because of Patient's X-ray exposure. The aim of this study was to evaluate the effectiveness of low-dose PET/ CT image through the CTAC and QAC of patient study and phantom study. Materials and Methods: We used the discovery 710 PET/CT (GE). We used the NEMA IEC body phantom for evaluating the PET data corrected by ultra-low dose CT attenuation correction method and NU2-94 phantom for uniformity. After injection of 70.78 MBq and 22.2 MBq of 18 F-FDG were done to each of phantom, PET/CT scans were obtained. PET data were reconstructed by using of CTAC of which dose was for the diagnosis CT and Q. AC of which was only for attenuation correction. Quantitative analysis was performed by use of horizontal profile and vertical profile. Reference data which were corrected by CTAC were compared to PET data which was corrected by the ultra-low dose. The relative error was assessed. Patients with over weighted and normal weight also underwent a PET/CT scans according to low dose protocol and standard dose protocol. Relative error and signal to noise ratio of SUV were analyzed. Results: In the results of phantom test, phantom PET data were corrected by CTAC and Q.AC and they were compared each other. The relative error of Q.AC profile was been calculated, and it was shown in graph. In patient studies, PET data for overweight patient and normal weight patient were reconstructed by CTAC and Q.AC under routine dose and ultra-low dose. When routine dose was used, the relative error was small. When high dose was used, the result of overweight patient was effectively corrected by Q.AC. Conclusion: In phantom study, CTAC method with 80 kVp and 10 mA was resulted in bead hardening artifact. PET data corrected by ultra- low dose CTAC was not quantified, but those by the same dose were quantified properly. In patients' cases, PET data of over weighted patient could be quantified by Q.AC method. Its relative difference was not significant. Q.AC method was proper attenuation correction method when ultra-low dose was used. As a result, it is expected that Q.AC is a good method in order to reduce patient's exposure dose.

• Journal of the Korean association of regional geographers
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• v.9 no.3
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• pp.373-384
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• 2003

This study analyses the soil loss due to cropland increase in the Hoeryeung area of northeast Korea, using Landsat images of 1987 TM and 2001 ETM, together with DTED, soil and geological maps, and rainfall data of 20 years. Items of land cover and land use were categorized as cropland, settlement, forest, river zone, and sand deposit by supervised classification with spectral bands 1, 2 and 3. RUSLE model is used for estimation of soil loss, and AML language for calculation of soil loss volumes. Fourier transformation method is used for unification of the geographical grids between Landsat images and DTED. GTD was selected from 1:50,000 topographic map. Main sources of soil losses over 100 ton/year may be the river zone and settlement in the both times of 1987 and 2001, but the image of the 2001 shows that sources areas have developed up to the higher mountain slopes. In the cropland average, increases of hight and gradient are 24m and $0.8^{\circ}$ from 1987 to 2001. In the case of new developed cropland, average increases are 75m and $2.5^{\circ}$, and highest soil loss has occurred at the elevation between 300 and 500m. The soil loss 57 ton of 1987 year increased 85 ton of 2001 year. Soil loss is highest in $30{\sim}50^{\circ}$ slope zones in both years, but in 2001 year, soil loss increased under $30^{\circ}$ zones. The size of area over 200 ton/year, indicating higher risk of landslides, have increased from $28.6km^2$ of 1987 year to $48.8km^2$ of 2001 year.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.225-231
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• 2002

This study was carried out to investigate the possibility of improving the texture and flavor of Dasik by adding various types of sugar (syrup, honey) and flavor ingredients (omija, chija, coffee, green tea extract) to rice powder. Dasik samples were prepared, and the sensory quality and physical characteristics of those were compared. The moisture content of Dasik added with syrup was higher than that of honey. Coffee Dasik with syrup was the highest (23.6) in moisture content. In sensory quality, the omija and coffee Dasik showed the highest score in flavor quality (p<.001). Omija Dasik with honey and coffee Dasik with syrup showed the highest scores in overall acceptability (6.4, 6.2). Green tea Dasik with syrup showed the highest value in the lightness (L) of color. Omija Dasik with syrup showed the highest value in the redness (a) of color Chija Dasik was the highest in the yellowness(b) of color. In physical characteristics, the hardness was negatively correlated with the moistness, tenderness, and texture acceptability in sensory quality(p〈0.001). The cohesiveness was positively correlated with the overall acceptability in sensory quality (p〈0.01). In the relation of texture characteristics and sensory quality, the higher the moisture content, the lower the hardness and springiness were, but the higher the brittleness and the cohesiveness were(p〈.001). Overall, omija and coffee Dasik appeared to have desirable flavor, taste and overall acceptability.

• Journal of Radiation Protection and Research
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• v.25 no.1
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• pp.31-36
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• 2000

In radiotherapy, it may happen to radiate surrounding normal tissue because of inconsistent field size by changing patient position during treatment. We are going to analyze errors reduced by using immobilization device with Electonic portal imaging device(EPID) in this study. We had treated the twenty-one patients in pelvic region with 10 MV X-ray from Aug. 1998 to Aug. 1999 at Chungnam National University Hospital. All patients were treated at supine position during treatment. They were separated to two groups, 11 patients without device and 10 patients with immobilization device. We used styrofoam for immobilization device and measured the errors of anterior direction for x, y axis and lateral direction for z, y axis from simulation film to EPID image using matching technique. For no immobilization device group, the mean deviation values of x axis and y axis are 0.19 mm. 0.48 mm, respectively and the standard deviations of systematic deviation are 2.38 mm, 2.19 mm, respectively and of random deviation for x axis and y axis are 1.92 mm. 1.29 mm, respectively. The mean deviation values of z axis and y axis are -3.61 mm. 2.07 mm, respectively and the standard deviations of systematic deviation are 3.20 mm, 2.29 mm, respectively and of random deviation for z axis and y axis are 2.73 mm. 1.62 mm, respectively. For immobilization device group, the mean deviation values of x axis and y axis are 0.71 mm. -1.07 mm, respectively and the standard deviations of systematic deviation are 1.80 mm, 2.26 mm, respectively and of random deviation for x axis and y axis are 1.56 mm. 1.27 mm, respectively. The mean deviation values of z axis and y axis are -1.76 mm. 1.08 mm, respectively and the standard deviations of systematic deviation are 1.87 mm, 2.83 mm, respectively and of random deviation for x axis and y axis are 1.68 mm, 1.65 mm, respectively. Because of reducing random and systematic error using immobilization device, we had obtained good reproducibility of patient setup during treatment so that we recommend the use of immobilization device in pelvic region of radiation treatment.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.206-225
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• 2019

This paper examines the trade and development aspects of glass mirrors through the literature records of the Joseon Dynasty, and studies the characteristics of existing glass mirror crafts by referring to the terms and types shown in the literature. The glass mirror in the records had called western mirrors(西洋鏡, 洋鏡), glass mirrors(玻璃鏡, 玻瓈鏡), stone mirrors(石鏡), etc. Glass mirrors were imported mainly through trade with Russia and the Qing Dynasty since the 17th century and were banned from importation in the late Joseon Dynasty. These mirrors were something new that caused a great stirring in Joseon society in the 18th century, and in the 19th century, it grew larger as a commodity needed for everyday life, especially with trade with Japan. At that time, glass mirrors were used for various purposes, such as installing large glass at a store, which were not the standard mirror usage of confirming one's appearance. These mirrors surprised Koreans in Joseon who experienced them at Yanjing Liulichang(燕京 琉璃廠) in the 18th and 19th centuries. As a result, the demand for glass mirrors rapidly increased and quickly surpassed that of bronze mirrors. Consequentially, new crafts using glass mirrors instead of bronze mirrors in Joseon began to be produced and used after the 18th century. In particular, integrated flat boards of glass mirrors were developed as crafts used indoors. It was convenient to use the hair comb box, a long-time presence in Joseon society, with the bronze mirror. This kind of mirror remained apparent in various genre paintings, including the Taepyeong Seongsido(太平城市圖, 'A Thriving City in a Peaceful Era') collected the National Museum of Korea which reflect its populism of the times. Also, the Mirror Stand(鏡臺) used in the Qing Period was produced in Joseon, but there was a difference in the way of making the drawers and box shapes between two nations. On the other hand, the Face Mirror(面鏡) was made to look at the face. Various crafts made with the aesthetic sense of Joseon, such as the ox horn inlaying craft technique, were produced with auspicious designs. In the 19th century, glass mirrors were imported from European countries, such as France, Denmark, the Netherlands, and the United Kingdom, however after the end of the 19th century Japanese crafts were popular. Glass mirrors, which were popular in the Meiji and Taisho eras of Japan, were imported and also the Mirror Screen(鏡屛) using large glass mirrors were used. In particular, the mirror screen had developed wood furniture since the previous time, which were used for banquets and large spaces, such as the drawing room, and were imported from China and Japan. In addition, the western architectural effect of attaching a mirror to the wall was also attempted to adjust the brightness of the space and introduce another image and scenery in the mirror. This was done at Deoksugung Palace's Seokjojeon.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.43-53
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• 2005

This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.148-155
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• 2002

Multithreaded models improve the efficiency of parallel systems by combining inner parallelism, asynchronous data availability and the locality of von Neumann model. This model executes thread code which is generated by compiler and of which quality is given by the method of generation. But multithreaded models have the demerit that execution model is restricted to a specific platform. On the contrary, Java has the platform independency, so if we can translate from threads code to Java bytecode, we can use the advantages of multithreaded models in many platforms. Java executes Java bytecode which is intermediate language format for Java virtual machine. Java bytecode plays a role of an intermediate language in translator and Java virtual machine work as back-end in translator. But, Java bytecode which is translated from multithreaded models have the demerit that it is not secure. This paper, multhithread code whose feature of platform independent can execute in java virtual machine. We design and implement translator which translate from thread code of multithreaded code to Java bytecode and which check secure problems from Java bytecode.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.229-250
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• 1993

This study was performed to investigate the morphological and structural changes of bone tissues and the effects of irradiation on the mandibular bodies of rats which were fed low calcium diets. In order to carry out this experiment, 160 seven-week old Sprague-Dawley strain rats weighing about 150 gm were selected and equally divided into one normal diet group of 80 rats and one low calcium diet group with the remainder. These groups were then subdivided into two groups, 40 were assigned rats for each subdivided group, exposed to radiation. The Group 1 was composed of forty non-irradiated rats with normal diet, Group 2 of forty irradiated rats with normal diet, Group 3 forty non-irradiated rats with low calcium diet, and Group 4 forty irradiated rats with low calcium diet. The two irradiation groups received a single dose of 20 Gy on the jaw area only and irradiated with a cobalt-50 teletherapy unit. The rats with normal and low calcium diet groups were serially terminated by ten on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After termination, both sides of the dead rats mandible were removed and fixed with 10% neutral formalin. The bone density of mandibular body was measured by use of bone mineral densitometer(Model DPX -alpha, Lunar Corp., U.SA). Triga Mark ill nuclear reactor in Korea Atomic Research Institute was used for neutron activation and then calcium contents of mandibular body were measured by using a 4096 multichannel analyzer (EG and G ORTEC 919 MCA, U.SA). Also the mandibular body was radiographed with a soft X-ray apparatus(Hitex Co., Ltd., Japan). Thereafter, the obtained microradiograms were observed by a light microscope and were used for the morphometric analysis using a image analyzer(Leco 2001 System, Leco Co., Canada). The morphometric analysis was performed for parameters such as the total area, the bone area, the inner and outer perimeters of the bone. The obtained results were as follows: 1. In the morphometric analysis, total area and outer perimeter of the mandibular bodies of Group 3 were a little smaller than that of Group 1. The mean bone width and bone area were much smaller than that of Group 1 and the inner perimeter of Group 3 was much longer than that of Group 1. The total area and outer perimeter of Group 2 and Group 4 showed little difference. The mean bone width and bone area of Group 4 were smaller than that of Group 2 and the inner perimeter of Group 4 was longer than that of Group 2. 2. The remarkable decreases of the number and thickness of trabeculae and also the resorption of endosteal surface of cortical bone could be seen in the microradiogram of Group 3, Group 4 since the 3rd day of experiment. On the 21st day of experiment, the above findings could be more clearly seen in Group 4 than in Group 3. 3. The bone mineral density of Group 3 was lesser than that of Group 1 and the bone mineral density of Group 4 was lesser than that of Group 2 on the 7th, 14th, 21st days. The irradiation caused the bone mineral density to be decreased regardless of diet. In the case of Groups with low calcium diet, the bone mineral density was much decreased on the 21st day than on the 3rd day of experiment. 4. The calcium content in mandible of Group 3 was smaller than that of Group 1 throughout the experiment. roup 4 showed the least amount of calcium content. The irradiation caused the calcium content to be decreased regardless of diet. In the case of Groups with low calcium diet, the calcium content was much decreased on the 21st day than on the 3rd day of experiment. In conclusion, the present study demonstrated that morphological changs and decrease of bone mass due to resorption of bone by low calcium diet, and that the resorption of bone could be found in the spongeous bone and endosteal surface of cortical bone. So the problem of resorption of bone must be considered when the old and the postmenopausal women are taken radiotherapy because the irradiation seems to be accelerated the resorption of osteoporotic bone.