• Imaging Science in Dentistry
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• v.43 no.1
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• pp.7-15
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• 2013

Purpose: This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. Materials and Methods: The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. Result: The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. Conclusion: Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.

• Korean Journal of Optics and Photonics
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• v.14 no.6
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• pp.606-612
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• 2003

The self-imaging effect or lensless imaging effect of a phase line grating is theoretically analyzed by using Fresnel diffraction theory, then experimentally investigated. The self-imaging distance $z_{T,p}$, that is the imaging distance being perfectly copied from the phase distribution of the phase grating to its intensity distribution with the magnification of 1X, can be uniquely defined as the (4n-3) $z_{T,a}$/4(n=positive integers), where rte is the well-known self-imaging distance of an amplitude grating. When the coherent laser beam is illuminated at the phase grating, the self-imaged images were obtained at $z_{T,p}$= $z_{T,a}$/4 and $z_{T,p}$=5 $z_{T,a}$/4 without any optics. On the other side, the phase-reversed self-imaging was obviously observed at $z_{T,p}$ = 3 $z_{T,a}$/4. The visibility of self-imaged images of a phase line grating as a function of the number of slits of the input grating was measured by the FFT(Fast Fourier Transform) results of the self-imaging images. As a result a stationary maximum visibility of V = 0.10 can be obtained from a grating with more than 15 slit pairs.n 15 slit pairs.

• Journal of Fashion Business
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• v.3 no.1
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• pp.65-80
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• 1999

In this study, the researcher studied the historical background and the traditional culture about dress and ornament of Yunnan Province of China. The Results of the study are as follows. 1. In the Past, Derung's dress was very simple due to the influence of various factors, such as geography and history. Men wore shorts and covered diagonally a piece of cloth from left shoulders to right armpits and tied up the two ends on chests. Women covered crisscross two pieces of cloth from both shoulders to knee. 2. Achang people's dress and adornment has its own unique characteristic. Generally, men wear Jackets with buttons down the front and black trousers. Unmarried men like to wear white turbans, while most of married men usually wear dark blue ones. Women usually wear tight-sleeve blouses with buttons down the front and skirts. Unmarried women wear the hair in braids coil them on the top of their heads. They wear short blouses and trousers. Married women wear their hair Into buns and like to entwine black or blue cloth into high trubans. They wear short blouses and knee-length straight skirts. Achang knife enjoys high reputation and has a long history and an exquisite workmanship. All the men like to wear it. 3. The dress and adornment of the Lahu nationality has both the characteristic of farming culture and the style of nomadic culture of early times. Men usually wear short shirts with round necks and buttons down the front, loose-legged trousers, turbans or dark blue cloth caps Women's dress and adornment can be categorized into two styles. One is black cloth gown with buttons diagonally on the right front and waist-length slits on both sides. The edges of fronts and cuffs are edged with Silver ornaments and lace. They also wear trousers. The other is short blouse with round neck and short opening on th right front, straight skirt and colourful leggings with embroidered patterns. 4. The Hani people, men and women, old and young, like black colour and are fond of wearing black clothes. Men usually wear shirts with buttons down the front and trousers, entwining their heads with black or white cloth. The elderly people wear calottes. Women wear cloth blouses, skirts and trousers or shorts. Slight differences exist in the clothing and adornments according to region, branch and age 5. Blang people's dyeing technique with an exquisite method has a long history. Men wear dark blue long sleeve shirts with round necks and buttons down the front or arranged diagonally on the front and loose-legged trousers. Elderly men wear big turbans wdress and adornment varies greatly in different regions. 6. The Lisu people culture of dress and adornment has some unique characteristics. The styles and colours of their dress and adornment differ slightly from place to place. In the Nujiang area, Women wear black velvet Jackets over blouses with buttons arranged diagonally on the right front and long pleated ramie skirts. Men usually wear wraparound ramie gowns, with center vent, made of fabrics alternated with white and black cross stripes. They also wear cloth waistbands and trohile youngsters keep their hair short. Women's users. In the Lushui area, the dress and adornment is similar to that in the Nujing region, but women wear aprons and trousers instead of skirts. 7. The Nu people dress and adornment is simple but elegant Women are proficient in ramie-weaving. Men usually wear gowns With overlapping necks, knee-length trousers and leggings. They like to wear their hair long and entwine dark blue or white turbans. Women wear black and red vests over blouses with buttons arranged diagonally on the right front and ankle-length skirts. They also wear their hair long, make it into braids, and entwine dark blue or colourful cloth turbans. 8. Pumi men usually wear ramie shirts With buttons arranged diagonally on the right front, loose trousers and white sheepskin vests. Some also wear overcoats made of "pulu". Women's dress and adornment varies in different areas. In the Lanping and Weixi regions, women wear white short blouses with buttons arranged diagonally on the front and dark brown embroidered vests. They also wear trousers and blue or black cloth turbans. In the Ninglang and Yongsheng regions, women wear hemmed blouses With buttons arranged diagonally on the right front and drape sheepskin capes. They also wear white pleated skirts and use broad colourful cloth as their waistbands.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.45-52
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• 1995

This study is to compare A point doses in human pelvic phantom by film dosimetry, computer planning and manual calculation by using of along-away table. We developed tissue equivalent human pelvic phantom composed of four pieces of cylindrical acryl tubes with water, to simulate intracavitary radiation (ICR) in patients with cervix cancer. When the phantom assembled from 4 pieces, it has a small space for inserting Fletcher-Suit-Delclos applicator like a human vagina. Fletcher-Suit-Delclos applicator inserted into the space was packed tightly with furacin gauzes, and three $^{137}Cs$ sources with radioactivity of $15.7mg\;Ra-eq$ were inserted into the tandem. For the film dosimetry, two pieces of X-OMAT V film (Kodak Co.) of which planes include point A, were arranged orthogonally in the slits between phantoms. A point dose and iso-dose curves were measured by means of optical densitometer. A point doses by film dosimetry, RTP system and manual calculation by using of along-away table were compared, and iso-dose curves by film dosimetry and computer planning were also compared. The dose of A point was 51.2cGy/hr by film dosimetry, 46.7cGy/hr by RTP system and 47.9 cGy/hr by along-away table. A point dose by computer planning was similar to the dose by calculation using of along-away table with acceptable accuracy $({\pm}3%)$, however, the dose by film dosimetry was different from two others with about 10% error. Since most clinical beams contains a scatter component of low energy photons, the correlation between optical density and dose becomes tenuous. In addition, film suffers from several potential errors such as changes in processing conditions, interfilm emulsion differences, and artifacts caused by air pockets adjacent to the film. For these reasons, absolute dosimetry with film is impractical, however, it is very useful for checking qualitative patterns of a radiation distribution. In future, solid state dosimeter such as TLD must be used for the dosimetry of ionizing radiation. When considerable care is used, precision of approximately 3% may be obtained using TLD.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.249-260
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• 2007

Purpose: In order to enhance the quality of IMRT as employed in Korea, we developed a remote monitoring system. The feasibility of the system was evaluated by conducting a pilot study. Materials and Methods: The remote monitoring system consisted of a head and neck phantom and a user manual. The phantom contains a target and three OARs (organs at risk) that can be detected on CT images. TLD capsules were inserted at the center of the target and at the OARs. Two film slits for GafchromicEBT film were located on the axial and saggital planes. The user manual contained an IMRT planning guide and instructions for IMRT planning and the delivery process. After the manual and phantom were sent to four institutions, IMRT was planed and delivered. Predicted doses were compared with measured doses. Dose distribution along the two straight lines that intersected at the center of the axial film was measured and compared with the profiles predicted by the plan. Results: The measurements at the target agreed with the predicted dose within a 3% deviation. Doses at the OARs that represented the thyroid glands showed larger deviations (minimum 3.3% and maximum 19.8%). The deviation at OARs that represented the spiral cord was $0.7{\sim}1.4%$. The percentage of dose distributions that showed more than a 5% of deviation on the lines was $7{\sim}27%$ and $7{\sim}14%$ along the horizontal and vertical lines, respectively. Conculsion: Remote monitoring of IMRT using the developed system was feasible. With remote monitoring, the deviation at the target is expected to be small while the deviation at the OARs can be very large. Therefore, a method that is able to investigate the cause of a large deviation needs to be developed. In addition, a more clinically relevant measure for the two-dimensional dose comparison and pass/fail criteria need to be further developed.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)