• Progress in Medical Physics
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• v.26 no.4
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• pp.294-303
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• 2015

American Association of Physicists in Medicine (AAPM) Published Task Group 40 report which includes recommendations for comprehensive quality assurance (QA) for medical linear accelerator in 1994 and TG-142 report for recommendation for QA which includes procedures such as intensity-modulated radiotherapy (IMRT), stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) in 2010. Recently, Nuclear Safety and Security Commission (NSSC) published NSSC notification no. 2015-005 which is "Technological standards for radiation safety of medical field". This notification regulate to establish guidelines for quality assurance which includes organization and job, devices, methods/frequency/tolerances and action levels for QA, and to implement quality assurance in each medical institution. For this reason, all of these facilities using medical machine for patient treatment should establish items, frequencies and tolerances for proper QA for medical treatment machine that use the techniques such as non-IMRT, IMRT and SRS/SBRT, and perform quality assurance. For domestic, however, there are lack of guidelines and reports of Korean Society of Medical Physicists (KSMP) for reference to establish systematic QA report in medical institutes. This report, therefore, suggested comprehensive quality assurance system such as the scheme of quality assurance system, which is considered for domestic conditions, based the notification of NSSC and AAPM TG-142 reports. We think that the quality assurance system suggested for medical linear accelerator also help establishing QA system for another high-precision radiation treatment machines.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.101-106
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• 2000

Purpose : This study was peformed to evaluate the effectiveness and tolerance of craniospinal irradiation for patients with modulloblastoma and to define the optimal radiotherapeutic regimen. Materials and Methods : We retrospectively analyzed the records of 43 patients with modulloblastoma who were treated with external beam craniospinal radiotherapy at our institution between May, 1984 and April, 1998. Median follow up period was 47 months with range of 18 to U months. Twenty seven patients were male and sixteen patients were female, a male to female ratio of 1.7:1. Surgery consisted of biopsy alone in 5 patients, subtotal excision in 24 patients, and gross total excision in 14 patients. All of the patients were treated with craniospinal irradiation. All of the patients except four received at least 5,000 cGy to the posterior fossa and forty patients received more than 3,000 cGy to the spinal cord. Results : The overall survival rates at 5 and 7 years for entire group of patients were 57$\%$ and 56$\%$, respectively. Corresponding disease free survival rates were 60$\%$ and 51$\%$, respectively, The rates of disease control in the posterior fossa were 77$\%$ and 67$\%$ at 5 and 7 years. Gross total excision and subtotal excision resulted in 5 year overall survival rates of 76$\%$ and 66$\%$, respectively, In contrast, those patients who had biopsy alone had a 5 year survival rate of only 40$\%$. Posterior fossa was a component of failure in 11 of the 18 recurrences. Seven recurrences were isolated to the posterior fossa. Four patients had neuraxis recurrences, three had distant metastasis alone and four had multiple sites of failure, all involving the primary site. Conclusion : Craniospinal irradiation for patients with moduiloblastoma is an effective adjuvant treatment without significant treatment related toxicitles. There is room for Improvement in terms of posterior fossa control, especially in biopsy alone patients. The advances in radiotherapy including hypefractionation, stereotactic radiosurgery and 3D conformal radiotherapy would be evolved to improve the tumor control rate at primary site.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.105-109
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• 2020

Intensity-modulated radiotherapy(IMRT) has disadvantages such as increasing the low doses of irradiation to normal tissues and accumulated dose for the whole volume by leakage and transmission of the Multi Leaf Collimator (MLC). The accumulated dose and low dose may increase the occurrence of secondary malignant neoplasms. For this reasons, the jaw tracking function of the TrueBeam (Varian Medical Systems, Palo Alto, CA) was developed to reduce the leakage and transmission dose of the MLC with existing linear accelerators. But quantitative analysis of the dose reduction has not been verified. Therefore, in the present study, we intended to verify the clinical possibility of utilizing the jaw tracking function in brain tumor with comparison of treatment plans. To accomplish this, 3 types of original treatment plans were made using Eclipse11 (Varian Medical Systems, Palo Alto, CA): 1) beyond 2 cm distance from the Organs At Risk (OARs); 2) within 2 cm distance from the OARs; and 3) intersecting with the OARs. Jaw tracking treatment plans were also made with copies of the original treatment planning using Smart LMC Version 11.0.31 (Varian Medical Systems, Palo Alto, CA). A comparison between the 2 types of treatment planning methods was performed using the difference of the mean dose and maximum dose to the OARs in cumulative Dose Volume Histogram (DVH). In the DVH comparison, the maximum difference of 0.5 % was observed between the planning methods in the case of over 2 cm distance, and the maximum of 0.6 % was obtained for within the 2 cm distance. For the case intersecting with the OAR, the maximum difference of 2 % was achieved. According to these results, it could be realized that the differences of mean dose and maximum dose to the OARs was larger when the OARs and PTV were closer. Therefore, treatment plans with the jaw tracking function consistently affected the dose reduction and the clinical possibility could be verified.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.183-200
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• 1989

An experiment was conducted at the greenhouse of the International Rice Research Institute in 1987 to find out the character of dry matter production, the potential seed production ability and the ecological and physiological strategies to adaptation. For these, two rice cultivars, IR64(lowland rice) and UPLRi-5(upland rice), and seven weed species were used ; Echinochloa glabrescens Munro ex Hook. f., E. cress-galls ssp. hispidula (Retz.) Honda, E. colons (L.) Link, Monochoria vaginalis (Burin. f.), Ludwigia octovalvis Jacq.) Raven, Fimbristylis miliacea Vahl and Cyperus difformis L. Adaptation strategies of weed species varied by species. However, they had efficient seed production strategy through different ways. In general, sedge weed species (F. miliacea and C. difformis) produced great amount of seeds at the expense of seed size through greater ratooning ability and low relative dry weight for flowering. For broadleaved weed species, greater number of descendants were obtained through high plasticity and low relative dry weight for flowering (M. vaginalis) or greater growth ability through effective photosynthetic efficiency (L. octovalvis). Grass weed species, on the other hand, produced their seeds through effective growth (net assimilation rate and relative growth rate), high ratooning ability (except E. crus-galls ssp. hispidula) or low relative dry weight to maximum dry weight for flowering (E. glabrescens). The harvest indices of the weed species were considerably lower than those of rice. Fimbristylis miliacea had the greatest ratooning ability followed by C. difformis, E. colons and E. glabrescens. The greatest seed productivity was recorded by C. difformis (279, 000) and L. octovalvis (268,000) while rice produced the least number of seeds (1300-6100). Log seed weight had a negative linear relationship with log seed number (y=6.30-1.48X, $R=-0.965^{**}$). For all species plant plasticity response was not directly correlated with mortality response.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.277-282
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• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1529-1535
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• 1999

This study was done for the extraction of carotenoid from Phaffia rhodozyma in combination with PEF and other methods. PEF treatment conditions were $30{\sim}80\;kV/cm,\;100{\sim}1000\;Hz\;and\;100{\sim}1000\;{\mu}s$. In order to increase permeability of yeast cell wall, various methods such as freezing-thawing, mechanical treatment, solvents, permeabilizing agents, and yeast cell wall lytic enzyme were used before PEF treatment. The combination of PEF $(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ and conventional methods such as solvent and freezing-thawing pre-treatment had no effects on the extraction of carotenoid pigments. The extent of extracted carotenoid by the PEF $treatment(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ combined with yeast cell wall lytic enzyme and mechanical pre-treatment increased 52% and 69.8% more than the sum of that by each treatment, respectively. Permeabilizing agents, especially Tween 20 and capric acid, enhanced the extraction efficiency of carotenoid pigments from P. rhodozyma cells. These results indicated the feasibility for the continuous extracting carotenoid pigments from P. rhodozyma by PEF combined with other permeabilizing methods.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.4-25
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• 2013

Goli-su is the innovative special kind of the embroidery technique, which combines twining and interlacing skill with metal technology and makes the loops woven to each other with a strand. The loops floating on the space of the ground look like floating veins of sculpture and give people the feeling of the openwork. This kind of characteristic has some similarities with the lacework craft of Western Europe in texture and technique style, but it has its own features different from that of Western Europe. It mainly represents the splendid gloss with metallic materials in the Embroidered cloth, such as gold foil or wire. In the 10th century, early days of Goryo, we can see the basic Goli-su structure form of its initial period in the boy motif embroidery purse unearthed from the first level of Octagonal Nine-storied Pagoda of Woljeong-sa. In the Middle period of Joseon, there are several pieces of Goli-su embroidered relic called "Battle Flag of Goryo", which was taken by the Japanese in 1592 and is now in the Japanese temple. This piece is now converted into altar-table covers. In 18~19th century, two pairs of embroidered pillows in Joseon palace were kept intact, whose time and source are very accurate. The frame of the pillows was embroidered with Goli-su veins, and some gold foil papers were inserted into the inside. The triangle motif with silk was embroidered on the pillow. The stitch in the Needle-Looped embroidery is divided into three kinds according to comprehensive classification: 1. Goli-su ; 2. Goli-Kamgi-su ; 3. Goli-Saegim-su. From the 10th century newly establishing stage to the 13th century, Goli-su has appeared variational stitches and employed 2~3 dimensional color schemes gradually. According to the research of this thesis, we can still see this stitch in the embroidery pillow, which proves that Goli-suwas still kept in Korea in the 19th century. And in terms of the research achievement of this thesis, Archetype technology of Goli-su was restored. Han Sang-soo, Important Intangible Cultural Heritage No. 80 and Master of Embroidery already recreated the Korean relics of Goli-su in Joseon Dynasty. The Needle-Looped embriodery is the overall technological result of ancestral outstanding Metal craft, Twining and Interlacing craft, and Embroidery art. We should inherit, create, and seek the new direction in modern multi-dimensional and international industry societyon the basis of these research results. We can inherit the long history of embroidering, weaving, fiber processing, and expand the applications of other craft industries, and develop new advanced additional values of new dress material, fashion technology, ornament craft and artistic design. Thus, other crafts assist each other and broaden the expressive field to pursue more diversified formative beauty and beautify our life abundantly together.

• Journal of Korea Water Resources Association
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• v.45 no.9
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• pp.861-874
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• 2012

To fulfill applicability of Soil and Water Assessment Tool (SWAT) model, it is important that this model passes through a careful calibration and uncertainty analysis. In recent years, many researchers have come up with various uncertainty analysis techniques for SWAT model. To determine the differences and similarities of typical techniques, we applied three uncertainty analysis procedures to Chungju Dam watershed (6,581.1 $km^2$) of South Korea included in SWAT-Calibration Uncertainty Program (SWAT-CUP): Sequential Uncertainty FItting algorithm ver.2 (SUFI2), Generalized Likelihood Uncertainty Estimation (GLUE), Parameter Solution (ParaSol). As a result, there was no significant difference in the objective function values between SUFI2 and GLUE algorithms. However, ParaSol algorithm shows the worst objective functions, and considerable divergence was also showed in 95PPU bands with each other. The p-factor and r-factor appeared from 0.02 to 0.79 and 0.03 to 0.52 differences in streamflow respectively. In general, the ParaSol algorithm showed the lowest p-factor and r-factor, SUFI2 algorithm was the highest in the p-factor and r-factor. Therefore, in the SWAT model calibration and uncertainty analysis of the automatic methods, we suggest the calibration methods considering p-factor and r-factor. The p-factor means the percentage of observations covered by 95PPU (95 Percent Prediction Uncertainty) band, and r-factor is the average thickness of the 95PPU band.

• Science of Emotion and Sensibility
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• v.9 no.1
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• pp.49-61
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• 2006

The present mobile phone industry has significant effect on the domestic economy and has taken root as the core item that has the responsibility to lead the Korean economy for a considerable period of time. As the mobile phone market becomes gigantic, the mobile phone is being used by people in broader age bracket, and functions or designs preferred by people of various age are getting more diverse. Like that, as the mobile phone has greater effect on and meaning in our daily lives, consumers of mobile phone have growing expectation of the mobile phone Now, the core function of voice communication via the mobile phone is not a great concern to consumers. But the function, such as more convenient and friendly information input and output, processing and storage, and the design, which is more sophisticated and optimized for the user environment, are being demanded, not just the simple voice communication. And as the modern design is getting more similar to the objects of traditional high art consumed by consumers every day, the aesthetic aspect of design can play an important role, as the factor that differentiates the product, in creating new value which forms the spiritual and emotional value of human beings to improve the quality of living, and in addition, the willingness of consumers to buy is determined by the design that they prefer the most. Like that, a new design of mobile phone based on a new dimension and preferred by the consumers the most is urgently required to be developed by shedding light on the factors related to the preference of consumers on the basis of the analysis on the aesthetic aspect, which can be said to be the most critical factor in the design process. Therefore, this study aims to identity the common preference and different factors of aesthetic aspects through the analysis on the aesthetic aspects of the mobile phone preferred by users among countries, and figure out the formative artistic factors of aesthetic aspects that are considered to be important, in order to propose the guideline on the aesthetic aspect of mobile phone that can be applied to the design of mobile phone practically.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.269-275
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• 2003

Purpose: To evaluate the results of radiation management on recurrence, survival and prognostic factors of patients with nasopharyngeal cancer Materials and Methods: Forty-nine patients, treated for nasopharyngeal cancer by radiotherapy between January 1984 and June 2000, were retrospectively studied. All patients were followed up for at least 2.5 years. Their median age was 52 years (range 17$\~$78). The histological types were 21 squamous cell carcinoma, 25 undifferentiated carcinoma, and 3 adenoid cystic carcinoma. The tumor stages were as follows: T1 in 14 patients, T2 in 24, T3 in 3, and T4 in 8, and N0 in 17 patients, Nl in 15, N2 in 4 and N3 in 13. Stages I, IIa, IIb ,III, IV and IVb were 4, 7, 12, 5, 8, and 13 patients respectively. Radiation doses of 58$\~$70 Gy (median 68.7 Gy) were given to the nasopahryngeal and involved lymphatic areas and of 46 $\~$ 50 Gy to the uninvolved neck areas. Results: The overall 5 and 10-year actuarial and disease free survival rates were 54.53$\%$ and 47$\%$ and 55.7$\%$ and 45.3$\%$, respectively The overall five-year survival rates were 100$\%$ in stage I , 80$\%$ in stage IIa, 59.5$\%$ in stage IIIb, 40$\%$ in stage III, and 42.2$\%$ in stage IV tumors. Twenty-three patients fatted either loco-regionally or distantly. Incidences of local failure, regional failure and distant metastasis for the first failure were 20.4$\%$, 8.2$\%$ and 20.4$\%$, respectively. Local recurrences were 4.3$\%$ in T1, 12.5$\%$ in T2, 0$\%$ in T3, and 62.5$\%$ in T4 lesions. Distant metastasis was seen in 41.2$\%$ of N2-3 lesions. Fifty percent of local recurrence appeared within 2 years of treatment at the primary lesion, whereas 70$\%$ of distant metastasis appeared within 2 years following treatment. Young age, female, early T stage, N0 stage; and poorly differentiated carcinoma were all related with good survival. However only stage showed statistically significance. Conclusionn: Based on the results of this study, radiation therapy to nasopharyngeal cancer showed high local recurrence in T4 and increased metastasis in N2-3 lesions. To improve local failure, further radiation doses, such as stereotactic radiation or IMRT radiation, are necessary especially in T4 lesions. The high incidence of distant metastasis in positive lymph node patients, indicates that combined radiation and effective chemotherapeutic agents with appropriated schedule are necessary.