• Title/Summary/Keyword: Out of distribution

Search Result 8,341, Processing Time 0.051 seconds

Image Watermarking for Copyright Protection of Images on Shopping Mall (쇼핑몰 이미지 저작권보호를 위한 영상 워터마킹)

  • Bae, Kyoung-Yul
    • Journal of Intelligence and Information Systems
    • /
    • v.19 no.4
    • /
    • pp.147-157
    • /
    • 2013
  • With the advent of the digital environment that can be accessed anytime, anywhere with the introduction of high-speed network, the free distribution and use of digital content were made possible. Ironically this environment is raising a variety of copyright infringement, and product images used in the online shopping mall are pirated frequently. There are many controversial issues whether shopping mall images are creative works or not. According to Supreme Court's decision in 2001, to ad pictures taken with ham products is simply a clone of the appearance of objects to deliver nothing but the decision was not only creative expression. But for the photographer's losses recognized in the advertising photo shoot takes the typical cost was estimated damages. According to Seoul District Court precedents in 2003, if there are the photographer's personality and creativity in the selection of the subject, the composition of the set, the direction and amount of light control, set the angle of the camera, shutter speed, shutter chance, other shooting methods for capturing, developing and printing process, the works should be protected by copyright law by the Court's sentence. In order to receive copyright protection of the shopping mall images by the law, it is simply not to convey the status of the product, the photographer's personality and creativity can be recognized that it requires effort. Accordingly, the cost of making the mall image increases, and the necessity for copyright protection becomes higher. The product images of the online shopping mall have a very unique configuration unlike the general pictures such as portraits and landscape photos and, therefore, the general image watermarking technique can not satisfy the requirements of the image watermarking. Because background of product images commonly used in shopping malls is white or black, or gray scale (gradient) color, it is difficult to utilize the space to embed a watermark and the area is very sensitive even a slight change. In this paper, the characteristics of images used in shopping malls are analyzed and a watermarking technology which is suitable to the shopping mall images is proposed. The proposed image watermarking technology divide a product image into smaller blocks, and the corresponding blocks are transformed by DCT (Discrete Cosine Transform), and then the watermark information was inserted into images using quantization of DCT coefficients. Because uniform treatment of the DCT coefficients for quantization cause visual blocking artifacts, the proposed algorithm used weighted mask which quantizes finely the coefficients located block boundaries and coarsely the coefficients located center area of the block. This mask improves subjective visual quality as well as the objective quality of the images. In addition, in order to improve the safety of the algorithm, the blocks which is embedded the watermark are randomly selected and the turbo code is used to reduce the BER when extracting the watermark. The PSNR(Peak Signal to Noise Ratio) of the shopping mall image watermarked by the proposed algorithm is 40.7~48.5[dB] and BER(Bit Error Rate) after JPEG with QF = 70 is 0. This means the watermarked image is high quality and the algorithm is robust to JPEG compression that is used generally at the online shopping malls. Also, for 40% change in size and 40 degrees of rotation, the BER is 0. In general, the shopping malls are used compressed images with QF which is higher than 90. Because the pirated image is used to replicate from original image, the proposed algorithm can identify the copyright infringement in the most cases. As shown the experimental results, the proposed algorithm is suitable to the shopping mall images with simple background. However, the future study should be carried out to enhance the robustness of the proposed algorithm because the robustness loss is occurred after mask process.

A Study on the Regional Characteristics of Broadband Internet Termination by Coupling Type using Spatial Information based Clustering (공간정보기반 클러스터링을 이용한 초고속인터넷 결합유형별 해지의 지역별 특성연구)

  • Park, Janghyuk;Park, Sangun;Kim, Wooju
    • Journal of Intelligence and Information Systems
    • /
    • v.23 no.3
    • /
    • pp.45-67
    • /
    • 2017
  • According to the Internet Usage Research performed in 2016, the number of internet users and the internet usage have been increasing. Smartphone, compared to the computer, is taking a more dominant role as an internet access device. As the number of smart devices have been increasing, some views that the demand on high-speed internet will decrease; however, Despite the increase in smart devices, the high-speed Internet market is expected to slightly increase for a while due to the speedup of Giga Internet and the growth of the IoT market. As the broadband Internet market saturates, telecom operators are over-competing to win new customers, but if they know the cause of customer exit, it is expected to reduce marketing costs by more effective marketing. In this study, we analyzed the relationship between the cancellation rates of telecommunication products and the factors affecting them by combining the data of 3 cities, Anyang, Gunpo, and Uiwang owned by a telecommunication company with the regional data from KOSIS(Korean Statistical Information Service). Especially, we focused on the assumption that the neighboring areas affect the distribution of the cancellation rates by coupling type, so we conducted spatial cluster analysis on the 3 types of cancellation rates of each region using the spatial analysis tool, SatScan, and analyzed the various relationships between the cancellation rates and the regional data. In the analysis phase, we first summarized the characteristics of the clusters derived by combining spatial information and the cancellation data. Next, based on the results of the cluster analysis, Variance analysis, Correlation analysis, and regression analysis were used to analyze the relationship between the cancellation rates data and regional data. Based on the results of analysis, we proposed appropriate marketing methods according to the region. Unlike previous studies on regional characteristics analysis, In this study has academic differentiation in that it performs clustering based on spatial information so that the regions with similar cancellation types on adjacent regions. In addition, there have been few studies considering the regional characteristics in the previous study on the determinants of subscription to high-speed Internet services, In this study, we tried to analyze the relationship between the clusters and the regional characteristics data, assuming that there are different factors depending on the region. In this study, we tried to get more efficient marketing method considering the characteristics of each region in the new subscription and customer management in high-speed internet. As a result of analysis of variance, it was confirmed that there were significant differences in regional characteristics among the clusters, Correlation analysis shows that there is a stronger correlation the clusters than all region. and Regression analysis was used to analyze the relationship between the cancellation rate and the regional characteristics. As a result, we found that there is a difference in the cancellation rate depending on the regional characteristics, and it is possible to target differentiated marketing each region. As the biggest limitation of this study and it was difficult to obtain enough data to carry out the analyze. In particular, it is difficult to find the variables that represent the regional characteristics in the Dong unit. In other words, most of the data was disclosed to the city rather than the Dong unit, so it was limited to analyze it in detail. The data such as income, card usage information and telecommunications company policies or characteristics that could affect its cause are not available at that time. The most urgent part for a more sophisticated analysis is to obtain the Dong unit data for the regional characteristics. Direction of the next studies be target marketing based on the results. It is also meaningful to analyze the effect of marketing by comparing and analyzing the difference of results before and after target marketing. It is also effective to use clusters based on new subscription data as well as cancellation data.

The Relation Between Work-Related Musculoskeletal Symptoms and Rapid Upper Limb Assessment(RULA) among Vehicle Assembly Workers (자동차 조립 작업자들에서 상지 근골격계의 인간공학적 작업평가(Rapid Upper Limb Assessment) 결과와 자각증상과의 연관성)

  • Kim, Jae-Young;Kim, Hae-Joon;Choi, Jae-Wook
    • Journal of Preventive Medicine and Public Health
    • /
    • v.32 no.1
    • /
    • pp.48-59
    • /
    • 1999
  • Objectives. This study was conducted to evaluate the association between upper extremity musculoskeletal symptoms and Rapid Upper Limb Assessment(RULA) in vehicle assembly line workers. The goal of this study is to show the feasibility of RULA as a checklist for work related musculoskeletal symptoms (WMSDs) in Korean workers. Methods. The total number of 199 people from the department of assembly and 115 people from the department of Quality Control(QC) in automotive plant were subjects for this cross sectional study. A standard symptom questionnaire survey has been used for the individual characteristics, work history, musculosketal symptoms and non-occupational covariates. The data were obtained by applying one-on-one interview for the all subjects. RULA has been applied for ergonomic work posture analysis and the primary ergonomic risk sure was computed by RULA method. Association between upper extremity musculoskeletal symptoms and RULA were assessed by multiple logistic regression analysis. Results. A total of 314 workers was examined. The prevalence of musculoskeletal symptoms by NIOSH case definition was 62.4%. The distribution of musculoskeletal symptoms by the part of the body turned out to be following; back:41.4%, neck: 32.8%, shoulder: 26.4%, arm: 10.5% and hand:29.3%. The relationship of the individual RULA scores were statistically significant for the prevalence of musculoskeletal symptoms. As the result of the multiple logistic regressioin analysis, grand final score (OR=2.250 95% CI: 1.402-3.612) was associated with musculoskeletal symptoms in any part of the body.; upper arm score(OR=1.786 95% CI: 1.036-3.079) and posture score A(OR=1.634 95% CI: 1.016-2.626) in neck; muscel use score(OR=3.076 95% CI:1.782-5.310) and posture score A(OR=1.798 95% CI: 1.072-3.017) in shoulder; upper arm score(OR=1.715 95% CI: 1.083-2.715) and muscel use score(OR=2.057 95% CI:1.303-3.248) in neck & shoulder; muscle use score(OR=10.662 95% CI: 3.180-35.742) in arm; writst/wist score(OR=2.068 95% CI: 1.130-3.786) and muscle use score(OR=2.215 95% CI: 1.284-3.819) in hand & wrist.; muscle use score of trunk (OR=2.601 95% CI: 1.147-5.901) in back. Conclusions. Musculoskeletal symptoms of the extremities were strongly associated with individual RULA body score. These results show that RULA can be used as a useful assessment tool for the evaluation of musculoskeletal loading which is known to contribute to work-related musculoskeletal disorders. RULA also can be used as a screening tool or incorporated into a wider ergonomic assessment of epidemiological, physical, mental, environmental and organizational factors. As shown in this study, complement of the analysis system for the other risk factors and characterizing between the upper limb and back part will be needed for future work.

  • PDF

Study of nosocomial rotavirus infection in neonates admitted to a postpartum-care center (서울시내 1개 산후 조리원에서 시행한 로타바이러스 선별검사에 대한 분석)

  • Park, Ji Young;Kim, Dong Hwan;Bae, Seung Young;Choi, Chang Hee;Cho, Eun Young;Choi, Jeong Hoon;Kim, Sun Mi
    • Pediatric Infection and Vaccine
    • /
    • v.14 no.2
    • /
    • pp.145-154
    • /
    • 2007
  • Purpose : Rotavirus is one of the most important etiologic agents of nosocomial infections among the neonates. This study was designed to investigate nosocomial rotavirus infection in neonates who were admitted to a postpartum-care center after birth. Methods : From March 2005 to September 2006, 957 healthy neonates were examined for rotavirus antigen in stool by immunochromatographic method and 216 neonates were rotavirus antigen positive within 24 hours after admitted to a postpartum-care center. We reviewed the nursing charts retrospectively such as characteristics, monthly distribution, birth hospitals, delivery methods, feeding types and clinical manifestations. Results : Among 957 neonates, 216 neonates (22.6%) were rotavirus antigen positive and there were no differences in sex, birth weight, gestational age. Monthly positive rate of rotavirus antigen showed diversity from 10% to 36%. According to birth hospitals, positive rate showed diversity from 3.5% to 53.6%. Out of 957 neonates, 655 cases (68.4%) were born of vaginal delivery and mean hospitalized duration was 2.4 days, 302 cases (31.6%) were born of cesarean section and mean hospitalized duration was 5.7 days. 17.6% of vaginal delivery and 33.4% of cesarean section were rotavirus antigen positive. The positive rate was higher in neonates by cesarean section than vaginal delivery (P<0.001). According to feeding types, positive rate of rotavirus antigen was lower in breast-fed group than formula-fed group (P<0.001). Proportion of symptomatic case among rotavirus antigen positive was 34.7%. Most common clinical manifestation was diarrhea (61.3%), following poor feeding (45.3%), fever (40.0%), vomiting (25.3%), delayed weight gain (12.0%), and decreased urine amount (5.3%). Conclusion : Some neonates were already infected before admission to a postpartum-care center. Without meticulous management, nosocomial rotavirus infection would transmit rapidly in a postpartum-care center spreading to the community. Recommendation of breast-feeding, routine rotavirus screeing test with or without symptom, and isolation of all rotavirus antigen positive neonates in a postpartum-care center seem to be necessary. Also attentive hygiene education and further investigations of rotavirus infection in a postpartum-care center would be needed.

  • PDF

Study on The Distribution of Applied 32P into Different Forms of P Compounds in the Soils During Incubation (논·밭 토양(土壤)에 시용(柴用)된 32P의 토양중(土壤中) 상이(相異)한 인산화합물(燐酸化合物)로의 분배(分配)에 관(關)한 연구(硏究))

  • Hong, Jung-Kook;Hong, Chong-Woon;Park, Sang-Ji;Steenberg, Kjell
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.12 no.3
    • /
    • pp.117-124
    • /
    • 1979
  • The present work was carried out to study the fate of applied phosphorus labelled with $^{32}P$ and its availability to plants in soils subjected to different management practices. The results can be summarized as follows (Table 3): 1. The applied phosphorus was transformed into different phosphorus compounds in the soils depending upon the management practices and soil characteristics. 2. In the flooded paddy soil (pH 5.8) added P after one week of incubation was transformed into various fractions, the order of abundance being: Al-P> Ca-P$${\sim_\sim}$$Fe-P> Org.-P. After two weeks the order changed to: Fe-P> Al-P> Ca-P> Org.-P. The amounts of the Fe-P and Al-P fractions were found to increase from the second week of incubation whereas a decrease in Ca-P was noticed with the organic-P remaining constant. The amount of available P decreased from the first to the third week of incubation, but increased thereafter. 3. In the volcanic ash soil a major proportion of the applied phosphorus was found in the Fe-P fraction during the whole experimental period. The interconversions of the $^{32}P$ among the different phosphate fractions was not as evident as in the case of flooded rice soil. The recovery of applied P was low and remained constant throughout the incubation period. 4. In the upland soils relatively more of the applied phosphorus was found in the Ca-P fraction as compared with those of the other soils. As in the flooded paddy soil $^{32}P$ in the Ca-P fraction decreased with increasing incubation time, whereas in the Fe-P fraction it increased with time. The recovery of added phosphate as available P followed different patterns for the cultivated and the uncultivated soils. In the cultivated soils lit was relatively high and remained nearly constant during the whole incubation period. In the uncultivated soil on the other hand, it was high at the earlier time of incubation, but decreased with incubation time.

  • PDF

The Effect of Partially Used High Energy Photon on Intensity-modulated Radiation Therapy Plan for Head and Neck Cancer (두경부암 세기변조방사선치료 계획 시 부분적 고에너지 광자선 사용에 따른 치료계획 평가)

  • Chang, Nam Joon;Seok, Jin Yong;Won, Hui Su;Hong, Joo Wan;Choi, Ji Hun;Park, Jin Hong
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.25 no.1
    • /
    • pp.1-8
    • /
    • 2013
  • Purpose: A selection of proper energy in treatment planning is very important because of having different dose distribution in body as photon energy. In generally, the low energy photon has been used in intensity-modulated radiation therapy (IMRT) for head and neck (H&N) cancer. The aim of this study was to evaluate the effect of partially used high energy photon at posterior oblique fields on IMRT plan for H&N cancer. Materials and Methods: The study was carried out on 10 patients (nasopharyngeal cancer 5, tonsilar cancer 5) treated with IMRT in Seoul National University Bundang Hospital. CT images were acquired 3 mm of thickness in the same condition and the treatment plan was performed by Eclipse (Ver.7.1, Varian, Palo Alto, USA). Two plans were generated under same planing objectives, dose volume constraints, and eight fields setting: (1) The low energy plan (LEP) created using 6 MV beam alone, (2) the partially used high energy plan (PHEP) created partially using 15 MV beam at two posterior oblique fields with deeper penetration depths, while 6 MV beam was used at the rest of fields. The plans for LEP and PHEP were compared in terms of coverage, conformity index (CI) and homogeneity index (HI) for planning target volume (PTV). For organs at risk (OARs), $D_{mean}$ and $D_{50%}$ were analyzed on both parotid glands and $D_{max}$, $D_{1%}$ for spinal cord were analyzed. Integral dose (ID) and total monitor unit (MU) were compared as addition parameters. For the comparing dose to normal tissue of posterior neck, the posterior-normal tissue volume (P-NTV) was set on the patients respectively. The $D_{mean}$, $V_{20Gy}$ and $V_{25Gy}$ for P-NTV were evaluated by using dose volume histogram (DVH). Results: The dose distributions were similar with regard to coverage, CI and HI for PTV between the LEP and PHEP. No evident difference was observed in the spinal cord. However, the $D_{mean}$, $D_{50%}$ for both parotid gland were slightly reduced by 0.6%, 0.7% in PHEP. The ID was reduced by 1.1% in PHEP, and total MU for PHEP was 1.8% lower than that for LEP. In the P-NTV, the $D_{mean}$, $V_{20Gy}$ and $V_{25Gy}$ of the PHEP were 1.6%, 1.8% and 2.9% lower than those of LEP. Conclusion: Dose to some OARs and a normal tissue, total monitor unit were reduced in IMRT plan with partially used high energy photon. Although these reduction are unclear how have a clinical benefit to patient, application of the partially used high energy photon could improve the overall plan quality of IMRT for head and neck cancer.

  • PDF

Sensory and Mechanical characteristics of Wax gourd Jung Kwa by different recipes (동아정과의 재료배합비와 조리방법에 따른 Texture 특성)

  • 이효지;김현정
    • Korean journal of food and cookery science
    • /
    • v.17 no.4
    • /
    • pp.412-420
    • /
    • 2001
  • This study was conducted to identify the optimum cooking method and the ideal composition of Wax gourd Jung Kwa for the purpose of wide distribution. Wax gourd Jung Kwa was made by peeling off the wax gourd, digging out the stuff, slicing, soaking the pieces in ash water, and boiling slightly, then boiling down in honey, grain syrup. sugar, etc. As a result of sensory evaluation, the best color of Jung Kwa was observed in the recipe of pretreated wax gourd 300g, water 1 litre and grain syrup 495$m\ell$; for the flavor, hardness and chewiness, Pretreated wax gourd 300g, water 1 litre, corn syrup 475$m\ell$ and sugar 70g; for the adhesiveness, pretreated wax gourd 300g, water 1 litre and corn syrup 515$m\ell$; for the sweetness, pretreated wax gourd 300g, water 600$m\ell$ and sugar 90g and honey 120g. Overall Qualify was the highest in the recipe of pretreated wax gourd 300g, water 1 litre, com syrup 475$m\ell$ and sugar 70g, of which the sweetness was 74%. There were significant differences in all items (P<0.05). For mechanical characteristics, the maximum cutting force was the highest in the samples with the recipe of pretreated wax gourd 300g, water 1 litre, corn syrup 475$m\ell$ and sugar 70g, and there were significant differences among all items (P<0.05). The highest moisture content, 45.54%, was observed in the recipe of pretreated wax gourd 300g. water 1 litre and corn syrup 475$m\ell$. There were significant differences among all items (P<0.05). The L value(lightness) was the highest in the recipe of pretreated wax gourd 300g, water 1 litre, corn syrup 475 $m\ell$ and sugar 50g. The a value(redness) was the highest in the case of pretreated wax gourd 300g, water 1 litre, com syrup 475$m\ell$ and sugar 70g, which was almost red; and the b value(yellowness), wax gourd 300g, water 1 litre and corn syrup 475g, which gave almost Yellow color. Taking consideration of the above results, the most desirable recipe for wax gourd Jung Kwa was to mix the 300g of pretreated wax gourd with 20g of ash powder, boil them slightly for 2 min, soak them in cold water for 1 hour, and boil them down with 475$m\ell$ of com syrup, 70g of sugar, and 1 litre of water for 5 hours, resulting in the sweetness of 74%. The samples with above recipe were the best in flavor, chewiness and hardness in sensory evaluation, and showed the highest maximum cutting force and nearest red color in the mechanical test.

  • PDF

A Study on the Current Status and Location Characteristics of Stone Jangseung - Focusing on Doljangseung in Daejeon Area - (돌장승의 현황 및 입지특성에 관한 연구 - 대전지역 돌장승을 중심으로 -)

  • Lee, Dong-Hun;Heo, Sang-Hyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.42 no.1
    • /
    • pp.1-13
    • /
    • 2024
  • This study requires a strict distinction between the sculptures we call 'Jangseung' because their origins, history, or functions are different from each other. Therefore, a theoretical consideration was made through the origin and history of Jangseung. Currently, Jangseung is widely distributed throughout the country, but the Honam region shows the largest distribution, and 73 out of 167 locations nationwide remain in the Chungcheongnam-do region. Among these, there are 54 stone jangseungs in Jeollanam-do, 37 in Jeollabuk-do, and 19 in Jeollabuk-do. In particular, the original shape of the stone jangseungs in the Honam region is well preserved, and as a center of the agricultural economy, the jangseung culture is active in this region. It was popular, and many stone jangseungs were built in the Daejeon area amid social changes in the late Joseon Dynasty. However, in the South Chungcheong region, there is not much culture about stone jangseungs, but there is a village meaning and consciousness that stone jangseungs have, but it is true that research on stone jangseungs is insufficient in various aspects. Among them, the form of the stone jangseung built between the 17th and 19th centuries is a sculpture that contrasts with the wooden pillar-type jangseung that is common in the central region, and shows the simple mentality of the people of the Daejeon region without any embellishment. Through Jangseung, we were able to discover the unconscious and potential creativity of national aesthetic consciousness. Therefore, the purpose is to trace the change process of the stone jangseung in the Daejeon area, investigate the functional aspects of this structure, and based on this, examine the various current status and locational characteristics of the so-called stone jangseung. In addition, the wooden figures and stone statues that are now commonly known as Jangseung were each erected in different times and for different reasons. Centering around Daejeon, the study attempted to research and identify representative stone monuments or 'stone jangseungs' that appear as stone statues, and even suggest their form through locational characteristics and suggestions. As a result, traditional jangseungs have changed in various forms as times change, reaching their present form, and the religious elements of modern jangseungs made and erected today are weakened or disappeared, and are used as symbolic symbols or sculptures of tradition. Although it has lost its traditional function as an object of village faith, it functions as a milestone or sign at the entrance to a village or event site, or as an exhibition in special places. It was found that the modern jangseung is a representative symbol of Korean traditional culture and is being re-created as an artistic sculpture that expresses common, simple, natural beauty and humor. Therefore, through this study, based on more specific and systematic investigation and research on the jangseung, it was materialized into a more developed form considering its utilization plan to prevent miscellaneous spirits from entering the village through the currently existing stone jangseung and to improve the spatial space accordingly. It is believed that what is located at the entrance can greatly convey its meaning. Therefore, it is judged necessary to maintain the strong characteristics of folk religion without the sophistication of foreign religions for various deities.

Quality Assurance for Intensity Modulated Radiation Therapy (세기조절방사선치료(Intensity Modulated Radiation Therapy; IMRT)의 정도보증(Quality Assurance))

  • Cho Byung Chul;Park Suk Won;Oh Do Hoon;Bae Hoonsik
    • Radiation Oncology Journal
    • /
    • v.19 no.3
    • /
    • pp.275-286
    • /
    • 2001
  • Purpose : To setup procedures of quality assurance (OA) for implementing intensity modulated radiation therapy (IMRT) clinically, report OA procedures peformed for one patient with prostate cancer. Materials and methods : $P^3IMRT$ (ADAC) and linear accelerator (Siemens) with multileaf collimator are used to implement IMRT. At first, the positional accuracy, reproducibility of MLC, and leaf transmission factor were evaluated. RTP commissioning was peformed again to consider small field effect. After RTP recommissioning, a test plan of a C-shaped PTV was made using 9 intensity modulated beams, and the calculated isocenter dose was compared with the measured one in solid water phantom. As a patient-specific IMRT QA, one patient with prostate cancer was planned using 6 beams of total 74 segmented fields. The same beams were used to recalculate dose in a solid water phantom. Dose of these beams were measured with a 0.015 cc micro-ionization chamber, a diode detector, films, and an array detector and compared with calculated one. Results : The positioning accuracy of MLC was about 1 mm, and the reproducibility was around 0.5 mm. For leaf transmission factor for 10 MV photon beams, interleaf leakage was measured $1.9\%$ and midleaf leakage $0.9\%$ relative to $10\times\;cm^2$ open filed. Penumbra measured with film, diode detector, microionization chamber, and conventional 0.125 cc chamber showed that $80\~20\%$ penumbra width measured with a 0.125 cc chamber was 2 mm larger than that of film, which means a 0.125 cc ionization chamber was unacceptable for measuring small field such like 0.5 cm beamlet. After RTP recommissioning, the discrepancy between the measured and calculated dose profile for a small field of $1\times1\;cm^2$ size was less than $2\%$. The isocenter dose of the test plan of C-shaped PTV was measured two times with micro-ionization chamber in solid phantom showed that the errors upto $12\%$ for individual beam, but total dose delivered were agreed with the calculated within $2\%$. The transverse dose distribution measured with EC-L film was agreed with the calculated one in general. The isocenter dose for the patient measured in solid phantom was agreed within $1.5\%$. On-axis dose profiles of each individual beam at the position of the central leaf measured with film and array detector were found that at out-of-the-field region, the calculated dose underestimates about $2\%$, at inside-the-field the measured one was agreed within $3\%$, except some position. Conclusion : It is necessary more tight quality control of MLC for IMRT relative to conventional large field treatment and to develop QA procedures to check intensity pattern more efficiently. At the conclusion, we did setup an appropriate QA procedures for IMRT by a series of verifications including the measurement of absolute dose at the isocenter with a micro-ionization chamber, film dosimetry for verifying intensity pattern, and another measurement with an array detector for comparing off-axis dose profile.

  • PDF

Surgery Alone or Postoperative Adjuvant Radiotherapy in Rectal Cancer - With Respect to Survival, Pelvic Control, Prognostic Factor - (직장암에서 수술단독 또는 수술후 방사선치료 -생존율, 골반종양제어율, 예후인자를 중심으로-)

  • Nam, Taek-Keun;Ahn, Sung-Ja;Nah, Byung-Sik
    • Radiation Oncology Journal
    • /
    • v.19 no.4
    • /
    • pp.327-334
    • /
    • 2001
  • Purpose : To find out the role of postoperative adjuvant radiotherapy in the treatment of rectal cancer by comparing survival, pelvic control, complication rate, and any prognostic factor between surgery alone and postoperative radiotherapy group. Materials and methods : From Feb. 1982 to Dec. 1996 total 212 patients were treated by radical surgery with or without postoperative radiotherapy due to rectal carcinoma of modified Astler-Coiler stage $B2\~C3$. Of them, 18 patients had incomplete radiotherapy and so the remaining 194 patients were the database analyzed in this study. One hundred four patients received postoperative radiotherapy and the other 90 patients had surgery only. Radiotherapy was peformed in the range of $39.6\~55.8\;Gy$ (mean: 49.9 Gy) to the whole pelvis and if necessary, tumor bed was boosted by $5.4\~10\;Gy$. Both survival and pelvic control rates were calculated by Kaplan-Meier method and their statistical significance was tested by Log-rank test. Multivariate analysis was peformed by Cox proportional hazards model. Results : 5-year actuarial survival rate (5YSR) and 5-year disease-free survival rate (5YDFSR) of entire patients were $53\%\;and\;49\%$, respectively. 5YSRs of surgery alone group and adjuvant radiotherapy group were $63\%\;vs\;45\%$, respectively (p=0.03). This difference is thought to reflect uneven distribution of stages between two treatment groups (p<0.05 by $\chi^2-test$) with more advanced disease patients in adjuvant radiotherapy group. 5YSRs of surgery alone vs adjuvant radiotherapy group in MAC B2+3, C1, C2+3 were $68\%\;vs\;55\%$ (p=0.09), $100\%\;vs\;100\%$, $40\%\;vs\;33\%$ (p=0.71), respectively. 5YDFSRs of surgery alone vs adjuvant radiotherapy group in above three stages were $65\%\;vs\;49\%$ (p=0.14), $100\%\;vs\;100\%$, $33\%\;vs\;31\%$ (p=0.46), respectively. 5-year pelvic control rate (5YPCR) of entire patients was $72.5\%$. 5YPCRs of surgery alone and adjuvant radiotherapy group were $71\%\;vs\;74\%$, respectively (p=0.41). 5YPCRs of surgery alone vs adjuvant radiotherapy group in B2+3, C1, C2+3 were $79\%\;vs\;75\%$ (p=0.88), $100\%\;vs\;100\%$, $44\%\;vs\;68\%$ (p=0.01), respectively. Multivariate analysis showed that only stage was significant factor affecting overall and disease-free survival in entire patients and also in both treatment groups. In view of pelvic control, stage and operation type were significant in entire patients and only stage in surgery alone group but in adjuvant radiotherapy group, operation type instead of stage was the only significant factor in multivariate analysis as a negative prognostic factor in abdominoperineal resection cases. Conclusion : Our retrospective study showed that postoperative adjuvant radiotherapy could improve the pelvic control in MAC C2+3 group. To improve both pelvic control and survival in all patients with MAC B2 or more, other treatment modality such as concurrent continuous infusion of 5-FU, which is the most standard agent, with radiotherapy should be considered.

  • PDF