• 제목/요약/키워드: radiation problem

검색결과 573건 처리시간 0.026초

공간적응형 소스 분포 합성법을 사용한 임의의 반사응답을 갖는 전송선로 설계 (Design of Transmission Lines with Arbitrary Reflection Responses Using Synthesis Method for Spatially Adaptive Source Distribution)

  • 박의준
    • 대한전자공학회논문지TC
    • /
    • 제39권5호
    • /
    • pp.243-250
    • /
    • 2002
  • 임의 복사패턴을 만족시키는 배열안테나 소스 전류분포 합성시 사용하는 Woodward-Lawson 샘플링법은 우함수형 복사패턴 합성에 주로 사용되어 왔다. 본 연구에서는 이를 확장하여 기함수형 패턴도 만족시키는 비선형 소스 분포함수의 최적합성법을 제시하고, 이를 임의의 반사특성을 갖는 단일 및 결합선로의 불균일 모드 임피던스 프로필 합성에 동시에 적용하였다. 이 최적합성법은 주파수영역 반사패턴에 내재된 복소null점의 최적 섭동에 기본을 두고 있다. 제어된 반사패턴의 표본값으로부터 분산특성을 갖는 임피던스 프로필이 직접 계산되므로서 기존외 불균일선로 합성법보다 매우 간단함을 보였다. 그리고 서로 다른 임피던스간의 정합을 위한 기존이 테이퍼선로 이론에 기초한 불균일선론 합성법들을 탈피하여, 서로 같은 임피던스간의 불균일선로 합성도 가능케하므로서 본 연구에서 제시한 방법은 일반성을 가진다. 임의 통과대역을 갖는 필터 설계에 적용, 분석하므로서 타당성을 보였다.

물 재이용을 위한 하수처리장 방류수 색도의 자외선처리에 미치는 과산화수소의 영향 (Effect of Hydrogen Peroxide on UV Treatment of Color in Secondary Effluent for Reclamation)

  • 박기영;맹승규;김기팔;이석헌;권지향;안규홍
    • 상하수도학회지
    • /
    • 제18권3호
    • /
    • pp.377-384
    • /
    • 2004
  • In the present study, a feasibility of an advanced oxidation process using UV/Hydrogen peroxide($H_2O_2$) system equipped with a medium pressure lamp for secondary effluent reclamation was investigated. Initial concentration of $H_2O_2$ and pH were changed to determine the optimum operation condition for the system. The removal efficiency of color was than 80% with 14.3mg/L of initial $H_2O_2$ and 5 minute of contact time in the UV/$H_2O_2$ system. The color removal was analyzed using first-order reaction equation. The dependence of rate constant (k) on initial $H_2O_2$ represented the rational relationship with maximum value. Residual $H_2O_2$ caused increase of effluent COD, since analyzing agent, dichromate, reacted with $H_2O_2$ in the sample. Therefore, excess initial concentration of $H_2O_2$ would significantly affect effluent COD measurement. At pH variation experiment, both residual $H_2O_2$ and color showed peak in the neutral pH range with the same pattern. Effect of $H_2O_2$ dose also enhanced color removal but raised residual $H_2O_2$ problem in the continuous operation UV system. In conclusion, these results indicated that medium pressure UV/$H_2O_2$ system could be used to control color in the secondary effluent for reclamation and reuse.

국소마취하 상악 측절치 치근단 절제술 후 인식된 신경병성 비정형 치통 1예 -증례 보고- (A Neuropathic Atypical Odontalgia Recognized after the Apicoectomy under Local Anesthesia on the Maxillary Lateral Incisor -A Case Report-)

  • 모동엽;유재하;최병호;김하랑;이천의;김종배
    • 대한치과마취과학회지
    • /
    • 제10권1호
    • /
    • pp.20-26
    • /
    • 2010
  • This type of neuropathic pain(atypical odontalgia) is seen most often in middle-aged women or men after dentoalveolar operation. Atypical odontalgia probably is caused by deafferentation leading to intraneural changes in the medullary dorsal horn. Treatment of this problem is difficult, but some success has been reported in uncontrolled, open-labeled studies using high doses of tricyclic antidepressants. This is the management report of a patient case, that had a neuropathic atypical odontalgia recognized with the right maxillary lateral incisor. The patient was consulted to the Department of Pain Clinics, ENT & Neurology and diagnosed the adenoid cystic carcinoma on left cerebellum and right paranasal sinus with extension to the cavernous sinus. In spite of the osteoplastic craniotomy, neurosurgical mass removal and radiation therapy were done with chemotherapy, atypical odontalgia was continued. In addition to the consultation to Psychology, stress management and antidepressant medication were done and improved slowly.

소형 및 변형된 접지면을 이용한 신호선 복사성 방사 레벨의 감소 방법 (Reduction of Radiated Emission from Signal Traces Using Modified and Small-Sized Ground Patterns)

  • 박필성;이재욱;이택경;조춘식;김재흥;최형도
    • 한국전자파학회논문지
    • /
    • 제17권12호
    • /
    • pp.1189-1198
    • /
    • 2006
  • 본 논문에서는 다양한 접지면과 함께 단일 신호 선로 및 복수 신호 선로로부터의 복사성 방사 레벨과 신호간 커플링 현상을 관찰하고 좁은 접지면과 새로운 패턴을 이용하여 일정한 주파수 대역에서 신호 선로로부터의 복사성 방사 레벨의 감소를 얻을 수 있음을 접지면의 최적화 과정과 함께 기술하고 있다. 다양한 접지면과 함께 윗층에 설치된 신호 선로로부터의 복사 메커니즘의 예측 및 해석의 정당성을 각각 상용 소프트웨어와 실험을 통하여 검증하였다.

Profile and Survival of Tongue Cancer Patients in "Dharmais" Cancer Hospital, Jakarta

  • Sutandyo, Noorwati;Ramli, Ramadhan;Sari, Lenny;Soeis, Dewi Syafriyetti
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권5호
    • /
    • pp.1971-1975
    • /
    • 2014
  • Background: Tongue cancer is still a major health problem in most developing countries around the world. Statistics shown the number of tongue cancers, especially in early age, to be increasing, with poor survival. Objective: To analyze the characteristic profile of tongue cancer patients in Indonesia as well as the survival rate. Materials and Methods: A cross sectional study was conducted in Dharmais National Cancer Hospital by collecting general, clinical, and survival data of tongue cancer patients from medical records for January 2009 to April 2012. Results: Tongue cancer incidence increased year by year. The average age of tongue cancer patients was 47.5 years, and males predominated, accounting for 64.5% of cases. Most patients presented at an advanced stage (69.6%). The histopathology type was squamous cell carcinoma in the vast majoriy (96.8%). The therapies applied were surgery (45.6%), radiation (63.6%) and chemotherapy (57.6%). The survival rate after one year is 60.6% and after two years was 12.1%. In addition, median survival of tongue cancer patients was 20 months (95% confidence interval 9.07-30.9). The significant factor affecting survival was size of tumor with a hazard ratio of 3.18 (95% CI, 1.02-9.93; p 0.046) for largest versus smallest categories. Conclusions: In each year, the number of tongue cancer incidents in Indonesia is increasing. The age of tongue cancer patients in Indonesia is younger compared to other countries. Moreover, the survival rates are not high.

서울지역 라돈농도의 분포예측을 위한 공간분석법 연구 (Studies on the Spatial Analysis for Distribution Estimation of Radon Concentration at the Seoul Area)

  • 백승아;이태정;김신도;김동술
    • 한국대기환경학회지
    • /
    • 제24권5호
    • /
    • pp.538-550
    • /
    • 2008
  • Radon is an invisible, odorless, and radioactive gas. It is formed by the disintegration of radium, which is a decay product of uranium. Some amounts of radon gas and its products are present ubiquitously in the soil, water, and air. Particularly high radon levels occur in regions of high uranium content. Although radon is permeable into indoor environment not only through geological features (bed rock and permeability) but also through the construction materials and underground water, the radiation from the geological features is generally main exposure factor. So there can be a problem in a certain space such as the underground and/or relatively poor ventilation condition. In this study, a GIS technique was used in order to investigate spatial distribution of radon measured from sub- way stations of 1 thru 8 in Seoul, Korea in 1991, 1998, 2001, and 2006. Spatial analysis was applied to reproduce the radon distribution. We utilized spatial analysis techniques such as inverse distance weighted averaging (IDW) and kriging techniques which are widely used to relate between different spatial points. To validate the results from the analyses, the jackknife technique for an uncertainty test was performed. When the number of measuring sites was less than 100 and also when the number of omitted sites increased, the kriging technique was better than IDW. On the other hand, when the number of sites was over 100, IDW technique was better than kriging technique. Thus the selection of analytical tool was affected sensitives by the analysis based on the number of measuring sites.

측두하악관절 내장증 환자의 자기공명영상에서 관절 원판의 전방 이동에 관한 연구 (THE STUDY ON ANTERIOR DISPLACEMENT OF DISK IN PATIENTS OF TEMPOROMANDIBULAR JOINT INTERNAL DERANGEMENT IN MAGNETIC RESONACE IMAGING)

  • 문창수;조병욱;이용찬;이한욱;유한식;이열
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • 제15권3호
    • /
    • pp.189-197
    • /
    • 1993
  • Tempormandibular Joint pain and dysfunction is a common and important clinical problem. With the recent advances in imaging technology, radiologists have made major contribution to the understanding of TMJ disease. The MRI has several advantages over the conventional imaging methods. It is possible to obtain surprisingly precise images of internal hard and soft tissues with MRI. It is not invasive without ionizing radiation. The abnormal disk position has been thought as the cause of TMJ internal derangement. But there are few methods to relate disk position to TMJ internal derangement quantatively. The object of our study is to determine the amount of anterior displacement fo articular disk in symptomatic patients related each symptoms. Using the method of Dr. Drace, we studied the 38 joints of 22 persons with susceptable TMJ internal derangement. 1. In determining the anterior displacement of TMJ articular disk, the junction between the posterior band and bilaminar zone was useful. 2. The mean anterior displacement of disk in reduction group and without reduction group were $51.0^{\circ}C$ and $81.1^{\circ}C$ respectively. The difference was significant. 3. In the mean anterior displacement of disk, the pain without clicking group showed $84.8^{\circ}C$ and the clicking and pain group $70.8^{\circ}C$, the clicking group respectively.

  • PDF

RIA, Recombinant Immunoblot Assay 및 Nested RT-PCR에 의한 C형 간염바이러스 검출 (Detection of Hepatitis C Virus by RIA, Recombinant Immunoblot Assay and Nested RT-PCR)

  • 김재수;김종완;이연태
    • 대한바이러스학회지
    • /
    • 제30권2호
    • /
    • pp.151-159
    • /
    • 2000
  • Hepatitis C virus (HCV) is one of the important human pathogen that can cause acute and chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Recently, the third generation radiation immuno assay (RIA) method has been developed as a very sensitive test to detect anti-HCV antibody. However, false positive is the problem with RIA test. To solve this the RIA results were compared to those of 5-antigen recombinant immunoblot assay (5-RIBA) and reverse transcription-polymerase chain reaction (RT-PCR). Among 12,767 serum samples tested from clinic visitors, total 275 (2.2%) samples were antibody positive by RIA. RIBA was performed with 148 RIA positives cases but among them was shown eighty five was antibody positive and sixty three (42.6%) was negative result. However, nested RT-PCR test was shown also carried out with 43 positive, 6 intermediates and 25 negatives of RIBA. As a result of the nested RT-PCR results, HCV antigen were detected in RIBA positive, 33.3% (2/6) RIBA intermediate and 12% (3/25). Clinical syndrome of all 148 patients as a with chronic active hepatitis (46.0%), cirrhosis (18.9%), hepatocellular carcinoma (8.1%) and others (27.0%) and they were positive in reaction by RIA test. But RIBA positive patients with 34.9% of chronic active hepatitis, 18.6% of cirrhosis, 4.6% of hepatocellular carcinoma and 41.9% of others were detected to be positive case by nested RT-PCR.

  • PDF

국외 해체 사례 분석을 통한 국내 소규모 방사선이용시설 해체에 관한 연구 (Study on the Decommissioning of Small Nuclear Facility through Analyzing Foreign Decommissioning Practices)

  • 권다영;김용민
    • 한국방사선학회논문지
    • /
    • 제9권3호
    • /
    • pp.125-130
    • /
    • 2015
  • 방사선은 의료 분야 뿐 아니라 공업 분야, 농업 및 식품생명 분야 등에 이용되고, 소규모 방사선이용시설의 운영이 증가하고 있는 상황이다. 이에 소규모 방사선이용시설의 해체에 대한 관심을 가질 필요성이 있고, 시설 해체 시 발생될 문제점에 대해 예측해 볼 필요성이 있다. 원자력발전소 등의 대형방사선이용시설의 해체에 대한 대비는 진행되고 있으나, 상대적으로 위험성이 적은 소규모 방사선이용시설의 해체에 대해서는 대비가 부족한 상황이다. 사이클로트론의 방사화나 브라질 고이아니아의 방사성물질 누출사고를 생각해보면 소규모 방사선이용시설의 사고 시 그 영향은 대형 방사선이용시설에 비해 작지 않다. 이에 따라 본 연구에서는 국내에 비해 상대적으로 소규모 방사선이용시설 해체 사례가 많은 국외의 사례 중 국내에서 많이 가동되고 있는 사이클로트론, 방사선치료시설 등 시설별 특징에 대해 분석하였다. 또한, 소규모 방사선이용시설 해체 시 각 시설별 또는 공통적인 문제점으로는 시설과 선원의 재사용, 공간 부족, 이해 당사자의 개입, 대중의 방사선 노출이 나타났다. 이를 바탕으로 향후 소규모 방사선이용시설 해체 시 문제점을 해결할 수 있는 방안을 마련할 때 도움이 될 것으로 사료된다.

MCNPX를 이용한 의료용 선형가속장치의 광자 스펙트럼에 관한 연구 (A Study on Photon Spectrum in Medical Linear Accelerator Based on MCNPX)

  • 박은태;이동연;고성진;김정훈;강세식
    • 한국방사선학회논문지
    • /
    • 제8권5호
    • /
    • pp.249-254
    • /
    • 2014
  • 의료용 선형가속장치는 1952년에 개발된 이후 방사선 치료에 사용되어 왔으며 그 활용도가 더욱 증가하고 있다. 현재는 6 MeV 이상의 광자 에너지를 사용하는 고 에너지 방사선치료가 보편화되어 사용되고 있으나, 광핵반응에 의한 중성자의 생성으로 환자 및 술자에 대한 피폭이 문제가 되고 있다. 이에 본 연구에서는 MCNPX를 사용하여 의료용 선형가속장치에서 발생되는 6~24 MV 광자선의 스펙트럼을 분석하고, 평균에너지 및 텅스텐의 중성자 생성 임계에너지인 7.41 MeV 이상의 광자 개수를 평가하였다. 그 결과 8 MV를 시작으로 24 MV에서는 전체 검출 광자 수에 비해 0.59%의 비율로서 광핵 반응을 일으킬 수 있는 광자수가 증가함을 알 수 있었다.