• 제목/요약/키워드: Skin Depth

검색결과 371건 처리시간 0.026초

기성말뚝의 지지거동 (The Behavior of Bearing Capacity for the Precast files)

  • 박영호
    • 한국지반공학회논문집
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    • 제16권1호
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    • pp.107-116
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    • 2000
  • 4개 현장에 실물크기의 강관말뚝과 PC 및 PHC 말뚝의 축방향에 대한 지지거동을 알아보기 위하여, 강관말뚝에 스트레인게이지를 부착하고 항타시 계측기 손상여부를 조사하면서 동재하시험을 수행하였다. 아울러 동일한 말뚝에 대하여 2일과 7일 경과후에 정재하시험을 실시하여 하중-침하량 거동과 주면 및 선단지지력을 분리 측정하였다. 그 결과, CAPWAP 해석에 Davisson방법을 적용하여 구한 강관말뚝의 허용지지력은 정재하시험에서 구한 허용지지력 보다 약 2~33%정도 크게 나타났다. 그리고 정재하시험 결과에서 구한 산술평균한 허용지지력은 CAPWAP해석에서 Davisson's offset방법으로 구한 허용지지력보다 극한지지력에 FS=2.5를 적용하여 구한 허용지지력에 더 근접하는 경향을 보였다. 또한, 단위면적당 주면지지력은 깊이가 증가함에 따라 증가하였고, 말뚝선단부 1~2m 이내에서 발휘되는 비율이 상당히 큰 것으로 나타났다.

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방사선조사가 백서 이하선의 선세포에 미치는 영향에 관한 전자현미경적 연구 (AN ELECTRON MICROSCOPIC STUDY ON THE EFFECTS OF IRRADIATION ON THE ACINAR CELLS OF RAT PAROTID GLAND)

  • 고광준;이상래
    • 치과방사선
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    • 제18권1호
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    • pp.31-45
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    • 1988
  • The author studied the histopathologic changes according to a single or a split dose and the time after irradiation on the acinar cells of rat parotid gland. 99 Sprague Dawley rats, weighing about l20gm, were divided into control and 3 experimental groups. In experimental groups, GroupⅠ and Ⅱ were delivered a single dose of l5Gy, 18Gy and Group Ⅲ and Ⅳ were delivered two equal split doses of 9Gy, 10.5Gy for a 4 hours interval, respectively. The experimental groups were delivered by a cobalt-60 teletherapy unit with a dose rate of 222cGy/min, source-skin distance of 50㎝, depth of l㎝ and a field size of l2×5㎝. The animals were sacrificed at 1, 2, 3, 6, 12 hours, 1, 3, 7 days after irradiation and examined by light and electron microscopy. The results were as follows: 1. As the radiation dose increased and the acinar cells delivered a single dose exposure were more damaged, and the change of acinar cells appeared faster than those of a split dose exposure. 2. The histopathologic change of acinar cells appeared at 1 hour after irradiation. The recovery from damaged acinar cells appeared at 1 day after irradiation and there was a tendency that the recovery from damage of a split dose exposure was somewhat later than that of a single dose exposure. 3. Light microscope showed atrophic change of acinar cells and nucleus, degeneration and vesicle formation of cytoplasm, widening of intercellular space and interlobular space. 4. Electron microscope showed loss of nuclear membrane, degeneration of nucleus and nucleoli, clumping of cytoplasm, widening and degeneration of rough endoplasmic reticulum, loss of cristae of mitochondria, lysosome, autophagosome and lipid droplet. 5. Electron microscopically, the change of rough endoplasmic reticulum was the most prominent and this appeared at 1 hour after irradiation as early changes of acinar cells. The nuclear change appeared at 2 hours after irradiation and the loss of cristae of mitochondria was observed at 2 hours after irradiation in all experimental groups.

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A Monitor Unit Verification Calculation in IMRT as a Dosimetry QA

  • Kung, J.H.;Chen, G.T.Y.;Kuchnir, F.T.
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.68-73
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    • 2002
  • In standard teletherapy, a treatment plan is generated with the aid of a treatment planning system, but it is common to perform an independent monitor unit verification calculation (MUVC). In exact analogy, we propose and demonstrate that a simple and accurate MUVC in Intensity Modulated Radiotherapy (IMRT) is possible. We introduce a concept of Modified Clarkson Integration (MCI). In MCI, we exploit the rotational symmetry of scattering to simplify the dose calculation. For dose calculation along a central axis (CAX), we first replace the incident IMRT fluence by an azimuthally averaged fluence. Second, the Clarkson Integration is carried over annular sectors instead of over pie sectors. We wrote a computer code, implementing the MCI technique, in order to perform a MUVC for IMRT purposes. We applied the code to IMRT plans generated by CORVUS. The input to the code consists of CORVUS plan data (e.g., DMLC files, jaw settings, MU for each IMRT field, depth to isocenter for each IMRT field), and the output is dose contribution by individual IMRT field to the isocenter. The code uses measured beam data for Sc, Sp, TPR, (D/Mu)$\_$ref/ and includes effects from MLC transmission, and radiation field offset. On a 266 MHZ desktop computer, the code takes less than 15 sec to calculate a dose. The doses calculated with MCI algorithm agreed within +/- 3% with the doses calculated by CORVUS, which uses a 1cm x 1cm pencil beam in dose calculation. In the present version of MCI, skin contour variations and inhomogeneities were neglected.

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한국의 전자탐사 현황 (Electromagnetic Survey in Korea)

  • 조동행
    • 자원환경지질
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    • 제39권4호
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    • pp.427-440
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    • 2006
  • 다른 물리탐사법과는 달리, 전자탐사의 실질적인 국내 활용과 연구는 1980년대부터이다. 이렇게 늦게나마 시작하게 된 것은 1970년대 미국 유학한 네 명의 연구자들의 영향이고, 이 들과의 공동연구와 유대는 현재까지 지속되고 있다. 그 동안 국내 연구진이 이룬 성과는 괄목할 만 하다. 이제 우리는 MT와 CSAMT탐사, 지자기수직탐사, 소형루프탐사, VLF탐사, GPR탐사, 시간영역 전자탐사 등 전 분야에 걸쳐 국제 수준의 기술력을 확보하게 되었고 신기술인 고주파수 전자탐사, 시간영역 전자탐사, 역산기법 분야에서 창의 있는 연구 성과를 내고 있다. 활용 분야도 지하자원탐사에서 지반조사, 환경조사, 고고학조사, 구조물 결함조사, 땅굴조사 등으로 엄청나게 확장되었다. 아직도 자료해석이 난삽하기 이를 데 없는 전자탐사법을 한 단계 높일 결정적인 돌파구가 국내 연구진에 의해서 나올 날이 멀지 않을 것이다.

비자성 증기발생기 전열관의 원격장와전류 탐상 가능성 연구 (Feasibility Study of Remote Field Eddy Current Testing for Nonmagnetic Steam Generator Tubes)

  • 신영길
    • 비파괴검사학회지
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    • 제21권5호
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    • pp.518-525
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    • 2001
  • 증기발생기 전열관이 노후화 됨에 따라 새롭고 판단이 애매한 결함이 발생되기 시작하고 있다. 대부분의 결함은 전열관 외부에서 발생되어 진전된다. 일반 와전류탐상에서는 외부결함으로부터의 신호가 표피효과로 인해 내부결함으로부터의 신호보다 매우 약하기 때문에, 본 논문에서는 자성체 관 검사에서 내부 및 외부결함에 거의 같은 민감도를 보인 바 있는 원격장와전류 탐상을 비자성체인 전열관의 검사에 적용하기 위한 연구를 수행하였다. 유한요소 모델링을 통한 연구결과는 비자성체인 전열관에서 원격장와전류 효과가 나타나려면 탐상주파수가 수백 kHz가 되어야 하며, 여자코일과 센서코일간의 간격은 자성 관 검사시의 절반인 관 외경의 1.5배 정도가 되어야 함을 보였다. 이렇게 설계된 탐촉자를 사용하여 예측한 결함신호들은 이 검사방법이 내부 및 외부결함에 동일하게 민감하며, 위상신호의 세기와 결함깊이간에는 선형적인 비례관계가 존재함을 보여 주었다. 이러한 결과들은 비자성 증기발생기 전열관이라 할지라도 원격장와전류 탐상이 가능함을 말해 주고 있다.

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Analysis and reduction of thermal magnetic noise in liquid-He dewar for sensitive low-field nuclear magnetic resonance measurements

  • Hwang, S.M.;Yu, K.K.;Lee, Y.H.;Kang, C.S.;Kim, K.;Lee, S.J.
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권2호
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    • pp.20-23
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    • 2013
  • For sensitive measurements of micro-Tesla nuclear magnetic resonance (${\mu}T$-NMR) signal, a low-noise superconducting quantum interference device (SQUID) system is needed. We have fabricated a liquid He dewar for an SQUID having a large diameter for the pickup coil. The initial test of the SQUID system showed much higher low-frequency magnetic noise caused by the thermal magnetic noise of the aluminum plates used for the vapor-cooled thermal shield material. The frequency dependence of the noise spectrum showed that the noise increases with the decrease of frequency. This behavior could be explained from a two-layer model; one generating the thermal noise and the other one shielding the thermal noise by eddy-current shielding. And the eddy-current shielding effect is strongly dependent on the frequency through the skin-depth. To minimize the loop size for the fluctuating thermal noise current, we changed the thermal shield material into insulated thin Cu mesh. The magnetic noise of the SQUID system became flat down to 0.1 Hz with a white noise of 0.3 $fT/{\surd}Hz$, including the other noise contributions such as SQUID electronics and magnetically shielded room, etc, which is acceptable for low-noise ${\mu}T$-NMR experiments.

맥진 가압 프로파일 측정 시스템 개발 (Development of Pulse Diagnosis Hold-down Pressure Measurement System)

  • 이전;이유정;전영주;유현희;우영재;김종열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.1997-1998
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    • 2008
  • Pulse diagnosis is the one of the most important diagnostic process to traditional medical doctors. Although the pulse diagnosis position, Gwan is apart from Chon or Cheok by 10$\sim$20mm at most, traditional medical doctors applies different indent pressures and even they states different pulse images are felt at Chon, Gwan and Cheok. One the other hand, the education on pulse diagnosis behavior includes tantalizing problem caused by no tool for communication between trainer and trainee. On account of this situation, we tried to develop a system which can measure the hold-down pressure during a pulse diagnosis and compare the hold-down pressure profile of trainer and that of trainee. This system can be divided into three parts - pulse pressure sensing part, signal acquisition part and data storing part. A correction curve was generated by the relation between output voltages and standard weights. Using this system, 3 channel hold-down pressure profile of a oriental medical doctor were recorded three times. In the profile, three period were observed and all period included two process for searching the depth of pulsation and for classifying the pulse feeling into one or more of 28 pulse types. The maximum value of pulse profile was 1.3$kg{\cdot}f$ which was more than reported by previous chinese groups and the mean values of three channel ranged from 240$g{\cdot}f$ to 430$g{\cdot}f$. In frequency domain, each channel has some dominant frequency components - about 10Hz, 35Hz and 75Hz. In further study, we want to collect more profiles from lage number of oriental medicine doctors and hope to develop a measuring system which can measure the hold-down pressure on subject's skin directly.

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한국미용학회지 수록 논문의 연구동향 분석 (The Analysis of Study Trend on Journal of the Korean Society of Cosmetology)

  • 백경진;김미영
    • 한국의상디자인학회지
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    • 제11권1호
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    • pp.17-27
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    • 2009
  • The purpose of this study was to analyze the related to cosmetic studies and to offer the study directions. A journal selected for this study is The Korean Society of Cosmetology only registered on Korea Research Foundation. A total of 493 articles in journal of The Korean Society of Cosmetology were reviewed and analyzed carefully. The results of review and analysis were as follow: The articles of the Korean Society of Cosmetology were classified into varies sections by main subjects, which are Basic Science, Make-up, Hair, Skin, Cosmetic & Hair Product, Beauty History, Beauty Education, Fashion. From the groups of main subjects, it was then classified into secondary subjects. In the result of examined frequencies in main subject of the articles showed highest of 89 in basic science, 84 journals in Beauty Marketing related, 73 in Hair. And from the classified secondary subjects, highest frequencies showed in the study based on second in study based on Cosmetic of 46 and Aesthetician of 41 journals. The research trend in the field of cosmetics showed the quantitative increase of article publication in journals. However, the contents lacked in depth compared to subdivided fields and the target or the method of conduct researches were in disproportion. Therefore, clearness is necessary in definitions of the field of cosmetic study and the standard of division in each fields.

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개에서 경혈의 조직학적 관찰 (Histological Observation of Canine Acupoints)

  • 김명철;남치주;김무강;김종만;김덕환;이경렬;송치원;박창식
    • 한국임상수의학회지
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    • 제23권2호
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    • pp.102-104
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    • 2006
  • 본 연구의 목적은 개의 경혈에 관한 조직학적 소견을 관찰하는 것이다. 개(4마리)에서 내관(PC06), 간유(BL18), 신유(BL23) 및 방광유(BL28)에 1 cm 깊이로 자침을 실시하고, 경혈주위의 조직을 관찰하였다. 각 경혈의 주위조직을 현미경학적으로 관찰하였다. 신경섬유, 소혈관, 및 근방추체들은 인근 지점에서의 비경혈, 또는 피부, 피하조직 및 근육과 같은 부위에서의 비경혈에서도 가끔 발견 되지만, 모든 예의 침의 선단 주위에서 신경섬유, 소혈관, 및 근방추체가 발견되었다. 따라서, 신경섬유, 소혈관 및 근 방추체는 잠재성 경혈 수용체일수도 있다는 가능성이 제시된다.

내재적 혁신성과 상품 관심이 특정 상품에 대한 소비자 혁신성에 미치는 영향 (Effects of Innate Innovativeness and Product Interest on Product-Specific Consumer Innovativeness)

  • 정인희;조윤진
    • Human Ecology Research
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    • 제56권2호
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    • pp.167-174
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    • 2018
  • This study investigated consumer innovativeness by examining a relationship model of innate innovativeness, product interest, product-specific innovativenss, and actualized innovativeness for eight product items as well as observed gender differences in the variables. The eight product items for the survey were smartphones, movies, clothing, cars, skin care products/cosmetics, traveling, AI products, and books. An online survey was conducted in January 2018, and 400 responses from male and female consumers in their twenties and thirties, were analyzed using reliability test, descriptive statistics, regression, and ANCOVA. The positive effect of innate innovativeness and product interest on product-specific innovativeness, and positive effect of innate innovativeness and product-specific innovativeness on actualized innovativeness were confirmed. Product interest was found to have a stronger power on product-specific innovativeness than innate innovativeness. Gender differences in product interest, product-specific innovativeness, and actualized innovativeness were identified as hypothesized. Female consumer's clothing interest, clothing innovativenss, and actualized clothing innovativeness were higher than male consumers; in addition, male consumer's cars and AI interest, cars and AI innovativenss, and actualized cars and AI innovativeness were higher than female's. The controversial results that indicated the higher innate innovativeness of male consumers useful to further in-depth discussion and research. This study contributed to the theory construction of consumer innovativeness research areas and offered practical implications for new product launching and customer relationship management.