http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 최상현 (검색결과 577 건)
- 무료
- 기관 내 무료
- 유료
-
최상현,김찬형,허현도,김금배,김승훈 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.1
The mcroLion chamber, which has a small volume (0.0017cc) and a high sensitivity suitable for small field dosimetry, is an ionization chamber with liquid (isooctane) filling the cavity volume. In the present work, we used two alternative ways to estimate the beam quality correction factor <i>k<sup>micL</sup> <sub>Q,Q<sub>0</sub></sub></i> of the microLion chamber in the 6 MV photon beam from a Clinac iX accelerator (Varian, USA); Monte Carlo simulations and experimental methods. The Monte Carlo calculation (1.0183 ± 0.58%) agreed to within 0.56% with the experimental determination (1.024 ± 0.58%). The results from the two methods were in good agreement within acceptable uncertainties. We think that the averaged factor, 1.0212, could be used for the microLion chamber in reference dosimetry.
-
MIMO 레이다 환경에서 Polar Format Processing 기반 이동표적 이미징
최상현,양훈기 한국전자파학회 2019 한국전자파학회논문지 Vol.30 No.2
This study presents an imaging algorithm that can provide an image of a moving target in a multiple-input–multiple-output radar environment where multiple transmitting and receiving radars are fixed on the ground. The proposed algorithm, which is based on polar format processing using plane wave approximation, is shown to provide an unaliased image by using multiple transmitting radars even when the distances between the receiving radars are relatively large. We derive the conditions necessary to deploy the transmitting radars by which the resolution of the reconstructed image can be improved, while simultaneously reducing aliasing artifacts. Moreover, we offer a means of separating out each transmitting radar target echo. Finally, the performance of the proposed system is verified through a simulation.
-
철도교량의 구조건전성 모니터링을 위한 모달파라미터 산정 기법 분석
최상현,김민수 한국방재학회 2015 한국방재학회논문집 Vol.15 No.1
Since the railroad bridge is subjected to the heavy and periodic live load, which runs through a fixed path called the track, it is importantto accurately identify dynamic properties. In this paper, the applicability of existing representative modal analysis methods includingPS, FDD, p-LSCF, SSI BR and SSI CVA to a railroad bridge is examined and relative performance is compared. Also, consideringthe characteristics of a railroad bridge which has vibration of relatively high amplitude but short period, a method to obtain more accuratemodal parameter estimates is studied when more than single response measurement set is available. The review is performedusing a numerical model for a steel-concrete composite slab bridge and a commercial finite element analysis program, ABAQUS. 철도교량은 활하중의 비중이 크고 선로라는 정해진 경로를 주행하는 주기성 강한 열차 하중의 재하로 인하여 정확한 동적특성 파악이중요하다. 이 논문에서는 기존에 개발된 가장 대표적인 모달해석 기법인 PS, FDD, p-LSCF, SSI BR 및 SSI CVA의 철도교량에 대한적용성을 검토하고 성능 비교를 통하여 장단점을 분석하였다. 또한 상대적으로 진폭이 크나 지속시간이 짧은 철도교량에 대한 하나 이상의 측정데이터가 존재할 때, 보다 정확한 모달파라미터 산정을 위한 방법에 대한 검토도 수행하였다. 검토는 강재-콘크리트 합성 슬래브교량에 대한 수치해석 모델을 이용하였으며, 해석프로그램은 ABAQUS를 사용하였다.
-
-
아연제련공정 침전물 중 미반응 아연의 자력선별 회수를 위한 니켈 세멘테이션
최상현,Tam Thi Nguyen,유경근 한국자원공학회 2018 한국자원공학회지 Vol.55 No.2
아연제련공정 중 코발트 제거를 위해 세멘테이션을 이용한 정액공정을 실시하는데, 이 과정에서 발생하는 침전물은 코발트뿐만 아니라 안티몬, 구리 그리고 아연을 포함한다. 아연은 코발트의 안정적인 제거를 위해 과량 투입 하기 때문에 침전물 중 미반응 상태로 많이 남게 된다. 그러므로 본 연구에서는 미반응 아연을 회수하기 위한 자력선별 연구를 수행하였다. 이를 위해 아연정광 침출 모사액([Zn]=150 g/L, [Sb]=[Co]=10 mg/L, [Cu]=200 mg/L)에 강자성체 인 니켈 성분을 포함시킨 후 아연 분말을 투입하는 세멘테이션을 실시하여 니켈 성분을 포함하는 침전물을 생성시켰 다. 니켈의 초기 농도가 120 mg/L일 경우 자력선별이 불가능하였지만 초기 농도를 240 mg/L로 증가시키고 pH를 3.3-3.7, 온도를 85°C로 유지하며 30분간 세멘테이션을 실시하고 침전물을 자력선별한 경우, 자착물로 53.4% 니켈, 56.7% 구리, 48.2% 코발트, 57.0% 안티몬과 11.9%의 아연을 회수하고 비자착물로 88.1%의 아연을 농축시킬 수 있었다. A purification process using cementation to remove Co ions in the course of Zn metallurgy process generated precipitate containing Cu, Sb, Zn as well as Co. Because an excess amount of Zn is generally added to the cementation process to guarantee the Co removal, this study used a magnetic separation process to recover unreacted Zn powder. Nickel was added to simulated Zn leach solution ([Zn]=150 g/L, [Co]=[Sb]=10 mg/L, [Cu]=200 mg/L) and the precipitate with Ni component was generated by adding Zn powder to the solution. When the concentration of Ni was 120 mg/L, no magnetic separation of the precipitates was observed. In contrast, after the concentration of Ni increased to 240 mg/L, when the cementation test was performed for 30 minutes at 85°C and pH 3.3-3.7, and then precipitates were separated with a magnet, 53.4% Ni, 56.7% Cu, 48.2% Co, 57.0% Sb, and 11.9% Zn were recovered in the magnetic fraction, whereas 88.1% Zn was concentrated in the non-magnetic fraction.
-
-
-
최상현,박동욱,김금배,김동욱,이재기,신동오,Choi, Sang Hyoun,Park, Dong-wook,Kim, Kum Bae,Kim, Dong Wook,Lee, Jaiki,Shin, Dong Oh 한국의학물리학회 2015 의학물리 Vol.26 No.4
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.
-
-
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
