• 제목/요약/키워드: time-of-flight(TOF)

검색결과 406건 처리시간 0.046초

Low-noise fast-response readout circuit to improve coincidence time resolution

  • Jiwoong Jung;Yong Choi;Seunghun Back;Jin Ho Jung;Sangwon Lee;Yeonkyeong Kim
    • Nuclear Engineering and Technology
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    • 제56권4호
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    • pp.1532-1537
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    • 2024
  • Time-of-flight (TOF) PET detectors with fast-rise-time scintillators and fast-single photon time resolution silicon photomultiplier (SiPM) have been developed to improve the coincidence timing resolution (CTR) to sub-100 ps. The CTR can be further improved with an optimal bandwidth and minimized electronic noise in the readout circuit and this helps reduce the distortion of the fast signals generated from the TOF-PET detector. The purpose of this study was to develop an ultra-high frequency and fully-differential (UF-FD) readout circuit that minimizes distortion in the fast signals produced using TOF-PET detectors, and suppresses the impact of the electronic noise generated from the detector and front-end readout circuits. The proposed UF-FD readout circuit is composed of two differential amplifiers (time) and a current feedback operational amplifier (energy). The ultra-high frequency differential (7 GHz) amplifiers can reduce the common ground noise in the fully-differential mode and minimize the distortion in the fast signal. The CTR and energy resolution were measured to evaluate the performance of the UF-FD readout circuit. These results were compared with those obtained from a high-frequency and single ended readout circuit. The experiment results indicated that the UF-FD readout circuit proposed in this study could substantially improve the best achievable CTR of TOF-PET detectors.

Aortic arch를 포함한 Carotid angio 검사 시 Time of flight(TOF)의 유용성 평가 (Usefulness estimating of Time of flight(TOF) during Carotid angio inspection including Aortic arch)

  • 유영준
    • 대한디지털의료영상학회논문지
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    • 제15권1호
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    • pp.1-7
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    • 2013
  • Purpose : The Carotid Angio inspection including Aortic arch applied to wide area is conducted as the Contrast Enhance MR Angiography(CEA) which is using a contrast medium. However it is a burden not only for someone such as infants, pregnant women and patients suffering from kidney failure but continuous use of contrast medium also can be a burden for patients who has been taken follow up inspection since diagnose lesion already. The purpose of this study is to estimate a usefulness of the Time of Flight (TOF) by comparing with CEA. Materials and methods : 10 patients with an average age of 58 (from 45 to 75) who had MRA inspection in our hospital were studied using 3.0 Tesla Aachieva (Philips, Netherland) MRI system and Sense Neuro-Vascular 16 Channels Coil. The same patient was inspected both TOF and CEA simultaneously. The TOF inspection included from Aortic arch to Willis Circle by connecting 3 TOF stacks and so did CEA inspection. The quantitative analysis was conducted through signal to noise ratio(SNR) and contrast to noise ratio(CNR) with soft tissue by setting up an area of interest on CCA bifurcatoin, ICA, ECA, MCA and VA concerning obtained image. In case of qualitative analysis, 3 radiological technologists and 1 radiologist evaluated 4 items (1: Visibility of the blood vessel, 2: Image distortion measure, 3: Overlapping measure with vein, 4: Peripheral blood vessel description measure) into five points scale (1: Very bad, 2: Bad, 3: Normal 4: Good, 5: Very good). Results : Results for the quantitative analysis was obtained by calculating the average of 5 ROIs in case of SNR and CNR separately. Results of SNR, TOF were generally measured higher than CEA (In case of TOF were 166.1, 205.2, 154.39, 172.23, 161.95, and CEA were 92.05, 95.43, 84.76, 73.69, 88.3). But according to the result of CNR, both TOF and CEA were measured similarly as 67.62, 106.71, 55.9, 73.74, 63.46 for TOF and 67.82, 71.19, 60.52, 49.45, 64.07 for CEA. Throughout every results of each ROI, SNR showed statistically meaningful consequence (0.050.05). In case of qualitative analysis the average of each evaluated item was 4.2points and 4.28points in the item1, 2.93points and 4.55points in the item2, 4.6points and 3.13points in the item3, 2.88points and 4.6points in the item4. According to the results TOF was measured higher in the item3 while in the item2 and item4 CEA was higher and in case of the item1, both CEA and TOF were similar. To sum up statistically meaningful results (p<0.05) were shown in the item2, item3 and item4 but not in the item1 (p>0.05). Conclusions : Both TOF and CEA are complementary because each inspection has pros and cons, but when inspect wide area including Aortic arch normally CEA is conducted. But TOF inspection also can be considered as alternative in terms of patients who has difficulty in the contrast medium such as infants, pregnant women and patients suffering from kidney failure and patients during follow up.

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다시점 카메라와 깊이 카메라를 이용한 고화질 깊이 맵 제작 기술 (High-resolution Depth Generation using Multi-view Camera and Time-of-Flight Depth Camera)

  • 강윤석;호요성
    • 대한전자공학회논문지SP
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    • 제48권6호
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    • pp.1-7
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    • 2011
  • 깊이 카메라는 Time-of-Flight (TOF) 기술을 이용하여 장면 내 물체들의 거리 정보를 실시간으로 측정하며, 측정된 값은 깊이 영상으로 출력되어 양안식 혹은 다시점 카메라와 함께 장면의 고화질 깊이 맵을 제작하는 데 사용된다. 그러나 깊이 카메라 자체가 가지는 기술적 한계로 인하여 영상에 잡음과 왜곡이 포함되어 있기 때문에 이를 효과적으로 제거할 수 있는 기술이 요구되며, 처리 된 깊이 카메라 영상은 다양한 방법으로 색상 영상과 융합되어 장면의 깊이 정보를 생성할 수 있다. 본 논문에서는 이와 같이 다시 점 카메라와 깊이 카메라를 함께 사용하여 고화질의 깊이 정보를 획득할 수 있는 혼합형 카메라 방식의 원리와 깊이 영상 처리 및 깊이 생성을 위한 기술 동향을 설명한다.

Preliminary study of time-of-flight measurement for 3D position sensing system based on acoustic signals

  • Kim, Heung-Gi;Park, Youngjin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.79.4-79
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    • 2002
  • Our goal is the development of a system that estimates the location of interested point in a room with accuracy and low cost. Non-contacting position estimating method is widely used in various areas. Among these methods, acoustic signal-based method is the cheapest and provides reasonably accurate estimation as a result of many research efforts. Most of the acoustic-signal-based three-dimensional location estimators such as 3D sonic digitizer are using the ultrasound, and are organized with two procedures; time-of-flight (TOF) estimation and localization estimation. Since the errors in estimating the TOF could be accumulated with that of localization estimate, accuracy of TOF estimate is as...

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Development of a Rapid and Accurate Identification Method for Citrobacter Species Isolated from Pork Products Using a Matrix-Assisted Laser-Desorption Ionization Time-of-Flight Mass Spectrometry (MALDITOF MS)

  • Kwak, Hye-Lim;Han, Sun-Kyung;Park, Sunghoon;Park, Si Hong;Shim, Jae-Yong;Oh, Mihwa;Ricke, Steven C.;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • 제25권9호
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    • pp.1537-1541
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    • 2015
  • Previous detection methods for Citrobacter are considered time consuming and laborious. In this study, we have developed a rapid and accurate detection method for Citrobacter species in pork products, using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). A total of 35 Citrobacter strains were isolated from 30 pork products and identified by both MALDI-TOF MS and 16S rRNA gene sequencing approaches. All isolates were identified to the species level by the MALDI-TOF MS, while 16S rRNA gene sequencing results could not discriminate them clearly. These results confirmed that MALDITOF MS is a more accurate and rapid detection method for the identification of Citrobacter species.

초음파를 이용한 고체추진제 연소속도 측정 불확실도 평가 (Evaluation of Uncertainty in Burning Rate Measurement of Solid Propellant using Ultrasound)

  • 강토;송성진;김학준;고선필;오현택;김인철;유지창;정정용
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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    • pp.199-202
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    • 2008
  • 초음파를 이용한 고체추진제의 연소속도 측정방법은 한 번의 실험으로 넓은 범위의 압력에서 연소 속도를 구할 수 있는 장점이 있다. 하지만, TOF를 이용한 연소속도 측정방법은 압력에 따라 변화하는 초음파의 음속을 이용하여 잔존길이를 구하기 때문에 압력, 비행시간(TOF:Time of Flight), 고체추진제 초기길이에 따른 불확실도에 대한 평가를 하여 신뢰성을 얻어야 한다. 본 연구에서는 초음파를 이용하여 고체추진제의 연소속도를 측정할 때 발생하는 불확실도을 평가하여 고체추진제의 연소속도의 신뢰성을 확보하였다.

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고해상도 색상 영상을 이용한 저해상도 깊이 영상 보간법 (Low Resolution Depth Interpolation using High Resolution Color Image)

  • 이교윤;호요성
    • 스마트미디어저널
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    • 제2권4호
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    • pp.60-65
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    • 2013
  • 본 논문에서는 Time-of-Flight (TOF) 원리를 이용하여 획득한 저해상도 깊이 영상을 고해상도의 색상 영상에 정합하는 방법을 소개한다. 거리 정보 기반의 3차원 렌더링에서 깊이 영상은 렌더링 결과에 큰 영향을 끼치지만, 기존의 스테레오 정합은 색상 영상의 특성에 따라 성능이 크게 변하고, 깊이 정보를 획득하지 못하는 영역이 존재한다. 반면에 TOF 카메라는 적외선 센서를 통해 카메라로부터 물체까지의 거리를 직접 측정하여 영상으로 출력하기 때문에, 장면의 깊이 정보를 실시간으로 획득 할 수 있고 높은 정확도를 가지는 장점이 있다. 하지만 출력 영상의 해상도가 너무 작아 3차원 응용에 직접 이용하기가 어렵다. 또한, 색상 영상과 다른 카메라를 이용하기 때문에 두 영상의 3차원적 위치와 특성이 서로 다르다는 문제점을 갖는다. 따라서 해상도를 증가시키고 다른 두 카메라로 부터 찍힌 영상을 정합시키는 방법이 필요하다. 본 논문에서 제안하는 방법은 깊이 카메라에서 획득한 저해상도 깊이 정보를 고해상도 색상 정보를 이용하여 두 영상간의 정합이 이루어지도록 한다. 향상된 깊이 영상을 사용하여 3차원으로 복원한 실험을 통해, 제안하는 방법이 효과적으로 장면의 변위 정보를 생성함을 알 수 있다.

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돼지유래 Salmonella속 균의 동정을 위한 MALDI TOF MS 활용 (MALDI TOF MS for the identification of Salmonella spp. from swine)

  • 손준형;전우진;이영미;김선수
    • 한국동물위생학회지
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    • 제39권4호
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    • pp.247-251
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    • 2016
  • Salmonella is one of the most common bacteria that causes heavy losses in swine industry and major causative pathogen of food poisoning in public health. Various methods for the identification of Salmonella such as Gram staining, agglutination test, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) have been used. Several studies have demonstrated that Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI TOF) Mass Spectrometry (MS) identification is an efficient and inexpensive method for the rapid and routine identification of isolated bacteria. In this study, MALDI TOF MS could provide rapid, accurate identification of Salmonella spp. from swine compared with end point PCR and real time PCR.