• 한국방사선학회논문지
• /
• 제10권5호
• /
• pp.299-305
• /
• 2016

의료장비와 기술의 발달에도 불구하고 췌장암만 유일하게 기타 암질환과 비교하면 오진률이 높고 생존률이 낮은 질환이다. 따라서 췌장암은 조기 발견만이 생존율을 높일 수 있는 유일한 방법이며 췌장암의 정확한 위치를 찾는 것이 중요하다. Dual Point PET/CT 검사를 이용해서 췌장암의 조기 발견을 위한 최적의 Scan method를 제안하였다. PET/CT 검사의 Supine position에서 놓칠 수 있는 해부학적 영역을 환자의 position을 $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$ $75^{\circ}$ 변화에 따른 영상의 특징 및 유효성을 분석하였다. 그 결과 $90^{\circ}$ lateral recumbent position Scan에서 Pancreas tail 판별의 유용성을 발견하였다. Dual Point PET/CT 검사에서 상복부 특히 해부학적 구조상 췌장처럼 인접 장기와 중첩이 있는 경우, 췌장암이 의심될 때 PET/CT 지연검사에서 환자에게 충분한 수분섭취를 한 후 환자의 Position을 테이블과 수직 상태로 돌려 Lt 또는 Rt lateral Recumbent position 상태에서 PET/CT Scan을 시행하므로 위장, 간, 담낭 십이지장, 췌장 등의 장기를 이격시켜 해부학적 판별에 이점을 주는 검사방법 (JJ-Projection: lateral recumbent position scan)을 개발하였다. ROC curve 분석에서 JJ-Projection방법이 기존의 Supine scan 방식에서 얻은 영상보다 민감도가 95.2% 나타났다. 이것은 기존의 검사방식과 비교해볼 때 4.6 % 증가 하였다. 특이도는 87.5%로 6.9% 증가하였다. 조직검사로 생물학적 암으로 확정된 결과치와 비교해 볼 때 정확도는 94.1%로 기존 방식 86%에 비해 8.41 % 증가하였다. 그러므로 Dual Time Point PET/CT를 이용한 췌장암 판별 검사를 할 때 Delay scan에서 lateral recumbent position로 변경해서 Scan 하는 것이 기존의 일반적인 방법인 Supine position Scan보다 췌장암 조기 판별에 유용한 정보를 줄 수 있을 것으로 사료된다.

• Journal of Electrical Engineering and information Science
• /
• 제2권3호
• /
• pp.7-13
• /
• 1997

To overcome the large hardware overhead attendant in the full scan design, the concept of partial scan design has emerged with the virtue of less area and testability close to full scan. Combinational Structure has been developed to avoid the use of sequential test generator. But the patterns sifted on scan register have to be held for sequential depth period upon the aid of the dedicated HOLD circuit. In this paper, a new levelized structure is introduced aiming to exclude the need of extra HOLD circuit. The time to stimulate each scan latch is uniquely determined on this structure, hence each test pattern can e applied by scan shifting and then pulsing a system clock like the full scan but with much les scan flip-flops. Experimental results show that some sequential circuits are levelized by just scanning self-loop flip-flops.

• 한국BIM학회 논문집
• /
• 제9권2호
• /
• pp.21-28
• /
• 2019

Recently, many scan projects are gradually increasing for maintenance, construction. The scan data contains useful data, which can be generated in the target application from the facility, space. However, modeling the scan data required for the application requires a lot of cost. In example, the converting 3D point cloud obtained from scan data into 3D object is a time-consuming task, and the modeling task is still very manual. This research proposes Scan-to-Geometry Mapping Rule Definition (S2G-MD) which maps point cloud data to geometry for irregular building plane objects. The S2G-MD considers user use case variability. The method to define rules for mapping scan to geometry is proposed. This research supports the reverse engineering semi-automatic process for the building planar geometry from the user perspective.

• 한국BIM학회 논문집
• /
• 제12권3호
• /
• pp.39-51
• /
• 2022

3D scan technology can utilize real spatial information as it is in virtual space, so it can be usefully used in various fields such as reverse engineering of buildings and process management. Recently, with the development of ICT technology, more precise scan data can be obtained, and scan processing time has also been greatly reduced. In addition, the combination of software and scanning equipment used in 3D scanning technology is very diverse, and results are very different depending on which technology is used. Accordingly, there is a problem that it is difficult for a user who has no experience in 3D scanning technology to determine which technology and equipment should be used to obtain good results. In this study, 3D scan technologies mainly used at home and abroad are investigated, classified, and tested at actual construction sites to suggest considerations and suitable 3D scan methods when using 3D scans in construction sites. The test results were analyzed to evaluate the time it takes to scan, the final quality, and the user's convenience according to each technology method.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.728-731
• /
• 2009

A negative waveform having inverted polarity of conventional waveform during reset and sustain periods was proposed to improve the driving characteristics. In order to control the negative wall-charge distribution, a positive bias on the scan electrode was applied during reset period. Compared to 0 V scan-bias condition, at 8 V scan-bias the formative time lag was improved about 23.95 % and the average time lag was improved about 14.91 %. All experiments were performed with the 42-inch PDP module in XGA resolution.

• Korean Journal of Radiology
• /
• 제1권3호
• /
• pp.142-151
• /
• 2000

Objective: To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Materials and Methods: Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Results: Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. Conclusion: The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method.

• 정보처리학회논문지C
• /
• 제9C권3호
• /
• pp.359-366
• /
• 2002

인터넷의 발전과 더불어 해킹기법 또한 함께 발전하고 있다. 최근의 검색공격 형태는 한 기관의 네트워크를 대상으로 하기보다는 상위 도메인을 대상으로 대규모적인 공격 형태를 지니고 있다. 실질적으로 대응하기 위해서는 중앙시스템에서 취약점 검색공격을 탐지, 분석하고 조치할 수 있는 시스템이 있어야 한다. 침입시도탐지 관리시스템은 현재 국내 주요기관들에 설치된 다수의 침입시도탐지 시스템들로부터 받은 여러 탐지 정보를 실시간으로 수집 분석하여 효과적으로 이용하는데 유용하다. 대규모 네트워크의 환경에 적절한 구조를 갖으며 보다 고수준의 통합된 분석을 할 수 있는 실시간 침입시도탐지 관리시스템을 개발하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.256-259
• /
• 2003

This paper proposes OPTICAL MARKER fer registering process - one of the 3D measurement process : scan registering - merging - measurement. If the registering work is carried out manually, it can be accompanied with much time and many errors. Because the patterned marker make registering process automatic, many firms use it now. But the physical shape of existing markers is the source of the data loss caused by hiding surface, and the marker arrangement is the source of the time loss. The optical marker proposed in this paper has marker generator, organized a large number of binary coded control laser diode, separate from 3D scan object. So, it does not take much time for the marker disposition, and it is not the origin of the data loss, and the binary coded laser information make the auto-registering possible.

• 대한방사선기술학회지:방사선기술과학
• /
• 제17권1호
• /
• pp.77-86
• /
• 1994

The bone scan reflects the metabolic reaction of bone to a disease process, whether neoplastic, traumatic or inflammatory. In normal bone tissue, the labeled diphosphate complexes accumulate in the perivascular fluid next to the marrow cavity at the interface between uncalcified and calcified bone matrix. HMDP has the most rapid plasma clearance among the commonly used diphosphonate followed by MDP and then HEDP. I have studied about bone scan time by use of $^{99m}Tc-MDP$, and got 336 images from 112 patients. The result obtained as follow; 1. Accumulation rate of $^{99m}Tc-MDP$ is higher than other age groups in below 30-year old group. 2. Accumulation rate, in 10year old group, is 75.85% on 120min. but other groups are most high on 180 min. 3. The density differants between bone and soft tissue increased with time. 4. Image contrast is good in younger group than old.

• 대한원격탐사학회지
• /
• 제38권3호
• /
• pp.251-263
• /
• 2022

이 논문은 ScanSAR 영상화에 대한 새로운 아이디어를 소개한다. 버스트(Burst) 모드로 신호를 획득하는 ScanSAR의 전통적인 영상화는 버스트 간 영상을 연결하는 Azimuth stitching이 필요하여, 이 과정은 방사왜곡 및 위상왜곡을 유발한다. 전통적인 SPECAN 방법 대신 이 논문에서는 시간영역 교차상관을 이용하여 Azimuth stitching 과정 없이 영상화가 가능한 새로운 방법을 소개한다. 이 방법의 핵심 아이디어는 기준함수 밴드폭을 적절히 확장하여 시간영역 교차상관을 수행하면 Azimuth stitching 없이도 영상화가 가능하다는 점이다. 이 방법을 실제 위성 원시신호에 적용하여 영상 전 구간에서 영상품질과 방사왜곡 관점에서 우수한 성능을 검증하였다. 버스트 모드를 기반으로 하는 ScanSAR는 영상품질(3 dB 해상도, peak-to-sidelobe ratio (PSLR), 압축률, Speckle 잡음 등)은 모든 품질지표에서 도플러 주파수 전 영역 신호를 이용하는 Stripmap에 비해 낮을 수밖에 없다. 그러나, 각 활용분야 및 기술에 따라 선정된 특정 영상 품질지표 만을 개선할 수 있는 방법은 다양하다. 따라서 ScanSAR 영상화는 모든 활용분야에 획일적인 방법에 의한 영상화보다는, 각 활용에 따라 요구되는 품질지표 우선순위에 따라 최적화할 수 있는 영상화 방법을 적용하는 차별화 전략이 요구된다.