• Title/Summary/Keyword: Scan Method

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Digital Scan Converter Algorithm for Ultrsound Sector Scanner (초음파 섹터 스캐너를 위한 디지털 스캔 변환 기법)

  • 김근호;오정환
    • Journal of Biomedical Engineering Research
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    • v.17 no.4
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    • pp.469-478
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    • 1996
  • In the conventional digital ultrasound scanner, the reflected signal is sampled either in polar coordinates of R-$\theta$ method, or in Cartesian coordinates of uniform ladder algorithm (ULA). The R-$\theta$ scan method necessitates a coordinate transform process which makes hardware complex in comparison with ULA scan mrthoA In spite of this complexity, R-$\theta$ method has a good resolution in ultrasonographic (US) image, since scan direction of the US imaging is a radial direction. In this paper, a new digital scan converter is proposed, which is named the radius uniform ladder algorithm (RULA). The RULA has the rome scan direction as the US scanning in the radial direction and as the display space in the $\theta$ direction. In tllis new approach, sampled points we uniformly distributed in each horizontal line i.n well as in each radial ray so that the data are displayed in the Cartesian coordinates by the 1-D interpolation process. The propped algorithm has an uniform resolution in the periphery and the center field in comparison with equi-angle ULA and equi-interval ULA. To extend the scan angle, concentric square raster sampling (CSRS) is adopted with reduction of discontinuities on the junctions between horizontal scan and vertical scan. The discontinuities are reduced by using the hmction filtering along the $\theta$ direction.

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Effective Detecting Method of Nmap Idle Scan

  • Hwang, Jungsik;Kim, Minsoo
    • Journal of Advanced Information Technology and Convergence
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    • v.9 no.1
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    • pp.1-10
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    • 2019
  • In recent years, information collection of attacks through stealth port scanning technology has become more sophisticated. The most commonly used Nmap port scanner supports a variety of stealth scanning technologies along with the existing scanning techniques. Nmap also supports Idle scan that is different from conventional stealth scans. This is a more sophisticated stealth scan technique by applying the SYN scan and ACK scan techniques. In previous studies, the detection of Idle scanning was on zombie system, but was not on victim system. In this paper, we propose an effective detection method of Idle scan on victim system. The Idle scanning is composed of two stages; they are probing the zombie and victim system and scanning the victim system. We analyzed the characteristics of the two stages. The characteristics, we captured, are that SYN and RST packets are different from normal packet. We applied them to detection method, then Idle scanning is detected effectively.

New Driving Method for Fast Addressing of AC-Plasma Display Panel

  • Kim, Gun-Su;Choi, Hoon-Young;Lee, Seok-Hyun;Seo, Jeong-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.726-729
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    • 2003
  • A new driving method is proposed to reduce the address period. The scan time of new driving method overlaps with the next scan time during the discharge lag time. Thus, without reducing the address pulse width and the scan pulse width, the new addressing method can reduce the address period. The results show that the scan time of about 100ns ${\sim}$ 300ns can be overlapped without the misfiring,.

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Obstacle Avoidance of Mobile Robot using Scan Code Method (스캔코드법을 이용한 이동로봇의 장애물 회피)

  • Cho, Gyu-Sang
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2856-2858
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    • 2000
  • This paper proposes a scan code method for obstacle avoidance of mobile robot. Obstacles detected in a circular window are converted to scan codes and then to the steering angle. The safe rotating radius is obtained by the scan code to avoid the collision between robot and obstacle and. the minimum distance for rotation is calculated. Effectiveness of the method is illustrated through simulations, and the results show that the proposed method can be efficiently implemented to an unknown environment.

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Estimation of scan parameters for identification of the circular scanning radars (원형스캔 레이더 식별을 위한 스캔변수 추정기법)

  • Ryoo, Young-Jin;Ha, Hyoun-Joo;Kim, Whan-Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.6 s.312
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    • pp.105-112
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    • 2006
  • To improve the performance of identification for radars in an ES(Electronic warfare Support) system, it is necessary to estimate scan characteristics as well as the basic identification parameters such as frequency, pulse repetition interval and pulse width of radars. This paper presents the method of estimating the scan period and the scan beam width of circular scanning radars. The proposed method estimates the scan period using the quality of the autocorrelation of a periodic signal. And, it estimates the scan beam width using the linear interpolation and the proposed method of estimating the scan period. Simulation results are presented to show the performance of the proposed method.

The Method of Improvement by Illuminance Measurement of the CT Scan Room in a General Hospital Radiology (종합병원 영상의학과 CT 검사실의 조도 측정에 의한 향상 방안)

  • Kweon, Dae-Cheol;Yang, Sung-Hwan;Kang, Young-Sig
    • Journal of the Korean Institute of Plant Engineering
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    • v.23 no.4
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    • pp.51-56
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    • 2018
  • Computed tomography (CT) scan room in the department of radiology is very necessary to maintain pleasant and proper illuminance to relieve fatigue and inconvenience because it affects the work environment to the radiologist. Accordingly, this paper describes the method for measurement of illuminance that exposed to an environmental elements in a CT scan room of the hospital. Therefore, the purpose of this paper is to propose an optimal environment of CT scan room based on the measurement of illuminance. In addition, the 5 point method by KS C7612 was applied to measure the illuminance with illuminometer (Unfors xi light probe) in the CT scan room. In result of this paper, minimum value and maximum value of illuminance in the CT scan room was measured 212.7 lux and 354.8 lux, respectively. The illuminance of CT scan room was lower than KS A 3011. Finally, the work environment in CT scan room should provide higher illuminance for the comfortable environment of radiologists and patients.

Usefulness of Scan Position Change on Dual Time Point PET-CT in Pancreas Cancer (췌장암 Dual Time Point PET/CT 검사에서 Scan Position Change의 유용성 평가)

  • Chang, Boseok;Kim, Jae Ho
    • Journal of the Korean Society of Radiology
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    • v.10 no.5
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    • pp.299-305
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    • 2016
  • Despite of the development of medical equipments and technology. Pancreatic cancer has maked high false positive rate and low survival rate compared to other cancers. Therefore, early catch of pancreatic cancer is the only way to enhance the viability. It is important to find the exact location of the pancreas cancer in early stage. The method of optimum scan for early detection of pancreatic cancer on PET/CT exam is proposed. Examined the anatomical region that potentially can be missing from the supine position of ordinary pet/ct exam. The characteristics and usefulness of angle variation ($0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $90^{\circ}$) of patients scan position is analyzed. The proposed scan method (named JJ-projection) is bringing advantage of anatomical discrimination by separating stomach, liver, gallbladder duodenum and pancreas. ROC curve analysis is shows to advantage of the JJ-Projection method. The sensitivity has increased 4.6% than the supine delay scan method, the results sensitivity has increased from 91% to 95.2%. The specificity has increased from 75.1% to 84%. Compared with the results observed in cancer by biological biopsy, The accuracy has increased from 86.8% to 94.1%.

New Breast Measurement Technique and Bra Sizing System Based on 3D Body Scan Data

  • Oh, Seolyoung;Chun, Jongsuk
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.4
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    • pp.299-311
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    • 2014
  • Objective: The aim of this study was to develop a method for measuring breast size from three-dimensional (3D) body scan image data. Background: Previous bra studies established reference points by directly contacting the subject's naked skin to determine the boundary of the breast. But some subjects were uncomfortable with these types of measurements. This study examined noncontact methods of extracting breast reference points from 3D body scan data that were collected while subjects were wearing standardized soft bras. Method: 3D body scan data of 32 Korean women were analyzed. The subjects were selected from the Size Korea 2010 study. The breast landmarks were identified by graphic analyses of slicing contour lines on 3D body scan data. Results: Three methods determining bra cup size were compared. The M1 and M2 methods determined cup size by calculating the difference between bust girth and under-bust girth. The M3 method determined bra cup size by measuring breast arc length. Conclusion: The researchers proposed an anthropometric bra cup sizing system with the breast arc length (M3 method). It was measured from the geometrically defined landmarks on the 3D body scan slicing contour lines. The new bra cup size was highly correlated with breast depth. Application: The noncontact measuring method used in this study can be applied to the ergonomic studies measuring sensitive body parts.

Physical-Aware Approaches for Speeding Up Scan Shift Operations in SoCs

  • Lee, Taehee;Chang, Ik Joon;Lee, Chilgee;Yang, Joon-Sung
    • ETRI Journal
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    • v.38 no.3
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    • pp.479-486
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    • 2016
  • System-on-chip (SoC) designs have a number of flip-flops; the more flip-flops an SoC has, the longer the associated scan test application time will be. A scan shift operation accounts for a significant portion of a scan test application time. This paper presents physical-aware approaches for speeding up scan shift operations in SoCs. To improve the speed of a scan shift operation, we propose a layout-aware flip-flop insertion and scan shift operation-aware physical implementation procedure. The proposed combined method of insertion and procedure effectively improves the speed of a scan shift operation. Static timing analyses of state-of-the-art SoC designs show that the proposed approaches help increase the speeds of scan shift operations by up to 4.1 times that reached under a conventional method. The faster scan shift operation speeds help to shorten scan test application times, thus reducing test costs.

A Method for Quantifying the Risk of Network Port Scan (네트워크 포트스캔의 위험에 대한 정량화 방법)

  • Park, Seongchul;Kim, Juntae
    • Journal of the Korea Society for Simulation
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    • v.21 no.4
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    • pp.91-102
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    • 2012
  • Network port scan attack is the method for finding ports opening in a local network. Most existing IDSs(intrusion detection system) record the number of packets sent to a system per unit time. If port scan count from a source IP address is higher than certain threshold, it is regarded as a port scan attack. The degree of risk about source IP address performing network port scan attack depends on attack count recorded by IDS. However, the measurement of risk based on the attack count may reduce port scan detection rates due to the increased false negative for slow port scan. This paper proposes a method of summarizing 4 types of information to differentiate network port scan attack more precisely and comprehensively. To integrate the riskiness, we present a risk index that quantifies the risk of port scan attack by using PCA. The proposed detection method using risk index shows superior performance than Snort for the detection of network port scan.