• Title/Summary/Keyword: ISAR

Search Result 75, Processing Time 0.028 seconds

Mechanical irritation by protruding bone: A possible cause of breast implant rupture

  • Aitzetmuller, Matthias Michael;Haslhofer, David Johannes;Wenny, Raphael;Schmidt, Manfred;Duscher, Dominik;Huemer, Georg Michael
    • Archives of Plastic Surgery
    • /
    • v.45 no.5
    • /
    • pp.470-473
    • /
    • 2018
  • Although breast implants have been in clinical use for almost 6 decades and have undergone considerable development during this time, implant rupture is still a dreaded long-term complication. Some obvious external factors, such as trauma, can lead to implant rupture, but many studies have reported a high rate of "spontaneous" implant rupture. Herein, we present two cases with the aim of raising awareness of a new possible cause of "spontaneous" implant rupture: mechanical irritation by bony protrusions.

A Study on the Recent Analysis Method for the RCS Reduction for Naval Ships (함정 RCS 저감 설계를 위한 최신 분석기법 연구)

  • Ahn, Byung-Jun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.25 no.3
    • /
    • pp.333-338
    • /
    • 2014
  • In this paper, we researched the recent analysis method of RCS prediction for the naval ship and compared the new method with conventional one in respect of the effectiveness to improve a naval ship with low RCS. This paper included the process of analyzing RCS characteristics for naval ship using the numerical method and finding the hotspot by hourglass plot, ISAR image and etc.. Also we introduced the various design methods in order to reduce RCS.

The lateral intercostal artery perforator as an alternative donor vessel for free vascularized lymph node transplantation

  • Kwak, Min-Seok Daniel;Machens, Hans-Guenther
    • Archives of Plastic Surgery
    • /
    • v.45 no.3
    • /
    • pp.275-279
    • /
    • 2018
  • Chronic lymphedema is caused by an impairment of the lymphatic system due to primary or secondary causes. Vascularized lymph node transplantation (VLNT) is currently the most promising and frequently used technique besides lymphaticovenous anastomosis. However, the vessel anatomy in the lateral thoracic region is sometimes quite variable. Based on our experiences with vascular anatomical inconstancy in the lateral thoracic region, we planned a lateral intercostal artery perforator flap for VLNT in a female patient with chronic stage II lymphedema of both legs after cervical cancer treatment. After surgery, the patient reported significant improvement in limb volume and the accompanying symptoms. The limb circumference was reduced by an average of 19.2% at 6 months postoperatively. Despite having a short pedicle and small vessel caliber, the lateral intercostal artery perforator flap can safely be used for VLNT in lymphedema patients with anatomical variants.

Automation-considered SVO Logic for Verifying Authentication and Key Distribution Protocols (인증 및 키 분배 프로토콜의 논리성 검증을 위한 ASVO 로직)

  • 권태경;임선간;박해룡
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.13 no.5
    • /
    • pp.17-37
    • /
    • 2003
  • This paper presents the ASVO (Automation-considered SVO) Logic that can be used for verifying authentication and key distribution protocols. The ASVO logic was designed for automatic verification, in a way to modify the SVO logic, one of the most famous authentication logics. The ASVO logic is syntactically and semantically sound, and requires relatively simple verification steps. Also we implemented the Isabelle/ASVO system which supports semi-automated verification, by using the Isabelle/Isar system.

A Study on the RCS Analysis and Reduction Method of Unmanned Surface Vehicles (무인수상정의 RCS 해석 및 감소 방법에 대한 연구)

  • Han, Min-Seok;Ryu, Jae-Kwan;Hong, Soon-Kook
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.12 no.4
    • /
    • pp.425-433
    • /
    • 2019
  • In this paper, the RCS analysis of the 10m unmanned surface vehicles was performed, and the factors of RCS increase were analyzed. Modeling techniques by transforming a geometric shape can reduce the RCS area, which can be used to develop stealth unmanned surface vehicles. In order to reduce the RCS, the existing Top Mast part was moved 1m to the tail part, the 5 degree tilt angle was moved below 0.5 m, and additional guided walls were installed to minimize the influence on the center and surrounding corner reflecting structures. As a result of comparing and analyzing the RCS analysis value with the existing model, it can be seen that the reduced countermeasure model is -3.79 dB lower than the existing model for all elevations. In particular, it can be seen that the strong scattering phenomenon is substantially removed in the region except the sacrificial angle region. In addition, it can be seen that in the case of -5m to 2m where the guide wall is added, the reflected signal is improved up to 20 to 40 dB or more, so that it does not appear on the 2D ISAR image. RCS analysis of unmanned surface vehicles explained the process of analyzing and identifying problem location through distance profile analysis and ISAR image analysis.

Generation of ISAR Image for Realistic Target Model Using General Purpose EM Simulators (범용 전자기파 시뮬레이터를 이용한 사실적 표적 모델에 대한 역합성 개구면 레이다 영상 합성)

  • Kim, Seok;Nikitin, Konstantin;Ka, Min-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.26 no.2
    • /
    • pp.189-195
    • /
    • 2015
  • There are many research works on the SAR image generation using EM(Electro Magnetic) simulation. Particularly, there are several dedicated S/Ws for SAR image generation and analysis. But, most of them are not available to the public due to the reason for defense and security. In this paper, we describe the generation of ISAR images for a realistic target model using the general purpose EM simulator like FEKO. This method can benefit us many advantages like building the database of many targets for target recognition with cost-and-time effective way.

A Study on Automatic Target Recognition Using SAR Imagery (SAR 영상을 이용한 자동 표적 식별 기법에 대한 연구)

  • Park, Jong-Il;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.22 no.11
    • /
    • pp.1063-1069
    • /
    • 2011
  • NCTR(Non-Cooperative Target Recognition) and ATR(Automatic Target Recognition) are methodologies to identify military targets using radar, optical, and infrared images. Among them, a strategy to recognize ground targets using synthetic aperature radar(SAR) images is called SAR ATR. In general, SAR ATR consists of three sequential stages: detection, discrimination and classification. In this paper, a modification of the polar mapping classifier(PMC) to identify inverse SAR(ISAR) images has been made in order to apply it to SAR ATR. In addition, a preprocessing scheme can mitigate the effect from the clutter, and information on the shadow is employed to improve the classification accuracy.

RCS Prediction of Complex Targets (복합구조물의 RCS 예측)

  • 석성하;서태일;전상미;박해상;김효태
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.11 no.6
    • /
    • pp.929-938
    • /
    • 2000
  • A summary of the development and verifications of a computer code being developed at Pohang University of Science and Technology (POSTECH) for calculating the radar cross section(RCS) of complex targets is presented. The complex targets are modeled in terms of patches and wedges. This code utilizes physical optics, physical theory of diffraction and shooting and bouncing rays method to calculate the RCS of complex targets. For the verification of the RCS prediction code, a simple-shaped scale-model was manufactured and the RCS was measured at the POSTECH compact range. The obtained RCS was processed to give frequency-domain RCS patterns and ISAR images. The predicted RCS shows good agreement with measured one. The RCS prediction methods presented here are applicable to stealth design and target recognition.

  • PDF

Radar Imaging of Concrete Specimens with Improved Resolution Using Expanded Frequency Bandwidth (주파수 대역 확장을 이용한 콘크리트 시편의 레이더 영상 분해능 향상)

  • 임홍철;이주희
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.6 no.1
    • /
    • pp.13-21
    • /
    • 2002
  • Frequency bandwidth has been combined to determine adequate frequency bandwidth which is necessary for nondestructive testing when using inverse synthetic aperture radar(ISAR). For imaging inside of concrete specimens using radar, the principles of radar and signal processing are discussed. Experimental data obtained from radar measurement of three different concrete specimens at two different frequency bandwidths of 2∼3.4 GHz, 3.4∼5.8 GHz and these two frequencies are combined to obtain improved imagery. A signal processing scheme has been implemented to visualize inside concrete specimens. The influence of frequency bandwidth was analyzed in nondestructive testing by changing frequency bandwidth for concrete specimen.

An Experimental Study on the Semi-Automated Formal Verification of Cryptographic Protocols (암호프로토콜 논리성 자동 검증에 관한 연구)

  • 권태경;양숙현;김승주;임선간
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.13 no.1
    • /
    • pp.115-129
    • /
    • 2003
  • This paper presents a semi-automated formal verification method based on the famous SVO logic, and discusses its experimental results. We discuss several problems on automating the SVO logic and design its derivative, ASVO logic for automation. Also the proposed method is implemented by the Isabelle/Isar system. As a result, we verified the well-known weakness of the NSSK protocol that is vulnerable to the Denning-Sacco attack, using our Isabelle/ASVO system. Finally, we refined the protocol by following the logical consequence of the ASVO verification.