• Title/Summary/Keyword: Pulse-Compression

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MAGNETIC RESONANCE IMAGING APPEARANCE OF EPIDURAL HEMATOMA IN DOG (개의 경막외 혈종의 자기공명영상학적 진단)

  • Choi, Chi-Bong;Kim, Hwi-Yool;Kim, Su-Gwan;Bae, Chun-Sik
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.5
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    • pp.488-491
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    • 2005
  • A 3-year-old female, 5kg, Shih-tzu developed an acute onset of depression, disorientation, hypersalivation, nystagmus after falling down 2 meter height place. In plain skull radiography, there was fracture line in the frontal and parietal bones and next day magnetic resonance imaging examination was performed. Magnetic resonance imaging of the brain was performed with 3.0 Tesla unit. Under general anesthesia, the dog was placed in prone with its head positioned in a birdcage coil. Transverse, sagittal and coronal fast spin echo images of the brain were obtained with the following pulse sequences: T1 weighted images (TR = 560 ms and TE = 18.6 ms) and T2 weighted images (TR = 3500 ms and TE = 80 ms). Magnetic resonance imaging showed epidural hematoma in the left frontal area resulting in compression of the adjacent brain parenchyma. Left lateral ventricle was compressed secondarily and the longitudinal fissure shifted to the right, representing mass effect. The lesion was iso-to slightly hyperintense on T1 weighted image and iso-slightly hypointense signal on T2 weighted image. At necropsy, there was a skull fracture and epidural hematoma in the left frontal area. Magnetic resonance imaging of epidural hematoma is reviewed.

Subvalvular Pulmonic Stenosis with Congestive Heart Failure in a Yorkshire terrier (요크셔테리어종에서의 울혈성 심부전을 동반한 판막하형 폐동맥판 협착증)

  • 박현정;채형규;이승진;이영원;오태호;장광호;박성준
    • Journal of Veterinary Clinics
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    • v.18 no.4
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    • pp.452-454
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    • 2001
  • A two-month-old female Yorkshire terrier was referred to the Veterinary Teaching Hospital, College of Veterinary Medicine, Kyungpook national University. The patient was presented with a history of dyspnea, cough, exercise intolerance and abdominal distension, but she was appetence. In physical examination the puppy was coughed on slight tracheal compression. Rectal temperature, pulse and respiratory rate were normal, and grade 3/6 systolic murmur heard at the left heart base. The murmur was crescendo-decrescendo. Electrocardiography showed sinus arrhythmia, right-ventricular hypertrophy pattern, and right axis deviation. Thoracic radiography revealed cardiomegaly, bulging of the main pulmonary artery, and enlarged left side heart. Abdominal radiography revealed abdkominal distention. Echocardiography showed hypertrophy of right ventricle and turbulence in the pulmonary artery in parasternal oblique view. Subvalvular pulmonic stenosis was diagnosis based upon the clinical signs, physical examination, electrocardiography, radiography and echocardiography. We treated the patient with furosemide, enalapril and $\beta$-blocker. After the clinical signs of cough, abdominal distension and dyspnea were disappeared, she was on just $\beta$-blocker for prevention of occurrence of congestive heart failure. Now she was recovered her health, and she is not on any medication.

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Anaphylactic Shock Care during General Anesthesia -A Case Report- (전신마취 도중 유발된 아나필락시스 -증례보고-)

  • Choi, Byung-Ho;Sul, Sung-Han;Yoo, Jae-Ha
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.6 no.2 s.11
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    • pp.121-126
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    • 2006
  • Generalized anaphylaxis is a most dramatic and acutely life-threatening allergic reaction. Most fatalities from anaphylaxis occur within the first 30 minutes postantigenic exposure. The mechanism of generalized anaphylaxis is the reaction of IgE antibodies to an allergen that causes the release of histamine, bradykinin, and others. These chemical mediators cause the contraction of smooth muscles of the respiratory and intestinal tracts, as well as increased vascular permeability. Four major clinical symptoms are recognized: skin reactions, smooth muscle spasm (gastrointestinal and genitourinary tracts and respiratory smooth muscle), respiratory distress, and cardiovascular collapse. Epinephrine is the drug of choice for the management. Its syrnpathomimetic effects directly counteract most aspects of the attack. Respiration must be immediately supported by the establishment of a patent airway along with artificial ventilation. The circulation should be supported and the existing hypotension overcome by placing the victim in a position to allow gravity to aid venous return and by administering intravenous fluids, vasopressors, and corticosteroids. When an imperceptible pulse is evident, external cardiac compression must also be instituted. This is a case report of anaphylactic shock care during general anesthesia, possibly due to penicillin, pancuronium and others.

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Mechanisms of microparticle propulsion by laser ablation

  • Gojani, A.B.;Menezes, V.;Yoh, J.J.;Takayama, K.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.837-841
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    • 2008
  • Propulsion of gene coated micro-particles is desired for non-intrusive drug delivery inside biological tissue. This has been achieved by the development of a device that uses high power laser pulses. The present paper looks at the mechanisms of micro-particle acceleration. Initially, a high power laser pulse is focused onto the front side of a thin aluminium foil leading to its ablation. The ablation front drives a compression wave inside the foil, thus leading to the formation of a shock wave, which will later reflect from the rear side of the foil, due to acoustic impedance mismatch. The reflected wave will induce an opposite motion of the foil, characterized by a very high speed, of the order of several millimeters per microsecond. Micro-particles, which are deposited on the rear side of the foil, thus get accelerated and ejected as micro-projectiles and are able to penetrate several hundreds of micrometers inside tissue-like material. These processes have been observed experimentally by using high-speed shadowgraphy and considered analytically.

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Acquisition and Verification of Dynamic Compression Properties for SHPB of Woven Type CFRP (Woven Type CFRP의 SHPB에 대한 동적 압축 물성 획득 및 검증)

  • Park, Ki-hwan;Kim, Yeon-bok;Kim, Jeong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.5
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    • pp.363-372
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    • 2020
  • Dynamic compressive material properties at high strain rates is essential for improving the reliability of finite element analysis in dynamic environments, such as high-speed collisions and high-speed forming. In general, the dynamic compressive material properties for high strain rates can be obtained through SHPB equipment. In this study, SHPB equipment was used to acquire the dynamic compressive material properties to cope with the collision analysis of Woven tpye CFRP material, which is being recently applied to unmanned aerial vehicles. It is also used as a pulse shaper to secure a constant strain rate for materials with elastic-brittle properties and to improve the reliability of experimental data. In the case of CFRP material, since the anisotropic material has different mechanical properties for each direction, experiments were carried out by fabricating thickness and in-plane specimens. As a result of the SHPB test, in-plane specimens had difficulty in securing data reproducibility and reliability due to fracture of the specimens before reaching a constant strain rate region, whereas in the thickness specimens, the stress consistency of the specimens was excellent. The data reliability is high and a constant strain rate range can be obtained. Through finite element analysis using LS-dyna, it was confirmed that the data measured from the pressure rod were excessively predicted by the deformation of the specimen and the pressure rod.

A Study on ACFBD-MPC in 8kbps (8kbps에 있어서 ACFBD-MPC에 관한 연구)

  • Lee, See-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.49-53
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    • 2016
  • Recently, the use of signal compression methods to improve the efficiency of wireless networks have increased. In particular, the MPC system was used in the pitch extraction method and the excitation source of voiced and unvoiced to reduce the bit rate. In general, the MPC system using an excitation source of voiced and unvoiced would result in a distortion of the synthesis speech waveform in the case of voiced and unvoiced consonants in a frame. This is caused by normalization of the synthesis speech waveform in the process of restoring the multi-pulses of the representation segment. This paper presents an ACFBD-MPC (Amplitude Compensation Frequency Band Division-Multi Pulse Coding) using amplitude compensation in a multi-pulses each pitch interval and specific frequency to reduce the distortion of the synthesis speech waveform. The experiments were performed with 16 sentences of male and female voices. The voice signal was A/D converted to 10kHz 12bit. In addition, the ACFBD-MPC system was realized and the SNR of the ACFBD-MPC estimated in the coding condition of 8kbps. As a result, the SNR of ACFBD-MPC was 13.6dB for the female voice and 14.2dB for the male voice. The ACFBD-MPC improved the male and female voice by 1 dB and 0.9 dB, respectively, compared to the traditional MPC. This method is expected to be used for cellular telephones and smartphones using the excitation source with a low bit rate.

High Bit-Rates Quantization of the First-Order Markov Process Based on a Codebook-Constrained Sample-Adaptive Product Quantizers (부호책 제한을 가지는 표본 적응 프로덕트 양자기를 이용한 1차 마르코프 과정의 고 전송률 양자화)

  • Kim, Dong-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.1
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    • pp.19-30
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    • 2012
  • For digital data compression, the quantization is the main part of the lossy source coding. In order to improve the performance of quantization, the vector quantizer(VQ) can be employed. The encoding complexity, however, exponentially increases as the vector dimension or bit rate gets large. Much research has been conducted to alleviate such problems of VQ. Especially for high bit rates, a constrained VQ, which is called the sample-adaptive product quantizer(SAPQ), has been proposed for reducing the hugh encoding complexity of regular VQs. SAPQ has very similar structure as to the product VQ(PQ). However, the quantizer performance can be better than the PQ case. Further, the encoding complexity and the memory requirement for the codebooks are lower than the regular full-search VQ case. Among SAPQs, 1-SAPQ has a simple quantizer structure, where each product codebook is symmetric with respect to the diagonal line in the underlying vector space. It is known that 1-SAPQ shows a good performance for i.i.d. sources. In this paper, a study on designing 1-SAPQ for the first-order Markov process. For an efficient design of 1-SAPQ, an algorithm for the initial codebook is proposed, and through the numerical analysis it is shown that 1-SAPQ shows better quantizer distortion than the VQ case, of which encoding complexity is similar to that of 1-SAPQ, and shows distortions, which are close to that of the DPCM(differential pulse coded modulation) scheme with the Lloyd-Max quantizer.

Airborne Pulsed Doppler Radar Development (비행체 탑재 펄스 도플러 레이다 시험모델 개발)

  • Kwag, Young-Kil;Choi, Min-Su;Bae, Jae-Hoon;Jeon, In-Pyung;Yang, Ju-Yoel
    • Journal of Advanced Navigation Technology
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    • v.10 no.2
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    • pp.173-180
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    • 2006
  • An airborne radar is an essential aviation electronic system of the aircraft to perform various missions in all weather environments. This paper presents the design, development, and test results of the multi-mode pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRU units, which include ANTU(Antenna Unit), TRU(Tx Rx Unit), RSDU(Radar Signal & Data Processing Unit) and DISU(Display Unit). The developed technologies include the TACCAR processor, planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, DSP based Doppler FFT filtering, adaptive CFAR, IMU, and tracking capability. The design performance of the developed radar system is verified through various helicopter-borne field tests including MTD (Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.

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Cardiopulmonary Resuscitation Learning Experience, Knowledge, and Performance in Newly Graduated Nurses (일개 병원 신입간호사의 기본심폐소생술 학습경험, 지식 및 수행능력에 관한 연구)

  • Chun, Sun-Hee;Oh, Yun-Hee;Kim, Sung-Soo
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.18 no.2
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    • pp.201-209
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    • 2011
  • Purpose: The purpose of this study was to evaluate the learning experience, knowledge, and performance of cardiopulmonary resuscitation (CPR) in newly graduated nurses, and to identify differences related to learning experience. Methods: The participants were 114 new nurses in the hospital. They were asked to complete a questionnaire, which included CPR learning experience. They were evaluated by a written test and a skill test using a manikin and check list. Results: All participants attended CPR lectures and underwent practice while in university. Only 12.28% of participants were taught by a certified Basic Life Support (BLS) instructor. The mean scores of the written and skill tests were $79.82{\pm}12.69$ and $64.41{\pm}11.71$, respectively. The nurses lacked CPR knowledge related to checking breathing, the frequency of 30 chest compressions, compression rate, and automated external defibrillator use. They also lacked skill in performing CPR related to checking breathing and pulse and giving 2 breaths. CPR performance differed according to learning time (p=.047) and BLS educator (p=.029). Conclusion: The findings of this study reveal that CPR performance by newly graduated nurses is poor and suggest that CPR education by trained instructors, practice-based education, and reeducation programs must be provided to newly graduated nurses in the hospital.

Range Walk Compensated Squint Cross-Range Doppler Processing in Bistatic Radar (바이스태틱 레이더에서 Range Walk이 보상된 Squint Cross-Range 도플러 프로세싱)

  • Youn, Jae-Hyuk;Kim, Kwan-Soo;Yang, Hoon-Gee;Chung, Yong-Seek;Lee, Won-Woo;Bae, Kyung-Bin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1141-1144
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    • 2011
  • Range walk has been a major problem in achieving correct Doppler processing. This frequently occurs when range variation is severe just like in a bistatic radar or in high speed target scenario. This paper presents a range walk compensated range-Doppler processing algorithm applicable to the bistatic radar. In order for the compensation, a range-domain interpolation is applied for range compressed signal so that Doppler processing is performed along the evenly time-spaced range bins that contain target returns. Under a bistatic radar scenario, the proposed algorithm including a range domain pulse compression is mathematically described. Finally, the validity of the algorithm is demonstrated by simulation results showing the superiority of a SCDP(Squint Cross-range Doppler Processing) over an uncompensated Doppler processing.