• Title/Summary/Keyword: high frequency reconstruction

Search Result 98, Processing Time 0.029 seconds

Load-balanced Topology Maintenance with Partial Topology Reconstruction (부분 토폴로지 재구성 기법을 적용한 부하 균형 토폴로지 유지)

  • Hong, Youn-Sik;Lim, Hwa-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.12A
    • /
    • pp.1188-1197
    • /
    • 2010
  • A most important thing in a connected dominating set(CDS)-based routing in a wireless ad-hoc network is to select a minimum number of dominating nodes and then build a backbone network which is made of them. Node failure in a CDS is an event of non-negligible probability. For applications where fault tolerance is critical, a traditional dominating-set based routing may not be a desirable form of clustering. It is necessary to minimize the frequency of reconstruction of a CDS to reduce message overhead due to message flooding. The idea is that by finding alternative nodes within a restricted range and locally reconstructing a CDS to include them, instead of totally reconstructing a new CDS. With the proposed algorithm, the resulting number of dominating nodes after partial reconstruction of CDS is not changed and also its execution time is faster than well-known algorithm of construction of CDS by 20~40%. In the case of high mobility situation, the proposed algorithm gives better results for the performance metrics, packet receive ratio and energy consumption.

Reconstruction of Pharyngolaryngeal Defects with the Ileocolon Free Flap: A Comprehensive Review and How to Optimize Outcomes

  • Escandon, Joseph M.;Santamaria, Eric;Prieto, Peter A.;Duarte-Bateman, Daniela;Ciudad, Pedro;Pencek, Megan;Langstein, Howard N.;Chen, Hung-Chi;Manrique, Oscar J.
    • Archives of Plastic Surgery
    • /
    • v.49 no.3
    • /
    • pp.378-396
    • /
    • 2022
  • Several reconstructive methods have been reported to restore the continuity of the aerodigestive tract following resection of pharyngeal and hypopharyngeal cancers. However, high complication rates have been reported after voice prosthesis insertion. In this setting, the ileocolon free flap (ICFF) offers a tubularized flap for reconstruction of the hypopharynx while providing a natural phonation tube. Herein, we systematically reviewed the current evidence on the use of the ICFF for reconstruction of the aerodigestive tract. A systematic literature search was conducted across PubMed MEDLINE, Web of Science, ScienceDirect, Scopus, and Ovid MEDLINE(R). Data on the technical considerations and surgical and functional outcomes were extracted. Twenty-one studies were included. The mean age and follow-up were 54.65 years and 24.72 months, respectively. An isoperistaltic or antiperistaltic standard ICFF, patch flap, or chimeric seromuscular-ICFF can be used depending on the patients' needs. The seromuscular chimeric flap is useful to augment the closure of the distal anastomotic site. The maximum phonation time, frequency, and sound pressure level (dB) were higher with ileal segments of 7 to 15 cm. The incidence of postoperative leakage ranged from 0 to 13.3%, and the majority was occurring at the coloesophageal junction. The revision rate of the microanastomosis ranged from 0 to 16.6%. The ICFF provides a reliable and versatile alternative for reconstruction of middle-size defects of the aerodigestive tract. Its three-dimensional configuration and functional anatomy encourage early speech and deglutition without a prosthetic valve and minimal donor-site morbidity.

Image reconstruction of rotating objects using X-band CW signal (X-대역 단일 주파수 신호에 의한 회전물체의 영상재현)

  • Suh, Kyoung-Whoan;Shin, Seong-Won;Ra, Jung-Woong
    • Proceedings of the KIEE Conference
    • /
    • 1987.11a
    • /
    • pp.377-382
    • /
    • 1987
  • To obtain a high resolution microwave images, back scattering microwave fields from one, two, four poles on a rotating object is measured. A computation algorithm to reconstruct these poles images from measured data is programed. The program is tested for these poles on a rotating object for different frequency intervals in the X-Band. The more frequency data yield the reduction of side lobe level. The reconstructed image for the two pole objects having the diameter of 1cm and separated by 1 lamda, 2 lamda (lamda-3.75 cm) from the measured data is shown. And, the image of two objects having the different reflectivity coefficient from the measured data is also shown and it assumes that this reconstructing algorithm from the measured angular spectrum provides quite accurate images.

  • PDF

Circumferential Resection and Reconstruction of The Mediastinal Trachea Without Prosthesis for Tracheal Stenosis: A Report of 4 Cases (기관삽입관에 의한 기관협착증 의 외과적 치료: 4례 보고)

  • 박주철
    • Journal of Chest Surgery
    • /
    • v.10 no.1
    • /
    • pp.17-24
    • /
    • 1977
  • The present treatment of respiratory failure, using cuffed endotracheal and tracheostomy tube has produced, apparently with increasing frequency, three lesions which have serious ceminical manifestations such as tracheal stenosis, tracheomalasia, and localized tracheal erosion. Extensive resection and reconstruction of the trachea must be necessary because conservative treatment has generally failed in the fully developed stenotic lesion. of the mediastinal trachea following extensive resection is best accomplished by direct anastomosis of the patient`s own tracheobronchial tissue. Any replacement of the mediastinal trachea must be air tight and laterally rigid, and must heal dependably. A variety of materials has been used for substitution following circumferential excision of tracheal segments within the mediastinum. These attempts have often failed because of early leak or late stenosis. We have successfully performed circumferential resection and primary end-to-end anastomosis of the trachea for 4 cases of post-intubation tracheal stenosis located a few centimeter below the tracheostomy stoma in the period of 3 years between 1974 and 1976. The lesion in one patient was found in the upper trachea which was approached anteriorly through a cervicomediastinal incision with division of the upper sternum. Other three located in the lower half of the trachea were operated through a high transthoracic incision with appropriate hilar mobilization in addition to cervical flexion for the development of the cervical trachea into the mediastinum. There were no hospital death, but suture line granulations occurred in two patients were managed by bronchoscopic removal of granulations without difficulties.

  • PDF

A variable block-size transform coding by high-frequency energy (고주파 에너지에 의한 가변블럭 변환 부호화법)

  • 곽내정;이승희;송영준;안재형
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.5
    • /
    • pp.1089-1095
    • /
    • 1996
  • We propowe a variable block-size transform coding. The size of transform block is adapted by the activity of the block, If the activity is lower than the given threshold, then the block-size is enlarged. In this paper, we use the energy of the transformed cofficients with high frrequency instead of the block variance as the block activity. The computer simulation results show that the reconstruction image by the proposed activeity measure gives superior picture quality to that by the block variance and the mean absolute difference.

  • PDF

Analyzing for the Circumstancial Influence Factor in Building Maintenance Expenses (건축물 유지관리비의 환경적 영향 요인 분석)

  • Yang, Hoe-Ryeong;Shin, Han-Woo;Kim, Tae-Hui
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2013.11a
    • /
    • pp.120-121
    • /
    • 2013
  • Apartment houses maintenance like remodeling in at issue and the importance is getting higher. On this study, we analyzed a variety of the influence factor affected building's maintenance expenses. circumstance influence factor about maintenance expenses is classified into region(big city, small and medium city), (area of high snowfall), (downpour region), (earthquake region), location(waterfront, inland province), using condition(mixed use, single use), frequency of use(kindergarten, middle school, high school), architecture method(reconstruction, construction).

  • PDF

The Development Direction of the Fishehes Highschool based on Fishery Consciousness by Teachers in Kyungbuk Province (경북지역 수산계 고등학교 교사의 수산업 의식 분석에 의한 학교 발전 방안 모색)

  • KIM, Sam-Kon;PARK, Jong-Un;LEE, Sang-Cheol
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.14 no.2
    • /
    • pp.129-148
    • /
    • 2002
  • The purpose of this study was to investigate of fishery consciousness for fisheries high school teachers. The data was collected from 61 fisheries high school teachers in Kyungbuk Province. The treatment of materials are classified by level of academic careers, teaching careers. This research evaluated percentage to the frequency of reponses to each question and carried out $\chi^2$ - test, etc. The statistically significant level accounted for p<.05 and made use of SPSS10.0. The conclusion of the study were as follows: Strategic development of fisheries high school on fishery consciousness need to program with fishery characteristic, to promote maritime affairs had better systematic publicity activities. On educational system policy need to keep consistency of occupational education policy, change of titles of school and reconstruction of department, expand of carrier guidance direction. On high self-conceit of Hsheries high school teachers need to many discussion be based program of school itself and academic society. And director and vice-principle station region of islands, etc.

DCT-based Regularized High-Resolution Image Reconstruction Algorithm (DCT 기반의 정규화 된 고해상도 영상 복원 알고리즘)

  • 박진열;이승현;강문기
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.24 no.8B
    • /
    • pp.1558-1566
    • /
    • 1999
  • While high resolution images are required for various applications, aliased low-resolution images are only available due to the physical limitations of sensors. In this paper, we propose an algorithm to reconstruct a high resolution image from multiple aliased low-resolution images, which is based on the generalized multichannel deconvolution technique. The conventional approaches are based on the discrete Fourier transform (DFT) since the aliasing effect is easily analyzed in the frequency domain. However, the useful solution may not be available in many cases, i.e., the underdetermined cases or the insufficient subpixel information cases. In order to compensate for such ill-posedness, the generalized multichannel regularization was adopted in the spatial domain. Furthermore, the usage of the discrete cosine transform instead of the DFT leads to the computationally efficient reconstruction algorithm. The validity of the proposed algorithm is both theoretically and experimentally demonstrated in this paper. It is also shown that the effect of inaccurate motion information is reduced by regularization.

  • PDF

Audio Quality Enhancement at a Low-bit Rate Perceptual Audio Coding (저비트율로 압축된 오디오의 음질 개선 방법)

  • 서정일;서진수;홍진우;강경옥
    • The Journal of the Acoustical Society of Korea
    • /
    • v.21 no.6
    • /
    • pp.566-575
    • /
    • 2002
  • Low-titrate audio coding enables a number of Internet and mobile multimedia streaming service more efficiently. For the help of next-generation mobile telephone technologies and digital audio/video compression algorithm, we can enjoy the real-time multimedia contents on our mobile devices (cellular phone, PDA notebook, etc). But the limited available bandwidth of mobile communication network prohibits transmitting high-qualify AV contents. In addition, most bandwidth is assigned to transmit video contents. In this paper, we design a novel and simple method for reproducing high frequency components. The spectrum of high frequency components, which are lost by down-sampling, are modeled by the energy rate with low frequency band in Bark scale, and these values are multiplexed with conventional coded bitstream. At the decoder side, the high frequency components are reconstructed by duplicating with low frequency band spectrum at a rate of decoded energy rates. As a result of segmental SNR and MOS test, we convinced that our proposed method enhances the subjective sound quality only 10%∼20% additional bits. In addition, this proposed method can apply all kinds of frequency domain audio compression algorithms, such as MPEG-1/2, AAC, AC-3, and etc.

A Study on the HEVC Video Encoder PMR Block Design (HEVC 비디오 인코더 PMR 블록 설계에 대한 연구)

  • Lee, Sukho;Lee, Jehyun
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.12
    • /
    • pp.141-146
    • /
    • 2016
  • HEVC/H.265 is the latest joint video coding standard proposed by ITU-T SG 16 WP and ISO/IEC JTC 1/SC29/WG 11. In H.265, pictures are divided into a sequence of coding tree units(CTUs), and the CTU further is partitioned into multiple CUs to adapt to various local characteristics. Its coding efficiency is approximately two times high compared to previous standard H.264/AVC. However according to the size of extended CU(coding unit) and transform block, the hardware size of PMR(prediction/mode decision/reconstruction) block within video encoder is about 4 times larger than previous standard. In this study, we propose a new less complex hardware architecture of PMR block which has the most high complexity within encoder without any noticeable PSNR loss. Using this simplified block, we can shrink the overall size the H.265 encoder. For FHD image, it operates at clocking frequency of 300 MHz and frame rate of 60 fps. And also for the test image, the Bjøntegaard Delta (BD) bit rate increase about average 30 % in PMR prediction block, and the total estimated gate count of PMR block is around 1.8 M.