웨이브릿 변환에 기반한 적응 음향반향제거

류권열,안주원,문광석 釜慶大學校 1999 釜慶大學校 論文集 Vol.4 No.1

In this paper, an adaptive acoustic echo canceller based on the wavelet transform filter banks is proposed. The proposed algorithm improves the performance of AEC with a realtime process. The conjugate quadrature filter by Daubechies D4 wavelet is used for proposed wavelet subband filter banks. Adaptive filter coefficients of each subband are updated using LMS algorithm. Subband output signal vectors of adaptive filter are synthesized by synthesis filter banks. The output of adaptive filter is obtained a widband characteristics. As a result of computer simulation using the practical speech signal, the proposed method reduces noise level about l6dB.

객체 영역 우선 전송을 이용한 점진적 영상 부호화

류권열 위덕대학교 산업기술연구소 2001 산업기술연구소 논문집 Vol.5 No.1

기존의 접진적 영상 부호화 방법에서는 웨이브릿 변환 영상의 모든 계수가 동일한 우선 순위를 가지고, 중요도에 따라 정열된 계수들을 순서대로 부호화하므로 계수값이 큰 정보가 먼저 전송된다. 본 논문에서는 웨이브릿 변환 영상의 고주파 대역에서 객체 영역을 추출하고, 추출된 객체 영역에 포함되는 계수들을 우선적으로 부호화하여 전송하는 방법을 제안한다. 실험 결과, 제안한 방법은 동일한 압축률에서 기존의 방법보다 객체에 대한 정보가 많이 포함되기 때문에 복원 영상의 객체 영역에 대한 화질이 향상되었으며, 시각적으로 원 영상의 빠른 식별을 가능하게 하였다. In conventional progressive image coding method, coefficients with larger value are prior to transmitted, because all coefficients of wavelet transformed image are coded with same priority according to significance sequentially. In this paper, we propose object region prior transmission method that extracts object region on high frequency subband of wavelet transformed image, and coefficients of extracted object region are prior to transmitted after coding. Consequently, proposed method improve image quality of object region, and fast recognition of original image is possible visually, because it include more information of object region then conventional method on same compression rate.

웨이브릿 변환과 객체 인식영역을 이용한 영상검색

유권열 위덕대학교 산업기술연구소 2000 산업기술연구소 논문집 Vol.4 No.1

본 논문에서는 웨이브릿 변환영상에서 객체 인식영역을 추출하는 새로운 필터링 방법과, 추출된 객체 인식영역을 이용하여 특징벡터를 추출하는 객체기반 영상검색 방법을 제안한다. 기존의 방법은 특징벡터를 웨이브릿 변환영상의 부대역 전체에서 추출하기 때문에 불필요한 배경정보가 포함됨으로써 검색효율이 감소하였다. 제안한 방법은 객체영역에서 특징벡터를 추출하므로 더욱 정확한 정보가 추출될 뿐 아니라, 불필요한 배경정보를 제거함으로써 검색효율을 향상시킨다. 또한 특징벡터 수가 감소하여도 안정된 검색효율을 유지한다. 결론적으로, 영상의 특성에 따라 다소 차이는 있으나 2.5%~5.5%의 검색효율이 향상됨을 알 수 있었다. In this paper, we propose a new filtering method that extracts object recognition region of image applied to wavelet transform, and object based image retrieval method that extracts the feature vectors from extracted object recognition region. Conventional method that include unnecessary background information reduce retrieval efficiency, because of extract feature vectors from whole region of subband. On proposed method, it extracts accurate feature vectors and keep certainly retrieval efficiency in case of reduced feature vectors, because of extracts feature vectors from only extracted object region. And it improve retrieval efficiency, because of remove unnecessary background information. Consequently, retrieval efficiency is improved with 2.5%~5.5% values that has difference according to characteristics of image.

파노라믹 열 영상의 소형 표적 탐지 개선 알고리즘

이경환,류권열 위덕대학교 산업기술연구소 2004 산업기술연구소 논문집 Vol.8 No.1

본 논문에서는 파노라믹 적외선 경보 장치에 적합한 신호처리 방법을 제안하였다. 이 방법은 적외선 센서에 의해 스캔한 영역을 유사한 영역으로 나눈 후, 특성에 따라 Plateau값으로 변경하여 히스토그램을 변화시킨다. 제안 방법의 성능 평가는 실제 야외에서 획득된 파노라믹 적외선 영상에 대하여 컴퓨터 모의실험으로 이루어졌으며, 그 결과 위협체를 배경에서 시각적으로 구별됨을 보였다. This paper presents the signal processing of the panoramic thermal warning system that detects the small target such as aircraft and helicopter from afar. We develope the all round looking thermal imaging system which can scan all the way. This system acquires the panoramic images to reconstruct the IR images by revolving head of sensor typed line sensor at high speed. For detectoin, where the object of interest may be small, it is sometimes difficult to specify from object and background by conventional contrast enhancement methods. Therefore we use the adaptive plateau equalization algorithm each region to improve the contrast and make the hardware system which consists of the signal processing board for real-time display. We can verify the proposed method by the computer simulation and the hardware implementation.

오류 정정 스트림을 갖는 멀티스트림 기반 SPIHT 비디오 전송 기법

강경원,류권열 위덕대학교 산업기술연구소 2003 산업기술연구소 논문집 Vol.7 No.1

본 논문에서는 인터넷 환경의 비디오 파일 서비스에서, 클라이언트의 대역폭을 최대한 활용할 수 있는 효율적인 비디오 전송 방법을 제안한다. 제안한 방법은 QoS가 보장되지 않는 비동기적인 패킷망에서 TCP의 성능 향상을 위해 멀티스트림을 이용한 병렬 전송을 적용한다. 그리고 수신 버퍼링 처리에서 손실된 블록은 오류 정정 스트림을 이용하여 복원함으로써 네트워크 지터에 강인한 신뢰성 있는 비디오 전송을 가능하게 한다. In this paper, we propose the effective video transmission method that can be best using the bandwidth of clients on a video file service of the internet environment. The proposed method apply to the parallel transmission using multi-streams for improving of TCP efficiency on asynchronous packet network that, is not guarantee QoS. And it is robust to network jitter, and can do video transmission with reliability, because a lossed block is reconstructed using error correction steam in reception buffering process.

Distribution change of potato tuber moth, Phthorimaea operculella (Zeller), during 30 years in Korea

Min Kwon,Ju-Il Kim,Jong-Soo Ryu,June-Yeol Choi,Jeom-Rae Cho 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.10

The potato tuber moth (PTM, Phthorimaea operculella (Zeller)) is a serious pest of potato (Solanum tuberosum L.) plants in the field in regions with warm temperate to tropical climates, and of tubers stored under ambient temperatures post-harvest. Although PTM can be a minor to serious pest depending on the area and year, this pest is getting more and more serious to potato fields in Korea according to accidental surveys. Son (1979) represented 12.5℃ of average annual temperature as northern limit of distribution where corresponding to Youngdeog, Dalseong, Boseong and Jindo regions. Soon after, Choi and Park (1980) reported that the northern limit of PTM distribution coincided with -8℃ isotherm for average annual minimum temperature of January. In recent years, concerns on PTM occurrence and damage to potato are increasing due to climate change resulted in global warming. We carried out an extensive survey of PTM distribution using sex pheromone traps at 24 sites across the nation in 2009. As a result, we confirmed that the northern limit of PTM distribution climbed to southern Gyeonggi and middle Gangwon regions from Gyeongbuk and Chungbuk regions indicated by Choi and Park (1980). Hereafter, we are trying to investigate why drastic going northward of PTM happened in Korea. Here is one presumption that a sudden rise in average temperature has occurred during 30 years, from 6.34℃ in 1973 to 7.62℃ in 2007, especially around Daegwallyeong area where is a typical highland with 800 m high.

Ferritin Overload Suppresses Male Fertility Via altered Acrosome Reaction

Kwon, Woo-Sung,Rahman, Md Saidur,Kim, Ye-Ji,Ryu, Do-Yeol,Kahtun, Amena,Pang, Myung-Geol The Korean Society of Animal Reproduction 2015 Reproductive & developmental biology Vol.39 No.4

Iron is required for cell viability but is toxic in excess. While the iron-mediated malfunction of testicular cells is well appreciated, the underlying mechanism(s) of this effect and its relationship with fertility are poorly understood. Ferritin is a ubiquitous intracellular protein that controls iron storage, ferroxidase activity, immune response, and stress response in cells. Ferritin light chain protein (FTL) is the light subunit of the Ferritin. Previously, we had identified the FTL in bovine spermatozoa following capacitation. In present study, to investigate the role of Ferritin in sperm function, mice spermatozoa were incubated with multiple doses (1, 10 and $100{\mu}M$) of sodium nitroprusside (SNP), an iron donor. SNP was increased Ferritin levels in a dose-dependent manner. The Ferritin was detected on the acrosome in spermatozoa by immunocytochemistry. Short-term exposure of spermatozoa to SNP increased tyrosine phosphorylation and the acrosome reaction (AR). Finally, SNP affected a significant decrease in the rate of fertilization as well as blastocyst formation during early embryonic development. On the basis of these results, we propose that the effects of Ferritin on the AR may reduce overall sperm function leads to poor fertility in males and compromised embryonic development.

프랙탈 영상에서 계층적 블록 분할을 이용한 초기 영상 추정

류권열 위덕대학교 부설 전자기술연구소 1998 전자기술연구소 논문집 : 위덕대 Vol.2 No.1

프랙탈 영상 복호화는 임의의 초기 영상을 설정한 후, 변환 계수에 따라 축소 변환을 반복적으로 적용함으로써 원 영상을 복원한다. 복원 영상의 수렴속도는 초기 영상의 설정에 따라 다르기 때문에 고속 복호화를 위해서는 원 영상의 고정점에 가장 근접하는 초기 영상을 설정하여야 한다. 본 논문에서는 축소변환식의 중간값과 계층적 블럭 분할을 이용한 새로운 초기 영상 추정 방법을 제안한다. 제안한 방법에서 치역 블럭의 초기값은 bound() 함수를 이용하여 추정되므로 밝기 변화가 심한 경우를 포함한 모든 경우에 대해 정확한 추정이 가능하며, 계층적 블럭 분할에 의한 방법을 적용함으로써 더욱 고정점에 가까운 초기 영상을 추정한다. 실험 결과, 제안한 방법으로 추정한 초기 영상의 PSNR은 25.2 dB로써 기존의 방법에 비해 8.6 dB 향상되었으며, 복원 영상의 수렴에 소요되는 반복 변환 횟수는 1회로 나타났다. 결론적으로 복원 영상의 수렴에 소요되는 반복 변환 횟수를 2회 줄임으로써 61%의 계산량이 감소됨을 알 수 있었다. In fractal image decoding, the original image is reconstructed by iterated contractive transformations according to transformation parameters after selection of an arbitrary initial image. Because the convergence speed of reconstruction image is different according to select initial image, an initial image more nearer to the original image must be selected for fast decoding. In this paper, I propose an initial image estimation method by using middle value of contractive transformation function and hierarchical block partition of range block. In proposed method, more exact initial value of range block is estimated by using bound() function in case of all inclusive of large scale value and an initial image more nearer to a fixed point is estimated by using hierarchical block partition. From the simulation results of proposed method, PSNR of the initial estimated image by using proposed method is 25.2 dB that is improved 8.6 dB, and iterated transformation number for the convergence of reconstruction image is one time. It is shown that iterated transformation number reduced to two times, and the convergence speed of reconstruction image is improved with 61% reduction of computational complexity.

Thrombin-activatable fluorescent peptide incorporated gold nanoparticles for dual optical/computed tomography thrombus imaging

Kwon, Sung-Pil,Jeon, Sangmin,Lee, Sung-Hoon,Yoon, Hong Yeol,Ryu, Ju Hee,Choi, Dayil,Kim, Jeong-Yeon,Kim, Jiwon,Park, Jae Hyung,Kim, Dong-Eog,Kwon, Ick Chan,Kim, Kwangmeyung,Ahn, Cheol-Hee Elsevier 2018 Biomaterials Vol.150 No.-

<P><B>Abstract</B></P> <P>Thrombosis is an important pathophysiologic phenomenon in various cardiovascular diseases, which can lead to oxygen deprivation and infarction of tissues by generation of a thrombus. Thus, direct thrombus imaging can provide beneficial in diagnosis and therapy of thrombosis. Herein, we developed thrombin-activatable fluorescent peptide (TAP) incorporated silica-coated gold nanoparticles (TAP-SiO<SUB>2</SUB>@AuNPs) for direct imaging of thrombus by dual near-infrared fluorescence (NIRF) and micro-computed tomography (micro-CT) imaging, wherein TAP molecules were used as targeted thrombin-activatable peptide probes for thrombin-specific NIRF imaging. The freshly prepared TAP-SiO<SUB>2</SUB>@AuNPs had an average diameter of 39.8 ± 2.55 nm and they showed the quenched NIRF signal in aqueous condition, due to the excellent quenching effect of TAP molecules on the silica-gold nanoparticle surface. However, 30.31-fold higher NIRF intensity was rapidly recovered in the presence of thrombin <I>in vitro</I>, due to the thrombin-specific cleavage of quenched TAP molecules on the gold particle surface. Furthermore, TAP-SiO<SUB>2</SUB>@AuNPs were successfully accumulated in thrombus by their particle size-dependent capturing property, and they presented a potential X-ray absorption property in a dose-dependent manner. Finally, thrombotic lesion was clearly distinguished from peripheral tissues by dual NIRF/micro-CT imaging after intravenous injection of TAP-SiO<SUB>2</SUB>@AuNPs in the <I>in situ</I> thrombotic mouse model, simultaneously. This study showed that thrombin-activatable fluorescent peptide incorporated silica-coated gold nanoparticles can be potentially used as a dual imaging probe for direct thrombus imaging and therapy in clinical applications.</P>

객체지향 프로그램 종속성 그래프를 이용한 클래스 계층구조의 재구조화에 대한 연구

류희열,권재길 동의공업대학 2001 論文集 Vol.27 No.1

In this paper, we presents a restructuring method for class hierarchies which can optimize member variable and member function using Object-oriented Program Dependence Graph(OPDG). In the progress program evolution, if the member variable and member function is inserted and updated to classes, it can be included the useless code or unappropriate inheritance relationship. The reuse of such classes is caused to the code errors and the increase of maintenance cost. In this paper, we propose a restructuring method that removes the classes, member variables and member functions that don't exist relationship with the used object, variable and methods in main function and removes the same member functions and member variables of subclass as superclass, we can obtain the simplification of program code and the progress of system performance by eliminating unused member variables and member functions, It can be increased to the efficiency of program testing and maintenance.