• 제목/요약/키워드: POSTECH

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An FPGA-based Parallel Hardware Architecture for Real-time Eye Detection

  • Kim, Dong-Kyun;Jung, Jun-Hee;Nguyen, Thuy Tuong;Kim, Dai-Jin;Kim, Mun-Sang;Kwon, Key-Ho;Jeon, Jae-Wook
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제12권2호
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    • pp.150-161
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    • 2012
  • Eye detection is widely used in applications, such as face recognition, driver behavior analysis, and human-computer interaction. However, it is difficult to achieve real-time performance with software-based eye detection in an embedded environment. In this paper, we propose a parallel hardware architecture for real-time eye detection. We use the AdaBoost algorithm with modified census transform(MCT) to detect eyes on a face image. We parallelize part of the algorithm to speed up processing. Several downscaled pyramid images of the eye candidate region are generated in parallel using the input face image. We can detect the left and the right eye simultaneously using these downscaled images. The sequential data processing bottleneck caused by repetitive operation is removed by employing a pipelined parallel architecture. The proposed architecture is designed using Verilog HDL and implemented on a Virtex-5 FPGA for prototyping and evaluation. The proposed system can detect eyes within 0.15 ms in a VGA image.

Metallized Electrospun Nanofiber webs with Bulckled Configuration for Highly Transparent and Stretchable Conductors

  • Jin, Yusung;Hwang, Sunju;Jeong, Soo-Hwan
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.363.1-363.1
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    • 2016
  • Transparent and stretchable conductors are expected to be an essential component in future stretchable optoelectronic devices. Until now, two main methods have been commonly employed to fabricate transparent and stretchable conductors by using metal nanomaterials: creating buckling configurations and creating network configurations. In this report, a novel strategy for obtaining transparent and stretchable conductors is presented, one that employs these two main approaches simultaneously. To the best of our knowledge, this proposed configuration of a buckled long nanofiber network in this study has not yet been reported. In order to provide the transparent conductors with dual mode stretchability originating from simultaneous buckled and network configurations, a buckled Au@polyvinylpyrrolidone (PVP) nanofiber network (hereafter referred to BANN for convenience) was fabricated by transferring Au-metallized electrospun PVP nanofibers onto a prestrained polydimethylsiloxane (PDMS) substrate. Our BANN shows considerably lower strain sensitivity of resistance than that of straight Au@PVP nanofiber network. Durability tests conducted by performing cyclic tensile strain reveal that the relative change in resistance of BANN (prestrain = 20%) is quite small after 1000 cycles. We also demonstrate that this BANN exhibits superior performance over widely used indium tin oxide conductors with regard to high optical transmittance and low sheet resistance.

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해저 파이프라인의 전체 좌굴 제어 방법 비교 (A Comparative Study of Subsea Pipeline Global Buckling Control Method)

  • 김구;김도균;최한석;박규식
    • 복합신소재구조학회 논문집
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    • 제6권1호
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    • pp.51-58
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    • 2015
  • Global buckling is a bending of pipeline and it occurs when the stability of pipeline is distributed by excessive axial force. Subesea pipeline is subjected to axial force induced by temperature and pressure from well and resulting phenomena should be controlled in appropriate manner. Global buckling of subsea pipeline is still ongoing research subject and is studied various organization. In this study, various control methods such as buoyancy module, sleeper, and snake lay for global buckling of subsea pipeline were numerically investigated with various design parameters. From the numerical simulation results, the global buckling control method using sleepers shows better results than buoyancy module and snake lay control methods in the sense of combined stress after buckling. Furthermore, the global buckling of full scale pipeline of 80km with uneven seabed profile were successfully managed when the sleeper was installed.

Improved Receding Horizon Fourier Analysis for Quasi-periodic Signals

  • Kwon, Bo-Kyu;Han, Soohee;Han, Sekyung
    • Journal of Electrical Engineering and Technology
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    • 제12권1호
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    • pp.378-384
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    • 2017
  • In this paper, an efficient short-time Fourier analysis method for the quasi-periodic signals is proposed via an optimal fixed-lag finite impulse response (FIR) smoother approach using a receding horizon scheme. In order to deal with time-varying Fourier coefficients (FCs) of quasi-periodic signals, a state space model including FCs as state variables is augmented with the variants of FCs. Through an optimal fixed-lag FIR smoother, FCs and their increments are estimated simultaneously and combined to produce final estimates. A lag size of the optimal fixed-lag FIR smoother is chosen to minimize the estimation error. Since the proposed estimation scheme carries out the correction process with the estimated variants of FCs, it is highly probable that the smaller estimation error is achieved compared with existing approaches not making use of such a process. It is shown through numerical simulation that the proposed scheme has better tracking ability for estimating time-varying FCs compared with existing ones.

음절을 기반으로한 한국어 음성인식 (Korean Speech Recognition Based on Syllable)

  • 이영호;정홍
    • 전자공학회논문지B
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    • 제31B권1호
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    • pp.11-22
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    • 1994
  • For the conventional systme based on word, it is very difficult to enlarge the number of vocabulary. To cope with this problem, we must use more fundamental units of speech. For example, syllables and phonemes are such units, Korean speech consists of initial consonants, middle vowels and final consonants and has characteristic that we can obtain syllables from speech easily. In this paper, we show a speech recognition system with the advantage of the syllable characteristics peculiar to the Korean speech. The algorithm of recognition system is the Time Delay Neural Network. To recognize many recognition units, system consists of initial consonants, middle vowels, and final consonants recognition neural network. At first, our system recognizes initial consonants, middle vowels and final consonants. Then using this results, system recognizes isolated words. Through experiments, we got 85.12% recognition rate for 2735 data of initial consonants, 86.95% recognition rate for 3110 data of middle vowels, and 90.58% recognition rate for 1615 data of final consonants. And we got 71.2% recognition rate for 250 data of isolated words.

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Charateristics of Voltage Dependent Calcium Uptake and Norepinephrine Release in Hypothalamus of DOCA-salt Hypertensive Rats

  • Lee, Jean-Young;Kim, Hae-Jung;Jung, Eun-Young;Chung, Hye-Joo;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • 제1권2호
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    • pp.171-176
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    • 1993
  • Purpose of the present study was to clarify the role of noradrenergic neural activities in hypothalamus for either triggering or maintaining hypertension in deoxycorticosterone (DOCA)-salt hypertensive rats. Two groups of animals were prepared: 1) normotensive Wistar rats and 2) DOCA-salt induced hypertensive rats. Voltage dependent $^{45}Ca^{++}$ uptake, endogenous norepinephrine release, and the catecholamine content in the hypothalamus of DOCA-salt hypertensive and normotensive Wistar rats were compared. Animals at 4, 6 and 16 week-old of two groups were sacrificed by decapitation and hypothalamus was dissected out. Voltage dependent calcium uptake and norepinephrine release were determined from hypothalamic synaptosomes either in low potassium or high potassium stimulatory condition by using $^{45}Ca^{++}$ isotope and HPLC-ECD technique. Degrees of voltage dependent $^{45}Ca^{++}$ uptake and norepinephrine release in hypothalamic synaptosomes of 16-week-old DOCA-salt hypertensive rats were significantly greater than those of age matched normotensive control rats. The norepinephrine and dopamine contents of hypothalamus were about the same in two groups of animals. These results suggest that the alteration of evoked norepinephrine release related to calcium uptake in hypothalamus may play a role in the maintenance of hypertension in DOCA-salt hypertensive rats.

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Proteomics in Rheumatoid Arthritis Research

  • Park, Yune-Jung;Chung, Min Kyung;Hwang, Daehee;Kim, Wan-Uk
    • IMMUNE NETWORK
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    • 제15권4호
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    • pp.177-185
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    • 2015
  • Although rheumatoid arthritis (RA) is the most common chronic inflammatory autoimmune disease, diagnosis of RA is currently based on clinical manifestations, and there is no simple, practical assessment tool in the clinical field to assess disease activity and severity. Recently, there has been increasing interest in the discovery of new diagnostic RA biomarkers that can assist in evaluating disease activity, severity, and treatment response. Proteomics, the large-scale study of the proteome, has emerged as a powerful technique for protein identification and characterization. For the past 10 years, proteomic techniques have been applied to different biological samples (synovial tissue/fluid, blood, and urine) from RA patients and experimental animal models. In this review, we summarize the current state of the application of proteomics in RA and its importance in identifying biomarkers and treatment targets.

KOMSAR를 이용한 실제 항공기 ISAR 영상 제작 (ISAR Imaging of a Real Aircraft Using KOMSAR)

  • 김경태;정호령
    • 한국전자파학회논문지
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    • 제18권7호
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    • pp.717-722
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    • 2007
  • 표적에 대한 레이더 영상 중의 하나인 ISAR(Inverse Synthetic Aperture Radar) 영상은 표적에 대한 전자파 산란 특성에 대한 2차원 공간 분포를 나타낸다. 이러한 ISAR 영상은 원거리에서 레이더를 이용한 표적 식별에 주로 사용된다. 본 논문에서는 움직이는 실제 항공기에 대한 ISAR 영상을 얻기 위하여, 국방과학연구소에서 제작 및 운용하고 있는 KOMSAR(Korea Miniature Synthetic Aperture Radar) 장비를 이용하여 측정을 수행하였다 이렇게 얻어진 측정된 데이터에 포함되어 있는 표적의 움직임에 의한 위상 오차를 제거하기 위하여, 엔트로피 기반 ISAR 자동 초점 기법(autofocusing technique)을 사용하였다. 실험 결과, 실제 움직이는 항공기에 대한 ISAR 영상을 성공적으로 얻을 수 있었으며, 이는 향후 레이더를 이용한 표적식별에 중요한 기술적 토대가 마련되었음을 의미한다.

Stabilization of Compact Protein Structures by Macrocyclic Hosts Cucurbit[n]urils in the Gas Phase

  • Lee, Jong Wha;Park, Mi Hyun;Ju, Jeong Tae;Choi, Yun Seop;Hwang, Soo Min;Jung, Dong Jin;Kim, Hugh I.
    • Mass Spectrometry Letters
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    • 제7권1호
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    • pp.16-20
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    • 2016
  • Characterization of intact protein structures in the gas phase using electrospray ionization combined with ion mobility mass spectrometry has become an important tool of research. However, the biophysical properties that govern the structures of protein ions in the gas phase remain to be understood. Here, we investigated the impact of host-guest complexation of ubiquitin (Ubq) with macrocyclic host molecules, cucurbit[n]urils (CB[n]s, n = 6, 7), on its structure in the gas phase. We found that CB[n] complexation induces the formation of compact Ubq ions. Both CB[6] and CB[7] exhibited similar effects despite differences in their binding properties in solution. In addition, CB[n] attachment prevented Ubq from unfolding by collisional activation. Based on the experimental results, we suggest that CB[n]s prevent unfolding of Ubq during transfer to the gas phase to promote the formation of compact protein ions. Furthermore, interaction with positively charged residues per se is suggested to be the most important factor for the host-guest complexation effect.

쾌속 조형 기술을 이용한 바이오리액티의 개발 (Development of Bioreactor by Rapid Prototyping Technology)

  • 박정훈;이승재;이인환;조동우;이종원
    • 한국정밀공학회지
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    • 제26권3호
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    • pp.137-143
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    • 2009
  • It has been reported that mechanical stimulation takes a role in improving eel/ growth in skeletal system. Various research groups have been showed their own bioreactors which stimulate cell-seed three-dimensional scaffold. In this study, we hypothesized that the various conditions of mechanical stimulation would affect cell growth and proliferation. To prove our hypothesis, we designed a custom-made bioreactor capable of applying controlled compression to cell-encapsulated scaffolds. This device consisted of a circulation system and a compression system. Each parts of the bioreactor was fabricated using the rapid prototyping technology By using the rapid prototyping technology, we can modify and improve the bioreactor very rapidly For dynamic cell-culture, cell-encapsulated agarose gel was fabricated in 2% concentration. We performed dynamic cell-culture using this agarose gel and developed bioreactor in 3 days.