• Title/Summary/Keyword: 정방

Search Result 626, Processing Time 0.021 seconds

Image Segmentation using Multi-scale Normalized Cut (다중스케일 노멀라이즈 컷을 이용한 영상분할)

  • Lee, Jae-Hyun;Lee, Ji Eun;Park, Rae-Hong
    • Journal of Broadcast Engineering
    • /
    • v.18 no.4
    • /
    • pp.609-618
    • /
    • 2013
  • This paper proposes a fast image segmentation method that gives high segmentation performance as graph-cut based methods. Graph-cut based image segmentation methods show high segmentation performance, however, the computational complexity is high to solve a computationally-intensive eigen-system. This is because solving eigen-system depends on the size of square matrix obtained from similarities between all pairs of pixels in the input image. Therefore, the proposed method uses the small-size square matrix, which is obtained from all the similarities among regions obtained by segmenting locally an image into several regions by graph-based method. Experimental results show that the proposed multi-scale image segmentation method using the algebraic multi-grid shows higher performance than existing methods.

[ $H_{\infty}$ ] Design for Square Decoupling Controllers Using Genetic Algorithm (유전 알고리즘을 이용한 정방 비결합 제어기의 $H_{\infty}$ 설계)

  • Lee, Jong-Sung
    • Journal of the Institute of Electronics Engineers of Korea TE
    • /
    • v.42 no.4
    • /
    • pp.47-52
    • /
    • 2005
  • In this paper, the genetic algorithm is used to design a fixed order square decoupling $H_{\infty}$ controllers based on the Two-Degree-of-freedom standard model. The proposed decoupling $H_{\infty}$ controller which is minimizes the maximum energy in the output signal is designed to reduce the coupling properties between the input/output variables which make it difficult to control a system efficiently. A minimal set of assumptions for existence of the decoupling controller formula is described in the state-space formulas. It is verified by an example.

Extended Ontology Model based on DBMS (DBMS 기반의 온톨로지 확장 모델)

  • Lee, Mi-Kyoung;Kim, Pyung;Jung, Han-Min;Sung, Won-Kyung
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2006.10b
    • /
    • pp.284-288
    • /
    • 2006
  • 본 논문은 시맨틱 웹 기술이 융합된 지식기반 정보유통 플랫폼(OntoFrame-K$^{(R)}$)의 추론 서비스 시스템 (OntoThink-K$^{(R)}$)에서 이용되는 Persistent Model인 DBMS기반의 온톨로지 확장 모델에 대해 설명하고자 한다. OntoFrame-K$^{(R)}$는 대용량의 지식 데이터를 다루기 때문에 기존에 개발된 온톨로지 추론 엔진을 이용할 경우 많은 한계점을 가지게 된다. 따라서 우리는 대용량의 지식 데이터를 안정적으로 처리할 수 있으며 추론의 신뢰성과 정합성을 가지는 온톨로지 확장 모델을 설계, 구현하였다. 본 모듈은 OWL과 인스턴스 데이터를 트리플 형태로 변환하여 입력 받은 후, 온톨로지 스키마 규칙과 사용자 정의 규칙을 이용한 정방향 추론 방법으로 추론 서비스에서 필요한 지식데이터들을 생성하는 역할을 한다. 본 모델은 DBMS를 이용하여 대용량의 지식 데이터를 저장할 수 있으며, 추론 규칙에 따른 정방향 추론을 통해 지식 모델을 확장하기 때문에 데이터의 정합성이 보장된다.

  • PDF

Preparation Method of 20wt% $Al_2$$O_3$/3Y-$ZrO_2$Composite through in situ Transformation of m-$ZrO_2$and its Mechanical Properties (m-$ZrO_2$의 in situ transformation에 의한 20wt% $Al_2$$O_3$/3Y-$ZrO_2$복합체 제조 및 향상된 기계적 특성)

  • 강건택;임경란
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.12
    • /
    • pp.1187-1191
    • /
    • 2000
  • 정방정형 지르코니아를 상온에서 안정화시키는 이트리아와, 지르코니아의 저온 열화을 억제하고 파괴강도의 증가에 기여하는 알루미나를 YAG(5Al$_2$O$_3$.3Y$_2$O$_3$) 졸의 형태로 m-ZrO$_2$와 알루미나의 혼합 slurry에 첨가하여, m-ZrO$_2$를 yttria 안정화 지르코니아로의 in situ 변환과 동시에 알루미나의 분산도를 향상시키고자 하였다. 20wt% 알루미나-지르코니아(YSZ)의 복합체 (20ATZ)를 1450$^{\circ}$~150$0^{\circ}C$에서 상압소결하여 0.5$mu extrm{m}$ 이하의 균일한 미세구조로 얻었다. 이 복합체는 정방정형 지르코니아와 $\alpha$-알루미나 상으로만 이루어지었고, 소결밀도 >99% TD이었다. 제조된 복합체의 파괴강도는 810 MPa로, 고상법으로 $Al_2$O$_3$와 3Y-ZrO$_2$분말로부터 제조된 시편의 682 MPa 보다 약 20% 향상되었고, 파괴인성은 5.52 MPa.m$^{1}$2/로 고상법으로 제조된 시편의 5.39 MPa.m$^{1}$2/과 비슷하였다.

  • PDF

The electrical properties study with specific of phase transition of Lead Monoxide by PIB(Particle In Binder) (PIB(Particle In Binder) 방법으로 제조된 산화납의 특이상전이에 따른 전기적 특성 평가)

  • Kim, Sung-Hyun;Kim, Young-Bin;Jung, Suk-Hee;Kim, Min-Woo;Oh, Kyung-Min;Park, Ji-Gun
    • Journal of the Korean Society of Radiology
    • /
    • v.2 no.3
    • /
    • pp.19-25
    • /
    • 2008
  • Commercial analog x-ray detectors based on film cassettes have been showing problems such as with image storage and image transmission. Recently direct conversion material, photoconductor whit flat panel have been researched which generate the electron hole-pair (EHP). In this paper, we researched the electrical properties of the PbO and Lead(II) oxide PbO. film which fabricated by Particle-In-Binder(PIB) method. We compared tetragonal ${\alpha}$-PbO with orthorhombic ${\beta}$-PbO physical property. Tetragonal material was more than orthorhombic material in other paper. The solution was Poly Vinyl Butyral(PVB) in the PIB. We discussed about the sample of x-ray sensitivity, leakage current, Signal to Noise Rate and investigated SEM for the physical property of sample. We need to think more research ${\alpha}$-PbO material fabrication.

  • PDF

The Effect of Trivalent Cation Doping on the Low Temperature Phase Stability of 2Y-TZP (3가 양이온 산화물이 첨가된 2Y-TZP의 저온 상안정성)

  • Jang, Ju-Woong;Kim, Hak-Kwan;Lee, Deuk-Yong;Kim, Dae-Joon;Park, Sun-Min
    • Journal of the Korean Ceramic Society
    • /
    • v.39 no.11
    • /
    • pp.1055-1062
    • /
    • 2002
  • The phase stability and the Low Temperature Degradation(LTD) mechanism of Tetragonal Zirconia Polycrystals(TZP), sintered specimens of $Y_2O_3$-Stabilized Zirconia(2Y-TZP), doped with trivalent cations, were evaluated by investigating meachnical properties, Raman spectra, lattice parameter variation and the oxygen vacancy behavior under applied electric field. XRD observation was put forward on 2Y-TZP doped with trivalent cation whose ionic radii were larger than $Zr^{4+}(Sc^{3+},\;Yb^{3+},\;Y^{3+},\;Sm^{3+},\;Nd^{3+},\;La^{3+})$ up to 2 mol% and sintered at 1500 h for 1h. For $La^{3+}$ doping, the stability of tetragonal phase was degraded due to the formation of the pyrochlore phase $(La_2Zr_2O_7)$ as the dopant content increased above exceeded 0.5 mol%. As the dosage increased, tetragonal phase maintained for the case of $Sc^{3+}$, whose radius was similar to $Zr^{4+}$, on the other hand, the cubic phase was formed for the cases of $Yb^{3+},\;Y^{3+},\;Sm^{3+},\;Nd^{3+}$. As the radii of dopant cation increased, c/a ratio increased and it was experimentally observed that the amount of monoclinic phase decreased when the specimens were annealed at $220{\circ}C$ for 500 h.

Statistical Analysis of Meteorological Factors with the Leaf Quality of Flue-cured Tobacco II. The Proportion of the Respective Grades of the Thick Leaf and Meteorological Factors (황색종 잎담배 품질과 기상요인과의 관계분석 II. 추엽 등급별 수량분포와 기상요인)

  • 김정환;한원식;이용득
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.34 no.3
    • /
    • pp.229-234
    • /
    • 1989
  • In flue-cured tobacco, the relationships between the quality of tobacco leaves (productivity according to quality grade) and specific meteorological factors were noted showing different significances according to different seasons during the growing period of the tobacco plants. The thick leaf high quality was significantly correlated with average temperature in late April, late May, early July and late July. The degree of contribution was greatest in middle May and lowest in late May. In the highest and lowest temperatures, the relations to leaf quality had similar tendency like in the average temperature; the thick leaf low quality showed opposite tendency relative to the high quality in the degrees of correlations and contributions. Amount of precipitation was significantly correlated with the thick leaf high quality in late April, early May, middle May, late June and late July. The degree of positive contribution was shown in order of late April, middle July and early July, and that of negative one was in order of middle June, early June and late June, respectively. Duration of sunshine period was highly associated with thick leaf high quality of tobacco leaves in all of the growing season except for middle April and middle July. The degree of positive contribution was in order of late May, late April, early July and middle July, and that of the negative one was in order of late June, early May, middle June and middle May.

  • PDF

Outdoor Noise Propagation: Geometry Based Algorithm (옥외 소음의 전파: 음 추적 알고리즘)

  • 박지헌;김정태
    • The Journal of the Acoustical Society of Korea
    • /
    • v.21 no.4
    • /
    • pp.339-438
    • /
    • 2002
  • This paper presents a method to simulate noise propagation by a computer for outdoor environment. Sound propagated in 3 dimensional space generates reflected waves whenever it hits boundary surfaces. If a receiver is away from a sound source, it receives multiple sound waves which are reflected from various boundary surfaces in space. The algorithm being developed in this paper is based on a ray sound theory. If we get 3 dimensional geometry input as well as sound sources, we can compute sound effects all over the boundary surfaces. In this paper, we present two approaches to compute sound: the first approach, called forward tracing, traces sounds forwards from sound sources. while the second approach, called geometry based computation, computes possible propagation routes between sources and receivers. We compare two approaches and suggest the geometry based sound computation for outdoor simulation. Also this approach is very efficient in the sense we can save computational time compared to the forward sound tracing. Sound due to impulse-response is governed by physical environments. When a sound source waveform and numerically computed impulse in time is convoluted, the result generates a synthetic sound. This technique can be easily generalized to synthesize realistic stereo sounds for virtual reality, while the simulation result is visualized using VRML.

EFFECTS OF CONDENSATION TECHNIQUES AND CANAL SIZES ON THE MICROLEAKAGE OF ORTHOGRADE MTA APICAL PLUG IN SIMULATED CANALS (모조 근관의 크기와 충전 방법이 orthograde MTA apical plug의 미세누출에 미치는 영향)

  • Nam, Deuk-Lim;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
    • /
    • v.34 no.3
    • /
    • pp.208-214
    • /
    • 2009
  • The purpose of this study was to compare the dye leakage of MTA (mineral trioxide aggregate) apical plug produced by two orthograde placement techniques (hand condensation technique and ultrasonically assisted hand condensation technique). To simulate straight canal, 60 transparent acrylic blocks with straight canal were fabricated. These transparent acrylic blocks were divided into 2 groups (Group C; hand condensation technique (HC) and Group U; ultrasonically assisted hand condensation technique (UAHC)) of 30 blocks with each MTA application method. Each group was divided into 2 subgroups (n=15) with different canal size of #70 (subgroup C70 and subgroup U70) and #120 (subgroup C120 and subgroup U120). After apical plug was created, a wet paper point was placed over the MTA plug and specimen was kept in a humid condition at room temperature to allow MTA to set. After 24 hours, remaining canal space was backfilled using Obtura II. All specimens were transferred to floral form socked by 0.2% rhodamine B solution and stored in 100% humidity at room temperature. After 48 hours, resin block specimens were washed and scanned using a scanner. The maximum length of micro leakage was measured from the scanned images of four surfaces of each resin block using Photoshop 6.0. Statistical analysis was performed with Mann-Whitney U test. Group U of UAHC had significantly lower leakage than Group C of HC in #70-size canal (subgroup U70) (p<0.05).

Experimental Study for Modal Parameter Estimation of Structural Systems (구조물의 자유진동특성 추정을 위한 실험적 연구)

  • 윤정방;이형진
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1994.10a
    • /
    • pp.175-182
    • /
    • 1994
  • As for the safety evaluation of existing large-scale structures, methods for estimation of the structural and dynamic properties are studied. Sequential prediction error method in time domain and improved FRF estimator in frequency domain are comparatively studied. For this purpose, impact tests of 2 bay 3 floor steel frame structure are performed. Results from both methods are found to be consistent to each others, however those from the finite-element analysis are slightly different from experimental results.

  • PDF