• 제목/요약/키워드: Wave pattern

검색결과 930건 처리시간 0.03초

KCS 선형의 모형시험 및 CFD 해석을 통한 Newman-Sharma 파형저항 추정법의 검토 (Review of Newman-Sharma Wave Pattern Resistance Analysis Using Experimental and Computational Model Tests of KCS)

  • 김명수;김민창;서정화;석우찬
    • 대한조선학회논문집
    • /
    • 제60권2호
    • /
    • pp.76-85
    • /
    • 2023
  • The present study aims to review the wave pattern resistance analysis method suggested by the International Towing Tank Conference. From the experimental database of a container carrier ship model, the wave pattern measurement and resistance test results are utilized. The wave pattern resistance at the design Froude number is obtained to be compared with the wave making resistance of experiments. Wave pattern resistance is lower than wave making resistance by 1978 ITTC and uniform regardless of transverse location of wave cut. The method is also applied to the wave height field by Computational Fluid Dynamics (CFD) analyses with Froude number variation. Although numerical damping suppressed waves in downstream, waves around the hull and wave pattern resistance are properly predicted.

Longitudinal Cut 파형해석의 응용을 위한 특성연구 (Study on th Wave-Pattern Analysis by Longitudinal Cut Method)

  • 강신형;이영길
    • 대한조선학회지
    • /
    • 제18권1호
    • /
    • pp.9-18
    • /
    • 1981
  • The wave-pattern analysis has been one of important research tools in the towing tank, and applied for hull form design. The longitudinal-cut method of Newman and Sharma is adopted in KRIS deep towing tank. Instrumentations and data acquisition systems are developed for that. Local effects and truncation effects are estimated by using calculated wave patterns of simple source distributions. Wigley model of 2m is used to check the accuracy of the whole system. Cut positions and truncation points are changed to investigate characteristics of the wave-pattern analysis. Coefficients of wave-pattern resistance are low-estimated in comparison with those of Maruo and Ikehata. The general quality of the system is very good, but some more efforts to increase the accuracy are required. Two full-form models(one basic form, the other with bulbous bow) are tested to show high application-possibilities of the wave-pattern analysis for the hull form design.

  • PDF

ATInSAR HOLOGRAM OBSERVATIONS OF COASTAL WAVE REFARCTION

  • Marghany, Maged
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.438-440
    • /
    • 2003
  • This study is introducing a new approach of ATInSAR hologram for modeling wave refraction spectra pattern. TOPSAR data with L$_{-HH}$ and C-vv bands utilized spatial variation of wave refraction. Based on the phase information in along track interferometry, and ATInSAR hologram the quantitative information such swell wave height and spectra energy have been modeled. The phase information in ATInSAR hologram images can be transferred to wave refraction The ATInSAR hologram can be used to investigate the wave refraction pattern along the coastal waters. The fringe information pattern was shown to be useful in modeling wave refaction spectra varaition. The hologram interferometry wave refraction model consists of two sub-models. The purpose of first sub-model is to determine the swell wave height by using ATInSAR. Second sub-model aims to generate the holographic interferometry from the information of two wave spectra which detected by ATInSAR technique. The azimuth cut-off variations along the fringe patterns will be estimated. As azimuth cut-off contains the wave height information which could be used the significant wave height variation in convergence and divergence zone.

  • PDF

생체 기에 대한 피동공명적인 연구 (Study on the wave resonance-stimultion and receptionfor the BIO-KI)

  • 류경호;김경철;이용태
    • 동의생리병리학회지
    • /
    • 제17권2호
    • /
    • pp.263-274
    • /
    • 2003
  • The present condition of study on the wave-resonance for the bio-KI is observed. And the probroms of reception attendent on the stimulation of wave is observed centering around the sensory organ. The results is as follows: In the wave-resonant stand point, the tendency of studying on KI is showed in the several field all over the world. Because it is originated radionics, the wave-resonant tools of MRA insistenting minute-magnetism-resonance-apparatus need the more severe data in the side of electric circuit. The wave resonance apparatus according to the frequency occurance transmits low-frequency's vibration ratio to the electric stimulating aspect. The wave-water is considered on the application of wave-resonance transcription on the water, and needs the comprehension of torsion-field level. The wave-stimulation of the bio-KI and the reception of the sensory-organ is observed the connection of the sensory-organ and it's corresponding wave. The informations recorded in the wave are distinguished patternly. And the several shaping waves transmit the informations each other through the resonnance. The wave theory is explained the LEE(理) as the wave-pattern and the KI(氣) as the revelation of the patterned-wave in the LEE-KI theory(理氣論), moreover the SHIN(神) as the information of the wave-pattern and the KI as the energy of the wave and the JEUNG(精) as the material of the wave in the JEUNG-KI-SHIN theory(精氣神論). In this point, the study on the wave-resonance of bio-KI is thought that it is significantly in the study method for oriental medicine. The sum of the wave makes the moving body and forms the universe. It means that the several wave patterns gather and form new field. The pattern is a kind of the information and the information is not materially. The information of wave-pattern is the arrangement and the combination of the material source.

스마트 헬스케어 환경에서 복잡도를 고려한 R파 검출 및 QRS 패턴을 통한 향상된 부정맥 분류 방법 (R Wave Detection and Advanced Arrhythmia Classification Method through QRS Pattern Considering Complexity in Smart Healthcare Environments)

  • 조익성
    • 디지털산업정보학회논문지
    • /
    • 제17권1호
    • /
    • pp.7-14
    • /
    • 2021
  • With the increased attention about healthcare and management of heart diseases, smart healthcare services and related devices have been actively developed recently. R wave is the largest representative signal among ECG signals. R wave detection is very important because it detects QRS pattern and classifies arrhythmia. Several R wave detection algorithms have been proposed with different features, but the remaining problem is their implementation in low-cost portable platforms for real-time applications. In this paper, we propose R wave detection based on optimal threshold and arrhythmia classification through QRS pattern considering complexity in smart healthcare environments. For this purpose, we detected R wave from noise-free ECG signal through the preprocessing method. Also, we classify premature ventricular contraction arrhythmia in realtime through QRS pattern. The performance of R wave detection and premature ventricular contraction arrhythmia classification is evaluated by using 9 record of MIT-BIH arrhythmia database that included over 30 premature ventricular contraction. The achieved scores indicate the average of 98.72% in R wave detection and the rate of 94.28% in PVC classification.

20대 여성의 하반신 체형 유형에 따른 플레어스커트의 패턴 설계 (Pattern Making of the Flared Skirt According to the Lower Body Somatotype of the 20's Women)

  • 이연순;류지현;김경아
    • 한국의류산업학회지
    • /
    • 제10권5호
    • /
    • pp.660-667
    • /
    • 2008
  • The purpose of this study was to modify a Flared Skirt for women according to the somatotype of lower body. The subjects for the wear test were 3 students, who were in $mean{\pm}1{\sigma}$ each somatotype. The results of this study are as follows: First, the Flared Skirt pattern was modified according to each type. The front waist line rising measurement proposed for type 1 and type 2 were 0.5cm, because of lower front silhouette with waist shape. The back waist line rising measurement proposed for type 2 was 1cm and type 3 was 0.5cm, because of lower back shape with hip. Second, the wave-height of nodes were regular at front and back in type 1. Also, the wave-height of nodes were evenly distributed side and center. The variation ratio of wave-height of back nodes were lower than existing pattern in type 2 and type 3. It means the variation ratio of wave-height of back nodes were regular in modification pattern. Altogether, modification patterns were more regular and lower than existing pattern in the number of nodes, the distribution ratio of nodes, the wave-height of node, the variation ratio of wave height of nodes.

Design of the Pattern Adjustable Base Station Antenna for WCDMA Applications

  • Lee, Sang-Ho;Lee, Jung-Nam;Lee, Don-Shin;Park, Jong-Kweon;Kim, Hak-Sun
    • Journal of electromagnetic engineering and science
    • /
    • 제8권2호
    • /
    • pp.64-69
    • /
    • 2008
  • In this paper, we have proposed the pattern adjustable base station antenna for WCDMA applications. The proposed antenna consists of an omni-antenna(sleeve monopole) and two movable reflectors. The two reflectors can be controlled by mechanically and used to adjust the horizontal pattern of the base station antenna. The antenna was designed, fabricated, and measured. The antenna covers the entire WCDMA band for VSWR<1.4. The measured antenna gain is more than 15 dBi over the operating frequency range. By changing the angle (a) and the distance (d) of the antenna, the pattern adjustment of the proposed base station antenna is found to be possible.

수치모의를 통한 해운대 이안류의 주요 메커니즘 연구: 파랑의 벌집구조 (Numerical Study on a Dominant Mechanism of Rip Current at Haeundae Beach: Honeycomb Pattern of Waves)

  • 최준우;박원경;배재석;윤성범
    • 대한토목학회논문집
    • /
    • 제32권5B호
    • /
    • pp.321-329
    • /
    • 2012
  • 파향이 약간 다르게 진행하는 두 규칙파는 비선형적 상호작용에 기인하여 파봉선이 벌집구조와 유사한 모습을 갖는 현상이 발생하고, 벌집구조 모양의 파봉선 사이에 일정하게 파랑에너지가 매우 낮게 유지되는 노드선 영역이 생성된다. 이러한 파봉선 벌집구조 모양이 해변에 형성되면, 해안선 직각방향으로 생성되는 노드선 영역을 통하여 이안류가 발달하게 된다. 본 연구에서는 해변가에 형성되는 벌집구조 파봉선 현상이 해운대에서 발생하는 이안류의 주요한 메카니즘임을 확인하기 위하여, Boussinesq 파랑모형을 이용하여 일방향 규칙파에 의한 해운대 연안흐름의 수치해석을 수행하고 이를 분석하였다. 그 결과, 해운대 앞바다의 해저천퇴에 따른 파랑굴절로 파향이 서로 약간 다른 파랑들이 해안에 전파되고, 이에 따라 벌집구조가 형성되어 노드영역을 따라 이안류가 매우 잘 발달함을 확인할 수 있었다. 또한, 일정한 파고와 주기를 갖는 다양한 폭의 스펙트럼에 따른 불규칙파 수치모의를 수행하므로, 폭이 넓은 스펙트럼 파랑조건보다 규칙파에 가까운 폭이 좁은 스펙트럼의 파랑조건에서 이안류가 더 잘 발달하는 것을 확인하였다.

트레드 패턴을 고려한 타이어의 스탠딩 웨이브 현상에 대한 유한 요소 해석 (Finite Element Analysis on Standing Wave Phenomenon of a Tire Considering Tread Pattern)

  • 김기운;정현성
    • 한국자동차공학회논문집
    • /
    • 제14권2호
    • /
    • pp.76-83
    • /
    • 2006
  • Each tire has a critical speed at which a standing wave phenomenon occurs along the circumferential direction. If the standing waves are formed, the tire temperature is rapidly increased and it leads to tire failure eventually. As the formation of the standing waves is closely related to the tire stiffness, the effect of the tread pattern needs to be studied numerically. The standing wave phenomenon of a tire model with tread pattern is predicted by an explicit finite element method. The critical speed of the tire with tread pattern is in a good agreement with the experiment and is $15{\sim}20\;km/h$ lower than that of the tire without tread pattern. The effects of the inflation pressure and the vertical load on the critical speed are also investigated by using the tire model with tread pattern.

시가화지역 공간상 위치분배와 폭염현상과의 관계성: 5개 광역시 사례 (Relationship between the Spatial Allocation of Developed Area and the Heat Wave Phenomenon: The Case of Five Metropolitan Cities)

  • 강상준
    • 환경영향평가
    • /
    • 제30권3호
    • /
    • pp.175-185
    • /
    • 2021
  • 도시지역 폭염에 대한 보다 나은 이해를 위해서는 토지이용의 총량적 이해와 더불어서 토지이용의 공간적 위치분배와 폭염현상과의 관계성 이해도 필요하다. 본 연구의 목적은 군집개발과 파편화된 개발이 폭염일수와 순위상관관계를 보이고 있는지를 살펴보는 것이다. 주요연구방법으로는 형태학적공간패턴, 공간자기상관성, 스피어만상관성 분석을 이용하였다. 연구대상지는 대구, 광주, 울산, 부산, 대전광역시이며 폭염지표는 30년간 연간폭염일수로 설정하였다. 본 연구는 군집개발 유무보다는 나홀로 개발 등의 파편화개발방식이 폭염에 부정적이라는 점을 보여주고 있으며 이는 곧 개발형태가 폭염과 관계가 있음을 의미한다.