• Title/Summary/Keyword: Double-sided

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Study on Steady Flow Effects in Numerical Computation of Added Resistance of Ship in Waves

  • Lee, Jae-Hoon;Kim, Beom-Soo;Kim, Yonghwan
    • Journal of Advanced Research in Ocean Engineering
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    • v.3 no.4
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    • pp.193-203
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    • 2017
  • This study investigated the steady-flow effects present in the numerical computation of the resistance added to a ship in waves. For a ship advancing in the forward direction, a time-domain 3D Rankine panel method is applied to solve the ship motion problem, and the added resistance due to waves is calculated using a near-field method, with the direct integration of the second-order pressure on the hull surface. In the linear potential theory, the steady flow is approximated by the basis potential of a uniform flow or double-body flow in order to linearize the boundary conditions. By applying these two different linearization schemes, the coupling effects between steady and unsteady solutions were examined. Furthermore, in order to analyze the steady-flow effects on the hull geometry, the computation results for two realistic hull forms, a KVLCC2 tanker and DTC containership, were compared. In particular, the mj term, which represents the coupling effects under the body boundary condition, was evaluated considering the geometry of a non-wall-sided ship. Lastly, the characteristics of the linearization schemes were examined in relation to the disturbed waves around a ship and the components of added resistance.

Characteristics Comparison of Axial and Radial Flux Permanent Magnet Generators for 1.5kW Class Wind Power Systems (1.5kW급 풍력발전용 축자속/반경자속 영구자석 발전기의 특성 비교)

  • Ko, Kyoung-Jin;Jang, Seok-Myeong;Koo, Min-Mo;Lee, Sung-Ho;Han, Sang-Chul;Park, Young-Tae
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1075-1076
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    • 2011
  • This paper compares performance characteristics and mechanical design specifications of outer rotor radial flux type and double-sided axial flux type permanent magnet generator for 1.5-kW class small scale wind power applications to suggest most suitable type. In order to analyze electromagnetic performances of two different type generators, this paper performs generating performance and efficiency characteristic analysis from electrical parameters obtained by using nonlinear finite element analysis using commercial software, electromagnetic losses characteristics equations and d-q characteristics equation. Considering the derived electromagnetic performance, mechanical design specifications and manufacturing cost, the best suitable model for 1.5-kW class wind power system is determined, and its experiment was performed to validate the suggested analysis method.

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Double Outlet Left Atrium: A rare form of the atrioventricular septal defect with malposition of the atrial septum (좌심방 양심실 연결증 [DOLA])

  • Lee, Jae-Won;Seo, Gyeong-Pil
    • Journal of Chest Surgery
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    • v.18 no.2
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    • pp.273-278
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    • 1985
  • The case of a patient with abnormal position of the atrial septum resulting in a left atrium with two atrioventricular valves and a disconnected right atrium is presented with review of related articles. Anatomic details showed atrial situs solitus and a left sided cardiac apex. The right atrium received both venae cavae and a coronary sinus. No AV valve was found in the right atrium, and the floor of this chamber was placed above the posterior wall of right ventricular chamber. The atrial septum with secundum ASD was displaced to right anteriorly at its lower portion and inserted to right of tricuspid annulus. The tricuspid and mitral valve configuration was that of so-called partial ECD, i.e. mitral cleft with large anterior mitral leaflets. The ventricular septum was intact and both ventricular chambers were equally well developed with normal relationships. Surgical repair of this anomaly was performed by resecting the abnormally positioned lower part of the atrial septum, repairing the cleft of the anterior mitral leaflet, and septating the atrium for diverting the systemic and pulmonary venous blood to RV and LV, respectively.

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A study on the planning of circulation path through analysis of visitor's behavior and exhibition layout in museum exhibition area (관람행태 특성과 전시 레이아웃 분석에 의한 박물관 단위전시공간에서의 동선계획에 관한 연구)

  • Choi, Jun-Hyuck
    • Korean Institute of Interior Design Journal
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    • v.16 no.2 s.61
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    • pp.233-241
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    • 2007
  • Circulation planning for exhibition space depends on visitors, exhibition documents and exhibition space. To make visitors feel sympathy for the exhibition and meet visitors' movement and its spatial factors in the exhibition, guidelines for the planning layout of exhibition and exhibition space are needed. This research was aimed at gathering guidelines about the circulation planning for exhibition space for visitors who can acquire exhibition information in a natural way and enjoy the whole aspect of exhibition or enjoy preferential exhibition by investigating and analyzing viewing types of visitors, layout of exhibition and space unit exhibition. The result of this research was summarized as the following. 1) It needs optional viewing space large enough to be seen clearly so that all exhibition space can be seen at a glance at the main entrance of exhibition. 2) Layout of exhibition is needed for island-exhibition position and optional space preparation, when visitors pass by an article on exhibition short-cut. 3) Layout of exhibition is needed for double sided exhibition.

Development of Low Power Driven Inner Tap Inspection System capable of Wireless Communication with Video Equipment (영상기기와 무선통신이 가능한 저전력 구동의 이너탭 검사시스템 개발)

  • Ahn, Sung-Su
    • Journal of Korea Multimedia Society
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    • v.21 no.6
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    • pp.649-658
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    • 2018
  • In this paper, we propose a mechanical contact inner tap inspection system that can inspect the defect of the inner tap immediately after inner tap is processed within the machining center. The inspection module has the collet chuck structure, so it can mounted on the main spindle of the machining center during inspection. It was developed with a focus on inspection for tap having 20 mm depth which is primarily fabricated in automotive parts and has a double sided PCB-type control system including sensing function based on Zigbee module, micom and IR sensor for wireless transmission of measured data with low power operation, and also a battery for supplying electric power. The current consumption is 46.8mA in the inspection operation mode and 0.0268mA in the power saving mode for 3.7V of the applied power source, so that 30,000 times or more inspection can be performed with assumed 5 seconds inspection time for one tap. Experiments in test jig system and actual machining center confirm that the proposed inner tap inspection system can be applied to the batch process of simultaneous inspection after tapping in the machining center.

Simulation of Motion Accuracy Considering Loads in Linear Motion Units (부하를 고려한 직선운동유니트의 정밀도 시뮬레이션 기술)

  • Khim, Gyungho;Park, Chun Hong;Oh, Jeong Seok
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.5
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    • pp.405-413
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    • 2015
  • This paper presents the motion accuracy simulation considering loads such as workpiece weight, cutting force, cogging force of a linear motor, and force caused by misalignment and runout error of a ballscrew in linear motion units. The transfer function method is basically utilized to estimate 5-DOF motion errors, together with the equilibrium equations of force and moment on the table. The transfer function method is modified in order to consider clearance changed according to the loads in the double sided hydrostatic/aerostatic bearings. Then, the analytic model for predicting the 5-DOF motion errors is proposed with the modified transfer function method. Motion errors were simulated under different loading conditions in the linear motion units using hydrostatic, aerostatic, and linear motion bearings, respectively. And the proposed analytic model was verified by comparing the estimated and measured motion errors.

High Efficiency Crystalline Silicon Solar Cells (고효율 단결정 실리콘 태양전지)

  • Kim, D.S.;Cho, E.C.;Cho, Y.H.;Ebong, A.U.;Min, Y.S.;Lee, S.H.
    • Solar Energy
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    • v.17 no.1
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    • pp.17-26
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    • 1997
  • Since PESC(passivated emitter solar cell) was developed in 1985, high efficiency silicon solar cell technology based on planar technology has been improved in the order of PERC, Point Contact Solar Cell, PERL. BCSC and DSBC, which do not require photolithography, are expected to replace commercial screen printed cells because of its potential for low cost and high efficiency. In this paper, history and characteristics of each type of cells are reviewed.

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A Novel Unequal Broadband Out-of-Phase Power Divider Using DSPSLs

  • Lu, Yun Long;Dai, Gao-Le;Li, Kai
    • ETRI Journal
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    • v.36 no.1
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    • pp.116-123
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    • 2014
  • In this paper, a novel unequal broadband out-of-phase power divider (PD) is presented. Double-sided parallel-strip lines (DSPSLs) are employed to achieve an out-of-phase response. Also, an asymmetric dual-band matching structure with two external isolation resistors is utilized to obtain arbitrary unequal power division, in which the resistors are directly grounded for heat sinking. A through ground via (TGV), connecting the top and bottom sides of the DSPSLs, is used to short the isolation components. Additionally, this property can efficiently improve the broadband matching and isolation bandwidths. To investigate the proposed divider in detail, a set of design equations are derived based on the circuit theory and transmission line theory. The theoretical analysis shows that broadband responses can be obtained as proper frequency ratios are adopted. To verify the proposed concept, a sample divider with a power division of 2:1 is demonstrated. The measured results exhibit a broad bandwidth from 1.19 GHz to 2.19 GHz (59.2%) with a return loss better than 10 dB and port isolation of 18 dB.

Clinical Study of Choledochal Cyst (총담관낭의 임상적 고찰)

  • Rhim, Si-Yeon;Jung, Pung-Man
    • Advances in pediatric surgery
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    • v.9 no.2
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    • pp.81-88
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    • 2003
  • Congenital dilatation of the common bile duct (choledochal cyst) is an uncommon disease. Although the etiology is unknown yet, various theories such as distal obstruction of the common bile duct, congenital weakness of the duct and anomalous union of the pancreaticobiliary duct have been offered to explain the occurrence of choledochal cyst. Thirty - six cases of choledochal cyst over 22 years were analyzed clinically and classified according to Todani's classification and Kimura's anomalous union of pancreaticobiliary duct type. Todani type 1 consisted with 22 cases which were subdivided into 19 cases of type Ia, 1 case of type Ib and 2 of type Ic. Type IVa consisted with 14 cases including one case of Caroli's disease. There were 25 type BP cases and 10 type PB cases and 1 normal pancreatobiliary junction. Serum alkaline phosphatase was increased significantly in almost all cases. Seven patients (19.4%) had associated congenital anomalies such as double gallbladder, left - sided gallbladder, common bile duct web, biliary atresia, accessory hepatic duct, heterotopic pancreas, cleft lip and 2 cases of intestinal malrotation. All patients underwent cyst excision and Roux - en - Y hepaticojejunostomy and cholecystectomy. There was one death due to methicillin resistant Staphylococcus aureus sepsis.

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The Cultural Phenomena of the Post modern-Feminism and Contemporary Fashion (Post modern-Feminism의 문화 현상과 패션)

  • Shon, Mi-Hee
    • Journal of the Korean Society of Costume
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    • v.46
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    • pp.49-66
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    • 1999
  • The bisexuality deconstructivity and diversity that are great characteristics on the comtemporary fashion are showed in the fashion collections. The purpose of this paper is to investigate and analyze the influence of these characteristics made by the post modern-feminism fashion through the cultural pattern analysis. The post modern-feminism was analyzed by dividing the cultural pattern into 1) the deconstructivity of androcentrism -This characteristic was presented in the costume design that breaks the basic from of the line color and quality of the material showing in men's clothes. 2) By rejecting main current fashion -Subculture style appeared in main current fashion the boundary of main and anti-main current fashion was vagued and the phenomena that the identity of subgroup was weakened were showed. 3) In the coexistence of double-sided value -This characteristic was presented in the cross-dressing fashion that cut away women's slender part and men's rough part. 4) In the open-minded thought of gender -This tendency was reached an extreme from excessive exposure to design which gives the sexual stimulus. This paper is expected to be helpful to understand the contemporary fashion by treating the cultural category associated with post-modern feminism in relation to contemporary fashion and to establish the direction of 21 century fashion.

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