• Journal of Ship and Ocean Technology
• /
• 제8권4호
• /
• pp.17-25
• /
• 2004

Hull girder stress monitoring system for container ship uses four long-base-strain-gages at mid-ship to monitor the resultant stresses and the applied moment components of horizontal, vertical and torsional moments. The bending moments are estimated by using the conventional strain-moment relations, however, the torsional moment related to the warping strain requires the assumption of the shape of torsional moments over the hull girder. Though this shape could be a sine function with an adequate period, it largely depends upon certain empirical formulas. This paper introduces additional four long-base-strain-gages at mid-ship to derive the longitudinal slope of the warping strain because this slope is directly related to the torsional moment by Bi-moment concept. An open-channel-type cantilever beam has been selected as a simplified model for container ship and the result has proved that the suggested concepts can estimate the torsional component accurately. Finally this method can become reliable technique to derive all external moments in hull girder stress monitoring system for container ships.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.228-233
• /
• 2004

A derailment coefficient of railway vehicle is as one of important element that estimate running safety. Derailment coefficient is ratio of lateral load/vertical load happens in contact point between wheel and rail. Lateral load increases, dangerous of derailment can rise. There are ground and vehicle to measurement method of these derailment coefficient. Method of ground is simple, but when vehicles passes data of a point, there is shortcoming that acquire locally. Curved surface style wheel shape that use so far among vehicle method in this research wishes to be not but describe about static load test of wheel-set for derailment coefficient measurement that have plane plate shape that manufacture separate way and correction result etc. to test.

• 한국해양공학회지
• /
• 제11권3호
• /
• pp.29-38
• /
• 1997

Crack penetration behavior by fatigue crack propagation and measurements of AE before-and-after crack penetration were examined using SS41 steel plate. Experimental crack shape of SU type was in good agreement with calculated shape rather than S type. Crack propagation behavior on the front surface appears not to change markedly after penetration. However, crack growth on the back surface appears to accelerate as reported by author. As a crack propagates, AE occurred heavily just before penetration. Then, it decreases and crack is penetrating. A transition from plane strain to plane stress was observed by fractographic study. At this time, separation of fracture surface was shown which affects AE occurrence.

• 한국재료학회지
• /
• 제31권9호
• /
• pp.481-487
• /
• 2021

ZnO particles are successfully synthesized at 150 ℃ for 30 min using zinc acetate as the Zn source and 1,4-butanediol as solvent using a relatively facile and convenient glycol process. The effect of ammonium hydroxide amounts on the growth behavior and the morphological evolution of ZnO particles are investigated. The prepared ZnO nanoparticle with hexagonal structure exhibits a quasi-spherical shape with an average crystallite size of approximately 30 nm. It is also demonstrated that the morphology of ZnO particles can be controlled by 1,4-butanediol with an additive of ammonium hydroxide. The morphologies of ZnO particles are changed sequentially from a quasi-spherical shape to a rod-like shape and a hexagonal rod shape with a truncated pyramidal tip, exhibiting preferential growth along the [001] direction with increasing ammonium hydroxide amounts. It is demonstrated that much higher OH^- amounts can produce a nano-tip shape grown along the [001] direction at the corners and center of the (001) top polar plane, and a flat hexagonal symmetry shape of the bottom polar plane on ZnO hexagonal prisms. The results indicate that the presence of NH⁴⁺ and OH^- ions in the solution greatly affects the growth behaviors of ZnO particles. A sharp near-band-edge (NBE) emission peak centered at 383 nm in the UV region and a weak broad peak in the visible region between 450 nm and 700 nm are shown in the PL spectra of the ZnO synthesized using the glycol process, regardless of adding ammonium hydroxide. Although the broad peak of the deep-level-emission (DLE) increases with the addition of ammonium hydroxide, it is suggested that the prominent NBE emission peaks indicate that ZnO nanoparticles with good crystallization are obtained under these conditions.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -1
• /
• pp.9-11
• /
• 2002

We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

• Archives of Plastic Surgery
• /
• 제35권5호
• /
• pp.545-552
• /
• 2008

Purpose: The transaxillary approach for breast augmentation has been advocated for patients and surgeons for several decades. However, this blind technique had many disadvantages including, traumatic dissection, difficult hemostasis, displacement of implants, and ill-defined asymmetrical location of inframammary crease. In the present study, the precise endoscopic electrocautery dissection was applied to eliminate the limits of blunt dissection throughout the procedures. Methods: From December 2006 to December 2007, a total of 103 patients with an average age of 29.5 years underwent endoscopic assisted transaxillary dual plane augmentation mammoplasty. The mean implant size was 243 cc with the range between 150 and 350 cc. Through a 4 cm axillary incision, electrocautery dissection for submuscular pockets was carried out under the endoscopic control. The costal origin of pectoralis muscle was completely divided to expose subcutaneous tissue and to make type I dual plane. Results: Using the endoscopic dissection, we achieved good aesthetic results including a short recovery period, less morbidity, and symmetrical well-defined inframammary crease. Type I dual plane procedure could support the consistent inframammary fold shape and be applied to most patients without breast ptosis. Minor complications did not occur, however, four major complications of capsular contracture occurred. Conclusion: In contrast to the era of the blind techniques, endoscopic assisted transaxillary dual plane breast augmentation can now be performed effectively and reproducibly. With Its advantage, the axillary application of endoscopy for augmentation mammaplasty is useful to achieve the optimal cosmetic outcomes.

• 한국해양공학회지
• /
• 제13권3호통권33호
• /
• pp.12-20
• /
• 1999

In this paper, method for mapping a three-dimensional shape into the two-dimensional plane will be introduced. This method is referred to geometric modelling and means a transformation between the flat sheet and final surface. The initial blank shape represents the original configuration of the final shape formed into three dimensional surface. The initial constant constant area mapping hypothesis was used in this paper. This technique will be applied to the basic data for an interactive computer design capable of dealing with typical stamping process, including deep parts and complex shapes.

• 전자공학회논문지B
• /
• 제32B권8호
• /
• pp.1127-1136
• /
• 1995

In this paper, a morphological shape decomposition method is proposed for the purpose of pattern recognition and image compression. In the method, a structuring element that geometrical characteristics is more similar to the shape function is preselected. The shape is decomposed into the primitive elements corresponding to the structuring element. A gray scale image also is transformed into 8 bit plane images for the hierarchical reconstruction required in image communication systems. The shape in each bitplane is decomposed to the proposed method. Through the experiment. it is proved that the description error is reduced and the coding efficiency is improved.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
• /
• pp.266-273
• /
• 1998

The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions: (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, after shape finding analysis, cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1997년도 가을 학술발표회 논문집
• /
• pp.262-269
• /
• 1997

The purpose of this study is to survey the shape finding of the plane truss structures under the prescribed displacement mode by the shape analysis. The shape analysis is peformed by the existence condition of a solution and Moore-Penrose generalized inverse matrix, and the prescribed displacement mode is the homologous deformation of structures. The shape analysis of structures is a kind of inverse problem and become the problem of a nonlinear equation. Newton-Raphson method is used to improve the accuracy of approximated solution. To prove the accuracy and the effectiveness of this method, four different shape examples are analyzed.