• Journal of Drive and Control
• /
• v.11 no.3
• /
• pp.7-13
• /
• 2014

Everyday about 90% of cargos are delivered by ships, and thousands of vessels enter and depart the international container harbors such as Shanghai, Singapore, Hong Kong, Busan, Rotterdam, etc. Maneuvering at harbor is known as the most sophisticated and difficult procedure, because the effectiveness of actuators during low speed berthing is reduced. In this paper, a new berthing method is discussed. Tugboats are combined with damper systems to ensure safe berthing. A mathematical model describing the interaction between unactuated ship, tugboats and damper systems is presented. An optimal controller is designed to maneuver the ship without oscillation and overshoot. MCL (Marine Cybernetics Lab) model ship is used to evaluate the efficiency of the proposed approach through MatLab simulation.

• Korean Journal of Remote Sensing
• /
• v.8 no.2
• /
• pp.131-145
• /
• 1992

A low cost personal computer and image processing S/W were empolyed to derive Digtal Elevation Model(DEM) of tidal flat from multitemporal LANDSAT TM images, and to create three-dimensional(3D) perspective views of the tidel flat on Komso bay in west coasts of Korea. The method for generation of Digital Elevation Model(DEM) in tidal flat was considered by overlapping techniques of multitemporal LANDSAT TM images and interpolations. The boundary maps of tidal flat extracted from multitemporal images with different water high were digitally combined in x, y, z space with tide in formation and used as an inputcontour data to obtain an elevation model by interpolation using spline function. Elevation errors of less than $\pm$0.1m were achived using overlapping techniques and a spline interpolation approach, respectively. The derived DEM allows for the generation of a perspective grid and drape on the satellite image values to create a realistic terrain visualization model so that the tidal flat may be viewed from and desired direction. As the result of this study, we obtained elevation model of tidal flats which contribute to characterize of topography and monitoring of morphological evolution of tidal flats. Moreover, the modal generated here can be used for simulation of innudation according to tide and support other studies as a supplementary data set.

• Journal of Magnetics
• /
• v.18 no.3
• /
• pp.230-234
• /
• 2013

The $Ni_{0.5}Zn_{0.5}Fe_2O_4$ nanoparticles about 30 nm were prepared using sol-gel method with metal nitrates dissolved in 2-methoxyathanol. The concentrations of the metal nitrates are adjusted from 0.1 to 0.75 M in order to study the influence on the structural and magnetic properties. The structure and morphology characterization revealed that the crystallinity was improved and the nanoparticle size was increased with the nutrition solution concentrations up to 0.5 M. Degraded crystallinity together with decreased nanoparticle size were observed for concentration of 0.75 M. The saturation magnetization at room temperature reached maximum at 0.5 M, which can be explained by considering the crystallinity and size effect.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.1449-1452
• /
• 2009

현재 기업 및 공공기관에서는 산업기술 유출 방지를 위해 잔여데이터 완전삭제 등 보안기능이 구현된 디지털 복합기를 사용하고 있다. 이에 따라 국제적으로 특히 일본 평가기관들 중심으로 공통평가기준으로 평가 인증 많이 받고 있다. 그러나 국내에서는 MFP에 대한 인식과 평가 노하우(know-how)의 부족하여 평가 인증 방법에 미비한 상태이다, 본 논문에서는 MFP의 핵심 중요 기술인 잔여정보 완전삭제 기능을 공통평가기준으로 평가할 수 있는 국내 시험/평가 방법론을 제시하고자 한다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.216-221
• /
• 1998

A study on induction plasma deposition with ceramic materials, yttria-stabilized-zirconia ZrO$_2$-Y$_2$O$_3$ (m.p 264O $^{\circ}C$), was conducted with a view developing a new method for nuclear fuel fabrication Before making dense pellets more than 96％TD., the spraying condition was optimized through the process parameters, such as chamber pressure, plasma plate power powder spraying distance, sheath gas composition, probe position, particle size and powders different morphology. The results with a 5mm thick deposit on rectangular planar graphite substrates showed a 97.11％ theoretical density when the sheath gas flow rate was Ar/H$_2$120/20 l/min, probe position 8cm, particle size -75 ${\mu}{\textrm}{m}$ and spraying distance 22cm by AMDRY146 powder. The degree of influence of the main effects on density were powder morphology. particle size, sheath gas composition, plate power and spraying distance, in that order. Among the two parameter interactions, the sheath gas composition and chamber pressure affects density greatly. By using the multi-pellets mold wheel type, the pellet density did not exceed 94%T.D., owing to the spraying angle.

• Progress in Medical Physics
• /
• v.17 no.4
• /
• pp.232-237
• /
• 2006

The aim of this study was to develop the calculation algorithm of source strength of Ir-192 source In terms of the absorbed dose to water instead of an apparent activity (Ci). For this work the Multi Purpose Brachytherapy Phantom(MPBP) was developed, which was designed to locate the source and the chamber precisely at a specific position Inside the water phantom. The reference point of measurement was set at the 5 cm distance along the transverse axis of the source. For a brachytherapy source calibration, the absorbed dose to water calibration factor ($N_{D.W.Q}$) of an lonization chamber were determined and then apply standard protocols of absorbed dose to water. The calibration factor ($N_{D.W.Q}$) of the ion chamber (TM30013, PTW, Germany) was determined using the EGSnrcCPP Monte Carlo Code. The calculated calibration factor ($N_{D.W.Q}$) was 5.28 cGy/nC. The calculated factor was then used to determine the absorbed dose to water from which the air kerma strength for an Ir-192 source can be easily derived at the reference point (5 cm). The calculated air kerma strength showed discrepancies of -0.6% to +1.8% relative to the air kerma strength provided by the vendor, In this work we demonstrated that the air kerma strength ($S_k$) could be determined from the absorbed dose to water calibration factor for Ir-192 source. In audition, this source calibration method could be applied directly to the dose Calculation formalism of AAPM report TG-43.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.160-164
• /
• 2007

In the steel industry, there is a need to produce large forged parts for the automobile industries, the flight and shipping industries ad military industries. In the steel-industry application, a cogging technique for cast ingots is required, because the major parts are needed as one large body in order to obtain higher quality. Therefore, cogging process is the primary step in manufacturing of practically large open-die forging. In the cogging process, internal voids have to be eliminated as defects, The present work is concerned with the elimination of the internal voids in large ingots so as obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis are performed to investigate the overlap defect of cast ingots during cogging stage. The measure flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of void closure are performed by using the $DEFORM^{TM}$-3D. The calculated results of void closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the void closure can be investigated by the comparison of practical experiment and numerical analysis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.11
• /
• pp.1665-1670
• /
• 2006

The objective of this research was to provide the characterization and method for producing anti-E. coli O157:H7 antibodies in egg-laying hens and to determine if the antibody can restrain the proliferation of E. coli O157:H7 in-vitro. Selected antigenic fractions (whole cell, outer membrane protein and lipopolysaccharide (LPS)) from E. coli O157:H7 were injected to hens in order to produce anti-E. coli O157:H7 antibodies. The immune response and the egg yolk antibodies of laying hens against the whole cell, outer membrane protein and LPS antigens were monitored by ELISA. The level of antibodies against whole cell antigen monitored through ELISA sharply increased after the initial immunization, and it was found to be maximum on day 49 however, the level was maintained up to day 70. Antibodies (5 mg/ml) directed against the whole cell inhibited E. coli proliferation 10-13 times more than outer membrane protein or LPS. The antibody response against the whole cell antigens appeared to have higher activity in restraining the proliferation of E. coli O157:H7 than antibody against outer membrane protein or LPS. Results reflected that increasing the IgY's in the egg yolk could prevent greater economic losses due to human and animal health from pathogenic bacteria i.e. E. coli O157:H7.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.12
• /
• pp.1691-1695
• /
• 2006

The identification method that inflects real time ultrasound (RUT) and the potential application of marker assisted selection (MAS) for improvement of a cow population of Hanwoo (Korean Native cattle) was studied. The averages of RUT longissimus muscle area, RUT fat thickness, and RUT marbling score scanned at the 13th rib were 55.78 $cm^2$, 3.70 mm and 3.83 scores, respectively. We investigated the effects of the two SNPs (Kpn2 I and Msp I) in the leptin gene on carcass traits for Hanwoo cows by using ultrasound measurements. Genotype CC of the Kpn2 I had a significantly higher effect on back fat thickness (4.23 mm) and longissimus muscle area (57.57 $cm^2$) than genotype TT (3.14 mm, 53.93 $cm^2$, respectively, p<0.05). Genotype AA of the Msp I had a significantly higher effect only on marbling score (5.37) than genotype AB (3.57, p<0.05) and BB (3.37, p<0.05). Significant effects of SNPs in the leptin gene were found for the ultrasound measures of body composition in live cattle.

• Transactions of Materials Processing
• /
• v.16 no.4 s.94
• /
• pp.293-298
• /
• 2007

Recently, there is a need to produce a large forged part for the flight, shipping, some energies, and military industries, etc. Therefore, an open die forging technique of cast ingots is required to obtain higher quality of large size forged parts. Cogging process is one of the primary stages in many open die forging processes. In the cogging process prior to some open die forging processes, internal cavities have to be eliminated for defect-free. The present work is concerned with the elimination of the internal cavities in large ingots so as to obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis is performed to investigate the overlap defect of cast ingots during cogging stage. The measured flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of cavity closure is performed by using the $DEFORM^{TM}-3D$. The calculated results of cavity closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the cavity closure can be investigated by the comparison between practical experiment and numerical analysis.