• Journal of Plant Biotechnology
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• 제30권2호
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• pp.143-149
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• 2003

This experiment was carried out to confirm the stability of bar gene introduced into petunia plant through Agrobacerium-mediated transformation. Twenty-five transgenic plants T$_{0}$ plants, back cross (BC$_1$) populations to wild type and F$_1$plants between different T$_{0}$ plants were prepared, and polymerase chain reaction(PCR), PCR-Southern blot analysis, and field test with 0.1% Basta treatment were done. The results of PCR, PCR-Southern blot hybridization, and field test indicated that NPTII and bar gene introduced into the genome of petuina plants were stably transmitted to their progenies, and conferred the plants resistance to herbicide, Basta.sta.

• 한국해안해양공학회지
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• 제19권3호
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• pp.183-193
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• 2007

부분반사 전면 및 완전반사 후면을 갖는 반무한 방파제 및 방파제 개구부에 의한 파의 산란 현상에 대한 해석 해를 유도하였다. 이는 수심이 일정하고 파가 방파제에 직각으로 입사하는 경우에 적용 가능하며, 선형파 이론에 근거하여 변수 변환 및 좌표 변환을 통해 지배 방정식을 상미분 방정식으로 전환하여 구하였다. 본 연구에서 유도된 해석 해는 유한 요소 수치 모델의 결과와 비교하여 그 정확도를 비교하였는데, 꽤 정확한 결과를 보인다는 것을 알 수 있었다. 유도된 해석 해를 이용하여 방파제에서의 반사율에 따른 항 입구에서의 정온도에 미치는 효과를 조사하였다.

• 소성∙가공
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• 제15권2호
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• pp.118-125
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• 2006

API steel is used for line-pipe to transport the oil and natural gas. As the recent trends in the development of API steel are towards the use of larger diameter and thicker plate, many researches have been studied to achieve higher strength, higher toughness and lower yield ratio in API steel. However, the strength of API steel after pipe forming is changed depending on the competition of the Bauschinger effect and work hardening which are affected by the strain history during pipe forming process. So, the purpose of this study is to investigate the influence of microstructure on the Bauschinger effect for API steel. To change the microstructure of API steel we have changed the hot rolling condition and the amounts of V and Cu addition. The compression-tensile test and the microstructure observation by OM and TEM were conducted to investigate the yield strength drop and the correlation between the Bauschinger effect and microstructure of API steel. The experimental results show that the increase of polygonal ferrites volume fraction increases the Baushcinger effect due to the back stress which comes from the increase of mobile dislocation density at polygonal ferrite interior during the compressive deformation. The hot rolling condition was more effective on the Bauschinger effect in API steel than the small amount of V and Cu addition.

• 대한인간공학회지
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• 제22권1호
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• pp.57-67
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• 2003

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics. and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person. despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also. when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

• 소성∙가공
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• 제33권1호
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• pp.18-35
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• 2024

In the present work, the evolution rules for the internal variables including continuum damage factors are obtained using the thermodynamic framework, which are in turn facilitated to derive the elastic-plastic constitutive relation for the particulate composites. Using the Mori-Tanaka scheme, the homogenization on state and internal variables such as back-stress and damage factors is carried out to procure the rate independent plasticity relations. Moreover, the degradation of mechanical properties of constituents is depicted by the distinctive damages such that the phase and interfacial damages are treated individually accordingly, whereas the kinematic hardening is depicted by combining the Armstrong-Frederick and Phillips' back-stress evolutions. On the other hand, the present constitutive relation for each phase is expressed in terms of the respective damage-free effective quantities, then, followed by transformation into the damage affected overall nominal relations using the aforementioned homogenization concentration factors. An emphasis is placed on the qualitative analyses for strain localization by observing the perturbation growth instead of the conventional bifurcation analyses. It turns out that the proposed constitutive model offers a wide range of strain localization behavior depending on the evolution of various internal variable descriptions.

• 식물조직배양학회지
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• 제21권4호
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• pp.187-192
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• 1994

밀의 조직절편을 직접 유전자 전이에 의해서 형질전환시켰다. 기계적으로 잘려진 뿌리조직 절편은 pBl 121 plasmid DNA와 electroporation 방법으로 형질전환시켰으며 300mg/L kanamycin을 함유하는 MS 배지에서 배양하였다. 형질전환된 캘러스는 배양한 지 5-7일이내에 개시되었으며 4주 후 선발되었다. 형질전환 효율의 최적수준은 200 V/ 800uF이었으며 2.5%로 형성되었다. GUS 분석과 southern 분석은 뿌리절편과 절편유래 캘러스로부터 외래유전자의 발현과 안정한 형질전환이 이루어졌음을 보여주었다.

• 한국주조공학회지
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• 제32권3호
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• pp.138-143
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• 2012

This steel has been synthesized integrating concepts from Austempering Ductile Cast Iron (ADI) technology. While ADI has excellent mechanical and physical properties, the Young's modules of ADI is approximately 20% lower than steel. In addition, the presence of graphite nodules in ADI can be sites of crack initiation, where fracture takes place at graphite matrix interface. Because of this limitations of ADI, there has been a growing interest in austempered steels as structural materials in resent years. In this investigation, a new steel with microstructure composed of ferrite and austenite and with simultaneous high tensile strength (1,150 MPa) and high ductility (33%) was developed. The goal of this investigation is to obtain a better understanding of deformation and transformation behaviour in high carbon retained austenite(${\gamma}_{HC}$) and over-saturated ferrite(${\alpha}$) during the plastic deformation. A detailed study of the microstructure of this steel was carried out by means of X-ray diffraction (XRD) and electron back scattering diffraction (EBSD) technic. In this way it was shown that BCC phase (BCC) took up the larger part of the nominal strain whereas the a part of retained austenite responded to the mechanincal load by partial martensite transformation, and misorientation change in the retained austenite after plastic strain could be attributed to the large elongation.

• 농촌지도와개발
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• 제3권1호
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• pp.1-16
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• 1996

The purpose of this study was to interpret the transformation of Cooperative Groups for Agricultural Production(CGAP) with the change of the Agricultural Productive Force. The specific objectives were; 1) To investigate the change of agricultural labour-power, 2) To investigate the change of agricultural mechanization and arable land, 3) To interpret the transformation and content of CLAP. The population of farmhouseholds has decreased continuously since the late 1960s. Especially, with the move-outs of youth ages of twenties to forties, the condition of agricultural labour-power has been more serious. The processing of agricultural mechanization was a small scale step in the 1970s, but after the 1980s there was a spread of middle-large machines. However the usage rate of agricultural machines was constrained by the bad conditions of arable land. From the 1970s to now, the CGAP have bean processed by many kinds of patterns. In the 1970s, the lack of labour-power caused the creation of the Co-Working Team. After the late of 1970s, the wage of agricultural employees was raised, because the working population of agriculture was cut down. Also, the induction of agricultural machine was promoted. As a result, in the 1980s, the Machine-Using Team occurred due to these conditions of agricultural productive force. In the late of 1980s, the population decreased more rapidly, and the use of large machines were spread. Than farmhouseholds laking labour-power gave a trust to other farmhouseholds and Teams which had machines. In 1990, Given-Trust Cooperations were enacted by law, and in order to overcome the lack of labour-power, and solve the problem of the successors of agriculture, Cooperative Organizations were also enacted by law. Finally, in Korea from the 1970s to now, as the agricultural productive force has barn changed, the Co-Working Team was transformed into the Machine-Using Team, and the Machine-Using Team was transformed into the Given-Trust Cooperation, and the Cooperative Organization.

• Agricultural and Biosystems Engineering
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• 제3권1호
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• pp.18-28
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• 2002

Neural network based models were developed and evaluated for predicting corn yield from aerial images based on 1998 and 1994 image data. The model used images in multi-spectral bands such as R, G, B, and IR (Red, Green, Blue and Infrared). The inputs to the neural network consisted of mean and standard deviation of multispectral bands of the aerial images. Performances of several neural network architectures using back-propagation with momentum were compared. The maximum yield prediction accuracy obtained was 97.81%. The BPNN model prediction accuracy could be enhanced by using more number of observations to the model, other data transformation techniques, or by performing optical calibration of the aerial image.

• Clinical and Experimental Reproductive Medicine
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• 제43권1호
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• pp.51-53
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• 2016

Uterine fibroids are benign tumors of the myometrium with a diverse range of manifestations. Fibroids can dramatically increase in size during pregnancy due to the increase in estrogen levels. After delivery, the fibroids usually shrink back to their pre-pregnancy size. Uterine myomas may have many complications, including abnormal uterine bleeding, infertility, pressure on nearby organs, degeneration, and malignant transformation. No previous reports have indicated that a fistula may develop between a uterine fibroid and the bowel loops, although previous studies have documented the occurrence of fistulas from the uterus to the bowel following myomectomy or uterine artery embolization performed to treat a myoma. In our case report, we document the rare complication of a fistula occurring between a degenerated myoma in the posterior wall and the ileum 1 week postoperatively in a patient who underwent a Caesarean section but did not have a history of uterine artery embolization.