• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.525-526
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• 2007

• 식물분류학회지
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• 제40권2호
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• pp.113-117
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• 2010

국내에서 채집된 마름속 식물들을 동정한 결과, 열매가 대형인 Trapa bispinosa Roxb.가 확인되었다. Trapa bispinosa는 국내에서 마름(T. japonica Flerow)으로 동정되어 보고된 바 있으나, 마름속 식물의 중요 식별형질인 열매 형태와 크기에 대한 검토가 이루어지지 못하였다. 두 분류군의 열매에 대한 16개 정량형질을 조사하고, 이에 대한 주성분분석을 수행하였다. 열매 형질의 분석 결과, T. bispinosa는 마름에 비하여 열매의 너비와 두께가 크고, 열매의 뿔이 길고 비후된 특징을 가진다. 또한 전체 변이의 42.3%를 설명하는 주성분1에 의해서 마름과 뚜렷하게 구별되었다. 이번에 조사된 T. bispinosa는 마름과 구별되는 독립된 분류군으로 취급하는 것이 타당한 것으로 파악되며 일반명으로 '큰마름'을 부여하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7007-7009
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• 2015

Background: Tobacco use in various forms, including with Areca nut, causes several potentially malignant disorders. Many lesions may transform into oral squamous cell carcinoma. Although patients may be aware of the hazards of tobacco habits, the lesions by themselves are insidious in nature resulting in failure of patients to present to general dentists/specialists at early stages. Our aim was to study the types of habits prevalent in the region of Rourkela in Orissa and to assess the insidious nature of the lesions associated with these habits. Not many studies have been done from this part of India. Materials and Methods: A camp was conducted for habitual users of tobacco and its products, Areca nut and other mixed habit users. A thorough history was taken of the type, duration and frequency of habits, symptoms of patients along with clinical examination by a single examiner. The data was entered in detail into an excel sheet and analysed. Results: 54.7% had lesions and 60.9 % of them were asymptomatic and rest had mild burning sensation while eating. There was a very low awareness of the presence of lesions among the patients. Conclusions: There is a need to spread the awareness of the ill effects of the tobacco and other associated habits far and wide and more importantly educate the general public on the appearance of associated lesions as these are almost always insidious in nature. The patients can self-examine, detect lesions early when present and approach the dentist at the earliest opportunity.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4341-4346
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• 2012

Purpose: The aim of this study was to cast light on initiating molecular events associated with the development of premalignant oral lesions induced by tobacco and/or areca nut. Method: Immunohistochemical analyses of cell cycle regulatory proteins (LIMD1, RBSP3, p16, RB, phosphorylated RB, p53), EGFR and SH3GL2 (EGFR associated protein) were performed with inflammatory/ulcerative epithelium and adjacent hyperplastic/mild dysplastic lesions. Results: No change in expression of the proteins was seen in inflammatory epithelium. Reduced nuclear expression of LIMD1 was evident in ulcerative epithelium. In hyperplastic lesions, reduced expression of RBSP3, p16, SH3GL2 and overexpression of p-RB and EGFR were apparent. Reduced nuclear expression of p53 was observed in mild dysplastic lesions. Conclusion: Our data suggest that inactivation of LIMD1 in ulcerative epithelium might predispose the tissues to alterations of other cell cycle regulatory and EGFR signaling proteins needed for the development of premalignant oral lesions.

• Structural Engineering and Mechanics
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• 제55권3호
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• pp.639-654
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• 2015

Bolted joints are essential elements of mechanical structures and metal constructions. Although their static behaviour is fairly well known, their dynamic behaviour due to shocks and vibrations has been less studied, because of the large size of the finite element models needed for a detailed simulation. This work presents four different simplified models suitable for studying the dynamic behaviour of an elementary bolted joint. Three of them include contact elements to allow sliding of the screw head and the nut on the assembled parts, and the last one allows rotation between screw and nut. A penalty approach based on the Coulomb friction model is used to model contact. The results show that these models effectively represent the dynamic behaviour, with different accuracy depending on the model details. The last model simulates the self loosening of a bolt subjected to transversal vibrations.

• 한국기계가공학회지
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• 제6권2호
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• pp.3-8
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• 2007

Nonlinear property and contact matter are analyzed about the pipe applied with internal pressure through this study. The weakest part and its safety can be examined. Maximum equivalent stress is shown at the contact surface between bolt and nut. The value of contact stress with the pressure of 12MPa is increased 1.4 times as large as that with no pressure. The maximum contact pressure is shown at the clamp corner of the external surface on pipe. The value of contact pressure with the pressure of 12MPa is increased 1.4 times as large as that with no pressure. The radial deformation with no pressure is also increased greatly at the middle part of internal surface on pipe. But this maximum deformation on pipe with the pressure of 12MPa is shown at the part far away the support of pipe. This value is increased 5.7 times as large as that value with no pressure. As contact status, the sticking occurs most at the external surface of pipe. It also tends to occur at the contact surface between bolt and nut. At the external surface of pipe, the sticking in case of the pressure of 12MPa occurs more than that in case of no pressure.

• Composites Research
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• 제28권3호
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• pp.118-123
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• 2015

In the current study explain about the bio-based composites made by groundnut shell as reinforcement with polyester resin matrix. Groundnut shell is an abundantly available natural waste byproduct and poly ester resin is widely used to fabricate of composites for good balance of mechanical properties because it is relatively low price and ease of handling. Evaluate the mechanical properties of manufactured groundnut shell/polyester composites by varying the amounts (wt %) of groundnut shell. Particulate shell reinforced polyester composites incorporating varying amounts of groundnut shell (5, 10, 15 and 20%) were characterized for their tensile strength, flexural strength, and impact strength. The mechanical properties improved with increasing particle loading up to 15% and decreased thereafter. Increasing in strength with increased particle shell loading was attributed to increase in surface area which enhanced load transfer between the polyester matrix and ground shall particulates. Scanning electron microscopic studies have been carried out to study the morphology of the composite. Thermal studies and water absorption properties of the composites also studied in this paper.

• 한국정밀공학회지
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• 제32권6호
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• pp.523-528
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• 2015

As the sizes of mobile phones and watch phones decrease, the joining bolt for the products should also be decreased to a miniature size. However, the miniature-sized bolt has to support sufficient joining and anti-releasing torque to keep the product fastened. In this study, the thread shapes are designed to improve anti-releasing performance of bolts. Especially, when bolt materials is stronger than nut materials, the design of thread shapes is needed, like bolt for wood, to improve the fastening capability. Through the joining and releasing analyses of bolts, the thread shapes for SUS302 bolt and Mg alloy nut are newly designed. It was shown that the newly designed bolt has 20 % higher anti-releasing torque and 35% lower torque loosening slope compared to the standard bolt.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1633-1637
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• 2012

Introduction: The incidence of oral premalignant and malignant lesions is on the rise due to an increased number of people taking in tobacco and alcohol related habits. Material and Methods: 1028 patients with tobacco, alcohol and areca nut habits attending our Department of Oral Medicine and Radiology formed the study sample. An interviewer based questionnaire was used to record the habit details. All the patients were then examined clinically for the presence of lesions. Chi square and Fisher exact tests were used to assess the statistical significance of the study parameters. Results: Males had a higher prevalence and comprised 87.9% of the sample. The commonest habit in this study sample was smoking (39.2%) followed by smokeless tobacco use (28.1%). Out of the 1028 patients with habits 40% had no clinically detectable changes in their mucosa. Of the mucosal changes leukoplakia (14%) was the commonest. Conclusions: This study provided information about the habit trends in the patients visiting this institution. The study may serve as a useful tool in educating the patients about the deleterious effects of oral tobacco, alcohol and betel exposure.

• 소성∙가공
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• 제27권3호
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• pp.165-170
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• 2018

In order to increase the lifetimes of cold forging dies, insert rings are generally used. In this study, an insert ring and shrunk ring of the flange upsetting die were designed for the cold forging of an automotive wheel nut. The Stress distribution occurring in the die during forging was simulated using a commercial finite element analyzing program. The effects of the fitting interference and inclined angle of the insert ring on the compressive stress of the die inside were also investigated. The simulated data were compared with the real lifetimes of the forging dies. The maximum compressive stress acting on the edge of a forging die should have the most influence on die lifetime, an idea which could help develop the die design with the longest lifetime. The design of the most optimal forging die with the longest lifetime is made possible by analyzing the maximum inner pressure and principal stress between the shrunk ring and insert ring.