• 정보저장시스템학회논문집
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• 제3권2호
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• pp.54-58
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• 2007

Using metal/Si materials as a recording layer, we have achieved good results for a SR disc (super resolution disc). Mainly by controlling metal composition and the ratio of metal to Si of recording layer, signal qualities were greatly enhanced. At the mark length of 75nm, the best CNR (Carrier to Noise Ratio) was about 45dB. Write power was reduced down to about 6.5mW. LFN (Low Frequency Noise) could also be reduced down to 14dB. Single tone pattern jitters for every mark whose length is from 2T through 8T were achieved to be below 10%. The readout signal was stable sustaining CNR>40dB during about 15,000 times reading. The so-called "3T-problem" could be avoided.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.571-574
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• 2002

The photorefractive polymeric composite with good performance was prepared. The carbazole-substituted polysiloxane sensitized by 2,4,7-trinitro-9-fluorenone was used as a photoconducting medium and 1-[4-(2-nitrovinyl)phenyl]piperidine was added as an optically nonlinear chromophore. The photorefractive property of polymer was determined by diffraction efficiency using a 100 ㎛-thick film. The maximum diffraction efficiency ( ηmax) of 71% was obtained at the electric field of 70 V/ ㎛. The potential of the current polymer material as a holographic recording medium was evaluated by the demonstration of holographic recording and subsequent reading of optical image.

• ETRI Journal
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• 제30권4호
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• pp.600-602
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• 2008

A very small patch-type RFID tag antenna (UHF band) using ceramic material mountable on metallic surfaces is presented. The size of the proposed tag is 25 mm${\times}$25 mm${\times}$3 mm. The impedance of the antenna can be easily matched to the tag chip impedance by adjusting the size of the shorting plate of the patch and the size of the feeding loop. The measured maximum reading distance of the tag at 910 MHz was 5 m when it was mounted on a 400 mm${\times}$400 mm metallic surface. The proposed design is verified by simulation and measurements which show good agreement.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.107-114
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• 2002

This paper deals with the non-linear analysis of cantilever beams with constant volume. Numerical methods are developed for solving the elastica of cantilever ben subjected to a tip Point load and a tip couple. The linear, parabolic and sinusoidal tapers with the regular polygon cross-section are considered, whose material volume and span length are always held constant. The Runge-Kutta and Regula-Falsi methods, respectively, are used to integrate the governing differential equations and to compute the unknown value of the tip deflection. The numerical results obtained herein are shown in tables and figures. Also the shapes of strongest beams are determined by reading the minimum values form the deflection versus section ratio curves.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.115-122
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• 2002

The main purpose of this paper is to determine the static optimal shapes of tapered beams with constant volume. The linear, parabolic and sinusoidal tapers with the regular polygon cross-section are considered, whose material volume and span length are always held constant. The Runge-Kutta method is used to integrate the differential equation and also Shooting method is used to calculate the unknown boundary condition. Then the static optimal shapes are determined by reading the minimum values of the deflection versus section ratio curves plotted by the deflection data. In numerical examples, the various tapered beams are analyzed and those numerical results of this study are shown in figures.

• 영어영문학
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• 제57권6호
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• pp.1199-1212
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• 2011

This paper is to scrutinize Jean Rhys' Wide Sargasso Sea through a Marxist criticism. While critics were industriously excavating discourses of feminism, post-colonialism, and racism in the novel, they tended to regard the Marxist attribute as supplementary material and to diminish the significance not considering as an independent subject to be examined. However, the novel, in which all the major relationships are based on capital, exemplifies class conflict between the bourgeois and the proletariat. Marx and Engels believe that the foundation of our society is capital and that society evolves through class conflict to obtain more capital, and thus they assert people's relations are the product of the commodification of individuals. Furthering their study, Louis Althusser specifies the power system through the (repressive) state apparatus and the ideological state apparatus. With the theories of the thinkers' above, this paper analyzes the relationship between Annette and Mason, Antoinette and her nameless husband, allegedly Rochester, Rochester and Amelie, and Rochester and Daniel Cosway. This paper offers an alternative reading of a classical feminist and post-colonial text.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.945-953
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• 2006

The researchers in the field of cognitive science and learning science suggest that the teaching activity induces the elaborative and meaningful learning. Actually, lots of research findings have shown the beneficial effect of learning by teaching such as peer tutoring. But peer tutoring has some limitations in the practical learning context. To overcome some limitations, the new concept of "learning by teaching" through the agent called Teachable Agent. The teachable agent is a modified version of traditional intelligent tutoring system that assigns a role of tutor to teach the agent. The teachable agent monitors individual difference and provides a student with a chance for deep learning and motivation to learn by allowing them to play an active role in the process of learning. That is, The teaching activity induces the elaborative and meaningful learning. This study compared the effects of our teachable agent, KORI, and peer tutoring on the cognition and motivation. The field experiment was conducted to examine whether learning by teaching the teachable agent would be more effective than peer tutoring and reading condition. In the experiment, all participants took 30 minutes lesson on rock and rock cycle together to acquire the base knowledge in the domain. After the lesson, participants were randomly assigned to one of the three experimental conditions; reading condition, peer tutoring condition, and teachable agent condition. Next, participants of each condition moved into separated place and performed their own learning activity. After finishing all of the learning activities in each condition, all participants were instructed to rate the interestingness using a 5-point scale on their own learning activity and leaning material, and were given the comprehension test. The results indicated that the teachable agent condition and the peer tutoring condition showed more interests in the learning than the reading condition. It is suggested that teachable agent has more advantages in overcoming the several practical limitations of peer tutoring such as restrictions in time and place, tutor's cognitive burden, unnecessary interaction during peer tutoring. The applicability and prospects of the teachable agent as an efficient substitute for peer tutoring and traditional intelligent tutoring system were also discussed.

• 벤처창업연구
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• 제11권5호
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• pp.153-164
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• 2016

청소년들이 바람직한 사회인으로 성장할 수 있도록 자기효능감을 함양하고 자신에게 적합한 진로를 준비하며 창의성과 모험심을 갖추는 것은 매우 중요하다. 이런 시기에 다양하고 생생한 정보를 문자로 정제하여 전달하는 신문은 좋은 교재가 될 것이다. 본 논문에서는 청소년들의 신문구독여부로 확인한 'NIE(Newspaper In Education)의 수행여부'가 자기효능감 및 진로인식, 기업가정신의 함양에 미치는 영향을 분석하였다. 전국의 초등학교 고학년 및 중학생을 대상으로 한 283건의 설문조사를 통한 실증분석결과 다음과 같은 결론을 도출하였다. 청소년들의 신문구독은 자기효능감, 진로인식, 기업가정신에 긍정적인 영향을 미치는 것으로 나타났다. 또한 신문의 지속적인 구독은 자기효능감에 정(+)의 영향을 미치며, 이러한 자기효능감은 진로인식과 기업가정신에 정(+)의 영향을 미치는 것으로 나타났다. 이로서 신문을 활용한 특별한 프로그램을 실시하지 않더라도 신문을 구독하는 것만으로 자기효능감, 진로인식, 기업가정신의 함양에 도움이 됨을 알 수 있다. 이는 신문구독과정에서 접하는 많은 정보와 다양한 의견들이 청소년의 주관 형성에 도움이 되고, 직업에 대한 이해와 관심을 제고시키며, 창의 및 도전정신을 포함한 사회성의 발전에 기여하는 것으로 볼 수 있다. 본 연구는 청소년들의 신문활용교육이 자기효능감과 진로인식 뿐만 아니라 기업가정신에도 긍정적인 영향을 미치는 것을 확인한 최초의 연구로서 의미가 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.173-182
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• 2000

To find axial and lateral responses of impact-driven H piles in embankment(SM), the H piles are instrumented with electric strain gages, dynamic load test is performed during driving, and then the damage of strain gages is checked simultaneously. Axially and laterally static load tests are performed on the same piles after one to nine days as well. Then load-settlement behavior is measured. Furthermore, to find the set-up effect in H pile, No. 4, 16, 26, and R6 piles are restriked about 1, 2, and 14 days after driving. As results, ram height and pile capacity obtained from impact driving control method become 80cm and 210.3∼242.3ton, respectively. At 15 days after driving, allowable bearing capacity by CAPWAP analysis, which 2.5 of the factor of safety is applied for ultimate bearing capacity, increases 10.8%. Ultimate bearing capacity obtained from axially static load test is 306∼338ton. This capacity is 68.5∼75.7% at yield force of pile material and is 4∼4.5 times of design load. Allowable bearing capacity using 2 of the factor of safety is 153∼169ton. Initial stiffness response of the pile is 27.5ton/mm. As the lateral load increases, the horizontal load-settlement behaves linearly to which the lateral load reaches up to 17ton. This reason is filled with sand in the cavity formed between flange and web during pile driving. As the result of reading with electric strain gages, flange material of pile is yielded at 19ton in horizontal load. Thus allowable load of this pile material is 9.5ton when the factor of safety is 2.0. Allowable lateral displacement of this pile corresponding to this load is 23∼36mm in embankment.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.766-777
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• 2008

Currently in increasing number of urban tunnels with small overburden are excavated according to the principle of the New Austrian Tunneling Method (NATM). Successful design, construction and maintenance of NATM tunnel demands prediction, control and monitoring of ground displacement and support stress high accuracy. A magnetic anisotropy sensor is used for nondestructive measurement of stress on surfaces of a ferromagnetic material, such as steel. The sensor is built on the principle of the magneto-strictive effect in which changes in magnetic permeability due to deformation of a ferromagnetic material is measured in a nondestructive manner, which then can be translated into the absolute values of stresses existing on the surface of the material. This technique was applied to measure stresses of H-beams, used as tunnel support structures, to confirm expected measurement accuracy with reading error of about 10 to 20 MPa, which was confirmed by monitoring strains released during cutting tests The results show that this method could be one of the promising technologies for non-destructive stress measurement for safe construction and maintenance of underground rock structures encountered in civil and mining engineering.