• 정보처리학회논문지B
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• 제12B권1호
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• pp.69-80
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• 2005

본 논문에서는 기존 온톨러지를 가공하여 용도에 맞게 변환하는 방안을 모색하였다. 변환방법으로서는 범주정보 단순화와 구체화를 고안하였다. 이 각각은 다시 범주표제와 기저범주를 이용한 방법으로 나누어 생각하였다. 또한 상이한 범주집합들 사이의 관계를 밝히는 방법도 도출하였다. 정립한 변환 방법론을 활용하여, (1) Roget 시소러스로부터 7개의 범주로 구성된 '이야기 분석용 온톨러지'[32]의 원형을 구축하였고, (2) 이미 알려진 22가지 멀티미디어 게임 흡인요소를 바탕으로 세분화된 흡인요소 207가지를 발견할 수 있었으며[35], 그리고 (3) 10개의 심소와 22가지 멀티미디어 게임 흡인요소 사이의 관계를 밝혀낼 수 있었다[36].

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1316-1321
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• 1990

Molten steel level information of ladle is very important for process control in steelmaking process. At secondary refining process, measuring lance and snokel have to keep constant thier depth from molten steel surfaces. But, there is much slag on the molten steel surface. Besides, not only the thickness of slag is varied with refining condition, but also molten steel level is largely affected by firebrick errosion. Then, optical measuring method and/or by human eyes cannot detect true molten steel surface, but slag surface. This slag thickness is 300mm at maximum, then huge diameter eddy current sensor will be needed if that type sensor is applied. In addition to, cooling system is necessary because the molten steel and slag temperature is high. This is not practically. To solve this problem, immersion type levelmeter is developed. This sensor is made up from primary and secondary cylindrical coils. High frequency current is applied to primary coil. Electro-motive force from secondary coil is measured, which is varied with molten steel level. This complete set is installed within stainless steel long capsule and attached to top of lance. This sensor is immersed into molten steel bath of ladle or tundish with protection of expendable paper sleeve.

• Macromolecular Research
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• 제9권5호
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• pp.285-291
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• 2001

The polysulfone(PSf)/polyethersulfone(PES) blend membranes were prepared by an immersion precipitation method. N-methyl-2-pyrrolidone(NMP) was used as a solvent and water as a nonsolvent. The composition of the coagulation bath and the dope polymer concentration as well as the blend ratio of two polymers were varied. The membrane morphologies were interpreted on the basis of the phase diagram of the PSf/PES/NMP/water system. As the solvent content in the coagulation bath increased in the single polymer system, the number of macrovoids decreased and the morphology was changed from finger-like to cellular structure. In the given bath condition phase separation occurs earlier for the solutions of PSf/PES blend than for those of single polymer. A horizontally layered structure and horizontal protuberances inside the macrovoid were observed for the membranes formed from PSf/PES blend solutions. This peculiar structure formation can be interpreted by a PSf-rich/PES-rich phase separation followed by a polymer-rich/polymer-lean phase separation during the exchange of solvent and nonsolvent.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.7-17
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• 1991

The feasibility of treating three softwood(Japanese larch pitch pine, and Korean pine) thinned logs by double-diffusion treatment processes was investigated. Some posts were incised before immersion, and others were imersed in hot copper sulfate solution. Comparison among species indicated that. in general, pitch pine was most treatable and Japanese larch least treatable. For all three species, almost all treatment schedules gave consistently good penetration and high net retention, but very steep gradient of preservative distribution. As expected, the treatability was increased by the extension of immersion time, increased concentration of treating solution, incising. and heating of the first solution. Of the variables tested, it appears that heating of the first solution is the most important. From the data in this paper, it may be concluded that, if the first solution is not heated, the best schedule is #3. If the first solution is healed. it appears the best schedules are #10 or #11. Since heating of the first solution improves the treatability. schedules # 10 or :#11 are recommended if the cost of heating might be justified. The data presented in this paper indicate that double-diffusion treatment processes seem to offer a promise as a comparatively effective and easy-operating method of treating thinned logs for the small-scale production of treated stock.

• 한국치위생학회지
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• 제15권6호
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• pp.1091-1097
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• 2015

Objectives: The purpose of this study was to examine the relationship between educational satisfaction and learning participation of dental hygiene students. Method: A self-reported questionnaire was completed by 344 dental hygiene students in Gyeonggido, Chungcheongdo, and Gyeongsangdo from June 2 to 24, 2014, The questionnaire consisted of general characteristics of the subjects(3 items), choice reason of dental hygiene(7 items), educational satisfaction(22 items), and learning participation(11 items). The educational satisfaction and learning participation were assessed by Likert 5 points scale. Data were analyzed by a statistical package SPSS WIN 18.0. Results: Educational satisfaction included educational environments, teaching, educational content and educational effect. Learning participation included class flow, class participation and class readiness. Gyeongsangdo students tended to have higher score than other areas. The educational effect and teaching effect had more influence on learning participation. Conclusion: To improve the better dental hygiene education, it is important to prepare the effective educational methods and find out the influencing factors for class immersion.

• 한국표면공학회지
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• 제40권3호
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• pp.149-158
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• 2007

Of all components of MCFC(molten carbonate fuel cell), corrosion of separator is one of the most decisive factor for commercializing of MCFC. In order to provide better understanding of corrosion behavior and morphology for gas channel of separator plate, post-analysis after cell operation for 1200 hours at $650^{\circ}C$ was performed by optical microscope, SEM and EPMA. Intergranular corrosion was observed on gas channel of separator plate. Corrosion product layer was identified as Fe-oxide, Cr-oxide and Ni-oxide by EPMA, and oxide thickness was measured with a $60{\mu}m-150{\mu}m$. Also, gas channel of separator was damaged by severe intergrannular attack with post analysis in consistent with immersion test. Moreover, pitting on the channel plate was observed with a depth of $18{\sim}24{\mu}m$. The results of immersion method are well agreement with post analysis measurements.

• Corrosion Science and Technology
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• 제9권5호
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• pp.175-186
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• 2010

The auto industry is demanding more ductile high-strength steel grades to build lighter and stronger car bodies. The hot-dip galvanizing problems of these new steel grades are creating a demand for an improved method to control zinc wettability. The simplest way to improve zinc wettability on industrial hot-dip galvanizing lines is to increase the strip immersion temperature at zinc bath entry for enhancing the aluminothermic reaction. However, this practice increases the reactivity due to overheating the zinc in the snout which induces the formation of brittle Fe-Zn compounds at the strip/coating interface with the formation of higher amounts of dross in the zinc bath and snout contamination. Thus, this simple practice can only be utilized for short production periods of one to two hours without deteriorating coating quality. This problem has been solved by employing a technique that allows the use of a higher and attuned strip immersion temperature at zinc bath entry while still maintaining a constantly low zinc bath temperature. This has been proven to provide the solution for both the improved wettability and a significant reduction in the amounts of dross in the zinc bath.

• 한국콘텐츠학회논문지
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• 제18권1호
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• pp.487-492
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• 2018

본 연구의 목적은 가상현실 교육 서비스에서 동일한 서비스를 서로 다른 디바이스로 체험함에 따른 영향을 살펴보고자 한다. 이를 위해 HMD(헤드 마운트 디스플레이)와 테블릿 PC를 통한 교육을 진행하였으며, 두 가지 기기에서 동일한 교육을 제공하는 토클리쉬라는 영어 교육 서비스를 이용하여 총 37명의 피실험자를 대상으로 실험을 진행하였다. 그 결과, HMD를 사용한 피 실험자가 테블릿 PC를 이용한 피실험자 보다 동일한 교육을 체험하더라도 몰입, 사회적 자의식, 그리고 학습 동기가 더욱 높은 것으로 나타났다. 이 결과를 바탕으로 향후 가상현실 교육 서비스를 위한 시사점을 제시한다.

• 정보저장시스템학회논문집
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• 제3권1호
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• pp.1-4
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• 2007

A high density optical data storage device has been required for many years. In the field of the optical data storage, a near-field recording (NFR) technology is considered as a next generation one for achieving the high data density. Due to an evanescent wave effect occurred under 100nm distance which is the excessively small distance between the SIL and the disc, the most significant and difficult problem in this technology is to maintain a gap between a solid immersion lens (SIL) and a disc. Also, maintaining the gap under at least 50nm is required in the NFR gap servo system to use the evanescent wave effect efficiently. There are some institutes that have shown the novel gap servo control. In general, they use a mode switching servo method which consists of approach, hand-over and gap control mode. However there is a critical problem such as an overshoot at the tuning point from the approach mode to the hand-over mode, which may cause a collision between the SIL and the disc. In this paper, we show our NFR system and an improved gap servo system using an exponential function as the approach mode which can reduce the overshoot.

• 대한치과보철학회지
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• 제29권1호
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• pp.13-22
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• 1991

This study investigated the effects of surface treatment on the tensile bond strength of resinbonded prosthesis. The Rexillium III specimens were treated with $50{\mu}m\;Al_2O_3$ blasting. Type IV gold alloy specimens were treated with $400^{\circ}C$ heating and tin plating method. All specimens were bonded with MBAS composite resin cement and followed by immersion test into the $37^{\circ}C$ water bath for 7 days. The specimens were debonded in tension with an Instron machine and observed with SEM. The modes of failure were recorded also. The following conclusions were obtained : 1. The tensile bond strength decreased in following order. $50{\mu}m\;Al_2O_3$ basted Resillium III group, Type IV gold alloy group treated with $400^{\circ}C$ heat and tin plating type IV gold alloy group, and statistical significant differences were observed(p<0.05). 2. The tensile bond strength decreased in all groups after 7 days immersion test, but statistical significant differences were observed in Rexillium III specimens only. 3. The sharp and irregular surface were observed in Rexillium III, but $400^{\circ}C$ heat treated and tin plated groups had round and broad surface in SEM. 4. The models of bond failure were cohesive-adhesive failure mainly.