• 컴퓨터교육학회논문지
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• 제6권2호
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• pp.41-51
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• 2003

웹의 구조적인 특성으로 인해서 실제 원격 교육 시스템으로 교육 활동을 수행할 때 많은 제한점이 발생된다. 비연결성 프로토콜인 HTTP는 클라이언트의 요청 각각을 별도로 수행하며 연결 상태를 유지하지 않는다. 이것은 학습자의 접속상황을 유지 관리하고 학습자의 요청 정보를 추적하기 어렵게 만든다. 그리고 이는 한 학습자의 연결유지뿐만 아니라 다른 학습자들간의 상호작용 자체를 불가능하게 만든다. 본 연구는 학습자의 학습 활동을 추적할 수 있도록 하기 위해서 HTTP를 기반으로 하여 확장된 연결성 프로토콜인 CHTP를 개발하고, 새로운 원격교육 플랫폼을 구축하였다. 프로토콜 차원에서 표준화된 방식을 제안하기 때문에 개발된 웹 확장 플랫폼은 원격교육을 위한 시스템 구축을 효과적이고 용이하게 만들어 줄 것이다.

• 대한수학교육학회지:수학교육학연구
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• 제13권1호
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• pp.25-55
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• 2003

In the school mathematics, the negative numbers have been instructed by means of intuitive models(concrete situation models, number line model, colour counter model), inductive-extrapolation approach, and the formal approach using the inverse operation relations. These instructions on the negative numbers have caused students to have the difficulty in understanding especially why the rules of signs hold. It is due to the fact that those models are complicated, inconsistent, and incomplete. So, students usually should memorize the sign rules. In this study we studied on the didactical phenomenology of the negative numbers as a foundational study for the improvement of teaching negative numbers. First, we analysed the formal nature of the negative numbers and the cognitive obstructions which have showed up in the historic-genetic process of them. Second, we investigated what the middle school students know about the negative numbers and their operations, which they have learned according to the current national curriculum. The results showed that the degree they understand the reasons why the sign rules hold was low Third, we instructed the middle school students about the negative number and its operations using the formal approach as Freudenthal suggest ed. And we investigated whether students understand the formal approach or not. And we analysed the validity of the new teaching method of the negative numbers. The results showed that students didn't understand the formal approach well. And finally we discussed the directions for improving the instruction of the negative numbers on the ground of these didactical phenomenological analysis.

• Archives of Plastic Surgery
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• 제37권2호
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• pp.199-201
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• 2010

Purpose: Except for continuous suture in skin layer, stitching out in facial laceration, we have to hold each knots up and cut the knots by No. 11 blade or small scissors. However, we often have difficulty in stitching out the knots on children who do not cooperate well. Therefore we introduce an easy and fast stitch out method of pediatric lacerations. Methods: From January to May 2009, we studied 15 pediatric patients (mean age 5.6 years old) who had facial laceration on face or underwent any surgery on operation room. For easy stitch out, we left the one string of the first knot long enough to extend at the opposite end of laceration site. And then the extended string was fixed to skin using Steri-strip. Next we do simple interrupted suture including the extended traction nylon string inside the knot. Through this method, we can stitch out all knots simply by lifting up the traction nylon needless to hold the each knot one by one. Results: Until stitching out, the traction nylon was just right position and there was no normal tissue injury during stitch out all knots. Patients were satisfied with the short stitch out time. Conclusion: By using the traction nylon on pediatric laceration suture, we can stitch out all the knots with no normal tissue injury in less time.

• 해양환경안전학회지
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• 제23권5호
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• pp.541-548
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• 2017

본 연구에서는 해양플랜트설비 건조 현장에서 사용되고 있는 기존 고온 오일 플러싱 장비에 대한 성능개선을 위해 기존의 플러싱 장치에 사용되던 오일에 질소가스를 혼합한 고온 오일 플러싱 시스템에 대하여 국제표준화기구 코드(ISO code)를 기준으로 이론적 연구를 수행하였다. 연구를 위해 오일-질소가스 혼합유체 플러싱 시스템 공정을 설계 후 청정성능에 영향을 주는 혼합유체의 혼합비율, 온도, 레이놀즈수 및 액상분율 등에 대한 공정모사 결과도 분석하였다. 그 결과 관 직경과 가스상의 체적분률이 일정한 상태에서 혼합유체의 체적유량이 증가될수록 수평 유압배관 입출구의 액상분율 차이 ${\Delta}{\alpha}_L$ 값은 증가하게 되고 배관길이 방향의 위치에 따라 오일과 질소가스 기포 사이의 상분포가 달라짐을 확인했다. 이러한 상분포의 변화는 오일-질소가스 혼합유체 플러싱 시스템의 청정성능에도 커다란 영향을 줄 것으로 예상된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.113-114
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• 2000

The secondary electron emission coefficient(${\gamma}$) of vacuum annealed MgO films has been investigated by ${\gamma}-focused$ ion beam(${\gamma}-FIB$) system. The vacuum annealed MgO films have been found to have higher ${\gamma}$ values from 0.053 up to 0.121 than those for as-deposited MgO films from 0.026 up to 0.062 for $Ne^+$ ion energies ranged from 50eV to 200eV. Also it is found that ${\gamma}$ for air hold of vacuum annealed MgO layers for 24-hours is similar to that for vacuum annealed MgO films without any air-hold.

• 한국비블리아학회지
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• 제6권1호
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• pp.179-213
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• 1984

The history of recording and conserving for maintenance the human's memory from ancient times to modern's has brought about a lot of changing process of the recorded information media with developing in culture, and each society has made important recorded materials in his library as essentially the social apparatus. But most of them that were damaged by factors of the natural disaster, humidity, temperature, light, fungi and insects in the library, and were resulted in deterioration and losing the numerous materials. For removing the inevitable phases repeated, there are studying for counterplan of the fundamental environment factors about preservation, restoration and chemical research of materials in advanced countries, but I get a few researches about protecting the cultural properties. Therefore I research the survey of the actual conditions on 72 university libraries centering around them, and then I have researched the collection rate 81 percent, 58 university libraries. (local : 35, in seoul : 23) As the result of this research, I propose the model of the environment factors of conserving the library materials. 1) To apply the equipment of processing the radiant energy to the new construction and buildings. 2) To remove factors that occur fungi and insects by facilities being controlled relative humility, temperature, and to equip the ventilation arrangement in the library. 3) To shelve all acquired and bound materials after proceeding the vacuum fumigator. 4) Those who want to enter into the library stack were surely taken in sterilzing their hands and shoes, and must put on the gown. 5) To use the vacuum dusting thing (machine) for removing the dust without spreading out the floor of the library at any time. 6) To set up the gas automatic fire extinguisher worked by smoke sensor. 7) To assist the research into the preservation, natures and environment of recorded materials, and to supply financial funds for librarian. 8) To hold regularly the workshop be able to educate the methods of preservation materials by the constant system. (Library Association) 9) To add to responsibilities on certification of preservation materials for librarian. 10) To hold the constant committee system in each library. 11) To keep up with the ideal environment (humidity, temperature, light, ventilation, etc.) of preservation materials in the arrangement room, and to put on the gown.

• Journal of Oral Medicine and Pain
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• 제48권3호
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• pp.106-111
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• 2023

Purpose: In this study, we evaluate the potential of the relative ratio of capsular width (RCW) between the affected side (Aff) and non-affected side (Non-aff) in patients with temporomandibular joint (TMJ) arthralgia. We assessed whether RCW may hold greater diagnostic significance than the objective capsular width (CW) reported in previous studies when diagnosing arthralgia using ultrasonography (US). Methods: Forty-nine patients were assessed using US, excluding four patients with bilateral arthralgia. The patients were divided into two groups: 40 with unilateral arthralgia (UA), and nine without arthralgia (NA). We measured CW and masseter muscle thickness using US. Moreover, we employed RCW to analyze the variances between the groups. The numerical rating scale (NRS) and RCW were compared before and after dexamethasone injection in 10 patients who underwent follow-up evaluations. Results: Within the UA group, CW on the Aff was found to be significantly larger compared to the Non-aff (p<0.001). Additionally, RCW in the UA group was greater than that in the NA group (p<0.01). Furthermore, after dexamethasone injection, a reduction in the NRS and RCW values was observed in the 10 patients who were followed up. Conclusions: While previous studies have suggested a link between arthralgia and TMJ effusion, making CW a possible indirect diagnostic indicator for arthralgia, our findings propose that RCW could hold more diagnostic value than objective CW. However, additional studies are required to standardize the protocols for interpreting US results and determining the cutoff value of RCW in diagnosing TMJ arthralgia.

• 재무관리연구
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• 제21권2호
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• pp.99-123
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• 2004

본 연구는 국내 상장기업 중에서 2000년에서 2002년도까지 사모사채를 발행한 124건의 발행 정보와 공모사채 발행을 실시한 203건의 발행정보를 표본으로 기업의 사모사채 발행에 영향을 미치는 결정요인들을 분석하였다. 회사채 조달원천의 선택에 영향을 미치는 요인으로 정보비대칭, 재무위험, 대리인비용, 독점적 정보, 신용등급 등 5개 변수를 도입하였다. 기업에 대한 정보비대칭의 정도는 사모사채 발행의 선택에 유의적인 영향을 미치는 것으로 나타났다. 이는 정보비대칭에 따른 역선택을 회피하기 위한 수단으로 사모를 선택하는 것으로 보인다. 또한, 기업의 재무위험의 정도가 클수록 공모사채 발행보다는 사모사채 발행이 이루어지는 경향이 높은 것으로 나타났는데, 이러한 결과는 사모계약이 가지는 재무적 재조정의 수월성과 관련이 있는 것으로 보인다. 대리인비용의 경우에는 대용변수의 선택에 따라 상이한 결과를 보이고 있다. 먼저, 주가수익률이 높은 기업일수록 사모발행을 통해 자본을 조달하는 경향이 높은 것으로 나타났다. 즉 사모발행은 부채의 대리인비용을 감소시키기 위한 수단이 될 수 있다고 추정된다. Tobin의 Q 경우는 기업의 공모사채와 사모사채 선택 의사결정에 유의적인 영향을 주지 않는 것으로 나타났는데, Tobin Q값이 높은 기업들은 강탈문제(hold-up problem)를 회피하기 위해 공모시장에 접근하는 경향이 있는 것으로 추정된다. 한편, 독점적 정보와 관련하여 기업은 내부의 정보보호를 위해서 사모사채 발행에 대한 동인을 가지는 것으로 보인다. 신용등급이 투기등급에 해당하는 기업들의 사모발행 경향이 높은 것으로 판단되었다. 본 연구의 결과들은 정보비대칭의 문제점이 있는 기업이거나 또는 대리인문제를 해결하기 위한 수단으로서 사모사채 발행은 기업의 우선적 자금조달방법이 될 수 있다는 것을 시사하고 있다고 할 수 있다.

• 대한안전경영과학회지
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• 제16권2호
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• pp.111-119
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• 2014

This paper describes the design and implementation of a electromagnetic energy harvesting mechanism and electronic circuit for autonomous emergency call system. This analysis results show the power output of the proposed harvesting mechanism and circuit up to max power output 5V and it can hold up to 65 msec of the power generation and 10msec of the RF transmission. Based on the these testing results, the implementation of autonomous emergency call device without battery power or any external power source is feasible.

• Carbon letters
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• 제11권3호
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• pp.192-200
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• 2010

Common reed (Fragmites australis), a local invasive grass, was investigated as a possible feedstock for the production of activated carbon. Dried crushed stems were subjected to impregnation with phosphoric acid (30, 40 and 50%) followed by pyrolysis at $400{\sim}500^{\circ}C$ with final washing and drying. Obtained carbons were characterized by determining: carbon yield, ash content, slurry pH, textural properties and capacity to remove color bodies from factory-grade sugar liquor. Produced carbons possessed surface area up to 700 $m^2/g$, total pore volumes up to 0.37 $cm^3/g$, and proved to be microporous in nature. Decolorization of hot sugar liquor at $80^{\circ}C$ showed degrees of color removal of 60 up to 77% from initial color of 1100~1300 ICU, at a carbon dose of 1.0 g/100 ml liquor. No correlation seems to hold between synthesis conditions and % R but depends on the degree of microporosity. A commercial activated carbon N showed a comparative better color removal capacity of 91%. Common reed proved to be a viable carbon precursor for production of good adsorbing carbon suitable for decolorization in the sugar industry, as well as in other environmental remediation processes.