• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.245-251
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• 2004

This paper is studied on the effect of TiAlN coated Ball End Mill and MQL(Minimum Quantity Lubrication) cutting condition on cutting characteristic of high hardness steels. KP4 steels[HRC32] and STD11[HRC60] heat treated steels were used as the workpiece and WC-Co ball end mill and single and multi layer TiAlN coated ball end mill were utilized in the cutting tests. MQL device was used to spray botanical oil coolant. Result showed that TiAlN coated ball end mill were increased the cutting length than WC-Co ball end mill in the cutting speed[$245{\sim}320m/min$] about $2.3{\sim}5.7$ times for KP4 steels and about $2.5{\sim}4.3$ times far STD11 heat treated steels. The multi layer TiAlN coated ball end mill is good for KP4 steels than single layer coated.

• 열처리공학회지
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• 제23권5호
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• pp.245-248
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• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Ni/ITO (INI) multilayer films were deposited on the glass substrates with a reactive magnetron sputtering system without intentional substrate heating and then the influence of the Ni interlayer on the methanol gas sensitivity of ITO and INI film sensors were investigated. Although both ITO and INI film sensors have the same thickness of 100 nm, INI sensors have a sandwich structure of ITO 50 nm/Ni 5 nm/ITO 45 nm. The changes in the gas sensitivity of the film sensors caused by methanol gas ranging from 100 to 1000 ppm were measured. It is observed that the INI film sensors show the higher sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the INI film sensor have the potential to be used as improved methanol gas sensors.

• 대한지구과학교육학회지
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• 제5권3호
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• pp.245-255
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• 2012

The purposes of this research are to analyze preservice elementary teachers' degree of difficulty in classes of seasonal variation and suggest the measures of classes so that preservice elementary teachers can progress classes of seasonal variation effectively. To achieve them, the research was conducted for 90 first graders completing teaching method of elementary science in P university of education from Sep. to Dec. 2012. This research was conducted, based on the results of in-depth interview for 9 preservice elementary teachers who performed classes of seasonal variation, survey on the degree of class difficulty and evaluation of classes on 8 classes theme of Earth sector in elementary science. The results of this research are as follows. The first, preservice elementary teachers had relatively high class difficulty for teaching seasonal variation among the sector of the earth in elementary science. The second, in the evaluation of preservice elementary teachers' classes, the more the subject showed high class difficulty, the more the score of class evaluation was low. The reason is analyzed that high class difficulty reduces teacher's confidence. The third, preservice elementary teachers had insufficient knowledges and concepts which are basically necessary for the classes of seasonal variation. Especially, it was more serious for preservice elementary teachers who didn't learn Earth-science during their high school time. The fourth, it is necessery that concrete and systematical teaching method should be developed so as to improving preservice elementary teachers' teaching method for the classes of seasonal variation.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제22권4호
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• pp.245-259
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• 2019

I examine the discussions of studies related to feminist mathematics education and the implications of mathematics education in South Korea. In particular, I attempt to answer the following questions through literature reviews on feminist mathematics: What is the epistemological background of feminist mathematics education? How is feminist mathematics education defined and implemented? What does feminist mathematics education suggest in South Korea's mathematics curriculum? From the analysis of the literatures, I found that feminist mathematics education reflects not just the rights of female's rights but also a paradigm shift in epistemology of mathematics and philosophy of mathematics education. In this regard, feminist mathematics questions the existing mathematics education related to the female students who were marginalized in the composition and delivery of mathematics. Feminist mathematics education points out that in the course of the transfer of mathematical knowledge in schools, female students understand unilateral information procedurally without understanding the concept. Mathematics educators should consider alternative curricula that reflect the views of female students regarding the nature of mathematics. Students should be able to receive equal mathematics education in a school regardless of their gender. In this case, equal mathematics education refers to education methods that are suitable for both male and female students. The existing mathematics content and its teaching methods were designed based on the learning experiences of male students, which made them relatively difficult for female students to understand.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.245-256
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• 2021

This study is significant in determining the reduction of safety accidents by applying PDCA's theory by subdividing it into a case analysis technique for construction sites by PDCA's theory. For this study, accidents accounted for the largest proportion of each type of disaster in the construction site were considered, and safety accidents were reduced through the PDCA theory through prior research. The analysis method of this study derived improvement plans by applying PDCA techniques to plan, implement, confirm, review, and improve disaster accidents at construction sites. The conclusions of this study are as follows. In the plan, first of all, measures shall be taken to prepare a safety management plan, to verify the implementation of the plan, and to verify the degree of implementation by the field manager. In the implementation, first of all, it is necessary to introduce a safety education history system to strengthen the safety education curriculum to suit the site, as long-term work is impossible for field workers depending on field conditions. First of all, it is necessary to strengthen the installation of safety facilities, including "work scaffolding" and "conducting prevention facilities" at construction sites. In management review and improvement, the risk assessment system for construction sites needs to be expanded first°.

• 무역학회지
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• 제46권2호
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• pp.245-262
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• 2021

Despite the numerous advantages that CSR engagement can potentially offer, top managers may not always be willing to invest in CSR as they are expected to meet expectations of external constituents in the short run. Given that financial analysts' expectations are important short-term performance targets that top managers are motivated to meet, this study examines how performance relative to earnings forecasts issued by analysts affect top managers' decisions about CSR engagement. Using a sample of publicly listed U.S. firms from 2000 to 2016, we find that top managers are more likely to reduce discretionary expenditure on CSR activities as performance falls below analyst forecasts to improve financial performance in the following fiscal year. As performance exceeds analyst forecasts, top managers are motivated to reduce CSR investments in order to meet higher expectations of analysts. As financial analysts closely monitor the firms that they follow in order to publish investment advice to market participants, we find that analyst coverage weakens top managers' incentive to reduce CSR engagement. Overall, this research sheds meaningful insight into the contextual background in which the top managers are situated in when they make decisions on CSR engagement.

• 치위생과학회지
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• 제20권4호
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• pp.245-251
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• 2020

Background: This study tries to compare and analyze the removal effect of dental plaque of general dentifrice and pregnant women's dentifrice and quantify the results to provide basic data so that consumers can make reasonable choices when purchasing dentifrice, and also increase interest in the dental plaque. Methods: After forming a dental plaque (carbohydrate porridge) on the labial surface of the bovine teeth, a disclosing agent was applied. Then the same experimenter brushed the surface of the bovine teeth using an electric toothbrush and took photographs using a DSLR camera. Thereafter, the residual amount of dental plaque was analyzed using the ImageJ program, and SPSS 26.0 was used for statistical processing. Results: The average residual amount of dental plaque using the general dentifrice was 11.71% for Perio, 9.45% for Cliden, and 8.47% for 2080, and the average residual amount for the three types was approximately 9.88%. The average residual amount of dental plaque of pregnant women's dentifrice was 13.95% for Jeninmothers, 12.53% for Tntnmoms, and 12.63% for Mommiracle, and the average residual amount of the three types was approximately 13.04%. On comparing the average residual amount of dental plaque between general and pregnant women's dentifrices, it was observed to be 3.16% higher for the latter. However, the results were not statistically significant. Conclusion: According to the research results, there was no significant difference in removal effects of general dentifrice and pregnant women's dentifrice. In addition, when a pregnant woman uses the right toothbrushing method with pregnant women's dentifrice, it can prevent or inhibit the progression of the gestational periodontal disease. Therefore, we recommend pregnant women to use pregnant women's dentifrices.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.92-92
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• 2003

본 연구는 부착규조류에 따른 부착성 요각류 Tigriopus japonicus의 nauplius 생산력을 알아보기 위하여 실시하였다. 실험에 사용된 T. japonicus는 부산 동백섬 부경대학교 수산과학연구소 부근에 있는 tidal pool에서 동물성부유생물망으로 채집하였다. 먹이생물로는 부경대학교 한국해양 미세조류 은행에서 보관중인 부착규조류 중 중형종인 Caloneis schroder를 대표종으로 이와 크기가(14.8~27.5$\mu\textrm{m}$) 유사한 종들을 대상으로 형태를 현미경 하에서 관찰하고, 지역과 분리일자 등을 고려하여 유사종을 선별한 후 최종적으로 종의 유전적 유사성을 밝히기 위하여 RAPD-PCR (random amplified polymorphic DNA polymerase chain reaction)을 실시하였다. 이 중 Caloneis schroder와 유전적으로 유사성이 낮은 Navicula spp. (KMCC B-245, 393, 394, 581) 4종을 선별하여 T. japonicus의 먹이로 사용하여 포란한 암컷의 nauplius 생산력을 3반복 조사하였다. Genomic DNA는 대부분의 종에서 성공적으로 검출되었으며, 종에 따라 PCR 증폭산물이 나타나지 않은 경우도 있었으므로, PCR 산물이 나타난 종에 대해서만 분석하였고, 증폭된 DNA band는 대부분 크기 0.5~2.0kb 범위에서 나타났다. 실험에 사용된 부착규조류 간의 유사성을 알아보기 위하여 similarity matrix를 분석한 결과 F값의 범위는 0.00에서 1.00까지 였으며, Caloneis schroder와 유사성이 낮은 종들에 비하여 유사성이 높은 종들이 더 많이 나타났다. 이들을 먹이로 하여 포란한 T. japonicus의 실험구별 nauplius 평균 개체수를 살펴보면, KMCC B-394가 255.7마리로 가장 높았던 반면 KMCC B-581가 29.7마리로 가장 낮았다. 그 외 KMCC B-245가 120.0마리, KMCC B-393가 76.0마리, Caloneis schroder가 32.3마리 각각 나타났다. 이와같은 결과를 볼 때 T. japonicus의 nauplius 생산력은 규조 종에 따라 큰 차이가 있는 것으로 판단된다.

• 한국정보관리학회:학술대회논문집
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• 한국정보관리학회 1999년도 제6회 학술대회 논문집
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• pp.245-248
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• 1999

본 연구에서는 인터넷 환경의 정보검색 문제를 해결하기 위한 방안으로 메타데이터 기반구조인 PICS를 분석하여 인터넷 자원의 검색 및 필터링에 적용할 수 있는 요인들을 제시하였다. 또한 시스템의 실재 구현을 도모하기 위해 의학 정보를 위한‘OMNI-PICS’라는 등급체계의 프로토타입을 설정하고, 기계가독형 RAT파일을 설계하였다. 따라서 웹에서 특정 주제 영역을 다루는 주제게이트웨이들이 자원을 협력적으로 필터링하기 위한 표준 포맷으로 PICS 등급체계를 적용하여 운용할 수 있는 구체적 지침을 제공하였다.

• 영어어문교육
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• 제11권1호
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• pp.245-260
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• 2005

Various kinds of cognitive aspects must be inclusively considered for understanding to transitivity. Basically, transitivity is not a notion of pure lexical items, pure syntactic dimensions and only semantic interpretation. That is, transitivity is affected by the extralinguistic phenomena which contain speakers psychological and cognitive interpretations. It is based on human cognitive abilities to interpret the exact meaning of language expressions. To sum up, transitivity has a relation with the observer's (speaker's) cognitive interpretation within the entire contexts.