• Title/Summary/Keyword: $ED_s$

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Evaluation of Machinability by various cutting conditions in high machining using ball nose-end mills -Effects of cutting orientation and cutting environments- (볼엔드밀을 이용한 고속가공에서 가공경로와 가공환경에 따른 가공성 평가)

  • 이채문;김석원;이득우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.297-301
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    • 2002
  • High-speed machining generates concenter thermal/frictional damage at the cutting ed rapidly decreases the tool life. This paper I at determining the effect of cutter orienter the cutting environment on tool life, tool mechanism when down milling. In this paper, experiments were carried out in various tool and cutting environments, such as dry, wet compressed chilled air, tool life were measu evaluate machinability in high-speed milli difficult-to-cut material and die steel, Tool measured in horizontal upwards, horiz downwards, vertical upwards and vert downwards. In addition, tool life was measur dry, wet and compressed chilled air. For this a compressed chi1led-air system was manufact The results show that a horizontal cutter ori provided a longer tool life than a vertical orientation. With respect to the cutting envi compressed chilled air increased tool life. H the wet condition decreased tool life due thermal shock caused by excessive cooling high-speed mill ins and the compressed chilled had little effect.

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Relationship between Violence Response, Coping, and Burnout among Emergency Department Nurses (응급실 간호사의 폭력반응, 대응 및 소진간의 관계)

  • Yang, Jin-Hyang;Jung, Hye-Youn
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.16 no.1
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    • pp.103-111
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    • 2009
  • Purpose: The purpose of this study was to identify relationships between violence response, coping, and burnout among emergency department nurses. Method: This descriptive study using self report questionnaires was conducted from October 1 to October 20, 2008. Participants were 147 general nurses working in emergency departments in hospitals having over 500 beds and located in Busan. ANOVA and Pearson's correlation coefficients with SPSS PC+ WIN 14.0. were used to analyze the data. Results: Scores for violence response, coping, and burnout were 3.08 (1-5 scale), 2.57 (1-4 scale), and 3.22 (1-5 scale) respectively. There were significant differences in violence response and burnout by education, clinical careers, clinical careers in ED, and plans to work in the future, and no significant differences in coping by general characteristics. There was a significant and highly positive relationship between violence response and burnout. Conclusion: The degree of violence response and burnout was comparatively high, while that of coping was average. Therefore, it is necessary to develop effective programs related to prevention and coping with violence for nurses in emergency departments. Institutional measures by hospital authorities are also needed to improve the nursing quality by providing a safe workplace.

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Reflective action research on setting up and implementing mathematics tasks demanded students' high-level cognition (인지적 수준이 높은 수학 과제 설정과 실행에 관한 교사의 반성적 연구 -초등학교 2학년 길이재기를 중심으로-)

  • Park, Young-Eun;Kim, Nam-Gyun
    • Education of Primary School Mathematics
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    • v.10 no.2
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    • pp.77-110
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    • 2007
  • This study attempted to investigate how to students show high-level mathematical thinking in math classes. This paper describes how to setup the task for lead to a high - level of thinking out students and what efforts are required while a teacher tried to maintaining students's high-level cognition during the tasks implemented. The researcher as teacher analyzed the tasks of length measurement unit in 2-Ga elementary math textbooks, modified and created math tasks demanded students' high-level cognition, made instruction plans, and implemented those tasks maintaining the levels of cognitive demand of tasks. After that, the researcher reflected and analyzed the levels of cognitive demand of tasks of instruction and factors that cause to change intended high-level cognitive demand. After reflection, second roof of action research was conducted to 2-Na length measurement unit. This paper includes those results and reflections of practitioner.

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Structure Study of PbO-Ga$_2$O$_3$ Glasses Using Ga K-edge EXAFS Taken at Cryogenic Temperature (갈륨 K 흡수단의 저온 EXAFS를 이용한 PbO-Ga$_2$O$_3$ 유리의 구조 해석)

  • Choi, Yong-Gyu;Kim, Kyong-Hon;Chernov, Vladimir A;Heo, Jong
    • Journal of the Korean Ceramic Society
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    • v.35 no.11
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    • pp.1148-1154
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    • 1998
  • Ga K-edge EXAFS spectra of PbO-Ga2O3 glasses were recorded at liquid nitrogen temperature and analyz-ed in order to quantitatively understand the medium-range-order arrangement around gallium in the glasses. The second peak was generated from a backscattering of the neighbor balliums and the Ga-Ga distance is ~3.13 A with Ga coordination number of ~2.7 Therefore GaO4 tetrahedra are connected through the cor-ner~sharing mode and form their own clusters made of the tetrahedra sharing more than 3 corners while some chains or rings are also present. These connection schemes of the GaO4 tetrahedra are believed to form the substantial part of the network structure.

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A Study on the Analysis of Power Load Density and Electric Power Consumption in Apartment Housing (아파트의 전력부하밀도 및 전력소비 실태 분석 연구)

  • 이기홍;성세진
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.1
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    • pp.118-124
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    • 2001
  • To guide the esti-on of electric d e d and energy saving, this proposed the Power Laaddensity, Elechic pwer consumption and the installed state of Power facility. For this purp~se, it wasconducted a questionnaire survey of the consumption-cattern of Electric power in 1W a p a r t t housings.As a 1-esult it is found that (i) the d m u m value of Power Load density is 7.70[~A/m"l, (ii) the avtragevalue of Power Load dens'||'&'||' is ~ . ~ A / mm' dl (iiijthe average load rate is Ed[%]. Also, the consumptionof electricity one year at tlie whole a m n t s of couniry is 14,0X[GWyearl, it was equivalent to 7[%1 ofthe total-consunmhon of electricity one year at the whole of co1mtnr. co1mtnr.

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Unexpected Estrogenicity of Endocrine Disruptors may Evoke a Failure of Pregnancy Derived from Uterine Function: Overview of Their Possible Mechanism(s) through Steroid Receptors

  • Dang, V.H.;Nguyen, T.H.;Choi, K.C.;Jeung, E.B.
    • Journal of Embryo Transfer
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    • v.22 no.4
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    • pp.199-208
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    • 2007
  • Although many studies have focused on the biological and toxicological effects of phenol products, in particular, in reproductive tracts, the data about their effects in this estrogenic responsive tissue are much less clear. In addition, the in vitro and in vivo data concerning ED-adverse impacts in other endocrine organs, i.e. pituitary gland, are not understood well either. Thus, a further study is needed for providing a new insight into possible impacts of estrogenic EDs including phenol products in humans and wildlife. A combination of in vitro and in vivo system for examining EDs may bring better understanding into the regulatory mechanisms underlying EDs-induced events. In addition, this information may support for developing optimal screening methods of estrogenic EDs, in particular, phenol products.

Radical Scavenging Activity and Cytotoxicity of Maysin(C-glycosylflavone) isolated from Silks of Zea mays L.

  • Kim, Sun-Lim;Snook, Maurice-E;Lee, Jong-Ock
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.5
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    • pp.392-396
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    • 2003
  • Maysin, a C-glycosylflavone, was isolated from the silks of maize, Zea mays L. The ESI mass spectrum indicates that molecular weight of maysin is $577\textrm{M}^+$m/z, and the ether-linked sugar is rhamnose, $431\textrm{M}^+$m/z (MW$^{+}$-146). The DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity of maysin was higher than that of rutin. However, as compared with its aglycon luteolin, maysin showed the relatively moderate DPPH scavenging activity mainly due to the glycosylation of two sugars moieties, keto-fucose and rhamnose. In the in vitro cytotoxicity test against the five human tumor cell lines such as lung (A549), ovarian (SK-OV-3), melanoma (SK-MEL-2), central nerve system (XF-489), and colon (HCT-15), maysin exhibited the relatively weaker activities than cisplatin. The $\textrm{ED}_{50}$ values of maysin were 62.24, 43.18, 16.83, 37.22, and 32.09/$m\ell$, respectively. Result suggests that maysin is a potential cytotoxicity compound, particularly for human colon, central nerve system, and melanoma tumors.s.

The study on growth behavior of Nb(C,N) coating layer deposited by TRD based duplex surface treatment on JIS-SUJ2 (TRD 기반 2단 표면 처리법을 통해 JIS-SUJ2 표면에생성된 Nb(C,N)코팅층 성장 거동 연구)

  • Lee, Gyeong-Hun;Gang, Nam-Hyeon;Kim, Gi-Su;Lee, Gang-Sik
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.96-97
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    • 2015
  • 확산을 이용한 표면 개질법인 Thermo-Reactive Diffusion(TRD) 기술 기반 2단 표면처리를 통해 고경도의 Nb(C,N) 코팅층을 고탄소 베어링강인 JIS-SUJ2강에 형성시켰다. 2단 표면처리는 암모니아 가스 질화와 분말 확산 코팅법으로 구성된 2step 열처리이다. 본 연구에서는 가스질화 화합물층의 두께가 코팅층 성장 거동에 어떤 영향을 미치는지 알아보기 위해서 $550^{\circ}C$에서 3, 6시간 암모니아 가스 분위기에서 가스질화를 실시하고, $900^{\circ}C$에서 3시간 분말 확산법을 통해 표면 코팅층을 형성하였다. 생성된 코팅층의 형상과 두께 측정을 광학현미경(OM) 과 주자전자현미경(SEM)을 통해 한 결과, 가스 질화는 약 10uu와 16um, 최종 코팅층은 약 정도 생성이 되었음을 확인하였다. 코팅층의 성분 분석은, EDS, FE-EPMA, XPS 분석을 통해서 실시하였다. EDS와 FE-EPMA 원소 mapping을 통해 모재에 비해 높은 농도의 Nb, C 그리고 N이 코팅층 내부에 존재함을 확인하였다. XPS분석의 결합에너지 peak를 통해 NbC, NbN 그리고 Nb-oxide가 생성이 되었음을 분석하였다. 생성된 코팅층의 경도는 low mode에서 10회 측정한 후 평균값을 내었고, 각각 Hv이었다.

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Control of Electromagnetic Properties of High Initial Permeability Mn-Zn Ferrite with the Microstructure Control (미세구조 조절에 의한 고투자율 Mn-Zn Ferrite의 특성제어)

  • 도세욱;류지태;김정희;강태현;허원도
    • Resources Recycling
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    • v.7 no.4
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    • pp.50-54
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    • 1998
  • In order to obtain desired electromagnetic propertieι high initial permeability and good frequency dependance of initial p permeability, the adding effects of sevral seeds were experimented in Mn-Zn ferrite system. As adding seed grams, calcined at sintering temperature, abnormal grains were disappeared clearly but the density and the initial permcability of sintered Mn-Zn ferrite body were decreased. On the contrary, in case of adding seed rains which were calcined below the calcination temperatnre of matrix particle, abnormal grains remained but the initial permeability was increas$\xi$d with proper s$\xi$ed content. W With proper seed content, the initial permeability was increased by 10-20% but tbe $\alpha$ltoff frequency was not changed.

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A Strategic planning to develop regional pending problems of Honam Sea Grant college program and it's progress (호남지역 Sea Grant 사업의 지역현안과제 개발 및 발전방향에 대한 연구)

  • Nam Taek-Kun;Yang Won-Jae;Kim Dae-Hee;Yim Jeong-Bin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.171-175
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    • 2006
  • In this paper, the strategic planning to develop regional pending problems of Honam Sea Grant college program laund1ed in 2006 to support research and development, education and extension is tackled. First, the purpose of an strategic planning for Honam Sea Grant college program and development of its pending problems are discussed. Next, the needs of strategic planning established through individual demanders, managers and related organizations is introduced. Finally, network construction between domestic and overseas organizations is studied to build and maintain significant relationships with their constituents.

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