• Title/Summary/Keyword: school stress

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Estimation of Buckling and Ultimate Strength of a Perforated Plate under Thrust (면내압축하중을 받는 유공판의 좌굴 및 최종강도 평가에 관한 연구)

  • Park Joo-Shin;Ko Jae-Yong
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.129-135
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    • 2004
  • Plate has cutout inner bottom and girder and floor etc in hull construction absence is used much, and this is strength in case must be situated, but establish in region that high stress interacts sometimes fatally in region that there is no big problem usually by purpose of weight reduction, a person and change of freight, piping etc. Because cutout's existence gnaws in this place, and, elastic budding strength by load rouses large effect in ultimate strength. Therefore, perforated plate elastic budding strength and ultimate strength is one of important design criteria which must examine when decide structural elements size at early structure design step if ship. Therefore, and, reasonable elastic budding strength about perforated plate need design ultimate strength. Calculated ultimate strength change several aspect ratioes and cutout's dimension, and thickness in this investigation. Used program applied ANSYS F.E.M code based on finite element method

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A Study on Relationship between Smartphone User Pattern and Addiction

  • Lee, Myung-Suk;Lim, Young-Kyu
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.3
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    • pp.101-106
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    • 2018
  • The purpose of this study is to analyze the patterns of unconsciousness smartphone use by using an app and a self-administered survey on smartphone addiction comparatively and examine differences between recognition and behavior about actual smartphone use and examine how smartphone addiction influences learning. With an app installed in smartphones, this author collected and analyzed data about users' unconsciousness using patterns for a month. According to the results, there were significant differences found in users' recognition and actual time for use and also frequency of turning on the display. Also, 22% of the subjects used their smartphone over 8 hours a day, and 76% more than 5 hours. Over 95% turned on the display more than 100 times a day, and in extreme cases, they did more than 300 times. In the meantime, users not only in the smartphone addiction high risk group and the potential risk group but also in the general user group are found to use their smartphone too long and too much and frequently turn on the display. The apps that the general user group is mainly using are entertaining apps, and their school records are rather good, so excessive use does not always lead to addiction or learning disorder. Therefore, if we develop more diverse contents for learning and provide digital literacy education, smartphone use will bring more positive effects instead. In follow-up research, the app should be corrected to collect more accurate information, and as variables in personal areas, this researcher will also measure depression, anxiety, stress, self-esteem, and emotional control, and so on to see how they are associated with smartphone use.

Four Members of Heat Shock Protein 70 Family in Korean Rose Bitterling (Rhodeus uyekii)

  • Kim, Jung Hyun;Dong, Chun Mae;Kim, Julan;An, Cheul Min;Baek, Hae Ja;Kong, Hee Jeong
    • Development and Reproduction
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    • v.19 no.3
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    • pp.135-144
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    • 2015
  • Heat shock protein (HSP) 70, the highly conserved stress protein families, plays important roles in protecting cells against heat and other stresses in most animal species. In the present study, we identified and characterized four Hsp70 (RuHSP4, RuHSC70, RuHSP12A, RuGRP78) family proteins based on the expressed sequence tag (EST) analysis of the Korean rose bitterling R. uyekii cDNA library. The deduced RuHSP70 family has high amino acid identities of 72-99% with those of other species. Phylogenetic analysis revealed that RuHsp70 family clustered with fish groups (HSP4, HSC70, HSP12A, GRP78) proteins. Quantitative RT-PCR analysis showed the specific expression patterns of RuHsp70 family members in the early developmental stages and several tissues in Korean rose bitterling. The expression of 4 groups of Hsp70 family was detected in all tested tissue. Particularly, Hsp70 family of Korean rose bitterling is highly expressed in hepatopancreas and sexual gonad (testis and ovary). The expression of Hsp70 family was differentially regulated in accordance with early development stage of Rhodeus uyekii.

An enhanced root system developmental responses under drought by inoculation of rhizobacteria (Streptomyces mutabilis) contributed to the improvement of dry matter production in rice

  • Suralta, Roel R.;Cruz, Jayvee A.;Cabral, Maria Corazon J.;Niones, Jonathan M.;Yamauchi, Akira
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.231-231
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    • 2017
  • Drought limits rice production under upland condition. This study quantified the effect of rhizobacteria inoculation on rice root system developmental response to drought and its role in maintaining high soil water use, and dry matter production under drought using NSIC Rc192 (rainfed lowland rice variety). The source of inoculant was Streptomyces mutabilis, a recently isolated rhizobacteria containing plant growth promoting compounds such as ACC deaminase, indole-3-acetic acid and phosphatase (Cruz et al., 2014, 2015). In the first experiment, pre-germination inoculation of seeds with S. mutabilis significantly increased the shoot and root (radicle) length as well as root hair lengths, relative to the non-inoculated control. In the second experiment, rice plants inoculated with S. mutabilis and grown in rootbox with soil generally had greater total root length under drought regardless of the timing of inoculations, relative to the non-inoculated control. Consequently, improved root system development contributed to the increase in soil water uptake under drought and thus, dry matter production. Among inoculation treatments, one-time inoculation of S. mutabilis either at pre-germination or pre-drought stress at 14 days after sowing (DAS), had significantly greater shoot dry matter production than three-time inoculation at pre-germination, at thinning (3 DAS) and at pre-drought (14 DAS). This study demonstrated the effectiveness of rhizobacteria (S. mutabilis) containing growth promoting compounds for enhancing drought dehydration avoidance root traits and improving the growth of rice plants under drought condition.

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Emodin Isolated from Polygoni cuspidati Radix Inhibits TNF-α and IL-6 Release by Blockading NF-κB and MAP Kinase Pathways in Mast Cells Stimulated with PMA Plus A23187

  • Lu, Yue;Jeong, Yong-Tae;Li, Xian;Kim, Mi Jin;Park, Pil-Hoon;Hwang, Seung-Lark;Son, Jong Keun;Chang, Hyeun Wook
    • Biomolecules & Therapeutics
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    • v.21 no.6
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    • pp.435-441
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    • 2013
  • Emodin, a naturally occurring anthraquinone derivative isolated from Polygoni cuspidati radix, has several beneficial pharmacologic effects, which include anti-cancer, anti-diabetic, and anti-inflammatory activities. In this study, the authors examined the effect of emodin on the production of proinflammatory cytokines, such as, tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6, in mouse bone marrow-derived mast cells (BMMCs) stimulated with phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187. To investigate the mechanism responsible for the regulation of pro-inflammatory cytokine production by emodin, the authors assessed its effects on the activations of transcriptional factor nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and mitogen-activated protein kinases (MAPKs). Emodin attenuated the nuclear translocation of (NF)-${\kappa}B$ p65 and its DNA-binding activity by reducing the phosphorylation and degradation of $I{\kappa}B{\alpha}$ and the phosphorylation of $I{\kappa}B$ kinase B (IKK). Furthermore, emodin dose-dependently attenuated the phosphorylations of MAPKs, such as, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAP kinase, and the stress-activated protein kinases (SAPK)/c-Jun-N-terminal kinase (JNK). Taken together, the findings of this study suggest that the anti-inflammatory effects of emodin on PMA plus A23187-stimulated BMMCs are mediated via the inhibition of NF-${\kappa}B$ activation and of the MAPK pathway.

Reliability of COF Flip-chip Package using NCP (NCP 적용 COF 플립칩 패키지의 신뢰성)

  • Min, Kyung-Eun;Lee, Jun-Sik;Jeon, Je-Seog;Kim, Mok-Soon;Kim, Jun-Ki
    • Proceedings of the KWS Conference
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    • 2010.05a
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    • pp.74-74
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    • 2010
  • 모바일 정보통신기기를 중심으로 전자패키지의 초소형화, 고집적화를 위해 플립칩 공법의 적용이 증가되고 있는 추세이다. 플립칩 패키징 접합소재로는 솔더, ICA(Isotropic Conductive Adhesive), ACA(Anisotropic Conductive Adhesive), NCA(Non Conductive Adhesive) 등과 같은 다양한 접합소재가 사용되고 있다. 최근에는 언더필을 사용하는 플립칩 공법보다 미세피치 대응성을 위해 NCP를 이용한 플립칩 공법에 대한 요구가 증가되고 있는데, NCP의 상용화를 위해서는 공정성과 함께 신뢰성 확보가 필요하다. 본 연구에서는 LDI(LCD drive IC) 모듈을 위한 COF(Chip-on-Film) 플립칩 패키징용 NCP 포뮬레이션을 개발하고 이를 적용한 COF 패키지의 신뢰성을 조사하였다. 테스트베드는 면적 $1.2{\times}0.9mm$, 두께 $470{\mu}m$, 접속피치 $25{\mu}m$의 Au범프가 형성된 플리칩 실리콘다이와 접속패드가 Sn으로 finish된 폴리이미드 재질의 flexible 기판을 사용하였다. NCP는 에폭시 레진과 산무수물계 경화제, 이미다졸계 촉매제를 사용하여 다양하게 포뮬레이션을 하였다. DSC(Differential Scanning Calorimeter), TGA(Thermogravimetric Analysis), DEA(Dielectric Analysis) 등의 열분석장비를 이용하여 NCP의 물성과 경화거동을 확인하였으며, 본딩 후에는 보이드를 평가하고 Peel 강도를 측정하였다. 최적의 공정으로 제작된 COF 패키지에 대한 HTS (High Temperature Stress), TC (Thermal Cycling), PCT (Pressure Cooker Test)등의 신뢰성 시험을 수행한 결과 양산 적용 가능 수준의 신뢰성을 갖는 것을 확인할 수 있었다.

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Mechanical Behavior of Weldbond Joint of 1.2GPa Grade Ultra High Strength TRIP Steel for Car Body Applications (차체용 1.2GPa급 초고장력 TRIP강의 Weldbond 접합부의 기계적 거동)

  • Lee, Jong-Dae;Lee, So-Jeong;Bang, Jung-Hwan;Kim, Dong-Cheol;Kang, Mun-Jin;Kim, Mok-Soon;Kim, Jun-Ki
    • Journal of Welding and Joining
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    • v.32 no.5
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    • pp.44-49
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    • 2014
  • The effect of weldbond hybrid joining process on the mechanical behavior of single lap and L-tensile joints was investigated for the newly developed 1.2GPa grade ultra high strength TRIP(transformation induced plasticity) steel. In the case of single lap shear behavior, the weldbond joint of 1.2GPa TRIP steel showed lower maximum tensile load and elongation than that of the adhesive bonding only. It was considered to be due to the reduction of real adhesion area, which was caused by the degradation of adhesive near the spot weld, and the brittle fracture behavior of the spot weld joint. In the case of L-tensile behavior, however, the maximum tensile load of the weldbond joint of 1.2GPa TRIP steel was dramatically increased and the fracture mode was change to the base metal fracture which is desirable for the spot weld joint. These synergic effect of the weldbond hybrid joining process in 1.2GPa TRIP steel was considered to be due to the stress dissipation around the spot weld joint by the presence of adhesive which resulted in the change of crack propagation path.

A survey on the Needs of Residents' Health Education in a Community (일개 도시 지역주민의 보건교육 요구도 조사)

  • Moon, Myeong-Ja;Lee, Myung-Suk;Jang, Young-Sook;Choi, Hee-Chung;Kim, Hye-Ja;Kim, Hye-Suk;Park, Mi-Sun;Choi, Ja-Yun
    • Research in Community and Public Health Nursing
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    • v.15 no.1
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    • pp.44-55
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    • 2004
  • Purposes: Purposes of this study were to assess the needs of health education of residents and to determine the difference according to their general characteristics in a community. Method: Subjects consisted of 599 residents who live in the vicinity of M Catholic University, S dong, M city, Jeollanam do. Data were collected by 6 research assistants, using a self reported questionnaire from July 1, 2003 to July 31, 2003. Results: Subjects were mostly female (58.8%). 20 30 years old(45.2%), married (70.1%), high school graduates (42.1%), have an occupation(73.1%). have incomes less than 1.000,000 won(54.2%) and have a religion(59.8%). and the family type of the subjects was primarily nuclear(64.1%). The need for education about 'family health care management and medical examination' was the highest in 8 domains. The need for education about 'cancer' was the highest and 'family health care', 'stress and strategies', 'introduction of medical examination' and 'oral care' followed in 41 items. The differences in the needs of health education in all domains was found according to subjects' general characteristics. Conclusion: Further research is needed to develop a health education program based on participants' needs and general characteristics.

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Nonlinear Analysis of FRP Strengthened Reinforced Concrete Columns by Force-Based Finite Element Model (하중기반 유한요소모델에 의한 FRP 보강 철근콘크리트 기둥의 비선형 해석)

  • Cho, Chang-Geun
    • Journal of the Korea Concrete Institute
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    • v.25 no.5
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    • pp.529-537
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    • 2013
  • The aim of the current study is to develop a nonlinear isoparametric layered frame finite element (FE) analysis of FRP strengthened reinforced concrete (RC) beam or column members by a force-based FE formulation. In sections, concrete is modeled in the triaxial stress-strain relationship state and the FRP sheet is modeled as layered composite materials in two-dimension. The element stiffness matrix derived by the force-based FE has the force-interpolation functions without assuming the displacement shape functions. A lateral load test of RC column strengthened by GFRP sheets was analyzed by the developed force-based FE model. From comparative studies of the experimental and analysis results, it was shown to compare with the stiffness FE method that the force-based FE analysis could give more accurate predictions in the overall lateral load-deflection response as well as in nonlinear deformations and damages in the column plastic hinge region.

Research on the Job Image of the Students of the Department of Dental Technology for their Job as Dental Technician (Focused on Daegu) (치기공과 학생이 지각하는 치과기공사의 직업 이미지 조사 - 대구지역을 중심으로 -)

  • Choi, Ju-Young;Kim, Han-Gon
    • Journal of Technologic Dentistry
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    • v.33 no.4
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    • pp.505-516
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    • 2011
  • Purpose: The purpose of this study is to supply basic data to establish new image for dental technicians by reflecting onto the education of dental technicians by grasping the image of dental technicians with the subjects of students in department of dental technology. Methods: It was studied with self-filling-in method through structured questionnaire from September 26, to October 21, 2011, with 421 subjects of the students in the department of dental technology in two colleges in Daegu. SPSS 18.0 for Windows was used to analyze the data, and frequency and percentage were used for statistic analysis, and correlation analysis and Multiple Linear Regression Analysis were used with mean and SD per each question. Results: It showed the highest recognition that the dental technicians is a 'specialist' as 4.66; the dental technicians has strong responsibility in his work as 4.42; the dental technicians takes an important role in improvement of public oral health as 4.39; and the dental technicians has professional intelligence and high technique as 4.33. So, it was found that they had image of professional and important role for oral health, and had their pride and selfconfidence as future dental technicians. Meanwhile, it showed that they had negative related-image as well as a job, that the dental technicians is too busy as 4.48; it requires improvement on image in the future as 4.27; it is a hard job with too much stress as 4.13. Conclusion: It is required for us and school to have continuous change and effort to make the students in the department of dental technology have positive mind for the dental technology to make them have pride for their job.