• 제목/요약/키워드: grade resistance

검색결과 306건 처리시간 0.024초

초등과학영재들의 창의성 유형 분석 (Creativity Styles of Elementary Science Gifted Students)

  • 박신규;정원우;박영관;홍순천;박경미;김중욱
    • 영재교육연구
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    • 제21권4호
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    • pp.885-905
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    • 2011
  • 본 연구의 목적은 TTCT 도형 검사를 통해 초등과학영재들의 창의성 유형(style)을 알아보는 것이다. 이를 위해 영재학생 206명을 대상으로 TTCT도형 검사를 실시하였으며 Kim (2006)의 이론에 의해 창의성의 2가지 유형이 나타나는지 알아보기 위해 요인분석을 실시하였다. 이를 바탕으로 지역별, 학년별, 성별에 따른 창의성 유형 비율과 창의성 유형별 성에 따른 창의성 수준 차이가 있는지를 분석하였다. 연구 결과 TTCT 도형 검사는 창의성 수준(level)뿐만 아니라 창의성 유형 즉 적응적 유형과 혁신적 유형의 2가지로 분류할 수 있었다. 창의성 유형 비율을 보면 지역별, 학년별, 성별에 관계없이 적응적 유형이 혁신적 유형보다 많았다. 지역별의 경우 대도시일수록 적응적 유형이 많고 읍면지역일수록 혁신적 유형이 많았으며 학년일경우 6학년은 적응적 유형이 많았고 5학년은 혁신적 유형이 많았다. 성별일 경우 여학생은 적응적 유형이 남학생은 혁신적 유형이 많았다. 적응적 유형일 경우 여학생이 남학생보다 유의미하게 높았으며 혁신적 유형일 경우 유의미하지 않았지만 여학생이 남학생보다 높게 나타나 여학생이 남학생보다 창의성 수준이 높게 나타났다. 창의성 유형 분석을 통해 개인의 강점과 제한점을 알고 참여도를 높일 수 있을 것이다.

갭 입도 변화에 따른 사질토의 지지력 향상 효과 (Effect of Gap grade on Shear Strength of sandy soil)

  • 김갑부;문준호;구교영;전영우;김영욱
    • 한국산학기술학회논문지
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    • 제17권4호
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    • pp.319-324
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    • 2016
  • 입도분포가 다양한 입자크기로 이루어져 있는 지반은 일반적으로 지반의 강도가 좋다. 입도분포가 다양하지 않음에도 충분한 지지력을 가지고 있는 지반이 더러 있는데, 이러한 지반의 특징은 Gap 입도로 분포되어 있다는 것이다. 이를 바탕으로 유추하여보면 입자의 크기가 다양하지 않더라도 적절한 입도의 배치를 통해 강한 지반이 조성될 수 있음을 알 수 있다. 이 연구에서는 임의로 조성한 Gap 입도시료와 well, uniform 입도시료와의 내부마찰각의 변화에 대하여 고찰하였다. 큰 입자와 작은 입자 크기의 비율에 따라서 시료를 조성한 후 직접전단시험을 수행하여 지반의 강도정수를 구하고 결과를 비교 분석하였다. 연구결과 시료의 입자크기비와 내부마찰각을 연관시킬 수 있었으며 입도의 분포가 Gap이라고 하더라도 주어진 조건에서 가장 큰 입자 크기비를 가지고 있는 시료가 다양한 입도분포의 시료보다 큰 마찰력을 가질 수 있음을 알 수 있었다. 또한 중간입자크기를 가지고 있는 시료로 조성한 uniform시료보다도 같은 입자 크기의 Gap 입도 시료가 더 큰 강도를 지니고 있었다. 비교적 간단한 입도의 조정만으로도 대상 지반의 강도를 추가적으로 증대시킬 수 있는 공법개발의 기초를 확립하였다.

서울시내일부 고등학교 학생들의 흡연실태에 관한 조사연구 (A Survey on Cigarette Smoking Behavior of High School Students in Seoul)

  • 이영숙
    • 보건교육건강증진학회지
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    • 제1권1호
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    • pp.37-56
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    • 1983
  • It is well known that smoking habit is hazardous to health, especially for juvenile. The present study on smoking behavior of high school students in Seoul has two major objectives. The first objective is to find out the smoking behavior of high school students in Seoul. Toward this objective, individual's smoking experience has been examined as ever smoking and never smoking. The second objective is to determine the variables associated with their smoking behavior at the individual, family and school environment levels. For the data collection, the survey was carried out for the four high schools in Seoul from September 15 through October 15, 1982. The major findings are summarized as follows: 1. Smoking behavior of the students 1) Out of 1,278 respondents, 30.2% of them were found to be current smokers and 29.3% of them were former smokers. This implies that around 60% of school students in Seoul have experienced smoking. 2) A significant differences in the current smoking rates between two types of the school students were shown as 19.3% for day-time school and 42% for night-time school. 3) In terms of the current smoking behavior, the students who don't live with parents were higher in smoking rate than those of the living with parents. 2. Attitudes and knowledge about smoking 1) Attitudes of students toward smoking in high school days were shown that around 17% of them agreed with it and around 64% of them disagreed with it. 2) Around 99% of the respondents answered that their smoking is harmful for health. A source of the information about negative effects of smoking on health was 'Radio and TV' (23.9%) as the most influential, 'school teacher' (20.9%), 'Newspaper' (18.2%) and so on. 3. Behavioral analysis for the current smokers 1) The factors affected for motivation in the first smoking were 'curiosity' (59.7%), 'temptation of friend' (19.7%), 'resistance feeling, (7.1%), 'merely interest and pleasure' (6%) respectively. 2) The time of the first smoking was 'third grade of Junior-high school' (31.5%) as highest, 'first grade of Senior-high school' (23.7%) and 'second grade of Junior-high school' (14.7%). 3) An average daily number of cigarettes consuming of current smokers was seven cigarettes. 4. Family and school-mates influences on individual's smoking behavior 1) The data revealed a significant relationship between student's smoking and their parent's smoking behavior. Around 75% of the students whom both parents are smoking have experienced cigarette smoking. It was found that the individual's smoking behavior was influenced by his sibling. Around 65% of the students whom brothers are smoking have experienced cigarette smoking. 2) The 'Smoking-Index' of friendship network or a group explained individual's smoking behavior in the group. The result of dyad analysis of smoking behavior in the friendship network showed that a high score of 'Smoking-Index' tended to be explained an adoption of smoking behavior at the individual level in the group. on the other hand, a low score of 'Smoking-Index' explained non-smoking behavior in the group.

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Central Sarcopenia, Frailty and Comorbidity as Predictor of Surgical Outcome in Elderly Patients with Degenerative Spine Disease

  • Kim, Dong Uk;Park, Hyung Ki;Lee, Gyeoung Hae;Chang, Jae Chil;Park, Hye Ran;Park, Sukh Que;Cho, Sung Jin
    • Journal of Korean Neurosurgical Society
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    • 제64권6호
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    • pp.995-1003
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    • 2021
  • Objective : People are living longer and the elderly population continues to increase. The incidence of degenerative spinal diseases (DSDs) in the elderly population is quite high. Therefore, we are facing more cases of DSD and offering more surgical solutions in geriatric patients. Understanding the significance and association of frailty and central sarcopenia as risk factors for spinal surgery in elderly patients will be helpful in improving surgical outcomes. We conducted a retrospective cohort analysis of prospectively collected data to assess the impact of preoperative central sarcopenia, frailty, and comorbidity on surgical outcome in elderly patients with DSD. Methods : We conducted a retrospective analysis of patients who underwent elective spinal surgery performed from January 1, 2019 to September 30, 2020 at our hospital. We included patients aged 65 and over who underwent surgery on the thoracic or lumbar spine and were diagnosed as DSD. Central sarcopenia was measured by the 50th percentile of psoas : L4 vertebral index (PLVI) using the cross-sectional area of the psoas muscle. We used the Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale to measure frailty. Comorbidity was confirmed and scored using the Charlson Comorbidity Index (CCI). As a tool for measuring surgical outcome, we used the Clavien-Dindo (CD) classification for postoperative complications and the length of stay (LOS). Results : This study included 85 patients (35 males and 50 females). The mean age was 74.05±6.47 years. Using the K-FRAIL scale, four patients were scored as robust, 44 patients were pre-frail and 37 patients were frail. The mean PLVI was 0.61±0.19. According to the CD classification, 50 patients were classified as grade 1, 19 as grade 2, and four as grade 4. The mean LOS was 12.35±8.17 days. Multivariate stepwise regression analysis showed that postoperative complication was significantly associated with surgical invasiveness and K-FRAIL scale. LOS was significantly associated with surgical invasiveness and CCI. K-FRAIL scale showed a significant correlation with CCI and PLVI. Conclusion : The present study demonstrates that frailty, comorbidity, and surgical invasiveness are important risk factors for postoperative complications and LOS in elderly patients with DSD. Preoperative recognition of these factors may be useful for perioperative optimization, risk stratification, and patient counseling.

Electrochemical Study of Three Stainless Steel Alloys and Titanium Metal in Cola Soft Drinks

  • Peralta-Lopez, D.;Sotelo-Mazon, O.;Henao, J.;Porcayo-Calderon, J.;Valdez, S.;Salinas-Solano, G.;Martinez-Gomez, L.
    • Journal of Electrochemical Science and Technology
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    • 제8권4호
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    • pp.294-306
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    • 2017
  • Stainless steels and titanium alloys are widely used in the medical industry as replacement materials. These materials may be affected by the conditions and type of environment. In the same manner, soft drinks are widely consumed products. It is of interest for dental industry to know the behavior of medical-grade alloys when these are in contact with soft drinks, since any excessive ion release can suppose a risk for human health. In the present study, the electrochemical behavior of three stainless steel alloys and pure titanium was analyzed using three types of cola soft drinks as electrolyte. The objective of this study was to evaluate the response of these metallic materials in each type of solution (cola standard, light and zero). Different electrochemical techniques were used for the evaluation of the alloys, namely potentiodynamic polarization, linear polarization, and open-circuit potential measurements. The corrosion resistance of the stainless-steel alloys and titanium in the cola soft drinks was provided by the formation of a stable passive film formed by metal oxides. Scanning electron microscopy was used as a complementary technique to reveal corrosion phenomena at the surface of the materials evaluated.

Effect of Non-Alcoholic Fatty Liver Disease on Components of Metabolic Syndrome in Post-menopausal Women

  • Shim, Moon-Jung;Im, Jee-Aee
    • 대한의생명과학회지
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    • 제14권4호
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    • pp.225-231
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    • 2008
  • Non-alcoholic fatty liver disease (NAFLD) is associated with various metabolic abnormalities, including central obesity, type 2 diabetes, dyslipidemia, and high blood pressure. This suggests that NAFLD may represent the hepatic manifestation of the metabolic syndrome. In this study, we investigated unfavorable effects NAFLD on components of metabolic syndrome in post-menopause women. Eight hundred sixty-nine postmenopausal women were recruited for this study. The diagnosis of fatty liver was based on the results of abdominal ultrasonography. Serum levels of fasting glucose, total cholesterol, triglyceride, and HDL-cholesterol were measured. The prevalence of component of metabolic syndrome such as hypertension, hyperglycemia, hypertriglyceridemia, and low-HDL-cholesterol was significantly higher in subjects with NAFLD as compared with those without NAFLD. The moderate to severe grade of NAFLD presented higher levels of serum fasting glucose, fasting insulin, HOMA-IR, total cholesterol, and triglycerides than the mild NAFLD and the normal group. In conclusion, metabolic syndrome risk was increased in post-menopause women with NAFLD as compared with those without NAFLD. The severity of NAFLD affected metabolic syndrome risk factors. The optimal strategy for the treatment of NAFLD is likely to include lifestyle modifications and therapy to improve insulin resistance.

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AE에 의한 평면연삭의 가공특성 감시 및 이상진단 (Detection of abnormal conditions and monitoring of surface ginding characteristics by acoustic emission)

  • Lim, Y.H.;Kwon, D.H.;Choi, M.Y.;Lim, S.J.
    • 한국정밀공학회지
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    • 제12권4호
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    • pp.100-110
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    • 1995
  • This paper aims at reviewing the possibility of application over normal or abnormal, detection used by AE, and the characteristics of grinding processes. In this study, when WA-vitri-fied ' resinoid bond grinding wheels:36 kinds of grinding wheel and grinding depth were tuned at the surface grinding, the zone of AE signal generation is theoretically modelled and reviewed by grinding processes. The variation of grinding resistance( F$n^{9}$ $F_{t}$) and AE signal is detected in-process by the use of AE measuring system. The tests are carried out in accordance with grain size and grade of grinding wheels, and work-pieces-STD11 and STD61. According to the experiment's results, the following can be expected;as grinding time passes by, the relation of grinding depth and quantity of AE signal, observing on AE signal and grinding burn suggest the characteristics of grinding processes and evalution on the possibility of control of grinding machine, and monitoring abnormal conditions.e, and monitoring abnormal conditions.

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열가소성 분말 코팅소재 제조 및 난연특성 연구 (A Study on the Preparation of Thermoplastic Powder Coating Material and Its Flame Retardancy)

  • 이순홍;정화영
    • 한국안전학회지
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    • 제25권3호
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    • pp.45-52
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    • 2010
  • The purpose of this study is application to flame retardant powder coating(FRPC) material consisting of ammonium polyphosphate(APP) and magnesium hydroxide($Mg(OH)_2$) as a halogen free flame retardant into thermoplastic resin(LDPE-g-MAH). For improvement of adhesion, LDPE-g-MAH was synthesized from low density polyethylene(LDPE) and maleic anhydride(MAH). The mechanical properties as melt flow index, pencil hardness, cross-hatch adhesion and impact resistance of FRPC were measured. Also, the limited oxygen index(LOI) values were measured 17.3vol%, 31.1vol% and 33.7vol% for LDPE-g-MAH, FRPC-3(APP 15wt%, $Mg(OH)_2$ 15wt%) and FRPC-5(APP 30 wt%), respectively. The thermo gravimetry/differential thermal analysis(TG/DTA) of FPRC-3 was observed endothermic peak at $340^{\circ}C$ and $450^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by APP and $Mg(OH)_2$. It was showed V-0 grade for FRPC-3 and FRPC-4(APP 20wt%, $Mg(OH)_2$ 10wt%) that a char formation and drip suppressing effect, and combustion time reduced by UL94(vertical burning test). It was confirmed that flame retardancy was improved with the synergy effect because of char formation by APP and $Mg(OH)_2$.

산후 우울의 고찰: 정신신경면역계 상호작용을 중심으로 (A Review of Postpartum Depression: Focused on Psychoneuroimmunological Interaction)

  • 김윤미;안숙희
    • 여성건강간호학회지
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    • 제21권2호
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    • pp.106-114
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    • 2015
  • Purpose: The purpose of this review was to describe a psychoneuroimmunology (PNI) framework for postpartum depression (PPD) and discuss its implications for nursing research and practice for postpartum women. Methods: This study explored the role of hypothalamic-pituitary-adrenal (HPA) axis and inflammation as possible mediators of risk factors for PPD through literature review. Results: From this PNI view, human bodies are designed to respond with the reciprocal interactions among the neuro-endocrine and immune system when they are faced with physical or psychological stressors. Chronic stress induces alterations in the function of HPA axis, and a chronic low-grade inflammatory response is associated with depression. The dysfunctions of cytokines and HPA axis have been observed during the postpartum period. Stress promotes glucocorticoid receptor resistance, which can promote inflammatory responses. This, in turn, can contribute to the pathophysiology of depression. This can especially affect populations at vulnerable time-points, such as women in the postpartum. Conclusion: From a PNI perspective, well-designed prospective research evaluating the role of stress and inflammation as an etiology of PPD and the effect of stress reduction is warranted to prevent PPD.

강유전체 세라믹스를 이용한 전자식 안정기용 절전모듈 (Power-saving Module using Ferroelectric Ceramics for Electronic Ballast)

  • 신현용
    • 한국컴퓨터산업학회논문지
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    • 제6권5호
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    • pp.741-748
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    • 2005
  • 형광램프용 전자식 안정기의 효율개선 및 램프의 수명연장을 위하여 강유전체 커패시터와 시간지연스위칭회로로 구성된 절전모듈을 개발하고 적용하였다. 절전모듈에 사용된 강유전체 세라믹스를 이용하여 형광램프의 부저항특성과 최적화를 시키고, 시간지연회로를 통하여 점등초기 예열형에서 비예열형으로 스위칭시켜 점등 중 필라멘트에서 소비되는 전력을 제거함으로써 약 2W의 소비전력을 감소시켜 효율개선을 실현하였으며, 역기전력 제거기능을 통하여 점등 초기 형광램프 필라멘트에 가해지는 충격을 최소화함으로써 형광램프의 수명을 연장시켰다.

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