• 제목/요약/키워드: MFS

검색결과 167건 처리시간 0.028초

농업용 필댐의 안전진단등급 평가법 개선을 위한 퍼지논리 적용법 개발 (A Development of Fuzzy-Logic Application for Improving Safety Diagnosis Rating Method of Agricultural Fill Dam)

  • 윤성욱;유찬
    • 한국농공학회논문집
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    • 제65권4호
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    • pp.33-43
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    • 2023
  • In this study, it was developed and verified an application method of fuzzy-logic theory to the rating process of agricultural fill dam safety. A fuzzy-logic is very famous logical system when some decision making is made on the status of a lack of information. Three proxies were selected and configured membership functions (MFs) and these MFs were activated in the process of fuzzification procedures. Fuzzified vlaues were passed through the rule-based inference system, then fire strength could classified among cases of the rule-based inference system. To obtain final results, Mandani-type was adapted in the defuzzification process. As the results, it was shown the developed system can give a correct results that was compared with Matlab - fuzzy inference function. More ever it could perform the detailed analysis and improvement on the infrastructure safety rating process using classical diagnosis method.

Effect of RTA Treatment on $LiNbO_3$ MFS Memory Capacitors

  • Park, Seok-Won;Park, Yu-Shin;Lim, Dong-Gun;Moon, Sang-Il;Kim, Sung-Hoon;Jang, Bum-Sik;Junsin Yi
    • The Korean Journal of Ceramics
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    • 제6권2호
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    • pp.138-142
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    • 2000
  • Thin film $LiNbO_3$MFS (metal-ferroelectric-semiconductor) capacitor showed improved characteristics such as low interface trap density, low interaction with Si substrate, and large remanent polarization. This paper reports ferroelectric $LiNbO_3$thin films grown directly on p-type Si (100) substrates by 13.56 MHz RF magnetron sputtering system for FRAM (ferroelectric random access memory) applications. RTA (rapid thermal anneal) treatment was performed for as-deposited films in an oxygen atmosphere at $600^{\circ}C$ for 60sec. We learned from X-ray diffraction that the RTA treated films were changed from amorphous to poly-crystalline $LiNbO_3$which exhibited (012), (015), (022), and (023) plane. Low temperature film growth and post RTA treatments improved the leakage current of $LiNbO_3$films while keeping other properties almost as same as high substrate temperature grown samples. The leakage current density of $LiNbO_3$films decreased from $10^{-5}$ to $10^{-7}$A/$\textrm{cm}^2$ after RTA treatment. Breakdown electric field of the films exhibited higher than 500 kV/cm. C-V curves showed the clockwise hysteresis which represents ferroelectric switching characteristics. Calculated dielectric constant of thin film $LiNbO_3$illustrated as high as 27.9. From ferroelectric measurement, the remanent polarization and coercive field were achieved as 1.37 $\muC/\textrm{cm}^2$ and 170 kV/cm, respectively.

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Effect of Extremely Low Frequency Magnetic Fields on Gene Expression in Human Mammary Epithelial MCF10A Cells

  • Hong, Mi-Na;Lee, Hyung-Chul;Kim, Bong Cho;Lee, Yun-Sil;Gimm, Yoon-Myung;Myung, Sung-Ho;Lee, Jae-Seon
    • Journal of electromagnetic engineering and science
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    • 제12권4호
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    • pp.271-279
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    • 2012
  • The effects of extremely low frequency magnetic fields (ELF-MFs) on physiological processes at the cellular level remain unclear despite a number of studies. To investigate the effects of ELF-MFs on gene expression, we exposed human mammary epithelial MCF10A cells to fields of 1 mT magnetic flux density at 60 Hz for 4 and 16 h and measured the transcriptional responses of 24,000 genes using Illumina microarrays. In three independent experiments, we found no statistically significant alteration of expression levels for any of the genes assayed using a cutoff value of 1.2-fold. To confirm this result, we selected six genes with trends suggesting possible expression level changes, although these trends were not statistically significant, and investigated their expression levels further using a semiquantitative reverse-transcription polymerase chain reaction. In three independent experiments, we did not find any alterations in the expression levels of these genes. From these results, we conclude that ELF-MFs do not affect gene expression profiles under our exposure conditions.

제조업 생산직 근로자들의 직무스트레스와 피로와의 융복합적 관련성 (Convergence Relationship between Occupational Stress and Fatigue Symptoms among Blue Collar Workers in Manufacturing Plants)

  • 신은숙
    • 한국융합학회논문지
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    • 제7권1호
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    • pp.57-68
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    • 2016
  • 본 연구는 50명 미만의 소규모 제조업장 근로자들의 직무스트레스와 피로의 융복합적 관련성을 파악하며, 피로에 영향을 미치는 요인이 유의한지를 알아보고자 하였다. 조사대상은 50명 미만의 소규모 제조업장 14개소에 근무하고 있는 남성 근로자 428명으로 하였으며, 자료수집은 2015년 9월 1일부터 15일까지 스스로 작성하는 질문지를 통해 이루어 졌다. 연구결과, 조사대상의 피로수준은 직무스트레스(KOSS)수준과 유의한 양의 상관관계를 보였다. 피로수준에 영향을 미치는 요인으로는 성, BMI, 주관적 건강상태, 흡연상태, 규칙적인 운동여부, 커피음용여부, 외래진료유무, 직장생활의 만족도, 직무스트레스(KOSS)가 유의하게 나타난 변수이며 변수설명력은 34.1%이었다. 이상과 같은 결과는 소규모 제조업 남성 근로자들의 피로수준은 인구 사회학적 특성별, 건강관련 행위특성별, 직무관련 및 직무스트레스와 유의한 융복합적 관련성이 있음을 시사하고 있다.

Properties of Dy-doped $La_2O_3$ buffer layer for Fe-FETs with Metal/Ferroelectric/Insulator/Si structure

  • Im, Jong-Hyun;Kim, Kwi-Jung;Jeong, Shin-Woo;Jung, Jong-Ill;Han, Hui-Seong;Jeon, Ho-Seung;Park, Byung-Eun
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.140-140
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    • 2009
  • The Metal-ferroelectric-semiconductor (MFS) structure has superior advantages such as high density integration and non-destructive read-out operation. However, to obtain the desired electrical characteristics of an MFS structure is difficult because of interfacial reactions between ferroelectric thin film and Si substrate. As an alternative solution, the MFS structure with buffer insulating layer, i.e. metal-ferroelectric-insulator-semiconductor (MFIS), has been proposed to improve the interfacial properties. Insulators investigated as a buffer insulator in a MFIS structure, include $Ta_2O_5$, $HfO_2$, and $ZrO_2$ which are mainly high-k dielectrics. In this study, we prepared the Dy-doped $La_2O_3$ solution buffer layer as an insulator. To form a Dy-doped $La_2O_3$ buffer layer, the solution was spin-coated on p-type Si(100) wafer. The coated Dy-doped $La_2O_3$ films were annealed at various temperatures by rapid thermal annealing (RTA). To evaluate electrical properties, Au electrodes were thermally evaporated onto the surface of the samples. Finally, we observed the surface morphology and crystallization quality of the Dy-doped $La_2O_3$ on Si using atomic force microscopy (AFM) and x-ray diffractometer (XRD), respectively. To evaluate electrical properties, the capacitance-voltage (C-V) and current density-voltage (J-V) characteristics of Au/Dy-doped La2O3/Si structure were measured.

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소아 청소년의 과민성 장증후군이 식습관, 피로감에 미치는 영향에 관한 연구 (A Study on the Influence of Irritable Bowel Syndrome on Dietary Habits and Fatigue in Children and Adolescents)

  • 한예지;이선행;이진용
    • 대한한방소아과학회지
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    • 제31권3호
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    • pp.1-13
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    • 2017
  • Objectives The purpose of this study is to investigate how irritable bowel syndrome (IBS) affects fatigue scales and eating habits in children and adolescents using Rome IV criteria. Methods Questionnaires and The $PedsQL^{TM}$ Multidimensional Fatigue Scale (MFS) have been given to 211 children and adolescents aged 8 to 18 years old who were admitted to ${\bigcirc}{\bigcirc}$ university Korean medicine hospital pediatric departments, from 29th, July, 2016 to 12th, August, 2016 to evaluate their eating habits and fatigue. Additionally, PASW statistics 18.0 were used to analyze influence of irritable bowel syndrome on eating habits and fatigue in children and adolescents by using chi-square test, independent t-test and linear regression. Results In total of 211 subjects, 29 (13.7%) were diagnosed with IBS according to the Rome IV criteria. 1. There was a statistically significant difference (p<0.05) between IBS group and non-IBS group on a specific question in the eating habit questionnaire: the amount of sugar intake and the prevalence of IBS. 2. There was a statistically significant difference in general fatigue and cognitive fatigue categories when comparing the MFS subscores according to the prevalence of IBS. Conclusions Considering patients eating habits and fatigue is a necessary process for the successful treatment of irritable bowel syndrome. Korean medicine that maximizes quality of life while minimizing the potential risks to the patients of gastrointestinal disease should also include administrative interventions that may be helpful in the daily life of IBS patients.

피로환자에 사암침 치료 효과의 임상연구 (The Clinical Study on the Effect of SAAM Acupuncture Treatment for Patients with Fatigue)

  • 김수현;박회진;박현애;장준호;황규선;이소열
    • Journal of Acupuncture Research
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    • 제24권6호
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    • pp.149-157
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    • 2007
  • Objectives : This study was performed to evaluate the effect of SAAM acupuncture treatment for patients with fatigue. Methods : The clinical study was carried out with 56 fatigue patients who had visited the Fatigue Clinic in Dong-Seo Oriental Medical Hospital from April 2007 to September 2007. Patients were randomly assigned to two groups : SAAM acupuncture treatment group or control group. The acupuncture points used in the SAAM acupuncture treatment group were $LU_8$, $SP_3$, $HT_8$, $CV_6$, and $BL_{15}$. Acupuncture points used in the control group were non-acupoints near $LU_8$, $SP_3$, $HT_8$, $CV_6$, and $BL_{15}$. The patient's symptoms were assessed at baseline, after 1 week and after 2 weeks of treatment using theMultidimensional Fatigue Scale(MFS). Results : After 2 weeks, MFS score differences between the SAAM acupuncture treatment group and the control group were statistically significant(p<0.05). Conclusions : The results suggest that SAAM acupuncture treatment can be used to improve symptoms in patients with fatigue.

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레이져 증착법으로 제조된 (Ba,Sr)$TiO_3-MFSFET $구조의 성장 및 응력에 의한 강유전성

  • 전성진;한근조;강신충;이재찬
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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    • pp.87-87
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    • 1999
  • 본 연구에서는 Pulsed Laser Deposition(이하 PDL)방법을 이용하여 Si기판에 (Ba,Sr)TiO3(이하 BST)박막을 MFS-FET(Metal-Ferroelectric-Semiconductor Field-effect Transistor)구조로 제조하였으며 BST박막의 강유전성이 BST 박막에 유도되는 응력에 어떤 영향을 받는지 살펴보았다. 본 연구에서는 완충막을 사용함으로써 BST박막과 완충막간의 격자부정합을 이용하여 BST박막에 강유전성을 유도하려고 하였다. 또한 MFS-FET구조의 BST박막에 유도되는 응력조절을 위하여 BST박막과 완충막의 두께를 변화하였으며 XRD를 통한 구조 분석 및 C-V test를 통한 전기적 특성을 관찰을 하였다. PLD법을 통해서 epitaxial 성장된 BST 박막에서는 Si에 epitaxial 성장된 완충막과의 격자부정합에 의한 BST박막내의 자발분극의 발생이 예상된다. 따라서, 본 연구는 강유전체의 자발분극에 의하여 발생되는 C-V 이력현상이 BST박막과 완충막과의 격자부정합에 의한 응력에 의해 발생될 것으로 예상하여, BST 박막에 유도되는 응력과 C-V 이력현상의 관계를 통하여 상온에서 상유전성을 갖는 BST가 응력에 의하여 어느 정도의 강유전성을 나타내는지를 밝히기 위해 진행되었다. 본 연구에서 사용된 완충막은 YSZ(Yttria Stabilized Zirconia)박막으로 0.4mTorrO2 분위기 하에서 600~80$0^{\circ}C$의 온도에서 증착하여 상형성을 살펴보았고 $700^{\circ}C$에서 epitaxial 성장을 확인하였으며 두께는 30~$\AA$으로 변화하였다. 또한 BST박막은 완충막과의 전압분배를 고려해 300~2000$\AA$으로 두께를 변화를 시키며 증착하였다. MFS 구조에서 Al 전극을 사용하여 완충막과 BST박막간의 두께 변화에 따른 Capacitance - Voltage(C-V) 측정을 하였으며 이를 통하여 강유전상의 특성인 C-V 이력현상을 관찰하였다. 그 결과 YSZ 박막에서는 C-V 이력현상이 나타나지 않았으며 BST 박막에서는 약 1.2V의 C-V이력현상이 보였다.

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급성기 신경계 환자에서 낙상 위험 사정 도구의 신뢰도 및 타당도 비교 (Comparison of the Reliability and Validity of Fall Risk Assessment Tools in Patients with Acute Neurological Disorders)

  • 김성렬;유성희;신용순;전지윤;김준우;강수정;최혜숙;이혜림;안영희
    • 성인간호학회지
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    • 제25권1호
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    • pp.24-32
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    • 2013
  • Purpose: The aim of the study was to identify the most appropriate fall-risk assessment tool for neurological patients in an acute care setting. Methods: This descriptive study compared the reliability and validity of three fall-risk assessment tools (Morse Fall Scale, MFS; St Thomas's Risk Assessment Tool in Falling Elderly Inpatients, STRATIFY; Hendrich II Fall Risk Model, HFRM II). We assessed patients who were admitted to the Department of Neurology, Neurosurgery, and Rehabilitation at Asan Medical Center between July 1 and October 31, 2011, using a constructive questionnaire including general and clinical characteristics, and each item from the three tools. We analyzed inter-rater reliability with the kappa value, and the sensitivity, specificity, predictive value, and the area under the curve (AUC) of the three tools. Results: The analysis included 1,026 patients, and 32 falls occurred during this study. Inter-rater reliability was above 80% in all three tools. and the sensitivity was 50.0% (MFS), 84.4%(STRATIFY), and 59.4%(HFRM II). The AUC of the STRATIFY was 82.8. However, when the cutoff point was regulated as not 50 but 40 points, the AUC of the MFS was higher at 83.7. Conclusion: These results suggest that the STRATIFY may be the best tool for predicting falls for acute neurological patients.

다단계 퓨전기법을 이용한 비유사도 기반 식별기의 최적화 (On Optimizing Dissimilarity-Based Classifier Using Multi-level Fusion Strategies)

  • 김상운;로버트 듀인
    • 전자공학회논문지CI
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    • 제45권5호
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    • pp.15-24
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    • 2008
  • 얼굴인식 등과 같은 고차원 식별문제에서는 샘플패턴의 수가 패턴의 차원보다 작아지게 된다. 이러한 상황에서 차원을 축소하기위해 선형판별분석법을 적용할 경우, 희소성(Small Sample Size: SSS)문제가 발생한다. 최근, SSS 문제를 해결하기 위하여 비유사도에 기반 한 식별법(Dissimilarity-Based Classification: DBC)을 이용하는 방법이 검토되었다. DBC에서는 특징 벡터 대신에 학습 샘플들로부터 추출한 프로토타입들과의 비유사도를 측정하여 입력 패턴을 식별하는 방법이다. 본 논문에서는 비유사도 표현단계와 DBC 학습단계에서 퓨전기법을 중복 적용하는 다단계 퓨전기법(Multi-level Fusion Strategies: MFS)으로 DBCs를 최적화시키는 방법을 제안한다. 제안 방법을 벤취마크 얼굴영상 데이터베이스를 대상으로 실험한 결과, 식별률을 향상시킬 수 있음을 확인하였다.