• Title/Summary/Keyword: Mass bias

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Recent Acupuncture Therapy for Polycystic Ovary Syndromes : Systematic Review (다낭성 난소 증후군의 침치료 연구에 관한 체계적 문헌고찰)

  • Kim, Se-Hwa;Hwang, Deok-Sang;Lee, Jin-Moo;Lee, Kyung-Sub;Lee, Chang-Hoon;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.27 no.2
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    • pp.71-82
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    • 2014
  • Objectives: The purpose of this systematic review was to overview and evaluate the efficacy of acupuncture treatment for women with polycystic ovary syndrome (PCOS). Methods: Relevant randomized controlled studies (RCTs) were identified by database searches in MEDLINE, EMBASE, and CENTRAL, up to Dec 2013, and by additional hand searches. Data were extracted regarding anovulation, hyperandrogenism, obesity indices. Meta-analyses were separatedly conducted for the symptoms of PCOS. The risk of bias was assessed. Results: Three studies which were included for analysis, but they showed severly heterogeneity therefore meta-analysis could not be performed. Outcomes for evaluating the efficacy of acupuncture treatment for PCOS were anovulation index (menstrual frequency), hyperandrogenism index (free testosterone) and obesity index (body-mass index). For menstrual frequency, acupuncture treatment consistently suggested an interventional benefit. Although other outcomes did not suggest any enough relevant evidence to interventional benefit for acupuncture treatment. Conclusions: Acupuncture treatment appeared to improve menstrual frequency in PCOS patients. Since a limited number of RCTs were available in the current literature and those studies were also clinically heterogeneous, further research is needed to gather evidence to support acupuncture therapy in PCOS.

Risk Factors of Breast Cancer in the Eastern Mediterranean Region: A Systematic Review and Meta-Analysis

  • Namiranian, Nasim;Moradi-Lakeh, Maziar;Razavi-Ratki, Seid Kazem;Doayie, Mahdyie;Nojomi, Marzieh
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9535-9541
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    • 2014
  • Background: Identifying risk factors of breast cancer is a key point for preventive strategies to reduce the incidence. The aim of current study was to determine most important risk factors for breast cancer in the Eastern Mediterranean Region (EMR) using a systematic review. Materials and Methods: PubMed, Scopus, Web of Science till August 24, 2012 and the reference lists of all included studies were searched. Analytic studies which had reported odds ratios (OR), relative risk (RR) or required data to calculate them were included. A total of 343 studies were critically appraised and finally 30 studies were meta-analyzed. Heterogeneity between the studies was assessed by $I^2$ and Cochran's Q. Egger's test was used to assess publication bias. Results: Twenty five casecontrol studies, one nested case-control and four cohort studies were included. The largest ORs were obtained for history of no live birth (2.25; 95%CI: 1.58-3.18), body mass index (BMI) more than 30 (2.21; 95%CI: 1.71-2.36), age at first pregnancy more than 30 years old (1.52; 95%CI: 1.30-1.77) and meat consumption more than three times per week (1.39; 95%CI: 1.03-1.87). The other important predictors were higher education and smoking as risk factors, physical activity and ovulatory stimulating medication as protective factors. Conclusions: The most important predictors of breast cancer in EMR were history of no live birth, BMI more than 30, age at first pregnancy more than 30 years old, physical inactivity and smoking. Almost all these risk factors are consistent with known risk factors for this cancer in other parts of the world.

Low-Temperature Si and SiGe Epitaxial Growth by Ultrahigh Vacuum Electron Cyclotron Resonance Chemical Vapor Deposition (UHV-ECRCVD)

  • Hwang, Ki-Hyun;Joo, Sung-Jae;Park, Jin-Won;Euijoon Yoon;Hwang, Seok-Hee;Whang, Ki-Woong;Park, Young-June
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.422-448
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    • 1996
  • Low-temperature epitaxial growth of Si and SiGe layers of Si is one of the important processes for the fabrication of the high-speed Si-based heterostructure devices such as heterojunction bipolar transistors. Low-temperature growth ensures the abrupt compositional and doping concentration profiles for future novel devices. Especially in SiGe epitaxy, low-temperature growth is a prerequisite for two-dimensional growth mode for the growth of thin, uniform layers. UHV-ECRCVD is a new growth technique for Si and SiGe epilayers and it is possible to grow epilayers at even lower temperatures than conventional CVD's. SiH and GeH and dopant gases are dissociated by an ECR plasma in an ultrahigh vacuum growth chamber. In situ hydrogen plasma cleaning of the Si native oxide before the epitaxial growth is successfully developed in UHV-ECRCVD. Structural quality of the epilayers are examined by reflection high energy electron diffraction, transmission electron microscopy, Nomarski microscope and atomic force microscope. Device-quality Si and SiGe epilayers are successfully grown at temperatures lower than 600℃ after proper optimization of process parameters such as temperature, total pressure, partial pressures of input gases, plasma power, and substrate dc bias. Dopant incorporation and activation for B in Si and SiGe are studied by secondary ion mass spectrometry and spreading resistance profilometry. Silicon p-n homojunction diodes are fabricated from in situ doped Si layers. I-V characteristics of the diodes shows that the ideality factor is 1.2, implying that the low-temperature silicon epilayers grown by UHV-ECRCVD is truly of device-quality.

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Dry Etching Characteristics of $YMnO_3$ Thin Films Using Inductively Coupled Plasma (유도결합 플라즈마를 이용한 $YMnO_3$ 박막의 건식 식각 특성 연구)

  • 민병준;김창일;창의구
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.2
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    • pp.93-98
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    • 2001
  • YMnO$_3$ films are excellent gate dielectric materials of ferroelectric random access memories (FRAMs) with MFSFET (metal -ferroelectric-semiconductor field effect transistor) structure because YMnO$_3$ films can be deposited directly on Si substrate and have a relatively low permittivity. Although the patterning of YMnO$_3$ thin films is the requisite for the fabrication of FRAMs, the etch mechanism of YMnO$_3$ thin films has not been reported. In this study, YMnO$_3$thin films were etched with Cl$_2$/Ar gas chemistries in inductively coupled plasma (ICP). The maximum etch rate of YMnO$_3$ film is 285$\AA$/min under Cl$_2$/(Cl$_2$+Ar) of 1.0, RF power of 600 W, dc-bias voltage of -200V, chamber pressure of 15 mTorr and substrate temperature of $25^{\circ}C$. The selectivities of YMnO$_3$ over CeO$_2$ and $Y_2$O$_3$ are 2.85, 1.72, respectively. The selectivities of YMnO$_3$ over PR and Pt are quite low. Chemical reaction in surface of the etched YMnO$_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS) surface of the selected YMnO$_3$ thin films was investigated with X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometry (SIMS). The etch profile was also investigated by scaning electron microscopy(SEM)

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유도결합 $Cl_2/CHF_3, Cl_2/CH_4, Cl_2/Ar $플라즈마를 이용한 InGaN 건식 식각 반응 기구 연구

  • 이도행;김현수;염근영;이재원;김태일
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.249-249
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    • 1999
  • GaN과 같은 III-nitride 반도체 관한 식각 기술의 연구는 blue-emitting laser diode(LD)를 위한 경면(mirror facet)의 형성뿐만아니라 새로운 display 용도의 light emitting diodes (LED), 고온에서 작동되는 광전소자 제조 등에도 그 중요성이 증대되고 있다. 최근에는 III-nitride 물질의 높은 식각속도와 미려하고 수직한 식각형상을 이루기 위하여 ECR(Electron Cyclotron Resonance)이나 ICP(Inductively Coupled Plasma)와 같은 고밀도 플라즈마 식각과 CAIBE(Chemically assisted ion beam etching)를 이용한 연구가 진행되고 있다. 현재 제조되어 지고 있는 LED 및 LD와 같은 광소자의 구조의 대부분은 p-GaN/AlGaN/InGaN(Q.W)/AlGaN/n-GaN 와 같은 여러 층의 형태로 이루어져 있다. 이중 InGaN는 광소자나 전자소자의 특성에 영향을 주는 가장 중요한 부분으로써 현재까지 보고된 식각연구는 undoped GaN에 대부분 집중되고 있고 이에 비해 소자 특성에 핵심을 이루는 InGaN의 식각특성에 관한 연구는 미흡한 상황이다. 본 연구에서는 고밀도 플라즈마원인 ICP 장비를 이용하여 InGaN를 식각하였고, 식각에는 Cl2/CH4, Cl2/Ar 플라즈마를 사용하였다. InGaN의 식각특성에 영향을 미치는 플라즈마의 특성을 관찰하기 위하여 quadrupole mass spectrometry(QMS)와 optical emission spectroscopy(PES)를 사용하였다. 기판 온도는 5$0^{\circ}C$, 공정 압력은 5,Torr에서 30mTorr로 변화시켰고 inductive power는 200~800watt, bias voltage는 0~-200voltage로 변화시켰으며 식각마스크로는 SiO2를 patterning 하여 사용하였다. n-GaN, p-GaN 층 이외에 광소자 제조시 필수적인 InGaN 층을 100% Cl2로 식각한 경우에 InGaN의 식각속도가 GaN에 비해 매우 낮은 식각속도를 보였다. Cl2 gas에 소량의 CH4나 Ar gas를 첨가하는 경우와 공정압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%Ar 플라즈마에서 공정 압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%CHF3 와 Cl2/10%Ar 플라즈마에서 공정압력을 15mTorr로 감소시키는 경우 InGaN과 GaNrks의 선택적인 식각이 가능하였다. InGaN의 식각속도는 Cl2/Ar 플라즈마의 이온에 의한 Cl2/CHF3(CH4) 플라즈마에서의 CHx radical 형성에 의하여 증가하는 것으로 사료되어 진다.

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Non-destructive Method for Selection of Soybean Lines Contained High Protein and Oil by Near Infrared Reflectance Spectroscopy

  • Choung, Myoung-Gun;Baek, In-Youl;Kang, Sung-Taeg;Han, Won-Young;Shin, Doo-Chull;Moon, Huhn-Pal;Kang, Kwang-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.5
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    • pp.401-406
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    • 2001
  • The applicability of non-destructive near infrared reflectance spectroscopic (NIRS) method was tested to determine the protein and oil contents of intact soybean [Glycine max (L.) Merr.] seeds. A total of 198 soybean calibration samples and 101 validation samples were used for NIRS equation development and validation, respectively. In the developed non-destructive NIRS equation for analysis of protein and oil contents, the most accurate equation was obtained at 2, 8, 6, 1(2nd derivative, 8 nm gap, 6 points smoothing, and 1 point second smoothing) and 2, 1, 20, 10 math treatment conditions with Standard Normal Variate and Detrend (SNVD) scatter correction method and entire spectrum (400-2500 nm) by using Modified Partial Least Squares (MPLS) regression, respectively. Validation of these non-destructive NIRS equations showed very low bias (protein: 0.060%, oil: -0.017%) and standard error of prediction (SEP, protein: 0.568 %, oil : 0.451 %) as well as high coefficient of determination ($R^2$, protein: 0.927, oil: 0.906). Therefore, these non-destructive NIRS equations can be applicable and reliable for determination of protein and oil content of intact soybean seeds, and non-destructive NIRS method could be used as a mass screening technique for selection of high protein and oil soybean in breeding programs.

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Anodic Oxidation of Silicon in EPW Solution (EPW 용액에서의 실리콘 양극 산화막 형성에 관한 연구)

  • Bu, Jong-Uk;Kim, Seon-Mi;Kim, Seung-Hui;Kim, Seong-Tae;Gwon, Suk-In
    • Journal of the Korean Vacuum Society
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    • v.2 no.2
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    • pp.181-187
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    • 1993
  • We have studied the anodic oxidation of silicon in the anisotropic etchant of EPW(Ethylenediamine, Pyrocatechol and Water) solution using the cyclic polarization technique. The samples have been characterized by means of X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometry (SIMS). The results of cyclic polarization experiments show that the anodic oxides formed on p- and n-type silicon wafers break down at the same potential while breakdown does not occur up to open circuit potential in the case of $p^+$-Si. Strong etch-resistance of $p^+$-XPS. SIMS depth profiles suggest that the critical concentration of boron for etch-stop to occur appears to be much higher than what is widely believed.

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Determination of Fatty Acid Composition in Peanut Seed by Near Infrared Reflectance Spectroscopy

  • Lee, Jeong Min;Pae, Suk-Bok;Choung, Myoung-Gun;Lee, Myoung-Hee;Kim, Sung-Up;Oh, Eun-young;Oh, Ki-Won;Jung, Chan-Sik;Oh, In Seok
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.61 no.1
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    • pp.64-69
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    • 2016
  • This study was conducted to develop a fast and efficient screening method to determine the quantity of fatty acid in peanut oil for high oleate breeding program. A total of 329 peanut samples were used in this study, 227 of which were considered in the calibration equation development and 102 were utilized for validation, using near infrared reflectance spectroscopy (NIRS). The NIRS equations for all the seven fatty acids had low standard error of calibration (SEC) values, while high R2 values of 0.983 and 0.991 were obtained for oleic and linoleic acids, respectively in the calibration equation. Furthermore, the predicted means of the two main fatty acids in the calibration equation were very similar to the means based on gas chromatography (GC) analysis, ranging from 36.7 to 77.1% for oleic acid and 7.1 to 42.7% for linoleic acid. Based on the standard error of prediction (SEP), bias values, and $R^2$ statistics, the NIRS fatty acid equations were accurately predicted the concentrations of oleic and linoleic acids of the validation sample set. These results suggest that NIRS equations of oleic and linoleic acid can be used as a rapid mass screening method for fatty acid content analysis in peanut breeding program.

APPLICATION OF SUPPORT VECTOR MACHINE TO THE PREDICTION OF GEO-EFFECTIVE HALO CMES

  • Choi, Seong-Hwan;Moon, Yong-Jae;Vien, Ngo Anh;Park, Young-Deuk
    • Journal of The Korean Astronomical Society
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    • v.45 no.2
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    • pp.31-38
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    • 2012
  • In this study we apply Support Vector Machine (SVM) to the prediction of geo-effective halo coronal mass ejections (CMEs). The SVM, which is one of machine learning algorithms, is used for the purpose of classification and regression analysis. We use halo and partial halo CMEs from January 1996 to April 2010 in the SOHO/LASCO CME Catalog for training and prediction. And we also use their associated X-ray flare classes to identify front-side halo CMEs (stronger than B1 class), and the Dst index to determine geo-effective halo CMEs (stronger than -50 nT). The combinations of the speed and the angular width of CMEs, and their associated X-ray classes are used for input features of the SVM. We make an attempt to find the best model by using cross-validation which is processed by changing kernel functions of the SVM and their parameters. As a result we obtain statistical parameters for the best model by using the speed of CME and its associated X-ray flare class as input features of the SVM: Accuracy=0.66, PODy=0.76, PODn=0.49, FAR=0.72, Bias=1.06, CSI=0.59, TSS=0.25. The performance of the statistical parameters by applying the SVM is much better than those from the simple classifications based on constant classifiers.

Electroacupuncture for Treatment of Polycystic Ovarian Syndrome: Systematic Review of Randomized Controlled Trials (다낭성 난소증후군의 전침 치료 연구에 관한 체계적 문헌 고찰)

  • Yoon, Jun-Geol;Park, Nam-Chun;Ji, Hae-Ri;Park, Kyoung-Sun;Hwang, Deok-Sang;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.31 no.4
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    • pp.39-53
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    • 2018
  • Objectives: The purpose of this review was to overview and evaluate the efficacy of electroacupunture for women with polycystic ovarian syndrome (PCOS) Methods: Relevant randomized controlled studies (RCTs) were identified by database searches in PubMED, EMBASE, OASIS, and Google scholar, up to May 2018. Data were extracted regarding hyperandrogenism, obesity and hyperinsulinemia indices. The risk of bias was assessed. Results: Five RCTs were included for analysis. In one RCT, electroacupuncture group had significantly lower free testosterone and testosterone, compared to no treatment group. However, The other RCTs showed no significant difference between two groups. For LH/FSH, Ferriman Gallway score, anti-mullerian hormone, body mass index, weight and waist, and insulin, electroacupuncture group showed no significant difference, compared to physical exercise, no treatment, and sham acupuncture group. Conclusions: Only a limited number of RCTs have been reported. At present, there is insufficient evidence to support the use of electroacupuncture for treatment of PCOS.