• 한국음향학회지
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• 제37권3호
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• pp.156-162
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• 2018

LMF(Least Mean Fourth) 알고리즘은 특히 비정규 잡음 상황에서 안정성 및 빠른 수렴성을 나타낼 뿐만아니라 추정 오차도 낮은 것으로 잘 알려져 있다. 최근 LMS (Least Mean Square) 알고리즘 분야에서는 가변 스텝 크기를 적용한 알고리즘들에 대한 관심이 증대되어 왔다. 그 이유는 가변 스텝 크기 LMS가 다양한 환경에서 고정 스텝 크기 LMS보다 우수한 결과를 내기 때문이다. 본 논문에선 LMF에 대한 가변 스텝 크기의 한 방법으로 기울기 평균 벡터를 사용한 가변 스텝 크기를 사용하는 LMF 알고리즘을 제안한다. 제안된 방법은 가변 스텝 크기 LMS와 마찬가지로 고정 스텝 크기 LMF보다 우수할 것이 예상된다. 본 논문은 그 우수성을 시불변 채널과 시변 채널 각각의 채널 환경하에서 시뮬레이션을 통하여 보인다.

• 한국해양학회지
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• 제14권2호
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• pp.45-53
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• 1979

The barometric factor is estimated at five stations in the Bay of Biscay from the linear regression between daily mean sea level and atmospheric pressure. The results show that the adjusted sea level change is important in amplitude in spite of the barometric response of the sea level to the atmospheric pressure. The cross-correlations between adjusted sea levels and the two components of wind stress suggest that the adjusted sea level is highly related to the longshore wind stress. The observed phase and the time lag between adjusted sea levels at adjacent stations aree consistent with the hypothesis of the northward travelling continental shelf waves.

• Journal of Nutrition and Health
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• 제32권2호
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• pp.182-188
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• 1999

A study was conducted on a group of 107 women, attending the three peripheral community clinics in Seoul and Kyunggi area for their prenatal care, to ascertain the relationship between maternal serum zinc concentration measured in pregnancy and several pregnancy outcomes. The serum zinc concentration was adjusted for estimated gestational age at the time of drawing blood. Mean daily zinc intake of the pregnant women estimated by a 24-hour recall method was 7.68$\pm$3.70$\mu\textrm{g}$/dl, 51% of RDA. and mean serum zinc concentration of the women was 94.03$\pm$36.99ug/dl. Adjusted maternal serum zinc level was significantly related to gestational maternal weight gain(p<0.05) and infant birth weight(p<0.05). Pregnant women with tgreater than 9kg weight gain during the gestation period had higher adjusted serum zinc levels than the subjects with less than 8kg weight gain. Adjusted serum zinc levels of mothers who delivered 3.0-3.5kg and greater than 4.0kg birth-weight infants were higher than those of mothers of low-birth-weight infants. Any association between maternal serum zinc level and gestational length, complications and morning sickness was not observed. There results suggest that the maternal serum zinc level may predict perhaps the author could be none specific.

• Communications for Statistical Applications and Methods
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• 제27권1호
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• pp.97-108
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• 2020

This paper compares several methods for estimating parameters of normal inverse Gaussian distribution. Ordinary maximum likelihood estimation and the method of moment estimation often do not work properly due to restrictions on parameters. We examine the performance of adjusted estimation methods along with the ordinary maximum likelihood estimation and the method of moment estimation by simulation and real data application. We also see the effect of the initial value in estimation methods. The simulation results show that the ordinary maximum likelihood estimator is significantly affected by the initial value; in addition, the adjusted estimators have smaller root mean square error than ordinary estimators as well as less impact on the initial value. With real datasets, we obtain similar results to what we see in simulation studies. Based on the results of simulation and real data application, we suggest using adjusted maximum likelihood estimates with adjusted method of moment estimates as initial values to estimate the parameters of normal inverse Gaussian distribution.

• 한국식품영양과학회지
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• 제28권2호
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• pp.484-491
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• 1999

To estimate annual changes in age adjusted mean of serum cholesterol and cholesterol intake in Korea during the past years, data from 21 literatures regarding for serum cholesterol level of Korean or National Nutrition Survey Reports from 1962 to 1995 were extracted for this study. Age standardization for mean serum cholesterol level was adjusted being based on Korean population composition in 1995. Mean of Korean serum cholesterol level depicted an increasing tendency from 1962 to 1995. Magnitude of changes in mean of serum cholesterol was big in the age old groups over 60th decade, but sex difference in the pattern was not observed. The estimated mean cholesterol intake was higher in the urban population than those of rural's and it increased linearly from 1969 to 1995. Major food sources for cholesterol were egg(39.3%), anchovy(8.3%), seafoods(35.2%) meat(13%) in 1995. From the results, it was estimated that mean serum cholesterol and daily cholesterol intake of Korean would be 178 mg/dl and 278mg/day in 1995, respectively.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5283-5286
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• 2014

Stage of cervical cancer may adversely affect the quality of life (QOL) among patients. The objective of this study was to predict the QOL among cervical cancer patients by the stage of their cancer. A cross-sectional study from September 2012 until January 2013 was conducted among cervical cancer patients who completed treatment. All patients completed a interviewer-guided questionnaire comprising four sections: (A) socio-demographic data, (B) medical history, (C) QOL measured by general health status questionnaire (QLQ-30) and (D) cervical cancer specific module CX-24 (EORTC) was used to measured patient's functional, symptom scale and their global health status. Results showed that global health status, emotional functioning and pain score were higher in stage III cervical cancer patients while role functioning was higher in stage I cervical cancer patients. Patients with stage IV cancer have a lower mean score in global health status (adjusted b-22.0, 95 CI% -35.6, -8.49) and emotional functioning (adjusted b -22.5, 95CI% -38.1, -6.69) while stage III had lower mean score in role functioning (adjusted b -14.3, 95CI% -25.4, -3.21) but higher mean score in pain (adjusted b 22.1, 95 CI% 8.56, 35.7). In conclusion, stage III and IV cervical cancers mainly affect the QOL of cervical cancer patients. Focus should be given to these subgroups to help in improving the QOL.

• 응용통계연구
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• 제17권1호
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• pp.105-117
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• 2004

본 논문에서는 선형추세를 갖는 모집단의 평균을 추정하기 위한 새로운 방법을 제시하였다. 이 방법은 변형계통추출에 의하여 표본을 뽑은 뒤 표본의 단순평균이 아니라 조정된 추정량을 사용하여 모평균을 추정하는 방법이다. 조정된 추정량을 정하는 데에 최소제곱법을 사용하였다. 제시된 방법은 선형 추세가 강할수록 효율적이라는 것이 밝혀졌으며, 무한초모집단 모형의 랜덤오차항의 분산인 $\sigma$$^2$이 매우 크지만 않다면 전통적인 방법들에 비해 상대적으로 효율적인 것으로 나타났다.

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.871-888
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• 2006

Many studies have been done to develop procedures to deal with missing values. Most common method is to reassign the other values to the missing data. The purpose of our study is to suggest adjusted Cohen methods and to compare the efficiency of them with other methods through a simulation study. The adjusted Cohen methods use an auxiliary variable to arrange ranking of the variable with missing values. It leads to a reduced mean square error(MSE) compared with the Cohen method.

• Clinics in Shoulder and Elbow
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• 제25권4호
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• pp.274-281
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• 2022

Background: In the present study, the age- and sex-adjusted Constant score (CS) in a normal Indian population was calculated and any differences with other population cohorts assessed. Methods: The study participants were patients who visited the outpatient department for problems other than shoulder and healthy volunteers from the local population. Patients without shoulder pain/discomfort during activity were included in the study. Subjects with any problem that might affect shoulder function (e.g., cervical, thoracic spine, rib cage deformity, inflammatory arthritis) were excluded. Constant scoring of all participants was performed by trained senior residents under the supervision of the senior faculty. Shoulder range of movement and strength were measured following recommendations given by the research and Development Committee of the European Society for Shoulder and Elbow Surgery (2008). A fixed spring balance was used for strength measurement; one end was fixed on the floor and the other end tied with a strap to the wrist of the participant, arm in 90° abduction in scapular plane with palm facing down. Results: Among the 248 subjects (496 shoulders), the average age was 37 years (range, 18-78 years), 65.7% were males (326 shoulders) and 34.3% females (170 shoulders). The mean CS was 84.6±2.9 (males, 86.1±3.0; females, 81.8±2.9). CS decreased significantly after 50 years of age in males and 40 years of age in females (p<0.05). The mean CS was lower than in previous studies for both males and females. Heavy occupation workers had higher mean CS (p<0.05). A linear standardized equation was estimated for calculating the adjusted CS for any age. Conclusions: Mean CS and its change with age differed from previous studies among various population cohorts.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.131-142
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• 1999

Estimators for domains and approximate estimators of their variance are derived using post-stratified complex sample. Furthermore we propose an adjusted variance estimator of a domain mean in case of considering the post-stratified complex sample as simple random sample. A simulation study based on the data of Farm Household Economy Survey is presented to compare variance estimators numerically. From the study we showed that our adjusted variance estimator compensate for the under-estimation problem considerably.