• 대한전기학회논문지
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• 제38권2호
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• pp.127-136
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• 1989

This paper describes the parameter convergence properties of an adaptive system to identify a single-input single-output plant model. It is demonstrated that, by using power spectrum analysis, the persistency of excitation (PE) condition in order to guarantee the exponential stability of the adaptive control system can be transformed into the positive definite behavior for the auto-correlation function matrix of adaptive signal. The existence of parameter nominal values can be analyzed by this condition and the convergence rates of parameter are determined by examining the auto-correlation function. We may use the sufficient richness (SR) of input spectrum instead of the PE condition to analyze the parameter boundedness. It can be shown that the eigen values of the auto-correlation function are always related with adaptive gain, input amplitude and positions or numbers of input spectra. In each case, the variation of parameter convergence rate can be also verified.

• 한국군사과학기술학회지
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• 제13권4호
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• pp.673-682
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• 2010

This paper describes and analyzes a various generation methods of the mutually orthogonal polyphase sequences with low cross-correlation peak sidelobe and low autocorrelation peak sidelobe levels. The mutual orthogonality is the key requirement of multi-static or MIMO(Multi-Input Multi-Output) radar systems which provides the good target detection and tracking performance. The polyphase sequences, which are generated by SA(Simulated Annealing) and GA(Genetic Algorithm), have been analyzed with ACF(Autocorrelation Function) PSL(Peak Sidelobe Level) and CCF(Crosscorrelation Function) level at the matched filter output. Also, the ambiguity function has been introduced and simulated for comparing Doppler properties of each sequence. We have suggested the phase selection rule for applying multi-static or MIMO systems.

• 동아시아식생활학회지
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• 제18권6호
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• pp.1089-1098
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• 2008

The principal objective of this study was to reveal the relationship between the menu management indicators and menu performance indicators in contract-foodservice operations. Menu indicators differed according to the type of business, type of contract, type of serving, and number of service lines. In accordance with the results of our correlation analysis, we noted significant correlations between menu performance indicators and menu management indicators. The first of these was the correlation between the food cost ration and meal counts, food loss, and the use of prepared vegetables. The second of these was the correlation between food cost per meal and forecasting error, food loss, and inventory turnover. The last of these correlations was the negative correlation between menu CSI(customer satisfaction index) and the use of prepared vegetables. According to the results of our canonical correlation analysis, 2 significant functions were identified. In the first function, we noted significant correlations between meal counts, use of prepared vegetables, food loss, and food cost ratio. Additionally, we noted significant correlations between forecasting error, inventory turnover, food loss, and food cost per meal in the second function. Menu management indicators had no influence on customer satisfaction.

• The Journal of Korean Physical Therapy
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• 제23권3호
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• pp.13-19
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• 2011

Purpose: In real life there are both straight-paths and curved-paths. To evaluate walking ability of both kinds, a figure-8 walking test (F8WT) was developed. The aim of this study was to validate the measure in hemiplegic patients with walking difficulties and to identify correlations of curved walking ability with straight walking ability, motor function, and walking performance ability. Methods: Twenty subjects participated in this study. Curved walking was measured by a F8WT. Straight walking ability was measured by a 10-meter walking test (10MWT). Dynamic balancea bility was measured by timed up and go (TUG) tests. Walking performance ability was measured using a modified motor assessment scale (MMAS). Motor function was measured by the Fugl-Meyer assessment (FMA) scale. Data were analyzed using Pearson correlation analysis. Linear regression analyses were performed to explore other functional tests in mobility ability by F8WT time, 10MWT (dependent variable). Results: There was a significant positive correlation of F8WT time with 10MWT and TUG. There was a significant negative correlation of F8WT time with MMAS and FMA-coordination. There was a significant positive correlation of 10MWT with TUG. There was a significant negative correlation of 10MWT with MMAS and FMA-coordination. The F8WT time for curved walking ability was attributed to 10MWT for straight walking ability as 94% level of contribution. Conclusion: The results suggest that the F8WT is a good instrument for measuring walking ability because there is a robust correlation of F8WT time with 10MWT, TUG, MMAS, and FMA-coordination in hemiplegic patients who, after stroke, have a mobility deficiency.

• 한국치위생학회지
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• 제19권1호
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• pp.65-78
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• 2019

Objectives: This study was conducted to characterize the impact of cognitive function and oral health status on mastication in senior citizens, ${\geq}65$ years of age, using senior centers in the city of Wonju, South Korea. Methods: A cross-sectional study consisting of a simple oral examination and survey questionnaires was performed in 154 individuals. General characteristics, subjective masticatory function, objective masticatory function, cognitive function, and oral health status were collected as variables. Correlation and multiple linear regression analyses were conducted. A p-value of <0.05 was considered to be statistically significant. Results: The subjective masticatory function was scored using the 5-point Likert scale. When subjective masticatory function was analyzed in groups according to cognitive function, the mean subjective masticatory function scores were 4.31, 4.09, and 3.29 in the normal group (cognitive score of ${\geq}16$), suspected dementia group (cognitive score of 1215), and mild dementia group (cognitive score of ${\leq}11$), respectively. Thus, subjective masticatory function decreased along with decreasing cognitive function. When cognitive function, subjective masticatory function, and objective masticatory function were compared with indicators of oral health status (number of functional teeth, oral dryness), subjective masticatory function exhibited a significant positive correlation with objective masticatory function (r=0.635, p<0.01), cognitive function (r=0.292, p<0.01), and total number of functional teeth, including prosthetic appliances (dentures) (r=0.305, p<0.01). According to the regression analysis, age, sex, number of functional teeth, and cognitive function affected subjective masticatory function. Conclusions: The results of this study revealed that age, sex, number of functional teeth, and cognitive function affected subjective masticatory function, whereas oral dryness did not. Therefore, dental professionals must consider subjective masticatory function when providing oral care in senior patients with low cognitive function.

• Nuclear Engineering and Technology
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• 제33권3호
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• pp.283-297
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• 2001

The CHF in PWR rod bundles is usually predicted by the local flow correlation approach based on subchannel analysis while difficulty exists due to the existence of spacer grids especially with mixing vanes. In order to evaluate the effect of spacer grids on CHF, the experimental rod bundle data with various types of spacer grids were analyzed using the subchannel code, COBRA-IV-i. For the Plain grid data, a CHF correlation was described as a function of local flow conditions and heated length, and then the residuals of the CHF in mixing vaned grids predicted by the correlation were examined in various kinds of grids. In order to compensate for the residual, three parameters, distances between grids and from the last grids to the CHF site, and equivalent hydraulic diameter were introduced into a grid parameter function representing the remaining effect of spacer grids predicted most of the CHF data points in plaing grids within $\pm$20 percent error band. Good agreement with the CHF data was also shown when the grid parameter function for mixing vaned grids of a specific design was used to compensate for the residuals of the CHF data predicted by the correlation.

• 한국통신학회논문지
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• 제36권9C호
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• pp.581-588
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• 2011

본 논문에서는 cosine 위상 binary offset carrier (BOC) 신호를 위한 코드 추적 기법을 제안한다. BOC 자기상관함수는 다수의 부상관함수들로 이루어져 있으며, 본 논문에서는 이러한 부상관함수들을 재결합함으로써 주변첨두가 없는 새로운 상관함수를 획득한다. 마지막으로 delay lock loop 에서 사용되는 자기상관함수를 제안한 상관함수로 대체함으로써 주변첨두로 인한 false lock 문제를 해결한다. 또한 모의실험 결과를 통해 제안한 기법이 기존의 기법에 비해 더 좋은 tracking error standard deviation (TESD) 성능을 가지는 것을 보인다.

• 한방재활의학과학회지
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• 제19권2호
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• pp.251-260
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• 2009

Objectives : To investigate reliability and validity of Korean translation of Western Ontario and McMaster Universities(WOMAC) osteoarthritis index. Methods : The reliablity, construct validity of the Korean WOMAC Index in the patient of knee osteoarthritis was investigated. Test-retest reliability was quantified with pearson's correlation coefficient and intraclass correlation coefficient. Internal consistency was quantified with Cronbach's ${\alpha}$. and construct validity with pearson's correlation coefficient by correlating of the Visual Analog Scale(VAS). Results : Test-retest reliability of Korean WOMAC Index for pain was 0.76 to 0.95, stiffness was 0.89 to 0.94, and physical function was 0.71 to 0.95. Intraclass correlation coefficient for pain was 0.76 to 0.94, stiffness was 0.54 to 0.89, and physical function was 0.70 to 0.95. Internal consistency were 0.94 and 0.94 for the first and second time, respectively. Construct validity for pain was 0.79, for stiffness was 0.66, and physical function was 0.67. Conclusions : The Korean translation of Western Ontario and McMaster Universities(WOMAC) osteoarthritis index is reliable, valid assessment tool in knee osteoarthritis.

• 한국통신학회논문지
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• 제37권5C호
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• pp.437-443
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• 2012

본 논문에서는 binary offset carrier (BOC) 신호 획득을 위한 새로운 BOC 상관함수를 제안한다. 구체적으로는 BOC 자기상관함수의 주변 첨두가 불규칙적인 모양을 한 부분상관함수의 합으로 인해 나타난다는 사실을 확인하고, 부분상관함수를 새롭게 조합함으로써 주변 첨두가 없는 새로운 상관함수를 생성한다. 제안한 방법은 어떠한 종류의 BOC 신호에 대해서도 주변 첨두가 없는 상관함수를 생성할 수 있으며, 모의실험을 통해 제안한 생성함수를 이용한 경우 기존의 상관함수들을 이용한 경우에 비해 더 좋은 신호 획득 성능을 제공한다는 것을 보인다.

• 대한물리의학회지
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• 제5권2호
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• pp.281-288
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• 2010

Purpose : The purpose of this study was to examine the correlation between Pediatric Balance Scale(PBS) and Gross Motor Function Measurement(GMFM) with cerebral palsy(CP) children. Methods : 31 ambulatory children with CP were recruited for this study. PBS is a modified version of the Berg’s Balance Scale to access the children with motor impairments. To access the motor functions that directly influence to the functional independence of the ambulatory CP children, total scores of standing category and walking/running/jumping category of GMFM were selectively compared with PBS score by Spearman correlation coefficient analysis. Results : The results revealed high correlation between PBS and GMFM scores both in standing and walking/running/jumping categories(r=.9). Conclusions : Therefore, this study indicates that PBS can be applied not only as a tool to access balance, but also as a measurement to predict and access the level of standing and ambulatory related functions of children with CP.