• Communications for Statistical Applications and Methods
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• 제6권3호
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• pp.849-860
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• 1999

This paper addresses the issue of estimating regression function with errors in variables using wavelets. We adopt a nonparametric approach in assuming that the regression function has no specific parametric form, To account for errors in covariates deconvolution is involved in the construction of a new class of linear wavelet estimators. using the wavelet characterization of Besov spaces the question of regression estimation with Besov constraint can be reduced to a problem in a space of sequences. Rates of convergence are studied over Besov function classes $B_{spq}$ using $L_2$ error measure. It is shown that the rates of convergence depend on the smoothness s of the regression function and the decay rate of characteristic function of the contaminating error.

• Journal of Computational Design and Engineering
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• 제3권4호
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• pp.337-348
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• 2016

An experimental approach is presented for the measurement of wear that is common in the threading of cold-forged steel. In this work, the first objective is to measure wear on various types of roll taps manufactured to tapping holes in microalloyed HR45 steel. Different geometries and levels of wear are tested and measured. Taking their geometry as the critical factor, the types of forming tap with the least wear and the best performance are identified. Abrasive wear was observed on the forming lobes. A higher number of lobes in the chamber zone and around the nominal diameter meant a more uniform load distribution and a more gradual forming process. A second objective is to identify the most accurate data-mining technique for the prediction of form-tap wear. Different data-mining techniques are tested to select the most accurate one: from standard versions such as Multilayer Perceptrons, Support Vector Machines and Regression Trees to the most recent ones such as Rotation Forest ensembles and Iterated Bagging ensembles. The best results were obtained with ensembles of Rotation Forest with unpruned Regression Trees as base regressors that reduced the RMS error of the best-tested baseline technique for the lower length output by 33%, and Additive Regression with unpruned M5P as base regressors that reduced the RMS errors of the linear fit for the upper and total lengths by 25% and 39%, respectively. However, the lower length was statistically more difficult to model in Additive Regression than in Rotation Forest. Rotation Forest with unpruned Regression Trees as base regressors therefore appeared to be the most suitable regressor for the modeling of this industrial problem.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.384-388
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• 1997

Recently,direct rolling process has been drawing increasing interests because production cost be greatly reduced by eliminating subsequent hot rolling processes. Such a process has been characterized to prosuce thin steel strip (thickness 1~5mm) directly from molten metal and to skip over the conventional hot rolling processes. However, since there are several process parameters, which affect the quality of product,and their relationship between the parametersare very complex,it is therefore very difficult to realize the process design and the quality control. To overcome these difficulties quantitative relationship between the parameters are investigated through a numerical analysis. Form these results, it is found that solidification final point is the most important paramter which is critical to quality of the strip. Also,the multiple regression model is obtianed to determine their relationship from the solidification final point and roll separating force which can be easily estimated

• 유통과학연구
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• 제12권9호
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• pp.47-52
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• 2014

Purpose - There has been little research on the variables influencing studio apartment values. This study aims to identify variables affecting the value of studio apartments in Seoul by empirically examining the interaction between sale prices and characteristics studio apartment characteristics. Research design, data, and methodology - We have analyzed data pertaining to 142 studio apartments in September 2010. A regression analysis model is constructed to test the significance of the variables in relation to the studio apartment sale prices per m2 in Seoul. Results - The age of the building is comparatively more significant than land use as the explanatory variable. Land price is the key variable affecting studio apartment sale prices and investors are willing to pay high implicit sale prices for locations that are associated with high land prices. Conclusions - The age of buildings explains a significant portion of the variability of the sale prices of studio apartment. Higher land prices result in higher sale prices for studio apartments. The older the buildings, the lower the sale prices of the studio apartments.

• 대한가정학회지
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• 제32권3호
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• pp.105-120
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• 1994

The purposes of this research are to find out general trends of mother-adolescent communication and family stress to estimate the differences of communication patterns and family stress according to sociodemographic and communication variables and to analyze communication variables influencing on family stress. The samples were selected from high school students and their mothers and 342 couples were used in final analysis. Barnes & Olson(1982)'s parent-adolescent communication scale(PACI) and McCubbin(1981)'s family stress scale(FILE) were used to measure mother-adolescent communication pattern and family stress. The data were analyzed by frequency, percentage, mean, Chi-square, F-test Duncan-test, multiple regression, Pearson's r, and Chronbach's α. The result are summerized as follows: 1) Mothers highly perceived mother-adolescent open communication pattern but adolescents highly revealed mother-adolescent close communication pattern. The general trends of family stress showed that adolescents stress is higher than mothers. 2) Communication patterns showed significant differences in mother's age, adolescent's sex and communication variables in mother's education and conversation variables. Generally when mothers and adolescents communicated insufficiently and were not satisfied with communication patterns family stress was increased. 3) Family stress was significantly different in communication patterns. Form the regression analysis it was found that communication patterns are crucial to family stress. Especially open communication pattern between mothers and adolescents was the most important among the communication patterns for family stress was reduced.

• KSBB Journal
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• 제26권4호
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• pp.357-364
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• 2011

This study was carried out to investigate the effects of agitation, aeration and scale-up on the mycelial growth, exo-polysaccharide (EPS) production, and mycelial morphology in the liquid culture of Ganoderma lucidum. A correlation between roughness and operating variables was also studied to scale-up the liquid culture of G. lucidum in a jar fermenter. When the agitation speed or aeration rate increased, the morphological form was changed from rough pellet to smooth pellet form. Increase of the agitation and aeration reduced the mycelial roughness. On the other hand, in the case of pellet size, it was not affected by aeration. The higher EPS production was obtained at approximately 17% of roughness and mycelial pellet size of 3~5 mm. The morphology at each fermenter was closely correlated with kLa value, and it was found that similarity of morphology would be used as a criteria of scale-up for liquid culture of G. lucidum.

• KDI Journal of Economic Policy
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• 제21권3_4호
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• pp.63-104
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• 1999

본 연구는 외환위기 발생 이후 취해진 고금리정책이 이후의 환율안정에 기여하였는가를 살펴보고 있다. 완전 변동환율제도로 이행된 1997년 12월 이후의 일별자료를 대상으로 표준적인 시계열모형을 사용하여 분석한 주요 결과는 금리상승이 환율의 평가절상을 유도하였다는 것이다. 축약형모형(reduced form regression)에서 나타난 환율의 금리에 대한 탄력성은, 부도율과 같은 위험(risk)변수를 통제한 단순회귀방정식뿐 아니라 VAR모형에서도 1을 소폭 상회하는 정도의 추정치를 얻을 수 있었다. 이러한 결과는 비록 외환위기 이후 환율안정화의 가장 큰 원동력이 외환유동성의 회복이었음에도 불구하고, 외환유동성이 회복될 때까지 단기적으로는 고금리정책이 환율안정화를 위하여 부분적으로 기여하였음을 시사한다고 할 수 있을 것이다.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.186-189
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• 1996

Neohesperidin dihydrochalcone(NHDC) is an intense sweetener with lingering aftertaste, which limits NHDC to use as a sweetener in food products. This study was conducted to examine the changes of teste quality of NHDC when using $\beta$-cyclodextrin($\beta$-CD) as a taste modifier. A series of $\beta$-CD(0.01%, 0.03%, 0.1%, 0.176%) was added to NHDC solution (100ppm) and the taste quality was evaluated by magnitude estimation. It was found that $\beta$-CD produced a significant effect in the reduction of aftertaste of NHDC(p<0.01) and sweetness as well.(p<0.001). Linear regression(log mean magnitude estimate versus $\beta$-CD concentration) analysis showed that the intensity of sweetness(n=-0.31) decreased more rapidly than that of aftertaste(m=-0.17). This result suggests the possibility that $\beta$-CD may form inclusion complex with NHDC, so that the hydrophobic portion is encapsulated in the cavity of $\beta$-CD and the carbohydrate moiety is oriented to the outside of the cavity. Or it may be that $\beta$-CD competes with the NHDC molecule for binding to the taste receptor, resulting in reduced perceived intensity.

• 정보처리학회논문지D
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• 제10D권2호
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• pp.293-300
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• 2003

인터넷의 급속한 성장과 웹 관련 기술이 더 복잡해지면서 웹 응용 소프트웨어의 품질과 신뢰성이 중요하게 되었다. 웹 기반 소프트웨어는 전 세계에 흩어져 있는 수많은 사용자들을 대상으로 한다는 면에서 품질과 시험 방법 또한 중요하다. 이 논문은 브라우저 객체를 이용하여 HTML 웹 페이지의 사용자 입력 부분에 대한 테스트 케이스를 자동적으로 실행할 수 있는 방안을 제시하고 Javascript로 매핑하여 자동화가 가능함을 보였다. 스크립트 작성기를 만들면 Javascript를 작성하는 오버헤드를 줄일 수도 있다. 작성된 테스트 스크립트는 웹 기반 소프트웨어의 리그레션 테스트에 반복적으로 사용할 수 있다.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.195-204
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• 2020

This research examines four specific objectives: (1) identifying factors that affect Vietnamese consumer attitudes towards smartphone advertising, (2) measuring the level of impact of the factors, (3) testing the difference of attitudes among groups of consumers with different characteristics in terms of gender, age, income, and academic level, and (4) proposing some managerial implications to have better Vietnamese consumer attitudes towards smartphone advertising. The study uses the online survey form via e-mail and Facebook in a convenience sampling method; the subjects surveyed are between the ages of 18 and 35, and all are in urban areas in Vietnam, and are using smartphones and accessing the internet and other phone applications. A sample of 490 respondents were valid and used for processing. The study employs a combination of qualitative and quantitative methods to analyze exploratory factors and linear multiple regression. The results reveal that there are five main factors affecting Vietnamese consumer attitudes towards smartphone advertising positively, arranged by reduced importance: entertainment, informativeness, credibility, non-irritation, permission and control. From that, the study offers some managerial suggestions for smartphone advertisers to improve their strategies and tatics to enhance their customer service, so that the smartphone advertising can attract people and help Vietnamese consumer in their buying behavior.