• Journal of Information Processing Systems
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• 제17권6호
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• pp.1083-1096
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• 2021

Compressed sensing-based matching pursuit algorithms can estimate the sparse channel of massive multiple input multiple-output systems with short pilot sequences. Although they have the advantages of low computational complexity and low pilot overhead, their accuracy remains insufficient. Simply multiplying the weight value and the estimated channel obtained in different iterations can only improve the accuracy of channel estimation under conditions of low signal-to-noise ratio (SNR), whereas it degrades accuracy under conditions of high SNR. To address this issue, an improved weighted matching pursuit algorithm is proposed, which obtains a suitable weight value u_op by training the channel data. The step of the weight value increasing with successive iterations is calculated according to the sparsity of the channel and u_op. Adjusting the weight value adaptively over the iterations can further improve the accuracy of estimation. The results of simulations conducted to evaluate the proposed algorithm show that it exhibits improved performance in terms of accuracy compared to previous methods under conditions of both high and low SNR.

• 대한지역사회영양학회지
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• 제12권3호
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• pp.247-258
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• 2007

This study was conducted to investigate weight control status and associated factors among health-related major female college students. The subjects consisted of 41 nutrition and 78 physical exercise major female college students. Nutrient intakes, biochemical index, nutrition knowledge (recognition and accuracy), interest of weight control, body satisfaction, self-recognition of health condition, self-evaluated body weight were studied. About 73% of nutrition and 79% of physical exercise major female students were in the normal range of BMI ($18.5{\sim}23$) and 2% of nutrition and 1% of physical exercise major female students were underweight, 10% of nutrition and 6% of physical exercise major female students were obese. There were no significant differences in height and weight by major but %body fat and WHR in physical exercise majors were significantly lower than nutrition major students (respectively p<0.01, p<0.05). Overall, nutrition intakes of subjects were not shown to be appropriate, especially Ca/P of subjects was shown $0.54{\sim}0.64$, fat% out of energy of subjects was shown $24.7{\sim}29.0$ and Na intake was shown above 2000mg. Recognition and accuracy of nutrition were higher than those of physical exercise majors (p<0.001). There were no significant differences in self-recognition of health condition, self-evaluated body weight, satisfaction of body shape by major and weight control attempt. But interest of weight control of attempter was higher than that of no-attempter in nutrition (p<0.05) and physical exercise major students (p<0.01). Significantly negative correlation was found in satisfaction of body and BMI, body fat mass, %bodyfat, WHR. And significantly positive correlation was found in interest of weight control and BMI, %bodyfat, WHR. It was noticeable to see that interest of weight control was positively correlated to accuracy and accuracy was negatively correlated to blood cholesterol level. Therefore, proper nutrition education for female college students is needed in order to improve their weight control-related health.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2002년도 추계학술대회
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• pp.289-312
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• 2002

This study suggests the Link weight analysis approach to choose input variables and an integrated model to make more accurate bankruptcy prediction model. the Link weight analysis approach is a method to choose input variables to analyze each input node's link weight which is the absolute value of link weight between an input nodes and a hidden layer. There are the weak-linked neurons elimination method, the strong-linked neurons selection method in the link weight analysis approach. The Integrated Model is a combined type adapting Bagging method that uses the average value of the four models, the optimal weak-linked-neurons elimination method, optimal strong-linked neurons selection method, decision-making tree model, and MDA. As a result, the methods suggested in this study - the optimal strong-linked neurons selection method, the optimal weak-linked neurons elimination method, and the integrated model - show much higher accuracy than MDA and decision making tree model. Especially the integrated model shows much higher accuracy than MDA and decision making tree model and shows slightly higher accuracy than the optimal weak-linked neurons elimination method and the optimal strong-linked neurons selection method.

• 한국안전학회지
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• 제37권1호
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• pp.41-48
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• 2022

Bridge engineering documents have essential contents that must be referenced continuously throughout a structure's entire life cycle, but research related to the quality of the contents is still lacking. XML schema matching is an excellent technique to improve the quality of stored data; however, it takes excessive computing time when applied to documents with many contents and a deep hierarchical structure, such as bridge engineering documents. Moreover, it requires a manual parametric study for matching elements' weight factors, maintaining a high matching accuracy. This study proposes an efficient weight-factor determination method based on an artificial neural network (ANN) model using the simplified XML schema-matching method proposed in a previous research to reduce the computing time. The ANN model was generated and verified using 580 data of document properties, weight factors, and matching accuracy. The proposed ANN-based schema-matching method showed superiority in terms of accuracy and efficiency compared with the previous study on XML schema matching for bridge engineering documents.

• 대한치과보철학회지
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• 제36권2호
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• pp.355-365
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• 1998

The purpose of this study is to evaluate the accuracy of four elastomeric interocclusal recording materials and the weight change according to different storage period (24 hours, 48hours, 7days) and different conditions (dry, wet). The techniques for establishing the intercuspal position were centic occlusion interocclusal record with four elastomeric interocclusal recording materials (Ramitec, Stat-BR, Blu-Mousse, Regisil) (experimental groups) and location of the cast in a position of maximum in-terdigitation using tactile and visual method(control group). To evaluate the accuracy of four elastomeric interocclusal recording materials, the quality of contacts between the mounted casts was compared with the results of an occlusal examination of the same subjects. The results were as follows : 1. The most accurate method of articulating study casts at the intercuspal position was by hand articulation and no significant differences in accuracy were observerd among the experimental groups. 2. In case of interocclusal records storaged in dry sealed plastic box, no significant differences in accuracy were observed among the experimental groups. 3. In case of interocclusal records storaged in water, there was significant inaccuracy in Ramitec group. 4. The biggest weight change was observed in Ramitec group in all storage conditions

• 한국생산제조학회지
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• 제5권4호
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• pp.121-128
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• 1996

In order to examine spindle deformation characteristics that affects the performance of dynmic cutting acuracy due to tool weight variation in a experimental spindle. thermal deformation value of operrative spindle by the axial displacement and the radial run out was measured according to the rise of spindle temperature through the laps of operation time and the change of rotational speed under the tool weight variation. A qualitative summary is as follows ; 1) The results show that the tool weight affcets the spindle temperature variation in a experimental spindle. 2) Radial run out and axial displacement was measured according to the rise of the spindle temperature and the performance of dynamic cutting accuracy was affected by the tool weight variation. 3) Axial displacement is 1.3 times larger than the radial run out in a experimental spindle conditions. 4) Axial displacement is continuously elongated when the tool weight is repeatly exchanged since the spindle themal deformaion, however, when the same tool weight is used. the displacement is still constant.

• 한국항해학회지
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• 제10권1호
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• pp.51-79
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• 1986

From time to time the light weight distribution has been discussed, It play an important part in the preliminary design state because of its influence on the available deadweight. Up to the past, the Light weight distribution acting on the ship has been estimated graphically by means of integraph or approximately by the simplified calculations. Recent development has made it possible to use Lloyd's coffin method or Robb's coffin method for Bulk Carrier, Tanker, Cargo ship where the hull weight is distributed based upon the $C_B$ The hull weight distribution is then super-composed by number of fixed weights(i.e. machinery , equipment, etc.) The authors built up the method by which the Light weight distribution is calculated using a computer. In the usual calculations, the higher accuracy is aimed at, the longer time would be taken, therefore the accuracy would not be so good as to be expected if the time is restricted. The method using a computer can dissolve these and calculated accurately in shorter time the Light weight distribution with less data.

• The Journal of Advanced Prosthodontics
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• 제16권2호
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• pp.91-104
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• 2024

PURPOSE. The objectives of the current study were to estimate the influence of self-reinforced hollow structures with a graded density on the dimensional accuracy, weight, and mechanical properties of Co-Cr objects printed with the direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS. Sixty-five dog-bone samples were manufactured to evaluate the dimensional accuracy of printing, weight, and tensile properties of DMLS printed Co-Cr. They were divided into Group 1 (control) (n = 5), Group 2, 3, and 4 with incorporated hollow structures based on (spherical, elliptical, and diamond) shapes; they were subdivided into subgroups (n = 5) according to the volumetric reduction (10%, 15%, 20% and 25%). Radiographic imaging and microscopic analysis of the fractographs were conducted to validate the created geometries; the dimensional accuracy, weight, yield tensile strength, and modulus of elasticity were calculated. The data were estimated by one-way ANOVA and Duncan's tests at P < .05. RESULTS. The accuracy test showed an insignificant difference in the x, y, z directions in all printed groups. The weight was significantly reduced proportionally to the reduced volume fraction. The yield strength and elastic modulus of the control group and Group 2 at 10% volume reduction were comparable and significantly higher than the other subgroups. CONCLUSION. The printing accuracy was not affected by the presence or type of the hollow geometry. The weight of Group 2 at 10% reduction was significantly lower than that of the control group. The yield strength and elastic modulus of the Group 2 at a 10% reduction showed means equivalent to the compact objects and were significantly higher than other subgroups.

• Perspectives in Nursing Science
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• 제9권1호
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• pp.24-35
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• 2012

Purpose: This research was performed to investigate Korean adolescents' body weight perception, appropriate weight change efforts, and factors that influencing these efforts. Methods: The data were obtained from 68,136 adolescents, aged 12~18 years from the 2007 Third Korean Youth' Risk Behavior Web-based Survey. Descriptive statistical analysis and odds ratio were calculated by logistic regression. Results: The distribution of the body mass index differed in boys and girls. The accuracy of body weight perception was shown in the order of the underweight (91.6%), overweigh t (73.3%), normal weight (55.4%), obesity (41.3%) groups. Adolescents with high perceived economic status tended to have a high prevalence of accuracy of body weight perception. The distribution of appropriate weight change efforts according to the actual body mass index showed that girls were trying to lose weight more than boys. The results of a logistic regression analysis regarding appropriate weight change efforts showed differences according to gender, perceived economic status, mother's educational level, and family affluence scale. Conclusion: Appropriate body weight perception and change management plans are needed for Korean adolescents. In addition, active weight change programs have to be established in the adolescents' living environments, such as schools.

• 지능정보연구
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• 제7권2호
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• pp.19-33
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• 2001

본 연구에서는 부도예측용 인공신경망의 입력노드 선정을 위한 휴리스틱으로 연결강도분석접근법을 제안한다. 연결강도분석은 학습이 끝난 인공신경망에서 입력노드와 은닉노드를 연결하는 연결가중치의 절대값 즉, 연결강도를 분석하여 입력변수를 선정하는 접근법으로, 선정기준에 따라 약체연결뉴론제거법과 강체연결뉴론선택법을 들 수 있다. 본 연구에서는 약체연결뉴론제거법, 강체연결뉴론선택법 그리고 이 두 기법을 통합한 통합 연결강도 모형을 제안하여 각각 의사결정트리 및 다변량판별분석에 의해 선정된 입력변수를 이용한 인공신경망 모형과 예측율을 비교한다. 실험 결과 본 연구에서 제안하고 있는 방법론이 의사결정트리나 다변량판별분석 기법보다 높은 예측율을 보여주었다. 특히 두 기법의 통합연결강도 모형의 경우에는 다른 단일 기법보다 높은 예측율을 보이고 있다.