• Communications for Statistical Applications and Methods
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• v.27 no.5
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• pp.523-533
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• 2020

This paper suggests three available methods for finding nonnegative estimates of variance components of the random effects in mixed models. The three proposed methods based on the concepts of projections are called projection method I, II, and III. Each method derives sums of squares uniquely based on its own method of projections. All the sums of squares in quadratic forms are calculated as the squared lengths of projections of an observation vector; therefore, there is discussion on the decomposition of the observation vector into the sum of orthogonal projections for establishing a projection model. The projection model in matrix form is constructed by ascertaining the orthogonal projections defined on vector subspaces. Nonnegative estimates are then obtained by the projection model where all the coefficient matrices of the effects in the model are orthogonal to each other. Each method provides its own system of linear equations in a different way for the estimation of variance components; however, the estimates are given as the same regardless of the methods, whichever is used. Hartley's synthesis is used as a method for finding the coefficients of variance components.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.320-323
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• 2007

The vacuum sealing method is adopted to minimize the residual impurity gas by enhancing a base vacuum level, and the resultant changes in the reset, address, and sustain discharge characteristics, such as a firing voltage, IR emission, and ICCD image, were examined in comparison with the conventional sealing method in the 42-in. AC-PDP. In the PDP cells fabricated by the vacuum sealing method, the ICCD observation illustrates that the discharge is initiated and extinguished very fast and its IR emission intensity is high.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.57-67
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• 2015

The aim of this study was to categorize and analyze the patterns of the observation type in the experiential learning through the science museum for elementary gifted students in science. Ten science-gifted students were included and analyzed in this study and during experiential learning in the science museum, the participants freely expressed their observation of their own languages and all observations and dialogue were recorded. The results are listed below. The cognitive aspect, especially question and response activity without their personal opinion, was the most frequently used item. Among the affective aspects, item for 'recommendation' was often used. In accordance to observation type, most participants overall observed single object independently of time. Also, participants mostly observed objects visually using qualitative method without manipulation. Therefore verbal interaction through question might have a positive effect on frequency and diversity of observation. Project learning, such as particular exhibition hall, exploratory time of concentration by students, or study paper will be capable of creating a effective observation learning in order to induce a variety of observation of science gifted students in the experiential learning through the science museum.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.145-159
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• 1996

We propose an adaptive searching method using some spatial relations among sample points to estimate the interesting area in the spatial population. The fundamental idea is to observe the neighboring sample points when a sample point is satified with some condition of an adaptive searching observation. For obseving the sample points with this method to estimate the area the sample size is decreased. From this result, we may expect to reduce the cost and time consuming in observation the sample points and to draw the shape of the interesting area without prior information of an spatial population. Some analytical simulation results are also presented.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.1
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• pp.71-83
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• 2018

Background & objectives: This study was aimed to identify the hand hygiene (HH) compliance and related factors among teachers working at child day care centers. Method: This study was done with 44 teachers working at home child day care center in Changwon. Data on hand hygiene compliance was measured using direct observation method from July to December, 2016 with structured observation sheet. Collected data was analyzed by descriptive statistics, and t-test or ANOVA using SPSS Statistics version 23.0. Result: Complete HH compliance rate was 54.0%, the highest in 'before having meals' (81.6%) and the lowest in 'after having meals' (25.8%). However, incomplete HH compliance rate was 34.5%, the highest in 'after contact with secretions' (47.8%) and the lowest in 'before having meals' (18.4%). The HH rate was related with working experience. Conclusion: The HH compliance rate among child care teachers was not satisfactory. About one quarter of child care teachers have taken hand hygiene related training. Therefore, child care teachers should be encouraged to participate in hand hygiene related education program regularly.

• Structural Engineering and Mechanics
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• v.34 no.6
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• pp.739-753
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• 2010

Pointing to the design requirement of prestressed space grid structure being the target cable force, the pretension scheme decision analysis method is studied when there's great difference between structural actual state and the analytical model. Based on recursive formulation of cable forces, the simulative recursive system for pretension process is established from the systematic viewpoint, including four kinds of parameters, i.e., system initial value (structural initial state), system input value (tensioning control force scheme), system state parameters (influence matrix of cable forces), system output value (pretension accomplishment). The system controllability depends on the system state parameters. Based on cable force observation values, the influence matrix for system state parameters can be calculated, making the system controllable. Next, the pretension scheme decision method based on cable force observation values can be formed on the basis of iterative calculation for recursive system. In this way, the tensioning control force scheme that can meet the design requirement when next cyclic supplemental tension finished is obtained. Engineering example analysis results show that the proposed method in this paper can reduce a lot of cyclic tensioning work and meanwhile the design requirement can be met.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.3
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• pp.9-17
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• 2015

PURPOSE: This paper aims to present the available angle to evaluate the severity of forward head posture (FHP) with the observation method and photographic method. METHODS: A cross-sectional observation research design study consisted of 29 subjects who was divided two groups (slight FHP group, moderate FHP group) in Eulji university was used. We evaluated the FHP and the angles including CranioVertebral Angle (CVA), Head Tilting Angle (HTA), Head Position Angle (HPA) and Forward Shoulder Angle (FSA) with the Body style S-8.0 (South Korea, LU Commerce). RESULTS: The mean of CVA, FSA from the slight FHP group was shown higher than moderate severe FHP group. According to independent t-test result, but there was no difference among all angles in two groups. The linear discriminate analysis showed the size of distinction of FSA was the biggest, and then CVA, HTA and HPA were in the order. 55.6% of FSA is properly classified in the slight FHP group. CONCLUSION: The FSA is the best to distinguish the severity of FHP and then CVA as the second best. Therefore, FSA is recommended to check the FHP.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.65-76
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• 2013

The water-table fluctuation (WTF) method has been often used for estimating groundwater recharge by analysis of waterlevel measurements in observation wells. An important assumption inherent in the method is that the water level rise is solely caused by precipitation recharge. For the observation wells located near a stream, however, the water-level can be highly affected by the stream level fluctuations as well as precipitation recharge. Therefore, in applying the WTF method, there should be consideration regarding the effect of stream-aquifer interactions. Analysis of water-level hydrographs from the National Groundwater Monitoring Wells of Korea showed that they could be classified into three different types depending on their responses to either precipitation recharge or stream level fluctuations. A simple groundwater flow model was used to analyze the errors of the WTF method, which were associated with stream-aquifer interactions. Not surprisingly, the model showed that the WTF method could greatly overestimate recharge, when it was used for the observation wells of which the water-level was affected by streams. Therefore, in Korea, where most groundwater hydrographs are acquired from wells nearby a stream, more caution is demanded in applying the WTF method.

• Journal of Soil and Groundwater Environment
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• v.25 no.2
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• pp.1-8
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• 2020

In general, the estimation of optimum yield for the radial collector well is determined by the empirical equation or numerical modeling, in which hydraulic conductivity of the aquifer is a main influence factor. Hydraulic conductivities of 164 soil samples collected from boreholes and horizontal wells (average length: about 50 m) installed during well construction in the Anseong stream were drawn in two-dimensional map by the Kriging method and utilized in this study. Hydraulic conductivity analyses by Representative Elementary Count (REC) indicated the average hydraulic conductivity is similar to that of the pumping test when the number of samples reaches about 1,000, which correspond to 1,000 ㎡. Pumping test was also conducted at 1 pumping well and 13 observation wells to estimate hydraulic conductivities at each observation well. REC analysis indicated that the average value of hydraulic conductivity calculated from at least four observation wells is valid as a representative value. The overall result suggested that multiple observation wells or multiple pumping-observation well systems that are located within the range of horizontal wells should be utilized to properly estimate the representative hydraulic conductivity values and the yield of a radial collector well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9C
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• pp.907-912
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• 2005

An efficient method for calculation of observation probability in CDHMM(Continous Density Hidden Markov Model) is proposed in this paper. the proposed algorithm, called FCOP(Fast Computation of Observation Probability), approximate obsewation probabilities in CDHMM by eliminating insignificant PDFs(Probability Density Functions) and reduces the computational load. When applied to a speech recognition system, the proposed FCOP algorithm can reduce the instruction cycles by $20\%-30\%$ and can also increase the recognition speed about $30\%$ while minimizing the loss in its recognition rate. When implemented on a practical cellular phone, the FCOP algorithm can increase its recognition speed about $30\%$ while suffering $0.2\%$ loss in recognition rate.