• Research in Vestibular Science
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• v.17 no.4
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• pp.152-159
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• 2018

Objectives: The Korean Dizziness Handicap Inventory (KDHI), which includes 25 patient-reported items, has been used to assess self-reported dizziness in Korean patients with Parkinson disease (PD). Nevertheless, few studies have examined the KDHI based on item-response theory within this population. The aim of our study was to address the feasibility and clinimetric properties of the KDHI instrument using polytomous Rasch measurement analysis. Methods: The unidimensionality, scale targeting, separation reliability, item difficulty (severity), and response category utility of the KDHI were statistically assessed based on the Andrich rating scale model. The utilities of the orderedresponse categories of the 3-point Likert scale were analyzed with reference to the probability curves of the response categories. The separation reliability of the KDHI was assessed based on person separation reliability (PSR), which is used to measure the capacity to discriminate among groups of patients with different levels of balance deficits. Results: Principal component analyses of residuals revealed that the KDHI had unidimensionality. The KHDI had satisfactory PSR and there were no disordered thresholds in the 3-point rating scale. However, the KDHI showed several issues for inappropriate scale targeting and misfit items (items 1 and 2) for Rasch model. Conclusions: The KDHI provide unidimensional measures of imbalance symptoms in patients with PD with adequate separation reliability. There was no statistical evidence of disorder in polytomous rating scales. The Rasch analysis results suggest that the KDHI is a reliable scale for measuring the imbalance symptoms in PD patients, and identified parts for possible amendments in order to further improve the linear metric scale.

• Journal of KIISE
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• v.42 no.10
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• pp.1286-1293
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• 2015

Most e-marketplaces build a reputation system that provides potential buyers with reputation scores of sellers in order for buyers to identify the sellers that are more reliable and trustworthy. The reputation scores are computed based on the aggregation of buyers' ratings. However, when these ratings are used to compute the reputation scores, the existing reputation systems do not make a distinction according to the following two criteria: the capability of the seller and the quality of an item. We claim that a reputation system needs to separate the two criteria in order to provide more precise information about the seller. In this paper, we propose a method to compute seller's reputation by separating the rating into the seller's score and the item's score. The proposed method computes the reputation of the seller's capability by using only the 'seller's score' and helps potential buyers to find reliable sellers who provide fast delivery and better service. In experiments, we propose a simulation strategy that reflects the real life of an E-marketplace and verify the effectiveness of our method by using the generated simulation data.

• Journal of Korea Water Resources Association
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• v.39 no.11 s.172
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• pp.905-914
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• 2006

For an accurate rainfall-runoff simulation in the river basin, not evaluation of runoff model but accurate runoff data are very important. In this study, SSARR model was applied to the Geum River basin and these results are compared with runoff data observed at the Gongju gauging station. The model results didn't good fit the discharge data determined from the rating curve at Gongju gauging station during normal and dry season, especially. For the reliability analysis for the existing rating curve, we observed new stream discharge set from 2003 to 2005. We also estimated long term runoff data from the base flow separation method and defined the hydraulic characteristics. The results show that the new observed stream discharge is similar to the rainfall-runoff model results but existing rating curve seems to be overestimated about 10-20% during normal and dry season. We found that the continuous monitoring and update for the existing rating curve at the gaging station are needed for accurate estimation of runoff data.

• Physical Therapy Korea
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• v.23 no.1
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• pp.46-54
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• 2016

Background: Rasch analysis estimates the probability that a respondent will endorse an item and select a particular rating for that item. It has the advantage of placing both the items and the person along a single ration scale and calibrates person ability and item difficulty onto an interval scale by logits. In addition, Rasch analysis is a useful tool for exploring the validity of questionnaires that have been developed using traditional methods. Therefore, it has been recommended as a method for developing and evaluating functional outcome measures. Objects: The purpose of this study was to investigate the item fit, item difficulty, and rating scale of the Korean version of the Fullerton Advanced Balance Scale (KFAB) using Rasch analysis. Methods: Total 97 subjects (39 males and 58 females) with dwelling elderly adults were participated, but 3 people were excluded for misfit persons. Rasch analysis was then done by means of the Winsteps program to determine the item fit, item difficulty, rating scale, and reliability of the KFAB. Results: In this study, the 'standing with feet together and eyes closed', 'two-footed jump', 'walk with head turns', and 'stand on foam, eyes closed' items shown misfit statistics. The most difficult item was 'stand on one leg', whereas the easiest item was 'turn in full circle'. The rating scale was acceptable with all criteria. Both item and person separation indices and reliability showed acceptable values. This would indicated that each domain covers a useful range of item difficulty that is appropriate for measuring a person with a wide range of functional ability. Conclusion: The KFAB has been proven reliable, valid and an appropriate tool with which to evaluate the balance of the elderly people.

• Journal of Korea Water Resources Association
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• v.49 no.3
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• pp.253-262
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• 2016

A Rating curve is a regression equation of discharge versus stage for a given point on a stream where the stream discharge is measured across the stream channel with a stage and discharge measurement. The curve is generally used to calculate discharge based on the stage. However, the existing approach showed problems in terms of estimating uncertainty associated with regression parameters including the separation parameter for low and high flow. In this regard, this study aimed to develop a new method for the aforementioned problems based on Bayesian approach, which can better estimate the parameter and its uncertainty. In addition, this study used a Bayesian Multi-Segmented (Bayesian M-S) model which is provided a comparison between the existing and proposed scheme. The proposed model showed better results for the parameter estimation than the existing approach, and provided better performance in terms of estimating uncertainty range.

• 재활복지
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• v.21 no.2
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• pp.169-190
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• 2017

The purpose of this study was to investigate item goodness-of-fit of Scale, Rasch rating scale model was applied to 5 dimensions 24 items of the Test of Performance Strategies (TOPS) in a sample of athletes with physical disabilities (n=215). An assumption to test Rasch Model, which is satisfaction of unidimensionality, is regarded through PCAR test, and WINSTEPS 3.65 program is used to test the goodness-of-fit of items. The results of this study were: First, 3-point rating category was appropriate for the TOPS instead of the existing 5-point rating category. Second, as a result of analyzing the goodness-of-fit of the items, 21 items of the TOPS were suitable, but 3 items were not. Third, the item reliability of person separation of the TOPS was acceptable, but the person reliability of item separation was not suitable and it was necessary to adjust the item order considering the difficulty level of the items. Fourth, as a result of comparing the individual attribute score and the difficulty level through the Item-Person Map, the distribution of the item difficulty distribution was shown to be biased in some factors compared to the personal attribute score distribution.

• The Plant Pathology Journal
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• v.26 no.3
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• pp.260-263
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• 2010

Scald, caused by Rhynchosporium secalis has been the major yield-reducing factor for barley production during the last decade. In this study, pathogenic groups of R. secalis were identified to obtain a global picture of the assembly of isolates involved in Syrian populations which is essential for the development of scald-resistant barley cultivars. To identify a number of pathogenic groups, 49 isolates collected over ten years from major barley growing areas in Syria were evaluated on five differential barley genotypes. Genotypes presented a continuous range of response from highly susceptible to moderately resistant, but none were immune to the disease. A cluster analysis placed isolates in six distinct differential pathogenic groups. Mean disease rating of 39.24% was the separation point between avirulent and virulent reactions. Isolate Rs46 exhibited distinct differential virulence patterns associated with high frequency across all genotypes. Hence, the data presented here provides crucial information for future selection of isolates to develop durable barley scald resistance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.130-140
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• 2001

This paper presents the performance of a parallel active power filter(PT) system in unbalanced load condition. The unbalanced load leads to negative sequence of current, and makes 120Hz ripple in the DC-link voltage forcing large capacitance and increases the rating of APF. thus, the separation of negative sequence is performed in synchronous reference frame and controlled to flow into supply network. The validity of the scheme is investigated through simulation and the experimental results for a prototype active power filter system rated at 10kVA.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.43-47
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• 2004

Most of LV customer has been composed the 3-phase four wire system distribution system which is supplying simultaneously at the 1-phase & 3-phase load. In this system, the composition of the power apparatus system is simple rather than conventional separation mode of the 1-phase & 3-phase, But due to uneven load unbalance or unclean power quality, various kinds such as do-rating or power losses become an issue. In this paper, we measured and analyzed voltage and current waveform in the field, compared with internationally allowable voltage unbalance limits.

• The Journal of Korean Academy of Sensory Integration
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• v.18 no.2
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• pp.15-28
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• 2020

Objective : The purpose of this study was to verify the construct validity of Short Sensory Profile-2 (SSP-2) for children with Autism Spectrum Disorder (ASD). Methods : Data were collected from SSP-2 for 120 parents of ASD children. Raw data were analyzed by applying the Rasch analysis to the goodness fit of person and item, item difficulty, rating scale, and separation reliability of SSP-2. Results : 7 persons in sensory processing area and 8 persons in behavioral response area were inappropriate criteria and excluded from the analysis. Item goodness-of-fit analysis determined that the If the Mnsq value is between 0.6 and 1.4 and the Z value is outside the ±2 range for nonconformity. this study All items in the instrument were found to have appropriate criteria. Item difficulty analysis in sensory processing area was high in item 13 (.48 logit) and low in item 10 (-.54 logit). In the behavioral response area, item 25 (1.58 logit) was high and item 30 (-.68 logit) was low. In the rating scale analysis, it was found that the 3-point scale is more appropriate than the 5-point scale. The separation reliability of sensory processing area was .90 and the behavioral response area was .95. Conclusion : This study verified the construct validity of SSP-2 and expected to be applied as a useful evaluation tool for children with ASD.