• Title/Summary/Keyword: statistical assessment

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Evaluation of Water Quality Prediction Models at Intake Station by Data Mining Techniques (데이터마이닝 기법을 적용한 취수원 수질예측모형 평가)

  • Kim, Ju-Hwan;Chae, Soo-Kwon;Kim, Byung-Sik
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.705-716
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    • 2011
  • For the efficient discovery of knowledge and information from the observed systems, data mining techniques can be an useful tool for the prediction of water quality at intake station in rivers. Deterioration of water quality can be caused at intake station in dry season due to insufficient flow. This demands additional outflow from dam since some extent of deterioration can be attenuated by dam reservoir operation to control outflow considering predicted water quality. A seasonal occurrence of high ammonia nitrogen ($NH_3$-N) concentrations has hampered chemical treatment processes of a water plant in Geum river. Monthly flow allocation from upstream dam is important for downstream $NH_3$-N control. In this study, prediction models of water quality based on multiple regression (MR), artificial neural network and data mining methods were developed to understand water quality variation and to support dam operations through providing predicted $NH_3$-N concentrations at intake station. The models were calibrated with eight years of monthly data and verified with another two years of independent data. In those models, the $NH_3$-N concentration for next time step is dependent on dam outflow, river water quality such as alkalinity, temperature, and $NH_3$-N of previous time step. The model performances are compared and evaluated by error analysis and statistical characteristics like correlation and determination coefficients between the observed and the predicted water quality. It is expected that these data mining techniques can present more efficient data-driven tools in modelling stage and it is found that those models can be applied well to predict water quality in stream river systems.

Application of Spatial Autocorrelation for Analysis of Spatial Distribution Characteristics of Birds Observed in Namdaecheon River, Muju-gun, Jeollabuk-do, Korea (무주 남대천에 서식하는 조류의 공간적 분포특성 분석을 위한 공간자기상관 적용 연구)

  • Kang, Jong-Hyun;Kim, Yong-Ki;Yeon, Myung-Hun
    • Journal of Environmental Impact Assessment
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    • v.22 no.5
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    • pp.467-479
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    • 2013
  • This study was conducted to find out characterization of spatial distribution of birds observed in river areas. Our bird survey was carried out 4 times at 31 sites from January to September in 2011. A total of 1,609 accumulated individuals belonging to 59 species, 28 families and 11 orders were observed. In the result of spatial autocorrelation analysis using the richness index of the maximum counts of each sites, we confirmed that the distribution of birds in Namdaecheon river was clustered and the tendency of spatial autocorrelation was apparent. The area of each sites within a 200m radius was classified in four biotope categories such as agricultural land, forest, residential area and water area, and the spatial autocorrelation was analysed about four types. In the result of spatial autocorrelation analysis for four biotope categories, all types were showed the positive spatial autocorrelation, but the type of water area was higher than other types. The positive correlation was found between the water area and water birds in statistical significance. However, the forest birds had non-significance values. Therefore, it is appropriate to focus on water birds except for forest birds, when researches of bird distribution in river ecosystem is conducted. The number of bird species and individuals increased as the riverside of water area was to widen. Thus, if the areas of riverside offering the feeding and roosting area increase, it will be accommodated many birds. Also, the areas of riverside should be maintained naturally because it is an important habitats of birds. Our study area is on the outskirts the city of higher rates of forest and agricultural land, it may be unreasonable to apply our results to the whole rivers. If the research about the river flowing around the city will be conducted, it is expected to be useful to the relation study area such as ecological river's restoration.

A Case Study on the Information Capacity Assessment Index of local Residents Using Score Card (스코어카드를 활용한 개인 및 지역정보화 수준 측정 사례연구)

  • Jeong, Hyeong-Chul;Cho, Young-Im
    • The Korean Journal of Applied Statistics
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    • v.21 no.6
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    • pp.1077-1091
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    • 2008
  • In this study, we consider to assess the information ability of individuals related to local information. Questionnaire surveys are frequently used for studies on the measuring of information index and such specified indexes of society development. However, if questionnaire papers measured individuals' abilities and such parts of quality, the subjective judgments of respondents cannot but be intervened. Therefore a method which will enable subjective points to be comparatively objectified is needed. In this study, when an attempt is being made to measure individuals' information capacity through questionnaire surveys as the process for calculating the standards of regional information levels. Cases have been looked at for times when, by using a scorecard, individuals' subjective survey result have been be changed to be comparatively objectified scores and such process. The logit model was used in the preparation of the scorecard. In this study, we have presented a clue which enables the comparative measurement about regional information gaps by using characteristics of regional population statistics.

Effectiveness of Additional Acupuncture Therapy for Lung Cancer Patients - A single group before-and-after, preliminary study - (폐암 환자에 대한 부가적인 침치료 효과 - 단일군, 전후, 예비임상 연구 -)

  • Kim, Do Hyung;Jeon, Doo Soo;Park, Seung Chan;Lee, Seung Eun;Cho, Woo Hyun;Han, Chang Woo;Kim, So Yeon;Choi, Jun-Yong;Kim, Yun Seong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.1
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    • pp.82-88
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    • 2014
  • This study is a single group before-and-after study aimed to evaluate the effectiveness of additional acupuncture therapy for lung cancer patients being treated with chemotherapy. Acupuncture therapy was conducted twice a day at least for a week. The effectiveness outcome measures were the Korean Functional Assessment of Cancer Therapy (FACT-L) and the Korean Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) at the baseline, discharge and four weeks after discharge, and visual analogue scale(VAS) checked daily from the baseline to discharge. Ten patients were enrolled, one patient had excluded due to acute exacerbation of lung cancer. The data of nine patients showed some improvement in all of FACT-L, FACIT-F and VAS, however, there were no statistical significance. Additional acupuncture therapy for lung cancer patients treated with chemotherapy might be beneficial to improve the quality of life(QoL) and to improve fatigue. Prospective trials with complex traditional Korean medicine interventions are needed to further investigation.

Assessing the Extent and Rate of Deforestation in the Mountainous Tropical Forest

  • Pujiono, Eko;Lee, Woo-Kyun;Kwak, Doo-Ahn;Lee, Jong-Yeol
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.315-328
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    • 2011
  • Landsat data incorporated with additional bands-normalized difference vegetation index (NDVI) and band ratios were used to assess the extent and rate of deforestation in the Gunung Mutis Nature Reserve (GMNR), a mountainous tropical forest in Eastern of Indonesia. Hybrid classification was chosen as the classification approach. In this approach, the unsupervised classification-iterative self-organizing data analysis (ISODATA) was used to create signature files and training data set. A statistical separability measurement-transformed divergence (TD) was used to identify the combination of bands that showed the highest distinction between the land cover classes in training data set. Supervised classification-maximum likelihood classification (MLC) was performed using selected bands and the training data set. Post-classification smoothing and accuracy assessment were applied to classified image. Post-classification comparison was used to assess the extent of deforestation, of which the rate of deforestation was calculated by the formula suggested by Food Agriculture Organization (FAO). The results of two periods of deforestation assessment showed that the extent of deforestation during 1989-1999 was 720.72 ha, 0.80% of annual rate of deforestation, and its extent of deforestation during 1999-2009 was 1,059.12 ha, 1.31% of annual rate of deforestation. Such results are important for the GMNR authority to establish strategies, plans and actions for combating deforestation.

An Analysis about the Features of Mathematical Learning of Middle School Students through the Distribution Graphs of the Responses Percentages in National Assessment of Educational Achievement (학업성취도 평가에서 답지 반응률 분포 그래프를 활용한 중학생의 수학과 학업 특성 분석)

  • Jo, Yun Dong;Lee, Kwang Sang
    • Journal of Educational Research in Mathematics
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    • v.25 no.1
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    • pp.1-19
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    • 2015
  • This paper aims to explore what we can improve in the curriculum, teaching-learning, and evaluation on the bases of the analyses of multiple-choice items set in National Assessment of Educational Achievement. For this goal, by using the distribution curves of the responses percentages, we will grasp the features of educational achievement which appear to students through an in-depth analysis about not only item itself but also the contents included in particular distracters. These analyses provide more information than the descriptive statistical values such as the mean of correct answer percentage and the discrimination of whole group and the mean of responses percentages of replies of subgroups. Because the distribution curves of the responses percentages reveal the transition from the lowest to the highest educational achievement very well. From these analyses we acquire the implications about the concept of prime factor or prime factorization, ratio(proportion) such as velocity, linear function, volume of cone, properties of solid figure, and probabilities of empty event and total event.

Injection Laryngoplasty with $Radiesse^{(R)}$ in Unilateral Vocal Fold Palsy : Preliminary Report (일측성 성대 마비에서 $Radiesse^{(R)}$를 이용한 성대 주입술 : 예비보고)

  • Jeon, Ju-Hyun;Park, Jun-Hee;Kim, Si-Hong;Kim, Na-Hyun;Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.19 no.2
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    • pp.117-122
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    • 2008
  • Background and Objectives: $Radiesse^{(R)}$ is a gell-formed material of calcium hydroxylapatite (CaHA) and carboxymethylcellulose (CMC) used for vocal fold injections. The authors aimed to study injection laryngoplasty with $Radiesse^{(R)}$, and determine the efficacy of $Radiesse^{(R)}$ for unilateral vocal cord palsy using objective and subjective measures. Materials and Method: Nine patients with unilateral vocal cord palsy received injection laryngoplasty with $Radiesse^{(R)}$ under general anesthesia from Jul. 2007 to Jan. 2008. $Radiesse^{(R)}$ was injected with 25gauze long needle perorally or percutaneously. The Acoustic, aerodynamic, stroboscopic analysis and pre-injection/post-injection perceptual assessment were evaluated in all patients. Results: Postoperative jitter and shimmer scores tended to diminish compared to preoperative scores, and maximum phonation time increased with statistical significantly. Stroboscopic findings demonstrated improvement postoperatively. The degree of hoarseness, which is a part of perceptual assessment, decreased after the procedure. Conclusion: $Radiesse^{(R)}$ may be an altemative material for injection laryngoplasty. We suggest long-term follow up with more cases.

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Influence of Self-Regulatory Resource and Self-Regulatory Modes on Fashion Product Purchase Intention (소비자의 자아조절자원과 자기조절모드가 패션제품의 구매의도에 미치는 영향)

  • Baek, So Ra;Hwang, Sun Jin
    • Human Ecology Research
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    • v.53 no.5
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    • pp.543-556
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    • 2015
  • This study examined the influence of self-regulatory resource depletion and self-regulatory modes on fashion product purchase intention. Initial research design dealt with differences of the resource depletion effect according to self-regulatory modes. The study used a 2 (self-regulatory resource depletion: depletion/non-depletion) ${\times}$ 2 (regulatory mode: assessment mode/locomotion mode) between-subjects factorial design. Second, the research design empirically analyzed the influence of self-regulatory resource depletion and self-regulatory mode on the fashion product purchase intention by each product group divided by type and involvement of fashion product. The subjects for the initial research were 255 university students in Seoul, Gyeonggi, and Daejeon. The subjects for the second research were 873 university students in Seoul and Daejeon. Collected data were analyzed with SPSS statistical package with reliability analysis, t -test, analysis of variance (ANOVA), and analysis of covariance (ANCOVA). The results were as follows. First, assessment-oriented consumers showed low purchase intentions about fashion products when self-regulatory resources were exhausted than when self-regulatory resource were not exhausted. Locomotion-oriented consumers, indicated no differences in purchase intention about fashion products regardless of self-regulatory resource depletion. Second, influences on purchase intention by self-regulatory resource depletion and self-regulatory mode were different according to the fashion product group. The results of this study implied that strategies should be differentiated when establishing a fashion industry marketing strategy according to the self-regulatory resource depletion and self-regulatory mode of consumers.

Quantitative assessment of periimplant bone density (HU) on CBCT image (CBCT 영상에서 무치악부 임프란트 매식체 주위골 골밀도(HU)의 정량적 평가)

  • Goo, Jong-Gook;Kim, Jin-Soo;Kim, Jae-Duk
    • Imaging Science in Dentistry
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    • v.38 no.1
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    • pp.1-5
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    • 2008
  • Purpose: The primary aims of this retrospective study were to compare subjective bone quality and bone quality based on the Hounsfield scale in different segments of the edentulous jaw, and to establish quantitative and objective assessment of the bone quality. Materials and Methods: Twenty eight randomly selected cone-beam computed tomographic (CBCT) scans were analyzed. For evaluation one hundred and twelve edentulous areas were selected. Implant recipient sites were evaluated visually for Lekholm and Zarb classification. The same sites were subsequently evaluated digitally using the Hounsfield scale with Vimplant$2.0^{TM}$, and the results were correlated with visual classification. Data was subject for statistical analysis in order to determine correlation between recorded HU and the regions of the mouth with the Kruskal-Wallis test. Results: The highest unit/mean density value (311 HU) was found in the anterior mandible, followed by 259 HU for the posterior mandible, 216 HU for the anterior maxilla, and 127 HU for the posterior maxilla. These results demonstrate a strong correlation for HU depending on the region of the mouth (p<0.001). The relationship between HU and type 4 bone was found to be significant (r=0.74). Conclusion: Knowledge of the Hounsfield value as a quantitative measurement of bone density can be helpful as a diagnostic tool by using $CBMercuRa6^{TM}$ with $Vimplant^{TM}$ software.

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A new method to measure the accuracy of intraoral scanners along the complete dental arch: A pilot study

  • Iturrate, Mikel;Lizundia, Erlantz;Amezua, Xabier;Solaberrieta, Eneko
    • The Journal of Advanced Prosthodontics
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    • v.11 no.6
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    • pp.331-340
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    • 2019
  • PURPOSE. The purpose of this study is to assess the accuracy of three intraoral scanners along the complete dental arch and evaluate the feasibility of the assessment methodology for further in vivo analysis. MATERIALS AND METHODS. A specific measurement pattern was fabricated and measured using a coordinate measuring machine for the assessment of control distances and angles. Afterwards, the pattern was placed and fixed in replica of an upper jaw for their subsequent scans (10 times) using 3 intraoral scanners, namely iTero Element1, Trios 3, and True Definition. 4 reference distances and 5 angles were measured and compared with the controls. Trueness and precision were assessed for each IOS: trueness, as the deviation of the measures from the control ones, while precision, as the dispersion of measurements in each reference parameter. These measurements were carried out using software for analyzing 3-dimensional data. Data analysis software was used for statistical and measurements analysis (α=.05). RESULTS. Significant differences (P<.05) were found depending on the intraoral scanner used. Best trueness values were achieved with iTero Element1 (mean from 10 ± 7 ㎛ to 91 ± 63 ㎛) while the worst values were obtained with Trios3 (mean from 42 ± 23 ㎛ to 174 ± 77 ㎛). Trueness analysis in angle measurements, as well as precision analysis, did not show conclusive results. CONCLUSION. iTero Element1 was more accurate than the current versions of Trios3 and True Definition. Importantly, the proposed methodology is considered reliable for analyzing accuracy in any dental arch length and valid for assessing both trueness and precision in an in vivo study.