• Title/Summary/Keyword: Error Analysis

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STANDARDIZATION STUDY FOR THE KOREAN VERSION OF THE LURIA-NEBRASKA NEUROPSYCHOLOGICAL BATTERY FOR CHILDREN II : EVALUATION OF THE VALIDITY & CLINICAL UTILITY OF THE KOREAN VERSION OF LNNB-C (한국판 아동용 Luria-Nebraska 신경심리 검사의 표준화 연구 II : 타당도 및 임상적 유용성 검증)

  • Shin, Min-Sup;Hong, Kang-E
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.5 no.1
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    • pp.70-82
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    • 1994
  • Present study was to evaluate the validity and the clinical utility of the Korean version of Luria-Nebraska Neuropsychological Battery for Children(LNNB-C) in various groups including normal, brain damaged attention deficit hyperactivity disordered(ADHD), and psychiatrically disordered. The Korean version of LNNB-C and BGT were administered to clinical groups consisted of 51 patients(19 brain damaged, 16 ADHD. and 16 psychiatric controls), and to normal group composed of 147 children between the age of 8 and It Also KEDI-WISC was administered D clinical groups as a part of comprehensive psychological assessment There were significant differences between the brain damaged and the normals on all scales of LNNB-C, and between the normals and the ADHD on 11 clinical scales and 3 summary scales, which indicate the clinical validity for the scales of the Korean version of LNNB-C. The significant differences between the ADHD and the brain damaged on 3 summary scales were found, suggesting that the summary scales might play an important role id discriminating between two groups. Multiple discriminant analysis showed that the Korean version of LNNB-C significantly discriminates 3 groups - normals, ADHD, and brain damaged. Percentages of correct classification were ranged from 62.5% in the ADHD to 98.6Ta in the normals. For further evaluating the discriminant validity of the LNNB-C, the discriminant power of each items were calculated, and 131 of the 147 items discriminated significantly between the brain damaged and the normals. The scales of LNNB-C significantly correlated with the error scores of BGT and the most of scales of KEDI-WISC. These results put together : strongly support the concurrent and the discriminant validity of the Korean version of LNNB-C in diagnosing brain damage. The limitations of present study and several issues for the luther study were discussed.

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Evaluating Impact Resistance of Externally Strengthened Steel Fiber Reinforced Concrete Slab with Fiber Reinforced Polymers (섬유 보강재로 외부 보강된 강섬유 보강 콘크리트 슬래브의 충격저항성능 평가)

  • Yoo, Doo-Yeol;Min, Kyung-Hwan;Lee, Jin-Young;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.293-303
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    • 2012
  • Recently, as construction technology improved, concrete structures not only became larger, taller and longer but were able to perform various functions. However, if extreme loads such as impact, blast, and fire are applied to those structures, it would cause severe property damages and human casualties. Especially, the structural responses from extreme loading are totally different than that from quasi-static loading, because large pressure is applied to structures from mass acceleration effect of impact and blast loads. Therefore, the strain rate effect and damage levels should be considered when concrete structure is designed. In this study, the low velocity impact loading test of steel fiber reinforced concrete (SFRC) slabs including 0%~1.5% (by volume) of steel fibers, and strengthened with two types of FRP sheets was performed to develop an impact resistant structural member. From the test results, the maximum impact load, dissipated energy and the number of drop to failure increased, whereas the maximum displacement and support rotation were reduced by strengthening SFRC slab with FRP sheets in tensile zone. The test results showed that the impact resistance of concrete slab can be substantially improved by externally strengthening using FRP sheets. This result can be used in designing of primary facilities exposed to such extreme loads. The dynamic responses of SFRC slab strengthened with FRP sheets under low velocity impact load were also analyzed using LS-DYNA, a finite element analysis program with an explicit time integration scheme. The comparison of test and analytical results showed that they were within 5% of error with respect to maximum displacements.

Assessment of statistical errors of articles published in the Journal of the Korean Academy of Prosthodontics: 2006 - 2010 (대한치과보철학회지에서 볼 수 있는 통계적 오류의 고찰(2006 - 2010))

  • Kang, Dong-Wan;Seo, Yunam;Oh, Nam-Sik;Lim, Hoi-Jeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.4
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    • pp.258-270
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    • 2012
  • Purpose: Use of inappropriate statistical methods may lead to incorrect conclusions and a waste of valuable resources. The goal of this study was to assess the frequency and the types of several common statistical errors in the published articles of the Journal of the Korean Academy of Prosthodontics (JKAP) for a 5-year period. Materials and methods: Of 336 articles in the JKAP published from 2006 to 2010, 255 articles using statistics were reviewed and classified by statistical method and year. The frequency and types of the statistical methods were examined, and the statistical errors were evaluated by the appropriateness of the experimental design, assumption check, independent outcomes, proper sample size and suitable use of statistical method. Statistical guidelines were completed based on the appropriateness. Results: Of the 255 articles using statistics, 193 articles (75.9%) used inferential statistics and 153 articles used SPSS statistical software (60.0%). Of the articles using inferential statistics, the three most frequently used statistical methods were ANOVA (41.5%), t-test (20.0%), and the nonparametric method (16.9%). The average rate of statistical errors was 61.2 percent, similar to the rate reported by several studies completed for the medical journal. Conclusion: After the whole analysis of the difference among the groups, post-hoc tests for the pairwise comparisons are required. The optimal sample size calculation is an essential part of this study protocol. To minimize the occurrence of statistical errors, statistical guidelines were developed according to each statistical test procedure and will contribute to the academic improvement in the JKAP.

Utilization of a Ubiquitous Environmental Sculptures Analysis (유비쿼터스 환경 조형물의 이용의식 실태 분석)

  • Kim, Dong-Chan;Cho, Hwee-In
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.15-22
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    • 2010
  • Today's rapid shifts toward a new paradigm are combining city spaces with reality and technology, which is known as a ubiquitous environment. An ubiquitous environment means that 'whenever' and 'wherever' become connected. It is a great possibility that this will change our future lifestyle. Korea has the biggest advantage in the implementation of this new environment, such as having an excellent network infrastructure. Using these attributes of a ubiquitous environment, changes are being made toward ubiquitous cities within developing fields of construction, landscaping, streets, art, and the environment. This research is based on background of research that activated media pole in public city space has been done research about reality of digital skill, fusion, and sense of ubitizen, and Kang-Nam U-street applied by ubiquitous technique. While reflecting an environment that can be utilized in a modern digital society, the application of ubiquitous technology to media pole can be a space for the two-way communication of the current paradigm. It would also be meaningful to create a new cultural space through media pole. Through evaluation, citizens of the ubiquitous age are going to interact to raise the satisfaction that media pole in city space can prevent giving direction to develop and trial and error about service ability, identity, and publicity. Finally, the media pole can be used as a fundamental element to suggest directions for change when viewed as future development.

Strategies about Optimal Measurement Matrix of Environment Factors Inside Plastic Greenhouse (플라스틱온실 내부 환경 인자 다중센서 설치 위치 최적화 전략)

  • Lee, JungKyu;Kang, DongHyun;Oh, SangHoon;Lee, DongHoon
    • Journal of Bio-Environment Control
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    • v.29 no.2
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    • pp.161-170
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    • 2020
  • There is systematic spatial variations in environmental properties due to sensitive reaction to external conditions at plastic greenhouse occupied 99.2% of domestic agricultural facilities. In order to construct 3 dimensional distribution of temperature, relative humidity, CO2 and illuminance, measurement matrix as 3 by 3 by 5 in direction of width, height and length, respectively, dividing indoor space of greenhouse was designed and tested at experimental site. Linear regression analysis was conducted to evaluate optimal estimation method in terms with horizontal and vertical variations. Even though sole measurement point for temperature and relative humidity could be feasible to assess indoor condition, multiple measurement matrix is inevitably required to improve spatial precision at certain time domain such as period of sunrise and sunset. In case with CO2, multiple measurement matrix could not successfully improve the spatial predictability during a whole experimental period. In case with illuminance, prediction performance was getting smaller after a time period of sunrise due to systematic interference such as indoor structure. Thus, multiple sensing methodology was proposed in direction of length at higher height than growing bed, which could compensate estimation error in spatial domain. Appropriate measurement matrix could be constructed considering the transition of stability in indoor environmental properties due to external variations. As a result, optimal measurement matrix should be carefully designed considering flexibility of construction relevant with the type of property, indoor structure, the purpose of crop and the period of growth. For an instance, partial cooling and heating system to save a consumption of energy supplement could be successfully accomplished by the deployment of multiple measurement matrix.

Analysis on the Dosimetric Characteristics of Tangential Breast Intensity Modulated Radiotherapy (유방암의 접선 세기조절 방사선치료 선량 특성 분석)

  • Yoon, Mee Sun;Kim, Yong-Hyeob;Jeong, Jae-Uk;Nam, Taek-Keun;Ahn, Sung-Ja;Chung, Wong-Ki;Song, Ju-Young
    • Progress in Medical Physics
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    • v.23 no.4
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    • pp.219-228
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    • 2012
  • The tangential breast intensity modulated radiotherapy (T-B IMRT) technique, which uses the same tangential fields as conventional 3-dimensional conformal radiotherapy (3D-CRT) plans with physical wedges, was analyzed in terms of the calculated dose distribution feature and dosimetric accuracy of beam delivery during treatment. T-B IMRT plans were prepared for 15 patients with breast cancer who were already treated with conventional 3D-CRT. The homogeneity of the dose distribution to the target volume was improved, and the dose delivered to the normal tissues and critical organs was reduced compared with that in 3D-CRT plans. Quality assurance (QA) plans with the appropriate phantoms were used to analyze the dosimetric accuracy of T-B IMRT. An ionization chamber placed at the hole of an acrylic cylindrical phantom was used for the point dose measurement, and the mean error from the calculated dose was $0.7{\pm}1.4%$. The accuracy of the dose distribution was verified with a 2D diode detector array, and the mean pass rate calculated from the gamma evaluation was $97.3{\pm}2.9%$. We confirmed the advantages of a T-B IMRT in the dose distribution and verified the dosimetric accuracy from the QA performance which should still be regarded as an important process even in the simple technique as T-B IMRT in order to maintain a good quality.

The NCAM Land-Atmosphere Modeling Package (LAMP) Version 1: Implementation and Evaluation (국가농림기상센터 지면대기모델링패키지(NCAM-LAMP) 버전 1: 구축 및 평가)

  • Lee, Seung-Jae;Song, Jiae;Kim, Yu-Jung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.307-319
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    • 2016
  • A Land-Atmosphere Modeling Package (LAMP) for supporting agricultural and forest management was developed at the National Center for AgroMeteorology (NCAM). The package is comprised of two components; one is the Weather Research and Forecasting modeling system (WRF) coupled with Noah-Multiparameterization options (Noah-MP) Land Surface Model (LSM) and the other is an offline one-dimensional LSM. The objective of this paper is to briefly describe the two components of the NCAM-LAMP and to evaluate their initial performance. The coupled WRF/Noah-MP system is configured with a parent domain over East Asia and three nested domains with a finest horizontal grid size of 810 m. The innermost domain covers two Gwangneung deciduous and coniferous KoFlux sites (GDK and GCK). The model is integrated for about 8 days with the initial and boundary conditions taken from the National Centers for Environmental Prediction (NCEP) Final Analysis (FNL) data. The verification variables are 2-m air temperature, 10-m wind, 2-m humidity, and surface precipitation for the WRF/Noah-MP coupled system. Skill scores are calculated for each domain and two dynamic vegetation options using the difference between the observed data from the Korea Meteorological Administration (KMA) and the simulated data from the WRF/Noah-MP coupled system. The accuracy of precipitation simulation is examined using a contingency table that is made up of the Probability of Detection (POD) and the Equitable Threat Score (ETS). The standalone LSM simulation is conducted for one year with the original settings and is compared with the KoFlux site observation for net radiation, sensible heat flux, latent heat flux, and soil moisture variables. According to results, the innermost domain (810 m resolution) among all domains showed the minimum root mean square error for 2-m air temperature, 10-m wind, and 2-m humidity. Turning on the dynamic vegetation had a tendency of reducing 10-m wind simulation errors in all domains. The first nested domain (7,290 m resolution) showed the highest precipitation score, but showed little advantage compared with using the dynamic vegetation. On the other hand, the offline one-dimensional Noah-MP LSM simulation captured the site observed pattern and magnitude of radiative fluxes and soil moisture, and it left room for further improvement through supplementing the model input of leaf area index and finding a proper combination of model physics.

Downscaling of Sunshine Duration for a Complex Terrain Based on the Shaded Relief Image and the Sky Condition (하늘상태와 음영기복도에 근거한 복잡지형의 일조시간 분포 상세화)

  • Kim, Seung-Ho;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.233-241
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    • 2016
  • Experiments were carried out to quantify the topographic effects on attenuation of sunshine in complex terrain and the results are expected to help convert the coarse resolution sunshine duration information provided by the Korea Meteorological Administration (KMA) into a detailed map reflecting the terrain characteristics of mountainous watershed. Hourly shaded relief images for one year, each pixel consisting of 0 to 255 brightness value, were constructed by applying techniques of shadow modeling and skyline analysis to the 3m resolution digital elevation model for an experimental watershed on the southern slope of Mt. Jiri in Korea. By using a bimetal sunshine recorder, sunshine duration was measured at three points with different terrain conditions in the watershed from May 15, 2015 to May 14, 2016. The brightness values of the 3 corresponding pixel points on the shaded relief map were extracted and regressed to the measured sunshine duration, resulting in a brightness-sunshine duration response curve for a clear day. We devised a method to calibrate this curve equation according to sky condition categorized by cloud amount and used it to derive an empirical model for estimating sunshine duration over a complex terrain. When the performance of this model was compared with a conventional scheme for estimating sunshine duration over a horizontal plane, the estimation bias was improved remarkably and the root mean square error for daily sunshine hour was 1.7hr, which is a reduction by 37% from the conventional method. In order to apply this model to a given area, the clear-sky sunshine duration of each pixel should be produced on hourly intervals first, by driving the curve equation with the hourly shaded relief image of the area. Next, the cloud effect is corrected by 3-hourly 'sky condition' of the KMA digital forecast products. Finally, daily sunshine hour can be obtained by accumulating the hourly sunshine duration. A detailed sunshine duration distribution of 3m horizontal resolution was obtained by applying this procedure to the experimental watershed.

A Study on a Quantified Structure Simulation Technique for Product Design Based on Augmented Reality (제품 디자인을 위한 증강현실 기반 정량구조 시뮬레이션 기법에 대한 연구)

  • Lee, Woo-Hun
    • Archives of design research
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    • v.18 no.3 s.61
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    • pp.85-94
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    • 2005
  • Most of product designers use 3D CAD system as a inevitable design tool nowadays and many new products are developed through a concurrent engineering process. However, it is very difficult for novice designers to get the sense of reality from modeling objects shown in the computer screens. Such a intangibility problem comes from the lack of haptic interactions and contextual information about the real space because designers tend to do 3D modeling works only in a virtual space of 3D CAD system. To address this problem, this research investigate the possibility of a interactive quantified structure simulation for product design using AR(augmented reality) which can register a 3D CAD modeling object on the real space. We built a quantified structure simulation system based on AR and conducted a series of experiments to measure how accurately human perceive and adjust the size of virtual objects under varied experimental conditions in the AR environment. The experiment participants adjusted a virtual cube to a reference real cube within 1.3% relative error(5.3% relative StDev). The results gave the strong evidence that the participants can perceive the size of a virtual object very accurately. Furthermore, we found that it is easier to perceive the size of a virtual object in the condition of presenting plenty of real reference objects than few reference objects, and using LCD panel than HMD. We tried to apply the simulation system to identify preference characteristics for the appearance design of a home-service robot as a case study which explores the potential application of the system. There were significant variances in participants' preferred characteristics about robot appearance and that was supposed to come from the lack of typicality of robot image. Then, several characteristic groups were segmented by duster analysis. On the other hand, it was interesting finding that participants have significantly different preference characteristics between robot with arm and armless robot and there was a very strong correlation between the height of robot and arm length as a human body.

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The study of quantitative analytical method for pH and moisture of Hanji record paper using non-destructive FT-NIR spectroscopy (비파괴 분석 방법인 푸리에 변환 근적외선 분광 분석을 이용한 한지 기록물의 산성도 및 함수율 정량 분석 연구)

  • Shin, Yong-Min;Park, Soung-Be;Lee, Chang-Yong;Kim, Chan-Bong;Lee, Seong-Uk;Cho, Won-Bo;Kim, Hyo-Jin
    • Analytical Science and Technology
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    • v.25 no.2
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    • pp.121-126
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    • 2012
  • It is essential to evaluate the quality of Hanji record paper without damaging the record paper by previous destructive methods. The samples were Hanji record paper produced in the 1900s. Near-infrared (NIR) spectrometer was used as a non destructive method for evaluating the quality of record papers. Fourier transform (FT) spectrometer was used with 12,500 to 4,000 $cm^{-1}$ wavenumber range for quantitative analysis and it has high accuracy and good signal-to-noise ratio. The acidity and moisture content of Hanji record paper were measured by integrating sphere as diffuse reflectance type. The acidity (pH) of chemical factors as a quality evaluated factor of Hanji was correlated to NIR spectrum. The NIR spectrum was pretreated to obtain the coefficients of optimum correlation. Multiplicative scatter correction (MSC) and First derivative of Savitzky-Golay were used as pretreated methods. The coefficients of optimum correlation were calculated by PLSR (partial least square regression). The correlation coefficients ($R^2$) of acidity had 0.92 on NIR spectra without pretreatment. Also the standard error of prediction (SEP) of pH was 0.24. And then the NIR spectra with pretreatment would have better correlation coefficient ($R^2$ = 0.98) and 0.19 as SEP on pH. For moisture contents, the linearity correlation without pretreatment was higher than the case with pretreatment (MSC, $1^{st}$ derivative). As the best result, the $R^2$ was 0.99 and SEP was 0.45. This indicates that it is highly proper to evaluate the quality of Hanji record papers speedily with integrated sphere and FT NIR analyzer as a non-destructive method.