• Title/Summary/Keyword: Relative bias

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A Study on Displacement Current Characteristics of DLPC Monolayer (I) (DLPC 인지질 단분자막의 변위전류 특성 연구 (I))

  • Song, Jin-Won;Lee, Kyung-Sup;Choi, Yong-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.117-122
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    • 2007
  • LB method is one of the most interesting technique to arrange certain molecular groups at precise position relative to others. Also, the LB deposition technique can fabricate extremely thin organic films with a high degree of control over their thickness and molecular architecture. In this way, new thin film materials can be built up at the molecular level, and the relationship between these artificial structures and the properties of materials can be explored. In this paper, evaluation of physical properties was made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DLPC. Lipid thin films were manufacture by detecting deposition for the accumulation and the current was measured after the electric bias was applied across the manufactured MIM device. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid mono-layer, it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

Atmospheric Correction and Velocity Aberration for Physical Sensor Modeling of High-Resolution Satellite Images (고해상도 위성영상의 센서모델링을 위한 대기 및 속도 보정)

  • Oh, Jae-Hong;Lee, Chang-No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.5
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    • pp.519-525
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    • 2011
  • High-resolution earth-observing satellites acquire substantial amount of geospatial images. In addition to high image quality, high-resolution satellite images (HRSI) provide unprecedented direct georegistration accuracy, which have been enabled by accurate orbit determination technology. Direct georegistration is carried out by relating the determined position and attitude of camera to the ground target, i.e., projecting an image point to the earth ellipsoid using the collinearity equation. However, the apparent position of ground target is displaced due to the atmosphere and satellite velocity causing significant georegistration bias. In other words, optic ray from the earth surface to satellite cameras at 400~900km altitude refracts due to the thick atmosphere which is called atmospheric refraction. Velocity aberration is caused by high traveling speed of earth-observing satellites, approximately 7.7 km/s, relative to the earth surface. These effects should be compensated for accurate direct georegistration of HRSI. Therefore, this study presents the equation and the compensation procedure of atmospheric refraction and velocity aberration. Then, the effects are simulated at different image acquisition geometry to present how much bias is introduced. Finally, these effects are evaluated for Quickbird and WorldView-1 based on the physical sensor model.

An Adaptive Bandwidth Selection Algorithm in Nonparametric Regression (비모수적 회귀선의 추정을 위한 bandwidth 선택 알고리즘)

  • Kyung Joon Cha;Seung Woo Lee
    • The Korean Journal of Applied Statistics
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    • v.7 no.1
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    • pp.149-158
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    • 1994
  • Nonparametric regression technique using kernel estimator is an attractive alternative that has received some attention, recently. The kernel estimate depends on two quantities which have to be provided by the user : the kernel function and the bandwidth. However, the more difficult problem is how to find an appropriate bandwidth which controls the amount of smoothing (see Silverman, 1986). Thus, in practical situation, it is certainly desirable to determine an appropriate bandwidth in some automatic fashion. Thus, the problem is to find a data-driven or adaptive (i.e., depending only on the data and then directly computable in practice) bandwidth that performs reasonably well relative to the best theoretical bandwidth. In this paper, we introduce a relation between bias and variance of mean square error. Thus, we present a simple and effective algorithm for selecting local bandwidths in kernel regression.

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The Effects of Consumer Beliefs for Food Certifications on Purchasing Intention Biases for the Certified Agricultural Products - A Case Analysis based on Tofu - (인증농산물의 구매편향성에 관한 연구 - 두부를 사례로 -)

  • Park, Jeong-A;Jang, Young-Soo
    • The Korean Journal of Food And Nutrition
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    • v.29 no.6
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    • pp.952-961
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    • 2016
  • The objective of this study is to examine the effects of consumer beliefs regarding three food certifications on their behavioral intention and the behavioral intention biases to purchase (purchasing intention biases) certified agricultural products as predicted by a subjective probability model. The food certifications used for this study are 'Organic food', 'Traceability system of food products,' and 'Hazard Analysis Critical Control Point (HACCP)'. Tofu (bean curd) was selected as being representative of agricultural food products, for the purposes of this study. In 2016, we surveyed 243 consumers regarding the strength of their belief regarding their prior beliefs relative to each certification, as well as the strength of their intention to purchase certified tofu based on their belief strengths for this study. The study resulted in the following findings: Firstly, consumers hold more than two different prior beliefs for each of the three certifications included in this study. Consumers' prior beliefs regarding these certifications have an impact on their consideration as to whether they plan to buy those certified agricultural products. Secondly, consumers try to persuade themselves to ensure that their particular belief about the product's certification could lead to a purchasing decision regarding that agricultural product.

Estimation of dose rate using radiative transfer equations (복사전달방정식을 이용한 조사율 추정)

  • 문윤섭;김유근;이영미
    • Journal of Environmental Science International
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    • v.11 no.12
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    • pp.1195-1204
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    • 2002
  • We calculated dose rate using radiative transfer equations to consider radiative processes distinctly. The dose rate at Pohang(36°02'N, 129°23'E) was calculated using measured ozone and meteorological data and two-stream approximations(quadrature, Eddington, delta Eddington, PIFM(practical improved flux method), discrete ordinate, delta discrete ordinate) are used in solving equation. The purpose of this study is to determine the most compatible radiative transfer approximation for simulating the radiative and photochemical processes of atmosphere through comparision between calculated and measured values. Dose rate of the biologically effective irradiance in the region 0.28-0.32 U m showed the highest value when quadrature and Eddington was used and lower value on condition that delta scaling was applied. Correlation coefficient between dose rate at surface using radiation transfer equation and measured UV-B at Pohang was 0.78, 0.79 and 0.81 when delta Eddington, PIFM and delta discrete ordinate were used. Also, in case of above approximations were used, MBE(Mean Bias Error) was within -0.3MED/30min and RMBE(Relative Mean Bias Error) was below 10% between 1200 LST and 1400 LST Approximations which are compatible in estimating radiative process are delta Eddington, PIFM and delta discrete ordinate. Especially, in case that radiative process is considered more detail, delta discrete ordinate increased the number of stream is proper.

A Study on Tertiarization in Korea: Test of Baumol's Hypothesis (한국의 서비스화에 대한 연구: Baumol 가설을 중심으로)

  • Seo, Hwan-Joo;Lee, Young-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.143-150
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    • 2007
  • Using a panel data of Korea for $1979{\sim}2002$, this study investigates the determinants of the service sector employment share in Korea. In order to analyze the impact of macroeconomic factors on the service sector's employment share we estimate a simple panel model which is in line with Baumol's model. The panel GMM estimation results show that: 1) The increase in the share of service-related jobs in total employment tends to rise with GDP per capita, which confirms demand-bias hypothesis proposed by Clark. 2) We find that a crucial role in this process has been played by the productivity gap. As Baumol's hypothesis or Baumolis disease, the expansion of the employment share in services relative to industry is the direct consequence of services' lower productivity performances.

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A Study on the Material Characteristics of Contacts on Bias Track Relay (바이어스 궤도계전기 접점의 재질 특성에 관한 연구)

  • Kim, Hee-Dae;Lee, Sung-Il
    • Journal of the Korean Society for Railway
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    • v.15 no.6
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    • pp.597-603
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    • 2012
  • The cases for selecting contact materials of Ag and AgC for Bias Track Relay are the studies and their safety evaluations are proposed in this paper. The welding at the relative low current has occurred in Ag contacts, but the one has not occurred in AgC contacts although the high currents flow since it has an excellent temperature characteristic. In the repetitive switching experiment, more unstable resistance and transfer phenomena has occurred in contacts as the switching numbers of AgC contacts increase, which results in more consumption of contacts. In the experiments, there exists a trade off relationship between welding and resistance variation. AgC contacts have excellent characteristics in welding, but the caution is required in using them since a lot of repetition switching produces much resistance variation. However, Ag contacts have excellent characteristics in repetitive switching, but weak ones in welding.

Adjustment of the Mean Field Rainfall Bias by Clustering Technique (레이더 자료의 군집화를 통한 Mean Field Rainfall Bias의 보정)

  • Kim, Young-Il;Kim, Tae-Soon;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.42 no.8
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    • pp.659-671
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    • 2009
  • Fuzzy c-means clustering technique is applied to improve the accuracy of G/R ratio used for rainfall estimation by radar reflectivity. G/R ratio is computed by the ground rainfall records at AWS(Automatic Weather System) sites to the radar estimated rainfall from the reflectivity of Kwangduck Mt. radar station with 100km effective range. G/R ratio is calculated by two methods: the first one uses a single G/R ratio for the entire effective range and the other two different G/R ratio for two regions that is formed by clustering analysis, and absolute relative error and root mean squared error are employed for evaluating the accuracy of radar rainfall estimation from two G/R ratios. As a result, the radar rainfall estimated by two different G/R ratio from clustering analysis is more accurate than that by a single G/R ratio for the entire range.

ASSESSING CALIBRATION ROBUSTNESS FOR INTACT FRUIT

  • Guthrie, John A.;Walsh, Kerry B.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1154-1154
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    • 2001
  • Near infra-red (NIR) spectroscopy has been used for the non-invasive assessment of intact fruit for eating quality attributes such as total soluble solids (TSS) content. However, little information is available in the literature with respect to the robustness of such calibration models validated against independent populations (however, see Peiris et al. 1998 and Guthrie et al. 1998). Many studies report ‘prediction’ statistics in which the calibration and prediction sets are subsets of the same population (e. g. a three year calibration validated against a set from the same population, Peiris et al. 1998; calibration and validation subsets of the same initial population, Guthrie and Walsh 1997 and McGlone and Kawano 1998). In this study, a calibration was developed across 84 melon fruit (R$^2$= 0.86$^{\circ}$Brix, SECV = 0.38$^{\circ}$Brix), which predicted well on fruit excluded from the calibration set but taken from the same population (n = 24, SEP = 0.38$^{\circ}$Brix with 0.1$^{\circ}$Brix bias), relative to an independent group (same variety and farm but different harvest date) (n = 24, SEP= 0.66$^{\circ}$ Brix with 0.1$^{\circ}$Brix bias). Prediction on a different variety, different growing district and time was worse (n = 24, SEP = 1.2$^{\circ}$Brix with 0.9$^{\circ}$Brix bias). Using an ‘in-line’ unit based on a silicon diode array spectrometer, as described in Walsh et al. (2000), we collected spectra from fruit populations covering different varieties, growing districts and time. The calibration procedure was optimized in terms of spectral window, derivative function and scatter correction. Performance of a calibration across new populations of fruit (different varieties, growing districts and harvest date) is reported. Various calibration sample selection techniques (primarily based on Mahalanobis distances), were trialled to structure the calibration population to improve robustness of prediction on independent sets. Optimization of calibration population structure (using the ISI protocols of neighbourhood and global distances) resulted in the elimination of over 50% of the initial data set. The use of the ISI Local Calibration routine was also investigated.

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Effectiveness of Non-Pharmacologic Interventions in Chemotherapy Induced Peripheral Neuropathy: A Systematic Review and Meta-Analysis (항암화학요법 관련 말초신경병증에 적용한 비약물적 중재의 효과: 체계적 문헌고찰 및 메타분석)

  • Oh, Pok-Ja;Kim, You Lim
    • Journal of Korean Academy of Nursing
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    • v.48 no.2
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    • pp.123-142
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    • 2018
  • Purpose: This study was conducted to evaluate the effectiveness of non-pharmacologic interventions in chemotherapy-induced peripheral neuropathy (CIPN). Methods: PubMed, Cochrane Library CENTRAL, EMBASE, CINAHL, and several Korean databases (Until August 2017) were searched. The main search strategy combined terms for peripheral neuropathy and presence of neoplasms. The risk of bias was assessed using the Cochrane's Risk of Bias tool for randomized studies and the Risk of Bias Assessment tool for non-randomized studies. To estimate the effect size, a meta-analysis of the studies was performed using the Rev Man 5.3 program of the Cochrane Library random-effects models were used in the analyses. Results: Twenty-two studies with a total of 954 participants met the inclusion criteria. Of the 22 studies, 12 were used to estimate the effect size of the non-pharmacologic interventions. The non-pharmacologic interventions used in patients with CIPN were exercise, acupuncture, massage, and foot bath. The acupuncture significantly reduced CIPN symptoms and signs (d=-0.71) and CIPN pain (d=-0.73) (p<.001). Massage and foot bath were also effective in reducing CIPN symptoms (d=-0.68; 95% CI=-1.05, -0.30; p<.001; $I^2=19%$).Exercises were effective in improving muscle strength and endurance(d=-0.55) and quality of life (d=-2.96), but they were not significantly effective in improving CIPN. Conclusion: Although these results provide little evidence of the effectiveness of acupuncture, massage, and foot bath in the treatment of CIPN, they suggest that these interventions can reduce CIPN symptoms in patients with cancer. However, the findings of this study should be interpreted with caution as there is a relative lack of data in this field, and additional well-designed studies are needed. PROSPERO registration: CRD42017076278.