• Title/Summary/Keyword: bias degree

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Frequency Adjustable Dual Composite Right/Left Handed Transmission Lines (주파수 가변성을 갖는 D-CRLH 전송 선로)

  • Lim, Jong-Sik;Koo, Ja-Kyung;Han, Sang-Min;Jeong, Yong-Chae;Ahn, Dal
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.12
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    • pp.1375-1382
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    • 2008
  • Frequency adjustable D-CRLH(dual-composite right/left handed) transmission lines, which solve the problem of design complexity and uncontrolled frequency of the existing structures, are proposed in this paper. The first design(type I), consisting of defected ground structure(DGS), island pattern in DGS, fixed stub and varactor diodes, controls $C_L$ in the parallel resonant circuit, while the second structure(type 2) composed of fixed DGS, shunt stub and diode adjusts $C_R$ in the series resonant circuit. The dual band frequency points which correspond to the meaningful electrical length of +/-90 degree in the RH/LH region are adjustable according to the bias voltage. The measurement shows that the LH frequency point which has -90 degree of electrical length are adjusted over $4.22{\sim}5.39\;GHz$ and $4.21{\sim}5.05\;GHz$ for type 1 and type 2, respectively, under $1{\sim}12\;V$ of bias voltage. In addition, the frequency Woo where RH turns over LH is controled over $3.26{\sim}4.22\;GHz$ for type 2 with the same bias condition.

The Effect of Visual Cue Deprivation for the Head Alignment on Unilateral Neglect Patient: Case Report (편측 무시 환자에서 시각 정보 차단이 머리 위치 정렬에 미치는 영향: 사례 연구)

  • Chang, Jong-Sung;Park, Jung-Mi;Lee, Mi-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.337-342
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    • 2013
  • PURPOSE: The Unilateral neglect is characterized by difficulty shifting attention to the side of space opposite the brain lesion and frequently reducing use of contralesional extremities. This study was to identify whether the visual deprivation was responsible for head position on unilateral neglect patient after stroke. METHODS: A patient with left middle cerebral artery infarction participated in the study. We assessed neglect using line bisection and star cancellation test. Patient was instructed to maintain correct alignment of trunk and head in a sit position. We evaluated degree of head lateral tilting and rotation. Then, patient was blocked visual input. Also, we evaluated head position in the same way. RESULTS: He scored 3 points in the line bisection test and 9 points star cancellation test. In postural evaluation, he had deviated posture such as lateral head tilting and rotation. After visual cue deprivation, patient showed different head position which was decreased degree of head tilting and rotation. CONCLUSION: For vertical body orientation, it was used multiple sensory references including the vestibular, somatosensory, and visual system. This finding suggested that abnormal posture of neglect patient could be related to the visual input. It has important clinical implications in terms of understanding the neglect.

Escape Theory Approach to Consumers' Belief Biases (소비자의 신념편향에 대한 도피이론적 접근)

  • Han, Woong-Hee
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.411-421
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    • 2014
  • This study investigated the effect of cognitive narrowing on the consumers' belief biases in the light of the escape theory. Current study researched the relationship between the cognitive narrowing and the consumers' belief biases. The result of this study is as below. The degree of the consumers' belief biases is higher when the degree of the cognitive narrowing is higher than lower. On the basis of this result, theoretical and practical implications were suggested and the limitations and future research were discussed.

Automatic Color Recognition System for Stockigt Sizing Test (I) - Bias of Stockigt sizing test based on observer's subjectiveness - (스테키히트 시험용 자동 발색 인지 시스템 개발을 위한 기초연구(I) - Stockigt 사이즈도 시험법에 영향을 주는 요인 분석 -)

  • 김재옥;김철환;박종열
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.1
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    • pp.1-8
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    • 2004
  • One of the most frequently used method for measurement of the degree of sizing (viz., hydrophobicity) is the Stockigt test. However, the Stockigt test was influenced by various factors such as dropping height, dropping amount, dropping speed and viewing angle. The resultant data of the sizing degree on the same specimen also varied according to different testers. Thus, the Stockigt test should be modified to be regarded as a highly reliable and reproducible standard method. For modifying the Stockigt test, it was required to quantify red coloration by reaction between 1% ferric chloride and 2% ammonium thiocyante during Stockigt testing. The cameras capturing the serial images during the red coloration process were the CMOS (Complementary Metal Oxide Semiconductor)-type and CCD (Charge Coupled Device)-type cameras. For measurement based on KS M 7025, the CCD-type camera must be used due to its high resolution, and on the other hand, for measurement based on Tappi Useful Method 429, the CMOS-type camera may be used owing to its low resolution. It was needed to covert the RGB values of a droplet image into HSV(Hue, Saturation, and Value) values because the human eyes are much closer to HSV than RGB. Among HSV values, the Hue value was accepted as the most reliable index consistent with the red coloration process by excluding the surrounding conditions such as light, tester's movement etc.

A Study on Comparison of Generalized Kappa Statistics in Agreement Analysis

  • Kim, Min-Seon;Song, Ki-Jun;Nam, Chung-Mo;Jung, In-Kyung
    • The Korean Journal of Applied Statistics
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    • v.25 no.5
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    • pp.719-731
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    • 2012
  • Agreement analysis is conducted to assess reliability among rating results performed repeatedly on the same subjects by one or more raters. The kappa statistic is commonly used when rating scales are categorical. The simple and weighted kappa statistics are used to measure the degree of agreement between two raters, and the generalized kappa statistics to measure the degree of agreement among more than two raters. In this paper, we compare the performance of four different generalized kappa statistics proposed by Fleiss (1971), Conger (1980), Randolph (2005), and Gwet (2008a). We also examine how sensitive each of four generalized kappa statistics can be to the marginal probability distribution as to whether marginal balancedness and/or homogeneity hold or not. The performance of the four methods is compared in terms of the relative bias and coverage rate through simulation studies in various scenarios with different numbers of raters, subjects, and categories. A real data example is also presented to illustrate the four methods.

Exports and Firm Innovation (수출이 기업혁신에 미치는 영향)

  • Yim, Jeong-Dae
    • Korea Trade Review
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    • v.44 no.3
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    • pp.227-252
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    • 2019
  • This study explores the effects of exports on the innovation of Korean firms listed on two Korean stock markets, the Korean Stock Exchange and the Korean Securities Dealers Quotations, between 1999 and 2016. By matching exporting firms to non-exporting ones with propensity score matching, this study accounts for a problem from sample selection bias that may arise from differences in firm-characteristics between the two groups. From the study results, first, both export participation and export volume significantly increase subsequent innovation performance, as measured by the number of patent applications. This result seems to support the "learning by exporting" hypothesis for Korean listed firms. Second, both export participation and export volume narrow innovation scope, proxied as the number of unique International Patent Classification (IPC) codes of the patent applied, the degree to which patents are concentrated in a particular class, and the degree of proximity in the patents. The findings of innovation scope suggest a possible explanation that the learning effect appears in familiar technology fields that firms have previously held, rather than in unfamiliar ones. Third, these results are robust using alternative proxies in the innovation scope, Tobit regressions to consider the non-trivial portion of sample firms with patent applications equal to zeros, and generalized method of moments (GMM) to control for the persistence of innovation measures hearing over years. Finally, the two main results are more pronounced in large firms than in small and medium-sized ones. As for Chaebol firms, however, these results do not appear.

Determination of Degree of Retrogradation of Cooked Rice by Near-Infrared Reflectance Spectroscopy (근적외 분광분석법에 의한 밥의 노화도측정)

  • Cho, Seung-Yong;Choi, Sung-Gil;Rhee, Chul
    • Korean Journal of Food Science and Technology
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    • v.26 no.5
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    • pp.579-584
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    • 1994
  • Near infrared reflectance(NIR) spectroscopy was used to determine the degree of retrogradation of cooked rice. Cooked rice samples were stored at $4^{\circ}C$ for 120 hours, and the degree of retrogradation was measured at every 6 hour during the storage time. Stored cooked rices were freeze-dried, milled and passed through a 100 mesh sieve. Enzymatic method using glucoamylase was used as reference method for the determination of the degree of retrogradation. Spectral differences due to retrogradation of cooked rice were observed at 1434, 1700, 1928, 2100, 2284 and 2320 nm. 32 samples of which moisture content were below 5% were used for calibration set, and 16 samples were used for validation set. High correlations were achieved between degree of retrogradation determined by conventional enzymatic method and by NIR with multiple correlation coefficient of 0.9753, and a standard error of calibration(SEC) of 3.64%. Comparable results were obtained with 3.91% of standard error of prediction(SEP), when the calibration equation was applied to independent group of samples of which moisture contents were in the range of calibration set. But when the calibration equation was applied to samples of which moisture contents were outer range of calibration set, SEP and bias were increased and correlation coefficient was decreased. The determination of degree of retrogradation was affected by sample moisture content. To determine degree of retrogradation of cooked rice by NIR using this calibration equation, it was suggested that sample moisture content should be controlled to below 5%.

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Ratio and Product Type Exponential Estimators of Population Mean in Double Sampling for Stratification

  • Tailor, Rajesh;Chouhan, Sunil;Kim, Jong-Min
    • Communications for Statistical Applications and Methods
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    • v.21 no.1
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    • pp.1-9
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    • 2014
  • This paper discusses the problem of estimation of finite population mean in double sampling for stratification. In fact, ratio and product type exponential estimators of population mean are proposed in double sampling for stratification. The biases and mean squared errors of proposed estimators are obtained upto the first degree of approximation. The proposed estimators have been compared with usual unbiased estimator, ratio and product estimators in double sampling for stratification. To judge the performance of the proposed estimators an empirical study has been carried out.

A Study on the bonding strength of the adhesive interlining according to cotton fabrics (면직물의 종류에 다른 접착심지의 접착강도에 관한 연구 -실의 굵기와 조직의 세탁에 따른 변화를 중심으로-)

  • 박채련
    • Journal of the Korean Home Economics Association
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    • v.33 no.6
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    • pp.179-186
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    • 1995
  • The purpose of this paper was to identify bonding strength by weave (plain weave, twill weave, satin weave) and counts(20 s, 40s) of the face cloth cotton 100% in the course of sewing process using by cotton fabric of adhesive interlining. The results of the study was as follows. 1. With the increased laundry, it revealed that the bonding strength was decreased to some degree regardless of the kinds of face cloth. 2. the bonding strength by the counts of the face cloth appeared in order of 40 s<20 s. 4. It was observed that there are no significant differences on the adhesive strength in the cutting directions which are an inclination warp, weft, bias in this experiment.

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Filling the Submicron Contact Holes with Al Alloys (AI 합금의 Contact Hole Filling 에 관한 연구)

  • 김용길
    • Journal of the Korean Vacuum Society
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    • v.2 no.4
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    • pp.474-479
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    • 1993
  • Submicron contact hole filling with aluminum alloys has been achieved with a multistep metallization method, which utilizes a metal " flow" or self-diffusion process at elevated temperatures after the metal was sputter-deposited. A multi-chamber, modular sputtering system was employed to deposit aluminum alloys and subsequently to anneal the deposited metal films under vacuum at high temperatures. The film were deposited on 200 mm wafers with planar, dc magnetron sputtering sources without anysubstrate bias. The basic process steps studied for the multistep metallization include an initial layer deposition at low temperatures less than $100^{\circ}C$, and an annealin gstep at elevated temperatures, between 450 and $550^{\circ}C$. The degree of planarization or step coverage was dependent strongly upon the temperature and time of the flow step and complete filling of the submicron contacts with aluminum alloys was achieved. Responsible mechanisms for the enhancement in step coverge and factros determining uniform and reproducible flow of aluminum alloys during the high temperauture step are discussed.discussed.

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