• Title/Summary/Keyword: intercept

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Relationship of Fixation Disparity and Heterophoria According to Fixation Distance (원, 근거리에서 주시시차와 사위와의 관계)

  • Kim, Chang-Jin;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.3
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    • pp.79-87
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    • 2008
  • Purpose: This study measured Y-intercept that means a fixation disparity, X-intercept that means a associated phoria and slope of a fixation disparity curve (FDC), which are variables of dissociated phoria and the FDC. We searched for the result value and examined the direction, distribution pattern and a variable that give an most affect on dissociated phoria and the FDC at distance and near. Also this study examined that there were statistically significant differences between distance and near, comparing the result value. Methods: We measured the dissociated phoria and the fixation disparity for 51 subjects at distance and near in June, 2007. All subjects ranged from 20 to 25 years of age (average 21.72${\pm}$1.88 years old) and had no eye disease. At distance the dissociated phoria measured with the distance MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the modified Mallett Far Unit (Bernell co., USA). At near the dissociated phoria measured with the near MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the Wesson fixation disparity card (American Optical co., USA). Results: The percentage distribution of types of fixation disparity curves was that at distance prevalence of Type I (74.6%) was the highest, followed by Type IV (17.6%) and Type II (3.9%), Type III (3.9%) and that at near prevalence of Type I (53.0%) was the highest, followed by Type III (29.4%), Type IV (13.7%) and Type II (3.9%). 2. There were significantly correlation in dissociated phoria, fixation disparity (Y-intercept) and associated phoria (X-intercept). 3. The fixation disparity at distance was most affected by associated phoria (X-intercept) (p=0.000). The distance dissociated phoria was most affected by fixation disparity (Y-intercept) (p=0.342), but the influence was weak. 4. The fixation disparity at near was most affected by associated phoria (X-intercept) (p=0.000). The near also dissociated phoria was most affected by associated phoria (X-intercept) (p=0.009). The result that compared the each variables with the same variables at distance and near had statistically significant on paired t-test for among dissociated phoria (t=7.529, p=0.000), X-intercept (t=5.860, p=0.000), the Y-intercept (t=4.640, p=0.000) but slope of the FDC did not differ significant (t=1.336 p=0.188). Conclusions: Relationship of fixation disparity and Heterophoria had close correlation at distance and near.

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Note on Use of $R^2$ for No-intercept Model

  • Do, Jong-Doo;Kim, Tae-Yoon
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.661-668
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    • 2006
  • There have been some controversies on the use of the coefficient of determination for linear no-intercept model. One definition of the coefficient of determination, $R^2={\sum}\;{\widehat{y^2}}\;/\;{\sum}\;y^2$, is being widely accepted only for linear no-intercept models though Kvalseth (1985) demonstrated some possible pitfalls in using such $R^2$. Main objective of this note is to report that $R^2$ is not a desirable measure of fit for the no-intercept linear model. In fact it is found that mean square error(MSE) could replace $R^2$ efficiently in most cases where selection of no-intercept model is at issue.

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Semiparametric Approach to Logistic Model with Random Intercept (준모수적 방법을 이용한 랜덤 절편 로지스틱 모형 분석)

  • Kim, Mijeong
    • The Korean Journal of Applied Statistics
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    • v.28 no.6
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    • pp.1121-1131
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    • 2015
  • Logistic models with a random intercept are useful to analyze longitudinal binary data. Traditionally, the random intercept of the logistic model is assumed to be parametric (such as normal distribution) and is also assumed to be independent to variables. Such assumptions are very strong and restricted for application to real data. Recently, Garcia and Ma (2015) derived semiparametric efficient estimators for logistic model with a random intercept without these assumptions. Their estimator shows the consistency where we do not assume any parametric form for the random intercept. In addition, the method is computationally simple. In this paper, we apply this method to analyze toenail infection data. We compare the semiparametric estimator with maximum likelihood estimator, penalized quasi-likelihood estimator and hierarchical generalized linear estimator.

Earliest Intercept Geometry Guidance to Improve Mid-Course Guidance in Area Air-Defence

  • Shin, Hyo-Sang;Tahk, Min-Jea;Tsourdos, A.;White, B.A.
    • International Journal of Aeronautical and Space Sciences
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    • v.11 no.2
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    • pp.118-125
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    • 2010
  • This paper describes a mid-course guidance strategy based on the earliest intercept geometry (EIG) guidance. An analytical solution and performance validation will be addressed for generalized mid-course guidance problems in area air-defence in order to improve reachability and performance. The EIG is generated for a wide range of possible manoeuvres of the challenging missile based on the guidance algorithm using differential geometry concepts. The main idea is that a mid-course guidance law can defend the area as long as it assures that the depending area and objects are always within the defended area defined by EIG. The velocity of Intercept Point in EIG is analytically derived to control the Intercept Geometry and the defended area. The proposed method can be applied in deciding a missile launch window and launch point for the launch phase.

Analysis of the Chip Waveforms for LPI Communication

  • Maing, Jun-Ho;Ryu, Heung-Gyoon;Lee, Dae-Il
    • Journal of electromagnetic engineering and science
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    • v.4 no.2
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    • pp.63-67
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    • 2004
  • DAM(Delay-And-Multiplier) intercept receiver usually detects the symbol rate of the transmitted DS spread spectrum signal for the feature extraction. It is important for secure communication to reduce the normalized output signal-to-noise ratio that is generated at the DAM intercept receiver as a measure of detectability. In this paper, several kinds of chip waveforms are novelly analyzed for LPI(Low-Probability of Intercept) communication against DAM intercept receiver. Consequently, it is shown that the rectangular chip waveform shows the best LPI performance in the bandwidth of 2/$T_c$TEX>, 4/$T_c$TEX>, and 6/$T_c$TEX>/. Except the rectangular waveform, kaiser chip waveform show better LPI performance than the other waveforms in the bandwidth of 4/$T_c$TEX> and 6/$T_c$TEX>.

A Study on the Detecting Method of Intercept Violation Vehicles Using an Image Detection Techniques (영상검지기법을 활용한 끼어들기 위반차량 검지 방법에 관한 연구)

  • Kim, Wan-Ki;Ryu, Boo-Hyung
    • Journal of the Korean Society of Safety
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    • v.23 no.6
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    • pp.164-170
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    • 2008
  • This research was verified detection way of intercept vehicles and performance evaluation after system installation using image detector as detection way of ground installation. By image recognition algorithm was on the trace of moving orbit of violation vehicles for detection way of intercept vehicles. When moving orbit is located special site, utilized geometric image calibration and DC-notch filter. These are cognitive system of license plate by making signal. Then, Bright Evidence Detection and Dark Evidence Detection were applied to after mixing. It is applied to way of Backward tracking for detection way of intercept vehicles. After the field evaluation of developed system, it should be analyzed the more high than recognition rate of minimum standards 80%. It should rise in the estimation of the site applicability is highly from now.

Relation of the Strength Parameter and the Unconfined Compressive Strength in Cemented Sand (고결모래의 강도정수와 일축압축강도 관계)

  • Lee, Moon-Joo;Choi, Sung-Kun;Cho, Yong-Soon;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.14-21
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    • 2008
  • In this study, a series of CID tests were performed on gypsum-cemented specimens to determin the cohesion intercept and the confined stress start to break the cementation bonds (${q_i}'_{(BP)}$). And the relationships between the unconfined compressive strength ($q_{ucs}$) and cohesion intercept or ${q_i}'_{(BP)}$ were investigated. From the experiments, it was concluded that the friction angle of cemented sands is not affected by cementation while the cohesion intercept of cemented sands significantly influenced by cementation and is constant before ${q_i}'_{(BP)}$. By an analytical interpretation, the failure strength of cemented specimen could be represented by summation of the failure strength of uncemented specimen and the unconfined compressive strength of cemented one. And the cohesion intercept of cemented specimen was represented as a linear relation with the unconfined compressive strength. Those analytical values of failure strength and cohesion intercept almost coincided with the experimental values of those. In addition, the ${q_i}'_{(BP)}$ also could be related with unconfined compressive strength linearly.

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Comparison of Some Methodologies for Vegetation Analysis in Transplanted Rice (이앙답에서 몇가지 식생분석방법들의 비교)

  • Kim, Soon-Chul;Keith Moody
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.3
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    • pp.310-318
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    • 1983
  • Four methods of vegetation analysis were compared to determine the most suitable method to use in transplanted rice. The highest number of weed species, 14 was obtained with the list quadrat method while the least number, 8 was obtained with the line intercept method. The clip quadrat method tended to overestimate weed species with a low moisture content such as Sagittaria trifolia L. and Ludwigia prostrata Roxb while for the list quadrat method, weed species with a high moisture content such as Sagittaria pygmaea Miq. and Monochoria vaginalis (Burm. f) Pres 1 were overestimated. With the line intercept method, weed species having conspicuous leaf blades such as S. trifolia and Potamogeton distinctus Benn. were dominant. Of the methods tested, the line intercept method was the least desirable because it accounted for the least number of weed species. Any of the others could be use for vegetation analysis without any significant problems arising. However, preference was given to the point quadrat method because of the ease of measurement. It was also less tedious and less time consuming than the other methods.

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A Study on Intercept Probability and Cost based Multi-layer Defense Interceptor Operating Method using Mathematical Model (수리모형을 이용한 요격확률 및 비용 기반의 다층 방어 요격미사일 운용방법 연구)

  • Seo, Minsu;Ma, Jungmok
    • Journal of the Korea Society for Simulation
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    • v.29 no.2
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    • pp.49-61
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    • 2020
  • It is important to operate a limited number of interceptors effectively to counter ballistic missile threats. The existing interceptor operating method determines the number of interceptors according to the level of TBM (Theater Ballistic Missile) engagement effectiveness applied to a defended asset. It can cause either excessive interceptor waste compared to the intercept probability or the intercept probability decrease. Thus, interceptor operating method must be decided considering the number of ballistic missiles, intercept probability and cost. This study proposes a mathematical model to improve the existing interceptor operating method. In addition, the efficiency indicator is proposed for trade-off between intercept probability and cost. As a result of the simulations, the mathematical model-based interceptor operating method can achieve better results than the existing interceptor operating method.

An Analysis Study about Relationship between Ballistic Coefficient and Accuracy of Predicted Intercept Point of Super-High Speed Targets (초고속 표적의 탄도계수와 예상요격지점 정확도의 상관관계 분석 연구)

  • Lee, Dong-Gwan;Cho, Kil-Seok;Shin, Jin-Hwa;Kim, Ji-Eun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.2
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    • pp.265-274
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    • 2014
  • A recent air defense missile system(ADMS) is required to have a capability to intercept super-high speed targets such as tactical ballistic missiles(TBMs) by performing engagement control efficiently. The air defense missile system should be ready to engage the TBMs as soon as the ADMS detects TBMs because falling velocity of TBM is very high and remaining time interval to engage TBM is very short. As a result, the ADMS has to predict the trajectories of TBMs accurately with estimated states of dynamics to generate predicted intercept point(PIP). In addition, it is needed to engage TBMs accurately via transmitting the obtained PIP data to the corresponding intercept missiles. In this paper, an analysis about the relationship between ballistic coefficient and PIP accuracy which is depending on geodetic height of the first detection of TBM is included and an issue about effective engagement control for the TBM is considered.