• Korean journal of applied entomology
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• v.52 no.3
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• pp.255-259
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• 2013

Two root mealybugs, Ripersiella multiporifera Jansen and Rhizoecus albidus Goux, were collected on imported Dracaena plants (Dracaenaceae) and Schlumbergera truncata (Haw.) Moran (Cactaceae) grown in greenhouses in Korea. Both species were probably introduced into greenhouses via the plant trade. Therefore, it reiterates the need to focus attention on the detection of root mealybugs at the ports of entry to prevent their introduction and establishment in the Korean environment. In this paper, additional information for the two species is provided with diagnoses, photographs along with host plant and distribution data for accurate species identification.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.8
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• pp.1-6
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• 1999

The only transmission characteristics in frequency domain is considered when using the tapered transmission line for wide-band impedance matching in MCM and MIC designs. In this paper, the distortion of an electrical pulse with rise/fall time resulting from dispersion and reflection as it propagates along a tapered microstrip line is investigated, and the delay time and distortion rate with respect to input and load impedances are analyzed on triangular and exponential tapered lines. A dispersion model of the phase constant proposed by Kirschning-Jansen is used to meet the frequency, accuracy and microstrip parametric requirements. The triangular tapered line shows both shorter delay time and higher distortion rate than those of the exponential tapered line. Furthermore, the amplitude of signal reflected from load point is calculated in time domain.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.109-115
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• 2001

Wavelet coefficients are known to have decorrelating properties, since wavelet is orthonormal transformation. but empirically, those wavelet coefficients of images, like edges, are not statistically independent. Jansen and Bultheel(1999) developed the empirical Bayes approach to improve the classical threshold algorithm using local characterization in Markov random field. They consider the clustering of significant wavelet coefficients with uniform distribution. In this paper, we developed wavelet thresholding algorithm using Laplacian distribution which is more realistic model.

• 전기의세계
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• v.19 no.6
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• pp.31-38
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• 1970

본문은 IEEE지 1970년월호 Spectrum에 나타난 서독내의 초고압송전선로에 관한 (Mr. J. Jansen)소개문으로서 철탑선로 및 애자설계에 서독기술자가 깊은 검토를 하여 서독에 알맞는 이상적인 송전망을 건설하여 왔다는 것이다. 현재 우리나라도 345kV 초고압송전망을 가까운 장래에 건설하고저 만반의 준비를 갖추고 있는 중이다. 따라서 서독의 초고압송전망에 관한 기사는 협소한 국토등 여건이 비슷한 우리에게 큰 참고가 될 부분이 많음으로 본지에 이것을 번역하여 관계기술자의 설계참고자료로 제공하고저 한다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.417-423
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• 2016

Develop a leg walking robot mechanisms with Janssen. Development item increases as the moving speed through the weight to set the leg to walk stably. The material is used the metal material was later used to produce a plastic using a 3D printer developed a walking robot with stable and lightweight material.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.183-205
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• 2013

A number of studies and models have focused on collaborative information behavior (CIB) in various contexts as the importance of research on CIB is recognized in information behavior research. This study compared and analyzed the models of CIB developed by Prekop (2002), Reddy and Jansen (2008), Shah (2008), Karunakaran, Spence and Reddy (2010), and Yue and He (2010), and discussed the direction of future studies of CIB. The future research strategies for overcoming the limitation of previous studies and models on CIB are to extend research object and context, to do holistic research approach tracing complexity of CIB, and to debate and verify the models of CIB. In particular, it needs to modify and improve the models based on the empirical research for domestic context.

• Journal of the Korean Society for information Management
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• v.24 no.4
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• pp.267-283
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• 2007

In this study, measures of distributional similarity such as KL-divergence are applied to cluster documents instead of traditional cosine measure, which is the most prevalent vector similarity measure for document clustering. Three variations of KL-divergence are investigated; Jansen-Shannon divergence, symmetric skew divergence, and minimum skew divergence. In order to verify the contribution of distributional similarities to document clustering, two experiments are designed and carried out on three test collections. In the first experiment the clustering performances of the three divergence measures are compared to that of cosine measure. The result showed that minimum skew divergence outperformed the other divergence measures as well as cosine measure. In the second experiment second-order distributional similarities are calculated with Pearson correlation coefficient from the first-order similarity matrixes. From the result of the second experiment, secondorder distributional similarities were found to improve the overall performance of document clustering. These results suggest that minimum skew divergence must be selected as document vector similarity measure when considering both time and accuracy, and second-order similarity is a good choice for considering clustering accuracy only.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1107-1114
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• 1999

In this paper, we analyze the effect of co-channel interferers coming from other systems with composite log-normal shadowing and Nakagami fading on the capacity of the imperfect power-controlled DS/CDMA cellular system. The analytical results are compared with the results of Prasad and Jansen in which they derive the result under the condition of imperfect power-control of DS/CDMA system and without considering interference. And the outage probability is calculated fro the effect of the log-normal/Nakagami faded inferers on DS/CDMA system using Schwartz and Yeh's method. With the deviation of outage probability, we analyzed the decreases in the capacity of DS/CDMA system with the variation of the paramenters of the imperfect power-control, the fadig index, the processing gain, the power ratio, the voice activity factor, and the number of interferers. Analysis reuslts have shown that the capacity of DS/CDMA system is very sensitive to the imperfect power-control and the number of interferers. It is shown that the DS/CDMA system capacity decreased according to increase of the deviation of the impertect power-control, the increase of the fading, and the increase of interferer number.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.5
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• pp.516-524
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• 1997

The propagation properties of various pulse signal types(square pulse, Gaussian pulse, trapezoid pulse, RF pulse) on coupled microstrip lines are investigated. Numerical integration technique which has its accuracy and is easily simulated, is used to obtain the time domain response of pulse signals. Frequency-dependent characteristics of coupled microstrip line is obtained using Jansen's approximate equation. The propagation properties of pulse signal on coupled microstrip lines is analyzed regarding to its geometric structure (relative permittivity ${varepsilon}_r$ substrate height h, strip width w of the microstrip line) and pulse width ${\tau}$ of signal pulse. The simulation results show that space between two lines is very significant parameter in pulse distortion in comparison of any other parameters. The results of this paper are compatible to the trade-off determination of relative permittivity, substrate height, strip width and pulse width of signal pulse when a design of MIC and MMIC is necessary.

• Advances in aircraft and spacecraft science
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• v.3 no.4
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• pp.503-521
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• 2016

Variances in turbomachinery blades caused by manufacturing, operation or regeneration can result in modified structural behavior. In this work, the scatter of geometrical and material properties of a turbine blade and its influence on structure performance is discussed. In particular, the vibration characteristics and the lifetime of a turbine blade are evaluated. Geometrical variances of the surface of the blades are described using the principal component analysis. The scatter in material properties is considered by 16 varying material parameters. Maximum vibration amplitudes and the number of load cycles the turbine blade can withstand are analyzed by finite element simulations incorporating probabilistic principles. The probabilistic simulations demonstrate that both geometrical and material variances have a significant influence on the scatter of vibration amplitude and lifetime. Dependencies are quantified and correlations between varied input parameters and the structural performance of the blade are detected.