• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7C
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• pp.581-586
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• 2010

The holographic data storage system stores multiple data pages by multiplexing. But the inter-page interference(IPI) caused by multiplexing reduces the intensity of the hologram. The simulation of the holographic storage systems has to consider the IPI. Therefore, we introduce a channel modeling that takes care of inter-page interference in the holographic data storage system. We simulate the performance of PRML detection on the hologrpahic data storage system with IPI modeling.

• Korean Journal of Cognitive Science
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• v.17 no.1
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• pp.29-52
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• 2006

There has been a claim that Interaction between the cerebral hemispheres could reduce the effect interfering information (Weissman & Banich, 1999). We ran three experiments to show that between-hemisphere separation of target and distractor could be more effective for reducing interference than Interaction between the hemispheres. In experiment 1, a colored box and a rotor name were presented to a single or to separate hemispheres. In experiment 2 and 3, a colored circle (distractor) was presented along with a colored box and a color name which was always printed in black. In experiment 3, a peripheral cue was presented either to the target location(66.7%) or to the distractor location(33.3%) Immediately before the presentation of stimuli. In all experiments, the participants were asked to deride whether the moaning of the color matched the rotor of the box, Ignoring the printed rotor of the word(Exp. 1), or the color of the circle(Exp. 2 & 3). There were three renditions of distractor (congruent, incongruent, and neutral) and two conditions of matching (between- and within-hemisphere matching). If interhemispheric interaction were effective for interference reduction, there should be a decrease in the interference in the between-hemisphere compared to the within-hemisphere matching condition. The results showed that there was no difference in the interference between the two matching conditions in Exp 1. In Exp 2 and in the target-cue renditions of Exp. 3, the amount of interference in the between-hemisphere condition was greater than that in the within-hemisphere condition. These findings are consistent with what we have previously reported (Sohn et al., 1996, Sohn & Lee, 2003). However, when the distractor was precued in Exp. 3, the amount of interference did not differ between the two marching conditions. These results suggest that between-hemisphere separation of target and distractor can be more effective for reducing response interference than interhemispheric communication. It implies a possible role of an interhemispheric shielding mechanism (Merola & Liederman, 1985) to prevent the transfer of task-irrelevant, harmful information across the hemispheres.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.777-782
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• 2017

The Signal Intelligence (SIGINT) system based on the adaptive beamformer, comprised of the AOA estimator followed by the interference canceller, is a cutting edge technology for collecting various signal information utilizing all sorts of devices such as the radar and satellite. In this paper, we present the efficient adaptive SIGINT structure consisted of an AOA estimator and an adaptive beamformer. For estimating AOA information of various signals, we employ the Multiple Signal Classification (MUSIC) algorithm and for efficiently suppressing high-power interference signals, we employ the Minimum Variance Distortionless Response (MVDR) algorithm. Also, we provide computer simulation examples to verify the performance of the presented adaptive beamformer structure.

• BMB Reports
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• v.43 no.4
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• pp.279-283
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• 2010

Polydnavirus genome is segmented and dispersed on host wasp chromosome. After replication, the segments form double- stranded circular DNAs and embedded in viral coat proteins. These viral particles are delivered into a parasitized host along with parasitoid eggs. A serine-rich protein (SRP) is predicted in a polydnavirus, Cotesia plutellae bracovirus (CpBV), genome in its segment no. 33 (CpBV-S33), creating CpBV-SRP1. This study explored its expression and physiological function in the diamondback moth, Plutella xylostella, larvae parasitized by C. plutellae. CpBV-SRP1 encodes 122 amino acids with 26 serines and several predicted phosphorylation sites. It is persistently expressed in all tested tissues of parasitized P. xylostella including hemocyte, fat body, and gut. Its physiological function was analyzed by injecting CpBV-S33 and inducing its expression in nonparasitized P. xylostella by a technique called SERI (segment expression and RNA interference). The expression of CpBV-SRP1 significantly impaired the spreading behavior and total cell count of hemocytes of treated larvae. Subsequent RNA interference of CpBV-SRP1 rescued the immunosuppressive response. This study reports the persistent expression of CpBV-SRP1 in a parasitized host and its parasitic role in suppressing the host immune response by altering hemocyte behavior and survival.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.963-968
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• 2009

This paper deals with shrink fit analysis of rotor by 2D cross-section, 2D axis-symmetry, and 3D FEM model. And this paper presents 2nd order approximation function of thermal expansion displacement by design variables (shape dimension, heating temperature, sleeve length, interference etc.), table of orthogonal array and RSM(response surface methodology). The possibility of the rotor with shrink fit is evaluated by thermal expansion displacement. If thermal expansion displacement is larger than interference, shrink fit enable to make the rotor. 2D axis-symmetry model and 3D model are more reasonable than 2D cross-section model, because stress and strain is different along length of shaft.

• Current Optics and Photonics
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• v.2 no.4
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• pp.303-307
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• 2018

We propose a simple ultraviolet (UV) sensor consisting of a conventional single-mode optical fiber capped with an azobenzene-moiety-containing polymer. The UV light changes the dimensions of the azobenzene polymer, as well as the refractive index of the material. Incident light with a wavelength of 1550 nm was reflected at the fiber/polymer and polymer/air interfaces, and interference of the reflected beams resulted in spectral interference that shifted the wavelength by 0.78 nm at a UV input power of $2.5mW/cm^2$. The UV sensor's response to wavelength is nonlinear and stable. The response speed of the sensor is limited by detection noise, which can be improved by modifying the insertion loss of the UV sensor and the signal-to-noise ratio of the detection system. The proposed compact UV sensor is easy to fabricate, is not susceptible to electromagnetic interference, and only reacts to UV light.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.2
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• pp.100-106
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• 2007

In this paper, the performance of OFDM(Orthogonal Frequency Division Multiplexing) and FMT(Filtered Multi-tone) Systems is compared under jamming environment. Two systems are multi-carrier systems to improve data rates. Through the comparison of two systems under jamming environment, the characteristics and strong/weak points of each system are analyzed.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.57-60
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• 1999

In many radio communication environments, there is a special component, called inter-symbol interference (ISI), mused by multipath time delay of signal and ISI components impose limitation of the data transmission rate. In this paper, we consider signaling pulse shapes, called partial response signaling (PRS), for minimizing the effect of ISI and show the improvement of performance by applying one of the partial-response signaling (PRS) pulses to two types of receiver system under dependent noise environments through the Monte-Carlo computer simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4A
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• pp.269-277
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• 2012

When there are mismatches between the beamforming steering vector and the array response vector for the desired signal, the performance can be severely degraded as the adaptive array attempts to suppress the desired signal as well as interferences. In this paper, an robust method is proposed for the adaptive array in the presence of both direction errors and random errors in the steering vector. The proposed method first finds a signal-plus-interference subspace (SIS) from the correlation matrix, which in turn is exploited to extract an interference subspace based on the structure of a uniform linear array (ULA), the effect of the desired signal direction vector being reduced as much as possible. Then, the weight vector is attained to be orthogonal to the interference subspace. Simulation shows that the proposed method, in terms of signal-to-interference plus noise ratio (SINR), outperforms existing ones such as the doubly constrained robust Capon beamformer (DCRCB).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.4
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• pp.285-301
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• 1988

The symbol error rate equations of multi-level quadrature PRS(QPRS) system have been derived in the individual and composite environment of Gaussian/impulsive noise, cochannel CW interference, carrier offset, phase jitter and fading. And using the derived error rate equations, the probability of error has been evaluated and shown in graphs as functions of carrier to noise power ratio, carrier to interference power ratio, phase error, impulsive index, the ration of Gaussian noise to impulsive noise power component, signal to noise power ration in phase locked loop(PLL), and fading figures. The rseults show that the error rate performances are generally more more degraded by impulsive noise than by Gaussian noise. But on the contrary the erors occurred more frequently by Gaussian noise than impulsive noise in a fading environment.