• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.285-294
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• 2004

Median Filters in the Signal Processing have been most widely used and have demonstrated the most strongest effects. This paper proposes the Adaptive Median Filters by using noise detection. The basic algorithm of the proposed filters is to determine whether noise or not by the each noise judgement standards, and then take the Median Filter if it satisfies the conditions as a result of judgement and returns to the original image(No Filters) if not. This paper presented Noise Detection by Local Variance and Local Central Variance for noise judgement, compared and analyzed the features and performance of existing [5]∼[10] Filters. Filter improved on the result of executing the existing filters at the same condition and showed the effects over that when it was judged with naked eyes. Accordingly, the Adaptive Median Filters by Local Variance and Local Central Variance was proven to have reinforced edge preservation ability and have the strong features for removing the Impulse Noise of the Median Filter.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.2
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• pp.104-115
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• 2005

Median filters in the signal processing have been most widely used and have demonstrated the strongest effects. This paper proposes the adaptive median filters with noise detection. The proposed basic algorithm of the filters is to judge whether or not the noises exist on the ground of The Noise Judgment Standards. Just in case the existence of the noises is verified by the algorithm, it takes the median filter. In order to judge the existence of the noises by the algorithm, this paper introduced the noise detection method by local central variance. As a result of comparing and analyzing the features and performance of the proposed filters and the existing [5]-[10] filters on the same conditions, it was verified that the former proved to be better than the latter, Observed even by naked eyes, it was similar, too. Accordingly, it's proved that the adaptive median filters by local central variance are useful in removing the impulse noise of the median filter and reinforce the edge preservation ability.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.27-31
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• 1997

액상법에 의한 단분산 ZnS입자의 합성을 60~9$0^{\circ}C$에서 행하여, 반응조건이 ZnS입자의 형태에 미치는 효과를 검토했다. ZnS입자의 형태는 반응 시간의 경과와 더불어 단분산으로부터 다분산 혹은 응집체로 변화하였다. 반응 온도 60~9$0^{\circ}C$에서 초기 농도적이 중간값이고, 반응시간이 짧을 경우 입경 0.2~0.8$\mu\textrm{m}$의 구상 단분산 입자를 얻었다. 또한 Ag$_2$NO$_3$, EtOH용액, $0^{\circ}C$에서, Ag$_2$S에 의한 ZnS의 균일 피복이 가능하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1006-1009
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• 2007

모바일 애드혹 네트워크는 기존의 셀룰러 네트워크와는 달리 고정된 기지국이 존재하지 않고 모바일 노드들만으로 구성된 네트워크이다. 모바일 애드혹 네트워크의 각각의 노드들은 제한된 자원과 한정된 용량을 가진 배터리로 동작한다. 만일 이 배터리를 모두 소모하게 된다면 중간 노드들이 다운이 되고, 결과적으로 전체 네트워크가 단절되는 문제가 발생할 수 있다. 이러한 문제점을 해결하기 위해서는 한정된 자원을 최대한 효율적으로 사용해야 한다. 이를 위해 본 논문에서는 클러스터 기반의 애드 혹 네트워크 환경에서 발생하는 경로 요청 시 클러스터 내부의 에너지 분산을 통한 네트워크 생존 시간을 연장시키고자 하였다. 효율적인 에너지 분산을 위해 칼만 필터를 통한 클러스터 내부의 트래픽 변화량을 예측하고, 예측값과 노드의 에너지 잔량을 기준으로 경로를 설정하도록 하였다. 실험 결과 생존 시간을 23% 증가시켰고, 칼만 필터를 통한 트래픽 변화량 예측값의 오차는 6.3%로 나타났다. 앞으로 칼만 필터의 관측값을 확장하여 예측값에 대한 오차를 줄이고, 보다 복잡한 네트워크 환경에 적용하는 연구가 필요하다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.749-751
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• 2009

Optical link design technique for compensating of distorted 40 Gbps ${\times}$ 24 channels WDM signals is researched. The considered optical link consists of optical phase conjugator (OPC) placed at 100 km and 900 km, which are non-midway of total transmission distance, and dispersion management (DM). It is confirmed that optimal net residual dispersions (NRD) are 800 ps/nm and 900 ps/nm when OPC placed at 100 km and 900 km, respectively.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.22-28
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• 2022

In order to install ultra wide band and ultra long-haul transmission link based on standard single mode fiber, optical signal distortion due to chromatic dispersion and nonlinear Kerr effect must to be compensated. In this paper, optical link consisted of dispersion management and optical phase conjugation is proposed for compensation of the distorted wavelength division multiplexed (WDM) channels. Dispersion map profile in the proposed dispersion-managed link is configured by periodic repetitive shape, and optical phase conjugator is placed at various position including the midway of total transmission length. It is confirmed from simulation results that when the residual dispersion per span (RDPS) selected in the proposed dispersion-managed link to be large, the compensation of distorted WDM channels in the non-midway OPC system is more improved than the conventional dispersion-managed link.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.351-353
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• 2018

The compensation characteristics are investigated as a function of the averaged residual dispersion per span (RDPS), which is different in each half transmission section, in dispersion-managed optical transmission links with a randomly distributed single mode fiber lengths and RDPS.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.517-522
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• 2021

Optical dispersion-managed link combined with optical phase conjugation for compensating of the distorted optical signals due to chromatic dispersion and nonlinear effects, which is required to implement long-haul wavelength division multiplexed system, is proposed and assessed in viewpoint of network topology flexibility. Optical phase conjugator capable to compensate for the distorted optical signal due to nonlinear effects is placed non-midway of total transmission distance. And, in dispersion-managed link, residual dispersion per span (RDPS) of each fiber spans in former half section and latter half section with respect to optical phase conjugator are different to each other. Simulation results show when the RDPS of each fiber sections in one half section makes it's own net residual dispersion slight different from another half section's net residual dispersion, the compensation effect in the proposed link configuration is more increased.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.1-4
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• 1970

The experimental studies were intended to clarify the effects of leaf yield calculations, and also aimed at estimating the correlations between some characters for the selection of desirable stocks of mulberry trees. The analysis of covariances was the variance components procedures in a replicated trial for the varieties, and also it was used to obtain the genotypic, phenotypic and environmental correlations between the eight characters-branch length, node number, branch diameter, branch number per stock, total branch weight, old branch weight, new shoot and leaf weight, and leaf weight, etc. The results obtained are summarized as follows: Phenotypic, genotypic and environmental covariances are shown in Table 1 and phenotypic correlations, genotypic correlations and environmental correlations are shown in Table 2. Genotypic correlations were slightly higher than the corresponding phenotypic correlations between the characters in the varieties, but the variation in values due to the change of environment appeared between the characters. Genotypic correlations between the leaf yield of mulberry trees and other characters indicated that high leaf yield was genetically correlated with six characters namely branch length, node number, branch number per stock, total branch weight, old branch weight and new shoot weight, etc. It was also observed that lower correlations were appeared between the leaf yield and branch diameter, and branch diameter and other all characters studied in both genotypic and phenotypic correlation coefficients.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.9
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• pp.520-529
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• 2002

This paper presents an approach for scheduling network messages with real-time dynamic algorithms. We present the method that calculates an intermediate relative deadline of the message based on the EDF(Earliest Deadline First) scheduling policy. We adjust the slack of message by using this intermediate relative deadline to allocate a priority of message. The priority of the message can be determined accurately by using the slack that calculates in our approach, which increases the schedulability efficiency of the message. As a result, we reduce the worst-case response time and improve the guarantee ratio of real-time messages. Also, we describe the analysis method to check the schedulability on message sets, and show the efficiency of our approach by comparing the results of the DM(Deadline Monotonic) approach and the existing EDF approach with that of the improved EDF in our approach through the simulation.