• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.7-15
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• 2008

In this paper, it is investigated that the limitation due to the asymmetry of optical power with respect to optical phase conjugator(OPC) in mid-span spectral inversion(MSSI) for compensating optical signal distortion due to group velocity dispersion(GVD) and nonlinearities generated in fiber by combining with lumped dispersion management(DM) technique into MSSI. Two kinds of lumped DM configuration(configuration A and configuration B) are considered and compared each other in this research. Configuration A consists of two dispersion compensating fiber(DCF) span positioned after transmitter and before receiver, respectively. Configuration B consists of two dispersion compensating fiber(DCF) span positioned before and after OPC placed at middle of total transmission link, respectively. It is confirmed that the transmission performances are more improved by the configuration A combined with MSSI than configuration B. Also, it is confirmed that the best performance of overall channels are obtained by making net residual dispersion(NRD) to have positive value in self phase modulation(SPM)-limited WDM transmission systems, irrelevant to the configuration of DM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.974-979
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• 2002

There are so many kind of a control program that is applied in various process fields such as power generation plant, water treatment plant, incinerator plant, chemical plant, cement plant etc.. Because an engineer in field edits and changes and debugs and tests properly control programs using text-based control language, it is very hard for the him to apply to plant. Therefore, this research implemented a graphical tool for control program builder that is applicable to various plants and usable engineers having a little knowledge for control language. I wish to run more efficiently precision process control offering function that can see visual expression about flow of control signal and intermediate output values of control program displayed in screen using this implemented function block builder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.473-483
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• 2004

In this paper, we numerically investigated the optimum pump light power best compensating for pulse distortion due to both chromatic dispersion and self phase modulation (SPM) as a function of channel input power in 8 channel ${\times}$ 40 Gbps wavelength division multiplexing (WDM systems. Also we investigated the allowable maximum channel input power dependence on modulation format and fiber dispersion coefficient in the various pump light power of OPC. The considered WDM transmission system is based on path-averaged intensity approximation (PAIA) mid-span spectral inversion (MSSI) compensation method, which has highly-nonlinear dispersion shifted fiber (HNL-SDF) as nonlinear medium of optical phase conjugator (OPC) in the mid-way of total transmission line. We confirmed that optimal pump light power of HNL-DSF OPC depend on modulation format, initial channel input power, total transmission length and fiber dispersion. But optimal pump light power of HNL-DSF OPC must be selected to make power conversion ratio to almost unity. And we confirmed that, if we allow a 1 dB eye opening penalty (EOP), the tolerable maximum channel input power is increased by using RZ than NRZ as modulation format when pump light power of HNL-DSF OPC is not optimal value but another values.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.959-966
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• 2009

Effective transmission distance depending on transmission capacity of WDM systems with inline dispersion management (DM) and optical phase conjugator (OPC) at middle of total transmission length is investigated. The range of net residual dispersion (NRD) resulting 1 dB eye opening penalty (EOP) in 1 Tbps WDM system, in which NRD controlled by only postcompensation, is also investigated. It is confirmed that effective transmission distances are increasedto longer than several hundreds kilometers by applying optimal NRD depending on transmission capacity and distance. And it is confirmed that in 1 Tbps WDM system if NRD is determined to +17 ps/nm, the maximum transmission distance is achieved, and, especially, in long-haul 1 Tbps WDM system the effective NRD range will be determined within positive value.

• Food Engineering Progress
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• v.14 no.1
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• pp.41-48
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• 2010

An optical method was introduced to investigate the dispersion stability of Saengshik beverages (SB) containing 3.7-11.7% Saengshik powder (SP). Time course changes in backscattering light flux (BSLF) from SB were monitored by a Turbiscan. BSLF in the bottom and top layers of SB increased by forming sediment and foam, respectively, while that in the middle layer decreased by clarifying. With SP levels, sedimentation in SB was retarded, but the height of total sedimentation layer was increased. A logarithmic model was developed to fit to the changes in BSLF with time, showing determination coefficients of 0.979-0.988. The levels of SP in SB influenced the migration speed of the clarification front as well as the numbers of separated layers; 2 layers in SB containing 3.7% SP, 3 in 5.7-9.7%, and 4 in 11.7%. Formation of clear layers started after 17-29 min and continued for 22-53 min. The clarification was retarded most in SB containing 7.7% SP, indicating the most stable SP level for the SB preparation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.4 s.304
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• pp.51-58
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• 2005

This paper proposes a robust scene change detection technique that uses the weighted chi-square test and the automated threshold-decision algorithms. The weighted chi-square test can subdivide the difference values of individual color channels by calculating the color intensities according to NTSC standard, and it can detect the scene change by joining the weighted color intensities to the predefined chi-square test which emphasize the comparative color difference values. The automated threshold-decision at algorithm uses the difference values of frame-to-frame that was obtained by the weighted chi-square test. At first, The Average of total difference values is calculated and then, another average value is calculated using the previous average value from the difference values, finally the most appropriate mid-average value is searched and considered the threshold value. Experimental results show that the proposed algorithms are effective and outperform the previous approaches.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.58-65
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• 2016

This paper presents optimization techniques to reduce the processing time of the dehazing method and proposes an efficient dehazing method based on them. In the proposed techniques, the atmospheric light is estimated based on the distributed sorting of the dark channel pixels, so as to reduce the computations. The normalization process required in the transmission estimation is simplified by the assumption that the atmospheric light is monochromatic. In addition, the dark channel is modified into the median dark channel in order to eliminate the transmission refinement process while achieving a comparable dehazing quality. The proposed dehazing method based on the optimization techniques is presented and its performance is investigated by developing a prototype system. When compared to the previous method, the proposed dehazing method reduces the processing time by 65% while maintaining the dehazing quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.207-212
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• 1992

To analyze the freezing phenomena of foodstuffs, the numerical freezing model with 3 steps was established. When water and 2% agar gel were used as samples, Neumann's solution was well matched with experimental results by the numerical model. However, in the case of 20% gelatin gel and pork meat, Weiner's solution was better than Neumann's solution. This numerical freezing model was proved to be good model to describe the freezing phenomena with phase change in the point of versatility and precision.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2008.10a
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• pp.126-130
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• 2008

본 연구에서는 남자 중학생을 대상으로 1) 티셔츠 단독무늬에서 어떤 감성을 느끼는지 알아보고, 2)선호하는 티셔츠가 무엇이며 그 특징은 무엇인지 알아보았다. 또, 3) 성격에 따라 티셔츠 단독무늬에서 느끼는 감성차이가 있는지에 대해 알아보았다. 본 연구의 연구문제를 실증적으로 조사하기 위하여 설문지법을 이용하였다. 설문지의 구성은 3부분으로 구성하여 1부에서는 MBTI를 이용한 성격유형에 관한 측정문항 2부에서는 의복행동에 관한 측정 문항 3부에서는 티셔츠 단독무늬에 대한 감성 측정 문항이 포함되었다. 본 연구는 인천 지역에 사는 중학생 380명을 대상으로 설문조사에 의해 진행 통계분석은 SPSS 10.0을 이용하여 t test와 분산분석, 대응분석 등으로 분석하였다. 이 중 무성의한 설문지를 제외한 총 331부를 자료 분석에 사용하였다. 본 연구의 결과는 다음과 같다. 첫째, 남자 중학생들이 선호하는 단독무늬는 인공물을 소재로 한 사실적인 모티브로 주변에서 쉽게 접할 수 있는 친근한 소재를 활용한 무늬였다. 반대로 친근하지 않은 소재나 이해하기 어려운 단독무늬는 선호하지 않는 것으로 조사되었다. 둘째, 단독무늬에 대한 감성은 성격유형에 따라 다르게 나타났다. 외향형인 학생들은 감성에 대해 극적으로 대답하는 반면, 내향형인 학생들은 중간값에 가깝게 대답하는 성향이 강하게 나타났고, 감각형/직관형에서의 감성차이는 모든 단독무늬에서 직관형 학생들의 선호도가 높게 나타났다. 사고형/감성형에서 나타난 특징은 특정감성이 두 성격유형 모두에서 높게 나타난 경우 항상 사고형 학생집단에서 더 높게 평가하고 있다는 것이다. 판단형/인식형에서는 감성에 따라 의미있는 차이가 가장 많이 나타난 것이 특징이다. 이 결과는 단독무늬에서 느끼는 감성차이가 판단형과 인식형에서 가장 크다는 것을 의미한다.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3479-3489
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• 2000

Most of the study on fairness control method for Distributed-Queue Dual-Bus(DQDB) have been performed under specific load types such as equal probability load types or symmetric load types. On Web-based internet enviroments client-server load types are more practical traffic patlerns than specrfic load types. In this paper, an effiective fairness control method to distribute DQDR network bandwidth fairly to all stations under a client-server load is proposed. In order to implement a dynamic bandwidth timing capabihty needed to distribute the bandwidth fairty at heavy loads, the proposed method uses two pararnetexs, one is an access hrnit to legulate each station's packet transmission and the other is the number of extra emply slots that are yielded to downstream stations. In point of implementation this mechanism is simpler and easier than Bandwidth Tuning Mechanism(BTM) that uses an intermediate pattern and an adptation function. Simulation results show that it outperforms othen mecharusms.