• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.6
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• pp.34-40
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• 2011

From the present paper researched about the Design of Image Rejection SSB Modulator for X-Band Monopulse RADAR using Waveguide Hybrid Coupler. Generally, SSB modulator mixes IF(RF) and LO signals, and then it converts to RF(IF) frequency band. In this case, in order to transmit one sideband from RF band, SSB modulator is demanded the removal of image and LO signal. The balanced mixer was designed using waveguide hybrid coupler and crystal mixer diode to mix LO and IF signal. And also the IF Amplifier was designed for IF(+) and IF(-) signal generation which have $90^{\circ}$ phase differences which are suitable in two crystal mixer diode inputs. In order to maintain a high electric reliability from high frequency band the waveguide and IF amplifier's case were manufactured with aluminum using deep brazing techniques. The test result of SSB modulator, LO and sideband signal rejection ratio were 14.2dB and 18.5dB respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.36-44
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• 2014

Broad band and wide area satellite communication has advantage that can be always communicate with anyone regardless of time and space. In the other hands, its communication quality is easy to be affected by interference signals. Due to the fact that interference signal can be transmitted from everywhere, it's hard to find the illegal source of signal and it has huge influence. In this paper, with this influence of interference signal, we introduce the interference rejection method, implementation and test result in the digital satellite communication processing the signal using variety of digital method. It will be useful information to improve the interference rejection function and also be helpful on the field of satellite communication.

• Journal of Information Technology Applications and Management
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• v.18 no.4
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• pp.169-181
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• 2011

The study developed the ideas of innovation resistance attitude in view of innovation delay, rejection, and objection. Authors developed the idea of innovation resistance attitudes of customers in view of innovation diffusion process. The study categorized the idea of resistance such as delay, rejection, and objection. The study hired the structural equation modeling to evaluate the relationships among the consumers' subjective variables such as incongruence, uncertainty, perceived performance, peer usage, and tradition orientation those were factored out by the survey test. These measured variables were analyzed into the innovation resistance related latent variables. The study provides the basic treatment to introduce new technologies and products to the superficially resisting customers. Those resisting customers might be future late adopters. The research results provide the basic arguments for prerequisite treatment to introduce smart phone in the global market place.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.425-428
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• 2012

We propose some properties for fuzzy hypotheses testing by the principle of the rate of internal division on delta-levels. By the rate of internal division, we show that the acceptance and rejection degree for fuzzy the fuzzy hypotheses and reduce the spread of the fuzzy variance with average of the center and left or right spread of fuzzy number data.

• Journal of the Korea Society for Simulation
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• v.9 no.2
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• pp.75-87
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• 2000

In this paper, nonstationary multiple sampling plans are discussed which are difficult to solve by analytical method when there exists dependency between the sample data. The initial solution is found by the sequential sampling plan using the sequential probability ration test. The number of acceptance and rejection in each step of the multiple sampling plan are found by grouping the sequential sampling plan's solution initially. The optimal multiple sampling plans are found by simulation. Four search methods are developed U and the optimum sampling plans satisfying the Type I and Type ll error probabilities. The performance of the sampling plans is measured and their algorithms are also shown. To consider the nonstationary property of the dependent sampling plan, simulation method is used for finding the lot rejection and acceptance probability function. As a numerical example Markov chain model is inspected. Effects of the dependency factor and search methods are compared to analyze the sampling results by changing their parameters.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.98-105
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• 1996

The design method of 85 GHz-115 GHz band single side-band filter using the principle of martin-puplett inteferometer is described. It has been designed by this method and also manufactured and tested. From the test results, not only the ratio of image singal rejection of 19 dB is obtained, but also the theoretical and experimental results of center frequency of pass-band and rejection-band show the validity of the theory. This manufactured filter was installed on 100GHz band SiS (superconductor insulator superconductor ) receiver for observing cosmic radio waves and tested. We found that this filter can be used a single side-band as well as double side-band mode. The design method which is presented in this paper can be used a single side-band filter for a heterodyne type sub-milimeter wave receiver.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.37.4-37
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• 2001

This paper presents a vibration-rejection control design for a magnetic suspension system which has strong non-linearity, open-loop unstable characteristics, high-order flexible modes, and parameter variations. The target plant to be controlled consists of a U-core electromagnet and a flexible rail. We describe the test rig and formulate the mathematical model and then we set up a control problem as the mixed sensitivity problem where the augmented plant is constructed with frequency weighting functions and the feedback controller is designed by using the H$\infty$ controller. The effectiveness of the designed controller for the magnetic suspension system with high-order flexible modes is validated and justified using several simulations. These results show that the magnetic suspension system is robustly stable against disturbance and gives the well-damped tracking performance ...

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.153-156
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• 2006

We propose some properties of fuzzy p-value and fuzzy significance level to the test statistics for the fuzzy hypotheses testing. Appling the principle of agreement index, we suggest two method for fuzzy hypothesis testing by fuzzy rejection region and fuzzy p-value with fuzzy hypothesis to separately ${\alpha}-level$.

• Journal of the Korean Ceramic Society
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• v.27 no.6
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• pp.721-728
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• 1990

Hydroxyapatite powders were synthesized with Ca/P=1.67 and pH=11 by precipitaton method, after characterization of these specimen, behavior in Ringer's solution and biocompatibility of hydroxyapatite, such as cytotoxity test and implantation test, were investigated. The hydroxyapatite ceramics had structural stability in Ringer's solution, and hydroxyapatite ceramics did not prevent cell growing and exhibit any cytotoxic effects. In implantation of hydroxyapatite ceramics into muscle under abdome of guinea pig, hydroxyapatite ceramics did not show any symptom of rejection for cellular texture.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.16-27
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• 2001

Objectives : This study was aimed to investigate stress and coping strategy in the families of schizophrenic patient, and changes of knowledge, stress and coping strategy after brief program of family education compared with control group Methods : The education group consisted of twenty four people who were families with schizophrenic patients and attended the brief program of family education. The control group consisted of twenty two people with schizophrenic inpatients. Self-report questionnaires such as Family Coping Questionnaire(FCQ), Patient Rejection Scale(PRS), Worry Questionnaire, Knowledge Questionnaire, Beck Depression Inventory(BDI), and State-Trait Anxiety Inventory(STAI) were administered to the education group and the control group, twice at the pre-test and post-test. Results : 1) In the education group, scores of worry questionnaire, BDI and STAI-S at the post-test were significantly lower than those at the pre-test. Social interests score of FCQ and knowledge questionnaire score at the post-test were significantly higher than those at the pre-test. In FCQ factors, social interests associated with avoidance strategy score at the post-test was significantly higher than that at the pre-test. However, in the control group, there was no significant difference in all questionnaires. 2) In the education group, significant positive correlation existed between calculated differences of worry questionnaire and STAI-S, and between worry questionnaire and STAI-T, whereas significant negative correlation existed between positive communication of FCQ and PRS, and between knowledge questionnaire and STAI-S. In the control group, significant negative correlation existed between information of FCQ and PRS, and between positive communication of FCQ and PRS. 3) In the education group, significant positive correlation existed between calculated differences of worry questionnaire and age of patient, whereas significant negative correlation existed between knowledge questionnaire and duration of illness. However, in the control group, there was no significant correlation. Conclusion : The brief program of family education was effective in increasing knowledge about schizophrenia, decreasing worry and anxiety about the patients in families with schizophrenic patient. In the education group as knowledge about schizophrenia increased, anxiety about schizophrenic patient decreased, but there was no significant correlation in the control group. As relative's rejection feeling about schizophrenic patient decreased, positive communication strategy increased in both groups. However, the control group was more affected by rejection feeling than the education group.