• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.359-366
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• 2009

MATLAB Autocode generation is a feature that converts a block diagram model in Simulink to a c program. Utilizing this function makes MATLAB/Simulink an integrated developing environment, from controller design to implementation. It can reduce development cost and time significantly. However, this automated process requires high reliability on the software, especially the original Simulink block diagram model. And thus, the verification of the codes becomes important. In this study, a UAV flight program which is generated with Simulink is validated and modified according to DO-178B. As a result of applying the procedures, the final program not only satisfied the functional requirement but is also verified with structural point of view with Decision Coverage 93%, Condition Coverage 95% and MC/DC 90%.

• Journal of IKEEE
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• v.26 no.1
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• pp.95-103
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• 2022

In this paper, the efficiency of a sensorless method with square-wave injection for a low-cost inverter, so called B4 inverter is presented. This inverter comprises only 4 switches to reduce system cost. It is distinguished from the conventional B6 inverter that has 6 of switching elements. The B4 inverter, injected a 1 kHz of harmonic wave, has been modelled using the functions and library in Matlab/Simulink. This paper described each component of sensorless algorithm. Among them, the Notch Filter is used to extract the harmonic component of the phase current and a second-order low-pass filter was used to reduce the ripple of the estimated speed. It is shown through simulation that the rotor angle of a permanent magnet synchronous motor is detected by multiplying the current waveform extracted using the notch filter by the harmonic voltage. The feasibility of the proposed method is shown through Simulink simulation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.164-165
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• 2015

Recently, the reason of using foamed concrete is for core of panel, filler of construction material to give lightness. However, cement causes environmental problem. The cement generates CO₂ but we normally use cement during manufacturing foamed concrete. Accordingly, this study focuses on dynamic properties of matrix according to the addition ratio of paper ash to make lightweight matrix with blast furnace slag and paper ash which are industrial by-product. The experiment progessed in order to select th optimum mixing ratio of the blast furnace slag and paper ash. There are totally 7 levels such as B100:P0, B95:P5, B90:P10, B85:P15, B80:P20, B75:P25, B70:P30 in this study. As a result of the test, B95:P5 matrix has the best density and compressive strength.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4B
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• pp.345-352
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• 2002

In this paper, in order to evaluate the performance of IS-95 system reverse link in white gaussian noise and rayleigh fading environment, we suggest epochal proposal to improve computer run-time and its efficiency is verified in terms of the number of samples. MC(Monte Carlo) simulation is the most popular simulation technique lately, but MC simulation requires a number of samples at low bit error rate. Therefore, MC cannot avoid the limit of computer run-time. To alleviate these problems, we apply the suggested method called central moment technique to the reverse link of the IS-95 system and can obtain discrete probability mass functions from Nth order central moments of the less number of received signal samples than those required in MC. Continuous cumulative probability distribution function can be accurately estimated by using interpolation and the improvement effect for the number of samples is proven.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.95-103
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• 2019

In this paper, we present a microstrip-to-substrate integrated waveguide(SIW) transition and microstrip-to-hollow SIW(HSIW) transition for Ku-band satellite communication systems. For the complete utilization of the HSIW, a structure filled with air instead of a dielectric material, a microstrip-to-HSIW transition is designed, fabricated, and compared with a microstrip-to-SIW transition. A back-to-back microstrip-to-SIW transition is measured in the range 12~18 GHz; it exhibits a return loss ${\geq}20dB$ and an insertion loss of $1.5{\pm}0.2dB$. In contrast, a back-to-back microstrip-to-HSIW transition exhibits a return loss of at least 15 dB and an insertion loss of $0.55{\pm}0.2dB$ in the same frequency range.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.70-80
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• 2006

The large portion of communication service areas move from a legacy wire-line voice service to mobile data service. For the purpose of satisfaction on market need, many communication systems should be installed and upgraded based on a mobile wide-band transmission facility. Recently, large part of communication service is based on internet protocol by packet switch techniques and required new technologies such as multimedia processing, QoS achievement, and mobility managememobile communication network such as IS-95A/B and CDMA2000-1X. In this paper, I analyzed the network architecture and service provision methods. in CDMA2000-1X nt. In korea, a CDMA communication technique is standardized for digital mobile communication systems. By using the analysed results, I will extract an efficient method for network evolution and a core technique for next generation mobile communication network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5187-5195
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• 2012

This study was performed to investigate the factors related to assertive behavior among non-smoking college students under secondhand smoke exposure. Data were collected from 246 non-smoking college students at one university in B city from October to November, 2011 and analyzed by multiple logistic regression. The factors related to assertive behavior were men(OR 3.173, 95% CI 1.676-6.005), with another smoker in household(OR 1.679, 95% CI 1.056-2.983), high level of perceived benefit(OR 2.821, 95% CI 1.044-7.623), high level of social influence(OR 3.753, 95% CI 1.845-7.634), high level of self efficacy(OR 4.140, 95% CI 2.159-7.941). It is necessary to develop and evaluate the health promotion program for enhancing of assertive behavior of non-smoking college students regarding of perceived benefit, social influence and self efficacy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6211-6217
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• 2014

Previous genome-wide association studies (GWAS) have implicated several single nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene with childhood acute lymphoblastic leukemia (ALL). However, replicated studies reported some inconsistent results in different populations. Using meta-analysis, we here aimed to clarify the nature of the genetic risks contributed by the two polymorphisms (rs10994982, rs7089424) for developing childhood ALL. Through searches of PubMed, EMBASE, and manually searching relevant references, a total of 14 articles with 16 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (95%CI) were calculated to assess the associations. Both SNPs rs10994982 and rs7089424 showed significant associations with childhood ALL risk in all genetic models after Bonferroni correction. Furthermore, subtype analyses of B-lineage ALL provided strong evidence that SNP rs10994982 is highly associated with the risk of developing B-hyperdiploid ALL. These results indicate that SNPs rs10994982 and rs7089424 are indeed significantly associated with increased risk of childhood ALL.

• Journal of Gastric Cancer
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• v.7 no.1
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• pp.9-15
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• 2007

Purpose: DNA methylation is an important epigenetic factor in tumorigenesis. We hypothesized that polymorphism of the promoter of the DNA methyltransferase 3b (DNMT3b) genes, which are responsible for regulating the methylation status of tumor suppressor genes, are associated with increased risk of gastric cancer. Materials and Methods: In this hospital-based case-control study, to determine the role of this polymorphism of the promoter of DNA methyltransferase 3b (DNMT3b) genes in gastric cancer, we genotyped 176 cases and 70 control subjects. To determine the genotype, we used a polymerase chain reaction restriction fragment length polymorphism assay. We compared alleles and genotypes between the two groups and revealed an association of DNMT3b promoter polymorphism with increased risk of gastric cancer in the Korean population. Results: Genotype frequencies were 14.8% (Cytosine-Cytosine), 71.6% (Cytosine-Thymine), and 13.6% (Thymine- Thymine) in the case patients and 40.0% (Cytosine-Cytosine), 42.9% (Cytosine-Thymine), and 17.1% (Thymine-Thymine) in the control subjects, respectively. Compared with CC homozygotes, CT heterozygotes had a 4.523-fold increased risk (OR, 2.13; 95% CI, 2.324~8.803), and the TT homozygotes had a 2.154-fold elevated risk (OR, 1.42; 95% CI, 0.899~85.165). For the T variant genotype (CT+TT), there was a 3.846-fold increased risk (OR, 1.88; 95% CI, 2.040~7.251). However, no significance was observed in the genotype distributions of both polymorphisms according to histopathology, stage of stomach cancer. The Ssame results were observed with Helicobacter infection. Conclusion: DNMT3b promoter polymorphism, especially the T variant genotype, is associated significantly with thean increased risk of gastric cancer.

• 대한공업교육학회지
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• v.44 no.1
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• pp.114-140
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• 2019

The purpose of this research is to analyze a principal's job at a Vocational High School using DACUM Task Analysis Method. The contents of this research are to set the order after deriving the duties and tasks of the principal., then to verify as the importance, difficulty, and frequency of each task, and also to indicate whether it is an essential capability to have in the early stages of one's duty. Finally, based on the job analysis results, a DACUM chart was developed by the principal of the Vocational High School. The DACUM Task Analysis Workshop was attended by one DACUM analyst with LEVEL - 1 license, seven DACUM members with more than four years experience, one secretary and two administrative assistants for a two-day period. The results of the research are as follows; First, the Vocational High School Principal is defined as a school administrator who operate the vocational education curriculum of in the specialized and customized high schools of industrial demand development and the job area. The analysis derived 11 duties and 95 tasks of the Principal. Second, the importance, difficulties, and frequency of each task were divided respectively into high (A), moderate (B), and low (C), and the consensus of the experts was made to determine whether the core capabilities are acquired early on the job. Third, based on the analysis results, a DACUM Task Analysis chart of the Vocational High School principals was presented. In addition, while engaged on the job of the vocational high school principal, a list of 49 general knowledge and abilities, 16 tools, Integrated data and fixtures are required. Along with 28 attitudes 33 future prospects and characteristics of the Vocational High School principal was presented.