• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1187-1200
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• 2002

This paper is concerned with the design or an LMI (Linear Matrix Inequality) -based H$\infty$ controller for a line of sight (LOS) stabilization system and with its robustness performance. The linearization of the system is necessary to analyze various nonlinear characteristics, but the linearization entails modeling uncertainties which reduce its performance. In addition, the stability of the LOS can be adversely affected by angular velocity disturbances while the vehicle is moving. As the vehicle accelerates, all the factors that are Ignored and simplified for the linearization tend to Inhibit the performance of the system. The robustness in the face of these uncertainties needs to be assured. This paper employs H$\infty$ control theory to address these problems and the LMI method to provide a suitable controller with minimal constraints for the system. Even though the system matrix does not have a full rank, the proposed method makes it possible to design a H$\infty$ controller and to deal with R and S matrices for reducing the system order. It can be also shown that the proposed robust controller has a better disturbance attenuation and tracking performance. The LMI method is also used to enhance the applicability of the proposed reduced-order H$\infty$ controller for the system given. The LMI-based H$\infty$ controller has superior disturbance attenuation and reference input tracking performance, compared with that of the conventional controller under real disturbances.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.372-383
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• 2011

Our study was carried out to develop the severity-adjustment model for length of stay in hospital for percutaneous coronary interventions so that we would analysis the factors on the variation in length of stay(LOS). The subjects were 1,011 percutaneous coronary interventions inpatients of the Korean National Hospital Discharge In-depth Injury Survey 2004-2006 data. The data were analyzed using t-test and ANOVA and the severity-adjustment model was developed using data mining technique. After yielding the standardized value of the difference between crude and expected length of stay, we analysed the variation of length of stay for percutaneous coronary interventions. There was variation of LOS in regional differences, size of sickbed and insurance type. The variation of length of stay controlling the case mix or severity of illness can be explained the factors of provider. This supply factors in LOS variations should be more studied for individual practice style or patient management practices and healthcare resources or environment. We expect that the severity-adjustment model using administrative databases should be more adapted in other diseases in practical.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.385-393
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• 2006

In this paper, we proposed a location estimation algorithm considering an extension of searching area in 2.45GHz band RTLS and analyzed its performance in terms of an average estimation error distance. The extendable searching area was assumed to be square of $300m{\times}300m$ and 2 dimensions. The arrangement shape of available readers was considered circle, rectangle, and shrinkage rectangle for extendable searching area. Also, we assumed that propagation path was LOS (Line-Of-Sight) environment, and analyzed the estimation error performance as a function of the number of received sub-blink considering an arrangement shape of available readers in searching area. From the results, compared with rectangle shape, circle shape showed the higher estimation accuracy. Also, we confirmed that the proposed location estimation algorithm provided high estimation accuracy in the shrinkage rectangle shape that was suitable for extension of searching area.

• BMB Reports
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• v.38 no.3
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• pp.320-327
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• 2005

Five ripening-related ACC synthase cDNA isoforms were cloned from 80% ripe papaya cv. 'Sinta' by reverse transcription-PCR using gene-specific primers. Clone 2 had the longest transcript and contained all common exons and three alternative exons. Clones 3 and 4 contained common exons and one alternative exon each, while clone 1, the most common transcript, contained only the common exons. Clone 5 could be due to cloning artifacts and might not be a unique cDNA fragment. Thus, there are only four isoforms of ACC synthase mRNA. Southern blot analysis indicates that all five clones came from only one gene existing as a single copy in the 'Sinta' papaya genome. Multiple sequence alignment indicates that the four isoforms arise from a single gene, possibly through alternative splicing mechanisms. All the putative alternative exons were present at the 5'-end of the gene comprising the N-terminal region of the protein. 'Sinta' ACC synthase cDNAs were of the capacs 1 type and are most closely related to a 1.4 kb capacs 1-type DNA(AJ277160) from Eksotika papaya. No capacs 2-type cDNAs were cloned from 'Sinta' by RT-PCR. This is the first report of possible alternative splicing mechanism in ripening-related ACC synthase genes in hybrid papaya, possibly to modulate or fine-tune gene expression relevant to fruit ripening.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.6
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• pp.20-26
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• 2008

Today, there are many high speed data access systems that provide the truly "anytime and anywhere" services. Especially, HSDPA (High Speed Data Packet Access), one of the main third generation mobile communication systems, provides 14.4Mbps maximum data throughput. However, HSDPA will fail to provide high data throughput in hostile multipath fading environments due to lack of LOS (Line of Sight). HAPS (High Altitude Platform Station) is one of the solutions to this problem. HAPS system not only provides Los, but it can also provide high data rate services to the conventional terrestrial systems. This paper proposes HAPS-HSDPA system model and compares performance of HSDPA and HAPS-HSDPA.

• Health Policy and Management
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• v.28 no.1
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• pp.53-69
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• 2018

Background: This study investigates association modified category medical specialization (CMS) and hospital charge, length of stay (LOS), and mortality among lumbar spine disease inpatients. Methods: This study used National Health Insurance Service-cohort sample database from 2002 to 2013, using stratified representative sampling released by the National Health Insurance Service. A total of 56,622 samples were analyzed. The primary analysis was based on generalized estimating equation model accounting for correlation among individuals within each hospital. Results: Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had a shorter LOS (estimate, -1.700; 95% confidence interval [CI], -1.886 to -1.514; p<0.0001). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had a lower mortality rate (odds ratio, 0.635; 95% CI, 0.521 to 0.775; p<0.0001). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had higher hospital cost per case (estimate, 192,658 Korean won; 95% CI, 125,701 to 259,614; p<0.0001). However, inpatients admitted with lumbar spine surgery patients at hospitals with higher modified CMS had lower hospital cost per case (estimate, -152,060 Korean won; 95% CI, -287,236 to -16,884; p=0.028). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had higher hospital cost per diem (estimate, 55,694 Korean won; 95% CI, 46,205 to 65,183; p<0.0001). Conclusion: Our results showed that increase in hospital specialization had a substantial effect on decrease in hospital cost per case, LOS, and mortality, and on increase in hospital cost per diem among lumbar spine disease surgery patients.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.117-124
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• 2004

A spherical earth surface is used for realistic analysis of the geometrical performance characteristics generated by 2-dimensional line-of-sight (LOS) tilt of the satellite imager using the Time Delay and Integration(TDI) technique. A 2-dimensional LOS tilt ever the spherical Earth surface is proposed to compensate geometric performance degradation caused by the satellite altitude decrease below the normal operation altitude. The compensation can be achieved by TDI re-match without degradation of modulation transfer function and with ground sample distance slightly increased. Effective methods of LOS tilt for the compensation are investigated. This study can be useful for mission assurance and flexibility in imager operation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.3
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• pp.197-208
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• 2021

Objectives: The purpose of this retrospective study was to evaluate the variables associated with length of stay (LOS), hospital costs, intensive care unit (ICU) use, and treatment outcomes in patients hospitalized for maxillofacial infections at a tertiary medical center in South Korea. Materials and Methods: A retrospective chart review was conducted for patients admitted for treatment of maxillofacial infections at Dankook University Hospital from January 1, 2011 through September 30, 2020. A total of 390 patient charts were reviewed and included in the final statistical analyses. Results: Average LOS and hospital bill per patient of this study was 11.47 days, and ₩4,710,017.25 ($4,216.67), respectively. Of the 390 subjects, 97.3% were discharged routinely following complete recovery, 1.0% expired following treatment, and 0.8% were transferred to another hospital. In multivariate linear regression analyses to determine variables associated with LOS, admission year, infection side, Flynn score, deep neck infection, cardiovascular disease, admission C-reactive protein (CRP) and glucose levels, number and length of surgical interventions, tracheostomy, time elapsed from admission to first surgery, and length of ICU stay accounted for 85.8% of the variation. With regard to the total hospital bill, significantly associated variables were age, type of insurance, Flynn score, number of comorbidities, admission CRP, white blood cell, and glucose levels, admission temperature, peak temperature, surgical intervention, the length, type, and location of surgery, tracheostomy, time elapsed from admission to first surgery, and length of ICU use, which accounted for 90.4% of the variation. Age and ICU use were the only variables significantly associated with unfavorable discharge outcomes in multivariate logistic regression analysis. Conclusion: For successful and cost-effective management of maxillofacial infections, clinicians to be vigilant about the decision to admit patients with maxillofacial infections, perform appropriate surgery at an adequate time, and admit them to the ICU.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.32-32
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• 2022

Abaca (Musa textilis L. Nee) is a native Musa species from the Philippines known for its natural fiber. Abaca fiber a.k.a. Manila hemp extracted from its pseudostems is considered one of the strongest fibers in the world. This is used for commodities such as ropes, papers, and money bills. Abaca is vulnerable to pests and diseases such as the Abaca Bunchy Top Disease (ABTD) caused by Abaca Bunchy Top Virus (ABTV) and Banana Bunchy Top Virus (BBTV). Inosa, one of the varieties of abaca utilized in the Philippines, is highly susceptible to ABTD. In contrast, Pacol (Musa balbisiana L.), a close relative of abaca, is highly resistant to the same disease. Here, we report the sequencing and de novo genome assembly of both abaca var. Inosa and banana var. Pacol. A total of ~16 Gb and ~21 Gb raw reads for Inosa and Pacol, respectively, were generated using Pacbio Hifi sequencing method and assembled with Hifiasm. High-quality de novo assemblies of both Musa species with 99% recovered as per BUSCO analysis were obtained. The assembled Inosa genome has a total length of ~654 Mb and N50 of 7 Mb while Pacol has a total length of 527 Mb and N50 of 3 Mb which are close to their estimated genome size of ~638 Mb and ~503 Mb, respectively. The information that can be derived from the de novo assembled genomes would provide a solid foundation for further research in disease resistance and fiber quality improvement in abaca.

• Journal of Advanced Navigation Technology
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• v.26 no.2
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• pp.91-98
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• 2022

Unmanned aircraft system traffic management (UTM) service for the safe operation of unmanned aerial vehicles (UAV) such as drones using commercial communication networks such as long-term evolution (LTE) and 5G in low-altitude areas of 150m or less is being studied in several countries. In this paper, whether it is possible to secure three-dimensional (3D) coverage for UTM service using the existing LTE cellular network for terrestrial usersis analyzed through simulations. The practicality in the real environment is confirmed by performing performance analysis in the actual topographical environment and the LTE base station layouts in Korea. According to the analysis results, as the altitude increases, the number of line-of-sight (LOS) interference base stations increases, resulting in a worse signal to interference plus noise ratio (SINR), but coverage is secured except for the limited areas within 150m. was confirmed to be possible. In addition, it is confirmed that a significant proportion of outage areas could be reduced by placing a small number of additional base stations for the outage area.