• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.171-174
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• 2006

A large number of service providers in countries all over the world have established GNSS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. In current GNSS network processing, all the geometric related information such as ionospheric free carrier phase ambiguities from all stations and satellites, tropospheric effects, orbit errors, receiver and satellite clock errors are estimated in one centralized Kalman filter. Although this approach provides an optimal solution to the estimation problem, however, the processing time increases cubically with the number of reference stations in the network. Until now one single Personal Computer with Pentium 3.06 GHz CPU can only process data from a network consisting of no more than 50 stations in real time. In order to process data for larger networks in real time and to lower the computational load, a federated filter approach can be considered. The main benefit of this approach is that each local filter runs with reduced number of states and the computation time for the whole system increases only linearly with the number of local sensors, thus significantly reduces the computational load compared to the centralized filter approach. This paper presents the technical aspect and performance analysis of the federated filter approach. Test results show that for a network of 100 reference stations, with the centralized approach, the network processing including ionospheric modeling and network ambiguity fixing needs approximately 60 hours to process 24 hours network data in a 3.06 GHz computer, which means it is impossible to run this network in real time. With the federated filter approach, only less than 1 hour is needed, 66 times faster than the centralized filter approach. The availability and reliability of network processing remain at the same high level.

• Korean Journal of Remote Sensing
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• v.20 no.6
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• pp.383-396
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• 2004

The application of spatial statistics to obtain the spatial uncertainty distributions in classification of remote sensing images is investigated in this paper. Two quantitative methods are presented for describing two kinds of uncertainty; one related to class assignment and the other related to the connection of reference samples. Three quantitative indices are addressed for the first category of uncertainty. Geostatistical simulation is applied both to integrate the exhaustive classification results with the sparse reference samples and to obtain the spatial uncertainty or accuracy distributions connected to those reference samples. To illustrate the proposed methods and to discuss the operational issues, the experiment was done on a multi-sensor remote sensing data set for supervised land-cover classification. As an experimental result, the two quantitative methods presented in this paper could provide additional information for interpreting and evaluating the classification results and more experiments should be carried out for verifying the presented methods.

• The Journal of Traditional Korean Medicine
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• v.15 no.1
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• pp.49-55
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• 2006

Objective: <千金方(Qianjinfang)> which documents a great amount of prescription of Acupuncture and moxibustion bikes an important role during the development of acupuncture and moxibustion. Thus, it have given rise us to the research-situation of Tang Dynasty China of previous period. This study was to outline the rules of choosing acupoints as well as the prescriptions of contemporary times in reference with <千金方(Qianjinfang)>, and to discuss the conception of acupuncture and moxibustion in <千金方(Qianjinfang)>. Method: Based on <千金方(Qianjinfang)>, the parameters were categorized to a certain scope, syndromes in different type were classified. Also numbers of acupoints, route of meridians locations, utilities of special acupoints even prescription methods were statistically analyzed in reference with <千金方(Qianjinfang)>. Results & Conclusion: Acupuncture prescription in <千金方(Qianjinfang)> was mostly presented by single acupoint and this was basic prescription of its rule of choosing acupoints. Choosing acupoint for the majority of various diseases started from choosing meridians with the disorder, but no rules for choosing acupoints was clear. There was basically various methods in choosing acupoints, but little were used by Biao-Ii meridian choosing method (表裏經配穴.) In the high frequency of use, wu-shu acupoints was higher used than other specific acupoints (特定穴). While wu-shu acupoints treated the major parts of the diseases, shu-mo acupoints were strictly used on system. Consequently : The theoretical basis originating the choosing rules of the acupoints and prescriptions was shown in <千金方(Qianjinfang)> as representative clinical reference, through which it was valuable to analyze the prescription rule and specificity of the acupoints.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.350-358
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• 2022

Objectives: For chemical risk assessment in workplaces, it is necessary to determine a reference value through hazard assessment. In general, OEL (Occupational Exposure Limit) is used for this value. However, since chemicals with OEL were not enough, the concept of DNEL (Derived No Effect Level) was introduced in chemical safety assessment. In this study, the possibility and approach of applying DNEL for chemical risk assessment in domestic workplaces were investigated. Methods: The characteristics of OEL and DNEL were investigated. In addition, ACGIH TLV and GESTIS DNEL were compared and the corresponding scopes were analyzed among the chemical substances notified in South Korea. Results: OEL and DNEL are similar concepts reflecting reference values that should not be exposed based on health effects. While their evaluation and derivation are determined based on similar information and procedures, they may vary depending on the responsible actor, data availability, principles of judgment, and more. As a result of the comparative analysis of ACGIH TLV and GESTIS DNEL, it was confirmed that there is some correlation between TWA and DNEL. The conservatism of DNEL was around 50%. Additionally, it was found that the available range of DNEL among chemicals in South Korea is considerable. Conclusions: This study showed that DNEL can be applied when assessing the risk of chemical substances in domestic workplaces considering several regards. However, since this is not the same level as OEL, we have proposed a proper approach to carry out risk assessment step by step.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.157-164
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• 1998

Various hantaviruses were isolated from HFRS patients and various rodent species, in many parts of the world. Bandicotas were captured at Yogyakarta, east region of Sumatura island, Indonesia; and 4 rodents species including Bandicotas were captured at Chiang Rai in Thailand during 1995. Sera were collected from captured bandicotas and other rodent spicies were screened for antibody test against Hantaan (HTN), Seoul (SEO), Puumala (PUU) and Sin Nombre (SN) viruses by immunofluoresence antibody assay (IFA). Hantavirus antigen in lung tissues were tested by IFA. Among 55 captured Bandicota indica in Indonesia, 14 (25.5%) were antibody positive against HTN, SEO, PUU and SN virus. Hantavirus antigen were detected from 5 (9.0%) out of 55 lungs tested. Among 34 captured Bandicota indica in Thailand, 9 (26.5%) were antibody positive against HTN, SEO, PUU and SN virus. Among 34 lungs tissues of Bandicota indica examined, 3 (8.8%) were antigen positive. In other rodent species, antibody positive against Hantaviruses of Rattus rattus, Rattus losea and Mus cervicolor were 4/62 (6.5%), 5/25 (20%), 1/1 (100%), respectively. But no one has antigen in their lung tissues. Antigen positive lungs suspension were inoculated into vero E6 cells for virus isolation and 4 viruses were isolated from Indonesian Badicota and 3 viruses from Thailand.

• Animal Bioscience
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• v.36 no.9
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• pp.1327-1335
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• 2023

Objective: When evaluating individuals with the same parent and no phenotype by pedigree best linear unbiased prediction (BLUP), it is difficult to explain carcass grade difference and select individuals because they have the same value in pedigree BLUP (PBLUP). However, single step GBLUP (ssGBLUP), which can estimate the breeding value suitable for the individual by adding genotype, is more accurate than the existing method. Methods: The breeding value and accuracy were estimated with pedigree BLUP and ssGBLUP using pedigree and genotype of 408 Hanwoo cattle from 16 families with the same parent among siblings produced by fertilized egg transplantation. A total of 14,225 Hanwoo cattle with pedigree, genotype and phenotype were used as the reference population. PBLUP obtained estimated breeding value (EBV) using the pedigree of the test and reference populations, and ssGBLUP obtained genomic EBV (GEBV) after constructing and H-matrix by integrating the pedigree and genotype of the test and reference populations. Results: For all traits, the accuracy of GEBV using ssGBLUP is 0.18 to 0.20 higher than the accuracy of EBV obtained with PBLUP. Comparison of EBV and GEBV of individuals without phenotype, since the value of EBV is estimated based on expected values of alleles passed down from common ancestors. It does not take Mendelian sampling into consideration, so the EBV of all individuals within the same family is estimated to be the same value. However, GEBV makes estimating true kinship coefficient based on different genotypes of individuals possible, so GEBV that corresponds to each individual is estimated rather than a uniform GEBV for each individual. Conclusion: Since Hanwoo cows bred through embryo transfer have a high possibility of having the same parent, if ssGBLUP after adding genotype is used, estimating true kinship coefficient corresponding to each individual becomes possible, allowing for more accurate estimation of breeding value.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.7
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• pp.550-555
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• 1999

This paper deals with the effect of lightning impulse current on electrical characteristics of ZnO blocks used in distribution lightning arrester. The electrical characteristics of ZnO blocks are degraded by overtime impulse current, and the degraded ZnO block is brought to a thermal runaway and finally destroyed. It is therefore important to estimate the change of electrical characteristics of ZnO blocks. In this study, an impulse current generator which can produce 8/20$[\mus]$, 3[㎄] and 4/10$[\mus]$, 5[㎄] waveform is designed and fabricated to simulate the lightning impulse current of power systems. Total energy applied to the ZnO blocks at each time is 739[J] in 8/20$[\mus]$, and 523[J] in 4/10$[\mus]$, impulse current, respectively. From the experimental results, the 3rd harmonic of the leakage current increases continuously with the number of applied impulse current, but no significant changes in residual voltage and in reference voltage are observed until the ZnO block is destroyed. Also, it is confirmed that the main factor on degradation of ZnO blocks is rather the total energy applied to ZnO blocks than the peak value of the impulse current.

• Physical Therapy Korea
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• v.16 no.4
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• pp.16-22
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• 2009

The purpose of this study was to investigate the trunk and lower extremity muscle activity induced by three different intensity conditions (intensity 1, 3, 5) of whole body vibration (WBV) during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Eleven healthy young subjects (6 males, 5 females) were recruited from university students. The collected EMG data were normalized using reference contraction (no vibration during bridging) and expressed as a percentage of reference voluntary contraction. To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus femoris muscles was not significantly different among three intensity conditions of WBV during bridging exercise (p>.05). However, there were significantly increased EMG activity of the medial hamstring muscle (p=.001) and medial gastrocnemius muscle (p=.027) in the intensity 3 condition compared with the intensity 1 condition. This result can be interpreted that vibration was absorbed through the distal muscles, plantar flexor and knee flexor.

• Journal of Haehwa Medicine
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• v.23 no.1
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• pp.21-55
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• 2014

Objectives : This report describes the original references of 154 formulas related to the use of Rhei Rhizoma main blended from Dongeuibogam. Methods : This study analyzes the original references of 154 formulas including Rhei Rhizoma as a key component in Dongeuibogam. Results : There were five types as follows: 1.There is no exact match between 154 formulas in Dongeuibogam and the original formulas in references. 2. Case that could not found the original formula in reference: 22%. 3. Case that the citation is the similar to the original reference: 4%. 4. Case that the citation is not same to expression but contents basically: 73%. 5. Case of addition of content: 1% Conclusions : Most formulas related to the use of Rhei Rhizoma main blended from Dongeuibogam are similar to the contents in the original references. But we can find that Heo Jun, who writes Dongeuibogam, modifies the contents for his intention of editing, idea and situation in Korea.

• Journal of Power Electronics
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• v.15 no.3
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• pp.712-720
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• 2015

A model predictive current control (MPCC) method that does not employ a cost function is proposed. The MPCC method can decrease common-mode voltages in loads fed by three-phase voltage-source inverters. Only non-zero-voltage vectors are considered as finite control elements to regulate load currents and decrease common-mode voltages. Furthermore, the three-phase future reference voltage vector is calculated on the basis of an inverse dynamics model, and the location of the one-step future voltage vector is determined at every sampling period. Given this location, a non-zero optimal future voltage vector is directly determined without repeatedly calculating the cost values obtained by each voltage vector through a cost function. Without utilizing the zero-voltage vectors, the proposed MPCC method can restrict the common-mode voltage within ± V_dc/6, whereas the common-mode voltages of the conventional MPCC method vary within ± V_dc/2. The performance of the proposed method with the reduced common-mode voltage and no cost function is evaluated in terms of the total harmonic distortions and current errors of the load currents. Simulation and experimental results are presented to verify the effectiveness of the proposed method operated without a cost function, which can reduce the common-mode voltage.