• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.419-428
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• 2005

The aim of this study was to provide data for the relief of asthenopia during binocular vision by determining the characteristics of ocular function in adults. A total of 260 subjects were between the age of 19-35years. We measured individually the refractive error correction, pupillary distance, optical center distance, phoria, convergence, accommodation and the AC/A as well as the asthenopia during binocular vision using a questionnaire. After analysis of factors affecting asthenopia, we also examined the reductive effect of asthenopia in subjects who had asthenopia using prism. To determine the factors affecting asthenopia during binocular vision, statistic analyses were carried out the multivariate Logistic regression model. The results of this study were as follow. The asthenopia during binocular vision was found 26.9% of subjects. Multivariate logistic regression model was used to determine factors affecting binocular vision of myopia. When the accommodation and convergence were low compared to being high, when subjects had esophoria or there was more exophoria, and when AC/A was lower than the standard, the rate of asthenopia was higher. Therefore the accommodation, convergence and AC/A could be predictive factors for asthenopia. We used prism for subjects who had asthenopia during binocular vision, the results showed that the symptom of asthenopia was eased up to 74.3%.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.327-334
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• 2018

Objective: The objective of the present study was to validate genes and genomic regions associated with carcass weight using a low-density single nucleotide polymorphism (SNP) Chip in Hanwoo cattle breed. Methods: Commercial Hanwoo steers (n = 220) were genotyped with 20K GeneSeek genomic profiler BeadChip. After applying the quality control of criteria of a call rate ${\geq}90%$ and minor allele frequency (MAF) ${\geq}0.01$, a total of 15,235 autosomal SNPs were left for genome-wide association (GWA) analysis. The GWA tests were performed using single-locus mixed linear model. Age at slaughter was fitted as fixed effect and sire included as a covariate. The level of genome-wide significance was set at $3.28{\times}10^{-6}$ (0.05/15,235), corresponding to Bonferroni correction for 15,235 multiple independent tests. Results: By employing EMMAX approach which is based on a mixed linear model and accounts for population stratification and relatedness, we identified 17 and 16 loci significantly (p<0.001) associated with carcass weight for the additive and dominant models, respectively. The second most significant (p = 0.000049) SNP (ARS-BFGL-NGS-28234) on bovine chromosome 4 (BTA4) at 21 Mb had an allele substitution effect of 43.45 kg. Some of the identified regions on BTA2, 6, 14, 22, and 24 were previously reported to be associated with quantitative trait loci for carcass weight in several beef cattle breeds. Conclusion: This is the first genome-wide association study using SNP chips on commercial Hanwoo steers, and some of the loci newly identified in this study may help to better DNA markers that determine increased beef production in commercial Hanwoo cattle. Further studies using a larger sample size will allow confirmation of the candidates identified in this study.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.51-62
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• 2003

This paper presents a novel survivor memeory management and decoding techniques with sequential backward state transition control in the trace back Viterbi decoder. The Viterbi algorithm is an maximum likelihood decoding scheme to estimate the likelihood of encoder state for channel error detection and correction. This scheme is applied to a broad range of digital communication such as intersymbol interference removing and channel equalization. In order to achieve the area-efficiency VLSI chip design with high throughput in the Viterbi decoder in which recursive operation is implied, more research is required to obtain a simple systematic parallel ACS architecture and surviver memory management. As a method of solution to the problem, this paper addresses a progressive decoding algorithm with sequential backward state transition control in the trace back Viterbi decoder. Compared to the conventional trace back decoding techniques, the required total memory can be greatly reduced in the proposed method. Furthermore, the proposed method can be implemented with a simple pipelined structure with systolic array type architecture. The implementation of the peripheral logic circuit for the control of memory access is not required, and memory access bandwidth can be reduced Therefore, the proposed method has characteristics of high area-efficiency and low power consumption with high throughput. Finally, the examples of decoding results for the received data with channel noise and application result are provided to evaluate the efficiency of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.66-74
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• 2010

Recently distributed video coding (DVC) is spotlighted for the environment which has restriction in computing resource at encoder. Wyner-Ziv (WZ) coding is a representative scheme of DVC. The WZ encoder independently encodes key frame and WZ frame respectively by conventional intra coding and channel code. WZ decoder generates side information from reconstructed two key frames (t-1, t+1) based on temporal correlation. The side information is regarded as a noisy version of original WZ frame. Virtual channel noise can be removed by channel decoding process. So the performance of WZ coding greatly depends on the performance of channel code. Among existing channel codes, Turbo code and LDPC code have the most powerful error correction capability. These channel codes use stochastically iterative decoding process. However the iterative decoding process is quite time-consuming, so complexity of WZ decoder is considerably increased. Analysis of the complexity of LPDCA with real video data shows that the portion of complexity of LDPCA decoding is higher than 60% in total WZ decoding complexity. Using the HDA (Hard Decision Aided) method proposed in channel code area, channel decoding complexity can be much reduced. But considerable RD performance loss is possible according to different thresholds and its proper value is different for each sequence. In this paper, we propose an adaptive HDA method which sets up a proper threshold according to sequence. The proposed method shows about 62% and 32% of time saving, respectively in LDPCA and WZ decoding process, while RD performance is not that decreased.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.462-469
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• 2015

This study carried out a topographic survey at a small-scale open-pit limestone mine in Korea (the Daesung MDI Seoggyo office) using a popular rotary-wing unmanned aerial vehicle (UAV, Drone, DJI Phantom2 Vision+). 89 sheets of aerial photos could be obtained as a result of performing an automatic flight for 30 minutes under conditions of 100m altitude and 3m/s speed. A total of 34 million cloud points with X, Y, Z-coordinates was extracted from the aerial photos after data processing for correction and matching, then an orthomosaic image and digital surface model with 5m grid spacing could be generated. A comparison of the X, Y, Z-coordinates of 5 ground control points measured by differential global positioning system and those determined by UAV photogrammetry revealed that the root mean squared errors of X, Y, Z-coordinates were around 10cm. Therefore, it is expected that the popular rotary-wing UAV photogrammetry can be effectively utilized in small-scale open-pit mines as a technology that is able to replace or supplement existing topographic surveying equipments.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.796-803
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• 1997

The PVT and $^2H$-NMR characteristic of main-chain dimer liquid crystals having structures such as ${\alpha}$, ${\omega}$-bis[4,4'-cyanobiphenyl) oxy] alkane(CBA-10) were studied. In this work, V-T curves obtained from isobaris measurements on various pressures, volume changes were observed at the nematic-isotropic and nematic-crystal phase transition. The volume changes at the transition exhibit slight odd-even effect with respect to the number of methylene unit n. The values of the$({\Delta}S_{tr})_V$ obtained at the NI transition for CBA-10 was $12.6J/mol{\cdot}K$. The values of $({\Delta}S_{CN})_V$ for the CN transition was estimated on the basis of DSC data : $65.3J/mol{\cdot}K$. For both transition, it was found that the correction about the volume change is significant, ranging from 40 to 60% of the total transition entropy observed under constant pressure. The RIS analysis of the spectra was performed so as to elucidate the conformational characteristics of the spacer in the nematic phase. The conformational entropy changes at both CN and NI interphases were estimated on the basis of the nematic conformations taken from the conformation map as well as those derived from the simulation. The estimated conformational entropy change values were then compared with the corresponding constant-volume entropies obtained from PVT measurements. The correspondence between both entropy values was found to be quite good in consideration of the uncertainties involved in both experiment and calculations.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.75-83
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• 1998

This study was done to recognize the importance of errors in measurements of cephalometric radiograph and to find the anatomical structures those need special care to select as a reference points through the detection of the systematic errors and estimation of random errors. For this purose, 100 cephalometric radiographs were prepared by usual manner and 61 reference points, and 130 measurement variables were established. Measurement errors were detected and estimated by the comparison of the 25 randomly-selected samples for repeated measurements with the main sample. The following results were obtained : 1. In comparison of the repeated measurements, there were statistical significant differences in 24 variables which were 18.4% of 130 total variables. 2. The frequency of the difference in identification of the reference points between the repeated measurements was very high in the root apex of upper incisor(as), the most posterior wall of maxilla(tu), soft tissue nasion(n'), soft tissue frontal eminence(ft), and ad3 in airway. 3. After correction of reference points marking until the level of below 5% significance, the range of random errors were from 0.67 to 1.71 degree or mm. 4. The variable shown the largest random error was the interincisal angle(ILs-ILi). 5. Measurement errors were mainly caused by the lack of precision in anatomic definitions and obscure radiographic image. From the above results, the author could find the high possibility of errors in cephalometric measurements and from this point, we should include error analysis in all the studies concerning measurments. In is essential to have a concept of error analysis not only for the investigator but also for a reader of other articles.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.75-79
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• 2015

Pulmonary arterial hypertension (PAH) is a common complication of Congenital heart defects (CHD) with left-to-right shunts, and PAH with increased pulmonary vascular resistance (PVR) is associated with considerable morbidity and mortality. General anesthesia (GA) can be life-threatening in patients with PAH, because the positive pressure ventilation during GA increases pulmonary arterial pressure and decreases pulmonary blood flow. This may also lead to hypoxia. Therefore, spontaneous ventilation may be safer than positive pressure ventilation in patients with PAH. A five-year-old male child, weighing 11 kg, with medical history showing a total correction of Tetralogy of Fallot (TOF) in 2009 and ongoing treatment with hypertension (HTN) medicine since 2007, visited the Dankook University Dental Hospital. He had multiple dental caries, and the treatment was completed under sevoflurane insufflation sedation via nasal cannula. The patient remained sedated throughout the operation while maintaining normal vital signs and spontaneous respiration. In conclusion, sevoflurane insufflation sedation may be a safer alternative to GA for the dental treatment of patients with PAH.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.539-547
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• 2019

Recently, the international community signed a climate change agreement to prevent global warming. Yet currently, the fossil fuels have been widely used in to supply building energy for cooling and heating. The Green Building certification (G-SEED), an energy efficiency rating for new or existing buildings requires that buildings meet certain conditions. Insulation is used as a building material to reduce the energy supply to buildings and to improve the thermal insulation, and it accounts for more than 90% of the total heat resistance provided by the building surface components that meet the energy-saving design standards of new buildings. In this investigation, a performance evaluation study was conducted through an experimental study by directly extracting the foam polystyrene insulation on-site during the remodeling of a building that was in the range of 22~38 years old. Through tests, it was found that the thermal conductivity of the extrusion method insulation (XPS) was reduced by 48% and the compressive strength of XPS decreased by 36% compared to KS M 3808, which is the initial quality standard. For bead method insulation (EPS) with a thickness of 50mm, the thermal conductivity, the compressive strength, and flexural failure load were similar to the initial quality standard. Therefore, in the calculation of the primary energy requirement per unit area per year, the performance of bead method insulation can be estimated simply by considering the thickness of the insulation, while a correction factor that considers its performance deterioration should be applied when extrusion method insulation is used.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.39-48
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• 2016

According to the order receipt report over the past 10 years the overseas construction business total trades were 54.05% and 68.09% done by the Middle East and other industrial facilities respectively. In the Middle East based on data collected in 2014 the country with most overseas construction business is Saudi Arabia with 34.10%, and the industrial facility occupies the larger share with 56%. Overseas construction business is suffering from a reduction in work orders in the Middle East because of the recent oil price reduction. At this point of view, it is necessary to consider economy fluctuation for the diversification of construction type and work orders. This study analyzed, focusing in Saudi Arabia how the economical fluctuations of nations of progress can affect overseas construction business' trade orders. The analysis results demonstrated that most construction types depends on GDP, investment fund. Also industrial facility can be substituted with Architecture and civil engineering. This work is expected to be used as a basis for trade order amount maintenance and construction type diversification.