• Journal of Environmental Science International
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• v.11 no.9
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• pp.945-954
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• 2002

The objective okgf this study is understanding and evaluation of temporal and spatial variation of pollutant loads by input sources for water quality management in Kamak Bay. Flow rate of rivers and ditches ranges from about $2,592-63,072m^3/d$ in October to $864-55,296m^3/d$ in January. In particular, the R2 predominated flow rate among input sources. Total COD, BOD, DIN and DIP loadings in January were about 896kg/d, 718kg/d, 2,152kg/d, and 154kg/d, respectively, which exceeded those of October. Lower POC/TOC levels are estimated in R2, and also in October. Temporal variation of pollutant loads were closely related to the human activity. Total discharging loadings of BOD, TN and TP by unit loading estimation were 4,993.0kg/d, 2,558.7kg/d, and 289.2kg/d, respectively, and were mainly affected by the population. Runoff ratio of BOD was about 0.14 in January Mean $NH_4^＋_-N$ and $PO_4\;^{3-}-P$ loadings from sediment were 16.23mg/$m^2$/d and 7.26mg/$m^2$/d, respectively. For the improvement of water quality in this area, not only pollutant loads of rivers and ditches but also benthic flux from sediment should be reduced within the limits of the environmental capacity.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1035-1037
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• 1992

Generally, fuel cell has characteristics of low voltage, large current and voltage variation under load change. Therefore, DC output voltage of fuel cell is too low to convert into AC with high efficiency and good performance. For this reason, fuel cell generating system is composed of DC-DC converter and inverter in cascade. This paper used 2-phase boost DC-DC converter to obtain low distortion waveform and reduce input-output current ripple, and discussed inverter which can be operated in independent drive mode and utility line interface drive mode. Then, the change of modes can be achived smoothly.

• International Journal of Contents
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• v.8 no.3
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• pp.42-51
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• 2012

Korea has entered into the Post Catching-up era and the necessity of new innovation strategy in response is being raised. This study argues the necessity of new innovation strategy and discusses the issue of co-ordination between R&D and Human Resource for that as the key factor. From empirical analysis, there seems to be restricted inflow of outstanding human resources to manufacturing sectors and lowering effectiveness of major even with the improved compatibility between major and job. Especially, it is severe in the industries with high R&D investment. It can be interpreted as an incoordination of the technological innovation efforts from the aspect of R&D investment with human resource utilization from the aspect of new human resource. The analytical result and interpretation suggests that there should be more active improvement on the co-ordination between innovative manufacturers' efforts and human resource utilization, in order to keep sustainable development.

• Genomics & Informatics
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• v.20 no.4
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• pp.49.1-49.7
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• 2022

Many packages for a meta-analysis of genome-wide association studies (GWAS) have been developed to discover genetic variants. Although variations across studies must be considered, there are not many currently-accessible packages that estimate between-study heterogeneity. Thus, we propose a python based application called Beta-Meta which can easily process a meta-analysis by automatically selecting between a fixed effects and a random effects model based on heterogeneity. Beta-Meta implements flexible input data manipulation to allow multiple meta-analyses of different genotype-phenotype associations in a single process. It provides a step-by-step meta-analysis of GWAS for each association in the following order: heterogeneity test, two different calculations of an effect size and a p-value based on heterogeneity, and the Benjamini-Hochberg p-value adjustment. These methods enable users to validate the results of individual studies with greater statistical power and better estimation precision. We elaborate on these and illustrate them with examples from several studies of infertility-related disorders.

• Environmental and Resource Economics Review
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• v.22 no.1
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• pp.53-76
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• 2013

This paper analyzed on the relationship between R&D productivity of renewable energy and the Emissions Trading Scheme using OECD's country-specific patents and R & D input data. We empirically tested whether this R & D productivity has been substantially improved before and after the implementation of the emissions trading scheme and whether emission trading scheme has been promoted technology progress of renewable energy. Analytical methods used in this study, Negative Binomial Models which was proposed by Hausman et al. (1984). According to the results of this analysis, the R & D productivity of renewable energy was improved by emissions trading scheme, which was statistically significant at the 99% confidence interval [CI]. The R&D productivity of renewable energy was higher in Annex I countries. This research is significant in that R&D productivity was analyzed in associated with the emission trading scheme rather than it was analyzed by simply comparing R&D productivity.

• Journal of Communications and Networks
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• v.15 no.4
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• pp.362-369
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• 2013

The optimal number of users achieving the maximum sum throughput is analyzed in zero-forcing (ZF) based multiuser multiple-input multiple-output (MIMO) systems with a large number of base station (BS) antennas. By utilizing deterministic ergodic sum rates for the ZF-beam forming (ZF-BF) and ZF-receiver (ZF-R) with a large number of BS antennas [1], [2], we can obtain the ergodic sum throughputs for the ZF-BF and ZF-R for the uplink and downlink frame structures, respectively. Then, we can also formulate and solve the optimization problems maximizing the ergodic sum throughputs with respect to the number of users. This paper shows that the approximate downlink sum throughput for the ZF-BF is a concave function and the approximate uplink sum throughput for the ZF-R is also a concave function in a feasible range with respect to the number of users. The simulation results verify the analyses and show that the derived numbers of users provide the maximum sum throughputs for the ZF-BF as well as ZF-R in multiuser MIMO systems with a large number of BS antennas.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.651-658
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• 2017

There were many studies on the development of radiation measuring instruments to detect the presence of radiation. In particular, the signal processing method and treatment without loss of the detection signal are very important. The common feature for these studies is the peak-hold method that keeps the peak value of input signal uniform for a short time, readouts its value, discharges electrical value, and then waits for next signal. We propose the new methodology to capture the pulse peak value from the radiation detector and read the value directly other than peak-hold method. This method has merit of accurate reading the input signal pulse peak value without complicate process of holding for a period or initializing of input signal, and then be verified to be adequate through simulation of actual example.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.763-769
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• 2023

Flight control computers for unmanned aerial vehicles are avionics that require high reliability and are generally designed to be multiplexed for margins on failures. The multiplexed flight control computer should include an interface through discrete signals and CCDL for synchronization and fault separation between channels. With the development of unmanned aerial vehicle technology, various types of platforms such as AAM and LPI are being developed in the private and military, which require advanced control performance for high-performance flight control and SWaP optimization of onboard equipment. In this paper, we designed a optimized flight control computer architecture for unmanned aerial vehicles for multiplexing processing and performed a software design for input and output control. In addition, input/output processing performance was evaluated through the implemented flight control computer and input/output software.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.764-768
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• 2002

In this paper, a double balanced gilbert cell MMIC mixer was realized in Tachyonics SiGe HBT technology. The fabricated mixer has 17 dB conversion gain, 9.8 dB noise figure, -4.2 dBm output 1 dB compression point, -27 dBc RF to IF isolation, and the good input, output matching characteristics. It draws 10 mA from a 3 V supply. The simulation and the measured results are closer to each other, which confirms accuracy of the model library and reliability of the process.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.6
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• pp.965-977
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• 2021

The study aimed to analyze the functional differences in 3D virtual garment programs and compare body scan data with the corresponding 3D virtual models. We selected 3D virtual garment programs, formed virtual models in a representative size for high-school male cyclists, and analyzed them using the Design-X program. The results were as follows. In the 3D virtual garment programs, the anthropometric items for virtual model forming differed significantly from the standard anthropometric items suggested by Size Korea. Comparing the lower body scan data and virtual models formed by the 3D virtual garment programs, the biggest difference was in the shapes of the waist and hips, i.e., the flatness values of the waist and hips were different for each program in the cross-section view. In the lower body, a data-input-based program was needed for changing the exact measurement position of the waist circumference and hips' shape in detail. If a 3D virtual garment program provides functions for the virtual model's joint angle input and free motion transformation, it is expected to be widely used in the sportswear industry.