• Journal of the Korea Computer Industry Society
• /
• v.6 no.3
• /
• pp.539-550
• /
• 2005

The spanning tree, which is being used the most widely in indoor wiring network, is chosen for the network topology of the optimal LAN design. To apply a spanning tree to GA, the concept of $Pr\ddot{u}fer$ numbers is used. $Pr\ddot{u}fer$ numbers can express he spanning tree in an efficient and brief way, and also can properly represent the characteristics of spanning trees. This paper uses Pareto Stratum-Niche Cubicle(PS-NC) GA by complementing the defect of the same priority allowance in non-dominated solutions of pareto genetic algorithm(PGA). By applying the PS-NC GA to the LAN design areas, the optimal LAN topology design in terms of minimizing both message delay time and connection-cost could be accomplished in a relatively short time. Numerical analysis has been done for a hypothetical data set. The results show that the proposed algorithm could provide better or good solutions for the multi-objective LAN design problem in a fairly short time.

• Korean Chemical Engineering Research
• /
• v.57 no.2
• /
• pp.210-218
• /
• 2019

Batch experiment studies were carried out on the adsorption of the major tar compound, 2-picoline, derived from the plant cell cultures of Taxus chinensis, using Sylopute while varying parameters such as initial 2-picoline concentration, contact time and adsorption temperature. The experimental data were fitted to the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Comparison of results revealed that the Langmuir isotherm model could account for the adsorption isotherm data with the highest accuracy among the four isotherm models considered. From the analysis of adsorption isotherms, it was found that adsorption capacity decreased with increasing temperature and the adsorption of 2-picoline onto Sylopute was favorable. The kinetic data were well described by the pseudo-second-order kinetic model, while intraparticle diffusion and boundary layer diffusion did not play a dominated role in 2-picoline adsorption according to the intraparticle diffusion model. Thermodynamic parameters revealed the exothermic, irreversible and non-spontaneous nature of adsorption. The isosteric heat of adsorption decreased as surface loading ($q_e$) increased, indicating a heterogeneous surface.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.212-215
• /
• 2022

In the era of so-called digital transformation today, the need for the construction and utilization of big data in various fields has increased. Today, a lot of data is produced and stored in a digital device and media-friendly manner, but the production and storage of data for a long time in the past has been dominated by print books. Therefore, the need for Optical Character Recognition (OCR) technology to utilize the vast amount of print books accumulated for a long time as big data was also required in line with the need for big data. In this study, a system for digitizing the structure and content of a document object inside a scanned book image is proposed. The proposal system largely consists of the following three steps. 1) Recognition of area information by document objects (table, equation, picture, text body) in scanned book image. 2) OCR processing for each area of the text body-table-formula module according to recognized document object areas. 3) The processed document informations gather up and returned to the JSON format. The model proposed in this study uses an open-source project that additional learning and improvement. Intelligent OCR proposed as a system in this study showed commercial OCR software-level performance in processing four types of document objects(table, equation, image, text body).

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.4
• /
• pp.147-156
• /
• 2023

Because the behavior of cable bridges is dominated by dynamic response and is relatively complex, short- and long-term field monitoring are often required to evaluate the bridge condition. If a permanent SHMS (Structural Health Monitoring System) is not installed, a portable monitoring system is needed for the checking of bridge condition. In this case, it can be difficult to operate the portable monitoring system due to limited conditions such as power and communication according to the location and type of the bridge. In this study, the portable-based smart structural response monitoring system is developed that can be effectively used for short- and long-term monitoring of cable bridges in Korea and Southeast Asia. The developed system is a multi-channel portable data acquisition and analyzer that can be operated for a long time in the field using its own power supply system, and is included with the automated analysis algorithm for the dynamic characteristics of cable bridges using real-time data. In order to evaluate the field applicability of the developed system, field demonstration was conducted on cable bridges in Korea and Vietnam. Through the demonstration, the reliability and efficiency of field operation of the developed system were confirmed, and additionally, the possibility of application to overseas markets was confirmed in cable bridge monitoring field.

• Korean Journal of Optics and Photonics
• /
• v.6 no.4
• /
• pp.259-265
• /
• 1995

Antireflection coatings on optical lenses commertially available in domestic market are optically analyzed. Transmission spectra and reflection spectra are collected using spectrophotometers. The apparent absorption spectra around the absorption band edge are dominated by the substrate absorption. The reflection spectra and the apparent absorption spectra at visible region between 400nm and 700nm show very strong correlation to each other except a couple samples. The discrepency observed in the latters are due to an increased absorption in visible region by the substrate, which is negative effect of these samples. An antireflection coating consisted of $SiO_2/TiO_2/SiO_2/ZrO_2/Cr$ is made on c-Si substrate for spectroscopic ellispometry analysis. A film-by-film coating is accomplished and between each film deposition, ex-situ spectroscopic ellipsometry measurements are made. The analysis of the spectroscopic ellipsometry data reveals that the average film densities of $ZrO_2$ and $TiO_2$ reach only 80% of their respective packing densities and thick films are inhomogeneous along film growth direction. Discussions are made toward in-situ, real-time monitoring of the film growth so that a real-time feedback is possible to achieve a post-correction to minor deviations occured in the previous step. step.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.31 no.3
• /
• pp.255-265
• /
• 2021

Objectives: The purpose of this study is to analyze the exposure characteristics of inorganic acids. Methods: We analyzed exposure data (n = 363,146) for six inorganic acids (hydrogen fluoride, hydrogen bromide, hydrogen chloride, phosphoric acid, nitric acid, and sulfuric acid) collected between 2017 and 2019 in South Korea. Measurement characteristics and exposure levels (ELs) were analyzed by inorganic acid, industry category, enterprise size, and measurement year. Results: Measurement percentage dominated in time-weighted average (TWA, 91%) compared to short term exposure limit (STEL) and Ceiling. Most of the measurements (79.7%) were collected from the manufacturing category of industry. Medians of ELs were mostly low (≤3% of the threshold limit), with the exception of sulfuric acid (4.6% of TWA and 10.5% of STEL). The percentages of exceeding 1% of the occupational exposure limits (OELs) in TWA were relatively high for sulfuric acid (35.8%) and hydrogen chloride (16.5%) compared to the other acids (4.2%-6.6%). In addition, the percentages of exceeding 1% of OELs in STEL or Ceiling were higher for sulfuric acid (22.9%), hydrogen chloride (12.3%), and nitric acid (8.2%) compared to the other acids (1.2%-1.9%). The small-sized enterprises showed higher ELs in TWA; contrarily, the large-sized enterprises had higher ELs in STEL or Ceiling. Conclusions: The measurement characteristics and ELs identified in this study could be useful for establishing safety and health policies for inorganic acids.

• The Bulletin of The Korean Astronomical Society
• /
• v.46 no.1
• /
• pp.52.1-52.1
• /
• 2021

We present the results of multi-epoch, multi-frequency monitoring of a blazar 4C +29.45, which was regularly monitored as part of the Interferometric Monitoring of GAmma-ray Bright AGNs program - a key science program of the Korean Very long baseline interferometry Network (KVN). Observations were conducted simultaneously at 22, 43, 86 and 129 GHz during the 4 years from December 2012 to December 2016. We also used additional data from the 15 GHz Owens Valley Radio Observatory (OVRO) monitoring program. From the 15 GHz light curve, we estimated the variability time scales of the source during several radio flux enhancements. We found that the source experiencesd 6 radio flux enhancements with variability time scales of 9-187 days during the observing period, yielding corresponding variability Doppler factors of 9-27. From the multi-frequency simultaneous KVN observations, we were able to obtain accurate radio spectra of the source and hence to more precisely measure the turnover frequencies 𝜈_r of synchrotron self-absorbed (SSA) emission with a mean value of ${\bar{\nu}_r}=28.9GHz$. Using jet geometry assumptions, we estimated the size of the emitting region at the turnover frequency. Taking into account these results, we found that the equipartition magnetic field strength is up to two orders of magnitudes higher than the SSA magnetic field strength (0.6-99 mG). This is consistent with the source being particle dominated.

• Fashion & Textile Research Journal
• /
• v.15 no.4
• /
• pp.523-532
• /
• 2013

This study investigates risk reduction behavior with risk perception in outdoor wear purchase situations. Data were collected via a questionnaire from 400 consumers between the ages of 20 to 50 residing in Seoul and Kyonggi-do. Data analysis were conducted with SPSS 20 program on the reliability test, factor analysis, cluster analysis, t-test, ANOVA, and Duncan's multiple range test. Factor analyses were employed for the participation motivation of mountain climbing activities, risk reduction behavior and risk perception. Five factors were for the participation motivation of mountain climbing activities (health and fitness, external ostentation, achievement and excitement, improvement of climbing skills, and society). Five factors were for risk perception (fashionability loss and social risk, time and convenience loss, economic risk, performance risk, and psychological risk). Five factors were for the risk reduction behavior (interpersonal information sources use, marketer-dominated information sources use, professional information sources use, pre-purchase deliberation/observation/experience, and brand dependence). Three clusters were identified based on the motivation of outdoor activities (the affiliation/display, the health/internal informativeness and low motivation). The participation motivation for mountain climbing activities were varied. Manufacturers should increase efforts to develop products with good qualities at a reasonable cost as well as establish new marketing strategies since the risk of product performance and economic efficiency in the purchase of outdoor wear was a significant consumer perception.

• The Journal of Industrial Distribution & Business
• /
• v.11 no.4
• /
• pp.31-38
• /
• 2020

Purpose: At a time when the distribution industry is dominated by capital and technology, win-win growth among businesses groups (BGs) in wholesale market is becoming a social issue. Therefore, through analysis of market growth, market concentration (MC) and market power (MP), we want to identify the structure of the wholesale market and the competitiveness of the BGs in terms of market share (MS), sales-profit ratio (SPR), and labor productivity (LP) to explore the possibility of win-win growth. Market situation: Wholesale and Retail sales ratio (W/S) continues to increase, which also means inefficiency in distribution channels or opportunities in wholesale markets. Wholesale sales have grown 8.3 percent annually over the past 15 years, while the number of companies and workers has declined since 2017, which is why some restructuring is believed to begin in the wholesale industry. In terms of MC and MP, the growth potential of SBG can be found in FCB, ARM, FBT and CME BTs. Methodology and data: Through ANOVA and Regression Analysis, the 2015 Economic Census Data of KOSTAT was analyzed. Results: The results of ANOVA show that statistically significant SBG has a larger MS than LBG. The SPR was not different among BGs. LP is higher for LBG than for other BGs. Regression results show that the employment weight (EW) and the company size (SC) have positive effects on the MS, but the company weight (CW) and employment size (SE) have negative effects. In the case of SPR, the CW is positive and the EW is negative. In addition, LP appears to be more positive as SC in the BGs is larger. Conclusions: Although there is sufficient potential for SBG in the wholesale market, there is a problem that needs to increase LP. Therefore, the SBG needs to restructure in terms of number of companies and SC to improve the efficiency of employment. In terms of MC and MP, the SBG looks for possibilities in FCB, ARM, FBT and CME BTs. In addition, SBG that seeks higher returns with human services rather than simple sales is found to be competitive in the HHG, MES and CME BTs.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.7
• /
• pp.637-648
• /
• 2007

This paper presents a sensor fusion method based on indirect Kalman filter(IKF) for error compensation of low-cost inertial sensors and its application to the determination of attitude and position of small flying robots. First, the analysis of the measurement error characteristics to zero input is performed, focusing on the bias due to the temperature variation, to derive a simple nonlinear bias model of low-cost inertial sensors. Moreover, from the experimental results that the coefficients of this bias model possess non-deterministic (stochastic) uncertainties, the bias of low-cost inertial sensors is characterized as consisting of both deterministic and stochastic bias terms. Then, IKF is derived to improve long term stability dominated by the stochastic bias error, fusing low-cost inertial sensor measurements compensated by the deterministic bias model with non-inertial sensor measurement. In addition, in case of using intermittent non-inertial sensor measurements due to the unreliable data link, the upper and lower bounds of the state estimation error covariance matrix of discrete-time IKF are analyzed by solving stochastic algebraic Riccati equation and it is shown that they are dependant on the throughput of the data link and sampling period. To evaluate the performance of proposed method, experimental results of IKF for the attitude determination of a small flying robot are presented in comparison with that of extended Kaman filter which compensates only deterministic bias error model.