• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.249-254
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• 2001

A receiver ASIC for fiber optic modules of STM-1 optical communication has been fabricated with 0.65 $\mu\textrm{m}$ CMOS technology. The ASIC has a limit amplifier circuit for the 155.52 Mbps data reshaping, and a clock extraction circuit for the 155.52 MHz clock recovery. The ASIC has an acquisition aid and LOS monitoring circuit for properly operation with near 155.52 MHz clock frequency in case of the data loss due to transmission line open or data transfer fail. Measured results show that the circuit reshapes data from 5 mV to 1 V wide range of input voltage condition, add it recovers system clock with stable on any condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1812-1816
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• 2011

This research developed chemical flow control system(CFCS) essential for spinner equipment in nano semiconductor manufacturing process under the 100nm to prevent complex process defect due to missing spread after chemical injection. The devices developed in this research, which can be swiftly replaced in case abnormal state element changes or wafer manufacturing defect occurs, are anticipated to improve module yield as well as real-time monitoring on the state element. In addition, as a result of mounting H/W and S/W system to control detailed operation sequence in production line and executing performance check and verification, we can be exactly detected in five abnomal process type.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.823-828
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• 2006

For this study, an online particle counter was installed before and after the activated carbon filtration process of D water treatment plant where has advanced water treatment processes, produces average 900,000ton/day of drinking water and supply the produced drinking water to Busan citizens. We collected and analyzed particle count data for about 1 year. We inspected particle breakthrough in three out of sixteen filter processes operated at same conditions, i.e. 5th filter, 6th filter and 7th filter. According to the monitoring results, 6th and 7th filters showed similar results while 5th filter showed different results. When compared seasonal effect, the particle count for dry season was below 10 particles/ml while the particle count for August when monthly average rainfall is over 200mm was much higher than for dry season. In January and August, there was a difference in breakthrough particle size. In January, small particles in 2~3um were mainly detected while in August 10um particles were mainly detected and the size distribution was 40% of total count.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.28-35
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• 2022

This study is aimed to develop a safety diagnosis system for fire pumps that detects normal and abnormal signals for the stable operation of the system. Hence, the following activities were carried out: first, a threshold value was identified for the normal operation and six abnormal operations (adherence of impeller, absence of water source, separation of pump and motor, run-stop operation, air inflow into the casing, and reverse-phase loss of the power line) reflecting changes in the current, flow and pressure of fire pumps; secondly, based on the identified signals, an algorithm capable of detecting three abnormal signals was developed and in terms of hardware, a current, pressure and flow sensor suitable for the analogue input values of NI-6009 was designed and installed. This combination of the hardware and software is applicable as a diagnosis system to ensure the stable operation of fire pumps.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.379-386
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• 2005

[ $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ ] in driver cabins of subway line from 5 to 8 were monitored from 07:00 through 21:00 (or 19:30 or 20:00) on May. Driver cabin of subway line 7 showed the highest $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ concentrations. General Linear Model indicated that subway line, subway location (ground and underground track) and running time (morning and afternoon) significantly influenced the concentrations of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ (p=0.000). Daily profile of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$, expressed as an 30 minutes average, showed similar variation pattern over day period. These concentrations showed the highest concentrations between 07:00 and 09:00 of rush hour, slightly dropped and again rose slightly after 18:00. In correlation analysis, significant relations among $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ were detected (p<0.01). In particular, correlation coefficient between $PM_{10}\;and\;PM_{2.5}$ was highly significant (r=0.884). Regression analysis also concluded that $PM_{10}$ concentration significantly explained 71.4% of variation of $PM_{2.5}$ concentration (p=0.000, $R^2=0.714$). Correlations by CO with $PM_{10}\;and\;PM_{2.5}$ were 0.451 and 0.520, which were higher than those by $CO_2$. Further study is needed to examine the sources of $PM_{2.5}$ and CO in subway and to compare pollutants concentration among subway lines.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.71-77
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• 2001

This experiment was designed to improve the production efficiency of germ-line chimeric mice from phospholipase C (PLC)-$\beta$3 or peroxiredoxin (Prx) E -targeted ($\Delta$) ES cells by the investigating the manipulation conditions and characteristics of Jl ES cells. Four targeting clones were isolated to investigate the karyotypical and morphological stability prior to injection. All clones ($\Delta$PLC$\beta$-3 C3, $\Delta$Prx II C3, C10 and I5) showed more than 80% euploidism, however, most of $\Delta$PLC$\beta$-3 C3 clones were extensively differentiated compared to the other clones. Nine of 13 $\Delta$Prx II chimeras appeared to have at least 80% chimerism, whereas $\Delta$PLC$\beta$-3 C3 chimeras had 20% chimerism at most. Therefore, the morphological stability of ES cells under stable euploidism might mainly affect the production rate of high-coat chimeric mice. To increase the collection rate of injectable blastocysts (IBs), 5 to 10 week -aged C57BL/6J female mice were sacrificed at 3.5 days post-coitum. Ten week-aged mice were the most optimal IB donors by showing the highest collection rate (2.94/mouse) of injectable blastocysts without increase of non-injectable embryos (0.29/mouse). Foster mothers might be another factor because ICR x C57BL/6J F1 foster mother showed more increased productivity in litter size (2.8 vs. 5.6) and chimera (0 vs. 35.3%) than those of ICR foster mothers. In conclusion, the efficient production of germ-line chimeras mainly depends on the maintenance of ES cell morphology during targeting procedure, and the establishment of manipulation conditions might be a key point to maximize it.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.711-722
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• 2011

This study is aimed to estimate the $PM_{2.5}$ source apportionment at Seoul intensive monitoring site located in Seoul metropolitan area. Time-resolved chemical compositions of $PM_{2.5}$ are measured in real time using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF at Seoul intensive monitoring site in 2010. The mass concentration of $PM_{2.5}$ was simultaneously monitored with eight ionic species (${SO_4}^{2-}$, $NO_3{^-}$, $Cl^-$, $NH_4{^+}$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$), two carbonaceous species (OC and EC), and fourteen elements (Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Pb) in 1-hr interval. The data sets were then analyzed using EPA PMF version 3 to identify sources and contributions to $PM_{2.5}$ mass. EPA PMF modeling identified eight PM2.5 sources, including soil dust, secondary sulfate, secondary nitrate, motor vehicle, coal combustion, oil combustion, biomass burning, and municipal incineration. This study found that the average $PM_{2.5}$ mass was apportioned to anthropogenic sources such as motor vehicle, fuel combustion, and biomass burning (61%) and secondary aerosols, including sulfate and nitrate (38%).

• KSBB Journal
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• v.24 no.2
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• pp.207-211
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• 2009

In this study, the sensing membranes for detection of pH and dissolved oxygen(DO) were prepared by immobilizing 6-aminofluorescein or ruthenium complex onto the sol-gel matrixes of GPTMS, MTMS, and TEOS and then recoated with the mixture of hydrophobic sol-gel and graphite for light insulation. The pH and DO sensing membranes recoated with the light insulation layer showed a higher sensitivity than those without light insulation layer. The sensing membranes were immobilized on the wells of 24-well microplate and used to monitor the fluorescence intensity for pH and DO in E.coli JM109 and P.pastoris X-33 fermentation processes. The change of the fluorescence intensity in the DO sensing membrane agreed with the growth patterns of microorganisms, that the membranes are valuable to monitor the DO in fermentation processes. In the case of pH monitoring, the fluorescence intensity has showed good correlation to the off-line pH data, that the pH membranes are valuable to monitor pH values in fermentations.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.263-271
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• 2009

This study evaluated the flocs forming characteristics in the mixing zone to increase the coagulation effect in the drinking water plant. As a measuring tool of formed flocs, on-line particle dispersion analyzer (iPDA) was used in Y drinking water plant. To evaluate the forming flocs, many parameters such as poly amine, coagulant dosing amount, raw water turbidity, and pH was applied in this study. During the periods of field test, poly aluminium chloride (PACl) as a coagulant was used. With the increase of the raw water turbidities, poly amine was also added as one of aids for increasing in coagulation efficiency. The turbidity and pH of raw water was ranged from 7 to 9 and from 25 to 140 NTU, respectively. The increasing of raw water turbidity brought the bigger floc sizes accordingly. From a regression analysis, $R^2$ value was 0.8040 as a function of T, raw water turbidity. Floc size index (FSI) was obtained from a correlation equation as follows; FSI = 0.9388logT - 0.3214 Also, polyamine gave the bigger flocs the moment it is added to the coagulated water in the rapid mixing zone. One of parameters influencing the floc sizes was the addition of powdered active carbon(PAC) in the mixing zone. In case of higher turbidity of raw water, $R^2$ value was 0.9050 in the parameters of [PACl] and [PAC]; FSI = $0.0407[T]^{0.324}[PACI]^{0.769}[PAC]^{0.178}$ On-line floc monitor was beneficial to evaluate the flocs sizes depending on the many parameters consisting raw water properties, bring the profitable basic data to control the mixing zone more effectively.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.117-121
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• 2007

The number of internet users and the scale of electronic on-line trading are on the increase due to the development of information technology and the internet. The aim of this study was to monitor the accuracy of country-of-origin labels and the indicated contents of meat available by electronic on-line trading by using a structural interview sheet for 100 on-line meat product markets. The result of this investigation showed a 100% level of accuracy for business name and telephone number whereas the company address, meat manufacturer and supplier, and business registration were less reliable. We also investigated the accuracy of site policy, e-mail address, and fax number. The results showed that the accuracy of fax numbers was the lowest. The product name and the kind of meat actually in the product showed a 100% level of conformity, while the price (96.3%), place of origin (93.6%), capacity (90.4%), meat parts (80.9%) and contents of the product (73.4%) showed a relatively low level of conformity. Serious safety issues were exposed by the disturbingly low 20.2% accuracy of indicated expiration dates and 5.3% accuracy of indicated manufacturing dates. To ensure food safety, it is essential to improve consumer understanding and trust regarding food safety through continuous public relations. More education and information are needed to raise consumer awareness of the facts versus myths regarding food safety.