• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.245-251
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• 2006

The main idea of this study is to turn attention on the question of good cooling ability of customer substations in large district heating networks. The main reason for that is based on our experience that the optimization of district heating very often is directed toward production, whereas questions of optimal distribution are neglected if only the necessary load can be supplied and the customer's request for comfort is met. Our view is that low return temperature(operational temperature differences, ${\Delta}T$) in district heating systems is an Important feature for efficient net operation and gives both economic and operational benefits to the district heating supplier Furthermore, it is as well a prerequisite for meeting the customers demand for reliable supply of the heat load. However, in many practical cases we have seen that district heating return temperatures are higher than necessary. Hence, the aim of the study is to propose and verify a method for detection of the most critical consumers of the net and to identify the reasons for resulting high return temperature. From the results, temperature control system is presented as one of the most important reason of high return temperature in DH networks.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.367-372
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• 2019

Deactivation of aminoglycosides by their modifying enzymes, including a number of aminoglycoside O-phosphotransferases, is the most ubiquitous resistance mechanism in aminoglycoside-resistant pathogens. Nonetheless, in a couple of biosynthetic pathways for gentamicins, fortimicins, and istamycins, phosphorylation of aminoglycosides seems to be a unique and initial step for the creation of a natural defensive structural feature such as a 3',4'-dideoxy scaffold. Our aim was to elucidate the biochemical details on the beginning of these C3',4'-dideoxygenation biosynthetic steps for aminoglycosides. The biosynthesis of istamycins must surely involve these 3',4'-didehydroxylation steps, but much less has been reported in terms of characterization of istamycin biosynthetic genes, especially about the phosphotransferase-encoding gene. In the disruption and complementation experiments pointing to a putative gene, istP, in the genome of wild-type Streptomyces tenjimariensis, the function of the istP gene was proved here to be a phosphotransferase. Next, an in-frame deletion of a known phosphotransferase-encoding gene forP from the genome of wild-type Micromonospora olivasterospora resulted in the appearance of a hitherto unidentified fortimicin shunt product, namely 3-O-methyl-FOR-KK1, whereas complementation of forP restored the natural fortimicin metabolite profiles. The bilateral complementation of an istP gene (or forP) in the ${\Delta}forP$ mutant (or ${\Delta}istP$ mutant strain) successfully restored the biosynthesis of 3',4'-dideoxy fortimicins and istamycins, thus clearly indicating that they are interchangeable launchers of the biosynthesis of 3',4'-dideoxy types of 1,4-diaminocyclitol antibiotics.

• Ocean and Polar Research
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• v.37 no.2
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• pp.127-140
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• 2015

A continuous series of 60 snow samples was collected at a 2.5-cm interval from a 1.5-m snow pit at a site on the Styx Glacier Plateau in Victoria Land, Antarctica, during the 2011/2012 austral summer season. Various chemical components (${\delta}D$, ${\delta}^{18}O$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $SO_4{^2-}$, $NO_3{^-}$, $F^-$, $CH_3SO_3{^-}$, $CH_3CO_2{^-}$ and $HCO_2{^-}$) were determined to understand the highly resolved seasonal variations of these species in the coastal atmosphere near the Antarctic Jang Bogo station. Based on vertical profiles of ${\delta}^{18}O$, $NO_3{^-}$and MSA, which showed prominent seasonal changes in concentrations, the snow samples were dated to cover the time period from 2009 austral winter to 2012 austral summer with a mean accumulation rate of $226kgH_2Om^{-2}yr^{-1}$. Our snow profiles show pronounced seasonal variations for all the measured chemical species with a different pattern between different species. The distinctive feature of the occurrence patterns of the seasonal variations is clearly linked to changes in the relative strength of contributions from various natural sources (sea salt spray, volcanoes, crust-derived dust, and marine biogenic activities) during different short-term periods. The results allow us to understand the transport pathways and input mechanisms for each species and provide valuable information that will be useful for investigating long-term (decades to century scale periods) climate and environmental changes that can be deduced from an ice core to be retrieved from the Styx Glacier Plateau in the near future.

• Journal of information and communication convergence engineering
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• v.5 no.2
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• pp.140-143
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• 2007

Fingerprint Recognition System is made up of Off-line treatment and On-line treatment; the one is registering all the information of there trieving features which are retrieved in the digitalized fingerprint getting out of the analog fingerprint through the fingerprint acquisition device and the other is the treatment making the decision whether the users are approved to be accessed to the system or not with matching them with the fingerprint features which are retrieved and database from the input fingerprint when the users are approaching the system to use. In matching between On-line and Off-line treatment, the most important thing is which features we are going to use as the standard. Therefore, we have been using "Delta" and "Core" as this standard until now, but there might have been some deficits not to exist in every person when we set them up as the standards. In order to handle the users who do not have those features, we are still using the matching method which enables us to make up of the spanning tree or the triangulation with the relations of the spanned feature. However, there are some overheads of the time on these methods and it is not sure whether they make the correct matching or not. In this paper, introduces a new data structure, called Union and Division, representing binary fingerprint image. Minutiae detecting procedure using Union and Division takes, on the average, 32% of the consuming time taken by a minutiae detecting procedure without using Union and Division.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.229-232
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• 1999

We have measured the temperature dependence of thermoelectric power (TEP) and resistivity for the Sr$_{1-x}K_xBiO_3$ superconductor (x=0.45-0.6). At T=10.2K, the resisitivity starts to increase from zero and a rather broad superconducting phase transition (${\Delta}$T ${\sim}$ 2.3K) is observed. TEP at room temperature has a small negative value ( S =-1.96${\mu}$V/K), characteristic of metallic-like TEP. The temperature dependence of TEP shows two distinct features. With decreasing temperature from room temperature, the absolute value of TEP decreases and the sign of TEP changes from negative to positive around 200k. Also, the negative slope of TEP(dS/dT) decreases substantially and becomes rather flat at around 160k, which is a feature already noted in Ba$_{1-x}K_xBiO_3$[1].

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.909-921
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• 1995

The objective of this paper is to develop an algorithm for a real-time automatic fingerprint recognition system. The algorithm employs the Fast Fourier Transform (FFT) in determining the directions of ridges in fingerprint images, and utilizes statistical information in recognizing the fingerprints. The information used in fingerprint recognition is based on the dircetions along ridge curves and characteristic points such as core points and delta points. In order to find ridge directions, the algorithm applies the FFT to a small block of the size 8x8 pixels, and decides the directions by interpreting the resulted Fourier spectrum. By using the FFT, the algorithm does not require conventional preprocessing procedures such as smoothing, binarization, thinning, and restorationl. Finally, in matching two fingerprint images, the algorithm searches and compares two kinds of feature blocks, one as the blocks where the dircetions cannot be defined from the Fourier spectrum, and the other as the blocks where the changes of directions become abrupt. The proposed algorithm has been implemented on a SunSparc-2 workstation under the Open Window environment. In the experiment, the proposed algorithm has been applied to a set of fingerprint images obtained by a prism system. The result has shown that while the rate of Type II error - Incorrect recognition of two different fingerprints as the identical fingerprints - is held at 0.0%, the rate of Type I error - Incorrect recognition of two identical fingerprints as the different ones - is 2.2%.

• Journal of the Korean earth science society
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• v.33 no.7
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• pp.608-617
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• 2012

The symbiotic nova Z Andromedae (And) was investigated, using the high dispersion spectra of spectral resolution, ${\Delta}{\lambda}{\sim}-0.1{\AA}$. The spectral observations were done with (1) the Hamilton Echelle Spectrograph (HES) and the high resolution spectra (exposures=1800s and 3600s) were obtained at Lick Observatory in 2001 August $30^{th}$ (phase ${\Phi}$=0.77), and 2002 August $12^{th}$ (phase ${\Phi}$=0.22), (2) with the Bohyunsan Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory and the high resolution spectra (exposure=1200s) were secured in 2009 October $21^{st}$ (phase ${\Phi}$=0.70). From both the HES and BOES spectral data in the $3600{\AA}-9500{\AA}$ wavelengths, we extracted the emission lines of HI, HeI, and HeII, which have been decomposed into double or triple Gaussian components for 3 consecutive phases. The emission zones responsible for these components appear to be closely related with the orbital motion of a white dwarf or a giant star. The presence of the Raman scattering $H{\alpha}$ broad wing feature and the kinematic characteristics of the line profile observed in each phase imply that the Z And emission lines are mostly from two Lagrangian points, $L_1$ and $L_2$, and the accretion disk around the white dwarf star. The Z And was most active in 2009 and 2001 during the outburst phase, while it remained quiescent in 2002 in spite of the complex line profiles.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.206-216
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• 2013

The emotion plays a critical role in human's daily life including learning, action, decision and communication. In this paper, emotion discrimination classifier is designed to reduce system complexity through reduced selection of dominant features from biosignals. The photoplethysmography(PPG), skin temperature, skin conductance, fontal and parietal electroencephalography(EEG) signals were measured during 4 types of movie watching associated with the induction of neutral, sad, fear joy emotions. The genetic algorithm with support vector machine(SVM) based fitness function was designed to determine dominant features among 24 parameters extracted from measured biosignals. It shows maximum classification accuracy of 96.4%, which is 17% higher than that of SVM alone. The minimum error features selected are the mean and NN50 of heart rate variability from PPG signal, the mean of PPG induced pulse transit time, the mean of skin resistance, and ${\delta}$ and ${\beta}$ frequency band powers of parietal EEG. The combination of parietal EEG, PPG, and skin resistance is recommendable in high accuracy instrumentation, while the combinational use of PPG and skin conductance(79% accuracy) is affordable in simplified instrumentation.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.18-24
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• 2017

This study was conducted to determine the anti-inflammatory effect of essential oil extracted from the wood of Chamaecyparis obtusa Sieb. et Zucc. Endl. (Cupressaceae). The essential oil was extracted from the wood of C. obtusa by hydrodistillation method, and conducted the analysis on the chemical composition of the extracted C. obtusa wood oil through GC-MS. The major constituents of the oil were found to be: ${\alpha}-pinene$ (11.4%), cadinene (5.4%), ${\delta}-cadiene$ (9.0%), ${\tau}-muurolol$ (22.2%), ${\alpha}-cadinol$ (20.8%) etc. We attempted to identify the anti-inflammatory activities of the oil when it is injected in the lipopolysaccharide (LPS)-stimulated RBL-2H3 cells, along with its effects on the secretion of interleukin-4 (IL-4), interleukin-13 (IL-13), ${\beta}-hexosaminidase$. According to the cell viability analysis conducted by MTT assay, the oil in $10^{-7}{\sim}10^{-5}%$concentration showed no effect on the cell viability. After RBL-2H3 cells treated by LPS stimulation were exposed to $10^{-7}%$ concentration of C. obtusa wood oil, the expression levels of IL-4, IL-13 within the cell were observed to remarkably decrease. Also, it was attenuated the release of ${\beta}-hexosaminidase$ from mast cells to a significantly meaningful level. These results suggest that C. obtusa wood oil exerts the anti-inflammatory effect, by regulating the expression of inflammatory cytokines, which is a valuable feature to be highly utilized as the functional materials in the future.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.407-411
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• 2002

Ternary sequences are digital codes consisting of discrete values -1, 0, and 1 only. They are advantageous in that the correlation can be carried out using additions only. Also, they feature an ideal circular autocorrelation function, but in channel characterization tasks, the usual requirement is that the linear autocorrelation function be ideal, i.e., a Kronecker delta function. In this article, we consider two approaches to improving their linear autocorrelation or crosscorrelation properties: one is an inverse filtering method with thresholding, and the other is a singular value decomposition (SVD) method. Both methods are simulated under noisy circumstances. The inverse filtering method resulted in an improvement in peak sidelobe level of about 11 dB at an SNR of 30 dB, and the SVD method showed similar performances, albeit more sensitive to noise depending on the singular value selection strategy.