• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1338-1346
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• 2004

The positions of rotating sound sources have been localized by experiments with the Doppler effects removed. In order to de-Dopplerize the sound signals emitted from moving sources, two kinds of signal reconstruction methods were applied. One is the forward propagation method and the other is the backward propagation method. Forward propagation method analyze the source emission time based on the instantaneous distance between sensors and the assumed source position, then the signals are reconstructed with respect to the emission time. On the other hand, the backward method uses time delay to do-Dopplerize the acquired data for the received time of reference. In both techniques. the reconstructed signal data were processed using beamforming algorithm to produce power distributions at the frequencies of interest. Experiments have been carried out for varying frequencies, rotating speeds and the object distances. It is shown that the forward propagation method gives better performance in locating source position than the backward propagation method.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.247-255
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• 1992

In order to estimate effects of air pollution for herbs in the plnus thunbergii forests arrounding onsan industrial complex, this study was surveyed. number of species of herb also had a difference over 10 species by distance at the source of air pollution, and species diversity and evennes were also increasing at remote sites in industrial complex as woody plants. At the vicinity of industrial complex, $SDR_4$ of calamagrostis arundinatios arundinacea., miscanthus sinensis and cymbopogon tortilis var. goeringii were very high, and those of lianas as cocculus trilobus, lonicera japonica and paederia scandens, and phytolacca americana were low, but because of being higher than other sites, it was able to inferred that lianas had a tolerance to air pollution. The composition of biological spectra of herbs showed to type of $H-D_1-R_{2-3}-1$ at near site in the source of air pollution and $H-D_1-R_{1-3}-t$ at the other sites, and the propotion of lians forms were relatively high at the vicinity of industril complex.

• Geosystem Engineering
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• v.21 no.6
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• pp.309-317
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• 2018

We employ a three-dimensional indirect boundary element method (BEM) to simulate temperature change around an underground liquefied natural gas storage cavern. The indirect BEM (IBEM) uses fictitious heat source strength on boundary elements as basic variables which are solved from equations of boundary conditions and then used to compute the temperature change at other points in the considered problem domain. The IBEM requires evaluation of singular integration for temperature change due to heat conduction from a constant heat source on a planar (triangular) region. The singularity can be eliminated by a semi-analytical integration scheme. However, it is found that the semi-analytical integration scheme yields sharp temperature gradient for points close to vertices of triangle. This affects the accuracy of heat flux, if they are evaluated by finite difference method at these points. This difficulty can be overcome by a combination of using a direct numerical integration for these points and the semi-analytical scheme for other points distance away from the vertices. The IBEM and the hybrid integration scheme have been verified with an analytic solution and then used to the application of the underground storage.

• Earthquakes and Structures
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• v.6 no.2
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• pp.141-161
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• 2014

This article presents a new generation of empirical ground motion models for the prediction of response spectral accelerations in soil conditions, specifically developed for the Vrancea intermediate-depth seismic source. The strong ground motion database from which the ground motion prediction model is derived consists of over 800 horizontal components of acceleration recorded from nine Vrancea intermediate-depth seismic events as well as from other seventeen intermediate-depth earthquakes produced in other seismically active regions in the world. Among the main features of the new ground motion model are the prediction of spectral ordinates values (besides the prediction of the peak ground acceleration), the extension of the magnitudes range applicability, the use of consistent metrics (epicentral distance) for this type of seismic source, the extension of the distance range applicability to 300 km, the partition of total standard deviation in intra- and inter-event standard deviations and the use of a national strong ground motion database more than two times larger than in the previous studies. The results suggest that this model is an improvement of the previous generation of ground motion prediction models and can be properly employed in the analysis of the seismic hazard of Romania.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.139-148
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• 2022

Research into wireless sensor networks (WSNs) is a trendy issue with a wide range of applications. With hundreds to thousands of nodes, most wireless sensor networks interact with each other through radio waves. Limited computational power, storage, battery, and transmission bandwidth are some of the obstacles in designing WSNs. Clustering and routing procedures have been proposed to address these concerns. The wireless sensor network's most complex and vital duty is routing. With the Greedy Perimeter Stateless Routing method (GPSR), an efficient and responsive routing protocol is built. In packet forwarding, the nodes' locations are taken into account while making choices. In order to send a message, the GPSR always takes the shortest route between the source and destination nodes. Weighted directed graphs may be constructed utilising four distinct distance metrics, such as Euclidean, city block, cosine, and correlation distances, in this study. NS-2 has been used for a thorough simulation. Additionally, the GPSR's performance with various distance metrics is evaluated and verified. When compared to alternative distance measures, the proposed GPSR with correlation distance performs better in terms of packet delivery ratio, throughput, routing overhead and average stability time of the cluster head.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.227-233
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• 2017

Purpose: The purpose of this study was to evaluate the validity of digital models fabricated by difference optical source of non-contact 3D dental scanner. Methods: A master model with the prepared upper full arch tooth was used. Stone model(N=10) were produced from master model, and on the other hands, digital models were made with the 3D dental scanner(Blue, white, red optical source). The linear distance between the reference points were measured and analyzed on the Delcam $Copycad^{(R)}$ graphic software. The results were statistically analyzed using the one-way ANOVA and Tukey's HSD test(${\alpha}=0.05$). Results: There were considerable differences in mean values between optical source within each color(blue, white, red), and this difference was not statistically significant(p>0.05). Conclusion : Three different color of dental scanner optical source showed clinically acceptable accuracies of full arch digital model produced by them. Besides, these results will have to be confirmed in further clinical studies.

• Korean Journal of Optics and Photonics
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• v.28 no.1
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• pp.16-21
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• 2017

A systematic understanding of the effects of high-intensity flash sources on the human eye is strongly needed, not only for proper use of the sources, but for human eye health. In this study, the exposure-limit distance (ELD), indicating the minimal safe distance in case of seeing by chance a high-intensity flash, is proposed. The optical procedures to determine the ELD of a high-intensity flash are clarified, and the dependence of ELD on its parameters such as luminous intensity, duration, and radius of a flash are thoroughly investigated. From this investigation it is obvious that, while being weakly dependent on duration, the ELD is nearly proportional to the luminous intensity and the radius of a flash. The proposed ELD as an intuitive safety-indicating parameter is more useful and intuitive than the other characteristic parameters of a high-intensity flash. The ELD is expected to be an essential parameter as a safety indicator, to characterize the performance of a high-intensity flash and to promote the safety of the human eye.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.375-380
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• 2006

Endocrine disrupting chemicals (EDC) have been emphasized due to their threats in human health. Waste incinerator emission has been emphasized as a source of EDC including polychlorinateddibenzofurans(PCDD/F) and other carcinogenic polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene (1-OHP) has been used as an exposure biomarker for the PAHs. On the other hand, etheno-DNA adducts, e.g. 1, $N^6-ethenodeoxyadenosine({\varepsilon}dA)$, has been developed as an useful effective or response biomarker for carcinogenesis. Thus, I investigated association between urinary 1-OHP and ${\varepsilon}dA$ levels due to distance from an incinerator which was built more 10 years ago in the middle of a farm in P city. I designated the EDC-high and low exposed group due to distance from the incinerator, i.e. within 2.5km and $5.0{\sim}7.5km$ from the incinerator, respectively. The study subjects were age and sex-matched males and females (mean age, $61.3{\pm}9.6$ yrs; total 40 persons, male, 10; female, 10 for the each group). Urinary 1-OHP and ${\varepsilon}dA$ were analyzed with HPLC-FD and IP-HPLC-FD, respectively. As results, the distance from the incinerator was not associated with urinary 1-OHP nor ${\varepsilon}dA$ levels (p=0.43 and 0.82, respectively). On the other hand, urinary ${\varepsilon}dA$ levels were significantly higher in the hyperlipidemia group (N=10) than normal group (N=30). In conclusion, urinary 1-OHP nor ${\varepsilon}dA$ levels can not be suggested as an incinerator-related exposure nor effective biomarker. However, not only distance from the incinerator bot also systemic approaches including wind and soil contamination are required to assume exposure levels of incinerator-related EDC.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.5
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• pp.562-573
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• 2008

Concentrations of volatile organic compounds (VOCs) measured from the local industrial sources in Wanju industrial complex during June $2007{\sim}January$ 2008. The samples were collected from the primary sources (6 emission points) in 4 major factories in Wanju industrial complex as well as two general sources in Wanju County to elucidate the abundances of speciated VOCs and their spacial and temporal distributions depending on source bases. Industrial sources are as follows; fabricated metal manufacture, motor vehicle manufacture, rubber and plastic manufacture, and chemical manufacture factories. Two general source samples were collected from gasoline gas station and dry cleaning shop in urban area. In order to understand the near source influence at receptor, samples from the two receptor sites (one is at center of the industrial complex and the other site is at distance residential area downwind from the center) were collected with sample canister, and analyzed by using GC/MSD. The concentrations from different sources were compared and discussed. The mass contributions of the speciated VOCs to total VOCs measured from industrial sources and ambient ai r at two receptors were presented and discussed.