• Tunnel and Underground Space
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• v.23 no.6
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• pp.572-580
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• 2013

In this case study, I examined the microseismic safety management system of Deep Heat Mining Basel (DHMB) as EGS Geothermal Project which was conducted in Basel, Switzerland. EGS Geothermal Power projects which require induced seismic event by stimulation for creation of EGS geothermal reservoir have to be controlled pressure and flow rate of stimulation by establishment of microseismic safety management system. Traffic light system and Communication response procedure of DHMB project to respond step by step corresponding microseismic event intensity through continuous monitoring during stimulation period have been managed and established in advance of stimulation. However, the project was discontinued because of an earthquake to occur larger than expected one due to post-injection seismicity occurring in the geothermal reservoir after completion of injection for stimulation. The result of post analysis, Real-time traffic light system was verified to need a establishment of new microseismic safe management system to be considered post-injection seismicity phenomenon.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.39-47
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• 1997

This paper presents a single board digital signal processing system which can perform two-dimensional (2-D) digital infinite impulse response (IIR) filtering in realtime. We have developed an architecture to provide not only the necessary computational power but also a balance of the system input/output and computational requirements. The architecture achieves large system throughput by using highly parallel processing at both the system and processor levels. It reduces system data communication requirements significantly by taking advantage of a custom-designed processor and by providing each processor with its own input and ouput channel. After system initialization, almost 100 percent of the time is used for data processing. Data transfers occur concurrently with data processing. The functional level simulation reveals that the system throughput can reach as high as one pixel per system cycle. With only 10MHz clock frequency system, it can implement up to fourth order 2-D IIR filters for video-rate data ($512\times512$ pixels per frame at 30 frames per second). If we increase the system frequency, the system can be used for the preprocessing and postprocessing of video signal of HDTV.

• Korea Journal of Hospital Management
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• v.7 no.4
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• pp.123-151
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• 2002

The objective of this study is to analyze the causal relationship of hospital inpatient's perceived quality, overall satisfaction, service value, and future intention to revisit. To carry out this objective, first we analyzed the dimensions of inpatient care service quality using SERVQUAL scale. The SERVQUAL scale is based on the gap theory, that is, the difference of patients' expectations and the actually received medical care service in hospital. On the basis of this theory, we measured the inpatient's perceived service quality and overall patient satisfaction. Data was gathered from a self-administered questionnaire at a 980 bed university hospital in Inchon City. These questionnaire measuring the service quality were distributed to 250 inpatients. The response rate was 66.4%. A total of 166 questionnaires was finally analyzed. To categorize medical service quality, the factor analysis was performed on 42 items. The reliability and validity of these items was evaluated. Finally to test 6 hypotheses, we analyzed the causal relationship of service quality, overall satisfaction, service value, and intention to revisit through the structural equation modeling(SEM). The major results of this study are as follows. First, the dimension of inpatient service quality was categorized into 7 dimensions, that is, personal caring, communication, access, physical environment, facilities and equipment, cleanliness, appropriateness and health status. Second, the reliability and validity of inpatient service quality items was satisfied. Third, as a result of structural equation modeling, the effect of inpatient's perceived service quality on overall satisfaction, service value, and intention to revisit was statistically significant. And total effect on intention to revisit as the core endogenous variable was perceived service quality(1.100), patient satisfaction(0.006), and service value(0.605).

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.617-621
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• 2004

In recent, researchers in the field of Bioinformatics need to analyze thousands of genome sequences efficiently according to introduce of new analysis methods and technologies such as genome expression microchip. This rapid growth in the field of bio-engineering needs computing resources to analyze rapidly for genome sequences, but it does not introduce the computing resources due to an enormous investment expense. The core factor of this study is integrated environment based PC-Cluster system & high speed access rate up to 155Mbps, continuous collection system for bio-information at home and abroad. The results of the study are establishment & stabilization of information and communication infrastructure, establishment & stabilization of high performance computer network up to 155Mbps, development of PC-Cluster system with 32 nodes, a parallel BLAST on Cluster system, which can provides scalable speedup in terms of response time, and development of collection & search system for bio-information.

• Journal of Sensor Science and Technology
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• v.8 no.5
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• pp.400-406
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• 1999

Piezoresistive flow sensors with four different types of microbeam structures were fabricated using (100), n/$n^+$/n three-layer silicon wafer and their characteristics were investigated. Piezoresistors were formed through boron diffusion and its values were about $1\;k{\Omega}$. Three-dimensional silicon microbeams were constructed by porous silicon micromachining and curled microbeams were fabricated by the difference in the thermal expansion coefficient between silicon and metal. The output response of the fabricated sensor was evaluated through half- bridge. The output voltage increased with increasing length of microbeam at the same flow velocity, while the detectable measurement range extended with decreasing length of microbeam. The output voltage of the fabricated sensors were increased with quotient of 3.2 of the flow rate since the stress of the beam versus the gas flow showed non-linear characteristics.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.30.2-30.2
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• 2010

It is a mistaken impression that the midlatitude ionosphere was a very stable region with well-known morphology and physical mechanism. However, the large disturbances of midlatitude ionospheric contents in response to global thermospheric changes during geomagnetic storms are reported in recent studies using global GPS TEC map and space-born thermospheric UV images, and its importance get higher with the increasing application areas of space navigation systems and radio communication which are mostly used in the midlatitudes. Positive and negative storm phases are used to describe increase and decrease of ionospheric electron density. Negative storms result generally from the enhanced loss rate of electron density according to the neutral composition changes which are initiated by Joule heating in high-latitudes during geomagnetic storms. In contrast, positive ionospheric storms have not been well understood because of rare measurements to explain the mechanisms. The large enhancements of ground-based GPS TEC in Korea were observed on 8 and 10 November 2004. The positive ionospheric storm was continued except for dawn on 8 November, and its maximum value is ~65 TECU of ~3 times compared with the monthly mean TEC values. The other positive phase on 10 November begin to occur in day sector and lasted for more than 6 hours. The O/N2 ratios from GUVI/TIMED satellite show ~1.2 in northern hemisphere and ~0.3 in southern hemisphere of the northeast Asian sector on 8 and 10 November. We suggest the asymmetric features of O/N2 ratios in the Northeast Asian sector may play an important role in the measured GPS TEC enhancements in Korea because global thermospheric wind circulation can globally change the chemical composition during geomagnetic storms.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.469-472
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• 2008

In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.1
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• pp.245-269
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• 2017

To assess and understand the level of job burnout among the medical librarians and identify the factors affecting it, email survey, consisting of questions regarding personal background, organization characteristics, degree of burnout, and coping activities, was administered for two weeks in December 2016, to the librarians in 138 institutions affiliated with the Korean Medical Library Association. MBI-GS is used as a burnout measuring instrument. Data collected from 158 librarians (response rate 65.6%), were analyzed by descriptive statistics, t-test, ANOVA, and correlation analysis methods. According to MB-GS norm, respondents experience moderate level of exhaustion and professional efficacy, however the level of cynicism is extremely high. There are significant statistical differences in burnout, depending on age, medical librarian certificate, work experience, type of library, job coverage, and coping activities. There are also statistical significant correlations between workload, role conflict, decision making process and performance evaluation, organization communication, IT environment, continuing education and burnout. Based on the results, recommendations to alleviate burnout are suggested in individual, organizational, and professional association context.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.607-615
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• 2021

Cytokines are protein mediators that possess the ability to assist cell-to-cell communication in immune system-related activities. In general, pathogen endotoxins activate the release of inflammatory mediators, and with time, there is an increase in the cytokine levels in the body. Interleukin (IL)-6 mediates the acute-phase inflammatory response, and elevated IL-6 levels have been reported in peritoneal fluids of women with pelvic inflammation and endometriosis, thereby associating it with oocyte quality and infertility. To overcome subfertility or infertility in humans and animals, the present study was done to examine the effect of recombinant IL-6 on porcine oocytes matured in vitro and subsequently to determine the fertilization rate and embryo development. Porcine oocytes were incubated with varying concentrations of IL-6 (0 - 2 ㎍·mL^-1) for 44 h followed by in vitro fertilization and culturing of the oocytes. The oocytes or embryos were fixed with 3.7% paraformaldehyde (PFA) and stained with fluorescence dyes, and the meiotic spindle, chromosome organization, fertilization status and embryo development were subsequently assessed under a fluorescence microscope. We observed induction of an abnormal meiotic spindle alignment in the oocytes incubated with IL-6 compared to the control oocytes incubated without IL-6. Moreover, significantly decreased fertilization rates and embryo development were observed for oocytes incubated with IL-6 (p < 0.05). Thus, an increased IL-6 level during oocyte maturation could be associated with fertilization failure due to an aberrant chromosomal alignment and a disruption of the cortical granules. Taken together, our results indicate that successful assisted reproduction can be achieved by controlling the levels of inflammatory cytokines.

• Journal of IKEEE
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• v.26 no.2
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• pp.287-291
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• 2022

In general, as the amplitude and phase information of the physical layer channel impulse response change rapidly in time and frequency according to the high-speed movement of the vehicles in V2X communication systems, it is difficult to accurately estimate these channels at the receiving end. In order to effectively overcome this problem, midamble-based channel estimation methods in which mid-ambles are periodically inserted into a packet have been recently considered. However, as the number of midambles increases, we suffer from the spectral efficiency loss. To relieve such a loss, in this paper, we propose a new bidirectional averaging channel estimation method that combines the existing data pilot-based channel estimation methods and the mid-ambles. Finally, through the simulation results, we demonstrate that the proposed method outperforms the existing mid-amble method in terms of packet error rate with fewer number of mid-ambles.