• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.617-620
• /
• 2008

지열에너지는 지구 내부의 깊은 곳에서부터 발생하는 열과 상부 지각에서 방사성 동위원소의 붕괴에 의한 열에 의해 발생한다. 지열에너지는 다른 신재생에너지(수력, 풍력, 태양력, 조력, 바이오 매스등)에 비하여 가동효율이 높고, 지속가능한 재활용 자원으로 경제적 효율성이 높아 전 세계적으로 활용도와 잠재성이 높은 신재생에너지의 하나로 각광 받고 있다. 따라서, 지열에너지의 사용은 화석 연료 사용의 상당부분을 대체할 수 있고, 온실가스의 배출도 줄일 수 있다. 현재 우리나라의 지열에너지 이용은 저온성 지열에너지를 이용한 냉난방에 국한되어 있지만, 앞으로의 지열에너지 이용은 Enhanced Geothermal System(EGS) 을 이용한 지열에너지 개발에 초점이 맞추어질 것이다. 현재의 지열에너지 개발을 용이하게 하고, 또한 미래의 지열에너지 개발에 대비하여 우리나라의 이용가능한 지열에너지 부존량을 파악하기 위해 본 연구를 수행하였다. 연구 수행에는1560개 열물성 자료(밀도, 비열, 열전도도), 353개 지표 지열류량 자료, 180개 열생산율 자료와 54개의 지표온도 자료가 사용되었다. 우리나라의 지표에서부터 1 km 깊이 간격별로 5 km 깊이까지 지열에너지 부존량을 산출한 결과 지표에서 부터 5 km 깊이까지의 추출 가능한 지열에너지의 총 부존량은 $1.01{\times}10^{23}$ J로 산출되었다. 지열에너지 부존량을 Toe(석유환산톤) 로 환산하면 $2.40{\times}10^{12}$ Toe 가 된다. 추출한 지열에너지 자원의 2%를 사용한다고 가정 했을때 약 480억 Toe 이다. 이는 2006년 우리나라 전체 1차 에너지 총 소비량(2.33억 Toe)을 고려 했을때 약 200년 동안 사용할 수 있는 양이다.

• MALSORI
• /
• no.52
• /
• pp.61-84
• /
• 2004

This study investigates the Korean native speakers' English liquid perception and production. Perception and production experiments were each conducted twice before and after a short period of explicit learning process of phonetic characteristics of English liquids. The results showed that correlation between perception and production varied depending on factors. In both perception and production, word-final position was the most difficult, and cluster position was the easiest. A considerable improvement was observed in word-initial and medial positions in production, whereas no improvement was achieved in word-final position, especially in production. This study is also concerned with the formant structures of Korean native speakers' production of English liquids in order to see what acoustic features are highly correlated with Korean native speakers' production accuracy of English liquids. The results showed that F2 did not show a high correlation while F3 was a strong correlate of the production accuracy.

• Phonetics and Speech Sciences
• /
• v.10 no.3
• /
• pp.41-48
• /
• 2018

This study examined the acoustic characteristics of Korean alveolar fricatives of normal children. Developing children aged 3 and 7, typically produced 2 types of nonsense syllables containing alveolar fricative /sV/ and /VsV/ sequences where V was any one of three corner vowels (/i, a, and u/). Stimuli containing the speech materials used in a production experiment were presented randomly to 12 speech language pathologists (SLPs) for a perception test. The SLPs responded by selecting one of seven alternative sounds. Acoustic measures such as duration of frication noise, normalized intensity, skewness, and center of gravity were examined. There was significant difference in acoustic measures when comparing vowels. Comparison of syllable structures indicated statistically significant differences in duration of frication noise and normalized intensity. Acoustic parameters could account for the perceptual data. Relating the acoustic and perception data by means of logistic regression suggests that duration of frication noise and normalized intensity are the primary cues to perceiving Korean fricatives.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2004.10a
• /
• pp.396-399
• /
• 2004

어떤 집단에서든 그 구성원의 효율적인 관리가 무엇보다 중요하다. 이러한 효율적인 관리는 집단의 구성원이 많을수록 한 개인이 방대한 자료를 분석 및 관리하기에는 많은 어려움이 있다. 본 논문에서는 이 많은 자료를 바탕으로 퍼지 추론을 이용하여 근태 관리 시스템을 개발하였다. 먼저 퍼지입력 변수로는 출입구에 미리 설치되어 있는 지문 도어락과 관리실의 PC를 통해 사원들의 출퇴근 시간과 월별 근무시간, 월별 근무일수, 월별 조퇴 및 지각일수를 산출한 후 월별 휴가일수를 입력한다. 이 입력 데이터 값으로 퍼지 연산을 수행 후 구성원 개개인의 월별 성실도를 결정하였다.

• Bulletin of the Korean Space Science Society
• /
• 2010.04a
• /
• pp.37.2-37.2
• /
• 2010

GPS 관측자료를 이용하여 최근 발생한 칠레지진에 의한 지각의 변위를 결정하고 결과를 분석하였다. 고정밀 측지용 이중주파수 GPS 수신기 및 안테나가 장착된 관측소의 자료를 처리하면 수mm 정밀도로 관측소의 위치를 결정할 수 있으며, 수년간의 관측자료가 누적되면 연간 mm급의 움직임도 관측할 수 있어 판운동이나 지진, 단층연구 등에 널리 활용되고 있다. 이번 2010년 2월 27일 칠레 중서부에서 발생한 지진은 인근 지역을 30 cm 이상 움직였을 것으로 예상되며 8.8의 대형 지진규모와 많은 인명 및 재산피해를 유발시켜 학계뿐만 아니라 일반 언론에도 많은 주목을 받고 있다. 이 연구에서는 지진이 발생한 지역 부근에 위치한 국제 GPS 기준망의 GPS 관측자료를 처리하여 지진 발생 전후의 변위를 산출하고 분석하였다. 자료처리를 위해 Bernese GPS S/W 5.0을 사용하였고 24시간단위 자료에 대해 이중차분방법과 단독정밀측위방법을 사용하였다. 또한 지진이 발생 도중의 변위를 관찰하기 위해 이동측위방법을 사용하여 30초마다의 움직임을 계산하였다.

• Proceedings of the Korean Society for Quality Management Conference
• /
• 2006.04a
• /
• pp.3-7
• /
• 2006

현대 기업은 경영 전략의 방향 및 평가를 위하여 고객만족도를 조사한다. 특히 서비스업에서는 많은 경우 SERVQUAL 점수를 이용하여 고객만족도를 평가한다 SERVQUAL은 고객의 기대와 지각의 차이를 조사하여 고객만족도를 평가하며 22 개의 평가항목은 5가지의 품절특성 (유형성, 신뢰성, 대응성, 확신성 공감성)에 대한 SERVQUAL 접수로 산출된다. WSERVQUAL 접수는 SERVQUAL 점수에 단순평균방식과 상대적 중요도를 가중한 가중접수로 계산되는 방법으로 상대적 중요도를 파악하기 위하여 기존에서는 중요도에 대한 고객의 의견을 파악하여 적용하였으나 본 논문에서는 임성욱의 잠재적 고객만족 개선지수 (PCSI Index)를 적용하여 고객의 향후 잠재적 만족개선정도에 관한 내용을 포함한 가중치를 산정할 수 있는 방법론을 제시하였다.

• Economic and Environmental Geology
• /
• v.28 no.1
• /
• pp.19-24
• /
• 1995

Based upon the lead isotopic compositions of the galenas collected from Pb-Zn ore deposits distributed in the eastern and southern parts of the Gyeongsang basin, we investigated what kinds of source materials were involved in the formation of these ore deposits and compared the lead isotopic characteristics of these ore deposits with those of the ore deposits in the Taebaegsan area. The isotopic compositions of the common leads from Pb-Zn ore deposits in the Gyeongsang basin show the variation with the relatively limited range ($^{206}Pb/^{204}Pb=18.156{\sim}18.377$, $^{207}Pb/^{204}Pb=15.482{\sim}15.638$, and $^{208}Pb/^{204}Pb=37.953{\sim}38.605$). They are plotted on or below ore lead growth curve(Cumming & Richards, 1975) and average crustal lead evolution curve (Stacey & Kramer, 1975). In the plumbotectonic model IV(Zartman & Haines, 1988), they are plotted between the evolution curves of mantle and orogene. But the lead isotopic compositions of the common leads in the Taebaegsan area are plotted on and above upper crust curve. Considering the above-mentioned lead isotopic characteristics, the linear trend shown in the isotopic compositions of the common leads in the Gyeongsang basin can be considered as the mixing isochron between high radiogenic crustal materials such as the Ryongnam massif and low radiogenic materials derived from depleted mantle or materials with relatively low U/Pb and Th/U ratios.

• Phonetics and Speech Sciences
• /
• v.12 no.4
• /
• pp.1-8
• /
• 2020

Traditionally it has been understood that the aspirated and lenis stops in Seoul Korean are distinguished primarily by voice onset time (VOT) and secondarily by other cues such as the fundamental frequency (F0) of the following vowel. However, recent studies on stop production have shown that the aspirated and lenis stops are currently merging in VOT and that they are now differentiated primarily by F0. In the present study, we examined whether the currently reported change in the production domain would be also found in the perception domain. To this end, an auditory identification task was conducted using speech materials of varying VOT and F0 values with young and older male and female Seoul listeners. Results revealed that all listener groups used both VOT and F0 to distinguish the lenis vs. aspirated stops but they used the F0 cue more reliably than the VOT cue in discriminating the stop contrast. The effects of gender and age were found only in the VOT cue (i.e., not in the F0 cue), with the greatest VOT cue weight in older males and the smallest in young females, which is in line with recent production studies.

• Economic and Environmental Geology
• /
• v.47 no.4
• /
• pp.441-453
• /
• 2014

Thermal and physical properties were measured on 206 Jurassic granite samples obtained from three boreholes in the central part of Korea. Thermal conductivity(${\lambda}$), thermal diffusivity(${\alpha}$), and specific heat(Cp) were measured in a laboratory; the average values are ${\lambda}$=2.813 W/mK, ${\alpha}=1.296mm^2/sec$, and Cp=0.816 J/gK, respectively. In addition, porosity(${\phi}$), and dry and saturated density(${\rho}$) were measured in the laboratory; the average values are ${\phi}$=0.01, ${\rho}(dry)=2.662g/cm^3$ and ${\rho}(saturated)=2.67g/cm^3$, respectively. Thermal diffusivity of 10 granite samples were measured with increasing temperature from $25^{\circ}C$ to $200^{\circ}C$. In this study, we found that thermal diffusivity at $200^{\circ}C$ is about 30% lower than thermal diffusivity at $25^{\circ}C$. In correlation analysis, thermal conductivity increases with increasing thermal diffusivity. However, thermal conductivity does not show good correlation with porosity and density. Consequently, we know that thermal conductivity of granite would be more influenced by mineral composition than by porosity. We also derived ${\rho}=-2.393{\times}{\phi}+2.705$ from density and porosity data. XRD and XRF analysis were performed to investigate effects of mineral and chemical composition on thermal conductivity. From those results, we found that thermal conductivity increases with increasing quartz and $SiO_2$, and decreases with increasing albite and $Al_2O_3$. Regression analysis using those mineral and chemical composition were carried out ; we found $K=0.0294V_{Quartz}+1.93$ for quartz, $K=0.237W_{SiO_2}-14.09$ for $SiO_2$, and $K=0.053W_{SiO_2}-0.476W_{Al_2O_3}+6.52$ for $SiO_2$ and $Al_2O_3$. Specific gravities were measured on 10 granite samples in the laboratory. The measured specific gravity depends on chemical compositions of granite. Therefore, specific gravity can be estimated by the felsic-mafic index(F) that is calculated from chemical composition. The estimated specific gravity ranges from 2.643 to 2.658. The average relative error between measured and estimated specific gravities is 0.677%.

• Journal of the Korean earth science society
• /
• v.34 no.2
• /
• pp.109-119
• /
• 2013

Duibaejae basalts from Goseong, Gangwon-do, are divided into the lower basalt and the upper basalt depending on the properties, such as occurrence, mineral compositions, and major and trace compositions of the basalts. The lower basalts have characteristics of agglomerate rocks as well as contain, crustal and mantle xenoliths, and olivine, pyroxene, and plagioclase xenocrysts. The upper basalts with columnar joints contain relatively more mantle xenolith and olivine xenocryst than the lower basalts. The major and trace element compositions suggest that the composition of the upper basalts is close to primary magma composition. Enrichment and depletion patterns of the trace and the rare-earth elements of the lower basalts are similar to those of the upper basalts, whereas the lower basalts are more LREE enriched than the upper basalts. The source magmas of the lower and upper basalts from Duibaejae volcanic edifice were generated from about 0.8-1.2% and 3.7-4.0% batch melting of garnet peridotite, respectively. The abundance of granite xenolith, and plagioclase and quartz xenocrysts with reaction rim indicates that the lower basalts, compared with upper basalts, might have been assimilated with the crustal materials during ascending to surface.