• 품질경영학회지
• /
• 제38권4호
• /
• pp.504-511
• /
• 2010

A fuze detonator comprising star shells is an important device so that its failure usually leads to failure of the shells. In this paper, accelerated degradation tests of RD1333 (lead azide) using temperature stress were performed, and then degradation data of explosive power for the detonator were analyzed to predict the storage lifetime of detonator. Degradation data analysis to estimate the storage lifetime is based on a distribution-based degradation process. Statistical distribution parameters of explosive power degradation measures at each time were estimated for each temperature level, and then reliability of the detonator for each accelerated temperature level was estimated using both time-varying distribution parameters and critical level of explosive power. Arrhenius model was applied to estimate storage lifetime of the detonator under the field temperature condition. Accelerated distribution-based degradation analysis to estimate storage lifetime is explained in detail, and estimation results are compared to field data of storage lifetime in this paper.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2004년도 정기학술대회
• /
• pp.303-311
• /
• 2004

This paper presents the reliability estimation of door hinge for home appliances, which consists of bushing and shaft. The predominant failure mechanism of bushing made of polyoxymethylene(POM) is brittle fracture due to decrease of strength caused by voids existing, and that of shaft made of acrylonitrile-butadiene-styrene(ABS) is creep due to plastic deformation caused by excessive temperature and lowering of glass transition temperature by absorbed moisture. Since the brittle fracture of bushing is overstress failure mechanism, the load-strength interference model is used to estimate the failure rate of it along with failure analysis. By the way, the creep of shaft is wearout failure mechanism, and an accelerated life test is then planned and implemented to estimate its lifetime. Through the technical review about failure mechanism, temperature and humidity are selected as accelerating variables. Assuming Weibull lifetime distribution and Eyring model, the life-stress relationship and acceleration factor, B$_{10}$ life and its lower bound with 90% confidence at worst case use condition are estimated by analyzing the accelerated life test data.a.

• 대한기관식도과학회지
• /
• 제6권2호
• /
• pp.152-158
• /
• 2000

Backgroud and Objectives： Because the pain is subjective in human, we frequently need the objective tool for estimation of pain. The Visual Analog Scale (VAS) is a method for pain grading, but it is also a subjective method. The purpose of this study is to seek an objective method for measurement of pain. Author suggests that the estimation of local body temperature may be associated with the severity of pain in tonsillar disease and the change of it measured by Digital Infrared Thermographic Imaging (DITI), may also be correlated with the change of pain. Materials and Method : Four groups were selected and measured for VAS and body temperature in DITI. Group A and B were post-tonsillectomy groups divided by age. Group C was acute tonsillitis group. Group D was peritonsillar abscess group. Results : In Group A and B, the subjective VAS was significantly correlated with objective local body temperature (correlation coefficient r=0.673, 0.647) and significant correlation was also present in acute tonsillitis and peritonsillar abscess groups(r=0.596,0.642). Conclusion : The change of pain was strongly associated with that of local body temperature in tonsillar disease. DITI is a useful method for objective grading of pain and can be used for the study of postoperatve pain and effectiveness of pain control.

• 한국식품과학회지
• /
• 제22권5호
• /
• pp.582-589
• /
• 1990

본 고에서는 Equivalent time과 Equivalent temperature를 활용하여 Kinetic parameters를 결정하는 새로운 방법을 제안하였다. 본 방법의 타당성을 두 가지의 kinetic data 즉, 계산치와 실험치를 이용하여 예시하였다. 계산치는 그 Kinetics가 잘 알려진 세 가지 화학반응에 대해 임의의 등온가열조건을 적용하여 계산하였고 실험치는 2% 설탕용액을 사용하여 0.0005N 염산용액을 사용하여 가수분해가 일어나는 정도를 효소반응을 이용하여 측정하였다. 본 방법에 의해 결정된 활성화 에너지와 Frequency factor는 각각 $104.74{\pm}1.87KJ/mol$과 $5.26{\times}10^{14)hr^{-1}$이었으며 이들 값은 보고된 결과와 잘 일치되었다.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2008년도 동계학술발표대회 논문집
• /
• pp.440-445
• /
• 2008

In this paper, new methodology is proposed to estimate the cooling load using areas of building group and predicted weather data. Only three parameters such as maximum, minimum temperature and building area are necessary to obtain hourly distribution of cooling load for the next day. The maximum and minimum temperature that are used for input parameters can be obtained from forecasted weather data. The areas of building group are used for setting several parameters that are used for estimate cooling loads. Benchmarking building(research building) is selected to validate the performance of the proposed method, and the estimated cooling loads in hourly bases are calculated and compared with the measured data for benchmarking building. The estimated results show fairly good agreement with the measured data for benchmarking building.

• 자원ㆍ환경경제연구
• /
• 제27권2호
• /
• pp.287-313
• /
• 2018

본 연구는 전력수요의 냉방 및 난방 수요를 측정하고 분석한다. 이를 위해 냉난방기온효과를 추정하고 이를 Chang et al. (2014)의 전력수요함수 모형에 적용하여 전력수요를 기본수요, 냉방수요 그리고 난방수요로 분해하였다. 1999년 1월부터 2016년 12월의 한국의 일반용과 주택용 전력수요를 분석한 결과, 난방수요의 증가율이 기본수요와 냉방수요의 증가율을 월등히 상회하였으며 특히 일반용에서 난방수요 증가가 두드러졌다. 평년기온으로 통제한 기온보정된 난방수요는 실현된 난방수요보다 상대적으로 '더' 증가하였고, 냉방수요는 반대로 기온보정된 수요가 실현된 수요에 비해서 '덜' 증가하였다. 본 논문은 전력수요 내의 냉방 및 난방수요를 측정할 뿐 아니라 경제주체들의 전력수요 변화 패턴을 확인했다는 점에 의의가 있으며, 추정 결과들은 향후 전력수요예측과 에너지수요관리 정책 수립에 도움을 줄 수 있을 것으로 기대된다.

• 한국기후변화학회지
• /
• 제6권2호
• /
• pp.95-104
• /
• 2015

To discuss whether we have credible estimations about historical surface temperature evolution since industrial revolution or not, present study investigates consistencies and differences of averaged surface air temperature since 1900 between the multiple data sources: Hadley Center Climate Research Unit (HadCRU4) surface air temperature data, ECMWF 20 Century Reanalysis data (ERA20CR), and NCEP 20 Century Reanalysis data (NCEP20CR). Averaged surface temperatures are obtained for the global, polar (90S~60S, 60N~0N), midlatitude (60S~30S, 30N~60N), tropical (30S~30N) region, separately. From the analysis, we show that: 1) spatio-temporal inhomogenity and scarcity of HadCRU4 data are not major obstacles in the reliable estimation of global surface air temperature. 2) Globally averaged temperature variability is largely contributed by those of tropical and midlatitude, which occupy more than 70% of earth surface in area. 3) Both data show consistent temperature variability in tropical region. 4) ERA20CR does not capture warm period over Arctic region in early 1900s, which is obvious feature in HadCRU4 data. Discrepancies among datasets suggest that high-level caution is needed especially in the interpretation of large Arctic warming in the early 1900s, which is often regarded as a natural variability in the Arctic region.

• 한국토양비료학회지
• /
• 제46권5호
• /
• pp.359-364
• /
• 2013

This study was conducted to develop a model to estimate crop leaf surface temperature. The results were as following; A definition for the daily time based on elapsed time from the midnight (00:00) as "E&E time" with the unit of Kmin. was suggested. The model to estimate the scaled temperature ($T^*e$) of crop leaf surface temperature by scale factor ($T^*$) according to the "E&E time : Kmin."(X) was developed as eq. (1) $T^*e=0.5{\cdot}sin(X+780)+0.5$ (2) $T^*=(Tx-Tn)/(Tm-Tn)$, Tx : Daily leaf temperature, Tm : Daily maximum leaf temperature, Tn : Daily minimum leaf temperature. Relative sensitivity of the measured temperature compared to the estimated temperature of red pepper, soybean and persimmon was 1.078, 1.033 and 0.973, respectively.

• 한국항해항만학회지
• /
• 제35권5호
• /
• pp.401-406
• /
• 2011

경제적 여유와 함께 사람들의 요구가 다양화 되면서 해양 레저에 대한 관심이 증가하고 있다. 삼면이 바다인 우리나라는 바다를 이용한 해양 레저의 잠재력이 매우 높기 때문에 해양 리조트 개발이 증가할 것으로 예상된다. 그러나 이미 포화상태에 이르렀으며 또한 환경문제를 내포하고 있는 매립에 의한 개발은 상당한 어려움이 따를 것으로 예상된다. 이에 대한 대안으로 플로팅 건축에 의한 개발이 확대될 것으로 기대되지만 플로팅에 의한 해상호텔에 대한 연구는 아직 초보적인 단계에 있으며 이용객의 쾌적성에 직접적인 영향을 미치는 공조 설비 용량을 선정하기 위한 부하계산에 대한 연구는 전무하다고 할 수 있다. 본 연구에서는 육상의 일반적인 호텔과 선박의 공조부하 계산법을 비교 분석함으로써 해상호텔의 공조부하계산방법에 대해 검토한다.

• 농촌계획
• /
• 제23권4호
• /
• pp.153-168
• /
• 2017

The main objective of this study was to assess reference evapotranspiration based on multiple GCMs (General Circulation Models) and estimation methods. In this study, 10 GCMs based on the RCP (Representative Concentration Pathway) 4.5 scenario were used to estimate reference evapotranspiration. 54 ASOS (Automated Synoptic Observing System) data were constructed by statistical downscaling techniques. The meteorological variables of precipitation, maximum temperature and minimum temperature, relative humidity, wind speed, and solar radiation were produced using GCMs. For the past and future periods, we estimated reference evapotranspiration by GCMs and analyzed the statistical characteristics and analyzed its uncertainty. Five methods (BC: Blaney-Criddle, HS: Hargreaves-Samani, MK: Makkink, MS: Matt-Shuttleworth, and PM: Penman-Monteith) were selected to analyze the uncertainty by reference evapotranspiration estimation methods. We compared the uncertainty of reference evapotranspiration method by the variable expansion and analyzed which variables greatly influence reference evapotranspiration estimation. The posterior probabilities of five methods were estimated as BC: 0.1792, HS: 0.1775, MK: 0.2361, MS: 0.2054, and PM: 0.2018. The posterior probability indicated how well reference evapotranspiration estimated with 10 GCMs for five methods reflected the estimated reference evapotranspiration using the observed data. Through this study, we analyzed the overall characteristics of reference evapotranspiration according to GCMs and reference evapotranspiration estimation methods The results of this study might be used as a basic data for preparing the standard method of reference evapotranspiration to derive the water management method under climate change.