• 제목/요약/키워드: 평균온도분포

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Statistical Probability Analysis of Storage Temperatures of Domestic Refrigerator as a Risk Factor of Foodborne Illness Outbreak (식중독 발생 위해인자로서 가정용 냉장고의 온도에 대한 확률분포 분석)

  • Bahk, Gyung-Jin
    • Korean Journal of Food Science and Technology
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    • v.42 no.3
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    • pp.373-376
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    • 2010
  • The objective of this study was to present the proper probability distribution model based on the data obtained from surveys on domestic refrigerator food storage temperatures in home. Domestic refrigerator temperatures were determined as risk factors in foodborne disease outbreaks for microbial risk assessment (MRA). The temperature was measured by directly visiting 139 homes using a data logger from May to September of 2009. The overall mean temperature for all the refrigerators in the survey was $3.53{\pm}2.96^{\circ}C$, with 23.6% of the refrigerators measuring above $5^{\circ}C$. Probability distributions were also created using @RISK program based on the measured temperature data. Statistical ranking was determined by the goodness of fit (GOF, i.e., the Kolmogorov-Smirnov (KS) or Anderson-Darling (AD) test) to determine the proper probability distribution model. This result showed that the LogLogistic (-10.407, 13.616, 8.6107) distribution was found to be the most appropriate for the MRA model. The results of this study might be directly used as input variables in exposure evaluation for conducting MRA.

A Study on Thermal Deformations of AC7A Tire Mold Casting Material by Pre-Heating Temperatures of Permanent Casting System (금형주조장치의 예열온도에 따른 타이어 몰드용 AC7A 주조재의 열변형에 관한 연구)

  • Choi, Je-Se;Choi, Byung-Hui
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2596-2603
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    • 2013
  • The precision and endurance of tire mold are very important factors to decide the quality of tire. However, the investigation on the thermal deformation of tire mold has a lot of trouble because the tire mold is produced in airtight permanent casting material. In this study, the thermal deformations such as temperature, displacement and stress distributions inside the AC7A tire mold casting material were analyzed by numerical analysis according to the preheating temperature of permanent casting device. In order to verify the results of numerical analysis, the experiments for temperature measurement of the AC7A casting material were carried out under the same condition with numerical analysis. For the numerical analysis, "COMSOL Multiphysics" was used. The preheating temperatures were set up $150^{\circ}C$, $200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$, respectively. The thermal deformations were calculated in each case. When the preheating temperature is $300^{\circ}C$, displacement and stress are the lowest with 0.25mm and 0.351GPa, but the temperature is the highest with $374.27^{\circ}C$. When the experimental results were compared with the numerical results, there were some temperature differences because of the latent heat by phase change heat transfer. However, the cooling patterns were almost similar except for the latent heat section.

Estimation of changes in probability snow depth due to the rising global average temperature (지구평균온도 상승에 따른 확률 적설심 변화 추정)

  • Heeseong Park;Gunhui Chung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.274-274
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    • 2023
  • 기후변화의 영향으로 겨울철 적설의 양상이 과거와는 많이 달라진 것으로 보인다. 따라서 미래의 적설이 어떤 확률로 발생할 것인지도 과거에 비해 많이 달라질 것으로 예상된다. 하지만 어떤 정도로 달라질 것인지는 정확하게 알 수가 없다. 본 연구에서는 이를 합리적으로 추정하기 위해 일본에서 수행한 대규모 기후 앙상블 모의실험 결과로 생성된 d4PDF(Data for Policy Decision Making for Future Change) 자료 중 적설과 기온 자료를 이용하여 일 최심적설심을 모의하고 연최대치계열을 작성하여 과거의 최심적설심 연최대치분포와 비교하여 분위사상법을 통해 모형의 오차를 보정한 후 미래 지구평균온도 상승 시의 기후모의 결과에 적용함으로써 지구평균온도 상승 정도에 따라 우리나라의 적설양상과 확률적설심이 어떻게 변화할 것인지 추정해 보았다. 연구의 결과는 미래 적설과 관련된 설계와 방재 목적에 참고적으로 활용될 수 있을 것이다.

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Implementation of Semi-Automatic Intermittent Flow Type Hydroponics Smart Farm using Arduino (아두이노를 활용한 반자동 간헐흐름식 수경재배 스마트팜 구현)

  • Jang, Dong-Hwan;Kim, Dae-Hee;Lee, Sung-Jin;Moon, Sang-ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.376-378
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    • 2021
  • According to the 2020 Global Climate Report released by the World Meteorological Organization, the average temperature of the Earth in 2019 was measured 1.1℃ higher on average than the temperature measured between 1850 and 1900 before industrialization. The change in average temperature affects the distribution of plants, and according to the vulnerability analysis paper, it can be seen that there is a change in the distribution area of plants when the average temperature rises. In this paper, to cope with these environmental changes, we propose a method of fabricating intermittent flow hydroponic smart farms using Arduino and sensors and controlling them through PCs and applications. The manufactured hydroponic smart farm identifies the farm's temperature and humidity, positive pH concentration, illumination, and water quality to check the amount of pumping, supplement LED control, sensor condition, overall management and cultivation of the farm, and grows in an appropriate environment.

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A Study on Monitoring of Gas Temperature in Boiler Furnace (보일러 화로내 연소가스 온도분포 구현에 관한 연구)

  • Jang, Seok-Won
    • Journal of Energy Engineering
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    • v.15 no.3 s.47
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    • pp.188-193
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    • 2006
  • This paper intends to present theoretical study and its application result of the way of the temperature distribution embodiment through the production of subdivided nod's temperature from the average, maximum and minimum temperature following acoustic speed measurement with a set of acoustic speed meters at the arbitrary section in the furnace. By measuring the acoustic speed between the speed meters, flue gas temperature field can be determined. Then Subdivided arbitrary grid's temperatures can be infered out of surrounding nod's temperature distribution, and finally the entire grid's temperature distribution will be found. In this article, theoretical background, related system setup. and real application result are examined and discussed.

A study of the removal efficiency of acidic gas at various operating conditions using Computation Fluid Dynamics (전산유체역학을 이용한 반건식 반응기의 운전조건에 따른 산성가스제거효율에 관한연구)

  • Lee, Geon-Ju
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.1
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    • pp.93-101
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    • 2011
  • The modeling of SDR was carried out for the application of the solid waste incineration system. To find optimum operating condition for removal of acidic gases, computation fluid dynamic(CFD) model was used. In this study, the temperature profile of SDR(spray dry reactor) and the gas velocity profile for different models were investigated. In this model, the diameter of SDR was 3 meter and the height of SDR was 9 meter. The amount of inlet combustion gas of SDR was $6,125Nm^3/hr$ and the inlet temperature of SDR was 493 K. The amount of lime injection of SDR was 151 kg/hr. When the inlet shape of SDR was changed, the temperatur of SDR was changed and the gas velocity of SDR was 0.48 m/sec to 1.17m/sec and the outlet gas velocity of SDR was 6.9 m/sec to 7.42m/sec As a result of modeling, the average velocities in SDR and outlet were 0.489 m/sec and 7.424 m/sec, respectively, in which the temperature of outlet in SDR was 448 K.

Transition of Natural Convective Flows Subjected to Small-Wave-Number Sinusoidal Wall Temperatures with Phase Difference (위상 차이가 있는 작은 파동수의 정현적인 벽면 온도 하에서의 자연 대류 유동의 천이)

  • Yoo, Joo-Sik
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.300-311
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    • 2008
  • This study investigates the natural convection of air(Pr=0.7) between two walls having a small- wave- number sinusoidal temperature distributions with a phase difference. The wave number and the phase difference of wall temperatures are k=0.5 and ㄱ/2, respectively. In the conduction-dominated regime at small Rayleigh number, two slightly inclined cells are formed over one wave length. At higher Rayleigh number, however, multicellular convection occurs in thermally unstable region. A spatial symmetry is intermittently broken in the transient period at the Rayleigh number near the critical value. The steady-state flows always satisfy the spatial symmetry. A steep increase of Nusselt number occurs near the Rayleigh number at which transition of flow pattern occurs.

고리 3호기 7주기 운전자료 분석

  • 김재학;이창호;송재웅
    • Nuclear Engineering and Technology
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    • v.26 no.1
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    • pp.149-159
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    • 1994
  • 노심설계의 검증을 통하여 설계의 신뢰성을 확인하며 이는 발전소 운전의 안전성과 경제성을 향상시킬 수 있는 발판이 된다. 본 보고서는 국산핵연료를 장전한 고리 3호기 7주기의 운전자료 중에서 핵설계와 관련한 인자의 측정치를 설계치와 비교 분석하고 평가하였다. 비교대상이 된 핵특성인자는 반응도 관련 자료인 임계붕소농도, 제어봉가, 등온온도계수 및 감속재온도계수등이고 출력분포 관련자료인 핵반응률 분포, 집합체 출력분포, 반경방향 첨두출력 F$\Delta$H/$^{N}$ , 축방향 출력분포, 축방향 첨두출력 Fq(z)및 노심 평균 축방향 출력편차(AO)등이다. 이들 인자들에 대한 설계치는 측정치와 잘 일치하였으며, 모두 안전성 관련 제한치이내로 만족함을 확인하였다. 또한 이러한 비교 분석을 통하여 후속주기의 핵설계에 운전자료를 반영할 수 있는 근거를 마련하였다.

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영광 2호기 4주기 운전자료 비교 분석

  • 이기복;배창준
    • Nuclear Engineering and Technology
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    • v.25 no.3
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    • pp.470-479
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    • 1993
  • 노심설계의 검증을 통하여 설계의 신뢰성이 확인되며 이는 발전소 운전의 안전성과 경제성을 향상시킬 수 있는 발판이 된다. 본 기고문은 국산핵연료가 장전되었던 영광 2호기 4주기의 운전자료 중에서 핵설계와 관련한 인자의 측정치를 설계치와 비교 분석하고 평가하였다. 비교대상이 된 핵 특성인자는 반응도 관련 자료인 임계붕소농도, 제어봉가, 등온온도계수 및 감속재온도계수 둥이고 출력분포 관련자료인 핵반응률 분포, 집합체 출력분포, 반경방향 첨두출력 F_ $\Delta$H/$^{N}$ , 축방향 출력분포, 축방향 첨두출력 Fq(z) 및 노심 평균 축방향 출력편차(AO)등이다. 이들 인자들에 대한 설계치는 측정치와 잘 일치하였으며, 모두 안전성 관련 제한치이내로 만족함을 확인하였다. 또한 운전자료의 비교 분석을 통하여 후속주기의 핵설계에 반영할 수 있는 근거를 마련하였다.

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Development of Axial Power Distribution Monitoring System Using Two-Level Encore Detector (상하부 2개의 노외계측기를 이용한 축방향 출력분포 감시계통 개발)

  • Chi, Sung-Goo;Song, Jae-Woong;Ahn, Dwak-Hwan;Kuh, Jung-Eui
    • Nuclear Engineering and Technology
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    • v.21 no.4
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    • pp.294-301
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    • 1989
  • The Axial Power Distribution Monitoring System(APDMS) program was developed to calculate a detailed axial power distribution using two-level excore detector, cold leg temperature and control rod position signals. The unnormalized two-level excore detector signals were corrected for the rod shadowing factor determined by control rod position and for the temperature shadowing factor calculated based on cold leg temperature. A shape annealing matrix was then applied to the corrected excore detector response to yield peripheral power. After the core average power was obtained using linear relationship bet-ween core average and peripheral power, the boundary point power correction coefficient was applied to core average power in order to obtain boundary power for both upper and lower core axial boundaries. Then, the axial power distribution was synthesized by spline approximation. In spite of burnup, power level, control rod postion and axial offset changes, the comparisons of axial power distributions between BOXER simulation program and APDMS results showed good agreements within 5% root mean square error for Kori Unit 3 Cycle 4.

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