• 한국산업융합학회 논문집
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• 제23권5호
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• pp.773-787
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• 2020

In the injection molding process, the controlling stability of products quality is a very important factor in terms of productivity. Even when the optimum process conditions for the desired product quality are applied, uncontrollable external factors such as ambient temperature and humidity cause inevitable changes in the state of the melt resin, mold temperature. etc. Therefore, it is very difficult to maintain prodcut quality. In this study, a system that learns the correlation between process variables and product weight through artificial neural networks and predicts process conditions for the target weight was established. Then, when a disturbance occurs in the injection molding process and fluctuations in the weight of the product occur, the stability control of the product quality was performed by ANN predicting a new process condition for the change of weight. In order to artificially generate disturbance in the injection molding process, controllable factors were selected and changed among factors not learned in the ANN model. Initially, injection molding was performed with a polypropylene having a melt flow index of 10 g/10min, and then the resin was replaced with a polypropylene having a melt floiw index of 33 g/10min to apply disturbance. As a result, when the disturbance occurred, the deviation of the weight was -0.57 g, resulting in an error of -1.37%. Using the control method proposed in the study, through a total of 11 control processes, 41.57 g with an error of 0.00% in the range of 0.5% deviation of the target weight was measured, and the weight was stably maintained with 0.15±0.07% error afterwards.

• 펄프종이기술
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• 제48권3호
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• pp.5-13
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• 2016

This study investigated the effects of different factors on the migration of a fluorescent whitening agent (FWA) from paper treated with FWAs to non-fluorescent papers. FWA migration experiments were carried out in vertical and friction contacts between the papers dyed with FWAs and non-fluorescent papers. During the experiments, we identified the effects of the addition and types of FWAs, contact time, temperature, and relative humidity (RH) on FWA migration. The fluorescence indices of the non-fluorescent papers were measured before and after the migration experiments, and the Student's t test, a statistical tool, was utilized to compare results from different migration experiments. In vertical contact experiments, FWA migration to non-fluorescent paper was observed at $30^{\circ}C$ and 70% RH; this was attributed to the high moisture content of the paper. FWA migration did not occur significantly at $23^{\circ}C$ and 50% RH. In the friction contact experiments, FWA migrations were identified at both temperature conditions and RH percentages. The addition and types of FWAs did not increase the fluorescence index of non-fluorescent papers. Therefore, it was concluded that the moisture content of paper and the friction contact affected FWA migration from the papers containing internal and surface FWAs.

• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.19-27
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• 2009

In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate were analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1) The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. According to the building height, the highest temperature was increased by $2.1^{\circ}C$ from 2-story to 5-story building and the absolute humidity by 2.1g/kg maximum and the wind velocity by 1.0m/s was decreased from 2-story to 20-story building. (2) Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature. In the last, deriving the combination of building coverage and building height is needed to obtain effectiveness of the urban built environment planning at the point of the urban climate. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analyzing urban climate phenomenon.

• Journal of Animal Science and Technology
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• 제63권4호
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• pp.872-883
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• 2021

We evaluated the effects of heat stress on physiological responses and milk production in Holstein and Jersey cows reared in Korea. The mean average temperature-humidity index (THI) increased significantly from May to August and then decreased until October. The mean average rectal temperature (RT) was increased in Holstein cows compared with Jersey cows, as the THI values increased from 61 to 85. The average respiratory rate (RR) was increased in Jersey cows compared with Holstein cows when the THI value increased from 61 to 85. The average surface temperature of the rumen and udder was higher in Jersey cows than in Holstein cows when the THI value increased from 61 to 85. No significant difference was noted with respect to relative serum volumes between the breeds and THI ranges, but we measured significant changes in serum pH in Holstein and Jersey cows when the THI value increased from 61 to 85. Milk production was not significantly changed in Holstein cows when the THI increased from 61 to 85, but milk production and milk protein content were significantly altered in Jersey cows when the THI increased from 61 to 85. Current study suggests that Holstein cows still have an advantage in terms of the economic returns of dairy farms in Korea. Therefore, further research is required regarding the heat tolerance of Jersey cows in Korean climatic conditions.

• 한국농림기상학회지
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• 제14권1호
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• pp.1-10
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• 2012

본 연구는 디지털예보(현 동네예보) 자료를 활용하여 우리나라의 산불위험예보의 정확도 향상은 물론 기상에 의한 산불위험지수를 산출하여 한반도의 산불위험예보 체계를 구축하는데 있다. 한반도 지역의 산불발생위험을 나타내는 기상지수(daily weather index, DWI)를 산출하기 위해 기상청의 5km 격자간격의 디지털예보자료를 이용하였다. DWI 분석을 위해 온도, 습도, 풍속 UV, 1시간 강우량, 12시간 강우량을 대상으로 한반도 전역에 대한 기상요소별 기후분포도를 제작하였다. 한반도의 기상에 의한 일일 DWI 산출을 위해 대형산불이 자주 발생하는 강원도 지역의 산불발생확률식 $[1+{\exp}\{-(2.494+(0.004{\times}T_{max})-(0.008{\times}EF))\}]^{-1}$을 적용하였다. 기상예보자료의 예측정확도 검증을 위해 RDAPS, 디지털예보, 실황자료 모두 2005년 12월 12일 15시 자료를 대상으로 비교 분석한 결과 76개 기상관측소에서 관측한 실황자료에 대응하는 기상요소별 디지털예보의 예측값이 RDAPS 추출 자료보다 향상된 예측결과를 보였다. 산불위험예보 정확도 검증을 위해 사용한 실황자료와 디지털예보자료의 평균오차는 평균 기온 $0.2^{\circ}C$, 실효습도 2.4%, 평균풍속 2.2m/s로 나타나 큰 변이는 없었지만, 평균풍속에서 실측값과 예측값간의 차이가 있는 것으로 나타났다. 디지털예보자료를 활용할 경우 RDAPS 자료보다 산불위험예보의 정확도가 크게 향상되는 결과를 얻을 수 있었으며, 산불위험예보의 정확도 검증을 위해 실황자료와 디지털예보자료를 적용하여 예측된 전국 233개 시 군 구의 평균 산불위험지수를 각각 추출하여 비교한 결과 $R^2$=0.854의 높은 정확도를 보였다. 산불위험도가 가장 높은 15시의 실제 76개소에서 관측한 기상자료를 적용하여 전국의 산불위험지수를 예측한 값은 70.5로 디지털예보자료를 적용하여 예측한 위험지수(70.0)와 0.5의 오차를 보여 예측력이 개선되었음을 확인할 수 있었다. 따라서 디지털예보를 적용할 경우 실황자료와의 예측력이 검증된 만큼 향후 기상에 의한 한반도의 산불발생위험지수를 보다 정확하게 계산하는데 유용하게 이용할 수 있을 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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• pp.355-365
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• 2010

The aim of this study was to investigate the effect of supplemental recombinant bovine somatotropin (rbST) and cooling with misters and fans on renal function in relation to regulation of body fluids in different stages of lactation in crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each, housing in a normal shaded barn (NS) and in a shaded barn with a mister-fans cooling system (MF). The experiment in each group was divided into 3 phases, early- (Day 75 postpartum), mid- (Day 135 postpartum), and late stage of lactation (Day 195 postpartum). The pre-treatment study was conducted on the starting day of each stage of lactation and the treatment study was performed after the end of the pre-treatment, during which the animal was injected with 500 mg of rbST (POSILAC) every 14 days for three times. During the study, ambient temperature at the hottest period daily in the MF barn was significantly lower, while relative humidity was higher than that of the NS barn. The temperature humidity index (THI) in both barns ranged from 79-85 throughout the periods of study. Cows in the MF barn showed a lower rectal temperature and respiration rate as compared with cows in the NS barn. The effect of rbST administration increased both rectal temperature and respiration rates of cows housed in either the NS or MF barn. Milk yield significantly increased in cows treated with rbST in all stages of lactation. Increases in mammary blood flow, accompanied by increases of total body water (TBW), extracellular fluid (ECF), blood volume (BV) and plasma volume (PV), were observed in both groups of cows receiving rbST in all stages of lactation. No alterations of renal blood flow and glomerular filtration rate were observed in cows receiving rbST, but decreases in urinary excretion and fractional excretion of sodium, potassium and chloride ions appeared to correlate with reduction in the rate of urine flow and osmolar clearance during rbST administration. These results suggest that the effect of rbST supplementation to cows housed either in NS or MF barns on body fluid volume expansion is attributable to changes in the rate of electrolyte excretion by the kidney. The increased availability of renal tubular reabsorption of sodium, potassium and chloride ions during rbST treatment was a major factor in retaining body water through its colligative properties in exerting formation of an osmotic force mechanism.

• 한국조경학회지
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• 제47권3호
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• pp.12-21
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• 2019

다양한 운동장 포장재료(인조잔디, 천연잔디, 마사토)가 인간 열 환경에 미치는 영향을 알아보기 위해 초 가을철 미기후자료(기온, 습도, 풍속, 태양 및 지구복사에너지)를 측정하여 비교분석하여 보았다. 그 결과, 포장재료에 따른 기온, 습도, 풍속은 평균적으로 차이가 크지 않았으며, 평균복사온도에서 가장 큰 차이를 보여주었다. 태양복사에너지에서는 태양복사에너지 반사율(알베도)이 가장 높았던 천연잔디에서, 지구복사에너지에서는 지표면 온도가 가장 높았던 인조잔디에서 가장 높은 복사에너지를 인체에 보내는 것으로 나타났다. 인간 열환경지수 PET에서는 인조잔디>마사토>천연잔디 순으로 나타났으며, 천연잔디포장이 인조잔디포장보다 최대 2/3 단계 평균적으로 1/2 단계 낮은 열환경을, 마사토 포장은 인조잔디포장보다 최대 2/3 단계 평균적으로 1/3 단계 낮은 열환경을 조성할 수 있는 것으로 나타났다. 천연잔디포장은 마사토 포장에 비해 최대 1/3 단계 낮은 열환경을 조성할 수 있는 것으로 나타났다. UTCI에서는 PET보다 더 작은 차이를 보이는 것으로 나타났다. 그러므로, 운동장을 포함한 옥외공간 설계 시 계획단계에서부터 재료 선정에 신중을 기하여야 할 것이다.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.207-210
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• 2005

Ubiquitous computing is one of the key technology areas in the "Project on Development of Ubiquitous computing and network technology" promoted by the Ministry of Science and Technology as a frontier business of the $21^{st}$ century in Korea, which is based on the new concept merging physical space and computer-based cyber space. With recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low-power consumption wireless micro sensor nodes have been available. Using these smart sensor nodes, there are many activities to monitor real world, for example, habitat monitoring, earthquake monitoring and so on. In this paper, we introduce web-based real environment monitoring system incorporating wireless sensor nodes. It collects sensing data produced by some wireless sensor nodes and stores them into a database system to analyze. Our environment monitoring system is composed of a networked camera and environmental sensor nodes, which are called Mica2 and developed by University of California at Berkeley. We have modified and ported network protocols over TinyOS and developed a monitoring application program using the MTS310 and MTS420 sensors that are able to observe temperature, relative humidity, light and accelerator. The sensed data can be accessed user-friendly because our environment monitoring system supports web-based user interface. Moreover, in this system, we can setup threshold values so the system supports a function to inform some anomalous events to administrators. Especially, the system shows two useful pre-processed data as a kind of practical uses: a discomfort index and a septicity index. To make both index values, the system restores related data from the database system and calculates them according to each equation relatively. We can do enormous works using wireless sensor technologies, but just environment monitoring. In this paper, we show just one of the plentiful applications using sensor technologies.

• 한국인터넷방송통신학회논문지
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• 제20권5호
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• pp.127-133
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• 2020

WHO 산하 국제 암 연구소 에서는 미세먼지를 1급 발암물질로 지정했다. 미세먼지는 대기 중에 떠다니며 눈에 보이지 않을 정도로 작은 먼지를 말한다. 미세먼지는 주로 석탄이나 석유 같은 화석연료의 연소과정에서 배출되며, 페질환, 페렴, 심장질환을 유발 할 수 있는 위험 인자 이다. 환경부에서는, 최근 미세먼지 측정소 10곳의 산출자료를 분석한 결과, 약 60% 정도가 기존 대기측정농도가 더 높게 나오는 오류가 있다고 발표하였다. 미세먼지를 정확하게 예측하기 위해서는, 풍향, 측정위치를 반드시 보정해야 한다. 본 논문에서는 이러한 문제점을 해결하기 위해서, 퍼지 규칙을 이용해서 이러한 문제점을 해결하였다. 뿐만 아니라, 길거리 보행자가 실제로 느끼는 미세먼지 체감지수를 산출하기 위해서, 본 논문에서는 날씨조건, 온도조건, 습도조건, 바람조건을 고려한 미세먼지 체감지수 산출 컴퓨터 모의실험을 수행 하였다.

• 한국환경보건학회지
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• 제1권1호
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• pp.9-13
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• 1974

For the purpose of determining the degree of freshness and bacterial contamiation of poultry farm eggs, the author collected 550 specimens from poultry farm, during the period from July 22 through October 3, 1973. Eggs of poultry farm were stored at $4{\pm} 1{\circ}$(Relative humidity 67~86%), $18\pm 1\circ$(70~80%) and $25\pm 1\circ$(73~82%) during 20 days. The results are summarized as follows: 1) Egg weight was decreased $0.97\pm 0.27$ gm at $4\pm 1\circ$, $1.68\pm 0.25$ gm at $18\pm 1\circ$ and $2.76\pm 0.30$ gm at $25\pm 1\circ$ after 20 days. 2) Specific gravity of fresh eggs was found to average 1.0785. 3) Yolk index of fresh eggs was found to average 0.419. 4) The regression equation between Yolk index and days was obtained y=0.417-0.001x (r=-0.481, p<0.05) at $4\pm 1\circ$, y=0.394-0.004 x (r=-0.738, p<0.01) at $18\pm 1\circ$ and y=0.391-0.011 x (r=-0.958, p<0.001) at $25\pm 1\circ$. 5) The regression equation between Yolk index and NaCl concentration (specific gravity) was obtained y=-0.001+0.04 x (r=0.796, p<0.001). 6) pH of albumin was changed from 8.0 to 8.8, 9.2 and 9.3 at $4\pm 1\circ$, $18\pm 1\circ$ and $25\pm 1\circ$ after 20 days. 7) Total Viable Bacteria in air cell was increased slowly according to the stored period at each temperature.