• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.283-288
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• 2016

Optimizing the number of ad clicks is a large-scale learning problem that is central to the multi-billion-dollar mobile advertising industry. There are currently several optimization methods being used, including ad mediation and ad positioning. Recently, researchers have recommended using ad refresh interval as a new method for optimizing mobile advertising. This paper applies that new method to optimize content duration for mobile ads. The result achieved from this optimization study could further increase revenue for mobile advertisers and publishers. This research has high applicability for the growing mobile advertising industry. It also lays out a solid background for future research in this promising area.

• Journal of the Korean Wood Science and Technology
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• 제51권5호
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• pp.381-391
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• 2023

Densification is a technique used to improve biomass quality in wood pellet manufacturing and torrefaction treatment. In this study, the effects of torrefaction on the quality of Calliandra wood pellets were investigated, and pellets of Calliandra wood (Calliandra calothyrsus) and bark were evaluated. The study was conducted using a completely randomized design with two treatment factors, namely torrefaction temperature (250℃ and 300℃) and torrefaction duration (30, 45, and 60 min). The results showed that the interaction between temperature and torrefaction duration significantly affected the compressive strength, proximate value, and calorific value of the torrefied Calliandra wood pellets. An increase in the temperature and torrefaction duration decreased the compressive strength, moisture content, volatile matter content, and ash content of the torrefied Calliandra wood pellets. Conversely, the calorific value of Calliandra wood pellets increased with increasing temperature and torrefaction duration. The best-quality Calliandra wood pellets were produced at a torrefaction temperature and duration of 300℃ and 60 min, respectively. In terms of important quality parameters, ash content of 0.90% and calorific value of 6,303.80 cal/g were observed, which complied with the quality standards of Indonesian National Standard 8675:2018 and Deutsche Industrie Norm 51731.

• 생물환경조절학회지
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• 제13권2호
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• pp.120-123
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• 2004

본 연구는 망실 하우스 내에서 봄감자 재배 시. brushing 처리가 감자의 도장 방지와 생육과 수량 및 체내 전분함량에 미치는 효과를 구명하기 위하여 수행하였다. 지상부의 생육은 생육 후반기로 갈수록, brushing 처리시간이 길수록 감소하였다. 측지 수도 처리시간이 길수록 감소하는 경향이었다. 경장과 경경은 5월 6일에는 처리간에 비슷하였으나 생육 후반기로 갈수록 모든 처리에서 증가하였는데 평균적으로 30∼36mg/100 $\textrm{cm}^2$였다. 지상부ㆍ지하부의 생체중과 건물중은 처리시간이 긴 것이 무거웠고, 전분 함량은 무처리에 비해 brushing 처리한 것이, 그리고 처리시간이 긴 것이 높았다.

• Journal of Ecology and Environment
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• 제33권1호
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• pp.47-57
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• 2010

To understand day-to-day fluctuations in soil moisture content in Seoul, I simulated daily soil moisture content from 1908 to 2009 using long-term climatic precipitation and temperature data collected at the Surface Synoptic Meteorological Station in Seoul for the last 98 years with a hydrological simulation model, BROOK. The output data set from the BROOK model allowed me to examine day-to-day fluctuations and the severity and duration of droughts in the Seoul area. Although the soil moisture content is highly dependent on the occurrence of precipitation, the pattern of changes in daily soil moisture content was clearly quite different from that of precipitation. Generally, there were several phases in the dynamics of daily soil moisture content. The period from mid-May to late June can be categorized as the initial period of decreasing soil moisture content. With the initiation of the monsoon season in late June, soil moisture content sharply increases until mid-July. From the termination of the rainy season in mid-July, daily soil moisture content decreases again. Highly stochastic events of typhoons from late June to October bring large amount of rain to the Korean peninsula, culminating in late August, and increase the soil moisture content again from late August to early September. From early September until early October, another sharp decrease in soil moisture content was observed. The period from early October to mid-May of the next year can be categorized as a recharging period when soil moisture content shows an increasing trend. It is interesting to note that no statistically significant increase in mean annual soil moisture content in Seoul, Korea was observed over the last 98 years. By simulating daily soil moisture content, I was also able to reconstruct drought phenomena to understand the severity and duration of droughts in Seoul area. During the period from 1908 to 2009, droughts in the years 1913, 1979, 1939, and 2006 were categorized as 'severe' and those in 1988 and 1982 were categorized as 'extreme'. This information provides ecologists with further potential to interpret natural phenomenon, including tree growth and the decline of tree species in Korea.

• 한국작물학회지
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• 제52권4호
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• pp.375-379
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• 2007

저장기간이 벼 생태형에 따라 미립 특성에 영향하는 정도를 검토하기 위하여 자포니카형, 통일형 및 통일형에서 유래된 1대잡종형의 정조를 $4{\sim}40$개월간 외부환경이 제어되지 않은 종자 저장실에 저장하여 저장기간에 따른 물리화학적 특성 변화에 대하여 조사한 결과는 다음과 같다. 1. 종자 발아율은 저장기간이 길어짐에 따라 낮아졌는데 자포니카형은 16개월 저장시 66.7%, 28개월 저장시 2.5%로 크게 떨어졌고 40개월 후에는 전혀 발아되지 않았으며, 통일형과 1대잡종형은 28개월까지는 뚜렷한 차이가 없었으나 40개월에는 각각 54.0% 및 67.9%로 발아율의 차이를 보였다. 2. 현미 경도는 통일형, 1대잡종형, 자포니카형의 순서로 높았으며 저장기간에 따른 유의한 차이는 없었다. 3. 알카리 붕괴도는 저장기간이 길어짐에 따라 증가하는 경향이었으며, 단백질 함량은 완만하게 감소하였고, 아밀로즈 함량은 일정한 경향이 없었다. 4. 전당 함량과 환원당 함량은 저장기간이 경과함에 따라 증가하였는데 저장 28 개월 이내에서 증가폭이 컷고 그 이후는 완만한 증가를 보였다. 5. 전당 함량에 대한 환원당 함량의 비율은 저장기간이 길수록 전당 함량보다는 환원당 함량의 증가가 많아서 비율이 높아졌다.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.67-73
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• 1995

This study was undertaken to investigate the effect of heat treatment on the dynamic viscoelasticity of three species of Phyllostachys bambusoides, Phyllostachys nigra var. henonis and Phyllostachys pubescens, grown in southern Korea. The bamboo was treated for 3~24 hours at $60{\sim}180^{\circ}C$, and then was treated in a climatic chamber for 3~48 hours at $40^{\circ}C$ and 95% relative humidity. The results obtained are summarized as follows : 1. Dynamic Young's modulus decreased with increasing temperature and duration of the heat treatment. 2. Internal friction decreased with increasing treatment duration. 3. Moisture absorption decreased with increasing temperature and duration of the heat treatment. 4. Dynamic viscoelasticity decreased, whereas internal friction slowly increased, with increasing moisture content.

• 한국식품영양과학회지
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• 제24권5호
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• pp.785-789
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• 1995

참기름의 회분식 압착 최적화와 압착요인들의 상호관계를 규명하기 위하여 생참깨와 볶은 참깨를 온도($30, 40, 50, 60^{\circ}C$), 압력(10, 30, 50, 70MPa), 압착 시간(5, 7, 9, 11min) 및 수분 함량(2.5, 4.5, 6.5, 8.5%) 별로 압착하였다. 추출율은 수분 함량 2.5~4.5%, 30~$50^{\circ}C$, 30~50MPa일 때 높았으며, 수분 함량을 4.5% 이상으로 증가시키면 급격히 감소하였다. 최적 조건은 생참깨가 온도 $40.1^{\circ}C$, 압력 54.4MPa, 압착 시간 21.7분, 수분 함량 1.3%이었으며, 볶음 참깨는 각각 $44.4^{\circ}C$, 37.8MPa, 14.4분, 2.52%이었다. 최적 조건에서의 추출율은 생참깨가 84.6%, 볶음 참깨가 81.7%이었다. 통계분석 결과 수분 함량이 기름의 추출율에 가장 큰 영향을 미쳤으며, 그 다음으로는 압력, 온도 순이었다. 상호작용 효과는 압력X수분 함량, 온도X수분 함량, 온도X압력의 영향이 컸다. 온도(T), 압력(P), 압착 시간(D) 및 수분 함량(M)과 기름 추출율(Y) 간에는 생참깨가 $Y=18.20$ $35.66P$＋$24.52M-4.45P^{2}-1.20TM-4.02PM-6.62M^{2},\;r^{2}=0.89$, 볶은 참깨가 $Y=117.93$＋$16.40P-58.61M-2.75P^{2}$＋$1.79TM-1.65PM$＋$7.16M^{2},\;r^{2}$$=0.91$의 관계를 보였다.

• 상하수도학회지
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• 제29권1호
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• pp.107-122
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• 2015

The purpose of this study is to analyze the structural stability of pavement due to water infiltration at the road with infiltration trench as using the FEM(finite element analysis). Five cases for FEM is divided considering the amount of rainfall and rain duration time. The results of FEM show that the more rainfall in a short period time is faster the change of moisture content. Also, it is the proportional relationship between and changing area of moisture content of more than 40% due to rainfall. Case 3 and 4 are necessary to check the installation of infiltration trench because of moisture content of more than 40%, recovery time of initial moisture content, and changing area of more than 40%. Case 1,2, and 5 have no a significant effect on road pavement structure due to lower moisture content and shorter duration time of higher moisture content.

• 대한간호학회지
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• 제25권2호
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• pp.193-209
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• 1995

The purpose of this study was to determine the effect of intermittent low - intensity, short duration exercise during hindlimb suspension on the mass, relative weight, myofibrillar protein content, cross-sectional area of Type I and Type II fibers and SDH activity in Type II(plantaris) muscle. To examine the effectiveness of intermittent low-intensity, short duration exercise on mass, myofibrillar protein content and fiber size, the hindlimbs of adult female Wistar rats were suspended(HS) and half of these rats walked on a treadmill for 45 min/day(9 min every 2h) at 5m /min and a 15$^{\circ}$grade (HS-EX). Plantaris wet weight was 19.67% significantly smaller(p<0.005) and relative plantaris weight was 6.25% smaller compared with those of control rats following seven days of hindlimb suspension. Plantaris wet weight and relative plantaris weight increased by 27.66%, 12.22% each through intermit-tent exercise during hindlimb suspension(p<0.005, p<0.05), moreover, plantaris wet weight and relative plantaris weight of the HS-EX rats were similar to those of control rats. Soleus wet weight and relative soleus weight decreased significantly by 31% and 22.0% in the HS rats(p<0.05). Soleus wet weight and relative soleus weight increased by 10.41%, 25.64% respectively through intermittent ex-ercise during hindlimb suspension, furthermore, soleus wet weight and relative weight of the HS-EX rats were closer to those of control rats. Myofibrillar protein content of plantaris and soleus decreased significantly by 51.49%, 59.65% each, following seven days of hindlimb suspension (p<0.005) Myofibrillar protein content of plantaris and soleus increased by 51.79%, 75.47% each with significance through intermittent exercise during hindlimb suspension(p<0.005). Myofibrillar protein content of plantaris and soleus in HS-EX rats was smaller than that of control rats. No change was observed in fiber type percentage following 1 week of hindlimb suspension or exercise during hindlimb suspension. The type I fiber cross-sectional area of both soleus and plantaris muscle was 18.72% and 41.07% lower in the HS than that of the controls (p<0.05, p<.001), that of both muscles was 6.60% and 29. 3％ greater in the HS-EX than that of the HS rats. HS plus intermittent low- intensity short duration exercise resulted in Type I fiber cross-sectional area closer to the controls. Type II fiber cross-sectional area of both plantaris and soleus muscle was 22.45% and 22.58% sl nailer in the HS than in the controls, that of both muschles in the HS-EX was 14.10%, 5.78% greater than HS. Intermittent exercise during hindlimb suspension resulted in Type I, II fiber cross-sectional area closer to the control value. There was no change in SDH activity following 1week of hindlimb suspension or exercise during hindlimb suspension in the plantaris muscle. The results suggest that intermittent low intensity short duration exercise can ameliorate Type II muscular atrophy Induced by hindlimb suspension.

• 폴리머
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• 제24권4호
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• pp.529-537
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• 2000

본 연구에서는 압출된 PP sheets를 각기 다른 조사량으로 조사 가교시켜, 겔 분율 차이에 따른 세 종류의 샘플을 만든 다음, 회분식 공정을 통해 초임계 유체 (supercritical fluid) 상태의 $CO_2$를 발포제로 사용하여 발포시켰다. 이때, 겔 분율의 차이 및 고압 반응기 내에서 충진 압력과 충진 시간이 셀 구조에 미치는 영향을 관찰하였다. 다음으로, 발포조건에 따른 셀 구조 변화를 알아보기 위해 발포온도와 발포시간을 변화시키면서 실험하였다. 고분자 샘플 내로 침투한 가스의 양은 겔 분율의 차이에 의한 변화가 거의 없었으며, 충진 압력이 2000 psi 이상일 경우 충진 압력의 영향에도 큰 영향을 받지 않았다. 겔 분율이 낮은 샘플은 발포온도나, 발포시간이 증가함에 따라 셀 크기가 불균일하게 증가하였으나, 겔 분율이 높은 샘플은 높은 발포온도와 발포시간에서도 균일하게 셀 크기를 유지하며 안정한 구조를 나타내었다.