• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.115-122
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• 2011

The impacts of elevated temperature and $CO_2$ were studied on the seedlings of Maackia amurensis and Viburnum opulus var. calvescens. The seedlings were grown in controlled-environment growth chambers with four combinations of temperature and $CO_2$ treatments: $25^{\circ}C$ + ambient $CO_2$ (400 ppm), $25^{\circ}C$ + elevated $CO_2$ (800 ppm), $30^{\circ}C$ + ambient $CO_2$ (400 ppm), and $30^{\circ}C$ + elevated $CO_2$ (800 ppm). Under elevated temperature and $CO_2$ concentration, the dry weight decreased in seedlings of M. amurensis, but increased in seedlings of V. opulus var. calvescens. In addition, the shoot to root (S/R) ratio in M. amurensis reduced but that of V. opulus var. calvescens increased under elevated $CO_2$ concentration. The S/R ratios of two tree species increased under higher temperature. M. amurensis represented lower carboxylation efficiency under higher temperature and $CO_2$ concentration and that of V. opulus var. calvescens showed lower values under the only higher temperature. Photosynthetic pigment content of in the leaves of M. amurensis was lower under higher $CO_2$ concentration and higher under the increase of temperature, but that of V. V. opulus var. calvescens decreased according to the increase of temperature. Chlorophyll a/b ratios of M. amurensis and V. V. opulus var. calvescens decreased obviously with the increase of $CO_2$ concentration and temperature, respectively. In conclusion, the growth and physiological responses under the environmental changes such as temperature and $CO_2$ concentration depend on the tree species. Therefore, more studies are needed to predict the response of each tree species against the climate changes.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.549-555
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• 2017

The production of ginseng cultivation is decreasing due to shortage of cultivated land and climate change, so additional methods are needed. Therefore, the physiological and morphological characteristics of finebubble were analyzed by applying them to ginseng cultivation which is the representative crop of Korea. The application of fine bubble water to 2 year old ginseng showed that stem length and leaf were increased, and weight increased as main root increased in root. In particular, it is shown that the weight of roots increases with the increase of leaf size. This is because the total chlorophyll content is high and it is judged to be related to the increase of photosynthesis efficiency. When the results of this study were confirmed, it was confirmed that ginseng cultivation using fine bubbles showed no inhibition of growth of ginseng. According to the results of physiological characteristics and subdividing results, It was confirmed that the growth of about 10% to 15% of the growth was increased and that the growth of ginseng was increased by applying the fine bubble when growing ginseng.

• Feed Journal
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• v.4 no.7 s.35
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• pp.108-115
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• 2006

우리나라는 사계절이 뚜렷한 기후적 환경으로 여름철 한낮의 외부온도가 35℃ 이상이 되는 날이 계속되고, 야간에도 25℃ 이상인 열대야가 지속되는 날이 많다. 이러한 조건하에서 양돈 생산성 향상을 위해서는 돼지의 사육환경과 성장단계별 적절한 사양기술을 투입하여야만 한다. 돼지는 생리적으로 추위에 의한 영향보다는 여름철 더위에 의한 영향을 쉬게 받으며, 이로 인해 자돈의 쇠약, 압사,수태율 저하, 번식장애 등으로 생산성 저하의 원인이 되며, 사육기간 중에 일시적인 고온스트레스가 돼지가 생존하는 동안 능력의 저하를 초래하게 된다. 특히 하절기 양돈장은 우기와 무더위로 인한 돈사내 온도의 급상승과 더불어 습도의 불균형에 의한 환경적 스트레스로 번식능력과 생산성에 크게 영향을 미칠 수 있으며,돼지에 일시적인 고온 스트레스 피해는 장기간 계속되며, 생존하는 동안 능력저하를 초래하기 때문에 농장별 사육여건에 따른 성장저해 요인을 제거하는 안목이 필요한 계절이다. 즉,5~9월 모돈에 고온스트레스가 가해지면 11~12월, 다음해 1월 모돈의 분만율은 최저가 되고 , 이 시기에 생산된 자돈은 추운겨울을 이겨내야 함으로 육성률도 낮아지며, 이로 인해 4~7월의 출하성적은 최저가 되는 것이다. 따라서 모돈 관리는 5~9월이 집중관리가 필요한 시기이기도 하다. 고온 다습한 환경 하에서 어미돼지는 영양불균형과 생체리듬의 파괴로 인하여 신생자돈의 폐사가 증가할 수도 있고,이유 후 1주일 이내 발정 재귀율이 약 30%정도 감소하고 무발정돈이 많이 발생되며, 수태가 되어도 조기 배아사멸 및 흡수로 인하여 수태율이 25%까지 감소될 수 있다. 현재 국내 양돈농가에는 예년과 같이 돼지 조모성질환의 발생이 늘어나고 있고, 어려움을 겪고 있는 농장이 많은 것으로 조사 보고되어지고 있는데, 이는 농장에 사육되는 돈군이 외부환경에 대한 적응능력과 질병에 저항력이 부족하여 쉽게 질병에 노출되어 발생함으로 농장에는 돼지가 스트레스를 받지 않게 외부 환경과 사양관리 측면에 심혈을 기울려 강건한 축군을 유지하려는 노력이 무엇보다 우선되어져야 한다고 생각된다. 따라서 본고에서는 여름철에 돼지 스트레스를 줄이고 생산성을 향상시키기 위해 돼지의 생리변화와 돈사 급수설비와 사료관리 및 사육관리에 대해 알아보고자 한다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.56-56
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• 2020

감초는 다년생 콩과(Leguminocae) 식물로 국내에서 시중가격이 높은 만주감초가 일부 재배되고 있다. 우리나라에서 감초 재배법이 불완전한 상황에서 한반도의 기후변화에 의한 온도 상승은 약용작물의 생산 및 품질에 많은 영향을 미칠 것으로 예상되므로 본 연구에서는 재배환경 중 온도 조건만 조절할 수 있는 온도구배터널(temperature gradient tunnel system)을 이용하여 4개의 T1(외기온도+0.5~1.3℃), T2(+1.3~2.2℃), T3(+2.2~3.2℃), T4(+3.2~4.0℃) 처리로 온도구배 하여 4년생 만주감초(Glycyrrhiza uralensis F.)를 재배하였다. 지하부가 오래된 모주와 신초1의 경우 저온(T1)과 중간구간(T2, T3)에서 초장과 총화수가 우세하였고, 번식이 가장 늦은 신초2의 경우 중간구간(T2, T3)에서의 생육 및 개화반응이 뚜렷했다. 각 온도처리구마다 3개의 감초 개체를 선발하여 모주의 정단으로부터 5개의 성엽을 채취하였다. Reverse transcription quantitative PCR (RT-qPCR)은 AccuPower® GreenStar^TM RT-qPCR Master Mix (Bioneer, Korea)를 이용하여 진행되었다. Primer 디자인은 NCBI Primer-blast 프로그램을 사용해 제작하였고 ABI StepOne real time system (Applied Biosystem)의 melting curve analysis에서 one-peak test를 통해 gene specific primer임을 확인하였다. 각 온도처리구의 감초 잎에서 RNA를 추출하였고, RT-qPCR을 통해 감초의 유전자 발현양상을 비교, 분석하였다. Phytochrome interacting factor 4 (PIF4)는 식물 호르몬을 유발하는 전사조절을 조정함으로써 고온 신호전달에 핵심적인 역할을 수행한다. 활성화된 Phytochrome B(PhyB)는 PIF4의 활성을 억제한다고 알려졌다. Eukaryotic initiation factors(eIFs)는 mRNA 번역 개시인자로 유전자 발현과 특정 단백질 생산을 조절하는 역할을 한다. 본 결과는 온도조건에서 반응하는 생리적 변화를 전사체 수준에서 조사 분석하여 생리해석의 기초자료로 활용, 국내 감초 재배를 위한 환경조건 구명 및 적지 선정 기초자료로서 활용을 기대한다.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.955-965
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• 2007

Safety helmets are used widely in various industries by workers since they are legally required to wear them. However, thermal discomfort is one of the major complaints from helmet users. To relieve this problem, frozen gelled packs can be considered for use inside the helmets. In this paper, tests were performed on humans to evaluate the physiological strains of wearing safety helmets and to investigate the effects of using frozen gelled packs inside the helmets. Experiments were conducted in a climatic chamber of WBGT $33{\pm}1^{\circ}C$ under four differed experimental conditions: 1) not wearing a safety helmet(NH); 2) wearing a safety helmet with frozen gelled pack A(HA); 3) wearing a safety helmet with frozen gelled pack B(HB); and 4) wearing only a safety helmet(OH). The results were as follows. First, when comparing NH with OH, physiological responses such as $\bar{T}_{sk},\;T_r$, HR and sweat rate were significantly higher in OH and subjective sensations were reported as less hot and more comfortable than NH(p<.05). Second, in regard to the frozen gelled packs inserted inside the safety helmets, some physiological responses in HA were different from those in HB, according to the two different types of packs. HA was hotter, more uncomfortable and less exhausted than HB. However, result from both HA and HB were lower than those from OH in terms of temperature and humidity inside safety helmet, sweat rate, $T_r$ increase, heat storage(p<.05). When wearing safety helmets with frozen gelled packs, it was shown that heat strain can be alleviated. These results are expected to help millions of workers who complain that wearing safety helmets is uncomfortable and messy.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.337-345
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• 2023

Estimating the rice heading date is one of the most crucial agricultural tasks related to productivity. However, due to abnormal climates around the world, it is becoming increasingly challenging to estimate the rice heading date. Therefore, a more objective classification method for estimating the rice heading date is needed than the existing methods. This study, we aimed to classify the rice heading stage from various images using a CNN classification model. We collected top-view images taken from a drone and a phenotyping tower, as well as slanted-view images captured with a RGB camera. The collected images underwent preprocessing to prepare them as input data for the CNN model. The CNN architectures employed were ResNet50, InceptionV3, and VGG19, which are commonly used in image classification models. The accuracy of the models all showed an accuracy of 0.98 or higher regardless of each architecture and type of image. We also used Grad-CAM to visually check which features of the image the model looked at and classified. Then verified our model accurately measure the rice heading date in paddy fields. The rice heading date was estimated to be approximately one day apart on average in the four paddy fields. This method suggests that the water head can be estimated automatically and quantitatively when estimating the rice heading date from various paddy field monitoring images.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.57-63
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• 2024

As global warming worsens, it is feared that higher ambient temperatures and relative humidity might result in a more intense heat stress for livestock animals, especially broilers, which lack sweat glands for thermoregulation and have been selectively bred for rapid growth. Therefore, strategic livestock management is needed to mitigate the adverse effects of heat stress on broilers. In Korea's poultry farming systems, tunnel-ventilated broiler houses and pad cooling systems are commonly installed to lower indoor temperatures during the summer. However, caution is advised with pad cooling systems as they can increase the humidity inside the houses, potentially causing further harm. This study aimed to evaluate the effectiveness of pad cooling systems in tunnel-ventilated broiler house by assessing the reduction in indoor temperature using the Temperature-Humidity Index (THI), which accounts for the impact of relative humidity. Temperature and humidity data were collected during the summer (Jun to Sep) from eight farms with tunnel-ventilated broiler house located in different regions of Korea. The farms were divided into two groups based on the use of pad cooling systems is used, and temperature and humidity data, along with THI values, were analyzed two weeks before the birds were marketed. Meta-analysis results showed that at the hottest time of the day, 14:00, farms with pad cooling systems had significantly lower indoor temperatures compared to the control group, but observed an increase in indoor temperatures by 16:00 (p<0.05). There is no significant difference in relative humidity (p>0.05). The THI values decreased in the treatment group with cooling pads compared to the control group starting from 15:00, suggesting a diminished effect (p<0.05). This study indicates the potential for developing optimal operational guidelines for cooling pads to reduce heat stress in broilers during the summer season.

• Journal of the Korean Geographical Society
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• v.37 no.4
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• pp.357-370
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• 2002

Present work aims to investigate the species composition, physiognomy and distribution of arctic-alpine and alpine plants(AAP) of the Korean Peninsula. The dominance of AAP in the northern Korea may be due to the frequent exchanges of floras with circumpolar regions for the seek of the glacial refugia during the alternate Pleistocene glacial epochs. The post-glacial climatic amelioration pushed AAP back northwards and upwards, so they now shows disjunctive distribution on separate mountain tops. The diverse morphological adaptations of AAP to severe environmental conditions, viz. the dominance of perennial species, stunted tree growth, multiple protection of leaves, krummholz, and dwarf shrubs, are the result of long-term graduall development which have safeguarded the survival of AAP in a such a harsh cryo-climatic area. The appearance of the Korean endemic AAP reflects the long-term isolation of species in Korea, and the local environmental diversities which have both accentuated this isolation and aided the development of genetic diversity. Evergreen broad-leaved AAP at c. 1,500m to 1,800m and above are now endangered because of the competition from down-slope plants, and from the global warming.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.261-268
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• 2019

Climate change and drought stress are having profound impacts on crop growth and development by altering crop physiological processes including photosynthetic activity. But finding a rapid, efficient, and non-destructive method for estimating environmental stress responses in the leaf and canopy is still a difficult issue for remote sensing research. We compared the relationships between photochemical reflectance index(PRI) and various optical and experimental indices on soybean drought stress under climate change conditions. Canopy photosynthesis trait, biomass change, chlorophyll fluorescence(Fv/Fm), stomatal conductance showed significant correlations with midday PRI value across the drought stress period under various climate conditions. In high temperature treatment, PRI were more sensitive to enhanced drought stress, demonstrating the negative effect of the high temperature on the drought stress. But high CO₂ concentration alleviated the midday depression of both photosynthesis and PRI. Although air temperature and CO₂ concentration could affect PRI interpretation and assessment of canopy radiation use efficiency(RUE), PRI was significantly correlated with canopy RUE both under climate change and drought stress conditions, indicating the applicability of PRI for tracking the drought stress responses in soybean. However, it is necessary to develop an integrated model for stress diagnosis using PRI at canopy level by minimizing the influence of physical and physiological factors on PRI and incorporating the effects of other vegetation indices.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.898-906
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• 2018

To investigate the effect of yellow dust on phytoplankton, a field survey and physiological experiments were carried out in the waters near Taean Peninsula from April 22 to 26, 2006, when yellow dust occurred. Phytoplankton populations during the yellow dust period were in the range of $26{\sim}290{\times}10^3cells{\cdot}L^{-1}$, a somewhat low standing crop. An increase in diatoms (a main taxonomic group), especially benthic diatoms such as Paralia sulcate, a typical species for active mixed sea water areas, was also remarkable. In addition, the Chl-a concentration after yellow dust exceeded the Chl-a concentration change range according to the tide before yellow dust. As the concentration of yellow sand increased in a yellow sand treatment experiment, primary productivity decreased, and the maximum assimilation number showed the same tendency. In the 48h culture experiment, primary productivity of the test group was lower than that of the control group at the early stage (T0) of yellow sand treatment, but after 48 hours (T48), the test group showed higher primary productivity than the control group. In particular, the primary productivity of the test group significantly increased to 321 % after 48 hours. Therefore, strong physical environment accompanied by yellow dust may temporarily inhibit the growth of phytoplankton in the waters adjacent to China in the early stage of yellow dust, but the formation of stable water mass has also been identified as a potential factor promoting the growth of phytoplankton.