• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.04a
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• pp.89-89
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• 2001

종이는 목재섬유와 물의 현탁액을 스크련을 통해 균일하게 분산시킨 판상섬유 제품 으로서 가격이 저렴하고, 열, 전기절연성, 필터기능, 난연성 및 폐기성이 우수하여 다양한 분 야에서 활용되고 있다. 특히 최근에는 종이의 고부가가치화, 차별화를 위하여 내열성, 전기 절연성, 내수성, 기계적 특성, 내약품성, 생체적응성을 지닌 다양한 기능지가 개발되어 식품, 전기, 전자, 건축, 화학, 의료 관련 산업에 있어서 주요 재료로 이용되고 있다. 특히 전기, 전 자산업 발전과 더불어 전기절연성이 우수한 종이의 역할과 수요는 크게 증대되고 있으며 산 업발전의 핵심적인 제품으로서 자리매김을 하고 있다. 하지만 국내의 경우 전기절연지와 관 련된 제품 및 생산기술 부족으로 전량을 수입에 의존하고 있는 실정이며, 그 수입량은 앞으 로 전기 및 전자 산업의 발전으로 인해 더욱 증가할 것으로 예상된다. 이러한 수입의존성을 극복하기 위해서는 전기절연지와 관련된 제품개발 및 생산기술에 관한 연구가 시급히 요청 되고 있다. 이러한 기술의 국산화는 수입 대체 효과 뿐만 아니라 관련 산업의 발전에도 기 여할 수 있을 것으로 예상되며 수출산업으로 성장할 수 있을 것으로 예상된다. 종이의 전기적 성질은 유전상수, 유전손실율과 같은 유전적 특성과 전기저항, 절연 파괴강도의 기계적 특성으로 구분할 수 있다. 종이의 전기적 성질 가운데 유전율은 전기장 에 대한 종이의 물리화학적인 반응으로 일반적으로 종이의 밀도와 종이를 구성하는 성분의 쌍극자 모멘트에 비례하며 온도에 따라서도 변화한다. 일반적으로 온도가 상승하면 열에너 지를 얻게된 쌍극자가 전기장에 배열됨으로써 유전율이 상승하지만 온도가 유리전이점 이상 으로 높아질 경우 열적 교란에 의해서 분극 능력이 감소하게 되어 유전완화 현상이 나타난 다. 전기절연지로 사용될 종이의 절연특성을 이해하기 위해서는 사용환경에 따른 유전적 특 성 및 tan$\delta$에 관한 연구가 펼요하다. 본 연구에서는 종이의 유전특성을 개선하기 위해서 펼름형성능력이 우수한 polyvinyl alcoholCPV A)과 aery lonitrile을 이용하여 시아노에틸화한 P PYA의 표면처리에 따른 종이의 유전적 특성의 변화를 검토하였다. 그 결과 PYA에 도입된 시아노에틸기에 의해 유전율을 증가시킬 수 있음을 확인하였다. 또 본 연구에 적용된 시험 범위에서는 온도상승에 따라 유전율이 상승하였다.

• Journal of the Korean Ceramic Society
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• v.24 no.2
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• pp.155-160
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• 1987

The investigation includes the application of $ZrSiO_4-Cd(SxSe_{1-x})$stain to ceramic body. The currently developed stain was compared to the commercially available stain in applying to ceremic glaze. Two stains (currently developed and commecially available) were mixed with frits and applied to ceramic tiles. The tiles were fired at 850 to 120$0^{\circ}C$ and tested by colorimeter in X.Y.Z. axis of the wavelength ranging from 580nm to 650nm. Applicability 18 stains to ceramic body was investigated by ISCC-NBS of Munsell color nomenclature. $ZrSiO_4-Cd(SxSe_{1-x})$stain is as good as V and Pr series stain in mixing composition of frits 9 to 1. It maintains red color at 100$0^{\circ}C$ in the mixture of frits, and shows as the strong acid resistance stain.

• Journal of Korean Society of Forest Science
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• v.28 no.1
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• pp.31-35
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• 1975

The present study explored the rapid effect of low temperature on the freezing resistance of dehardening twigs of three apple cultivars and sweet cherry. The effect of low temperature was depending upon the thawing treatment following to the low temperature treatment. When the freezing temperature to $-9^{\circ}C$ for three hours followed by thawing treatment ($5^{\circ}C$) was given repeatedly twice, the low temperature increased apparently the cold hardiness of apple and cherry by 3 to $9^{\circ}C$. On the other hand, when the freezing temperature ($-9^{\circ}C$) for ten hours was pretreated without thawing, the low temperature appeared not affecting the cold resistance of the twigs. The role of freezing-thawing temperature cycle in nature was discussed as a signal of environmental stimulus to which dehardening plant may be responding to increase their cold hardiness so as to adapt against the damage of late frost in early spring.

• 건강소식
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• v.30 no.2 s.327
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• pp.12-13
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• 2006

일반적으로 아이들은 어른보다 활동적인 경향이 있어 적절한 체력수준을 유지한다. 그러나 해부학적, 생리학적, 심리학적으로 미성숙하기 때문에 운동프로그램을 고안할 때 특별한 주의가 필요하다.아이들을 위한 운동프로그램에서 가장 중요한 것이 안정성이다. 아이들은 신체활동 시 부상률이 높고, 지구성운동이 과할 경우 골단성장판을 다칠 수 있기 때문에 더욱 안정에 유의한다. 또한 아이들은 성인에 비해 열자극에 적응하는데 상대적으로 무력하므로 온도가 높은 여름날 야외에서 운동할 경우, 물을 많이 섭취하게 하고 자주 휴식을 취하도록 한다.

• Journal of Mushroom
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• v.15 no.2
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• pp.84-87
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• 2017

Although ear mushroom (Auricularia auricula-judae) is cultivated worldwide, there are a limited number of commercial cultivars in Korea. Recent increase in the import of ear mushroom from China threatens the domestic farming. The present study introduces a new thermotolerant cultivar of ear mushroom, designated 'Hyeonyu', developed by mating monokaryons obtained from JBAA11 and CAA1 strains. The optimal growth temperature for Hyeonyu was 26-36?. The periods of primordia formation and fruit-body growth were 27 and 15 days, respectively. The average mushroom yield per bag (1 kg) was 350 g. Random amplification of polymorphic DNA (RAPD) analysis with OPA1 and OPA7 primers identified polymorphic DNA bands between the control, the new variety Hyeonyu, and a Chinese variety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.697-702
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• 2016

To control permanent magnet synchronous motors smoothly, it is important to know the exact parameter values of the stator resistance, various inductances, and the flux linkage of the permanent magnet. In practice, these parameters vary due to a variable operating point, temperature change, or a fault. This paper proposes a MRAS (Model Reference Adaptive System) based parameter estimator and adaptive control scheme. Owing to the non-linearity of the system equation with respect to these parameters, although many schemes proposed previously assumed that some parameters are known, all the parameters were assumed to be unknown. The simulation results revealed the effectiveness of the proposed algorithm.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.6
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• pp.25-30
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• 2013

In nanoscale MOSFET technology, aging effects such as Negative Bias Temperature Instability(NBTI), Hot carrier Injection(HCI), Time Dependent Dielectric Breakdown (TDDB) and so on which affect circuit reliability can lead to severe degradation of digital circuit performance. Therefore, this paper has proposed the adaptive compensation circuit to overcome the aging effects of digital circuits. The proposed circuit deploys a power gating structure with variable power switch width and variable forward body-biasing voltage in order to adaptively compensate for aging induced performance degradation, and has been designed in 45nm technology.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.324-332
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• 2018

BACKGROUND: Insects are ectothermic organisms in terrestrial ecosystems and play various roles such as controlling plant biomass and maintaining species diversity. Because insects are ectothermic, their physiological responses are very sensitive to environmental temperature which determines survival and distribution of insect population and that affects climate change. This study aimed to identification of genes contributing to fitness under high temperature. METHODS AND RESULTS: To identify genes contributing to fitness under high temperature, the transcriptomes of fat body in Plutella xyostella larva have been analyzed via next generation sequencing. From the fat body transcriptomes, structure-related proteins, heat shock proteins, antioxidant enzymes and detoxification proteins were identified. Genes encoding proteins such as structural proteins (cuticular proteins, chitin synthase and actin), stress-related protein (cytochrome P450), heat shock protein and antioxidant enzyme (catalase) were up-regulated at high temperature. In contrast expression of glutathione S transferase was down-regulated. CONCLUSION: Identifications of temperature-specific up- or down-regulated genes can be useful for detecting temperature adaptation and understanding physiological responses in insect pests.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.297-303
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• 2014

Heat manipulation at early age has been known to help chickens cope with heat stress later in life. The present study was conducted to determine the effects of early heat conditioning at 5 days of age on performance in broilers when re-exposed to heat stress later in life. Day-old, 256 Arbor Acre boiler chicks were housed in two identical rooms where all broilers were exposed to a 23-h light: 1-h dark cycle throughout the study and provided with feed and water ad libitum. At the age of 5 days, one group was exposed to $37^{\circ}C$ for 24 hours and then returned to the temperature at which control birds were maintained (early heat condition group) while the other was maintained without heat modulation (Control). On 21 days, broilers were regrouped into 4 groups (CON+CON: control+control; CON+HS: control+heat stress; HC+CON: heat conditioning+control; HC+HS: heat conditioning+heat stress), and given 7 days for adaptation. On 28 days, birds in one room were exposed to heat stress ($21^{\circ}C{\rightarrow}31^{\circ}C$) for 3 days whereas those in the other were at room temperature. Heat stress resulted in decreased feed intake, water intake, and body weight gain (P<0.05), but increased rectal temperature and mortality (P<0.05). No beneficial effects of heat conditioning were detected when broilers were exposed to heat stress again at later in life. The present results were discussed together with other studies regarding possible differences in methods such as ages of breeders and strains, which may have resulted in the failure of heat conditioning to help broilers resist heat stress.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.1-8
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• 2008

The concept of growing degree-days (GDD) is widely accepted as a tool to relate plant growth, development, and maturity to temperature. Information on GDD can be used to predict the yield and quality of several crops, flowering date of fruit trees, and insect activity related to agriculture and forestry. When GDD is expressed on a spatial basis, it helps identify the limits of geographical areas suitable for production of various crops and to evaluate areas agriculturally suitable for new or nonnative plants. The national digital climate maps (NDCM, the fine resolution, gridded climate data for climatological normal years) are not provided on a daily basis but on a monthly basis, prohibiting GDD calculation. We applied a widely used GDD estimation method based on monthly data to a part of the NDCM (for Hapcheon County) to produce the spatial GDD data for each month with three different base temperatures (0, 5, and $10^{\circ}C$). Synthetically generated daily temperatures from the NCDM were used to calculate GDD over the same area and the deviations were calculated for each month. The monthly-data based GDD was close to the reference GDD using daily data only for the case of base temperature $0^{\circ}C$. There was a consistent overestimation in GDD with other base temperatures. Hence, we estimated spatial GDD with base temperature $0^{\circ}C$ over the entire nation for the current (1971-2000, observed) and three future (2011-2040, 2041-2070, and 2071-2100, predicted) climatological normal years. Our estimation indicates that the annual GDD in Korea may increase by 38% in 2071-2100 compared with that in 1971-2000.