• 한국재료학회지
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• 제26권9호
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• pp.460-467
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• 2016

Activated carbons (ACs) have been used as EDLC (electric double-layer capacitor) electrode materials due to their high specific area, stability, and ecological advantages. In order to prepare ACs with high density and crystallinity, coal tar pitch (CTP) was activated by $K_2CO_3$ and the textural and electrochemical properties of the obtained ACs were investigated. Although the CTP ACs formed by $K_2CO_3$ activation had much smaller specific surface area and pore volume than did the CTP ACs formed by KOH activation, their volumetric specific capacitance (F/cc) levels as electrode materials for EDLC were comparable due to their higher density and micro-crystallinity. Structural characterization and EDLC-electrode performance were studied with different activation conditions of $CTP/K_2CO_3$ ratio, activation temperature, and activation period.

• 대한건축학회연합논문집
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• 제20권6호
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• pp.113-119
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• 2018

Occupancy-based heating control is effective in reducing heating energy by preventing unnecessary heating during unoccupied period. Various technologies on detecting human occupancy have been developed using complicated machine learning algorithm and stochastic methodologies. This study aims at deriving low-cost and simple algorithm of occupancy inference that can be implemented to residential buildings. The core concept of the algorithm is to combine the occupancy probabilities based on indoor CO2 concentration and PIR(passive infrared) signals. The probability was estimated by applying different levels of decrement ratio depending on CO2 concentration change rate and aggregated PIR signals. The developed algorithm was validated by comparing the inference results with the occupancy schedule in a real residential building. The results showed that the inference algorithm can achieve the accuracy of 75~99%, which would be successfully implemented to the control of residential heating systems.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2004년도 학술대회지
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• pp.35-45
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• 2004

This paper reviewed effects of global climatic changes on wetland biogeochemistry, Wetlands play key roles in global as well as local material cycle, which includes carbon sequestration, $CH_4$ emission and DOC leaching, Increased air temperature, elevated $CO_2$ levels and changed precipitation patterns are believed to affect those processes substantially by modifying oxygen supply, carbon sources, and decomposition rates. For example, elevated $CO_2$ may increase $CH_4$ emission as well as DOC leaching from wetlands. In addition, interactions of multiple effects warrant further investigation.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.81-83
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• 2003

The potential advantages of the hybrid welding process are improved weld penetration, enhanced gap tolerance, control of weld metal composition, and improved weld quality in comparison to laser or arc welding. Especially, the deep penetration of hybrid welding is very attractive in welding of thick plates. In this study, therefore, the influence of arc power in hybrid welding on detailed bead dimensions at different laser power levels was investigated.

• 원예과학기술지
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• 제30권5호
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• pp.501-508
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• 2012

Reducing carbon dioxide ($CO_2$) exhaust has become a major issue for society in the last few years, especially since the initial release of the Kyoto Protocol in 1997 that strictly limited the emissions of greenhouse gas for each country. One of the primary sectors affecting the levels of atmospheric greenhouse gases is agriculture where $CO_2$ is not only consumed by plants but also produced from various types of soil and agricultural ecosystems including greenhouses. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Optimum control of greenhouse $CO_2$ enrichment based on accurate monitoring of the added $CO_2$ can improve profitability through efficient crop production and reduce environmental impact, compared to traditional management practices. In this study, a sensor-based control system that could estimate the required $CO_2$ concentration considering emission from soil for cucumber greenhouses was developed and evaluated. The relative profitability index (RPI) was defined by the ratio of growth rate to supplied $CO_2$. RPI for a greenhouse controlled at lower set point of $CO_2$ concentration (500 ${\mu}mol{\cdot}mol^{-1}$) was greater than that of greenhouse at higher set point (800 ${\mu}mol{\cdot}mol^{-1}$). Evaluation tests to optimize $CO_2$ enrichment concluded that the developed control system would be applicable not only to minimize over-exhaust of $CO_2$ but also to maintain the crop profitability.

• 생물환경조절학회지
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• 제19권4호
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• pp.177-183
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• 2010

연소식 $CO_2$ 발생기 사용시 사용하는 연료에 따라서 발생되는 $CO_2$ 농도 및 유해가스 농도를 비교 분석하는 것을 목표로 하였다. 사용 연료로는 등유, LPG, LNG를 이용하였다. 연소식 $CO_2$ 발생기는 등유사용 국내제품을 설치한 온실(A), 외국제품을 설치한 온실(B), LPG 사용 국내제품과 외국제품을 설치한 온실 2개소(C와 D) 및 LNG 사용 온실(E)을 선정하였다. 측정은 서울대학교 농생명과학공동기기원(NICEM)의 실내공기질 분석 시스템의 일부 측정시스템을 온실로 이동하여 측정하였다. 연소식 $CO_2$ 발생기 작동 유무에 따른 $CO_2$ 가스 증감은 $NO_x$류의 증감에 정의 상관을 보였으며, 사용 연식에 따른 버너의 내구성 저하에 따른 유해가스 발생량이 증가하였다. CO 농도가 매우 높게 나올 경우에는 발생기 내부에 컨버터를 장착하여 농도를 저감시켜 직물의 생리장해를 예방시킬 필요가 있었다. 전체적으로 $CO_2$ 발생에 따른 유해가스 농도는 최근 설치된 장치에서는 큰 문제가 없었으며 가장 낮은 유해가스 발생량은 국산 LPG 제품을 사용한 D 온실이었다.

• Advances in Traditional Medicine
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• 제2권2호
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• pp.113-118
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• 2002

Falun Gong (FG) is an advanced system of cultivation and practice, which is beneficial for both mind and body. In this study we investigated the effects of FG on the production of cytokines in FG practitioner (FGP). To study whether plasma cytokines levels were affected by FG, their levels were analyzed. The amount of $interferon-{\gamma}$ $(IFN-{\gamma})$, interleukin (IL)-2, IL-4 and IL-6 (2.5-fold for $IFN-{\gamma}$, 1.2-fold for IL-2, 2.1-fold for IL-4 and 2.5-fold for IL-6, respectively) were significantly higher in the FGP group than normal group (P<0.05). Peripheral blood mononuclear cells obtained from normal healthy control and FGP were cultured for 24 h in the presence or absence of lipopolysaccharide. The amount of $IFN-{\gamma}$, IL-2, IL-4 and IL-6 in culture supernatant was quantified. However, there were no significant differences in the level of the same cytokines between the normal and FGP group. These data suggest that FG cultivation may contribute to immune-enhancement in vivo.

• 한국자원식물학회지
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• 제11권2호
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• pp.119-123
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• 1998

Effects of elevated CO2 and temperature on nitrogen (N) uptake , leaf N concentration, N partitioning , N use efficiency (NUE) and grain yield of pot and field grown rice (Oryza sativa. L.cv. Chukwangbyeo) under canopy-like conditions were studied over three years. Rice plants were grown in pots and in the field in temperature gradient chambers containing either ambient(350ppm) or elevated CO2 concentrations (690 or 650ppm) in conbination with either four or seven temperature regimes ranging form ambient temperature(AT) to AT plus 3$^{\circ}C$. There were three N supplies 94g or 6g m-2 to 20g or 48g m-2.Elevated CO2 increased N uptake in field-grown rice ; the magnitude of this effect was thelargest (+15%) at the highest N level. However, in pot-grown rice, N uptake was suppressed with the effect was the largest at high N levels. Leaf N concentration declined at elevated CO2 mainly due to a decrease in N partitiioning to the leaf blades. Air temperature had little effect on the N parameters mentioned previously, wherease NUE for spikelet production declined rapidly with increased temperature irrespective of CO2 concentration. The response of the biomass to elevated CO2 varied with N level, with the greatest response at 20g N m-2 (+30%) . At AT, where high temperature-induced sterility was generally not observed, elevated CO2 increased yield. However, the magnitude of this effect varied greatly (2-39%) with N level, and was mainly dependent on the magnitude of the increase in spikelet number.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.260-265
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• 2022

This study aimed to determine whether lactate dehydrogenase (LDH) levels in coronavirus disease (COVID-19) patients in Korea were higher than those in patients without COVID-19, and the effect of sex and age on LDH levels. A retrospective, observational study was conducted to measure LDH levels in 247 and 225 female and male COVID-19 patients, respectively, who were admitted to the study hospital between April 1 and October 30, 2020. Serum LDH levels were measured using an automated analyzer. Results: LDH levels were elevated in both male and female patients with COVID-19. Among patients with COVID-19, LDH levels were higher in males than in females, and LDH levels were higher in patients with COVID-19 than in patients in the control group. In the analysis of differences in LDH levels by age, LDH levels in patients with COVID-19 increased statistically significantly with age in males and females (males: p=0.001, females: p=0.001). By examining the differences in LDH levels according to sex and age, this study contributed to the basic biochemical data available in Korea, particularly regarding patients with COVID-19. Further research may be needed to examine confounding variables.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.539-545
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• 2001

Undoped and Co$^{2+}$ $\alpha$-Ga$_2$S$_3$ thin films were grown by spray pyrolysis method. It has been found that these thin films have a monoclinic structure and direct optical energy gap and indirect were located to 3.477eV and 3.123 eV at 10K respectively. In the photoluminescence due to a D0A(donor-acceptor) pair recombination were observed at 502 nm and 671 nm for the $\alpha$-Ga$_2$S$_3$ thin film, where is excited by the 325 nm-line of He-Cd laser. These peaks are identified to be corresponding to the electron transition between the energy levels of Co$^{2+}$ ion sited a the T$_{d}$ symmetry point in the $\alpha$-Ga$_2$S$_3$;Co$^{2+}$ thin film. film.