• Clean Technology
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• v.25 no.3
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• pp.245-255
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• 2019

Pressurized oxy-fuel combustion is a promising technology for $CO_2$ capture with a benefit of improving power plant efficiency compared with atmospheric oxy-fuel combustion. Prior to $CO_2$ compression in this process, a flue gas condenser (FGC) is used to remove $H_2O$ while recovering the latent heat. At the same time, the FGC has a potential for high-efficiency removal of $SO_x$ and $NO_x$ by exploiting their good solubility in water. In this study, experiments were carried out in a lab-scale, direct contact FGC under different pressures varying between 1 and 20 bar to evaluate the removal efficiency of $SO_2$ and $NO_x$ for individual gases and their mixture. In the tests for individual gases, 20% and 76% of $NO_x$ was removed at 1 bar and 10 bar, respectively. Even higher removal efficiencies were achieved for $SO_2$, and also these were maintained for longer as the pressure increased. In the tests for $SO_2$ and $NO_x$ mixture, the removal efficiency of $NO_x$ increased from 13% at 1 bar to 56% at 20 bar because of higher solubility at elevated pressures. $SO_2$ in the mixture was initially dissolved almost completely and then increased by 1,219 ppm at 1 bar and by 165 ppm at 20 bar. Overall, the removal efficiency of $SO_2$ and $NO_x$ was increased at elevated pressures, but it was lower in the mixture compared with individual gases at identical conditions because of a lower pH and associated chemical reactions in water.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.171-183
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• 1995

이 논문은 특정 기기산업의 기술적 구조와 현황의 분석 및 파악을 위한 제 품.기술 관련도라는 새로운 개념을 제시한다. 제품.기술 관련도란 분석대상산 업의 주요 제품들을 도출하고 각각의 제품에 관련된 기술들을 부품기술을 중심으로 파악하여 매트릭스의 형태로 도시한 것을 의미한다. 제품. 기술 관 련도상의 제품에 대해서는 전문가의 의견에 의해 측정된 기술수준과 주된 획득방법(국산화율)을 파악한다. 한편, 제품에 관련되는 기술은 기본적인 기능을 발휘하는 제품의 생산에 소요되는 기본기술과 제품의 성능향상을 위하여 필요한 성능관련기술 등으로 구분하여 분석된다. 이러한 제품.기술 관련도는 국내 기기산업의 각 분야별 기술수준, 부품군의 기술수준 등을 도출하고 상호관련성을 파악하는데 유용한 방법으로 활용될수 있다. 특히 제품군과 부품군간의 관계 도출, 기술수준 혹은 구산화율이 낮은 제품에 관련된 부품 및 기술의 파악, 국내의 기술수준이 낮은 부품에 관련되는 제품 및 제품군, 제품의 성능이 향상에 관련된 기술등의 파악이 용이하다. 본 논문에서는 제품.기술 관련도를 한국의 정보통신기기산업에 시험적으로 적용하여 정보통신 기기분야의 제품 및 기술 구조, 그리고 경쟁력을 분석하여 보았다. 국내 정보통신기기산업의 전체적인 기술수준은 자체적으로 기술을 보유하고 있으나 성능면에서 매우 미약한 소화 및 모방 단계의 수준이라고 해석할수 있다. 한편 부품기술은 아직도 소화및 모방단계에 머무르고 있으며, 개별소자와 수동부품의 기술수준이 매우 낮게 나타났다. 분야별로 볼 때 무선통신기기, 방송기기, 정보기기의 순으로 기술수준이 낮으며, 무선통신기기분야이 발전을 위해서는 고주파 부품의 기술 발전이 선행되어야 할것으로 보인다.라 제시된 외주위탁 전략과 현재의 외주위 탁 전략이 일치할 때 정보 시스템에 대한 사용자 만족도가 보다 높은 것으 로 나타났다. 할 수 있는 효율적인 distributed system를 개발하는 것을 제시하였다. 본 논문은 데이타베이스론의 입장에서 아직 정립되어 있지 않은 분산 환경하에서의 관계형 데이타베이스의 데이타관리의 분류체계를 나름대로 정립하였다는데 그 의의가 있다. 또한 이것의 응용은 현재 분산데이타베이스 구축에 있어 나타나는 기술적인 문제점들을 어느정도 보완할 수 있다는 점에서 그 중요성이 있다.ence of a small(IxEpc),hot(Tex> SOK) core which contains two tempegatlue peaks at -15" east and north of MDS. The column density of HCaN is (1-3):n1014cm-2. Column density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.172-180
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• 2023

In the current study, four groups; control, 500, 1000, and 2000 mg/L, were treated to investigate the effects of physiological and growth characteristics on Machilus thunbergii under various fertilization levels. As a result of the physiological response to the fertilization treatment, the fertilized group demonstrated relatively higher levels of A, ITE, WUEi, V_camx, PI_abs, and SFI_abs in comparison to the control. The best photosynthetic mechanism was most clearly seen at 1000 mg/L, which involved gas exchange through active stomatal opening and closing. For a productive photosynthetic mechanism. As seen in the growth response of M. thunbergii to fertilization treatment, the fertilized group has significantly higher height, DRC, leaf dry weight, stem dry weight, total dry weight, LWR, and SWR than the control group. A healthy seedling quality index was particularly evident at 1000 mg/L, and other growth indicators were also at a decent level. 500 mg /L also demonstrated growth characteristics that were comparable to those at 1000 mg/L. As a result, M. thunbergii featured the best physiological and growth characteristics in response to the fertilization treatment at 1000 mg/L, and 500 mg/L also showed a similar trend, which is considered to be a good option from an economical perspective.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.291-297
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• 2015

We investigated the effects of dietary pearlzyme (mudflat-bacteria origin protease) on growth performance and development of digestive organs in broilers. Two hundred forty, 4 day-old female Ross broiler chicks were divided into 2 groups (control vs. pearlzyme) which were randomly housed in 8 pens with 15 chicks/pen. They were fed one of two diets containing pearlzyme at 0 or 0.1% for 4 weeks. Dietary pearlzyme resulted in significant increase in body weight during the first week of the experiment (p<0.05). With age, weight gain and feed efficiency continued to decrease reaching significant level during the last week. Mortality was 3.3% in control but not in pearlzyme during the entire period of the experiment. Dietary pearlzyme resulted in increased weight (p<0.05) in the ceca and rectum, and increased length in the ceca (p<0.05). However, there were tendencies to increase the weight of the gizzard (p<0.071) but to decrease the length of the small intestine (p<0.068). The results of the current study show that dietary pearlzyme affects weight gain and the development of digestive organs.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.291-296
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• 2012

Triploids are a useful tool for biomass production and molecular breeding of trees with a long life span. Triploids of the poplar 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa) have been developed by crossing between female diploids and a male tetraploid. The tetraploid was developed around the 1970s at Korea Forest Research Institute by colchicine-induced chromosome doubling. Seedlings of the $F_1$ generation were analyzed using flow cytometry to verify their ploidy status. The mean relative fluorescence index of 3 F1 poplars, labeled as Line- 1, Line-17, Line-18, were approximately 1.5 times higher than those of diploid poplars, and the results clearly indicated that they were triploids. The phenotype of the F1 poplars included larger leaves and thicker stem than diploids, and abnormal leaf morphology, especially in the triploid 'Line-18'. Three triploid lines developed roots more slowly and had less roots than diploid. However, 3 poplar cytotypes (2x, Line-1, Line-17) rooted within 10 days on MS medium. In contrast, compared with the 3 cytotypes, the Line-18 showed about 80% and 70% in the rooting rate and the number of roots. The triploid poplars could be directly utilized for biomass production and with their sterility, they could serve as basic material for genetic transformation. In addition, flow cytometric analysis proved to be an effective and reliable method for screening forest trees for their ploidy level.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.473-479
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• 2019

Gryllus bimaculatus (GB) has recently been registered as a food variety in Korea. In the present study, we prepared protein hydrolysates from GB and evaluated their antioxidant capacity. Protein hydrolysates were prepared from dried GB using enzymatic hydrolysis using five different proteases, and protein hydrolysates showing high hydrolysis value (alcalase, flavourzyme, and neutrase) were separated further into fractions ${\leq}3kDa$ and then lyophilized. Based on $RC_{50}$ values of hydrolysates (${\leq}3kDa$) obtained from four different antioxidant analyses, the flavourzyme hydrolysates showed relatively high levels of antioxidant capacity among the three hydrolysates, and in particular, it showed considerably strong antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The flavourzyme hydrolysate also significantly inhibited peroxidation of linoleic acid. These results suggest that protein hydrolysates from GB represent potential sources of natural antioxidants. Our current studies are focused on identification of active peptides from the flavourzyme hydrolysate.

• International Area Studies Review
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• v.21 no.1
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• pp.97-117
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• 2017

This research highlights the process of adopting cloud computing technology from users' perspective. Concentrating on perceived mechanism from employees side that lead to job performance at work. Cloud computing, the new player in our modern business environment, authors employ diffusion of innovation theory to capture how this new technology affect employees in workplace in terms of job performance. Education for this new system and managerial support by firm were used as moderating variable to test dependent variable, job performance. Research was done through survey from total 284 people working in metropolitan area at South Korea. The result shows that cloud computing system affect positively on work efficiency, and the extent of diffusion factors that influence from the most to least are as follow: 1. Users' Skill, 2. System Quality, 3. Information Quality, 4. Group Awareness, 5. Attitude towards New System. To test diffusion factors of cloud computing and job performance, South Korean people actually felt that cloud computing help their job performance and the extent of diffusion factors that influence from the most to least are as follow: 1. Users' Skill, 2. System Quality, 3. Information Quality, 4. Attitude towards New System, 5. Group Awareness. As for diffusion factors of cloud computing and productivity, result proved that cloud computing really helps firms, and the extent of diffusion factors that influence from the most to least are as follow: 1. Information Quality, 2. Attitude towards New System, 3. Group Awareness, 4. System Quality, 5. Users' Skill. Two moderating variables, employee education and managerial support were tested to prove whether these two variables affect the job performance and the result displays positive affect for both two factors. To conclude, adopting cloud computing helps firms by increase employees' work efficiency and job performance. In order to accelerate the process employees education really matters because users' skill is the most crucial among diffusion factors.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.1022-1031
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• 2016

Relationships of standing biomass with biodiversity and structural diversity were examined in the Quercus mongolica-dominated forest in Mt. Jeombong, Gangwon-do. We examined the standing biomass of the Q. mongolia community ($311.1ton{\cdot}ha^{-1}$) from 2004 to 2013, and the observed major species were Q. mongoilca, Carpinus cordata, Tilia amurensis whose standing biomasses were $206.3ton{\cdot}ha^{-1}$ (66.3%), $36.9ton{\cdot}ha^{-1}$ (11.9%), and $30.6ton{\cdot}ha^{-1}$ (9.8%), respectively. Although the number of Q. mongolica individuals was very small compared with total density, the reason that Q. mongolica showed the most biomass than other species is due to greater average diameter at breast height (DBH) and the higher number of $DBH{\geq}50cm$ individuals. We calculated the range of Shannon index (H') and Shannon evenness (J') in the Q. mongolica community, and they were gradually increased in time, showing 2.015~2.166, 0.673~0.736, respectively. Their H' and J' showed positive linear relationships with their standing biomass. This indicates that the spatial distribution of the standing biomass in Q. mongoilca community becomes more homogeneous with time and this homogenization appears in various species in the community. In addition, we estimated biomass-species index (BS) and abundance-biomass-speciesdiversity (ABS) and they also showed gradual increase in time, ranging from 3.746 to 3.811 and from 4.781 to 5.028, respectively. Their indices showed positive linear relationships with the standing biomass. This can be explained from the observations of variations in standing biomass with tree diameters as the differences in the average standing biomass in the community have reduced gradually in time. Moreover, it is expected that increase in the structure diversity of the Q. mongoilca community enhances the efficiency in carbon sequestration and productivity, so the community can be developed to a more sustainable ecosystem with more abundant resources. Thus, applications of uneven-aged plantations with considerations of local ecological properties can be a very efficient reforestation method to ensure stable support of biodiversity and productivity.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.29-39
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• 2017

This study examined the effects of adding dried blood mixed with Macsumsuk to the feed of broiler chickens. The blood had been dried at $200^{\circ}C$ in an ultra-high-temperature injection system and mixed in a 70:30 proportion of blood meal to Macsumsuk. The experiment consisted of four treatment groups of 150 chickens each. The control group received common broiler feed only, while treatment groups T1, T2, and T3 received feed supplemented with 0.5, 1.0, and 3.0% of the blood meal/Macsumsuk mixture, respectively. The diets were fed for a total of 35 days. Compared with the controls, body weight gain was improved in groups T1 (1,621 g), T2 (1,749 g), and T3 (1,739 g) (1,621-1,749 g vs. 1,448.5 g, respectively) and feed efficiency increased (p<0.01). The carcass rate in group T3 was higher by 83.26% than that in the controls (75.96 %) (p<0.01). The water holding capacity (WHC) increased in groups T1 and T2 (62.27 and 63.80% respectively) compared with controls (p<0.01). The intestine length was longer in groups T1 and T2 (53.98-55.48) than in controls (45.81) (p<0.01). Adding 0.5-1.0% of the dried blood meal Macsumsuk supplement resulted in a significant reduction in the cholesterol content (39.28~47.34 mg/100 g) compared with the controls (50.44 mg/100 g) (p<0.001); furthermore, the proportions of fatty acids including oleic (C18:1n9), ${\gamma}-linoleic$ (C18:3n6), eicosenoic (C20:1n9), and arachidonic (C20:4n6) acids were significantly increased (p<0.01). Compared with controls, the proportion of unsaturated fatty acids (UFA), mono-unsaturated fatty acids (MUFA), and proportion of UFA / SFA in group T1 was (68.66 vs. 69.35%, 51.22 vs 52.00%, and 2.19 vs. 2.26%, respectively) (p<0.05). However, the amino acid content of cystine and methionine of the treatment group (0.43~0.57%) was significantly higher than that of controls (0.38~0.46%) (p<0.05). Overall, supplementing the feed with 0.5-1.0% of the mixture of blood meal Macsumsuk improved productivity by increasing weight gain and feed efficiency, improved meat quality by increasing the water-holding capacity and levels of unsaturated fatty acids, and improved meat color.

• Journal of the Korean Geotechnical Society
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• v.40 no.1
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• pp.5-14
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• 2024

PHC piles demonstrate superior resistance to compression and bending moments, and their factory-based production enhances quality assurance and management processes. Despite these advantages that have resulted in widespread use in civil engineering and construction projects, the design process frequently relies on empirical formulas or N-values to estimate the soil-pile friction, which is crucial for bearing capacity, and this reliance underscores a significant lack of experimental validation. In addition, environmental factors, e.g., the pH levels in groundwater and the effects of seawater, are commonly not considered. Thus, this study investigates the influence of vibrating machine foundations on PHC pile models in consideration of the effects of varying pH conditions. Concrete model piles were subjected to a one-month conditioning period in different pH environments (acidic, neutral, and alkaline) and under the influence of seawater. Subsequent repeated direct shear tests were performed on the pile-soil interface, and the disturbed state concept was employed to derive parameters that effectively quantify the dynamic behavior of this interface. The results revealed a descending order of shear stress in neutral, acidic, and alkaline conditions, with the pH-influenced samples exhibiting a more pronounced reduction in shear stress than those affected by seawater.