• 한국재료학회지
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• 제23권2호
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• pp.89-97
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• 2013

The study of grinding behavior characteristics on aluminum powders and carbon nano tubes (CNTs) has recently gained scientific interest due to their useful effect in enhancing advanced nano materials and components, which significantly improves the property of new mechatronics integrated materials and components. We performed a series of dry grinding experiments using a planetary ball mill to systematically investigate the grinding behavior during Al/CNTs nano composite fabrication. This study focused on a comparative study of the various experimental conditions at several variations of rotation speeds, grinding time and with and without CNTs. The results were monitored for the particle size distribution, median diameter, crystal structure from XRD pattern and particle morphology at a given grinding time. It was observed that pure aluminum powders agglomerated with low rotation speed and completely enhanced powder agglomeration. However, Al/CNTs composites were achieved at maximum experiment conditions (350 rpm, 60 min.) of this study by a mechanical alloy process for Al/CNTs mixed powders because the grinding behavior of Al/CNTs composite powder was affected by addition of CNTs. Indeed, the powder morphology and crystal size of the composite powders changed more by an increase of grinding time and rotation speed.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.891-901
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• 2014

본 연구에서는 미용실 이용고객의 성향은 제공되는 서비스요소와 함께 감성마케팅으로 대변되는 외적요소인 디스플레이 요소에도 많은 영향을 받고 있다 이렇듯 디스플레이 요소가 중요하게 작용하고 있는 현 시점에 미용실 고객의 라이프스타일이 디스플레이 구성요소에 어떠한 영향을 미치는 지와 미용실 고객의 라이프스타일에 따른 고객 만족 차이를 살펴보고 미용실의 디스플레이 구성요소가 고객만족에 어떠한 영향을 미칠 것인지 살펴보아 미용실 경영자에게 효율적이고 능률적인 미용실 디스플레이에 대한 아이디어를 제공함으로써 고객만족을 위한 전략을 수립하는데 유용한 정보를 제공하고자 하였다. 연구결과는 조명과 전체적인 분위기에 가장 영향을 미치는 라이프스타일 요인은 '편의지향형'이며, (p<0.05 수준)에 통계적으로 유의적인 영향을 미치는 것으로 나타났다. 색채에 가장 영향을 미치는 라이프스타일 요인은 '외모유행지향형'이며, (p<0.05 수준)에 통계적으로 유의적인 영향을 미치는 것으로 나타났다.

• 대한기계학회논문집A
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• 제20권4호
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• pp.1123-1132
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• 1996

It has been reported that high temperature structural components represent the phenomenon of material degradation according to a long term service under high temperature and pressure. Especially, fossile power plant components using the fossil fuel and heavy oil are affected by dewpoint corrosion of $H_2SO_4$produced during a combustion. Therefore, the service materials subjected to high temperature and pressure may occur the stress corrosion cracking. The object of this paper is to investigate SCC susceptibility according to the material degradation of the high temperature structural materials in dewpoint corrosive environment-$H_2SO_4$.The obtained results are summarized as follows : 1) In case of secondary superheater tube, the fractograph of dimple is observed at the concentration of $H_2SO_4$-5%. When the concentration of $H_2SO_4$ is above 10%, the fracture mode is shifted from a transgranular fracture to an quasi-intergranular fracture according to the increment of concentration. 2) In the relationship between [$\Delta$DBTT]$_sp$ and SCC susceptibility, it is confirmed that the greater material degradation degree is, the higher SCC susceptibility is. In addition, it can be known that SP test is useful test method to evaluate SCC susceptibility for high temperature structural components. 3) When [$\Delta$DBTT]$_sp$ is above 17$17^{\circ}C$ the SCC fracture behavior is definitely observed with SCC susceptibility of above 0.4.

• 한국유기농업학회지
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• 제7권2호
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• pp.107-114
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• 1999

몇가지 土壤微生物劑의 處理가 배추의 收量과 土壤 및 植物體의 化學成分, 그리고 微生物相에 미치는 影響을 調査하였다. 모든 微生物劑 處理區에서 無處理에 비하여 收量이 增加하였고, 糖度 또한 增加하여 微生物劑의 處理가 배추의 收量뿐만 아니라 品質의 向上에도 매우 效果的이라고 思料되었다. 植物體의 化學成分을 調査한 結果, MPK+Compost 處理區에서 Fe와 Zn 含量이 매우 높았으나 有意性은 없었고, 다른 成分들은 處理區間에서 差異가 없었다. 土壤의 化學成分에서는 Tomi 處理區에서 K와 Mg의 含量이 높았으나, 다른 處理區에서는 差異가 없었다. 土壤의 微生物相을 調査한 結果, 總細菌數에서는 Tomi 處理區가 가장 높았고 Husk+Palma 및 MPK+Husk+Palma 處理區에서도 높게 나타났다. Bacillus는 MPK+Husk+Palma 處理區가 가장 높았고 Husk+Palma와 Tomi 處理區에서도 몹시 增加되었다. Actinomycetes와 fungi에서도 Tomi 處理區가 매우 增加하였으나, 다른 處理區間에는 差異가 없었고, psedomonas에서도 各 處理間에 差異가 없었다.

• 농업과학연구
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• 제46권1호
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• pp.33-44
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• 2019

This study was conducted to examine the components of phytoncide from a pine forest in the southern temperate zone. Recent studies have found that a large amount of phytoncide is released not only from cypress trees but also from pine trees. Because the amount released is the highest during summer, we selected a warm climate region in the southern temperate zone and measured the concentration in the month of August. To capture the phytoncide from the forest atmosphere, we used the adsorption tube method with a mini pump and successfully gathered 9 L of forest air at a flow rate of 150 mL/min. We performed duplicate sampling from two different tubes installed at the same location and derived the mean value. A gas chromatography/mass spectrometer detector with thermal desorption spectroscopy was utilized to perform quantitative and qualitative analyses of the captured material. The results showed that the average phytoncide particle of the pine forest in the southern temperate zone contained a number of components as follows in descending order: ${\alpha}$-Pinene (39%, $0.28ng/m^3$), followed by ${\beta}$-Pinene (16%, $0.11ng/m^3$), D-Limonene (8%, $0.06ng/m^3$), camphor (6%, $0.04ng/m^3$), camphene (6%, $0.04ng/m^3$), and p-Cymene (5%, $0.04ng/m^3$). There were also 13 additional phytoncide components in trace amounts. The results of this study are expected to provide a useful dataset for building a "Healing-forest".

• 자원리싸이클링
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• 제30권4호
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• pp.3-10
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• 2021

도시광산의 대표적인 사례인 폐 전자부품 재활용 분야는 유용한 선별기술의 개발이 필요하다. 본 연구에서는 전자부품들을 4개의 그룹으로 선별하기 위해 딥러닝에 의한 이미지 식별을 기반으로 한 선별기를 개발하였다. 전자부품들은 폐 인쇄회로기판으로부터 회수되었으며, 처리 후 차이점에 따라 분리되어야 한다. 선별기는 GPU, 카메라, 컨베이어벨트, 공기 압축기로 이루어진 워크스테이션으로 구성되어있다. 컨베이어벨트(벨트 속도: 6cm/s) 위에 있는 작은 크기(3.5cm 이하)의 전자부품들을 데이터로 가져와 학습했다. 이미지 식별의 정확도는 종류에 따라 96%, 그리고 그룹에 따라 99%였다. 벨트속도와 압축공기의 블로다운 시간과 같은 작동조건에 변화를 주었을 때, 이미지 식별의 정확도 그리고 블로다운에 의한 회수율을 측정하여 선별의 최적 조건을 결정했다. 최적조건에서 이미지 분류의 정확도는 그룹별로 98.7%였다. 선별 효율은 70% 이상이었다.

• Nutrition Research and Practice
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• 제16권2호
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• pp.233-247
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• 2022

BACKGROUND/OBJECTIVES: The objective of this study was to describe the development process of the Korean Healthy Eating Index (KHEI) based on the Korea National Health and Nutrition Examination Survey (KNHANES). SUBJECTS/METHODS: The components of KHEI were selected based on Dietary Guidelines for Koreans, domestic and overseas dietary quality indices, and results of the analysis of association with chronic diseases. The standards for scoring of KHEI were selected based on the 2015 Dietary Reference Intakes for Koreans (KDRI). The KHEI scores of Korean adults were calculated using a 1-day 24-h recall data in the 2013-2015 KNHANES. RESULTS: The KHEI included eight adequacy components evaluating the proper intake of recommended foods such as fruit, vegetable, and milk and three moderation components evaluating the consumption of food that limit intake such as sodium and saturated fatty acid. In addition, three balance components assessing the balance of energy intake were included. The KHEI score was defined to range from the minimum of 0 point to the maximum of 100 points. Among Korean adults, the total KHEI score was 63.2 out of 100. Gender and age differences were found in the average of total KHEI scores. Women showed higher score than men (61.7 in men and 64.7 in women, respectively). By age group, 20s and 30s showed the lowest scores with 57.4 and 61.1 respectively, and the scores increased with age by peaking at 67.8 in ages 60-69 and slowed down again in ages 70 or over. CONCLUSIONS: The KHEI can be useful for establishing and assessing national nutritional policies and in epidemiological studies to assess the relationship between overall dietary quality and chronic diseases. KHEI will need to be continuously updated to reflect changes in dietary guidelines and the KDRI.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.57-68
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• 2023

Flavor is an important sensory trait of chicken meat. The free amino acid (FAA) and nucleotide (NT) components of meat are major factors affecting meat flavor during the cooking process. As a genetic approach to improve meat flavor, we performed a genome-wide association study (GWAS) to identify the potential candidate genes related to the FAA and NT components of chicken breast meat. Measurements of FAA and NT components were recorded at the age of 10 weeks from 764 and 767 birds, respectively, using a White leghorn and Yeonsan ogye crossbred F2 chicken population. For genotyping, we used 60K Illumina single-nucleotide polymorphism (SNP) chips. We found a total of nine significant SNPs for five FAA traits (arginine, glycine, lysine, threonine content, and the essential FAAs and one NT trait (inosine content), and six significant genomic regions were identified, including three regions shared among the essential FAAs, arginine, and inosine content traits. A list of potential candidate genes in significant genomic regions was detected, including the KCNRG, KCNIP4, HOXA3, THSD7B, and MMUT genes. The essential FAAs had significant gene regions the same as arginine. The genes related to arginine content were involved in nitric oxide metabolism, while the inosine content was possibly affected by insulin activity. Moreover, the threonine content could be related to methylmalonyl-CoA mutase. The genes and SNPs identified in this study might be useful markers in chicken selection and breeding for chicken meat flavor.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.431-431
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• 2016

Typical Cu(In,Ga)Se2 (CIGS)-based solar cells have a buffer layer between CIGS absorber layer and transparent ZnO front electrode, which plays an important role in improving the cell performance. Among various buffer materials, chemical bath deposition (CBD)-ZnS is being steadily studied to alternative to conventional CdS and the efficiency of CBD-ZnS/CIGS solar cell shows the comparable values with that of CdS/CIGS solar cell. The intriguing thing is that reversible changes occur after exposure to illumination due to the metastable defect states in completed ZnS/CIGS solar cell, which induces an improvement of solar cell performance. Thus, it implies that the understanding of metastable defects in CBD-ZnS/CIGS solar cell is important issue. In this study, we fabricate the ITO/i-ZnO/CBD-ZnS/CIGS/Mo/SLG solar cells by controlling the NH4OH mole concentration (from 2 M to 3.5 M) of CBD-ZnS buffer layer and observe their conversion efficiency with and without light soaking for 1 hr. From the results, NH4OH mole concentration and light exposure can significantly affect the CBD-ZnS/CIGS solar cell performance. In order to investigate that which layer can contain metastable defect states to influence on solar cell performance, impedance spectroscopy and capacitance profiling technique with exposure to illumination have been applied to CBD-ZnS/CIGS solar cell. These techniques give a very useful information on the density of states within the bandgap of CIGS, free carriers density, and light-induced metastable effects. Here, we present the rearranged charge distribution after exposure to illumination and suggest the origin of the metastable defect states in CBD-ZnS/CIGS solar cell.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.234-234
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• 2017

Recent abnormal weather, especially continued rainfall during sowing season causes difficulty in proper sowing of wheat and delayed sowing after November 15 is concerned about freezing damage during winter, resulting in reduction of wheat yield. To correspond government policy of crop sufficiency improvement and produce and supply raw wheat and barley steadily, expansion of cultivation area is necessary and spring sowing of wheat is required. To obtain basic information on the improvement of spring sown wheat and barley production, comparison and path coefficients analysis was conducted for yield and yield related components from autumn and spring sown wheat and barley. Path analyses were known as very useful in clarifying the effects of yield components on grain yield formation, which were not accurately reflected in simple correlation anaylses. Most cultivated 5 wheat and 9 barley cultivars were sown on October and February at Cheon-ju province according to standard sowing method. For the spring sowing of wheat and barley, the varieties having vernalization degree I~III are seeded in the mid of February and seeding rate is 200~250kg/ha which is increased by 25% than autumn sowing. N-fertilizer of 95 kg/ha and the same amount of P, K dressed in autumn are applied at once as basal fertilizer. The magnitude of direct effect in each yield components on yield was in sequence as follows. In autumn wheat, grain number per $spike{\geq}$ the number of spike per $m^2$>1000-grain weight and in spring wheat, grain number per $ spike{\geq}the$ number of spike per $m^2$> 1000-grain weight. In autumn naked barley, 1000-grain weight> the number of spike per $m^2$, grain number per spike and in spring barely, the number of spike per $m^2$> grain number per spike > 1000-grain weight. In autumn covered barley, grain number per spike>the number of spike per $m^2$ and in spring coverd barley, the number of spike per $m^2$> grain number per spike, 1000-grain weight. In autumn malt barley, the number of spike per $m^2$>1000-grain weight and in spring malt barley, the direct effects of three yield components were similar. According to the path analysis of yield components for spring sown wheat and barley, it was suggested that adequate number of spike per $m^2$ was most important factor for yield increase.