• Journal of Ginseng Research
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• 제34권4호
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• pp.274-281
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• 2010

This experiment was conducted to examine ginseng lines resistant and susceptible to high-temperature injury and to investigate characteristics of the selected lines: leaf burning phenomenon, chlorophyll content, quantum yield, and maximum light interception rate. The leaf burning phenomenon incidence rates of the resistant lines Yunpoong, high-temperature injury resistance (HTIR)1, HTIR2, and HTIR3 were low: 5.8%, 3.6%, 4.0%, and 1.9%, respectively. Resistance of the susceptible lines Chunpoong, high-temperature injury susceptible (HTIS)1, and HTIS2 was high: 58.5%, 23.2%, and 21.7%, respectively. The chlorophyll content (SPAD value) of the resistant lines Yunpoong, HTIR1, HTIR2, and HTIR3, which were exposed to high temperatures and intense light, remained as high at 24.8, 27.9, 24.9, and 30.6, respectively, but that of the susceptible lines Chunpoong, HTIS1, and HTIS2 was low at 21.0, 21.1, and 20.1, respectively. During the summer season, the quantum yield of the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) changed little, but that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) changed dramatically. The maximum light interception rate (Fm/Fv value) for the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) was as high as 0.848, 0.794, 0.805, and 0.813, respectively, while that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) was 0.678, 0.642, and 0.717, respectively. Based on these results, the high-temperature injury-resistant lines seemed to be less susceptible to high light, even at high temperatures. Future studies on red ginseng quality and its active ingredients in resistant ginseng lines and field experimentation will be conducted to verify the potential of the resistant lines.

• 한국환경과학회지
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• 제8권6호
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• pp.717-724
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• 1999

This experiment was performed on three parts with prepared coagulants. (1) The characterization of coagulation for PACI coagulants. (2) Comparison of the characterization of coagulation with PAS and PACI coagulants. And (3) Comparison of the characterization of coagulation for the addition of calcium with PACI. Coagulation experiments were conducted with several dosages and pH for each coagulants. For the characterization of coagulation with PACI coagulants, coagulation of Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of the three coagulants can be considered as r=2.2 > 2.0 > 2.35 which are also the order of higher polymeric aluminum contents. For the comparison of the characterization of coagulation for PAS and PACI coagulants, PAS (r=0.75) coagulants was more effective than other coagulant for the removal of organic matters by sweep floc mechanism with $A;(OH)_{3(S)}$. For comparison of the characterization of coagulation for the addition of calcium with PACI, the presence of divalent cation like $Ca^{2+}$ was supposed to influence the complex formation of organic anions. From the result of test on coagulation at various pH ranges, the PACI was least affected by the coagulation pH, and the addition of calcium to PACI was very effective for the removal of turbidity and organic materials over broader pH range (pH 4-9).

• Journal of Ginseng Research
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• 제45권6호
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• pp.717-725
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• 2021

Background: Korean Red Ginseng (KRG) is a traditional herb that has several beneficial properties including anti-aging, anti-inflammatory, and autophagy regulatory effects. However, the mechanisms of these effects are not well understood. In this report, the underlying mechanisms of anti-inflammatory and autophagy-promoting effects were investigated in aged mice treated with KRG-water extract (WE) over a long period. Methods: The mechanisms of anti-inflammatory and autophagy-promoting activities of KRG-WE were evaluated in kidney, lung, liver, stomach, and colon of aged mice using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), quantitative RT-PCR (qRT-PCR), and western blot analysis. Results: KRG-WE significantly suppressed the mRNA expression levels of inflammation-related genes such as interleukin (IL)-1β, IL-8, tumor necrosis factor (TNF)- α, monocyte chemoattractant protein-1 (MCP-1), and IL-6 in kidney, lung, liver, stomach, and colon of the aged mice. Furthermore, KRG-WE downregulated the expression of transcription factors and their protein levels associated with inflammation in lung and kidney of aged mice. KRG-WE also increased the expression of autophagy-related genes and their protein levels in colon, liver, and stomach. Conclusion: The results suggest that KRG can suppress inflammatory responses and recover autophagy activity in aged mice.

• Journal of Yeungnam Medical Science
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• 제10권2호
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• pp.369-379
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• 1993

Dual energy x-ray absorptiometry(DEXA)를 이용하여 골밀도에 영향을 줄 인자가 없는 소아 80명을 대상으로 제2-4요추에서 골밀도를 측정하여 연령군과 Tanner stage의 변화에 따른 골밀도의 변화를 연구하고 골밀도와 연령, 체중, 신장, 골 연령, 성별, 혈청칼슘, 무기인, 부갑상선호르몬과 Alkaline phosphatase 등과의 상관관계를 알아본 결과, 골밀도는 연령(r=0.696), 체중(r=0.693), 신장(r=0.717), 골연령(r=0.690) 및 Tanner stage(r=0.636) 와 유의한 상관관계가 있었으나 (r>0.6) 골대사의 지표인 혈청 칼슘, 무기인, 부갑상선 호르몬 ALP나 성별과는 유의한 상관관계가 없었으며, 특히 남, 여 그리고 전체 환아 각각의 경우에서 연령, 체중, 신장과 골밀도의 직선적 상관관계(남아 : 연령 y=0.4223+0.0289x, 체중 y=0.3879+0.0087x, 신장 y=0.1362+0.0042x 여아 : 연령 y=0.3731+0.0494x, 체중 y=0.3206+0.014x, 신장 y=0.0782+0.0070x 전체 : 연령 y=0.4113+0.0354x, 체중 y=0.3690+0.0107x, 신장 y=0.0628+0.0051x)가 있었다. 연구대상 소아를 4개의 연령군(1군 : 2개월-1세미만, 2군 : 1세이상-5세이하, 3군 : 6세이상-10세이하, 4군 : 11세 이상-15세이하)으로 나누어 조사한 결과 연령군에 따른 골밀도($g/cm^2$)의 증가는 1군(BMD : $0.335{\pm}0.175$)과 2군(BMD : $0.627{\pm}0.200$) 그리고 3군(BMD : $0.714{\pm}0.1896$)과 4군(BMD : $0.873{\pm}0.163$)에서 유의하게 증가하였으나(P<0.05), 2군과 3군사이에서는 유의한 골밀도의 증가를 관찰할 수 없었으며 남녀간 골밀도의 차이는 없었다(p<0.05). 또한 Tanner stage의 발달에 따라서는 골밀도($g/cm^2$)는 Tanner stage 1에서는 $0.547{\pm}0.234$, Tanner stage 2에서는 $0.783{\pm}0.136$, Tanner stage 3에서는 $0.998{\pm}0.080$으로서 모든 단계에서 유의하게 증가하였다(p<0.05). 이상의 결과에 의하면 DEXA로 측정한 골밀도는 연령, 체중과 신장 등의 증가와 유의한 상관관계가 있고 이들은 성장 속도가 빠른 연령에서 유의하게 증가하였으며 특히 성적 성숙도의 발달에 따라 유의하게 증가하였다.

• 대한공업교육학회지
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• 제35권2호
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• pp.140-158
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• 2010

과학기술교육의 수월성을 높이기 위해 기술과 담당 교사들의 역할이 매우 긴요하다는 인식 아래 이 연구는 내재적, 외재적 요인이 광주, 전라남도 소재 중 고등학교 기술과 담당 교사의 직무만족과 교직몰입에 미치는 영향을 분석하였다. 수집된 자료를 SPSS 통계 프로그랩을 통해 유의도 수준 p<.05 혹은 그 이상에서 다중회귀분석하였다. 교사들의 교직만족도는 M = 3.91, 교직몰입도는 M=3.69 이었다. 그들의 교직 만족에 대한 5개의 내재적 요인-성취, 일 자체, 책무성, 인정, 성장 가능성 등과 5개 외재적 요인-직업안정, 직무환경, 보수, 감독기술, 인간관계 등의 통합적 영향력은 R=.717, $R^2$=.515로 나타났으며 모두 유의하였다. 위 10개 요인들의 통합적 작용은 교사의 직무만족의 변화량에 대하여 51.5% ($R^2$=.515)의 설명력을 가지고 있었다. 이들 중, 보수가 가장 중요했고 다음이 성취였다. 이들의 통합이 교사들의 교직몰입에 미치는 영향을 분석한 결과, R=.785, $R^2$ =.616은 유의하였다. 통합은 교직몰입의 변화량에 대하여 61.6% ($R^2$=.616)의 설명력을 가지고 있었다. 요인별 중요성에서는 성취가 가장 높았고 책무성은 다음이었다. 10개 요인의 복합 투입량을 높이면 교사들의 교직만족과 교직몰입은 높아질 수 있다. 특히 보수와 성취도를 높여주는 것이 교직만족도 향상에, 그리고 성취와 책무성을 높이는 것은 교직몰입에 상대적으로 더 효과적이다. 본 연구는 광주와 전남의 중 고등학교 기술과 담당 교사들을 대상으로 했기 때문에 연구결과를 전국적으로 혹은 타 분야 담당 교사들에게 일반화하는 데는 한계가 있다.

• 대한원격탐사학회지
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• 제37권4호
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• pp.699-717
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• 2021

South Korea is pushing for the advancement of crop production technology to achieve food self-sufficiency and meet the demand for safe food. A medium-sized satellite for agriculture is being launched in 2023 with the aim of collecting and providing information on agriculture, not only in Korea but also in neighboring countries. The satellite is to be equipped with various sensors, though reference data for ground information are lacking. Hyperspectral remote sensing combined with 1st derivative is an efficient tool for the identification of agricultural crops. In our study, we develop a system for hyperspectral analysis of the ground-based reflectance spectrum, which is monitored seven times during the cultivation period of three soybean crops using a PSR-2500 hyperspectral sensor. In the reflection spectrum of soybean canopy, wavelength variations correspond with stages of soybean growths. The spectral reflection characteristics of soybeans can be divided according to growth into the vegetative (V)stage and the reproductive (R)stage. As a result of the first derivative analysis of the spectral reflection characteristics, it is possible to identify the characteristics of each wavelength band. Using our developed monitoring system, we observed that the near-infrared (NIR) variation was largest during the vegetative (V1-V3) stage, followed by a similar variation pattern in the order of red-edge and visible. In the reproductive stage (R1-R8), the effect of the shape and color of the soybean leaf was reflected, and the pattern is different from that in the vegetative (V) stage. At the R1 to R6 stages, the variation in NIR was the largest, and red-edge and green showed similar variation patterns, but red showed little change. In particular, the reflectance characteristics of the R1 stage provides information that could help us distinguish between the three varieties of soybean that were studied. In the R7-R8 stage, close to the harvest period, the red-edge and NIR variation patterns and the visible variation patterns changed. These results are interpreted as a result of the large effects of pigments such as chlorophyll for each of the three soybean varieties, as well as from the formation and color of the leaf and stem. The results obtained in this study provide useful information that helps us to determine the wavelength width and range of the optimal band for monitoring and acquiring vegetation information on crops using satellites and unmanned aerial vehicles (UAVs)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.717-720
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• 2005

Acoustic loads generated by a rocket propulsion system cause severe random vibrations on payloads. In developing a new launch vehicle, a random vibration level must be specified before the detailed design of payloads or electronic equipments. This paper deals with prediction procedures of a random vibration level on payload section of KSLV-I. The prediction is based on statistical energy analysis. In order to verify the prediction methodology, test and analysis on a sub-scale payload section are performed. The predicted results subject to very high level of acoustic loads show a good agreement with the test results performed in the high intensity acoustic chamber. The predicted random vibration level on payload section of KSLV-I is also presented in this paper.

• 동력기계공학회지
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• 제21권3호
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• pp.45-50
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• 2017

This paper presents the Coefficient of performance(COP) and mass flow ratio of cascade refrigeration system with respect to refrigerants appling to high temperature cycle. The operating parameters considered in this study include degree of superheating and subcooling, compressor efficiency, evaporating temperature, condensing temperature and internal heat exchanger effectiveness in high temperature cycle. The result of this study is as follows : The COP of cascade system increases with increasing degree of superheating and subcooling, compressor efficiency and internal heat exchanger effectiveness except increasing condensing temperature. The mass flow ratio of low and high temperature cycle increases with increasing evaporating temperature and condensing temperature, but decreases with increasing internal heat exchanger effectiveness, degree of superheating and subcooling. Also, the mass flow ratio has no correlation with compressor efficiency at high temperature cycle.

• 한국생활과학회지
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• 제19권4호
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• pp.709-717
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• 2010

This study investigated the properties and functions of wool and silk dyed with Catechu by examining the effects of dying conditions such as dye concentration, dying temperature, dyeing time, pH level and pre-mordants. These conditions were examined in relation to dye uptake and color changes, washing fastness, light fastness, ultraviolet-cut ability and antimicrobial ability of the dyed fabrics. Catechu showed good affinity to silk fiber. Langmuir adsorption isotherm was obtained, and so it was considered that ionic bondings are formed between Catechu and protein fiber. As the dyeing time and temperature is increased, the dyeability of both silk and wool fabrics also increases. At high temperatures the color of dyed fabrics changes from Y and YR to R. Wool is effective in using Al, Cu, Fe mordant, while silk is effective only in using only Cu mordants. The dyeability was shown to be improved at low pH levels. Additionally, both washing fastness and light fastness were shown to be low. However, the fabric color gradually changed to red was due to mailard reaction of catechol tannin causingby repeated washing and sunlight. The ultraviolet-cut ability was improved for cotton fabric dyed with Catechu. Also, dyed fabric with Catechu showed very good antimicrobial abilities at 99.9%.

• 소성∙가공
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• 제12권8호
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• pp.710-717
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• 2003

The implicit, finite element analysis program for analyzing the springback in the warm forming process of aluminum alloy sheets was developed. For the description of planar anisotropy in warm forming temperatures, Barlat's yield function is employed, and the power law type constitutive equation is used in terms of working temperatures for the depiction of work hardening in high temperatures. Also, Jetture's 4-node shell elements are introduced for reflecting the mechanical behavior of aluminum alloy sheet and the non-steady heat balance equations are solved for considering heat gain and loss during the forming process. For the springback evaluation, Newton-Raphson iteration method is introduced for overcoming the geometric nonlinearlity problem. In order to verify the validity of the FEM program developed, the stretching bending and springback processes are simulated. Though springback analysis results are slightly bigger than experimental ones, they have the same trend of the decreasing springback as the forming temperature increases.