This study was aimed to determine the changes in CO2 concentration according to the temperatures of daytime and nighttime in the CO2 supplemental greenhouse, and to compare calculated supplementary CO2 concentration during winter and spring cultivation seasons. CO2 concentrations in experimental greenhouses were analyzed by selecting representative days with different average temperatures due to differences in integrated solar radiation at the growth stage of leaf area index (LAI) 2.0 during the winter season of 2022 and 2023 years. The CO2 concentration was 459, 299, 275, and 239 μmol·mol-1, respectively at 1, 2, 3, and 4 p.m. after the CO2 supplementary time (10:00-13:00) under the higher temperature (HT, > 18°C daytime temp. avg. 31.7, 26.8, 23.8, and 22.4°C, respectively), while it was 500, 368, 366, 364 μmol·mol-1, respectively under the lower temperature (LT, < 18°C daytime temp. avg. 22.0, 18.9, 15.0, and 13.7°C, respectively), indicating the CO2 reduction was significantly higher in the HT than that of LT. During the nighttime, the concentration of CO2 gradually increased from 6 p.m. (346 μmol·mol-1) to 3 a.m. (454 μmol·mol-1) in the HT with a rate of 11 μmol·mol-1 per hour (240 tomatoes, leaf area 330m2), while the increase was very lesser under the LT. During the spring season, the CO2 concentration measured just before the start of CO2 fertilization (7:30 a.m.) in the CO2 enrichment greenhouse was 3-4 times higher in the HT (>15°C nighttime temperature avg.) than that of LT (< 15°C nighttime temperature avg.), and the calculated amount of CO2 fertilization on the day was also lower in HT. All the integrated results indicate that CO2 concentrations during the nighttime varies depending on the temperature, and the increased CO2 is a major source of CO2 for photosynthesis after sunrise, and it is necessary to develop a model formula for CO2 supplement considering the nighttime CO2 concentration.
With the increasing attention to environmental pollution caused by particulate matter globally, the automotive industry has also become increasingly interested in particulate matter, especially particulate matter generated by automobile brake systems. Here, we designed a coating composition and analyzed its mechanical properties to reduce particulate matter generated by brake systems during braking of vehicles. We designed a composition to check the mechanical properties change by adding Cr3C2 and YSZ to the WC-Ni-Cr composite composition. Based on the designed composition, coating samples were manufactured, and the coating properties were analyzed by Vickers hardness and ball-on-disk tests. As a result of the experiments, we found that the hardness and friction coefficient of the coating increased as the amount of Cr3C2 added decreased. Furthermore, we found that the hardness of the coating layer decreased when YSZ was added at 20vol%, but the friction coefficient was higher than the composition with Cr3C2 addition.
This study focused on improving the phase stability and mechanical properties of yttria-stabilized zirconia (YSZ), commonly utilized in gas turbine engine thermal barrier coatings, by incorporating Gd2O3, Er2O3, and TiO2. The addition of 3-valent rare earth elements to YSZ can reduce thermal conductivity and enhance phase stability while adding the 4-valent element TiO2 can improve phase stability and mechanical properties. Sintered specimens were prepared with hot-press equipment. Phase analysis was conducted with X-ray diffraction (XRD), and mechanical properties were assessed with Vickers hardness equipment. The research results revealed that, except for Z10YGE10T, most compositions predominantly exhibited the t-phase. Increasing the content of 3-valent rare earth oxides resulted in a decrease in the monoclinic phase and an increase in the tetragonal phase. In addition, the t(400) angle decreased while the t(004) angle increased. The addition of 10 mol% of 3-valent rare-earth oxides discarded the t-phase and led to the complete development of the c-phase. Adding 10 mol% TiO2 increased hardness than YSZ.
The blockage rate for three kinds of nets commonly used in agricultural facilities was assessed by using the image acquisition and its relevant processing. By using both empirical relations presented by Idel’chik and Richards and Robinson, and the blockage rate obtained from the image processing, the pressure drop through the nets was predicted and also compared with wind tunnel experiment results. The results of the study showed that the blockage rate of the net was discriminated according to such factors as the magnitude of nets, the existence of inside threads, the thickness and number of threads. In addition, the blockage rate for the incident angle of 0° when the wind blew at the front had the range of 0.22-0.29 (0.22-0.32 when considering whole incident angles from 0° to 45° by 15°). For the nets with the blockage rate of about 30% or below, the prediction by the empirical relations of by Idel’chik and Richards and Robinson showed a little higher pressure drop overall than that of the wind tunnel test, but the use of the empirical relations and the blockage rate could be thought of as providing effectively meaningful guidelines for the safe design of agricultural facilities including nets because the wind tunnel test has been tedious and expensive. Further research and potential application on the prediction technique of the pressure drop, regarding both a subtle deformation by the wind and manufacturing methods with regard to the level of knots and the existence of inside threads, needs to be done for the nets with higher blockage rate.
본 연구는 국내 가정에서 사용하고 있는 냉장고 및 냉 동고의 온도 분포에 대한 현황을 파악하기 위하여 냉장고 대상 25가구, 냉동고 대상 25가구를 선정하고 온도 측정 을 시행하였다. 가정용 냉장 및 냉동고의 실제 공간상의 온도 분포 조사 결과, 냉장고 대상 가구에서 측정된 온도 는 최저 -8.2oC, 최고 15.8oC, 평균 3.73oC로 조사되었으며, 공간 위치별 온도 분포는 문 보관 칸 5.06±1.69oC, 내부 벽면 4.18±1.19oC, 내부 보관함 3.41±1.36oC로 내부 보관함 의 온도가 가장 낮았고, 각 위치에서 상단 및 하단의 유의 적인 온도 차이는 문 보관 칸에서만 확인되었다(P<0.01). 냉 동고 대상 가구에서 측정된 온도는 최저 -30.3oC, 최고 0.7oC, 평균 -17.95oC로 조사되었으며, 공간 위치별 온도 분포는 문 보관 칸 -17.19±1.68oC, 내부 벽면 -17.81±1.07oC, 내부 보관함 -18.78±1.72oC로 냉장고 결과와 동일하게 내부 보 관함의 온도가 가장 낮고, 문 보관 칸에서만 상·하단의 유 의적인 온도 차가 확인되었다(P<0.01). 냉장·냉동고 내에 서 위치별 최대 온도 차이는 각각 2.18oC, 2.02oC로 확인 되었으며, 결론적으로 냉장·냉동고 전체의 온도가 일정하 게 유지되는 것이 아니며, 보관되는 위치별로 유의적인 편 차가 존재하는 것으로 나타났다. 이에 따라 냉장·냉동고 제조사와 공공기관에서 식품별 권장 보관 위치를 고객들 에게 적극적으로 권고하고, 각 가정에서는 온도 변화에 민 감한 식품을 보관할 경우 문쪽 보관을 지양하는 등 보관 관리 의식을 가져야 할 것으로 사료된다.
This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the ‘Cheongmyeong Gaual’ variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37′ N 128°32′ E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.
Ipomoea aquatic is a leafy vegetable of the Convolvulaceae family, and is a tropical plant widely inhabiting southern China and Southeast Asia, and is widely known as Morning Glory in the West. In this study, the anti-inflammatory effects of ethyl acetate extract from Ipomoea aquatic extracts (IAE) were tested against lipopolysaccharide (LPS)-induced activation microglia BV2 cells. The production of nitric oxide (NO) and cell viability were measured using the Griess reagent and MTT assay, respectively. Inflammatory cytokine [interleukin (IL)-6, tumor necrosis factor (TNF)-, and interleukin-1 (IL-1)] were detected qPCR in LPS induced BV-2 cells. Subsequently, nuclear factor (NF)-B, mitogen-activated protein kinases (MAPKs), and nuclear factor erythroid-2-related factor 2 (Nrf2) were analyzed through western blot analyses and immunofluorescence. Ipomoea aquatic down-regulated of inflammatory markers and up-regulated anti-inflammatory and anti-oxidants in BV2 cells.
축산물 중 잔류허용기준이 설정되어 관리하고 있는 농약 azocyclotin, cyhexatin, fenbutatin oxide는 대표적인 유 기주석계 살비제이다. 기존 시험법은 가스크로마토그래피 를 사용하여 정량한계가 높고 분석 시 재현성이 떨어져 이에 대한 개선이 필요한 실정으로 본 연구에서는 비교적 간편하며 시간이 적게 소요되는 QuEChERS법을 활용하여 azocyclotin, cyhexatin, fenbutatin oxide의 시험법을 마련하 고자 하였다. 1% 아세트산을 함유한 아세트산에틸:아세토 니트릴(1:1) 혼합액을 이용하여 진탕 추출 후 d-SPE로 정 제하고 이를 농축 후 LC-MS/MS를 이용한 시험법을 개발 하였다. Azocyclotin, cyhexatin 및 fenbutatin oxide의 결정 계수(R2)는 0.99 이상으로 높은 직선성을 확인하였으며 정 량한계는 0.01 mg/kg으로 높은 감도를 나타내었다. 대표 축산물 5종(소, 돼지, 닭, 계란, 우유)에서 LOQ(0.01 mg/ kg), MRL(0.05 mg/kg), MRL 10배(0.5 mg/kg)의 농도에서 회수율 실험을 한 결과 평균 회수율이 76.4-115.3% 및 84.4-110.8%이었으며, 상대표준편차는 25.3% 이하로 나타 났다. 본 연구는 Codex 가이드라인(CAC/GL 40-1993, 2003) 및 ‘식품의약품안전처 식품의약품안전평가원의 식 품등 시험법 마련 표준절차에 관한 가이드라인(2016)’에 적합한 수준임을 확인하였다. 따라서 본 연구에서 확립한 시험법은 축산물 중 잔류할 수 있는 azocyclotin, cyhexatin, fenbutatin oxide의 안전관리를 위한 공정시험법으로 활용 가능할 것으로 판단된다.
The major active components of Astragalus membranaceus (AM) are isoflavones, which exist in the form of various glycosides. Nuruk is a traditional fermentation starter in Korea, and is suitable for the biotransformation of isoflavone glycosides because it contains various microorganisms and enzymes. This study was performed to determine changes in the isoflavones and antioxidant properties of AM fermented (AF) with nuruk over 24 hours. AF was sampled after 0, 2, 4, 6, 12, 18, and 24 h of fermentation, and calycosin 7-glucoside, ononin, calycosin, and formononetin content, and the antioxidant properties of AF were analyzed. The total phenolic content increased with fermentation time, and the ABTS radical scavenging activity increased until 6 h of fermentation and then decreased. During fermentation, the isoflavone glycosides decreased significantly as fermentation time increased. The contents of calycosin and formononetin, which are aglycons of calycosin-7-glucoside and ononin, increased from 100.54 μg/g to 276.84 μg/g and from 56.29 μg/g to 123.04 μg/g, respectively, at 18 h of fermentation. Significant correlations were observed between fermentation time, isoflavone content, and antioxidant properties. The results of this study showed that fermentation with nuruk is suitable for the biotransformation of isoflavones in AM.
이 연구는 오늘날 해외 한국학이 비약적으로 발전할 수 있었던 요인 중 하나로 한국의 경제성장을 주목하며, 미국 주요 대학의 한국 경제 관련 강좌의 특징을 분석하였다. 그 결과, 첫째 ‘한국 경제’에만 초점을 둔 강좌는 찾기 어려웠으나, 한국의 역사, 문화, 사회를 이해하기 위한 한국학 강좌에서 한국의 경제는 한국을 읽어내는 주요 배경 또는 한국 사회에 영향을 미친 핵심적인 요인으로 나타났다. 둘째, 한국 경제 관 련 강좌는 ‘한국 경제’라는 특정 주제에 주목하기보다, 아시아 국가 간 관계, 그리고 아시아 지역 국가들의 경제, 산업, 금융, 무역이 어떻게 연결되며 그 특징이 무엇인지 집중하고 있으며, 경제‧경영 이론을 설명 할 때 하나의 사례로 제시되는 특징이 있다.
This study aimed to investigate the effects of Centella asiatica powder on the quality characteristics and storage stability of goat meat Tteokgalbi. The goat meat Tteokgalbi samples were prepared with four different quantities (0, 0.5, 1, and 1.5%) of Centella asiatica powder. The moisture content of the samples containing Centella asiatica powder was significantly lower than that of the control (p<0.05). The protein content of the samples containing Centella asiatica powder was significantly higher than that of the control (p<0.05). As the proportion of Centella asiatica powder increased, the pH, L*, and a* values of the uncooked and cooked samples decreased (p<0.05). The water holding capacity and the cooking yield of the uncooked and cooked samples were higher in the samples containing Centella asiatica powder than in the control (p<0.05). Also, with the increasing amounts of the Centella asiatica powder, the thiobarbituric acid reactive substance (TBARS) levels decreased. The 1-1.5% Centella asiatica powder group showed lower levels of volatile basic nitrogen (VBN) than the other groups as per the assay (p<0.05). The results indicate that Centella asiatica powder could enhance the quality characteristics and storage stability of goat meat Tteokgabi.
This study examines the characteristics of berries from secondary bearing shoots of ‘Scintilla’ southern highbush blueberry, grown hydroponically in the Jinju, Gimhae, and Uiryeong regions of Gyeongnam Province. Typically, ‘Scintilla’ forms flower buds at the tips of regular bearing shoots during the previous season, yielding berries in the current season. However, under heated cultivation, we observed a proliferation of secondary bearing shoots that produce berries in the same growing season. Flowering and harvesting on secondary bearing shoots were delayed by 52 and 36 days, respectively, compared to regular bearing shoots. However, these shoots exhibited a 54% increase in diameter and a 10% increase in length. We found no significant difference in berry size and soluble solid content between the two types of shoots. Notably, berries from the secondary bearing shoots had higher potassium and lower calcium and magnesium concentrations. We conclude that berries from secondary bearing shoots could be marketable, provided the bushes are healthy. These findings provide valuable insights for optimizing cultural practices to improve the yield and quality of blueberries under specific environmental conditions.
This study aims to analyze the sensory characteristic of cooked rice made with 10 types of rice varieties produced in South Korea using descriptive analysis. Twelve subjects who cook rice regularly, at least once a week, were recruited for the study and participated as descriptive panelists. A total of 29 descriptive terms were developed to describe the sensory characteristics of cooked rice. The findings showed that there were significant differences in the sensory attributes, specifically the appearance and texture attributes among the rice varieties. Among the varieties, Haedeul, Ilpum, and Koshihikari were observed to have a large quantity of rice germ and a relatively yellowish appearance. In contrast, Samkwang, Chamdream, and Yeonghojinmi were relatively whiter than the other samples. Odae, Saecheongmoo, and Sindongjin were rated high in the attributes of roughness, hardness, and chewiness, and Jinsang was rated high in moisture, bitterness, stickiness, and wholeness of rice grains. The differences in the appearance and texture of these rice varieties are likely to significantly impact consumer preferences. Furthermore, the development of customized menus based on the sensory characteristics of the different varieties of rice could encourage consumers to purchase these varieties.
To harvest marketable cucumbers, high quality seedlings must be used. Producing seedlings in the greenhouse during the low radiation period decreases marketability due to insufficient light for growth. Supplemental lighting with artificial light of different quality can be used to improve low light conditions and produce high quality seedlings. Therefore, this study was conducted to select the appropriate supplemental light sources on the growth and seedling quality of grafted cucumber seedlings during the low radiation period. Three cultivars of cucumber were used as scions for grafting; ‘NakWonSeongcheongjang’, ‘Sinsedae’, and ‘Goodmorning baekdadagi’. Figleaf gourd (Cucurbita ficifolia) ‘Heukjong’ was used as the rootstock. The seeds were sown on January 26, 2023, and grafted on February 9, 2023. After graft-taking, cucumbers in plug trays were treated with RB light-emitting diodes (LED, red and blue LED, red:blue = 8:2), W LED (white LED, R:G:B = 5:3:2), and HPS (high-pressure sodium lamp), respectively. Non-treatment was used as the control. Supplemental lighting was applied 2 hours before sunrise and 2 hours after sunset for 19 days. The stem diameter and fresh and dry weights of roots did not differ significantly by supplemental light sources. The plant height and hypocotyl length were decreased in W LED. However, the leaf length, leaf width, leaf area, and fresh and dry weights of shoots were the highest in the RB LED. Seedling qualities such as crop growth rate, net assimilation rate, and compactness were also increased in RB LED and W LED. After transplanting, most of the growth was not significant, but early yield of cucumber was higher in LED than non-treatment. In conclusion, using RB LED, W LED for supplemental light source during low radiation period in grafted cucumber seedlings improved growth, seedling quality, and early yield of cucumber.
아미노글리코사이드계 항생제(Aminoglycosides, AGs) 는 그람음성균과 양성균에 광범위하게 작용하는 동물용 의약품으로, 최근 배양육에 사용된다고 알려져 있어, 안 전성 관리를 위한 분석법 마련이 반드시 필요하다. AGs 는 고극성 화합물로 성분 간의 분리를 위해 이온쌍 시 약(ion-pairing reagent, IPR)을 사용하고 있으나 IPR을 이동상에 첨가하는 기존 분석방법의 경우 용매가 흐르 는 동안 질량분석기로 주입되는 IPR로 인해 기기적인 문 제가 발생할 가능성이 높아, IPR를 바이알에 직접 첨가 하는 분석방법을 검토하였다. 본 연구에서 10종 AGs 성 분에 대한 분석방법을 확인하고 유효성을 검증하였다. 검출한계와 정량한계는 각각 0.0001-0.0038 mg/kg 와 0.004-0.011 mg/kg의 범위로 나타났으며, 0.01-0.5 mg/ kg 범위 내의 직선성(R2)은 0.99 이상이었다. AGs의 시 료 회수율을 확인하고자 소고기와 세포배양배지(cell culture medium) 매질에서 회수율과 상대표준편차로 나 타낸 정밀도를 확인한 결과 각각 70.7-120.6% 및 0.2 to 24.7%로 나타났다. 기존의 이동상에 IP 첨가 방법과 비 교하였을 때 유사한 수준으로 양호하였다. 검증된 AGs 분석법은 국내 유통되는 닭고기, 소고기, 돼지고기 15품 목과 배양육 배지 첨가제 6품목에 적용해보았다. 그 결 과 국내 유통되는 육류 15품목 모두 AGs 성분이 검출 되지 않았으나, 세포배양배지에서 streptomycin은 695.85- 1152.71 mg/kg, dehydrostreptomyci은 6.35-11.11 mg/kg 로 검출되었다. 따라서 IRR을 바이알에 직접 첨가하는 LC-MS/MS 방식은 육류, 세포배양배지, 배지첨가제 중 AGs 분석 및 안전성 평가를 위한 기초자료로 활용될 것 으로 기대된다.
식물구계학적 특정종은 식물상 정보를 이용한 지역환경을 평가하는 주요 수단이며, 종의 선정과 평가는 식물구계 정보에 의거해서 이루어진다. 본 연구는 이러한 식물구계에 대해 학술적 진의를 규명하고자 하였다. 식물구계 관련 핵심문헌 7편을 검토하였으며, 식물구계 적용 근거를 비교 검증하였다. 1919년의 Nakai 울릉도 식물상 조사보고서는 식물구계에 관련한 일반적인 지리구분(지방)을 처음으로 기재했다. Oh는 1977년에 한국의 유관속식물에 대한 식물지리구계도를 처음으로 제시하였 다. 1978년에는 Lee & Yim이 중부와 남부를 가르는 구계도를 제시했고, 그 밖에 많은 연구자들에 의해 식물구계 경계는 조정되고 개정되었다. 마침내 2018년에는 Lee & Yim (1978)에서 변형된 식물구계학적 특정종의 식물구계도가 채택되었다. 그런데 이러한 식물구계들은 연구자 간에 차이가 있었고, 구계 지표 식물의 불일치성도 확인되었다. 그럼에도 그런 상이성에 대한 근거는 찾을 수 없었다. 결론적으로 도식화된 모든 식물구계도는 선험적으로 그은 임의 선에 의존하고 있었다. 본 연구는 식물구계학적 특정종이 환경영향평가 및 국가 식물상 평가를 위한 과학적 수단으로서 그 실효성과 실체성을 확보하기 위해 다음의 두 가지 생태학적 전략을 제안했다 : 종분포 고유성(nativeness) 정보를 바탕으로 하는 식물상 및 식물구계의 성취와 서식처 기반(habitat-based) 식물상 장기모니터링 시스템의 구축.
본 연구는 국내 유통 조미건어포 27건 중 프로피온산, 안 식향산, 소브산 함량을 분석하였다. 식품의약품안전처 식 품공전의 분석 방법으로 GC-FID를 이용하여 프로피온산 을 분석하였고 HPLC-DAD를 이용하여 안식향산과 소브 산을 분석하였다. 그 결과 총 27건 중 프로피온산은 16건 (검출률 59%), 안식향산은 불검출, 소브산은 7건(검출률 26%)이 검출되었다. 조미건어포에서 프로피온산은 ND- 125.10 mg/kg의 농도로 검출이 되었으며 이는 미생물 최 소저해농도 이하의 수치로 보존 효과를 나타낼 수 없는 농도로 보여 의도적으로 첨가되지는 않았을 것으로 사료 된다. 또한, 소브산의 경우 소르빈산 칼륨이 표기된 시료 에서만 검출되었으며 표기된 시료 8건 중 7건에서만 검출 이 되었다. 소브산 검출 시료의 경우 658.18 mg/kg의 농도 까지 검출이 되었으며, 이는 그 사용 기준에 적합한 수치 였다. 본 연구는 향후 조미건어포에 대한 안전 관리를 위 한 기초자료로 사용될 수 있을 것으로 사료된다.
This study was conducted to investigate the growth characteristics of cucumber (Cucumis sativus L. ‘Joeunbaekdadagi’) and tomato (Solanum lycopersicum L. ‘Dotaerang Dia’) seedlings by light intensities and CO2 concentrations in a closed-type plant production system (CPPS). Cucumber and tomato seeds were sown in 50-cell trays and germinated in CPPS at air temperature 25 ± 1°C and relative humidity 50 ± 10% for 4 days. After germination, the CO2 concentrations and light intensity treatment were treated at 500 (ambient), 1,000, and 1,500 μmol·mol-1 and 100, 200, and 300 μmol·m-2·s-1 photosynthetic photon flux density (PPFD), respectively. The leaf area of cucumber showed the highest value in CO2 1,500 μmol·mol-1. However, the leaf area of the tomato had no significant difference in CO2 concentrations and light intensities treatments. In cucumber and tomato both seedlings, the growth and quality such as compactness and leaf area rate were increased with the increase of light intensity, and there were highest in 300 μmol·m-2·s-1. The root surface and number of root tips of cucumber and tomato seedlings were significantly increased with the increase in light intensity. In conclusion, the regulation of the CO2 concentrations and light intensity can control the growth and quality of cucumber and tomato seedlings in CPPS, especially, increasing the light intensity can improve more significantly the growth and quality of seedlings.
ITO 투명 전극 필름은 디스플레이, 전기 자동차 등 산업 전 범위에서 널리 사용되는 전자 재료이다. 본 연구에서는 이러한 indium tin oxide (ITO) 필름의 열성형 안정성을 향상시키기 위하여 Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) 전도성 고분자 코팅 용액 조성을 결정하였다. 1000 S/cm의 고 전도성을 보이는 PEDOT:PSS 용액에 끓는점이 각기 다른 4가지 종류의 용매를 희석하였고, 코팅 전 후 면저항 변화를 분석하였다. 또한 380~800 nm 영역의 광 투과율 분 석 및 Raman 스펙트럼 분석을 통하여 PEDOT:PSS 박막이 코팅된 ITO 투명 전극의 전기적 특성 결정 메커니즘을 규명하였 다. 230°C 열성형 공정 결과 ITO 필름은 113% 연신 상태에서 이미 전기 전도성을 읽었지만, ethylene glycol을 희석 용매로 사용하여 얻어진 전도성 고분자 박막이 적용된 ITO 필름은 126% 고 연신 상태에서도 초기 60 Ω/sq 면저항을 246 Ω/sq로 유지하는 우수한 전기 전도성을 보였다.
PURPOSES : This study aims to examine actual cases of providing detour information in accidental situations such as traffic accidents and road construction through a VMS installed on national highways in metropolitan areas with alternative routes, as well as cases of simultaneously providing travel time information on parallel paths such as national and regular highways. For each case, we analyzed whether the provision of VMS traffic information leads to route changes and substantial effects. METHODS : To analyze traffic changes on the main and detour roads based on the detour information provided on traffic accidents in actual cases, the traffic volume and speed on the accident day were compared with those on the same days and at the same time of the day (regular days) based on the VDS data of the main and detour roads. Cases providing more detour information on road construction were investigated by examining three time periods: one week from construction initiation and one week before and after the construction period (regular days). The traffic volume and speed on the main road were compared based on the VDS data, and those on the detour road were compared based on data made available by private entities. Regarding the cases of simultaneously providing drivers with comparative information on travel time over parallel sections of national and regular highways, traffic situation changes in highways were analyzed in the following special traffic control periods (New Year's Day, NY Day), during which congestion is expected due to heavy traffic: before and after the provision of comparative information for 2015 New Year's Day and 2016 NY Day. RESULTS : The detour rate related to route changes based on the detour information for traffic accidents was 35%. On the detour route, the traffic volume increases as traffic from the main road is absorbed. However, the average travel speeds did not differ significantly. When further detour information regarding a road construction project was provided, the detour rate from the main road was 21%. The travel speeds were similar, except on the first day of construction. Almost no changes were observed in the first section of the detour. The speed slightly decreased in the second section but did not significantly hinder the traffic flow. When comparative traffic time information on parallel routes (national highways and expressways) was provided, the traffic volume increased to some extent after the report was provided for every case. However, the data frequency rate in the 5-min unit, which was still under the congestion speed standard (40 km/h), decreased. This indicates that traffic congestion was significantly relieved. CONCLUSIONS : Previous studies on detour rates or route changes based on VMS traffic information have focused on VMS instruments on expressways. Although their estimates were based on simulated situations, this study used actual VMS installed on national highways. In addition, this study utilizes the existing case records of national highway ITS centers, covering traffic situation monitoring, measures for accidental situations, etc., in regular times or special traffic control periods, as well as statistical data, including ITS real-time traffic information. The analysis results of this study accurately represent situations on actual roads and can be utilized to analyze future ITS operation and installation project effects.