Dynamic stability (DS) in the wheel tracking (WT) test is used as a basic index of rut-resistance for asphalt mixtures. In general, the deeper rut depth is obtained from the weaker mixture, resulting in the lower DS value. On the other hand, the shallower rut depth is obtained from the stronger mixture, resulting in the higher DS. However, it is not always the case when the DS is calculated by the existing method because the DS is simply determined based on the slope at the final stage of the rut depth-cycle curve. Specifically, in the case of the depth-cycle curve showing a steeper slope in the early part but flatter slope in last part, the DS is calculated to be higher than the curve showing a ever-increasing slope throughout the test. As long as the last part of slope is flatter, the deeper final rut depth is evaluated to show a higher DS than the little final rut depth. Therefore, a reasonable method for DS evaluation need to be established. Several new methods were suggested by considering the early, middle and final parts of rut depth to determine a reasonable DS. The results have shown that those new methods have demonstrated a significant improvement in distinguishing similarly performing mixtures. The result also showed that $DS_2$ had better correlation with SD than any other methods , representing the rutting resistance of asphalt mixture very well. The new DS calculation method is relatively simple and easy to follow. More validatin study is required for practical application.
Transactions of the Korean Society of Mechanical Engineers A
/
v.38
no.12
/
pp.1415-1420
/
2014
Super-critical $CO_2$ ($S-CO_2$) Brayton cycle has been considered to replace the current steam Rankine cycle in Sodium-cooled Fast Reactor (SFR) in order to improve the inherent safety and thermal efficiency. Several austenitic alloys are considered as the structural materials for high temperature $S-CO_2$ environment.. Microstructural change after long-term exposure to high temperature $S-CO_2$ environment could affect to the mechanical properties. In this study, candidate materials (austenitic stainless steels and Alloy 800HT) were exposed to $S-CO_2$ to assess oxidation resistance and the change in tensile properties. Loss of ductility was observed for some austenitic stainless steels even after 250 h exposure. The contribution of $S-CO_2$ environment on such changes was analyzed based on the characterization of the surface oxide and carburization of the materials in which 316H and 800H showed different oxidation behaviors.
Background: The early detection of anthracycline- induced cardiotoxicity is very important since it might be useful in prevention of cardiac decompensation. This study was designed with the intent of assessing the usefulness of cardiac troponin T (cTnT) and NT- Pro BNP estimation in early prediction of anthracycline induced cardiotoxicity. Materials and Methods: In this prospective study histologically proven breast cancer patients who were scheduled to receive anthracycline containing combination chemotherapy as a part of multimodality treatment were enrolled. Baseline cardiac evaluation was performed by echocardiography (ECHO) and biomarkers like cardiac troponin T (cTnT) and N terminal- pro brain natriuretic peptide (NT- Pro BNP). All patients underwent cTnT and NT- Pro BNP estimation within 24 hours of each cycle of chemotherapy and were followed up after 6 months of initiation of chemotherapy. Any changes in follow up ECHO were compared to ECHO at baseline and cTnT and NT- Pro BNP levels after each cycle of anthracycline-based chemotherapy. Results: Initial data were obtained for 33 patients. Mean change in left ventricular diastolic diameter (LVDD) within 6 months was $0.154{\pm}0.433cms$ (p value=0.049). Seven out of 33 patients had an increase in biomarker cTnT levels (p value=0.5). A significant change in baseline and follow up LVDD was observed in patients with raised cTnT levels (p value=0.026) whereas no change was seen in ejection fraction (EF) and left atrial diameters (LAD) within 6 months of chemotherapy. NT- Pro BNP levels increased in significant number of patients (p value ${\leq}0.0001$) but no statistically significant change was observed in the ECHO parameters within 6 months. Conclusions: Functional monitoring is a poorly effective method in early estimation of anthracycline induced cardiac dysfunction. Estimation of biomarkers after chemotherapy may allow stratification of patients in various risk groups, thereby opening window for interventional strategies in order to prevent permanent damage to the myocardium.
Journal of the Korean Association of Geographic Information Studies
/
v.18
no.1
/
pp.156-169
/
2015
This study was to evaluate the RCP climate change impact on hydrological components in the Imha-Dam watershed using SWAT(Soil and Water Assessment Tool) Model. The model was calibrated for six year(2002~2007) and validated for six year(2008~2013) using daily observed streamflow data at three watershed stations. The overall simulation results for the total released volume at this point appear reasonable by showing that coefficient of determination($R^2$) were 0.70~0.85 and Nash-Sutcliffe model efficiency(NSE) were 0.67-0.82 for streamflow, respectively. For future hydrologic evaluation, the HadGEM3-RA climate data by scenarios of Representative Concentration Pathway(RCP) 4.5 and 8.5 of the Korea Meteorological Administration were adopted. The biased future data were corrected using 34 years(1980~2013, baseline period) of weather data. Precipitation and temperature showed increase of 10.8% and 4.9%, respectively based on the baseline data. The impacts of future climate change on the evapotranspiration, soil moisture, surface runoff, lateral flow, return flow and streamflow showed changes of +11.2%, +1.9%, +10.0%, +12.1%, +18.2%, and +11.2%, respectively.
Due to the recent development of system semiconductors, technical innovation for the electric devices of the automobile industry is rapidly progressing. In particular, the electric device of automobiles is accelerating technology development competition among automobile parts makers, and the development cycle is also changing rapidly. Due to these changes, the importance of strategic planning for R&D is further strengthened. Due to the paradigm shift in the automobile industry, the Product-Technical Roadmap (P/TRM), one of the R&D strategies, analyzes technology forecasting, technology level evaluation, and technology acquisition method (Make/Collaborate/Buy) at the planning stage. The product-technical roadmap is a tool that identifies customer needs of products and technologies, selects technologies and sets development directions. However, most companies are developing the product-technical roadmap through a qualitative method that mainly relies on the technical papers, patent analysis, and expert Delphi method. In this study, empirical research was conducted through simulations that can supplement and strengthen the product-technical roadmap centered on the automobile industry by fusing Gartner's hype cycle, cumulative moving average-based data preprocessing, and deep learning (LSTM) time series analysis techniques. The empirical study presented in this paper can be used not only in the automobile industry but also in other manufacturing fields in general. In addition, from the corporate point of view, it is considered that it will become a foundation for moving forward as a leading company by providing products to the market in a timely manner through a more accurate product-technical roadmap, breaking away from the roadmap preparation method that has relied on qualitative methods.
Kim, Sung-Wan;Yun, Da-Woon;Jeon, Bub-Gyu;Kim, Seong-Do
Journal of the Korea institute for structural maintenance and inspection
/
v.26
no.4
/
pp.30-39
/
2022
Maintaining structural integrity of major apparatuses in a nuclear power plant, including piping system, is recognized as a critical safety issue. The integrity of piping system is also a critical matter related to the safety of a nuclear power plant. The actual failure mode of a piping system due to a seismic load is the leakage due to a fatigue crack, and the structural damage mechanism is the low-cycle fatigue due to large relative displacement that may cause plastic deformation. In this study, in-plane cyclic loading tests were conducted under various constant amplitudes using specimens composed of steel straight pipes and a steel pipe tee in the piping system of a nuclear power plant. The loading amplitude was increased to consider the relative displacement generated in the piping system under seismic loads, and the test was conducted until leakage, which is the limit state of the steel pipe tee, occurred due to fatigue cracks. The limit state of the steel pipe tee was expressed using a damage model based on the damage index that used the force-displacement relationship. As a result, it was confirmed that the limit state of the steel pipe tee can be quantitatively expressed using the damage index.
Expanded polystyrene (EPS) is the most commonly used fresh food refrigeration insulation in Korea and Europe. Moreover, as the use of disposable packaging materials has increased significantly along with non-face-to-face delivery services since the COVID-19 crisis, social issues related to waste disposal are also being raised. Therefore, in this study, the life cycle of EPS boxes for fresh food is focused on the factors that have a large difference between incineration and landfill including recycling in Europe and Korea in the disposal process after use, and raw materials and energy in the manufacturing process, which account for a large portion of the environmental impact value. We tried to compare the environmental impact of evaluation. Overall, the raw material production stage, box manufacturing stage, and packaging stage have similar processes in Europe and Korea, but unlike Europe, Korea, which lacks landfills and incineration facilities, has focused on expanding the recycling rate. It was necessary to do an environmental impact assessment. Data affecting the environment were derived based on 2019 and 2020 data for Korea and 2017 and 2020 data for Europe. In order to predict the future environmental impact assessment, assumptions about the disposal rate in 2025 and 2030 were introduced and evaluated. As a result of this study, it was found that the raw material production stage of EPS boxes, which have similar processes in both Korea and Europe, has the greatest effect on the global warming effect of Korean EPS boxes. However, Korea, which has a relatively high recycling rate in the disposal process compared to incineration and landfill, showed better environmental performance than Europe in most impact indicators except freshwater eutrophication. In particular, Korea has increased the overall recycling rate compared to Europe by replacing various recyclable materials such as building materials and sundries with XPS (extruded polystyrene) recycled materials. In conclusion, it was found that increasing the recycling rate rather than incinerating and landfilling EPS boxes for fresh food in the domestic EPS industry has relatively less environmental load compared to Europe.
In the railroad rolling stock depot, long-term maintenance tasks is done regularly every two or four year basis to maintain the functionality of equipments and rolling stock body or for the repair operation of the heavily damaged rolling stocks by fatal accidents. This paper addresses the computer simulation model building for the rolling stock maintenance shop for the CDC(Commuter Diesel Car) and Generator Car planned to be constructed at Daejon Rolling Stock Depot, which will be moved from Yongsan Rolling Stock Depot. We evaluated the processing capacity of two layout design alternatives based on the maintenance process chart through the developed simulation models. The performance measures are the number of processed cars per year, the cycle time, shop utilization, work in process and the average number waiting car for input. The simulation result shows that one design alternative outperforms another design alternative in every aspect and superior design alternative can process total 340 number of trains per year 15% more than the proposed target within the current average cycle time.
Jin-Young Kim;Yoo Jin Hong;Kyunghwa Han;Suji Lee;Young Jin Kim;Byoung Wook Choi;Hye-Jeong Lee
Korean Journal of Radiology
/
v.23
no.2
/
pp.172-179
/
2022
Objective: We aimed to evaluate the ostium of right coronary artery of anomalous origin from the left coronary sinus (AORL) with an interarterial course throughout the cardiac cycle on CT and analyze the clinical significance of the ostial findings. Materials and Methods: From January 2011 to December 2015, 68 patients (41 male, 57.3 ± 12.1 years) with AORL with an interarterial course and retrospective cardiac CT data were included. AORL was classified as high or low ostial location based on the pulmonary annulus in the diastolic and systolic phases on cardiac CT. In addition, the height, width, height/width ratio, area, and angle of the ostium were measured in both cardiac phases. After cardiac CT, patients were followed until December 31, 2020 for major adverse cardiac events (MACE). Clinical and CT characteristics associated with MACE were explored using Cox regression analysis. Results: During a median follow-up period of 2071 days (interquartile range, 1180.5-2747.3 days), 13 patients experienced MACE (19.1%, 13/68). Seven (10.3%, 7/68) had the ostial location change from high in the diastolic phase to low in the systolic phase. In the univariable analysis, younger age (hazard ratio [HR] = 0.918, p < 0.001), high ostial location (HR = 4.008, p = 0.036), larger height/width ratio (HR = 5.621, p = 0.049), and smaller ostial angle (HR = 0.846, p = 0.048) in the systolic phase were significant predictors of MACE. In multivariable cox regression analysis, younger age (adjusted HR = 0.917, p = 0.002) and high ostial location in the systolic phase (adjusted HR = 4.345, p = 0.026) were independent predictors of MACE. Conclusion: The ostial location of AORL with an interarterial course can change during the cardiac cycle, and high ostial location in the systolic phase was an independent predictor of MACE.
Chung, In Young;Seo, Yong Bae;Yang, Ji Young;Kwon, Ki sung;Kim, Gun Do
Journal of Food Hygiene and Safety
/
v.33
no.4
/
pp.280-288
/
2018
In this study, an approach for the analysis of the five cephalopod species (octopus, long-arm octopus, squid, wet-foot octopus, beka squid) consumed in the Republic of Korea is developed. The samples were collected from the Southeast Asian countries Thailand, Indonesia, Vietnam, and China. The SYBR-green-based real-time qPCR method, based on the mitochondrial DNA genome of the five cephalopods was developed and validated. The intergroup variations in the mitochondrial DNA are evident in the bioinformatic analysis of the mitochondrial genomic DNA sequences of the five groups. Some of the highly-conserved and slightly-variated regions are identified in the mitochondrial cytochrome-c-oxidase subunit I (COI) gene, 16s ribosomal RNA (16s rRNA) gene, and 12s ribosomal RNA (12s rRNA) gene of these groups. To specify each five cephalopod groups, specific primer sets were designed from the COI, 16s rRNA and 12s rRNA regions. The specific primer sets amplified the DNA using the SYBR-green-based real-time PCR system and 11 commercially secured animal tissues: Octopus vulgaris, Octopus minor, Todarodes pacificus, Dosidicus gigas, Sepia esculenta, Amphioctopus fangsiao, Amphioctopus aegina, Amphioctopus marginatus, Loliolus beka, Loligo edulis, and Loligo chinensis. The results confirmed by a conveient way to calculate relative amplification levels between different samples in that it directly uses the threshold cycles (Ct)-value range generated by the qPCR system from these samples. This genomic DNA-based molecular technique provides a quick, accurate, and reliable method for the taxonomic classification of the animal tissues using the real-time qPCR.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.