• Title/Summary/Keyword: historical evaluation

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Traffic Correction System Using Vehicle Axles Counts of Piezo Sensors (피에조센서의 차량 축 카운트를 활용한 교통량보정시스템)

  • Jung, Seung-Weon;Oh, Ju-Sam
    • The Journal of the Korea Contents Association
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    • v.21 no.1
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    • pp.277-283
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    • 2021
  • Traffic data by vehicle classification are important data used as basic data in various fields such as road and traffic design. Traffic data is collected through permanent and temporary surveys and is provided as an annual average daily traffic (AATD) in the statistical yearbook of road traffic. permanent surveys are collected through traffic collection equipment (AVC), and the AVC consists of a loop sensor that detects traffic volume and a piezo sensor that detects the number of axes. Due to the nature of the buried type of traffic collection equipment, missing data is generated due to failure of detection equipment. In the existing method, it is corrected through historical data and the trend of traffic around the point. However, this method has a disadvantage in that it does not reflect temporal and spatial characteristics and that the existing data used for correction may also be a correction value. In this study, we proposed a method to correct the missing traffic volume by calculating the axis correction coefficient through the accumulated number of axes acquired by using a piezo sensor that can detect the axis of the vehicle. This has the advantage of being able to reflect temporal and spatial characteristics, which are the limitations of the existing methods, and as a result of comparative evaluation, the error rate was derived lower than that of the existing methods. The traffic volume correction system using axis count is judged as a correction method applicable to the field system with a simple algorithm.

Evaluation of hydropower dam water supply capacity (III): development and application of drought operation rule for hydropower dams in Han river (발전용댐 이수능력 평가 연구 (III): 한강수계 발전용댐 가뭄단계별 운영기준 개발 및 효과 분석)

  • Jeong, Gimoon;Kang, Doosun;Kim, Taesoon
    • Journal of Korea Water Resources Association
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    • v.55 no.7
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    • pp.531-543
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    • 2022
  • Integrated water resources management (IWRM) has focused on efficient response to various water related disasters by climate change. In particular, more flexible usage of conventional water resources infrastructures is expected to provide an eco-friendly water management. Multi-purpose dams and water supply dams are well known as water management facilities for securing and supplying water in drought season. Recently, based on the report '2021 multi-purpose use of hydropower dams in Han river', contribution of hydropower dams on water resources management is becoming more significant beyond the traditional role of hydropower generation. In drought conditions, the dams control water supply depending on the pre-defined drought stages. In the case of multi-purpose dams, an operation standard during drought has been already prepared and applied; however, for the hydropower dams, specific standards are not fully prepared yet in South Korea. In this study, a method for calculation of standard water storage and discharge reduction of hydropower dams according to drought stage is newly proposed reflecting the characteristics of hydropower dams. The proposed method was applied to the hydropower dams in Han river, where six hydropower dams are located. A case study of the historical droughts occurred in 2014-2017 demonstrated that the proposed hydropower dam operation rule could improve the water supply stability under severe drought conditions compared to the conventional operations. In the future, the role of hydropower dams for water resources management is expected to become more important, and this study can be widely used for water supply planning such as drought response using hydropower dams.

Evaluation of the Stability of Ipseok-dae Columnar Joints in Mudeungsan National Park Using 3DEC (3DEC을 이용한 무등산국립공원 입석대 주상절리대의 안정성 평가)

  • Noh, Jeongdu;Kang, Seong Sueng
    • The Journal of Engineering Geology
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    • v.32 no.3
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    • pp.351-361
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    • 2022
  • Numerical analysis performed to predict the behavior of Ipseok-dae columnar joints in Mudeungsan National Park to understand their stability and movement. The numerical analysis technique, 3DEC, is based on the discrete element method that can analysis discontinuities. The analysis used data for material properties derived from laboratory tests, which found that average density was 2.68 kN/m3, average normal stiffness was 3.15 GPa/m, average shear stiffness was 1.00 GPa/m, average cohesion was 0.51 MPa, and the average friction angle was 33°. The Ipseok-dae columnar joints were modeled on the basis of the field survey data for 15 joints located between the observation platform and the hiking trail. The numerical analysis assessed the behavior of each columnar joint by interpreting the displacement of the edges of its upper and lower surfaces. The greatest maximum displacement was found in columnar joint No. 6, and the greatest minimum displacement was found in joint No. 11. Analyzing the movements of five discontinuities in joint No. 11 indicated that the maximum displacement occurred at the 2nd level. The other levels were ordered 5th, 4th, 1st, and 3rd in terms of subsequent greatest displacements. Considering the total displacement in the 15 studied joints, the Ipseok-dae columnar joints are judged to be stable. However, considering the cultural and historical value of Mudeungsan National Park, it is regarded that the currents slope stability should be maintained by monitoring the individual rock blocks of the joints.

Learning Ability Prediction System for Developing Competence Based Curriculum: Focusing on the Case of D-University (역량중심 교육과정 개발을 위한 학업성취도 예측 시스템: D대학 사례를 중심으로)

  • Kim, Sungkook;Oh, Chang-Heon
    • Journal of Practical Engineering Education
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    • v.14 no.2
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    • pp.267-277
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    • 2022
  • Achievement at university is recognized in a comprehensive sense as the level of qualitative change and development that students have embodied as a result of their experience in university education. Therefore, the academic achievement of university students will be given meaning in cooperation with the historical and social demands for diverse human resources such as creativity, leadership, and global ability, but it is practically an indicator of the outcome of university education. Measurement of academic achievement by such credits involves many problems, but in particular, standardization of academic achievement by credits based on evaluation methods, contents, and university rankings is a very difficult problem. In this study, we present a model that uses machine learning techniques to predict whether or not academic achievement is excellent for D-University graduates. The variables used were analyzed using up to 96 personal information and bachelor's information such as graduation year, department number, department name, etc., but when establishing a future education course, only the data after enrollment works effectively. Therefore, the items to be analyzed are limited to the recommended ability to improve the academic achievement of the department/student. In this research, we implemented an academic achievement prediction model through analysis of core abilities that reflect the philosophy, goals, human resources image, and utilized machine learning to affect the impact of the introduction of the prediction model on academic achievement. We plan to apply the results of future research to the establishment of curriculum and student guidance conducted in the department to establish a basis for improving academic achievement.

Analysis of Construction Conditions Change due to Climate Change (기후변화에 의한 건설시공환경 변화 분석)

  • Bae, Deg Hyo;Lee, Byong Ju;Jung, Il Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4D
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    • pp.513-521
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    • 2008
  • The objective of this study is the evaluation of the impact on the construction condition due to historical observation data and IPCC SRES A2 climate change scenario. For this purpose, daily precipitation and daily mean temperature data which have been observed over the past 30 years by Korea Meteorological Administration are collected and applied. Also, A2 scenarios during 2011~2040 and 2051~2080 are used for this analysis. According to the results of trend analyses on annual precipitation and annual mean temperature, they are on the increase mostly. The available working day and the day occurred an extreme event are used as correlation indices between climate factor and construction condition. For the past observation data, linear regression and Mann-Kendall test are used to analyze the trend on the correlation index. As a result, both working day and extreme event occurrence day are increased. Likewise, for the future, variation analysis showed the similar result to that of the past and the occurrence frequency of extreme events is increased obviously. Therefore, we can project to increase flood damage potential on the construction site by climate change.

A Study on the Design Diagnostic Guideline in Crowdfunding for Makers (메이커스(Makers)를 위한 크라우드 펀딩 디자인 진단 가이드라인에 관한 연구)

  • Oh, In Kyun;Lee, Jang Woo
    • Korea Science and Art Forum
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    • v.35
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    • pp.281-292
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    • 2018
  • Crowd funding is also called social funding because of SNS that it helps early start-up founder and makers to raise money for idea product production. Recently, the funding platform has recorded high growth rates. As a result, the government in Korea has introduced various support policies for the crowd funding. The purpose of this study is to develop a diagnostic design guideline for product design oriented makers based on the historical situation. The paper writer applied literature survey and expert interview as research methods. The literature survey focused on internet news and previous research studies. The expert interview was conducted for 10 specialist people and divided for the second time. As a result of the text survey, the current guideline was lacking in design and in detail. Researchers have been informed through previous paper that information transfer text and images are important factors for funding success. In the first interview with seven special participants, we made a draft design guideline for social funding with a two-step process and nine themes. We, research and three professional people having a evaluation experience, conducted verification and supplementation for establishing the design guider with a three-step process and eight themes in the next interview. The design guideline for crowd funding, it can be used by money funding manager apart from design makers. Through the results of this paper, researchers are expected to prevent problems and contribute to healthy crowd funding ecosystem development.

Historical Classification and Evaluation Character of Pumpkin and Squash Genetic Resources (Cucurbita spp.) Reserved in National Agrobiodiversity Center (농업유전자원센터 호박속 자원의 구분 및 특성)

  • Eunae Yoo;Gyu-Taek Cho;Do Yoon Hyun;Kyung Jun Lee;Ik Jang;Jungyoon Yi;Seungbum Lee;SeongHoon Kim;Sookyeong Lee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2020.08a
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    • pp.39-39
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    • 2020
  • 호박(Cucurbita spp.)은 박과 호박속 식물로 원산지는 열대 남아메리카로 추정되며 1년생 혹은 다년생 초본으로서 우리나라를 포함한 전 세계에서 널리 분포하고 있다. 호박은 비타민A와 비타민C가 풍부하고 이뇨작용 효과가 탁월해 피부를 좋게 하고 부기를 빼주는 것으로 보고되고 있다. 본 연구에서는 농업유전자원센터에서 보유한 호박속 자원의 내력과 형태적인 특성을 그룹화하여 자원 활용을 위한 기초자료를 제공하고자 하였다. 농업유전자원센터에서 보유한 호박속 등록자원은 총 5종(C.pepo, C. moschata, C.maxima, C.argyrosperma, C .ficifolia) 1,640자원으로 주요 원산지는 한국 589자원(35.9%), 미국 122자원(7.4%), 러시아 79자원(4.8%), 멕시코 49자원(4.2%), 터키 56자원(3.4%)이었으며 국내 원산의 경우 강원도에서 수집된 자원이 66자원으로 가장 많았다. 전체 1,640 자원 중 재래종은 733자원(44.7%)을 차지하였으며 다음으로는 육성품종이 133자원(8%)으로 많았다. 생장형이 조사 된 301자원 대부분이 덩굴성이며 준왜성 16자원, 왜성 14자원이 있었다. 호박은 과실 모양과 색, 잎 모양, 줄기 모양 등 생육 특성이 매우 다양하게 조사 되었으며 과경 등 몇 가지 특징은 완벽하지 않지만 종(species)을 구분하는 간이적인 지표로 사용되는 것으로 조사되었다. 흰가루병 저항성 자원은 조사 된 1,170 자원 중 우리나라 재래종인 참호박(IT104575)을 포함한 7자원이 조사되었다. 293개 자원의 과실당도는 2.2~15.4brix까지 다양했으며 당도 12brix 이상 자원은 IT200650을 포함하여 6자원이 조사되었다. 본 연구에서 조사된 호박속 자원의 내력 및 생육 특성은 육종소재의 기초 정보로서 이용되고 있으며 자원 내력정보의 보완, 형질과 기능성 물질 분석 등 추가적인 연구를 통해 연구소재의 기초 정보로서 활용의 가치가 더 커질 것으로 보인다.

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Seismic Performance Evaluation of Unreinforced and ECC-jacketed Masonry Fences using Shaking Table Test (진동대실험을 사용한 비보강 및 ECC 자켓 보강 조적담장의 내진성능평가)

  • Yonghun Lee;Jinwoo Kim;Jae-Hwan Kim;Tae-Sung Eom;Sang-Hyun Lee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.182-192
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    • 2023
  • In this study, the efficacy of Engineered Cementitious Composite(ECC) jacket for masonry fences subjected to lateral dynamic load was experimentally verified through a shaking table test, comparing it with the performance of an unreinforced masonry(URM) fence. Firstly, dominant frequencies, modal damping ratios and deformed shapes were identified through an impact hammer test. URM and ECC-strengthened fences with heights of 940mm and 970mm had natural frequencies of 6.4 and 35.3Hz, and first modal damping ratios of 7.0 and 5.3%, respectively. Secondly, a shaking table test was conducted in the out-of-plane direction, applying a historical earthquake, El Centro(1940) scaled from 25 to 300%. For the URM fence, flexural cracking occurred at the interface of brick and mortar joint(i.e., bed joint) at the ground motion scaled to 50%, and out-of-plane overturning failure followed during the subsequent test conducted at the ground motion scaled to 30%. On the other hand, the ECC-jacketed fence showed a robust performance without any crack or damage until the ground motion scaled to 300%. Finally, the base shear forces exerted upon the URM and ECC-jacketed fences by the ground motions scaled to 25~300% were evaluated and compared with the ones calculated according to the design code. In contrast to the collapse risk of the URM fence at the ground motion of 1,000-year return period, the ECC-jacketed fence was estimated to remain safe up to the 4,800-year return period ground motion.

The Burden of the Population and People during the Reign of Tang Taizong before His Invasion of Goguryeo in 645 (당 태종 '정관(貞觀)의 치'와 가정(苛政) - 645년 고당 전쟁 이전 조세·요역 수탈의 실상 -)

  • Choi Jin-yeoul
    • Journal of the Daesoon Academy of Sciences
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    • v.49
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    • pp.365-399
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    • 2024
  • Tang Taizong was regarded as the emperor with the idea of cherishing the common people, paying close attention to his subjects' military service, and mobilizing of the people as recorded in Zhenguan Zhengyao (Essentials for Government), from the Zhenguan period during the reign of Tang Taizong. Contrary to the above, in reality, Li Shimin, the name of Tang Taizong, mobilized many subjects in the construction of Luoyang Palace in second capital city called Dongdu and Jiucheng Palace, a summer palace during Sui-Tang dynasty, and he requisitioned the subjects of Guannei Province and Longyou Province to install and protect provisional powers and a county in the Gaochang Kingdom. Given his antinomic behavior, the evaluation of Li Shimin as an ideal Confucian monarch should be reconsidered based on Zhenguan zhengyao and other historical records. Dividing the 19 years before Goguryeo-Tang War in 645 into two periods, from the throne to 637 and from 639-644, the subjects were burdened by the construction of Luoyang Palace and Jiucheng Palace in the former period. In the latter period, after the conquest of the Gaochang Kingdom, there was a requisition for the transport of troops and supplies to be stationed in Xizhou, a reorganized prefecture and counties in the Gaochang Kingdom territory; probably mainly limited to the provinces of Guannei and Lungyou, which were geographically close to the West Regin that is now known as Xinjiang Uygur Autonomous Region. The burden in the latter period was relatively less than in the former period. Even so, the number of households in 639, fourteenth year of Tang Taizong's reign, was only 34.1% and 26.8%, respectively, in 609, the sixth year of Sui Yangdi's reign. In this situation, Taizong's Goguryeo Invasion was not conducted in an economically situation during the early days of the Tang Dynasty.

User Information Needs Analysis based on Search Terms Log of the Presidential Archives Portal (대통령기록포털 검색어 로그 분석 기반 이용자 정보요구 분석)

  • Suhyeon Lee;Hyo-Jung Oh
    • Journal of Korean Society of Archives and Records Management
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    • v.24 no.3
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    • pp.23-44
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    • 2024
  • In recent years, there has been a significant increase in the importance of curation services that analyze user information requests to provide tailored information within extensive information resources. This study aims to identify user information needs by analyzing search term logs from the Presidential Archives Portal to enhance the utilization value of presidential records, which possess high historical significance. In addition, by evaluating the portal's search performance, this study seeks to determine whether the Presidential Archives Portal is providing archival information services that meet users' information needs and to suggest areas for improvement through digital record curation services. To achieve these objectives, topic analysis and word network analysis were conducted based on search term logs spanning the past eight years. The search quality of the Presidential Archives Portal was evaluated from an accuracy perspective, focusing on areas with high user demand, and recommendations were drawn based on the results of the analysis. As a preliminary study for digital record curation of presidential records, this study is significant because it identifies specific user information needs and quantifies the search quality of archival portal sites to improve user satisfaction.