• Title/Summary/Keyword: Model assessment

Search Result 6,471, Processing Time 0.035 seconds

Convergence Study in Development of Severity Adjustment Method for Death with Acute Myocardial Infarction Patients using Machine Learning (머신러닝을 이용한 급성심근경색증 환자의 퇴원 시 사망 중증도 보정 방법 개발에 대한 융복합 연구)

  • Baek, Seol-Kyung;Park, Hye-Jin;Kang, Sung-Hong;Choi, Joon-Young;Park, Jong-Ho
    • Journal of Digital Convergence
    • /
    • v.17 no.2
    • /
    • pp.217-230
    • /
    • 2019
  • This study was conducted to develop a customized severity-adjustment method and to evaluate their validity for acute myocardial infarction(AMI) patients to complement the limitations of the existing severity-adjustment method for comorbidities. For this purpose, the subjects of KCD-7 code I20.0 ~ I20.9, which is the main diagnosis of acute myocardial infarction were extracted using the Korean National Hospital Discharge In-depth Injury survey data from 2006 to 2015. Three tools were used for severity-adjustment method of comorbidities : CCI (charlson comorbidity index), ECI (Elixhauser comorbidity index) and the newly proposed CCS (Clinical Classification Software). The results showed that CCS was the best tool for the severity correction, and that support vector machine model was the most predictable. Therefore, we propose the use of the customized method of severity correction and machine learning techniques from this study for the future research on severity adjustment such as assessment of results of medical service.

A study on estimation of optimal reserves for multi-purpose reservoirs considering climate change (기후변화를 고려한 다목적댐의 적정 예비율 산정 연구)

  • Chae, Heechan;Ji, Jungwon;Yi, Jaeeung
    • Journal of Korea Water Resources Association
    • /
    • v.51 no.spc
    • /
    • pp.1127-1134
    • /
    • 2018
  • According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), climate change increases the frequency of abnormal weather phenomenon. As the frequency of abnormal weather phenomenon increases, frequency of disasters related to water resources such as floods and droughts also increases. Drought is the main factor that directly affects water supply. Recently, the intensity of drought and the frequency of drought occurrence have increased in Korea. So, there is a need for water resource securing technology for stable water supply. Korean Water Plan mentioned that water reserves concept is necessary for stable water supply. Most multi-purpose reservoirs in Korea have emergency storage in addition to conservation storage used for water supply. However, there is no clear use standard for emergency storage. This study investigated the use of reservoir reserves for stable water supply. In order to consider the climate change impact, the AR5-based hydrological scenario was used as inflow data for the reservoir simulation model. Reservoir simulations were carried out in accordance with the utilization conditions of emergency storage and water supply adjustment standard. The optimal reserves for each multi-purpose reservoirs was estimated using simulation results.

Development of BMD Phantom using 3D Printing (3D 프린팅을 이용한 골밀도 팬텀 개발)

  • Lee, Junho;Choi, Kwan-Yong;Hong, Sung-Yong
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.2
    • /
    • pp.185-192
    • /
    • 2019
  • DXA is the most commonly used BMD examination equipment with the best performance on reflecting the biological alteration with tiny change of bone density. In spite of the importance of the quality control to maintain the accuracy and precision of the examination, considerable number of hospitals are not conducting QC due to the difficulty and high cost of the phantom product. This study develops the cross revision phantom with 3D printer and the change of the degree of infilling filaments which can be readily secured, and provides the usefulness assessment of the developed phantom by comparing with existing products. The Hounsfield Units of ABS, TPU, PLA, 30% Cu-PLA, and 30% Al-PLA are assessed. The Hounsfield Units result at infilling rate 100% was $-149.74{\pm}2.36$, $-55.62{\pm}7.14$, $-7.68{\pm}3.82$, $87.53{\pm}1.07$, and $1795.20{\pm}16.15$. The L1, L2, L3 BMD of 3D printing phantom with linear regression model were $0.620{\pm}0.010g/cm^2$, $1.092{\pm}0.025g/cm^2$, $1.554{\pm}0.026g/cm^2$ which are statistically relevant to the existing phantom products. This result provides the base line data for various medical phantom produce and capability of proper quality control of DXA equipment.

Predicting the Potential Habitat and Risk Assessment of Amaranthus patulus using MaxEnt (Maxent를 활용한 가는털비름(Amaranthus patulus)의 잠재서식지 예측 및 위험도 평가)

  • Lee, Yong Ho;Na, Chea Sun;Hong, Sun Hea;Sohn, Soo In;Kim, Chang Suk;Lee, In Yong;Oh, Young Ju
    • Korean Journal of Environmental Biology
    • /
    • v.36 no.4
    • /
    • pp.672-679
    • /
    • 2018
  • This study was conducted to predict the potential distribution and risk of invasive alien plant, Amaranthus patulus, in an agricultural area of South Korea. We collected 254 presence localities of A. patulus using field survey and literature search and stimulated the potential distribution area of A. patulus using maximum entropy modeling (MaxEnt) with six climatic variables. Two different kinds of agricultural risk index, raster risk index and regional risk index, were estimated. The 'raster risk index' was calculated by multiplying the potential distribution by the field area in $1{\times}1km$ and 'regional risk index' was calculated by multiplying the potential distribution by field area proportion in the total field of South Korea. The predicted potential distribution of A. patulus was almost matched with actual presence data. The annual mean temperature had the highest contribution for distribution modeling of A. patulus. Area under curve (AUC) value of the model was 0.711. The highest regions were Gwangju for potential distribution, Jeju for 'raster risk index' and Gyeongbuk for 'regional risk index'. This different ranks among the index showed the importance about the development of various risk index for evaluating invasive plant risk.

UX Design Evaluation and its Approach to Mobile Applications for Smart Appliances (스마트 애플리케이션 UX 디자인 평가 접근 방법)

  • You, Si Cheon;Choi, Jinyoung;Sim, Mihee
    • Smart Media Journal
    • /
    • v.8 no.3
    • /
    • pp.70-79
    • /
    • 2019
  • Implementing UX design that meets user expectations has become an important variable that determines the prominence of smart home appliances. This study addresses the UX design evaluation issues in mobile application development of smart home appliances. As an experimental research subject, the UX design evaluation contents were set up for the mobile application of , the demand of which is surging recently. The purpose of the research is to explore the significance of the UX design user evaluation method in smart home applications, and to suggest how to achieve the mixing of quantitative and qualitative evaluation methods. The main findings are as follows. First, we found that user evaluation can positively impact the direction of UX design. Secondly, we found that the mixing of 'quantitative' and 'qualitative' methods works complementarily to UX design evaluation. Research implications are as follows. The UX design evaluation process can be performed efficiently as long as we distinguish between the roles of quantitative evaluation and qualitative evaluation. For example, through qualitative evaluation such as 'Honeycomb model', can be identified in terms of 'exploratory', and through qualitative evaluation such as 'in-depth user interview', can be identified in terms of 'assessment' and 'validation'.

Development of Korean SPAR(Soil-Plant-Atmosphere-Research) System for Impact Assessment of Climate Changes and Environmental Stress (기후변화 및 환경스트레스 영향평가를 위한 한국형 SPAR(Soil-Plant-Atmosphere-Research) 시스템의 개발)

  • Sang, Wan-Gyu;Kim, Jun-Hwan;Shin, Pyong;Baek, Jae-Kyeong;Lee, Yun-Ho;Cho, Jung-Il;Seo, Myung-Chul
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.21 no.3
    • /
    • pp.187-195
    • /
    • 2019
  • The needs for precise diagnostics and farm management-decision aids have increased to reduce the risk of climate change and environmental stress. Crop simulation models have been widely used to search optimal solutions for effective cultural practices. However, limited knowledge on physiological responses to environmental variation would make it challenging to apply crop simulation models to a wide range of studies. Advanced research facilities would help investigation of plant response to the environment. In the present study, the sunlit controlled environment chambers, known as Korean SPAR (Soil-Plant-Atmosphere-Research) system, was developed by renovating existing SPAR system. The Korean SPAR system controls and monitors major environmental variables including atmospheric carbon dioxide concentration, temperature and soil moisture. Furthermore, plants are allowed to grow under natural sunlight. Key physiological and physical data such as canopy photosynthesis and respiration, canopy water and nutrient use over the whole growth period are also collected automatically. As a case study, it was shown that the Korean SPAR system would be useful for collection of data needed for understanding the growth and developmental processes of a crop, e.g., soybean. In addition, we have demonstrated that the canopy photosynthetic data of the Korean SPAR indicate the precise representation of physiological responses to environment variation. As a result, physical and physiological data obtained from the Korean SPAR are expected to be useful for development of an advanced crop simulation model minimizing errors and confounding factors that usually occur in field experiments.

The Distribution of Responsibility and Authority upon Public Record Appraisal : Focused on 'Citizen Participation Appraisal' (공공기록 평가의 책임과 권한의 분배 '시민참여 평가'를 중심으로)

  • Lee, Kyong Rae
    • The Korean Journal of Archival Studies
    • /
    • no.60
    • /
    • pp.49-88
    • /
    • 2019
  • Today, the civil society plays a key role not only in criticizing and monitoring the functions of the state and the market, but also as an active producer of public services by complementing the government and the public sector. Public records management is also becoming more and more popular. In the case of appraisal and selection, which is the core area of record management, discussions about citizen participation are becoming more serious than any other areas. The concept of 'proactive appraisal', which has emerged as a paradigm of citizens' participation in appraisal, reminds us that citizens themselves are the subjects of public records and are no longer alienated from the appraisal system. The problem is, while the growth of the Korean civil society about institutional participation is spreading rapidly, but citizen participation is hard to find in the field of public records. The purpose of this paper is to examine the role of citizen participation in the process of appraisal of public records, and to debunk the role of citizen participation in the appraisal processes by exploring the examples in the UK, Canada, and Australia. This paper emphasizes that the appraisal system of the national public records in crisis today could be largely restored through the domestic application of this active citizen participation cases. First of all, this study presents a conceptual appraisal model that could reflect citizen participation in the field of record management along with the analyses of the advanced cases in some western countries. Specifically, this paper focuses on presenting the models of 'appraisal documentation' and 'governance-based appraisal', reflecting the active citizen participation. This study suggests that these citizens' participatory evaluation models should be settled in Korea in the future and we should urgently discuss 'citizen participation appraisal'.

Landslide Susceptibility Assessment Considering the Saturation Depth Ratio by Rainfall Change (강우변화에 따른 토층 내 침투깊이를 고려한 산사태위험지수 개발)

  • Kwak, Jae Hwan;Kim, Man-Il;Lee, Seung-Jae
    • The Journal of Engineering Geology
    • /
    • v.28 no.4
    • /
    • pp.687-699
    • /
    • 2018
  • Understanding rain infiltration into the ground is an important feature of landslide risk evaluation. In this study, a landslide risk index for the study area is suggested, wherein the result of the landslide risk evaluation, based on the factor of safety (FS), is used. The landslide risk index is a landslide risk prediction index that utilizes the saturated depth ratio of the ground. Based on the landslide risk result for the study area, it was found that the FS was first to decrease. However, it gradually became convergent over the 50-year rainfall intensity study period, a result that is similar to the relationship between the saturated depth ratio and soil thickness. Moreover, saturated depth was also found to be deeper on gentle slopes than steep slopes. As such, the landslide risk index, based on the Inhu-ri study result, is thus suggested. Additionally, the suggested landslide risk index was compared and analyzed against the rainfall intensity of previous landslide experience. Results thus revealed that almost all landslides that occurred were over 0.7, which is the second grade, based on the landslide risk index.

Exploring Changes in Multi-ethnic Students' Mathematics Achievement Motivation : A Longitudinal Study using Expectancy-Value Theory (다문화가정 학생의 수학학업성취 동기 변화 연구: 기대가치 이론에 따른 종단연구)

  • Cho, Eunhye;Hwang, Sunghwan
    • The Mathematical Education
    • /
    • v.58 no.1
    • /
    • pp.101-120
    • /
    • 2019
  • The goal of this study was to apply an expectancy-value model(Wigfield & Eccles, 2000) to explain changes in six multi-ethnic students' achievement motivation in mathematics during sixth (2012) to eighth (2014) grades. In order to achieve this goal, we used narrative research methods. Although individual students' achievement motivation and mathematics related life experiences differed, there are some common factors influencing their motivation development, especially (a) roles played by parents and teachers; (b) assessment of peers' competencies; (c) past learning experiences related to mathematics curriculum; (d) perception of the relationship between mathematics competency and other subjects; (e) home backgrounds; and (f) perceived task values. In this study, we achieved some insight into why some multi-ethnic students are willing to study hard to get good scores while others are uninterested in mathematics, and why some multi-ethnic students are likely to pursue new mathematical tasks and persist despite challenges, while others easily give up studying mathematics in the face of adversity. We argue that in order to increase and sustain multi-ethnic students' achievement motivation, educators and parents should recognize that motivation is contextually formulated in the intersection of current people, time, and space, not a personal entity formed in an individual's mind. The findings of this study shed light on the development of achievement motivation and can inform efforts to develop multi-ethnic students' positive motivation, which might influence their mathematics achievement and success in school.

Development And Applying Detailed Competencies For Elementary School Students' Data Collection, Analysis, and Representation (초등학생의 데이터 수집, 분석, 표현 수업을 위한 세부역량 개발 및 적용)

  • Suh, Woong;Ahn, Seongjin
    • Journal of The Korean Association of Information Education
    • /
    • v.23 no.2
    • /
    • pp.131-139
    • /
    • 2019
  • From 2019, software education has become a required subject for all elementary school students. However, many teachers are still unfamiliar with how the classes should be instructed. So this paper presented the meaning, detailed competencies and achievement standard in order to help in the collection, analysis and representation of data among the computational thinking that are key to software education. And it also suggested the applicability of the classes. The full course of the paper is summarized as follows. First, existing studies have summarized the meaning, detail and achievement standard of data related competencies. Based on this, a preliminary investigation was instructed. Pilot study carried out both FGI and closed questions at the same time. This was done in response to the survey's questionnaire reflecting the opinions of experts. Second, the results of the questionnaire generated as a result of the above were verified for validity, stability, and reliability among the PhD, PhD courses, software education teachers, and software education workers. Third, I developed and applied the five lessons as a class objective as 'Choosing collection method-Select the collection method according to the problem situation.', 'Searching for meaning of data-Understand what the analyzed data mean..', 'Using various expression methods-Use a variety of expression tools.' using the backward design model to integrate education, class, and assessment. As a result, the detailed competencies of data collection, analysis, and representation and achievement standard were presented. This may help in setting specific and specific criteria for what direction classes are recommended when planning data-related classes in elementary schools.