• Title/Summary/Keyword: Model Improvement

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An Experimental Study on Generation and Measurement Method of EG/AD Model Ice at Cold Room for Improvement of Its Properties (EG/AD 모형빙 정도 향상을 위한 콜드룸에서의 생성기법 및 계측기법 연구)

  • Cho, Seong-Rak;Jeong, Seong-Yeob;Ha, Jung-Seok;Kang, Kuk-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.6
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    • pp.414-420
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    • 2013
  • Generation and measurement methods of EG/AD model ice, which is used in KIOST ice model basin are investigated for improvement of its properties. Temperature of seed water, air temperature in the freezing phase and the target air temperature in the tempering phase were changed in the cold room, and the properties of model ice was measured in this conditions. We also verified a conventional measuring method of flexural strength of model ice caused a little measuring error in cold room, so that we suggested a new measuring method that must be used higher supports than double the thickness of the model ice. In this study, we improved the generation and measurement technique of EG/AD model ice, and the developed procedure at cold room can be applied to the KIOST ice model basin.

Efficient Counterexample Generation for Safety Violation in Model Checking (모델 체킹에서 안전성 위반에 대한 효율적인 반례 생성)

  • Lee Tae-hoon;Kwon Gi-hwon
    • The KIPS Transactions:PartD
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    • v.12D no.1 s.97
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    • pp.81-90
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    • 2005
  • Given a model and a property, model checking determines whether the model satisfies the property. In case the model does not satisfy the property model checking gives a counterexample which explains where the violation occurs. Since counterexamples are useful for model debugging as well as model understanding, counterexample generation is one of the indispensable components in the model checking tool. This paper presents efficient counterexample generation techniques when a safety property is falsified. These techniques are used to solve Push Push games which consist of 50 games. As a result, all the games are solved with the proposed techniques. However, with the original NuSMV, 42 games are solved but 8 failed. In addition, we obtain $86{\%}$ time improvement and $62{\%}$ space improvement compared to the original NuSMV in solving the game.

Effects of a Compassion Improvement Program for Clinical Nurses on Compassion Competence and Empathic Communication (임상간호사를 위한 공감증진 프로그램이 공감역량과 공감화법에 미치는 효과)

  • Jeong, In Ja;Park, Mi Kyung
    • Korean Journal of Occupational Health Nursing
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    • v.33 no.1
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    • pp.12-25
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    • 2024
  • Purpose: This quasi-experimental study used a non-equivalent control group pretest-posttest design with clinical nurses to develop a compassion improvement program and verify its effects on compassion competence and empathic communication. Methods: The Triandis Interpersonal Behavior model (Triandis, 1980) was used as a theoretical framework, and a compassion improvement program was developed based on the ADDIE model. The experimental treatment in the program was conducted for 120 minutes per session, once a week, for a total of six sessions. The data collection and research period ranged from September 7 to November 16. It involved a pre-survey of measured variables, six sessions of experimental treatment, a post-survey, and a follow-up survey in sequence. The collected data were analyzed using the statistical program SPSS/WIN 25.0 and then based on a t-test and repeated measures ANOVA to verify the effectiveness of the program. Results: Clinical nurses participating in the compassion improvement program showed improved compassion competence (F=8.00, p=.001) due to the cultivation of insight, sensitivity, and communication skills. In addition, the improvement in attentive listening (F=3.32, p=.024) indicated that the program was partially effective in empathic communication. Conclusion: The compassion improvement program for clinical nurses, which was developed in this study, is expected to be useful in nursing practice. In other words, the compassion improvement program may contribute to creating a positive atmosphere in the workplace for nurses and an empathic relationship between nurses and healthcare recipients through improvement in the compassion competence of nurses. If the compassion improvement program is continuously implemented as a facilitating condition, it will greatly help prevent the turnover of clinical nurses, assist them in adapting to hospital life, and enhance the quality of nursing care.

Laser Process Proximity Correction for Improvement of Critical Dimension Linearity on a Photomask

  • Park, Jong-Rak;Kim, Hyun-Su;Kim, Jin-Tae;Sung, Moon-Gyu;Cho, Won-Il;Choi, Ji-Hyun;Choi, Sung-Woon
    • ETRI Journal
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    • v.27 no.2
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    • pp.188-194
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    • 2005
  • We report on the improvement of critical dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for the fabrication of photomasks. Rule-based laser process proximity correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), arrayed contact (A/C) and isolated contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

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The Effects of POE Model on Science Process Skills and Academic Achievement in Domain 'Earth and Space' of Elementary School Science (초등과학의 '지구와 우주' 분야에서 POE 수업모형 적용이 과학탐구능력 및 학업성취도에 미치는 영향)

  • Lee, Sang-Bong;Lee, Yong-Seob
    • Journal of the Korean Society of Earth Science Education
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    • v.3 no.2
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    • pp.132-140
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    • 2010
  • The purpose of this research is to explore the effects of the POE(Prediction-Observation-Explanation) teaching-learning model on the academic achievement and the capability of scientific inquiry of elementary school students. POE teaching-learning model is a three stage process modeling scientific inquiry : Prediction, Observation, and Explanation. This research is to see the effectiveness of the POE method in earth science class by applying this simple practical strategy out of various methods in science teaching with the purpose of improving the capability of scientific inquiry and the academic achievement of learners. The findings of the study are as follows: First, the POE strategy in science teaching-learning was found effective for the improvement of learners' scientific inquiry capability. Second, the POE strategy in science teaching-learning is effective for the improvement of learners' academic achievement in science. The findings mentioned above suggest that using the POE strategy in science class of elementary science education has significant effects on improvement of scientific academic achievement and scientific inquiry capability of learners compared with the general science teaching-learning strategy. It also shows to be highly recommendable for use in science class.

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DESIGN FOR AERODYNAMIC NOISE REDUCTION OF RAILWAY TRACTION MOTOR USING LBM (격자볼츠만기법을 이용한 전동차용 견인전동기 공력소음 저감 설계)

  • Kim, J.H.;Ki, H.C.;Byun, S.J.;Rho, J.H.
    • Journal of computational fluids engineering
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    • v.22 no.1
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    • pp.103-109
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    • 2017
  • The aerodynamic noise reduction of railway traction motor is required to satisfy new enhanced Korean noise regulations for a train. This paper is the study result on a noise reduction of a railway traction motor using Lattice Boltzmann Method(LBM). To verify the reliability of numerical analysis, the noise performance of the base model evaluated using LBM, and calculated result was compared with the experimental data. In addition, main noise sources were selected to design parameters through analyzing the flow field of the base model. Based on the noise sources analysis result, a design improvement model of traction motor for this study was derived to reduce the noise. The performance of a design improvement model was evaluated by applying a validated numerical scheme. As a result, it was confirmed that the noise was reduced due to the suppression of the internal turbulent flow components.

Developing Reference Model for National Cybersecurity Strategy Establishment and Improvement (국가 사이버보안 전략 수립과 개선을 위한 참조 모델 개발)

  • YUN, Jaesuk
    • Convergence Security Journal
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    • v.16 no.4
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    • pp.53-61
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    • 2016
  • A number of countries have been developing and implementing national cybersecurity strategy to prevent damages caused by cyber threats and to minimize damages when they happened. However, there are a lot of differences and disparities in respective strategies with their own background and needs. A vulnerability in some places can be a global problem, so various guidelines have been developed by relevant organizations including international organizations to support the establishment of national cybersecurity strategies and improvement of them. In this paper, with analysis on the guidelines for the establishment of national cybersecurity strategies, reference model consisting of common elements of strategies was suggested. And several recommendations for the improvement measures for Korean national cybersecurity strategies were explained with a comparison of the reference model.

IMPROVEMENT OF THE LOCA PSA MODEL USING A BEST-ESTIMATE THERMAL-HYDRAULIC ANALYSIS

  • Lee, Dong Hyun;Lim, Ho-Gon;Yoon, Han Young;Jeong, Jae Jun
    • Nuclear Engineering and Technology
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    • v.46 no.4
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    • pp.541-546
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    • 2014
  • Probabilistic Safety Assessment (PSA) has been widely used to estimate the overall safety of nuclear power plants (NPP) and it provides base information for risk informed application (RIA) and risk informed regulation (RIR). For the effective and correct use of PSA in RIA/RIR related decision making, the risk estimated by a PSA model should be as realistic as possible. In this work, a best-estimate thermal-hydraulic analysis of loss-of-coolant accidents (LOCAs) for the Hanul Nuclear Units 3&4 is first carried out in a systematic way. That is, the behaviors of peak cladding temperature (PCT) were analyzed with various combinations of break sizes, the operating conditions of safety systems, and the operator's action time for aggressive secondary cooling. Thereafter, the results of the thermal-hydraulic analysis have been reflected in the improvement of the PSA model by changing both accident sequences and success criteria of the event trees for the LOCA scenarios.

A System Dynamics Model for Evaluation of Maintenance Cost Policy in Deteriorated School Building (노후 학교건물의 유지관리비용 정책 평가를 위한 시스템 다이내믹스 모델)

  • Kang, Suhyun;Kim, Sangyong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.12
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    • pp.181-188
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    • 2019
  • The maintenance of school building is pivotal issue. However, it is difficult to obtain basic analysis data for LCC(Lifecycle Cost) analysis and maintenance planning of school building. Therefore, this study proposed System Dynamics(SD) techniques to make maintenance decisions for school building. The interaction between the major parameters related to the aging of a building, maintenance activities, and cost were expressed in Causal Loop Diagram. Based on this, the formula for the relationship between causal maps was defined and converted to Stock and Flow Diagram. Through the completed SD model the 50-year plan of 214 educational building were tested by considered in account budget, maintainability, and budget allocation opinions. As a result, the integrated SD model demonstrated that it can support strategic decision making by identifying the status class and LCC behavior of school buildings by scenario. According to the scenario analysis, the rehabilitation action of preventive maintenance that primarily repairs the buildings in condition grade C showed the best performance improvement effect relative to the cost. Therefore, if the proposed SD model is expanded to consider the effects of other educational policies, the crucial performance improvement budget can be estimated in the long-term perspective.

Hygrothermal Performance Improvement Plan of Standard Model for Rural Housing and Wooden Housing (농촌주택 및 목조주택 표준모델 구조체의 습·열 환경 성능 개선 방안)

  • Yoo, Dong-Wan;Lee, Tae-Goo
    • Journal of the Korean Institute of Rural Architecture
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    • v.23 no.4
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    • pp.63-71
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    • 2021
  • The purpose of this study was to investigate whether the standard models for rural housing and wooden housing model have performance for hygrothermal and to propose a way of improvement relevant to hygrothermal performance for those models. All of the models to be analyzed were found to have some parts that were absent of stability in terms of performance for hygrothermal. In the process of analyzing the causes and proposing improvement measures, the following conclusions were derived. Fist, The exterior surface of the structure should be composed of a structure with good moisture permeability, and for the interior surface, a variable vapor retarder paper should be applied in consideration of the reverse condensation phenomenon in summer. Second, in terms of performance for hygrothermal, applications of external insulation plaster finish to the exterior wall or of ventilation method using a rafter vent on the roof should be avoided. Third, a rain screen method with a ventilation layer should be applied to the exterior wall, and a method of constructing ventilation layer separated from the insulation layer with a vapor retarder paper should be applied to the roof. Fourth, the application of insulation materials having capillary action, such as wood fiber insulation board or cellulose insulation board, contributes to more stable performance for hygrothermal.