• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.1
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• pp.24-34
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• 1990

In this paper, the formulation of a new simplified finite element is made to analyze the ultimate strength of damaged tubular members subjected to combined axial force and end moment. A damaged tubular member that has the bending deformation and the local dent is modeled by beam elements. Tangent elastic stiffness matrix of a beam element which contains the effect of the geometric nonlinearity is derived by using the updated Lagrangian approach. Here the contribution of the stiffness in the dented area is neglected since its resistance against the external loads is considered to be small. A fully plastic interaction curve of the element under combined loads taking account of the local dent effect is selected as a yielding criterion at each nodal point. Also tangent elasto-plastic stiffness matrix of the element is formulated by plastic node method. Comparison with the present solution and the existing experimental results is made showing that the present method gives quite an accurate solution.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.123-130
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• 2003

This paper presents a new striped checkpointing scheme for serverless cluster computers, where the local disks are attached to the cluster nodes collectively form a distributed RAID with a single I/O space. Striping enables parallel I/O on the distributed disks and staggering avoids network bottleneck in the distributed RAID. We demonstrate how to reduce the checkpointing overhead and increase the availability by striping and staggering dynamically for communication intensive applications. Linpack HPC Benchamark and MPI programs are applied to these checkpointing schemes for performance evaluation on the 16-nodes cluster system. Benchmark results prove the benefits of the striped checkpointing scheme compare to the existing schemes, and these results are useful to design the efficient checkpointing scheme for fast rollback recovery from any single node failure in a cluster system.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.9-9
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• 1992

시뮬레이션(simulation)은 실 시스템(real system)의 효과적이고 효율적인 운영을 도모하기 위하여 실 시스템의 동작을 이해하고 분석, 예측, 평가하는 과학적인 문제해결 접근방법이다. 시뮬레이션 수행단계는 실 시스템의 행위를 정확히 반영하도록 타당한 모델을 구축하는 모델링 단계와 모델에 의도하는 명령어들을 컴퓨터 프로그램으로 작성하는 구현단계로 나누어진다. 시뮬레이션 모델은 시간, 상태, 확률변수, 상호규칙 등의 여러 관점에 따라 다양하게 존재하는데, DEVS(Descrete EVent system Specification) 모델은 연속적인 시간상에서 이산적으로 발생하는 사건에 따라 시스템의 상태를 분석할 수 있고 모델링 및 시뮬레이션 방법론의 형식화를 위한 견고한 이론적 기반을 제공하고 있다. 또한, DEVS 모델은 모듈적, 계층적 특성을 제공하고 집합론에 근거한 수학적 형식구조를 제공하여 실 시스템에 대한 체계적인 분석과정을 수행하게 되어 보다 현실적인 모델링을 가능하게 한다. 그러나 타당하지 못한 DEVS 모델이 구축되면 시뮬레이션을 통한 분석결과의 신뢰성이 떨어져 아무런 효과가 없고 경제적인 손실만이 따른다. DEVS 모델에 대한 기존의 타당성 검사가 많은 시간과 노력이 요구되고, 반복적인 DEVS 모델링 과정으로 인한 전문적이고 경험적인 지식을 요구한다. 또한, 모델설계자에 의해 설정된 실험 프레임하에서 DEVS 모델의 구성요소에 속하는 상태전이함수, 시간진행함수 및 출력함수에 대하여 commutative 성질의 보전성 검사가 어렵다는 문제점을 가지고 있다. 본 연구에서는 이와 같은 문제점을 해결하기 위하여, DEVS 모델에 대한 타당성 검사를 SPN(Stochastic Petri Net) 모델로 변환하여 SPN 모델을 이용하는 간단하고 효과적인 타당성 검사 방법을 제안한다. 먼저, DEVs 모델에 대한 개념과 기존의 DEVS 모델에 대한 타당성 검사 방법을 고찰하고 그 문제점에 대하여 자세히 설명한다. DEVS 모델의 타당성 검사에 이용하는 SPN 모델에 대한 개념과 DEVS 모델과 행위적으로 동등한 SNP 모델로 변환을 위한 관점을 제조명하다. 동일한 관점에서 두 모델의 상태표현이 같도록 DEVS 모델이 SPN 모델로 표현됨을 보이는 변환이론을 제시하고 변환이론을 바탕으로 모델 변환과정을 제시한다. 모델 변환이론과 변환고정을 기본으로 타당성 검사를 위한 새로운 동질함수(homogeneous function)를 정의하고 이와 함께 SPN 모델의 특성을 이용하여 DEVS 모델에 대한 타당성 검사 방법을 새롭게 제안한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.927-934
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• 2023

With the recent growth of the companion animal market, various social issues related to companion animals have also come to the forefront. Notable problems include incidents of dog bites, the challenge of managing abandoned companion animals, euthanasia, animal abuse, and more. As potential solutions, a variety of training programs such as companion animal-focused broadcasts and educational apps are being offered. However, these options might not be very effective for novice caretakers who are uncertain about what to prioritize in training. While training apps that are relatively easy to access have been widely distributed, apps that allow users to directly engage in training and learn through hands-on experience are still insufficient. In this paper, we propose a more efficient AR-based mobile app for companion animal training, utilizing the Unity engine. The results of usability evaluations indicated increased user engagement due to the inclusion of elements that were previously absent. Moreover, training immersion was enhanced, leading to improved learning outcomes. With further development and subsequent verification and production, we anticipate that this app could become an effective training tool for novice caretakers planning to adopt companion animals, as well as for experienced caretakers.

• Journal of Korean Academy of Nursing
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• v.54 no.2
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• pp.224-236
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• 2024

Purpose: This study aimed to evaluate the effects of a mobile-based breastfeeding promotion program (M-BFGDM) that helps mothers with gestational diabetes. Methods: Forty-seven mothers participated in the study, of whom 22 were in the experimental group and 25 in the control group. To verify the effects, a lag design before and after the non-equivalence control group was used. The data collection for the experimental group was done before and after the intervention. Results: In the results, breastfeeding knowledge showed a significant difference in the interaction between measurement period and group (χ² = 8.14, p = .017), whereas breastfeeding intention did not show a significant difference in the interaction (χ² = 4.73, p = .094). There was no difference in self-efficacy interaction (F = 0.13, p = .856). The breastfeeding method showed no difference in interaction (F = 0.04, p = .952), whereas cross-analysis showed a significant difference in breastfeeding practice rate between the experimental group and the control group at 1 month postpartum (χ² = 7.59, p = .006). Conclusion: A mobile-based breastfeeding promotion program was developed and applied for gestational diabetic mothers, resulting in an increase in breastfeeding knowledge and an improvement in breastfeeding practice rate one month after childbirth. In addition, M-BFGDM managed to create a breastfeeding practice environment with fewer time and place restrictions. A program study that complements motivation is needed to improve breastfeeding in pregnant diabetic mothers in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.803-814
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• 2022

The Lao government is continuously developing hydro-power dams in addition to the existing eight power plants in the Nam Ngum River basin and is expanding the power capacity of the existing power plants to meet the expected increase in electricity demand. Accordingly, the Lao government has requested an update on the existing reservoir operating rule curve in order to run the power plants efficiently. To this end, this study reviewed the current independent operating system as well as the joint operating system in order to maximize the annual power generation produced by a power plant by using CSUDP, general-purpose dynamic programming (DP) software. The appropriate operating regulation curve forms (URC/LRC, MRC) were extracted from the DP results, and the annual power generations were simulated by inputting them as the basic operating data of the reservoir operation set of the HEC-ResSim program. By synthesizing the amount of the annual power generation simulated, the existing operation regulation curve, the operational performance, and the opinion of the field operator, the optimal reservoir operation regulation curves that maximize the annual power generation of the target power plant were developed. Results revealed that a system operating in conjunction with the reservoir produces about 2.5 % more power generation than an independent reservoir due to the synergistic effect of the connection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.586-594
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• 2020

The purpose of this study is to propose interventions on emotional labor and health issues through verifying the mediating effects of depression and anxiety on the relationship between emotional labor and somatic symptoms in medical workers. For this study, a sample of 200 medical workers completed the questionnaires of the Korean Emotional Labor Scale, the Patient Health Questionnaire-15, the Patient Health Questionnaire-9, and the Generalized Anxiety Disorder-7. The data was analyzed using the SPSS 25.0 program. The results of this study can be summarized as follows. 1. Results showed a risk of emotional labor, depression, and somatic symptoms in medical workers. 2. The risk group of the emotional labor's 4 factors (excluding organizational support and protection system) had a significantly higher level of depression compared with the normal group. Particularly in emotional dissonance and impairment, depression in the risk group was moderate, while depression in the normal group was normal. 3. Only emotional dissonance and impairment had a significant influence on somatic symptoms. Reflecting the results, the mediating effects of depression and anxiety on the relationship between emotional dissonance and impairment and somatic symptoms were verified. Results showed that depression had a partial mediating effect, whereas anxiety did not have a mediating effect. Finally, we discuss the necessity of dealing with emotional dissonance and depression in emotional labor and health issues.

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.90-105
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• 2009

This study analyzed current programs practiced by science-gifted education centers. This study was based on concerns of 18 science teachers on six science-gifted education centers of the Seoul Metropolitan Office of Education that had local representatives. For this study, we collected data using journals, documents, reports, survey reviews and interviews with science teachers. Science teachers were concerned about the selection and identification of gifted students, education periods, curriculum, and student evaluation. More authentic measurement for students' potential ability were needed for the identification and selection process. If the purpose of science-gifted centers was to be met, the number of students selected should be determined by local differences rather than regional equality. The curriculum and educational period could make good use of time allotted for vacation to increase lesson periods. Lessons based on strategies like contests for improving the students' creativity, free inquiry and communication skills had to be encouraged. A consistent system for science-gifted education from primary school to high school was needed.

• Journal of Music and Human Behavior
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• v.14 no.2
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• pp.19-43
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• 2017

This study aimed to examine the effects of a reciprocal attention intervention on the joint attention behaviors of children with autism spectrum disorder (ASD) by comparing the music and nonmusic conditions. An alternating treatment design was applied as one of the single subject designs and the reciprocal attention intervention included music and nonmusic conditions implemented alternately within a session. The participants were four children between the ages 4 and 5 years and each participant who participated in 23 intervention sessions that followed the sequence of baseline (3 sessions), treatment (15 sessions), and follow-up (5 sessions). The music condition consisted of structured joint instrument playing, trials for attentional shift, and interactive instrument playing. The nonmusic condition consisted of joint toy play, trials for attentional shift, and turn taking-based play. The occurrence of target behaviors (i. e., joint attention behavior, eye gaze, and joint action) was analyzed across sessions. At pretest and posttest, the Early Social Communication Scale was administered. All participants showed increasing tendency in all target behaviors, but such occurrence was greater in the music condition than in the nonmusic condition. The findings support the use of a reciprocal attention intervention with musical stimuli to effectively improve joint attention in this population.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.263-270
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• 2020

This study evaluates the structural behavior of connected long-span beams applied for excavation in urban areas with a narrow street. Generally, the reliability of the connection is reduced owing to the defect of the upper flange in the connection. An improved connection part was developed to complement the defects in the connected long-span beam. A finite element analysis based on a commercial program, ABAQUS, was employed to evaluate the behavior of the improved connection part. A numerical analysis model was proposed to analyze the high-strength bolt connection and the composite behavior of steel and concrete applied to the improved connection. The suitability of the proposed numerical analysis was verified by comparing the experimental and numerical analysis results of the references. Using the proposed numerical analysis method, the improved and general connections were analyzed and compared with each other. The stress distribution and elastic-plastic behavior of the long-span beam were analyzed numerically. The analysis confirmed that 25% of the compressive stress was improved, resulting in the improvement of structural safety and performance.