• Title/Summary/Keyword: Problem Behaviors

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Electrochemical Behaviors of Graphite/LiNi0.6Co0.2Mn0.2O2 Cells during Overdischarge (흑연과 LiNi0.6Co0.2Mn0.2O2로 구성된 완전지의 과방전 중 전기화학적 거동분석)

  • Bong Jin Kim;Geonwoo Yoon;Inje Song;Ji Heon Ryu
    • Journal of the Korean Electrochemical Society
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    • v.26 no.1
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    • pp.11-18
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    • 2023
  • As the use of lithium-ion secondary batteries is rapidly increasing due to the rapid growth of the electric vehicle market, the disposal and recycling of spent batteries after use has been raised as a serious problem. Since stored energy must be removed in order to recycle the spent batteries, an effective discharging process is required. In this study, graphite and NCM622 were used as active materials to manufacture coin-type half cells and full cells, and the electrochemical behavior occurring during overdischarge was analyzed. When the positive and negative electrodes are overdischarged respectively using a half-cell, a conversion reaction in which transition metal oxide is reduced to metal occurs first in the positive electrode, and a side reaction in which Cu, the current collector, is corroded following decomposition of the SEI film occurs in the negative electrode. In addition, a side reaction during overdischarge is difficult to occur because a large polarization at the initial stage is required. When the full cell is overdischarged, the cell reaches 0 V and the overdischarge ends with almost no side reaction due to this large polarization. However, if the full cell whose capacity is degraded due to the cycle is overdischarged, corrosion of the Cu current collector occurs in the negative electrode. Therefore, cycled cell requires an appropriate treatment process because its electrochemical behavior during overdischarge is different from that of a fresh cell.

The Effects of Environmental Education Program using Action Learning on the Environmental Literacy and Self-efficacy of Elementary Students (액션러닝을 활용한 환경교육 프로그램이 초등학생의 환경소양과 자기효능감에 미치는 영향)

  • Jin Jeon;Keum Hyun So
    • Journal of Science Education
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    • v.47 no.2
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    • pp.139-153
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    • 2023
  • This study aimed to investigate the effect of environmental education programs using action learning on elementary school students' environmental literacy and self-efficacy. To this end, an environmental education program using action learning was applied to 22 sixth graders of 'A' Elementary School in Busan. The results of this study were as follows. First, environmental education programs using action learning were effective in improving the environmental literacy of elementary school students. After implementing the environmental education program using action learning, students' environmental values, cognitive, and procedural ability changed positively. Environmental issues awareness and ecological knowledge improved, and there was a significant increase in environmental behavior and environmental function. Second, environmental education programs using action learning were effective in enhancing the self-efficacy of elementary school students. After implementing environmental education programs using action learning, students' confidence in problem solving and their ability to judge their behaviors improved. Third, elementary school students showed active participation and interest when conducting environmental education programs using action learning. Students have become open to protecting the environment when they find problems, devise solutions, and practice them. After reflection, it was confirmed that students' immersion and satisfaction in class were high as a solution was reached, leading to efforts to sell items they did not use and donate profits to environmental protection organizations.

Analysis of the Involving Mechanism of Kim Eun-Sook Drama : Focused on the Audience's Predictability and the Activities of Constructing Hypotheses (김은숙 드라마 <도깨비>의 몰입기제 구축과정 분석 - 관람자 예측성과 가설 구성 활동을 중심으로 -)

  • Kim, Eui-Jun
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.2
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    • pp.79-91
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    • 2019
  • In the entertainment industry, risk management is crucial for securing competitiveness due to the risk of investment. The competitiveness of contents is reinforced when external factors such as industrial environment and internal factors centering on involving mechanism are simultaneously provided. The involving mechanism is a form of cognitive response behavior of the audience and occurs through signal processing of the brain when watching the image contents. The signal processing of the brain related to the contents watching is mainly performed in the working memory area, and in the case of the captivating movie, the information other than the contents transmitted to the audience is blocked to generate a temporary dissociation state. A dissociation state similar to a symptom such as hypnosis or amnesia occurs when the audience's level of involving is high. On the other hand, contents information in which the audience is concentrating his attention is used intensively for constructing future thinking through an episodic buffer while the inflow of external information is relatively blocked or delayed. The spectator's future thinking configuration takes the form of a hypothesis-forming activity and is based on the predictability of the brain. When these hypothesized behaviors correspond to the problem solving simulation of story and predictability which is an evolutionary function of the brain, the audience' s brain is involved in the contents at a high level. In order for the act to be effective, the factors such as the background of the hypothesis, the subject of the hypothesis, the internal information of the person, the type and position and quantity of the hypothesis information, and the hypothesis relevance and type of information are important. Based on these factors, analysis of the Kim Eun Sook Drama 'Goblin' shows that the above elements are operated in a very organic and meaningful way.

A qualitative study on the adjustment process of families adopting an older child (연장입양가족의 적응과정에 대한 질적 연구 : 주 양육자인 입양모의 입장에서)

  • Chung, Ick-Joong;Kwon, Ji-Sung;Min, Sung-Hye;Shin, Hye-Won
    • Korean Journal of Social Welfare Studies
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    • v.42 no.1
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    • pp.399-432
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    • 2011
  • The purpose of this study is to understand the adjustment process of families adopting an older child, and to generate a substantial theory. To achieve this purpose, we conducted in-depth interviews with mothers adopting an older child and analyzed data with qualitative analysis approach. From the analysis, theoretical model has been made, and the model includes the adoptive families' diverse experiences, barriers to adjustment as well as resources and strategies that they mobilized and used for smooth adjustment. Their experiences in the process of adjustment consisted of five phases: unfamiliar meeting, shock, fighting alone without support, control, and stability. Barriers to adjustment process were composed of adoptees' problem behaviors, loss of time, lack of preparation, lack of experiences, repetition of the vicious circle, withstanding alone, improper resources, lack of support, and being criticized. Resources and strategies that families adopting an older child utilized were individual resources and ability such as rearing experiences, intellectual ability, willingness, belief, and perspective change; family system such as spouse and other offsprings; informal support system such as extended families, relatives, friends, neighbors, and other families adopting an older child; formal resources such as adoption workers and helping professionals. From our results, we suggested policy and practice guidelines to help adjustment experiences for families adopting an older child.

Firms' Switching Intention to Cloud Based Digital Trade: Perspective of the Push-Pull-Mooring Model

  • In-Seong Lee;Sok-Tae Kim
    • Journal of Korea Trade
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    • v.26 no.6
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    • pp.20-40
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    • 2022
  • Purpose - In recent times, the international trade environment has been changing rapidly, centering on the online market. In the post-COVID-19 era, small and medium-sized trading companies are facing the problem of not being properly provided with overseas market research, market trend analysis, and trade-related information. Cloud-based digital trade is being sought as an alternative to solve these problems; however, there is a lack of research on the intention to switch to digital trade among small and medium-sized trading companies. Therefore, this study empirically analyzes the intention to switch to digital trade based on the migration theory, and through this, attempts to identify each factor that affects the intention to switch to digital trade. Design/methodology - In this study, in order to identify factors influencing intention to switch to digital trade and innovation resistance of small and medium-sized trading companies, through previous research on migration theory and the PPM (Push, Pull, Mooring) model, each variable was selected for the purpose of the study. Based on this, a research model was established for the factors affecting switching to digital trade of small and medium-sized trading companies and empirically analyzed. In addition, considering the differences in the innovation propensity and maturity of information infrastructure of trading companies as the recipients of innovation, this study analyzes the moderating effect of the mooring effect and seeks ways to establish specific strategies according to the degree. Findings - As a result of empirical analysis, the pull effect was found to have the greatest influence on intention to switch to digital trade. However, the pull factor was found to have an effect on user resistance, and it was confirmed that it was a factor simultaneously inducing positive and negative consumption behaviors among users. In addition, it was found that the higher the company's innovation propensity, the higher the pull effect's influence on the intention to switch, and analysis showed that the push effect had no influence. In addition, companies with high information infrastructure maturity were expected to have a relatively high level of intention to switch compared to companies with low information infrastructure maturity, and the difference between the two groups was found not to be statistically significant. Originality/value - This study is a timely study in that it demonstrated the effect on the switching to cloud-based digital trade for small and medium-sized trading companies and that the cloud system related to digital trade is in full swing. There are academic implications in that it revealed that the pull effect is an important factor in the intention to switch to cloud service. Practical implications were presented in that small and medium-sized trading companies suggested ways to increase the value of the cloud system for switching to digital trade and a way to increase the switching ratio by minimizing the mooring effect. In addition, the study argues that active institutional support from the government is needed to activate cloud service.

A Nonlinear Truss Finite Element Model for Structures with Negative Poisson Effect Accompanied by Tensile Buckling (인장 좌굴 현상을 수반하는 음의 포아송 효과를 가지는 구조물 해석을 위한 비선형 트러스 유한요소 모델)

  • Tae-Wan Kim;Jun-Sik Kim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.3
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    • pp.193-201
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    • 2023
  • In this study, a nonlinear truss finite element is developed to analyze structures with negative Poisson effect-induced tensile buckling. In general, the well-known buckling phenomenon is a stability problem under a compressive load, whereas tensile buckling occurs because of local compression caused by tension. It is not as well-known as classical buckling because it is a recent study. The mechanism of tensile buckling can be briefly explained from an energy standpoint. The nonlinear truss finite element with a torsional spring is formulated because the finite element has not been reported in the literature yet. The post-buckling analysis is then performed using the generalized displacement control method, which reveals that the torsional spring plays an important role in tensile buckling. Structures that mimic a negative Poisson effect can be constructed using such post-buckling behaviors, and one of the possible applications is a mechanical switch. The results obtained are compared to those of analytical solutions and commercial finite element analysis to assess the validity of the proposed finite element model. The numerical results show that the developed finite element model could be a viable option for the basic design of nonlinear structures with a negative Poisson effect.

Developments of Advanced Connection Type for Improvements of Mixed Structures(I) : 3D Nonlinear Analysis of the Various Connection Types for Deriving Advanced Connection Type (혼합구조의 성능 향상을 위한 개선된 접합방식의 개발 (I) : 개선된 접합방식을 도출하기 위한 3차원 비선형 해석)

  • Yun, Ik Jung;Huh, Taik Nyung;Kim, Moon Kyum;Cho, Sung Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1A
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    • pp.89-94
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    • 2008
  • The problem of interaction between the structures interconnected at discrete points as like composite structures, has a attracted considerable attention for a prolonged period of time. Recently, mixed structures are applied for overcoming structural limits by developed countries. In this paper, advanced connection type of mixed structures are presented by numerical approach. Also it is performed on extensive literature review from theoretical method to numerical analysis. For analysing behaviors of mixed structures according to connection type, 2 different connections and 1 reinforced connection are compared by 3D nonlinear numerical analysis. Nonlinear analysis of mixed structures is carried out by utilizing contact elements of a general purpose structural analysis computer program(ABAQUS). By using 6 criteria, each connections are investigated. From this result, proper reinforcing and well designed connection type are proposed. And results also show that the deflections which are induced by discontinuity on mixed structures, has a linear distribution that should decrease as applying proposed connection type.

Geotechnical Hybrid Simulation System for the Quantitative Prediction of the Residual Deformation in the Liquefiable Sand During and After Earthquake Motion (액상화 가능 지반의 진동 도중 및 후의 잔류 변형에 대한 정량적 예측을 위한 하이브리드 시뮬레이션 시스템)

  • Kwon, Young Cheul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1C
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    • pp.43-52
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    • 2006
  • Despite several constitutive models have been proposed and applied, it is still difficult to choose a suitable model and to estimate adequate analysis parameters. Furthermore, a cyclic shear behavior under the volume change caused by the seepage is more complex. None of the constitutive model is available at present in the expression of the cyclic behavior of soil under an additional volume change condition by seepage. Therefore, a new geotechnical hybrid simulation system which can control the pore water immigration was developed. The system enables a quantitative evaluation of the residual deformation such as lateral spreading and settlement caused by the liquefaction. The seismic responses in a one-dimensional slightly inclined multilayered soil system are taken into consideration, and the soils are governed by both equation of motion and the continuity equation. Furthermore, the estimation and the selection of the soil parameter for the representation of the strong nonlinearity of the material are not required, because soil behaviors under the earthquake motions are directly introduced instead of a numerical soil constitutive model. This paper presents the concept and specifications of the system. By applying the system to an example problem, the permeability effect on the seismic response during cyclic shear is studied. The importance of the volume change characteristics of sandy soil during and after cyclic shear is shown in conclusion.

Understanding Assessment for Feeding Disorders in Autistic Spectrum Disorders: A Literature Review (자폐 스펙트럼 장애 섭식장애 평가의 이해: 문헌 고찰)

  • Min, Kyoung-Chul;Kim, Bo-Kyeong
    • Therapeutic Science for Rehabilitation
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    • v.13 no.2
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    • pp.9-25
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    • 2024
  • Objective : Children with autism spectrum disorder (ASD) commonly suffer from feeding disorders. Major feeding problems include mealtime behavior problems, picky eating, and a lack of food variety can lead to nutritional problems, developmental and social limitations, and stress for the caregivers. A review of the latest literature was conducted to gain an in-depth understanding of assessment tools for feeding disorders in children with ASD. Method : This study analyzed assessments to identify feeding problems in ASD based on previous studies searched through keywords such as ASD, ASD feeding problem, and ASD feeding evaluation. Results : The ASD feeding disorder assessment was divided into direct and indirect assessments. Indirect assessment, in which caregivers measure a child's situation using questionnaires, is mainly used. The assessment of feeding disorders in children with ASD was divided into 1) mealtime behavior, 2) sensory processing, 3) food consumption, and 4) others. Conclusion : As the main feeding disorder characteristics of children with ASD are very diverse, a comprehensive evaluation is necessary but is still limited. Swallowing rehabilitation experts, such as occupational therapists, should apply comprehensive assessment tools based on a basic understanding of the feeding problems, behaviors, and sensations in ASD.

A Study on the Historical Development of Research Community in Korea: Focused on the Government Supported Institutes (연구자 집단의 성장과 변천: 정부 출연 연구 기관을 중심으로)

  • Park Jin-Hee
    • Journal of Science and Technology Studies
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    • v.6 no.1 s.11
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    • pp.119-152
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    • 2006
  • This paper deals with the historical development of research community in Korea. As the former studies of the korean scientific community show, the government supported institutes played an important role in the formation of research community. Therefore the theme of this study is concerned with the historical development of the government supported institutes and the features of their researcher group. In this paper following questions will be answered: How the social status of these researcher group is changed, what kind of response on social problems or national politics they had, and which characteristic they showed with regards to the identity problem. After the korean liberation the government institutes, such as the Chungang Kongop Yonguso(industrial research center)and the Korean Atomic Energy Research Institute, contributed to the development of the first generation of research group. However this research group could hardly identify themselves as researcher, because they spent much time on testing, evaluation or education. The identity problem is also resulted from the deficiency of authority as research institute. The status of researcher had no difference from that of civil servant. With the establishment of KIST the korean research community came into blossom. The government supported institutes, which were founded after the model of KIST, allowed quantitative and qualitative growth of research community. Thanks to the guarantee of institutional authority and the new reward system, the researcher could get respect and improve its social status. During this period the researcher volunteered to help the government policies. We can find often the nationalistic statements in the research community. During 1990s the research group demonstrated different behaviors and attitude toward the government. The nationalistic ideology disappeared. Instead of that, the research group criticized the government policies and took actions against the government. Those changes are related with the lowered position of government supported institutes.

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