• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.169-175
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• 2024

In this study, we developed control system for stable teleoperation of supermicrosurgical robot platform. The supermicrosurgical robot platform is designed to perform precise anastomosis with micro vessels ranging from 0.3 mm to 0.7 mm. The robotic assistance could help more precise manipulation then manual surgery with the help of motion scaling and tremor filtering. However, since the robotic system could cause several vulnerabilities, control system for stable teleoperation should be preceded. Therefore, we first designed control system including inverse kinematics solver, clutch error interpolator and finite state machine. The inverse kinematics solver was designed to minimized inertial motion of the manipulator and tested by applying orientational motion. To make robot slowly converges to the leader's orientation when orientational error was occurred during clutch, the SLERP was used to interpolate the error. Since synchronized behavior of two manipulators and independent behavior of manipulator both exist, two layered finite state machines were designed. Finally, the control system was evaluated by experiment and showed intended behavior, while maintaining low pose error.

• Asia-Pacific Journal of Business
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• v.14 no.4
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• pp.151-161
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• 2023

Purpose - In this study, we examine the factors related to the asset allocation decisions of individual investors who 1) directly invest in stocks or bonds, 2) indirectly invest in various fund products (excluding CMA and MMF), and 3) invest in both products. Design/methodology/approach - We collect a sample of 3,000 individual investors and investigate the factors influencing investment behavior, especially the diversification tendency in asset allocation, with the "Investor Behavior Survey" that is conducted jointly by the Korea Financial Investment Association and the Korea Gallup Research Institute in 2011 and 2012. Findings - Our regression analyses estimate the marginal effects of various factors such as the amount of total financial assets, monthly income, occupation, age, and gender. The results reveal that male investors with manual labor occupations were less inclined to diversify their investments compared to female investors in office jobs. Additionally, higher monthly income is associated with a greater inclination toward diversification. Therefore, if a positive relationship exists between income and educational level, we may suggest that higher educational levels lead to a greater tendency for diversification. Research implications or Originality - Interestingly, investors who engage in direct investments tend to exhibit a weaker diversification tendency as the amount of their direct investment increases. On the other hand, investors who engage in both direct and indirect investments show a weaker diversification tendency as the amount of total financial assets increases. This suggests that the investment style of investors is closely related to their diversification behavior.

• Journal of Coastal Disaster Prevention
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• v.5 no.4
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• pp.163-172
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• 2018

To propose the design technique and the execution manual of the LWFS(Lightweight Foamed Soil) method using dredged soil, the operation system for the test-bed integrated management, and to establish an amendment for the domestic quantity per unit and specifications, and a strategy for its internationalization. In order to utilize the dredged soil from the coastal area as a construction material, we constructed the embankment with LWFS on soft ground and monitored its behavior. As a result, it can be expected that the use of LWFS as an embankment material on the soft ground can improve the economic efficiency by reducing the depth and period of soil improvement as well as the uses of nearby dredged soil. To verify the utilization of the dredged soil as a material for light-weighted roadbed, soft ground and foundation ground, and surface processing, perform an experimental construction for practical structures and analyze the behavior. It is expected to be able to improve the soft ground with dredged soil and develop technique codes and manuals of the dredged soil reclamation by constructing a test-bed in the same size of the fields, and establish the criteria and manual of effective dredged soil reclamation for practical use. The application technology of the dredged soil reclamation during harbor constructions and dredged soil reclamation constructions can be reflected during the working design stage. By using the materials immediately that occur from the reclamation during harbor and background land developments, the development time will decrease and an increase of economic feasibility will happen. It is expected to be able to apply the improved soil at dredged soil reclamation, harbor and shore protection construction, dredged soil purification projects etc. Future-work for develop the design criteria and guideline for the technology of field application of dredged soil reclamation is that review the proposed test-bed sites, consult with the institutions relevant with the test-bed, establish the space planning of the test-bed, licensing from the institutions relevant with the test-bed, select a test-bed for the dredged soil disposal area.

• Journal of the Korean GEO-environmental Society
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• v.11 no.12
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• pp.27-35
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• 2010

The structures built under the groundwater level are affected by the buoyancy force, which is hydrostatic pressure in the up direction. Recently, buoyancy-resistant anchor method has been applied in many cases of the construction of the important structure of large size, which is built under the groundwater level so that it takes high uplift pressure. Even if the construction cost of the method is very high, it surely increases the safety rate. However, the diagnosis of the performance of the buoyancy-resistant permanent anchor and the investigation of resistance mechanism are still insufficient. Especially, the long-term behavior of the anchor has not been studied well due to the difficulty in observation procedure. The contribution of this paper is the establishment of reasonable design methodology. We have measured anchor axial forces for 10 years after the construction, by using an automated measurement and a manual measurement by establishing a load cell in anchor head. Through the data collected from the measurements, we analyze the construction-step behavior of the anchor according to the self-weight variation of the building and the long-term behavior (i.e. movement within 10 years after the construction) of the anchor according to the passage of time.

• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.215-224
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• 2004

The inelastic lateral-torsional buckling behavior of the beam-columns and the columns was investigated in this paper. The energy method was deployed to study the inelastic buckling behavior of the beam-columns and columns. which requires the iterative solution of a fourth-order eigenproblem. Hitherto, the patterns of residual stress that satisfies the I-section manufacturing in Korea is not available, therefore the pattern of residual stress used in this study is a 'well-known' simplified pattern. The simplified pattern of the residual stresses is incorporated with the flow theory of plasticity to model the inelastic response. Firstly, this study investigates the inelastic lateral-torsional buckling behavior of the I-section beam-columns under a concentric axial compressive force and uniform bending, and the effect of residual stress on the inelastic buckling behavior of beam-columns is studied. The study is then extended to the inelastic buckling of the columns by eliminating a bending moment. These results are compared it with the design method in the Korean Steel Designers Manual (KSDM 1995). This study has found that design method in KSDM (1995) is excessively conservative.

• Earthquakes and Structures
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• v.15 no.3
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• pp.335-350
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• 2018

This paper presents numerical modelling, modal testing, finite element model updating, linear and nonlinear earthquake behavior of a reinforced concrete building model. A 1/2 geometrically scale, two-storey, reinforced concrete frame model with raft base were constructed, tested and analyzed. Modal testing on the model using ambient vibrations is performed to illustrate the dynamic characteristics experimentally. Finite element model of the structure is developed by ANSYS software and dynamic characteristics such as natural frequencies, mode shapes and damping ratios are calculated numerically. The enhanced frequency domain decomposition method and the stochastic subspace identification method are used for identifying dynamic characteristics experimentally and such values are used to update the finite element models. Different parameters of the model are calibrated using manual tuning process to minimize the differences between the numerically calculated and experimentally measured dynamic characteristics. The maximum difference between the measured and numerically calculated frequencies is reduced from 28.47% to 4.75% with the model updating. To determine the effects of the finite element model updating on the earthquake behavior, linear and nonlinear earthquake analyses are performed using 1992 Erzincan earthquake record, before and after model updating. After model updating, the maximum differences in the displacements and stresses were obtained as 29% and 25% for the linear earthquake analysis and 28% and 47% for the nonlinear earthquake analysis compared with that obtained from initial earthquake results before model updating. These differences state that finite element model updating provides a significant influence on linear and especially nonlinear earthquake behavior of buildings.

• Journal of dental hygiene science
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• v.21 no.1
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• pp.52-62
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• 2021

Background: This study aims to provide basic data for development of the level-based oral health care program depending on the mother's oral health literacy by finding out how mother's oral health literacy can effect on the preschool children's oral health and behavior. Methods: The survey was conducted on 192 mothers who have preschool children and the data were analyzed by t-test, ANOVA, multiple regression analysis to identify differences in verbal and functional oral health literacy. Results: The study showed statistical significance (p<0.05) in educational level depending on differences in verbal and functional oral health literacy by sociodemographic factor. In differences in verbal and functional literacy depending on experience of education for oral health behavior and oral health, statistical significance (p<0.05) was showed highly on verbal and functional literacy in the case that subjects have an experience of education for oral health and their children have not been experienced of oral illness. And when it comes to the case that subjects have experience of education for oral health within one to two years, statistical significance was showed highly on verbal literacy. It showed that verbal and functional oral health literacy effects to oral health care behavior of children judging from results that the higher level of mother's verbal oral health literacy, the higher score of children's oral health knowledge, attitude and behavior. Conclusion: It is necessary to develop the systematic program which is appropriate for characteristics of each oral period in childhood depending on level of primary caregiver's oral health literacy, and systematic education should be preceded to enhance the literacy of the caregiver. It is considered necessary to improve the oral health care of children by developing a manual for oral health care education to enhance primary caregiver's oral health literacy.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.6
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• pp.97-118
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• 2021

This study empirically examines the effect of the psychological empowerment of airline cabin crews on customer-focused job performance attitude, service behavior by CSM, and service behavior beyond CSM. The research model and associated hypotheses were verified with the structural equation model. The findings of the study reveal that psychological empowerment has a effect on customer-focused job performance attitude and service behavior by CSM, but no effect on service behavior beyond CSM. And it is also shown that customer-focused job performance attitude has an effect on service behavior by CSM but no effect on service behavior beyond CSM. In addition, customer-focused job performance attitude shows a mediating effect between psychological empowerment and service behavior by CSM. On the other hand, it is analyzed that there is no mediating effect between psychological empowerment and service behavior beyond CSM. This study implies that the psychological empowerment and customer-focused job performance attitude of cabin crews are important at point of contact with customers to improve service quality, and psychological empowerment reinforces service behavior by CSM on the premise of customer-focused job performance attitude.

• Journal of the korean veterinary medical association
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• v.34 no.10
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• pp.715-725
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• 1998

우리 사람들은 자신의 생각을 다른 사람들에게 전하고자 할 때 언어를 주로 이용하고 보조적인 수단으로 몸짓을 한다. 사용하는 언어가 달라 소통이 어려울 때는 부득이 몸짓으로만 서로 의견을 나누게 되는데 손짓과 발짓은 물론 얼굴의 표정까지 동원된다. 물론 언어를 이용한 의사전달 만큼 정확하지도 못하고 시간적으로도 효율적이지 못하지만 그런 대로 급한 문제는 해결할 수 있는 경우가 않다. 동물들이 서로의 의사소통을 위하여 어떤 형태의 언어 및 언어에 가까운 음성기호를 이용할 능력이 있는지에 대하여는 학자들 간에도 논란이 계속되고 있으나 분명한 것은 어떤 방법으로든 동물들도 제나름대로 자신의 의사를 전달하고 또한 상대편이 전하고자 하는 뜻을 파악하여 이에 적절히 대처를 한다는 점이다. 이런 점에서 동물들을 대상으로 하는 학문인 수의분야에서는 우리 인간들에게 익숙한 언어와 행동이 아닌 동물들의 독특한 의사전달 방법을 정확히 이해하는 것이 무엇보다도 중요하다는 점을 인식하는 것이 필요하다 동물의 행동 하나 하나는 인간의 행동과 마찬가지로 나름대로의 의미를 지니고 있다. 이러한 동물의 행동을 인간의 눈 높이에서가 아닌 동물이 표현하고자 하는 행동 언어적인 측면에서의 이해가 필요한 것이다. 야생동물의 행동양식에 대한 연구는 생래학적으로 비교적 많이 이루어진 편이나 가축화된 동물들에 대하여는 체계적이고 비교학적인 연구가 아직도 부족한 실정이다. 특히 우리 나라에서는 이 분야에 대한 연구는 물론 외국의 연구내용에 대하여도 적극적인 소개가 이루어지지 못하였고 아울러 여러 분야에 실제 적용은 더욱 어려웠다. 동물의 건강을 책임지고 있는 우리 수의 분야는 물론, 가축을 사양하는 축산학 분야 및 모든 동물관련 분야에서 효율적이고 바람직한 동물과 인간의 관계를 구축하기 위하여는 무엇보다도 동물의 행동을 인간의 언어사용 측면에서 이해하려는 노력이 필요하다 하겠다. 이러한 일차적인 필요성에 조금이나마 도움이 되고자 하는 바람으로 외국문헌을 중심으로 인간의 생활과 밀접한 관계를 지닌 여러 동물들의 행동과 그 의미를 소개하고자 한다. 아울러, 소개되는 내용은 Domestic Animal Behavior for Veterinarians and Animal Scientists (제3판, Katherine A. Houpt 지음), Animal Behavior (Tim Halliday 지음), Canine and Feline Behavior Problems(Stefanie Schwartz 지음), Journal of Conpendium on Continuing Education for the Practicing Veterinarian,그리고The Merck Veterinary Manual의 Behavior와 같은 참고문헌에 크게 의존하여 기술된 것임을 밝힌다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.26 no.3
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• pp.149-158
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• 2015

Objectives : The objective of this study was to identify the risky behavior subtypes in adolescents with depression, and the relationship between those subtypes and suicide attempt. Methods : Ninety adolescents who met the Diagnostic and Statistical Manual of Mental Disorders-4th edition criteria for major depressive disorder, dysthymia, or depressive disorder not otherwise specified participated in the study. Participants were interviewed about suicidal attempts, non-suicidal self-injuries. Smoking, drinking behaviors, and searching for the word "suicide" on the internet, negative life events including bulling-bullied experiences, and history of abuse were also included with questionnaires. Results : The results of cluster analysis showed that four risky behaviors were divided into three clusters : non-risky type, characterized by few risky behaviors ; delinquency type, which was characterized by smoking and drinking ; non-suicidal self-injury type. In non-suicidal self-injury type, percentage of girls was higher and clinical symptoms were more severe than delinquency type. In addition, delinquency type members could be a bully, while non-suicidal self-injury type members could be abused by a family member. Logistic regression analysis showed that both risky behavior subtypes were significant predictors of suicide attempt. Conclusion : These results suggest that two types of risky behaviors of depressed adolescents have an effect on the suicide attempts independently. Then, the implications and limitations of the study were discussed and directions for future studies were suggested.