• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.160-171
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• 1999

The paper examines the ride performance enhancement that can be obtained by applying hydraulic semiactive vibration absorbers(SAVa) to alter the compliance characteristics of the seat/wheel suspension system. The work relies on a consistent model of the (nonlinear) hydrodynamics of the SAVA. A recently developed Lyapunov control scheme is used to provide regulation.. The performance is first examined assuming a quarter car with a seat/seat mounted mass. The paper then employs a quarter car/seat with a two mass ISO model of the seated human . The simulated results indicated that a reduction of 45% of the peak vertical acceleration is achievable with new system.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.383-391
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• 2010

The present study evaluated a preliminary control room (CR) design of radioactive waste facility using the $JACK^{(R)}$ human simulation system. Four digital humanoids ($5^{th}$, $50^{th}$, $95^{th}$, and $99^{th}$ percentiles) were used in the ergonomic evaluation. The first three were selected to represent 90% of the target population (Korean males aged 20 to 50 years) and the last to reflect the secular trend of stature for next 20 years in South Korea. The preliminary CR design was assessed by checking its compliance to ergonomic guidelines specified in NUREG-0700 and conducting an in-depth ergonomic analysis with a digital prototype of the CR design and the digital humanoids in terms of postural comfort, reachability, visibility, and clearance. For identified design problems, proper design changes and their validities were examined using JACK. A revised CR design suggested in the present study would contribute to effective and safe operations of the CR as well as operators' health in the workplace.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1294-1297
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• 2003

With the development of medical field, many kinds of operations have been performed on human articulation. Arthroscopic surgery, which has Irrigation Pumping System for security of operator vision and washing spaces of operation, has been used for more merits than others. In this paper, it is presented that the research on a reliable control algorithm of the pumping system instrument for arthroscopic surgery. Before clinical operation, the flexible artificial articulation model is used for realizing the model the most same as human's and the algorithm has been exploited for it. This system is considered of the following; limited sensing point, dynamic effect by compliance, time delay by fluid flow and so on. The system is composed with a pressure controller, a regulator for keeping air pressure, an airtight tank that can have distilled water packs, artificial articulation and a measuring system, and has controlled by the feedback of pressure sensor on the artificial articulation. Also the system has applied to Smith Predictor for time delay and the parameter estimation method for the most suitable system with both the experiment data and modeling. In this paper, the pressure error that is between an air pressure tank and an artificial articulation was measured so that the system could be presumed and then the controller had developed for performing State-Feedback. Finally, the controller with a real microprocessor has realized. The confidence of system can be proved by applying this control algorithm to an artificial articulation experiment material.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1593-1597
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• 2003

The home service robot supports human beings by performing various kinds of works at home. This paper presents a simple control method for opening a door from the viewpoint of the mobile manipulation. The simulation shows various results of path planning and motion planning for opening a door. The joint trajectories were generated by the simulation system. In general, a six-axis force/torque sensor at an end-effector is needed in order to maintain the static equilibrium of the manipulator. But we show another method. From three components of applied forces which was directly obtained by the three-axis force sensor and three components of applied forces which was indirectly estimated by the joint-torque sensors, all of joint torques that will exactly balance forces at the end-effector in the static situation can be found. It is more practical method than using a six-axis force sensor in a wrist. Experimental results have shown that the opening a door can be realized more effectively from the suggested control method of mobile manipulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.243-253
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• 2016

Company strengthen various information security policy and activity in order to protect important information assets that the company has been dealing with and prevents information security accidents such as personal information spill. However, some study said these policy and activity increase employee's information security stress and still information security accidents by employees have happened so far. Therefore, this study will review preceding theories and studies used in many various fields including Information Security areas needed to explain human's behavioral intention and determinants and summarize characteristic factors that have influence on control of human's behavioral intention in the results of the above theories and studies. Secondly, this study will implement exploratory analysis on characteristic factors perceived by employees that has been stemmed from various company's information security policy and activity in order to increase employee/'s information security compliance intention under the its surrounding security circumstance. Thirdly, this study will fulfil multiple-regression analysis in order to identify cause-effect relationship between employee's perceived information security stress and employee's perceived characteristic factor. Finally, this study will explain casual relationship with same analysis methods between information security stress and information security compliance intention based on results of the survey conducted on the financial firm's employees with same analysis methods.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.5
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• pp.398-406
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• 2003

In modular fixturing systems, a given part or a subassembly is fixed by placing fixture elements such as locators and clamps adequately on a plate with a lattice of holes. It is known that the minimal number of point contacts to restrict translational and rotational motions on a plane is four and the type of three locators and a clamp(3L/1C) is the minimal future. Brost and Goldberg developed the complete algorithm to automatically synthesize 3L/1C types of fixtures which satisfy the condition of form closure. Due to the nature of the fixture, the clearance between the fixture and the part is extremely small. It is hard to load the part repeatedly and accurately for human as well as for robot. However the condition of loadability has not been taken into account in the B&G algorithm. In this paper, a new method to decide a given fixture to be loadable by using configuration space is proposed. A method to plan for a part to be loaded by using compliance safely even in the presence of control and sensing uncertainty is proposed is well.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.4
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• pp.417-425
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• 2012

This paper presents reference ZMP trajectory generation and implementation for a biped robot via linear inverted dumbbell model (LIDM), which can consider the effect of external momentum on the center of mass (COM) of robot. Based on a reference ZMP trajectory derived by using LIDM, a base trajectory is proposed not only to make the locomotion of robot similar to that of human but also to facilitate its implementation and tuning. In order to realize a dynamic walking using the proposed trajectory, compliance, impedance and ZMP tracking controllers are adopted together. Extensive experiments show that the proposed locomotion of a biped robot is stable and also, similar to that of human. Further researches on balance recovery of a biped robot will be carried out to guarantee its robust locomotion in combination with the proposed trajectory.

• Safety and Health at Work
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• v.10 no.4
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• pp.476-481
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• 2019

Background: Mystery shopping is a method in which a company monitors quality of service and employee conduct and compliance with regulations using an evaluator posing as a customer. It is a typical tool of customer-centered bureaucratic control insofar as it provides overall and standardized evaluation of intangible elements of customer service as well as physical elements of service environments. The purpose of this study is to examine how mystery shopping is related to the health status of service workers in South Korea. Methods: Data from semistructured interviews with 15 workers were collected from January to April 2019 to obtain information on service worker experiences with mystery shopping. Data were analyzed using the constant comparison method. Results: Mystery shopping limits worker autonomy and stiffens the workplace environment by standardizing and monitoring labor processes for service workers. In addition, mystery shopping heightens work stress through increased labor intensity. Five mechanisms by which mystery shopping affects service worker health are identified and comprise (1) multifaceted and multilayered surveillance, (2) evaluator subjectivity and irrational requirements, (3) standardized rules combined with high pressure to achieve sales, (4) self-esteem degradation because of evaluator results, and (5) musculoskeletal disorders because of strict adherence to labor processes based on evaluator results. Conclusion: Mystery shopping as an evaluation method should be reconsidered not only in terms of health problems but also in terms of organizational efficiency and issues of human rights.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.99-108
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• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.

• Nutrition Research and Practice
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• v.16 no.4
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• pp.450-463
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• 2022

BACKGROUND/OBJECTIVES: Adolescents who skip breakfast have an increased prevalence of chronic diseases. Thus, we aimed to evaluate whether the intake of rice-based breakfast had positive effects on blood glucose indices and to determine the possibility of diabetes prevalence in Korean youths who habitually skip breakfast. SUBJECTS/METHODS: In this randomized parallel-group controlled trial, 81 subjects who were suitable for compliance among 105 middle-and high-school students aged 12-18 years who usually skipped breakfast were included in this study (rice-meal group [RMG], n = 26; wheat-meal group [WMG], n = 29; general-meal group [GMG], n = 26). The RMG and WMG received a rice-based breakfast and a wheat-based breakfast for 12 weeks, respectively. The anthropometric indices, blood glucose indices, and metabolites were measured at baseline and the endpoint, respectively. RESULTS: The mean body weights in the RMG, WMG, and GMG groups at the endpoint were 62.44 kg, 61.80 kg, and 60.28 kg, respectively, and the mean body weights of the WMG and GMG groups at the endpoint were significantly higher than that at baseline (P < 0.05). The levels of fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly decreased in the RMG group at the endpoint compared to baseline (P < 0.05, P < 0.05, respectively). The levels of tryptophan and tyrosine in the WMG group at the endpoint were significantly higher than that those at baseline (P < 0.01, P < 0.05, respectively). CONCLUSIONS: Rice-based breakfast has positive effects on fasting insulin levels and HOMA-IR in Korean adolescents who skip breakfast. Additionally, it was found that a skipping breakfast could increase the prevalence of diabetes in adolescents who skip breakfast. Therefore, in addition to reducing breakfast skipping, it is vital to develop a rice-based menu that fits teenage preferences to prevent chronic diseases such as diabetes.