• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.187-189
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• 2022

As the structure and operation method of MASS(Maritime Autonomous Surface Ship) are discussed accroding to the IMO degree, the interest and necessity for remote operators who manage and supervise the operation of MASS are increasing gradually. The form of MASS operation is clearly accompanied by various changes including new technologies and equipment in comparison with the current operation of ship. In IMO Degree 2 and 3, the capabilities that remote operators who will operate them must differ from those of existing seafarers(navigation officers, engineers and ratings). Regarding this remote operation, the NI(Nautical Institute) is the first in the world to present a syllabus and a curriculum of qualification for remote operator. Based on this, the paper introduces and compares the education model of MASS remote control operation and NI model, and further uses it as basic data for the creation of curriculum for future MASS remote operator.

• Advances in aircraft and spacecraft science
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• v.5 no.2
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• pp.277-294
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• 2018

In the space industry, structures undergo several vibration and acoustic tests in order to verify their design and give confidence that they will survive the launch and other critical in-orbit dynamic scenarios. At component level, vibration tests are conducted with the aim to reach local or global interface loads without exceeding the design loads. So, it is often necessary to control and limit the input based on a load criterion. This means the test engineer should be able to assess the interface loads, even when load cannot be measured. This paper presents various approaches to evaluate interface loads using measured accelerations and by referring to mass operators. Various methods, from curve fitting techniques to finite element-based methods are presented. The methods are compared using signals with known imperfection to identify strengths and weaknesses of each mass operator definition.

• Journal of the Korean Mathematical Society
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• v.38 no.2
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• pp.349-363
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• 2001

The analytic in mass operator-valued Feynman integral is related to integration with respect to unbounded set functions formed from the semigroup obtained by analytic continuation of the heat semigroup and the spectral measure of multiplication by characteristics functions.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.347-352
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• 2022

The paper presents how to update impedance control parameters for dual-arm manipulators using EMG signals and motions of the operator. Since the hand motions of the dual-arm are modeled to be the mass-spring-damper system in this paper, the impedance parameter update method is an important issue to reflect the operator's force. However, task space inertia to be used as the mass parameter goes to infinity if the manipulator approaches a kinematic singularity. To alleviate this issue, the impedance (stiffness and damping) parameters are divided with a diagonal element of the task space inertia. Also, the stiffness and damping matrices are updated using the normalized EMG signals captured from the operator's forearm. Through this process, the motion of the dual-arm manipulator is more stabilized even though it approaches the kinematic singularity.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.223-229
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• 1996

a simpel coordinate transformaton method is suggested that converts Schr$\"{o}$dinger's equation involving a position-dependent effective mass in a heterostructure to an equation involving a positon-independent effective mass. This method enables the conceptual study of the effect of the positon-dependent effective mass inserted between the divergence operator and the gradient operator in Schr$\"{o}$dinger's equation. It is also shown that the characteristics such as a transmission coefficient in various heterostructures involving a position-dependent effective masses can be obtained iwth ease by the suggested method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.221-222
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• 2023

국제해사기구(IMO)는 자율운항선박(MASS)의 안전한 운항을 위해 해사안전위원회(MSC), 법률위원회(LEG) 및 해상교통간소화위원회(FAL)에서 협약규정식별작업(RSE)을 완료하고 각 위원회별로 MASS의 안전한 운항을 위한 조치방안에 대해 검토 중에 있다. RSE 결과를 반영하여 향후 MASS Code 개발과정에서 원격운항자(Remote Operator)가 중요한 검토사항이 될 것으로 식별됨에 따라 원격운항자가 갖추어야 할 최저역량에 대해 제시하였다. 또한 MASS Code 개발과정에서 논의될 운항모드(Mode of Operation)에서 원격운항자에게 필요한 역량에 대해서도 검토하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.4
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• pp.217-223
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• 2012

In this note we examine the effects on subnormality of adding a new weight or changing some weights for a given subnormal weighted shift. We consider a subnormal weighted shift with a positive point mass at the origin by means of continuous functions. Finally, we introduce some methods for evaluating point mass at the origin about moment measures associated with weighted shifts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.210-214
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• 2007

A simulation program has been developed to evaluate operator seat vibration for earth-moving machinery and decide whether a seat meets the requirements imposed by ISO 7096. An operator seat is assumed as a linear system composed of a mass, a spring, and a damper mounted on a platform. The program evaluates the transmissibility at resonance, and the SEAT factors for a light person and a heavy person. The developed program can be utilized effectively in designing a new operator seat.

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.23-29
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• 2013

When a human operator interacts with a virtual wall that is modeled as a virtual spring model, the lager the stiffness of the virtual spring is, the more realistic the operator feels that the virtual wall is. In the previous studies, it is shown that the maximum available stiffness of a virtual spring to guarantee the stability can be increased when the first-order-hold method is applied, however the effects of a human impedance on the stability are not considered. This paper presents the effects of a human impedance on stability of haptic system with a virtual spring and a first-order-hold (FOH) method. The human impedance model is modeled as a linear second-order system model. The relations between the maximum available stiffness of a virtual spring and the human impedance such as a mass, a damping and a stiffness are analyzed through the MATLAB simulation. It is shown that the maximum available stiffness is proportional to the square root of the human mass or damping respectively.

• Coupled systems mechanics
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• v.8 no.2
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• pp.129-146
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• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.