• Proceedings of the KSME Conference
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• 2001.06b
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• pp.241-246
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• 2001

This paper introduces modeling and solution for the dynamics of pipeline inspection gauge (PIG) flow in natural gas pipeline. Without of bypass flow, the dynamic behavior of the PIG depends on the different pressure between the rear and nose parts, which is generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. With bypass flow, the PIG dynamics also depends on the amount of bypass flow across its body. The mathematical model are derived for unsteady compressible flow of the PIG driving and expelled gas, and for dynamics of the PIG. The bypass flow is assumed to be incompressible with the condition of its Mach number smaller than 0.45. The method of characteristic (MOC) and the Runge-Kutta method are used to solve the system governing equations. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. The simulation results show that the derived mathematical model and the proposed solution are effective for estimation the dynamics of the PIG with and without bypass flow under given operational condition.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.3
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• pp.5-24
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• 2010

The public library is the local centre and gateway of knowledge and information. Therefore, the library should be funded and operated by local government and the governing body will be responsible for matters of policy of the library. However, recently public libraries in Korea have faced enormous policy challenges such as the damage of its identity, outsourcing or contracting-out of management, and the general chaos of its administrative system. This paper aims to analyze the current level of infrastructure and policies of public libraries and to review the wrong path and the right path of library policies focused on establishing a library foundation and outsourcing library management in Seoul and Incheon.

• Advances in aircraft and spacecraft science
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• v.5 no.3
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• pp.335-348
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• 2018

The structural dynamics (SD) behavior of Elastic Flapping Wings (EFWs) is investigated analytically as a novel approach in EFWs analysis. In this regard an analytical SD solution of EFW undergoing a prescribed rigid body motion is initially derived, where the governing equations are expressed in modal space. The inertial forces are also analytically computed utilizing the actuator induced acceleration effects on the wing structure, while due to importance of analytical solution the linearity assumption is also considered. The formulated initial-value problem is solved analytically to study the EFW structural responses, where the effect of structure-actuator frequency ratio, structure-flapping frequency ratio as well as the structure damping ratio on the EFW pick amplitude is analyzed. A case study is also simulated in which the wing is modeled as an elastic beam with shell elements undergoing a prescribed sinusoidal motion. The corresponding EFW transient and steady response in on-off servo behavior is investigated. This study provides a conceptual understanding for the overall EFW SD behavior in the presence of inertial forces plus the servo dynamics effects. In addition to the substantial analytical results, the study paves a new mathematical way to better understanding the complex role of SD in dynamic EFWs behavior. Specifically, similar mathematical formulations can be carried out to investigate the effect of aerodynamics and/or gravity.

• Advances in nano research
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• v.13 no.3
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• pp.297-312
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• 2022

Coughing and breath shortness are common symptoms of nano (small) cell lung cancer. Smoking is main factor in causing such cancers. The cancer cells form on the soft tissues of lung. Deformation behavior and wave vibration of lung affected when cancer cells exist. Therefore, in the current work, phase velocity behavior of the small cell lung cancer as a main part of the body via an exact size-dependent theory is presented. Regarding this problem, displacement fields of small cell lung cancer are obtained using first-order shear deformation theory with five parameters. Besides, the size-dependent small cell lung cancer is modeled via nonlocal stress/strain gradient theory (NSGT). An analytical method is applied for solving the governing equations of the small cell lung cancer structure. The novelty of the current study is the consideration of the five-parameter of displacement for curved panel, and porosity as well as NSGT are employed and solved using the analytical method. For more verification, the outcomes of this reports are compared with the predictions of deep neural network (DNN) with adaptive optimization method. A thorough parametric investigation is conducted on the effect of NSGT parameters, porosity and geometry on the phase velocity behavior of the small cell lung cancer structure.

• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.751-764
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• 2023

In practical engineering such as aerial refueling pipes, the boundary of the fluid-conveying pipe is difficult to be completely immovable. Pipes under movable and immovable boundaries are controlled by different dominant nonlinear factors, where the boundary mobility will affect the nonlinear dynamic characteristics, which should be focused on for adopting different strategies for vibration suppression and control. The nonlinear dynamic instability characteristics of functionally graded fluid-conveying pipes lying on a viscoelastic foundation under movable and immovable boundary conditions are systematically studied for the first time. Nonlinear factors involving nonlinear inertia and nonlinear curvature for pipes with a movable boundary as well as tensile hardening and nonlinear curvature for pipes with an immovable boundary are comprehensively considered during the derivation of the governing equations of the principal parametric resonance. The stability boundary and amplitude-frequency bifurcation diagrams are obtained by employing the two-step perturbation- incremental harmonic balance method (TSP-IHBM). Results show that the movability of the boundary of the pipe has a great influence on the vibration amplitude, bifurcation topology, and the physical meanings of the stability boundary due to different dominant nonlinear factors. This research has guidance significance for nonlinear dynamic design of fluid-conveying pipe with avoiding in the instability regions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1232-1236
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• 2004

In the Far-Eastern traditional medicine, Oi[Energy] implies a wide range of meaning and is emphasized. There is nothing that is not related to this Qi, as seen in physiology, pathology, the relationship between human body and nature, the movements of intestines and gyeongnak[energy networks], the process of outbreak and change of illness, remedial laws, the features and effects of drugs, and so on. Accordingly, Nei Jing also says, 'every sickness arises from OL' The Qi has multi-meanings, and each of lots Of past physicians researched and analyzed it in different perspective, thus making the Qi-theories much richer. Still. there were not so many physicians who discussed the theme of Daqi. The denomination of Daqi is seen in Nei Jing and Jin Gui Yao Lue, and the physicians like Yu Chang in Ming dynasty and Zhang Xi Chun in Cheng dynasty, etc. applied and utilized Daqi by exploring its functional actions for human life and associating it with clinical practices. Yu Chang said that Daqi is Xiong Zong Yangqi[Positive Energy in Breast] governing every Qi, and that if this Qi is full, it spreads through body and protects the body from sickness, and vice versa. Summarizing his researches on the Daqi in Jin Gui Yao Lue and on the opinions of Yu Chang as well as his experiences, Chang Xi Chun maintained that the Qi accumulated in breast must be named Daqi, which constitutes the contents of Zongqi[Chief Energy] mentioned in Nei Jing. Once the Qi is vacant, breathing is not smooth, whole body is enervated, spirit becomes dim, thinking ability falls drastically. Furthermore, if the Qi is extremely vacant or more worsens, breathing stops. And he prescribed the medicines including Sheng Xian Tang as remedies against the symptom of Daqi XiaXian[Fall in Great Energy]. The recognitions of Daqi by Yu Chang and Zhang Xi Chun are consistent with each other. At any rate, their theories and prescriptions may be high in practical value in contemporary clinics.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.143-150
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• 1996

This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

• The Korean Journal of Archival Studies
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• no.28
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• pp.155-180
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• 2011

This study presents how to vitalize the record management of the provinces by investigating the current issues and by identifying the universality and the distinctiveness of the record management in local agencies. However, it only deals with the system of the record management, focusing on the history of the provinces. Although the related projects conducted by the provinces of Korea consist of various types, including publishing the local history, creating the activities of local cultural institutes, and collecting and organizing the historical records, these have not been active in many regions with insignificant achievements. In this regard, local self-governing bodies need to actively fulfill the duty of the management not only for the administrative archives but also for the historical archives by aggressively interpreting the associated parts suggested by the Act on the Management of Public Archives. Ultimately, it is proper to integrate theses two functions. Moreover, an effective collection is the core part of the record management of history. Therefore, a 'committee' with experts should provide in-depth views from planning to post-processing stages. Meanwhile, a consensus on the importance and the necessity of the historical archive management between owners and concerned parties should be formed during the collection process. In conclusion, each local autonomous entity should make sure of the active record management of history through establishing their own mid to long-term development plans, securing experts in archive management, as well as providing the service for record contents.

• Korean Journal of Environment and Ecology
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• v.27 no.3
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• pp.405-412
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• 2013

The aim of this study was to suggest fundamental data for managing forest trail efficiently from the aspect of users near metropolitan city of Daegu, and to reveal the differences in visiting motivation and satisfaction on forest trail between regional users and distant users, which based upon the convenience of accessibility. As a result of questionnaire survey on the users of forest trail, it was revealed that they mostly visited recreational and therapeutic purposes. Most users were also satisfied with forest trail experiences without any differences between groups. Regarding to trail facilities, however, regional users within 30 minutes distances from the trail were significantly dissatisfied with the facilities. It was suggested that improving facilities and programs for recreational and therapeutic purposes should be established for regional users in the policy of self governing body.

• Journal of Arbitration Studies
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• v.14 no.2
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• pp.135-172
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• 2004

While doing business in China foreign companies occasionally find themselves embroiled in disputes with Chinese individuals, companies or the Chinese Government. There are three primary ways to resolve a commercial dispute in China are negotiation, arbitration and litigation. The best way of dispute resolution is negotiation as it is the least expensive method and the working relationship of both parties concerned in dispute. But negotiations do not always give rise to resolution. Arbitration is the next choice. Unless the parties concerned can agree to resort to arbitration after the dispute has arisen, the underlying contract namely, sales contract or separate agreement must show that disputes will be resolved by arbitration. Agreements to arbitration specify arbitration body and governing law. There are two Chinese government -sponsored arbitration bodies for handling cases involving at least one foreign party: China International Economic and Trade Arbitration Commission(CIETAC) and China Maritime Arbitration Commission(CMAC) for maritime disputes. Contracts regarding foreign companies doing business in China often designate CIETAC arbitration. CIETAC distinguishes between two kinds of dispute resolutions, foreign-related arbitration and domestic arbitration. For a dispute to be classified as foreign-related arbitration, one of the companies must be a foreign entity without a major production facility or investment in China. CIETAC has published rules which govern the selection of a panel if the contract does not specify how the choice of arbitration will be handled. CIETAC's list of arbitrators for foreign-related disputes, from which CIETAC's arbitrators must en chosen, includes may non-Chines arbitrators. But many foreign experts believe that some aspects of CIETAC needs to be improved. The purpose of this paper is to improve the understanding of arbitration in China, CIETAC by way of studying the current situation and improvement of international commercial arbitration in China.