• Journal of Korean Society for Quality Management
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• v.51 no.1
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• pp.97-117
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• 2023

Purpose: The purpose of this study is to examine the factors affecting the intention to continue using the metaverse platform service from the user's point of view. Methods: The study conducted a survey of experienced people using Zepeto, Ifland, Gather Town, Zep, Roblox, Fortnite, and Minecraft, which are virtual world types among metaverse types, and valid 415 data were analyzed by SPSS (ver 22.0) and R (ver 4.1.0) program packages. Results: As a result of empirical analysis, it was found that interactivity and social presence among the characteristics of metaverse affected expectation confirmation, and sensory affordance and functional affordance affected expectation confirmation as affordance factors. In addition, all four characteristics of metaverse, reliability, playfulness, interactivity, and social presence, were found to have the greatest affect on perceived usefulness, and it was analyzed that playfulness, social presence, and reliability were influenced in order. The affordance factor was also found to have a positive effect on physical affordance, sensory affordance, and functional affordance. This study was found that it had a positive effect on the relationship between expectation confirmation and satisfaction and the relationship between perceived usefulness and satisfaction. satisfaction was analyzed to lead to continuance intention. Conclusion: This study is meaningful in that it examines the perspective of users who can be called customers of metaverse platform services. Based on the results of this study, it is expected to have a significant effect on the development of metaverse platform services not only on platform operators that provide metaverse platform services but also on providers who plan events and education using metaverse platform services.

• Journal of Welding and Joining
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• v.32 no.3
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• pp.95-101
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• 2014

Joining of grey cast iron by fusion welding has much difficulties for its extremely low ductility and low toughness because of the flake form of the graphite. And the brittle microstructure, i.e. ledeburite may be formed during fusion welding by its rapid cooling rates. By these kinds of welding problem, preheat and post heat treatment temperature must be increased to avoid weld crack or welding problems. In order to avoid these fusion welding problem, friction welding of cast iron was carried out for improving joint soundness, establishing friction welding variables. There is no factor for evaluating friction weldability in continuous drive type friction welding. In this point of view, this study proposed the parameters for calculating friction weld heat input. The results obtained are as follows ; 1. There was a close relationship between tensile strength and flash appearance of friction welded joint. 2. Tensile strength was decreased and flash was severely oxidized as increasing frictional heating time. 3. As increased forging pressure $P_2$, flash had a large crack and tensile strength was decreased. 4. As powdered graphite by rotational frictional force induced flat surface and hindered plastic flow of metal, tensile strength of welded joint was decreased. 5. Heat input for continuous drive type friction welding could be calculated by the factors of $P_1$, $P_2$ and upset distance(${\delta}$).

• Journal of Chest Surgery
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• v.10 no.2
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• pp.299-314
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• 1977

Clinical experience on 16 cases of open heart surgery under the extracorporeal circulation with mild or moderate hypothermia and partial hemodilution technique at the National Medical Center during the period from June 1976 to October 1977. Nine of sixteen were congenital heart disease and seven were acquired heart disease. The age of the patient ranged between 6 and 48 years. The body weight varied from 18.5kg to 60kg and body surface area 0. 79-1.70m2. The average priming volume of pump oxygenator was 2080 ml, which was consisted fresh ACD blood, buffered Hartmann`s solution, Mannitol, 50% dextrose in water and Vit. C. The average hemodilution rate was 27%. The average flow 2.3 L/min/m2 or 80 ml/min and the duration of perfusion varied from 31 min to 270 min with average of 107 min. The perfusion was carried out under the mild or moderate hypothermia using core cooling alone in 10 cases, core cooling and local myocardial cooling with $0-4^{\circ}C$ physiologic saline in 2 cases. From a hemodynamic point of view, the blood pressure dropped down around 80 mmHg after the initiation of perfusion follwed by increase to safety level and stable during the perfusion. The central venous pressure remained within normal limits. In most cases, hemoglobin and hematocrit decreased during and after the perfusion. Hemogiobin level was decreased, average of 20.6 %, hematocrit 18.6%, pletelets 55% postoperatively. Plasma hemoglobin increased moderately, from preperfusion average valve of 7.79 mg % to post-perfusion value of 54.7 mg %. Electrolytes changes during cardiopulmonary bypass showed definite hypokalemia but changes of Na, Ca were not definite. Arterial blood gas analysis during cardiopulmonary bypass suggested that the metabolic acidosis which was accompanied by respiratory alkalosis which was corrected postoperatively. As the opera tive complication, transient hemoglobinuria in 4 cases and neurological signs in 2 cases were all cured. There were 2 death cases and operative mortality rate was 12.5%.

• Earthquakes and Structures
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• v.13 no.2
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• pp.165-176
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• 2017

Multi-Axial Testing System (MATS) is a 6-DOF loading system located at National Center for Research on Earthquake Engineering (NCREE) in Taiwan for advanced seismic testing of structural components or sub-assemblages. MATS was designed and constructed for a large variety of structural testing, especially for the specimens that require to be subjected to vertical and longitudinal loading simultaneously, such as reinforced concrete columns and lead rubber bearings. Functionally, MATS consists of a high strength self-reacting frame, a rigid platen, and a large number of servo-hydraulic actuators. The high strength self-reacting frame is composed of two post-tensioned A-shape reinforced concrete frames interconnected by a steel-and-concrete composite cross beam and a reinforced concrete reacting base. The specimen can be anchored between the top cross beam and the bottom rigid platen within a 5-meter high and 3.25-meter wide clear space. In addition to the longitudinal horizontal actuators that can be installed for various configurations, a total number of 13 servo-hydraulic actuators are connected to the rigid platen. Degree-of-freedom control of the rigid platen can be achieved by driving these actuators commanded by a digital controller. The specification and information of MATS in detail are described in this paper, providing the users with a technical point of view on the design, application, and limitation of MATS. Finally, future potential application employing advanced experimental technology is also presented in this paper.

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.181-188
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• 2019

People can easily use a shared economic service system based on ICT technology. Most of the shared economic services are provided by private companies, and discussion on public goods is insufficient. If we look at the current shared economic service from the point of view of courier service, $\ddot{U}ber^{\prime}s$ system can be an alternative. The post office courier service uses ICT technology but differs from the service of the shared economy. This study uses Delphi analyzer method and AHP methodology to derive important factors in introducing shared economic system. As a result, socioeconomic characteristics were found to be the most important in the upper tier, and the shared economic platform, sharing of idle resources, popularization of smartphone, and increase of e - commerce were the four important factors in the lower tier. In order to maximize efficiency, which is the essence of the shared economy, the necessity of introduction into the shared economic system and important factors in the introduction of public goods are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.952-958
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• 2011

Industrialization played an important role in modernization and the birth of modern architecture. The changes caused by the industrialization and people's faith in its output are reflected in an attempt to associate the concepts and process of architecture with industrialization. In the course of incorporating architecture into the industrialization process, it became necessary to understand the architecture from practical point of view connecting it directly with scientific technology rather than in the context of historical tradition in the past. Understanding architecture as a kind of industrial production signifies two concepts. One is regarding perception of architectural outputs. The other is regarding the intention to proceed architectural process as a process of industrial production. The purpose of this study is to review the changes in the architecture influenced by industrialization from post-industrialization through early modern period and to analyze its significance and influence.

• Journal of Families and Better Life
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• v.27 no.1
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• pp.61-71
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• 2009

The purpose of this study was to resolve the issues of inferior housing environment and the population decrease in rural community by improving the environment and attracting urban inhabitants. A simulation on the costs and the local programs was operated from a point of view that Pension Insurance House with Long-term Lease and a plan for the program in connection with local resources should be accompanied to attract urban inhabitants. The study was carried out through mainly documents analysis and specialists' opinions. The simulation results are as follows. Firstly, the pre-existing rural housing development projects have only emphasized the hardware, while underestimated the post-management with operating programs. The software should be underlined when Pension Insurance House is developed. Secondly, as a result of the simulation on construction expenditure and the operating and maintenance cost for 30 years, about 82.3 million Wons are necessary residential expenses for 15 years per unit. Thirdly, in case of MUJU County, it has made the most of its pre-existing institutions. It's medical institutions provide medical care system with health education, facilities related leisure and culture offer recreational programs and the local community center and its program of each town helps new habitants adopt to the rural life. Additionally, the employment project of a local welfare center allow people living in a rural community to continue their careers with their talents and interests through local class programs for a life worth living. Lastly, guide for getting information of rural life, local community gathering and preliminary education should be carried out to reduce expectant tenants' incompatibility and assist them settle down early. The community program expansion is also required at the local government level.

• Korean Journal of Remote Sensing
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• v.27 no.3
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• pp.379-388
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• 2011

At present, GEOBIA (Geographic Object-based Image Analysis), heir of OBIA (Object-based Image Analysis), is regarded as an important methodology by object-oriented paradigm for remote sensing, dealing with geo-objects related to image segmentation and classification in the different view point of pixel-based processing. This also helps to directly link to GIS applications. Thus, GEOBIA software is on the booming. The main theme of this study is to look into the applicability of geo-spatial processing open source to GEOBIA. However, there is no few fully featured open source for GEOBIA which needs complicated schemes and algorithms, till It was carried out to implement a preliminary system for GEOBIA running an integrated and user-oriented environment. This work was performed by using various open sources such as OTB or PostgreSQL/PostGIS. Some points are different from the widely-used proprietary GEOBIA software. In this system, geo-objects are not file-based ones, but tightly linked with GIS layers in spatial database management system. The mean shift algorithm with parameters associated with spatial similarities or homogeneities is used for image segmentation. For classification process in this work, tree-based model of hierarchical network composing parent and child nodes is implemented by attribute join in the semi-automatic mode, unlike traditional image-based classification. Of course, this integrated GEOBIA system is on the progressing stage, and further works are necessary. It is expected that this approach helps to develop and to extend new applications such as urban mapping or change detection linked to GIS data sets using GEOBIA.

• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.383-390
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• 2024

When measuring the radiated noise of an underwater vehicle, the range information between the vehicle and the receiver is an important factor, but since Global Positioning System (GPS) is not available in underwater, an alternative method is needed. As an alternative, the range is measured by estimating the arrival time, arrival time difference, and arrival frequency difference using a separate acoustic signal. However, errors occur due to the channel environment, and these outliers become obstacles in continuously measuring range. In this paper, we propose a method to reduce errors by curve fitting with a function in the form of a V-curve as a post-processing to remove outliers that occurred in the process of measuring range information. Simulation, lake and sea trials were conducted to verify the performance of the proposed method. In the results of the lake trial, the range estimation error was reduced by about 85 % from the Root Mean Square Error (RMSE) point of view.

• International Area Studies Review
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• v.14 no.2
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• pp.297-323
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• 2010

The distinguished feature of the economic relationship between China and Africa during the cold war is the one that there was economic point of view at all even though such a huge trade between the two countries. It was caused by purely ideological and political purpose of China. because of the giant stream of time which is called as 'the cold war', it has been replaced with other conceptions: 'aid' or 'support.' Since the end of the cold war, however, the relationship between China and Africa has been showing noticeable features; political and ideological purposes are getting less meaningful or excluded completely. In 1990, China was based on the pragmatism, which is a rigorous sense of economy, and Africa was getting popular as an emerging market, which is not only performing as a stable energy supplier but also making trade and direct investment is possible. Also, it has implications for Korea that seriously considers putting more efforts into expanding its influence on all over the trade relations which includes investment and import-export in the emerging market: Africa.