• The Journal of Korean Institute of Communications and Information Sciences
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• v.2 no.1
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• pp.20-28
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• 1977

The shipping business which consistutes main stream of foreign trades in the world desires more larger and higher speed ships to convey a large amount of cargo at a time rapidly and safely. They also want to introduce new techniques into transportation system so to meet the rapid growing demand of maritime mobile communications with the improvement of efficiency of radio apparatus and reduction of the hard labors of radio operators mechanization and modernization of radio apparatus is necessary. Now HF band is used mainly for communications between maritime mobile stations and coast stations but the quality of received signal is not so good and the coverage is not sufficient by the condition of propagation of waves. There is also limitation of channel capacity in HF band. So to cope with or improve of these defects and meet the demands of modern maritime communication it is essential to introduce maritime satellite communication system in this field. By using the maritime satellite we can establish high quality communication circuits as maritime Telex, Faximile, high speed data transmission line and can expand coverages. Therefore industrial rationalization of marine transportation is possible with the reduction of painful labors of radio operators by improving safety and promoting of efficiency of movement of ships and freights. Obviously it is prospected that the introduction of maritime satellite communication system will bring a rapid promotion of its usuage in maritime mobile communication field and also anticipated that maritime satellite communication system will be a main current in maritime mobile communication field over the world in the near future with moderated cost of transmission links as in the case of INTELSAT in the past 10 years after its first launching.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.74-81
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• 2015

As one of urban infrastructure system, the electricity substation is critical for urban life and industrial activity as the electricity demands get higher than ever. However the substation is generally regarded as unpleasant or dangerous facility, which finally results in the continuous opposition movement by resident due to the belief of unidentified negative effect in apartment prices. Accordingly, as the scientifically objective and quantitative analysis is required to solve the social conflict, this study intends to examine the variation affected by urban infrastructure system, expecially for substation. After the independent variable defining the price of apartment and the dependent variable, which is apartment price, are identified and their spatial data has been filed, the forecasting model has been developed through the hedonic price function as well as artificial neural networks system. The research finding indicated that the spatial range affected by substation is not notable and the range of some case was applicable for less than 600m. It is expected that these research findings can be applied for establishing the one of solid cases for the analysis of economical effect to local housing market by the urban infrastructure system.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.163-174
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• 2012

This study was conducted to seek improvements by correcting problems of the qualification system of theatrical art technicians, which has a relatively weak foundation, compared to other national industrial qualifications. Through the previous researches, this study attempted to seek main issues and development plans in the field of theatrical art technology, while carrying out in-depth interviews for theatrical art technicians. With the results of this study, problems of the existing system can be largely divided into two kinds. Firstly, the existing system is mostly focused on performance places, especially large-sized public performance halls. Secondly, as a problem in terms of management, the existing system has non-professional management subjects and non-convenience regarding the number of qualification tests and places only in Seoul and once a year. This study grasped problems based on practical demands of the related industry through in-depth interviews with experts, thus seeking proper solutions. What matters most is that the present system should be converted from performance place-centered management to performance-centered management. In other words, by expanding qualification-acquired experts into all the performances, the system should practically contribute to improving the quality of performances and expanding the treatment of experts, which is the fundamental purpose of this system. Moreover, it is needed to seek a plan to expand the convenience of applicants for the procedures and methods of acquiring qualifications.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.263-271
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• 2017

The application of mass spectrometry to polymer science has rapidly increased since the development of MALDI-TOF MS. This review summarizes current polymer analysis methods using MALDI-TOF MS, which has been extensively applied to analyze the average molecular weight of biopolymers and synthetic polymers. Polymer sequences have also been analyzed to reveal the structures and composition of monomers. In addition, the analysis of unknown end-groups and the determination of polymer concentrations are very important applications. Hyphenated techniques using MALDI-tandem MS have been used for the analysis of fragmentation patterns and end-groups, and also the combination of SEC and MALDI-TOF MS techniques is recommended for the analysis of complex polymers. Moreover, MALDI-TOF MS has been utilized for the observation of polymer degradation. Ion mobility MS, TOF-SIMS, and MALDI-TOF-imaging are also emerging technologies for polymer characterization because of their ability to automatically fractionate and localize polymer samples. The determination of polymer characteristics and their relation to the material properties is one of the most important demands for polymer scientists; the development of software and instrument for higher molecular mass range (> 100 kD) will increase the applications of MALDI-TOF MS for polymer scientists.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.612-618
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• 2019

In the unmanned vehicle industry, the market is exploding due to the rapid development of public and private demands along with the technological development of the 4th Industrial Revolution. In addition, unmanned mobiles are being used for communication services. In this paper, we analyzed the communication performance of unmanned aerial vehicle according to the characteristics of Doppler frequency. The Doppler frequency was calculated using the geometric model of the unmanned aerial vehicle, and the Doppler frequency of 10km, 30km, 300km, 1000km per hour and the BER performance by AWGN were measured by considering the unmanned high speed unmanned vehicle based on the position of the controller. The Doppler frequency model uses a Dent model and adds additive white Gaussian noise (AWGN) to check the bit errors of the transmitter and receiver. Low speed unmanned vehicles generally exhibited a BER performance of 0.2, while high speed unmanned vehicles generally exhibited a BER performance of 0.06. As the frequency band increases at the same speed, the BER performance increases, and when the speed increases in the same frequency band, the BER performance decreases. This is confirmed by the simulation results to predict theoretically predictable BER performance. In the frequency bands of 2.6 GHz, 5 GHz, and 28 GHz, the BER characteristics by Doppler frequency and the BER characteristics by controller function are verified. effect was confirmed.

• 대한공업교육학회지
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• v.34 no.1
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• pp.19-43
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• 2009

An ideology what a modern society seeks is lifelong employment through lifelong learning. The single word which draws the attainment is lifelong vocational competency development. This study is designed for exploring its possibility and limit of a redesign of it, and tries to propose efficiently a redesign idea of a vocational educational path. To this end, it was analyzed by a subject for a national human resource foundation plan and a lifelong bocational competency development foundation plan. In addition to that, it was covered a structure and content analysis of main laws and regulations which are a base of policy making. An educational path could be divided into an area of formal education system, an area of workplace for labors, and an area of lifelong vocational competency development. And the insights were drawn by pulling apart an operational situation of main organizations and a recurrent process of the educational path. The redesign plan of a vocational education path we did analyze to activate lifelong vocational competency development system is deduced as following. Firstly, it should be re-organized with a direction towards an effective manpower training to be linked with skills and demands required by an industry. Secondly, it should be generalized for a model of recurrence between work and learning and its alternation for lifelong vocational competency development. Thirdly, it should create a cluster in the region for lifelong vocational competency development so that it is to form an efficient network to have a division of labor and its liaison with cooperative relationship.

• 대한공업교육학회지
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• v.38 no.2
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• pp.136-155
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• 2013

The purpose of this study is to analysis the recognition of engineering professionals in Primary and middle school education. For the study, survey was proceeded through experts in engineering. The result of research follows. First, experts in engineering recognized that engineering has a significant impact in the national economic development and competitiveness. Experts in engineering, had a recognition consistent to some extent for engineering. and we have found engineering's own characteristics that emphasize "problem solving and design, innovation and creativity, economy optimization". Second, experts in engineering recognized that engineering education in Primary and middle school rarely take place, and also does not provide enough information for students. Third, experts in engineering recognized that engineering education is very needed in Primary and middle school. Through this, students can understand creative design problem-solving process. In addition, Experts of engineering, have a variety of educational demands for School level to the level of engineering education should start, level educational purposes, how to apply effective and so on.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.2
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• pp.71-81
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• 1987

Nowadays, the high development of industrial technique demands the optimal design of marine structures to be welded under the water, because the underwater welding of the ship hull and marine structures can decrease manpower and cost of production. However there is not available at present any report on fatigue behavior about underwater welded joints. In this paper under tention- tension repeated fatigue stress with frequency of 10 cycles per second by local controlled system, the fatigue strength properties of underwater welded joints of SM41A-2 Plate-to-Plate of 10 mm thickness were experimentally examined. The results obtained were as follows : 1) The fatigue strength of underwater welded joints of SM41A-2 was peaked at the heat input of about 1, 400 joule/mm(180 A, 36 V), while, at the heat input of more than about 1, 100 joule/mm (160 A, 33 V) that of the underwater welds at the higher than cycle of life rather than the lower cycle was higher than that of the base metal but lower than that of the atmosphere welds on account of both cooling and notch effects. 2) The fatigue limit of underwater welds increased with an increase of heat input resulting in a peak of that at the heat input of about 1, 400 joule/mm and then decreased gradually. 3) The fatigue strength at N cycles was peaked between the heat input of about 1, 400 and 1, 700 joule/mm where the strain was rapidly increased. 4) It was confirmed that the optimal zone of heat input condition for obtaining the underwater welds fatigue strength higher than that of the base metal exists, and if out of this zone, the fatigue strength of the underwater welds was lower than that of the base metal because of lack weld penetration, inclusion of slag, voids, etc. 5) By the fatigue test, the underwater welds fractured brittly without visual deformation, so the strain was remarkably less than of the atmosphere welds. 6) The fatigue life factor was peaked at the heat input of about 1, 600 joule/mm (200 A, 36 V) at which the mean strain is a little higher than that of the base metal but quite lower than those of the atmosphere welds, resulting in good underwater welds because both fatigue strength and ductility of the underwater welds are higher than those of the base metal at such heat input.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.117-124
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• 2017

In the face of current environment of changing markets and increasing competition, regional financial institutions are also attempting to meet the needs of customers using various methods such as offering new services that satisfy customer demands. This study seeks to determine for regional financial institutions which service products and quality factors affect customer satisfaction and loyalty, and compare service products and service quality sources with the goal of observing the comparative importance of each service factor. This sample is conducted by visiting customer survey from October 7th to October 30th, 2015 to Korea Credit Union Cooperative Association and Seoul Consumer Association. The sample is analyzed as follows. interest rate, deduction, insurance and welfare business had a significant effect on customer satisfaction level among the commodity factors of local financial institution, and accessibility, professionalism and empathy affect service satisfaction level. Second, customer satisfaction has a significant effect on customer loyalty. In addition to the interest rate and professionalism factors, it is analyzed that deductions, insurance and welfare projects and empathy are important factors in the local financial institutions contributing to the local economy while providing financial convenience to local residents. This study suggests key points that regional financial institutions can use to differentiate their image in the competitive financial markets.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.1049-1064
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• 2005

The demands of increasingly complicated software have led to the proliferation of object-oriented design methodologies in embedded systems. To execute a system designed with objects in target hardware, a task set should be derived from the objects, representing how many tasks reside in the system and which task processes which event arriving at an object. The derived task set greatly influences the responsiveness of the system. Nevertheless, it is very difficult to derive an optimal task set due to the discrepancy between objects and tasks. Therefore, the common method currently used by developers is to repetitively try various task sets. This paper proposes Scenario-based Implementation Synthesis Architecture (SISA) to solve this problem. SISA encompasses a method for deriving a task set from a system designed with objects as well as its supporting development tools and run-time system architecture. A system designed with SISA not only consists of the smallest possible number of tasks, but also guarantees that the response time for each event in the system is minimized. We have fully implemented SISA by extending the ResoRT development tool and applied it to an existing industrial PBX system. The experimental results show that maximum response times were reduced $30.3\%$ on average compared to when the task set was derived by the best known existing methods.