• Journal of Electrical Engineering and Technology
• /
• v.12 no.5
• /
• pp.1902-1915
• /
• 2017

This paper presents the evaluation of a three-phase three-level DC-DC converter which achieves the soft switching condition for all switches in the circuit and uses the phase-shift PWM strategy to adjust electric power at the output side. According to the analysis, the operation modes can be categorized into two cases: in the first case, where the phase shift angle is less than 120 degrees and in the second case, where the phase shift angle is more than 120 degrees. The outer switches of the circuit operate under ZVS condition and the inner switches operate under ZVZCS condition. It has been discovered that under ZCS condition of the inner switches, when the blocking capacitors decrease, they make the voltage across the blocking capacitor higher so the current reduce rapidly. A three-phase three-level DC-DC converter has a maximum efficiency of 93.5% when its load is of 5.7 kW. The results from the experiment have been compared to the results obtained by the $MATLAB^{(R)}$ simulator in order to confirm the validity of the proposed converter.

• Korean Institute of Interior Design Journal
• /
• v.14 no.4 s.51
• /
• pp.122-133
• /
• 2005

This study could begin with the improvement of computer graphic technology The graphic technology is the standards of computer technology level and up-to-date technology intensive. Above all, the technology of virtual reality has developed rapidly and the development of the program has changed from professional one only for the experts to easy of access ones for the space designers. Moreover, the program which major internet user's can experience the virtual model has been made, as the development of virtual reality technology that is based on the web. These graphic technology and the development of the web helped to extract human experiences on the space design step. However, to find the meeting point with real recognition is not easy though the virtual reality technology develops. Because the real space is made up of various senses that people feel in their surroundings. But, this study was possible because most of the space recognition is based on the visual organ, even though it can't satisfy all sensible factors that we feel in reality. Therefore, the significant of this study is the standards and criteria of evaluation, the technological proposal, expecting to make more advanced alternative design than before.

• Management & Information Systems Review
• /
• v.2
• /
• pp.311-334
• /
• 1998

By decreasing in CPU price and development of computer assembling technology, personal computer fake a good chance to accelerate its supply. Recently, as being introduced new computing technology so called multi media, teaming assist system which is based on single media such as studying book, cassette tape, video tape, or something else is rapidly being replaced by new assist education system based on multi media in which it is operated by the personal computer. In the computer assist education system, there is an evaluation module which appraise learner's study level into the next study strategy. At the view of this point, this part is very important. In this part, there are some factors like Importance, complexity, or difficulty which commonly include fuzzy factors in our surrounding. But until now, we are still out of the level to handle the evaluation module adequately among the some studies. In this study, we would like to suggest a new module that evaluate learning achievement of ICAI which have a variety of fuzzy environment. We combine Independent fuzzy environment like importance, complexity, difficulty into making total evaluation of learner's achievement. By the result, with expressing by linguistic form, this study can provide the theoretical basis in which we will be able to carry out sentence toward evaluation among elementary school.

• Journal of Korean Institute of Industrial Engineers
• /
• v.41 no.5
• /
• pp.481-487
• /
• 2015

In the product development stage, it is very important to ensure demanded quality level before moving to the full-scale manufacturing. For example, in developing guided weapons, live-fire tests are required to verify the final performance of the weapons which are very expensive. The quality evaluation of the guided weapons needs destructive testing, which makes it necessary to test as small number of samples as possible. This paper presents sampling inspection plans and calculating system for finite population guided weapons, which can meet the demanded quality level and confidence level with the minimum number of performance tests. The result of this paper can be useful for any kind of costly destructive testing.

• The Journal of Society for e-Business Studies
• /
• v.12 no.2
• /
• pp.155-194
• /
• 2007

Currently, Ubiquitous Computing Technology(UCT)-based service scenarios play an important role in estimating the potential of UCT-based service. The purpose of the study is to propose a multidimensional evaluation(ME) methodology for UCT-based service scenarios regarding their possibilities of realization for the future. Our approach contributes to extend service level management in Information Technology Service Management(ITSM) by evaluating the level of a new service in advance. ME consists of three dimensions: technological evaluations, business-oriented evaluations, and user-oriented evaluations. The three types of evaluations are mutually harmonized to check the overall possibility of realization and validity for certain UCT-based service scenarios. Theoretically, ME is developed to overcome the extant evaluation methods for UCT-based service scenarios, which are limited in the number of evaluation criterions. It is also conceived to cope with the limitation of economical evaluation methods (e.g., technological valuation, estimation of financial outcomes such as ROI, ROA, etc. that are difficult to give meaningful results because most of UCT-based services are not fully realized so far. From the practical perspectives, in addition, our approach can be applied to a variety of scenarios due to its domain-independent approach.

• Environmental Analysis Health and Toxicology
• /
• v.30 no.sup
• /
• pp.2.1-2.11
• /
• 2015

Objectives This study presents a methodology that enables a quantitative assessment of green chemistry technologies. Methods The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of "greenness" i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. Results The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. Conclusions The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.36 no.2
• /
• pp.317-324
• /
• 2016

This paper is to provide information for quantitative evaluation of suspension bridge engineering and construction technology, technology development, and long-span bridge R&D agenda. Technology classification structure and key words are established and survey to identify technology level is performed. Then, competitiveness of patents and journal articles is evaluated for Korea, USA, Japan, Germany, France, and England. As a result, USA and Japan are generally competitive countries for all technology categories based on patents and journal articles. Korea is grouped in upper-middle class for overall technology level of suspension bridge. However, there are some variances among the level of technologies. This research results could be utilized as reference to establish future long-span bridge R&D. Also, it can be a standardized methodology to compare technology levels among countries.

• International Journal of Knowledge Content Development & Technology
• /
• v.8 no.1
• /
• pp.51-77
• /
• 2018

This study aimed to determine eco-friendly factors on the aspects of library service, materials provided or handled by the library, and programs including educational programs. Furthermore, it was setup to perform a trial evaluation for the eco-friendliness of the library based on the determined evaluation standards by this study. Results are as follows; First, regarding the question of 'Do employees of the library think that establishment of green libraries is necessary?', the employees of the libraries responded yes by 65.52%, but only 4.6% responded that it would not be necessary. Second, in analyzing the most important evaluation areas of green libraries according to the opinions of the libraries' employees, they were ranked in order: the indoor environment, energy and prevention of environmental pollution, and material and resource areas. Third, 11 areas were determined to evaluate the level of greening in the libraries; the highest averages were scored 510 for the area of energy and prevention of environmental pollution, 415 for the area of library resource, and 320 for the area of indoor environment. Last, the libraries were graded based on actual data according to the results to measure the level of greening, two libraries were graded as Diamond, the highest grade, accounting for 15.39% of all libraries; Gold and Silver grades accounted for another 15.39%, together five Certified graded libraries accounted for 38.46%, which was the highest rate among the libraries. Any library scoring less than 20% when compared to the full score was graded as Non-certified, and one library, which scored 15.06% fell into this category. The results of this study set up to serve as basic data for the direction of development for green libraries in our country, as well as reference for the employees of libraries in constructing or remodeling library buildings, establishing service infrastructure, providing information service, and planning library duties in an eco-friendly way.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.27 no.3
• /
• pp.221-227
• /
• 2022

The reliability improvement of PV systems is an important factor in reducing the cost of PV energy because it is closely related to the annual energy production as well as the maintenance cost of PV systems. The reliability of PV inverters plays a key role in the reliability of PV systems because it is regarded as one of the most reliable critical parts of PV systems. The lifetime evaluation of PV inverters considering the mission profile in the design phase plays an important role in reliability design to ensure the required lifetime of PV inverters. In this paper, the lifetime of representative single-phase T-type and I-type NPC inverters are comparatively evaluated by considering the mission profile of a PV system recorded at Iza, Spain. Furthermore, the effect of the pulse width modulation methods on the lifetime is also discussed. The lifetime evaluation of PV inverters is performed at the component-level first and then the system level by considering all power devices.

• Journal of Korea Technology Innovation Society
• /
• v.12 no.1
• /
• pp.137-164
• /
• 2009

As a means to address the modes of developing institutional evaluation system aimed at improving performances of GRIs, this study looked into the influential relations where institutional evaluation system has an impact on receptivity of evaluation outcomes and performances of institutes optimize their performances. After making analysis, it was confirmed that the National Research Council for Economics, Humanities and Social Sciences' institutional evaluation system for GRIs had a positive (+) influence on performances of research institutes, and receptivity of evaluation outcomes is related to performances of research institutes. In addition, it was also confirmed that institutes with high performances, in general, have high level of receptivity of evaluation outcomes along with positive recognition of institutional evaluation system. However, weaknesses of the Council's institutional evaluation system for GRIs resulted in low level of receptivity amongst GRIs, and thus there is limitation on the government and the Council in the active utilization of evaluation outcomes. Finally, it addressed the limitations and areas for improvement in relation to research outcomes.