• Communications of the Korean Mathematical Society
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• v.16 no.1
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• pp.67-73
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• 2001

We classify self-converse oriented trees into two types, namely, bicentral self-converse oriented trees and central ones, according to their centers and characterize these tow types. Using characterizations and Polya enumeration theorem, we derive the ordinary generating function for self-converse oriented trees.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.11
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• pp.95-103
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• 1997

A robust center estimation tecnique of n-fold engineering parts is presented, which use self-organizing neural networks with generating and merging learning for training neural units. To estimate the center of the n-fold engineering parts using neural networks, the segmented boundaries of the interested part are approximated to strainght lines, and the temporal estimated centers by thecosine theorem which formed between the approximaged straight line and the reference point, , are indexed as (.sigma.-.theta.) parameteric vecstors. Then the entries of parametric vectors are fed into self-organizing nerual network. Finally, the center of the n-fold part is extracted by mean of generating and merging learning of the neurons. To accelerate the learning process, neural network uses an adaptive learning rate function to the merging process and a self-adjusting activation to generating process. Simulation results show that the centers of n-fold engineering parts are effectively estimated by proposed technique, though not knowing the error distribution of estimated centers and having less information of boundaries.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1C
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• pp.130-137
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• 2010

An uplink indoor positioning system is proposed in the present work, where the acoustic signals are solely used for positioning. The underlying acoustic signals include whistle, finger snap, and hands-clapping. In the proposed method, positioning is achieved by finding the time-difference-of-arrivals using several self-generating sounds. To evaluate the feasibility of the signals and their positioning accuracies, the database of 100 persons about self-generating acoustic signals is built up. The results show that the hands-clapping sound is the most suitable for acoustic-based indoor positioning.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.560-565
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• 2011

This paper proposes the design of micro energy harvesting system by using thermoplastic polyurethane(TPU), which harvests electric energy from the kinetic energy of pedestrian and drives the desired load, and applied it to the self-generating shoes. Also, we designed the buck-boost converter in discontinuous conduction mode(DCM) which functions as a resistor emulator(RE) such that converter's average input current is proportional to input voltage, and it results in transfer of maximum power to buck-boost converter according to control behavior that converter's input resistance is matched with TPU's internal resistance. Therefore, this paper confirms the validity of proposed control scheme and possibility of application for self-generating shoes, from the obtained characteristic of designed micro energy harvesting system by using a TPU and buck-boost converter in DCM.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.4
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• pp.236-240
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• 2010

This study demonstrates the use of a chemical containing potassium superoxide (KO2) to convert carbon dioxide (CO$_2$) in air to oxygen (O$_2$). A oxygen generating closed-circuit SCBA (self contained breathing apparatus) removes carbon dioxide by a chemical reaction with potassium dioxide that consumes the carbon dioxide and produces oxygen. Considering the disasters, there is a need to develop strategies to enable the introduction of self-contained self rescuers (SCSR). The potassium superoxide reacts with the wears breath to produce oxygen and absorb carbon dioxide. If the respiration rate of a person is 5 MET (metabolic equivalent), to say 30 L/min, at disaster such as fire, mass of potassium superoxide was evaluated as 33.3 g with yield and safety factor. Four researchers tested on a laboratory treadmill breathing through SCSRs in a closed circuit, it appears useable for 9 minutes.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.76-84
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• 1999

The demand of Small Self-generating System (SSS) including Small Cogeneration System (SCS) is constantly increasing with the need of electricity and/or thermal in office, hospital, hotel, and small factory, etc. It is especially recommended to operate SCS in the heat-following mode to maximize the efficiency of generator. In case of the heat-following mode SCS has got to be connected to distribution system so as to send surplus power to the utility or receive the short power from utility. But the interconnection of SSS with distribution system causes a few problems such as the bad power quality, and low security. If SSS is not promptly disconnected after faults occur (Islanding of SSS), it can not only damage equipment of utility and adjacent customers but also endanger life of human due to overvoltage or overcurrent. In this paper it has been deeply discussed if interconnection of engine self-generator/control system satisfies the protective requirement for SSS or not. 500 kW engine generator running in the Jodo island has been used to perform the analysis of interconnection.

• ALGAE
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• v.34 no.1
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• pp.35-43
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• 2019

Genetic study of haploid organisms offers the advantage that mutant phenotypes are directly displayed, but has the disadvantage that strains carrying lethal mutations are not readily maintained. We describe an approach for generating and performing genetic analysis of diploid strains of Chlamydomonas reinhardtii, which is normally haploid. First protocol utilizes self-mating diploid strains that will facilitate the genetic analysis of recessive lethal mutations by offering a convenient way to produce homozygous diploids in a single mating. Second protocol is designed to reduce the chance of contamination and the accumulation of spontaneous mutations for long-term storage of mutant strains. Third protocol for inducing the meiotic program is also included to produce haploid mutant strains following tetraploid genetic analysis. We discuss implication of self-fertile strains for the future of Chlamydomonas research.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.584-587
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• 2006

An energy generating greenhouse based on fluoropolymer envelope and fresnel lens is proposed. The outstanding properties of the fluoropolymer films make them very suitable for large scale solar applications. Extremely high optical transmission over the whole solar spectrum, combined with mechanical strength, and durability allows us to design a highly optimized greenhouses for both plant growing and energy generation. Systems such as photovoltaic triple junction cells are especially attractive since they have up to 35% efficiency with much less cell material when the sun beam is focused with concentrators such as fresnel lenses. Cooling such devices will enhance the efficiency and provide useful thermal energy that could be further utilized for various applications depending on the local demands. This article introduces the basic ideas and principles of the energy generating greenhouses as a first step towards the actual deployment of such systems under Korean environment.

• Asia pacific journal of information systems
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• v.29 no.3
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• pp.428-447
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• 2019

This paper investigates how firms increase customer acceptance of self-service technologies in retail, and the impact of self-efficacy on customer experience, satisfaction, and loyalty. We conducted our empirical research by administering 308 questionnaires to customers of self-service convenience stores in China. We employed a structural equation model to analyze the relationship between service quality, revisit intention, and word of mouth. The results indicate that perceived service quality significantly influences customer satisfaction, with the service quality of self-service retail and experience value being important factors in consumer acceptance of self-service retail stores. Additionally, we investigated the relationship between customer experience value, satisfaction, and loyalty, and found that self-service retail stores exert a significant impact on perceived self-efficacy. Informed by the research on customer acceptance of self-service technologies in retail, promoting further development of self-service retail technologies can effectively aid companies in generating profit while offering more convenience to customers.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.648-657
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• 2012

This study is examined for the effects of question generating strategy and feedback(teacher feedback and student peer reviews) on science achievement, self-efficiency and perception of the class in the middle school. Three classes of middle school 1st grade in a city were sampled for the study. The students in comparative group took traditional lessons and solved questions presented on worksheets distributed by a teacher. On the other hand, the students in the experimental groups 1 and 2 generated and solved questions by themselves after traditional lessons and then participated in the activity with peer's feedback and teacher's feedback, respectively. A self-efficiency test had been conducted before the treatments and the various tests such as achievement, self-efficiency and the perception of the class were carried out after treatments. The statistical results were analysed by ANCOVA, MANCOVA and t-test. The results of this study were as follows: First, there was significant difference between the control and experimental groups in the science achievement test (p<.01). But there was no significant difference between the experimental groups (p>.05). Second, both of the experimental groups showed enhanced self-efficiency compared with comparative group (p<.01). In sub-areas of self-efficiency, there were also meaningful results in the area of self-efficiency for control experimental group 1(p<.01), and in the area of difficulty preferences for experimental group 2 (p<.01). Third, the experimental group 1, given teacher's feedback, showed more positive perception of the class than the experimental group 2 that was given peer's feedback (p<.01).