• 대한수학회논문집
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• 제16권1호
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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.

• 전자공학회논문지C
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• 제34C권11호
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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.

• 한국통신학회논문지
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• 제35권1C호
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• pp.130-137
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• 2010

본 논문에서는 상향 실내음향측위를 위한 자체발성음으로서 휘파람소리, 손가락딱소리, 박수소리의 시간 및 주파수영역, 상관 및 전력스펙트럼밀도, 최대지연시간, 최대주파수, 대역폭 분석을 통해 여러 자체발성음의 측위음원으로서의 적합성을 판단한다. 그리고 자체발성음의 도달지연시간차에 기반을 둔 실내측위시스템을 설계하고 그 성능을 평가한다. 자체발성음 분석과 측위성능평가를 위해 여성과 남성 각 50명씩, 총 100명의 자체발성음 데이터베이스를 구축해 활용하였다.

• 전기학회논문지
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• 제60권3호
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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.

• 한국산업보건학회지
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• 제20권4호
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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.

• 에너지공학
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• 제8권1호
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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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• 제34권1호
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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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• 한국신재생에너지학회 2006년도 춘계학술대회
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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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• 제29권3호
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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.

• 대한화학회지
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• 제56권5호
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• pp.648-657
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• 2012

본 연구는 문제 생성 전략과 피드백 방법이 중학생들의 과학 성취도, 자기 효능감 및 수업에 대한 인식에 미치는 영향을 알아보았다. 대도시에 소재한 중학교 1학년 3개 반을 대상으로 비교 집단은 전통적인 수업과 교사가 배부한 학습지의 문제를 풀도록 하였고, 실험 집단 1, 2는 전통적인 수업을 받은 후 문제를 생성하고 동료에 의한 피드백과 교사에 의한 피드백을 각각 받도록 하였다. 수업 전 자기 효능감 검사가 실시되었으며 수업 후에는 과학 성취도, 자기 효능감 및 수업에 대한 인식 검사가 이루어졌다. 결과 분석을 위하여 공분산분석, 다변량 공분산분석과 t-검정을 실시하였다. 연구 결과는 다음과 같다. 첫째, 과학 성취도에 있어서 비교 집단과 실험 집단들 간에는 큰 차이가 있었으나(p<.01), 실험 집단 간에는 차이가 없었다(p>.05). 둘째, 실험 집단은 비교 집단에 비해 자기 효능감에서 우수한 효과를 나타냈으며(p<.01), 실험 집단 1은 자기 효능감의 하위 영역 중 자기조절 부분에서(p<.01), 실험 집단 2는 과제 난이도 선호 부분에서(p<.01) 통계적으로 유의미한 결과가 나타났다. 셋째, 문제를 생성한 후 교사에 의한 피드백을 받은 실험 집단 2가 동료에 의해 피드백을 받은 실험 집단 1에 비해 수업에 대한 인식은 더 긍정적인 것으로 나타났다.