• Title/Summary/Keyword: 자기현상

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A Study on the Driving of Ballast for 35W Class (T5 Class) Fluorescent Lamp using a Piezoelectric Transformer Characteristic (압전 변압기 특성을 이용한 35W급(T5급) 형광등용 안정기 구동에 관한 연구)

  • Hwang, Lark-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.638-644
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    • 2008
  • It is required small size electronic ballast to fullfill the design philosophy of miniaturizing in the application of slim lamps. However, the traditional magnetic ballasts operated at 50-60Hz have been suffered from noticeable flicker, high loss, large crest factor and heavy weight. In this study, in order to solve these problems, It was proposed for driving 35W Class fluorescent lamp in the new type of electronic ballast, which is composed of rectifier, active power factor corrector, series resonant half bridge inverter and piezoelectric transformer. A 35W class(T5 class) fluorescent lamp is driven to successful by the fabricated ballast with piezoelectric transformer. Experimental results, It is proposed to driving the lamp using a electronic ballast at operating frequency of $75{\sim}79kHz$ approximatively. It is operated after for 25 min that were obtained good results of the input power factor of 0.95 and efficiency of 86%, respectively.

A Perspective of Science and Technology Studies (STS) for Economy: the Performativity Thesis (과학기술학(STS)이 경제현상을 바라보는 방식: 수행성 테제를 중심으로)

  • Kim, Byoung Soo
    • Journal of Science and Technology Studies
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    • v.17 no.2
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    • pp.81-111
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    • 2017
  • In this paper, I focus on the performativity thesis introduced and developed by Science and Technology Studies (STS) scholars such as Callon, MacKenzie, etc. since the mid 1990s. The performativity thesis was discussed in economic sociology by STS scholars has been pervaded to other research areas including general economics, accounting, finance and so on. The main idea of the thesis is that economic theories perform, shape, and format economy rather than just describe economy. I show that the thesis is based on the traditional STS ideas such as performativity derived from Merton's self-fulfilling prophecy and the actor-network theory. Although the thesis has been criticised by various researchers from both inside and outside STS, it has provided meaningful implications for understanding economic phenomenon from a viewpoint of STS. Furthermore, reflexive researches for performativity of STS theories can be discussed in the next stage.

A Study on the Family Reunion Experience of Adults Discharged from Childcare Welfare Facilities - Grounded Theory Approach - (아동양육시설 퇴소 성인들의 원가족 재회 경험 연구: 근거이론(Grounded Theory) 연구 접근)

  • Hwang, Suyon
    • Korean Journal of Family Social Work
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    • no.60
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    • pp.31-71
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    • 2018
  • This study focused on analysis of experience for adults' reunion with original family members who had lived in child care facilities during the childhood and adolescence. It was researched based on the grounded theory from nineteen participants have interacted with their own separated family members for more than ten years after had been reunited with them. As written in the result section of the study using the paradigm model analysis showed that it was caused by feel regret by reunion, absence of belonging and repeated abandoned wound. The contextual condition appeared as sensitive memories as wounded and frustration of compensation mentality. The centralization phenomenon came in a whirlpool of emotion. The intervention condition appeared as recognition of filial piety, support system for parents and healing their parents mind. The action-interaction showed up as revenge with good will, setting own boding free, inspire of own pride, family reconciliation. The consequence appeared as family sublimation, successful execution of life task and getting living foundation. This research made practical and political proposals based on above result and described the limitations of the study and the proposals for the latter study.

A study on Paul Ricoeur's theory of mutual recognition for the establishment of a mutual relationship between cultures (문화 간 상호성 확립을 위한 리쾨르(P. Ricoeur)의 인정 이론 고찰)

  • Kim, Jung-hyun
    • Journal of Korean Philosophical Society
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    • v.139
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    • pp.23-45
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    • 2016
  • This paper analyzes Paul Ricoeur's theory of mutual recognition with the concern for the establishment of a desirable relationship between cultures. Ricoeur tries to construct his own theory via Hegel and Honneth. He thinks, according to their theory, the state of being recognized could not arrive eternally. This means that the struggle for recognition could continue permanently. To put an end to the struggle for recognition, Ricoeur introduces the state of peace made possible by the exchange of ceremonial gifts. In other words, the struggle could be eliminated symbolically thorough the exchange of gifts. The mutuality established by this process however, can not accomplish its meaning without overcoming the original dissymmetry between one and the other in which phenomenology has a keen interest. To integrate the dissymmetry into mutuality, Ricoeur gives attention to 'between' the giver and the receiver in the system of gift exchange. He carries out this task by securing a just distance, or a distance in proximity.

A Method of Commerce Activation of the Old City-Center of Jeju City Using Augmented Reality Technology (증강현실을 활용한 원도심 상권 활성화방안)

  • Lee, Bongkyu
    • Journal of Convergence for Information Technology
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    • v.9 no.11
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    • pp.1-7
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    • 2019
  • Jeju City is one of the cities where decline of old city-center is appearing due to the reduction of residential and floating population. The decline of old city-center of Jeju City has been on the rise since the 1990s, and has been intensifying in the 2000s. Jeju City is currently activating specific policies to ensure activation and diversification of the local commercial area. In this paper, we propose a new method to increase the number of visitors to Jeju-Mokkwana by using Augmented Reality technology for activating commerce of old city-center. Various Augmented Reality contents based on smart-phone are implemented and operated in Jeju-Mokkwana. Also the survey is conducted to 574 visitors who have experienced online/offline promotion for analyzing effects. Survey results show that the proposed method can be effectively used to activate the old city-center by increasing the floating population.

The Influence of Frequency on Wayside Transmitter of ATP System upon Reinforcing Bars in Concrete Slab Track (콘크리트 슬래브궤도에서 철근이 ATP시스템 지상자의 주파수에 미치는 영향)

  • Kim, Min-Seok;Yoon, In-Mo;Ko, Jun-Seog;Lee, Jong-Woo
    • Journal of the Korean Society for Railway
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    • v.11 no.6
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    • pp.536-542
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    • 2008
  • In concrete slab track, the signal current using wayside transmitter of ATP (Automatic Train Protection) system is influenced by reinforcing bars. The magnetic coupling between reinforcing bars and wayside transmitter of ATP system as a filter makes an input current distorted. So, it makes an alternating current signal with a desirable size not transmit to on-board system of a train. Way to decrease the distortion of an input current signal frequency is to avoid maximum induction current frequency. And the induction phenomenon between reinforcing bars insulated and wayside transmitter of ATP system does not occur. In this paper, we represent the model about wayside transmitter of ATP system and reinforcing bars on the concrete slab tracks, and calculated the parameters demanded for the model. Also, we demonstrated it through the Maxwell program. Furthermore, we calculated impedance on wayside transmitter used in KVB system and ERTMS/ETCS system which are a kind of ATP system, frequency response of induction current, using Matlab, and demonstrated the validity of it, using PSpice program.

The Effect of Incoherent Pumping in Electromagnetically Induced Absorption (전자기 유도 흡수에서의 비결맞음 펌핑 효과)

  • Moon, Han-Sub;Kim, Sook-Yung;Kim, Kyung-Dae;Lee, Chung-Hee;Lee, Rim;Kim, Haeng-Hwa;Kim, Joong-Bok
    • Korean Journal of Optics and Photonics
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    • v.13 no.5
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    • pp.449-454
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    • 2002
  • We have studied the effects of incoherent pumping on EIA at the transition between the $F_g=2$ ground state and the $F_e=3$ excited state in $^{85}Rb\;D_1$-line. Generally, the studies about EIA have been done in the cycling transition, where the population has no loss to other states. In the case of EIA by using the $^{85}Rb\;D_1$ transition line, the population is transferred to the other hyperfine state due to optical pumping. We incoherently pumped the atoms from $F_g=3\;to\;F_g=2$ with the pumping beam, which is resonant at the transition from $F_g=3\;to\;F_g=2$. We were able to observe the effects of incoherent pumping depending on the power and the polarization of the pumping beam.

Qualitative Research on Gambling Experience of Male College Students -Focused on Sports Toto- (남자 대학생의 도박 경험에 관한 질적 연구 - 스포츠토토를 중심으로 -)

  • Choi, Jung-Hyun;Yang, Young-Mi;Kim, Seong-Ui
    • Journal of Convergence for Information Technology
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    • v.9 no.3
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    • pp.44-55
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    • 2019
  • The purpose of this study was to investigate the experiences of male college students through sport toto gambling and to provide basic data on the prevention program for male college gambling addicts. Participants in the study were eight male college students who were interviewed in depth and analyzed according to Colaizzi's phenomenological study method. As a result of this study, four categories of experiences were derived as follows: Like the wind that rushes to the sea, Tears of remorse, A locked down life and On a dream day. Research shows that sports toto is easy to access and has a lot of interesting factors, however it has been found out that male college students have a great risk of falling into addiction aiming to win at once like ordinary gamblers. Therefore, this study suggests that gambling preventive education and counseling are necessary for male college students who like sports.

A Study on Coating Film Thickness Measurement in vehicle Using Eddy Current Coil Sensor (와전류 코일 센서를 통한 차량용 코팅막 측정에 관한 연구)

  • Park, Hwa-Beom;Kim, Young-Kil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.9
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    • pp.1131-1138
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    • 2019
  • The importance of coatings has been increasing for different purposes such as prevention of static electricity of auto parts or products, improvement of abrasion and corrosion resistance, and enhancement of esthetics. As a method for measuring the thickness of a coating film, a contact method with probe is commonly used. However, it is problematic that accuracy of the sensor is degraded due to sensor output distortion or load phenomenon, which is caused by a change in magnetic permeability of the core. In this study, we propose a method to reduce the measurement error of the coating film by applying the optimized circuit design and the thickness measurement algorithm to the problems caused by the nonlinear characteristics. The tests result which have been taken with different thickness coating samples show that the measurement accuracy is within ${\pm}2%$.

A Study on the Meaning and Value of Korean Indie Band Records (한국 인디 밴드 활동 기록의 의미와 가치 연구)

  • Jang, Hyung Oh;Yim, Jin Hee
    • The Korean Journal of Archival Studies
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    • no.52
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    • pp.171-212
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    • 2017
  • Music has been created and played in various environments over a long time, with each piece having distinct sentiments and stories. Different people can have varying interpretations of one song depending on their viewpoints shaped by personal experiences and attitudes. In fact, the audience's understanding may differ greatly from the songwriter's intended message. Knowing this, music can serve as a reflection of one's contemporary sentiment. In the works of art such as music, the creator's intention becomes the background of the work or, sometimes, the main meaning. However, given that popular music is often under the control of companies and distributors and influenced by "capital," creators are required to adjust to mainstream preferences and, therefore, cannot fully express themselves in their music. On the other hand, indie music allows creators to pursue their own music given its "independence" from capital. With this, this study aims to collect and analyze data on the activities that Korean indie bands carry out, and examine their meaning and significance in society.