• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.53-53
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• 2010

지표위의 어떤 지점에서의 지구자기의 수평분력 방향과 진북방향 사이의 각을 편각(Declination)이라고 정의한다. 쉽게 말하면 편각은 나침반의 자침이 가러 키는 방향과 진북방향과의 사이 각을 말한다. 대부분의 사람들은 나침반의 자침이 북자기극(North magnetic pole)을 가러킨다고 잘못알고 있다. 지구 다이나모설(Geodynamo theory)에 의하면 주로 철(약 90%)로 구성된 외핵 속에서 계속 생성 유지되고 있는 복잡한 (각각 나선형(helical)의 회전축에 대체로 평행하거나 평행하지 않은) 대류(Convection currents)에 수반하는 전류가 복잡한 지구자기장을 형성한다. 지표상에서 측정한 지구자기장의 자료를 Spherical harmonic analysis 으로 분석하면 한 개의 커다란 쌍극자(Dipole) (Inclined geocentric dipole 또는 주된 자기장(Main field) 이라고 부름), 적도쌍극자(Equatorial dipole), 4극자 (Quadrupoles), 8극자(Octupoles) 등의 여러 개의 크고 작은 쌍극자들의 총합이 지구자기장의 근원인 것처럼 해석되고 있다. 어떤 지점에서의 지구자기장의 방향은 외핵에서 생성된 천체 자기장에서 Main field를 제거한 나머지 자기장과, 상부 맨틀(upper mantle), 지각 및 지표상에 존재하는 인공 물체 또는 암석 및 광석 등의 잔류자기 및 유도자기 그리고 지형 등의 영향으로 결정된다. 어떤 지점에서의 지구자기장의 방향은 태양풍(Solar wind)과 전리층 사이의 상호작용 등의 외부자장(external field)의 영향도 받는다. 비쌍극자 자장(Non-dipole field)은 지표상에서 측정되는 총자기장에서 외핵에서 생성된 주된 자기장(Main field) 즉, 지구의 회전축에서 약 11.5도 기울어진 쌍극자 자장을 제거하고 남는 자기장을 말한다. 따라서 편각은 비쌍극자자장의 영향을 가장 많이 받는다. 비쌍극자 자장은 정지한 상태의 자장(standing field) 과 매년 서쪽으로 약 0.2도 움직이는 Westward drift하는 자장으로 크게 두 가지로 구분된다. 쌍극자 자장의 방향은 매우 느리게 변하지만 그 세기는 현재 비교적으로 빠르게 약해지고 있다. 비교적으로 매우 빠르게 변하는 비쌍극자 자장의 변화를 영년변화(Secular variation) 이라고 한다.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.317-329
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• 2019

Instagram, a photo and image centered social networking service, has received increasing attention these days, from scholars and practitioners. However, little is known about the social and psychological factors that lead consumers to use this service. To provide a baseline understanding on Instagram users, the current study was conducted to discover perfectionistic self-presentation tendency expressed by the Instagram users and explore the relationships between identified perfectionistic self-presentation and intention to use Instagram variables with 250 participants. In addition, this study tried to determine the moderator effect of self-efficacy and self-construal. A comprehensive survey was directed and a total of 380 participants were recruited to verify anticipated hypotheses and research questions. The research results suggest that perfectionistic self-presentation has five sub factors: others conscious self-presentation, subjective self-presentation, environmental adaptation self-presentation, self-expansion self-presentation, and social self-presentation. The implications of this research findings are discussed.

• Industry Promotion Research
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• v.6 no.2
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• pp.55-62
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• 2021

The number of single-parent families in South Korea increased since 2000, related to a sharp rise in the divorce rate of 50s and an increase in male mortality rates among those aged 40s-50s. Middle-aged single mothers experience a critical period realizing self-actualization needs, while being in the middle adulthood from the lifespan developmental perspective. In this respect, it is significant to study self-actualization of middle-aged single mothers through guided imagery and music (GIM) in order to provide them with psychological support. This study was conducted from September 2018 to June 2020, and the GIM sessions were conducted at least 10 times. Four participants were selected among the middle-aged single mothers. The imagery experiences of participants in the GIM sessions were classified into four sub-elements: physicalness, emotion, memory, and sense. Within those sub-elements, eight semantic units were categorized into 46 elements. Finally, 152 semantic units were derived. Moreover, the self-actualization which participants experienced through GIM presented three archetypal images: shadow, persona, and the self. In the GIM sessions, experiences of putting their negative emotions associated with family into words and changing passive self-imagery into active one enabled participants to bring the shadow into their consciousness, there by recognizing their positive and bright internal self. Furthermore, participants could map that their current status as people marginalized by siblings and parents, enraged and holding double standards for others, was suppressed by their 'good daughter' and 'religious' personas. This realization lead them to realize and restore their persona. The use of GIM in the study allowed participants to elicit re-experiences of the negative events, while experiencing various imagery and music. This process helped participants achieve self-actualization.

• Journal of the Korean Magnetics Society
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• v.20 no.3
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• pp.100-105
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• 2010

For predicting magnetic signals due to the remanent magnetization distributed on a ferromagnetic ship hull, this paper presents an efficient methodology for solving inverse problems, where the material sensitivity analysis based on the continuum mechanics is combined with the equivalent magnetic models. To achieve this, the 3D magnetic charge model and the magnetic dipole moment model are introduced and material sensitivity formulae applicable to each equivalent model are derived. The formulae offer the first-order gradient information of an objective function with respect to the variation of the magnetic charge or magnetic dipole and so an optimal solution can be easily obtained regardless of the number of design variables. To validate the proposed method, the numerical results are comparison with the real measurements of a mock-up model.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.172-180
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• 1986

The Hammett's substituent constants were analyzed for the substituted-benzoic acid, -benzene and -naphthalene by LCAO MO method. Hammett's ${\sigma}$-values have been theoretically proved to treat as the sum of independent contribution of inductive effect and resonance effect. That is, Is (static inductive effect) and Id (dynamic inductive effect) corresponding to inductive effect are chosen as net charge and approximate self atom polarizability indices respectively, and ${\Delta}E^{HOMO}$ which is the difference in HOMO energy level between substituted molecule and unsubstituted molecule as resonance effect. In conclusion, it has been found that the observed ${\sigma}$-values depend on the sum of Id, Is and ${\Delta}E^{HOMO}$.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.146-146
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• 1995

본 논문은 유도전동기의 운전조작시에 발생되는 자계변화특성에 대하여 기술하였다. 본 측정시스템은 자기적분형 자계센서, 증폭기, 능동형 적분기로 이루어졌으며, 교정실험에 대한 측정계의 주파수대역과 감도는 각각 20[Hz]∼0.234[mV/μT]이다. 유도전동기의 기동과 정상운전중에 발생하는 자계성분을 측정하였으며, 고조파 성분을 고속 푸리에 변환기법으로 분석하였다. 유도전동기의 직입기동시에는 단일성 펄스자계가 강하게 발생하였으며, 이의 피크치는 정상상태의 값보다 5배이상 크게 나타났다. 이러한 긴 과도시간과 강한 자계의 세기는 전동기의 큰 인덕턴스와 동특성에 기인된다. 유도전동기의 정상운전시에는 유도전동기의 극수에 의존하는 기본파에 대한 분조파의 자계성분이 관측되었다. 또한, 자계의 분조파 성분은 전동기의 토크 변동으로 불균일한 회전토크로 인해 생기는 맥동전류와 전압플리커에 의해서 발생하는 것으로 생각된다. 인버터구동형 유도전동기에서는 직입기동에 비하여 많은 고조파 성분이 발생되고 있었으며, 특히 전동기의 구동주파수가 낮을수록 맥동토크에 의한 전류변화로 고조파 성분은 더욱 증가하였다.

• Journal of the Korean Magnetics Society
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• v.7 no.4
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• pp.180-185
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• 1997

Variations of core loss and coercivity with heat treatment condition have been studied in amorphous ribbon core specimens. All measurements were performed at 10 kHz with a maximum induction of 0.1 T. With increasing annealing time, both core loss and coercivity of core specimens decreased first, reaching minimum values, and increased thereafter. Specimen heat treated in an air showed better soft magnetic properties than those treated in Ar atmosphere. The specimens annealed under magnetic field higher than 6 Oe in radial direction showed reduced core loss and coercivity. The field annealing effects were increased with increasing cooling rate near Curie temperature of the material. The specimen annealed under an applied field in perpendicular direction of the core showed increased coercivity and decreased permeability.

• Journal of the Korean Magnetics Society
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• v.10 no.4
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• pp.178-182
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• 2000

We have constructed a rotational loss measuring system which consists of two yoke system for rotational magnetization and 4-channel transient recording system for Hx, Hy, Bx and By measurements. Using the constructed measuring system, we have mesaured rotational energy loss for non-oriented electrical steel sheets. Rotational energy loss was depending on the angle between B-search coil and H-search coil, and the direction of rotation (clockwise and counter clockwise). The average of the rotational energy losses under clockwise and counter clockwise was independent of the angle between B-search coil and H-search coil, and we could improve measuring uncertainty using the averaged rotational energy losses.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.4
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• pp.465-472
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• 2013

Since 1990, Agency for Defense Development is operating the non-magnetic laboratory for the development of key technology for the underwater magnetic stealth part, the research of the magnetic application weapons and the technical support for Korean Navy. Recently, we installed the new three-axis earth magnetic field simulator and the measurement system in the non-magnetic laboratory which is replacing the existing outdated facility. In this paper, we deal with the detailed design result of the earth magnetic field simulator and the measurement system. Also, we describe the effective method to separate the permanent and the induced magnetic field from the measured data for a scaled model ship using the earth magnetic field simulator and the measurement system.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.783-793
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• 2013

Neo-liberalism after IMF bailout made the Korean book market flushing with rose due to the alleged self-development books. Vision of self-development books under neoliberal social system is inevitably reduced to a means of capital pursuing commercialization in line with improving the competitiveness of privates through the development of human resources. Characteristics of self-development books, which attributes personal fail to personal responsibility and lack of essential element compared to others in a competitive society, trap individuals forced to choose into anxiety and helplessness. Self-development and healing is a complementary relationship. Human beings needs healing -healing humanities- in the process of self-development. Therefore, humanities should trigger developing and perceiving his own 'reflexive life skills'. Individual's sense of happiness in life and his own experience is very important, and the conscious relationship about their own feelings could elicit 'self-reinforcement'.