• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.178-186
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• 2004

This paper proposes a two-phase RCD-PWM scheme which is much better than a three-phase RCD-PWM scheme from the standpoint of the broadening and linearizing effect of the power spectrum. To implement the proposed scheme and conventional scheme, the experiment based on the SAB-Cl67 micro-controller was executed. Based on the space vector modulation technique, the duty ratio of the pulses is calculated using the SAB-Cl67 and each of PWM pulses is located randomly in each switching interval. The power spectrum of the output voltage, output current, the d.c link current and the acoustic noise radiated from inverter drives are experimentally investigated. 1'hen, the performance of the proposed scheme was compared and discussed with the conventional scheme.

• KSBB Journal
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• v.8 no.1
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• pp.83-88
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• 1993

Lipase was separated using reverse mlcelles in a spray column. The 50 mM AOT-Isooctane solution was used as reverse micellar solution for the extraction of lipase (crude containing 25% Protein). Ionic strength was controlled by KCl(0.1M KCl for extraction, 0.5M KCl for back exlractlon). Acetate buffer and phosphate buffer were used for control of pH. The efficiencies of extraction and stripping were 30% and 50%. An increase of circulation did not change the efficiency of extraction in forward extraction. The optimum flow rate was around 0.10ml/sec.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.4
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• pp.310-317
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• 2007

In this paper, the system equation for the balanced two-phase induction motor is derived and the characteristics for speed control is also analyzed in the region of constant torque and constant power. The modified vector control theory is applied to two-phase motor drive system. The speed of two-phase motor drive can be controlled precisely by the modified indirect vector control theory. The modified vector control theory is simpler comparing to the conventional vector control because of the simpler axis transformation. The computer simulations and the experimental results presented to confirm the vector control for two-phase inverter fed two phase induction motor system.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.218.1-218.1
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• 2013

GeSbTe 삼원계 칼코겐화물 합금은 광디스크 및 상변화 메모리에서 활성물질로 사용되는 대표적인 재료이다. GeSbTe 합금은 결정질 상과 비정질 상의 두 종류의 상을 갖는데 그 상에 따라 반사율 및 전기저항이 서로 다르기 때문에 활성물질로서 작용한다. GeSbTe 합금 구성원소의 일부를 포함하는 두 종류의 물질로 접합을 형성하고 열처리 공정을 수행함으로써 GeSbTe 합금을 국부적으로 생성하는 방법이 최근에 보고되었다. 이러한 방법을 상변화 메모리 소자 제조에 이용하면 GeSbTe 합금을 제한된 영역에 나노 스케일로 만드는 것이 가능해져서 GeSbTe 합금의 상변화를 유도하는데 필요한 프로그래밍 전류를 낮추는 효과를 얻을 수 있다. 상변화 메모리 소자 내에서의 GeSbTe 합금의 두께 또는 크기는 상변화 메모리 소자의 동작 특성을 좌우하는 중요한 파라미터이며 이것은 열처리 공정 조건에 따라 결정되므로 열처리 공정 조건에 따라 GeSbTe 합금이 생성되는 양상이 어떻게 변화하는지를 밝힐 필요가 있다. 따라서 본 연구에서는 다양한 열처리 온도 조건에서 Ge-Sb-Te 삼성 분계에서의 구성 원소들의 상호확산 거동을 조사하였다. 순수한 Ge 박막과 조성이 다른 SbTe 박막의 접합을 형성하고 773K까지의 온도 범위에서 열처리를 실시하였다. Auger 수직 분석을 이용하여 Ge, Sb, 및 Te 원소의 깊이 방향의 확산 정도를 조사하였으며 그 결과로서 열처리 온도가 증가함에 따라 상호확산 정도가 심해지고 Te 원소가 상호확산에 있어서 중요한 역할을 한다는 사실을 확인하였다.

• Asia Marketing Journal
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• v.3 no.2
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• pp.69-91
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• 2001

고객이 서비스상의 실패에 대해 때로는 강한 부정적 반응을 보이기에 서비스를 제공하는 조직의 서비스회복능력은 고객만족을 달성하기 위해 강력하고 효율적으로 운영되어야 한다. 따라서 본 연구는 온라인상의 서비스인 ISP업체(10개의 회사)를 대상으로 온라인 서비스 상에서 고객이 서비스상의 불만을 경험할 때 기업이 고객의 불만을 회복시켜 만족으로 전환시키려는 회복속성들이 실제로 고객이 가지는 분배상의 공정성, 절차상의 공정성 및 상호작용 공정성에 어떤 영향을 미치는가를 실증적으로 검증하기 위한 것이다. 이를 위해 10개의 ISP업체를 선정하고 해당 업체에 대해 불만을 가진 고객들이 기업의 불만제거 노력에 대해 평가하도록 하였다. 가설 검증을 위해 LISREL을 이용하여 서비스의 회복속성인 보상, 신속한 반응, 무반응, 사과, 사전보상제공 등이 분배상공정성, 절차상 공정성, 상호작용 공정성에 직접적으로 미치는 효과를 파악하고 이 공정성의 요인들이 만족에 미치는 영향도 실증적으로 검증하였다. 온라인 상이라는 새로운 환경을 고려하여 기존의 모델에서 간과된 부분을 확인하기 위해 확장 모델을 제시하여 새로운 의미를 가진 경로가 존재하는지 확인하고 이 부분에서 유의적인지 않은 경로를 배제한 수정모델을 제시하였다. 기존의 연구를 바탕으로 제시된 가설은 연구모델에서 경로 계수를 추정하고 이에 대한 t값을 통해 검증하였다. 본 연구에서 제시하는 시사점으로는 고객의 서비스 실패 및 회복상황에 대한 평가의 이론적 원칙을 설명하고 관리자에게 각각의 서비스 실패와 일치하는 서비스 회복전략을 제시하여 운영상의 가이드 라인을 제시한다고 할 수 있다

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.502-510
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• 2013

The purpose of this paper investigate the general definition of Tense and the concepts about Aspect. I consider the correlation between the lexical and the grammatical aspect. Tense is an inflection type of a verb that indicates the time, tense is grammatical categories. Tense has the current tense and the past tense in English. If we recognize aspect as a grammatical category, that the subject of in description will be confined to the grammatical expression. In contrast, when considered as a category of meaning, lexical and grammatical representation is the expression target. Therefore, aspect is stated as a grammatical category. Specially, the aspect of English, there is only a progressive tense and perfect tense. In this case, the progressive aspect is progressive tense and the perfect aspect is perfect tense. Chapter 2, I investigate the definition of the tense of many scholars and define the usage of each tense. In Chapter 3, I exhibit the definition of the Aspect. Aspect is grammatical and semantic one. Tense and Aspect is a simple grammar category, but they have a various spectrum. Therefore, As the definition of the Tense and Aspect becomes clear it will be helpful to students who are received English education. In addition, the definition about tense and aspect needs in variety of areas, more research is needed.

• Journal of Service Research and Studies
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• v.10 no.3
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• pp.119-138
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• 2020

Unlike the era of manufacturing-oriented industrial economy in the past, the era of service economy has characteristics intangible goods center, knowledge universalization, and expansion of needs, and many things that are of the economy are changing. In the past, the change in the environment was not fast, so even after analyzing the changed environment and deriving the talent needed for the company, it was possible to maintain a talent for the organization for a long time, so it is not proactive to build and apply talent. It became difficult to manage effectively. Therefore, in this paper, we conducted a normative study for deriving a desirable talent model rather than a descriptive human resource model. Human resources image suitable for the modern service economy era, the modern economic society and modern spirit were analyzed and reflected. The model in which the two opposing members of the organization, managers and employees, interact intensely and balance dialectically. A desirable talent in a modern organization must play the role of a manager, and the management and talent models in a modern organization can be said to be connected to each other like the front and back sides of a coin. The philosophy of human resources was presented in five dimensions: human, historical, social, economic, and management. The human resource model from eight factors: mastery, rationality, wisdom, customer orientation, innovation, flexibility, autonomy, collaboration. This study suggested that general talent model may vary depending on the company's type, empirical follow-up studies are needed the talents in each company in the future.

• Journal of the Mineralogical Society of Korea
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• v.15 no.3
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• pp.161-169
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• 2002

high pressure and temperature conditions. However, those results are not consistent with one another, and phase boundary between ilmenite and perovskite phases determined only from the quenching method may be not so reliable at all. Therefore, in-situ high pressure-temperature (hP-T) X-ray diffraction measurements were performed up to 19 GPa and $700^{\circ}C$ in a large volume press apparatus using synchrotron radiation. Experimental results show that perovskite phase is stable at pressures above 16 GPa, and transforms back to $LiNbO_3$phase near 15 CPa at room temperature, and that the perovskite-ilmenite transition is back and forth near 15 CPa at $500^{\circ}C$. LiNbO$_3$phase transforms to ilmenite at 13 CPa and $300^{\circ}C$ and at 10.8 CPa and $400^{\circ}C$, respectively. These data indicate that $LiNbO_3$phase may have a stability region in the hP-T phase diagram and that the perovskite-ilmenite phase boundary would be quite different from that previously reported.

• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.161-169
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• 2003

A phase transformation study on a synthetic amorphous diopside, $(Ca,Mg)SiO_3$has been carried out up to ∼30 GPa, and ∼$1000^{\circ}C$ using a diamond anvil cell and YAG laser heating system, respectively. A starting amorphous material shows a direct transition to cubic $(Ca,Mg)SiO_3$perovskite at high pressure, which contradicts to the crystalline diopside phase transformation sequence disproportionating into mixtures of the orthorhombic$ MgSiO_3$perovskite and the cubic $CaSiO_3$perovskite phases. This discrepancy might be due to the different starting materials as well as the temperature variations at each specific experiment performed. The present phase transfor mation sequence would modify the mineralogical assemblage in the Earth transition region and the lower mantle depending upon the pressure, temperature and the oxygen partial pressure.

• Membrane Journal
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• v.19 no.2
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• pp.122-128
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• 2009

We prepared monodispersed spherical silica microgels by controlling various conditions of emulsification procedure using a lab-scale membrane emulsification system equipped with SPG (Shirasu porous glass) porous membrane having pore size of $1.5{\mu}m$. We determined the effects of process parameters of membrane emulsification (ratio of dispersed phase to continuous phase, sodium silicate concentration, emulsifier concentration, dispersed phase pressure, stirring speed) on the mean size and size distribution of silica microgels. The increase of the ratio of dispersed phase to continuous phase, dispersed phase pressure and sodium silicate concentration led to the increase in the mean size of microgels. On the contrary, the increase in emulsifier concentration and stirring speed of the continuous phase caused the reduction of the mean size of microgels. Through controlling these parameters, monodisperse spherical silica microgels with about $6{\mu}m$ of the mean size were finally prepared.