• Journal of Korea Port Economic Association
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• v.29 no.1
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• pp.1-22
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• 2013

Logistics service is one of the most frequently addressed competitive edges exercised by container terminals that face fierce competition. Many of researches have tried to assess the logistics service quality and attempted to propose the strategic ways to manage it. However, it has been known that quality is a multi-dimensional construct and not all quality attributes are viewed as equally important to customers. Each quality attribute has different implications for customer satisfaction. Timko (1993) has developed customer satisfaction (CS) coefficient based on Kano model. The CS coefficient is indicative of how strongly a service quality may influence customer satisfaction. This study attempted to identify the satisfying/dissatisfying quality factors using Kano model and CS coefficient. In so doing, several satisfying and dissatisfying quality attributes in logistics service quality were identified.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1410-1411
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• 2008

본 연구에서 인덕터에 PGS를 삽입함으로써 인덕터의 품질계수를 향상하여 LNA의 잡음 지수 특성 향상에 대해 연구하였다. 인덕터의 품질계수를 향상시키기 위해 다구찌 실험계획법을 이용하여 인덕터에 삽입되는 PGS의 도체 면적이 최소화 할수록 품질계수를 높일 수 있다. PGS가 없는 인덕터와 PGS를 삽입한 인덕터를 LNA에 적용 시뮬레이션 하였다. PGS가 없는 인덕터 보다는 PGS가 있는 인덕터를 사용함으로써 LNA의 전력 이득과 잡음 지수 특성을 향상시킬 수 있음을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.21 no.7
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• pp.600-605
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• 2002

In this paper, a Negative Impedance Converter (NIC) circuit was employed for the electro-mechanical characteristic control of a thickness mode piezoelectric vibrator. Two circular plane piezoelectric vibrators were bonded together and the NIC circuit was connected to one of the vibrators. The theoretical and experimental analysis of the characteristics shown that the quality factor and the electro-acoustic efficiency of the vibrator with the NIC circuit could be improved by 20 times and 2.5 times, respectively.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.137-140
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• 2005

본 논문은 낮은 품질계수의 공진기를 사용한 여파기의 통과대역 평탄도를 개선하기 위한 2단 상보 여파기의 설계를 연구하였다. 품질계수로 인해 상보 여파기 평탄도 특성 변화를 고려하여 낮은 품질계수의 공진기를 사용하고, 기존의 여파기 설계공식에 그대로 적용할 수 있는 상보 여파기의 설계변수를 제시하였다. 제시한 설계변수로 상보 여파기를 설계하여 전체적인 통과 대역 평탄도를 1dB 이내로 만들 수 있었다.

• Korean Journal of Materials Research
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• v.8 no.11
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• pp.1043-1047
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• 1998

The effect of CuO and CdO addition on the microwave dielectric properties of $BiNbO_4$, ceramics were investigated. As the content of CdO increased, sintered density and quality factor decreased. With increasing sintering temperature, both the dielectric constant and quality factor increased. In the case of specimen sintered at $960^{\circ}C$ with addition of 0.03 wt% of CuO and CdO, respectively. the microwave dielectric properties obtained were dielectric constant of 41.2, quality factor ($Q{\times}f_0$) of 6,500 (at 5.6GHz), temperature coefficient of resonant frequency of $3ppm^{\circ}C$.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.583-587
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• 2004

Kano는 만족 불만족이라는 풀질의 주관적 측면과 물리적 충족$\cdot$불충족이라는 풀질의 객관적 측면을 한께 고려하는 풀질의 이원적 인식방법을 제시하려다. 본 연구에서는 고객만족계수의 개념을 이용하여 Kano 품질분석에 사용되는 품질특성의 심층적인 해석을 시도하였다

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.124-127
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• 2010

본 논문에서는 소형 SMD 솔레노이드 형태의 RF 칩 인덕터의 최적 구조를 도출하였다. $1.0\times0.5\times0.5mm^3$ 크기의 96% $Al_2O_3$ 코아는 $40{\mu}m$ 직경의 구리 코일을 4회 권선하여 8.57nH의 인덕턴스, 37.6의 품질계수와 6.05GHz의 SRF를 가진다. $40{\mu}m$ 직경의 구리 코일을 0.35mm 솔레노이드 길이로 중앙에 6회 권선하였을 경우가 250MHz11.2nH의 인덕턴스, 29.8의 품질계수와 5.6GHz의 SRF로 가장 우수하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.81-84
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• 2006

다양한 멀티미디어 사용 환경 조건에 적합한 컨텐츠를 제공하기 위해서는 다양한 소비 환경을 반영할 수 있는 스케일러블 비디오의 제공이 필요하다. 이러한 스케일러블 비디오의 경우, 다양한 조합의 프레임 율, SNR, 공간해상도를 가지는 비디오가 가능하므로 사용자에 게 최적의 품질을 제공하는 조합을 결정해야 할 필요가 있다. 따라서 본 논문에서는 프레임율, SNR, 공간해상도 그리고 영상의 모션 속도에 따라 변동할 수 있는 영상 품질을 나타낼 수 있는 새로운 영상 품질 메트릭을 주관적 평가를 통하여 제안한다. 제안한 품질 메트릭은 주관적 품질평가 선호도와의 상관계수(correlation coefficient)가 PSNR과 주관적 품질평가 점수와의 상관계수 평균값에 비해 높은 값을 보였다. 본 논문에서 제안한 품질 메트릭은 다양한 조합의 부호화 조건에 따른 품질측정이 가능하여 제한적인 멀티미디어 소비환경에서 최적의 부호화 조건을 결정할 수 있다.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.63-69
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• 2005

For many years, the compressive strength of concrete has been regarded as an important index in determining concrete pavement quality. The compressive strength of the sample cores from the field has been used as quality index of concrete pavement. However, this process is time consuming and requires a lot of labor. Recently, the M-E Design Methodology in the pavement design based on the elastic modulus has been adopted. Therefore, several NDT methodologies have been adopted for QA/QC in the field and for the pavement design. Among various NDT methods, the wave propagation method can be used to measure the elastic modulus of concrete because the wave velocity is directly related to the elastic modulus. Therefore, in this study the wave propagation method was used for estimating the concrete modulus. The relationship between the compressive strength measured in he laboratory and the elastic modulus measured by the wave propagation method was analyzed, and the compressive strength was estimated from the elastic modulus for various mix types. The results showed that the relationship between the elastic modulus and the compressive strength was observed and the relationship varied depending on the aggregate types.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.353-358
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• 2020

In the case of a general spiral inductor, the orientation of the port is affected as it has an asymmetric structure. In this paper, a single-layered spiral inductor that can have a symmetrical structure is proposed, and the simulation and frequency characteristics are analyzed. The general spiral inductor shows a large difference in frequency-inductance characteristics, frequency-quality factor characteristics, and self-resonant frequency according to the standard of the port, while the proposed symmetric spiral inductor has an inductance of 2.7nH, a quality factor of about 7.86, and a self-resonant frequency of about 14.1GHz without changing the port. Compared to the general spiral inductor having a large difference depending on the port, it was confirmed that the influence on the port direction was small. However, it was confirmed that the mutual inductance decreased compared to the occupied area of the coil, resulting in a low inductance, and the resistance of the coil increased more than the increase in the inductance, and the quality factor was also lowered. In the future, it is expected that inductance and quality factor can be improved through a 2-layer symmetrical spiral structure.