• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.114-120
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• 2004

The paper proposes a method calculate the allocations of real power losses in transmission lines to individual loads based on loss distribution factors and compares them with those using marginal loss factors. The proposed method is implemented by defining loss distribution factors and analysing the individual loads' shares in the transmission line losses. Computer simulations on a 9-bus sample system verify effectiveness of the algorithm proposed and give an assertion that it is desirable to allocate power losses to loads using loss distribution factors rather than based on marginal loss factors.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1031-1040
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• 2023

Propagation characteristics in line-of-sight(LOS) paths in 3, 6, 10, and 17 GHz frequency bands were measured and analyzed in two different indoor corridors: second floors of Buildings D2 and E2. The measurement was designed to measure when the receiving antenna moved at 0.5 m intervals from 3 m to 30 m, while the transmission antenna was fixed. The analysis of the two indoor corridors was compared by applying basic transmission loss, root mean square (RMS) delay spread, and K-factor. For basic transmission loss, the loss coefficient of the floating intercept path loss model was higher in the indoor corridor of Building E2 than in that of Building D2. Similarly, the RMS delay spread in the time domain was greater in the indoor corridor of Building E2. However, the indoor corridor of Building D2 exhibited higher K-factor in the 3, 6, and 17 GHz bands with lower wave propagation in the 10 GHz band. Despite the 2 indoor corridors being identical, the propagation characteristics varied due to different internal structures and materials. The results provide measurement data for ITU-R Recommendations regarding various indoor environments.

• Journal of ILASS-Korea
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• v.28 no.2
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• pp.62-67
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• 2023

Recently, the global automobile industry is aiming for a transition from internal combustion locomotives to zero-emission vehicles. Electric vehicles powered by battery energy can operate at peak performance and improve fuel economy by applying multiple motors or multi-speed transmissions. In order to design a two-speed transmission, it is necessary to evaluate and analyze the application system and performance of electric vehicles. In this study, control performance optimization of a twostage battery electric vehicle equipped with an AMT-based automatic transmission was performed and performance according to control pattern changes was analyzed. In order to improve the operating efficiency of the motor, the shift control that sets the optimal operating point according to the vehicle speed and required torque was derived from the motor efficiency map. The performance of battery energy consumption and transmission loss energy according to the hysteresis interval was analyzed and optimized. The hysteresis interval applied to the optimal shift map acted as a factor in reducing the frequency and loss of shifts. It has been shown that keeping the hysteresis interval at about 4 km/h can reduce energy consumption while reducing the number of shifts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.221-225
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• 2007

Recently, on account of stress relief and settlement of a healthy drinking culture, many people are visiting a song practice room. In case of such song practice room, since the mechanical voice through a loud accompaniment-music and microphone is on using, there has made a very loud noise, and it influences a lot to the adjacent other space and song practice room booth. Consequently, from the designing stage an efficient measures for soundproof and sound-insulation should be arranged. However, as most of the song practice room wall-bodies that already built up or under construction step were constructed merely with consideration on an interior-wise factor only, it is suffering at the soundproof and sound-insulation. Reflecting such viewpoint, this Study has measured Sound Transmission Loss on the subject for the song practice room wall-body recently built up, and based on the actually measured data, by practice of comparison?analysis on it using various evaluation methods, would intends to present a fundamental material for establishment an efficient sound-insulation measure.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.838-839
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• 2007

전력산업의 시장구조는 과점형태의 불완전 경쟁의 구조로 해석하는 것이 일반적이다. 또한 전기의 물리적 특성상 송전선로에서는 전력손실이 발생하게 되는데, 본 논문은 과점시장 모델로서 쿠르노(Cournot)모델을 사용하여 손실을 포함한 내쉬 균형점을 해석한다. 지역별 한계가격(Locational Marginal Price ; LMP)와는 달리 계통한계가격(System Marginal Price ; SMP)는 손실에 대한 가격신호를 시장에 반영하기 어렵기 때문에 손실과 함께 한계송전손실계수(Marginal Loss Factor ; MLF)를 적용하여 균형상태의 시장거래가치를 비교분석한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.291-300
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• 2000

This paper proposes the new hybrid analysis of vibration in the medium to high frequency ranges including PFA and SEA concept. The core part of this method is the applications of coupling loss factor(CLF) instead of power transmission, reflection coefficients in boundary condition. This method shows very promising compared to the classical PFA for the various damping loss factors and wide ranges of frequencies. Besides this paper presents the applicable method in Power Flow Finite Element Method by forming the joint element matrix with CLF. These hybrid concepts are expected to improve SEA and PFA methods in vibration analysis.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.69-73
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• 2002

In ceramic systems, many components including embedded passives and TRL(transmission line) are used for composition of 3-dimensional circuit. So the exact analysis on this components, As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of stripline structure have a large effect on the charactersistics of transmission lines. In this research, of effect of material and geometrical factors on the characteristics of stripline structure is analyzed and quantified by simulation and measurement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1020-1023
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• 2004

Recently, Cooling tower are used the necessary element in a residential area and living space on the viewpoint of indoor temperature control. The purpose of this study is to assistance the comfortable environment and economical measures of noise transmission mechanism on tile cooling tower. The results show that noise evaluation interact the main factor of distance reduction and diffraction reduction. Noise criterion apply to the NC level and equivalent transmission loss about already the design of noise reduction.

• ETRI Journal
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• v.36 no.1
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• pp.106-115
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• 2014

In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone-type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is $0.318mm{\times}0.318mm$, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than -12.9 dB from 5 GHz to 50 GHz and an insertion loss better than -1.13 dB in the same frequency range.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.2
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• pp.97-104
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• 2005

Usually, propagation attenuation of millimeter wave occurs by rainfall, snowfall, temperature, effect of pressure of air. In 60GHz wave band wireless communication network, temperature change becomes big factor of propagation loss department. Also, temperature change causes disturbance of 60GHz frequency at transceiver. In this study, we used 60GHz transceiver and found propagation loss of wireless path and operating frequency disturbance characteristics. In transceiver that there is no temperature compensated device, operating frequency of TX changed by 60.865GHz at temperature of $-5^{\circ}C$, and appeared by 60.730GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 100MHz, greatly. But, in transceiver that there is temperature compensated device, operating frequency of TX changed by 60.830GHz at temperature of $-5^{\circ}C$, and appeared by 60.710GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 20MHz. According to these result, we constructed between buildings examination wireless site for point to point wireless communication using 60GHz band transceivers who have do temperature compensated device, and investigated data transmission characteristics about ambient temperature change. Therefore, if use transceiver that have temperature compensated device, may overcome the wireless transmission error in 60GHz band wireless communication LAN networks despite of ambient temperature change.