• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.543-552
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• 2002

Wireless Session Protocol(WSP) which was updated and supplemented based on HyperText Transfer Protocol(HTTP) was designed by Wireless Application Protocol(WAP) forum regarding the characteristics of wireless environment. WSP improved the performance in wireless network, and introduced various facilities considering wireless environment. In this paper, we more improve the performance of WSP adding protocol message compression capability; we cail improved WSP protocol as WSP+. And, we analysis the performance of each protocol with WSP and WSP+ implementation. As a result of experiment, the capability which proposed in this paper reduced a response traffic about 45%. In $10^{-4}$ bit error rate, we also found the packet loss rate and time delay per transaction of WSP+ was improved over 40%. Finally, we found that the protocol message compression capability reduces message retransmission count in transaction layer and shorten the delay time per transaction by reducing a message size.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.237-244
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• 2006

I/Q phase unbalance caused by non-ideal circuit components is inevitable physical phenomenons and leads to performance degradation when we implement a practical coherent M-ary phase shift keying(M-PSK) demodulator. In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate(BER) of uniform M-PSK with I/Q phase unbalance over an additive white Gaussian noise(AWGN) channel. First we derive a BER expression for the k-th bit of 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and general average BER expression for M-PSK with I/Q phase unbalance. This result can readily be applied to numerical evaluation for various cases of practical interest in an I/Q unbalanced M-PSK system, because the one- and two-dimensional Gaussian Q-functions can be easily and directly computed using commonly available mathematical software tools.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.35-41
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• 2014

PURPOSES : The dynamic modulus for a specimen can be determined by using either the non-destructed or destructed testing method. The Impact Resonance Testing (IRT) is the one of the non-destructed testing methods. The MTS has proved the source credibility and has the disadvantages which indicate the expensive equipment to operate and need a lot of manpower to manufacture the specimens because of the low repeatability with an experiment. To overcome these shortcomings from MTS, the objective of this paper is to compare the dynamic modulus obtained from IRT with MTS result and prove the source credibility. METHODS : The dynamic modulus obtained from IRT could be determined by using the Resonance Frequency (RF) from the Frequency Response Function (FRF) that derived from the Fourier Transform based on the Frequency Analysis of the Digital Signal Processing (DSP)(S. O. Oyadigi; 1985). The RF values are verified from the Coherence Function (CF). To estimate the error, the Root Mean Squared Error (RMSE) method could be used. RESULTS : The dynamic modulus data obtained from IRT have the maximum error of 8%, and RMSE of 2,000MPa compared to the dynamic modulus measured by the Dynamic Modulus Testing (DMT) of MTS testing machine. CONCLUSIONS : The IRT testing method needs the prediction model of the dynamic modulus for a Linear Visco-Elastic (LVE) specimen to improve the suitability.

• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.313-322
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• 2005

Recently, as the remodeling market gradually substitute for new construction market and safety diagnosis for reconstruction apartment become a matter of principal Interest, it is demanded that scientific diagnosis and evaluation for existing concrete structure state. And it is increasing that the significance for reliability of data which is used for estimating the concrete compressive strength by nondestructive test. As a result, it is found that different proposal to material age and hitting angle is good to improving the reliability of presumption of concrete compressive strength in the linear hitting rebound test hammer. And for the reason that mutual relation between the compressive strength and rebound degree is highest in linear hitting rebound test hammer 25mm in all portion according to early md middle material age and hitting angle except the early material age $-45^{\circ}$, analysis showed that linear hitting rebound test hammer is more reliable than existing schmidt hammer in presumption of concrete compressive strength.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.257-267
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• 2018

The purpose of this study was to evaluate the effects of an ESP module program which combines Keller's ARCS model for the $1^{st}$ grade nursing students. Students' learning motivation and academic achievement were compared between an intervention group and a control group and their perception and subjective effects on the module program were identified. Quantitative data showed that the overall level of learning motivation in the intervention group was significantly higher than that in the control group (t=2.391, p=.019). No significant difference was found on the level of academic achievement between two groups (t=0.116, p=.098). Contents analysis on the qualitative data showed that ESP module program was interesting, effective, helpful for understanding clinical settings, and giving confidence and satisfaction. According to the result, it is assumed that the ESP module program which combines ARCS model can be effective in motivating the $1^{st}$ grade nursing students to learn nursing contents and English.

• Korean journal of food and cookery science
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• v.3 no.2
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• pp.68-74
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• 1987

Objective and subjective methods were performed together for TPA analysis of acorn mook, and their correlations were analyzed. As the result of sensory evaluation, hardness and fracturability were most important factors for prediction of preference. Meanwhile, compression test with Instron Universal Testing Machine revealed that P1(maximum peak in first bite) was very effective factor representing the cheracteristics of first bite, and that P2 the latter peak in first bite) was valuable for prediction of characteristics of second bite.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.6
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• pp.630-639
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• 2001

This study proposes a new calculation method for generating real nighttime lamp-lit images. In order to improve the color appearance in the prediction of a nighttime lamp-lighted scene, the lamp-lit image is synthesized based on spectral distribution using the estimated local spectral distribution of the headlamps and the surface reflectance of every object. The Principal component analysis method is introduced to estimate the surface color of an object, and the local spectral distribution of the headlamps is calculated based on the illuminance data and spectral distribution of the illuminating headlamps. HID and halogen lamps are utilized to create beam patterns and captured road scenes are used as background images to simulate actual headlamp-lit images on a monitor. As a result, the reproduced images presented a color appearance that was very close to a real nighttime road image illuminated by single and multiple headlamps compared to the conventional graphic-based algorithm.

• Journal of Navigation and Port Research
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• v.37 no.5
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• pp.559-565
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• 2013

The purpose of this study is to prioritize improvement factors of the tug services in terms of the structural problem, operating system and the present condition of the tug at each port in Korea. It was identified that the tug operating system needs to be mostly improved among the improvement factors of the tug services in Korea. In addition, free contract and rotating system were found to be important factors which need to be improved comparing to other factors such as service quality, tug rules, operating practices of council for tug operation and customer factor. The service attitude of the tug companies was regarded as an important element. And the tug entry system appeared to be an important item. Finally, laws relating to tug business needs to be revised which allow new tug companies enter into the market. As the result of AHP analysis for tug systems and service improvement factors, some fundamental changes of tug operation systems are urgently needed.

• Journal of Broadcast Engineering
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• v.25 no.1
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• pp.113-116
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• 2020

This paper proposes a Quality of Experience (QoE) evaluation experiment to measure the effects of 360-degree video and sensory effects on the subject's degree of immersion, satisfaction, and sense of presence. The test subject responds to a questionnaire about the degree of immersion, satisfaction, and sense of presence after experiencing a 360-degree video accompanied by sensory effects while wearing a head-mounted display (HMD) with a scent diffusion device. As a result of the response analysis, it was confirmed that the proposed experimental method is suitable for measuring the subject's degree of immersion, satisfaction, and sense of presence about 360-degree video and sensory effects. On the other hand, inserting a gray screen for comparison experiments while watching a 360-degree video was found to cause a significant decrease in immersion and realism.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.3
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• pp.268-276
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• 2013

In this paper, we introduce the technologies to handle the interference in the heterogeneous network and evaluate the performance of enhanced Inter-Cell Interference Coordination (enhanced ICIC, eICIC) techniques that are being introduced in 3GPP Release 10. In the time-domain eICIC scheme, time-domain resources are scheduled to avoid the interference by using Almost Blank Subframe (ABS) and Cell Range Expansion (CRE). To mitigate the cross-tier interference between macro and femtocell, it is important to efficiently combine the ABS and CRE in heterogeneous network. Since it is hard to evaluate the total throughput of heterogeneous network numerically, we evaluate the total throughput by using system level simulation (SLS). As a result of evaluation, the throughputs of many different cases of combination of ABS and CRE are compared.