• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.1
• /
• pp.86-91
• /
• 2012

To provide high voice quality of real-time voice communication based on telematics exposed to various noise environments, the noise reduction algorithm with low computing load is required to effectively remove the noise. In this paper, we propose a noise reduction algorithm based on Mel-Filter and illustrate the proposed algorithm comparing with conventional noise reduction algorithms. As a experimental result that evaluates the performance of the noise reduction algorithms under the car and babble noise environments, the proposed noise reduction algorithm has the lower computing load with the similar PESQ score compared to the conventional noise reduction algorithms. It proves that the proposed noise reduction algorithm can efficiently remove the noise in mobile telematics.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.9 no.5
• /
• pp.80-86
• /
• 2010

This paper presents automated music story video generation technique as one of entertainment features that is equipped in multimedia system of the vehicle. The automated music story video generation is a system that automatically creates stories to accompany musics with photos stored in user's mobile phone by connecting user's mobile phone with multimedia systems in vehicles. Users watch the generated music story video at the same time. while they hear the music according to mood. The performance of the automated music story video generation is measured by accuracies of music classification, photo classification, and text-keyword extraction, and results of user's MOS-test.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.3
• /
• pp.48-54
• /
• 2012

The quality of real-time voice communication over Internet Protocol networks based on telematics is affected by network impairments such as delays, jitters, and packet loss. To resolve this issue, this paper proposes a receiver-based enhancing method of VoIP speech quality. The proposed method enables users to deliver high-quality voice using playout control and signal reconstruction, which consists of concealment of lost packets, adaptive playout-buffer scheduling using active jitter estimation, and smooth interpolation between two signals in a transition region. The proposed algorithm achieves higher Perceptual Evaluation of Speech Quality (PESQ) values and low buffering delay than the reference algorithm.

• Journal of the Korean Arthroscopy Society
• /
• v.1 no.1
• /
• pp.102-107
• /
• 1997

Discoid meniscus has been well known to a frequent anomaly of meniscus and much reported in diagnosis and treatment. But, associated X-ray findings have not been known well. We reported its significance of X-ray findings in discoid meniscus. From May 1995 to May 1997, 31 cases of discoid meniscus were compared with 51 cases of nondiseoid meniscus both confirmed by arthroscopy, with simple X-my findings. Both groups were evaluated by X-ray findings in view of lateral joint space widening, peripheral spur of lateral joint space, sclerotic change of lateral tibial plateau, concave lateral tibial plateau, flattening of lateral femoral condyle, hypoplasia of lateral femoral condyle and high riding fibula. The results of analysis were as follows: 1. Widening of lateral joint space, sclerotic change of lateral tibial plateau and cupping of lateral tibial plateau were statistically significant in discoid meniscus. 2. X-ray findings in discoid meniscus were not associated with patient's injury history and symptom duration. 3. Other X-ray findings were not related in discoid meniscus significantly. X-ray findings with patient's history and physical examination arc helpful in the diagnosis of discoid meniscus.

• The Journal of the Acoustical Society of Korea
• /
• v.32 no.6
• /
• pp.541-547
• /
• 2013

The speech quality of multi-party audio telephony between two, three or more participants is decreased by audio volume imbalance, audio volume saturation and noise level increase. To solve this issue, this paper proposes an advanced audio mixing algorithm for software-based multi-point control unit. Our approach is based on the combined voice activity detection and gain control technique that consists of a set of algorithms that classify audio signals, estimate audio volumes, adjust gain factors and mix audio signals of all channels. The proposed audio mixing algorithm is computationally efficient, delivers high-quality speech, and is suitable for use in any practical multi-party audio telephony.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.218-219
• /
• 2010

온라인 전기자동차는 도로에 매설된 급전선로로부터 유도자계를 통하여 비접촉 방식으로 전기를 집전 받아 정차 및 주행 중에 충전하는 자동차이다. 이러한 비접촉 충전을 위해서는 도로에 매설된 급전 시스템과 차량 하부에 장착된 집전 시스템이 필요하며, 급전 시스템은 다시 급전 인버터와 급전선로로, 집전 시스템은 집전 모듈(pick-up)과 집전 레귤레이터로 구성된다. 본 논문에서는 급집전 시스템 각각의 장치를 소개하며, 더불어 구축된 시스템의 성능에 대해서도 소개한다.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.94-94
• /
• 2009

The purpose of this study is to identify the principal factor controlling transverse residual stress at the weldment for joining unit hull blocks. In order to do it, the comprehensive FE analyses were carried out to evaluate the effect of distance between fillet and butt weldments, in-plane and out-of-plane restraint degree on the amount and distribution of transverse residual stress in way of the weldments between unit hull blocks. In accordance with FEA results, principal factor controlling the amount of transverse residual stress at the weldments was identified as in-plane restraint degree of butt weldment for unit blocks. The effect of other variables on the transverse residual stress was very small relatively. Based on the results, it can be concluded that the proper distance between fillet weldment for stiffener and butt weldment for joining unit blocks should be determined in consideration of in-plane restraint intensity of butt weldments.

• Journal of Welding and Joining
• /
• v.33 no.1
• /
• pp.80-86
• /
• 2015

The purpose of this study is to establish the predictive method of the angular distortion caused by the line heating process with high frequency induction heating. In order to do it, the heat input model for the high frequency induction heating system was established through comparing the temperature evaluation results obtained by both FEA and experiment. The critical heating conditions to prevent the degradation of the work piece with various thicknesses were identified by FEA and microstructure test results. Under the critical heating conditions, the extensive line heating tests were performed. According to the test results, it was found that the angular distortion behavior of the heated plates could be defined as the function of heat intensity and the rigidity of heated plate. In addition, it was clarified that the angular distortion strongly depended on the size of test specimen such as the length and the width of the heated plate. Based on these results, the predictive equation for the angular distortion was established with the function of heat intensity, bending rigidity and size of heated plate.

• Journal of Welding and Joining
• /
• v.30 no.5
• /
• pp.51-56
• /
• 2012

The purpose of this study is to evaluate the distortion and the residual stress of GTA tubular welds between tube and head. In order to do it, the heat input model for GTA welding process was first developed by experiment and FE analyses. The welding distortion and the residual stress distribution of the tubular welds according to welding pass and various restraint degrees were evaluated by using FEA with the heat input model. From FEA results, it was found that the residual stress and the radial distortion at the weld toe of tube part decrease with a decrease in the number of welding pass. However, the maximum residual stresses in each direction of tubular welds are almost constant regardless of the external restraint degree. It was mainly due to the high internal restraint of the welds.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.4
• /
• pp.81-86
• /
• 2009

This research is a part of the Intelligent Urban Facility Management project of the Korean Land Spatialization Group (KGSL). First, this study started from the investigation of existing u-City service model in order to drive essential components and considerations for the urban facilities management system. Considering the driven conclusions, this study finally proposed the new classification system of urban facilities management service model and the adequate application method in u-City.