• Journal of Broadcast Engineering
• /
• v.1 no.1
• /
• pp.67-73
• /
• 1996

In general, the high quality audio coding(HQAC) has the structure of the convertional data compression techniques combined with moodels of human perception. The primary auditory characteristic applied to HQAC is the masking effect in the spectral domain. Therefore spectral techniques such as the subband coding or the transform coding are widely used[1][2]. However no effort has yet been made to apply the temporal masking effect and temporal redundancy removing method in HQAC. The audio data compression method proposed in this paper eliminates statistical and perceptual redundancies in both temporal and spectral domain. Transformed audio signal is divided into packets, which consist of 6 frames. A packet contains 1536 samples($256{\times}6$) :nd redundancies in packet reside in both temporal and spectral domain. Both redundancies are elminated at the same time in each packet. The psychoacoustic model has been improved to give more delicate results by taking into account temporal masking as well as fine spectral masking. For quantization, each packet is divided into subblocks designed to have an analogy with the nonlinear critical bands and to reflect the temporal auditory characteristics. Consequently, high quality of reconstructed audio is conserved at low bit-rates.

• Journal of Satellite, Information and Communications
• /
• v.11 no.2
• /
• pp.55-59
• /
• 2016

Conventional RF energy harvesting systems can harvest energy and decode information from same source as an Hybirid-AP (H-AP). However, harvesting efficiency is seriously dependent on distance between users and H-AP. Therefore, in this paper, we proposed a transmission model for RF harvesting consisting of information and power source separately called Decoupled RF Energy harvesting networks. Main purpose of this paper is to maximize energy efficiency under various constraints of transmit power from H-AP and power beacon (PB), minimum quality of service and quality of harvested power of each users. To measure proposed model's performance, we proposed optimal time scheduling algorithms for energy efficiency (EE) maximization using Lagrangian dual decomposition theory that locally maximizes the EE by obtaining suboptimal values of three arguments : transmit power of H-AP, transmit power of PB, frame splitting factor. Experiment results show that the proposed energy-efficient algorithms converge within a few iterations with its optimality and greatly improve the EE compared to that of baseline schemes.

• The Journal of the Korea Contents Association
• /
• v.15 no.2
• /
• pp.11-20
• /
• 2015

In this paper, we develop an intelligent mobile surveillance system based on binary CDMA for the unmanned automatic tracking and surveillance. That is, we implement a intelligent surveillance system using the binary CDMA wireless communication technology which is applied the merit of CDMA and TDMA on it complexly. This system is able to monitor the site of the accident on network in real time and process the various situations by implementing the security surveillance system. This system pursues an object by the 360-degree using camera, expands image using a PTZ(Pan/Tilt/Zoom) camera zooming function, identifies the mobile objects image within a screen and transfers the identified image to the remote site. Finally, we show the efficiency of the implemented system through the simulation of the controlled situations, such as tracking coverage on objects, object expansion, object detection number, monitoring the remote transferred image, number of frame per second by the image output signal etc..

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.39 no.1
• /
• pp.67-74
• /
• 2002

A study on image searching and management techniques is actively developed by user requirements for multimedia information that are existing as images, audios, texts data from various information processing devices. If we can automatically detect and segment changing scenes from real-time image sequences, we can improve an effectiveness of image searching systems. In this paper, we propose cut detection techniques based on image color distribution and we evaluated its performance on various real-time image sequences. Results of experiments show that the proposed method are robust on various image patterns than color histogram method using statistical informations of images. Also, these methods can be used for cut detection on real-time image sequences.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3301-3306
• /
• 2012

In LED chip packaging, die bonding is a very important process which fixes the LED chip on the lead frame to provide enough strength for the next process. Conventional pick-up device of the die bonder is simply operated by up and down motion of a collet and an ejector pin. However, this method may cause undesired problems such as position misalignment and/or severe die damage when the pick-up device reaches the die. In this study, to minimize the position alignment error and die damage, a die bonder is developed by adopting a new pick-up head for precise alignment and high speed feeding. To evaluate structural stability of the designed system, required finite element model of the die bonder is generated, and structural analysis is performed. Vibration analysis of the pick-up head is also performed using developed finite element model at operation frequency range. As a result of the analysis, deformation, stress, and natural frequency of the die bonder are investigated.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.2
• /
• pp.41-50
• /
• 2020

Acting is an act of expressing personality, image, sound, tempo, and movement flexibility in order to effectively express fictional characters in the play. It is said to refer to the action or mood of the person performing the character. In addition, all these acts are important elements of the media that the director wants to convey the subject of the work to the audience. In particular, the actor relies on the ambience, image and passionate role of winning and losing in theatrical film. In addition, more than 60% of the afterimages or remaining images in the film are images of the actor's acting or movement, and the trend of the actor. This study is not about acting divided by Conti, who is under the control of directors and directors. The purpose of this study is to analyze the aesthetic response and analyze the inner half of the suspense in the act and to help influence the expression that is effective in expressing the play.

• Journal of Aerospace System Engineering
• /
• v.16 no.4
• /
• pp.17-27
• /
• 2022

In this study, a deep learning-based network that can predict the aerodynamic characteristics of airfoils was designed, and the feasibility of the proposed network was confirmed by applying aerodynamic data generated by Xfoil. The prediction of aerodynamic characteristics according to the variation of airfoil thickness was performed. Considering the angle of attack, the coordinate data of an airfoil is converted into image data using signed distance function. Additionally, the distribution of the pressure coefficient on airfoil is expressed as reduced data via proper orthogonal decomposition, and it was used as the output of the proposed network. The test data were constructed to evaluate the interpolation and extrapolation performance of the proposed network. As a result, the coefficients of determination of the lift coefficient and moment coefficient were confirmed, and it was found that the proposed network shows benign performance for the interpolation test data, when compared to that of the extrapolation test data.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.8
• /
• pp.85-90
• /
• 2022

In this study, to reduce the time and cost disadvantages of the traditional motion graphic production method in order to realize the movement of a virtual camera identical to that of the real camera, motion graphics virtualization using AR Core-based mobile device real-time tracking data A method for creating a camera is proposed. The proposed method is a method that simplifies the tracking operation in the video file stored after shooting, and simultaneously proceeds with shooting on an AR Core-based mobile device to determine whether or not tracking is successful in the shooting stage. As a result of the experiment, there was no difference in the motion graphic result image compared to the conventional method, but the time of 6 minutes and 10 seconds was consumed based on the 300frame image, whereas the proposed method has very high time efficiency because this step can be omitted. At a time when interest in image production using virtual augmented reality and various studies are underway, this study will be utilized in virtual camera creation and match moving.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2001.10a
• /
• pp.338-341
• /
• 2001

본 연구는 현재 정부의 규제완화 및 다양한 대체서비스의 등장으로 인해 점차 시장내 경쟁이 심화되어 가고 있는 기업용 전용선 서비스 시장에 있어 향후 경쟁상황이 어떻게 진행될지에 대한 연구를 통하여 이에 속한 기업들의 향후 시장전략을 제시하는 것을 목적으로 하고 있다. 향후 경쟁상황을 예측하는데 있어 본 연구에서는 사용하는 방법론으로 첫째, 기업용 전용선 서비스 시장의 전체 수요예측을 우선적으로 실시한 후 둘째, 전체 시장의 수요를 바탕으로 이에 속하는 개별 서비스간의 경쟁관계와 대체관계에 의한 개별 서비스 수요를 예측하게 된다. 이상과 같은 서비스간의 수요를 도출함으로써 시장내 경쟁상황과 경쟁정도를 파악하게 된다. 현재 기업용 전용선 서비스 시장의 경우 가장 큰 특징이 바로 신규 대체 서비스들의 등장이고, 이들 서비스에 의해 전체 시장규모가 얼마나 성장할 것인지, 전체 시장에서 개별 서비스들의 기여도는 어느 정도가 되는지가 최대 관심사이다. 이에 대한 문제를 해결하기 위해 본 연구에서는 신규 대체 서비스가 시장에 진입하였을 때 파급효과가 얼마나 되는지를 추정하여 수요를 예측하였다. 이에 대한 추정결과 연구대상으로 하고 있는 전용회선서비스, 프레임릴레이서비스, 가상사설망서비스에서 전용회선서비스에 대한 타 유사서비스들의 영향력은 그리 크지 않는 것으로 나타났으며, 이에 반해 가상사설망서비스는 프레임릴레이서비스를 대체하고 있는 것으로 분석되었다. 연구 결과를 통해 사업자들은 향후 시장경쟁 상황을 예측할 수 있기 때문에 이에 대해 적절한 사업전략을 수립하는데 큰 도움을 얻게 되리라 기대한다.적 분할납품 전략 적용 수요지로 선택하고 사이버 거래를 통해 생성된 물류가 부분적 분할납품 전략 적용 수요지에 분배되게 함으로써 각 분배 센타의 재고 완충역할을 수행하게 한다. 이에 따라 안전 재고 및 역 배송을 최소화 할 수 있을 뿐 아니라 미 출고로 인한 손실을 최소화하며 고객의 서비스를 일정하게 유지시킬 수 있을 것으로 기대된다.증진, 페기물 발생 억제 분야에 상당한 성공을 거두었으며, 지금도 지속적으로 유지 관리 및 미비한 부분(CAER, 등)의 향상에 노력하고 있다. Dow Korea의 수입 판매 부분에 주로 관련된 Product Stewardship 및 Distribution Code는 여러 사업부 및 여러 지역(미국, 유럽, 아시아 등)에 위치한 담당자가 관련된 까닭에 가장 복잡한 부분이어서 많은 인력과 시간을 소비하면서 노력하고 있으나 아직까지 소정의 목표에 도달하지 못했으며, 2000년 말에 모든 실행지침이 실행되도록 목표, 실행 계획 및 조직을 수정하여 노력하고 있다.lumn density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.9B
• /
• pp.751-759
• /
• 2008

Carrier Ethernet backbone network integrates distributed layer-2 based metro networks. In this networks, Multiple Spanning Tree Protocol (MSTP) has been uscd as a main routing protocol that allows multiple spanning trees in a network. A better routing protocol called IEEE802.1aq - Shortest Path Bridging (SPB) is recently proposed, that generates the shortest spanning tree per a destination node. As SPB provides a routing path per a destination node, there is no way to adapt network traffic at normal condition. If we are free from the principle of "a spanning tree per a destination node", we can achieve adaptive routing. Based on this philosophy, we propose a new spanning tree based protocol - Edge Node Divided Spanning Tree (ENDIST). ENDIST divides an edge node into sub-nodes as many as connecting links from the node and each sub-node generates a single shortest path tree based on SPB. Depending on network or nodal status, ENDIST chooses a better routing path by flow-basis. This added traffic engineering ability contributes to enhanced throughput and reduced delay in backbone networks. The simulation informs us that ENDIST's throughput under heavy load performs about 3.4-5.8 and 1.5-2.0 times compared with STP's and SPB's one respectively. Also, we verified that ENDIST's throughput corresponds to the theoretical upper bound at half of cases we investigated. This means that the proposed ENDIST is a dramatically enhanced and the close-to-perfect spanning tree based routing schemes.