리프팅을 기반으로한 무선채널 환경에서의 에러에 유연한 SPIHT 압축

池仁鎬 弘益大學校 産業技術硏究所 2005 産業技術 Vol.15 No.-

Compressed still image or video bitstreams require protection from channel errors in a wireless channel. Embedded Zerotree Coding(EZW), SPIHT could have provided unprecedented high performance in image compression with low complexity. But wavelet zerotree coding algorithms are producing variable-length codewords, extremely sensitive to bit errors. The idea is to partition the output bitstream from the SPIHT coder into consecutive blocks of length . Then, to each block, checksum bits and zero bits are added to the end to flush the memory and terminate the decoding trellis at the zero state. In SPIHT method a single-bit transmission error may lead to a loss of synchronization between encoder and decoder execution paths, which would lead to a total collapse of decoded video quality. Therefore a major concern of designer is the control of errors so that reliable transmission can be obtained. So we proposed a new error-resilient SPIHT compression based on lifting in wireless channel.

웨어러블 IT 기기에 적용 가능한 초소형 진자 발전기에 관한 연구

지인호,신승중 한국인터넷방송통신학회 2022 한국인터넷방송통신학회 논문지 Vol.22 No.3

In this study, Among the electromagnetic induction power generation (EMG) techniques, the design specifications of the RFPM were set, and a suitable test prototype was manufactured through finite element analysis (FEM, 2D) required for characteristic calculation. In addition, a dedicated testing device (Dynamo-Tester) was designed and manufactured to measure and analyze the test prototype. The test product was measured with a test device and the result is analyzed to suggest a method that can be applied by generating as much output power as possible to charge the battery of the wearable IT device using actual kinetic energy of the human body. As a result of the test, the output power was 1.679W and the efficiency was 79.31% under the conditions of rotation speed of 780.9rpm, torque of 0.264kgf/cm, and load current of 73.6~73.9mA. Therefore, it was analyzed that it was possible to charge the wearable device with the output of the ultra-small RFPM pendulum generator. 본 연구에서는 전자기 유도 발전(EMG) 기법 중 RFPM의 설계사양을 설정하고 특성 계산에 필요한 유한요소해석(FEM, 2D)을 통하여 이에 적합한 시험 시제품을 제작하였다. 또한 시험용 프로토타입의 측정, 분석을 하기위하여 전용검사장치를 설계, 제작하였다. 검사장치로 시험품을 측정하였으며, 그 결과를 분석하여 실제 인체 운동 에너지를 이용하여 웨어러블 IT 기기의 배터리에 충전이 가능한 만큼 출력전력이 생성되어 적용할 수 있는 방법을 제시하고자 한다. 시험결과, 회전수 780.9rpm, 토크 0.264kgf/cm, 부하전류 73.6∼73.9mA의 조건에서 출력 1.679W, 효율 79.31%로측정되었다. 따라서 초소형 RFPM 진자 발전기의 출력으로 웨어러블 기기에 충전이 가능한 것으로 분석되었다.

발표 12 : EDTA 계 무전해 구리 도금 액의 조성 변화에 따른 도금 층의 특성에 관한 연구

지인호,이재호,김영환 대한금속재료학회 ( 구 대한금속학회 ) 2000 대한금속재료학회 학술대회 개요집 Vol.2000 No.0

인체 운동 에너지를 이용한 진자 발전기에 관한 연구

지인호,신승중,Jee, In-Ho,Shin, Seung-Jung 한국인터넷방송통신학회 2022 한국인터넷방송통신학회 논문지 Vol.22 No.5

In this study, Electromagnetic Induction Power Generation (EMG) is a structure consisting of a stator and a permanent magnet rotor, and is a method that enables power generation by using the kinetic energy of the human arm. Among them, the axial flux permanent magnet (AFPM) technique is a method that can act sensitively to the kinetic energy of the arm at a slow speed of the human body, and has a simple structure and can be designed and manufactured with an ultra-small size. Under the conditions of size of ø46×11mm, rotation speed of 7Hz (420rpm), output voltage 0.4VAC, output current 4.5mA, and output power 30mW were measured and analyzed the same as the target specification. Therefore, the purpose of this study is to study the power generation of the pendulum applying the AFPM (Axial Flux Permanent Magnet) technique to charge power to smart devices with kinetic energy of the human body.

계층적 트리의 집합 분할 알고리즘(SPIHT)에 기반한 에러에 강하고 가변적인 웨이브렛 비디오 코덱에 관한 연구

지인호 한국인터넷방송통신학회 2023 한국인터넷방송통신학회 논문지 Vol.23 No.1

Compressed still image or video bitstreams require protection from channel errors in a wireless channel. Embedded Zerotree Coding(EZW), SPIHT could have provided unprecedented high performance in image compression with low complexity. If bit error is generated by dint of wireless channel transmission problem, the loss of synchronization on between encoder and decoder causes serious performance degradation. But wavelet zerotree coding algorithms are producing variable-length codewords, extremely sensitive to bit errors. The idea is to partition the lifting coefficients. A many partition of lifting transform coefficients distributes channel error from wireless channel to each partition. Therefore synchronization problem that caused quality deterioration in still image and video stream was improved.

코히어런트 광통신시스템의 DPSK 복조에 관한 이론적 고찰

지인호,장홍식 한국통신학회 1997 韓國通信學會論文誌 Vol.22 No.5

It is known that the Differential Phase Shift Keying (DPSK) modulation scheme in the coherent optical communication system is suitable for design of long-distance transmission system because its receiver performance is 3-5dB better than ASK and FSK. In this paper, we descrive a fundamental understanding of the effects of laser phase noise on the performance of coherent lighwave communication systems. Formulas are derived for the bit error rate in homodyne and heterodyne DPSK. Based on detailed mathematical analysis and estimates, we explain the following finding. DPSK can operates at rates only 300 times greater than the laser linewidth.

계층적 깊이 영상으로 표현된 다시점 영상의 효과적인 압축 기술

지인호 한국인터넷방송통신학회 2014 한국인터넷방송통신학회 논문지 Vol.14 No.4

다시점 비디오는 카메라 수만큼의 컬러영상들과 깊이 영상들이 존재하므로 막대한 양의 데이터를 갖게 되어서, 그 양을 줄이는 새로운 압축 기술 개발이 필수적이다. 최근 계층적 깊이 영상(Layered Depth Image : LDI)의 개념을 이용하여 깊이 정보를 포함하는 다시점 비디오를 효과적으로 압축 부호화하는 기술이 주목 받고 있다. 이 방법은 여러 시점의 깊이 정보와 워핑(warping) 함수를 사용하여 다시점의 컬러와 깊이 영상을 합성하여 하나의 데이터 구조를 만드는 방법이다. 본 논문에서는 계층적 깊이 영상에서 실제 거리를 이용하고 오버랩(overlap) 문제를 해결하고 그리고 컬러 변환을 기반으로 복원을 위해서 추가되는 데이터의 양을 감소시켜 압축 성능을 향상시키는 방법을 제안하였다. Since multi-view video exists a number of camera color image and depth image, it has a huge of data. Thus, a new compression technique is indispensable for reducing this data. Recently, the effective compression encoding technique for multi-view video that used in layered depth image concepts is a remarkable. This method uses several view point of depth information and warping function, synthesizes multi-view color and depth image, becomes one data structure. In this paper we use actual distance for solving overlap in layered depth image that reduce required data for reconstructing in color-based transform. In experimental results, we confirmed high compression performance and good quality of reconstructed image.

MC-CDMA 시스템에서 주파수 대역 효율에 관한 연구

지인호,Jee, Innho 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.6

MC-CDMA 기법에서 효과적인 주파수 자원을 사용하기 위한 부채널 간섭을 줄이기 위해서 FFT 기법대신에 2 채널 필터 뱅크 기법을 제안하였다. 웨이브렛 특성을 가지는 원형 필터 뱅크는 보다 적은 sidelobe를 가지도록 설계되므로 가장 가까운 상호채널 간섭과 부호간의 간섭은 효과적으로 감소된다. 제안하는 MC-CDMA 시스템의 확산신호는 보다 적은 chip rate가 요구되고 자기상관 특징을 고려하지 않는 Walsh 코드가 최적의 신호 세트로 사용된다. 우리는 백색잡음 채널과 임의의 정현파 방해자가 존재하는 조건하에서 제안된 시스템의 성능을 추정하기 위해서 비트 오차 속도와 신호대잡음비를 고려하였다. 기존의 FFT 기반의 MC-CDMA 모의시험 결과와 비교하여 제안된 시스템이 간섭 효과를 줄이는 관점에서 기존의 MC-CDMA 기법보다 좋은 성능을 나타냄을 증명하였다. We propose 2-channel filter bank method instead of FFT method to decrease sub-channel interference for using of efficient frequency resource in MC-CDMA method. Since a prototype filter of filter bank having wavelet characteristic is designed having more less side-lobe, the nearest co-channel interference and inter symbol interference are decreased efficiently. Since the spreading signal of suggesting MC-CDMA system is being demanded for less chip rate and is not being considering for autocorrelation characteristic, the Walsh code can be used as a optimal orthogonal signal set. We consider bit error rate and signal to noise ratio to estimate the performance of suggested system on condition that white noise channel and arbitrary sinusoidal jammer are existing. As a result of comparing to traditional FFT-based MC-CDMA simulation result, our suggested system has shown better performance than traditional MC-CDMA method on the side of minimizing interference effect.

리프팅 구조를 경유한 고속의 DCT 계산 알고리즘에 관한 연구

지인호 한국인터넷방송통신학회 2023 한국인터넷방송통신학회 논문지 Vol.23 No.6

We show the design of fast invertible block transforms that can replace the DCT in future wireless and portable computing application. This is called binDCT. In binDCT, both the forward and the inverse transforms can be implemented using only binary shift and addition operation. And the binDCT inherits all desirable DCT characteristics such as high coding gain, no DC leakage, symmetric basis functions, and recursive construction. The binDCT also inherits all lifting properties such as fast implementations, invertible integer-to-integer mapping, in-place computation. Thus, this method has advantage of fast implementation for complex DCT calculations. In this paper, we present computation costs and performance analysis between DCT and binDCT using Shapiro's EZW.

동심원 모자이크의 실시간 표현을 위한 데이터 압축 알고리즘에 관한 연구

지인호,안홍영 한국인터넷방송통신학회 2010 한국인터넷방송통신학회 논문지 Vol.10 No.1