• Korean Journal of Remote Sensing
• /
• v.14 no.3
• /
• pp.213-222
• /
• 1998

Electro-Optical Camera(EOC) is the main payload of the KOrea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including a Digital Terrain Elevation Map(DTEM). This instalment which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510~730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response, the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the users of EOC data. The modulation transfer function of EOC was measured as greater than 16 % at Nyquist frequency over the entire field of view, which exceeds its requirement of larger than 10 %. The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.49 no.3
• /
• pp.8-14
• /
• 2012

Improving the speed of image processing is in great demand according to spread of high quality visual media or massive image applications such as 3D TV or movies, AR(Augmented reality). SIMD computer attached to a host computer can accelerate various image processing and massive data operations. MAMS is a multi-access memory system which is, along with multiple processing elements(PEs), adequate for establishing a high performance pipelined SIMD machine. MAMS supports simultaneous access to pq data elements within a horizontal, a vertical, or a block subarray with a constant interval in an arbitrary position in an $M{\times}N$ array of data elements, where the number of memory modules(MMs), m, is a prime number greater than pq. MAMS-PP4 is the first realization of the MAMS architecture, which consists of four PEs in a single chip and five MMs. This paper presents implementation of image processing algorithms and performance analysis for MAMS-PP16 which consists of 16 PEs with 17 MMs in an extension or the prior work, MAMS-PP4. The newly designed MAMS-PP16 has a 64 bit instruction format and application specific instruction set. The author develops a simulator of the MAMS-PP16 system, which implemented algorithms can be executed on. Performance analysis has done with this simulator executing implemented algorithms of processing images. The result of performance analysis verifies consistent response of MAMS-PP16 through the pyramid operation in image processing algorithms comparing with a Pentium-based serial processor. Executing the pyramid operation in MAMS-PP16 results in consistent response of processing time while randomly response time in a serial processor.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.5
• /
• pp.336-343
• /
• 2018

We herein present the design and fabrication of a Rx core chip operating in the X-band (10.5~13 GHz) using Win's commercial $0.25-{\mu}m$ GaAs pHEMT process technology. The X-band core chip comprises a low-noise amplifier, a four-bit phase shifter, and a serial-to-parallel data converter. The size is $1.75mm{\times}1.75mm$, which is the state-of-the-art size. The gain and noise figure are more than 10 dB but less than 2 dB, and both the input and output return losses are less than 10 dB. The RMS phase error is less than $5^{\circ}$, and the P1dB is 2 dBm at 12.5 GHz, the performance of which is equivalent to other GaAs core chips. The fabricated core chip was packaged in a QFN package type with a size of $3mm{\times}3mm$ for the convenience of assembly. We confirmed that the performance of the packaged core chip was almost the same as that of the chip itself.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.1
• /
• pp.129-136
• /
• 2004

In this paper, we proposed quad variable rates ADPCM coding method for efficient speech transmission and real time porcessing is implemented on TMS320C6711-DSP. The modified ADPCM with four variable coding rates, 16[kbps], 24[kbps], 32[kbps] and 40[kbps] are used for speech window samples for good quality speech transmission at a small data bits and real time encoding and decoding is implemented using DSP. ZCR is used to identify the influence of the noise on the speech signal and to decide the rate change threshold. For noise superior signals, low coding rates are applied to minimize data bit and for noise inferior signals, high coding rates are applied to enhance the speech quality. In most speech telecommunications, silent period takes more than half of the signals, speech quality close to 40[kbps] can be obtained at comparabley low data bits and this is shown by simulation and experiments. TMS320C6711-DSK board has 128K flash memory and performance of 1333MIPS and has meets the requirements for real time implementation of proposed coding algorithm.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.32 no.4
• /
• pp.340-355
• /
• 1996

In order to suggest the useful information of fishing ground, a data base system on 32bit personal computer was constructed and handled by using the catch data of Korean tuna long-line, catch by species, fishing time and place, fish price and etc. mainly from 1975 to 1992. The results obtained are as follows ; In the fishing ground displaying catch rate, the catch rate has reduced as time passed, and this penomenon was more evident in Indian. And yellowfin have high catch tate in the Western Pacific of low latitute region, bigeye tuna have in the Eastern. The region of high catch rate of bigeye tuna was moved from the Indian and the Atlantic to the Pacific. The patterns of catch numbers of yellowfin and bigeye tuna appeared nearly same that, having nothing to do with catch numbers in all oceans. The region of least catch was the Northwestern Pacific, the regions of most catch were the Western Indian and the Pacific of low latitute. As to simulation of fishing ground estimation, there were economical grounds in the Western Pacific of low latitute region, the Eastern Pacific of this, the Western Indian, the Eastern Indian, and the Atlantic, in order.

• Journal of Advanced Navigation Technology
• /
• v.6 no.1
• /
• pp.37-43
• /
• 2002

This paper describes the performance evaluation and analysis of Wireless Local Area Network (W-LAN) in the 5 GHz ISM-band in compliance with IEEE 802.11a. At present, most W-LAN products are based on 2.4 GHz band, but low speed (11Mbps) has the limitation to serve systems demanding high-speed data transmission. To solve this problem, it is necessary to design next generation W-LAN system with 54Mbps in the 5GHz. It is sure that implementation of next generation W-LAN will bring competitive advantages. In particular, it will support telecommunications for high-speed mobile environments as well as for fixed places such as a school zone, a lecture room, a hospital and other premises. A few simulation methods are applied to more accurate and reliable performance analysis of next generation W-LAN. To verify if continuous data service is supported for a high-speed mobile notebook, multi-path fading channels between wireless Access Point (AP) and wireless Network Interface Card (NIC) are modeled. In addition, low interference is analyzed via convolutional codes and Orthogonal Frequency-Division Multiplexing (OFDM). Also, to obtain reliable Bit Error Rate (BER), a single tap Least Mean Square (LMS) equalizer is applied. Given the above simulation, next generation W-LAN is an ideal solution for continuous data transmission in high-speed mobile environments.

• Journal of Distribution Science
• /
• v.12 no.2
• /
• pp.105-112
• /
• 2014

Purpose - This research undertakes to understand the trade structures of both China and Japan to strengthen Sino-Japan economic cooperation and examines impediments to trade between the 2 countries to analyze causes which affect trade and to examine improvements in these areas to find out ways of trade expansion. Through this survey of a defined period of time, we can identify the structural factors of trade dependence in the relationship between China and Japan. Research design, data, methodology - The data were collected from Korea Traders Association, Korea Customs Office and UN Comtrade, from which whole table indexes are calculated by author. This research methodology uses trade related indexes to focus on analyzing comparative advantages based on time-series analysis statistics data (2000~2012), by using the analysis index of Trade Intensity Index (TII), Revealed Comparative Advantage Index (RCA) and Trade Specialization Index (TSI). Results - The export ratio for China against Japan was a little higher in 2000 at 2.867 and the export ratio for China against Japan was sustained in 2005. However, it diminished gradually and reached 1.263 in 2012. During the whole period of 2000~2012, the indexes were maintained without any significant change. However, they are still moving closer to -1. Especially, in 2012 it is the closest it has been to -1. Therefore, Japan has a comparative advantage toward export specialization. On the other hand, China has a comparative advantage toward import specialization. For the whole research period, all indexes were much smaller than 1, which means that China has comprehensively had a comparative disadvantage against Japan for the past 10 years when compared to other industries, even though it had improved in 2000. Conclusions - The summary of conclusions based on empirical analysis research are as follows: First, per the Trade Intensity Index of industries between the 2 countries, we can conclude that export ratio index is 2.867, based on the formula, in 2000, which means the export ratio of China against Japan is a little bit higher. Furthermore, the ratios of 2.259 and 1.263 are indicated in 2005 and 2012 respectively which mean the export ratio of China against Japan was maintained in 2005 but was diminishing gradually as the index is 1.263 in 2012. Second, per the Trade Specialization Index of the shipping industry between China and Japan, -0.379 is indicated in 2000, -0.368 in 2005 and -0.568 in 2012. Looking at the whole period of 2000~2012, the indexes were maintained without any significant change. However, they are still moving closer to -1. Especially, in 2012 it is the closest it has been to -1. Third, per the Revealed Comparative Advantage Index of the automobile industry between China and Japan, the RCA indexes in 2005 and 2012 are 0.246 and 0.306 respectively which are still far from 1 even though the index is improved compared to 2000's value of 0.0001. Therefore, the Chinese automobile industry is very much at a comparative disadvantage to that of the Japanese automobile industry.

• The KIPS Transactions:PartC
• /
• v.16C no.5
• /
• pp.661-668
• /
• 2009

The Extended real-time Polling Service (ErtPS) is proposed tosupport QoS of VoIP service with silence suppression which generates variable size data packets in IEEE 802.16e systems. If the silence is suppressed, VoIP should support Comfort Noise Generation (CNG) which generates comfort noise for receiver's auditory sense to notify the status of connection to the user. CNG mode in silent-period generates a data with lower bit rate at long packet transmission intervals in comparison with talk-spurt. Therefore, if the ErtPS, which is designed to support service flows that generate data packets on a periodic basis, is applied to silent-period, resources of the uplink are used inefficiently. In this paper, we proposed the Improved ErtPS algorithm for efficient resource utilization of the silent-period in VoIP traffic supporting CNG. In the proposed algorithm, the base station allocates bandwidth depending on the status of voice at the appropriate interval by havingthe user inform the changes of voice status. The Improved ErtPS utilizes the Cannel Quality Information Channel (CQICH) which is an uplink subchannel for delivering quality information of channel to the base station on a periodic basis in 802.16e systems. We evaluated the performance of proposed algorithm using OPNET simulator. We validated that proposed algorithm improves the bandwidth utilization of the uplink and packet transmission latency

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.10
• /
• pp.82-94
• /
• 2015

In this paper, we propose hardware prefetch mechanism with an efficient cache replacement policy by giving priority to the trigger block in which a spatial region and producing a spatial region by using the displacement field. It could be taken into account the sequence of the program since a history is based on the trigger block of history record, and it could be quickly prefetching the instructions or data address by adding a stored value to the trigger address and displacement field since a history is stored as a displacement value. Also, we proposed a method of replacing at random by the cache replacement policy from the low priority block when the cache area is full after giving priority to the trigger block. We analyzed using the memory simulator program gem5 and PARSEC benchmark to assess the performance of the hardware prefetcher. As a result, compared to the existing hardware prefecture to generate the spatial region using a bit vector, L1 data cache miss rate was reduced about 44.5% on average and an average of 26.1% of L1 instruction misses occur. In addition, IPC (Instruction Per Cycle) showed an improvement of about 23.7% on average.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.43 no.4 s.310
• /
• pp.123-132
• /
• 2006

In this paper, the digital video and audio system is improved so that various digital video data formats in DVD disc, and digital audio data formats through the S/PDIF ports may be decoded. It is not easy to implement all decoding functions of video and audio by a DVD processor. The special structure in audio decoding circuit is proposed in this system so as to have simultaneously almost same video and audio performance in quality. By dividing the decoding circuit separately into video and audio part, the audio quality can be dramatically improved together with supporting several audio formats and with several effects. In order to satisfy the perfect audio system to support to audio decoding formats, it is just enough to get the expensive, complicated decoder. However, it may be not easy to get this expensive decoder in near future. Therefore it is rather to adopt the downloading method by which the host should download the appropriate code into memory by detecting the corresponding audio bit streams. It is proved that this method may be efficient in the point of sharing resource of audio data for video decoding.