• Korean Journal of Plant Resources
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• v.13 no.1
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• pp.54-60
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• 2000

To investigate the effects of Oenanthe javanica sap (OJS) on plasma lipid composition, several biochemical parameters such as total cholesterol, HDL-cholesterol, triglyceride, GOT, GPT and malodialdehyde were compared in the four groups as follows: a normal group with basal diet, a control group with high-fat diet, a treatment group with high-fat diet and OJS 1 ml/kg, and the other treatment group with high-fat diet and OJS 1.5 mg/kg. In addition, the body weight change, food intake and food efficiency ratios were measured. In this study, treatment groups decreased plasma total cholesterol levels.

• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1027-1036
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• 2020

In this study, a cloud-based processing method using Agisoft Metashape, a commercial software, and Amazon web service, a cloud computing service, is introduced and evaluated to quickly generate high-precision 3D realistic data from large volume UAV images acquired in disaster sites. Compared with on-premises method using a local computer and cloud services provided by Agisoft and Pix4D, the processes of aerial triangulation, 3D point cloud and DSM generation, mesh and texture generation, ortho-mosaic image production recorded similar time duration. The cloud method required uploading and downloading time for large volume data, but it showed a clear advantage that in situ processing was practically possible. In both the on-premises and cloud methods, there is a difference in processing time depending on the performance of the CPU and GPU, but notso much asin a performance benchmark. However, it wasfound that a laptop computer equipped with a low-performance GPU takes too much time to apply to in situ processing.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.844-848
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• 2002

Araki[5]등은 Mambo[1]의 대리 서명 방식을 확장하여 대리 서명자의 부재시 또 다른 대리 서명자가 원 서명자를 대신해서 서명을 생성할 수 있는 다단계(multi-level) 대리 서명 방식을 제안하였다. 그러나 그들이 제안한 방식은 검증자가 전송받은 서명이 타당한 서명자들로부터 생성된 것인지 확신할 수 없는 문제점과 다단계 환경(예를 들어 위임 서명 유효기간 재설정)에 적합한 위임 서명 키 생성이 어렵다는 문제점이 있다. 따라서 본 논문에서는 전자적 처리 환경에 좀더 안전하고 융통성있는 응용을 위해 보증 위임 대리 서명 방식과 proxy-signcryption 방식을 확장한 다단계 대리 서명 방식을 제안하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1037-1043
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• 2006

There has been proposed an algorithm to reduce data burst processing delay in group scheduling in core nodes of optical burst switching networks. Since, in this algorithm, look-up tables containing all the void time information in scheduling windows are generated as soon as the primary group scheduling session terminates, it becomes faster to reassign dropped data bursts to proper voids in different data channels by referring to the tables. The group scheduling with this algorithm showed almost the same channel utilization as the one without using the algorithm but performed a little better in both burst loss probability and wavelength conversion rate. On the other hand, per-burst processing time has been reduced dramatically in the load region of higher than 0.8, showing a factor of 2.1 reduction at 0.9.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.122-131
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• 2000

In this paper, we propose a cell scheduling algorithm for input queueing ATM switch. The input queueing architecture is attractive for building an ultra-high speed ATM (Asynchronous Transfer Mode) switch. We proposea WMUCS (Weighted Matrix Unit Cell Scheduler) based on the MUCS which resolves HOL blocking and outputport contention. The MUCS algorithm selects an optimal set of entries as winning cells from traffic matrix (weightmatrix). Our WMUCS differs from the MUCS in generating weight matrices. This change solves the starvationproblem and it reduces the cell loss variance. The performance of the proposed algorithm is evaluated by thesimulation program written in C++. The simulation results show that the maximum throughput, the average celldelay, and the cell loss rate are significantly improved. We can see that the performance of WMUCS is excellentand the cost-effective implementation of the ATM switch using proposed cell scheduling algorithm.

• The KIPS Transactions:PartC
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• v.15C no.1
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• pp.31-36
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• 2008

The clock frequency difference of sensor nodes is one of main parameters in TOF estimation and affect to degrade ranging algorithms to estimate positions of mobile nodes in wireless sensor networks. The specification of IEEE802.15.4a describes asynchronous TWR and SDS-TWR insensitive to frequency difference without any additional network synchronization. But the TWR and SDS-TWR can not eliminate sufficiently the effect of frequency difference of node pair, packet processing delay and its difference. Especially use of low cost oscillator with wide range offset, sensor node with different hardware and software can make the positioning errors worse. We propose an estimation method of frequency differences, and apply the measured frequency differences to TWR and SDS-TWR. We evaluate the performance of the proposed algorithm with simulation, and make certain that the proposed method enhances the performance of existing algorithms with positioning errors less than 25 cm.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.107-117
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• 2020

With the recent development of autonomous vehicles, various sensors installed in vehicles have become common, and big data generated from those sensors is increasingly being used in the transportation field. In this study, we proposed a grid index method to efficiently process real-time vehicle sensing big data and public data such as road weather. The applicability and effect of the proposed grid space division method and grid ID generation method were analyzed. We created virtual data based on DTG data and mapped to the road link based on coordinates. As a result of analyzing the data processing speed in grid index method, the data processing performance improved by more than 2,400 times compared to the existing link unit processing method. In addition, in order to analyze the efficiency of the proposed technology, the virtually generated data was mapped and visualized.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2980-2988
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• 1998

This paper describes the design of asynchronous adders based on carry selection and carry bypass techniques. The designs are faster than existing asynchronous adders which are based on ripple carry technique. It is caused by reducing the carry transfer time by using carry selection and carry bypass techniques. Also, the design uses tree structure to reduce the completion sensing time. The proposed adders are designed with CMOS domino logic and experimented with HSPICE simulator. Experimental results show that the proposed adders can be faster about 50% in average cases than previous ripple carry adders.

• The Magazine of the IEIE
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• v.41 no.6
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• pp.18-26
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• 2014

신호의 표현과 압축은 밀접하게 연관되어 있다. 만약 매우 효과적인 신호 표현 방식을 찾을 수 있다면 매우 높은 비율로 신호 압축이 가능하다. 또한 효과적인 신호 표현 방식을 통해 우수한 성능과 낮은 복잡도를 갖는 신호 추정 방식을 유도할 수도 있다. 효과적인 신호 표현 방식은 대상 신호 자체의 성질과 관련되어 있다. 영상 신호등 매우 일반적인 신호가 적절한 변환을 통해 산재된 신호(sparse signal)가 될 수 있음을 많은 연구를 통해 볼 수 있다. 이러한 사실이 compressive sensing(CS)의 기반이다. 즉 신호가 어떠한 변환을 통해 산재된 신호로 표현될 수 있다면 매우 적은 수의 샘플로 이러한 신호를 알아낼 수 있다는 것을 Donoho와 Candes 등이 보였고 이것이 가능한 다양한 조건에 등에 대해 연구되었다. CS는 신호 처리에 근본적인 문제인 효과적인 신호 표현 방식에 직접 연관되어 매우 다양한 분야에 적용될 수 있다. 이 논문에서 CS의 기본적인 개념을 소개한 후 CS가 레이더 신호 처리에 어떻게 도움이 될 수 있는지 살펴본다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.213-216
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• 1996

HDTV는 DTV에 비해 공간해상도가 4∼6배 이상됨에 따라 처리할 샘플수가 증가하게 된다. 따라서 기존의 DTV급으로 개발된 칩세트나 코덱을 그대로 HDTV 코덱 개발에 적용하기가 어렵게 된다. 따라서 HDTV의 높은 샘플링 주파수 때문에 HDTV 코덱은 화면분할 방식과 같은 새로운 코덱 구조를 가지게 되며, 그 분할된 각각은 기존의 DTV급 코덱으로 처리할 수 있게 된다. 이 때 각 대역마다 발생되는 부호화된 비트수가 다르기 때문에 일정한 전송율로 채널을 통하여 전송되기 위해서 버퍼 및 율제어 방식에 필요하게 된다. 본 논문에서는 각 대역별 영상의 특성과 버퍼 상황에 따라 적응적으로 율제어를 수행함으로써 화질의 균일성을 도모하고 부호화 효율을 증가시킬 수 있는 새로운 율제어 방식을 제안하였다. 또한 장면 전환이 발생했을 때에도 적응적으로 율제어를 수행할 수 있는 장면전환 검출 및 이를 이용한 적응적 율제어방식을 제안하였다.