• Journal of Embryo Transfer
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• v.18 no.1
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• pp.81-84
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• 2003

This study was performed to produce Hanwoo-fetal fibroblast cell clone transferred to Holstein recipient. It was coming on the parturition but didn't show parturition signs until 272 days from the embryo transfer. For the induction of normal parturition, dexamethasone (20 mg) were injected with IM on 272 day and PG $F_{2a}$ (25 mg) plus estradiol (20 mg) was injected with IM after 24hrs. Forty-eight hours after dexamethasone injection, we could find parturition signs and delivered healthy male of offspring (40 kg) about 50 hrs after it's injection. However the recipient was showed retention of afterbirth.h.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.12-19
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• 2017

In this paper a super-resolution time delay estimation algorithm that estimates the time delays of spread spectrum signals using sparse signal reconstruction approach is introduced. So far, the correlation method has been mostly used to estimate the time delays of spread spectrum signals. However it fails to accurately estimate the time delays in the case where the signals are spaced within approximately 1 PN chip duration and a further processing should be applied to the correlation outputs in order to enhance the resolution capability. Recently sparse signal approaches attract much interest in the area of directions-of-arrival estimation, of which SPICE is the most representative. Thus we introduce a super-resolution time delay estimation algorithm based on the SPICE approach and compare its performance with that of MUSIC algorithm by applying them to the ISO/IEC 24730-2.1 RTLS system.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.107-118
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• 2010

Wireless communication technologies including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) enable the development of more sophisticated and effective traffic information systems. This study presents a method to estimate vehicular travel times in a vehicular ad hoc network (VANET) environment. A novel feature of the proposed method is estimating individual vehicle travel times through advanced on-board units in each vehicle, referred to as self-estimated travel time in this study. The method uses travel information including vehicle position and speed at each given time step transmitted through the V2V and V2I communications. Vehicle trajectory data obtained from the VISSIM simulator is used for evaluating the accuracy of estimated travel times. Relevant technical issues for successful field implementation are also discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2A
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• pp.119-127
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• 2012

In this paper a super-resolution time delay estimation algorithm is developed for real-time locating systems (RTLSs) that employ a direct-sequence spread spectrum technique, along with its performance analysis in multipath environments. The classical correlation method provides relatively good performance in line-of-sight (LOS) environments but its performance seriously degrades in multipath environments, especially when signals are spaced closer than a PN chip. Therefore we shall develop a super-resolution time delay estimation algorithm that may estimate the time delays of multipath signals even in closely spaced multipath environments using the MUSIC algorithm for direction-of-arrival estimation and analyze its performance by applying the algorithm to the ISO/IEC 24730-2.1 RTLS system. 

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1883-1890
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• 2013

Location detection technology (LDT) is one of the core techniques for location based service (LBS) in wireless communication for improving resource management and quality of services. The location of a mobile station (MS) is estimated using the time of arrival (TOA) technique based on three circles with centers corresponding to coordinates of three base stations (BSs) and radius corresponding to distances between MS and BSs. For accurately estimating the location of MS, three circles should meet at a point for the trilateration method, but they generally do not meet a point because the radius is increased depending on the number of time delay for estimating the distance between MS and BS and the carrier frequency. The increased three circles intersect at six points and the three intersection points among them should be generally placed close to coordinate of the location for the specific MS. In this paper, we propose the shortest distance algorithm for TOA trilateration method, to select three interior intersection points from entire six points. The proposed approach selects three intersection points with the shortest distances between coordinates of MS and intersection points and determines the averaged coordinate of the selected three points, as the location of the specific MS. We demonstrate the performance of the proposed algorithm using a typical computer simulation example.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.197-207
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• 2015

In this research, Check the problems through analysis of traffic accidents while the elderly walking. Propose a way to reduce elderly traffic accidents. Therefore, analyzing the characteristics(by time and place etc) in order to reduce the traffic accident in the elderly pedestrian. Proposed the following Policy alternatives. First, Build a pedestrian safety island on the center of the road. Secondly, Should install the pedestrian crossing signal facilities which show the spare time and the guard rail to prevent crosswalk. Third, Should expend the installation area of pedestrian-operating traffic signal. Fourth, the night lighting facilities shall be installed nearby Crosswalk. Finally, Should appoint the elderly care area. Measures presented in this study, I hope they can be the basic data for the elderly in traffic safety policies for the elderly in accordance with the advent of aging society.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.4
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• pp.188-194
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• 2014

V2I(Vehicular to Infrastructure) is a one kind of communication systems which is used between the base stations and mobile objects. In V2I communication system, it is difficult to obtain the desired communication performance. Beamforming technology is to find the optimal path. and it can be improved the communication performance. MUSIC algorithm can be estimated the direction of arrival. The directional vector of received signals and the eigenvector has orthogonal property. MUSIC algorithm uses this property. In V2I communication environment, real time optimal path is changed. By the high computational complexity of the MUSIC algorithm, the optimal path estimation error is generated. In this paper, we propose a method of computation reduction algorithm for MUSIC algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1077-1083
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• 2012

The jamming countermeasures in GNSS includes anti-jamming technique and jammer localization technique. In both techniques, direction of jamming signal is important and generally the MUSIC algorithm is used to find the direction of jamming signal. The MUSIC is super-resolution algorithm for detecting incident direction of signal. But, the search time of MUSIC algorithm is too long because all candidates of incidence angle are searched. This paper proposes the new method that has less computational burdens and therefore faster than the conventional MUSIC algorithm. The proposed method improves performance speed by reducing unnecessary calculations. In the proposed method, the cost function of conventional MUSIC algorithm is decomposed into the sum of squares and if the partial sum of cost function is larger than the minimum cost function so far, then the candidate is rejected and next candidates are searched. If the computed cost function is less than the minimum cost function so far, the minimum cost function so far is replaced with newly computed value. The performance of the proposed method was compared with the conventional MUSIC algorithm using the simulation. The accuracy of the estimaed direction of jamming signal was same as the conventional MUSIC while the search speed of the proposed method was 1.15 times faster than the conventional MUSIC.

• Proceedings of The KACE
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• 2017.08a
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• pp.201-204
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• 2017

빅 데이터의 시대가 도래하면서 이전보다 데이터로부터 유의미한 정보를 추출하는 것에 대한 연구가 활발하게 진행되고 있다. 딥러닝은 텍스트, 이미지, 동영상 등 다양한 데이터에 대한 학습을 가능하게 할 뿐만 아니라 높은 학습 정확도를 보임으로써 차세대 머선러닝 기술로 각광 받고 있다. 그러나 딥러닝은 일반적으로 학습해야하는 데이터가 많을 뿐만 아니라 학습에 요구되는 시간이 매우 길다. 또한 데이터의 전처리 수준과 학습 모델 튜닝에 의해 학습정확도가 크게 영향을 받기 때문에 활용이 어렵다. 딥러닝에서 학습에 요구되는 데이터의 양과 연산량이 많아지면서 분산 처리 프레임워크 기반 분산 학습을 통해 학습 정확도는 유지하면서 학습시간을 단축시키는 사례가 많아지고 있다. 본 연구에서는 범용 분산 처리 프레임워크인 아파치 스파크에서 데이터 병렬화 기반 분산 학습 모델을 활용하여 모바일 빅 데이터 분석을 위한 딥러닝을 구현한다. 딥러닝을 구현할 때 분산학습을 통해 학습 속도를 높이면서도 학습 정확도를 높이기 위한 모델 튜닝 방법을 연구한다. 또한 스파크의 분산 병렬처리 효율을 최대한 끌어올리기 위해 파티션 병렬 최적화 기법을 적용하여 딥러닝의 학습속도를 향상시킨다.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.390-394
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• 2007

시간과 장소에 구애받지 않고 실시간으로 정보를 전달받을 수 있는 유비쿼터스 시대가 도래함에 있어서 실시간으로 움직이는 대상물의 위치를 알아내는 기술은 가장 근본적이며 필수적인 요소라 할 수 있다. 추측항법(Dead Reckoning)은 움직이는 대상물에 외부의 도움 없이 자신의 방향각과 가속도, 시간을 관측할 수 있는 관성항법장치(Inertial Navigation System)를 장착하여 이전의 위치 정보를 바탕으로 현재의 위치를 관측하는 방법이다. 또한 RFID(Radio Frequency IDentification)는 이러한 유비쿼터스 근거리무선통신의 핵심 기술로서 본 논문에서는 RFID에 기반한 위치 결정 시스템에 실시간 변화하는 대상물의 위치를 예측하기 위해 추측항법과 칼만필터(Kalman-filter)의 개념을 적용시켰다. 또한 RMSE(Root Mean Square Error)값을 통해 칼만필터의 적용에 따른 정확도의 향상과 각 디자인 요소들의 변화에 따라 위치의 정확도가 어떠한 변화를 갖는지를 분석하였다. 시뮬레이션 결과 칼만필터를 적용했을 때 이전보다 RMSE값이 현저히 작아지는 결과를 통해 위치의 정확도가 크게 향상되는 것을 확인하였다. 또한 RFID의 탐지 범위는 정확도에 큰 영향을 미칠 수 있는 주된 요소가 아니며, RFID 탐지 범위의 표준편차가 작을수록 위치 정확도는 높아지고, RFID 태그의 탐지 확률이 높을수록 RMSE 값의 변동이 작은 안정된 시스템을 갖으며 위치의 정확도 또한 높아진다는 것을 확인하였다.