• Fire Science and Engineering
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• v.33 no.6
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• pp.152-158
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• 2019

This study examined the socio-economic and clinical characteristics associated with the use of ambulance services among pregnant, childbearing, and postpartum women based on data from the 2008-2016 Korea Health Panel. The analysis revealed that among the pregnant, childbearing, and postpartum women, the proportion using all ambulance services was 18.9% whereas 12.0% used private and 119 ambulances. Moreover, among those using ambulance services, delivery was the most common reason (38.7%) followed by complications of labor and delivery (20.0%) and pregnancy with abortive outcome (17.3%). There were statistically significant differences between the users and non-users of ambulance services in terms of the average annual household income, emergency arrival time, and delayed arrival at the emergency room. As childbirth becomes more complicated due to low fertility and elderly mothers, the expansion and improvement of ambulance services as a social safety net for pregnant, childbearing, and postpartum women will become increasingly important.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.243-249
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• 2020

With the development of the 4th Industry Revolution and the progress of related technologies, people have been using various services in a more convenient way in their daily lives. Among these technologies, the smart mobility is a service that effectively transports people or packets from the origin to the final destination using a variety of methods/vehicles. With respect to the smart mobility technology, the shuttle service is operational at the final destination. The conventional shuttle operation only takes into account the shuttle operability and does not consider the shuttle-passenger efficiency at all by the one-way routing. Therefore, in this paper, we propose the smart shuttle algorithm that can change the routes to efficiently support boarding passengers. Our proposed scheme consists of 3 algorithms: the shuttle operating algorithm, the re-routable shuttle traveling algorithm, and the passenger-riding algorithm. All those 3 algorithms are effectively co-operated and collaborated for better performance. In-depth experiments were conducted to analyze and to show the superior performance, resulting in an average 23.6% reduction of destination-arrival time per passenger, average 10.37% reduction of shuttle-waiting time per passenger, and average 15.38% decrease of shuttle traveling time per hour. This proves that our smart shuttle traveling scheme reveals the whole remarkable performance, effectively using the re-routable characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.708-717
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• 2017

Tracking of sound-location is widely used in various area such as intelligent CCTV, video conference and voice commander. In this paper we introduce the real-time sound-location tracking method for smart lecture system using TDoA(Time Difference of Arrival) with orthogonal microphone array on the ceiling. Through discussion on some models of TDoA detection, cross correlation method using linear microphone array is proposed. Orthogonal array with 5 microphone could detect omni direction of sound-location. For real-time detection we adopt the threshold of received energy for eliminating no-voice interval, signed cross correlation for reducing computational complexity. The detected azimuth angles are processed using median filter for lowering the angle deviation. The proposed system is implemented with high performance MCU of TMS320F379D and MEMs microphone module and shows the accuracy of 0.5 and 6.5 in degree for white noise and lectured voice, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.663-669
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• 2011

In this study, the optimal length of left-turn lane in permissive left-turn signal system at the signalized intersection which has a left-turn bay is estimated. It is a simulation analysis using the queueing theory that estimate the length of left-turn lane. Traffic density conform to the standards of operating a permissive left-turn system of the Practical Manual Traffic Safety Facilities. And each of a left-turn arrival rate, a left-turn service rate, left-turn average queueing time, for green time average queueing vehicle, for red time average queueing vehicle and average queueing vehicle cycle is calculated. As a result of this study, we would learn how much the space should be secured at the signalized intersection which has a left-turn bay. The methodology using the queueing theory to work out the optimal length of waiting lane in the permissive left-turn signal system was presented.

• Analytical Science and Technology
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• v.18 no.6
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• pp.483-490
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• 2005

Mass resolution of the time of flight aerosol mass spectrometer for an aerosol component analysis depends on the initial direction and the initial energy of the ions. We have found that the shape of the optimum post focusing electric field is not linear. The maximum electric potential should be applied to the ions whose initial direction is 90 degree. To check on the post focusing effects, we have installed a laser ablation mass spectrometer. By using this LA-MS, we have found that the average energy distribution of the laser ablated ions is 8 eV. To establish the optimum mass resolution, a time delay and a high voltage are needed, and the results of the study show that 1500 nsec, and 3.7 kV are the optimum parameters for our system respectively. The isotope mass signals of copper show a good resolution.

• Convergence Security Journal
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• v.6 no.1
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• pp.33-43
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• 2006

RFID System has an advantage that it need not touch an objects for identification of many objects. Because it is working through wireless communication. Also, So many objects can be identified with RFID System at once. However, although RFID System has convenience like above, it has serious privacy concern at the same time. If RFID System is working with an target object through wireless communication, other objects will respond to RFID System signal as well as a target object. Hence, RFID System can be easily exposed user privacy by attacker. In this paper, We propose RFID system authentication model in order to protecting user privacy and traking. Proposed RFID system is operating that not only server authenticate RFID reader but also RFID reader and tag authenticate mutually by using symetric cryptography that operating with tiny and simple processing.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.1
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• pp.9-16
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• 2005

Accurate and reliable tracking of train is essential for the train control system. The fixed block system which utilizes track circuit has been used widely for the detection of train position. As an alternative, the moving block system has the advantage over the fixed block system since it enables shorter headway and easier maintenance. This paper presents a new technique for the train tracking system which uses radio signal for the train position detection. The proposed algorithm uses the phase difference of arrival of radio signal for the detection of train position. Experimental verification of the algorithm is presented in the paper.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.9-12
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• 2001

In this paper, the natural space-time coding is applied for a DS-CDMA system with multiple transmit/receive antennas in a Rayleigh fading channel. With difference of arrival times from transmit antennas a modified maximum likelihood (ML) decoding algorithm is proposed for the space-time coded DS-CDMA system. The proposed decoding algorithm performs ML decoding over the transition of two consecutive branches by using a modified branch metric with the partial autocorrelation. By simulation, it is shown that the proposed decoding algorithm achieves significant performance improvement over the ML decoding algorithm without the modified branch metric.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.191-194
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• 2009

유엔의 통계에 의하면, 2020 년에 전세계 60 세이상의 인구는 10 억까지 달성하고, 2050 년, 전세계에 20 억 가까운 노인 인구가 생존하게 됩니다. 끊임없이 증가되는 세계의 노령화 문제 때문에, 혼자 생활하는 독거 노인은 끊임없이 증가하고, 동시에 노인들의 순환기질환 관련 위험성은 증대하고 있다. 따라서 본 디자인연구는 이러한 노인들의 문제를 해결하기 위해 외형은 손목 시계와 같이 손목에 차는 형태로 연구되었으며, 심장과 혈압 항상 검사 측정하는 기능이 있어서, 그 수치가 안전을 위협하고 있을 때, 119 나 친척들 또는 담당의사에게 전화로 응급처리를 요청하게 되고, GPRS 는 스스로 작동, 병원에 응급조치와 함께 가장 짧은 시간에 도착할 수 있도록 것을 한다. 동시에 제품에는 환자의 진료카드가 있어 담당의사가 아니라도 진료를 할 수 있도록 하는 기능을 가진 기기에 대하여 연구하였다. 이러한 기기가 노인들에게 사용되기 위해서는 노인의 특성을 고려한 특징적인 연구가 필요하며, 노인의 감성에 맞는 기기의 특성을 파악 적용하는 문제를 연구하였다.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.149-152
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• 2002

In this paper, an adaptive interference canceller (AIC) Is applied to the space-time coded DS-CDMA system in fading channels with arrival time difference from multiple transmit antennas In a CDMA system, arrival time difference causes not only inter-antenna and Inter-symbol interference but also multiple-access Interference even in a downlink. To mitigate the effect of the Interferences an AIC and ML decoding joint scheme Is proposed fur a space-time coded DS-CDMA system in which an adaptation process of tile AIC is merged in the Viterbi decoding algorithm. The performance of the proposed receiver is evaluated for the system with two transmit antennas. It is shown that the proposed receiver achieves significant performance improvement over the ML decoding receiver without the AIC