• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.221-223
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• 2004

Accurate and reliable tracking system is essential for the central train control system. There are two systems widely being used, one is the fixed block system which utilizes the track circuit for the detection of train position, the other is the moving block system which has the advantage over the former since it enables shorter radio signal for the train position detection. In this paper a new algorithm is proposed which uses signal's phase difference of arrival to detect the train position. Experimental verification of the algorithm is presented in the paper.

• Genomics & Informatics
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• v.19 no.4
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• pp.36.1-36.11
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• 2021

Predicting individual traits and diseases from genetic variants is critical to fulfilling the promise of personalized medicine. The genetic variants from genome-wide association studies (GWAS), including variants well below GWAS significance, can be aggregated into highly significant predictions across a wide range of complex traits and diseases. The recent arrival of large-sample public biobanks enables highly accurate polygenic predictions based on genetic variants across the whole genome. Various statistical methodologies and diverse computational tools have been introduced and developed to computed the polygenic risk score (PRS) more accurately. However, many researchers utilize PRS tools without a thorough understanding of the underlying model and how to specify the parameters for the best performance. It is advantageous to study the statistical models implemented in computational tools for PRS estimation and the formulas of parameters to be specified. Here, we review a variety of recent statistical methodologies and computational tools for PRS computation.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.683-687
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• 2007

In last decades, several linearization methods for the AOA measurements have been proposed, for example, Gauss-Newton method and Closed-Form solution. Gauss-Newton method can achieve high accuracy, but the convergence of the iterative process is not always ensured if the initial guess is not accurate enough. Closed-Form solution provides a non-iterative solution and it is less computational. It does not suffer from convergence problem, but estimation error is somewhat larger. This paper proposes a Self-Tuning Weighted Least Square AOA algorithm that is a modified version of the conventional Closed-Form solution. In order to estimate the error covariance matrix as a weight, a two-step estimation technique is used. Simulation results show that the proposed method has smaller positioning error compared to the existing methods.

• Korean Management Science Review
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• v.29 no.3
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• pp.1-11
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• 2012

This paper considers a localization problem in time difference of arrival (TDOA)-based radio frequency identification (RFID) systems. To estimate the position of a target tag, this paper suggests three localization algorithms that use benchmark tags. The benchmark tags are the same type as the target tag, but either the locations or distance of the benchmark tags are known. Two algorithms use the benchmarks for auxiliary information to improve the estimation accuracy of the other localization algorithms such as least squared estimator (LSE). The other one utilizes the benchmarks as essential tags to estimate the location. Numerical tests show that the localization accuracy can be improved by using benchmark tags especially when an algorithm using the LSE is applied to the localization problem. Furthermore, this paper shows that our benchmark algorithm is valuable when the measurement noise is large.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1229-1234
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• 2004

Accurate and reliable tracking system is essential for the central train control system. There are two systems widely being used. one is the fixed block system which utilizes the track circuit for the detection of train position. the other is the moving block system which has the advantage over the former since it enables shorter radio signal for the train position detection. In this paper a new algorithm is proposed which uses signal's phase difference of arrival to detect the train position. Experimental verification of the algorithm is presented in the paper.

• The Korean Journal of Emergency Medical Services
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• v.18 no.2
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• pp.125-136
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• 2014

Purpose: We aimed to improve the survival rates of out-of-hospital cardiac arrest patients. Methods: We analyzed data regarding cardiopulmonary resuscitation (CPR) outcomes and clinical characteristics of out-of-hospital cardiac arrest patients. The data included prehospital emergency medical service reports of 207 patients, 135 patients of Heart Saver, who survived over 72 hours after return of spontaneous circulation (ROSC) in Gyeonggi-do from January, 2012 to December, 2013. Data were analyzed using SPSS 18.0 descriptive statistics. Results: Among patients who achieved ROSC, 87.6% were men and 73.6% were aged 41-70 years; 86.7% were cases of witnessed cardiac arrest, and cardiopulmonary resuscitation was performed by bystanders in 65.9% of cases. The initial electrocardiogram showed ventricular fibrillation or pulseless ventricular tachycardia in 96.3% of patients. The call time was 1.0 minutes, arrival time was 6.3 minutes, time spent at the scene was 8.0 minutes, hospital arrival time was 10.0 minutes, and total CPR duration was 9.6 minutes. The certificate of them was paramedics in 89.6%. Conclusion: To improve the survival rates of out-of-hospital cardiac arrest patients, standard prehospital care for these patients and educational programs regarding CPR for lay rescues should be developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1131-1137
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• 2009

In this paper, a resource management technique for digital duplexing (DD) systems using orthogonal frequency division multiple access (OFDMA) is proposed. The proposed technique can reduce the dynamic range of the signal received at the subscriber station (SS) and minimize the effects of inter-symbol interference (ISI) and inter-carrier interference (ICI) due to the time difference of arrival (TDoA) without using a cyclic suffix. It is shown by computer simulation that the proposed technique can reduce the number of bits for an analog-to-digital converter (ADC) and increase the signal-to-interference and noise ratio (SINR) significantly.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.300-309
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• 2003

The Japanese developed the first Car navigation system in 1981 with the advent of Honda, which was known as the car inertial navigation system. Now days, It is possible to search the shortest route to and from places and arrival time using the internet via cell phone to the driver based on GIS and GPS. However, even with a good navigation system, it losses the shortest route when there is an average speed of the vehicle being between S-15 kilometers. Therefore, in order to improve the vehicle waiting time and average vehicle speed, we are suggesting an optimal green time algorithm using fuzzy adaptive control, where there are different traffic intersection lengths, and lanes. In this paper, to be able to assist the driver and forecast the optimal traffic information with regards to the road conditions; dangerous roads, construction work and estimation of arrival time at their destination using internet.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.580-581
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• 2007

전력시장의 환경변화와 전력소비자들의 다양성 그리고 전력소비자들의 다양한 요구를 수용하기 위해서 확률론적 전력공급 신뢰도 평가에 대한 사회적 요구가 커지고 있다. 과거 전력계통의 신뢰도 평가는 발전계통만을 대상으로 하는 HLI에서의 신뢰도평가였으나 최근 송전망을 포함한 복합전력계통의 신뢰도 평가에 대한 관심과 연구가 진행되고 있다. 복합전력계통의 신뢰도 평가에서는 일반적으로 각 부하지점별 공급지장 가능성 등을 시뮬레이션을 통해 산정한다. 본 연구에서는 각 부하지점에서의 공급가능용량을 확률론적으로 평가하는 방법을 보인다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.185-195
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• 2017

In recent years, unexpected bridge fire accidents have increased because of augmenting the number of traffic volumes and hazardous materials by the increment in traffics and distribution business. Furthermore, in accordance with the effort of using the under space of bridges, the ratio of occupied by combustible materials like oil tanker or lorry has been increased. As a result, the occurrence of bridge fire has been growing drastically. In order to mitigate the accident of bridge fire, risk assessment of bridge fire has been studied, however, practical risk models considering safety from users' viewpoints were scarce. This study represented quantitative risk assessment model applicable to national road bridges in Korea. The primary factors with significant impacts on bridge fire accidents was chosen such as clearance height, materials of bridges, arrival time of fire truck and fire intensity. The selected factors were used for Fire Dynamics Simulation (FDS) and the peak temperature calculated by FDS in accordance with the fire duration and fire intensity. The risk assessment model in bridge fire reflected the FDS analysis results, the fire damage criteria, and the grade of fire truck arrival time was established. Response plans for bridge fire accidents according to the risk assessment output has been discussed. Lastly, distances between bridges and fire stations were calculated by GIS network analysis. Based on the suggested assessment model and methodology, sample bridges were selected and graded for the risk assessment.