• Journal of the Korean Society for Railway
• /
• v.14 no.1
• /
• pp.6-10
• /
• 2011

This article deals with a problem of setting reliability targets of the railroad systems where the punctuality target is given to the operator and a penalty is imposed for the year when the target is not met. The operator should set the reliability targets of the railroad system and sub-systems because the reliability affects the expected number of years when the penalty is imposed. This paper presents a procedure for setting the service reliability target and equations to calculate the expected number of years when the penalty is imposed and the probability that the operator should pay the penalty per year according to the mean kilometer between service failures of the railroad system and sub-systems.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04d
• /
• pp.49-51
• /
• 2003

가입자망과 메트로 광 가입자망에서 광범위한 적용범위에 대해 광 기술을 선도하는 기존의 WDM은 증가하는 사용자 수를 수용하는 데 어려움을 가지며 WDM은 채널간의 잡음에 의한 제한과 유효 채널의 최대가 WDM 채널에서 광 증폭기 이득의 균일성에 의해 제한받는다. 따라서 사용자 수를 증가시키고 데이터량을 확장시킬 수 있는 CDMA 기술 도입이 하나의 대안으로 요구된다. 본 논문에서는 SMF에서 수십 km 거리를 갖는 가입자망에서 Prime sequence code를 사용한 2.5Gb/s 광 COMA 신호의 색분산 패널티에 대해 연구하였다. 시스템 모델에서, 색분산 패널티, 파형과 디코드된 신호의 아이 다이어그램(eye diagram)이 결과로써 보여지며, prime sequence code 수의 증가에 대해 Chirp 파라미터를 갖는 코드화된 신호의 색분산 패널티를 보인다. 이러한 접근은 pseudo-orthogonality를 가지는 비동기식 광 CDMA의 디자인에 특히 적합할 것이다.

• Korean Journal of Optics and Photonics
• /
• v.10 no.1
• /
• pp.64-67
• /
• 1999

We have been implemented 10 Gb/s-320 km of dispersion-shifted fiber (DSF) transmission. The optical link consists of a 10 Gb/s optical transceiver, an optical booster amplifier, 3 sets of optical in-line amplifiers, an optical preamplifier and transmission fibers. Firstly, we investigated the Q-factor characteristics in terms of optical signal to noise ratio (OSNR) of 320 km of DSF, measured receiver sensitivity is -27 dBm and power penalty is 2 dB, respectively. We concluded that optical SNR degradation and path penalty gives rise to 1 dB penalty, respectively.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.1
• /
• pp.313-320
• /
• 2000

PEM algorithm cannot expend repeated algorithm, if penalty function is transcendental function. However, OSL algorithm has an advantage that repeated algorithm is easily derived, even though penalty function which has a complicated transcendental function. In spite of this advantage, this algorithm is restricted in convergence region of smoothing constant which increase penalized log-likelihood, so we cannot get the optimal image restoration because it cannot provide us with a various smoothing constant value for the digital image restoration. In this paper, in order to resolve the disadvantage of OSL algorithm, we would like to suggest the algorithm with smoothing constant enlarge the tolerance limit range of convergence and to find not only properties of its convergence but also usefulness of suggested algorithm through digital image simulation.

• Journal of Korean Society of Transportation
• /
• v.23 no.6 s.84
• /
• pp.71-80
• /
• 2005

With rapid development Telematics industry, the concern of dynamic road pricing system is increasing. In this study, the change of traffic flows according to traffic information and variation of congestion road prices related to the dynamic road pricing was analyzed. In this study, three facts were unfolded. First, high delay penalty and low delay penalty drivers are shown different reaction for the different congestion road prices. Second, the higher congestion road prices the more drivers convert their route from toll road to non toll road. Third, high penalty drivers are converting to toll road than low delay penalty drivers under same congestion road prices. This study has reached the conclusion that dynamic congestion pricing has a high possibility for traffic management.

• The Journal of the Acoustical Society of Korea
• /
• v.43 no.3
• /
• pp.314-323
• /
• 2024

Recently, a score-penalty method has been used for the acoustic passive tracking of marine mammals. The interesting aspect of this technique lies in the loss function, which has a penalty term representing the mismatch between the measured signal and the modeled signal, while the traditional time-domain matched-field processing is positively considering the match between them. In this study, we apply the score-penalty method into the depth estimation of a passive target with a known source waveform. Assuming deep ocean environments with uncertainties in the sound speed profile, we evaluate the score-penalty method, comparing it with the time-domain matched field processing method. We shows that the score-penalty method is more accurate than the time-domain matched field processing method in the ocean environment with weak mismatch of sound speed profile, and has better efficiency. However, in the ocean enviroment with strong mismatch of the sound speed profile, the score-penalty method also fails in the depth estimation of a target, similar to the time-domain matched-field processing method.

• Journal of the Korea Society for Simulation
• /
• v.16 no.3
• /
• pp.1-9
• /
• 2007

Travel time between two points depends upon whether it is a rush hour or not in metropolitan area. It is true that there is big differences on the time required to get through the area whether going in busy morning or near noon. Another issue is that there exist many delivery points which closely located each other; so no need to consider traveling hours among these points. We designed an efficient procedure to reduce the complexity by considering closely located delivery points as one big delivery point. A computer simulation model is constructed for comparison purposes of the developed heuristic with the optimum solution.

• Korean Journal of Optics and Photonics
• /
• v.10 no.1
• /
• pp.73-79
• /
• 1999

Semiconductor optical switch modules of 1$\times$2, 1$\times$4, and 4$\times$4 types for 1550 nm optical communication systems were fabricated by using laser welding technique, embodying in 30-pin butterfly package. For better coupling efficiency between switch chip and optical fiber, tapered fibers of 10~15mm lens radii were used, which provided up to 60% optical coupling efficiency. With the help of new laser hammering process, we could recover the lost optical power almost completely up to average 82% of initially obtained power. The fabricated optical switch modules showed good thermal stability of less than 5% degradation even after 200 times thermal cycling test. The 2.5 Gbps optical transmission characteristics of the 4$\times$4 switch module showed low sensitivities of less than -30dB for all possible switching paths. The transmission penalties of 1$\times$2 switch module at $10^{-10}$ BER were 0.6dB and 0.7dB for 50Xm and 90 Km optical fibers, respectively.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04a
• /
• pp.9-11
• /
• 2000

최근에 캐쉬의 성능이 전체 시스템에 미치는 영향이 커짐에 따라 캐쉬의 성능을 모델링하고 향상시키기 위한 많은 연구가 진행되고 있다. 본 논문에서는 네 가지 종류의 캐쉬모델을 가정하고 분기명령어 비율, 캐쉬미스율, 분기예측 실패율 등의 파라메터를 이용하여 수퍼스칼라 프로세서에서의 명령어 패치율을 해석적으로 모델링하였다. 시뮬레이션 결과 분기예측실패가 명령어 패치율에 미치는 영향보다는 캐쉬미스율이나 캐쉬미스 패널티의 증가로 인한 패치율의 감소가 더욱 큰 폭으로 나타났다.

• Journal of the Korea Convergence Society
• /
• v.11 no.2
• /
• pp.207-214
• /
• 2020

The objective of this study is to analyze the effect of the quality of the Internal Accounting Control System(IACS) on Executive compensation, and to determine whether this relationship depends on the effectiveness of corporate governance. For the analysis, 6,343 firm-year data listed on the Korea Exchange from 2011 to 2016 were used. The results are as follows. First, Executive compensation was decreased in companies with low quality of IACS to provide a penalty for management. Second, the negative relationship between the weaknesses of IACS and Executive compensation was found to be strengthened when the corporate governance was effectively operated. These findings suggest that information about the quality of the IACS can be usefully used to reasonably identify the executive compensation policy, and that corporate governance needs to be operated more efficiently.