• Progress in Superconductivity and Cryogenics
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• v.16 no.1
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• pp.32-35
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• 2014

Recently, many researches on the system of superconducting power supply and superconducting magnetic energy storage (SMES) using high temperature superconducting (HTS) tapes has been progressed. Those kinds of superconducting devices use the heater trigger switches that have a control delay problem at moments of heating up and cooling down. One way to reduce the time delay is using a different HTS tape at trigger part. For example, HTS tape having lower critical temperature can reduce time delay of heating up and heating down stage for heater trigger operation. This paper deals with resistances joint with different kinds of HTS tapes which have different properties to verify usefulness of the suggested method. Three kinds of commercial HTS tapes with different specifications are selected as samples and two kinds of solders are used for comparison. Joint is performed with temperature and pressure controllable joint machine and the joint characteristics are analyzed under the repeatable conditions.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.7
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• pp.72-85
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• 1998

In this paper, we propose a new method that sequentially estimates TDOA(Time Delay Of Arrival) and FDOA(Frequency Delay Of Arrival) for extracting the information about the bearing and relative velocity of a target in passive radar or sonar arrays. The objective is to efficiently estimate the TDOA and FDOA between two sensor signal measurements, corrupted by correlated Gaussian noise sources in an unknown way. The proposed method utilizes the one dimensional slice function of the third order cumulants between the two sensor measurements, by which the effect of correlated Gaussian measurement noises can be significantly suppressed for the estimation of TDOA. Because the proposed sequential algoritjhm uses the one dimensional complex ambiguity function based on the TDOA estimate from the first step, the amount of computations needed for accurate estimationof FDOA can be dramatically reduced, especially for the cases where high frequency resolution is required. It is demonstrated that the proposed algorithm outperforms existing TDOA/FDOA estimation algorithms based on the ML(maximum likelihood) criterionandthe complex ambiguity function of the third order cumulant as well, in the MSE(mean squared error) sense and computational burden. Various numerical resutls on the detection probability, MSE and the floatingpoint computational burden are presented via Monte-Carlo simulations for different types of noises, different lengths of data, and different signal-to-noise ratios.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.162-164
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• 2006

There are concern on possible health effects from exposure to electric and magnetic fields. One reflection of this concern is the considerable controversy, delay, and cost increases involved in the construction of utility lines and facilities. To meet such challenges, in this paper we investigated magnetic fields reduction techniqies such as general compaction, in-span compaction, cruciform, vertical, 3way splits phase, and 4way splits phase. As results, we found 1 spacer in-span compaction was appropriate in Korea in view of effectiveness and economy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8A
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• pp.1134-1143
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• 2000

We propose a scheduling algorithm, Bandwidth Allocation Scheme (BAS), that guarantees bounded delay in a switching node. It is based on the notion of the GPS (Generalized Processor Sharing) mechanism, which has clarified the concept of fair queueing with a fluid-flow hypothesis of traffic modeling. The main objective of this paper is to determine the session-level weights that define the GPS sewer. The way of introducing and derivation of the so-called system equation' implies the approach we take. With multiple classes of traffic, we define a set of service curves:one for each class. Constrained to the required profiles of individual service curves for delay satisfaction, the sets of weights are determined as a function of both the delay requirements and the traffic parameters. The schedulability test conditions, which are necessary to implement the call admission control, are also derived to ensure the proposed bandwidth allocation scheme' be able to support delay guarantees for all accepted classes of traffic. It is noticeable that the values of weights are tunable rather than fixed in accordance with the varying system status. This feature of adaptability is beneficial towards the enhanced efficiency of bandwidth sharing.

• Science of Emotion and Sensibility
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• v.16 no.3
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• pp.293-304
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• 2013

Procrastination is an irrational choice to delay high-priority work in order to avoid its unpleasantness, despite the fact that the negativity will not cease if the work still remains undone. We hypothesized that (1) people underestimate the future negativity (i.e., delay neutralization) and (2) in order to complete work in a timely manner, one should project oneself into the future so as to recognize that the negativity associated with an activity does not diminish over time. Especially, negative future thinking that is unrelated to the consequence was hypothesized to reduce delay neutralization of negativity. In the present study, undergraduate students made a series of choices between delayed-but-longer and immediate-but-shorter assignment by employing an inter-temporal choice paradigm. We tracked how positive and negative episodic future thinking influenced the degree to which negativity is neutralized over time (Experiment 1). Following this, we confined the experimental condition to negative thinking about the future (Experiment 2). Participants neutralized negativity involved in assignment as a function of time, suggesting that procrastination arises from the delay neutralization of the negativity. Critically, such neutralization was significantly reduced when participants imagined a negative future event, but this did not occur when they imagined a positive future event (Experiment 1), or when participants did not think about the future (Experiment 1, 2). Our findings suggest that, prior to making a decision between work and indulgence, imagining negative future events can be an effective way to reduce the neutralization of delayed negativity and, in turn, procrastination.

• Journal of Drive and Control
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• v.15 no.3
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• pp.21-28
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• 2018

We propose a tension controller based on a time-delay estimation (TDE) technique for a winding machine. Firstly, we perform the necessary calculations to derive a mathematical model of the winding machine. In this sense, it is revealed that the roll radius of the winding machine is characteristically seen to be increasing or decreasing during the winding process. That being said, it is noted that the parameters of the winding machine are coupled and constantly changing during this process. Understandably then, it is noted that the model is shown to be nonlinear and time-varying. Secondly, we propose the way to apply the TDE based controller which is the so-called Time-delay Control (TDC). The TDC utilizes the time-delayed information intentionally to compensate the nonlinear and time-varying characteristics. As we have seen, the proposed controller consists of two parts: one is a TDE component, and the other is an error dynamics component which is defined by a user. In a computer simulation based on the Matlab/Simulink program, the proposed controller is compared with a conventional PID controller, which is widely used in the tension control of the winding machine. The proposed controller reduces the incidence of overshoot and steady-state error in the tension control, as compared to the conventional PID controller.

• Korean Journal of Poultry Science
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• v.26 no.2
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• pp.109-118
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• 1999

Hen's eggs have been regarded as one of the best animal bioreactors to produce biologically active peptides originated from many organisms including human. Despite the last decade's efforts to produce transgenic chicken for any commercial purposes, the results so far reported are very disappointing, indicating that hen's eggs are very difficult to crack for transgenesis. Comparatively large female gamete with enormous amount of yolk may be one of the major obstacles in achieving a similar feat to those of other vertebrate species including mouse, sheep, fish and frog. The delay or less efficiency evidenced may instruct to try an alternative way of gens transfer into chicken egg. Sperm-mediated gene transfer is one of them, and may require a great deal of understanding of mechanisms involved in early fertilization and embryonic development. In other animals where the technique was successful, basic mechanisms have been well studied and established only by painstaking efforts for decades. This paper discusses the accumulated knowledge on early fertilization mechanism in the chicken and how can this information be utilitzed to find the alternative gene transfer in making transgenic chicken.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.107-118
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• 2003

Highway Capacity Manual (HCM) provides an analytical delay estimation model to assist the evaluation of traffic at a signalized intersection. The model revised and included in the HCM published in the year 2000 reflects the results of recent studies and is utilized in various fields of transportation studies. For the implementation of the model in the case of permitted left turns, the HCM supplement provides a computational procedure to adjust the saturation flow rate of permitted left toms. The model however, is originally designed for a protected movement and thus underestimates the delay of permitted left turns due to its difference right-of-way nature. This document describes (1) a review of the theoretical background of the HCM delay estimation model, (2) problems embedded in the model for the delay estimation of permitted left turns, (3) a proposed model developed in this study to improve the delay estimation for permitted left turns and (4) a set of verification tests. In order to reflect various traffic and control conditions in the test, simulation studies were performed to by using the field data based on 120 different permitted left-turn scenarios. Comparison studies conducted between sets of delays estimated by the HCM and the proposed models against a set of the CORSIM delays and showed that the proposed model improved the estimation of the permitted left-turn delays. The explanatory variable of the relationship between the HCM delay and the simulation delay was 0.47 and the one between the delay estimated by the proposed model and the simulation delay was 0.77.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7B
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• pp.481-488
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• 2005

As the demand on the multimedia application increases, the congestion control algorithm for the multimedia applications becomes an important research issue. The ultimate goal of congestion control is to adapt the trans-mission rate at the sender to the mont of network resource available on the forward path. In general, the congestion control algorithms use the round trip time(RTT) to estimate the network congestion on the forward path. however, since the RTT includes the delay on both forward and backward paths, it is possible for the algorithms using the RTT to make a wrong decision such as deciding the congestion on the forward path due to the congestion built on the backward path. In this paper, we enhance the performance of RRC-OTT(Receiver-based rate control with one-way Trip Time) algorithm, which uses the one-way trip time(OTT) to estimate the network congestion. By separating the estimation mechanism on the forward path from the backward path, the performance of RRC-OTT algorithm is hardly affected by the congestion built on the backward path.

• Geophysics and Geophysical Exploration
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• v.5 no.1
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• pp.18-22
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• 2002

As a single arrival traveltime, maximum energy arrival traveltime has been known as the most proper operator for Kirchhoff migration. In case of the model having the simple structure, both the first arrival traveltime and the maximum energy arrival traveltime can be used as the correct operators for Kirchhoff migration. However for some model having the complex and high velocity contrast structure, the migration using the first arrival traveltime can't give the correct depth section. That is, traveltime to be required in Kirchhoff migration is the maximum energy traveltime, but, needs considerably more calculation time than that of first arrival. In this paper, we propose the method for calculating the traveltime approximated to the maximum energy arrival using one-way wave equation. After defining the WAS(Wrap Around Suppression) factor to be used for calculating the first arrival traveltime using one-way wave equation as the function of lateral grid interval and depth and considering the delay time of source wavelet. we calculate the traveltime approximated to the maximum energy arrival. to verify the validity of this traveltime, we applied this to the migraion for simple structure and complex structure and compared the depth section with that obtained by using the first arrival traveltime.